arch/parisc/kernel/traps.c

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This source file includes following definitions.
printbinary
print_gr
print_fr
show_regs
do_show_stack
parisc_show_stack
show_stack
is_valid_bugaddr
die_if_kernel
handle_gdb_break
handle_break
default_trap
transfer_pim_to_trap_frame
parisc_terminate
handle_interruption
initialize_ivt
early_trap_init
trap_init
   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/arch/parisc/traps.c
   4  *
   5  *  Copyright (C) 1991, 1992  Linus Torvalds
   6  *  Copyright (C) 1999, 2000  Philipp Rumpf <prumpf@tux.org>
   7  */
   8 
   9 /*
  10  * 'Traps.c' handles hardware traps and faults after we have saved some
  11  * state in 'asm.s'.
  12  */
  13 
  14 #include <linux/sched.h>
  15 #include <linux/sched/debug.h>
  16 #include <linux/kernel.h>
  17 #include <linux/string.h>
  18 #include <linux/errno.h>
  19 #include <linux/ptrace.h>
  20 #include <linux/timer.h>
  21 #include <linux/delay.h>
  22 #include <linux/mm.h>
  23 #include <linux/module.h>
  24 #include <linux/smp.h>
  25 #include <linux/spinlock.h>
  26 #include <linux/init.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/console.h>
  29 #include <linux/bug.h>
  30 #include <linux/ratelimit.h>
  31 #include <linux/uaccess.h>
  32 #include <linux/kdebug.h>
  33 
  34 #include <asm/assembly.h>
  35 #include <asm/io.h>
  36 #include <asm/irq.h>
  37 #include <asm/traps.h>
  38 #include <asm/unaligned.h>
  39 #include <linux/atomic.h>
  40 #include <asm/smp.h>
  41 #include <asm/pdc.h>
  42 #include <asm/pdc_chassis.h>
  43 #include <asm/unwind.h>
  44 #include <asm/tlbflush.h>
  45 #include <asm/cacheflush.h>
  46 #include <linux/kgdb.h>
  47 #include <linux/kprobes.h>
  48 
  49 #include "../math-emu/math-emu.h"       /* for handle_fpe() */
  50 
  51 static void parisc_show_stack(struct task_struct *task,
  52         struct pt_regs *regs);
  53 
  54 static int printbinary(char *buf, unsigned long x, int nbits)
  55 {
  56         unsigned long mask = 1UL << (nbits - 1);
  57         while (mask != 0) {
  58                 *buf++ = (mask & x ? '1' : '0');
  59                 mask >>= 1;
  60         }
  61         *buf = '\0';
  62 
  63         return nbits;
  64 }
  65 
  66 #ifdef CONFIG_64BIT
  67 #define RFMT "%016lx"
  68 #else
  69 #define RFMT "%08lx"
  70 #endif
  71 #define FFMT "%016llx"  /* fpregs are 64-bit always */
  72 
  73 #define PRINTREGS(lvl,r,f,fmt,x)        \
  74         printk("%s%s%02d-%02d  " fmt " " fmt " " fmt " " fmt "\n",      \
  75                 lvl, f, (x), (x+3), (r)[(x)+0], (r)[(x)+1],             \
  76                 (r)[(x)+2], (r)[(x)+3])
  77 
  78 static void print_gr(char *level, struct pt_regs *regs)
  79 {
  80         int i;
  81         char buf[64];
  82 
  83         printk("%s\n", level);
  84         printk("%s     YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI\n", level);
  85         printbinary(buf, regs->gr[0], 32);
  86         printk("%sPSW: %s %s\n", level, buf, print_tainted());
  87 
  88         for (i = 0; i < 32; i += 4)
  89                 PRINTREGS(level, regs->gr, "r", RFMT, i);
  90 }
  91 
  92 static void print_fr(char *level, struct pt_regs *regs)
  93 {
  94         int i;
  95         char buf[64];
  96         struct { u32 sw[2]; } s;
  97 
  98         /* FR are 64bit everywhere. Need to use asm to get the content
  99          * of fpsr/fper1, and we assume that we won't have a FP Identify
 100          * in our way, otherwise we're screwed.
 101          * The fldd is used to restore the T-bit if there was one, as the
 102          * store clears it anyway.
