sys/powerpc/powerpc/trap.c

   1 /*-
   2  * Copyright (C) 1995, 1996 Wolfgang Solfrank.
   3  * Copyright (C) 1995, 1996 TooLs GmbH.
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. All advertising materials mentioning features or use of this software
  15  *    must display the following acknowledgement:
  16  *      This product includes software developed by TooLs GmbH.
  17  * 4. The name of TooLs GmbH may not be used to endorse or promote products
  18  *    derived from this software without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
  21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  23  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  26  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  27  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  28  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  29  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  *
  31  * $NetBSD: trap.c,v 1.58 2002/03/04 04:07:35 dbj Exp $
  32  */
  33
  34 #include <sys/cdefs.h>
  35 __FBSDID("$FreeBSD$");
  36
  37 #include <sys/param.h>
  38 #include <sys/kdb.h>
  39 #include <sys/proc.h>
  40 #include <sys/ktr.h>
  41 #include <sys/lock.h>
  42 #include <sys/mutex.h>
  43 #include <sys/pioctl.h>
  44 #include <sys/ptrace.h>
  45 #include <sys/reboot.h>
  46 #include <sys/syscall.h>
  47 #include <sys/sysent.h>
  48 #include <sys/systm.h>
  49 #include <sys/kernel.h>
  50 #include <sys/uio.h>
  51 #include <sys/signalvar.h>
  52 #include <sys/vmmeter.h>
  53
  54 #include <security/audit/audit.h>
  55
  56 #include <vm/vm.h>
  57 #include <vm/pmap.h>
  58 #include <vm/vm_extern.h>
  59 #include <vm/vm_param.h>
  60 #include <vm/vm_kern.h>
  61 #include <vm/vm_map.h>
  62 #include <vm/vm_page.h>
  63
  64 #include <machine/_inttypes.h>
  65 #include <machine/altivec.h>
  66 #include <machine/cpu.h>
  67 #include <machine/db_machdep.h>
  68 #include <machine/fpu.h>
  69 #include <machine/frame.h>
  70 #include <machine/pcb.h>
  71 #include <machine/pmap.h>
  72 #include <machine/psl.h>
  73 #include <machine/trap.h>
  74 #include <machine/spr.h>
  75 #include <machine/sr.h>
  76
  77 #define FAULTBUF_LR     0
  78 #define FAULTBUF_R1     1
  79 #define FAULTBUF_R2     2
  80 #define FAULTBUF_CR     3
  81 #define FAULTBUF_R13    4
  82
  83 static void     trap_fatal(struct trapframe *frame);
  84 static void     printtrap(u_int vector, struct trapframe *frame, int isfatal,
  85                     int user);
  86 static int      trap_pfault(struct trapframe *frame, int user);
  87 static int      fix_unaligned(struct thread *td, struct trapframe *frame);
  88 static int      handle_onfault(struct trapframe *frame);
  89 static void     syscall(struct trapframe *frame);
  90
  91 #ifdef __powerpc64__
  92        void     handle_kernel_slb_spill(int, register_t, register_t);
  93 static int      handle_user_slb_spill(pmap_t pm, vm_offset_t addr);
  94 extern int      n_slbs;
  95 #endif
  96
  97 struct powerpc_exception {
  98         u_int   vector;
  99         char    *name;
 100 };
 101
 102 #ifdef KDTRACE_HOOKS
 103 #include <sys/dtrace_bsd.h>
 104
 105 int (*dtrace_invop_jump_addr)(struct trapframe *);
 106 #endif
 107
 108 static struct powerpc_exception powerpc_exceptions[] = {
 109         { EXC_CRIT,     "critical input" },
 110         { EXC_RST,      "system reset" },
 111         { EXC_MCHK,     "machine check" },
 112         { EXC_DSI,      "data storage interrupt" },
 113         { EXC_DSE,      "data segment exception" },
 114         { EXC_ISI,      "instruction storage interrupt" },
 115         { EXC_ISE,      "instruction segment exception" },
 116         { EXC_EXI,      "external interrupt" },
 117         { EXC_ALI,      "alignment" },
 118         { EXC_PGM,      "program" },
 119         { EXC_FPU,      "floating-point unavailable" },
 120         { EXC_APU,      "auxiliary proc unavailable" },
 121         { EXC_DECR,     "decrementer" },
 122         { EXC_FIT,      "fixed-interval timer" },
 123         { EXC_WDOG,     "watchdog timer" },
 124         { EXC_SC,       "system call" },
 125         { EXC_TRC,      "trace" },
 126         { EXC_FPA,      "floating-point assist" },
 127         { EXC_DEBUG,    "debug" },
 128         { EXC_PERF,     "performance monitoring" },
 129         { EXC_VEC,      "altivec unavailable" },
 130         { EXC_VSX,      "vsx unavailable" },
 131         { EXC_ITMISS,   "instruction tlb miss" },
 132         { EXC_DLMISS,   "data load tlb miss" },
 133         { EXC_DSMISS,   "data store tlb miss" },
 134         { EXC_BPT,      "instruction breakpoint" },
 135         { EXC_SMI,      "system management" },
 136         { EXC_VECAST_G4,        "altivec assist" },
