sys/dev/hwpmc/hwpmc_mod.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2003-2008 Joseph Koshy
   5  * Copyright (c) 2007 The FreeBSD Foundation
   6  * Copyright (c) 2018 Matthew Macy
   7  * All rights reserved.
   8  *
   9  * Portions of this software were developed by A. Joseph Koshy under
  10  * sponsorship from the FreeBSD Foundation and Google, Inc.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  */
  34
  35 #include <sys/cdefs.h>
  36 __FBSDID("$FreeBSD$");
  37
  38 #include <sys/param.h>
  39 #include <sys/domainset.h>
  40 #include <sys/eventhandler.h>
  41 #include <sys/gtaskqueue.h>
  42 #include <sys/jail.h>
  43 #include <sys/kernel.h>
  44 #include <sys/kthread.h>
  45 #include <sys/limits.h>
  46 #include <sys/lock.h>
  47 #include <sys/malloc.h>
  48 #include <sys/module.h>
  49 #include <sys/mount.h>
  50 #include <sys/mutex.h>
  51 #include <sys/pmc.h>
  52 #include <sys/pmckern.h>
  53 #include <sys/pmclog.h>
  54 #include <sys/priv.h>
  55 #include <sys/proc.h>
  56 #include <sys/queue.h>
  57 #include <sys/resourcevar.h>
  58 #include <sys/rwlock.h>
  59 #include <sys/sched.h>
  60 #include <sys/signalvar.h>
  61 #include <sys/smp.h>
  62 #include <sys/sx.h>
  63 #include <sys/sysctl.h>
  64 #include <sys/sysent.h>
  65 #include <sys/syslog.h>
  66 #include <sys/systm.h>
  67 #include <sys/vnode.h>
  68
  69 #include <sys/linker.h>         /* needs to be after <sys/malloc.h> */
  70
  71 #include <machine/atomic.h>
  72 #include <machine/md_var.h>
  73
  74 #include <vm/vm.h>
  75 #include <vm/vm_extern.h>
  76 #include <vm/pmap.h>
  77 #include <vm/vm_map.h>
  78 #include <vm/vm_object.h>
  79
  80 #include "hwpmc_soft.h"
  81
  82 #define PMC_EPOCH_ENTER() struct epoch_tracker pmc_et; epoch_enter_preempt(global_epoch_preempt, &pmc_et)
  83 #define PMC_EPOCH_EXIT() epoch_exit_preempt(global_epoch_preempt, &pmc_et)
  84
  85 /*
  86  * Types
  87  */
  88
  89 enum pmc_flags {
  90         PMC_FLAG_NONE     = 0x00, /* do nothing */
  91         PMC_FLAG_REMOVE   = 0x01, /* atomically remove entry from hash */
  92         PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */
  93         PMC_FLAG_NOWAIT   = 0x04, /* do not wait for mallocs */
  94 };
  95
  96 /*
  97  * The offset in sysent where the syscall is allocated.
  98  */
  99
 100 static int pmc_syscall_num = NO_SYSCALL;
 101 struct pmc_cpu          **pmc_pcpu;      /* per-cpu state */
 102 pmc_value_t             *pmc_pcpu_saved; /* saved PMC values: CSW handling */
 103
 104 #define PMC_PCPU_SAVED(C,R)     pmc_pcpu_saved[(R) + md->pmd_npmc*(C)]
 105
 106 struct mtx_pool         *pmc_mtxpool;
 107 static int              *pmc_pmcdisp;    /* PMC row dispositions */
 108
 109 #define PMC_ROW_DISP_IS_FREE(R)         (pmc_pmcdisp[(R)] == 0)
 110 #define PMC_ROW_DISP_IS_THREAD(R)       (pmc_pmcdisp[(R)] > 0)
 111 #define PMC_ROW_DISP_IS_STANDALONE(R)   (pmc_pmcdisp[(R)] < 0)
 112
 113 #define PMC_MARK_ROW_FREE(R) do {                                         \
 114         pmc_pmcdisp[(R)] = 0;                                             \
 115 } while (0)
 116
 117 #define PMC_MARK_ROW_STANDALONE(R) do {                                   \
 118         KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \
 119                     __LINE__));                                           \
 120         atomic_add_int(&pmc_pmcdisp[(R)], -1);                            \
 121         KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()),              \
 122                 ("[pmc,%d] row disposition error", __LINE__));            \
 123 } while (0)
 124
 125 #define PMC_UNMARK_ROW_STANDALONE(R) do {                                 \
 126         atomic_add_int(&pmc_pmcdisp[(R)], 1);                             \
 127         KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \
 128                     __LINE__));                                           \
 129 } while (0)
 130
 131 #define PMC_MARK_ROW_THREAD(R) do {                                       \
 132         KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \
 133                     __LINE__));                                           \
 134         atomic_add_int(&pmc_pmcdisp[(R)], 1);                             \
 135 } while (0)
 136
 137 #define PMC_UNMARK_ROW_THREAD(R) do {                                     \
 138         atomic_add_int(&pmc_pmcdisp[(R)], -1);                            \
 139         KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \
 140                     __LINE__));                                           \
 141 } while (0)
 142
 143
 144 /* various event handlers */
 145 static eventhandler_tag pmc_exit_tag, pmc_fork_tag, pmc_kld_load_tag,
 146     pmc_kld_unload_tag;
 147
 148 /* Module statistics */
 149 struct pmc_driverstats pmc_stats;
 150
 151
 152 /* Machine/processor dependent operations */
 153 static struct pmc_mdep  *md;
 154
 155 /*
 156  * Hash tables mapping owner processes and target threads to PMCs.
 157  */
 158
 159 struct mtx pmc_processhash_mtx;         /* spin mutex */
 160 static u_long pmc_processhashmask;
 161 static LIST_HEAD(pmc_processhash, pmc_process)  *pmc_processhash;
 162
 163 /*
 164  * Hash table of PMC owner descriptors.  This table is protected by
 165  * the shared PMC "sx" lock.
 166  */
 167
 168 static u_long pmc_ownerhashmask;
 169 static LIST_HEAD(pmc_ownerhash, pmc_owner)      *pmc_ownerhash;
 170
 171 /*
 172  * List of PMC owners with system-wide sampling PMCs.
 173  */
 174
 175 static CK_LIST_HEAD(, pmc_owner)                        pmc_ss_owners;
 176
 177 /*
 178  * List of free thread entries. This is protected by the spin
 179  * mutex.
 180  */
 181 static struct mtx pmc_threadfreelist_mtx;       /* spin mutex */
 182 static LIST_HEAD(, pmc_thread)                  pmc_threadfreelist;
 183 static int pmc_threadfreelist_entries=0;
 184 #define THREADENTRY_SIZE                                                \
 185 (sizeof(struct pmc_thread) + (md->pmd_npmc * sizeof(struct pmc_threadpmcstate)))
 186
 187 /*
 188  * Task to free thread descriptors
 189  */
 190 static struct grouptask free_gtask;
 191
 192 /*
 193  * A map of row indices to classdep structures.
 194  */
 195 static struct pmc_classdep **pmc_rowindex_to_classdep;
 196
 197 /*
 198  * Prototypes
 199  */
 200
 201 #ifdef  HWPMC_DEBUG
 202 static int      pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS);
 203 static int      pmc_debugflags_parse(char *newstr, char *fence);
 204 #endif
 205
 206 static int      load(struct module *module, int cmd, void *arg);
 207 static int      pmc_add_sample(ring_type_t ring, struct pmc *pm, struct trapframe *tf);
 208 static void     pmc_add_thread_descriptors_from_proc(struct proc *p,
 209     struct pmc_process *pp);
 210 static int      pmc_attach_process(struct proc *p, struct pmc *pm);
 211 static struct pmc *pmc_allocate_pmc_descriptor(void);
 212 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p);
 213 static int      pmc_attach_one_process(struct proc *p, struct pmc *pm);
 214 static int      pmc_can_allocate_rowindex(struct proc *p, unsigned int ri,
 215     int cpu);
 216 static int      pmc_can_attach(struct pmc *pm, struct proc *p);
 217 static void     pmc_capture_user_callchain(int cpu, int soft, struct trapframe *tf);
 218 static void     pmc_cleanup(void);
 219 static int      pmc_detach_process(struct proc *p, struct pmc *pm);
 220 static int      pmc_detach_one_process(struct proc *p, struct pmc *pm,
 221     int flags);
 222 static void     pmc_destroy_owner_descriptor(struct pmc_owner *po);
 223 static void     pmc_destroy_pmc_descriptor(struct pmc *pm);
 224 static void     pmc_destroy_process_descriptor(struct pmc_process *pp);
 225 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p);
 226 static int      pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm);
 227 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po,
 228     pmc_id_t pmc);
 229 static struct pmc_process *pmc_find_process_descriptor(struct proc *p,
 230     uint32_t mode);
 231 static struct pmc_thread *pmc_find_thread_descriptor(struct pmc_process *pp,
 232     struct thread *td, uint32_t mode);
 233 static void     pmc_force_context_switch(void);
 234 static void     pmc_link_target_process(struct pmc *pm,
 235     struct pmc_process *pp);
 236 static void     pmc_log_all_process_mappings(struct pmc_owner *po);
 237 static void     pmc_log_kernel_mappings(struct pmc *pm);
 238 static void     pmc_log_process_mappings(struct pmc_owner *po, struct proc *p);
 239 static void     pmc_maybe_remove_owner(struct pmc_owner *po);
 240 static void     pmc_process_csw_in(struct thread *td);
 241 static void     pmc_process_csw_out(struct thread *td);
 242 static void     pmc_process_exit(void *arg, struct proc *p);
 243 static void     pmc_process_fork(void *arg, struct proc *p1,
 244     struct proc *p2, int n);
 245 static void     pmc_process_samples(int cpu, ring_type_t soft);
 246 static void     pmc_release_pmc_descriptor(struct pmc *pmc);
 247 static void     pmc_process_thread_add(struct thread *td);
 248 static void     pmc_process_thread_delete(struct thread *td);
 249 static void     pmc_process_thread_userret(struct thread *td);
 250 static void     pmc_remove_owner(struct pmc_owner *po);
 251 static void     pmc_remove_process_descriptor(struct pmc_process *pp);
 252 static void     pmc_restore_cpu_binding(struct pmc_binding *pb);
 253 static void     pmc_save_cpu_binding(struct pmc_binding *pb);
 254 static void     pmc_select_cpu(int cpu);
 255 static int      pmc_start(struct pmc *pm);
 256 static int      pmc_stop(struct pmc *pm);
 257 static int      pmc_syscall_handler(struct thread *td, void *syscall_args);
 258 static struct pmc_thread *pmc_thread_descriptor_pool_alloc(void);
 259 static void     pmc_thread_descriptor_pool_drain(void);
 260 static void     pmc_thread_descriptor_pool_free(struct pmc_thread *pt);
 261 static void     pmc_unlink_target_process(struct pmc *pmc,
 262     struct pmc_process *pp);
 263 static int generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp);
 264 static int generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp);
 265 static struct pmc_mdep *pmc_generic_cpu_initialize(void);
 266 static void pmc_generic_cpu_finalize(struct pmc_mdep *md);
 267 static void pmc_post_callchain_callback(void);
 268 static void pmc_process_threadcreate(struct thread *td);
 269 static void pmc_process_threadexit(struct thread *td);
 270 static void pmc_process_proccreate(struct proc *p);
 271 static void pmc_process_allproc(struct pmc *pm);
 272
 273 /*
 274  * Kernel tunables and sysctl(8) interface.
 275  */
 276
 277 SYSCTL_DECL(_kern_hwpmc);
 278 SYSCTL_NODE(_kern_hwpmc, OID_AUTO, stats, CTLFLAG_RW, 0, "HWPMC stats");
 279
 280
 281 /* Stats. */
 282 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_ignored, CTLFLAG_RW,
 283                                    &pmc_stats.pm_intr_ignored, "# of interrupts ignored");
 284 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_processed, CTLFLAG_RW,
 285                                    &pmc_stats.pm_intr_processed, "# of interrupts processed");
 286 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, intr_bufferfull, CTLFLAG_RW,
 287                                    &pmc_stats.pm_intr_bufferfull, "# of interrupts where buffer was full");
 288 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscalls, CTLFLAG_RW,
 289                                    &pmc_stats.pm_syscalls, "# of syscalls");
 290 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, syscall_errors, CTLFLAG_RW,
 291                                    &pmc_stats.pm_syscall_errors, "# of syscall_errors");
 292 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests, CTLFLAG_RW,
 293                                    &pmc_stats.pm_buffer_requests, "# of buffer requests");
 294 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, buffer_requests_failed, CTLFLAG_RW,
 295                                    &pmc_stats.pm_buffer_requests_failed, "# of buffer requests which failed");
 296 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, log_sweeps, CTLFLAG_RW,
 297                                    &pmc_stats.pm_log_sweeps, "# of ?");
 298 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, merges, CTLFLAG_RW,
 299                                    &pmc_stats.pm_merges, "# of times kernel stack was found for user trace");
 300 SYSCTL_COUNTER_U64(_kern_hwpmc_stats, OID_AUTO, overwrites, CTLFLAG_RW,
 301                                    &pmc_stats.pm_overwrites, "# of times a sample was overwritten before being logged");
 302
 303 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH;
 304 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_RDTUN,
 305     &pmc_callchaindepth, 0, "depth of call chain records");
 306
 307 char pmc_cpuid[64];
 308 SYSCTL_STRING(_kern_hwpmc, OID_AUTO, cpuid, CTLFLAG_RD,
 309         pmc_cpuid, 0, "cpu version string");
 310 #ifdef  HWPMC_DEBUG
 311 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS;
 312 char    pmc_debugstr[PMC_DEBUG_STRSIZE];
 313 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr,
 314     sizeof(pmc_debugstr));
 315 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags,
 316     CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NOFETCH,
 317     0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags");
 318 #endif
 319
 320
 321 /*
 322  * kern.hwpmc.hashrows -- determines the number of rows in the
 323  * of the hash table used to look up threads
 324  */
 325
 326 static int pmc_hashsize = PMC_HASH_SIZE;
 327 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_RDTUN,
 328     &pmc_hashsize, 0, "rows in hash tables");
 329
 330 /*
 331  * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU
 332  */
 333
 334 static int pmc_nsamples = PMC_NSAMPLES;
 335 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_RDTUN,
 336     &pmc_nsamples, 0, "number of PC samples per CPU");
 337
 338 static uint64_t pmc_sample_mask = PMC_NSAMPLES-1;
 339
 340 /*
 341  * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool.
 342  */
 343
 344 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE;
 345 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_RDTUN,
 346     &pmc_mtxpool_size, 0, "size of spin mutex pool");
 347
 348
 349 /*
 350  * kern.hwpmc.threadfreelist_entries -- number of free entries
 351  */
 352
 353 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_entries, CTLFLAG_RD,
 354     &pmc_threadfreelist_entries, 0, "number of avalable thread entries");
 355
 356
 357 /*
 358  * kern.hwpmc.threadfreelist_max -- maximum number of free entries
 359  */
 360
 361 static int pmc_threadfreelist_max = PMC_THREADLIST_MAX;
 362 SYSCTL_INT(_kern_hwpmc, OID_AUTO, threadfreelist_max, CTLFLAG_RW,
 363     &pmc_threadfreelist_max, 0,
 364     "maximum number of available thread entries before freeing some");
 365
 366
 367 /*
 368  * security.bsd.unprivileged_syspmcs -- allow non-root processes to
 369  * allocate system-wide PMCs.
 370  *
 371  * Allowing unprivileged processes to allocate system PMCs is convenient
 372  * if system-wide measurements need to be taken concurrently with other
 373  * per-process measurements.  This feature is turned off by default.
 374  */
 375
 376 static int pmc_unprivileged_syspmcs = 0;
 377 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RWTUN,
 378     &pmc_unprivileged_syspmcs, 0,
 379     "allow unprivileged process to allocate system PMCs");
 380
 381 /*
 382  * Hash function.  Discard the lower 2 bits of the pointer since
 383  * these are always zero for our uses.  The hash multiplier is
 384  * round((2^LONG_BIT) * ((sqrt(5)-1)/2)).
 385  */
 386
 387 #if     LONG_BIT == 64
 388 #define _PMC_HM         11400714819323198486u
 389 #elif   LONG_BIT == 32
 390 #define _PMC_HM         2654435769u
 391 #else
 392 #error  Must know the size of 'long' to compile
 393 #endif
 394
 395 #define PMC_HASH_PTR(P,M)       ((((unsigned long) (P) >> 2) * _PMC_HM) & (M))
 396
 397 /*
 398  * Syscall structures
 399  */
 400
 401 /* The `sysent' for the new syscall */
 402 static struct sysent pmc_sysent = {
 403         .sy_narg =      2,
 404         .sy_call =      pmc_syscall_handler,
 405 };
 406
 407 static struct syscall_module_data pmc_syscall_mod = {
 408         .chainevh =     load,
 409         .chainarg =     NULL,
 410         .offset =       &pmc_syscall_num,
 411         .new_sysent =   &pmc_sysent,
 412         .old_sysent =   { .sy_narg = 0, .sy_call = NULL },
 413         .flags =        SY_THR_STATIC_KLD,
 414 };
 415
 416 static moduledata_t pmc_mod = {
 417         .name =         PMC_MODULE_NAME,
 418         .evhand =       syscall_module_handler,
 419         .priv =         &pmc_syscall_mod,
 420 };
 421
 422 #ifdef EARLY_AP_STARTUP
 423 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SYSCALLS, SI_ORDER_ANY);
 424 #else
 425 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY);
 426 #endif
 427 MODULE_VERSION(pmc, PMC_VERSION);
 428
 429 #ifdef  HWPMC_DEBUG
 430 enum pmc_dbgparse_state {
 431         PMCDS_WS,               /* in whitespace */
 432         PMCDS_MAJOR,            /* seen a major keyword */
 433         PMCDS_MINOR
 434 };
 435
 436 static int
 437 pmc_debugflags_parse(char *newstr, char *fence)
 438 {
 439         char c, *p, *q;
 440         struct pmc_debugflags *tmpflags;
 441         int error, found, *newbits, tmp;
 442         size_t kwlen;
 443
 444         tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO);
 445
 446         p = newstr;
 447         error = 0;
 448
 449         for (; p < fence && (c = *p); p++) {
 450
 451                 /* skip white space */
 452                 if (c == ' ' || c == '\t')
 453                         continue;
 454
 455                 /* look for a keyword followed by "=" */
 456                 for (q = p; p < fence && (c = *p) && c != '='; p++)
 457                         ;
 458                 if (c != '=') {
 459                         error = EINVAL;
 460                         goto done;
 461                 }
 462
 463                 kwlen = p - q;
 464                 newbits = NULL;
 465
 466                 /* lookup flag group name */
 467 #define DBG_SET_FLAG_MAJ(S,F)                                           \
 468                 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0)  \
 469                         newbits = &tmpflags->pdb_ ## F;
 470
 471                 DBG_SET_FLAG_MAJ("cpu",         CPU);
 472                 DBG_SET_FLAG_MAJ("csw",         CSW);
 473                 DBG_SET_FLAG_MAJ("logging",     LOG);
 474                 DBG_SET_FLAG_MAJ("module",      MOD);
 475                 DBG_SET_FLAG_MAJ("md",          MDP);
 476                 DBG_SET_FLAG_MAJ("owner",       OWN);
 477                 DBG_SET_FLAG_MAJ("pmc",         PMC);
 478                 DBG_SET_FLAG_MAJ("process",     PRC);
 479                 DBG_SET_FLAG_MAJ("sampling",    SAM);
 480
 481                 if (newbits == NULL) {
 482                         error = EINVAL;
 483                         goto done;
 484                 }
 485
 486                 p++;            /* skip the '=' */
 487
 488                 /* Now parse the individual flags */
 489                 tmp = 0;
 490         newflag:
 491                 for (q = p; p < fence && (c = *p); p++)
 492                         if (c == ' ' || c == '\t' || c == ',')
 493                                 break;
 494
 495                 /* p == fence or c == ws or c == "," or c == 0 */
 496
 497                 if ((kwlen = p - q) == 0) {
 498                         *newbits = tmp;
 499                         continue;
 500                 }
 501
 502                 found = 0;
 503 #define DBG_SET_FLAG_MIN(S,F)                                           \
 504                 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0)  \
 505                         tmp |= found = (1 << PMC_DEBUG_MIN_ ## F)
 506
 507                 /* a '*' denotes all possible flags in the group */
 508                 if (kwlen == 1 && *q == '*')
 509                         tmp = found = ~0;
 510                 /* look for individual flag names */
 511                 DBG_SET_FLAG_MIN("allocaterow", ALR);
 512                 DBG_SET_FLAG_MIN("allocate",    ALL);
 513                 DBG_SET_FLAG_MIN("attach",      ATT);
 514                 DBG_SET_FLAG_MIN("bind",        BND);
 515                 DBG_SET_FLAG_MIN("config",      CFG);
 516                 DBG_SET_FLAG_MIN("exec",        EXC);
 517                 DBG_SET_FLAG_MIN("exit",        EXT);
 518                 DBG_SET_FLAG_MIN("find",        FND);
 519                 DBG_SET_FLAG_MIN("flush",       FLS);
 520                 DBG_SET_FLAG_MIN("fork",        FRK);
 521                 DBG_SET_FLAG_MIN("getbuf",      GTB);
 522                 DBG_SET_FLAG_MIN("hook",        PMH);
 523                 DBG_SET_FLAG_MIN("init",        INI);
 524                 DBG_SET_FLAG_MIN("intr",        INT);
 525                 DBG_SET_FLAG_MIN("linktarget",  TLK);
 526                 DBG_SET_FLAG_MIN("mayberemove", OMR);
 527                 DBG_SET_FLAG_MIN("ops",         OPS);
 528                 DBG_SET_FLAG_MIN("read",        REA);
 529                 DBG_SET_FLAG_MIN("register",    REG);
 530                 DBG_SET_FLAG_MIN("release",     REL);
 531                 DBG_SET_FLAG_MIN("remove",      ORM);
 532                 DBG_SET_FLAG_MIN("sample",      SAM);
 533                 DBG_SET_FLAG_MIN("scheduleio",  SIO);
 534                 DBG_SET_FLAG_MIN("select",      SEL);
 535                 DBG_SET_FLAG_MIN("signal",      SIG);
 536                 DBG_SET_FLAG_MIN("swi",         SWI);
 537                 DBG_SET_FLAG_MIN("swo",         SWO);
 538                 DBG_SET_FLAG_MIN("start",       STA);
 539                 DBG_SET_FLAG_MIN("stop",        STO);
 540                 DBG_SET_FLAG_MIN("syscall",     PMS);
 541                 DBG_SET_FLAG_MIN("unlinktarget", TUL);
 542                 DBG_SET_FLAG_MIN("write",       WRI);
 543                 if (found == 0) {
 544                         /* unrecognized flag name */
 545                         error = EINVAL;
 546                         goto done;
 547                 }
 548
 549                 if (c == 0 || c == ' ' || c == '\t') {  /* end of flag group */
 550                         *newbits = tmp;
 551                         continue;
 552                 }
 553
 554                 p++;
 555                 goto newflag;
 556         }
 557
 558         /* save the new flag set */
 559         bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags));
 560
 561  done:
 562         free(tmpflags, M_PMC);
 563         return error;
 564 }
 565
 566 static int
 567 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS)
 568 {
 569         char *fence, *newstr;
 570         int error;
 571         unsigned int n;
 572
 573         (void) arg1; (void) arg2; /* unused parameters */
 574
 575         n = sizeof(pmc_debugstr);
 576         newstr = malloc(n, M_PMC, M_WAITOK|M_ZERO);
 577         (void) strlcpy(newstr, pmc_debugstr, n);
 578
 579         error = sysctl_handle_string(oidp, newstr, n, req);
 580
 581         /* if there is a new string, parse and copy it */
 582         if (error == 0 && req->newptr != NULL) {
 583                 fence = newstr + (n < req->newlen ? n : req->newlen + 1);
 584                 if ((error = pmc_debugflags_parse(newstr, fence)) == 0)
 585                         (void) strlcpy(pmc_debugstr, newstr,
 586                             sizeof(pmc_debugstr));
 587         }
 588
 589         free(newstr, M_PMC);
 590
 591         return error;
 592 }
 593 #endif
 594
 595 /*
 596  * Map a row index to a classdep structure and return the adjusted row
 597  * index for the PMC class index.
 598  */
 599 static struct pmc_classdep *
 600 pmc_ri_to_classdep(struct pmc_mdep *md, int ri, int *adjri)
 601 {
 602         struct pmc_classdep *pcd;
 603
 604         (void) md;
 605
 606         KASSERT(ri >= 0 && ri < md->pmd_npmc,
 607             ("[pmc,%d] illegal row-index %d", __LINE__, ri));
 608
 609         pcd = pmc_rowindex_to_classdep[ri];
 610
 611         KASSERT(pcd != NULL,
 612             ("[pmc,%d] ri %d null pcd", __LINE__, ri));
 613
 614         *adjri = ri - pcd->pcd_ri;
 615
 616         KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num,
 617             ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri));
 618
 619         return (pcd);
 620 }
 621
 622 /*
 623  * Concurrency Control
 624  *
 625  * The driver manages the following data structures:
 626  *
 627  *   - target process descriptors, one per target process
 628  *   - owner process descriptors (and attached lists), one per owner process
 629  *   - lookup hash tables for owner and target processes
 630  *   - PMC descriptors (and attached lists)
 631  *   - per-cpu hardware state
 632  *   - the 'hook' variable through which the kernel calls into
 633  *     this module
 634  *   - the machine hardware state (managed by the MD layer)
 635  *
 636  * These data structures are accessed from:
 637  *
 638  * - thread context-switch code
 639  * - interrupt handlers (possibly on multiple cpus)
 640  * - kernel threads on multiple cpus running on behalf of user
 641  *   processes doing system calls
 642  * - this driver's private kernel threads
 643  *
 644  * = Locks and Locking strategy =
 645  *
 646  * The driver uses four locking strategies for its operation:
 647  *
 648  * - The global SX lock "pmc_sx" is used to protect internal
 649  *   data structures.
