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   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * arch/sh64/kernel/traps.c
   7  *
   8  * Copyright (C) 2000, 2001  Paolo Alberelli
   9  * Copyright (C) 2003, 2004  Paul Mundt
  10  * Copyright (C) 2003, 2004  Richard Curnow
  11  *
  12  */
  13
  14 /*
  15  * 'Traps.c' handles hardware traps and faults after we have saved some
  16  * state in 'entry.S'.
  17  */
  18 #include <linux/sched.h>
  19 #include <linux/kernel.h>
  20 #include <linux/string.h>
  21 #include <linux/errno.h>
  22 #include <linux/ptrace.h>
  23 #include <linux/timer.h>
  24 #include <linux/mm.h>
  25 #include <linux/smp.h>
  26 #include <linux/smp_lock.h>
  27 #include <linux/init.h>
  28 #include <linux/delay.h>
  29 #include <linux/spinlock.h>
  30 #include <linux/kallsyms.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/sysctl.h>
  33 #include <linux/module.h>
  34
  35 #include <asm/system.h>
  36 #include <asm/uaccess.h>
  37 #include <asm/io.h>
  38 #include <asm/atomic.h>
  39 #include <asm/processor.h>
  40 #include <asm/pgtable.h>
  41
  42 #undef DEBUG_EXCEPTION
  43 #ifdef DEBUG_EXCEPTION
  44 /* implemented in ../lib/dbg.c */
  45 extern void show_excp_regs(char *fname, int trapnr, int signr,
  46                            struct pt_regs *regs);
  47 #else
  48 #define show_excp_regs(a, b, c, d)
  49 #endif
  50
  51 static void do_unhandled_exception(int trapnr, int signr, char *str, char *fn_name,
  52                 unsigned long error_code, struct pt_regs *regs, struct task_struct *tsk);
  53
  54 #define DO_ERROR(trapnr, signr, str, name, tsk) \
  55 asmlinkage void do_##name(unsigned long error_code, struct pt_regs *regs) \
  56 { \
  57         do_unhandled_exception(trapnr, signr, str, __stringify(name), error_code, regs, current); \
  58 }
  59
  60 spinlock_t die_lock;
  61
  62 void die(const char * str, struct pt_regs * regs, long err)
  63 {
  64         console_verbose();
  65         spin_lock_irq(&die_lock);
  66         printk("%s: %lx\n", str, (err & 0xffffff));
  67         show_regs(regs);
  68         spin_unlock_irq(&die_lock);
  69         do_exit(SIGSEGV);
  70 }
  71
  72 static inline void die_if_kernel(const char * str, struct pt_regs * regs, long err)
  73 {
  74         if (!user_mode(regs))
  75                 die(str, regs, err);
  76 }
  77
  78 static void die_if_no_fixup(const char * str, struct pt_regs * regs, long err)
  79 {
  80         if (!user_mode(regs)) {
  81                 const struct exception_table_entry *fixup;
  82                 fixup = search_exception_tables(regs->pc);
  83                 if (fixup) {
  84                         regs->pc = fixup->fixup;
  85                         return;
  86                 }
  87                 die(str, regs, err);
  88         }
  89 }
  90
  91 DO_ERROR(13, SIGILL,  "illegal slot instruction", illegal_slot_inst, current)
  92 DO_ERROR(87, SIGSEGV, "address error (exec)", address_error_exec, current)
  93
  94
  95 /* Implement misaligned load/store handling for kernel (and optionally for user
  96    mode too).  Limitation : only SHmedia mode code is handled - there is no
  97    handling at all for misaligned accesses occurring in SHcompact code yet. */
  98
  99 static int misaligned_fixup(struct pt_regs *regs);
 100
 101 asmlinkage void do_address_error_load(unsigned long error_code, struct pt_regs *regs)
 102 {
 103         if (misaligned_fixup(regs) < 0) {
 104                 do_unhandled_exception(7, SIGSEGV, "address error(load)",
 105                                 "do_address_error_load",
 106                                 error_code, regs, current);
 107         }
 108         return;
 109 }
 110
 111 asmlinkage void do_address_error_store(unsigned long error_code, struct pt_regs *regs)
 112 {
 113         if (misaligned_fixup(regs) < 0) {
 114                 do_unhandled_exception(8, SIGSEGV, "address error(store)",
 115                                 "do_address_error_store",
 116                                 error_code, regs, current);
 117         }
 118         return;
 119 }
 120
 121 #if defined(CONFIG_SH64_ID2815_WORKAROUND)
 122
 123 #define OPCODE_INVALID      0
 124 #define OPCODE_USER_VALID   1
 125 #define OPCODE_PRIV_VALID   2
 126
 127 /* getcon/putcon - requires checking which control register is referenced. */
 128 #define OPCODE_CTRL_REG     3
 129
 130 /* Table of valid opcodes for SHmedia mode.