 137         { EXC_THRM,     "thermal management" },
 138         { EXC_RUNMODETRC,       "run mode/trace" },
 139         { EXC_LAST,     NULL }
 140 };
 141
 142 static const char *
 143 trapname(u_int vector)
 144 {
 145         struct  powerpc_exception *pe;
 146
 147         for (pe = powerpc_exceptions; pe->vector != EXC_LAST; pe++) {
 148                 if (pe->vector == vector)
 149                         return (pe->name);
 150         }
 151
 152         return ("unknown");
 153 }
 154
 155 void
 156 trap(struct trapframe *frame)
 157 {
 158         struct thread   *td;
 159         struct proc     *p;
 160 #ifdef KDTRACE_HOOKS
 161         uint32_t inst;
 162 #endif
 163         int             sig, type, user;
 164         u_int           ucode;
 165         ksiginfo_t      ksi;
 166
 167         PCPU_INC(cnt.v_trap);
 168
 169         td = curthread;
 170         p = td->td_proc;
 171
 172         type = ucode = frame->exc;
 173         sig = 0;
 174         user = frame->srr1 & PSL_PR;
 175
 176         CTR3(KTR_TRAP, "trap: %s type=%s (%s)", td->td_name,
 177             trapname(type), user ? "user" : "kernel");
 178
 179 #ifdef KDTRACE_HOOKS
 180         /*
 181          * A trap can occur while DTrace executes a probe. Before
 182          * executing the probe, DTrace blocks re-scheduling and sets
 183          * a flag in its per-cpu flags to indicate that it doesn't
 184          * want to fault. On returning from the probe, the no-fault
 185          * flag is cleared and finally re-scheduling is enabled.
 186          *
 187          * If the DTrace kernel module has registered a trap handler,
 188          * call it and if it returns non-zero, assume that it has
 189          * handled the trap and modified the trap frame so that this
 190          * function can return normally.
 191          */
 192         if (dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, type) != 0)
 193                 return;
 194 #endif
 195
 196         if (user) {
 197                 td->td_pticks = 0;
 198                 td->td_frame = frame;
 199                 if (td->td_cowgen != p->p_cowgen)
 200                         thread_cow_update(td);
 201
 202                 /* User Mode Traps */
 203                 switch (type) {
 204                 case EXC_RUNMODETRC:
 205                 case EXC_TRC:
 206                         frame->srr1 &= ~PSL_SE;
 207                         sig = SIGTRAP;
 208                         ucode = TRAP_TRACE;
 209                         break;
 210
 211 #ifdef __powerpc64__
 212                 case EXC_ISE:
 213                 case EXC_DSE:
 214                         if (handle_user_slb_spill(&p->p_vmspace->vm_pmap,
 215                             (type == EXC_ISE) ? frame->srr0 : frame->dar) != 0){
 216                                 sig = SIGSEGV;
 217                                 ucode = SEGV_MAPERR;
 218                         }
 219                         break;
 220 #endif
 221                 case EXC_DSI:
 222                 case EXC_ISI:
 223                         sig = trap_pfault(frame, 1);
 224                         if (sig == SIGSEGV)
 225                                 ucode = SEGV_MAPERR;
 226                         break;
 227
 228                 case EXC_SC:
 229                         syscall(frame);
 230                         break;
 231
 232                 case EXC_FPU:
 233                         KASSERT((td->td_pcb->pcb_flags & PCB_FPU) != PCB_FPU,
 234                             ("FPU already enabled for thread"));
 235                         enable_fpu(td);
 236                         break;
 237
 238                 case EXC_VEC:
 239                         KASSERT((td->td_pcb->pcb_flags & PCB_VEC) != PCB_VEC,
 240                             ("Altivec already enabled for thread"));
 241                         enable_vec(td);
 242                         break;
 243
 244                 case EXC_VSX:
 245                         KASSERT((td->td_pcb->pcb_flags & PCB_VSX) != PCB_VSX,
 246                             ("VSX already enabled for thread"));
 247                         if (!(td->td_pcb->pcb_flags & PCB_VEC))
 248                                 enable_vec(td);
 249                         if (!(td->td_pcb->pcb_flags & PCB_FPU))
 250                                 save_fpu(td);
 251                         td->td_pcb->pcb_flags |= PCB_VSX;
 252                         enable_fpu(td);
 253                         break;
 254
 255                 case EXC_VECAST_G4:
 256                 case EXC_VECAST_G5:
 257                         /*
 258                          * We get a VPU assist exception for IEEE mode
 259                          * vector operations on denormalized floats.