 650  *
 651  *   Calls into the module by syscall() start with this lock being
 652  *   held in exclusive mode.  Depending on the requested operation,
 653  *   the lock may be downgraded to 'shared' mode to allow more
 654  *   concurrent readers into the module.  Calls into the module from
 655  *   other parts of the kernel acquire the lock in shared mode.
 656  *
 657  *   This SX lock is held in exclusive mode for any operations that
 658  *   modify the linkages between the driver's internal data structures.
 659  *
 660  *   The 'pmc_hook' function pointer is also protected by this lock.
 661  *   It is only examined with the sx lock held in exclusive mode.  The
 662  *   kernel module is allowed to be unloaded only with the sx lock held
 663  *   in exclusive mode.  In normal syscall handling, after acquiring the
 664  *   pmc_sx lock we first check that 'pmc_hook' is non-null before
 665  *   proceeding.  This prevents races between the thread unloading the module
 666  *   and other threads seeking to use the module.
 667  *
 668  * - Lookups of target process structures and owner process structures
 669  *   cannot use the global "pmc_sx" SX lock because these lookups need
 670  *   to happen during context switches and in other critical sections
 671  *   where sleeping is not allowed.  We protect these lookup tables
 672  *   with their own private spin-mutexes, "pmc_processhash_mtx" and
 673  *   "pmc_ownerhash_mtx".
 674  *
 675  * - Interrupt handlers work in a lock free manner.  At interrupt
 676  *   time, handlers look at the PMC pointer (phw->phw_pmc) configured
 677  *   when the PMC was started.  If this pointer is NULL, the interrupt
 678  *   is ignored after updating driver statistics.  We ensure that this
 679  *   pointer is set (using an atomic operation if necessary) before the
 680  *   PMC hardware is started.  Conversely, this pointer is unset atomically
 681  *   only after the PMC hardware is stopped.
 682  *
 683  *   We ensure that everything needed for the operation of an
 684  *   interrupt handler is available without it needing to acquire any
 685  *   locks.  We also ensure that a PMC's software state is destroyed only
 686  *   after the PMC is taken off hardware (on all CPUs).
 687  *
 688  * - Context-switch handling with process-private PMCs needs more
 689  *   care.
 690  *
 691  *   A given process may be the target of multiple PMCs.  For example,
 692  *   PMCATTACH and PMCDETACH may be requested by a process on one CPU
 693  *   while the target process is running on another.  A PMC could also
 694  *   be getting released because its owner is exiting.  We tackle
 695  *   these situations in the following manner:
 696  *
 697  *   - each target process structure 'pmc_process' has an array
 698  *     of 'struct pmc *' pointers, one for each hardware PMC.
 699  *
 700  *   - At context switch IN time, each "target" PMC in RUNNING state
 701  *     gets started on hardware and a pointer to each PMC is copied into
 702  *     the per-cpu phw array.  The 'runcount' for the PMC is
 703  *     incremented.
 704  *
 705  *   - At context switch OUT time, all process-virtual PMCs are stopped
 706  *     on hardware.  The saved value is added to the PMCs value field
 707  *     only if the PMC is in a non-deleted state (the PMCs state could
 708  *     have changed during the current time slice).
 709  *
 710  *     Note that since in-between a switch IN on a processor and a switch
 711  *     OUT, the PMC could have been released on another CPU.  Therefore
 712  *     context switch OUT always looks at the hardware state to turn
 713  *     OFF PMCs and will update a PMC's saved value only if reachable
 714  *     from the target process record.
 715  *
 716  *   - OP PMCRELEASE could be called on a PMC at any time (the PMC could
 717  *     be attached to many processes at the time of the call and could
 718  *     be active on multiple CPUs).
 719  *
 720  *     We prevent further scheduling of the PMC by marking it as in
 721  *     state 'DELETED'.  If the runcount of the PMC is non-zero then
 722  *     this PMC is currently running on a CPU somewhere.  The thread
 723  *     doing the PMCRELEASE operation waits by repeatedly doing a
 724  *     pause() till the runcount comes to zero.
 725  *
 726  * The contents of a PMC descriptor (struct pmc) are protected using
 727  * a spin-mutex.  In order to save space, we use a mutex pool.
 728  *
 729  * In terms of lock types used by witness(4), we use:
 730  * - Type "pmc-sx", used by the global SX lock.
 731  * - Type "pmc-sleep", for sleep mutexes used by logger threads.
 732  * - Type "pmc-per-proc", for protecting PMC owner descriptors.
 733  * - Type "pmc-leaf", used for all other spin mutexes.
 734  */
 735
 736 /*
 737  * save the cpu binding of the current kthread
 738  */
 739
 740 static void
 741 pmc_save_cpu_binding(struct pmc_binding *pb)
 742 {
 743         PMCDBG0(CPU,BND,2, "save-cpu");
 744         thread_lock(curthread);
 745         pb->pb_bound = sched_is_bound(curthread);
 746         pb->pb_cpu   = curthread->td_oncpu;
 747         thread_unlock(curthread);
 748         PMCDBG1(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu);
 749 }
 750
 751 /*
 752  * restore the cpu binding of the current thread
 753  */
 754
 755 static void
 756 pmc_restore_cpu_binding(struct pmc_binding *pb)
 757 {
 758         PMCDBG2(CPU,BND,2, "restore-cpu curcpu=%d restore=%d",
 759             curthread->td_oncpu, pb->pb_cpu);
 760         thread_lock(curthread);
 761         if (pb->pb_bound)
 762                 sched_bind(curthread, pb->pb_cpu);
 763         else
 764                 sched_unbind(curthread);
 765         thread_unlock(curthread);
 766         PMCDBG0(CPU,BND,2, "restore-cpu done");
 767 }
 768
 769 /*
 770  * move execution over the specified cpu and bind it there.
 771  */
 772
 773 static void
 774 pmc_select_cpu(int cpu)
 775 {
 776         KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
 777             ("[pmc,%d] bad cpu number %d", __LINE__, cpu));
 778
 779         /* Never move to an inactive CPU. */
 780         KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive "
 781             "CPU %d", __LINE__, cpu));
 782
 783         PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d", cpu);
 784         thread_lock(curthread);
 785         sched_bind(curthread, cpu);
 786         thread_unlock(curthread);
 787
 788         KASSERT(curthread->td_oncpu == cpu,
 789             ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__,
 790                 cpu, curthread->td_oncpu));
 791
 792         PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d ok", cpu);
 793 }
 794
 795 /*
 796  * Force a context switch.
 797  *
 798  * We do this by pause'ing for 1 tick -- invoking mi_switch() is not
 799  * guaranteed to force a context switch.
 800  */
 801
 802 static void
 803 pmc_force_context_switch(void)
 804 {
 805
 806         pause("pmcctx", 1);
 807 }
 808
 809 uint64_t
 810 pmc_rdtsc(void)
 811 {
 812 #if defined(__i386__) || defined(__amd64__)
 813         if (__predict_true(amd_feature & AMDID_RDTSCP))
 814                 return rdtscp();
 815         else
 816                 return rdtsc();
 817 #else
 818         return get_cyclecount();
 819 #endif
 820 }
 821
 822 /*
 823  * Get the file name for an executable.  This is a simple wrapper
 824  * around vn_fullpath(9).
 825  */
 826
 827 static void
 828 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath)
 829 {
 830
 831         *fullpath = "unknown";
 832         *freepath = NULL;
 833         vn_fullpath(curthread, v, fullpath, freepath);
 834 }
 835
 836 /*
 837  * remove an process owning PMCs
 838  */
 839
 840 void
 841 pmc_remove_owner(struct pmc_owner *po)
 842 {
 843         struct pmc *pm, *tmp;
 844
 845         sx_assert(&pmc_sx, SX_XLOCKED);
 846
 847         PMCDBG1(OWN,ORM,1, "remove-owner po=%p", po);
 848
 849         /* Remove descriptor from the owner hash table */
 850         LIST_REMOVE(po, po_next);
 851
 852         /* release all owned PMC descriptors */
 853         LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) {
 854                 PMCDBG1(OWN,ORM,2, "pmc=%p", pm);
 855                 KASSERT(pm->pm_owner == po,
 856                     ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po));
 857
 858                 pmc_release_pmc_descriptor(pm); /* will unlink from the list */
 859                 pmc_destroy_pmc_descriptor(pm);
 860         }
 861
 862         KASSERT(po->po_sscount == 0,
 863             ("[pmc,%d] SS count not zero", __LINE__));
 864         KASSERT(LIST_EMPTY(&po->po_pmcs),
 865             ("[pmc,%d] PMC list not empty", __LINE__));
 866
 867         /* de-configure the log file if present */
 868         if (po->po_flags & PMC_PO_OWNS_LOGFILE)
 869                 pmclog_deconfigure_log(po);
 870 }
 871
 872 /*
 873  * remove an owner process record if all conditions are met.
 874  */
 875
 876 static void
 877 pmc_maybe_remove_owner(struct pmc_owner *po)
 878 {
 879
 880         PMCDBG1(OWN,OMR,1, "maybe-remove-owner po=%p", po);
 881
 882         /*
 883          * Remove owner record if
 884          * - this process does not own any PMCs
 885          * - this process has not allocated a system-wide sampling buffer
 886          */
 887
 888         if (LIST_EMPTY(&po->po_pmcs) &&
 889             ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) {
 890                 pmc_remove_owner(po);
 891                 pmc_destroy_owner_descriptor(po);
 892         }
 893 }
 894
 895 /*
 896  * Add an association between a target process and a PMC.
 897  */
 898
 899 static void
 900 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp)
 901 {
 902         int ri;
 903         struct pmc_target *pt;
 904 #ifdef INVARIANTS
 905         struct pmc_thread *pt_td;
 906 #endif
 907
 908         sx_assert(&pmc_sx, SX_XLOCKED);
 909
 910         KASSERT(pm != NULL && pp != NULL,
 911             ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp));
 912         KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)),
 913             ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d",
 914                 __LINE__, pm, pp->pp_proc->p_pid));
 915         KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1),
 916             ("[pmc,%d] Illegal reference count %d for process record %p",
 917                 __LINE__, pp->pp_refcnt, (void *) pp));
 918
 919         ri = PMC_TO_ROWINDEX(pm);
 920
 921         PMCDBG3(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p",
 922             pm, ri, pp);
 923
 924 #ifdef  HWPMC_DEBUG
 925         LIST_FOREACH(pt, &pm->pm_targets, pt_next)
 926             if (pt->pt_process == pp)
 927                     KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets",
 928                                 __LINE__, pp, pm));
 929 #endif
 930
 931         pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK|M_ZERO);
 932         pt->pt_process = pp;
 933
 934         LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next);
 935
 936         atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc,
 937             (uintptr_t)pm);
 938
 939         if (pm->pm_owner->po_owner == pp->pp_proc)
 940                 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER;
 941
 942         /*
 943          * Initialize the per-process values at this row index.
 944          */
 945         pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ?
 946             pm->pm_sc.pm_reloadcount : 0;
 947
 948         pp->pp_refcnt++;
 949
 950 #ifdef INVARIANTS
 951         /* Confirm that the per-thread values at this row index are cleared. */
 952         if (PMC_TO_MODE(pm) == PMC_MODE_TS) {
 953                 mtx_lock_spin(pp->pp_tdslock);
 954                 LIST_FOREACH(pt_td, &pp->pp_tds, pt_next) {
 955                         KASSERT(pt_td->pt_pmcs[ri].pt_pmcval == (pmc_value_t) 0,
 956                             ("[pmc,%d] pt_pmcval not cleared for pid=%d at "
 957                             "ri=%d", __LINE__, pp->pp_proc->p_pid, ri));
 958                 }
 959                 mtx_unlock_spin(pp->pp_tdslock);
 960         }
 961 #endif
 962 }
 963
 964 /*
 965  * Removes the association between a target process and a PMC.
 966  */
 967
 968 static void
 969 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp)
 970 {
 971         int ri;
 972         struct proc *p;
 973         struct pmc_target *ptgt;
 974         struct pmc_thread *pt;
 975
 976         sx_assert(&pmc_sx, SX_XLOCKED);
 977
 978         KASSERT(pm != NULL && pp != NULL,
 979             ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp));
 980
 981         KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc,
 982             ("[pmc,%d] Illegal ref count %d on process record %p",
 983                 __LINE__, pp->pp_refcnt, (void *) pp));
 984
 985         ri = PMC_TO_ROWINDEX(pm);
 986
 987         PMCDBG3(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p",
 988             pm, ri, pp);
 989
 990         KASSERT(pp->pp_pmcs[ri].pp_pmc == pm,
 991             ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__,
 992                 ri, pm, pp->pp_pmcs[ri].pp_pmc));
 993
 994         pp->pp_pmcs[ri].pp_pmc = NULL;
 995         pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0;
 996
 997         /* Clear the per-thread values at this row index. */
 998         if (PMC_TO_MODE(pm) == PMC_MODE_TS) {
 999                 mtx_lock_spin(pp->pp_tdslock);
1000                 LIST_FOREACH(pt, &pp->pp_tds, pt_next)
1001                         pt->pt_pmcs[ri].pt_pmcval = (pmc_value_t) 0;
1002                 mtx_unlock_spin(pp->pp_tdslock);
1003         }
1004
1005         /* Remove owner-specific flags */
1006         if (pm->pm_owner->po_owner == pp->pp_proc) {
1007                 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS;
1008                 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER;
1009         }
1010
1011         pp->pp_refcnt--;
1012
1013         /* Remove the target process from the PMC structure */
1014         LIST_FOREACH(ptgt, &pm->pm_targets, pt_next)
1015                 if (ptgt->pt_process == pp)
1016                         break;
1017
1018         KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found "
1019                     "in pmc %p", __LINE__, pp->pp_proc, pp, pm));
1020
1021         LIST_REMOVE(ptgt, pt_next);
1022         free(ptgt, M_PMC);
1023
1024         /* if the PMC now lacks targets, send the owner a SIGIO */
1025         if (LIST_EMPTY(&pm->pm_targets)) {
1026                 p = pm->pm_owner->po_owner;
1027                 PROC_LOCK(p);
1028                 kern_psignal(p, SIGIO);
1029                 PROC_UNLOCK(p);
1030
1031                 PMCDBG2(PRC,SIG,2, "signalling proc=%p signal=%d", p,
1032                     SIGIO);
1033         }
1034 }
1035
1036 /*
1037  * Check if PMC 'pm' may be attached to target process 't'.
1038  */
1039
1040 static int
1041 pmc_can_attach(struct pmc *pm, struct proc *t)
1042 {
1043         struct proc *o;         /* pmc owner */
1044         struct ucred *oc, *tc;  /* owner, target credentials */
1045         int decline_attach, i;
1046
1047         /*
1048          * A PMC's owner can always attach that PMC to itself.
1049          */
1050
1051         if ((o = pm->pm_owner->po_owner) == t)
1052                 return 0;
1053
1054         PROC_LOCK(o);
1055         oc = o->p_ucred;
1056         crhold(oc);
1057         PROC_UNLOCK(o);
1058
1059         PROC_LOCK(t);
1060         tc = t->p_ucred;
1061         crhold(tc);
1062         PROC_UNLOCK(t);
1063
1064         /*
1065          * The effective uid of the PMC owner should match at least one
1066          * of the {effective,real,saved} uids of the target process.
1067          */
1068
1069         decline_attach = oc->cr_uid != tc->cr_uid &&
1070             oc->cr_uid != tc->cr_svuid &&
1071             oc->cr_uid != tc->cr_ruid;
1072
1073         /*
1074          * Every one of the target's group ids, must be in the owner's
1075          * group list.
1076          */
1077         for (i = 0; !decline_attach && i < tc->cr_ngroups; i++)
1078                 decline_attach = !groupmember(tc->cr_groups[i], oc);
1079
1080         /* check the read and saved gids too */
1081         if (decline_attach == 0)
1082                 decline_attach = !groupmember(tc->cr_rgid, oc) ||
1083                     !groupmember(tc->cr_svgid, oc);
1084
1085         crfree(tc);
1086         crfree(oc);
1087
1088         return !decline_attach;
1089 }
1090
1091 /*
1092  * Attach a process to a PMC.
1093  */
1094
1095 static int
1096 pmc_attach_one_process(struct proc *p, struct pmc *pm)
1097 {
1098         int ri, error;
1099         char *fullpath, *freepath;
1100         struct pmc_process      *pp;
1101
1102         sx_assert(&pmc_sx, SX_XLOCKED);
1103
1104         PMCDBG5(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm,
1105             PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm);
1106
1107         /*
1108          * Locate the process descriptor corresponding to process 'p',
1109          * allocating space as needed.
1110          *
1111          * Verify that rowindex 'pm_rowindex' is free in the process
1112          * descriptor.
1113          *
1114          * If not, allocate space for a descriptor and link the
1115          * process descriptor and PMC.
1116          */
1117         ri = PMC_TO_ROWINDEX(pm);
1118
1119         /* mark process as using HWPMCs */
1120         PROC_LOCK(p);
1121         p->p_flag |= P_HWPMC;
1122         PROC_UNLOCK(p);
1123
1124         if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) {
1125                 error = ENOMEM;
1126                 goto fail;
1127         }
1128
1129         if (pp->pp_pmcs[ri].pp_pmc == pm) {/* already present at slot [ri] */
1130                 error = EEXIST;
1131                 goto fail;
1132         }
1133
1134         if (pp->pp_pmcs[ri].pp_pmc != NULL) {
1135                 error = EBUSY;
1136                 goto fail;
1137         }
1138
1139         pmc_link_target_process(pm, pp);
1140
1141         if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) &&
1142             (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0)
1143                 pm->pm_flags |= PMC_F_NEEDS_LOGFILE;
1144
1145         pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */
1146
1147         /* issue an attach event to a configured log file */
1148         if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) {
1149                 if (p->p_flag & P_KPROC) {
1150                         fullpath = kernelname;
1151                         freepath = NULL;
1152                 } else {
1153                         pmc_getfilename(p->p_textvp, &fullpath, &freepath);
1154                         pmclog_process_pmcattach(pm, p->p_pid, fullpath);
1155                 }
1156                 free(freepath, M_TEMP);
1157                 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
1158                         pmc_log_process_mappings(pm->pm_owner, p);
1159         }
1160
1161         return (0);
1162  fail:
1163         PROC_LOCK(p);
1164         p->p_flag &= ~P_HWPMC;
1165         PROC_UNLOCK(p);
1166         return (error);
1167 }
1168
1169 /*
1170  * Attach a process and optionally its children
1171  */
1172
1173 static int
1174 pmc_attach_process(struct proc *p, struct pmc *pm)
1175 {
1176         int error;
1177         struct proc *top;
1178
1179         sx_assert(&pmc_sx, SX_XLOCKED);
1180
1181         PMCDBG5(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm,
1182             PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm);
1183
1184
1185         /*
1186          * If this PMC successfully allowed a GETMSR operation
1187          * in the past, disallow further ATTACHes.
1188          */
1189
1190         if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0)
1191                 return EPERM;
1192
1193         if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0)
1194                 return pmc_attach_one_process(p, pm);
1195
1196         /*
1197          * Traverse all child processes, attaching them to
1198          * this PMC.
1199          */
1200
1201         sx_slock(&proctree_lock);
1202
1203         top = p;
1204
1205         for (;;) {
1206                 if ((error = pmc_attach_one_process(p, pm)) != 0)
1207                         break;
1208                 if (!LIST_EMPTY(&p->p_children))
1209                         p = LIST_FIRST(&p->p_children);
1210                 else for (;;) {
1211                         if (p == top)
1212                                 goto done;
1213                         if (LIST_NEXT(p, p_sibling)) {
1214                                 p = LIST_NEXT(p, p_sibling);
1215                                 break;
1216                         }
1217                         p = p->p_pptr;
1218                 }
1219         }
1220
1221         if (error)
1222                 (void) pmc_detach_process(top, pm);
1223
1224  done:
1225         sx_sunlock(&proctree_lock);
1226         return error;
1227 }
1228
1229 /*
1230  * Detach a process from a PMC.  If there are no other PMCs tracking
1231  * this process, remove the process structure from its hash table.  If
1232  * 'flags' contains PMC_FLAG_REMOVE, then free the process structure.
1233  */
1234
1235 static int
1236 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags)
1237 {
1238         int ri;
1239         struct pmc_process *pp;
1240
1241         sx_assert(&pmc_sx, SX_XLOCKED);
1242
1243         KASSERT(pm != NULL,
1244             ("[pmc,%d] null pm pointer", __LINE__));
1245
1246         ri = PMC_TO_ROWINDEX(pm);
1247
1248         PMCDBG6(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x",
1249             pm, ri, p, p->p_pid, p->p_comm, flags);
1250
1251         if ((pp = pmc_find_process_descriptor(p, 0)) == NULL)
1252                 return ESRCH;
1253
1254         if (pp->pp_pmcs[ri].pp_pmc != pm)
1255                 return EINVAL;
1256
1257         pmc_unlink_target_process(pm, pp);
1258
1259         /* Issue a detach entry if a log file is configured */
1260         if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE)
1261                 pmclog_process_pmcdetach(pm, p->p_pid);
1262
1263         /*
1264          * If there are no PMCs targeting this process, we remove its
1265          * descriptor from the target hash table and unset the P_HWPMC
1266          * flag in the struct proc.
1267          */
1268         KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc,
1269             ("[pmc,%d] Illegal refcnt %d for process struct %p",
1270                 __LINE__, pp->pp_refcnt, pp));
1271
1272         if (pp->pp_refcnt != 0) /* still a target of some PMC */
1273                 return 0;
1274
1275         pmc_remove_process_descriptor(pp);
1276
1277         if (flags & PMC_FLAG_REMOVE)
1278                 pmc_destroy_process_descriptor(pp);
1279
1280         PROC_LOCK(p);
1281         p->p_flag &= ~P_HWPMC;
1282         PROC_UNLOCK(p);
1283
1284         return 0;
1285 }
1286
1287 /*
1288  * Detach a process and optionally its descendants from a PMC.
1289  */
1290
1291 static int
1292 pmc_detach_process(struct proc *p, struct pmc *pm)
1293 {
1294         struct proc *top;
1295
1296         sx_assert(&pmc_sx, SX_XLOCKED);
1297
1298         PMCDBG5(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm,
1299             PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm);
1300
1301         if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0)
1302                 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE);
1303
1304         /*
1305          * Traverse all children, detaching them from this PMC.  We
1306          * ignore errors since we could be detaching a PMC from a
1307          * partially attached proc tree.
1308          */
1309
1310         sx_slock(&proctree_lock);
1311
1312         top = p;
1313
1314         for (;;) {
1315                 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE);
1316
1317                 if (!LIST_EMPTY(&p->p_children))
1318                         p = LIST_FIRST(&p->p_children);
1319                 else for (;;) {
1320                         if (p == top)
1321                                 goto done;
1322                         if (LIST_NEXT(p, p_sibling)) {
1323                                 p = LIST_NEXT(p, p_sibling);
1324                                 break;
1325                         }
1326                         p = p->p_pptr;
1327                 }
1328         }
1329
1330  done:
1331         sx_sunlock(&proctree_lock);
1332
1333         if (LIST_EMPTY(&pm->pm_targets))
1334                 pm->pm_flags &= ~PMC_F_ATTACH_DONE;
1335
1336         return 0;
1337 }
1338
1339
1340 /*
1341  * Thread context switch IN
1342  */
1343
1344 static void
1345 pmc_process_csw_in(struct thread *td)
1346 {
1347         int cpu;
1348         unsigned int adjri, ri;
1349         struct pmc *pm;
1350         struct proc *p;
1351         struct pmc_cpu *pc;
1352         struct pmc_hw *phw;
1353         pmc_value_t newvalue;
1354         struct pmc_process *pp;
1355         struct pmc_thread *pt;
1356         struct pmc_classdep *pcd;
1357
1358         p = td->td_proc;
1359         pt = NULL;
1360         if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL)
1361                 return;
1362
1363         KASSERT(pp->pp_proc == td->td_proc,
1364             ("[pmc,%d] not my thread state", __LINE__));
1365
1366         critical_enter(); /* no preemption from this point */
1367
1368         cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */
1369
1370         PMCDBG5(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p,
1371             p->p_pid, p->p_comm, pp);
1372
1373         KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
1374             ("[pmc,%d] weird CPU id %d", __LINE__, cpu));
1375
1376         pc = pmc_pcpu[cpu];
1377
1378         for (ri = 0; ri < md->pmd_npmc; ri++) {
1379
1380                 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL)
1381                         continue;
1382
1383                 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)),
1384                     ("[pmc,%d] Target PMC in non-virtual mode (%d)",
1385                         __LINE__, PMC_TO_MODE(pm)));
1386
1387                 KASSERT(PMC_TO_ROWINDEX(pm) == ri,
1388                     ("[pmc,%d] Row index mismatch pmc %d != ri %d",
1389                         __LINE__, PMC_TO_ROWINDEX(pm), ri));
1390
1391                 /*
1392                  * Only PMCs that are marked as 'RUNNING' need
1393                  * be placed on hardware.
1394                  */
1395
1396                 if (pm->pm_state != PMC_STATE_RUNNING)
1397                         continue;
1398
1399                 KASSERT(counter_u64_fetch(pm->pm_runcount) >= 0,
1400             ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm,
1401                  (unsigned long)counter_u64_fetch(pm->pm_runcount)));
1402
1403                 /* increment PMC runcount */
1404                 counter_u64_add(pm->pm_runcount, 1);
1405
1406                 /* configure the HWPMC we are going to use. */
1407                 pcd = pmc_ri_to_classdep(md, ri, &adjri);
1408                 pcd->pcd_config_pmc(cpu, adjri, pm);
1409
1410                 phw = pc->pc_hwpmcs[ri];
1411
1412                 KASSERT(phw != NULL,
1413                     ("[pmc,%d] null hw pointer", __LINE__));
1414
1415                 KASSERT(phw->phw_pmc == pm,
1416                     ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__,
1417                         phw->phw_pmc, pm));
1418
1419                 /*
1420                  * Write out saved value and start the PMC.
1421                  *
1422                  * Sampling PMCs use a per-thread value, while
1423                  * counting mode PMCs use a per-pmc value that is
1424                  * inherited across descendants.