 103          * PA2.0 book says "thou shall not use fstw on FPSR/FPERs" - T-Bone */
 104         asm volatile ("fstd %%fr0,0(%1) \n\t"
 105                       "fldd 0(%1),%%fr0 \n\t"
 106                       : "=m" (s) : "r" (&s) : "r0");
 107 
 108         printk("%s\n", level);
 109         printk("%s      VZOUICununcqcqcqcqcqcrmunTDVZOUI\n", level);
 110         printbinary(buf, s.sw[0], 32);
 111         printk("%sFPSR: %s\n", level, buf);
 112         printk("%sFPER1: %08x\n", level, s.sw[1]);
 113 
 114         /* here we'll print fr0 again, tho it'll be meaningless */
 115         for (i = 0; i < 32; i += 4)
 116                 PRINTREGS(level, regs->fr, "fr", FFMT, i);
 117 }
 118 
 119 void show_regs(struct pt_regs *regs)
 120 {
 121         int i, user;
 122         char *level;
 123         unsigned long cr30, cr31;
 124 
 125         user = user_mode(regs);
 126         level = user ? KERN_DEBUG : KERN_CRIT;
 127 
 128         show_regs_print_info(level);
 129 
 130         print_gr(level, regs);
 131 
 132         for (i = 0; i < 8; i += 4)
 133                 PRINTREGS(level, regs->sr, "sr", RFMT, i);
 134 
 135         if (user)
 136                 print_fr(level, regs);
 137 
 138         cr30 = mfctl(30);
 139         cr31 = mfctl(31);
 140         printk("%s\n", level);
 141         printk("%sIASQ: " RFMT " " RFMT " IAOQ: " RFMT " " RFMT "\n",
 142                level, regs->iasq[0], regs->iasq[1], regs->iaoq[0], regs->iaoq[1]);
 143         printk("%s IIR: %08lx    ISR: " RFMT "  IOR: " RFMT "\n",
 144                level, regs->iir, regs->isr, regs->ior);
 145         printk("%s CPU: %8d   CR30: " RFMT " CR31: " RFMT "\n",
 146                level, current_thread_info()->cpu, cr30, cr31);
 147         printk("%s ORIG_R28: " RFMT "\n", level, regs->orig_r28);
 148 
 149         if (user) {
 150                 printk("%s IAOQ[0]: " RFMT "\n", level, regs->iaoq[0]);
 151                 printk("%s IAOQ[1]: " RFMT "\n", level, regs->iaoq[1]);
 152                 printk("%s RP(r2): " RFMT "\n", level, regs->gr[2]);
 153         } else {
 154                 printk("%s IAOQ[0]: %pS\n", level, (void *) regs->iaoq[0]);
 155                 printk("%s IAOQ[1]: %pS\n", level, (void *) regs->iaoq[1]);
 156                 printk("%s RP(r2): %pS\n", level, (void *) regs->gr[2]);
 157 
 158                 parisc_show_stack(current, regs);
 159         }
 160 }
 161 
 162 static DEFINE_RATELIMIT_STATE(_hppa_rs,
 163         DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST);
 164 
 165 #define parisc_printk_ratelimited(critical, regs, fmt, ...)     {             \
 166         if ((critical || show_unhandled_signals) && __ratelimit(&_hppa_rs)) { \
 167                 printk(fmt, ##__VA_ARGS__);                                   \
 168                 show_regs(regs);                                              \
 169         }                                                                     \
 170 }
 171 
 172 
 173 static void do_show_stack(struct unwind_frame_info *info)
 174 {
 175         int i = 1;
 176 
 177         printk(KERN_CRIT "Backtrace:\n");
 178         while (i <= MAX_UNWIND_ENTRIES) {
 179                 if (unwind_once(info) < 0 || info->ip == 0)
 180                         break;
 181 
 182                 if (__kernel_text_address(info->ip)) {
 183                         printk(KERN_CRIT " [<" RFMT ">] %pS\n",
 184                                 info->ip, (void *) info->ip);
 185                         i++;
 186                 }
 187         }
 188         printk(KERN_CRIT "\n");
 189 }
 190 
 191 static void parisc_show_stack(struct task_struct *task,
 192         struct pt_regs *regs)
 193 {
 194         struct unwind_frame_info info;
 195 
 196         unwind_frame_init_task(&info, task, regs);
