sys/dev/hwpmc/hwpmc_mod.c

   1 /*-
   2  * Copyright (c) 2003-2008 Joseph Koshy
   3  * Copyright (c) 2007 The FreeBSD Foundation
   4  * All rights reserved.
   5  *
   6  * Portions of this software were developed by A. Joseph Koshy under
   7  * sponsorship from the FreeBSD Foundation and Google, Inc.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  *
  30  */
  31
  32 #include <sys/cdefs.h>
  33 __FBSDID("$FreeBSD$");
  34
  35 #include <sys/param.h>
  36 #include <sys/eventhandler.h>
  37 #include <sys/jail.h>
  38 #include <sys/kernel.h>
  39 #include <sys/kthread.h>
  40 #include <sys/limits.h>
  41 #include <sys/lock.h>
  42 #include <sys/malloc.h>
  43 #include <sys/module.h>
  44 #include <sys/mount.h>
  45 #include <sys/mutex.h>
  46 #include <sys/pmc.h>
  47 #include <sys/pmckern.h>
  48 #include <sys/pmclog.h>
  49 #include <sys/priv.h>
  50 #include <sys/proc.h>
  51 #include <sys/queue.h>
  52 #include <sys/resourcevar.h>
  53 #include <sys/rwlock.h>
  54 #include <sys/sched.h>
  55 #include <sys/signalvar.h>
  56 #include <sys/smp.h>
  57 #include <sys/sx.h>
  58 #include <sys/sysctl.h>
  59 #include <sys/sysent.h>
  60 #include <sys/systm.h>
  61 #include <sys/vnode.h>
  62
  63 #include <sys/linker.h>         /* needs to be after <sys/malloc.h> */
  64
  65 #include <machine/atomic.h>
  66 #include <machine/md_var.h>
  67
  68 #include <vm/vm.h>
  69 #include <vm/vm_extern.h>
  70 #include <vm/pmap.h>
  71 #include <vm/vm_map.h>
  72 #include <vm/vm_object.h>
  73
  74 #include "hwpmc_soft.h"
  75
  76 /*
  77  * Types
  78  */
  79
  80 enum pmc_flags {
  81         PMC_FLAG_NONE     = 0x00, /* do nothing */
  82         PMC_FLAG_REMOVE   = 0x01, /* atomically remove entry from hash */
  83         PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */
  84 };
  85
  86 /*
  87  * The offset in sysent where the syscall is allocated.
  88  */
  89
  90 static int pmc_syscall_num = NO_SYSCALL;
  91 struct pmc_cpu          **pmc_pcpu;      /* per-cpu state */
  92 pmc_value_t             *pmc_pcpu_saved; /* saved PMC values: CSW handling */
  93
  94 #define PMC_PCPU_SAVED(C,R)     pmc_pcpu_saved[(R) + md->pmd_npmc*(C)]
  95
  96 struct mtx_pool         *pmc_mtxpool;
  97 static int              *pmc_pmcdisp;    /* PMC row dispositions */
  98
  99 #define PMC_ROW_DISP_IS_FREE(R)         (pmc_pmcdisp[(R)] == 0)
 100 #define PMC_ROW_DISP_IS_THREAD(R)       (pmc_pmcdisp[(R)] > 0)
 101 #define PMC_ROW_DISP_IS_STANDALONE(R)   (pmc_pmcdisp[(R)] < 0)
 102
 103 #define PMC_MARK_ROW_FREE(R) do {                                         \
 104         pmc_pmcdisp[(R)] = 0;                                             \
 105 } while (0)
 106
 107 #define PMC_MARK_ROW_STANDALONE(R) do {                                   \
 108         KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \
 109                     __LINE__));                                           \
 110         atomic_add_int(&pmc_pmcdisp[(R)], -1);                            \
 111         KASSERT(pmc_pmcdisp[(R)] >= (-pmc_cpu_max_active()),              \
 112                 ("[pmc,%d] row disposition error", __LINE__));            \
 113 } while (0)
 114
 115 #define PMC_UNMARK_ROW_STANDALONE(R) do {                                 \
 116         atomic_add_int(&pmc_pmcdisp[(R)], 1);                             \
 117         KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \
 118                     __LINE__));                                           \
 119 } while (0)
 120
 121 #define PMC_MARK_ROW_THREAD(R) do {                                       \
 122         KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \
 123                     __LINE__));                                           \
 124         atomic_add_int(&pmc_pmcdisp[(R)], 1);                             \
 125 } while (0)
 126
 127 #define PMC_UNMARK_ROW_THREAD(R) do {                                     \
 128         atomic_add_int(&pmc_pmcdisp[(R)], -1);                            \
 129         KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \
 130                     __LINE__));                                           \
 131 } while (0)
 132
 133
 134 /* various event handlers */
 135 static eventhandler_tag pmc_exit_tag, pmc_fork_tag, pmc_kld_load_tag,
 136     pmc_kld_unload_tag;
 137
 138 /* Module statistics */
 139 struct pmc_op_getdriverstats pmc_stats;
 140
 141 /* Machine/processor dependent operations */
 142 static struct pmc_mdep  *md;
 143
 144 /*
 145  * Hash tables mapping owner processes and target threads to PMCs.
 146  */
 147
 148 struct mtx pmc_processhash_mtx;         /* spin mutex */
 149 static u_long pmc_processhashmask;
 150 static LIST_HEAD(pmc_processhash, pmc_process)  *pmc_processhash;
 151
 152 /*
 153  * Hash table of PMC owner descriptors.  This table is protected by
 154  * the shared PMC "sx" lock.
 155  */
 156
 157 static u_long pmc_ownerhashmask;
 158 static LIST_HEAD(pmc_ownerhash, pmc_owner)      *pmc_ownerhash;
 159
 160 /*
 161  * List of PMC owners with system-wide sampling PMCs.
 162  */
 163
 164 static LIST_HEAD(, pmc_owner)                   pmc_ss_owners;
 165
 166
 167 /*
 168  * A map of row indices to classdep structures.
 169  */
 170 static struct pmc_classdep **pmc_rowindex_to_classdep;
 171
 172 /*
 173  * Prototypes
 174  */
 175
 176 #ifdef  HWPMC_DEBUG
 177 static int      pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS);
 178 static int      pmc_debugflags_parse(char *newstr, char *fence);
 179 #endif
 180
 181 static int      load(struct module *module, int cmd, void *arg);
 182 static int      pmc_attach_process(struct proc *p, struct pmc *pm);
 183 static struct pmc *pmc_allocate_pmc_descriptor(void);
 184 static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p);
 185 static int      pmc_attach_one_process(struct proc *p, struct pmc *pm);
 186 static int      pmc_can_allocate_rowindex(struct proc *p, unsigned int ri,
 187     int cpu);
 188 static int      pmc_can_attach(struct pmc *pm, struct proc *p);
 189 static void     pmc_capture_user_callchain(int cpu, int soft, struct trapframe *tf);
 190 static void     pmc_cleanup(void);
 191 static int      pmc_detach_process(struct proc *p, struct pmc *pm);
 192 static int      pmc_detach_one_process(struct proc *p, struct pmc *pm,
 193     int flags);
 194 static void     pmc_destroy_owner_descriptor(struct pmc_owner *po);
 195 static void     pmc_destroy_pmc_descriptor(struct pmc *pm);
 196 static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p);
 197 static int      pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm);
 198 static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po,
 199     pmc_id_t pmc);
 200 static struct pmc_process *pmc_find_process_descriptor(struct proc *p,
 201     uint32_t mode);
 202 static void     pmc_force_context_switch(void);
 203 static void     pmc_link_target_process(struct pmc *pm,
 204     struct pmc_process *pp);
 205 static void     pmc_log_all_process_mappings(struct pmc_owner *po);
 206 static void     pmc_log_kernel_mappings(struct pmc *pm);
 207 static void     pmc_log_process_mappings(struct pmc_owner *po, struct proc *p);
 208 static void     pmc_maybe_remove_owner(struct pmc_owner *po);
 209 static void     pmc_process_csw_in(struct thread *td);
 210 static void     pmc_process_csw_out(struct thread *td);
 211 static void     pmc_process_exit(void *arg, struct proc *p);
 212 static void     pmc_process_fork(void *arg, struct proc *p1,
 213     struct proc *p2, int n);
 214 static void     pmc_process_samples(int cpu, int soft);
 215 static void     pmc_release_pmc_descriptor(struct pmc *pmc);
 216 static void     pmc_remove_owner(struct pmc_owner *po);
 217 static void     pmc_remove_process_descriptor(struct pmc_process *pp);
 218 static void     pmc_restore_cpu_binding(struct pmc_binding *pb);
 219 static void     pmc_save_cpu_binding(struct pmc_binding *pb);
 220 static void     pmc_select_cpu(int cpu);
 221 static int      pmc_start(struct pmc *pm);
 222 static int      pmc_stop(struct pmc *pm);
 223 static int      pmc_syscall_handler(struct thread *td, void *syscall_args);
 224 static void     pmc_unlink_target_process(struct pmc *pmc,
 225     struct pmc_process *pp);
 226 static int generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp);
 227 static int generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp);
 228 static struct pmc_mdep *pmc_generic_cpu_initialize(void);
 229 static void pmc_generic_cpu_finalize(struct pmc_mdep *md);
 230
 231 /*
 232  * Kernel tunables and sysctl(8) interface.
 233  */
 234
 235 SYSCTL_DECL(_kern_hwpmc);
 236
 237 static int pmc_callchaindepth = PMC_CALLCHAIN_DEPTH;
 238 SYSCTL_INT(_kern_hwpmc, OID_AUTO, callchaindepth, CTLFLAG_RDTUN,
 239     &pmc_callchaindepth, 0, "depth of call chain records");
 240
 241 #ifdef  HWPMC_DEBUG
 242 struct pmc_debugflags pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS;
 243 char    pmc_debugstr[PMC_DEBUG_STRSIZE];
 244 TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr,
 245     sizeof(pmc_debugstr));
 246 SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags,
 247     CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NOFETCH,
 248     0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags");
 249 #endif
 250
 251 /*
 252  * kern.hwpmc.hashrows -- determines the number of rows in the
 253  * of the hash table used to look up threads
 254  */
 255
 256 static int pmc_hashsize = PMC_HASH_SIZE;
 257 SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_RDTUN,
 258     &pmc_hashsize, 0, "rows in hash tables");
 259
 260 /*
 261  * kern.hwpmc.nsamples --- number of PC samples/callchain stacks per CPU
 262  */
 263
 264 static int pmc_nsamples = PMC_NSAMPLES;
 265 SYSCTL_INT(_kern_hwpmc, OID_AUTO, nsamples, CTLFLAG_RDTUN,
 266     &pmc_nsamples, 0, "number of PC samples per CPU");
 267
 268
 269 /*
 270  * kern.hwpmc.mtxpoolsize -- number of mutexes in the mutex pool.
 271  */
 272
 273 static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE;
 274 SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_RDTUN,
 275     &pmc_mtxpool_size, 0, "size of spin mutex pool");
 276
 277
 278 /*
 279  * security.bsd.unprivileged_syspmcs -- allow non-root processes to
 280  * allocate system-wide PMCs.
 281  *
 282  * Allowing unprivileged processes to allocate system PMCs is convenient
 283  * if system-wide measurements need to be taken concurrently with other
 284  * per-process measurements.  This feature is turned off by default.
 285  */
 286
 287 static int pmc_unprivileged_syspmcs = 0;
 288 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RWTUN,
 289     &pmc_unprivileged_syspmcs, 0,
 290     "allow unprivileged process to allocate system PMCs");
 291
 292 /*
 293  * Hash function.  Discard the lower 2 bits of the pointer since
 294  * these are always zero for our uses.  The hash multiplier is
 295  * round((2^LONG_BIT) * ((sqrt(5)-1)/2)).
 296  */
 297
 298 #if     LONG_BIT == 64
 299 #define _PMC_HM         11400714819323198486u
 300 #elif   LONG_BIT == 32
 301 #define _PMC_HM         2654435769u
 302 #else
 303 #error  Must know the size of 'long' to compile
 304 #endif
 305
 306 #define PMC_HASH_PTR(P,M)       ((((unsigned long) (P) >> 2) * _PMC_HM) & (M))
 307
 308 /*
 309  * Syscall structures
 310  */
 311
 312 /* The `sysent' for the new syscall */
 313 static struct sysent pmc_sysent = {
 314         .sy_narg =      2,
 315         .sy_call =      pmc_syscall_handler,
 316 };
 317
 318 static struct syscall_module_data pmc_syscall_mod = {
 319         .chainevh =     load,
 320         .chainarg =     NULL,
 321         .offset =       &pmc_syscall_num,
 322         .new_sysent =   &pmc_sysent,
 323         .old_sysent =   { .sy_narg = 0, .sy_call = NULL },
 324         .flags =        SY_THR_STATIC_KLD,
 325 };
 326
 327 static moduledata_t pmc_mod = {
 328         .name =         PMC_MODULE_NAME,
 329         .evhand =       syscall_module_handler,
 330         .priv =         &pmc_syscall_mod,
 331 };
 332
 333 #ifdef EARLY_AP_STARTUP
 334 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SYSCALLS, SI_ORDER_ANY);
 335 #else
 336 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY);
 337 #endif
 338 MODULE_VERSION(pmc, PMC_VERSION);
 339
 340 #ifdef  HWPMC_DEBUG
 341 enum pmc_dbgparse_state {
 342         PMCDS_WS,               /* in whitespace */
 343         PMCDS_MAJOR,            /* seen a major keyword */
 344         PMCDS_MINOR
 345 };
 346
 347 static int
 348 pmc_debugflags_parse(char *newstr, char *fence)
 349 {
 350         char c, *p, *q;
 351         struct pmc_debugflags *tmpflags;
 352         int error, found, *newbits, tmp;
 353         size_t kwlen;
 354
 355         tmpflags = malloc(sizeof(*tmpflags), M_PMC, M_WAITOK|M_ZERO);
 356
 357         p = newstr;
 358         error = 0;
 359
 360         for (; p < fence && (c = *p); p++) {
 361
 362                 /* skip white space */
 363                 if (c == ' ' || c == '\t')
 364                         continue;
 365
 366                 /* look for a keyword followed by "=" */
 367                 for (q = p; p < fence && (c = *p) && c != '='; p++)
 368                         ;
 369                 if (c != '=') {
 370                         error = EINVAL;
 371                         goto done;
 372                 }
 373
 374                 kwlen = p - q;
 375                 newbits = NULL;
 376
 377                 /* lookup flag group name */
 378 #define DBG_SET_FLAG_MAJ(S,F)                                           \
 379                 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0)  \
 380                         newbits = &tmpflags->pdb_ ## F;
 381
 382                 DBG_SET_FLAG_MAJ("cpu",         CPU);
 383                 DBG_SET_FLAG_MAJ("csw",         CSW);
 384                 DBG_SET_FLAG_MAJ("logging",     LOG);
 385                 DBG_SET_FLAG_MAJ("module",      MOD);
 386                 DBG_SET_FLAG_MAJ("md",          MDP);
 387                 DBG_SET_FLAG_MAJ("owner",       OWN);
 388                 DBG_SET_FLAG_MAJ("pmc",         PMC);
 389                 DBG_SET_FLAG_MAJ("process",     PRC);
 390                 DBG_SET_FLAG_MAJ("sampling",    SAM);
 391
 392                 if (newbits == NULL) {
 393                         error = EINVAL;
 394                         goto done;
 395                 }
 396
 397                 p++;            /* skip the '=' */
 398
 399                 /* Now parse the individual flags */
 400                 tmp = 0;
 401         newflag:
 402                 for (q = p; p < fence && (c = *p); p++)
 403                         if (c == ' ' || c == '\t' || c == ',')
 404                                 break;
 405
 406                 /* p == fence or c == ws or c == "," or c == 0 */
 407
 408                 if ((kwlen = p - q) == 0) {
 409                         *newbits = tmp;
 410                         continue;
 411                 }
 412
 413                 found = 0;
 414 #define DBG_SET_FLAG_MIN(S,F)                                           \
 415                 if (kwlen == sizeof(S)-1 && strncmp(q, S, kwlen) == 0)  \
 416                         tmp |= found = (1 << PMC_DEBUG_MIN_ ## F)
 417
 418                 /* a '*' denotes all possible flags in the group */
 419                 if (kwlen == 1 && *q == '*')
 420                         tmp = found = ~0;
 421                 /* look for individual flag names */
 422                 DBG_SET_FLAG_MIN("allocaterow", ALR);
 423                 DBG_SET_FLAG_MIN("allocate",    ALL);
 424                 DBG_SET_FLAG_MIN("attach",      ATT);
 425                 DBG_SET_FLAG_MIN("bind",        BND);
 426                 DBG_SET_FLAG_MIN("config",      CFG);
 427                 DBG_SET_FLAG_MIN("exec",        EXC);
 428                 DBG_SET_FLAG_MIN("exit",        EXT);
 429                 DBG_SET_FLAG_MIN("find",        FND);
 430                 DBG_SET_FLAG_MIN("flush",       FLS);
 431                 DBG_SET_FLAG_MIN("fork",        FRK);
 432                 DBG_SET_FLAG_MIN("getbuf",      GTB);
 433                 DBG_SET_FLAG_MIN("hook",        PMH);
 434                 DBG_SET_FLAG_MIN("init",        INI);
 435                 DBG_SET_FLAG_MIN("intr",        INT);
 436                 DBG_SET_FLAG_MIN("linktarget",  TLK);
 437                 DBG_SET_FLAG_MIN("mayberemove", OMR);
 438                 DBG_SET_FLAG_MIN("ops",         OPS);
 439                 DBG_SET_FLAG_MIN("read",        REA);
 440                 DBG_SET_FLAG_MIN("register",    REG);
 441                 DBG_SET_FLAG_MIN("release",     REL);
 442                 DBG_SET_FLAG_MIN("remove",      ORM);
 443                 DBG_SET_FLAG_MIN("sample",      SAM);
 444                 DBG_SET_FLAG_MIN("scheduleio",  SIO);
 445                 DBG_SET_FLAG_MIN("select",      SEL);
 446                 DBG_SET_FLAG_MIN("signal",      SIG);
 447                 DBG_SET_FLAG_MIN("swi",         SWI);
 448                 DBG_SET_FLAG_MIN("swo",         SWO);
 449                 DBG_SET_FLAG_MIN("start",       STA);
 450                 DBG_SET_FLAG_MIN("stop",        STO);
 451                 DBG_SET_FLAG_MIN("syscall",     PMS);
 452                 DBG_SET_FLAG_MIN("unlinktarget", TUL);
 453                 DBG_SET_FLAG_MIN("write",       WRI);
 454                 if (found == 0) {
 455                         /* unrecognized flag name */
 456                         error = EINVAL;
 457                         goto done;
 458                 }
 459
 460                 if (c == 0 || c == ' ' || c == '\t') {  /* end of flag group */
 461                         *newbits = tmp;
 462                         continue;
 463                 }
 464
 465                 p++;
 466                 goto newflag;
 467         }
 468
 469         /* save the new flag set */
 470         bcopy(tmpflags, &pmc_debugflags, sizeof(pmc_debugflags));
 471
 472  done:
 473         free(tmpflags, M_PMC);
 474         return error;
 475 }
 476
 477 static int
 478 pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS)
 479 {
 480         char *fence, *newstr;
 481         int error;
 482         unsigned int n;
 483
 484         (void) arg1; (void) arg2; /* unused parameters */
 485
 486         n = sizeof(pmc_debugstr);
 487         newstr = malloc(n, M_PMC, M_WAITOK|M_ZERO);
 488         (void) strlcpy(newstr, pmc_debugstr, n);
 489
 490         error = sysctl_handle_string(oidp, newstr, n, req);
 491
 492         /* if there is a new string, parse and copy it */
 493         if (error == 0 && req->newptr != NULL) {
 494                 fence = newstr + (n < req->newlen ? n : req->newlen + 1);
 495                 if ((error = pmc_debugflags_parse(newstr, fence)) == 0)
 496                         (void) strlcpy(pmc_debugstr, newstr,
 497                             sizeof(pmc_debugstr));
 498         }
 499
 500         free(newstr, M_PMC);
 501
 502         return error;
 503 }
 504 #endif
 505
 506 /*
 507  * Map a row index to a classdep structure and return the adjusted row
 508  * index for the PMC class index.
 509  */
 510 static struct pmc_classdep *
 511 pmc_ri_to_classdep(struct pmc_mdep *md, int ri, int *adjri)
 512 {
 513         struct pmc_classdep *pcd;
 514
 515         (void) md;
 516
 517         KASSERT(ri >= 0 && ri < md->pmd_npmc,
 518             ("[pmc,%d] illegal row-index %d", __LINE__, ri));
 519
 520         pcd = pmc_rowindex_to_classdep[ri];
 521
 522         KASSERT(pcd != NULL,
 523             ("[pmc,%d] ri %d null pcd", __LINE__, ri));
 524
 525         *adjri = ri - pcd->pcd_ri;
 526
 527         KASSERT(*adjri >= 0 && *adjri < pcd->pcd_num,
 528             ("[pmc,%d] adjusted row-index %d", __LINE__, *adjri));
 529
 530         return (pcd);
 531 }
 532
 533 /*
 534  * Concurrency Control
 535  *
 536  * The driver manages the following data structures:
 537  *
 538  *   - target process descriptors, one per target process
 539  *   - owner process descriptors (and attached lists), one per owner process
 540  *   - lookup hash tables for owner and target processes
 541  *   - PMC descriptors (and attached lists)
 542  *   - per-cpu hardware state
 543  *   - the 'hook' variable through which the kernel calls into
 544  *     this module
 545  *   - the machine hardware state (managed by the MD layer)
 546  *
 547  * These data structures are accessed from:
 548  *
 549  * - thread context-switch code
 550  * - interrupt handlers (possibly on multiple cpus)
 551  * - kernel threads on multiple cpus running on behalf of user
 552  *   processes doing system calls
 553  * - this driver's private kernel threads
 554  *
 555  * = Locks and Locking strategy =
 556  *
 557  * The driver uses four locking strategies for its operation:
 558  *
 559  * - The global SX lock "pmc_sx" is used to protect internal
 560  *   data structures.
 561  *
 562  *   Calls into the module by syscall() start with this lock being
 563  *   held in exclusive mode.  Depending on the requested operation,
 564  *   the lock may be downgraded to 'shared' mode to allow more
 565  *   concurrent readers into the module.  Calls into the module from
 566  *   other parts of the kernel acquire the lock in shared mode.
 567  *
 568  *   This SX lock is held in exclusive mode for any operations that
 569  *   modify the linkages between the driver's internal data structures.
 570  *
 571  *   The 'pmc_hook' function pointer is also protected by this lock.
 572  *   It is only examined with the sx lock held in exclusive mode.  The
 573  *   kernel module is allowed to be unloaded only with the sx lock held
 574  *   in exclusive mode.  In normal syscall handling, after acquiring the
 575  *   pmc_sx lock we first check that 'pmc_hook' is non-null before
 576  *   proceeding.  This prevents races between the thread unloading the module
 577  *   and other threads seeking to use the module.