1425                  */
1426                 if (PMC_TO_MODE(pm) == PMC_MODE_TS) {
1427                         if (pt == NULL)
1428                                 pt = pmc_find_thread_descriptor(pp, td,
1429                                     PMC_FLAG_NONE);
1430
1431                         KASSERT(pt != NULL,
1432                             ("[pmc,%d] No thread found for td=%p", __LINE__,
1433                             td));
1434
1435                         mtx_pool_lock_spin(pmc_mtxpool, pm);
1436
1437                         /*
1438                          * If we have a thread descriptor, use the per-thread
1439                          * counter in the descriptor. If not, we will use
1440                          * a per-process counter.
1441                          *
1442                          * TODO: Remove the per-process "safety net" once
1443                          * we have thoroughly tested that we don't hit the
1444                          * above assert.
1445                          */
1446                         if (pt != NULL) {
1447                                 if (pt->pt_pmcs[ri].pt_pmcval > 0)
1448                                         newvalue = pt->pt_pmcs[ri].pt_pmcval;
1449                                 else
1450                                         newvalue = pm->pm_sc.pm_reloadcount;
1451                         } else {
1452                                 /*
1453                                  * Use the saved value calculated after the most
1454                                  * recent time a thread using the shared counter
1455                                  * switched out. Reset the saved count in case
1456                                  * another thread from this process switches in
1457                                  * before any threads switch out.
1458                                  */
1459
1460                                 newvalue = pp->pp_pmcs[ri].pp_pmcval;
1461                                 pp->pp_pmcs[ri].pp_pmcval =
1462                                     pm->pm_sc.pm_reloadcount;
1463                         }
1464                         mtx_pool_unlock_spin(pmc_mtxpool, pm);
1465                         KASSERT(newvalue > 0 && newvalue <=
1466                             pm->pm_sc.pm_reloadcount,
1467                             ("[pmc,%d] pmcval outside of expected range cpu=%d "
1468                             "ri=%d pmcval=%jx pm_reloadcount=%jx", __LINE__,
1469                             cpu, ri, newvalue, pm->pm_sc.pm_reloadcount));
1470                 } else {
1471                         KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC,
1472                             ("[pmc,%d] illegal mode=%d", __LINE__,
1473                             PMC_TO_MODE(pm)));
1474                         mtx_pool_lock_spin(pmc_mtxpool, pm);
1475                         newvalue = PMC_PCPU_SAVED(cpu, ri) =
1476                             pm->pm_gv.pm_savedvalue;
1477                         mtx_pool_unlock_spin(pmc_mtxpool, pm);
1478                 }
1479
1480                 PMCDBG3(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue);
1481
1482                 pcd->pcd_write_pmc(cpu, adjri, newvalue);
1483
1484                 /* If a sampling mode PMC, reset stalled state. */
1485                 if (PMC_TO_MODE(pm) == PMC_MODE_TS)
1486                         pm->pm_pcpu_state[cpu].pps_stalled = 0;
1487
1488                 /* Indicate that we desire this to run. */
1489                 pm->pm_pcpu_state[cpu].pps_cpustate = 1;
1490
1491                 /* Start the PMC. */
1492                 pcd->pcd_start_pmc(cpu, adjri);
1493         }
1494
1495         /*
1496          * perform any other architecture/cpu dependent thread
1497          * switch-in actions.
1498          */
1499
1500         (void) (*md->pmd_switch_in)(pc, pp);
1501
1502         critical_exit();
1503
1504 }
1505
1506 /*
1507  * Thread context switch OUT.
1508  */
1509
1510 static void
1511 pmc_process_csw_out(struct thread *td)
1512 {
1513         int cpu;
1514         int64_t tmp;
1515         struct pmc *pm;
1516         struct proc *p;
1517         enum pmc_mode mode;
1518         struct pmc_cpu *pc;
1519         pmc_value_t newvalue;
1520         unsigned int adjri, ri;
1521         struct pmc_process *pp;
1522         struct pmc_thread *pt = NULL;
1523         struct pmc_classdep *pcd;
1524
1525
1526         /*
1527          * Locate our process descriptor; this may be NULL if
1528          * this process is exiting and we have already removed
1529          * the process from the target process table.
1530          *
1531          * Note that due to kernel preemption, multiple
1532          * context switches may happen while the process is
1533          * exiting.
1534          *
1535          * Note also that if the target process cannot be
1536          * found we still need to deconfigure any PMCs that
1537          * are currently running on hardware.
1538          */
1539
1540         p = td->td_proc;
1541         pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE);
1542
1543         /*
1544          * save PMCs
1545          */
1546
1547         critical_enter();
1548
1549         cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */
1550
1551         PMCDBG5(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p,
1552             p->p_pid, p->p_comm, pp);
1553
1554         KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
1555             ("[pmc,%d weird CPU id %d", __LINE__, cpu));
1556
1557         pc = pmc_pcpu[cpu];
1558
1559         /*
1560          * When a PMC gets unlinked from a target PMC, it will
1561          * be removed from the target's pp_pmc[] array.
1562          *
1563          * However, on a MP system, the target could have been
1564          * executing on another CPU at the time of the unlink.
1565          * So, at context switch OUT time, we need to look at
1566          * the hardware to determine if a PMC is scheduled on
1567          * it.
1568          */
1569
1570         for (ri = 0; ri < md->pmd_npmc; ri++) {
1571
1572                 pcd = pmc_ri_to_classdep(md, ri, &adjri);
1573                 pm  = NULL;
1574                 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm);
1575
1576                 if (pm == NULL) /* nothing at this row index */
1577                         continue;
1578
1579                 mode = PMC_TO_MODE(pm);
1580                 if (!PMC_IS_VIRTUAL_MODE(mode))
1581                         continue; /* not a process virtual PMC */
1582
1583                 KASSERT(PMC_TO_ROWINDEX(pm) == ri,
1584                     ("[pmc,%d] ri mismatch pmc(%d) ri(%d)",
1585                         __LINE__, PMC_TO_ROWINDEX(pm), ri));
1586
1587                 /*
1588                  * Change desired state, and then stop if not stalled.
1589                  * This two-step dance should avoid race conditions where
1590                  * an interrupt re-enables the PMC after this code has
1591                  * already checked the pm_stalled flag.
1592                  */
1593                 pm->pm_pcpu_state[cpu].pps_cpustate = 0;
1594                 if (pm->pm_pcpu_state[cpu].pps_stalled == 0)
1595                         pcd->pcd_stop_pmc(cpu, adjri);
1596
1597                 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0,
1598                         ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm,
1599                          (unsigned long)counter_u64_fetch(pm->pm_runcount)));
1600
1601                 /* reduce this PMC's runcount */
1602                 counter_u64_add(pm->pm_runcount, -1);
1603
1604                 /*
1605                  * If this PMC is associated with this process,
1606                  * save the reading.
1607                  */
1608
1609                 if (pm->pm_state != PMC_STATE_DELETED && pp != NULL &&
1610                     pp->pp_pmcs[ri].pp_pmc != NULL) {
1611                         KASSERT(pm == pp->pp_pmcs[ri].pp_pmc,
1612                             ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__,
1613                                 pm, ri, pp->pp_pmcs[ri].pp_pmc));
1614
1615                         KASSERT(pp->pp_refcnt > 0,
1616                             ("[pmc,%d] pp refcnt = %d", __LINE__,
1617                                 pp->pp_refcnt));
1618
1619                         pcd->pcd_read_pmc(cpu, adjri, &newvalue);
1620
1621                         if (mode == PMC_MODE_TS) {
1622                                 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d val=%jd (samp)",
1623                                     cpu, ri, newvalue);
1624
1625                                 if (pt == NULL)
1626                                         pt = pmc_find_thread_descriptor(pp, td,
1627                                             PMC_FLAG_NONE);
1628
1629                                 KASSERT(pt != NULL,
1630                                     ("[pmc,%d] No thread found for td=%p",
1631                                     __LINE__, td));
1632
1633                                 mtx_pool_lock_spin(pmc_mtxpool, pm);
1634
1635                                 /*
1636                                  * If we have a thread descriptor, save the
1637                                  * per-thread counter in the descriptor. If not,
1638                                  * we will update the per-process counter.
1639                                  *
1640                                  * TODO: Remove the per-process "safety net"
1641                                  * once we have thoroughly tested that we
1642                                  * don't hit the above assert.
1643                                  */
1644                                 if (pt != NULL)
1645                                         pt->pt_pmcs[ri].pt_pmcval = newvalue;
1646                                 else {
1647                                         /*
1648                                          * For sampling process-virtual PMCs,
1649                                          * newvalue is the number of events to
1650                                          * be seen until the next sampling
1651                                          * interrupt. We can just add the events
1652                                          * left from this invocation to the
1653                                          * counter, then adjust in case we
1654                                          * overflow our range.
1655                                          *
1656                                          * (Recall that we reload the counter
1657                                          * every time we use it.)
1658                                          */
1659                                         pp->pp_pmcs[ri].pp_pmcval += newvalue;
1660                                         if (pp->pp_pmcs[ri].pp_pmcval >
1661                                             pm->pm_sc.pm_reloadcount)
1662                                                 pp->pp_pmcs[ri].pp_pmcval -=
1663                                                     pm->pm_sc.pm_reloadcount;
1664                                 }
1665                                 mtx_pool_unlock_spin(pmc_mtxpool, pm);
1666                         } else {
1667                                 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri);
1668
1669                                 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (count)",
1670                                     cpu, ri, tmp);
1671
1672                                 /*
1673                                  * For counting process-virtual PMCs,
1674                                  * we expect the count to be
1675                                  * increasing monotonically, modulo a 64
1676                                  * bit wraparound.
1677                                  */
1678                                 KASSERT(tmp >= 0,
1679                                     ("[pmc,%d] negative increment cpu=%d "
1680                                      "ri=%d newvalue=%jx saved=%jx "
1681                                      "incr=%jx", __LINE__, cpu, ri,
1682                                      newvalue, PMC_PCPU_SAVED(cpu,ri), tmp));
1683
1684                                 mtx_pool_lock_spin(pmc_mtxpool, pm);
1685                                 pm->pm_gv.pm_savedvalue += tmp;
1686                                 pp->pp_pmcs[ri].pp_pmcval += tmp;
1687                                 mtx_pool_unlock_spin(pmc_mtxpool, pm);
1688
1689                                 if (pm->pm_flags & PMC_F_LOG_PROCCSW)
1690                                         pmclog_process_proccsw(pm, pp, tmp, td);
1691                         }
1692                 }
1693
1694                 /* mark hardware as free */
1695                 pcd->pcd_config_pmc(cpu, adjri, NULL);
1696         }
1697
1698         /*
1699          * perform any other architecture/cpu dependent thread
1700          * switch out functions.
1701          */
1702
1703         (void) (*md->pmd_switch_out)(pc, pp);
1704
1705         critical_exit();
1706 }
1707
1708 /*
1709  * A new thread for a process.
1710  */
1711 static void
1712 pmc_process_thread_add(struct thread *td)
1713 {
1714         struct pmc_process *pmc;
1715
1716         pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE);
1717         if (pmc != NULL)
1718                 pmc_find_thread_descriptor(pmc, td, PMC_FLAG_ALLOCATE);
1719 }
1720
1721 /*
1722  * A thread delete for a process.
1723  */
1724 static void
1725 pmc_process_thread_delete(struct thread *td)
1726 {
1727         struct pmc_process *pmc;
1728
1729         pmc = pmc_find_process_descriptor(td->td_proc, PMC_FLAG_NONE);
1730         if (pmc != NULL)
1731                 pmc_thread_descriptor_pool_free(pmc_find_thread_descriptor(pmc,
1732                     td, PMC_FLAG_REMOVE));
1733 }
1734
1735 /*
1736  * A userret() call for a thread.
1737  */
1738 static void
1739 pmc_process_thread_userret(struct thread *td)
1740 {
1741         sched_pin();
1742         pmc_capture_user_callchain(curcpu, PMC_UR, td->td_frame);
1743         sched_unpin();
1744 }
1745
1746 /*
1747  * A mapping change for a process.
1748  */
1749
1750 static void
1751 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm)
1752 {
1753         int ri;
1754         pid_t pid;
1755         char *fullpath, *freepath;
1756         const struct pmc *pm;
1757         struct pmc_owner *po;
1758         const struct pmc_process *pp;
1759
1760         freepath = fullpath = NULL;
1761         MPASS(!in_epoch(global_epoch_preempt));
1762         pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath);
1763
1764         pid = td->td_proc->p_pid;
1765
1766         PMC_EPOCH_ENTER();
1767         /* Inform owners of all system-wide sampling PMCs. */
1768         CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
1769             if (po->po_flags & PMC_PO_OWNS_LOGFILE)
1770                         pmclog_process_map_in(po, pid, pkm->pm_address, fullpath);
1771
1772         if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL)
1773                 goto done;
1774
1775         /*
1776          * Inform sampling PMC owners tracking this process.
1777          */
1778         for (ri = 0; ri < md->pmd_npmc; ri++)
1779                 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL &&
1780                     PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
1781                         pmclog_process_map_in(pm->pm_owner,
1782                             pid, pkm->pm_address, fullpath);
1783
1784   done:
1785         if (freepath)
1786                 free(freepath, M_TEMP);
1787         PMC_EPOCH_EXIT();
1788 }
1789
1790
1791 /*
1792  * Log an munmap request.
1793  */
1794
1795 static void
1796 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm)
1797 {
1798         int ri;
1799         pid_t pid;
1800         struct pmc_owner *po;
1801         const struct pmc *pm;
1802         const struct pmc_process *pp;
1803
1804         pid = td->td_proc->p_pid;
1805
1806         PMC_EPOCH_ENTER();
1807         CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
1808             if (po->po_flags & PMC_PO_OWNS_LOGFILE)
1809                 pmclog_process_map_out(po, pid, pkm->pm_address,
1810                     pkm->pm_address + pkm->pm_size);
1811         PMC_EPOCH_EXIT();
1812
1813         if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL)
1814                 return;
1815
1816         for (ri = 0; ri < md->pmd_npmc; ri++)
1817                 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL &&
1818                     PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
1819                         pmclog_process_map_out(pm->pm_owner, pid,
1820                             pkm->pm_address, pkm->pm_address + pkm->pm_size);
1821 }
1822
1823 /*
1824  * Log mapping information about the kernel.
1825  */
1826
1827 static void
1828 pmc_log_kernel_mappings(struct pmc *pm)
1829 {
1830         struct pmc_owner *po;
1831         struct pmckern_map_in *km, *kmbase;
1832
1833         MPASS(in_epoch(global_epoch_preempt) || sx_xlocked(&pmc_sx));
1834         KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)),
1835             ("[pmc,%d] non-sampling PMC (%p) desires mapping information",
1836                 __LINE__, (void *) pm));
1837
1838         po = pm->pm_owner;
1839
1840         if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE)
1841                 return;
1842         if (PMC_TO_MODE(pm) == PMC_MODE_SS)
1843                 pmc_process_allproc(pm);
1844         /*
1845          * Log the current set of kernel modules.
1846          */
1847         kmbase = linker_hwpmc_list_objects();
1848         for (km = kmbase; km->pm_file != NULL; km++) {
1849                 PMCDBG2(LOG,REG,1,"%s %p", (char *) km->pm_file,
1850                     (void *) km->pm_address);
1851                 pmclog_process_map_in(po, (pid_t) -1, km->pm_address,
1852                     km->pm_file);
1853         }
1854         free(kmbase, M_LINKER);
1855
1856         po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE;
1857 }
1858
1859 /*
1860  * Log the mappings for a single process.
1861  */
1862
1863 static void
1864 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p)
1865 {
1866         vm_map_t map;
1867         struct vnode *vp;
1868         struct vmspace *vm;
1869         vm_map_entry_t entry;
1870         vm_offset_t last_end;
1871         u_int last_timestamp;
1872         struct vnode *last_vp;
1873         vm_offset_t start_addr;
1874         vm_object_t obj, lobj, tobj;
1875         char *fullpath, *freepath;
1876
1877         last_vp = NULL;
1878         last_end = (vm_offset_t) 0;
1879         fullpath = freepath = NULL;
1880
1881         if ((vm = vmspace_acquire_ref(p)) == NULL)
1882                 return;
1883
1884         map = &vm->vm_map;
1885         vm_map_lock_read(map);
1886
1887         VM_MAP_ENTRY_FOREACH(entry, map) {
1888
1889                 if (entry == NULL) {
1890                         PMCDBG2(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly "
1891                             "NULL! pid=%d vm_map=%p\n", p->p_pid, map);
1892                         break;
1893                 }
1894
1895                 /*
1896                  * We only care about executable map entries.
1897                  */
1898                 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) ||
1899                     !(entry->protection & VM_PROT_EXECUTE) ||
1900                     (entry->object.vm_object == NULL)) {
1901                         continue;
1902                 }
1903
1904                 obj = entry->object.vm_object;
1905                 VM_OBJECT_RLOCK(obj);
1906
1907                 /*
1908                  * Walk the backing_object list to find the base
1909                  * (non-shadowed) vm_object.
1910                  */
1911                 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
1912                         if (tobj != obj)
1913                                 VM_OBJECT_RLOCK(tobj);
1914                         if (lobj != obj)
1915                                 VM_OBJECT_RUNLOCK(lobj);
1916                         lobj = tobj;
1917                 }
1918
1919                 /*
1920                  * At this point lobj is the base vm_object and it is locked.
1921                  */
1922                 if (lobj == NULL) {
1923                         PMCDBG3(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d "
1924                             "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj);
1925                         VM_OBJECT_RUNLOCK(obj);
1926                         continue;
1927                 }
1928
1929                 vp = vm_object_vnode(lobj);
1930                 if (vp == NULL) {
1931                         if (lobj != obj)
1932                                 VM_OBJECT_RUNLOCK(lobj);
1933                         VM_OBJECT_RUNLOCK(obj);
1934                         continue;
1935                 }
1936
1937                 /*
1938                  * Skip contiguous regions that point to the same
1939                  * vnode, so we don't emit redundant MAP-IN
1940                  * directives.
1941                  */
1942                 if (entry->start == last_end && vp == last_vp) {
1943                         last_end = entry->end;
1944                         if (lobj != obj)
1945                                 VM_OBJECT_RUNLOCK(lobj);
1946                         VM_OBJECT_RUNLOCK(obj);
1947                         continue;
1948                 }
1949
1950                 /*
1951                  * We don't want to keep the proc's vm_map or this
1952                  * vm_object locked while we walk the pathname, since
1953                  * vn_fullpath() can sleep.  However, if we drop the
1954                  * lock, it's possible for concurrent activity to
1955                  * modify the vm_map list.  To protect against this,
1956                  * we save the vm_map timestamp before we release the
1957                  * lock, and check it after we reacquire the lock
1958                  * below.
1959                  */
1960                 start_addr = entry->start;
1961                 last_end = entry->end;
1962                 last_timestamp = map->timestamp;
1963                 vm_map_unlock_read(map);
1964
1965                 vref(vp);
1966                 if (lobj != obj)
1967                         VM_OBJECT_RUNLOCK(lobj);
1968
1969                 VM_OBJECT_RUNLOCK(obj);
1970
1971                 freepath = NULL;
1972                 pmc_getfilename(vp, &fullpath, &freepath);
1973                 last_vp = vp;
1974
1975                 vrele(vp);
1976
1977                 vp = NULL;
1978                 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath);
1979                 if (freepath)
1980                         free(freepath, M_TEMP);
1981
1982                 vm_map_lock_read(map);
1983
1984                 /*
1985                  * If our saved timestamp doesn't match, this means
1986                  * that the vm_map was modified out from under us and
1987                  * we can't trust our current "entry" pointer.  Do a
1988                  * new lookup for this entry.  If there is no entry
1989                  * for this address range, vm_map_lookup_entry() will
1990                  * return the previous one, so we always want to go to
1991                  * the next entry on the next loop iteration.
1992                  *
1993                  * There is an edge condition here that can occur if
1994                  * there is no entry at or before this address.  In
1995                  * this situation, vm_map_lookup_entry returns
1996                  * &map->header, which would cause our loop to abort
1997                  * without processing the rest of the map.  However,
1998                  * in practice this will never happen for process
1999                  * vm_map.  This is because the executable's text
2000                  * segment is the first mapping in the proc's address
2001                  * space, and this mapping is never removed until the
2002                  * process exits, so there will always be a non-header
2003                  * entry at or before the requested address for
2004                  * vm_map_lookup_entry to return.
2005                  */
2006                 if (map->timestamp != last_timestamp)
2007                         vm_map_lookup_entry(map, last_end - 1, &entry);
2008         }
2009
2010         vm_map_unlock_read(map);
2011         vmspace_free(vm);
2012         return;
2013 }
2014
2015 /*
2016  * Log mappings for all processes in the system.
2017  */
2018
2019 static void
2020 pmc_log_all_process_mappings(struct pmc_owner *po)
2021 {
2022         struct proc *p, *top;
2023
2024         sx_assert(&pmc_sx, SX_XLOCKED);
2025
2026         if ((p = pfind(1)) == NULL)
2027                 panic("[pmc,%d] Cannot find init", __LINE__);
2028
2029         PROC_UNLOCK(p);
2030
2031         sx_slock(&proctree_lock);
2032
2033         top = p;
2034
2035         for (;;) {
2036                 pmc_log_process_mappings(po, p);
2037                 if (!LIST_EMPTY(&p->p_children))
2038                         p = LIST_FIRST(&p->p_children);
2039                 else for (;;) {
2040                         if (p == top)
2041                                 goto done;
2042                         if (LIST_NEXT(p, p_sibling)) {
2043                                 p = LIST_NEXT(p, p_sibling);
2044                                 break;
2045                         }
2046                         p = p->p_pptr;
2047                 }
2048         }
2049  done:
2050         sx_sunlock(&proctree_lock);
2051 }
2052
2053 /*
2054  * The 'hook' invoked from the kernel proper
2055  */
2056
2057
2058 #ifdef  HWPMC_DEBUG
2059 const char *pmc_hooknames[] = {
2060         /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */
2061         "",
2062         "EXEC",
2063         "CSW-IN",
2064         "CSW-OUT",
2065         "SAMPLE",
2066         "UNUSED1",
2067         "UNUSED2",
2068         "MMAP",
2069         "MUNMAP",
2070         "CALLCHAIN-NMI",
2071         "CALLCHAIN-SOFT",
2072         "SOFTSAMPLING",
2073         "THR-CREATE",
2074         "THR-EXIT",
2075         "THR-USERRET",
2076         "THR-CREATE-LOG",
2077         "THR-EXIT-LOG",
2078         "PROC-CREATE-LOG"
2079 };
2080 #endif
2081
2082 static int
2083 pmc_hook_handler(struct thread *td, int function, void *arg)
2084 {
2085         int cpu;
2086
2087         PMCDBG4(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function,
2088             pmc_hooknames[function], arg);
2089
2090         switch (function)
2091         {
2092
2093         /*
2094          * Process exec()
2095          */
2096
2097         case PMC_FN_PROCESS_EXEC:
2098         {
2099                 char *fullpath, *freepath;
2100                 unsigned int ri;
2101                 int is_using_hwpmcs;
2102                 struct pmc *pm;
2103                 struct proc *p;
2104                 struct pmc_owner *po;
2105                 struct pmc_process *pp;
2106                 struct pmckern_procexec *pk;
2107
2108                 sx_assert(&pmc_sx, SX_XLOCKED);
2109
2110                 p = td->td_proc;
2111                 pmc_getfilename(p->p_textvp, &fullpath, &freepath);
2112
2113                 pk = (struct pmckern_procexec *) arg;
2114
2115                 PMC_EPOCH_ENTER();
2116                 /* Inform owners of SS mode PMCs of the exec event. */
2117                 CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
2118                     if (po->po_flags & PMC_PO_OWNS_LOGFILE)
2119                             pmclog_process_procexec(po, PMC_ID_INVALID,
2120                                 p->p_pid, pk->pm_entryaddr, fullpath);
2121                 PMC_EPOCH_EXIT();
2122
2123                 PROC_LOCK(p);
2124                 is_using_hwpmcs = p->p_flag & P_HWPMC;
2125                 PROC_UNLOCK(p);
2126
2127                 if (!is_using_hwpmcs) {
2128                         if (freepath)
2129                                 free(freepath, M_TEMP);
2130                         break;
2131                 }
2132
2133                 /*
2134                  * PMCs are not inherited across an exec():  remove any
2135                  * PMCs that this process is the owner of.
2136                  */
2137
2138                 if ((po = pmc_find_owner_descriptor(p)) != NULL) {
2139                         pmc_remove_owner(po);
2140                         pmc_destroy_owner_descriptor(po);
2141                 }
2142
2143                 /*
2144                  * If the process being exec'ed is not the target of any
2145                  * PMC, we are done.
2146                  */
2147                 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) {
2148                         if (freepath)
2149                                 free(freepath, M_TEMP);
2150                         break;
2151                 }
2152
2153                 /*
2154                  * Log the exec event to all monitoring owners.  Skip
2155                  * owners who have already received the event because
2156                  * they had system sampling PMCs active.
2157                  */
2158                 for (ri = 0; ri < md->pmd_npmc; ri++)
2159                         if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) {
2160                                 po = pm->pm_owner;
2161                                 if (po->po_sscount == 0 &&
2162                                     po->po_flags & PMC_PO_OWNS_LOGFILE)
2163                                         pmclog_process_procexec(po, pm->pm_id,
2164                                             p->p_pid, pk->pm_entryaddr,
2165                                             fullpath);
2166                         }
2167
2168                 if (freepath)
2169                         free(freepath, M_TEMP);
2170
2171
2172                 PMCDBG4(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d",
2173                     p, p->p_pid, p->p_comm, pk->pm_credentialschanged);
2174
2175                 if (pk->pm_credentialschanged == 0) /* no change */
2176                         break;
2177
2178                 /*
2179                  * If the newly exec()'ed process has a different credential
2180                  * than before, allow it to be the target of a PMC only if
2181                  * the PMC's owner has sufficient privilege.
