Pileus Git - ~andy/linux/blob - arch/mips/kernel/unaligned.c

   1 /*
   2  * Handle unaligned accesses by emulation.
   3  *
   4  * This file is subject to the terms and conditions of the GNU General Public
   5  * License.  See the file "COPYING" in the main directory of this archive
   6  * for more details.
   7  *
   8  * Copyright (C) 1996, 1998, 1999, 2002 by Ralf Baechle
   9  * Copyright (C) 1999 Silicon Graphics, Inc.
  10  *
  11  * This file contains exception handler for address error exception with the
  12  * special capability to execute faulting instructions in software.  The
  13  * handler does not try to handle the case when the program counter points
  14  * to an address not aligned to a word boundary.
  15  *
  16  * Putting data to unaligned addresses is a bad practice even on Intel where
  17  * only the performance is affected.  Much worse is that such code is non-
  18  * portable.  Due to several programs that die on MIPS due to alignment
  19  * problems I decided to implement this handler anyway though I originally
  20  * didn't intend to do this at all for user code.
  21  *
  22  * For now I enable fixing of address errors by default to make life easier.
  23  * I however intend to disable this somewhen in the future when the alignment
  24  * problems with user programs have been fixed.  For programmers this is the
  25  * right way to go.
  26  *
  27  * Fixing address errors is a per process option.  The option is inherited
  28  * across fork(2) and execve(2) calls.  If you really want to use the
  29  * option in your user programs - I discourage the use of the software
  30  * emulation strongly - use the following code in your userland stuff:
  31  *
  32  * #include <sys/sysmips.h>
  33  *
  34  * ...
  35  * sysmips(MIPS_FIXADE, x);
  36  * ...
  37  *
  38  * The argument x is 0 for disabling software emulation, enabled otherwise.
  39  *
  40  * Below a little program to play around with this feature.
  41  *
  42  * #include <stdio.h>
  43  * #include <sys/sysmips.h>
  44  *
  45  * struct foo {
  46  *         unsigned char bar[8];
  47  * };
  48  *
  49  * main(int argc, char *argv[])
  50  * {
  51  *         struct foo x = {0, 1, 2, 3, 4, 5, 6, 7};
  52  *         unsigned int *p = (unsigned int *) (x.bar + 3);
  53  *         int i;
  54  *
  55  *         if (argc > 1)
  56  *                 sysmips(MIPS_FIXADE, atoi(argv[1]));
  57  *
  58  *         printf("*p = %08lx\n", *p);
  59  *
  60  *         *p = 0xdeadface;
  61  *
  62  *         for(i = 0; i <= 7; i++)
  63  *         printf("%02x ", x.bar[i]);
  64  *         printf("\n");
  65  * }
  66  *
  67  * Coprocessor loads are not supported; I think this case is unimportant
  68  * in the practice.
  69  *
  70  * TODO: Handle ndc (attempted store to doubleword in uncached memory)
  71  *       exception for the R6000.
  72  *       A store crossing a page boundary might be executed only partially.
  73  *       Undo the partial store in this case.
  74  */
  75 #include <linux/context_tracking.h>
  76 #include <linux/mm.h>
  77 #include <linux/signal.h>
  78 #include <linux/smp.h>
  79 #include <linux/sched.h>
  80 #include <linux/debugfs.h>
  81 #include <linux/perf_event.h>
  82
  83 #include <asm/asm.h>
  84 #include <asm/branch.h>
  85 #include <asm/byteorder.h>
  86 #include <asm/cop2.h>
  87 #include <asm/fpu.h>
  88 #include <asm/fpu_emulator.h>
  89 #include <asm/inst.h>
  90 #include <asm/uaccess.h>
  91 #include <asm/fpu.h>
  92 #include <asm/fpu_emulator.h>
  93
  94 #define STR(x)  __STR(x)
  95 #define __STR(x)  #x
  96
  97 enum {
  98         UNALIGNED_ACTION_QUIET,
  99         UNALIGNED_ACTION_SIGNAL,
 100         UNALIGNED_ACTION_SHOW,
 101 };
 102 #ifdef CONFIG_DEBUG_FS
 103 static u32 unaligned_instructions;
 104 static u32 unaligned_action;
 105 #else
 106 #define unaligned_action UNALIGNED_ACTION_QUIET
 107 #endif
 108 extern void show_registers(struct pt_regs *regs);
 109
 110 #ifdef __BIG_ENDIAN
 111 #define     LoadHW(addr, value, res)  \
 112                 __asm__ __volatile__ (".set\tnoat\n"        \
 113                         "1:\tlb\t%0, 0(%2)\n"               \
 114                         "2:\tlbu\t$1, 1(%2)\n\t"            \
 115                         "sll\t%0, 0x8\n\t"                  \
 116                         "or\t%0, $1\n\t"                    \
 117                         "li\t%1, 0\n"                       \
 118                         "3:\t.set\tat\n\t"                  \
 119                         ".insn\n\t"                         \
 120                         ".section\t.fixup,\"ax\"\n\t"       \
 121                         "4:\tli\t%1, %3\n\t"                \
 122                         "j\t3b\n\t"                         \
 123                         ".previous\n\t"                     \
 124                         ".section\t__ex_table,\"a\"\n\t"    \
 125                         STR(PTR)"\t1b, 4b\n\t"              \