 578  *
 579  * - Lookups of target process structures and owner process structures
 580  *   cannot use the global "pmc_sx" SX lock because these lookups need
 581  *   to happen during context switches and in other critical sections
 582  *   where sleeping is not allowed.  We protect these lookup tables
 583  *   with their own private spin-mutexes, "pmc_processhash_mtx" and
 584  *   "pmc_ownerhash_mtx".
 585  *
 586  * - Interrupt handlers work in a lock free manner.  At interrupt
 587  *   time, handlers look at the PMC pointer (phw->phw_pmc) configured
 588  *   when the PMC was started.  If this pointer is NULL, the interrupt
 589  *   is ignored after updating driver statistics.  We ensure that this
 590  *   pointer is set (using an atomic operation if necessary) before the
 591  *   PMC hardware is started.  Conversely, this pointer is unset atomically
 592  *   only after the PMC hardware is stopped.
 593  *
 594  *   We ensure that everything needed for the operation of an
 595  *   interrupt handler is available without it needing to acquire any
 596  *   locks.  We also ensure that a PMC's software state is destroyed only
 597  *   after the PMC is taken off hardware (on all CPUs).
 598  *
 599  * - Context-switch handling with process-private PMCs needs more
 600  *   care.
 601  *
 602  *   A given process may be the target of multiple PMCs.  For example,
 603  *   PMCATTACH and PMCDETACH may be requested by a process on one CPU
 604  *   while the target process is running on another.  A PMC could also
 605  *   be getting released because its owner is exiting.  We tackle
 606  *   these situations in the following manner:
 607  *
 608  *   - each target process structure 'pmc_process' has an array
 609  *     of 'struct pmc *' pointers, one for each hardware PMC.
 610  *
 611  *   - At context switch IN time, each "target" PMC in RUNNING state
 612  *     gets started on hardware and a pointer to each PMC is copied into
 613  *     the per-cpu phw array.  The 'runcount' for the PMC is
 614  *     incremented.
 615  *
 616  *   - At context switch OUT time, all process-virtual PMCs are stopped
 617  *     on hardware.  The saved value is added to the PMCs value field
 618  *     only if the PMC is in a non-deleted state (the PMCs state could
 619  *     have changed during the current time slice).
 620  *
 621  *     Note that since in-between a switch IN on a processor and a switch
 622  *     OUT, the PMC could have been released on another CPU.  Therefore
 623  *     context switch OUT always looks at the hardware state to turn
 624  *     OFF PMCs and will update a PMC's saved value only if reachable
 625  *     from the target process record.
 626  *
 627  *   - OP PMCRELEASE could be called on a PMC at any time (the PMC could
 628  *     be attached to many processes at the time of the call and could
 629  *     be active on multiple CPUs).
 630  *
 631  *     We prevent further scheduling of the PMC by marking it as in
 632  *     state 'DELETED'.  If the runcount of the PMC is non-zero then
 633  *     this PMC is currently running on a CPU somewhere.  The thread
 634  *     doing the PMCRELEASE operation waits by repeatedly doing a
 635  *     pause() till the runcount comes to zero.
 636  *
 637  * The contents of a PMC descriptor (struct pmc) are protected using
 638  * a spin-mutex.  In order to save space, we use a mutex pool.
 639  *
 640  * In terms of lock types used by witness(4), we use:
 641  * - Type "pmc-sx", used by the global SX lock.
 642  * - Type "pmc-sleep", for sleep mutexes used by logger threads.
 643  * - Type "pmc-per-proc", for protecting PMC owner descriptors.
 644  * - Type "pmc-leaf", used for all other spin mutexes.
 645  */
 646
 647 /*
 648  * save the cpu binding of the current kthread
 649  */
 650
 651 static void
 652 pmc_save_cpu_binding(struct pmc_binding *pb)
 653 {
 654         PMCDBG0(CPU,BND,2, "save-cpu");
 655         thread_lock(curthread);
 656         pb->pb_bound = sched_is_bound(curthread);
 657         pb->pb_cpu   = curthread->td_oncpu;
 658         thread_unlock(curthread);
 659         PMCDBG1(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu);
 660 }
 661
 662 /*
 663  * restore the cpu binding of the current thread
 664  */
 665
 666 static void
 667 pmc_restore_cpu_binding(struct pmc_binding *pb)
 668 {
 669         PMCDBG2(CPU,BND,2, "restore-cpu curcpu=%d restore=%d",
 670             curthread->td_oncpu, pb->pb_cpu);
 671         thread_lock(curthread);
 672         if (pb->pb_bound)
 673                 sched_bind(curthread, pb->pb_cpu);
 674         else
 675                 sched_unbind(curthread);
 676         thread_unlock(curthread);
 677         PMCDBG0(CPU,BND,2, "restore-cpu done");
 678 }
 679
 680 /*
 681  * move execution over the specified cpu and bind it there.
 682  */
 683
 684 static void
 685 pmc_select_cpu(int cpu)
 686 {
 687         KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
 688             ("[pmc,%d] bad cpu number %d", __LINE__, cpu));
 689
 690         /* Never move to an inactive CPU. */
 691         KASSERT(pmc_cpu_is_active(cpu), ("[pmc,%d] selecting inactive "
 692             "CPU %d", __LINE__, cpu));
 693
 694         PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d", cpu);
 695         thread_lock(curthread);
 696         sched_bind(curthread, cpu);
 697         thread_unlock(curthread);
 698
 699         KASSERT(curthread->td_oncpu == cpu,
 700             ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__,
 701                 cpu, curthread->td_oncpu));
 702
 703         PMCDBG1(CPU,SEL,2, "select-cpu cpu=%d ok", cpu);
 704 }
 705
 706 /*
 707  * Force a context switch.
 708  *
 709  * We do this by pause'ing for 1 tick -- invoking mi_switch() is not
 710  * guaranteed to force a context switch.
 711  */
 712
 713 static void
 714 pmc_force_context_switch(void)
 715 {
 716
 717         pause("pmcctx", 1);
 718 }
 719
 720 /*
 721  * Get the file name for an executable.  This is a simple wrapper
 722  * around vn_fullpath(9).
 723  */
 724
 725 static void
 726 pmc_getfilename(struct vnode *v, char **fullpath, char **freepath)
 727 {
 728
 729         *fullpath = "unknown";
 730         *freepath = NULL;
 731         vn_fullpath(curthread, v, fullpath, freepath);
 732 }
 733
 734 /*
 735  * remove an process owning PMCs
 736  */
 737
 738 void
 739 pmc_remove_owner(struct pmc_owner *po)
 740 {
 741         struct pmc *pm, *tmp;
 742
 743         sx_assert(&pmc_sx, SX_XLOCKED);
 744
 745         PMCDBG1(OWN,ORM,1, "remove-owner po=%p", po);
 746
 747         /* Remove descriptor from the owner hash table */
 748         LIST_REMOVE(po, po_next);
 749
 750         /* release all owned PMC descriptors */
 751         LIST_FOREACH_SAFE(pm, &po->po_pmcs, pm_next, tmp) {
 752                 PMCDBG1(OWN,ORM,2, "pmc=%p", pm);
 753                 KASSERT(pm->pm_owner == po,
 754                     ("[pmc,%d] owner %p != po %p", __LINE__, pm->pm_owner, po));
 755
 756                 pmc_release_pmc_descriptor(pm); /* will unlink from the list */
 757                 pmc_destroy_pmc_descriptor(pm);
 758         }
 759
 760         KASSERT(po->po_sscount == 0,
 761             ("[pmc,%d] SS count not zero", __LINE__));
 762         KASSERT(LIST_EMPTY(&po->po_pmcs),
 763             ("[pmc,%d] PMC list not empty", __LINE__));
 764
 765         /* de-configure the log file if present */
 766         if (po->po_flags & PMC_PO_OWNS_LOGFILE)
 767                 pmclog_deconfigure_log(po);
 768 }
 769
 770 /*
 771  * remove an owner process record if all conditions are met.
 772  */
 773
 774 static void
 775 pmc_maybe_remove_owner(struct pmc_owner *po)
 776 {
 777
 778         PMCDBG1(OWN,OMR,1, "maybe-remove-owner po=%p", po);
 779
 780         /*
 781          * Remove owner record if
 782          * - this process does not own any PMCs
 783          * - this process has not allocated a system-wide sampling buffer
 784          */
 785
 786         if (LIST_EMPTY(&po->po_pmcs) &&
 787             ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)) {
 788                 pmc_remove_owner(po);
 789                 pmc_destroy_owner_descriptor(po);
 790         }
 791 }
 792
 793 /*
 794  * Add an association between a target process and a PMC.
 795  */
 796
 797 static void
 798 pmc_link_target_process(struct pmc *pm, struct pmc_process *pp)
 799 {
 800         int ri;
 801         struct pmc_target *pt;
 802
 803         sx_assert(&pmc_sx, SX_XLOCKED);
 804
 805         KASSERT(pm != NULL && pp != NULL,
 806             ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp));
 807         KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)),
 808             ("[pmc,%d] Attaching a non-process-virtual pmc=%p to pid=%d",
 809                 __LINE__, pm, pp->pp_proc->p_pid));
 810         KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= ((int) md->pmd_npmc - 1),
 811             ("[pmc,%d] Illegal reference count %d for process record %p",
 812                 __LINE__, pp->pp_refcnt, (void *) pp));
 813
 814         ri = PMC_TO_ROWINDEX(pm);
 815
 816         PMCDBG3(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p",
 817             pm, ri, pp);
 818
 819 #ifdef  HWPMC_DEBUG
 820         LIST_FOREACH(pt, &pm->pm_targets, pt_next)
 821             if (pt->pt_process == pp)
 822                     KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets",
 823                                 __LINE__, pp, pm));
 824 #endif
 825
 826         pt = malloc(sizeof(struct pmc_target), M_PMC, M_WAITOK|M_ZERO);
 827         pt->pt_process = pp;
 828
 829         LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next);
 830
 831         atomic_store_rel_ptr((uintptr_t *)&pp->pp_pmcs[ri].pp_pmc,
 832             (uintptr_t)pm);
 833
 834         if (pm->pm_owner->po_owner == pp->pp_proc)
 835                 pm->pm_flags |= PMC_F_ATTACHED_TO_OWNER;
 836
 837         /*
 838          * Initialize the per-process values at this row index.
 839          */
 840         pp->pp_pmcs[ri].pp_pmcval = PMC_TO_MODE(pm) == PMC_MODE_TS ?
 841             pm->pm_sc.pm_reloadcount : 0;
 842
 843         pp->pp_refcnt++;
 844
 845 }
 846
 847 /*
 848  * Removes the association between a target process and a PMC.
 849  */
 850
 851 static void
 852 pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp)
 853 {
 854         int ri;
 855         struct proc *p;
 856         struct pmc_target *ptgt;
 857
 858         sx_assert(&pmc_sx, SX_XLOCKED);
 859
 860         KASSERT(pm != NULL && pp != NULL,
 861             ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp));
 862
 863         KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt <= (int) md->pmd_npmc,
 864             ("[pmc,%d] Illegal ref count %d on process record %p",
 865                 __LINE__, pp->pp_refcnt, (void *) pp));
 866
 867         ri = PMC_TO_ROWINDEX(pm);
 868
 869         PMCDBG3(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p",
 870             pm, ri, pp);
 871
 872         KASSERT(pp->pp_pmcs[ri].pp_pmc == pm,
 873             ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__,
 874                 ri, pm, pp->pp_pmcs[ri].pp_pmc));
 875
 876         pp->pp_pmcs[ri].pp_pmc = NULL;
 877         pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0;
 878
 879         /* Remove owner-specific flags */
 880         if (pm->pm_owner->po_owner == pp->pp_proc) {
 881                 pp->pp_flags &= ~PMC_PP_ENABLE_MSR_ACCESS;
 882                 pm->pm_flags &= ~PMC_F_ATTACHED_TO_OWNER;
 883         }
 884
 885         pp->pp_refcnt--;
 886
 887         /* Remove the target process from the PMC structure */
 888         LIST_FOREACH(ptgt, &pm->pm_targets, pt_next)
 889                 if (ptgt->pt_process == pp)
 890                         break;
 891
 892         KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found "
 893                     "in pmc %p", __LINE__, pp->pp_proc, pp, pm));
 894
 895         LIST_REMOVE(ptgt, pt_next);
 896         free(ptgt, M_PMC);
 897
 898         /* if the PMC now lacks targets, send the owner a SIGIO */
 899         if (LIST_EMPTY(&pm->pm_targets)) {
 900                 p = pm->pm_owner->po_owner;
 901                 PROC_LOCK(p);
 902                 kern_psignal(p, SIGIO);
 903                 PROC_UNLOCK(p);
 904
 905                 PMCDBG2(PRC,SIG,2, "signalling proc=%p signal=%d", p,
 906                     SIGIO);
 907         }
 908 }
 909
 910 /*
 911  * Check if PMC 'pm' may be attached to target process 't'.
 912  */
 913
 914 static int
 915 pmc_can_attach(struct pmc *pm, struct proc *t)
 916 {
 917         struct proc *o;         /* pmc owner */
 918         struct ucred *oc, *tc;  /* owner, target credentials */
 919         int decline_attach, i;
 920
 921         /*
 922          * A PMC's owner can always attach that PMC to itself.
 923          */
 924
 925         if ((o = pm->pm_owner->po_owner) == t)
 926                 return 0;
 927
 928         PROC_LOCK(o);
 929         oc = o->p_ucred;
 930         crhold(oc);
 931         PROC_UNLOCK(o);
 932
 933         PROC_LOCK(t);
 934         tc = t->p_ucred;
 935         crhold(tc);
 936         PROC_UNLOCK(t);
 937
 938         /*
 939          * The effective uid of the PMC owner should match at least one
 940          * of the {effective,real,saved} uids of the target process.
 941          */
 942
 943         decline_attach = oc->cr_uid != tc->cr_uid &&
 944             oc->cr_uid != tc->cr_svuid &&
 945             oc->cr_uid != tc->cr_ruid;
 946
 947         /*
 948          * Every one of the target's group ids, must be in the owner's
 949          * group list.
 950          */
 951         for (i = 0; !decline_attach && i < tc->cr_ngroups; i++)
 952                 decline_attach = !groupmember(tc->cr_groups[i], oc);
 953
 954         /* check the read and saved gids too */
 955         if (decline_attach == 0)
 956                 decline_attach = !groupmember(tc->cr_rgid, oc) ||
 957                     !groupmember(tc->cr_svgid, oc);
 958
 959         crfree(tc);
 960         crfree(oc);
 961
 962         return !decline_attach;
 963 }
 964
 965 /*
 966  * Attach a process to a PMC.
 967  */
 968
 969 static int
 970 pmc_attach_one_process(struct proc *p, struct pmc *pm)
 971 {
 972         int ri;
 973         char *fullpath, *freepath;
 974         struct pmc_process      *pp;
 975
 976         sx_assert(&pmc_sx, SX_XLOCKED);
 977
 978         PMCDBG5(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm,
 979             PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm);
 980
 981         /*
 982          * Locate the process descriptor corresponding to process 'p',
 983          * allocating space as needed.
 984          *
 985          * Verify that rowindex 'pm_rowindex' is free in the process
 986          * descriptor.
 987          *
 988          * If not, allocate space for a descriptor and link the
 989          * process descriptor and PMC.
 990          */
 991         ri = PMC_TO_ROWINDEX(pm);
 992
 993         if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL)
 994                 return ENOMEM;
 995
 996         if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */
 997                 return EEXIST;
 998
 999         if (pp->pp_pmcs[ri].pp_pmc != NULL)
1000                 return EBUSY;
1001
1002         pmc_link_target_process(pm, pp);
1003
1004         if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) &&
1005             (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) == 0)
1006                 pm->pm_flags |= PMC_F_NEEDS_LOGFILE;
1007
1008         pm->pm_flags |= PMC_F_ATTACH_DONE; /* mark as attached */
1009
1010         /* issue an attach event to a configured log file */
1011         if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE) {
1012                 if (p->p_flag & P_KPROC) {
1013                         fullpath = kernelname;
1014                         freepath = NULL;
1015                 } else {
1016                         pmc_getfilename(p->p_textvp, &fullpath, &freepath);
1017                         pmclog_process_pmcattach(pm, p->p_pid, fullpath);
1018                 }
1019                 free(freepath, M_TEMP);
1020                 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
1021                         pmc_log_process_mappings(pm->pm_owner, p);
1022         }
1023         /* mark process as using HWPMCs */
1024         PROC_LOCK(p);
1025         p->p_flag |= P_HWPMC;
1026         PROC_UNLOCK(p);
1027
1028         return 0;
1029 }
1030
1031 /*
1032  * Attach a process and optionally its children
1033  */
1034
1035 static int
1036 pmc_attach_process(struct proc *p, struct pmc *pm)
1037 {
1038         int error;
1039         struct proc *top;
1040
1041         sx_assert(&pmc_sx, SX_XLOCKED);
1042
1043         PMCDBG5(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm,
1044             PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm);
1045
1046
1047         /*
1048          * If this PMC successfully allowed a GETMSR operation
1049          * in the past, disallow further ATTACHes.
1050          */
1051
1052         if ((pm->pm_flags & PMC_PP_ENABLE_MSR_ACCESS) != 0)
1053                 return EPERM;
1054
1055         if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0)
1056                 return pmc_attach_one_process(p, pm);
1057
1058         /*
1059          * Traverse all child processes, attaching them to
1060          * this PMC.
1061          */
1062
1063         sx_slock(&proctree_lock);
1064
1065         top = p;
1066
1067         for (;;) {
1068                 if ((error = pmc_attach_one_process(p, pm)) != 0)
1069                         break;
1070                 if (!LIST_EMPTY(&p->p_children))
1071                         p = LIST_FIRST(&p->p_children);
1072                 else for (;;) {
1073                         if (p == top)
1074                                 goto done;
1075                         if (LIST_NEXT(p, p_sibling)) {
1076                                 p = LIST_NEXT(p, p_sibling);
1077                                 break;
1078                         }
1079                         p = p->p_pptr;
1080                 }
1081         }
1082
1083         if (error)
1084                 (void) pmc_detach_process(top, pm);
1085
1086  done:
1087         sx_sunlock(&proctree_lock);
1088         return error;
1089 }
1090
1091 /*
1092  * Detach a process from a PMC.  If there are no other PMCs tracking
1093  * this process, remove the process structure from its hash table.  If
1094  * 'flags' contains PMC_FLAG_REMOVE, then free the process structure.
1095  */
1096
1097 static int
1098 pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags)
1099 {
1100         int ri;
1101         struct pmc_process *pp;
1102
1103         sx_assert(&pmc_sx, SX_XLOCKED);
1104
1105         KASSERT(pm != NULL,
1106             ("[pmc,%d] null pm pointer", __LINE__));
1107
1108         ri = PMC_TO_ROWINDEX(pm);
1109
1110         PMCDBG6(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x",
1111             pm, ri, p, p->p_pid, p->p_comm, flags);
1112
1113         if ((pp = pmc_find_process_descriptor(p, 0)) == NULL)
1114                 return ESRCH;
1115
1116         if (pp->pp_pmcs[ri].pp_pmc != pm)
1117                 return EINVAL;
1118
1119         pmc_unlink_target_process(pm, pp);
1120
1121         /* Issue a detach entry if a log file is configured */
1122         if (pm->pm_owner->po_flags & PMC_PO_OWNS_LOGFILE)
1123                 pmclog_process_pmcdetach(pm, p->p_pid);
1124
1125         /*
1126          * If there are no PMCs targeting this process, we remove its
1127          * descriptor from the target hash table and unset the P_HWPMC
1128          * flag in the struct proc.
1129          */
1130         KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc,
1131             ("[pmc,%d] Illegal refcnt %d for process struct %p",
1132                 __LINE__, pp->pp_refcnt, pp));
1133
1134         if (pp->pp_refcnt != 0) /* still a target of some PMC */
1135                 return 0;
1136
1137         pmc_remove_process_descriptor(pp);
1138
1139         if (flags & PMC_FLAG_REMOVE)
1140                 free(pp, M_PMC);
1141
1142         PROC_LOCK(p);
1143         p->p_flag &= ~P_HWPMC;
1144         PROC_UNLOCK(p);
1145
1146         return 0;
1147 }
1148
1149 /*
1150  * Detach a process and optionally its descendants from a PMC.
1151  */
1152
1153 static int
1154 pmc_detach_process(struct proc *p, struct pmc *pm)
1155 {
1156         struct proc *top;
1157
1158         sx_assert(&pmc_sx, SX_XLOCKED);
1159
1160         PMCDBG5(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm,
1161             PMC_TO_ROWINDEX(pm), p, p->p_pid, p->p_comm);
1162
1163         if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0)
1164                 return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE);
1165
1166         /*
1167          * Traverse all children, detaching them from this PMC.  We
1168          * ignore errors since we could be detaching a PMC from a
1169          * partially attached proc tree.
1170          */
1171
1172         sx_slock(&proctree_lock);
1173
1174         top = p;
1175
1176         for (;;) {
1177                 (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE);
1178
1179                 if (!LIST_EMPTY(&p->p_children))
1180                         p = LIST_FIRST(&p->p_children);
1181                 else for (;;) {
1182                         if (p == top)
1183                                 goto done;
1184                         if (LIST_NEXT(p, p_sibling)) {
1185                                 p = LIST_NEXT(p, p_sibling);
1186                                 break;
1187                         }
1188                         p = p->p_pptr;
1189                 }
1190         }
1191
1192  done:
1193         sx_sunlock(&proctree_lock);
1194
1195         if (LIST_EMPTY(&pm->pm_targets))
1196                 pm->pm_flags &= ~PMC_F_ATTACH_DONE;
1197
1198         return 0;
1199 }
1200
1201
1202 /*
1203  * Thread context switch IN
1204  */
1205
1206 static void
1207 pmc_process_csw_in(struct thread *td)
1208 {
1209         int cpu;
1210         unsigned int adjri, ri;
1211         struct pmc *pm;
1212         struct proc *p;
1213         struct pmc_cpu *pc;
1214         struct pmc_hw *phw;
1215         pmc_value_t newvalue;
1216         struct pmc_process *pp;
1217         struct pmc_classdep *pcd;
1218
1219         p = td->td_proc;
1220
1221         if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL)
1222                 return;
1223
1224         KASSERT(pp->pp_proc == td->td_proc,
1225             ("[pmc,%d] not my thread state", __LINE__));
1226
1227         critical_enter(); /* no preemption from this point */
1228
1229         cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */
1230
1231         PMCDBG5(CSW,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p,
1232             p->p_pid, p->p_comm, pp);
1233
1234         KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
1235             ("[pmc,%d] weird CPU id %d", __LINE__, cpu));
1236
1237         pc = pmc_pcpu[cpu];
1238
1239         for (ri = 0; ri < md->pmd_npmc; ri++) {
1240
1241                 if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL)
1242                         continue;
1243
1244                 KASSERT(PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)),
1245                     ("[pmc,%d] Target PMC in non-virtual mode (%d)",
1246                         __LINE__, PMC_TO_MODE(pm)));
1247
1248                 KASSERT(PMC_TO_ROWINDEX(pm) == ri,
1249                     ("[pmc,%d] Row index mismatch pmc %d != ri %d",
1250                         __LINE__, PMC_TO_ROWINDEX(pm), ri));
1251
1252                 /*
1253                  * Only PMCs that are marked as 'RUNNING' need
1254                  * be placed on hardware.