2182                  */
2183
2184                 for (ri = 0; ri < md->pmd_npmc; ri++)
2185                         if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL)
2186                                 if (pmc_can_attach(pm, td->td_proc) != 0)
2187                                         pmc_detach_one_process(td->td_proc,
2188                                             pm, PMC_FLAG_NONE);
2189
2190                 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc,
2191                     ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__,
2192                         pp->pp_refcnt, pp));
2193
2194                 /*
2195                  * If this process is no longer the target of any
2196                  * PMCs, we can remove the process entry and free
2197                  * up space.
2198                  */
2199
2200                 if (pp->pp_refcnt == 0) {
2201                         pmc_remove_process_descriptor(pp);
2202                         pmc_destroy_process_descriptor(pp);
2203                         break;
2204                 }
2205
2206         }
2207         break;
2208
2209         case PMC_FN_CSW_IN:
2210                 pmc_process_csw_in(td);
2211                 break;
2212
2213         case PMC_FN_CSW_OUT:
2214                 pmc_process_csw_out(td);
2215                 break;
2216
2217         /*
2218          * Process accumulated PC samples.
2219          *
2220          * This function is expected to be called by hardclock() for
2221          * each CPU that has accumulated PC samples.
2222          *
2223          * This function is to be executed on the CPU whose samples
2224          * are being processed.
2225          */
2226         case PMC_FN_DO_SAMPLES:
2227
2228                 /*
2229                  * Clear the cpu specific bit in the CPU mask before
2230                  * do the rest of the processing.  If the NMI handler
2231                  * gets invoked after the "atomic_clear_int()" call
2232                  * below but before "pmc_process_samples()" gets
2233                  * around to processing the interrupt, then we will
2234                  * come back here at the next hardclock() tick (and
2235                  * may find nothing to do if "pmc_process_samples()"
2236                  * had already processed the interrupt).  We don't
2237                  * lose the interrupt sample.
2238                  */
2239                 DPCPU_SET(pmc_sampled, 0);
2240                 cpu = PCPU_GET(cpuid);
2241                 pmc_process_samples(cpu, PMC_HR);
2242                 pmc_process_samples(cpu, PMC_SR);
2243                 pmc_process_samples(cpu, PMC_UR);
2244                 break;
2245
2246         case PMC_FN_MMAP:
2247                 pmc_process_mmap(td, (struct pmckern_map_in *) arg);
2248                 break;
2249
2250         case PMC_FN_MUNMAP:
2251                 MPASS(in_epoch(global_epoch_preempt) || sx_xlocked(&pmc_sx));
2252                 pmc_process_munmap(td, (struct pmckern_map_out *) arg);
2253                 break;
2254
2255         case PMC_FN_PROC_CREATE_LOG:
2256                 pmc_process_proccreate((struct proc *)arg);
2257                 break;
2258
2259         case PMC_FN_USER_CALLCHAIN:
2260                 /*
2261                  * Record a call chain.
2262                  */
2263                 KASSERT(td == curthread, ("[pmc,%d] td != curthread",
2264                     __LINE__));
2265
2266                 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR,
2267                     (struct trapframe *) arg);
2268
2269                 KASSERT(td->td_pinned == 1,
2270                         ("[pmc,%d] invalid td_pinned value", __LINE__));
2271                 sched_unpin();  /* Can migrate safely now. */
2272
2273                 td->td_pflags &= ~TDP_CALLCHAIN;
2274                 break;
2275
2276         case PMC_FN_USER_CALLCHAIN_SOFT:
2277                 /*
2278                  * Record a call chain.
2279                  */
2280                 KASSERT(td == curthread, ("[pmc,%d] td != curthread",
2281                     __LINE__));
2282
2283                 cpu = PCPU_GET(cpuid);
2284                 pmc_capture_user_callchain(cpu, PMC_SR,
2285                     (struct trapframe *) arg);
2286
2287                 KASSERT(td->td_pinned == 1,
2288                     ("[pmc,%d] invalid td_pinned value", __LINE__));
2289
2290                 sched_unpin();  /* Can migrate safely now. */
2291
2292                 td->td_pflags &= ~TDP_CALLCHAIN;
2293                 break;
2294
2295         case PMC_FN_SOFT_SAMPLING:
2296                 /*
2297                  * Call soft PMC sampling intr.
2298                  */
2299                 pmc_soft_intr((struct pmckern_soft *) arg);
2300                 break;
2301
2302         case PMC_FN_THR_CREATE:
2303                 pmc_process_thread_add(td);
2304                 pmc_process_threadcreate(td);
2305                 break;
2306
2307         case PMC_FN_THR_CREATE_LOG:
2308                 pmc_process_threadcreate(td);
2309                 break;
2310
2311         case PMC_FN_THR_EXIT:
2312                 KASSERT(td == curthread, ("[pmc,%d] td != curthread",
2313                     __LINE__));
2314                 pmc_process_thread_delete(td);
2315                 pmc_process_threadexit(td);
2316                 break;
2317         case PMC_FN_THR_EXIT_LOG:
2318                 pmc_process_threadexit(td);
2319                 break;
2320         case PMC_FN_THR_USERRET:
2321                 KASSERT(td == curthread, ("[pmc,%d] td != curthread",
2322                     __LINE__));
2323                 pmc_process_thread_userret(td);
2324                 break;
2325
2326         default:
2327 #ifdef  HWPMC_DEBUG
2328                 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function));
2329 #endif
2330                 break;
2331
2332         }
2333
2334         return 0;
2335 }
2336
2337 /*
2338  * allocate a 'struct pmc_owner' descriptor in the owner hash table.
2339  */
2340
2341 static struct pmc_owner *
2342 pmc_allocate_owner_descriptor(struct proc *p)
2343 {
2344         uint32_t hindex;
2345         struct pmc_owner *po;
2346         struct pmc_ownerhash *poh;
2347
2348         hindex = PMC_HASH_PTR(p, pmc_ownerhashmask);
2349         poh = &pmc_ownerhash[hindex];
2350
2351         /* allocate space for N pointers and one descriptor struct */
2352         po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO);
2353         po->po_owner = p;
2354         LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */
2355
2356         TAILQ_INIT(&po->po_logbuffers);
2357         mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN);
2358
2359         PMCDBG4(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p",
2360             p, p->p_pid, p->p_comm, po);
2361
2362         return po;
2363 }
2364
2365 static void
2366 pmc_destroy_owner_descriptor(struct pmc_owner *po)
2367 {
2368
2369         PMCDBG4(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)",
2370             po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm);
2371
2372         mtx_destroy(&po->po_mtx);
2373         free(po, M_PMC);
2374 }
2375
2376 /*
2377  * Allocate a thread descriptor from the free pool.
2378  *
2379  * NOTE: This *can* return NULL.
2380  */
2381 static struct pmc_thread *
2382 pmc_thread_descriptor_pool_alloc(void)
2383 {
2384         struct pmc_thread *pt;
2385
2386         mtx_lock_spin(&pmc_threadfreelist_mtx);
2387         if ((pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) {
2388                 LIST_REMOVE(pt, pt_next);
2389                 pmc_threadfreelist_entries--;
2390         }
2391         mtx_unlock_spin(&pmc_threadfreelist_mtx);
2392
2393         return (pt);
2394 }
2395
2396 /*
2397  * Add a thread descriptor to the free pool. We use this instead of free()
2398  * to maintain a cache of free entries. Additionally, we can safely call
2399  * this function when we cannot call free(), such as in a critical section.
2400  *
2401  */
2402 static void
2403 pmc_thread_descriptor_pool_free(struct pmc_thread *pt)
2404 {
2405
2406         if (pt == NULL)
2407                 return;
2408
2409         memset(pt, 0, THREADENTRY_SIZE);
2410         mtx_lock_spin(&pmc_threadfreelist_mtx);
2411         LIST_INSERT_HEAD(&pmc_threadfreelist, pt, pt_next);
2412         pmc_threadfreelist_entries++;
2413         if (pmc_threadfreelist_entries > pmc_threadfreelist_max)
2414                 GROUPTASK_ENQUEUE(&free_gtask);
2415         mtx_unlock_spin(&pmc_threadfreelist_mtx);
2416 }
2417
2418 /*
2419  * A callout to manage the free list.
2420  */
2421 static void
2422 pmc_thread_descriptor_pool_free_task(void *arg __unused)
2423 {
2424         struct pmc_thread *pt;
2425         LIST_HEAD(, pmc_thread) tmplist;
2426         int delta;
2427
2428         LIST_INIT(&tmplist);
2429         /* Determine what changes, if any, we need to make. */
2430         mtx_lock_spin(&pmc_threadfreelist_mtx);
2431         delta = pmc_threadfreelist_entries - pmc_threadfreelist_max;
2432         while (delta > 0 &&
2433                    (pt = LIST_FIRST(&pmc_threadfreelist)) != NULL) {
2434                 delta--;
2435                 LIST_REMOVE(pt, pt_next);
2436                 LIST_INSERT_HEAD(&tmplist, pt, pt_next);
2437         }
2438         mtx_unlock_spin(&pmc_threadfreelist_mtx);
2439
2440         /* If there are entries to free, free them. */
2441         while (!LIST_EMPTY(&tmplist)) {
2442                 pt = LIST_FIRST(&tmplist);
2443                 LIST_REMOVE(pt, pt_next);
2444                 free(pt, M_PMC);
2445         }
2446 }
2447
2448 /*
2449  * Drain the thread free pool, freeing all allocations.
2450  */
2451 static void
2452 pmc_thread_descriptor_pool_drain()
2453 {
2454         struct pmc_thread *pt, *next;
2455
2456         LIST_FOREACH_SAFE(pt, &pmc_threadfreelist, pt_next, next) {
2457                 LIST_REMOVE(pt, pt_next);
2458                 free(pt, M_PMC);
2459         }
2460 }
2461
2462 /*
2463  * find the descriptor corresponding to thread 'td', adding or removing it
2464  * as specified by 'mode'.
2465  *
2466  * Note that this supports additional mode flags in addition to those
2467  * supported by pmc_find_process_descriptor():
2468  * PMC_FLAG_NOWAIT: Causes the function to not wait for mallocs.
2469  *     This makes it safe to call while holding certain other locks.
2470  */
2471
2472 static struct pmc_thread *
2473 pmc_find_thread_descriptor(struct pmc_process *pp, struct thread *td,
2474     uint32_t mode)
2475 {
2476         struct pmc_thread *pt = NULL, *ptnew = NULL;
2477         int wait_flag;
2478
2479         KASSERT(td != NULL, ("[pmc,%d] called to add NULL td", __LINE__));
2480
2481         /*
2482          * Pre-allocate memory in the PMC_FLAG_ALLOCATE case prior to
2483          * acquiring the lock.
2484          */
2485         if (mode & PMC_FLAG_ALLOCATE) {
2486                 if ((ptnew = pmc_thread_descriptor_pool_alloc()) == NULL) {
2487                         wait_flag = M_WAITOK;
2488                         if ((mode & PMC_FLAG_NOWAIT) || in_epoch(global_epoch_preempt))
2489                                 wait_flag = M_NOWAIT;
2490
2491                         ptnew = malloc(THREADENTRY_SIZE, M_PMC,
2492                             wait_flag|M_ZERO);
2493                 }
2494         }
2495
2496         mtx_lock_spin(pp->pp_tdslock);
2497
2498         LIST_FOREACH(pt, &pp->pp_tds, pt_next)
2499                 if (pt->pt_td == td)
2500                         break;
2501
2502         if ((mode & PMC_FLAG_REMOVE) && pt != NULL)
2503                 LIST_REMOVE(pt, pt_next);
2504
2505         if ((mode & PMC_FLAG_ALLOCATE) && pt == NULL && ptnew != NULL) {
2506                 pt = ptnew;
2507                 ptnew = NULL;
2508                 pt->pt_td = td;
2509                 LIST_INSERT_HEAD(&pp->pp_tds, pt, pt_next);
2510         }
2511
2512         mtx_unlock_spin(pp->pp_tdslock);
2513
2514         if (ptnew != NULL) {
2515                 free(ptnew, M_PMC);
2516         }
2517
2518         return pt;
2519 }
2520
2521 /*
2522  * Try to add thread descriptors for each thread in a process.
2523  */
2524
2525 static void
2526 pmc_add_thread_descriptors_from_proc(struct proc *p, struct pmc_process *pp)
2527 {
2528         struct thread *curtd;
2529         struct pmc_thread **tdlist;
2530         int i, tdcnt, tdlistsz;
2531
2532         KASSERT(!PROC_LOCKED(p), ("[pmc,%d] proc unexpectedly locked",
2533             __LINE__));
2534         tdcnt = 32;
2535  restart:
2536         tdlistsz = roundup2(tdcnt, 32);
2537
2538         tdcnt = 0;
2539         tdlist = malloc(sizeof(struct pmc_thread*) * tdlistsz, M_TEMP, M_WAITOK);
2540
2541         PROC_LOCK(p);
2542         FOREACH_THREAD_IN_PROC(p, curtd)
2543                 tdcnt++;
2544         if (tdcnt >= tdlistsz) {
2545                 PROC_UNLOCK(p);
2546                 free(tdlist, M_TEMP);
2547                 goto restart;
2548         }
2549         /*
2550          * Try to add each thread to the list without sleeping. If unable,
2551          * add to a queue to retry after dropping the process lock.
2552          */
2553         tdcnt = 0;
2554         FOREACH_THREAD_IN_PROC(p, curtd) {
2555                 tdlist[tdcnt] = pmc_find_thread_descriptor(pp, curtd,
2556                                                    PMC_FLAG_ALLOCATE|PMC_FLAG_NOWAIT);
2557                 if (tdlist[tdcnt] == NULL) {
2558                         PROC_UNLOCK(p);
2559                         for (i = 0; i <= tdcnt; i++)
2560                                 pmc_thread_descriptor_pool_free(tdlist[i]);
2561                         free(tdlist, M_TEMP);
2562                         goto restart;
2563                 }
2564                 tdcnt++;
2565         }
2566         PROC_UNLOCK(p);
2567         free(tdlist, M_TEMP);
2568 }
2569
2570 /*
2571  * find the descriptor corresponding to process 'p', adding or removing it
2572  * as specified by 'mode'.
2573  */
2574
2575 static struct pmc_process *
2576 pmc_find_process_descriptor(struct proc *p, uint32_t mode)
2577 {
2578         uint32_t hindex;
2579         struct pmc_process *pp, *ppnew;
2580         struct pmc_processhash *pph;
2581
2582         hindex = PMC_HASH_PTR(p, pmc_processhashmask);
2583         pph = &pmc_processhash[hindex];
2584
2585         ppnew = NULL;
2586
2587         /*
2588          * Pre-allocate memory in the PMC_FLAG_ALLOCATE case since we
2589          * cannot call malloc(9) once we hold a spin lock.
2590          */
2591         if (mode & PMC_FLAG_ALLOCATE)
2592                 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc *
2593                     sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO);
2594
2595         mtx_lock_spin(&pmc_processhash_mtx);
2596         LIST_FOREACH(pp, pph, pp_next)
2597             if (pp->pp_proc == p)
2598                     break;
2599
2600         if ((mode & PMC_FLAG_REMOVE) && pp != NULL)
2601                 LIST_REMOVE(pp, pp_next);
2602
2603         if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL &&
2604             ppnew != NULL) {
2605                 ppnew->pp_proc = p;
2606                 LIST_INIT(&ppnew->pp_tds);
2607                 ppnew->pp_tdslock = mtx_pool_find(pmc_mtxpool, ppnew);
2608                 LIST_INSERT_HEAD(pph, ppnew, pp_next);
2609                 mtx_unlock_spin(&pmc_processhash_mtx);
2610                 pp = ppnew;
2611                 ppnew = NULL;
2612
2613                 /* Add thread descriptors for this process' current threads. */
2614                 pmc_add_thread_descriptors_from_proc(p, pp);
2615         }
2616         else
2617                 mtx_unlock_spin(&pmc_processhash_mtx);
2618
2619         if (ppnew != NULL)
2620                 free(ppnew, M_PMC);
2621
2622         return pp;
2623 }
2624
2625 /*
2626  * remove a process descriptor from the process hash table.
2627  */
2628
2629 static void
2630 pmc_remove_process_descriptor(struct pmc_process *pp)
2631 {
2632         KASSERT(pp->pp_refcnt == 0,
2633             ("[pmc,%d] Removing process descriptor %p with count %d",
2634                 __LINE__, pp, pp->pp_refcnt));
2635
2636         mtx_lock_spin(&pmc_processhash_mtx);
2637         LIST_REMOVE(pp, pp_next);
2638         mtx_unlock_spin(&pmc_processhash_mtx);
2639 }
2640
2641 /*
2642  * destroy a process descriptor.
2643  */
2644
2645 static void
2646 pmc_destroy_process_descriptor(struct pmc_process *pp)
2647 {
2648         struct pmc_thread *pmc_td;
2649
2650         while ((pmc_td = LIST_FIRST(&pp->pp_tds)) != NULL) {
2651                 LIST_REMOVE(pmc_td, pt_next);
2652                 pmc_thread_descriptor_pool_free(pmc_td);
2653         }
2654         free(pp, M_PMC);
2655 }
2656
2657
2658 /*
2659  * find an owner descriptor corresponding to proc 'p'
2660  */
2661
2662 static struct pmc_owner *
2663 pmc_find_owner_descriptor(struct proc *p)
2664 {
2665         uint32_t hindex;
2666         struct pmc_owner *po;
2667         struct pmc_ownerhash *poh;
2668
2669         hindex = PMC_HASH_PTR(p, pmc_ownerhashmask);
2670         poh = &pmc_ownerhash[hindex];
2671
2672         po = NULL;
2673         LIST_FOREACH(po, poh, po_next)
2674             if (po->po_owner == p)
2675                     break;
2676
2677         PMCDBG5(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> "
2678             "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po);
2679
2680         return po;
2681 }
2682
2683 /*
2684  * pmc_allocate_pmc_descriptor
2685  *
2686  * Allocate a pmc descriptor and initialize its
2687  * fields.
2688  */
2689
2690 static struct pmc *
2691 pmc_allocate_pmc_descriptor(void)
2692 {
2693         struct pmc *pmc;
2694
2695         pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO);
2696         pmc->pm_runcount = counter_u64_alloc(M_WAITOK);
2697         pmc->pm_pcpu_state = malloc(sizeof(struct pmc_pcpu_state)*mp_ncpus, M_PMC, M_WAITOK|M_ZERO);
2698         PMCDBG1(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc);
2699
2700         return pmc;
2701 }
2702
2703 /*
2704  * Destroy a pmc descriptor.
2705  */
2706
2707 static void
2708 pmc_destroy_pmc_descriptor(struct pmc *pm)
2709 {
2710
2711         KASSERT(pm->pm_state == PMC_STATE_DELETED ||
2712             pm->pm_state == PMC_STATE_FREE,
2713             ("[pmc,%d] destroying non-deleted PMC", __LINE__));
2714         KASSERT(LIST_EMPTY(&pm->pm_targets),
2715             ("[pmc,%d] destroying pmc with targets", __LINE__));
2716         KASSERT(pm->pm_owner == NULL,
2717             ("[pmc,%d] destroying pmc attached to an owner", __LINE__));
2718         KASSERT(counter_u64_fetch(pm->pm_runcount) == 0,
2719             ("[pmc,%d] pmc has non-zero run count %ld", __LINE__,
2720                  (unsigned long)counter_u64_fetch(pm->pm_runcount)));
2721
2722         counter_u64_free(pm->pm_runcount);
2723         free(pm->pm_pcpu_state, M_PMC);
2724         free(pm, M_PMC);
2725 }
2726
2727 static void
2728 pmc_wait_for_pmc_idle(struct pmc *pm)
2729 {
2730 #ifdef INVARIANTS
2731         volatile int maxloop;
2732
2733         maxloop = 100 * pmc_cpu_max();
2734 #endif
2735         /*
2736          * Loop (with a forced context switch) till the PMC's runcount
2737          * comes down to zero.
2738          */
2739         pmclog_flush(pm->pm_owner, 1);
2740         while (counter_u64_fetch(pm->pm_runcount) > 0) {
2741                 pmclog_flush(pm->pm_owner, 1);
2742 #ifdef INVARIANTS
2743                 maxloop--;
2744                 KASSERT(maxloop > 0,
2745                     ("[pmc,%d] (ri%d, rc%ld) waiting too long for "
2746                         "pmc to be free", __LINE__,
2747                          PMC_TO_ROWINDEX(pm), (unsigned long)counter_u64_fetch(pm->pm_runcount)));
2748 #endif
2749                 pmc_force_context_switch();
2750         }
2751 }
2752
2753 /*
2754  * This function does the following things:
2755  *
2756  *  - detaches the PMC from hardware
2757  *  - unlinks all target threads that were attached to it
2758  *  - removes the PMC from its owner's list
2759  *  - destroys the PMC private mutex
2760  *
2761  * Once this function completes, the given pmc pointer can be freed by
2762  * calling pmc_destroy_pmc_descriptor().
2763  */
2764
2765 static void
2766 pmc_release_pmc_descriptor(struct pmc *pm)
2767 {
2768         enum pmc_mode mode;
2769         struct pmc_hw *phw;
2770         u_int adjri, ri, cpu;
2771         struct pmc_owner *po;
2772         struct pmc_binding pb;
2773         struct pmc_process *pp;
2774         struct pmc_classdep *pcd;
2775         struct pmc_target *ptgt, *tmp;
2776
2777         sx_assert(&pmc_sx, SX_XLOCKED);
2778
2779         KASSERT(pm, ("[pmc,%d] null pmc", __LINE__));
2780
2781         ri   = PMC_TO_ROWINDEX(pm);
2782         pcd  = pmc_ri_to_classdep(md, ri, &adjri);
2783         mode = PMC_TO_MODE(pm);
2784
2785         PMCDBG3(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri,
2786             mode);
2787
2788         /*
2789          * First, we take the PMC off hardware.
2790          */
2791         cpu = 0;
2792         if (PMC_IS_SYSTEM_MODE(mode)) {
2793
2794                 /*
2795                  * A system mode PMC runs on a specific CPU.  Switch
2796                  * to this CPU and turn hardware off.
2797                  */
2798                 pmc_save_cpu_binding(&pb);
2799
2800                 cpu = PMC_TO_CPU(pm);
2801
2802                 pmc_select_cpu(cpu);
2803
2804                 /* switch off non-stalled CPUs */
2805                 pm->pm_pcpu_state[cpu].pps_cpustate = 0;
2806                 if (pm->pm_state == PMC_STATE_RUNNING &&
2807                         pm->pm_pcpu_state[cpu].pps_stalled == 0) {
2808
2809                         phw = pmc_pcpu[cpu]->pc_hwpmcs[ri];
2810
2811                         KASSERT(phw->phw_pmc == pm,
2812                             ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)",
2813                                 __LINE__, ri, phw->phw_pmc, pm));
2814                         PMCDBG2(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri);
2815
2816                         critical_enter();
2817                         pcd->pcd_stop_pmc(cpu, adjri);
2818                         critical_exit();
2819                 }
2820
2821                 PMCDBG2(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri);
2822
2823                 critical_enter();
2824                 pcd->pcd_config_pmc(cpu, adjri, NULL);
2825                 critical_exit();
2826
2827                 /* adjust the global and process count of SS mode PMCs */
2828                 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) {
2829                         po = pm->pm_owner;
2830                         po->po_sscount--;
2831                         if (po->po_sscount == 0) {
2832                                 atomic_subtract_rel_int(&pmc_ss_count, 1);
2833                                 CK_LIST_REMOVE(po, po_ssnext);
2834                                 epoch_wait_preempt(global_epoch_preempt);
2835                         }
2836                 }
2837
2838                 pm->pm_state = PMC_STATE_DELETED;
2839
2840                 pmc_restore_cpu_binding(&pb);
2841
2842                 /*
2843                  * We could have references to this PMC structure in
2844                  * the per-cpu sample queues.  Wait for the queue to
2845                  * drain.
2846                  */
2847                 pmc_wait_for_pmc_idle(pm);
2848
2849         } else if (PMC_IS_VIRTUAL_MODE(mode)) {
2850
2851                 /*
2852                  * A virtual PMC could be running on multiple CPUs at
2853                  * a given instant.
2854                  *
2855                  * By marking its state as DELETED, we ensure that
2856                  * this PMC is never further scheduled on hardware.
2857                  *
2858                  * Then we wait till all CPUs are done with this PMC.
2859                  */
2860                 pm->pm_state = PMC_STATE_DELETED;
2861
2862
2863                 /* Wait for the PMCs runcount to come to zero. */
2864                 pmc_wait_for_pmc_idle(pm);
2865
2866                 /*
2867                  * At this point the PMC is off all CPUs and cannot be
2868                  * freshly scheduled onto a CPU.  It is now safe to
2869                  * unlink all targets from this PMC.  If a
2870                  * process-record's refcount falls to zero, we remove
2871                  * it from the hash table.  The module-wide SX lock
2872                  * protects us from races.
2873                  */
2874                 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) {
2875                         pp = ptgt->pt_process;
2876                         pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */
2877
2878                         PMCDBG1(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt);
2879
2880                         /*
2881                          * If the target process record shows that no
2882                          * PMCs are attached to it, reclaim its space.
2883                          */
2884
2885                         if (pp->pp_refcnt == 0) {
2886                                 pmc_remove_process_descriptor(pp);
2887                                 pmc_destroy_process_descriptor(pp);
2888                         }
2889                 }
2890
2891                 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */
2892
2893         }
2894
2895         /*
2896          * Release any MD resources
2897          */
2898         (void) pcd->pcd_release_pmc(cpu, adjri, pm);
2899
2900         /*
2901          * Update row disposition
2902          */
2903
2904         if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm)))
2905                 PMC_UNMARK_ROW_STANDALONE(ri);
2906         else
2907                 PMC_UNMARK_ROW_THREAD(ri);
2908
2909         /* unlink from the owner's list */
2910         if (pm->pm_owner) {
2911                 LIST_REMOVE(pm, pm_next);
2912                 pm->pm_owner = NULL;
2913         }
2914 }
2915
2916 /*
2917  * Register an owner and a pmc.