 131    Form a 10-bit value by concatenating the major/minor opcodes i.e.
 132    opcode[31:26,20:16].  The 6 MSBs of this value index into the following
 133    array.  The 4 LSBs select the bit-pair in the entry (bits 1:0 correspond to
 134    LSBs==4'b0000 etc). */
 135 static unsigned long shmedia_opcode_table[64] = {
 136         0x55554044,0x54445055,0x15141514,0x14541414,0x00000000,0x10001000,0x01110055,0x04050015,
 137         0x00000444,0xc0000000,0x44545515,0x40405555,0x55550015,0x10005555,0x55555505,0x04050000,
 138         0x00000555,0x00000404,0x00040445,0x15151414,0x00000000,0x00000000,0x00000000,0x00000000,
 139         0x00000055,0x40404444,0x00000404,0xc0009495,0x00000000,0x00000000,0x00000000,0x00000000,
 140         0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
 141         0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
 142         0x80005050,0x04005055,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
 143         0x81055554,0x00000404,0x55555555,0x55555555,0x00000000,0x00000000,0x00000000,0x00000000
 144 };
 145
 146 void do_reserved_inst(unsigned long error_code, struct pt_regs *regs)
 147 {
 148         /* Workaround SH5-101 cut2 silicon defect #2815 :
 149            in some situations, inter-mode branches from SHcompact -> SHmedia
 150            which should take ITLBMISS or EXECPROT exceptions at the target
 151            falsely take RESINST at the target instead. */
 152
 153         unsigned long opcode = 0x6ff4fff0; /* guaranteed reserved opcode */
 154         unsigned long pc, aligned_pc;
 155         int get_user_error;
 156         int trapnr = 12;
 157         int signr = SIGILL;
 158         char *exception_name = "reserved_instruction";
 159
 160         pc = regs->pc;
 161         if ((pc & 3) == 1) {
 162                 /* SHmedia : check for defect.  This requires executable vmas
 163                    to be readable too. */
 164                 aligned_pc = pc & ~3;
 165                 if (!access_ok(VERIFY_READ, aligned_pc, sizeof(unsigned long))) {
 166                         get_user_error = -EFAULT;
 167                 } else {
 168                         get_user_error = __get_user(opcode, (unsigned long *)aligned_pc);
 169                 }
 170                 if (get_user_error >= 0) {
 171                         unsigned long index, shift;
 172                         unsigned long major, minor, combined;
 173                         unsigned long reserved_field;
 174                         reserved_field = opcode & 0xf; /* These bits are currently reserved as zero in all valid opcodes */
 175                         major = (opcode >> 26) & 0x3f;
 176                         minor = (opcode >> 16) & 0xf;
 177                         combined = (major << 4) | minor;
 178                         index = major;
 179                         shift = minor << 1;
 180                         if (reserved_field == 0) {
 181                                 int opcode_state = (shmedia_opcode_table[index] >> shift) & 0x3;
 182                                 switch (opcode_state) {
 183                                         case OPCODE_INVALID:
 184                                                 /* Trap. */
 185                                                 break;
 186                                         case OPCODE_USER_VALID:
 187                                                 /* Restart the instruction : the branch to the instruction will now be from an RTE
 188                                                    not from SHcompact so the silicon defect won't be triggered. */
 189                                                 return;
 190                                         case OPCODE_PRIV_VALID:
 191                                                 if (!user_mode(regs)) {
 192                                                         /* Should only ever get here if a module has
 193                                                            SHcompact code inside it.  If so, the same fix up is needed. */
 194                                                         return; /* same reason */
 195                                                 }
 196                                                 /* Otherwise, user mode trying to execute a privileged instruction -
 197                                                    fall through to trap. */
 198                                                 break;
 199                                         case OPCODE_CTRL_REG:
 200                                                 /* If in privileged mode, return as above. */
 201                                                 if (!user_mode(regs)) return;
 202                                                 /* In user mode ... */
 203                                                 if (combined == 0x9f) { /* GETCON */
 204                                                         unsigned long regno = (opcode >> 20) & 0x3f;
 205                                                         if (regno >= 62) {