1255                  */
1256
1257                 if (pm->pm_state != PMC_STATE_RUNNING)
1258                         continue;
1259
1260                 /* increment PMC runcount */
1261                 atomic_add_rel_int(&pm->pm_runcount, 1);
1262
1263                 /* configure the HWPMC we are going to use. */
1264                 pcd = pmc_ri_to_classdep(md, ri, &adjri);
1265                 pcd->pcd_config_pmc(cpu, adjri, pm);
1266
1267                 phw = pc->pc_hwpmcs[ri];
1268
1269                 KASSERT(phw != NULL,
1270                     ("[pmc,%d] null hw pointer", __LINE__));
1271
1272                 KASSERT(phw->phw_pmc == pm,
1273                     ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__,
1274                         phw->phw_pmc, pm));
1275
1276                 /*
1277                  * Write out saved value and start the PMC.
1278                  *
1279                  * Sampling PMCs use a per-process value, while
1280                  * counting mode PMCs use a per-pmc value that is
1281                  * inherited across descendants.
1282                  */
1283                 if (PMC_TO_MODE(pm) == PMC_MODE_TS) {
1284                         mtx_pool_lock_spin(pmc_mtxpool, pm);
1285
1286                         /*
1287                          * Use the saved value calculated after the most recent
1288                          * thread switch out to start this counter.  Reset
1289                          * the saved count in case another thread from this
1290                          * process switches in before any threads switch out.
1291                          */
1292                         newvalue = PMC_PCPU_SAVED(cpu,ri) =
1293                             pp->pp_pmcs[ri].pp_pmcval;
1294                         pp->pp_pmcs[ri].pp_pmcval = pm->pm_sc.pm_reloadcount;
1295                         mtx_pool_unlock_spin(pmc_mtxpool, pm);
1296                 } else {
1297                         KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC,
1298                             ("[pmc,%d] illegal mode=%d", __LINE__,
1299                             PMC_TO_MODE(pm)));
1300                         mtx_pool_lock_spin(pmc_mtxpool, pm);
1301                         newvalue = PMC_PCPU_SAVED(cpu, ri) =
1302                             pm->pm_gv.pm_savedvalue;
1303                         mtx_pool_unlock_spin(pmc_mtxpool, pm);
1304                 }
1305
1306                 PMCDBG3(CSW,SWI,1,"cpu=%d ri=%d new=%jd", cpu, ri, newvalue);
1307
1308                 pcd->pcd_write_pmc(cpu, adjri, newvalue);
1309
1310                 /* If a sampling mode PMC, reset stalled state. */
1311                 if (PMC_TO_MODE(pm) == PMC_MODE_TS)
1312                         CPU_CLR_ATOMIC(cpu, &pm->pm_stalled);
1313
1314                 /* Indicate that we desire this to run. */
1315                 CPU_SET_ATOMIC(cpu, &pm->pm_cpustate);
1316
1317                 /* Start the PMC. */
1318                 pcd->pcd_start_pmc(cpu, adjri);
1319         }
1320
1321         /*
1322          * perform any other architecture/cpu dependent thread
1323          * switch-in actions.
1324          */
1325
1326         (void) (*md->pmd_switch_in)(pc, pp);
1327
1328         critical_exit();
1329
1330 }
1331
1332 /*
1333  * Thread context switch OUT.
1334  */
1335
1336 static void
1337 pmc_process_csw_out(struct thread *td)
1338 {
1339         int cpu;
1340         int64_t tmp;
1341         struct pmc *pm;
1342         struct proc *p;
1343         enum pmc_mode mode;
1344         struct pmc_cpu *pc;
1345         pmc_value_t newvalue;
1346         unsigned int adjri, ri;
1347         struct pmc_process *pp;
1348         struct pmc_classdep *pcd;
1349
1350
1351         /*
1352          * Locate our process descriptor; this may be NULL if
1353          * this process is exiting and we have already removed
1354          * the process from the target process table.
1355          *
1356          * Note that due to kernel preemption, multiple
1357          * context switches may happen while the process is
1358          * exiting.
1359          *
1360          * Note also that if the target process cannot be
1361          * found we still need to deconfigure any PMCs that
1362          * are currently running on hardware.
1363          */
1364
1365         p = td->td_proc;
1366         pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE);
1367
1368         /*
1369          * save PMCs
1370          */
1371
1372         critical_enter();
1373
1374         cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */
1375
1376         PMCDBG5(CSW,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p,
1377             p->p_pid, p->p_comm, pp);
1378
1379         KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
1380             ("[pmc,%d weird CPU id %d", __LINE__, cpu));
1381
1382         pc = pmc_pcpu[cpu];
1383
1384         /*
1385          * When a PMC gets unlinked from a target PMC, it will
1386          * be removed from the target's pp_pmc[] array.
1387          *
1388          * However, on a MP system, the target could have been
1389          * executing on another CPU at the time of the unlink.
1390          * So, at context switch OUT time, we need to look at
1391          * the hardware to determine if a PMC is scheduled on
1392          * it.
1393          */
1394
1395         for (ri = 0; ri < md->pmd_npmc; ri++) {
1396
1397                 pcd = pmc_ri_to_classdep(md, ri, &adjri);
1398                 pm  = NULL;
1399                 (void) (*pcd->pcd_get_config)(cpu, adjri, &pm);
1400
1401                 if (pm == NULL) /* nothing at this row index */
1402                         continue;
1403
1404                 mode = PMC_TO_MODE(pm);
1405                 if (!PMC_IS_VIRTUAL_MODE(mode))
1406                         continue; /* not a process virtual PMC */
1407
1408                 KASSERT(PMC_TO_ROWINDEX(pm) == ri,
1409                     ("[pmc,%d] ri mismatch pmc(%d) ri(%d)",
1410                         __LINE__, PMC_TO_ROWINDEX(pm), ri));
1411
1412                 /*
1413                  * Change desired state, and then stop if not stalled.
1414                  * This two-step dance should avoid race conditions where
1415                  * an interrupt re-enables the PMC after this code has
1416                  * already checked the pm_stalled flag.
1417                  */
1418                 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate);
1419                 if (!CPU_ISSET(cpu, &pm->pm_stalled))
1420                         pcd->pcd_stop_pmc(cpu, adjri);
1421
1422                 /* reduce this PMC's runcount */
1423                 atomic_subtract_rel_int(&pm->pm_runcount, 1);
1424
1425                 /*
1426                  * If this PMC is associated with this process,
1427                  * save the reading.
1428                  */
1429
1430                 if (pm->pm_state != PMC_STATE_DELETED && pp != NULL &&
1431                     pp->pp_pmcs[ri].pp_pmc != NULL) {
1432                         KASSERT(pm == pp->pp_pmcs[ri].pp_pmc,
1433                             ("[pmc,%d] pm %p != pp_pmcs[%d] %p", __LINE__,
1434                                 pm, ri, pp->pp_pmcs[ri].pp_pmc));
1435
1436                         KASSERT(pp->pp_refcnt > 0,
1437                             ("[pmc,%d] pp refcnt = %d", __LINE__,
1438                                 pp->pp_refcnt));
1439
1440                         pcd->pcd_read_pmc(cpu, adjri, &newvalue);
1441
1442                         if (mode == PMC_MODE_TS) {
1443                                 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (samp)",
1444                                     cpu, ri, PMC_PCPU_SAVED(cpu,ri) - newvalue);
1445
1446                                 /*
1447                                  * For sampling process-virtual PMCs,
1448                                  * newvalue is the number of events to be seen
1449                                  * until the next sampling interrupt.
1450                                  * We can just add the events left from this
1451                                  * invocation to the counter, then adjust
1452                                  * in case we overflow our range.
1453                                  *
1454                                  * (Recall that we reload the counter every
1455                                  * time we use it.)
1456                                  */
1457                                 mtx_pool_lock_spin(pmc_mtxpool, pm);
1458
1459                                 pp->pp_pmcs[ri].pp_pmcval += newvalue;
1460                                 if (pp->pp_pmcs[ri].pp_pmcval >
1461                                     pm->pm_sc.pm_reloadcount)
1462                                         pp->pp_pmcs[ri].pp_pmcval -=
1463                                             pm->pm_sc.pm_reloadcount;
1464                                 KASSERT(pp->pp_pmcs[ri].pp_pmcval > 0 &&
1465                                     pp->pp_pmcs[ri].pp_pmcval <=
1466                                     pm->pm_sc.pm_reloadcount,
1467                                     ("[pmc,%d] pp_pmcval outside of expected "
1468                                     "range cpu=%d ri=%d pp_pmcval=%jx "
1469                                     "pm_reloadcount=%jx", __LINE__, cpu, ri,
1470                                     pp->pp_pmcs[ri].pp_pmcval,
1471                                     pm->pm_sc.pm_reloadcount));
1472                                 mtx_pool_unlock_spin(pmc_mtxpool, pm);
1473
1474                         } else {
1475                                 tmp = newvalue - PMC_PCPU_SAVED(cpu,ri);
1476
1477                                 PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (count)",
1478                                     cpu, ri, tmp);
1479
1480                                 /*
1481                                  * For counting process-virtual PMCs,
1482                                  * we expect the count to be
1483                                  * increasing monotonically, modulo a 64
1484                                  * bit wraparound.
1485                                  */
1486                                 KASSERT(tmp >= 0,
1487                                     ("[pmc,%d] negative increment cpu=%d "
1488                                      "ri=%d newvalue=%jx saved=%jx "
1489                                      "incr=%jx", __LINE__, cpu, ri,
1490                                      newvalue, PMC_PCPU_SAVED(cpu,ri), tmp));
1491
1492                                 mtx_pool_lock_spin(pmc_mtxpool, pm);
1493                                 pm->pm_gv.pm_savedvalue += tmp;
1494                                 pp->pp_pmcs[ri].pp_pmcval += tmp;
1495                                 mtx_pool_unlock_spin(pmc_mtxpool, pm);
1496
1497                                 if (pm->pm_flags & PMC_F_LOG_PROCCSW)
1498                                         pmclog_process_proccsw(pm, pp, tmp);
1499                         }
1500                 }
1501
1502                 /* mark hardware as free */
1503                 pcd->pcd_config_pmc(cpu, adjri, NULL);
1504         }
1505
1506         /*
1507          * perform any other architecture/cpu dependent thread
1508          * switch out functions.
1509          */
1510
1511         (void) (*md->pmd_switch_out)(pc, pp);
1512
1513         critical_exit();
1514 }
1515
1516 /*
1517  * A mapping change for a process.
1518  */
1519
1520 static void
1521 pmc_process_mmap(struct thread *td, struct pmckern_map_in *pkm)
1522 {
1523         int ri;
1524         pid_t pid;
1525         char *fullpath, *freepath;
1526         const struct pmc *pm;
1527         struct pmc_owner *po;
1528         const struct pmc_process *pp;
1529
1530         freepath = fullpath = NULL;
1531         pmc_getfilename((struct vnode *) pkm->pm_file, &fullpath, &freepath);
1532
1533         pid = td->td_proc->p_pid;
1534
1535         /* Inform owners of all system-wide sampling PMCs. */
1536         LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
1537             if (po->po_flags & PMC_PO_OWNS_LOGFILE)
1538                 pmclog_process_map_in(po, pid, pkm->pm_address, fullpath);
1539
1540         if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL)
1541                 goto done;
1542
1543         /*
1544          * Inform sampling PMC owners tracking this process.
1545          */
1546         for (ri = 0; ri < md->pmd_npmc; ri++)
1547                 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL &&
1548                     PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
1549                         pmclog_process_map_in(pm->pm_owner,
1550                             pid, pkm->pm_address, fullpath);
1551
1552   done:
1553         if (freepath)
1554                 free(freepath, M_TEMP);
1555 }
1556
1557
1558 /*
1559  * Log an munmap request.
1560  */
1561
1562 static void
1563 pmc_process_munmap(struct thread *td, struct pmckern_map_out *pkm)
1564 {
1565         int ri;
1566         pid_t pid;
1567         struct pmc_owner *po;
1568         const struct pmc *pm;
1569         const struct pmc_process *pp;
1570
1571         pid = td->td_proc->p_pid;
1572
1573         LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
1574             if (po->po_flags & PMC_PO_OWNS_LOGFILE)
1575                 pmclog_process_map_out(po, pid, pkm->pm_address,
1576                     pkm->pm_address + pkm->pm_size);
1577
1578         if ((pp = pmc_find_process_descriptor(td->td_proc, 0)) == NULL)
1579                 return;
1580
1581         for (ri = 0; ri < md->pmd_npmc; ri++)
1582                 if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL &&
1583                     PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
1584                         pmclog_process_map_out(pm->pm_owner, pid,
1585                             pkm->pm_address, pkm->pm_address + pkm->pm_size);
1586 }
1587
1588 /*
1589  * Log mapping information about the kernel.
1590  */
1591
1592 static void
1593 pmc_log_kernel_mappings(struct pmc *pm)
1594 {
1595         struct pmc_owner *po;
1596         struct pmckern_map_in *km, *kmbase;
1597
1598         sx_assert(&pmc_sx, SX_LOCKED);
1599         KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)),
1600             ("[pmc,%d] non-sampling PMC (%p) desires mapping information",
1601                 __LINE__, (void *) pm));
1602
1603         po = pm->pm_owner;
1604
1605         if (po->po_flags & PMC_PO_INITIAL_MAPPINGS_DONE)
1606                 return;
1607
1608         /*
1609          * Log the current set of kernel modules.
1610          */
1611         kmbase = linker_hwpmc_list_objects();
1612         for (km = kmbase; km->pm_file != NULL; km++) {
1613                 PMCDBG2(LOG,REG,1,"%s %p", (char *) km->pm_file,
1614                     (void *) km->pm_address);
1615                 pmclog_process_map_in(po, (pid_t) -1, km->pm_address,
1616                     km->pm_file);
1617         }
1618         free(kmbase, M_LINKER);
1619
1620         po->po_flags |= PMC_PO_INITIAL_MAPPINGS_DONE;
1621 }
1622
1623 /*
1624  * Log the mappings for a single process.
1625  */
1626
1627 static void
1628 pmc_log_process_mappings(struct pmc_owner *po, struct proc *p)
1629 {
1630         vm_map_t map;
1631         struct vnode *vp;
1632         struct vmspace *vm;
1633         vm_map_entry_t entry;
1634         vm_offset_t last_end;
1635         u_int last_timestamp;
1636         struct vnode *last_vp;
1637         vm_offset_t start_addr;
1638         vm_object_t obj, lobj, tobj;
1639         char *fullpath, *freepath;
1640
1641         last_vp = NULL;
1642         last_end = (vm_offset_t) 0;
1643         fullpath = freepath = NULL;
1644
1645         if ((vm = vmspace_acquire_ref(p)) == NULL)
1646                 return;
1647
1648         map = &vm->vm_map;
1649         vm_map_lock_read(map);
1650
1651         for (entry = map->header.next; entry != &map->header; entry = entry->next) {
1652
1653                 if (entry == NULL) {
1654                         PMCDBG2(LOG,OPS,2, "hwpmc: vm_map entry unexpectedly "
1655                             "NULL! pid=%d vm_map=%p\n", p->p_pid, map);
1656                         break;
1657                 }
1658
1659                 /*
1660                  * We only care about executable map entries.
1661                  */
1662                 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) ||
1663                     !(entry->protection & VM_PROT_EXECUTE) ||
1664                     (entry->object.vm_object == NULL)) {
1665                         continue;
1666                 }
1667
1668                 obj = entry->object.vm_object;
1669                 VM_OBJECT_RLOCK(obj);
1670
1671                 /*
1672                  * Walk the backing_object list to find the base
1673                  * (non-shadowed) vm_object.
1674                  */
1675                 for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
1676                         if (tobj != obj)
1677                                 VM_OBJECT_RLOCK(tobj);
1678                         if (lobj != obj)
1679                                 VM_OBJECT_RUNLOCK(lobj);
1680                         lobj = tobj;
1681                 }
1682
1683                 /*
1684                  * At this point lobj is the base vm_object and it is locked.
1685                  */
1686                 if (lobj == NULL) {
1687                         PMCDBG3(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d "
1688                             "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj);
1689                         VM_OBJECT_RUNLOCK(obj);
1690                         continue;
1691                 }
1692
1693                 vp = vm_object_vnode(lobj);
1694                 if (vp == NULL) {
1695                         if (lobj != obj)
1696                                 VM_OBJECT_RUNLOCK(lobj);
1697                         VM_OBJECT_RUNLOCK(obj);
1698                         continue;
1699                 }
1700
1701                 /*
1702                  * Skip contiguous regions that point to the same
1703                  * vnode, so we don't emit redundant MAP-IN
1704                  * directives.
1705                  */
1706                 if (entry->start == last_end && vp == last_vp) {
1707                         last_end = entry->end;
1708                         if (lobj != obj)
1709                                 VM_OBJECT_RUNLOCK(lobj);
1710                         VM_OBJECT_RUNLOCK(obj);
1711                         continue;
1712                 }
1713
1714                 /*
1715                  * We don't want to keep the proc's vm_map or this
1716                  * vm_object locked while we walk the pathname, since
1717                  * vn_fullpath() can sleep.  However, if we drop the
1718                  * lock, it's possible for concurrent activity to
1719                  * modify the vm_map list.  To protect against this,
1720                  * we save the vm_map timestamp before we release the
1721                  * lock, and check it after we reacquire the lock
1722                  * below.
1723                  */
1724                 start_addr = entry->start;
1725                 last_end = entry->end;
1726                 last_timestamp = map->timestamp;
1727                 vm_map_unlock_read(map);
1728
1729                 vref(vp);
1730                 if (lobj != obj)
1731                         VM_OBJECT_RUNLOCK(lobj);
1732
1733                 VM_OBJECT_RUNLOCK(obj);
1734
1735                 freepath = NULL;
1736                 pmc_getfilename(vp, &fullpath, &freepath);
1737                 last_vp = vp;
1738
1739                 vrele(vp);
1740
1741                 vp = NULL;
1742                 pmclog_process_map_in(po, p->p_pid, start_addr, fullpath);
1743                 if (freepath)
1744                         free(freepath, M_TEMP);
1745
1746                 vm_map_lock_read(map);
1747
1748                 /*
1749                  * If our saved timestamp doesn't match, this means
1750                  * that the vm_map was modified out from under us and
1751                  * we can't trust our current "entry" pointer.  Do a
1752                  * new lookup for this entry.  If there is no entry
1753                  * for this address range, vm_map_lookup_entry() will
1754                  * return the previous one, so we always want to go to
1755                  * entry->next on the next loop iteration.
1756                  *
1757                  * There is an edge condition here that can occur if
1758                  * there is no entry at or before this address.  In
1759                  * this situation, vm_map_lookup_entry returns
1760                  * &map->header, which would cause our loop to abort
1761                  * without processing the rest of the map.  However,
1762                  * in practice this will never happen for process
1763                  * vm_map.  This is because the executable's text
1764                  * segment is the first mapping in the proc's address
1765                  * space, and this mapping is never removed until the
1766                  * process exits, so there will always be a non-header
1767                  * entry at or before the requested address for
1768                  * vm_map_lookup_entry to return.
1769                  */
1770                 if (map->timestamp != last_timestamp)
1771                         vm_map_lookup_entry(map, last_end - 1, &entry);
1772         }
1773
1774         vm_map_unlock_read(map);
1775         vmspace_free(vm);
1776         return;
1777 }
1778
1779 /*
1780  * Log mappings for all processes in the system.
1781  */
1782
1783 static void
1784 pmc_log_all_process_mappings(struct pmc_owner *po)
1785 {
1786         struct proc *p, *top;
1787
1788         sx_assert(&pmc_sx, SX_XLOCKED);
1789
1790         if ((p = pfind(1)) == NULL)
1791                 panic("[pmc,%d] Cannot find init", __LINE__);
1792
1793         PROC_UNLOCK(p);
1794
1795         sx_slock(&proctree_lock);
1796
1797         top = p;
1798
1799         for (;;) {
1800                 pmc_log_process_mappings(po, p);
1801                 if (!LIST_EMPTY(&p->p_children))
1802                         p = LIST_FIRST(&p->p_children);
1803                 else for (;;) {
1804                         if (p == top)
1805                                 goto done;
1806                         if (LIST_NEXT(p, p_sibling)) {
1807                                 p = LIST_NEXT(p, p_sibling);
1808                                 break;
1809                         }
1810                         p = p->p_pptr;
1811                 }
1812         }
1813  done:
1814         sx_sunlock(&proctree_lock);
1815 }
1816
1817 /*
1818  * The 'hook' invoked from the kernel proper
1819  */
1820
1821
1822 #ifdef  HWPMC_DEBUG
1823 const char *pmc_hooknames[] = {
1824         /* these strings correspond to PMC_FN_* in <sys/pmckern.h> */
1825         "",
1826         "EXEC",
1827         "CSW-IN",
1828         "CSW-OUT",
1829         "SAMPLE",
1830         "UNUSED1",
1831         "UNUSED2",
1832         "MMAP",
1833         "MUNMAP",
1834         "CALLCHAIN-NMI",
1835         "CALLCHAIN-SOFT",
1836         "SOFTSAMPLING"
1837 };
1838 #endif
1839
1840 static int
1841 pmc_hook_handler(struct thread *td, int function, void *arg)
1842 {
1843
1844         PMCDBG4(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function,
1845             pmc_hooknames[function], arg);
1846
1847         switch (function)
1848         {
1849
1850         /*
1851          * Process exec()
1852          */
1853
1854         case PMC_FN_PROCESS_EXEC:
1855         {
1856                 char *fullpath, *freepath;
1857                 unsigned int ri;
1858                 int is_using_hwpmcs;
1859                 struct pmc *pm;
1860                 struct proc *p;
1861                 struct pmc_owner *po;
1862                 struct pmc_process *pp;
1863                 struct pmckern_procexec *pk;
1864
1865                 sx_assert(&pmc_sx, SX_XLOCKED);
1866
1867                 p = td->td_proc;
1868                 pmc_getfilename(p->p_textvp, &fullpath, &freepath);
1869
1870                 pk = (struct pmckern_procexec *) arg;
1871
1872                 /* Inform owners of SS mode PMCs of the exec event. */
1873                 LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
1874                     if (po->po_flags & PMC_PO_OWNS_LOGFILE)
1875                             pmclog_process_procexec(po, PMC_ID_INVALID,
1876                                 p->p_pid, pk->pm_entryaddr, fullpath);
1877
1878                 PROC_LOCK(p);
1879                 is_using_hwpmcs = p->p_flag & P_HWPMC;
1880                 PROC_UNLOCK(p);
1881
1882                 if (!is_using_hwpmcs) {
1883                         if (freepath)
1884                                 free(freepath, M_TEMP);
1885                         break;
1886                 }
1887
1888                 /*
1889                  * PMCs are not inherited across an exec():  remove any
1890                  * PMCs that this process is the owner of.
1891                  */
1892
1893                 if ((po = pmc_find_owner_descriptor(p)) != NULL) {
1894                         pmc_remove_owner(po);
1895                         pmc_destroy_owner_descriptor(po);
1896                 }
1897
1898                 /*
1899                  * If the process being exec'ed is not the target of any
1900                  * PMC, we are done.