2918  */
2919
2920 static int
2921 pmc_register_owner(struct proc *p, struct pmc *pmc)
2922 {
2923         struct pmc_owner *po;
2924
2925         sx_assert(&pmc_sx, SX_XLOCKED);
2926
2927         if ((po = pmc_find_owner_descriptor(p)) == NULL)
2928                 if ((po = pmc_allocate_owner_descriptor(p)) == NULL)
2929                         return ENOMEM;
2930
2931         KASSERT(pmc->pm_owner == NULL,
2932             ("[pmc,%d] attempting to own an initialized PMC", __LINE__));
2933         pmc->pm_owner  = po;
2934
2935         LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next);
2936
2937         PROC_LOCK(p);
2938         p->p_flag |= P_HWPMC;
2939         PROC_UNLOCK(p);
2940
2941         if (po->po_flags & PMC_PO_OWNS_LOGFILE)
2942                 pmclog_process_pmcallocate(pmc);
2943
2944         PMCDBG2(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p",
2945             po, pmc);
2946
2947         return 0;
2948 }
2949
2950 /*
2951  * Return the current row disposition:
2952  * == 0 => FREE
2953  *  > 0 => PROCESS MODE
2954  *  < 0 => SYSTEM MODE
2955  */
2956
2957 int
2958 pmc_getrowdisp(int ri)
2959 {
2960         return pmc_pmcdisp[ri];
2961 }
2962
2963 /*
2964  * Check if a PMC at row index 'ri' can be allocated to the current
2965  * process.
2966  *
2967  * Allocation can fail if:
2968  *   - the current process is already being profiled by a PMC at index 'ri',
2969  *     attached to it via OP_PMCATTACH.
2970  *   - the current process has already allocated a PMC at index 'ri'
2971  *     via OP_ALLOCATE.
2972  */
2973
2974 static int
2975 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu)
2976 {
2977         enum pmc_mode mode;
2978         struct pmc *pm;
2979         struct pmc_owner *po;
2980         struct pmc_process *pp;
2981
2982         PMCDBG5(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d "
2983             "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu);
2984
2985         /*
2986          * We shouldn't have already allocated a process-mode PMC at
2987          * row index 'ri'.
2988          *
2989          * We shouldn't have allocated a system-wide PMC on the same
2990          * CPU and same RI.
2991          */
2992         if ((po = pmc_find_owner_descriptor(p)) != NULL)
2993                 LIST_FOREACH(pm, &po->po_pmcs, pm_next) {
2994                     if (PMC_TO_ROWINDEX(pm) == ri) {
2995                             mode = PMC_TO_MODE(pm);
2996                             if (PMC_IS_VIRTUAL_MODE(mode))
2997                                     return EEXIST;
2998                             if (PMC_IS_SYSTEM_MODE(mode) &&
2999                                 (int) PMC_TO_CPU(pm) == cpu)
3000                                     return EEXIST;
3001                     }
3002                 }
3003
3004         /*
3005          * We also shouldn't be the target of any PMC at this index
3006          * since otherwise a PMC_ATTACH to ourselves will fail.
3007          */
3008         if ((pp = pmc_find_process_descriptor(p, 0)) != NULL)
3009                 if (pp->pp_pmcs[ri].pp_pmc)
3010                         return EEXIST;
3011
3012         PMCDBG4(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok",
3013             p, p->p_pid, p->p_comm, ri);
3014
3015         return 0;
3016 }
3017
3018 /*
3019  * Check if a given PMC at row index 'ri' can be currently used in
3020  * mode 'mode'.
3021  */
3022
3023 static int
3024 pmc_can_allocate_row(int ri, enum pmc_mode mode)
3025 {
3026         enum pmc_disp   disp;
3027
3028         sx_assert(&pmc_sx, SX_XLOCKED);
3029
3030         PMCDBG2(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode);
3031
3032         if (PMC_IS_SYSTEM_MODE(mode))
3033                 disp = PMC_DISP_STANDALONE;
3034         else
3035                 disp = PMC_DISP_THREAD;
3036
3037         /*
3038          * check disposition for PMC row 'ri':
3039          *
3040          * Expected disposition         Row-disposition         Result
3041          *
3042          * STANDALONE                   STANDALONE or FREE      proceed
3043          * STANDALONE                   THREAD                  fail
3044          * THREAD                       THREAD or FREE          proceed
3045          * THREAD                       STANDALONE              fail
3046          */
3047
3048         if (!PMC_ROW_DISP_IS_FREE(ri) &&
3049             !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) &&
3050             !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri)))
3051                 return EBUSY;
3052
3053         /*
3054          * All OK
3055          */
3056
3057         PMCDBG2(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode);
3058
3059         return 0;
3060
3061 }
3062
3063 /*
3064  * Find a PMC descriptor with user handle 'pmcid' for thread 'td'.
3065  */
3066
3067 static struct pmc *
3068 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid)
3069 {
3070         struct pmc *pm;
3071
3072         KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc,
3073             ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__,
3074                 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc));
3075
3076         LIST_FOREACH(pm, &po->po_pmcs, pm_next)
3077             if (pm->pm_id == pmcid)
3078                     return pm;
3079
3080         return NULL;
3081 }
3082
3083 static int
3084 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc)
3085 {
3086
3087         struct pmc *pm, *opm;
3088         struct pmc_owner *po;
3089         struct pmc_process *pp;
3090
3091         PMCDBG1(PMC,FND,1, "find-pmc id=%d", pmcid);
3092         if (PMC_ID_TO_ROWINDEX(pmcid) >= md->pmd_npmc)
3093                 return (EINVAL);
3094
3095         if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) {
3096                 /*
3097                  * In case of PMC_F_DESCENDANTS child processes we will not find
3098                  * the current process in the owners hash list.  Find the owner
3099                  * process first and from there lookup the po.
3100                  */
3101                 if ((pp = pmc_find_process_descriptor(curthread->td_proc,
3102                     PMC_FLAG_NONE)) == NULL) {
3103                         return ESRCH;
3104                 } else {
3105                         opm = pp->pp_pmcs[PMC_ID_TO_ROWINDEX(pmcid)].pp_pmc;
3106                         if (opm == NULL)
3107                                 return ESRCH;
3108                         if ((opm->pm_flags & (PMC_F_ATTACHED_TO_OWNER|
3109                             PMC_F_DESCENDANTS)) != (PMC_F_ATTACHED_TO_OWNER|
3110                             PMC_F_DESCENDANTS))
3111                                 return ESRCH;
3112                         po = opm->pm_owner;
3113                 }
3114         }
3115
3116         if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL)
3117                 return EINVAL;
3118
3119         PMCDBG2(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm);
3120
3121         *pmc = pm;
3122         return 0;
3123 }
3124
3125 /*
3126  * Start a PMC.
3127  */
3128
3129 static int
3130 pmc_start(struct pmc *pm)
3131 {
3132         enum pmc_mode mode;
3133         struct pmc_owner *po;
3134         struct pmc_binding pb;
3135         struct pmc_classdep *pcd;
3136         int adjri, error, cpu, ri;
3137
3138         KASSERT(pm != NULL,
3139             ("[pmc,%d] null pm", __LINE__));
3140
3141         mode = PMC_TO_MODE(pm);
3142         ri   = PMC_TO_ROWINDEX(pm);
3143         pcd  = pmc_ri_to_classdep(md, ri, &adjri);
3144
3145         error = 0;
3146
3147         PMCDBG3(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri);
3148
3149         po = pm->pm_owner;
3150
3151         /*
3152          * Disallow PMCSTART if a logfile is required but has not been
3153          * configured yet.
3154          */
3155         if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) &&
3156             (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)
3157                 return (EDOOFUS);       /* programming error */
3158
3159         /*
3160          * If this is a sampling mode PMC, log mapping information for
3161          * the kernel modules that are currently loaded.
3162          */
3163         if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
3164             pmc_log_kernel_mappings(pm);
3165
3166         if (PMC_IS_VIRTUAL_MODE(mode)) {
3167
3168                 /*
3169                  * If a PMCATTACH has never been done on this PMC,
3170                  * attach it to its owner process.
3171                  */
3172
3173                 if (LIST_EMPTY(&pm->pm_targets))
3174                         error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH :
3175                             pmc_attach_process(po->po_owner, pm);
3176
3177                 /*
3178                  * If the PMC is attached to its owner, then force a context
3179                  * switch to ensure that the MD state gets set correctly.
3180                  */
3181
3182                 if (error == 0) {
3183                         pm->pm_state = PMC_STATE_RUNNING;
3184                         if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER)
3185                                 pmc_force_context_switch();
3186                 }
3187
3188                 return (error);
3189         }
3190
3191
3192         /*
3193          * A system-wide PMC.
3194          *
3195          * Add the owner to the global list if this is a system-wide
3196          * sampling PMC.
3197          */
3198
3199         if (mode == PMC_MODE_SS) {
3200                 /*
3201                  * Log mapping information for all existing processes in the
3202                  * system.  Subsequent mappings are logged as they happen;
3203                  * see pmc_process_mmap().
3204                  */
3205                 if (po->po_logprocmaps == 0) {
3206                         pmc_log_all_process_mappings(po);
3207                         po->po_logprocmaps = 1;
3208                 }
3209                 po->po_sscount++;
3210                 if (po->po_sscount == 1) {
3211                         atomic_add_rel_int(&pmc_ss_count, 1);
3212                         CK_LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext);
3213                         PMCDBG1(PMC,OPS,1, "po=%p in global list", po);
3214                 }
3215         }
3216
3217         /*
3218          * Move to the CPU associated with this
3219          * PMC, and start the hardware.
3220          */
3221
3222         pmc_save_cpu_binding(&pb);
3223
3224         cpu = PMC_TO_CPU(pm);
3225
3226         if (!pmc_cpu_is_active(cpu))
3227                 return (ENXIO);
3228
3229         pmc_select_cpu(cpu);
3230
3231         /*
3232          * global PMCs are configured at allocation time
3233          * so write out the initial value and start the PMC.
3234          */
3235
3236         pm->pm_state = PMC_STATE_RUNNING;
3237
3238         critical_enter();
3239         if ((error = pcd->pcd_write_pmc(cpu, adjri,
3240                  PMC_IS_SAMPLING_MODE(mode) ?
3241                  pm->pm_sc.pm_reloadcount :
3242                  pm->pm_sc.pm_initial)) == 0) {
3243                 /* If a sampling mode PMC, reset stalled state. */
3244                 if (PMC_IS_SAMPLING_MODE(mode))
3245                         pm->pm_pcpu_state[cpu].pps_stalled = 0;
3246
3247                 /* Indicate that we desire this to run. Start it. */
3248                 pm->pm_pcpu_state[cpu].pps_cpustate = 1;
3249                 error = pcd->pcd_start_pmc(cpu, adjri);
3250         }
3251         critical_exit();
3252
3253         pmc_restore_cpu_binding(&pb);
3254
3255         return (error);
3256 }
3257
3258 /*
3259  * Stop a PMC.
3260  */
3261
3262 static int
3263 pmc_stop(struct pmc *pm)
3264 {
3265         struct pmc_owner *po;
3266         struct pmc_binding pb;
3267         struct pmc_classdep *pcd;
3268         int adjri, cpu, error, ri;
3269
3270         KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__));
3271
3272         PMCDBG3(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm,
3273             PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm));
3274
3275         pm->pm_state = PMC_STATE_STOPPED;
3276
3277         /*
3278          * If the PMC is a virtual mode one, changing the state to
3279          * non-RUNNING is enough to ensure that the PMC never gets
3280          * scheduled.
3281          *
3282          * If this PMC is current running on a CPU, then it will
3283          * handled correctly at the time its target process is context
3284          * switched out.
3285          */
3286
3287         if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)))
3288                 return 0;
3289
3290         /*
3291          * A system-mode PMC.  Move to the CPU associated with
3292          * this PMC, and stop the hardware.  We update the
3293          * 'initial count' so that a subsequent PMCSTART will
3294          * resume counting from the current hardware count.
3295          */
3296
3297         pmc_save_cpu_binding(&pb);
3298
3299         cpu = PMC_TO_CPU(pm);
3300
3301         KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
3302             ("[pmc,%d] illegal cpu=%d", __LINE__, cpu));
3303
3304         if (!pmc_cpu_is_active(cpu))
3305                 return ENXIO;
3306
3307         pmc_select_cpu(cpu);
3308
3309         ri = PMC_TO_ROWINDEX(pm);
3310         pcd = pmc_ri_to_classdep(md, ri, &adjri);
3311
3312         pm->pm_pcpu_state[cpu].pps_cpustate = 0;
3313         critical_enter();
3314         if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0)
3315                 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial);
3316         critical_exit();
3317
3318         pmc_restore_cpu_binding(&pb);
3319
3320         po = pm->pm_owner;
3321
3322         /* remove this owner from the global list of SS PMC owners */
3323         if (PMC_TO_MODE(pm) == PMC_MODE_SS) {
3324                 po->po_sscount--;
3325                 if (po->po_sscount == 0) {
3326                         atomic_subtract_rel_int(&pmc_ss_count, 1);
3327                         CK_LIST_REMOVE(po, po_ssnext);
3328                         epoch_wait_preempt(global_epoch_preempt);
3329                         PMCDBG1(PMC,OPS,2,"po=%p removed from global list", po);
3330                 }
3331         }
3332
3333         return (error);
3334 }
3335
3336 static struct pmc_classdep *
3337 pmc_class_to_classdep(enum pmc_class class)
3338 {
3339         int n;
3340
3341         for (n = 0; n < md->pmd_nclass; n++)
3342                 if (md->pmd_classdep[n].pcd_class == class)
3343                         return (&md->pmd_classdep[n]);
3344         return (NULL);
3345 }
3346
3347 #if defined(HWPMC_DEBUG) && defined(KTR)
3348 static const char *pmc_op_to_name[] = {
3349 #undef  __PMC_OP
3350 #define __PMC_OP(N, D)  #N ,
3351         __PMC_OPS()
3352         NULL
3353 };
3354 #endif
3355
3356 /*
3357  * The syscall interface
3358  */
3359
3360 #define PMC_GET_SX_XLOCK(...) do {              \
3361         sx_xlock(&pmc_sx);                      \
3362         if (pmc_hook == NULL) {                 \
3363                 sx_xunlock(&pmc_sx);            \
3364                 return __VA_ARGS__;             \
3365         }                                       \
3366 } while (0)
3367
3368 #define PMC_DOWNGRADE_SX() do {                 \
3369         sx_downgrade(&pmc_sx);                  \
3370         is_sx_downgraded = 1;                   \
3371 } while (0)
3372
3373 static int
3374 pmc_syscall_handler(struct thread *td, void *syscall_args)
3375 {
3376         int error, is_sx_downgraded, op;
3377         struct pmc_syscall_args *c;
3378         void *pmclog_proc_handle;
3379         void *arg;
3380
3381         c = (struct pmc_syscall_args *)syscall_args;
3382         op = c->pmop_code;
3383         arg = c->pmop_data;
3384         /* PMC isn't set up yet */
3385         if (pmc_hook == NULL)
3386                 return (EINVAL);
3387         if (op == PMC_OP_CONFIGURELOG) {
3388                 /*
3389                  * We cannot create the logging process inside
3390                  * pmclog_configure_log() because there is a LOR
3391                  * between pmc_sx and process structure locks.
3392                  * Instead, pre-create the process and ignite the loop
3393                  * if everything is fine, otherwise direct the process
3394                  * to exit.
3395                  */
3396                 error = pmclog_proc_create(td, &pmclog_proc_handle);
3397                 if (error != 0)
3398                         goto done_syscall;
3399         }
3400
3401         PMC_GET_SX_XLOCK(ENOSYS);
3402         is_sx_downgraded = 0;
3403         PMCDBG3(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op,
3404             pmc_op_to_name[op], arg);
3405
3406         error = 0;
3407         counter_u64_add(pmc_stats.pm_syscalls, 1);
3408
3409         switch (op) {
3410
3411
3412         /*
3413          * Configure a log file.
3414          *
3415          * XXX This OP will be reworked.
3416          */
3417
3418         case PMC_OP_CONFIGURELOG:
3419         {
3420                 struct proc *p;
3421                 struct pmc *pm;
3422                 struct pmc_owner *po;
3423                 struct pmc_op_configurelog cl;
3424
3425                 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) {
3426                         pmclog_proc_ignite(pmclog_proc_handle, NULL);
3427                         break;
3428                 }
3429
3430                 /* mark this process as owning a log file */
3431                 p = td->td_proc;
3432                 if ((po = pmc_find_owner_descriptor(p)) == NULL)
3433                         if ((po = pmc_allocate_owner_descriptor(p)) == NULL) {
3434                                 pmclog_proc_ignite(pmclog_proc_handle, NULL);
3435                                 error = ENOMEM;
3436                                 break;
3437                         }
3438
3439                 /*
3440                  * If a valid fd was passed in, try to configure that,
3441                  * otherwise if 'fd' was less than zero and there was
3442                  * a log file configured, flush its buffers and
3443                  * de-configure it.
3444                  */
3445                 if (cl.pm_logfd >= 0) {
3446                         error = pmclog_configure_log(md, po, cl.pm_logfd);
3447                         pmclog_proc_ignite(pmclog_proc_handle, error == 0 ?
3448                             po : NULL);
3449                 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) {
3450                         pmclog_proc_ignite(pmclog_proc_handle, NULL);
3451                         error = pmclog_close(po);
3452                         if (error == 0) {
3453                                 LIST_FOREACH(pm, &po->po_pmcs, pm_next)
3454                                     if (pm->pm_flags & PMC_F_NEEDS_LOGFILE &&
3455                                         pm->pm_state == PMC_STATE_RUNNING)
3456                                             pmc_stop(pm);
3457                                 error = pmclog_deconfigure_log(po);
3458                         }
3459                 } else {
3460                         pmclog_proc_ignite(pmclog_proc_handle, NULL);
3461                         error = EINVAL;
3462                 }
3463         }
3464         break;
3465
3466         /*
3467          * Flush a log file.
3468          */
3469
3470         case PMC_OP_FLUSHLOG:
3471         {
3472                 struct pmc_owner *po;
3473
3474                 sx_assert(&pmc_sx, SX_XLOCKED);
3475
3476                 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) {
3477                         error = EINVAL;
3478                         break;
3479                 }
3480
3481                 error = pmclog_flush(po, 0);
3482         }
3483         break;
3484
3485         /*
3486          * Close a log file.
3487          */
3488
3489         case PMC_OP_CLOSELOG:
3490         {
3491                 struct pmc_owner *po;
3492
3493                 sx_assert(&pmc_sx, SX_XLOCKED);
3494
3495                 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) {
3496                         error = EINVAL;
3497                         break;
3498                 }
3499
3500                 error = pmclog_close(po);
3501         }
3502         break;
3503
3504         /*
3505          * Retrieve hardware configuration.
3506          */
3507
3508         case PMC_OP_GETCPUINFO: /* CPU information */
3509         {
3510                 struct pmc_op_getcpuinfo gci;
3511                 struct pmc_classinfo *pci;
3512                 struct pmc_classdep *pcd;
3513                 int cl;
3514
3515                 memset(&gci, 0, sizeof(gci));
3516                 gci.pm_cputype = md->pmd_cputype;
3517                 gci.pm_ncpu    = pmc_cpu_max();
3518                 gci.pm_npmc    = md->pmd_npmc;
3519                 gci.pm_nclass  = md->pmd_nclass;
3520                 pci = gci.pm_classes;
3521                 pcd = md->pmd_classdep;
3522                 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) {
3523                         pci->pm_caps  = pcd->pcd_caps;
3524                         pci->pm_class = pcd->pcd_class;
3525                         pci->pm_width = pcd->pcd_width;
3526                         pci->pm_num   = pcd->pcd_num;
3527                 }
3528                 error = copyout(&gci, arg, sizeof(gci));
3529         }
3530         break;
3531
3532         /*
3533          * Retrieve soft events list.
3534          */
3535         case PMC_OP_GETDYNEVENTINFO:
3536         {
3537                 enum pmc_class                  cl;
3538                 enum pmc_event                  ev;
3539                 struct pmc_op_getdyneventinfo   *gei;
3540                 struct pmc_dyn_event_descr      dev;
3541                 struct pmc_soft                 *ps;
3542                 uint32_t                        nevent;
3543
3544                 sx_assert(&pmc_sx, SX_LOCKED);
3545
3546                 gei = (struct pmc_op_getdyneventinfo *) arg;
3547
3548                 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0)
3549                         break;
3550
3551                 /* Only SOFT class is dynamic. */
3552                 if (cl != PMC_CLASS_SOFT) {
3553                         error = EINVAL;
3554                         break;
3555                 }
3556
3557                 nevent = 0;
3558                 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) {
3559                         ps = pmc_soft_ev_acquire(ev);
3560                         if (ps == NULL)
3561                                 continue;
3562                         bcopy(&ps->ps_ev, &dev, sizeof(dev));
3563                         pmc_soft_ev_release(ps);
3564
3565                         error = copyout(&dev,
3566                             &gei->pm_events[nevent],
3567                             sizeof(struct pmc_dyn_event_descr));
3568                         if (error != 0)
3569                                 break;
3570                         nevent++;
3571                 }
3572                 if (error != 0)
3573                         break;
3574
3575                 error = copyout(&nevent, &gei->pm_nevent,
3576                     sizeof(nevent));
3577         }
3578         break;
3579
3580         /*
3581          * Get module statistics
3582          */
3583
3584         case PMC_OP_GETDRIVERSTATS:
3585         {
3586                 struct pmc_op_getdriverstats gms;
3587 #define CFETCH(a, b, field) a.field = counter_u64_fetch(b.field)
3588                 CFETCH(gms, pmc_stats, pm_intr_ignored);
3589                 CFETCH(gms, pmc_stats, pm_intr_processed);
3590                 CFETCH(gms, pmc_stats, pm_intr_bufferfull);
3591                 CFETCH(gms, pmc_stats, pm_syscalls);
3592                 CFETCH(gms, pmc_stats, pm_syscall_errors);
3593                 CFETCH(gms, pmc_stats, pm_buffer_requests);
3594                 CFETCH(gms, pmc_stats, pm_buffer_requests_failed);
3595                 CFETCH(gms, pmc_stats, pm_log_sweeps);
3596 #undef CFETCH
3597                 error = copyout(&gms, arg, sizeof(gms));
3598         }
3599         break;
3600
3601
3602         /*
3603          * Retrieve module version number
3604          */
3605
3606         case PMC_OP_GETMODULEVERSION:
3607         {
3608                 uint32_t cv, modv;
3609
3610                 /* retrieve the client's idea of the ABI version */
3611                 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0)
3612                         break;
3613                 /* don't service clients newer than our driver */
3614                 modv = PMC_VERSION;
3615                 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) {
3616                         error = EPROGMISMATCH;
3617                         break;
3618                 }
3619                 error = copyout(&modv, arg, sizeof(int));
3620         }
3621         break;
3622
3623
3624         /*
3625          * Retrieve the state of all the PMCs on a given
3626          * CPU.
3627          */
3628
3629         case PMC_OP_GETPMCINFO:
3630         {
3631                 int ari;
3632                 struct pmc *pm;
3633                 size_t pmcinfo_size;
3634                 uint32_t cpu, n, npmc;
3635                 struct pmc_owner *po;
3636                 struct pmc_binding pb;
3637                 struct pmc_classdep *pcd;
3638                 struct pmc_info *p, *pmcinfo;
3639                 struct pmc_op_getpmcinfo *gpi;
3640
3641                 PMC_DOWNGRADE_SX();
3642
3643                 gpi = (struct pmc_op_getpmcinfo *) arg;
3644
3645                 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0)
3646                         break;
3647
3648                 if (cpu >= pmc_cpu_max()) {
3649                         error = EINVAL;
3650                         break;
3651                 }
3652
3653                 if (!pmc_cpu_is_active(cpu)) {
3654                         error = ENXIO;
3655                         break;
3656                 }
3657
3658                 /* switch to CPU 'cpu' */
3659                 pmc_save_cpu_binding(&pb);
3660                 pmc_select_cpu(cpu);
3661
3662                 npmc = md->pmd_npmc;
3663
3664                 pmcinfo_size = npmc * sizeof(struct pmc_info);
3665                 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK | M_ZERO);
3666
3667                 p = pmcinfo;
3668
3669                 for (n = 0; n < md->pmd_npmc; n++, p++) {
3670
3671                         pcd = pmc_ri_to_classdep(md, n, &ari);
3672
3673                         KASSERT(pcd != NULL,
3674                             ("[pmc,%d] null pcd ri=%d", __LINE__, n));
3675
3676                         if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0)
3677                                 break;
3678
3679                         if (PMC_ROW_DISP_IS_STANDALONE(n))
3680                                 p->pm_rowdisp = PMC_DISP_STANDALONE;
3681                         else if (PMC_ROW_DISP_IS_THREAD(n))
3682                                 p->pm_rowdisp = PMC_DISP_THREAD;
3683                         else
3684                                 p->pm_rowdisp = PMC_DISP_FREE;
3685
3686                         p->pm_ownerpid = -1;
3687
3688                         if (pm == NULL) /* no PMC associated */
3689                                 continue;
3690
3691                         po = pm->pm_owner;
3692
3693                         KASSERT(po->po_owner != NULL,
3694                             ("[pmc,%d] pmc_owner had a null proc pointer",
3695                                 __LINE__));
3696
3697                         p->pm_ownerpid = po->po_owner->p_pid;
3698                         p->pm_mode     = PMC_TO_MODE(pm);
3699                         p->pm_event    = pm->pm_event;
3700                         p->pm_flags    = pm->pm_flags;
3701
3702                         if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
3703                                 p->pm_reloadcount =
3704                                     pm->pm_sc.pm_reloadcount;
3705                 }
3706
3707                 pmc_restore_cpu_binding(&pb);
3708
3709                 /* now copy out the PMC info collected */
3710                 if (error == 0)
3711                         error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size);
3712
3713                 free(pmcinfo, M_PMC);
3714         }
3715         break;
3716
3717
3718         /*
3719          * Set the administrative state of a PMC.  I.e. whether
3720          * the PMC is to be used or not.