 197 
 198         do_show_stack(&info);
 199 }
 200 
 201 void show_stack(struct task_struct *t, unsigned long *sp)
 202 {
 203         parisc_show_stack(t, NULL);
 204 }
 205 
 206 int is_valid_bugaddr(unsigned long iaoq)
 207 {
 208         return 1;
 209 }
 210 
 211 void die_if_kernel(char *str, struct pt_regs *regs, long err)
 212 {
 213         if (user_mode(regs)) {
 214                 if (err == 0)
 215                         return; /* STFU */
 216 
 217                 parisc_printk_ratelimited(1, regs,
 218                         KERN_CRIT "%s (pid %d): %s (code %ld) at " RFMT "\n",
 219                         current->comm, task_pid_nr(current), str, err, regs->iaoq[0]);
 220 
 221                 return;
 222         }
 223 
 224         bust_spinlocks(1);
 225 
 226         oops_enter();
 227 
 228         /* Amuse the user in a SPARC fashion */
 229         if (err) printk(KERN_CRIT
 230                         "      _______________________________ \n"
 231                         "     < Your System ate a SPARC! Gah! >\n"
 232                         "      ------------------------------- \n"
 233                         "             \\   ^__^\n"
 234                         "                 (__)\\       )\\/\\\n"
 235                         "                  U  ||----w |\n"
 236                         "                     ||     ||\n");
 237         
 238         /* unlock the pdc lock if necessary */
 239         pdc_emergency_unlock();
 240 
 241         /* maybe the kernel hasn't booted very far yet and hasn't been able 
 242          * to initialize the serial or STI console. In that case we should 
 243          * re-enable the pdc console, so that the user will be able to 
 244          * identify the problem. */
 245         if (!console_drivers)
 246                 pdc_console_restart();
 247         
 248         if (err)
 249                 printk(KERN_CRIT "%s (pid %d): %s (code %ld)\n",
 250                         current->comm, task_pid_nr(current), str, err);
 251 
 252         /* Wot's wrong wif bein' racy? */
 253         if (current->thread.flags & PARISC_KERNEL_DEATH) {
 254                 printk(KERN_CRIT "%s() recursion detected.\n", __func__);
 255                 local_irq_enable();
 256                 while (1);
 257         }
 258         current->thread.flags |= PARISC_KERNEL_DEATH;
 259 
 260         show_regs(regs);
 261         dump_stack();
 262         add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
 263 
 264         if (in_interrupt())
 265                 panic("Fatal exception in interrupt");
 266 
 267         if (panic_on_oops)
 268                 panic("Fatal exception");
 269 
 270         oops_exit();
 271         do_exit(SIGSEGV);
 272 }
 273 
 274 /* gdb uses break 4,8 */
 275 #define GDB_BREAK_INSN 0x10004
 276 static void handle_gdb_break(struct pt_regs *regs, int wot)
 277 {
 278         force_sig_fault(SIGTRAP, wot,
 279                         (void __user *) (regs->iaoq[0] & ~3));
 280 }
 281 
 282 static void handle_break(struct pt_regs *regs)
 283 {
 284         unsigned iir = regs->iir;
 285 
 286         if (unlikely(iir == PARISC_BUG_BREAK_INSN && !user_mode(regs))) {
 287                 /* check if a BUG() or WARN() trapped here.  */
 288                 enum bug_trap_type tt;
 289                 tt = report_bug(regs->iaoq[0] & ~3, regs);
 290                 if (tt == BUG_TRAP_TYPE_WARN) {
 291                         regs->iaoq[0] += 4;
 292                         regs->iaoq[1] += 4;
 293                         return; /* return to next instruction when WARN_ON().  */
 294                 }
 295                 die_if_kernel("Unknown kernel breakpoint", regs,
 296                         (tt == BUG_TRAP_TYPE_NONE) ? 9 : 0);