1901                  */
1902                 if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) {
1903                         if (freepath)
1904                                 free(freepath, M_TEMP);
1905                         break;
1906                 }
1907
1908                 /*
1909                  * Log the exec event to all monitoring owners.  Skip
1910                  * owners who have already received the event because
1911                  * they had system sampling PMCs active.
1912                  */
1913                 for (ri = 0; ri < md->pmd_npmc; ri++)
1914                         if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) {
1915                                 po = pm->pm_owner;
1916                                 if (po->po_sscount == 0 &&
1917                                     po->po_flags & PMC_PO_OWNS_LOGFILE)
1918                                         pmclog_process_procexec(po, pm->pm_id,
1919                                             p->p_pid, pk->pm_entryaddr,
1920                                             fullpath);
1921                         }
1922
1923                 if (freepath)
1924                         free(freepath, M_TEMP);
1925
1926
1927                 PMCDBG4(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d",
1928                     p, p->p_pid, p->p_comm, pk->pm_credentialschanged);
1929
1930                 if (pk->pm_credentialschanged == 0) /* no change */
1931                         break;
1932
1933                 /*
1934                  * If the newly exec()'ed process has a different credential
1935                  * than before, allow it to be the target of a PMC only if
1936                  * the PMC's owner has sufficient privilege.
1937                  */
1938
1939                 for (ri = 0; ri < md->pmd_npmc; ri++)
1940                         if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL)
1941                                 if (pmc_can_attach(pm, td->td_proc) != 0)
1942                                         pmc_detach_one_process(td->td_proc,
1943                                             pm, PMC_FLAG_NONE);
1944
1945                 KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt <= (int) md->pmd_npmc,
1946                     ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__,
1947                         pp->pp_refcnt, pp));
1948
1949                 /*
1950                  * If this process is no longer the target of any
1951                  * PMCs, we can remove the process entry and free
1952                  * up space.
1953                  */
1954
1955                 if (pp->pp_refcnt == 0) {
1956                         pmc_remove_process_descriptor(pp);
1957                         free(pp, M_PMC);
1958                         break;
1959                 }
1960
1961         }
1962         break;
1963
1964         case PMC_FN_CSW_IN:
1965                 pmc_process_csw_in(td);
1966                 break;
1967
1968         case PMC_FN_CSW_OUT:
1969                 pmc_process_csw_out(td);
1970                 break;
1971
1972         /*
1973          * Process accumulated PC samples.
1974          *
1975          * This function is expected to be called by hardclock() for
1976          * each CPU that has accumulated PC samples.
1977          *
1978          * This function is to be executed on the CPU whose samples
1979          * are being processed.
1980          */
1981         case PMC_FN_DO_SAMPLES:
1982
1983                 /*
1984                  * Clear the cpu specific bit in the CPU mask before
1985                  * do the rest of the processing.  If the NMI handler
1986                  * gets invoked after the "atomic_clear_int()" call
1987                  * below but before "pmc_process_samples()" gets
1988                  * around to processing the interrupt, then we will
1989                  * come back here at the next hardclock() tick (and
1990                  * may find nothing to do if "pmc_process_samples()"
1991                  * had already processed the interrupt).  We don't
1992                  * lose the interrupt sample.
1993                  */
1994                 CPU_CLR_ATOMIC(PCPU_GET(cpuid), &pmc_cpumask);
1995                 pmc_process_samples(PCPU_GET(cpuid), PMC_HR);
1996                 pmc_process_samples(PCPU_GET(cpuid), PMC_SR);
1997                 break;
1998
1999         case PMC_FN_MMAP:
2000                 sx_assert(&pmc_sx, SX_LOCKED);
2001                 pmc_process_mmap(td, (struct pmckern_map_in *) arg);
2002                 break;
2003
2004         case PMC_FN_MUNMAP:
2005                 sx_assert(&pmc_sx, SX_LOCKED);
2006                 pmc_process_munmap(td, (struct pmckern_map_out *) arg);
2007                 break;
2008
2009         case PMC_FN_USER_CALLCHAIN:
2010                 /*
2011                  * Record a call chain.
2012                  */
2013                 KASSERT(td == curthread, ("[pmc,%d] td != curthread",
2014                     __LINE__));
2015
2016                 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_HR,
2017                     (struct trapframe *) arg);
2018                 td->td_pflags &= ~TDP_CALLCHAIN;
2019                 break;
2020
2021         case PMC_FN_USER_CALLCHAIN_SOFT:
2022                 /*
2023                  * Record a call chain.
2024                  */
2025                 KASSERT(td == curthread, ("[pmc,%d] td != curthread",
2026                     __LINE__));
2027                 pmc_capture_user_callchain(PCPU_GET(cpuid), PMC_SR,
2028                     (struct trapframe *) arg);
2029                 td->td_pflags &= ~TDP_CALLCHAIN;
2030                 break;
2031
2032         case PMC_FN_SOFT_SAMPLING:
2033                 /*
2034                  * Call soft PMC sampling intr.
2035                  */
2036                 pmc_soft_intr((struct pmckern_soft *) arg);
2037                 break;
2038
2039         default:
2040 #ifdef  HWPMC_DEBUG
2041                 KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function));
2042 #endif
2043                 break;
2044
2045         }
2046
2047         return 0;
2048 }
2049
2050 /*
2051  * allocate a 'struct pmc_owner' descriptor in the owner hash table.
2052  */
2053
2054 static struct pmc_owner *
2055 pmc_allocate_owner_descriptor(struct proc *p)
2056 {
2057         uint32_t hindex;
2058         struct pmc_owner *po;
2059         struct pmc_ownerhash *poh;
2060
2061         hindex = PMC_HASH_PTR(p, pmc_ownerhashmask);
2062         poh = &pmc_ownerhash[hindex];
2063
2064         /* allocate space for N pointers and one descriptor struct */
2065         po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK|M_ZERO);
2066         po->po_owner = p;
2067         LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */
2068
2069         TAILQ_INIT(&po->po_logbuffers);
2070         mtx_init(&po->po_mtx, "pmc-owner-mtx", "pmc-per-proc", MTX_SPIN);
2071
2072         PMCDBG4(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p",
2073             p, p->p_pid, p->p_comm, po);
2074
2075         return po;
2076 }
2077
2078 static void
2079 pmc_destroy_owner_descriptor(struct pmc_owner *po)
2080 {
2081
2082         PMCDBG4(OWN,REL,1, "destroy-owner po=%p proc=%p (%d, %s)",
2083             po, po->po_owner, po->po_owner->p_pid, po->po_owner->p_comm);
2084
2085         mtx_destroy(&po->po_mtx);
2086         free(po, M_PMC);
2087 }
2088
2089 /*
2090  * find the descriptor corresponding to process 'p', adding or removing it
2091  * as specified by 'mode'.
2092  */
2093
2094 static struct pmc_process *
2095 pmc_find_process_descriptor(struct proc *p, uint32_t mode)
2096 {
2097         uint32_t hindex;
2098         struct pmc_process *pp, *ppnew;
2099         struct pmc_processhash *pph;
2100
2101         hindex = PMC_HASH_PTR(p, pmc_processhashmask);
2102         pph = &pmc_processhash[hindex];
2103
2104         ppnew = NULL;
2105
2106         /*
2107          * Pre-allocate memory in the FIND_ALLOCATE case since we
2108          * cannot call malloc(9) once we hold a spin lock.
2109          */
2110         if (mode & PMC_FLAG_ALLOCATE)
2111                 ppnew = malloc(sizeof(struct pmc_process) + md->pmd_npmc *
2112                     sizeof(struct pmc_targetstate), M_PMC, M_WAITOK|M_ZERO);
2113
2114         mtx_lock_spin(&pmc_processhash_mtx);
2115         LIST_FOREACH(pp, pph, pp_next)
2116             if (pp->pp_proc == p)
2117                     break;
2118
2119         if ((mode & PMC_FLAG_REMOVE) && pp != NULL)
2120                 LIST_REMOVE(pp, pp_next);
2121
2122         if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL &&
2123             ppnew != NULL) {
2124                 ppnew->pp_proc = p;
2125                 LIST_INSERT_HEAD(pph, ppnew, pp_next);
2126                 pp = ppnew;
2127                 ppnew = NULL;
2128         }
2129         mtx_unlock_spin(&pmc_processhash_mtx);
2130
2131         if (pp != NULL && ppnew != NULL)
2132                 free(ppnew, M_PMC);
2133
2134         return pp;
2135 }
2136
2137 /*
2138  * remove a process descriptor from the process hash table.
2139  */
2140
2141 static void
2142 pmc_remove_process_descriptor(struct pmc_process *pp)
2143 {
2144         KASSERT(pp->pp_refcnt == 0,
2145             ("[pmc,%d] Removing process descriptor %p with count %d",
2146                 __LINE__, pp, pp->pp_refcnt));
2147
2148         mtx_lock_spin(&pmc_processhash_mtx);
2149         LIST_REMOVE(pp, pp_next);
2150         mtx_unlock_spin(&pmc_processhash_mtx);
2151 }
2152
2153
2154 /*
2155  * find an owner descriptor corresponding to proc 'p'
2156  */
2157
2158 static struct pmc_owner *
2159 pmc_find_owner_descriptor(struct proc *p)
2160 {
2161         uint32_t hindex;
2162         struct pmc_owner *po;
2163         struct pmc_ownerhash *poh;
2164
2165         hindex = PMC_HASH_PTR(p, pmc_ownerhashmask);
2166         poh = &pmc_ownerhash[hindex];
2167
2168         po = NULL;
2169         LIST_FOREACH(po, poh, po_next)
2170             if (po->po_owner == p)
2171                     break;
2172
2173         PMCDBG5(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> "
2174             "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po);
2175
2176         return po;
2177 }
2178
2179 /*
2180  * pmc_allocate_pmc_descriptor
2181  *
2182  * Allocate a pmc descriptor and initialize its
2183  * fields.
2184  */
2185
2186 static struct pmc *
2187 pmc_allocate_pmc_descriptor(void)
2188 {
2189         struct pmc *pmc;
2190
2191         pmc = malloc(sizeof(struct pmc), M_PMC, M_WAITOK|M_ZERO);
2192
2193         PMCDBG1(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc);
2194
2195         return pmc;
2196 }
2197
2198 /*
2199  * Destroy a pmc descriptor.
2200  */
2201
2202 static void
2203 pmc_destroy_pmc_descriptor(struct pmc *pm)
2204 {
2205
2206         KASSERT(pm->pm_state == PMC_STATE_DELETED ||
2207             pm->pm_state == PMC_STATE_FREE,
2208             ("[pmc,%d] destroying non-deleted PMC", __LINE__));
2209         KASSERT(LIST_EMPTY(&pm->pm_targets),
2210             ("[pmc,%d] destroying pmc with targets", __LINE__));
2211         KASSERT(pm->pm_owner == NULL,
2212             ("[pmc,%d] destroying pmc attached to an owner", __LINE__));
2213         KASSERT(pm->pm_runcount == 0,
2214             ("[pmc,%d] pmc has non-zero run count %d", __LINE__,
2215                 pm->pm_runcount));
2216
2217         free(pm, M_PMC);
2218 }
2219
2220 static void
2221 pmc_wait_for_pmc_idle(struct pmc *pm)
2222 {
2223 #ifdef HWPMC_DEBUG
2224         volatile int maxloop;
2225
2226         maxloop = 100 * pmc_cpu_max();
2227 #endif
2228         /*
2229          * Loop (with a forced context switch) till the PMC's runcount
2230          * comes down to zero.
2231          */
2232         while (atomic_load_acq_32(&pm->pm_runcount) > 0) {
2233 #ifdef HWPMC_DEBUG
2234                 maxloop--;
2235                 KASSERT(maxloop > 0,
2236                     ("[pmc,%d] (ri%d, rc%d) waiting too long for "
2237                         "pmc to be free", __LINE__,
2238                         PMC_TO_ROWINDEX(pm), pm->pm_runcount));
2239 #endif
2240                 pmc_force_context_switch();
2241         }
2242 }
2243
2244 /*
2245  * This function does the following things:
2246  *
2247  *  - detaches the PMC from hardware
2248  *  - unlinks all target threads that were attached to it
2249  *  - removes the PMC from its owner's list
2250  *  - destroys the PMC private mutex
2251  *
2252  * Once this function completes, the given pmc pointer can be freed by
2253  * calling pmc_destroy_pmc_descriptor().
2254  */
2255
2256 static void
2257 pmc_release_pmc_descriptor(struct pmc *pm)
2258 {
2259         enum pmc_mode mode;
2260         struct pmc_hw *phw;
2261         u_int adjri, ri, cpu;
2262         struct pmc_owner *po;
2263         struct pmc_binding pb;
2264         struct pmc_process *pp;
2265         struct pmc_classdep *pcd;
2266         struct pmc_target *ptgt, *tmp;
2267
2268         sx_assert(&pmc_sx, SX_XLOCKED);
2269
2270         KASSERT(pm, ("[pmc,%d] null pmc", __LINE__));
2271
2272         ri   = PMC_TO_ROWINDEX(pm);
2273         pcd  = pmc_ri_to_classdep(md, ri, &adjri);
2274         mode = PMC_TO_MODE(pm);
2275
2276         PMCDBG3(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri,
2277             mode);
2278
2279         /*
2280          * First, we take the PMC off hardware.
2281          */
2282         cpu = 0;
2283         if (PMC_IS_SYSTEM_MODE(mode)) {
2284
2285                 /*
2286                  * A system mode PMC runs on a specific CPU.  Switch
2287                  * to this CPU and turn hardware off.
2288                  */
2289                 pmc_save_cpu_binding(&pb);
2290
2291                 cpu = PMC_TO_CPU(pm);
2292
2293                 pmc_select_cpu(cpu);
2294
2295                 /* switch off non-stalled CPUs */
2296                 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate);
2297                 if (pm->pm_state == PMC_STATE_RUNNING &&
2298                     !CPU_ISSET(cpu, &pm->pm_stalled)) {
2299
2300                         phw = pmc_pcpu[cpu]->pc_hwpmcs[ri];
2301
2302                         KASSERT(phw->phw_pmc == pm,
2303                             ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)",
2304                                 __LINE__, ri, phw->phw_pmc, pm));
2305                         PMCDBG2(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri);
2306
2307                         critical_enter();
2308                         pcd->pcd_stop_pmc(cpu, adjri);
2309                         critical_exit();
2310                 }
2311
2312                 PMCDBG2(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri);
2313
2314                 critical_enter();
2315                 pcd->pcd_config_pmc(cpu, adjri, NULL);
2316                 critical_exit();
2317
2318                 /* adjust the global and process count of SS mode PMCs */
2319                 if (mode == PMC_MODE_SS && pm->pm_state == PMC_STATE_RUNNING) {
2320                         po = pm->pm_owner;
2321                         po->po_sscount--;
2322                         if (po->po_sscount == 0) {
2323                                 atomic_subtract_rel_int(&pmc_ss_count, 1);
2324                                 LIST_REMOVE(po, po_ssnext);
2325                         }
2326                 }
2327
2328                 pm->pm_state = PMC_STATE_DELETED;
2329
2330                 pmc_restore_cpu_binding(&pb);
2331
2332                 /*
2333                  * We could have references to this PMC structure in
2334                  * the per-cpu sample queues.  Wait for the queue to
2335                  * drain.
2336                  */
2337                 pmc_wait_for_pmc_idle(pm);
2338
2339         } else if (PMC_IS_VIRTUAL_MODE(mode)) {
2340
2341                 /*
2342                  * A virtual PMC could be running on multiple CPUs at
2343                  * a given instant.
2344                  *
2345                  * By marking its state as DELETED, we ensure that
2346                  * this PMC is never further scheduled on hardware.
2347                  *
2348                  * Then we wait till all CPUs are done with this PMC.
2349                  */
2350                 pm->pm_state = PMC_STATE_DELETED;
2351
2352
2353                 /* Wait for the PMCs runcount to come to zero. */
2354                 pmc_wait_for_pmc_idle(pm);
2355
2356                 /*
2357                  * At this point the PMC is off all CPUs and cannot be
2358                  * freshly scheduled onto a CPU.  It is now safe to
2359                  * unlink all targets from this PMC.  If a
2360                  * process-record's refcount falls to zero, we remove
2361                  * it from the hash table.  The module-wide SX lock
2362                  * protects us from races.
2363                  */
2364                 LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) {
2365                         pp = ptgt->pt_process;
2366                         pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */
2367
2368                         PMCDBG1(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt);
2369
2370                         /*
2371                          * If the target process record shows that no
2372                          * PMCs are attached to it, reclaim its space.
2373                          */
2374
2375                         if (pp->pp_refcnt == 0) {
2376                                 pmc_remove_process_descriptor(pp);
2377                                 free(pp, M_PMC);
2378                         }
2379                 }
2380
2381                 cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */
2382
2383         }
2384
2385         /*
2386          * Release any MD resources
2387          */
2388         (void) pcd->pcd_release_pmc(cpu, adjri, pm);
2389
2390         /*
2391          * Update row disposition
2392          */
2393
2394         if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm)))
2395                 PMC_UNMARK_ROW_STANDALONE(ri);
2396         else
2397                 PMC_UNMARK_ROW_THREAD(ri);
2398
2399         /* unlink from the owner's list */
2400         if (pm->pm_owner) {
2401                 LIST_REMOVE(pm, pm_next);
2402                 pm->pm_owner = NULL;
2403         }
2404 }
2405
2406 /*
2407  * Register an owner and a pmc.
2408  */
2409
2410 static int
2411 pmc_register_owner(struct proc *p, struct pmc *pmc)
2412 {
2413         struct pmc_owner *po;
2414
2415         sx_assert(&pmc_sx, SX_XLOCKED);
2416
2417         if ((po = pmc_find_owner_descriptor(p)) == NULL)
2418                 if ((po = pmc_allocate_owner_descriptor(p)) == NULL)
2419                         return ENOMEM;
2420
2421         KASSERT(pmc->pm_owner == NULL,
2422             ("[pmc,%d] attempting to own an initialized PMC", __LINE__));
2423         pmc->pm_owner  = po;
2424
2425         LIST_INSERT_HEAD(&po->po_pmcs, pmc, pm_next);
2426
2427         PROC_LOCK(p);
2428         p->p_flag |= P_HWPMC;
2429         PROC_UNLOCK(p);
2430
2431         if (po->po_flags & PMC_PO_OWNS_LOGFILE)
2432                 pmclog_process_pmcallocate(pmc);
2433
2434         PMCDBG2(PMC,REG,1, "register-owner pmc-owner=%p pmc=%p",
2435             po, pmc);
2436
2437         return 0;
2438 }
2439
2440 /*
2441  * Return the current row disposition:
2442  * == 0 => FREE
2443  *  > 0 => PROCESS MODE
2444  *  < 0 => SYSTEM MODE
2445  */
2446
2447 int
2448 pmc_getrowdisp(int ri)
2449 {
2450         return pmc_pmcdisp[ri];
2451 }
2452
2453 /*
2454  * Check if a PMC at row index 'ri' can be allocated to the current
2455  * process.
2456  *
2457  * Allocation can fail if:
2458  *   - the current process is already being profiled by a PMC at index 'ri',
2459  *     attached to it via OP_PMCATTACH.
2460  *   - the current process has already allocated a PMC at index 'ri'
2461  *     via OP_ALLOCATE.
2462  */
2463
2464 static int
2465 pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu)
2466 {
2467         enum pmc_mode mode;
2468         struct pmc *pm;
2469         struct pmc_owner *po;
2470         struct pmc_process *pp;
2471
2472         PMCDBG5(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d "
2473             "cpu=%d", p, p->p_pid, p->p_comm, ri, cpu);
2474
2475         /*
2476          * We shouldn't have already allocated a process-mode PMC at
2477          * row index 'ri'.
2478          *
2479          * We shouldn't have allocated a system-wide PMC on the same
2480          * CPU and same RI.
2481          */
2482         if ((po = pmc_find_owner_descriptor(p)) != NULL)
2483                 LIST_FOREACH(pm, &po->po_pmcs, pm_next) {
2484                     if (PMC_TO_ROWINDEX(pm) == ri) {
2485                             mode = PMC_TO_MODE(pm);
2486                             if (PMC_IS_VIRTUAL_MODE(mode))
2487                                     return EEXIST;
2488                             if (PMC_IS_SYSTEM_MODE(mode) &&
2489                                 (int) PMC_TO_CPU(pm) == cpu)
2490                                     return EEXIST;
2491                     }
2492                 }
2493
2494         /*
2495          * We also shouldn't be the target of any PMC at this index
2496          * since otherwise a PMC_ATTACH to ourselves will fail.
2497          */
2498         if ((pp = pmc_find_process_descriptor(p, 0)) != NULL)
2499                 if (pp->pp_pmcs[ri].pp_pmc)
2500                         return EEXIST;
2501
2502         PMCDBG4(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok",
2503             p, p->p_pid, p->p_comm, ri);
2504
2505         return 0;
2506 }
2507
2508 /*
2509  * Check if a given PMC at row index 'ri' can be currently used in
2510  * mode 'mode'.
2511  */
2512
2513 static int
2514 pmc_can_allocate_row(int ri, enum pmc_mode mode)
2515 {
2516         enum pmc_disp   disp;
2517
2518         sx_assert(&pmc_sx, SX_XLOCKED);
2519
2520         PMCDBG2(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode);
2521
2522         if (PMC_IS_SYSTEM_MODE(mode))
2523                 disp = PMC_DISP_STANDALONE;
2524         else
2525                 disp = PMC_DISP_THREAD;
2526
2527         /*
2528          * check disposition for PMC row 'ri':
2529          *
2530          * Expected disposition         Row-disposition         Result
2531          *
2532          * STANDALONE                   STANDALONE or FREE      proceed
2533          * STANDALONE                   THREAD                  fail
2534          * THREAD                       THREAD or FREE          proceed
2535          * THREAD                       STANDALONE              fail
2536          */
2537
2538         if (!PMC_ROW_DISP_IS_FREE(ri) &&
2539             !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) &&
2540             !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri)))
2541                 return EBUSY;
2542
2543         /*
2544          * All OK
2545          */
2546
2547         PMCDBG2(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode);
2548
2549         return 0;
2550
2551 }
2552
2553 /*
2554  * Find a PMC descriptor with user handle 'pmcid' for thread 'td'.
2555  */
2556
2557 static struct pmc *
2558 pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid)
2559 {
2560         struct pmc *pm;
2561
2562         KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc,
2563             ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__,
2564                 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc));
2565
2566         LIST_FOREACH(pm, &po->po_pmcs, pm_next)
2567             if (pm->pm_id == pmcid)
2568                     return pm;
2569
2570         return NULL;
2571 }
2572
2573 static int
2574 pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc)
2575 {
2576
2577         struct pmc *pm, *opm;
2578         struct pmc_owner *po;
2579         struct pmc_process *pp;
2580
2581         KASSERT(PMC_ID_TO_ROWINDEX(pmcid) < md->pmd_npmc,
2582             ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__,
2583                 PMC_ID_TO_ROWINDEX(pmcid), md->pmd_npmc));
2584         PMCDBG1(PMC,FND,1, "find-pmc id=%d", pmcid);
2585
2586         if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) {
2587                 /*
2588                  * In case of PMC_F_DESCENDANTS child processes we will not find
2589                  * the current process in the owners hash list.  Find the owner
2590                  * process first and from there lookup the po.