3721          */
3722
3723         case PMC_OP_PMCADMIN:
3724         {
3725                 int cpu, ri;
3726                 enum pmc_state request;
3727                 struct pmc_cpu *pc;
3728                 struct pmc_hw *phw;
3729                 struct pmc_op_pmcadmin pma;
3730                 struct pmc_binding pb;
3731
3732                 sx_assert(&pmc_sx, SX_XLOCKED);
3733
3734                 KASSERT(td == curthread,
3735                     ("[pmc,%d] td != curthread", __LINE__));
3736
3737                 error = priv_check(td, PRIV_PMC_MANAGE);
3738                 if (error)
3739                         break;
3740
3741                 if ((error = copyin(arg, &pma, sizeof(pma))) != 0)
3742                         break;
3743
3744                 cpu = pma.pm_cpu;
3745
3746                 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) {
3747                         error = EINVAL;
3748                         break;
3749                 }
3750
3751                 if (!pmc_cpu_is_active(cpu)) {
3752                         error = ENXIO;
3753                         break;
3754                 }
3755
3756                 request = pma.pm_state;
3757
3758                 if (request != PMC_STATE_DISABLED &&
3759                     request != PMC_STATE_FREE) {
3760                         error = EINVAL;
3761                         break;
3762                 }
3763
3764                 ri = pma.pm_pmc; /* pmc id == row index */
3765                 if (ri < 0 || ri >= (int) md->pmd_npmc) {
3766                         error = EINVAL;
3767                         break;
3768                 }
3769
3770                 /*
3771                  * We can't disable a PMC with a row-index allocated
3772                  * for process virtual PMCs.
3773                  */
3774
3775                 if (PMC_ROW_DISP_IS_THREAD(ri) &&
3776                     request == PMC_STATE_DISABLED) {
3777                         error = EBUSY;
3778                         break;
3779                 }
3780
3781                 /*
3782                  * otherwise, this PMC on this CPU is either free or
3783                  * in system-wide mode.
3784                  */
3785
3786                 pmc_save_cpu_binding(&pb);
3787                 pmc_select_cpu(cpu);
3788
3789                 pc  = pmc_pcpu[cpu];
3790                 phw = pc->pc_hwpmcs[ri];
3791
3792                 /*
3793                  * XXX do we need some kind of 'forced' disable?
3794                  */
3795
3796                 if (phw->phw_pmc == NULL) {
3797                         if (request == PMC_STATE_DISABLED &&
3798                             (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) {
3799                                 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED;
3800                                 PMC_MARK_ROW_STANDALONE(ri);
3801                         } else if (request == PMC_STATE_FREE &&
3802                             (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) {
3803                                 phw->phw_state |=  PMC_PHW_FLAG_IS_ENABLED;
3804                                 PMC_UNMARK_ROW_STANDALONE(ri);
3805                         }
3806                         /* other cases are a no-op */
3807                 } else
3808                         error = EBUSY;
3809
3810                 pmc_restore_cpu_binding(&pb);
3811         }
3812         break;
3813
3814
3815         /*
3816          * Allocate a PMC.
3817          */
3818
3819         case PMC_OP_PMCALLOCATE:
3820         {
3821                 int adjri, n;
3822                 u_int cpu;
3823                 uint32_t caps;
3824                 struct pmc *pmc;
3825                 enum pmc_mode mode;
3826                 struct pmc_hw *phw;
3827                 struct pmc_binding pb;
3828                 struct pmc_classdep *pcd;
3829                 struct pmc_op_pmcallocate pa;
3830
3831                 if ((error = copyin(arg, &pa, sizeof(pa))) != 0)
3832                         break;
3833
3834                 caps = pa.pm_caps;
3835                 mode = pa.pm_mode;
3836                 cpu  = pa.pm_cpu;
3837
3838                 if ((mode != PMC_MODE_SS  &&  mode != PMC_MODE_SC  &&
3839                      mode != PMC_MODE_TS  &&  mode != PMC_MODE_TC) ||
3840                     (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) {
3841                         error = EINVAL;
3842                         break;
3843                 }
3844
3845                 /*
3846                  * Virtual PMCs should only ask for a default CPU.
3847                  * System mode PMCs need to specify a non-default CPU.
3848                  */
3849
3850                 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) ||
3851                     (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) {
3852                         error = EINVAL;
3853                         break;
3854                 }
3855
3856                 /*
3857                  * Check that an inactive CPU is not being asked for.
3858                  */
3859
3860                 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) {
3861                         error = ENXIO;
3862                         break;
3863                 }
3864
3865                 /*
3866                  * Refuse an allocation for a system-wide PMC if this
3867                  * process has been jailed, or if this process lacks
3868                  * super-user credentials and the sysctl tunable
3869                  * 'security.bsd.unprivileged_syspmcs' is zero.
3870                  */
3871
3872                 if (PMC_IS_SYSTEM_MODE(mode)) {
3873                         if (jailed(curthread->td_ucred)) {
3874                                 error = EPERM;
3875                                 break;
3876                         }
3877                         if (!pmc_unprivileged_syspmcs) {
3878                                 error = priv_check(curthread,
3879                                     PRIV_PMC_SYSTEM);
3880                                 if (error)
3881                                         break;
3882                         }
3883                 }
3884
3885                 /*
3886                  * Look for valid values for 'pm_flags'
3887                  */
3888
3889                 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW |
3890                     PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN |
3891                     PMC_F_USERCALLCHAIN)) != 0) {
3892                         error = EINVAL;
3893                         break;
3894                 }
3895
3896                 /* PMC_F_USERCALLCHAIN is only valid with PMC_F_CALLCHAIN */
3897                 if ((pa.pm_flags & (PMC_F_CALLCHAIN | PMC_F_USERCALLCHAIN)) ==
3898                     PMC_F_USERCALLCHAIN) {
3899                         error = EINVAL;
3900                         break;
3901                 }
3902
3903                 /* PMC_F_USERCALLCHAIN is only valid for sampling mode */
3904                 if (pa.pm_flags & PMC_F_USERCALLCHAIN &&
3905                         mode != PMC_MODE_TS && mode != PMC_MODE_SS) {
3906                         error = EINVAL;
3907                         break;
3908                 }
3909
3910                 /* process logging options are not allowed for system PMCs */
3911                 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags &
3912                     (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) {
3913                         error = EINVAL;
3914                         break;
3915                 }
3916
3917                 /*
3918                  * All sampling mode PMCs need to be able to interrupt the
3919                  * CPU.
3920                  */
3921                 if (PMC_IS_SAMPLING_MODE(mode))
3922                         caps |= PMC_CAP_INTERRUPT;
3923
3924                 /* A valid class specifier should have been passed in. */
3925                 pcd = pmc_class_to_classdep(pa.pm_class);
3926                 if (pcd == NULL) {
3927                         error = EINVAL;
3928                         break;
3929                 }
3930
3931                 /* The requested PMC capabilities should be feasible. */
3932                 if ((pcd->pcd_caps & caps) != caps) {
3933                         error = EOPNOTSUPP;
3934                         break;
3935                 }
3936
3937                 PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d",
3938                     pa.pm_ev, caps, mode, cpu);
3939
3940                 pmc = pmc_allocate_pmc_descriptor();
3941                 pmc->pm_id    = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class,
3942                     PMC_ID_INVALID);
3943                 pmc->pm_event = pa.pm_ev;
3944                 pmc->pm_state = PMC_STATE_FREE;
3945                 pmc->pm_caps  = caps;
3946                 pmc->pm_flags = pa.pm_flags;
3947
3948                 /* XXX set lower bound on sampling for process counters */
3949                 if (PMC_IS_SAMPLING_MODE(mode)) {
3950                         /*
3951                          * Don't permit requested sample rate to be less than 1000
3952                          */
3953                         if (pa.pm_count < 1000)
3954                                 log(LOG_WARNING,
3955                                         "pmcallocate: passed sample rate %ju - setting to 1000\n",
3956                                         (uintmax_t)pa.pm_count);
3957                         pmc->pm_sc.pm_reloadcount = MAX(1000, pa.pm_count);
3958                 } else
3959                         pmc->pm_sc.pm_initial = pa.pm_count;
3960
3961                 /* switch thread to CPU 'cpu' */
3962                 pmc_save_cpu_binding(&pb);
3963
3964 #define PMC_IS_SHAREABLE_PMC(cpu, n)                            \
3965         (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state &           \
3966          PMC_PHW_FLAG_IS_SHAREABLE)
3967 #define PMC_IS_UNALLOCATED(cpu, n)                              \
3968         (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL)
3969
3970                 if (PMC_IS_SYSTEM_MODE(mode)) {
3971                         pmc_select_cpu(cpu);
3972                         for (n = pcd->pcd_ri; n < (int) md->pmd_npmc; n++) {
3973                                 pcd = pmc_ri_to_classdep(md, n, &adjri);
3974                                 if (pmc_can_allocate_row(n, mode) == 0 &&
3975                                     pmc_can_allocate_rowindex(
3976                                             curthread->td_proc, n, cpu) == 0 &&
3977                                     (PMC_IS_UNALLOCATED(cpu, n) ||
3978                                      PMC_IS_SHAREABLE_PMC(cpu, n)) &&
3979                                     pcd->pcd_allocate_pmc(cpu, adjri, pmc,
3980                                         &pa) == 0)
3981                                         break;
3982                         }
3983                 } else {
3984                         /* Process virtual mode */
3985                         for (n = pcd->pcd_ri; n < (int) md->pmd_npmc; n++) {
3986                                 pcd = pmc_ri_to_classdep(md, n, &adjri);
3987                                 if (pmc_can_allocate_row(n, mode) == 0 &&
3988                                     pmc_can_allocate_rowindex(
3989                                             curthread->td_proc, n,
3990                                             PMC_CPU_ANY) == 0 &&
3991                                     pcd->pcd_allocate_pmc(curthread->td_oncpu,
3992                                         adjri, pmc, &pa) == 0)
3993                                         break;
3994                         }
3995                 }
3996
3997 #undef  PMC_IS_UNALLOCATED
3998 #undef  PMC_IS_SHAREABLE_PMC
3999
4000                 pmc_restore_cpu_binding(&pb);
4001
4002                 if (n == (int) md->pmd_npmc) {
4003                         pmc_destroy_pmc_descriptor(pmc);
4004                         pmc = NULL;
4005                         error = EINVAL;
4006                         break;
4007                 }
4008
4009                 /* Fill in the correct value in the ID field */
4010                 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n);
4011
4012                 PMCDBG5(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x",
4013                     pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id);
4014
4015                 /* Process mode PMCs with logging enabled need log files */
4016                 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW))
4017                         pmc->pm_flags |= PMC_F_NEEDS_LOGFILE;
4018
4019                 /* All system mode sampling PMCs require a log file */
4020                 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode))
4021                         pmc->pm_flags |= PMC_F_NEEDS_LOGFILE;
4022
4023                 /*
4024                  * Configure global pmc's immediately
4025                  */
4026
4027                 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) {
4028
4029                         pmc_save_cpu_binding(&pb);
4030                         pmc_select_cpu(cpu);
4031
4032                         phw = pmc_pcpu[cpu]->pc_hwpmcs[n];
4033                         pcd = pmc_ri_to_classdep(md, n, &adjri);
4034
4035                         if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 ||
4036                             (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) {
4037                                 (void) pcd->pcd_release_pmc(cpu, adjri, pmc);
4038                                 pmc_destroy_pmc_descriptor(pmc);
4039                                 pmc = NULL;
4040                                 pmc_restore_cpu_binding(&pb);
4041                                 error = EPERM;
4042                                 break;
4043                         }
4044
4045                         pmc_restore_cpu_binding(&pb);
4046                 }
4047
4048                 pmc->pm_state    = PMC_STATE_ALLOCATED;
4049                 pmc->pm_class   = pa.pm_class;
4050
4051                 /*
4052                  * mark row disposition
4053                  */
4054
4055                 if (PMC_IS_SYSTEM_MODE(mode))
4056                         PMC_MARK_ROW_STANDALONE(n);
4057                 else
4058                         PMC_MARK_ROW_THREAD(n);
4059
4060                 /*
4061                  * Register this PMC with the current thread as its owner.
4062                  */
4063
4064                 if ((error =
4065                     pmc_register_owner(curthread->td_proc, pmc)) != 0) {
4066                         pmc_release_pmc_descriptor(pmc);
4067                         pmc_destroy_pmc_descriptor(pmc);
4068                         pmc = NULL;
4069                         break;
4070                 }
4071
4072
4073                 /*
4074                  * Return the allocated index.
4075                  */
4076
4077                 pa.pm_pmcid = pmc->pm_id;
4078
4079                 error = copyout(&pa, arg, sizeof(pa));
4080         }
4081         break;
4082
4083
4084         /*
4085          * Attach a PMC to a process.
4086          */
4087
4088         case PMC_OP_PMCATTACH:
4089         {
4090                 struct pmc *pm;
4091                 struct proc *p;
4092                 struct pmc_op_pmcattach a;
4093
4094                 sx_assert(&pmc_sx, SX_XLOCKED);
4095
4096                 if ((error = copyin(arg, &a, sizeof(a))) != 0)
4097                         break;
4098
4099                 if (a.pm_pid < 0) {
4100                         error = EINVAL;
4101                         break;
4102                 } else if (a.pm_pid == 0)
4103                         a.pm_pid = td->td_proc->p_pid;
4104
4105                 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0)
4106                         break;
4107
4108                 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) {
4109                         error = EINVAL;
4110                         break;
4111                 }
4112
4113                 /* PMCs may be (re)attached only when allocated or stopped */
4114                 if (pm->pm_state == PMC_STATE_RUNNING) {
4115                         error = EBUSY;
4116                         break;
4117                 } else if (pm->pm_state != PMC_STATE_ALLOCATED &&
4118                     pm->pm_state != PMC_STATE_STOPPED) {
4119                         error = EINVAL;
4120                         break;
4121                 }
4122
4123                 /* lookup pid */
4124                 if ((p = pfind(a.pm_pid)) == NULL) {
4125                         error = ESRCH;
4126                         break;
4127                 }
4128
4129                 /*
4130                  * Ignore processes that are working on exiting.
4131                  */
4132                 if (p->p_flag & P_WEXIT) {
4133                         error = ESRCH;
4134                         PROC_UNLOCK(p); /* pfind() returns a locked process */
4135                         break;
4136                 }
4137
4138                 /*
4139                  * we are allowed to attach a PMC to a process if
4140                  * we can debug it.
4141                  */
4142                 error = p_candebug(curthread, p);
4143
4144                 PROC_UNLOCK(p);
4145
4146                 if (error == 0)
4147                         error = pmc_attach_process(p, pm);
4148         }
4149         break;
4150
4151
4152         /*
4153          * Detach an attached PMC from a process.
4154          */
4155
4156         case PMC_OP_PMCDETACH:
4157         {
4158                 struct pmc *pm;
4159                 struct proc *p;
4160                 struct pmc_op_pmcattach a;
4161
4162                 if ((error = copyin(arg, &a, sizeof(a))) != 0)
4163                         break;
4164
4165                 if (a.pm_pid < 0) {
4166                         error = EINVAL;
4167                         break;
4168                 } else if (a.pm_pid == 0)
4169                         a.pm_pid = td->td_proc->p_pid;
4170
4171                 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0)
4172                         break;
4173
4174                 if ((p = pfind(a.pm_pid)) == NULL) {
4175                         error = ESRCH;
4176                         break;
4177                 }
4178
4179                 /*
4180                  * Treat processes that are in the process of exiting
4181                  * as if they were not present.
4182                  */
4183
4184                 if (p->p_flag & P_WEXIT)
4185                         error = ESRCH;
4186
4187                 PROC_UNLOCK(p); /* pfind() returns a locked process */
4188
4189                 if (error == 0)
4190                         error = pmc_detach_process(p, pm);
4191         }
4192         break;
4193
4194
4195         /*
4196          * Retrieve the MSR number associated with the counter
4197          * 'pmc_id'.  This allows processes to directly use RDPMC
4198          * instructions to read their PMCs, without the overhead of a
4199          * system call.
4200          */
4201
4202         case PMC_OP_PMCGETMSR:
4203         {
4204                 int adjri, ri;
4205                 struct pmc *pm;
4206                 struct pmc_target *pt;
4207                 struct pmc_op_getmsr gm;
4208                 struct pmc_classdep *pcd;
4209
4210                 PMC_DOWNGRADE_SX();
4211
4212                 if ((error = copyin(arg, &gm, sizeof(gm))) != 0)
4213                         break;
4214
4215                 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0)
4216                         break;
4217
4218                 /*
4219                  * The allocated PMC has to be a process virtual PMC,
4220                  * i.e., of type MODE_T[CS].  Global PMCs can only be
4221                  * read using the PMCREAD operation since they may be
4222                  * allocated on a different CPU than the one we could
4223                  * be running on at the time of the RDPMC instruction.
4224                  *
4225                  * The GETMSR operation is not allowed for PMCs that
4226                  * are inherited across processes.
4227                  */
4228
4229                 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) ||
4230                     (pm->pm_flags & PMC_F_DESCENDANTS)) {
4231                         error = EINVAL;
4232                         break;
4233                 }
4234
4235                 /*
4236                  * It only makes sense to use a RDPMC (or its
4237                  * equivalent instruction on non-x86 architectures) on
4238                  * a process that has allocated and attached a PMC to
4239                  * itself.  Conversely the PMC is only allowed to have
4240                  * one process attached to it -- its owner.
4241                  */
4242
4243                 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL ||
4244                     LIST_NEXT(pt, pt_next) != NULL ||
4245                     pt->pt_process->pp_proc != pm->pm_owner->po_owner) {
4246                         error = EINVAL;
4247                         break;
4248                 }
4249
4250                 ri = PMC_TO_ROWINDEX(pm);
4251                 pcd = pmc_ri_to_classdep(md, ri, &adjri);
4252
4253                 /* PMC class has no 'GETMSR' support */
4254                 if (pcd->pcd_get_msr == NULL) {
4255                         error = ENOSYS;
4256                         break;
4257                 }
4258
4259                 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0)
4260                         break;
4261
4262                 if ((error = copyout(&gm, arg, sizeof(gm))) < 0)
4263                         break;
4264
4265                 /*
4266                  * Mark our process as using MSRs.  Update machine
4267                  * state using a forced context switch.
4268                  */
4269
4270                 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS;
4271                 pmc_force_context_switch();
4272
4273         }
4274         break;
4275
4276         /*
4277          * Release an allocated PMC
4278          */
4279
4280         case PMC_OP_PMCRELEASE:
4281         {
4282                 pmc_id_t pmcid;
4283                 struct pmc *pm;
4284                 struct pmc_owner *po;
4285                 struct pmc_op_simple sp;
4286
4287                 /*
4288                  * Find PMC pointer for the named PMC.
4289                  *
4290                  * Use pmc_release_pmc_descriptor() to switch off the
4291                  * PMC, remove all its target threads, and remove the
4292                  * PMC from its owner's list.
4293                  *
4294                  * Remove the owner record if this is the last PMC
4295                  * owned.
4296                  *
4297                  * Free up space.
4298                  */
4299
4300                 if ((error = copyin(arg, &sp, sizeof(sp))) != 0)
4301                         break;
4302
4303                 pmcid = sp.pm_pmcid;
4304
4305                 if ((error = pmc_find_pmc(pmcid, &pm)) != 0)
4306                         break;
4307
4308                 po = pm->pm_owner;
4309                 pmc_release_pmc_descriptor(pm);
4310                 pmc_maybe_remove_owner(po);
4311                 pmc_destroy_pmc_descriptor(pm);
4312         }
4313         break;
4314
4315
4316         /*
4317          * Read and/or write a PMC.
4318          */
4319
4320         case PMC_OP_PMCRW:
4321         {
4322                 int adjri;
4323                 struct pmc *pm;
4324                 uint32_t cpu, ri;
4325                 pmc_value_t oldvalue;
4326                 struct pmc_binding pb;
4327                 struct pmc_op_pmcrw prw;
4328                 struct pmc_classdep *pcd;
4329                 struct pmc_op_pmcrw *pprw;
4330
4331                 PMC_DOWNGRADE_SX();
4332
4333                 if ((error = copyin(arg, &prw, sizeof(prw))) != 0)
4334                         break;
4335
4336                 ri = 0;
4337                 PMCDBG2(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid,
4338                     prw.pm_flags);
4339
4340                 /* must have at least one flag set */
4341                 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) {
4342                         error = EINVAL;
4343                         break;
4344                 }
4345
4346                 /* locate pmc descriptor */
4347                 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0)
4348                         break;
4349
4350                 /* Can't read a PMC that hasn't been started. */
4351                 if (pm->pm_state != PMC_STATE_ALLOCATED &&
4352                     pm->pm_state != PMC_STATE_STOPPED &&
4353                     pm->pm_state != PMC_STATE_RUNNING) {
4354                         error = EINVAL;
4355                         break;
4356                 }
4357
4358                 /* writing a new value is allowed only for 'STOPPED' pmcs */
4359                 if (pm->pm_state == PMC_STATE_RUNNING &&
4360                     (prw.pm_flags & PMC_F_NEWVALUE)) {
4361                         error = EBUSY;
4362                         break;
4363                 }
4364
4365                 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) {
4366
4367                         /*
4368                          * If this PMC is attached to its owner (i.e.,
4369                          * the process requesting this operation) and
4370                          * is running, then attempt to get an
4371                          * upto-date reading from hardware for a READ.
4372                          * Writes are only allowed when the PMC is
4373                          * stopped, so only update the saved value
4374                          * field.
4375                          *
4376                          * If the PMC is not running, or is not
4377                          * attached to its owner, read/write to the
4378                          * savedvalue field.
4379                          */
4380
4381                         ri = PMC_TO_ROWINDEX(pm);
4382                         pcd = pmc_ri_to_classdep(md, ri, &adjri);
4383
4384                         mtx_pool_lock_spin(pmc_mtxpool, pm);
4385                         cpu = curthread->td_oncpu;
4386
4387                         if (prw.pm_flags & PMC_F_OLDVALUE) {
4388                                 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) &&
4389                                     (pm->pm_state == PMC_STATE_RUNNING))
4390                                         error = (*pcd->pcd_read_pmc)(cpu, adjri,
4391                                             &oldvalue);
4392                                 else
4393                                         oldvalue = pm->pm_gv.pm_savedvalue;
4394                         }
4395                         if (prw.pm_flags & PMC_F_NEWVALUE)
4396                                 pm->pm_gv.pm_savedvalue = prw.pm_value;
4397
4398                         mtx_pool_unlock_spin(pmc_mtxpool, pm);
4399
4400                 } else { /* System mode PMCs */
4401                         cpu = PMC_TO_CPU(pm);
4402                         ri  = PMC_TO_ROWINDEX(pm);
4403                         pcd = pmc_ri_to_classdep(md, ri, &adjri);
4404
4405                         if (!pmc_cpu_is_active(cpu)) {
4406                                 error = ENXIO;
4407                                 break;
4408                         }
4409
4410                         /* move this thread to CPU 'cpu' */
4411                         pmc_save_cpu_binding(&pb);
4412                         pmc_select_cpu(cpu);
4413
4414                         critical_enter();
4415                         /* save old value */
4416                         if (prw.pm_flags & PMC_F_OLDVALUE)
4417                                 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri,
4418                                          &oldvalue)))
4419                                         goto error;
4420                         /* write out new value */
4421                         if (prw.pm_flags & PMC_F_NEWVALUE)
4422                                 error = (*pcd->pcd_write_pmc)(cpu, adjri,
4423                                     prw.pm_value);
4424                 error:
4425                         critical_exit();
4426                         pmc_restore_cpu_binding(&pb);
4427                         if (error)
4428                                 break;
4429                 }
4430
4431                 pprw = (struct pmc_op_pmcrw *) arg;
4432
4433 #ifdef  HWPMC_DEBUG
4434                 if (prw.pm_flags & PMC_F_NEWVALUE)
4435                         PMCDBG3(PMC,OPS,2, "rw id=%d new %jx -> old %jx",
4436                             ri, prw.pm_value, oldvalue);
4437                 else if (prw.pm_flags & PMC_F_OLDVALUE)
4438                         PMCDBG2(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue);
4439 #endif
4440
4441                 /* return old value if requested */
4442                 if (prw.pm_flags & PMC_F_OLDVALUE)
4443                         if ((error = copyout(&oldvalue, &pprw->pm_value,
4444                                  sizeof(prw.pm_value))))
4445                                 break;
4446
4447         }
4448         break;
4449
4450
4451         /*
4452          * Set the sampling rate for a sampling mode PMC and the
4453          * initial count for a counting mode PMC.
4454          */
4455
4456         case PMC_OP_PMCSETCOUNT:
4457         {
4458                 struct pmc *pm;
4459                 struct pmc_op_pmcsetcount sc;
4460
4461                 PMC_DOWNGRADE_SX();
4462
4463                 if ((error = copyin(arg, &sc, sizeof(sc))) != 0)
4464                         break;
4465
4466                 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0)
4467                         break;
4468
4469                 if (pm->pm_state == PMC_STATE_RUNNING) {
4470                         error = EBUSY;
4471                         break;
4472                 }
4473
4474                 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) {
4475                         /*
4476                          * Don't permit requested sample rate to be less than 1000
4477                          */
4478                         if (sc.pm_count < 1000)
4479                                 log(LOG_WARNING,
4480                                         "pmcsetcount: passed sample rate %ju - setting to 1000\n",
4481                                         (uintmax_t)sc.pm_count);
4482                         pm->pm_sc.pm_reloadcount = MAX(1000, sc.pm_count);
4483                 } else
4484                         pm->pm_sc.pm_initial = sc.pm_count;
4485         }
4486         break;
4487
4488
4489         /*
4490          * Start a PMC.
4491          */
4492
4493         case PMC_OP_PMCSTART:
4494         {
4495                 pmc_id_t pmcid;
4496                 struct pmc *pm;
4497                 struct pmc_op_simple sp;
4498
4499                 sx_assert(&pmc_sx, SX_XLOCKED);
4500
4501                 if ((error = copyin(arg, &sp, sizeof(sp))) != 0)
4502                         break;
4503
4504                 pmcid = sp.pm_pmcid;
4505
4506                 if ((error = pmc_find_pmc(pmcid, &pm)) != 0)
4507                         break;
4508
4509                 KASSERT(pmcid == pm->pm_id,
4510                     ("[pmc,%d] pmcid %x != id %x", __LINE__,
4511                         pm->pm_id, pmcid));
4512
4513                 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */
4514                         break;
4515                 else if (pm->pm_state != PMC_STATE_STOPPED &&
4516                     pm->pm_state != PMC_STATE_ALLOCATED) {
4517                         error = EINVAL;
4518                         break;
4519                 }
4520
4521                 error = pmc_start(pm);
4522         }
4523         break;
4524
4525
4526         /*
4527          * Stop a PMC.