 260                          * Emulating this is a giant pain, so for now,
 261                          * just switch off IEEE mode and treat them as
 262                          * zero.
 263                          */
 264
 265                         save_vec(td);
 266                         td->td_pcb->pcb_vec.vscr |= ALTIVEC_VSCR_NJ;
 267                         enable_vec(td);
 268                         break;
 269
 270                 case EXC_ALI:
 271                         if (fix_unaligned(td, frame) != 0) {
 272                                 sig = SIGBUS;
 273                                 ucode = BUS_ADRALN;
 274                         }
 275                         else
 276                                 frame->srr0 += 4;
 277                         break;
 278
 279                 case EXC_DEBUG: /* Single stepping */
 280                         mtspr(SPR_DBSR, mfspr(SPR_DBSR));
 281                         frame->srr1 &= ~PSL_DE;
 282                         frame->cpu.booke.dbcr0 &= ~(DBCR0_IDM || DBCR0_IC);
 283                         sig = SIGTRAP;
 284                         ucode = TRAP_TRACE;
 285                         break;
 286
 287                 case EXC_PGM:
 288                         /* Identify the trap reason */
 289 #ifdef AIM
 290                         if (frame->srr1 & EXC_PGM_TRAP) {
 291 #else
 292                         if (frame->cpu.booke.esr & ESR_PTR) {
 293 #endif
 294 #ifdef KDTRACE_HOOKS
 295                                 inst = fuword32((const void *)frame->srr0);
 296                                 if (inst == 0x0FFFDDDD &&
 297                                     dtrace_pid_probe_ptr != NULL) {
 298                                         struct reg regs;
 299                                         fill_regs(td, &regs);
 300                                         (*dtrace_pid_probe_ptr)(&regs);
 301                                         break;
 302                                 }
 303 #endif
 304                                 sig = SIGTRAP;
 305                                 ucode = TRAP_BRKPT;
 306                         } else {
 307                                 sig = ppc_instr_emulate(frame, td->td_pcb);
 308                                 if (sig == SIGILL) {
 309                                         if (frame->srr1 & EXC_PGM_PRIV)
 310                                                 ucode = ILL_PRVOPC;
 311                                         else if (frame->srr1 & EXC_PGM_ILLEGAL)
 312                                                 ucode = ILL_ILLOPC;
 313                                 } else if (sig == SIGFPE)
 314                                         ucode = FPE_FLTINV;     /* Punt for now, invalid operation. */
 315                         }
 316                         break;
 317
 318                 case EXC_MCHK:
 319                         /*
 320                          * Note that this may not be recoverable for the user
 321                          * process, depending on the type of machine check,
 322                          * but it at least prevents the kernel from dying.