2591                  */
2592                 if ((pp = pmc_find_process_descriptor(curthread->td_proc,
2593                     PMC_FLAG_NONE)) == NULL) {
2594                         return ESRCH;
2595                 } else {
2596                         opm = pp->pp_pmcs[PMC_ID_TO_ROWINDEX(pmcid)].pp_pmc;
2597                         if (opm == NULL)
2598                                 return ESRCH;
2599                         if ((opm->pm_flags & (PMC_F_ATTACHED_TO_OWNER|
2600                             PMC_F_DESCENDANTS)) != (PMC_F_ATTACHED_TO_OWNER|
2601                             PMC_F_DESCENDANTS))
2602                                 return ESRCH;
2603                         po = opm->pm_owner;
2604                 }
2605         }
2606
2607         if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL)
2608                 return EINVAL;
2609
2610         PMCDBG2(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm);
2611
2612         *pmc = pm;
2613         return 0;
2614 }
2615
2616 /*
2617  * Start a PMC.
2618  */
2619
2620 static int
2621 pmc_start(struct pmc *pm)
2622 {
2623         enum pmc_mode mode;
2624         struct pmc_owner *po;
2625         struct pmc_binding pb;
2626         struct pmc_classdep *pcd;
2627         int adjri, error, cpu, ri;
2628
2629         KASSERT(pm != NULL,
2630             ("[pmc,%d] null pm", __LINE__));
2631
2632         mode = PMC_TO_MODE(pm);
2633         ri   = PMC_TO_ROWINDEX(pm);
2634         pcd  = pmc_ri_to_classdep(md, ri, &adjri);
2635
2636         error = 0;
2637
2638         PMCDBG3(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, mode, ri);
2639
2640         po = pm->pm_owner;
2641
2642         /*
2643          * Disallow PMCSTART if a logfile is required but has not been
2644          * configured yet.
2645          */
2646         if ((pm->pm_flags & PMC_F_NEEDS_LOGFILE) &&
2647             (po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)
2648                 return (EDOOFUS);       /* programming error */
2649
2650         /*
2651          * If this is a sampling mode PMC, log mapping information for
2652          * the kernel modules that are currently loaded.
2653          */
2654         if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
2655             pmc_log_kernel_mappings(pm);
2656
2657         if (PMC_IS_VIRTUAL_MODE(mode)) {
2658
2659                 /*
2660                  * If a PMCATTACH has never been done on this PMC,
2661                  * attach it to its owner process.
2662                  */
2663
2664                 if (LIST_EMPTY(&pm->pm_targets))
2665                         error = (pm->pm_flags & PMC_F_ATTACH_DONE) ? ESRCH :
2666                             pmc_attach_process(po->po_owner, pm);
2667
2668                 /*
2669                  * If the PMC is attached to its owner, then force a context
2670                  * switch to ensure that the MD state gets set correctly.
2671                  */
2672
2673                 if (error == 0) {
2674                         pm->pm_state = PMC_STATE_RUNNING;
2675                         if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER)
2676                                 pmc_force_context_switch();
2677                 }
2678
2679                 return (error);
2680         }
2681
2682
2683         /*
2684          * A system-wide PMC.
2685          *
2686          * Add the owner to the global list if this is a system-wide
2687          * sampling PMC.
2688          */
2689
2690         if (mode == PMC_MODE_SS) {
2691                 if (po->po_sscount == 0) {
2692                         LIST_INSERT_HEAD(&pmc_ss_owners, po, po_ssnext);
2693                         atomic_add_rel_int(&pmc_ss_count, 1);
2694                         PMCDBG1(PMC,OPS,1, "po=%p in global list", po);
2695                 }
2696                 po->po_sscount++;
2697
2698                 /*
2699                  * Log mapping information for all existing processes in the
2700                  * system.  Subsequent mappings are logged as they happen;
2701                  * see pmc_process_mmap().
2702                  */
2703                 if (po->po_logprocmaps == 0) {
2704                         pmc_log_all_process_mappings(po);
2705                         po->po_logprocmaps = 1;
2706                 }
2707         }
2708
2709         /*
2710          * Move to the CPU associated with this
2711          * PMC, and start the hardware.
2712          */
2713
2714         pmc_save_cpu_binding(&pb);
2715
2716         cpu = PMC_TO_CPU(pm);
2717
2718         if (!pmc_cpu_is_active(cpu))
2719                 return (ENXIO);
2720
2721         pmc_select_cpu(cpu);
2722
2723         /*
2724          * global PMCs are configured at allocation time
2725          * so write out the initial value and start the PMC.
2726          */
2727
2728         pm->pm_state = PMC_STATE_RUNNING;
2729
2730         critical_enter();
2731         if ((error = pcd->pcd_write_pmc(cpu, adjri,
2732                  PMC_IS_SAMPLING_MODE(mode) ?
2733                  pm->pm_sc.pm_reloadcount :
2734                  pm->pm_sc.pm_initial)) == 0) {
2735                 /* If a sampling mode PMC, reset stalled state. */
2736                 if (PMC_IS_SAMPLING_MODE(mode))
2737                         CPU_CLR_ATOMIC(cpu, &pm->pm_stalled);
2738
2739                 /* Indicate that we desire this to run. Start it. */
2740                 CPU_SET_ATOMIC(cpu, &pm->pm_cpustate);
2741                 error = pcd->pcd_start_pmc(cpu, adjri);
2742         }
2743         critical_exit();
2744
2745         pmc_restore_cpu_binding(&pb);
2746
2747         return (error);
2748 }
2749
2750 /*
2751  * Stop a PMC.
2752  */
2753
2754 static int
2755 pmc_stop(struct pmc *pm)
2756 {
2757         struct pmc_owner *po;
2758         struct pmc_binding pb;
2759         struct pmc_classdep *pcd;
2760         int adjri, cpu, error, ri;
2761
2762         KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__));
2763
2764         PMCDBG3(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm,
2765             PMC_TO_MODE(pm), PMC_TO_ROWINDEX(pm));
2766
2767         pm->pm_state = PMC_STATE_STOPPED;
2768
2769         /*
2770          * If the PMC is a virtual mode one, changing the state to
2771          * non-RUNNING is enough to ensure that the PMC never gets
2772          * scheduled.
2773          *
2774          * If this PMC is current running on a CPU, then it will
2775          * handled correctly at the time its target process is context
2776          * switched out.
2777          */
2778
2779         if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)))
2780                 return 0;
2781
2782         /*
2783          * A system-mode PMC.  Move to the CPU associated with
2784          * this PMC, and stop the hardware.  We update the
2785          * 'initial count' so that a subsequent PMCSTART will
2786          * resume counting from the current hardware count.
2787          */
2788
2789         pmc_save_cpu_binding(&pb);
2790
2791         cpu = PMC_TO_CPU(pm);
2792
2793         KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
2794             ("[pmc,%d] illegal cpu=%d", __LINE__, cpu));
2795
2796         if (!pmc_cpu_is_active(cpu))
2797                 return ENXIO;
2798
2799         pmc_select_cpu(cpu);
2800
2801         ri = PMC_TO_ROWINDEX(pm);
2802         pcd = pmc_ri_to_classdep(md, ri, &adjri);
2803
2804         CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate);
2805         critical_enter();
2806         if ((error = pcd->pcd_stop_pmc(cpu, adjri)) == 0)
2807                 error = pcd->pcd_read_pmc(cpu, adjri, &pm->pm_sc.pm_initial);
2808         critical_exit();
2809
2810         pmc_restore_cpu_binding(&pb);
2811
2812         po = pm->pm_owner;
2813
2814         /* remove this owner from the global list of SS PMC owners */
2815         if (PMC_TO_MODE(pm) == PMC_MODE_SS) {
2816                 po->po_sscount--;
2817                 if (po->po_sscount == 0) {
2818                         atomic_subtract_rel_int(&pmc_ss_count, 1);
2819                         LIST_REMOVE(po, po_ssnext);
2820                         PMCDBG1(PMC,OPS,2,"po=%p removed from global list", po);
2821                 }
2822         }
2823
2824         return (error);
2825 }
2826
2827
2828 #ifdef  HWPMC_DEBUG
2829 static const char *pmc_op_to_name[] = {
2830 #undef  __PMC_OP
2831 #define __PMC_OP(N, D)  #N ,
2832         __PMC_OPS()
2833         NULL
2834 };
2835 #endif
2836
2837 /*
2838  * The syscall interface
2839  */
2840
2841 #define PMC_GET_SX_XLOCK(...) do {              \
2842         sx_xlock(&pmc_sx);                      \
2843         if (pmc_hook == NULL) {                 \
2844                 sx_xunlock(&pmc_sx);            \
2845                 return __VA_ARGS__;             \
2846         }                                       \
2847 } while (0)
2848
2849 #define PMC_DOWNGRADE_SX() do {                 \
2850         sx_downgrade(&pmc_sx);                  \
2851         is_sx_downgraded = 1;                   \
2852 } while (0)
2853
2854 static int
2855 pmc_syscall_handler(struct thread *td, void *syscall_args)
2856 {
2857         int error, is_sx_downgraded, op;
2858         struct pmc_syscall_args *c;
2859         void *pmclog_proc_handle;
2860         void *arg;
2861
2862         c = (struct pmc_syscall_args *)syscall_args;
2863         op = c->pmop_code;
2864         arg = c->pmop_data;
2865         if (op == PMC_OP_CONFIGURELOG) {
2866                 /*
2867                  * We cannot create the logging process inside
2868                  * pmclog_configure_log() because there is a LOR
2869                  * between pmc_sx and process structure locks.
2870                  * Instead, pre-create the process and ignite the loop
2871                  * if everything is fine, otherwise direct the process
2872                  * to exit.
2873                  */
2874                 error = pmclog_proc_create(td, &pmclog_proc_handle);
2875                 if (error != 0)
2876                         goto done_syscall;
2877         }
2878
2879         PMC_GET_SX_XLOCK(ENOSYS);
2880         is_sx_downgraded = 0;
2881
2882         PMCDBG3(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op,
2883             pmc_op_to_name[op], arg);
2884
2885         error = 0;
2886         atomic_add_int(&pmc_stats.pm_syscalls, 1);
2887
2888         switch (op) {
2889
2890
2891         /*
2892          * Configure a log file.
2893          *
2894          * XXX This OP will be reworked.
2895          */
2896
2897         case PMC_OP_CONFIGURELOG:
2898         {
2899                 struct proc *p;
2900                 struct pmc *pm;
2901                 struct pmc_owner *po;
2902                 struct pmc_op_configurelog cl;
2903
2904                 if ((error = copyin(arg, &cl, sizeof(cl))) != 0) {
2905                         pmclog_proc_ignite(pmclog_proc_handle, NULL);
2906                         break;
2907                 }
2908
2909                 /* mark this process as owning a log file */
2910                 p = td->td_proc;
2911                 if ((po = pmc_find_owner_descriptor(p)) == NULL)
2912                         if ((po = pmc_allocate_owner_descriptor(p)) == NULL) {
2913                                 pmclog_proc_ignite(pmclog_proc_handle, NULL);
2914                                 error = ENOMEM;
2915                                 break;
2916                         }
2917
2918                 /*
2919                  * If a valid fd was passed in, try to configure that,
2920                  * otherwise if 'fd' was less than zero and there was
2921                  * a log file configured, flush its buffers and
2922                  * de-configure it.
2923                  */
2924                 if (cl.pm_logfd >= 0) {
2925                         error = pmclog_configure_log(md, po, cl.pm_logfd);
2926                         pmclog_proc_ignite(pmclog_proc_handle, error == 0 ?
2927                             po : NULL);
2928                 } else if (po->po_flags & PMC_PO_OWNS_LOGFILE) {
2929                         pmclog_proc_ignite(pmclog_proc_handle, NULL);
2930                         pmclog_process_closelog(po);
2931                         error = pmclog_close(po);
2932                         if (error == 0) {
2933                                 LIST_FOREACH(pm, &po->po_pmcs, pm_next)
2934                                     if (pm->pm_flags & PMC_F_NEEDS_LOGFILE &&
2935                                         pm->pm_state == PMC_STATE_RUNNING)
2936                                             pmc_stop(pm);
2937                                 error = pmclog_deconfigure_log(po);
2938                         }
2939                 } else {
2940                         pmclog_proc_ignite(pmclog_proc_handle, NULL);
2941                         error = EINVAL;
2942                 }
2943         }
2944         break;
2945
2946         /*
2947          * Flush a log file.
2948          */
2949
2950         case PMC_OP_FLUSHLOG:
2951         {
2952                 struct pmc_owner *po;
2953
2954                 sx_assert(&pmc_sx, SX_XLOCKED);
2955
2956                 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) {
2957                         error = EINVAL;
2958                         break;
2959                 }
2960
2961                 error = pmclog_flush(po);
2962         }
2963         break;
2964
2965         /*
2966          * Close a log file.
2967          */
2968
2969         case PMC_OP_CLOSELOG:
2970         {
2971                 struct pmc_owner *po;
2972
2973                 sx_assert(&pmc_sx, SX_XLOCKED);
2974
2975                 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) {
2976                         error = EINVAL;
2977                         break;
2978                 }
2979
2980                 error = pmclog_close(po);
2981         }
2982         break;
2983
2984         /*
2985          * Retrieve hardware configuration.
2986          */
2987
2988         case PMC_OP_GETCPUINFO: /* CPU information */
2989         {
2990                 struct pmc_op_getcpuinfo gci;
2991                 struct pmc_classinfo *pci;
2992                 struct pmc_classdep *pcd;
2993                 int cl;
2994
2995                 gci.pm_cputype = md->pmd_cputype;
2996                 gci.pm_ncpu    = pmc_cpu_max();
2997                 gci.pm_npmc    = md->pmd_npmc;
2998                 gci.pm_nclass  = md->pmd_nclass;
2999                 pci = gci.pm_classes;
3000                 pcd = md->pmd_classdep;
3001                 for (cl = 0; cl < md->pmd_nclass; cl++, pci++, pcd++) {
3002                         pci->pm_caps  = pcd->pcd_caps;
3003                         pci->pm_class = pcd->pcd_class;
3004                         pci->pm_width = pcd->pcd_width;
3005                         pci->pm_num   = pcd->pcd_num;
3006                 }
3007                 error = copyout(&gci, arg, sizeof(gci));
3008         }
3009         break;
3010
3011         /*
3012          * Retrieve soft events list.
3013          */
3014         case PMC_OP_GETDYNEVENTINFO:
3015         {
3016                 enum pmc_class                  cl;
3017                 enum pmc_event                  ev;
3018                 struct pmc_op_getdyneventinfo   *gei;
3019                 struct pmc_dyn_event_descr      dev;
3020                 struct pmc_soft                 *ps;
3021                 uint32_t                        nevent;
3022
3023                 sx_assert(&pmc_sx, SX_LOCKED);
3024
3025                 gei = (struct pmc_op_getdyneventinfo *) arg;
3026
3027                 if ((error = copyin(&gei->pm_class, &cl, sizeof(cl))) != 0)
3028                         break;
3029
3030                 /* Only SOFT class is dynamic. */
3031                 if (cl != PMC_CLASS_SOFT) {
3032                         error = EINVAL;
3033                         break;
3034                 }
3035
3036                 nevent = 0;
3037                 for (ev = PMC_EV_SOFT_FIRST; (int)ev <= PMC_EV_SOFT_LAST; ev++) {
3038                         ps = pmc_soft_ev_acquire(ev);
3039                         if (ps == NULL)
3040                                 continue;
3041                         bcopy(&ps->ps_ev, &dev, sizeof(dev));
3042                         pmc_soft_ev_release(ps);
3043
3044                         error = copyout(&dev,
3045                             &gei->pm_events[nevent],
3046                             sizeof(struct pmc_dyn_event_descr));
3047                         if (error != 0)
3048                                 break;
3049                         nevent++;
3050                 }
3051                 if (error != 0)
3052                         break;
3053
3054                 error = copyout(&nevent, &gei->pm_nevent,
3055                     sizeof(nevent));
3056         }
3057         break;
3058
3059         /*
3060          * Get module statistics
3061          */
3062
3063         case PMC_OP_GETDRIVERSTATS:
3064         {
3065                 struct pmc_op_getdriverstats gms;
3066
3067                 bcopy(&pmc_stats, &gms, sizeof(gms));
3068                 error = copyout(&gms, arg, sizeof(gms));
3069         }
3070         break;
3071
3072
3073         /*
3074          * Retrieve module version number
3075          */
3076
3077         case PMC_OP_GETMODULEVERSION:
3078         {
3079                 uint32_t cv, modv;
3080
3081                 /* retrieve the client's idea of the ABI version */
3082                 if ((error = copyin(arg, &cv, sizeof(uint32_t))) != 0)
3083                         break;
3084                 /* don't service clients newer than our driver */
3085                 modv = PMC_VERSION;
3086                 if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) {
3087                         error = EPROGMISMATCH;
3088                         break;
3089                 }
3090                 error = copyout(&modv, arg, sizeof(int));
3091         }
3092         break;
3093
3094
3095         /*
3096          * Retrieve the state of all the PMCs on a given
3097          * CPU.
3098          */
3099
3100         case PMC_OP_GETPMCINFO:
3101         {
3102                 int ari;
3103                 struct pmc *pm;
3104                 size_t pmcinfo_size;
3105                 uint32_t cpu, n, npmc;
3106                 struct pmc_owner *po;
3107                 struct pmc_binding pb;
3108                 struct pmc_classdep *pcd;
3109                 struct pmc_info *p, *pmcinfo;
3110                 struct pmc_op_getpmcinfo *gpi;
3111
3112                 PMC_DOWNGRADE_SX();
3113
3114                 gpi = (struct pmc_op_getpmcinfo *) arg;
3115
3116                 if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0)
3117                         break;
3118
3119                 if (cpu >= pmc_cpu_max()) {
3120                         error = EINVAL;
3121                         break;
3122                 }
3123
3124                 if (!pmc_cpu_is_active(cpu)) {
3125                         error = ENXIO;
3126                         break;
3127                 }
3128
3129                 /* switch to CPU 'cpu' */
3130                 pmc_save_cpu_binding(&pb);
3131                 pmc_select_cpu(cpu);
3132
3133                 npmc = md->pmd_npmc;
3134
3135                 pmcinfo_size = npmc * sizeof(struct pmc_info);
3136                 pmcinfo = malloc(pmcinfo_size, M_PMC, M_WAITOK);
3137
3138                 p = pmcinfo;
3139
3140                 for (n = 0; n < md->pmd_npmc; n++, p++) {
3141
3142                         pcd = pmc_ri_to_classdep(md, n, &ari);
3143
3144                         KASSERT(pcd != NULL,
3145                             ("[pmc,%d] null pcd ri=%d", __LINE__, n));
3146
3147                         if ((error = pcd->pcd_describe(cpu, ari, p, &pm)) != 0)
3148                                 break;
3149
3150                         if (PMC_ROW_DISP_IS_STANDALONE(n))
3151                                 p->pm_rowdisp = PMC_DISP_STANDALONE;
3152                         else if (PMC_ROW_DISP_IS_THREAD(n))
3153                                 p->pm_rowdisp = PMC_DISP_THREAD;
3154                         else
3155                                 p->pm_rowdisp = PMC_DISP_FREE;
3156
3157                         p->pm_ownerpid = -1;
3158
3159                         if (pm == NULL) /* no PMC associated */
3160                                 continue;
3161
3162                         po = pm->pm_owner;
3163
3164                         KASSERT(po->po_owner != NULL,
3165                             ("[pmc,%d] pmc_owner had a null proc pointer",
3166                                 __LINE__));
3167
3168                         p->pm_ownerpid = po->po_owner->p_pid;
3169                         p->pm_mode     = PMC_TO_MODE(pm);
3170                         p->pm_event    = pm->pm_event;
3171                         p->pm_flags    = pm->pm_flags;
3172
3173                         if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
3174                                 p->pm_reloadcount =
3175                                     pm->pm_sc.pm_reloadcount;
3176                 }
3177
3178                 pmc_restore_cpu_binding(&pb);
3179
3180                 /* now copy out the PMC info collected */
3181                 if (error == 0)
3182                         error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size);
3183
3184                 free(pmcinfo, M_PMC);
3185         }
3186         break;
3187
3188
3189         /*
3190          * Set the administrative state of a PMC.  I.e. whether
3191          * the PMC is to be used or not.
3192          */
3193
3194         case PMC_OP_PMCADMIN:
3195         {
3196                 int cpu, ri;
3197                 enum pmc_state request;
3198                 struct pmc_cpu *pc;
3199                 struct pmc_hw *phw;
3200                 struct pmc_op_pmcadmin pma;
3201                 struct pmc_binding pb;
3202
3203                 sx_assert(&pmc_sx, SX_XLOCKED);
3204
3205                 KASSERT(td == curthread,
3206                     ("[pmc,%d] td != curthread", __LINE__));
3207
3208                 error = priv_check(td, PRIV_PMC_MANAGE);
3209                 if (error)
3210                         break;
3211
3212                 if ((error = copyin(arg, &pma, sizeof(pma))) != 0)
3213                         break;
3214
3215                 cpu = pma.pm_cpu;
3216
3217                 if (cpu < 0 || cpu >= (int) pmc_cpu_max()) {
3218                         error = EINVAL;
3219                         break;
3220                 }
3221
3222                 if (!pmc_cpu_is_active(cpu)) {
3223                         error = ENXIO;
3224                         break;
3225                 }
3226
3227                 request = pma.pm_state;
3228
3229                 if (request != PMC_STATE_DISABLED &&
3230                     request != PMC_STATE_FREE) {
3231                         error = EINVAL;
3232                         break;
3233                 }
3234
3235                 ri = pma.pm_pmc; /* pmc id == row index */
3236                 if (ri < 0 || ri >= (int) md->pmd_npmc) {
3237                         error = EINVAL;
3238                         break;
3239                 }
3240
3241                 /*
3242                  * We can't disable a PMC with a row-index allocated
3243                  * for process virtual PMCs.
3244                  */
3245
3246                 if (PMC_ROW_DISP_IS_THREAD(ri) &&
3247                     request == PMC_STATE_DISABLED) {
3248                         error = EBUSY;
3249                         break;
3250                 }
3251
3252                 /*
3253                  * otherwise, this PMC on this CPU is either free or
3254                  * in system-wide mode.
3255                  */
3256
3257                 pmc_save_cpu_binding(&pb);
3258                 pmc_select_cpu(cpu);
3259
3260                 pc  = pmc_pcpu[cpu];
3261                 phw = pc->pc_hwpmcs[ri];
3262
3263                 /*
3264                  * XXX do we need some kind of 'forced' disable?
3265                  */
3266
3267                 if (phw->phw_pmc == NULL) {
3268                         if (request == PMC_STATE_DISABLED &&
3269                             (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) {
3270                                 phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED;
3271                                 PMC_MARK_ROW_STANDALONE(ri);
3272                         } else if (request == PMC_STATE_FREE &&
3273                             (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) {
3274                                 phw->phw_state |=  PMC_PHW_FLAG_IS_ENABLED;
3275                                 PMC_UNMARK_ROW_STANDALONE(ri);
3276                         }
3277                         /* other cases are a no-op */
3278                 } else
3279                         error = EBUSY;
3280
3281                 pmc_restore_cpu_binding(&pb);
3282         }
3283         break;
3284
3285
3286         /*
3287          * Allocate a PMC.