 297         }
 298 
 299 #ifdef CONFIG_KPROBES
 300         if (unlikely(iir == PARISC_KPROBES_BREAK_INSN)) {
 301                 parisc_kprobe_break_handler(regs);
 302                 return;
 303         }
 304 
 305 #endif
 306 
 307 #ifdef CONFIG_KGDB
 308         if (unlikely(iir == PARISC_KGDB_COMPILED_BREAK_INSN ||
 309                 iir == PARISC_KGDB_BREAK_INSN)) {
 310                 kgdb_handle_exception(9, SIGTRAP, 0, regs);
 311                 return;
 312         }
 313 #endif
 314 
 315         if (unlikely(iir != GDB_BREAK_INSN))
 316                 parisc_printk_ratelimited(0, regs,
 317                         KERN_DEBUG "break %d,%d: pid=%d command='%s'\n",
 318                         iir & 31, (iir>>13) & ((1<<13)-1),
 319                         task_pid_nr(current), current->comm);
 320 
 321         /* send standard GDB signal */
 322         handle_gdb_break(regs, TRAP_BRKPT);
 323 }
 324 
 325 static void default_trap(int code, struct pt_regs *regs)
 326 {
 327         printk(KERN_ERR "Trap %d on CPU %d\n", code, smp_processor_id());
 328         show_regs(regs);
 329 }
 330 
 331 void (*cpu_lpmc) (int code, struct pt_regs *regs) __read_mostly = default_trap;
 332 
 333 
 334 void transfer_pim_to_trap_frame(struct pt_regs *regs)
 335 {
 336     register int i;
 337     extern unsigned int hpmc_pim_data[];
 338     struct pdc_hpmc_pim_11 *pim_narrow;
 339     struct pdc_hpmc_pim_20 *pim_wide;
 340 
 341     if (boot_cpu_data.cpu_type >= pcxu) {
 342 
 343         pim_wide = (struct pdc_hpmc_pim_20 *)hpmc_pim_data;
 344 
 345         /*
 346          * Note: The following code will probably generate a
 347          * bunch of truncation error warnings from the compiler.
 348          * Could be handled with an ifdef, but perhaps there
 349          * is a better way.
 350          */
 351 
 352         regs->gr[0] = pim_wide->cr[22];
 353 
 354         for (i = 1; i < 32; i++)
 355             regs->gr[i] = pim_wide->gr[i];
 356 
 357         for (i = 0; i < 32; i++)
 358             regs->fr[i] = pim_wide->fr[i];
 359 
 360         for (i = 0; i < 8; i++)
 361             regs->sr[i] = pim_wide->sr[i];
 362 
 363         regs->iasq[0] = pim_wide->cr[17];
 364         regs->iasq[1] = pim_wide->iasq_back;
 365         regs->iaoq[0] = pim_wide->cr[18];
 366         regs->iaoq[1] = pim_wide->iaoq_back;
 367 
 368         regs->sar  = pim_wide->cr[11];
 369         regs->iir  = pim_wide->cr[19];
 370         regs->isr  = pim_wide->cr[20];
 371         regs->ior  = pim_wide->cr[21];
 372     }
 373     else {
 374         pim_narrow = (struct pdc_hpmc_pim_11 *)hpmc_pim_data;
 375 
 376         regs->gr[0] = pim_narrow->cr[22];
 377 
 378         for (i = 1; i < 32; i++)
 379             regs->gr[i] = pim_narrow->gr[i];
 380 
 381         for (i = 0; i < 32; i++)
 382             regs->fr[i] = pim_narrow->fr[i];
 383 
 384         for (i = 0; i < 8; i++)
 385             regs->sr[i] = pim_narrow->sr[i];
 386 
 387         regs->iasq[0] = pim_narrow->cr[17];
 388         regs->iasq[1] = pim_narrow->iasq_back;
 389         regs->iaoq[0] = pim_narrow->cr[18];
 390         regs->iaoq[1] = pim_narrow->iaoq_back;
 391 
 392         regs->sar  = pim_narrow->cr[11];
 393         regs->iir  = pim_narrow->cr[19];
 394         regs->isr  = pim_narrow->cr[20];
 395         regs->ior  = pim_narrow->cr[21];
 396     }
 397 
 398     /*
 399      * The following fields only have meaning if we came through
 400      * another path. So just zero them here.
 401      */
 402 
 403     regs->ksp = 0;
 404     regs->kpc = 0;
 405     regs->orig_r28 = 0;
 406 }
 407 
 408 
 409 /*
 410  * This routine is called as a last resort when everything else
 411  * has gone clearly wrong. We get called for faults in kernel space,
 412  * and HPMC's.