 126                         STR(PTR)"\t2b, 4b\n\t"              \
 127                         ".previous"                         \
 128                         : "=&r" (value), "=r" (res)         \
 129                         : "r" (addr), "i" (-EFAULT));
 130
 131 #define     LoadW(addr, value, res)   \
 132                 __asm__ __volatile__ (                      \
 133                         "1:\tlwl\t%0, (%2)\n"               \
 134                         "2:\tlwr\t%0, 3(%2)\n\t"            \
 135                         "li\t%1, 0\n"                       \
 136                         "3:\n\t"                            \
 137                         ".insn\n\t"                         \
 138                         ".section\t.fixup,\"ax\"\n\t"       \
 139                         "4:\tli\t%1, %3\n\t"                \
 140                         "j\t3b\n\t"                         \
 141                         ".previous\n\t"                     \
 142                         ".section\t__ex_table,\"a\"\n\t"    \
 143                         STR(PTR)"\t1b, 4b\n\t"              \
 144                         STR(PTR)"\t2b, 4b\n\t"              \
 145                         ".previous"                         \
 146                         : "=&r" (value), "=r" (res)         \
 147                         : "r" (addr), "i" (-EFAULT));
 148
 149 #define     LoadHWU(addr, value, res) \
 150                 __asm__ __volatile__ (                      \
 151                         ".set\tnoat\n"                      \
 152                         "1:\tlbu\t%0, 0(%2)\n"              \
 153                         "2:\tlbu\t$1, 1(%2)\n\t"            \
 154                         "sll\t%0, 0x8\n\t"                  \
 155                         "or\t%0, $1\n\t"                    \
 156                         "li\t%1, 0\n"                       \
 157                         "3:\n\t"                            \
 158                         ".insn\n\t"                         \
 159                         ".set\tat\n\t"                      \
 160                         ".section\t.fixup,\"ax\"\n\t"       \
 161                         "4:\tli\t%1, %3\n\t"                \
 162                         "j\t3b\n\t"                         \
 163                         ".previous\n\t"                     \
 164                         ".section\t__ex_table,\"a\"\n\t"    \
 165                         STR(PTR)"\t1b, 4b\n\t"              \
 166                         STR(PTR)"\t2b, 4b\n\t"              \
 167                         ".previous"                         \
 168                         : "=&r" (value), "=r" (res)         \
 169                         : "r" (addr), "i" (-EFAULT));
 170
 171 #define     LoadWU(addr, value, res)  \
 172                 __asm__ __volatile__ (                      \
 173                         "1:\tlwl\t%0, (%2)\n"               \
 174                         "2:\tlwr\t%0, 3(%2)\n\t"            \
 175                         "dsll\t%0, %0, 32\n\t"              \
 176                         "dsrl\t%0, %0, 32\n\t"              \
 177                         "li\t%1, 0\n"                       \
 178                         "3:\n\t"                            \
 179                         ".insn\n\t"                         \
 180                         "\t.section\t.fixup,\"ax\"\n\t"     \
 181                         "4:\tli\t%1, %3\n\t"                \
 182                         "j\t3b\n\t"                         \
 183                         ".previous\n\t"                     \
 184                         ".section\t__ex_table,\"a\"\n\t"    \
 185                         STR(PTR)"\t1b, 4b\n\t"              \
 186                         STR(PTR)"\t2b, 4b\n\t"              \
 187                         ".previous"                         \
 188                         : "=&r" (value), "=r" (res)         \
 189                         : "r" (addr), "i" (-EFAULT));
 190
 191 #define     LoadDW(addr, value, res)  \
 192                 __asm__ __volatile__ (                      \
 193                         "1:\tldl\t%0, (%2)\n"               \
 194                         "2:\tldr\t%0, 7(%2)\n\t"            \
 195                         "li\t%1, 0\n"                       \
 196                         "3:\n\t"                            \
 197                         ".insn\n\t"                         \
 198                         "\t.section\t.fixup,\"ax\"\n\t"     \
 199                         "4:\tli\t%1, %3\n\t"                \
 200                         "j\t3b\n\t"                         \
 201                         ".previous\n\t"                     \
 202                         ".section\t__ex_table,\"a\"\n\t"    \
 203                         STR(PTR)"\t1b, 4b\n\t"              \
 204                         STR(PTR)"\t2b, 4b\n\t"              \
 205                         ".previous"                         \