 323                          */
 324                         sig = SIGBUS;
 325                         ucode = BUS_OBJERR;
 326                         break;
 327
 328                 default:
 329                         trap_fatal(frame);
 330                 }
 331         } else {
 332                 /* Kernel Mode Traps */
 333
 334                 KASSERT(cold || td->td_ucred != NULL,
 335                     ("kernel trap doesn't have ucred"));
 336                 switch (type) {
 337 #ifdef KDTRACE_HOOKS
 338                 case EXC_PGM:
 339                         if (frame->srr1 & EXC_PGM_TRAP) {
 340                                 if (*(uint32_t *)frame->srr0 == EXC_DTRACE) {
 341                                         if (dtrace_invop_jump_addr != NULL) {
 342                                                 dtrace_invop_jump_addr(frame);
 343                                                 return;
 344                                         }
 345                                 }
 346                         }
 347                         break;
 348 #endif
 349 #ifdef __powerpc64__
 350                 case EXC_DSE:
 351                         if ((frame->dar & SEGMENT_MASK) == USER_ADDR) {
 352                                 __asm __volatile ("slbmte %0, %1" ::
 353                                         "r"(td->td_pcb->pcb_cpu.aim.usr_vsid),
 354                                         "r"(USER_SLB_SLBE));
 355                                 return;
 356                         }
 357                         break;
 358 #endif
 359                 case EXC_DSI:
 360                         if (trap_pfault(frame, 0) == 0)
 361                                 return;
 362                         break;
 363                 case EXC_MCHK:
 364                         if (handle_onfault(frame))
 365                                 return;
 366                         break;
 367                 default:
 368                         break;
 369                 }
 370                 trap_fatal(frame);
 371         }
 372
 373         if (sig != 0) {
 374                 if (p->p_sysent->sv_transtrap != NULL)
 375                         sig = (p->p_sysent->sv_transtrap)(sig, type);
 376                 ksiginfo_init_trap(&ksi);
 377                 ksi.ksi_signo = sig;
 378                 ksi.ksi_code = (int) ucode; /* XXX, not POSIX */
 379                 /* ksi.ksi_addr = ? */
 380                 ksi.ksi_trapno = type;
 381                 trapsignal(td, &ksi);
 382         }
 383
 384         userret(td, frame);
 385 }
 386
 387 static void
 388 trap_fatal(struct trapframe *frame)
 389 {
 390
 391         printtrap(frame->exc, frame, 1, (frame->srr1 & PSL_PR));
 392 #ifdef KDB
 393         if ((debugger_on_panic || kdb_active) &&
 394             kdb_trap(frame->exc, 0, frame))
 395                 return;
 396 #endif
 397         panic("%s trap", trapname(frame->exc));
 398 }
 399
 400 static void
 401 printtrap(u_int vector, struct trapframe *frame, int isfatal, int user)
 402 {
 403         uint16_t ver;
 404
 405         printf("\n");
 406         printf("%s %s trap:\n", isfatal ? "fatal" : "handled",
 407             user ? "user" : "kernel");
 408         printf("\n");
 409         printf("   exception       = 0x%x (%s)\n", vector, trapname(vector));
 410         switch (vector) {
 411         case EXC_DSE:
 412         case EXC_DSI:
 413         case EXC_DTMISS:
 414                 printf("   virtual address = 0x%" PRIxPTR "\n", frame->dar);
 415 #ifdef AIM
 416                 printf("   dsisr           = 0x%lx\n",
 417                     (u_long)frame->cpu.aim.dsisr);
 418 #endif
 419                 break;
 420         case EXC_ISE:
 421         case EXC_ISI:
 422         case EXC_ITMISS:
 423                 printf("   virtual address = 0x%" PRIxPTR "\n", frame->srr0);
 424                 break;
 425         case EXC_MCHK:
 426                 ver = mfpvr() >> 16;
 427 #if defined(AIM)
 428                 if (MPC745X_P(ver))
 429                         printf("    msssr0         = 0x%lx\n",
 430                             (u_long)mfspr(SPR_MSSSR0));
 431 #elif defined(BOOKE)
 432                 printf("   mcsr           = 0x%lx\n", (u_long)mfspr(SPR_MCSR));
 433 #endif
 434                 break;
 435         }
 436 #ifdef BOOKE
 437         printf("   esr             = 0x%" PRIxPTR "\n",
 438             frame->cpu.booke.esr);
 439 #endif
 440         printf("   srr0            = 0x%" PRIxPTR "\n", frame->srr0);
 441         printf("   srr1            = 0x%lx\n", (u_long)frame->srr1);
 442         printf("   lr              = 0x%" PRIxPTR "\n", frame->lr);
 443         printf("   curthread       = %p\n", curthread);
 444         if (curthread != NULL)
 445                 printf("          pid = %d, comm = %s\n",
 446                     curthread->td_proc->p_pid, curthread->td_name);
 447         printf("\n");
 448 }
 449
 450 /*
 451  * Handles a fatal fault when we have onfault state to recover.  Returns
 452  * non-zero if there was onfault recovery state available.