3288          */
3289
3290         case PMC_OP_PMCALLOCATE:
3291         {
3292                 int adjri, n;
3293                 u_int cpu;
3294                 uint32_t caps;
3295                 struct pmc *pmc;
3296                 enum pmc_mode mode;
3297                 struct pmc_hw *phw;
3298                 struct pmc_binding pb;
3299                 struct pmc_classdep *pcd;
3300                 struct pmc_op_pmcallocate pa;
3301
3302                 if ((error = copyin(arg, &pa, sizeof(pa))) != 0)
3303                         break;
3304
3305                 caps = pa.pm_caps;
3306                 mode = pa.pm_mode;
3307                 cpu  = pa.pm_cpu;
3308
3309                 if ((mode != PMC_MODE_SS  &&  mode != PMC_MODE_SC  &&
3310                      mode != PMC_MODE_TS  &&  mode != PMC_MODE_TC) ||
3311                     (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) {
3312                         error = EINVAL;
3313                         break;
3314                 }
3315
3316                 /*
3317                  * Virtual PMCs should only ask for a default CPU.
3318                  * System mode PMCs need to specify a non-default CPU.
3319                  */
3320
3321                 if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) ||
3322                     (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) {
3323                         error = EINVAL;
3324                         break;
3325                 }
3326
3327                 /*
3328                  * Check that an inactive CPU is not being asked for.
3329                  */
3330
3331                 if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) {
3332                         error = ENXIO;
3333                         break;
3334                 }
3335
3336                 /*
3337                  * Refuse an allocation for a system-wide PMC if this
3338                  * process has been jailed, or if this process lacks
3339                  * super-user credentials and the sysctl tunable
3340                  * 'security.bsd.unprivileged_syspmcs' is zero.
3341                  */
3342
3343                 if (PMC_IS_SYSTEM_MODE(mode)) {
3344                         if (jailed(curthread->td_ucred)) {
3345                                 error = EPERM;
3346                                 break;
3347                         }
3348                         if (!pmc_unprivileged_syspmcs) {
3349                                 error = priv_check(curthread,
3350                                     PRIV_PMC_SYSTEM);
3351                                 if (error)
3352                                         break;
3353                         }
3354                 }
3355
3356                 /*
3357                  * Look for valid values for 'pm_flags'
3358                  */
3359
3360                 if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW |
3361                     PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN)) != 0) {
3362                         error = EINVAL;
3363                         break;
3364                 }
3365
3366                 /* process logging options are not allowed for system PMCs */
3367                 if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags &
3368                     (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) {
3369                         error = EINVAL;
3370                         break;
3371                 }
3372
3373                 /*
3374                  * All sampling mode PMCs need to be able to interrupt the
3375                  * CPU.
3376                  */
3377                 if (PMC_IS_SAMPLING_MODE(mode))
3378                         caps |= PMC_CAP_INTERRUPT;
3379
3380                 /* A valid class specifier should have been passed in. */
3381                 for (n = 0; n < md->pmd_nclass; n++)
3382                         if (md->pmd_classdep[n].pcd_class == pa.pm_class)
3383                                 break;
3384                 if (n == md->pmd_nclass) {
3385                         error = EINVAL;
3386                         break;
3387                 }
3388
3389                 /* The requested PMC capabilities should be feasible. */
3390                 if ((md->pmd_classdep[n].pcd_caps & caps) != caps) {
3391                         error = EOPNOTSUPP;
3392                         break;
3393                 }
3394
3395                 PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d",
3396                     pa.pm_ev, caps, mode, cpu);
3397
3398                 pmc = pmc_allocate_pmc_descriptor();
3399                 pmc->pm_id    = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class,
3400                     PMC_ID_INVALID);
3401                 pmc->pm_event = pa.pm_ev;
3402                 pmc->pm_state = PMC_STATE_FREE;
3403                 pmc->pm_caps  = caps;
3404                 pmc->pm_flags = pa.pm_flags;
3405
3406                 /* switch thread to CPU 'cpu' */
3407                 pmc_save_cpu_binding(&pb);
3408
3409 #define PMC_IS_SHAREABLE_PMC(cpu, n)                            \
3410         (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state &           \
3411          PMC_PHW_FLAG_IS_SHAREABLE)
3412 #define PMC_IS_UNALLOCATED(cpu, n)                              \
3413         (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL)
3414
3415                 if (PMC_IS_SYSTEM_MODE(mode)) {
3416                         pmc_select_cpu(cpu);
3417                         for (n = 0; n < (int) md->pmd_npmc; n++) {
3418                                 pcd = pmc_ri_to_classdep(md, n, &adjri);
3419                                 if (pmc_can_allocate_row(n, mode) == 0 &&
3420                                     pmc_can_allocate_rowindex(
3421                                             curthread->td_proc, n, cpu) == 0 &&
3422                                     (PMC_IS_UNALLOCATED(cpu, n) ||
3423                                      PMC_IS_SHAREABLE_PMC(cpu, n)) &&
3424                                     pcd->pcd_allocate_pmc(cpu, adjri, pmc,
3425                                         &pa) == 0)
3426                                         break;
3427                         }
3428                 } else {
3429                         /* Process virtual mode */
3430                         for (n = 0; n < (int) md->pmd_npmc; n++) {
3431                                 pcd = pmc_ri_to_classdep(md, n, &adjri);
3432                                 if (pmc_can_allocate_row(n, mode) == 0 &&
3433                                     pmc_can_allocate_rowindex(
3434                                             curthread->td_proc, n,
3435                                             PMC_CPU_ANY) == 0 &&
3436                                     pcd->pcd_allocate_pmc(curthread->td_oncpu,
3437                                         adjri, pmc, &pa) == 0)
3438                                         break;
3439                         }
3440                 }
3441
3442 #undef  PMC_IS_UNALLOCATED
3443 #undef  PMC_IS_SHAREABLE_PMC
3444
3445                 pmc_restore_cpu_binding(&pb);
3446
3447                 if (n == (int) md->pmd_npmc) {
3448                         pmc_destroy_pmc_descriptor(pmc);
3449                         pmc = NULL;
3450                         error = EINVAL;
3451                         break;
3452                 }
3453
3454                 /* Fill in the correct value in the ID field */
3455                 pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n);
3456
3457                 PMCDBG5(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x",
3458                     pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id);
3459
3460                 /* Process mode PMCs with logging enabled need log files */
3461                 if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW))
3462                         pmc->pm_flags |= PMC_F_NEEDS_LOGFILE;
3463
3464                 /* All system mode sampling PMCs require a log file */
3465                 if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode))
3466                         pmc->pm_flags |= PMC_F_NEEDS_LOGFILE;
3467
3468                 /*
3469                  * Configure global pmc's immediately
3470                  */
3471
3472                 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) {
3473
3474                         pmc_save_cpu_binding(&pb);
3475                         pmc_select_cpu(cpu);
3476
3477                         phw = pmc_pcpu[cpu]->pc_hwpmcs[n];
3478                         pcd = pmc_ri_to_classdep(md, n, &adjri);
3479
3480                         if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 ||
3481                             (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) {
3482                                 (void) pcd->pcd_release_pmc(cpu, adjri, pmc);
3483                                 pmc_destroy_pmc_descriptor(pmc);
3484                                 pmc = NULL;
3485                                 pmc_restore_cpu_binding(&pb);
3486                                 error = EPERM;
3487                                 break;
3488                         }
3489
3490                         pmc_restore_cpu_binding(&pb);
3491                 }
3492
3493                 pmc->pm_state    = PMC_STATE_ALLOCATED;
3494
3495                 /*
3496                  * mark row disposition
3497                  */
3498
3499                 if (PMC_IS_SYSTEM_MODE(mode))
3500                         PMC_MARK_ROW_STANDALONE(n);
3501                 else
3502                         PMC_MARK_ROW_THREAD(n);
3503
3504                 /*
3505                  * Register this PMC with the current thread as its owner.
3506                  */
3507
3508                 if ((error =
3509                     pmc_register_owner(curthread->td_proc, pmc)) != 0) {
3510                         pmc_release_pmc_descriptor(pmc);
3511                         pmc_destroy_pmc_descriptor(pmc);
3512                         pmc = NULL;
3513                         break;
3514                 }
3515
3516                 /*
3517                  * Return the allocated index.
3518                  */
3519
3520                 pa.pm_pmcid = pmc->pm_id;
3521
3522                 error = copyout(&pa, arg, sizeof(pa));
3523         }
3524         break;
3525
3526
3527         /*
3528          * Attach a PMC to a process.
3529          */
3530
3531         case PMC_OP_PMCATTACH:
3532         {
3533                 struct pmc *pm;
3534                 struct proc *p;
3535                 struct pmc_op_pmcattach a;
3536
3537                 sx_assert(&pmc_sx, SX_XLOCKED);
3538
3539                 if ((error = copyin(arg, &a, sizeof(a))) != 0)
3540                         break;
3541
3542                 if (a.pm_pid < 0) {
3543                         error = EINVAL;
3544                         break;
3545                 } else if (a.pm_pid == 0)
3546                         a.pm_pid = td->td_proc->p_pid;
3547
3548                 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0)
3549                         break;
3550
3551                 if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pm))) {
3552                         error = EINVAL;
3553                         break;
3554                 }
3555
3556                 /* PMCs may be (re)attached only when allocated or stopped */
3557                 if (pm->pm_state == PMC_STATE_RUNNING) {
3558                         error = EBUSY;
3559                         break;
3560                 } else if (pm->pm_state != PMC_STATE_ALLOCATED &&
3561                     pm->pm_state != PMC_STATE_STOPPED) {
3562                         error = EINVAL;
3563                         break;
3564                 }
3565
3566                 /* lookup pid */
3567                 if ((p = pfind(a.pm_pid)) == NULL) {
3568                         error = ESRCH;
3569                         break;
3570                 }
3571
3572                 /*
3573                  * Ignore processes that are working on exiting.
3574                  */
3575                 if (p->p_flag & P_WEXIT) {
3576                         error = ESRCH;
3577                         PROC_UNLOCK(p); /* pfind() returns a locked process */
3578                         break;
3579                 }
3580
3581                 /*
3582                  * we are allowed to attach a PMC to a process if
3583                  * we can debug it.
3584                  */
3585                 error = p_candebug(curthread, p);
3586
3587                 PROC_UNLOCK(p);
3588
3589                 if (error == 0)
3590                         error = pmc_attach_process(p, pm);
3591         }
3592         break;
3593
3594
3595         /*
3596          * Detach an attached PMC from a process.
3597          */
3598
3599         case PMC_OP_PMCDETACH:
3600         {
3601                 struct pmc *pm;
3602                 struct proc *p;
3603                 struct pmc_op_pmcattach a;
3604
3605                 if ((error = copyin(arg, &a, sizeof(a))) != 0)
3606                         break;
3607
3608                 if (a.pm_pid < 0) {
3609                         error = EINVAL;
3610                         break;
3611                 } else if (a.pm_pid == 0)
3612                         a.pm_pid = td->td_proc->p_pid;
3613
3614                 if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0)
3615                         break;
3616
3617                 if ((p = pfind(a.pm_pid)) == NULL) {
3618                         error = ESRCH;
3619                         break;
3620                 }
3621
3622                 /*
3623                  * Treat processes that are in the process of exiting
3624                  * as if they were not present.
3625                  */
3626
3627                 if (p->p_flag & P_WEXIT)
3628                         error = ESRCH;
3629
3630                 PROC_UNLOCK(p); /* pfind() returns a locked process */
3631
3632                 if (error == 0)
3633                         error = pmc_detach_process(p, pm);
3634         }
3635         break;
3636
3637
3638         /*
3639          * Retrieve the MSR number associated with the counter
3640          * 'pmc_id'.  This allows processes to directly use RDPMC
3641          * instructions to read their PMCs, without the overhead of a
3642          * system call.
3643          */
3644
3645         case PMC_OP_PMCGETMSR:
3646         {
3647                 int adjri, ri;
3648                 struct pmc *pm;
3649                 struct pmc_target *pt;
3650                 struct pmc_op_getmsr gm;
3651                 struct pmc_classdep *pcd;
3652
3653                 PMC_DOWNGRADE_SX();
3654
3655                 if ((error = copyin(arg, &gm, sizeof(gm))) != 0)
3656                         break;
3657
3658                 if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0)
3659                         break;
3660
3661                 /*
3662                  * The allocated PMC has to be a process virtual PMC,
3663                  * i.e., of type MODE_T[CS].  Global PMCs can only be
3664                  * read using the PMCREAD operation since they may be
3665                  * allocated on a different CPU than the one we could
3666                  * be running on at the time of the RDPMC instruction.
3667                  *
3668                  * The GETMSR operation is not allowed for PMCs that
3669                  * are inherited across processes.
3670                  */
3671
3672                 if (!PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)) ||
3673                     (pm->pm_flags & PMC_F_DESCENDANTS)) {
3674                         error = EINVAL;
3675                         break;
3676                 }
3677
3678                 /*
3679                  * It only makes sense to use a RDPMC (or its
3680                  * equivalent instruction on non-x86 architectures) on
3681                  * a process that has allocated and attached a PMC to
3682                  * itself.  Conversely the PMC is only allowed to have
3683                  * one process attached to it -- its owner.
3684                  */
3685
3686                 if ((pt = LIST_FIRST(&pm->pm_targets)) == NULL ||
3687                     LIST_NEXT(pt, pt_next) != NULL ||
3688                     pt->pt_process->pp_proc != pm->pm_owner->po_owner) {
3689                         error = EINVAL;
3690                         break;
3691                 }
3692
3693                 ri = PMC_TO_ROWINDEX(pm);
3694                 pcd = pmc_ri_to_classdep(md, ri, &adjri);
3695
3696                 /* PMC class has no 'GETMSR' support */
3697                 if (pcd->pcd_get_msr == NULL) {
3698                         error = ENOSYS;
3699                         break;
3700                 }
3701
3702                 if ((error = (*pcd->pcd_get_msr)(adjri, &gm.pm_msr)) < 0)
3703                         break;
3704
3705                 if ((error = copyout(&gm, arg, sizeof(gm))) < 0)
3706                         break;
3707
3708                 /*
3709                  * Mark our process as using MSRs.  Update machine
3710                  * state using a forced context switch.
3711                  */
3712
3713                 pt->pt_process->pp_flags |= PMC_PP_ENABLE_MSR_ACCESS;
3714                 pmc_force_context_switch();
3715
3716         }
3717         break;
3718
3719         /*
3720          * Release an allocated PMC
3721          */
3722
3723         case PMC_OP_PMCRELEASE:
3724         {
3725                 pmc_id_t pmcid;
3726                 struct pmc *pm;
3727                 struct pmc_owner *po;
3728                 struct pmc_op_simple sp;
3729
3730                 /*
3731                  * Find PMC pointer for the named PMC.
3732                  *
3733                  * Use pmc_release_pmc_descriptor() to switch off the
3734                  * PMC, remove all its target threads, and remove the
3735                  * PMC from its owner's list.
3736                  *
3737                  * Remove the owner record if this is the last PMC
3738                  * owned.
3739                  *
3740                  * Free up space.
3741                  */
3742
3743                 if ((error = copyin(arg, &sp, sizeof(sp))) != 0)
3744                         break;
3745
3746                 pmcid = sp.pm_pmcid;
3747
3748                 if ((error = pmc_find_pmc(pmcid, &pm)) != 0)
3749                         break;
3750
3751                 po = pm->pm_owner;
3752                 pmc_release_pmc_descriptor(pm);
3753                 pmc_maybe_remove_owner(po);
3754                 pmc_destroy_pmc_descriptor(pm);
3755         }
3756         break;
3757
3758
3759         /*
3760          * Read and/or write a PMC.
3761          */
3762
3763         case PMC_OP_PMCRW:
3764         {
3765                 int adjri;
3766                 struct pmc *pm;
3767                 uint32_t cpu, ri;
3768                 pmc_value_t oldvalue;
3769                 struct pmc_binding pb;
3770                 struct pmc_op_pmcrw prw;
3771                 struct pmc_classdep *pcd;
3772                 struct pmc_op_pmcrw *pprw;
3773
3774                 PMC_DOWNGRADE_SX();
3775
3776                 if ((error = copyin(arg, &prw, sizeof(prw))) != 0)
3777                         break;
3778
3779                 ri = 0;
3780                 PMCDBG2(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid,
3781                     prw.pm_flags);
3782
3783                 /* must have at least one flag set */
3784                 if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) {
3785                         error = EINVAL;
3786                         break;
3787                 }
3788
3789                 /* locate pmc descriptor */
3790                 if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0)
3791                         break;
3792
3793                 /* Can't read a PMC that hasn't been started. */
3794                 if (pm->pm_state != PMC_STATE_ALLOCATED &&
3795                     pm->pm_state != PMC_STATE_STOPPED &&
3796                     pm->pm_state != PMC_STATE_RUNNING) {
3797                         error = EINVAL;
3798                         break;
3799                 }
3800
3801                 /* writing a new value is allowed only for 'STOPPED' pmcs */
3802                 if (pm->pm_state == PMC_STATE_RUNNING &&
3803                     (prw.pm_flags & PMC_F_NEWVALUE)) {
3804                         error = EBUSY;
3805                         break;
3806                 }
3807
3808                 if (PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm))) {
3809
3810                         /*
3811                          * If this PMC is attached to its owner (i.e.,
3812                          * the process requesting this operation) and
3813                          * is running, then attempt to get an
3814                          * upto-date reading from hardware for a READ.
3815                          * Writes are only allowed when the PMC is
3816                          * stopped, so only update the saved value
3817                          * field.
3818                          *
3819                          * If the PMC is not running, or is not
3820                          * attached to its owner, read/write to the
3821                          * savedvalue field.
3822                          */
3823
3824                         ri = PMC_TO_ROWINDEX(pm);
3825                         pcd = pmc_ri_to_classdep(md, ri, &adjri);
3826
3827                         mtx_pool_lock_spin(pmc_mtxpool, pm);
3828                         cpu = curthread->td_oncpu;
3829
3830                         if (prw.pm_flags & PMC_F_OLDVALUE) {
3831                                 if ((pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) &&
3832                                     (pm->pm_state == PMC_STATE_RUNNING))
3833                                         error = (*pcd->pcd_read_pmc)(cpu, adjri,
3834                                             &oldvalue);
3835                                 else
3836                                         oldvalue = pm->pm_gv.pm_savedvalue;
3837                         }
3838                         if (prw.pm_flags & PMC_F_NEWVALUE)
3839                                 pm->pm_gv.pm_savedvalue = prw.pm_value;
3840
3841                         mtx_pool_unlock_spin(pmc_mtxpool, pm);
3842
3843                 } else { /* System mode PMCs */
3844                         cpu = PMC_TO_CPU(pm);
3845                         ri  = PMC_TO_ROWINDEX(pm);
3846                         pcd = pmc_ri_to_classdep(md, ri, &adjri);
3847
3848                         if (!pmc_cpu_is_active(cpu)) {
3849                                 error = ENXIO;
3850                                 break;
3851                         }
3852
3853                         /* move this thread to CPU 'cpu' */
3854                         pmc_save_cpu_binding(&pb);
3855                         pmc_select_cpu(cpu);
3856
3857                         critical_enter();
3858                         /* save old value */
3859                         if (prw.pm_flags & PMC_F_OLDVALUE)
3860                                 if ((error = (*pcd->pcd_read_pmc)(cpu, adjri,
3861                                          &oldvalue)))
3862                                         goto error;
3863                         /* write out new value */
3864                         if (prw.pm_flags & PMC_F_NEWVALUE)
3865                                 error = (*pcd->pcd_write_pmc)(cpu, adjri,
3866                                     prw.pm_value);
3867                 error:
3868                         critical_exit();
3869                         pmc_restore_cpu_binding(&pb);
3870                         if (error)
3871                                 break;
3872                 }
3873
3874                 pprw = (struct pmc_op_pmcrw *) arg;
3875
3876 #ifdef  HWPMC_DEBUG
3877                 if (prw.pm_flags & PMC_F_NEWVALUE)
3878                         PMCDBG3(PMC,OPS,2, "rw id=%d new %jx -> old %jx",
3879                             ri, prw.pm_value, oldvalue);
3880                 else if (prw.pm_flags & PMC_F_OLDVALUE)
3881                         PMCDBG2(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue);
3882 #endif
3883
3884                 /* return old value if requested */
3885                 if (prw.pm_flags & PMC_F_OLDVALUE)
3886                         if ((error = copyout(&oldvalue, &pprw->pm_value,
3887                                  sizeof(prw.pm_value))))
3888                                 break;
3889
3890         }
3891         break;
3892
3893
3894         /*
3895          * Set the sampling rate for a sampling mode PMC and the
3896          * initial count for a counting mode PMC.
3897          */
3898
3899         case PMC_OP_PMCSETCOUNT:
3900         {
3901                 struct pmc *pm;
3902                 struct pmc_op_pmcsetcount sc;
3903
3904                 PMC_DOWNGRADE_SX();
3905
3906                 if ((error = copyin(arg, &sc, sizeof(sc))) != 0)
3907                         break;
3908
3909                 if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0)
3910                         break;
3911
3912                 if (pm->pm_state == PMC_STATE_RUNNING) {
3913                         error = EBUSY;
3914                         break;
3915                 }
3916
3917                 if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
3918                         pm->pm_sc.pm_reloadcount = sc.pm_count;
3919                 else
3920                         pm->pm_sc.pm_initial = sc.pm_count;
3921         }
3922         break;
3923
3924
3925         /*
3926          * Start a PMC.
3927          */
3928
3929         case PMC_OP_PMCSTART:
3930         {
3931                 pmc_id_t pmcid;
3932                 struct pmc *pm;
3933                 struct pmc_op_simple sp;
3934
3935                 sx_assert(&pmc_sx, SX_XLOCKED);
3936
3937                 if ((error = copyin(arg, &sp, sizeof(sp))) != 0)
3938                         break;
3939
3940                 pmcid = sp.pm_pmcid;
3941
3942                 if ((error = pmc_find_pmc(pmcid, &pm)) != 0)
3943                         break;
3944
3945                 KASSERT(pmcid == pm->pm_id,
3946                     ("[pmc,%d] pmcid %x != id %x", __LINE__,
3947                         pm->pm_id, pmcid));
3948
3949                 if (pm->pm_state == PMC_STATE_RUNNING) /* already running */
3950                         break;
3951                 else if (pm->pm_state != PMC_STATE_STOPPED &&
3952                     pm->pm_state != PMC_STATE_ALLOCATED) {
3953                         error = EINVAL;
3954                         break;
3955                 }
3956
3957                 error = pmc_start(pm);
3958         }
3959         break;
3960
3961
3962         /*
3963          * Stop a PMC.
3964          */
3965
3966         case PMC_OP_PMCSTOP:
3967         {
3968                 pmc_id_t pmcid;
3969                 struct pmc *pm;
3970                 struct pmc_op_simple sp;
3971
3972                 PMC_DOWNGRADE_SX();
3973
3974                 if ((error = copyin(arg, &sp, sizeof(sp))) != 0)
3975                         break;
3976
3977                 pmcid = sp.pm_pmcid;
3978
3979                 /*
3980                  * Mark the PMC as inactive and invoke the MD stop
3981                  * routines if needed.