 206                         : "=&r" (value), "=r" (res)         \
 207                         : "r" (addr), "i" (-EFAULT));
 208
 209 #define     StoreHW(addr, value, res) \
 210                 __asm__ __volatile__ (                      \
 211                         ".set\tnoat\n"                      \
 212                         "1:\tsb\t%1, 1(%2)\n\t"             \
 213                         "srl\t$1, %1, 0x8\n"                \
 214                         "2:\tsb\t$1, 0(%2)\n\t"             \
 215                         ".set\tat\n\t"                      \
 216                         "li\t%0, 0\n"                       \
 217                         "3:\n\t"                            \
 218                         ".insn\n\t"                         \
 219                         ".section\t.fixup,\"ax\"\n\t"       \
 220                         "4:\tli\t%0, %3\n\t"                \
 221                         "j\t3b\n\t"                         \
 222                         ".previous\n\t"                     \
 223                         ".section\t__ex_table,\"a\"\n\t"    \
 224                         STR(PTR)"\t1b, 4b\n\t"              \
 225                         STR(PTR)"\t2b, 4b\n\t"              \
 226                         ".previous"                         \
 227                         : "=r" (res)                        \
 228                         : "r" (value), "r" (addr), "i" (-EFAULT));
 229
 230 #define     StoreW(addr, value, res)  \
 231                 __asm__ __volatile__ (                      \
 232                         "1:\tswl\t%1,(%2)\n"                \
 233                         "2:\tswr\t%1, 3(%2)\n\t"            \
 234                         "li\t%0, 0\n"                       \
 235                         "3:\n\t"                            \
 236                         ".insn\n\t"                         \
 237                         ".section\t.fixup,\"ax\"\n\t"       \
 238                         "4:\tli\t%0, %3\n\t"                \
 239                         "j\t3b\n\t"                         \
 240                         ".previous\n\t"                     \
 241                         ".section\t__ex_table,\"a\"\n\t"    \
 242                         STR(PTR)"\t1b, 4b\n\t"              \
 243                         STR(PTR)"\t2b, 4b\n\t"              \
 244                         ".previous"                         \
 245                 : "=r" (res)                                \
 246                 : "r" (value), "r" (addr), "i" (-EFAULT));
 247
 248 #define     StoreDW(addr, value, res) \
 249                 __asm__ __volatile__ (                      \
 250                         "1:\tsdl\t%1,(%2)\n"                \
 251                         "2:\tsdr\t%1, 7(%2)\n\t"            \
 252                         "li\t%0, 0\n"                       \
 253                         "3:\n\t"                            \
 254                         ".insn\n\t"                         \
 255                         ".section\t.fixup,\"ax\"\n\t"       \
 256                         "4:\tli\t%0, %3\n\t"                \
 257                         "j\t3b\n\t"                         \
 258                         ".previous\n\t"                     \
 259                         ".section\t__ex_table,\"a\"\n\t"    \
 260                         STR(PTR)"\t1b, 4b\n\t"              \
 261                         STR(PTR)"\t2b, 4b\n\t"              \
 262                         ".previous"                         \
 263                 : "=r" (res)                                \
 264                 : "r" (value), "r" (addr), "i" (-EFAULT));
 265 #endif
 266
 267 #ifdef __LITTLE_ENDIAN
 268 #define     LoadHW(addr, value, res)  \
 269                 __asm__ __volatile__ (".set\tnoat\n"        \
 270                         "1:\tlb\t%0, 1(%2)\n"               \
 271                         "2:\tlbu\t$1, 0(%2)\n\t"            \
 272                         "sll\t%0, 0x8\n\t"                  \
 273                         "or\t%0, $1\n\t"                    \
 274                         "li\t%1, 0\n"                       \
 275                         "3:\t.set\tat\n\t"                  \
 276                         ".insn\n\t"                         \
 277                         ".section\t.fixup,\"ax\"\n\t"       \
 278                         "4:\tli\t%1, %3\n\t"                \
 279                         "j\t3b\n\t"                         \
 280                         ".previous\n\t"                     \
 281                         ".section\t__ex_table,\"a\"\n\t"    \
 282                         STR(PTR)"\t1b, 4b\n\t"              \
 283                         STR(PTR)"\t2b, 4b\n\t"              \
 284                         ".previous"                         \
 285                         : "=&r" (value), "=r" (res)         \
 286                         : "r" (addr), "i" (-EFAULT));