 453  */
 454 static int
 455 handle_onfault(struct trapframe *frame)
 456 {
 457         struct          thread *td;
 458         faultbuf        *fb;
 459
 460         td = curthread;
 461         fb = td->td_pcb->pcb_onfault;
 462         if (fb != NULL) {
 463                 frame->srr0 = (*fb)[FAULTBUF_LR];
 464                 frame->fixreg[1] = (*fb)[FAULTBUF_R1];
 465                 frame->fixreg[2] = (*fb)[FAULTBUF_R2];
 466                 frame->fixreg[3] = 1;
 467                 frame->cr = (*fb)[FAULTBUF_CR];
 468                 bcopy(&(*fb)[FAULTBUF_R13], &frame->fixreg[13],
 469                     19 * sizeof(register_t));
 470                 return (1);
 471         }
 472         return (0);
 473 }
 474
 475 int
 476 cpu_fetch_syscall_args(struct thread *td, struct syscall_args *sa)
 477 {
 478         struct proc *p;
 479         struct trapframe *frame;
 480         caddr_t params;
 481         size_t argsz;
 482         int error, n, i;
 483
 484         p = td->td_proc;
 485         frame = td->td_frame;
 486
 487         sa->code = frame->fixreg[0];
 488         params = (caddr_t)(frame->fixreg + FIRSTARG);
 489         n = NARGREG;
 490
 491         if (sa->code == SYS_syscall) {
 492                 /*
 493                  * code is first argument,
 494                  * followed by actual args.
 495                  */
 496                 sa->code = *(register_t *) params;
 497                 params += sizeof(register_t);
 498                 n -= 1;
 499         } else if (sa->code == SYS___syscall) {
 500                 /*
 501                  * Like syscall, but code is a quad,
 502                  * so as to maintain quad alignment
 503                  * for the rest of the args.
 504                  */
 505                 if (SV_PROC_FLAG(p, SV_ILP32)) {
 506                         params += sizeof(register_t);
 507                         sa->code = *(register_t *) params;
 508                         params += sizeof(register_t);
 509                         n -= 2;
 510                 } else {
 511                         sa->code = *(register_t *) params;
 512                         params += sizeof(register_t);
 513                         n -= 1;
 514                 }
 515         }
 516
 517         if (p->p_sysent->sv_mask)
 518                 sa->code &= p->p_sysent->sv_mask;
 519         if (sa->code >= p->p_sysent->sv_size)
 520                 sa->callp = &p->p_sysent->sv_table[0];
 521         else
 522                 sa->callp = &p->p_sysent->sv_table[sa->code];
 523
 524         sa->narg = sa->callp->sy_narg;
 525
 526         if (SV_PROC_FLAG(p, SV_ILP32)) {
 527                 argsz = sizeof(uint32_t);
 528
 529                 for (i = 0; i < n; i++)
 530                         sa->args[i] = ((u_register_t *)(params))[i] &
 531                             0xffffffff;
 532         } else {
 533                 argsz = sizeof(uint64_t);
 534
 535                 for (i = 0; i < n; i++)
 536                         sa->args[i] = ((u_register_t *)(params))[i];
 537         }
 538
 539         if (sa->narg > n)
 540                 error = copyin(MOREARGS(frame->fixreg[1]), sa->args + n,
 541                                (sa->narg - n) * argsz);
 542         else
 543                 error = 0;
 544
 545 #ifdef __powerpc64__
 546         if (SV_PROC_FLAG(p, SV_ILP32) && sa->narg > n) {
 547                 /* Expand the size of arguments copied from the stack */
 548
 549                 for (i = sa->narg; i >= n; i--)
 550                         sa->args[i] = ((uint32_t *)(&sa->args[n]))[i-n];
 551         }
 552 #endif
 553
 554         if (error == 0) {
 555                 td->td_retval[0] = 0;
 556                 td->td_retval[1] = frame->fixreg[FIRSTARG + 1];
 557         }
 558         return (error);
 559 }
 560
 561 #include "../../kern/subr_syscall.c"
 562
 563 void
 564 syscall(struct trapframe *frame)
 565 {
 566         struct thread *td;
 567         struct syscall_args sa;
 568         int error;
 569
 570         td = curthread;
 571         td->td_frame = frame;
 572
 573 #ifdef __powerpc64__
 574         /*
 575          * Speculatively restore last user SLB segment, which we know is
 576          * invalid already, since we are likely to do copyin()/copyout().