 413  */
 414 void parisc_terminate(char *msg, struct pt_regs *regs, int code, unsigned long offset)
 415 {
 416         static DEFINE_SPINLOCK(terminate_lock);
 417 
 418         (void)notify_die(DIE_OOPS, msg, regs, 0, code, SIGTRAP);
 419         bust_spinlocks(1);
 420 
 421         set_eiem(0);
 422         local_irq_disable();
 423         spin_lock(&terminate_lock);
 424 
 425         /* unlock the pdc lock if necessary */
 426         pdc_emergency_unlock();
 427 
 428         /* restart pdc console if necessary */
 429         if (!console_drivers)
 430                 pdc_console_restart();
 431 
 432         /* Not all paths will gutter the processor... */
 433         switch(code){
 434 
 435         case 1:
 436                 transfer_pim_to_trap_frame(regs);
 437                 break;
 438 
 439         default:
 440                 /* Fall through */
 441                 break;
 442 
 443         }
 444             
 445         {
 446                 /* show_stack(NULL, (unsigned long *)regs->gr[30]); */
 447                 struct unwind_frame_info info;
 448                 unwind_frame_init(&info, current, regs);
 449                 do_show_stack(&info);
 450         }
 451 
 452         printk("\n");
 453         pr_crit("%s: Code=%d (%s) at addr " RFMT "\n",
 454                 msg, code, trap_name(code), offset);
 455         show_regs(regs);
 456 
 457         spin_unlock(&terminate_lock);
 458 
 459         /* put soft power button back under hardware control;
 460          * if the user had pressed it once at any time, the 
 461          * system will shut down immediately right here. */
 462         pdc_soft_power_button(0);
 463         
 464         /* Call kernel panic() so reboot timeouts work properly 
 465          * FIXME: This function should be on the list of
 466          * panic notifiers, and we should call panic
 467          * directly from the location that we wish. 
 468          * e.g. We should not call panic from
 469          * parisc_terminate, but rather the oter way around.
 470          * This hack works, prints the panic message twice,
 471          * and it enables reboot timers!
 472          */
 473         panic(msg);
 474 }
 475 
 476 void notrace handle_interruption(int code, struct pt_regs *regs)
 477 {
 478         unsigned long fault_address = 0;
 479         unsigned long fault_space = 0;
 480         int si_code;
 481 
 482         if (code == 1)
 483             pdc_console_restart();  /* switch back to pdc if HPMC */
 484         else
 485             local_irq_enable();
 486 
 487         /* Security check:
 488          * If the priority level is still user, and the
 489          * faulting space is not equal to the active space
 490          * then the user is attempting something in a space
 491          * that does not belong to them. Kill the process.
 492          *
 493          * This is normally the situation when the user
 494          * attempts to jump into the kernel space at the
 495          * wrong offset, be it at the gateway page or a
 496          * random location.
 497          *
 498          * We cannot normally signal the process because it
 499          * could *be* on the gateway page, and processes
 500          * executing on the gateway page can't have signals
 501          * delivered.
 502          * 
 503          * We merely readjust the address into the users
 504          * space, at a destination address of zero, and
 505          * allow processing to continue.