 287
 288 #define     LoadW(addr, value, res)   \
 289                 __asm__ __volatile__ (                      \
 290                         "1:\tlwl\t%0, 3(%2)\n"              \
 291                         "2:\tlwr\t%0, (%2)\n\t"             \
 292                         "li\t%1, 0\n"                       \
 293                         "3:\n\t"                            \
 294                         ".insn\n\t"                         \
 295                         ".section\t.fixup,\"ax\"\n\t"       \
 296                         "4:\tli\t%1, %3\n\t"                \
 297                         "j\t3b\n\t"                         \
 298                         ".previous\n\t"                     \
 299                         ".section\t__ex_table,\"a\"\n\t"    \
 300                         STR(PTR)"\t1b, 4b\n\t"              \
 301                         STR(PTR)"\t2b, 4b\n\t"              \
 302                         ".previous"                         \
 303                         : "=&r" (value), "=r" (res)         \
 304                         : "r" (addr), "i" (-EFAULT));
 305
 306 #define     LoadHWU(addr, value, res) \
 307                 __asm__ __volatile__ (                      \
 308                         ".set\tnoat\n"                      \
 309                         "1:\tlbu\t%0, 1(%2)\n"              \
 310                         "2:\tlbu\t$1, 0(%2)\n\t"            \
 311                         "sll\t%0, 0x8\n\t"                  \
 312                         "or\t%0, $1\n\t"                    \
 313                         "li\t%1, 0\n"                       \
 314                         "3:\n\t"                            \
 315                         ".insn\n\t"                         \
 316                         ".set\tat\n\t"                      \
 317                         ".section\t.fixup,\"ax\"\n\t"       \
 318                         "4:\tli\t%1, %3\n\t"                \
 319                         "j\t3b\n\t"                         \
 320                         ".previous\n\t"                     \
 321                         ".section\t__ex_table,\"a\"\n\t"    \
 322                         STR(PTR)"\t1b, 4b\n\t"              \
 323                         STR(PTR)"\t2b, 4b\n\t"              \
 324                         ".previous"                         \
 325                         : "=&r" (value), "=r" (res)         \
 326                         : "r" (addr), "i" (-EFAULT));
 327
 328 #define     LoadWU(addr, value, res)  \
 329                 __asm__ __volatile__ (                      \
 330                         "1:\tlwl\t%0, 3(%2)\n"              \
 331                         "2:\tlwr\t%0, (%2)\n\t"             \
 332                         "dsll\t%0, %0, 32\n\t"              \
 333                         "dsrl\t%0, %0, 32\n\t"              \
 334                         "li\t%1, 0\n"                       \
 335                         "3:\n\t"                            \
 336                         ".insn\n\t"                         \
 337                         "\t.section\t.fixup,\"ax\"\n\t"     \
 338                         "4:\tli\t%1, %3\n\t"                \
 339                         "j\t3b\n\t"                         \
 340                         ".previous\n\t"                     \
 341                         ".section\t__ex_table,\"a\"\n\t"    \
 342                         STR(PTR)"\t1b, 4b\n\t"              \
 343                         STR(PTR)"\t2b, 4b\n\t"              \
 344                         ".previous"                         \
 345                         : "=&r" (value), "=r" (res)         \
 346                         : "r" (addr), "i" (-EFAULT));
 347
 348 #define     LoadDW(addr, value, res)  \
 349                 __asm__ __volatile__ (                      \
 350                         "1:\tldl\t%0, 7(%2)\n"              \
 351                         "2:\tldr\t%0, (%2)\n\t"             \
 352                         "li\t%1, 0\n"                       \
 353                         "3:\n\t"                            \
 354                         ".insn\n\t"                         \
 355                         "\t.section\t.fixup,\"ax\"\n\t"     \
 356                         "4:\tli\t%1, %3\n\t"                \
 357                         "j\t3b\n\t"                         \
 358                         ".previous\n\t"                     \
 359                         ".section\t__ex_table,\"a\"\n\t"    \
 360                         STR(PTR)"\t1b, 4b\n\t"              \
 361                         STR(PTR)"\t2b, 4b\n\t"              \
 362                         ".previous"                         \
 363                         : "=&r" (value), "=r" (res)         \
 364                         : "r" (addr), "i" (-EFAULT));
 365
 366 #define     StoreHW(addr, value, res) \
 367                 __asm__ __volatile__ (                      \