 577          */
 578         __asm __volatile ("slbmte %0, %1; isync" ::
 579             "r"(td->td_pcb->pcb_cpu.aim.usr_vsid), "r"(USER_SLB_SLBE));
 580 #endif
 581
 582         error = syscallenter(td, &sa);
 583         syscallret(td, error, &sa);
 584 }
 585
 586 #ifdef __powerpc64__
 587 /* Handle kernel SLB faults -- runs in real mode, all seat belts off */
 588 void
 589 handle_kernel_slb_spill(int type, register_t dar, register_t srr0)
 590 {
 591         struct slb *slbcache;
 592         uint64_t slbe, slbv;
 593         uint64_t esid, addr;
 594         int i;
 595
 596         addr = (type == EXC_ISE) ? srr0 : dar;
 597         slbcache = PCPU_GET(slb);
 598         esid = (uintptr_t)addr >> ADDR_SR_SHFT;
 599         slbe = (esid << SLBE_ESID_SHIFT) | SLBE_VALID;
 600
 601         /* See if the hardware flushed this somehow (can happen in LPARs) */
 602         for (i = 0; i < n_slbs; i++)
 603                 if (slbcache[i].slbe == (slbe | (uint64_t)i))
 604                         return;
 605
 606         /* Not in the map, needs to actually be added */
 607         slbv = kernel_va_to_slbv(addr);
 608         if (slbcache[USER_SLB_SLOT].slbe == 0) {
 609                 for (i = 0; i < n_slbs; i++) {
 610                         if (i == USER_SLB_SLOT)
 611                                 continue;
 612                         if (!(slbcache[i].slbe & SLBE_VALID))
 613                                 goto fillkernslb;
 614                 }
 615
 616                 if (i == n_slbs)
 617                         slbcache[USER_SLB_SLOT].slbe = 1;
 618         }
 619
 620         /* Sacrifice a random SLB entry that is not the user entry */
 621         i = mftb() % n_slbs;
 622         if (i == USER_SLB_SLOT)
 623                 i = (i+1) % n_slbs;
 624
 625 fillkernslb:
 626         /* Write new entry */
 627         slbcache[i].slbv = slbv;
 628         slbcache[i].slbe = slbe | (uint64_t)i;
 629
 630         /* Trap handler will restore from cache on exit */
 631 }
 632
 633 static int
 634 handle_user_slb_spill(pmap_t pm, vm_offset_t addr)
 635 {
 636         struct slb *user_entry;
 637         uint64_t esid;
 638         int i;
 639
 640         esid = (uintptr_t)addr >> ADDR_SR_SHFT;
 641
 642         PMAP_LOCK(pm);
 643         user_entry = user_va_to_slb_entry(pm, addr);
 644
 645         if (user_entry == NULL) {
 646                 /* allocate_vsid auto-spills it */
 647                 (void)allocate_user_vsid(pm, esid, 0);
 648         } else {
 649                 /*
 650                  * Check that another CPU has not already mapped this.
 651                  * XXX: Per-thread SLB caches would be better.
 652                  */
 653                 for (i = 0; i < pm->pm_slb_len; i++)
 654                         if (pm->pm_slb[i] == user_entry)
 655                                 break;
 656
 657                 if (i == pm->pm_slb_len)
 658                         slb_insert_user(pm, user_entry);
 659         }
 660         PMAP_UNLOCK(pm);
 661
 662         return (0);
 663 }
 664 #endif
 665
 666 static int
 667 trap_pfault(struct trapframe *frame, int user)
 668 {
 669         vm_offset_t     eva, va;
 670         struct          thread *td;
 671         struct          proc *p;
 672         vm_map_t        map;
 673         vm_prot_t       ftype;
 674         int             rv;
 675 #ifdef AIM
 676         register_t      user_sr;
 677 #endif
 678
 679         td = curthread;
 680         p = td->td_proc;
 681         if (frame->exc == EXC_ISI) {
 682                 eva = frame->srr0;
 683                 ftype = VM_PROT_EXECUTE;
 684                 if (frame->srr1 & SRR1_ISI_PFAULT)
 685                         ftype |= VM_PROT_READ;
 686         } else {
 687                 eva = frame->dar;
 688 #ifdef BOOKE
 689                 if (frame->cpu.booke.esr & ESR_ST)
 690 #else
 691                 if (frame->cpu.aim.dsisr & DSISR_STORE)
 692 #endif
 693                         ftype = VM_PROT_WRITE;
 694                 else
 695                         ftype = VM_PROT_READ;
 696         }
 697
 698         if (user) {
 699                 KASSERT(p->p_vmspace != NULL, ("trap_pfault: vmspace  NULL"));
 700                 map = &p->p_vmspace->vm_map;
 701         } else {
 702 #ifdef BOOKE
 703                 if (eva < VM_MAXUSER_ADDRESS) {
 704 #else
 705                 if ((eva >> ADDR_SR_SHFT) == (USER_ADDR >> ADDR_SR_SHFT)) {
 706 #endif
 707                         map = &p->p_vmspace->vm_map;
 708
 709 #ifdef AIM
 710                         user_sr = td->td_pcb->pcb_cpu.aim.usr_segm;
 711                         eva &= ADDR_PIDX | ADDR_POFF;
 712                         eva |= user_sr << ADDR_SR_SHFT;
 713 #endif
 714                 } else {
 715                         map = kernel_map;
 716                 }
 717         }
 718         va = trunc_page(eva);
 719
 720         /* Fault in the page. */
 721         rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
 722         /*
 723          * XXXDTRACE: add dtrace_doubletrap_func here?