3982                  */
3983
3984                 if ((error = pmc_find_pmc(pmcid, &pm)) != 0)
3985                         break;
3986
3987                 KASSERT(pmcid == pm->pm_id,
3988                     ("[pmc,%d] pmc id %x != pmcid %x", __LINE__,
3989                         pm->pm_id, pmcid));
3990
3991                 if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */
3992                         break;
3993                 else if (pm->pm_state != PMC_STATE_RUNNING) {
3994                         error = EINVAL;
3995                         break;
3996                 }
3997
3998                 error = pmc_stop(pm);
3999         }
4000         break;
4001
4002
4003         /*
4004          * Write a user supplied value to the log file.
4005          */
4006
4007         case PMC_OP_WRITELOG:
4008         {
4009                 struct pmc_op_writelog wl;
4010                 struct pmc_owner *po;
4011
4012                 PMC_DOWNGRADE_SX();
4013
4014                 if ((error = copyin(arg, &wl, sizeof(wl))) != 0)
4015                         break;
4016
4017                 if ((po = pmc_find_owner_descriptor(td->td_proc)) == NULL) {
4018                         error = EINVAL;
4019                         break;
4020                 }
4021
4022                 if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) {
4023                         error = EINVAL;
4024                         break;
4025                 }
4026
4027                 error = pmclog_process_userlog(po, &wl);
4028         }
4029         break;
4030
4031
4032         default:
4033                 error = EINVAL;
4034                 break;
4035         }
4036
4037         if (is_sx_downgraded)
4038                 sx_sunlock(&pmc_sx);
4039         else
4040                 sx_xunlock(&pmc_sx);
4041 done_syscall:
4042         if (error)
4043                 atomic_add_int(&pmc_stats.pm_syscall_errors, 1);
4044
4045         return (error);
4046 }
4047
4048 /*
4049  * Helper functions
4050  */
4051
4052
4053 /*
4054  * Mark the thread as needing callchain capture and post an AST.  The
4055  * actual callchain capture will be done in a context where it is safe
4056  * to take page faults.
4057  */
4058
4059 static void
4060 pmc_post_callchain_callback(void)
4061 {
4062         struct thread *td;
4063
4064         td = curthread;
4065
4066         /*
4067          * If there is multiple PMCs for the same interrupt ignore new post
4068          */
4069         if (td->td_pflags & TDP_CALLCHAIN)
4070                 return;
4071
4072         /*
4073          * Mark this thread as needing callchain capture.
4074          * `td->td_pflags' will be safe to touch because this thread
4075          * was in user space when it was interrupted.
4076          */
4077         td->td_pflags |= TDP_CALLCHAIN;
4078
4079         /*
4080          * Don't let this thread migrate between CPUs until callchain
4081          * capture completes.
4082          */
4083         sched_pin();
4084
4085         return;
4086 }
4087
4088 /*
4089  * Interrupt processing.
4090  *
4091  * Find a free slot in the per-cpu array of samples and capture the
4092  * current callchain there.  If a sample was successfully added, a bit
4093  * is set in mask 'pmc_cpumask' denoting that the DO_SAMPLES hook
4094  * needs to be invoked from the clock handler.
4095  *
4096  * This function is meant to be called from an NMI handler.  It cannot
4097  * use any of the locking primitives supplied by the OS.
4098  */
4099
4100 int
4101 pmc_process_interrupt(int cpu, int ring, struct pmc *pm, struct trapframe *tf,
4102     int inuserspace)
4103 {
4104         int error, callchaindepth;
4105         struct thread *td;
4106         struct pmc_sample *ps;
4107         struct pmc_samplebuffer *psb;
4108
4109         error = 0;
4110
4111         /*
4112          * Allocate space for a sample buffer.
4113          */
4114         psb = pmc_pcpu[cpu]->pc_sb[ring];
4115
4116         ps = psb->ps_write;
4117         if (ps->ps_nsamples) {  /* in use, reader hasn't caught up */
4118                 CPU_SET_ATOMIC(cpu, &pm->pm_stalled);
4119                 atomic_add_int(&pmc_stats.pm_intr_bufferfull, 1);
4120                 PMCDBG6(SAM,INT,1,"(spc) cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d",
4121                     cpu, pm, (void *) tf, inuserspace,
4122                     (int) (psb->ps_write - psb->ps_samples),
4123                     (int) (psb->ps_read - psb->ps_samples));
4124                 callchaindepth = 1;
4125                 error = ENOMEM;
4126                 goto done;
4127         }
4128
4129
4130         /* Fill in entry. */
4131         PMCDBG6(SAM,INT,1,"cpu=%d pm=%p tf=%p um=%d wr=%d rd=%d", cpu, pm,
4132             (void *) tf, inuserspace,
4133             (int) (psb->ps_write - psb->ps_samples),
4134             (int) (psb->ps_read - psb->ps_samples));
4135
4136         KASSERT(pm->pm_runcount >= 0,
4137             ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm,
4138                 pm->pm_runcount));
4139
4140         atomic_add_rel_int(&pm->pm_runcount, 1);        /* hold onto PMC */
4141
4142         ps->ps_pmc = pm;
4143         if ((td = curthread) && td->td_proc)
4144                 ps->ps_pid = td->td_proc->p_pid;
4145         else
4146                 ps->ps_pid = -1;
4147         ps->ps_cpu = cpu;
4148         ps->ps_td = td;
4149         ps->ps_flags = inuserspace ? PMC_CC_F_USERSPACE : 0;
4150
4151         callchaindepth = (pm->pm_flags & PMC_F_CALLCHAIN) ?
4152             pmc_callchaindepth : 1;
4153
4154         if (callchaindepth == 1)
4155                 ps->ps_pc[0] = PMC_TRAPFRAME_TO_PC(tf);
4156         else {
4157                 /*
4158                  * Kernel stack traversals can be done immediately,
4159                  * while we defer to an AST for user space traversals.
4160                  */
4161                 if (!inuserspace) {
4162                         callchaindepth =
4163                             pmc_save_kernel_callchain(ps->ps_pc,
4164                                 callchaindepth, tf);
4165                 } else {
4166                         pmc_post_callchain_callback();
4167                         callchaindepth = PMC_SAMPLE_INUSE;
4168                 }
4169         }
4170
4171         ps->ps_nsamples = callchaindepth;       /* mark entry as in use */
4172
4173         /* increment write pointer, modulo ring buffer size */
4174         ps++;
4175         if (ps == psb->ps_fence)
4176                 psb->ps_write = psb->ps_samples;
4177         else
4178                 psb->ps_write = ps;
4179
4180  done:
4181         /* mark CPU as needing processing */
4182         if (callchaindepth != PMC_SAMPLE_INUSE)
4183                 CPU_SET_ATOMIC(cpu, &pmc_cpumask);
4184
4185         return (error);
4186 }
4187
4188 /*
4189  * Capture a user call chain.  This function will be called from ast()
4190  * before control returns to userland and before the process gets
4191  * rescheduled.
4192  */
4193
4194 static void
4195 pmc_capture_user_callchain(int cpu, int ring, struct trapframe *tf)
4196 {
4197         struct pmc *pm;
4198         struct thread *td;
4199         struct pmc_sample *ps, *ps_end;
4200         struct pmc_samplebuffer *psb;
4201 #ifdef  INVARIANTS
4202         int ncallchains;
4203         int nfree;
4204 #endif
4205
4206         psb = pmc_pcpu[cpu]->pc_sb[ring];
4207         td = curthread;
4208
4209         KASSERT(td->td_pflags & TDP_CALLCHAIN,
4210             ("[pmc,%d] Retrieving callchain for thread that doesn't want it",
4211                 __LINE__));
4212
4213 #ifdef  INVARIANTS
4214         ncallchains = 0;
4215         nfree = 0;
4216 #endif
4217
4218         /*
4219          * Iterate through all deferred callchain requests.
4220          * Walk from the current read pointer to the current
4221          * write pointer.
4222          */
4223
4224         ps = psb->ps_read;
4225         ps_end = psb->ps_write;
4226         do {
4227 #ifdef  INVARIANTS
4228                 if ((ps->ps_pmc == NULL) ||
4229                     (ps->ps_pmc->pm_state != PMC_STATE_RUNNING))
4230                         nfree++;
4231 #endif
4232                 if (ps->ps_nsamples != PMC_SAMPLE_INUSE)
4233                         goto next;
4234                 if (ps->ps_td != td)
4235                         goto next;
4236
4237                 KASSERT(ps->ps_cpu == cpu,
4238                     ("[pmc,%d] cpu mismatch ps_cpu=%d pcpu=%d", __LINE__,
4239                         ps->ps_cpu, PCPU_GET(cpuid)));
4240
4241                 pm = ps->ps_pmc;
4242
4243                 KASSERT(pm->pm_flags & PMC_F_CALLCHAIN,
4244                     ("[pmc,%d] Retrieving callchain for PMC that doesn't "
4245                         "want it", __LINE__));
4246
4247                 KASSERT(pm->pm_runcount > 0,
4248                     ("[pmc,%d] runcount %d", __LINE__, pm->pm_runcount));
4249
4250                 /*
4251                  * Retrieve the callchain and mark the sample buffer
4252                  * as 'processable' by the timer tick sweep code.
4253                  */
4254                 ps->ps_nsamples = pmc_save_user_callchain(ps->ps_pc,
4255                     pmc_callchaindepth, tf);
4256
4257 #ifdef  INVARIANTS
4258                 ncallchains++;
4259 #endif
4260
4261 next:
4262                 /* increment the pointer, modulo sample ring size */
4263                 if (++ps == psb->ps_fence)
4264                         ps = psb->ps_samples;
4265         } while (ps != ps_end);
4266
4267 #ifdef  INVARIANTS
4268         KASSERT(ncallchains > 0 || nfree > 0,
4269             ("[pmc,%d] cpu %d didn't find a sample to collect", __LINE__,
4270                 cpu));
4271 #endif
4272
4273         KASSERT(td->td_pinned == 1,
4274             ("[pmc,%d] invalid td_pinned value", __LINE__));
4275         sched_unpin();  /* Can migrate safely now. */
4276
4277         /* mark CPU as needing processing */
4278         CPU_SET_ATOMIC(cpu, &pmc_cpumask);
4279
4280         return;
4281 }
4282
4283 /*
4284  * Process saved PC samples.
4285  */
4286
4287 static void
4288 pmc_process_samples(int cpu, int ring)
4289 {
4290         struct pmc *pm;
4291         int adjri, n;
4292         struct thread *td;
4293         struct pmc_owner *po;
4294         struct pmc_sample *ps;
4295         struct pmc_classdep *pcd;
4296         struct pmc_samplebuffer *psb;
4297
4298         KASSERT(PCPU_GET(cpuid) == cpu,
4299             ("[pmc,%d] not on the correct CPU pcpu=%d cpu=%d", __LINE__,
4300                 PCPU_GET(cpuid), cpu));
4301
4302         psb = pmc_pcpu[cpu]->pc_sb[ring];
4303
4304         for (n = 0; n < pmc_nsamples; n++) { /* bound on #iterations */
4305
4306                 ps = psb->ps_read;
4307                 if (ps->ps_nsamples == PMC_SAMPLE_FREE)
4308                         break;
4309
4310                 pm = ps->ps_pmc;
4311
4312                 KASSERT(pm->pm_runcount > 0,
4313                     ("[pmc,%d] pm=%p runcount %d", __LINE__, (void *) pm,
4314                         pm->pm_runcount));
4315
4316                 po = pm->pm_owner;
4317
4318                 KASSERT(PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)),
4319                     ("[pmc,%d] pmc=%p non-sampling mode=%d", __LINE__,
4320                         pm, PMC_TO_MODE(pm)));
4321
4322                 /* Ignore PMCs that have been switched off */
4323                 if (pm->pm_state != PMC_STATE_RUNNING)
4324                         goto entrydone;
4325
4326                 /* If there is a pending AST wait for completion */
4327                 if (ps->ps_nsamples == PMC_SAMPLE_INUSE) {
4328                         /* Need a rescan at a later time. */
4329                         CPU_SET_ATOMIC(cpu, &pmc_cpumask);
4330                         break;
4331                 }
4332
4333                 PMCDBG6(SAM,OPS,1,"cpu=%d pm=%p n=%d fl=%x wr=%d rd=%d", cpu,
4334                     pm, ps->ps_nsamples, ps->ps_flags,
4335                     (int) (psb->ps_write - psb->ps_samples),
4336                     (int) (psb->ps_read - psb->ps_samples));
4337
4338                 /*
4339                  * If this is a process-mode PMC that is attached to
4340                  * its owner, and if the PC is in user mode, update
4341                  * profiling statistics like timer-based profiling
4342                  * would have done.
4343                  */
4344                 if (pm->pm_flags & PMC_F_ATTACHED_TO_OWNER) {
4345                         if (ps->ps_flags & PMC_CC_F_USERSPACE) {
4346                                 td = FIRST_THREAD_IN_PROC(po->po_owner);
4347                                 addupc_intr(td, ps->ps_pc[0], 1);
4348                         }
4349                         goto entrydone;
4350                 }
4351
4352                 /*
4353                  * Otherwise, this is either a sampling mode PMC that
4354                  * is attached to a different process than its owner,
4355                  * or a system-wide sampling PMC.  Dispatch a log
4356                  * entry to the PMC's owner process.
4357                  */
4358                 pmclog_process_callchain(pm, ps);
4359
4360         entrydone:
4361                 ps->ps_nsamples = 0; /* mark entry as free */
4362                 atomic_subtract_rel_int(&pm->pm_runcount, 1);
4363
4364                 /* increment read pointer, modulo sample size */
4365                 if (++ps == psb->ps_fence)
4366                         psb->ps_read = psb->ps_samples;
4367                 else
4368                         psb->ps_read = ps;
4369         }
4370
4371         atomic_add_int(&pmc_stats.pm_log_sweeps, 1);
4372
4373         /* Do not re-enable stalled PMCs if we failed to process any samples */
4374         if (n == 0)
4375                 return;
4376
4377         /*
4378          * Restart any stalled sampling PMCs on this CPU.
4379          *
4380          * If the NMI handler sets the pm_stalled field of a PMC after
4381          * the check below, we'll end up processing the stalled PMC at
4382          * the next hardclock tick.
4383          */
4384         for (n = 0; n < md->pmd_npmc; n++) {
4385                 pcd = pmc_ri_to_classdep(md, n, &adjri);
4386                 KASSERT(pcd != NULL,
4387                     ("[pmc,%d] null pcd ri=%d", __LINE__, n));
4388                 (void) (*pcd->pcd_get_config)(cpu,adjri,&pm);
4389
4390                 if (pm == NULL ||                        /* !cfg'ed */
4391                     pm->pm_state != PMC_STATE_RUNNING || /* !active */
4392                     !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)) || /* !sampling */
4393                     !CPU_ISSET(cpu, &pm->pm_cpustate) || /* !desired */
4394                     !CPU_ISSET(cpu, &pm->pm_stalled)) /* !stalled */
4395                         continue;
4396
4397                 CPU_CLR_ATOMIC(cpu, &pm->pm_stalled);
4398                 (*pcd->pcd_start_pmc)(cpu, adjri);
4399         }
4400 }
4401
4402 /*
4403  * Event handlers.
4404  */
4405
4406 /*
4407  * Handle a process exit.
4408  *
4409  * Remove this process from all hash tables.  If this process
4410  * owned any PMCs, turn off those PMCs and deallocate them,
4411  * removing any associations with target processes.
4412  *
4413  * This function will be called by the last 'thread' of a
4414  * process.
4415  *
4416  * XXX This eventhandler gets called early in the exit process.
4417  * Consider using a 'hook' invocation from thread_exit() or equivalent
4418  * spot.  Another negative is that kse_exit doesn't seem to call
4419  * exit1() [??].
4420  *
4421  */
4422
4423 static void
4424 pmc_process_exit(void *arg __unused, struct proc *p)
4425 {
4426         struct pmc *pm;
4427         int adjri, cpu;
4428         unsigned int ri;
4429         int is_using_hwpmcs;
4430         struct pmc_owner *po;
4431         struct pmc_process *pp;
4432         struct pmc_classdep *pcd;
4433         pmc_value_t newvalue, tmp;
4434
4435         PROC_LOCK(p);
4436         is_using_hwpmcs = p->p_flag & P_HWPMC;
4437         PROC_UNLOCK(p);
4438
4439         /*
4440          * Log a sysexit event to all SS PMC owners.
4441          */
4442         LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
4443             if (po->po_flags & PMC_PO_OWNS_LOGFILE)
4444                     pmclog_process_sysexit(po, p->p_pid);
4445
4446         if (!is_using_hwpmcs)
4447                 return;
4448
4449         PMC_GET_SX_XLOCK();
4450         PMCDBG3(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid,
4451             p->p_comm);
4452
4453         /*
4454          * Since this code is invoked by the last thread in an exiting
4455          * process, we would have context switched IN at some prior
4456          * point.  However, with PREEMPTION, kernel mode context
4457          * switches may happen any time, so we want to disable a
4458          * context switch OUT till we get any PMCs targeting this
4459          * process off the hardware.
4460          *
4461          * We also need to atomically remove this process'
4462          * entry from our target process hash table, using
4463          * PMC_FLAG_REMOVE.
4464          */
4465         PMCDBG3(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid,
4466             p->p_comm);
4467
4468         critical_enter(); /* no preemption */
4469
4470         cpu = curthread->td_oncpu;
4471
4472         if ((pp = pmc_find_process_descriptor(p,
4473                  PMC_FLAG_REMOVE)) != NULL) {
4474
4475                 PMCDBG2(PRC,EXT,2,
4476                     "process-exit proc=%p pmc-process=%p", p, pp);
4477
4478                 /*
4479                  * The exiting process could the target of
4480                  * some PMCs which will be running on
4481                  * currently executing CPU.
4482                  *
4483                  * We need to turn these PMCs off like we
4484                  * would do at context switch OUT time.
4485                  */
4486                 for (ri = 0; ri < md->pmd_npmc; ri++) {
4487
4488                         /*
4489                          * Pick up the pmc pointer from hardware
4490                          * state similar to the CSW_OUT code.
4491                          */
4492                         pm = NULL;
4493
4494                         pcd = pmc_ri_to_classdep(md, ri, &adjri);
4495
4496                         (void) (*pcd->pcd_get_config)(cpu, adjri, &pm);
4497
4498                         PMCDBG2(PRC,EXT,2, "ri=%d pm=%p", ri, pm);
4499
4500                         if (pm == NULL ||
4501                             !PMC_IS_VIRTUAL_MODE(PMC_TO_MODE(pm)))
4502                                 continue;
4503
4504                         PMCDBG4(PRC,EXT,2, "ppmcs[%d]=%p pm=%p "
4505                             "state=%d", ri, pp->pp_pmcs[ri].pp_pmc,
4506                             pm, pm->pm_state);
4507
4508                         KASSERT(PMC_TO_ROWINDEX(pm) == ri,
4509                             ("[pmc,%d] ri mismatch pmc(%d) ri(%d)",
4510                                 __LINE__, PMC_TO_ROWINDEX(pm), ri));
4511
4512                         KASSERT(pm == pp->pp_pmcs[ri].pp_pmc,
4513                             ("[pmc,%d] pm %p != pp_pmcs[%d] %p",
4514                                 __LINE__, pm, ri, pp->pp_pmcs[ri].pp_pmc));
4515
4516                         KASSERT(pm->pm_runcount > 0,
4517                             ("[pmc,%d] bad runcount ri %d rc %d",
4518                                 __LINE__, ri, pm->pm_runcount));
4519
4520                         /*
4521                          * Change desired state, and then stop if not
4522                          * stalled. This two-step dance should avoid
4523                          * race conditions where an interrupt re-enables
4524                          * the PMC after this code has already checked
4525                          * the pm_stalled flag.
4526                          */
4527                         if (CPU_ISSET(cpu, &pm->pm_cpustate)) {
4528                                 CPU_CLR_ATOMIC(cpu, &pm->pm_cpustate);
4529                                 if (!CPU_ISSET(cpu, &pm->pm_stalled)) {
4530                                         (void) pcd->pcd_stop_pmc(cpu, adjri);
4531                                         pcd->pcd_read_pmc(cpu, adjri,
4532                                             &newvalue);
4533                                         tmp = newvalue -
4534                                             PMC_PCPU_SAVED(cpu,ri);
4535
4536                                         mtx_pool_lock_spin(pmc_mtxpool, pm);
4537                                         pm->pm_gv.pm_savedvalue += tmp;
4538                                         pp->pp_pmcs[ri].pp_pmcval += tmp;
4539                                         mtx_pool_unlock_spin(pmc_mtxpool, pm);
4540                                 }
4541                         }
4542
4543                         atomic_subtract_rel_int(&pm->pm_runcount,1);
4544
4545                         KASSERT((int) pm->pm_runcount >= 0,
4546                             ("[pmc,%d] runcount is %d", __LINE__, ri));
4547
4548                         (void) pcd->pcd_config_pmc(cpu, adjri, NULL);
4549                 }
4550
4551                 /*
4552                  * Inform the MD layer of this pseudo "context switch
4553                  * out"
4554                  */
4555                 (void) md->pmd_switch_out(pmc_pcpu[cpu], pp);
4556
4557                 critical_exit(); /* ok to be pre-empted now */
4558
4559                 /*
4560                  * Unlink this process from the PMCs that are
4561                  * targeting it.  This will send a signal to
4562                  * all PMC owner's whose PMCs are orphaned.
4563                  *
4564                  * Log PMC value at exit time if requested.
4565                  */
4566                 for (ri = 0; ri < md->pmd_npmc; ri++)
4567                         if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) {
4568                                 if (pm->pm_flags & PMC_F_NEEDS_LOGFILE &&
4569                                     PMC_IS_COUNTING_MODE(PMC_TO_MODE(pm)))
4570                                         pmclog_process_procexit(pm, pp);
4571                                 pmc_unlink_target_process(pm, pp);
4572                         }
4573                 free(pp, M_PMC);
4574
4575         } else
4576                 critical_exit(); /* pp == NULL */
4577
4578
4579         /*
4580          * If the process owned PMCs, free them up and free up
4581          * memory.
4582          */
4583         if ((po = pmc_find_owner_descriptor(p)) != NULL) {
4584                 pmc_remove_owner(po);
4585                 pmc_destroy_owner_descriptor(po);
4586         }
4587
4588         sx_xunlock(&pmc_sx);
4589 }
4590
4591 /*
4592  * Handle a process fork.
4593  *
4594  * If the parent process 'p1' is under HWPMC monitoring, then copy
4595  * over any attached PMCs that have 'do_descendants' semantics.
4596  */
4597
4598 static void
4599 pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *newproc,
4600     int flags)
4601 {
4602         int is_using_hwpmcs;
4603         unsigned int ri;
4604         uint32_t do_descendants;
4605         struct pmc *pm;
4606         struct pmc_owner *po;
4607         struct pmc_process *ppnew, *ppold;
4608
4609         (void) flags;           /* unused parameter */
4610
4611         PROC_LOCK(p1);
4612         is_using_hwpmcs = p1->p_flag & P_HWPMC;
4613         PROC_UNLOCK(p1);
4614
4615         /*
4616          * If there are system-wide sampling PMCs active, we need to
4617          * log all fork events to their owner's logs.