 506          */
 507         if (((unsigned long)regs->iaoq[0] & 3) &&
 508             ((unsigned long)regs->iasq[0] != (unsigned long)regs->sr[7])) { 
 509                 /* Kill the user process later */
 510                 regs->iaoq[0] = 0 | 3;
 511                 regs->iaoq[1] = regs->iaoq[0] + 4;
 512                 regs->iasq[0] = regs->iasq[1] = regs->sr[7];
 513                 regs->gr[0] &= ~PSW_B;
 514                 return;
 515         }
 516         
 517 #if 0
 518         printk(KERN_CRIT "Interruption # %d\n", code);
 519 #endif
 520 
 521         switch(code) {
 522 
 523         case  1:
 524                 /* High-priority machine check (HPMC) */
 525                 
 526                 /* set up a new led state on systems shipped with a LED State panel */
 527                 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_HPMC);
 528 
 529                 parisc_terminate("High Priority Machine Check (HPMC)",
 530                                 regs, code, 0);
 531                 /* NOT REACHED */
 532                 
 533         case  2:
 534                 /* Power failure interrupt */
 535                 printk(KERN_CRIT "Power failure interrupt !\n");
 536                 return;
 537 
 538         case  3:
 539                 /* Recovery counter trap */
 540                 regs->gr[0] &= ~PSW_R;
 541 
 542 #ifdef CONFIG_KPROBES
 543                 if (parisc_kprobe_ss_handler(regs))
 544                         return;
 545 #endif
 546 
 547 #ifdef CONFIG_KGDB
 548                 if (kgdb_single_step) {
 549                         kgdb_handle_exception(0, SIGTRAP, 0, regs);
 550                         return;
 551                 }
 552 #endif
 553 
 554                 if (user_space(regs))
 555                         handle_gdb_break(regs, TRAP_TRACE);
 556                 /* else this must be the start of a syscall - just let it run */
 557                 return;
 558 
 559         case  5:
 560                 /* Low-priority machine check */
 561                 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_LPMC);
 562                 
 563                 flush_cache_all();
 564                 flush_tlb_all();
 565                 cpu_lpmc(5, regs);
 566                 return;
 567 
 568         case  PARISC_ITLB_TRAP:
 569                 /* Instruction TLB miss fault/Instruction page fault */
 570                 fault_address = regs->iaoq[0];
 571                 fault_space   = regs->iasq[0];
 572                 break;
 573 
 574         case  8:
 575                 /* Illegal instruction trap */
 576                 die_if_kernel("Illegal instruction", regs, code);
 577                 si_code = ILL_ILLOPC;
 578                 goto give_sigill;
 579 
 580         case  9:
 581                 /* Break instruction trap */
 582                 handle_break(regs);
 583                 return;
 584 
 585         case 10:
 586                 /* Privileged operation trap */
 587                 die_if_kernel("Privileged operation", regs, code);
 588                 si_code = ILL_PRVOPC;
 589                 goto give_sigill;
 590 
 591         case 11:
 592                 /* Privileged register trap */
 593                 if ((regs->iir & 0xffdfffe0) == 0x034008a0) {
 594 
 595                         /* This is a MFCTL cr26/cr27 to gr instruction.
 596                          * PCXS traps on this, so we need to emulate it.
 597                          */
 598 
 599                         if (regs->iir & 0x00200000)
 600                                 regs->gr[regs->iir & 0x1f] = mfctl(27);
 601                         else
 602                                 regs->gr[regs->iir & 0x1f] = mfctl(26);
 603 
 604                         regs->iaoq[0] = regs->iaoq[1];
 605                         regs->iaoq[1] += 4;
 606                         regs->iasq[0] = regs->iasq[1];
 607                         return;
 608                 }
 609 
 610                 die_if_kernel("Privileged register usage", regs, code);
 611                 si_code = ILL_PRVREG;
 612         give_sigill:
 613                 force_sig_fault(SIGILL, si_code,
 614                                 (void __user *) regs->iaoq[0]);
 615                 return;
 616 
 617         case 12:
 618                 /* Overflow Trap, let the userland signal handler do the cleanup */
 619                 force_sig_fault(SIGFPE, FPE_INTOVF,
 620                                 (void __user *) regs->iaoq[0]);
 621                 return;
 622                 
 623         case 13:
 624                 /* Conditional Trap
 625                    The condition succeeds in an instruction which traps
 626                    on condition  */
 627                 if(user_mode(regs)){
 628                         /* Let userspace app figure it out from the insn pointed
 629                          * to by si_addr.
 630                          */
 631                         force_sig_fault(SIGFPE, FPE_CONDTRAP,
 632                                         (void __user *) regs->iaoq[0]);
 633                         return;
 634                 } 
 635                 /* The kernel doesn't want to handle condition codes */
 636                 break;
 637                 
 638         case 14:
 639                 /* Assist Exception Trap, i.e. floating point exception. */
 640                 die_if_kernel("Floating point exception", regs, 0); /* quiet */
 641                 __inc_irq_stat(irq_fpassist_count);
 642                 handle_fpe(regs);
 643                 return;
 644 
 645         case 15:
 646                 /* Data TLB miss fault/Data page fault */
 647                 /* Fall through */
 648         case 16:
 649                 /* Non-access instruction TLB miss fault */
 650                 /* The instruction TLB entry needed for the target address of the FIC
 651                    is absent, and hardware can't find it, so we get to cleanup */
 652                 /* Fall through */
 653         case 17:
 654                 /* Non-access data TLB miss fault/Non-access data page fault */
 655                 /* FIXME: 