4528          */
4529
4530         case PMC_OP_PMCSTOP:
4531         {
4532                 pmc_id_t pmcid;
4533                 struct pmc *pm;
4534                 struct pmc_op_simple sp;
4535
4536                 PMC_DOWNGRADE_SX();
4537
4538                 if ((error = copyin(arg, &sp, sizeof(sp))) != 0)
4539                         break;
4540
4541                 pmcid = sp.pm_pmcid;
4542
4543                 /*
4544                  * Mark the PMC as inactive and invoke the MD stop
4545                  * routines if needed.
4546                  */
4547
4548                 if ((error = pmc_find_pmc(pmcid, &pm)) != 0)
4549                         break;
4550
4551                 KASSERT(pmcid == pm->pm_id,
4552                     ("[pmc,%d] pmc id %x != pmcid %x", __LINE__,
4553                         pm->pm_id, pmcid));
4554
4555                 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */
4556                         break;
4557                 else if (pm->pm_state != PMC_STATE_RUNNING) {
4558                         error = EINVAL;
4559                         break;
4560                 }
4561
4562                 error = pmc_stop(pm);
4563         }
4564         break;
4565
4566
4567         /*
4568          * Write a user supplied value to the log file.
4569          */
4570
4571         case PMC_OP_WRITELOG:
4572         {
4573                 struct pmc_op_writelog wl;
4574                 struct pmc_owner *po;
4575
4576                 PMC_DOWNGRADE_SX();
4577
4578                 if ((error = copyin(arg, &wl, sizeof(wl))) != 0)
4579                         break;
4580
4581                 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) {
4582                         error = EINVAL;
4583                         break;
4584                 }
4585
4586                 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) {
4587                         error = EINVAL;
4588                         break;
4589                 }
4590
4591                 error = pmclog_process_userlog(po, &wl);
4592         }
4593         break;
4594
4595
4596         default:
4597                 error = EINVAL;
4598                 break;
4599         }
4600
4601         if (is_sx_downgraded)
4602                 sx_sunlock(&pmc_sx);
4603         else
4604                 sx_xunlock(&pmc_sx);
4605 done_syscall:
4606         if (error)
4607                 counter_u64_add(pmc_stats.pm_syscall_errors, 1);
4608
4609         return (error);
4610 }
4611
4612 /*
4613  * Helper functions
4614  */
4615
4616
4617 /*
4618  * Mark the thread as needing callchain capture and post an AST.  The
4619  * actual callchain capture will be done in a context where it is safe
4620  * to take page faults.
4621  */
4622
4623 static void
4624 pmc_post_callchain_callback(void)
4625 {
4626         struct thread *td;
4627
4628         td = curthread;
4629
4630         /*
4631          * If there is multiple PMCs for the same interrupt ignore new post
4632          */
4633         if (td->td_pflags & TDP_CALLCHAIN)
4634                 return;
4635
4636         /*
4637          * Mark this thread as needing callchain capture.
4638          * `td->td_pflags' will be safe to touch because this thread
4639          * was in user space when it was interrupted.
4640          */
4641         td->td_pflags |= TDP_CALLCHAIN;
4642
4643         /*
4644          * Don't let this thread migrate between CPUs until callchain
4645          * capture completes.
4646          */
4647         sched_pin();
4648
4649         return;
4650 }
4651
4652 /*
4653  * Find a free slot in the per-cpu array of samples and capture the
4654  * current callchain there.  If a sample was successfully added, a bit
4655  * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook
4656  * needs to be invoked from the clock handler.
4657  *
4658  * This function is meant to be called from an NMI handler.  It cannot
4659  * use any of the locking primitives supplied by the OS.
4660  */
4661
4662 static int
4663 pmc_add_sample(ring_type_t ring, struct pmc *pm, struct trapframe *tf)
4664 {
4665         int error, cpu, callchaindepth, inuserspace;
4666         struct thread *td;
4667         struct pmc_sample *ps;
4668         struct pmc_samplebuffer *psb;
4669
4670         error = 0;
4671
4672         /*
4673          * Allocate space for a sample buffer.
4674          */
4675         cpu = curcpu;
4676         psb = pmc_pcpu[cpu]->pc_sb[ring];
4677         inuserspace = TRAPF_USERMODE(tf);
4678         ps = PMC_PROD_SAMPLE(psb);
4679         if (psb->ps_considx != psb->ps_prodidx &&
4680                 ps->ps_nsamples) {      /* in use, reader hasn't caught up */
4681                 pm->pm_pcpu_state[cpu].pps_stalled = 1;
4682                 counter_u64_add(pmc_stats.pm_intr_bufferfull, 1);
4683                 PMCDBG6(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d",
4684                     cpu, pm, (void *) tf, inuserspace,
4685                     (int) (psb->ps_prodidx & pmc_sample_mask),
4686                     (int) (psb->ps_considx & pmc_sample_mask));
4687                 callchaindepth = 1;
4688                 error = ENOMEM;
4689                 goto done;
4690         }
4691
4692         /* Fill in entry. */
4693         PMCDBG6(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm,
4694             (void *) tf, inuserspace,
4695             (int) (psb->ps_prodidx & pmc_sample_mask),
4696             (int) (psb->ps_considx & pmc_sample_mask));
4697
4698         td = curthread;
4699         ps->ps_pmc = pm;
4700         ps->ps_td = td;
4701         ps->ps_pid = td->td_proc->p_pid;
4702         ps->ps_tid = td->td_tid;
4703         ps->ps_tsc = pmc_rdtsc();
4704         ps->ps_ticks = ticks;
4705         ps->ps_cpu = cpu;
4706         ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0;
4707
4708         callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ?
4709             pmc_callchaindepth : 1;
4710
4711         MPASS(ps->ps_pc != NULL);
4712         if (callchaindepth == 1)
4713                 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf);
4714         else {
4715                 /*
4716                  * Kernel stack traversals can be done immediately,
4717                  * while we defer to an AST for user space traversals.
4718                  */
4719                 if (!inuserspace) {
4720                         callchaindepth =
4721                             pmc_save_kernel_callchain(ps->ps_pc,
4722                                 callchaindepth, tf);
4723                 } else {
4724                         pmc_post_callchain_callback();
4725                         callchaindepth = PMC_USER_CALLCHAIN_PENDING;
4726                 }
4727         }
4728
4729         ps->ps_nsamples = callchaindepth;       /* mark entry as in use */
4730         if (ring == PMC_UR) {
4731                 ps->ps_nsamples_actual = callchaindepth;        /* mark entry as in use */
4732                 ps->ps_nsamples = PMC_USER_CALLCHAIN_PENDING;
4733         } else
4734                 ps->ps_nsamples = callchaindepth;       /* mark entry as in use */
4735
4736         KASSERT(counter_u64_fetch(pm->pm_runcount) >= 0,
4737             ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm,
4738                  (unsigned long)counter_u64_fetch(pm->pm_runcount)));
4739
4740         counter_u64_add(pm->pm_runcount, 1);    /* hold onto PMC */
4741         /* increment write pointer */
4742         psb->ps_prodidx++;
4743  done:
4744         /* mark CPU as needing processing */
4745         if (callchaindepth != PMC_USER_CALLCHAIN_PENDING)
4746                 DPCPU_SET(pmc_sampled, 1);
4747
4748         return (error);
4749 }
4750
4751 /*
4752  * Interrupt processing.
4753  *
4754  * This function is meant to be called from an NMI handler.  It cannot
4755  * use any of the locking primitives supplied by the OS.
4756  */
4757
4758 int
4759 pmc_process_interrupt(int ring, struct pmc *pm, struct trapframe *tf)
4760 {
4761         struct thread *td;
4762
4763         td = curthread;
4764         if ((pm->pm_flags & PMC_F_USERCALLCHAIN) &&
4765             (td->td_proc->p_flag & P_KPROC) == 0 &&
4766             !TRAPF_USERMODE(tf)) {
4767                 atomic_add_int(&td->td_pmcpend, 1);
4768                 return (pmc_add_sample(PMC_UR, pm, tf));
4769         }
4770         return (pmc_add_sample(ring, pm, tf));
4771 }
4772
4773 /*
4774  * Capture a user call chain.  This function will be called from ast()
4775  * before control returns to userland and before the process gets
4776  * rescheduled.
4777  */
4778
4779 static void
4780 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf)
4781 {
4782         struct pmc *pm;
4783         struct thread *td;
4784         struct pmc_sample *ps;
4785         struct pmc_samplebuffer *psb;
4786         uint64_t considx, prodidx;
4787         int nsamples, nrecords, pass, iter;
4788 #ifdef  INVARIANTS
4789         int ncallchains;
4790         int nfree;
4791         int start_ticks = ticks;
4792 #endif
4793         psb = pmc_pcpu[cpu]->pc_sb[ring];
4794         td = curthread;
4795
4796         KASSERT(td->td_pflags & TDP_CALLCHAIN,
4797             ("[pmc,%d] Retrieving callchain for thread that doesn't want it",
4798                 __LINE__));
4799
4800 #ifdef  INVARIANTS
4801         ncallchains = 0;
4802         nfree = 0;
4803 #endif
4804         nrecords = INT_MAX;
4805         pass = 0;
4806  restart:
4807         if (ring == PMC_UR)
4808                 nrecords = atomic_readandclear_32(&td->td_pmcpend);
4809
4810         for (iter = 0, considx = psb->ps_considx, prodidx = psb->ps_prodidx;
4811             considx < prodidx && iter < pmc_nsamples; considx++, iter++) {
4812                 ps = PMC_CONS_SAMPLE_OFF(psb, considx);
4813
4814         /*
4815          * Iterate through all deferred callchain requests.
4816          * Walk from the current read pointer to the current
4817          * write pointer.
4818          */
4819
4820 #ifdef  INVARIANTS
4821                 if (ps->ps_nsamples == PMC_SAMPLE_FREE) {
4822                         nfree++;
4823                         continue;
4824                 }
4825
4826                 if ((ps->ps_pmc == NULL) ||
4827                     (ps->ps_pmc->pm_state != PMC_STATE_RUNNING))
4828                         nfree++;
4829 #endif
4830                 if (ps->ps_td != td ||
4831                    ps->ps_nsamples != PMC_USER_CALLCHAIN_PENDING ||
4832                    ps->ps_pmc->pm_state != PMC_STATE_RUNNING)
4833                         continue;
4834
4835                 KASSERT(ps->ps_cpu == cpu,
4836                     ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__,
4837                         ps->ps_cpu, PCPU_GET(cpuid)));
4838
4839                 pm = ps->ps_pmc;
4840
4841                 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN,
4842                     ("[pmc,%d] Retrieving callchain for PMC that doesn't "
4843                         "want it", __LINE__));
4844
4845                 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0,
4846                     ("[pmc,%d] runcount %ld", __LINE__, (unsigned long)counter_u64_fetch(pm->pm_runcount)));
4847
4848                 if (ring == PMC_UR) {
4849                         nsamples = ps->ps_nsamples_actual;
4850                         counter_u64_add(pmc_stats.pm_merges, 1);
4851                 } else
4852                         nsamples = 0;
4853
4854                 /*
4855                  * Retrieve the callchain and mark the sample buffer
4856                  * as 'processable' by the timer tick sweep code.
4857                  */
4858
4859 #ifdef INVARIANTS
4860                 ncallchains++;
4861 #endif
4862
4863                 if (__predict_true(nsamples < pmc_callchaindepth - 1))
4864                         nsamples += pmc_save_user_callchain(ps->ps_pc + nsamples,
4865                        pmc_callchaindepth - nsamples - 1, tf);
4866
4867                 /*
4868                  * We have to prevent hardclock from potentially overwriting
4869                  * this sample between when we read the value and when we set
4870                  * it
4871                  */
4872                 spinlock_enter();
4873                 /*
4874                  * Verify that the sample hasn't been dropped in the meantime
4875                  */
4876                 if (ps->ps_nsamples == PMC_USER_CALLCHAIN_PENDING) {
4877                         ps->ps_nsamples = nsamples;
4878                         /*
4879                          * If we couldn't get a sample, simply drop the reference
4880                          */
4881                         if (nsamples == 0)
4882                                 counter_u64_add(pm->pm_runcount, -1);
4883                 }
4884                 spinlock_exit();
4885                 if (nrecords-- == 1)
4886                         break;
4887         }
4888         if (__predict_false(ring == PMC_UR && td->td_pmcpend)) {
4889                 if (pass == 0) {
4890                         pass = 1;
4891                         goto restart;
4892                 }
4893                 /* only collect samples for this part once */
4894                 td->td_pmcpend = 0;
4895         }
4896
4897 #ifdef INVARIANTS
4898         if ((ticks - start_ticks) > hz)
4899                 log(LOG_ERR, "%s took %d ticks\n", __func__, (ticks - start_ticks));
4900 #endif
4901
4902         /* mark CPU as needing processing */
4903         DPCPU_SET(pmc_sampled, 1);
4904 }
4905
4906 /*
4907  * Process saved PC samples.
4908  */
4909
4910 static void
4911 pmc_process_samples(int cpu, ring_type_t ring)
4912 {
4913         struct pmc *pm;
4914         int adjri, n;
4915         struct thread *td;
4916         struct pmc_owner *po;
4917         struct pmc_sample *ps;
4918         struct pmc_classdep *pcd;
4919         struct pmc_samplebuffer *psb;
4920         uint64_t delta;
4921
4922         KASSERT(PCPU_GET(cpuid) == cpu,
4923             ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__,
4924                 PCPU_GET(cpuid), cpu));
4925
4926         psb = pmc_pcpu[cpu]->pc_sb[ring];
4927         delta = psb->ps_prodidx - psb->ps_considx;
4928         MPASS(delta <= pmc_nsamples);
4929         MPASS(psb->ps_considx <= psb->ps_prodidx);
4930         for (n = 0; psb->ps_considx < psb->ps_prodidx; psb->ps_considx++, n++) {
4931                 ps = PMC_CONS_SAMPLE(psb);
4932
4933                 if (__predict_false(ps->ps_nsamples == PMC_SAMPLE_FREE))
4934                         continue;
4935                 pm = ps->ps_pmc;
4936                 /* skip non-running samples */
4937                 if (pm->pm_state != PMC_STATE_RUNNING)
4938                         goto entrydone;
4939
4940                 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0,
4941                     ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm,
4942                          (unsigned long)counter_u64_fetch(pm->pm_runcount)));
4943
4944                 po = pm->pm_owner;
4945
4946                 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)),
4947                     ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__,
4948                         pm, PMC_TO_MODE(pm)));
4949
4950
4951                 /* If there is a pending AST wait for completion */
4952                 if (ps->ps_nsamples == PMC_USER_CALLCHAIN_PENDING) {
4953                         /* if we've been waiting more than 1 tick to
4954                          * collect a callchain for this record then
4955                          * drop it and move on.
4956                          */
4957                         if (ticks - ps->ps_ticks > 1) {
4958                                 /*
4959                                  * track how often we hit this as it will
4960                                  * preferentially lose user samples
4961                                  * for long running system calls
4962                                  */
4963                                 counter_u64_add(pmc_stats.pm_overwrites, 1);
4964                                 goto entrydone;
4965                         }
4966                         /* Need a rescan at a later time. */
4967                         DPCPU_SET(pmc_sampled, 1);
4968                         break;
4969                 }
4970
4971                 PMCDBG6(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu,
4972                     pm, ps->ps_nsamples, ps->ps_flags,
4973                     (int) (psb->ps_prodidx & pmc_sample_mask),
4974                     (int) (psb->ps_considx & pmc_sample_mask));
4975
4976                 /*
4977                  * If this is a process-mode PMC that is attached to
4978                  * its owner, and if the PC is in user mode, update
4979                  * profiling statistics like timer-based profiling
4980                  * would have done.
4981                  *
4982                  * Otherwise, this is either a sampling-mode PMC that
4983                  * is attached to a different process than its owner,
4984                  * or a system-wide sampling PMC. Dispatch a log
4985                  * entry to the PMC's owner process.
4986                  */
4987                 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) {
4988                         if (ps->ps_flags & PMC_CC_F_USERSPACE) {
4989                                 td = FIRST_THREAD_IN_PROC(po->po_owner);
4990                                 addupc_intr(td, ps->ps_pc[0], 1);
4991                         }
4992                 } else
4993                         pmclog_process_callchain(pm, ps);
4994
4995         entrydone:
4996                 ps->ps_nsamples = 0; /* mark entry as free */
4997                 KASSERT(counter_u64_fetch(pm->pm_runcount) > 0,
4998                                 ("[pmc,%d] pm=%p runcount %ld", __LINE__, (void *) pm,
4999                                  (unsigned long)counter_u64_fetch(pm->pm_runcount)));
5000
5001                 counter_u64_add(pm->pm_runcount, -1);
5002         }
5003
5004         counter_u64_add(pmc_stats.pm_log_sweeps, 1);
5005
5006         /* Do not re-enable stalled PMCs if we failed to process any samples */
5007         if (n == 0)
5008                 return;
5009
5010         /*
5011          * Restart any stalled sampling PMCs on this CPU.
5012          *
5013          * If the NMI handler sets the pm_stalled field of a PMC after
5014          * the check below, we'll end up processing the stalled PMC at
5015          * the next hardclock tick.
5016          */
5017         for (n = 0; n < md->pmd_npmc; n++) {
5018                 pcd = pmc_ri_to_classdep(md, n, &adjri);
5019                 KASSERT(pcd != NULL,
5020                     ("[pmc,%d] null pcd ri=%d", __LINE__, n));
5021                 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm);
5022
5023                 if (pm == NULL ||                        /* !cfg'ed */
5024                     pm->pm_state != PMC_STATE_RUNNING || /* !active */
5025                     !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */
5026                         !pm->pm_pcpu_state[cpu].pps_cpustate  || /* !desired */
5027                     !pm->pm_pcpu_state[cpu].pps_stalled) /* !stalled */
5028                         continue;
5029
5030                 pm->pm_pcpu_state[cpu].pps_stalled = 0;
5031                 (*pcd->pcd_start_pmc)(cpu, adjri);
5032         }
5033 }
5034
5035 /*
5036  * Event handlers.
5037  */
5038
5039 /*
5040  * Handle a process exit.
5041  *
5042  * Remove this process from all hash tables.  If this process
5043  * owned any PMCs, turn off those PMCs and deallocate them,
5044  * removing any associations with target processes.
5045  *
5046  * This function will be called by the last 'thread' of a
5047  * process.
5048  *
5049  * XXX This eventhandler gets called early in the exit process.
5050  * Consider using a 'hook' invocation from thread_exit() or equivalent
5051  * spot.  Another negative is that kse_exit doesn't seem to call
5052  * exit1() [??].
5053  *
5054  */
5055
5056 static void
5057 pmc_process_exit(void *arg __unused, struct proc *p)
5058 {
5059         struct pmc *pm;
5060         int adjri, cpu;
5061         unsigned int ri;
5062         int is_using_hwpmcs;
5063         struct pmc_owner *po;
5064         struct pmc_process *pp;
5065         struct pmc_classdep *pcd;
5066         pmc_value_t newvalue, tmp;
5067
5068         PROC_LOCK(p);
5069         is_using_hwpmcs = p->p_flag & P_HWPMC;
5070         PROC_UNLOCK(p);
5071
5072         /*
5073          * Log a sysexit event to all SS PMC owners.
5074          */
5075         PMC_EPOCH_ENTER();
5076         CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
5077             if (po->po_flags & PMC_PO_OWNS_LOGFILE)
5078                     pmclog_process_sysexit(po, p->p_pid);
5079         PMC_EPOCH_EXIT();
5080
5081         if (!is_using_hwpmcs)
5082                 return;
5083
5084         PMC_GET_SX_XLOCK();
5085         PMCDBG3(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid,
5086             p->p_comm);
5087
5088         /*
5089          * Since this code is invoked by the last thread in an exiting
5090          * process, we would have context switched IN at some prior
5091          * point.  However, with PREEMPTION, kernel mode context
5092          * switches may happen any time, so we want to disable a
5093          * context switch OUT till we get any PMCs targeting this
5094          * process off the hardware.
5095          *
5096          * We also need to atomically remove this process'
5097          * entry from our target process hash table, using
5098          * PMC_FLAG_REMOVE.
5099          */
5100         PMCDBG3(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid,
5101             p->p_comm);
5102
5103         critical_enter(); /* no preemption */
5104
5105         cpu = curthread->td_oncpu;
5106
5107         if ((pp = pmc_find_process_descriptor(p,
5108                  PMC_FLAG_REMOVE)) != NULL) {
5109
5110                 PMCDBG2(PRC,EXT,2,
5111                     "process-exit proc=%p pmc-process=%p", p, pp);
5112
5113                 /*
5114                  * The exiting process could the target of
5115                  * some PMCs which will be running on
5116                  * currently executing CPU.
5117                  *
5118                  * We need to turn these PMCs off like we
5119                  * would do at context switch OUT time.
5120                  */
5121                 for (ri = 0; ri < md->pmd_npmc; ri++) {
5122
5123                         /*
5124                          * Pick up the pmc pointer from hardware
5125                          * state similar to the CSW_OUT code.
5126                          */
5127                         pm = NULL;
5128
5129                         pcd = pmc_ri_to_classdep(md, ri, &adjri);
5130
5131                         (void) (*pcd->pcd_get_config)(cpu, adjri, &pm);
5132
5133                         PMCDBG2(PRC,EXT,2, "ri=%d pm=%p", ri, pm);
5134
5135                         if (pm == NULL ||
5136                             !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)))
5137                                 continue;
5138
5139                         PMCDBG4(PRC,EXT,2, "ppmcs[%d]=%p pm=%p "
5140                             "state=%d", ri, pp->pp_pmcs[ri].pp_pmc,
5141                             pm, pm->pm_state);
5142
5143                         KASSERT(PMC_TO_ROWINDEX(pm) == ri,
5144                             ("[pmc,%d] ri mismatch pmc(%d) ri(%d)",
5145                                 __LINE__, PMC_TO_ROWINDEX(pm), ri));
5146
5147                         KASSERT(pm == pp->pp_pmcs[ri].pp_pmc,
5148                             ("[pmc,%d] pm %p != pp_pmcs[%d] %p",
5149                                 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc));
5150
5151                         KASSERT(counter_u64_fetch(pm->pm_runcount) > 0,
5152                             ("[pmc,%d] bad runcount ri %d rc %ld",
5153                                  __LINE__, ri, (unsigned long)counter_u64_fetch(pm->pm_runcount)));
5154
5155                         /*
5156                          * Change desired state, and then stop if not
5157                          * stalled. This two-step dance should avoid
5158                          * race conditions where an interrupt re-enables
5159                          * the PMC after this code has already checked
5160                          * the pm_stalled flag.
5161                          */
5162                         if (pm->pm_pcpu_state[cpu].pps_cpustate) {
5163                                 pm->pm_pcpu_state[cpu].pps_cpustate = 0;
5164                                 if (!pm->pm_pcpu_state[cpu].pps_stalled) {
5165                                         (void) pcd->pcd_stop_pmc(cpu, adjri);
5166
5167                                         if (PMC_TO_MODE(pm) == PMC_MODE_TC) {
5168                                                 pcd->pcd_read_pmc(cpu, adjri,
5169                                                     &newvalue);
5170                                                 tmp = newvalue -
5171                                                     PMC_PCPU_SAVED(cpu,ri);
5172
5173                                                 mtx_pool_lock_spin(pmc_mtxpool,
5174                                                     pm);
5175                                                 pm->pm_gv.pm_savedvalue += tmp;
5176                                                 pp->pp_pmcs[ri].pp_pmcval +=
5177                                                     tmp;
5178                                                 mtx_pool_unlock_spin(
5179                                                     pmc_mtxpool, pm);
5180                                         }
5181                                 }
5182                         }
5183
5184                         KASSERT((int64_t) counter_u64_fetch(pm->pm_runcount) > 0,
5185                             ("[pmc,%d] runcount is %d", __LINE__, ri));
5186
5187                         counter_u64_add(pm->pm_runcount, -1);
5188
5189                         (void) pcd->pcd_config_pmc(cpu, adjri, NULL);
5190                 }
5191
5192                 /*
5193                  * Inform the MD layer of this pseudo "context switch
5194                  * out"
5195                  */
5196                 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp);
5197
5198                 critical_exit(); /* ok to be pre-empted now */
5199
5200                 /*
5201                  * Unlink this process from the PMCs that are
5202                  * targeting it.  This will send a signal to
5203                  * all PMC owner's whose PMCs are orphaned.
5204                  *
5205                  * Log PMC value at exit time if requested.
5206                  */
5207                 for (ri = 0; ri < md->pmd_npmc; ri++)
5208                         if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) {
5209                                 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE &&
5210                                     PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm)))
5211                                         pmclog_process_procexit(pm, pp);
5212                                 pmc_unlink_target_process(pm, pp);
5213                         }
5214                 free(pp, M_PMC);
5215
5216         } else
5217                 critical_exit(); /* pp == NULL */
5218
5219
5220         /*
5221          * If the process owned PMCs, free them up and free up
5222          * memory.
5223          */
5224         if ((po = pmc_find_owner_descriptor(p)) != NULL) {
5225                 pmc_remove_owner(po);
5226                 pmc_destroy_owner_descriptor(po);
5227         }
5228
5229         sx_xunlock(&pmc_sx);
5230 }
5231
5232 /*
5233  * Handle a process fork.
5234  *
5235  * If the parent process 'p1' is under HWPMC monitoring, then copy
5236  * over any attached PMCs that have 'do_descendants' semantics.
5237  */
5238
5239 static void
5240 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc,
5241     int flags)
5242 {
5243         int is_using_hwpmcs;
5244         unsigned int ri;
5245         uint32_t do_descendants;
5246         struct pmc *pm;
5247         struct pmc_owner *po;
5248         struct pmc_process *ppnew, *ppold;
5249
5250         (void) flags;           /* unused parameter */
5251
5252         PROC_LOCK(p1);
5253         is_using_hwpmcs = p1->p_flag & P_HWPMC;
5254         PROC_UNLOCK(p1);
5255
5256         /*
5257          * If there are system-wide sampling PMCs active, we need to
5258          * log all fork events to their owner's logs.