 724          */
 725
 726         if (rv == KERN_SUCCESS)
 727                 return (0);
 728
 729         if (!user && handle_onfault(frame))
 730                 return (0);
 731
 732         return (SIGSEGV);
 733 }
 734
 735 /*
 736  * For now, this only deals with the particular unaligned access case
 737  * that gcc tends to generate.  Eventually it should handle all of the
 738  * possibilities that can happen on a 32-bit PowerPC in big-endian mode.
 739  */
 740
 741 static int
 742 fix_unaligned(struct thread *td, struct trapframe *frame)
 743 {
 744         struct thread   *fputhread;
 745         int             indicator, reg;
 746         double          *fpr;
 747
 748         indicator = EXC_ALI_OPCODE_INDICATOR(frame->cpu.aim.dsisr);
 749
 750         switch (indicator) {
 751         case EXC_ALI_LFD:
 752         case EXC_ALI_STFD:
 753                 reg = EXC_ALI_RST(frame->cpu.aim.dsisr);
 754                 fpr = &td->td_pcb->pcb_fpu.fpr[reg].fpr;
 755                 fputhread = PCPU_GET(fputhread);
 756
 757                 /* Juggle the FPU to ensure that we've initialized
 758                  * the FPRs, and that their current state is in
 759                  * the PCB.
 760                  */
 761                 if (fputhread != td) {
 762                         if (fputhread)
 763                                 save_fpu(fputhread);
 764                         enable_fpu(td);
 765                 }
 766                 save_fpu(td);
 767
 768                 if (indicator == EXC_ALI_LFD) {
 769                         if (copyin((void *)frame->dar, fpr,
 770                             sizeof(double)) != 0)
 771                                 return (-1);
 772                         enable_fpu(td);
 773                 } else {
 774                         if (copyout(fpr, (void *)frame->dar,
 775                             sizeof(double)) != 0)
 776                                 return (-1);
 777                 }
 778                 return (0);
 779                 break;
 780         }
 781
 782         return (-1);
 783 }
 784
 785 #ifdef KDB
 786 int db_trap_glue(struct trapframe *);           /* Called from trap_subr.S */
 787
 788 int
 789 db_trap_glue(struct trapframe *frame)
 790 {
 791         if (!(frame->srr1 & PSL_PR)
 792             && (frame->exc == EXC_TRC || frame->exc == EXC_RUNMODETRC
 793 #ifdef AIM
 794                 || (frame->exc == EXC_PGM
 795                     && (frame->srr1 & EXC_PGM_TRAP))
 796 #else
 797                 || (frame->exc == EXC_DEBUG)
 798 #endif
 799                 || frame->exc == EXC_BPT
 800                 || frame->exc == EXC_DSI)) {
 801                 int type = frame->exc;
 802
 803                 /* Ignore DTrace traps. */
 804                 if (*(uint32_t *)frame->srr0 == EXC_DTRACE)
 805                         return (0);
 806 #ifdef AIM
 807                 if (type == EXC_PGM && (frame->srr1 & EXC_PGM_TRAP)) {
 808 #else
 809                 if (frame->cpu.booke.esr & ESR_PTR) {
 810 #endif
 811                         type = T_BREAKPOINT;
 812                 }
 813                 return (kdb_trap(type, 0, frame));
 814         }
 815
 816         return (0);
 817 }
 818 #endif