 206                                                                 return;
 207                                                         }
 208                                                         /* Otherwise, reserved or privileged control register, => trap */
 209                                                 } else if (combined == 0x1bf) { /* PUTCON */
 210                                                         unsigned long regno = (opcode >> 4) & 0x3f;
 211                                                         if (regno >= 62) {
 212                                                                 return;
 213                                                         }
 214                                                         /* Otherwise, reserved or privileged control register, => trap */
 215                                                 } else {
 216                                                         /* Trap */
 217                                                 }
 218                                                 break;
 219                                         default:
 220                                                 /* Fall through to trap. */
 221                                                 break;
 222                                 }
 223                         }
 224                         /* fall through to normal resinst processing */
 225                 } else {
 226                         /* Error trying to read opcode.  This typically means a
 227                            real fault, not a RESINST any more.  So change the
 228                            codes. */
 229                         trapnr = 87;
 230                         exception_name = "address error (exec)";
 231                         signr = SIGSEGV;
 232                 }
 233         }
 234
 235         do_unhandled_exception(trapnr, signr, exception_name, "do_reserved_inst", error_code, regs, current);
 236 }
 237
 238 #else /* CONFIG_SH64_ID2815_WORKAROUND */
 239
 240 /* If the workaround isn't needed, this is just a straightforward reserved
 241    instruction */
 242 DO_ERROR(12, SIGILL,  "reserved instruction", reserved_inst, current)
 243
 244 #endif /* CONFIG_SH64_ID2815_WORKAROUND */
 245
 246
 247 #include <asm/system.h>
 248
 249 /* Called with interrupts disabled */
 250 asmlinkage void do_exception_error(unsigned long ex, struct pt_regs *regs)
 251 {
 252         PLS();
 253         show_excp_regs(__FUNCTION__, -1, -1, regs);
 254         die_if_kernel("exception", regs, ex);
 255 }
 256
 257 int do_unknown_trapa(unsigned long scId, struct pt_regs *regs)
 258 {
 259         /* Syscall debug */
 260         printk("System call ID error: [0x1#args:8 #syscall:16  0x%lx]\n", scId);
 261
 262         die_if_kernel("unknown trapa", regs, scId);
 263
 264         return -ENOSYS;
 265 }
 266
 267 void show_stack(struct task_struct *tsk, unsigned long *sp)
 268 {
 269 #ifdef CONFIG_KALLSYMS
 270         extern void sh64_unwind(struct pt_regs *regs);
 271         struct pt_regs *regs;
 272
 273         regs = tsk ? tsk->thread.kregs : NULL;
 274
 275         sh64_unwind(regs);
 276 #else
 277         printk(KERN_ERR "Can't backtrace on sh64 without CONFIG_KALLSYMS\n");
 278 #endif
 279 }
 280
 281 void show_task(unsigned long *sp)
 282 {
 283         show_stack(NULL, sp);
 284 }
 285
 286 void dump_stack(void)
 287 {
 288         show_task(NULL);
 289 }
 290 /* Needed by any user of WARN_ON in view of the defn in include/asm-sh/bug.h */
 291 EXPORT_SYMBOL(dump_stack);
 292
 293 static void do_unhandled_exception(int trapnr, int signr, char *str, char *fn_name,
 294                 unsigned long error_code, struct pt_regs *regs, struct task_struct *tsk)
 295 {
 296         show_excp_regs(fn_name, trapnr, signr, regs);
 297         tsk->thread.error_code = error_code;
 298         tsk->thread.trap_no = trapnr;
 299
 300         if (user_mode(regs))
 301                 force_sig(signr, tsk);
 302
 303         die_if_no_fixup(str, regs, error_code);
 304 }
 305
 306 static int read_opcode(unsigned long long pc, unsigned long *result_opcode, int from_user_mode)
 307 {
 308         int get_user_error;
 309         unsigned long aligned_pc;
 310         unsigned long opcode;
 311
 312         if ((pc & 3) == 1) {
 313                 /* SHmedia */
 314                 aligned_pc = pc & ~3;
 315                 if (from_user_mode) {
 316                         if (!access_ok(VERIFY_READ, aligned_pc, sizeof(unsigned long))) {
 317                                 get_user_error = -EFAULT;
 318                         } else {
 319                                 get_user_error = __get_user(opcode, (unsigned long *)aligned_pc);
 320                                 *result_opcode = opcode;
 321                         }
 322                         return get_user_error;
 323                 } else {
 324                         /* If the fault was in the kernel, we can either read
 325                          * this directly, or if not, we fault.