 656                          Still need to add slow path emulation code here!
 657                          If the insn used a non-shadow register, then the tlb
 658                          handlers could not have their side-effect (e.g. probe
 659                          writing to a target register) emulated since rfir would
 660                          erase the changes to said register. Instead we have to
 661                          setup everything, call this function we are in, and emulate
 662                          by hand. Technically we need to emulate:
 663                          fdc,fdce,pdc,"fic,4f",prober,probeir,probew, probeiw
 664                 */
 665                 fault_address = regs->ior;
 666                 fault_space = regs->isr;
 667                 break;
 668 
 669         case 18:
 670                 /* PCXS only -- later cpu's split this into types 26,27 & 28 */
 671                 /* Check for unaligned access */
 672                 if (check_unaligned(regs)) {
 673                         handle_unaligned(regs);
 674                         return;
 675                 }
 676                 /* Fall Through */
 677         case 26: 
 678                 /* PCXL: Data memory access rights trap */
 679                 fault_address = regs->ior;
 680                 fault_space   = regs->isr;
 681                 break;
 682 
 683         case 19:
 684                 /* Data memory break trap */
 685                 regs->gr[0] |= PSW_X; /* So we can single-step over the trap */
 686                 /* fall thru */
 687         case 21:
 688                 /* Page reference trap */
 689                 handle_gdb_break(regs, TRAP_HWBKPT);
 690                 return;
 691 
 692         case 25:
 693                 /* Taken branch trap */
 694                 regs->gr[0] &= ~PSW_T;
 695                 if (user_space(regs))
 696                         handle_gdb_break(regs, TRAP_BRANCH);
 697                 /* else this must be the start of a syscall - just let it
 698                  * run.
 699                  */
 700                 return;
 701 
 702         case  7:  
 703                 /* Instruction access rights */
 704                 /* PCXL: Instruction memory protection trap */
 705 
 706                 /*
 707                  * This could be caused by either: 1) a process attempting
 708                  * to execute within a vma that does not have execute
 709                  * permission, or 2) an access rights violation caused by a
 710                  * flush only translation set up by ptep_get_and_clear().
 711                  * So we check the vma permissions to differentiate the two.
 712                  * If the vma indicates we have execute permission, then
 713                  * the cause is the latter one. In this case, we need to
 714                  * call do_page_fault() to fix the problem.
 715                  */
 716 
 717                 if (user_mode(regs)) {
 718                         struct vm_area_struct *vma;
 719 
 720                         down_read(&current->mm->mmap_sem);
 721                         vma = find_vma(current->mm,regs->iaoq[0]);
 722                         if (vma && (regs->iaoq[0] >= vma->vm_start)
 723                                 && (vma->vm_flags & VM_EXEC)) {
 724 
 725                                 fault_address = regs->iaoq[0];
 726                                 fault_space = regs->iasq[0];
 727 
 728                                 up_read(&current->mm->mmap_sem);
 729                                 break; /* call do_page_fault() */
 730                         }
 731                         up_read(&current->mm->mmap_sem);
 732                 }
 733                 /* Fall Through */
 734         case 27: 
 735                 /* Data memory protection ID trap */
 736                 if (code == 27 && !user_mode(regs) &&
 737                         fixup_exception(regs))
 738                         return;
 739 
 740                 die_if_kernel("Protection id trap", regs, code);
 741                 force_sig_fault(SIGSEGV, SEGV_MAPERR,
 742                                 (code == 7)?