5259          */
5260         PMC_EPOCH_ENTER();
5261         CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
5262             if (po->po_flags & PMC_PO_OWNS_LOGFILE) {
5263                     pmclog_process_procfork(po, p1->p_pid, newproc->p_pid);
5264                         pmclog_process_proccreate(po, newproc, 1);
5265                 }
5266         PMC_EPOCH_EXIT();
5267
5268         if (!is_using_hwpmcs)
5269                 return;
5270
5271         PMC_GET_SX_XLOCK();
5272         PMCDBG4(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1,
5273             p1->p_pid, p1->p_comm, newproc);
5274
5275         /*
5276          * If the parent process (curthread->td_proc) is a
5277          * target of any PMCs, look for PMCs that are to be
5278          * inherited, and link these into the new process
5279          * descriptor.
5280          */
5281         if ((ppold = pmc_find_process_descriptor(curthread->td_proc,
5282                  PMC_FLAG_NONE)) == NULL)
5283                 goto done;              /* nothing to do */
5284
5285         do_descendants = 0;
5286         for (ri = 0; ri < md->pmd_npmc; ri++)
5287                 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL)
5288                         do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS;
5289         if (do_descendants == 0) /* nothing to do */
5290                 goto done;
5291
5292         /*
5293          * Now mark the new process as being tracked by this driver.
5294          */
5295         PROC_LOCK(newproc);
5296         newproc->p_flag |= P_HWPMC;
5297         PROC_UNLOCK(newproc);
5298
5299         /* allocate a descriptor for the new process  */
5300         if ((ppnew = pmc_find_process_descriptor(newproc,
5301                  PMC_FLAG_ALLOCATE)) == NULL)
5302                 goto done;
5303
5304         /*
5305          * Run through all PMCs that were targeting the old process
5306          * and which specified F_DESCENDANTS and attach them to the
5307          * new process.
5308          *
5309          * Log the fork event to all owners of PMCs attached to this
5310          * process, if not already logged.
5311          */
5312         for (ri = 0; ri < md->pmd_npmc; ri++)
5313                 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL &&
5314                     (pm->pm_flags & PMC_F_DESCENDANTS)) {
5315                         pmc_link_target_process(pm, ppnew);
5316                         po = pm->pm_owner;
5317                         if (po->po_sscount == 0 &&
5318                             po->po_flags & PMC_PO_OWNS_LOGFILE)
5319                                 pmclog_process_procfork(po, p1->p_pid,
5320                                     newproc->p_pid);
5321                 }
5322
5323  done:
5324         sx_xunlock(&pmc_sx);
5325 }
5326
5327 static void
5328 pmc_process_threadcreate(struct thread *td)
5329 {
5330         struct pmc_owner *po;
5331
5332         PMC_EPOCH_ENTER();
5333         CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
5334             if (po->po_flags & PMC_PO_OWNS_LOGFILE)
5335                         pmclog_process_threadcreate(po, td, 1);
5336         PMC_EPOCH_EXIT();
5337 }
5338
5339 static void
5340 pmc_process_threadexit(struct thread *td)
5341 {
5342         struct pmc_owner *po;
5343
5344         PMC_EPOCH_ENTER();
5345         CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
5346             if (po->po_flags & PMC_PO_OWNS_LOGFILE)
5347                         pmclog_process_threadexit(po, td);
5348         PMC_EPOCH_EXIT();
5349 }
5350
5351 static void
5352 pmc_process_proccreate(struct proc *p)
5353 {
5354         struct pmc_owner *po;
5355
5356         PMC_EPOCH_ENTER();
5357         CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
5358             if (po->po_flags & PMC_PO_OWNS_LOGFILE)
5359                         pmclog_process_proccreate(po, p, 1 /* sync */);
5360         PMC_EPOCH_EXIT();
5361 }
5362
5363 static void
5364 pmc_process_allproc(struct pmc *pm)
5365 {
5366         struct pmc_owner *po;
5367         struct thread *td;
5368         struct proc *p;
5369
5370         po = pm->pm_owner;
5371         if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)
5372                 return;
5373         sx_slock(&allproc_lock);
5374         FOREACH_PROC_IN_SYSTEM(p) {
5375                 pmclog_process_proccreate(po, p, 0 /* sync */);
5376                 PROC_LOCK(p);
5377                 FOREACH_THREAD_IN_PROC(p, td)
5378                         pmclog_process_threadcreate(po, td, 0 /* sync */);
5379                 PROC_UNLOCK(p);
5380         }
5381         sx_sunlock(&allproc_lock);
5382         pmclog_flush(po, 0);
5383 }
5384
5385 static void
5386 pmc_kld_load(void *arg __unused, linker_file_t lf)
5387 {
5388         struct pmc_owner *po;
5389
5390         /*
5391          * Notify owners of system sampling PMCs about KLD operations.
5392          */
5393         PMC_EPOCH_ENTER();
5394         CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
5395                 if (po->po_flags & PMC_PO_OWNS_LOGFILE)
5396                         pmclog_process_map_in(po, (pid_t) -1,
5397                             (uintfptr_t) lf->address, lf->filename);
5398         PMC_EPOCH_EXIT();
5399
5400         /*
5401          * TODO: Notify owners of (all) process-sampling PMCs too.
5402          */
5403 }
5404
5405 static void
5406 pmc_kld_unload(void *arg __unused, const char *filename __unused,
5407     caddr_t address, size_t size)
5408 {
5409         struct pmc_owner *po;
5410
5411         PMC_EPOCH_ENTER();
5412         CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
5413                 if (po->po_flags & PMC_PO_OWNS_LOGFILE)
5414                         pmclog_process_map_out(po, (pid_t) -1,
5415                             (uintfptr_t) address, (uintfptr_t) address + size);
5416         PMC_EPOCH_EXIT();
5417
5418         /*
5419          * TODO: Notify owners of process-sampling PMCs.
5420          */
5421 }
5422
5423 /*
5424  * initialization
5425  */
5426 static const char *
5427 pmc_name_of_pmcclass(enum pmc_class class)
5428 {
5429
5430         switch (class) {
5431 #undef  __PMC_CLASS
5432 #define __PMC_CLASS(S,V,D)                                              \
5433         case PMC_CLASS_##S:                                             \
5434                 return #S;
5435         __PMC_CLASSES();
5436         default:
5437                 return ("<unknown>");
5438         }
5439 }
5440
5441 /*
5442  * Base class initializer: allocate structure and set default classes.
5443  */
5444 struct pmc_mdep *
5445 pmc_mdep_alloc(int nclasses)
5446 {
5447         struct pmc_mdep *md;
5448         int     n;
5449
5450         /* SOFT + md classes */
5451         n = 1 + nclasses;
5452         md = malloc(sizeof(struct pmc_mdep) + n *
5453             sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO);
5454         md->pmd_nclass = n;
5455
5456         /* Add base class. */
5457         pmc_soft_initialize(md);
5458         return md;
5459 }
5460
5461 void
5462 pmc_mdep_free(struct pmc_mdep *md)
5463 {
5464         pmc_soft_finalize(md);
5465         free(md, M_PMC);
5466 }
5467
5468 static int
5469 generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp)
5470 {
5471         (void) pc; (void) pp;
5472
5473         return (0);
5474 }
5475
5476 static int
5477 generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp)
5478 {
5479         (void) pc; (void) pp;
5480
5481         return (0);
5482 }
5483
5484 static struct pmc_mdep *
5485 pmc_generic_cpu_initialize(void)
5486 {
5487         struct pmc_mdep *md;
5488
5489         md = pmc_mdep_alloc(0);
5490
5491         md->pmd_cputype    = PMC_CPU_GENERIC;
5492
5493         md->pmd_pcpu_init  = NULL;
5494         md->pmd_pcpu_fini  = NULL;
5495         md->pmd_switch_in  = generic_switch_in;
5496         md->pmd_switch_out = generic_switch_out;
5497
5498         return (md);
5499 }
5500
5501 static void
5502 pmc_generic_cpu_finalize(struct pmc_mdep *md)
5503 {
5504         (void) md;
5505 }
5506
5507
5508 static int
5509 pmc_initialize(void)
5510 {
5511         int c, cpu, error, n, ri;
5512         unsigned int maxcpu, domain;
5513         struct pcpu *pc;
5514         struct pmc_binding pb;
5515         struct pmc_sample *ps;
5516         struct pmc_classdep *pcd;
5517         struct pmc_samplebuffer *sb;
5518
5519         md = NULL;
5520         error = 0;
5521
5522         pmc_stats.pm_intr_ignored = counter_u64_alloc(M_WAITOK);
5523         pmc_stats.pm_intr_processed = counter_u64_alloc(M_WAITOK);
5524         pmc_stats.pm_intr_bufferfull = counter_u64_alloc(M_WAITOK);
5525         pmc_stats.pm_syscalls = counter_u64_alloc(M_WAITOK);
5526         pmc_stats.pm_syscall_errors = counter_u64_alloc(M_WAITOK);
5527         pmc_stats.pm_buffer_requests = counter_u64_alloc(M_WAITOK);
5528         pmc_stats.pm_buffer_requests_failed = counter_u64_alloc(M_WAITOK);
5529         pmc_stats.pm_log_sweeps = counter_u64_alloc(M_WAITOK);
5530         pmc_stats.pm_merges = counter_u64_alloc(M_WAITOK);
5531         pmc_stats.pm_overwrites = counter_u64_alloc(M_WAITOK);
5532
5533 #ifdef  HWPMC_DEBUG
5534         /* parse debug flags first */
5535         if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags",
5536                 pmc_debugstr, sizeof(pmc_debugstr)))
5537                 pmc_debugflags_parse(pmc_debugstr,
5538                     pmc_debugstr+strlen(pmc_debugstr));
5539 #endif
5540
5541         PMCDBG1(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION);
5542
5543         /* check kernel version */
5544         if (pmc_kernel_version != PMC_VERSION) {
5545                 if (pmc_kernel_version == 0)
5546                         printf("hwpmc: this kernel has not been compiled with "
5547                             "'options HWPMC_HOOKS'.\n");
5548                 else
5549                         printf("hwpmc: kernel version (0x%x) does not match "
5550                             "module version (0x%x).\n", pmc_kernel_version,
5551                             PMC_VERSION);
5552                 return EPROGMISMATCH;
5553         }
5554
5555         /*
5556          * check sysctl parameters
5557          */
5558
5559         if (pmc_hashsize <= 0) {
5560                 (void) printf("hwpmc: tunable \"hashsize\"=%d must be "
5561                     "greater than zero.\n", pmc_hashsize);
5562                 pmc_hashsize = PMC_HASH_SIZE;
5563         }
5564
5565         if (pmc_nsamples <= 0 || pmc_nsamples > 65535) {
5566                 (void) printf("hwpmc: tunable \"nsamples\"=%d out of "
5567                     "range.\n", pmc_nsamples);
5568                 pmc_nsamples = PMC_NSAMPLES;
5569         }
5570         pmc_sample_mask = pmc_nsamples-1;
5571
5572         if (pmc_callchaindepth <= 0 ||
5573             pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) {
5574                 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of "
5575                     "range - using %d.\n", pmc_callchaindepth,
5576                     PMC_CALLCHAIN_DEPTH_MAX);
5577                 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH_MAX;
5578         }
5579
5580         md = pmc_md_initialize();
5581         if (md == NULL) {
5582                 /* Default to generic CPU. */
5583                 md = pmc_generic_cpu_initialize();
5584                 if (md == NULL)
5585                         return (ENOSYS);
5586         }
5587
5588         KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1,
5589             ("[pmc,%d] no classes or pmcs", __LINE__));
5590
5591         /* Compute the map from row-indices to classdep pointers. */
5592         pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) *
5593             md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO);
5594
5595         for (n = 0; n < md->pmd_npmc; n++)
5596                 pmc_rowindex_to_classdep[n] = NULL;
5597         for (ri = c = 0; c < md->pmd_nclass; c++) {
5598                 pcd = &md->pmd_classdep[c];
5599                 for (n = 0; n < pcd->pcd_num; n++, ri++)
5600                         pmc_rowindex_to_classdep[ri] = pcd;
5601         }
5602
5603         KASSERT(ri == md->pmd_npmc,
5604             ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__,
5605             ri, md->pmd_npmc));
5606
5607         maxcpu = pmc_cpu_max();
5608
5609         /* allocate space for the per-cpu array */
5610         pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC,
5611             M_WAITOK|M_ZERO);
5612
5613         /* per-cpu 'saved values' for managing process-mode PMCs */
5614         pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc,
5615             M_PMC, M_WAITOK);
5616
5617         /* Perform CPU-dependent initialization. */
5618         pmc_save_cpu_binding(&pb);
5619         error = 0;
5620         for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) {
5621                 if (!pmc_cpu_is_active(cpu))
5622                         continue;
5623                 pmc_select_cpu(cpu);
5624                 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) +
5625                     md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC,
5626                     M_WAITOK|M_ZERO);
5627                 if (md->pmd_pcpu_init)
5628                         error = md->pmd_pcpu_init(md, cpu);
5629                 for (n = 0; error == 0 && n < md->pmd_nclass; n++)
5630                         error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu);
5631         }
5632         pmc_restore_cpu_binding(&pb);
5633
5634         if (error)
5635                 return (error);
5636
5637         /* allocate space for the sample array */
5638         for (cpu = 0; cpu < maxcpu; cpu++) {
5639                 if (!pmc_cpu_is_active(cpu))
5640                         continue;
5641                 pc = pcpu_find(cpu);
5642                 domain = pc->pc_domain;
5643                 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) +
5644                     pmc_nsamples * sizeof(struct pmc_sample), M_PMC,
5645                     DOMAINSET_PREF(domain), M_WAITOK | M_ZERO);
5646
5647                 KASSERT(pmc_pcpu[cpu] != NULL,
5648                     ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu));
5649
5650                 sb->ps_callchains = malloc_domainset(pmc_callchaindepth *
5651                     pmc_nsamples * sizeof(uintptr_t), M_PMC,
5652                     DOMAINSET_PREF(domain), M_WAITOK | M_ZERO);
5653
5654                 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++)
5655                         ps->ps_pc = sb->ps_callchains +
5656                             (n * pmc_callchaindepth);
5657
5658                 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb;
5659
5660                 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) +
5661                     pmc_nsamples * sizeof(struct pmc_sample), M_PMC,
5662                     DOMAINSET_PREF(domain), M_WAITOK | M_ZERO);
5663
5664                 sb->ps_callchains = malloc_domainset(pmc_callchaindepth *
5665                     pmc_nsamples * sizeof(uintptr_t), M_PMC,
5666                     DOMAINSET_PREF(domain), M_WAITOK | M_ZERO);
5667                 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++)
5668                         ps->ps_pc = sb->ps_callchains +
5669                             (n * pmc_callchaindepth);
5670
5671                 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb;
5672
5673                 sb = malloc_domainset(sizeof(struct pmc_samplebuffer) +
5674                     pmc_nsamples * sizeof(struct pmc_sample), M_PMC,
5675                     DOMAINSET_PREF(domain), M_WAITOK | M_ZERO);
5676                 sb->ps_callchains = malloc_domainset(pmc_callchaindepth *
5677                     pmc_nsamples * sizeof(uintptr_t), M_PMC,
5678                     DOMAINSET_PREF(domain), M_WAITOK | M_ZERO);
5679                 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++)
5680                         ps->ps_pc = sb->ps_callchains + n * pmc_callchaindepth;
5681
5682                 pmc_pcpu[cpu]->pc_sb[PMC_UR] = sb;
5683         }
5684
5685         /* allocate space for the row disposition array */
5686         pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc,
5687             M_PMC, M_WAITOK|M_ZERO);
5688
5689         /* mark all PMCs as available */
5690         for (n = 0; n < (int) md->pmd_npmc; n++)
5691                 PMC_MARK_ROW_FREE(n);
5692
5693         /* allocate thread hash tables */
5694         pmc_ownerhash = hashinit(pmc_hashsize, M_PMC,
5695             &pmc_ownerhashmask);
5696
5697         pmc_processhash = hashinit(pmc_hashsize, M_PMC,
5698             &pmc_processhashmask);
5699         mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf",
5700             MTX_SPIN);
5701
5702         CK_LIST_INIT(&pmc_ss_owners);
5703         pmc_ss_count = 0;
5704
5705         /* allocate a pool of spin mutexes */
5706         pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size,
5707             MTX_SPIN);
5708
5709         PMCDBG4(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx "
5710             "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask,
5711             pmc_processhash, pmc_processhashmask);
5712
5713         /* Initialize a spin mutex for the thread free list. */
5714         mtx_init(&pmc_threadfreelist_mtx, "pmc-threadfreelist", "pmc-leaf",
5715             MTX_SPIN);
5716
5717         /*
5718          * Initialize the callout to monitor the thread free list.
5719          * This callout will also handle the initial population of the list.
5720          */
5721         taskqgroup_config_gtask_init(NULL, &free_gtask, pmc_thread_descriptor_pool_free_task, "thread descriptor pool free task");
5722
5723         /* register process {exit,fork,exec} handlers */
5724         pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit,
5725             pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY);
5726         pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork,
5727             pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY);
5728
5729         /* register kld event handlers */
5730         pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load,
5731             NULL, EVENTHANDLER_PRI_ANY);
5732         pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload,
5733             NULL, EVENTHANDLER_PRI_ANY);
5734
5735         /* initialize logging */
5736         pmclog_initialize();
5737
5738         /* set hook functions */
5739         pmc_intr = md->pmd_intr;
5740         wmb();
5741         pmc_hook = pmc_hook_handler;
5742
5743         if (error == 0) {
5744                 printf(PMC_MODULE_NAME ":");
5745                 for (n = 0; n < (int) md->pmd_nclass; n++) {
5746                         pcd = &md->pmd_classdep[n];
5747                         printf(" %s/%d/%d/0x%b",
5748                             pmc_name_of_pmcclass(pcd->pcd_class),
5749                             pcd->pcd_num,
5750                             pcd->pcd_width,
5751                             pcd->pcd_caps,
5752                             "\20"
5753                             "\1INT\2USR\3SYS\4EDG\5THR"
5754                             "\6REA\7WRI\10INV\11QUA\12PRC"
5755                             "\13TAG\14CSC");
5756                 }
5757                 printf("\n");
5758         }
5759
5760         return (error);
5761 }
5762
5763 /* prepare to be unloaded */
5764 static void
5765 pmc_cleanup(void)
5766 {
5767         int c, cpu;
5768         unsigned int maxcpu;
5769         struct pmc_ownerhash *ph;
5770         struct pmc_owner *po, *tmp;
5771         struct pmc_binding pb;
5772 #ifdef  HWPMC_DEBUG
5773         struct pmc_processhash *prh;
5774 #endif
5775
5776         PMCDBG0(MOD,INI,0, "cleanup");
5777
5778         /* switch off sampling */
5779         CPU_FOREACH(cpu)
5780                 DPCPU_ID_SET(cpu, pmc_sampled, 0);
5781         pmc_intr = NULL;
5782
5783         sx_xlock(&pmc_sx);
5784         if (pmc_hook == NULL) { /* being unloaded already */
5785                 sx_xunlock(&pmc_sx);
5786                 return;
5787         }
5788
5789         pmc_hook = NULL; /* prevent new threads from entering module */
5790
5791         /* deregister event handlers */
5792         EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag);
5793         EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag);
5794         EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag);
5795         EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag);
5796
5797         /* send SIGBUS to all owner threads, free up allocations */
5798         if (pmc_ownerhash)
5799                 for (ph = pmc_ownerhash;
5800                      ph <= &pmc_ownerhash[pmc_ownerhashmask];
5801                      ph++) {
5802                         LIST_FOREACH_SAFE(po, ph, po_next, tmp) {
5803                                 pmc_remove_owner(po);
5804
5805                                 /* send SIGBUS to owner processes */
5806                                 PMCDBG3(MOD,INI,2, "cleanup signal proc=%p "
5807                                     "(%d, %s)", po->po_owner,
5808                                     po->po_owner->p_pid,
5809                                     po->po_owner->p_comm);
5810
5811                                 PROC_LOCK(po->po_owner);
5812                                 kern_psignal(po->po_owner, SIGBUS);
5813                                 PROC_UNLOCK(po->po_owner);
5814
5815                                 pmc_destroy_owner_descriptor(po);
5816                         }
5817                 }
5818
5819         /* reclaim allocated data structures */
5820         mtx_destroy(&pmc_threadfreelist_mtx);
5821         pmc_thread_descriptor_pool_drain();
5822
5823         if (pmc_mtxpool)
5824                 mtx_pool_destroy(&pmc_mtxpool);
5825
5826         mtx_destroy(&pmc_processhash_mtx);
5827         taskqgroup_config_gtask_deinit(&free_gtask);
5828         if (pmc_processhash) {
5829 #ifdef  HWPMC_DEBUG
5830                 struct pmc_process *pp;
5831
5832                 PMCDBG0(MOD,INI,3, "destroy process hash");
5833                 for (prh = pmc_processhash;
5834                      prh <= &pmc_processhash[pmc_processhashmask];
5835                      prh++)
5836                         LIST_FOREACH(pp, prh, pp_next)
5837                             PMCDBG1(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid);
5838 #endif
5839
5840                 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask);
5841                 pmc_processhash = NULL;
5842         }
5843
5844         if (pmc_ownerhash) {
5845                 PMCDBG0(MOD,INI,3, "destroy owner hash");
5846                 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask);
5847                 pmc_ownerhash = NULL;
5848         }
5849
5850         KASSERT(CK_LIST_EMPTY(&pmc_ss_owners),
5851             ("[pmc,%d] Global SS owner list not empty", __LINE__));
5852         KASSERT(pmc_ss_count == 0,
5853             ("[pmc,%d] Global SS count not empty", __LINE__));
5854
5855         /* do processor and pmc-class dependent cleanup */
5856         maxcpu = pmc_cpu_max();
5857
5858         PMCDBG0(MOD,INI,3, "md cleanup");
5859         if (md) {
5860                 pmc_save_cpu_binding(&pb);
5861                 for (cpu = 0; cpu < maxcpu; cpu++) {
5862                         PMCDBG2(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p",
5863                             cpu, pmc_pcpu[cpu]);
5864                         if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL)
5865                                 continue;
5866                         pmc_select_cpu(cpu);
5867                         for (c = 0; c < md->pmd_nclass; c++)
5868                                 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu);
5869                         if (md->pmd_pcpu_fini)
5870                                 md->pmd_pcpu_fini(md, cpu);
5871                 }
5872
5873                 if (md->pmd_cputype == PMC_CPU_GENERIC)
5874                         pmc_generic_cpu_finalize(md);
5875                 else
5876                         pmc_md_finalize(md);
5877
5878                 pmc_mdep_free(md);
5879                 md = NULL;
5880                 pmc_restore_cpu_binding(&pb);
5881         }
5882
5883         /* Free per-cpu descriptors. */
5884         for (cpu = 0; cpu < maxcpu; cpu++) {
5885                 if (!pmc_cpu_is_active(cpu))
5886                         continue;
5887                 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL,
5888                     ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__,
5889                         cpu));
5890                 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL,
5891                     ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__,
5892                         cpu));
5893                 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_UR] != NULL,
5894                     ("[pmc,%d] Null userret cpu sample buffer cpu=%d", __LINE__,
5895                         cpu));
5896                 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC);
5897                 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC);
5898                 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC);
5899                 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC);
5900                 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_UR]->ps_callchains, M_PMC);
5901                 free_domain(pmc_pcpu[cpu]->pc_sb[PMC_UR], M_PMC);
5902                 free_domain(pmc_pcpu[cpu], M_PMC);
5903         }
5904
5905         free(pmc_pcpu, M_PMC);
5906         pmc_pcpu = NULL;
5907
5908         free(pmc_pcpu_saved, M_PMC);
5909         pmc_pcpu_saved = NULL;
5910
5911         if (pmc_pmcdisp) {
5912                 free(pmc_pmcdisp, M_PMC);
5913                 pmc_pmcdisp = NULL;
5914         }
5915
5916         if (pmc_rowindex_to_classdep) {
5917                 free(pmc_rowindex_to_classdep, M_PMC);
5918                 pmc_rowindex_to_classdep = NULL;
5919         }
5920
5921         pmclog_shutdown();
5922         counter_u64_free(pmc_stats.pm_intr_ignored);
5923         counter_u64_free(pmc_stats.pm_intr_processed);
5924         counter_u64_free(pmc_stats.pm_intr_bufferfull);
5925         counter_u64_free(pmc_stats.pm_syscalls);
5926         counter_u64_free(pmc_stats.pm_syscall_errors);
5927         counter_u64_free(pmc_stats.pm_buffer_requests);
5928         counter_u64_free(pmc_stats.pm_buffer_requests_failed);
5929         counter_u64_free(pmc_stats.pm_log_sweeps);
5930         counter_u64_free(pmc_stats.pm_merges);
5931         counter_u64_free(pmc_stats.pm_overwrites);
5932         sx_xunlock(&pmc_sx);    /* we are done */
5933 }
5934
5935 /*
5936  * The function called at load/unload.
5937  */
5938
5939 static int
5940 load (struct module *module __unused, int cmd, void *arg __unused)
5941 {
5942         int error;
5943
5944         error = 0;
5945
5946         switch (cmd) {
5947         case MOD_LOAD :
5948                 /* initialize the subsystem */
5949                 error = pmc_initialize();
5950                 if (error != 0)
5951                         break;
5952                 PMCDBG2(MOD,INI,1, "syscall=%d maxcpu=%d",
5953                     pmc_syscall_num, pmc_cpu_max());
5954                 break;
5955
5956
5957         case MOD_UNLOAD :
5958         case MOD_SHUTDOWN:
5959                 pmc_cleanup();
5960                 PMCDBG0(MOD,INI,1, "unloaded");
5961                 break;
5962
5963         default :
5964                 error = EINVAL; /* XXX should panic(9) */
5965                 break;
5966         }
5967
5968         return error;
5969 }