 326                         */
 327                         *result_opcode = *(unsigned long *) aligned_pc;
 328                         return 0;
 329                 }
 330         } else if ((pc & 1) == 0) {
 331                 /* SHcompact */
 332                 /* TODO : provide handling for this.  We don't really support
 333                    user-mode SHcompact yet, and for a kernel fault, this would
 334                    have to come from a module built for SHcompact.  */
 335                 return -EFAULT;
 336         } else {
 337                 /* misaligned */
 338                 return -EFAULT;
 339         }
 340 }
 341
 342 static int address_is_sign_extended(__u64 a)
 343 {
 344         __u64 b;
 345 #if (NEFF == 32)
 346         b = (__u64)(__s64)(__s32)(a & 0xffffffffUL);
 347         return (b == a) ? 1 : 0;
 348 #else
 349 #error "Sign extend check only works for NEFF==32"
 350 #endif
 351 }
 352
 353 static int generate_and_check_address(struct pt_regs *regs,
 354                                       __u32 opcode,
 355                                       int displacement_not_indexed,
 356                                       int width_shift,
 357                                       __u64 *address)
 358 {
 359         /* return -1 for fault, 0 for OK */
 360
 361         __u64 base_address, addr;
 362         int basereg;
 363
 364         basereg = (opcode >> 20) & 0x3f;
 365         base_address = regs->regs[basereg];
 366         if (displacement_not_indexed) {
 367                 __s64 displacement;
 368                 displacement = (opcode >> 10) & 0x3ff;
 369                 displacement = ((displacement << 54) >> 54); /* sign extend */
 370                 addr = (__u64)((__s64)base_address + (displacement << width_shift));
 371         } else {
 372                 __u64 offset;
 373                 int offsetreg;
 374                 offsetreg = (opcode >> 10) & 0x3f;
 375                 offset = regs->regs[offsetreg];
 376                 addr = base_address + offset;
 377         }
 378
 379         /* Check sign extended */
 380         if (!address_is_sign_extended(addr)) {
 381                 return -1;
 382         }
 383
 384 #if defined(CONFIG_SH64_USER_MISALIGNED_FIXUP)
 385         /* Check accessible.  For misaligned access in the kernel, assume the
 386            address is always accessible (and if not, just fault when the
 387            load/store gets done.) */
 388         if (user_mode(regs)) {
 389                 if (addr >= TASK_SIZE) {
 390                         return -1;
 391                 }
 392                 /* Do access_ok check later - it depends on whether it's a load or a store. */
 393         }
 394 #endif
 395
 396         *address = addr;
 397         return 0;
 398 }
 399
 400 /* Default value as for sh */
 401 #if defined(CONFIG_SH64_USER_MISALIGNED_FIXUP)
 402 static int user_mode_unaligned_fixup_count = 10;
 403 static int user_mode_unaligned_fixup_enable = 1;
 404 #endif
 405
 406 static int kernel_mode_unaligned_fixup_count = 32;
 407
 408 static void misaligned_kernel_word_load(__u64 address, int do_sign_extend, __u64 *result)
 409 {
 410         unsigned short x;
 411         unsigned char *p, *q;
 412         p = (unsigned char *) (int) address;
 413         q = (unsigned char *) &x;
 414         q[0] = p[0];
 415         q[1] = p[1];
 416
 417         if (do_sign_extend) {
 418                 *result = (__u64)(__s64) *(short *) &x;
 419         } else {
 420                 *result = (__u64) x;
 421         }
 422 }
 423
 424 static void misaligned_kernel_word_store(__u64 address, __u64 value)
 425 {
 426         unsigned short x;
 427         unsigned char *p, *q;
 428         p = (unsigned char *) (int) address;
 429         q = (unsigned char *) &x;
 430
 431         x = (__u16) value;
 432         p[0] = q[0];
 433         p[1] = q[1];
 434 }
 435
 436 static int misaligned_load(struct pt_regs *regs,
 437                            __u32 opcode,
 438                            int displacement_not_indexed,
 439                            int width_shift,
 440                            int do_sign_extend)
 441 {
 442         /* Return -1 for a fault, 0 for OK */
 443         int error;
 444         int destreg;
 445         __u64 address;
 446
 447         error = generate_and_check_address(regs, opcode,
 448                         displacement_not_indexed, width_shift, &address);
 449         if (error < 0) {
 450                 return error;
 451         }
 452
 453         destreg = (opcode >> 4) & 0x3f;
 454 #if defined(CONFIG_SH64_USER_MISALIGNED_FIXUP)
 455         if (user_mode(regs)) {
 456                 __u64 buffer;
 457
 458                 if (!access_ok(VERIFY_READ, (unsigned long) address, 1UL<<width_shift)) {
 459                         return -1;
 460                 }
 461
 462                 if (__copy_user(&buffer, (const void *)(int)address, (1 << width_shift)) > 0) {
 463                         return -1; /* fault */
 464                 }
 465                 switch (width_shift) {
 466                 case 1:
 467                         if (do_sign_extend) {
 468                                 regs->regs[destreg] = (__u64)(__s64) *(__s16 *) &buffer;
 469                         } else {
 470                                 regs->regs[destreg] = (__u64) *(__u16 *) &buffer;
 471                         }