 743                                 ((void __user *) regs->iaoq[0]) :
 744                                 ((void __user *) regs->ior));
 745                 return;
 746 
 747         case 28: 
 748                 /* Unaligned data reference trap */
 749                 handle_unaligned(regs);
 750                 return;
 751 
 752         default:
 753                 if (user_mode(regs)) {
 754                         parisc_printk_ratelimited(0, regs, KERN_DEBUG
 755                                 "handle_interruption() pid=%d command='%s'\n",
 756                                 task_pid_nr(current), current->comm);
 757                         /* SIGBUS, for lack of a better one. */
 758                         force_sig_fault(SIGBUS, BUS_OBJERR,
 759                                         (void __user *)regs->ior);
 760                         return;
 761                 }
 762                 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC);
 763                 
 764                 parisc_terminate("Unexpected interruption", regs, code, 0);
 765                 /* NOT REACHED */
 766         }
 767 
 768         if (user_mode(regs)) {
 769             if ((fault_space >> SPACEID_SHIFT) != (regs->sr[7] >> SPACEID_SHIFT)) {
 770                 parisc_printk_ratelimited(0, regs, KERN_DEBUG
 771                                 "User fault %d on space 0x%08lx, pid=%d command='%s'\n",
 772                                 code, fault_space,
 773                                 task_pid_nr(current), current->comm);
 774                 force_sig_fault(SIGSEGV, SEGV_MAPERR,
 775                                 (void __user *)regs->ior);
 776                 return;
 777             }
 778         }
 779         else {
 780 
 781             /*
 782              * The kernel should never fault on its own address space,
 783              * unless pagefault_disable() was called before.
 784              */
 785 
 786             if (fault_space == 0 && !faulthandler_disabled())
 787             {
 788                 /* Clean up and return if in exception table. */
 789                 if (fixup_exception(regs))
 790                         return;
 791                 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC);
 792                 parisc_terminate("Kernel Fault", regs, code, fault_address);
 793             }
 794         }
 795 
 796         do_page_fault(regs, code, fault_address);
 797 }
 798 
 799 
 800 void __init initialize_ivt(const void *iva)
 801 {
 802         extern u32 os_hpmc_size;
 803         extern const u32 os_hpmc[];
 804 
 805         int i;
 806         u32 check = 0;
 807         u32 *ivap;
 808         u32 *hpmcp;
 809         u32 length, instr;
 810 
 811         if (strcmp((const char *)iva, "cows can fly"))
 812                 panic("IVT invalid");
 813 
 814         ivap = (u32 *)iva;
 815 
 816         for (i = 0; i < 8; i++)
 817             *ivap++ = 0;
 818 
 819         /*
 820          * Use PDC_INSTR firmware function to get instruction that invokes
 821          * PDCE_CHECK in HPMC handler.  See programming note at page 1-31 of
 822          * the PA 1.1 Firmware Architecture document.
 823          */
 824         if (pdc_instr(&instr) == PDC_OK)
 825                 ivap[0] = instr;
 826 
 827         /*
 828          * Rules for the checksum of the HPMC handler:
 829          * 1. The IVA does not point to PDC/PDH space (ie: the OS has installed
 830          *    its own IVA).
 831          * 2. The word at IVA + 32 is nonzero.
 832          * 3. If Length (IVA + 60) is not zero, then Length (IVA + 60) and
 833          *    Address (IVA + 56) are word-aligned.
 834          * 4. The checksum of the 8 words starting at IVA + 32 plus the sum of
 835          *    the Length/4 words starting at Address is zero.
 836          */
 837 
 838         /* Setup IVA and compute checksum for HPMC handler */
 839         ivap[6] = (u32)__pa(os_hpmc);
 840         length = os_hpmc_size;
 841         ivap[7] = length;
 842 
 843         hpmcp = (u32 *)os_hpmc;
 844 
 845         for (i=0; i<length/4; i++)
 846             check += *hpmcp++;
 847 
 848         for (i=0; i<8; i++)
 849             check += ivap[i];
 850 
 851         ivap[5] = -check;
 852 }
 853         
 854 
 855 /* early_trap_init() is called before we set up kernel mappings and
 856  * write-protect the kernel */
 857 void  __init early_trap_init(void)
 858 {
 859         extern const void fault_vector_20;
 860 
 861 #ifndef CONFIG_64BIT
 862         extern const void fault_vector_11;
 863         initialize_ivt(&fault_vector_11);
 864 #endif
 865 
 866         initialize_ivt(&fault_vector_20);
 867 }
 868 
 869 void __init trap_init(void)
 870 {
 871 }
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root/arch/parisc/kernel/traps.c

DEFINITIONS