4618          */
4619
4620         LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
4621             if (po->po_flags & PMC_PO_OWNS_LOGFILE)
4622                     pmclog_process_procfork(po, p1->p_pid, newproc->p_pid);
4623
4624         if (!is_using_hwpmcs)
4625                 return;
4626
4627         PMC_GET_SX_XLOCK();
4628         PMCDBG4(PMC,FRK,1, "process-fork proc=%p (%d, %s) -> %p", p1,
4629             p1->p_pid, p1->p_comm, newproc);
4630
4631         /*
4632          * If the parent process (curthread->td_proc) is a
4633          * target of any PMCs, look for PMCs that are to be
4634          * inherited, and link these into the new process
4635          * descriptor.
4636          */
4637         if ((ppold = pmc_find_process_descriptor(curthread->td_proc,
4638                  PMC_FLAG_NONE)) == NULL)
4639                 goto done;              /* nothing to do */
4640
4641         do_descendants = 0;
4642         for (ri = 0; ri < md->pmd_npmc; ri++)
4643                 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL)
4644                         do_descendants |= pm->pm_flags & PMC_F_DESCENDANTS;
4645         if (do_descendants == 0) /* nothing to do */
4646                 goto done;
4647
4648         /* allocate a descriptor for the new process  */
4649         if ((ppnew = pmc_find_process_descriptor(newproc,
4650                  PMC_FLAG_ALLOCATE)) == NULL)
4651                 goto done;
4652
4653         /*
4654          * Run through all PMCs that were targeting the old process
4655          * and which specified F_DESCENDANTS and attach them to the
4656          * new process.
4657          *
4658          * Log the fork event to all owners of PMCs attached to this
4659          * process, if not already logged.
4660          */
4661         for (ri = 0; ri < md->pmd_npmc; ri++)
4662                 if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL &&
4663                     (pm->pm_flags & PMC_F_DESCENDANTS)) {
4664                         pmc_link_target_process(pm, ppnew);
4665                         po = pm->pm_owner;
4666                         if (po->po_sscount == 0 &&
4667                             po->po_flags & PMC_PO_OWNS_LOGFILE)
4668                                 pmclog_process_procfork(po, p1->p_pid,
4669                                     newproc->p_pid);
4670                 }
4671
4672         /*
4673          * Now mark the new process as being tracked by this driver.
4674          */
4675         PROC_LOCK(newproc);
4676         newproc->p_flag |= P_HWPMC;
4677         PROC_UNLOCK(newproc);
4678
4679  done:
4680         sx_xunlock(&pmc_sx);
4681 }
4682
4683 static void
4684 pmc_kld_load(void *arg __unused, linker_file_t lf)
4685 {
4686         struct pmc_owner *po;
4687
4688         sx_slock(&pmc_sx);
4689
4690         /*
4691          * Notify owners of system sampling PMCs about KLD operations.
4692          */
4693         LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
4694                 if (po->po_flags & PMC_PO_OWNS_LOGFILE)
4695                         pmclog_process_map_in(po, (pid_t) -1,
4696                             (uintfptr_t) lf->address, lf->filename);
4697
4698         /*
4699          * TODO: Notify owners of (all) process-sampling PMCs too.
4700          */
4701
4702         sx_sunlock(&pmc_sx);
4703 }
4704
4705 static void
4706 pmc_kld_unload(void *arg __unused, const char *filename __unused,
4707     caddr_t address, size_t size)
4708 {
4709         struct pmc_owner *po;
4710
4711         sx_slock(&pmc_sx);
4712
4713         LIST_FOREACH(po, &pmc_ss_owners, po_ssnext)
4714                 if (po->po_flags & PMC_PO_OWNS_LOGFILE)
4715                         pmclog_process_map_out(po, (pid_t) -1,
4716                             (uintfptr_t) address, (uintfptr_t) address + size);
4717
4718         /*
4719          * TODO: Notify owners of process-sampling PMCs.
4720          */
4721
4722         sx_sunlock(&pmc_sx);
4723 }
4724
4725 /*
4726  * initialization
4727  */
4728 static const char *
4729 pmc_name_of_pmcclass(enum pmc_class class)
4730 {
4731
4732         switch (class) {
4733 #undef  __PMC_CLASS
4734 #define __PMC_CLASS(S,V,D)                                              \
4735         case PMC_CLASS_##S:                                             \
4736                 return #S;
4737         __PMC_CLASSES();
4738         default:
4739                 return ("<unknown>");
4740         }
4741 }
4742
4743 /*
4744  * Base class initializer: allocate structure and set default classes.
4745  */
4746 struct pmc_mdep *
4747 pmc_mdep_alloc(int nclasses)
4748 {
4749         struct pmc_mdep *md;
4750         int     n;
4751
4752         /* SOFT + md classes */
4753         n = 1 + nclasses;
4754         md = malloc(sizeof(struct pmc_mdep) + n *
4755             sizeof(struct pmc_classdep), M_PMC, M_WAITOK|M_ZERO);
4756         md->pmd_nclass = n;
4757
4758         /* Add base class. */
4759         pmc_soft_initialize(md);
4760         return md;
4761 }
4762
4763 void
4764 pmc_mdep_free(struct pmc_mdep *md)
4765 {
4766         pmc_soft_finalize(md);
4767         free(md, M_PMC);
4768 }
4769
4770 static int
4771 generic_switch_in(struct pmc_cpu *pc, struct pmc_process *pp)
4772 {
4773         (void) pc; (void) pp;
4774
4775         return (0);
4776 }
4777
4778 static int
4779 generic_switch_out(struct pmc_cpu *pc, struct pmc_process *pp)
4780 {
4781         (void) pc; (void) pp;
4782
4783         return (0);
4784 }
4785
4786 static struct pmc_mdep *
4787 pmc_generic_cpu_initialize(void)
4788 {
4789         struct pmc_mdep *md;
4790
4791         md = pmc_mdep_alloc(0);
4792
4793         md->pmd_cputype    = PMC_CPU_GENERIC;
4794
4795         md->pmd_pcpu_init  = NULL;
4796         md->pmd_pcpu_fini  = NULL;
4797         md->pmd_switch_in  = generic_switch_in;
4798         md->pmd_switch_out = generic_switch_out;
4799
4800         return (md);
4801 }
4802
4803 static void
4804 pmc_generic_cpu_finalize(struct pmc_mdep *md)
4805 {
4806         (void) md;
4807 }
4808
4809
4810 static int
4811 pmc_initialize(void)
4812 {
4813         int c, cpu, error, n, ri;
4814         unsigned int maxcpu;
4815         struct pmc_binding pb;
4816         struct pmc_sample *ps;
4817         struct pmc_classdep *pcd;
4818         struct pmc_samplebuffer *sb;
4819
4820         md = NULL;
4821         error = 0;
4822
4823 #ifdef  HWPMC_DEBUG
4824         /* parse debug flags first */
4825         if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags",
4826                 pmc_debugstr, sizeof(pmc_debugstr)))
4827                 pmc_debugflags_parse(pmc_debugstr,
4828                     pmc_debugstr+strlen(pmc_debugstr));
4829 #endif
4830
4831         PMCDBG1(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION);
4832
4833         /* check kernel version */
4834         if (pmc_kernel_version != PMC_VERSION) {
4835                 if (pmc_kernel_version == 0)
4836                         printf("hwpmc: this kernel has not been compiled with "
4837                             "'options HWPMC_HOOKS'.\n");
4838                 else
4839                         printf("hwpmc: kernel version (0x%x) does not match "
4840                             "module version (0x%x).\n", pmc_kernel_version,
4841                             PMC_VERSION);
4842                 return EPROGMISMATCH;
4843         }
4844
4845         /*
4846          * check sysctl parameters
4847          */
4848
4849         if (pmc_hashsize <= 0) {
4850                 (void) printf("hwpmc: tunable \"hashsize\"=%d must be "
4851                     "greater than zero.\n", pmc_hashsize);
4852                 pmc_hashsize = PMC_HASH_SIZE;
4853         }
4854
4855         if (pmc_nsamples <= 0 || pmc_nsamples > 65535) {
4856                 (void) printf("hwpmc: tunable \"nsamples\"=%d out of "
4857                     "range.\n", pmc_nsamples);
4858                 pmc_nsamples = PMC_NSAMPLES;
4859         }
4860
4861         if (pmc_callchaindepth <= 0 ||
4862             pmc_callchaindepth > PMC_CALLCHAIN_DEPTH_MAX) {
4863                 (void) printf("hwpmc: tunable \"callchaindepth\"=%d out of "
4864                     "range - using %d.\n", pmc_callchaindepth,
4865                     PMC_CALLCHAIN_DEPTH_MAX);
4866                 pmc_callchaindepth = PMC_CALLCHAIN_DEPTH_MAX;
4867         }
4868
4869         md = pmc_md_initialize();
4870         if (md == NULL) {
4871                 /* Default to generic CPU. */
4872                 md = pmc_generic_cpu_initialize();
4873                 if (md == NULL)
4874                         return (ENOSYS);
4875         }
4876
4877         KASSERT(md->pmd_nclass >= 1 && md->pmd_npmc >= 1,
4878             ("[pmc,%d] no classes or pmcs", __LINE__));
4879
4880         /* Compute the map from row-indices to classdep pointers. */
4881         pmc_rowindex_to_classdep = malloc(sizeof(struct pmc_classdep *) *
4882             md->pmd_npmc, M_PMC, M_WAITOK|M_ZERO);
4883
4884         for (n = 0; n < md->pmd_npmc; n++)
4885                 pmc_rowindex_to_classdep[n] = NULL;
4886         for (ri = c = 0; c < md->pmd_nclass; c++) {
4887                 pcd = &md->pmd_classdep[c];
4888                 for (n = 0; n < pcd->pcd_num; n++, ri++)
4889                         pmc_rowindex_to_classdep[ri] = pcd;
4890         }
4891
4892         KASSERT(ri == md->pmd_npmc,
4893             ("[pmc,%d] npmc miscomputed: ri=%d, md->npmc=%d", __LINE__,
4894             ri, md->pmd_npmc));
4895
4896         maxcpu = pmc_cpu_max();
4897
4898         /* allocate space for the per-cpu array */
4899         pmc_pcpu = malloc(maxcpu * sizeof(struct pmc_cpu *), M_PMC,
4900             M_WAITOK|M_ZERO);
4901
4902         /* per-cpu 'saved values' for managing process-mode PMCs */
4903         pmc_pcpu_saved = malloc(sizeof(pmc_value_t) * maxcpu * md->pmd_npmc,
4904             M_PMC, M_WAITOK);
4905
4906         /* Perform CPU-dependent initialization. */
4907         pmc_save_cpu_binding(&pb);
4908         error = 0;
4909         for (cpu = 0; error == 0 && cpu < maxcpu; cpu++) {
4910                 if (!pmc_cpu_is_active(cpu))
4911                         continue;
4912                 pmc_select_cpu(cpu);
4913                 pmc_pcpu[cpu] = malloc(sizeof(struct pmc_cpu) +
4914                     md->pmd_npmc * sizeof(struct pmc_hw *), M_PMC,
4915                     M_WAITOK|M_ZERO);
4916                 if (md->pmd_pcpu_init)
4917                         error = md->pmd_pcpu_init(md, cpu);
4918                 for (n = 0; error == 0 && n < md->pmd_nclass; n++)
4919                         error = md->pmd_classdep[n].pcd_pcpu_init(md, cpu);
4920         }
4921         pmc_restore_cpu_binding(&pb);
4922
4923         if (error)
4924                 return (error);
4925
4926         /* allocate space for the sample array */
4927         for (cpu = 0; cpu < maxcpu; cpu++) {
4928                 if (!pmc_cpu_is_active(cpu))
4929                         continue;
4930
4931                 sb = malloc(sizeof(struct pmc_samplebuffer) +
4932                     pmc_nsamples * sizeof(struct pmc_sample), M_PMC,
4933                     M_WAITOK|M_ZERO);
4934                 sb->ps_read = sb->ps_write = sb->ps_samples;
4935                 sb->ps_fence = sb->ps_samples + pmc_nsamples;
4936
4937                 KASSERT(pmc_pcpu[cpu] != NULL,
4938                     ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu));
4939
4940                 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples *
4941                     sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO);
4942
4943                 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++)
4944                         ps->ps_pc = sb->ps_callchains +
4945                             (n * pmc_callchaindepth);
4946
4947                 pmc_pcpu[cpu]->pc_sb[PMC_HR] = sb;
4948
4949                 sb = malloc(sizeof(struct pmc_samplebuffer) +
4950                     pmc_nsamples * sizeof(struct pmc_sample), M_PMC,
4951                     M_WAITOK|M_ZERO);
4952                 sb->ps_read = sb->ps_write = sb->ps_samples;
4953                 sb->ps_fence = sb->ps_samples + pmc_nsamples;
4954
4955                 KASSERT(pmc_pcpu[cpu] != NULL,
4956                     ("[pmc,%d] cpu=%d Null per-cpu data", __LINE__, cpu));
4957
4958                 sb->ps_callchains = malloc(pmc_callchaindepth * pmc_nsamples *
4959                     sizeof(uintptr_t), M_PMC, M_WAITOK|M_ZERO);
4960
4961                 for (n = 0, ps = sb->ps_samples; n < pmc_nsamples; n++, ps++)
4962                         ps->ps_pc = sb->ps_callchains +
4963                             (n * pmc_callchaindepth);
4964
4965                 pmc_pcpu[cpu]->pc_sb[PMC_SR] = sb;
4966         }
4967
4968         /* allocate space for the row disposition array */
4969         pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc,
4970             M_PMC, M_WAITOK|M_ZERO);
4971
4972         /* mark all PMCs as available */
4973         for (n = 0; n < (int) md->pmd_npmc; n++)
4974                 PMC_MARK_ROW_FREE(n);
4975
4976         /* allocate thread hash tables */
4977         pmc_ownerhash = hashinit(pmc_hashsize, M_PMC,
4978             &pmc_ownerhashmask);
4979
4980         pmc_processhash = hashinit(pmc_hashsize, M_PMC,
4981             &pmc_processhashmask);
4982         mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc-leaf",
4983             MTX_SPIN);
4984
4985         LIST_INIT(&pmc_ss_owners);
4986         pmc_ss_count = 0;
4987
4988         /* allocate a pool of spin mutexes */
4989         pmc_mtxpool = mtx_pool_create("pmc-leaf", pmc_mtxpool_size,
4990             MTX_SPIN);
4991
4992         PMCDBG4(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx "
4993             "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask,
4994             pmc_processhash, pmc_processhashmask);
4995
4996         /* register process {exit,fork,exec} handlers */
4997         pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit,
4998             pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY);
4999         pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork,
5000             pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY);
5001
5002         /* register kld event handlers */
5003         pmc_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, pmc_kld_load,
5004             NULL, EVENTHANDLER_PRI_ANY);
5005         pmc_kld_unload_tag = EVENTHANDLER_REGISTER(kld_unload, pmc_kld_unload,
5006             NULL, EVENTHANDLER_PRI_ANY);
5007
5008         /* initialize logging */
5009         pmclog_initialize();
5010
5011         /* set hook functions */
5012         pmc_intr = md->pmd_intr;
5013         pmc_hook = pmc_hook_handler;
5014
5015         if (error == 0) {
5016                 printf(PMC_MODULE_NAME ":");
5017                 for (n = 0; n < (int) md->pmd_nclass; n++) {
5018                         pcd = &md->pmd_classdep[n];
5019                         printf(" %s/%d/%d/0x%b",
5020                             pmc_name_of_pmcclass(pcd->pcd_class),
5021                             pcd->pcd_num,
5022                             pcd->pcd_width,
5023                             pcd->pcd_caps,
5024                             "\20"
5025                             "\1INT\2USR\3SYS\4EDG\5THR"
5026                             "\6REA\7WRI\10INV\11QUA\12PRC"
5027                             "\13TAG\14CSC");
5028                 }
5029                 printf("\n");
5030         }
5031
5032         return (error);
5033 }
5034
5035 /* prepare to be unloaded */
5036 static void
5037 pmc_cleanup(void)
5038 {
5039         int c, cpu;
5040         unsigned int maxcpu;
5041         struct pmc_ownerhash *ph;
5042         struct pmc_owner *po, *tmp;
5043         struct pmc_binding pb;
5044 #ifdef  HWPMC_DEBUG
5045         struct pmc_processhash *prh;
5046 #endif
5047
5048         PMCDBG0(MOD,INI,0, "cleanup");
5049
5050         /* switch off sampling */
5051         CPU_ZERO(&pmc_cpumask);
5052         pmc_intr = NULL;
5053
5054         sx_xlock(&pmc_sx);
5055         if (pmc_hook == NULL) { /* being unloaded already */
5056                 sx_xunlock(&pmc_sx);
5057                 return;
5058         }
5059
5060         pmc_hook = NULL; /* prevent new threads from entering module */
5061
5062         /* deregister event handlers */
5063         EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag);
5064         EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag);
5065         EVENTHANDLER_DEREGISTER(kld_load, pmc_kld_load_tag);
5066         EVENTHANDLER_DEREGISTER(kld_unload, pmc_kld_unload_tag);
5067
5068         /* send SIGBUS to all owner threads, free up allocations */
5069         if (pmc_ownerhash)
5070                 for (ph = pmc_ownerhash;
5071                      ph <= &pmc_ownerhash[pmc_ownerhashmask];
5072                      ph++) {
5073                         LIST_FOREACH_SAFE(po, ph, po_next, tmp) {
5074                                 pmc_remove_owner(po);
5075
5076                                 /* send SIGBUS to owner processes */
5077                                 PMCDBG3(MOD,INI,2, "cleanup signal proc=%p "
5078                                     "(%d, %s)", po->po_owner,
5079                                     po->po_owner->p_pid,
5080                                     po->po_owner->p_comm);
5081
5082                                 PROC_LOCK(po->po_owner);
5083                                 kern_psignal(po->po_owner, SIGBUS);
5084                                 PROC_UNLOCK(po->po_owner);
5085
5086                                 pmc_destroy_owner_descriptor(po);
5087                         }
5088                 }
5089
5090         /* reclaim allocated data structures */
5091         if (pmc_mtxpool)
5092                 mtx_pool_destroy(&pmc_mtxpool);
5093
5094         mtx_destroy(&pmc_processhash_mtx);
5095         if (pmc_processhash) {
5096 #ifdef  HWPMC_DEBUG
5097                 struct pmc_process *pp;
5098
5099                 PMCDBG0(MOD,INI,3, "destroy process hash");
5100                 for (prh = pmc_processhash;
5101                      prh <= &pmc_processhash[pmc_processhashmask];
5102                      prh++)
5103                         LIST_FOREACH(pp, prh, pp_next)
5104                             PMCDBG1(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid);
5105 #endif
5106
5107                 hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask);
5108                 pmc_processhash = NULL;
5109         }
5110
5111         if (pmc_ownerhash) {
5112                 PMCDBG0(MOD,INI,3, "destroy owner hash");
5113                 hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask);
5114                 pmc_ownerhash = NULL;
5115         }
5116
5117         KASSERT(LIST_EMPTY(&pmc_ss_owners),
5118             ("[pmc,%d] Global SS owner list not empty", __LINE__));
5119         KASSERT(pmc_ss_count == 0,
5120             ("[pmc,%d] Global SS count not empty", __LINE__));
5121
5122         /* do processor and pmc-class dependent cleanup */
5123         maxcpu = pmc_cpu_max();
5124
5125         PMCDBG0(MOD,INI,3, "md cleanup");
5126         if (md) {
5127                 pmc_save_cpu_binding(&pb);
5128                 for (cpu = 0; cpu < maxcpu; cpu++) {
5129                         PMCDBG2(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p",
5130                             cpu, pmc_pcpu[cpu]);
5131                         if (!pmc_cpu_is_active(cpu) || pmc_pcpu[cpu] == NULL)
5132                                 continue;
5133                         pmc_select_cpu(cpu);
5134                         for (c = 0; c < md->pmd_nclass; c++)
5135                                 md->pmd_classdep[c].pcd_pcpu_fini(md, cpu);
5136                         if (md->pmd_pcpu_fini)
5137                                 md->pmd_pcpu_fini(md, cpu);
5138                 }
5139
5140                 if (md->pmd_cputype == PMC_CPU_GENERIC)
5141                         pmc_generic_cpu_finalize(md);
5142                 else
5143                         pmc_md_finalize(md);
5144
5145                 pmc_mdep_free(md);
5146                 md = NULL;
5147                 pmc_restore_cpu_binding(&pb);
5148         }
5149
5150         /* Free per-cpu descriptors. */
5151         for (cpu = 0; cpu < maxcpu; cpu++) {
5152                 if (!pmc_cpu_is_active(cpu))
5153                         continue;
5154                 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_HR] != NULL,
5155                     ("[pmc,%d] Null hw cpu sample buffer cpu=%d", __LINE__,
5156                         cpu));
5157                 KASSERT(pmc_pcpu[cpu]->pc_sb[PMC_SR] != NULL,
5158                     ("[pmc,%d] Null sw cpu sample buffer cpu=%d", __LINE__,
5159                         cpu));
5160                 free(pmc_pcpu[cpu]->pc_sb[PMC_HR]->ps_callchains, M_PMC);
5161                 free(pmc_pcpu[cpu]->pc_sb[PMC_HR], M_PMC);
5162                 free(pmc_pcpu[cpu]->pc_sb[PMC_SR]->ps_callchains, M_PMC);
5163                 free(pmc_pcpu[cpu]->pc_sb[PMC_SR], M_PMC);
5164                 free(pmc_pcpu[cpu], M_PMC);
5165         }
5166
5167         free(pmc_pcpu, M_PMC);
5168         pmc_pcpu = NULL;
5169
5170         free(pmc_pcpu_saved, M_PMC);
5171         pmc_pcpu_saved = NULL;
5172
5173         if (pmc_pmcdisp) {
5174                 free(pmc_pmcdisp, M_PMC);
5175                 pmc_pmcdisp = NULL;
5176         }
5177
5178         if (pmc_rowindex_to_classdep) {
5179                 free(pmc_rowindex_to_classdep, M_PMC);
5180                 pmc_rowindex_to_classdep = NULL;
5181         }
5182
5183         pmclog_shutdown();
5184
5185         sx_xunlock(&pmc_sx);    /* we are done */
5186 }
5187
5188 /*
5189  * The function called at load/unload.
5190  */
5191
5192 static int
5193 load (struct module *module __unused, int cmd, void *arg __unused)
5194 {
5195         int error;
5196
5197         error = 0;
5198
5199         switch (cmd) {
5200         case MOD_LOAD :
5201                 /* initialize the subsystem */
5202                 error = pmc_initialize();
5203                 if (error != 0)
5204                         break;
5205                 PMCDBG2(MOD,INI,1, "syscall=%d maxcpu=%d",
5206                     pmc_syscall_num, pmc_cpu_max());
5207                 break;
5208
5209
5210         case MOD_UNLOAD :
5211         case MOD_SHUTDOWN:
5212                 pmc_cleanup();
5213                 PMCDBG0(MOD,INI,1, "unloaded");
5214                 break;
5215
5216         default :
5217                 error = EINVAL; /* XXX should panic(9) */
5218                 break;
5219         }
5220
5221         return error;
5222 }
5223
5224 /* memory pool */
5225 MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module");