 472                         break;
 473                 case 2:
 474                         regs->regs[destreg] = (__u64)(__s64) *(__s32 *) &buffer;
 475                         break;
 476                 case 3:
 477                         regs->regs[destreg] = buffer;
 478                         break;
 479                 default:
 480                         printk("Unexpected width_shift %d in misaligned_load, PC=%08lx\n",
 481                                 width_shift, (unsigned long) regs->pc);
 482                         break;
 483                 }
 484         } else
 485 #endif
 486         {
 487                 /* kernel mode - we can take short cuts since if we fault, it's a genuine bug */
 488                 __u64 lo, hi;
 489
 490                 switch (width_shift) {
 491                 case 1:
 492                         misaligned_kernel_word_load(address, do_sign_extend, &regs->regs[destreg]);
 493                         break;
 494                 case 2:
 495                         asm ("ldlo.l %1, 0, %0" : "=r" (lo) : "r" (address));
 496                         asm ("ldhi.l %1, 3, %0" : "=r" (hi) : "r" (address));
 497                         regs->regs[destreg] = lo | hi;
 498                         break;
 499                 case 3:
 500                         asm ("ldlo.q %1, 0, %0" : "=r" (lo) : "r" (address));
 501                         asm ("ldhi.q %1, 7, %0" : "=r" (hi) : "r" (address));
 502                         regs->regs[destreg] = lo | hi;
 503                         break;
 504
 505                 default:
 506                         printk("Unexpected width_shift %d in misaligned_load, PC=%08lx\n",
 507                                 width_shift, (unsigned long) regs->pc);
 508                         break;
 509                 }
 510         }
 511
 512         return 0;
 513
 514 }
 515
 516 static int misaligned_store(struct pt_regs *regs,
 517                             __u32 opcode,
 518                             int displacement_not_indexed,
 519                             int width_shift)
 520 {
 521         /* Return -1 for a fault, 0 for OK */
 522         int error;
 523         int srcreg;
 524         __u64 address;
 525
 526         error = generate_and_check_address(regs, opcode,
 527                         displacement_not_indexed, width_shift, &address);
 528         if (error < 0) {
 529                 return error;
 530         }
 531
 532         srcreg = (opcode >> 4) & 0x3f;
 533 #if defined(CONFIG_SH64_USER_MISALIGNED_FIXUP)
 534         if (user_mode(regs)) {
 535                 __u64 buffer;
 536
 537                 if (!access_ok(VERIFY_WRITE, (unsigned long) address, 1UL<<width_shift)) {
 538                         return -1;
 539                 }
 540
 541                 switch (width_shift) {
 542                 case 1:
 543                         *(__u16 *) &buffer = (__u16) regs->regs[srcreg];
 544                         break;
 545                 case 2:
 546                         *(__u32 *) &buffer = (__u32) regs->regs[srcreg];
 547                         break;
 548                 case 3:
 549                         buffer = regs->regs[srcreg];
 550                         break;
 551                 default:
 552                         printk("Unexpected width_shift %d in misaligned_store, PC=%08lx\n",
 553                                 width_shift, (unsigned long) regs->pc);
 554                         break;
 555                 }
 556
 557                 if (__copy_user((void *)(int)address, &buffer, (1 << width_shift)) > 0) {
 558                         return -1; /* fault */
 559                 }
 560         } else
 561 #endif
 562         {
 563                 /* kernel mode - we can take short cuts since if we fault, it's a genuine bug */
 564                 __u64 val = regs->regs[srcreg];
 565
 566                 switch (width_shift) {
 567                 case 1:
 568                         misaligned_kernel_word_store(address, val);
 569                         break;
 570                 case 2:
 571                         asm ("stlo.l %1, 0, %0" : : "r" (val), "r" (address));
 572                         asm ("sthi.l %1, 3, %0" : : "r" (val), "r" (address));
 573                         break;
 574                 case 3:
 575                         asm ("stlo.q %1, 0, %0" : : "r" (val), "r" (address));
 576                         asm ("sthi.q %1, 7, %0" : : "r" (val), "r" (address));
 577                         break;
 578
 579                 default:
 580                         printk("Unexpected width_shift %d in misaligned_store, PC=%08lx\n",
 581                                 width_shift, (unsigned long) regs->pc);
 582                         break;
 583                 }
 584         }
 585
 586         return 0;
 587
 588 }
 589
 590 #if defined(CONFIG_SH64_USER_MISALIGNED_FIXUP)
 591 /* Never need to fix up misaligned FPU accesses within the kernel since that's a real
 592    error. */
 593 static int misaligned_fpu_load(struct pt_regs *regs,
 594                            __u32 opcode,
 595                            int displacement_not_indexed,
 596                            int width_shift,
 597                            int do_paired_load)
 598 {
 599         /* Return -1 for a fault, 0 for OK */
 600         int error;
 601         int destreg;
 602         __u64 address;
 603
 604         error = generate_and_check_address(regs, opcode,
 605                         displacement_not_indexed, width_shift, &address);
 606         if (error < 0) {
 607                 return error;
 608         }
 609
 610         destreg = (opcode >> 4) & 0x3f;
 611         if (user_mode(regs)) {
 612                 __u64 buffer;
 613                 __u32 buflo, bufhi;
 614
 615                 if (!access_ok(VERIFY_READ, (unsigned long) address, 1UL<<width_shift)) {
 616                         return -1;
 617                 }
 618
 619                 if (__copy_user(&buffer, (const void *)(int)address, (1 << width_shift)) > 0) {
 620                         return -1; /* fault */
 621                 }
 622                 /* 'current' may be the current owner of the FPU state, so
 623                    context switch the registers into memory so they can be
 624                    indexed by register number. */
 625                 if (last_task_used_math == current) {
 626                         grab_fpu();
 627                         fpsave(&current->thread.fpu.hard);
 628                         release_fpu();
 629                         last_task_used_math = NULL;
 630                         regs->sr |= SR_FD;
 631                 }
 632
 633                 buflo = *(__u32*) &buffer;
 634                 bufhi = *(1 + (__u32*) &buffer);
 635
 636                 switch (width_shift) {
 637                 case 2:
 638                         current->thread.fpu.hard.fp_regs[destreg] = buflo;
 639                         break;
 640                 case 3:
 641                         if (do_paired_load) {
 642                                 current->thread.fpu.hard.fp_regs[destreg] = buflo;
 643                                 current->thread.fpu.hard.fp_regs[destreg+1] = bufhi;
 644                         } else {
 645 #if defined(CONFIG_LITTLE_ENDIAN)
 646                                 current->thread.fpu.hard.fp_regs[destreg] = bufhi;
 647                                 current->thread.fpu.hard.fp_regs[destreg+1] = buflo;
 648 #else
 649                                 current->thread.fpu.hard.fp_regs[destreg] = buflo;
 650                                 current->thread.fpu.hard.fp_regs[destreg+1] = bufhi;
 651 #endif
 652                         }
 653                         break;
 654                 default:
 655                         printk("Unexpected width_shift %d in misaligned_fpu_load, PC=%08lx\n",
 656                                 width_shift, (unsigned long) regs->pc);
 657                         break;
 658                 }
 659                 return 0;
 660         } else {
 661                 die ("Misaligned FPU load inside kernel", regs, 0);
 662                 return -1;
 663         }
 664
 665
 666 }
 667
 668 static int misaligned_fpu_store(struct pt_regs *regs,
 669                            __u32 opcode,
 670                            int displacement_not_indexed,
 671                            int width_shift,
 672                            int do_paired_load)
 673 {
 674         /* Return -1 for a fault, 0 for OK */
 675         int error;
 676         int srcreg;
 677         __u64 address;
 678
 679         error = generate_and_check_address(regs, opcode,
 680                         displacement_not_indexed, width_shift, &address);
 681         if (error < 0) {
 682                 return error;
 683         }
 684
 685         srcreg = (opcode >> 4) & 0x3f;
 686         if (user_mode(regs)) {
 687                 __u64 buffer;
 688                 /* Initialise these to NaNs. */
 689                 __u32 buflo=0xffffffffUL, bufhi=0xffffffffUL;
 690
 691                 if (!access_ok(VERIFY_WRITE, (unsigned long) address, 1UL<<width_shift)) {
 692                         return -1;
 693                 }
 694
 695                 /* 'current' may be the current owner of the FPU state, so
 696                    context switch the registers into memory so they can be
 697                    indexed by register number. */
 698                 if (last_task_used_math == current) {
 699                         grab_fpu();
 700                         fpsave(&current->thread.fpu.hard);
 701                         release_fpu();
 702                         last_task_used_math = NULL;
 703                         regs->sr |= SR_FD;
 704                 }
 705
 706                 switch (width_shift) {
 707                 case 2:
 708                         buflo = current->thread.fpu.hard.fp_regs[srcreg];
 709                         break;
 710                 case 3:
 711                         if (do_paired_load) {
 712                                 buflo = current->thread.fpu.hard.fp_regs[srcreg];
 713                                 bufhi = current->thread.fpu.hard.fp_regs[srcreg+1];
 714                         } else {
 715 #if defined(CONFIG_LITTLE_ENDIAN)
 716                                 bufhi = current->thread.fpu.hard.fp_regs[srcreg];
 717                                 buflo = current->thread.fpu.hard.fp_regs[srcreg+1];
 718 #else
 719                                 buflo = current->thread.fpu.hard.fp_regs[srcreg];
 720                                 bufhi = current->thread.fpu.hard.fp_regs[srcreg+1];
 721 #endif
 722                         }
 723                         break;
 724                 default:
 725                         printk("Unexpected width_shift %d in misaligned_fpu_store, PC=%08lx\n",
 726                                 width_shift, (unsigned long) regs->pc);
 727                         break;
 728                 }
 729
 730                 *(__u32*) &buffer = buflo;
 731                 *(1 + (__u32*) &buffer) = bufhi;
 732                 if (__copy_user((void *)(int)address, &buffer, (1 << width_shift)) > 0) {
 733                         return -1; /* fault */
 734                 }
 735                 return 0;
 736         } else {
 737                 die ("Misaligned FPU load inside kernel", regs, 0);
 738                 return -1;
 739         }
 740 }
 741 #endif
 742
 743 static int misaligned_fixup(struct pt_regs *regs)
 744 {
 745         unsigned long opcode;
 746         int error;
 747         int major, minor;
 748
 749 #if !defined(CONFIG_SH64_USER_MISALIGNED_FIXUP)
 750         /* Never fixup user mode misaligned accesses without this option enabled. */
 751         return -1;
 752 #else
 753         if (!user_mode_unaligned_fixup_enable) return -1;
 754 #endif
 755
 756         error = read_opcode(regs->pc, &opcode, user_mode(regs));
 757         if (error < 0) {
 758                 return error;
 759         }
 760         major = (opcode >> 26) & 0x3f;
 761         minor = (opcode >> 16) & 0xf;
 762
 763 #if defined(CONFIG_SH64_USER_MISALIGNED_FIXUP)
 764         if (user_mode(regs) && (user_mode_unaligned_fixup_count > 0)) {
 765                 --user_mode_unaligned_fixup_count;
 766                 /* Only do 'count' worth of these reports, to remove a potential DoS against syslog */
 767                 printk("Fixing up unaligned userspace access in \"%s\" pid=%d pc=0x%08x ins=0x%08lx\n",
 768                        current->comm, current->pid, (__u32)regs->pc, opcode);
 769         } else
 770 #endif
 771         if (!user_mode(regs) && (kernel_mode_unaligned_fixup_count > 0)) {
 772                 --kernel_mode_unaligned_fixup_count;
 773                 if (in_interrupt()) {
 774                         printk("Fixing up unaligned kernelspace access in interrupt pc=0x%08x ins=0x%08lx\n",
 775                                (__u32)regs->pc, opcode);
 776                 } else {
 777                         printk("Fixing up unaligned kernelspace access in \"%s\" pid=%d pc=0x%08x ins=0x%08lx\n",
 778                                current->comm, current->pid, (__u32)regs->pc, opcode);
 779                 }
 780         }
 781
 782
 783         switch (major) {
 784                 case (0x84>>2): /* LD.W */
 785                         error = misaligned_load(regs, opcode, 1, 1, 1);
 786                         break;
 787                 case (0xb0>>2): /* LD.UW */
 788                         error = misaligned_load(regs, opcode, 1, 1, 0);
 789                         break;
 790                 case (0x88>>2): /* LD.L */
 791                         error = misaligned_load(regs, opcode, 1, 2, 1);
 792                         break;
 793                 case (0x8c>>2): /* LD.Q */
 794                         error = misaligned_load(regs, opcode, 1, 3, 0);
 795                         break;
 796
 797                 case (0xa4>>2): /* ST.W */
 798                         error = misaligned_store(regs, opcode, 1, 1);
 799                         break;
 800                 case (0xa8>>2): /* ST.L */
 801                         error = misaligned_store(regs, opcode, 1, 2);
 802                         break;
 803                 case (0xac>>2): /* ST.Q */
 804                         error = misaligned_store(regs, opcode, 1, 3);
 805                         break;
 806
 807                 case (0x40>>2): /* indexed loads */
 808                         switch (minor) {
 809                                 case 0x1: /* LDX.W */
 810                                         error = misaligned_load(regs, opcode, 0, 1, 1);
 811                                         break;
 812                                 case 0x5: /* LDX.UW */
 813                                         error = misaligned_load(regs, opcode, 0, 1, 0);
 814                                         break;
 815                                 case 0x2: /* LDX.L */
 816                                         error = misaligned_load(regs, opcode, 0, 2, 1);
 817                                         break;
 818                                 case 0x3: /* LDX.Q */
 819                                         error = misaligned_load(regs, opcode, 0, 3, 0);
 820                                         break;
 821                                 default:
 822                                         error = -1;
 823                                         break;
 824                         }
 825                         break;
 826
 827                 case (0x60>>2): /* indexed stores */
 828                         switch (minor) {
 829                                 case 0x1: /* STX.W */
 830                                         error = misaligned_store(regs, opcode, 0, 1);
 831                                         break;
 832                                 case 0x2: /* STX.L */
 833                                         error = misaligned_store(regs, opcode, 0, 2);
 834                                         break;
 835                                 case 0x3: /* STX.Q */
 836                                         error = misaligned_store(regs, opcode, 0, 3);
 837                                         break;
 838                                 default:
 839                                         error = -1;
 840                                         break;
 841                         }
 842                         break;
 843
 844 #if defined(CONFIG_SH64_USER_MISALIGNED_FIXUP)
 845                 case (0x94>>2): /* FLD.S */
 846                         error = misaligned_fpu_load(regs, opcode, 1, 2, 0);
 847                         break;
 848                 case (0x98>>2): /* FLD.P */
 849                         error = misaligned_fpu_load(regs, opcode, 1, 3, 1);
 850                         break;
 851                 case (0x9c>>2): /* FLD.D */
 852                         error = misaligned_fpu_load(regs, opcode, 1, 3, 0);
 853                         break;
 854                 case (0x1c>>2): /* floating indexed loads */
 855                         switch (minor) {
 856                         case 0x8: /* FLDX.S */
 857                                 error = misaligned_fpu_load(regs, opcode, 0, 2, 0);
 858                                 break;
 859                         case 0xd: /* FLDX.P */
 860                                 error = misaligned_fpu_load(regs, opcode, 0, 3, 1);
 861                                 break;
 862                         case 0x9: /* FLDX.D */
 863                                 error = misaligned_fpu_load(regs, opcode, 0, 3, 0);
 864                                 break;
 865                         default:
 866                                 error = -1;
 867                                 break;
 868                         }
 869                         break;
 870                 case (0xb4>>2): /* FLD.S */
 871                         error = misaligned_fpu_store(regs, opcode, 1, 2, 0);
 872                         break;
 873                 case (0xb8>>2): /* FLD.P */
 874                         error = misaligned_fpu_store(regs, opcode, 1, 3, 1);
 875                         break;
 876                 case (0xbc>>2): /* FLD.D */
 877                         error = misaligned_fpu_store(regs, opcode, 1, 3, 0);
 878                         break;
 879                 case (0x3c>>2): /* floating indexed stores */
 880                         switch (minor) {
 881                         case 0x8: /* FSTX.S */
 882                                 error = misaligned_fpu_store(regs, opcode, 0, 2, 0);
 883                                 break;
 884                         case 0xd: /* FSTX.P */
 885                                 error = misaligned_fpu_store(regs, opcode, 0, 3, 1);
 886                                 break;
 887                         case 0x9: /* FSTX.D */
 888                                 error = misaligned_fpu_store(regs, opcode, 0, 3, 0);
 889                                 break;
 890                         default:
 891                                 error = -1;
 892                                 break;
 893                         }
 894                         break;
 895 #endif
 896
 897                 default:
 898                         /* Fault */
 899                         error = -1;
 900                         break;
 901         }
 902
 903         if (error < 0) {
 904                 return error;
 905         } else {
 906                 regs->pc += 4; /* Skip the instruction that's just been emulated */
 907                 return 0;
 908         }
 909
 910 }
 911
 912 static ctl_table unaligned_table[] = {
 913         {1, "kernel_reports", &kernel_mode_unaligned_fixup_count,
 914                 sizeof(int), 0644, NULL, &proc_dointvec},
 915 #if defined(CONFIG_SH64_USER_MISALIGNED_FIXUP)
 916         {2, "user_reports", &user_mode_unaligned_fixup_count,
 917                 sizeof(int), 0644, NULL, &proc_dointvec},
 918         {3, "user_enable", &user_mode_unaligned_fixup_enable,
 919                 sizeof(int), 0644, NULL, &proc_dointvec},
 920 #endif
 921         {0}
 922 };
 923
 924 static ctl_table unaligned_root[] = {
 925         {1, "unaligned_fixup", NULL, 0, 0555, unaligned_table},
 926         {0}
 927 };
 928
 929 static ctl_table sh64_root[] = {
 930         {1, "sh64", NULL, 0, 0555, unaligned_root},
 931         {0}
 932 };
 933 static struct ctl_table_header *sysctl_header;
 934 static int __init init_sysctl(void)
 935 {
 936         sysctl_header = register_sysctl_table(sh64_root, 0);
 937         return 0;
 938 }
 939
 940 __initcall(init_sysctl);
 941
 942
 943 asmlinkage void do_debug_interrupt(unsigned long code, struct pt_regs *regs)
 944 {
 945         u64 peek_real_address_q(u64 addr);
 946         u64 poke_real_address_q(u64 addr, u64 val);
 947         unsigned long long DM_EXP_CAUSE_PHY = 0x0c100010;
 948         unsigned long long exp_cause;
 949         /* It's not worth ioremapping the debug module registers for the amount
 950            of access we make to them - just go direct to their physical
 951            addresses. */
 952         exp_cause = peek_real_address_q(DM_EXP_CAUSE_PHY);
 953         if (exp_cause & ~4) {
 954                 printk("DM.EXP_CAUSE had unexpected bits set (=%08lx)\n",
 955                         (unsigned long)(exp_cause & 0xffffffff));
 956         }
 957         show_state();
 958         /* Clear all DEBUGINT causes */
 959         poke_real_address_q(DM_EXP_CAUSE_PHY, 0x0);
 960 }
 961