 368                         ".set\tnoat\n"                      \
 369                         "1:\tsb\t%1, 0(%2)\n\t"             \
 370                         "srl\t$1,%1, 0x8\n"                 \
 371                         "2:\tsb\t$1, 1(%2)\n\t"             \
 372                         ".set\tat\n\t"                      \
 373                         "li\t%0, 0\n"                       \
 374                         "3:\n\t"                            \
 375                         ".insn\n\t"                         \
 376                         ".section\t.fixup,\"ax\"\n\t"       \
 377                         "4:\tli\t%0, %3\n\t"                \
 378                         "j\t3b\n\t"                         \
 379                         ".previous\n\t"                     \
 380                         ".section\t__ex_table,\"a\"\n\t"    \
 381                         STR(PTR)"\t1b, 4b\n\t"              \
 382                         STR(PTR)"\t2b, 4b\n\t"              \
 383                         ".previous"                         \
 384                         : "=r" (res)                        \
 385                         : "r" (value), "r" (addr), "i" (-EFAULT));
 386
 387 #define     StoreW(addr, value, res)  \
 388                 __asm__ __volatile__ (                      \
 389                         "1:\tswl\t%1, 3(%2)\n"              \
 390                         "2:\tswr\t%1, (%2)\n\t"             \
 391                         "li\t%0, 0\n"                       \
 392                         "3:\n\t"                            \
 393                         ".insn\n\t"                         \
 394                         ".section\t.fixup,\"ax\"\n\t"       \
 395                         "4:\tli\t%0, %3\n\t"                \
 396                         "j\t3b\n\t"                         \
 397                         ".previous\n\t"                     \
 398                         ".section\t__ex_table,\"a\"\n\t"    \
 399                         STR(PTR)"\t1b, 4b\n\t"              \
 400                         STR(PTR)"\t2b, 4b\n\t"              \
 401                         ".previous"                         \
 402                 : "=r" (res)                                \
 403                 : "r" (value), "r" (addr), "i" (-EFAULT));
 404
 405 #define     StoreDW(addr, value, res) \
 406                 __asm__ __volatile__ (                      \
 407                         "1:\tsdl\t%1, 7(%2)\n"              \
 408                         "2:\tsdr\t%1, (%2)\n\t"             \
 409                         "li\t%0, 0\n"                       \
 410                         "3:\n\t"                            \
 411                         ".insn\n\t"                         \
 412                         ".section\t.fixup,\"ax\"\n\t"       \
 413                         "4:\tli\t%0, %3\n\t"                \
 414                         "j\t3b\n\t"                         \
 415                         ".previous\n\t"                     \
 416                         ".section\t__ex_table,\"a\"\n\t"    \
 417                         STR(PTR)"\t1b, 4b\n\t"              \
 418                         STR(PTR)"\t2b, 4b\n\t"              \
 419                         ".previous"                         \
 420                 : "=r" (res)                                \
 421                 : "r" (value), "r" (addr), "i" (-EFAULT));
 422 #endif
 423
 424 static void emulate_load_store_insn(struct pt_regs *regs,
 425         void __user *addr, unsigned int __user *pc)
 426 {
 427         union mips_instruction insn;
 428         unsigned long value;
 429         unsigned int res;
 430         unsigned long origpc;
 431         unsigned long orig31;
 432         void __user *fault_addr = NULL;
 433
 434         origpc = (unsigned long)pc;
 435         orig31 = regs->regs[31];
 436
 437         perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
 438
 439         /*
 440          * This load never faults.
 441          */
 442         __get_user(insn.word, pc);
 443
 444         switch (insn.i_format.opcode) {
 445                 /*
 446                  * These are instructions that a compiler doesn't generate.  We
 447                  * can assume therefore that the code is MIPS-aware and
 448                  * really buggy.  Emulating these instructions would break the
 449                  * semantics anyway.
 450                  */
 451         case ll_op:
 452         case lld_op:
 453         case sc_op:
 454         case scd_op:
 455
 456                 /*
 457                  * For these instructions the only way to create an address
 458                  * error is an attempted access to kernel/supervisor address
 459                  * space.
 460                  */
 461         case ldl_op:
 462         case ldr_op:
 463         case lwl_op:
 464         case lwr_op:
 465         case sdl_op:
 466         case sdr_op:
 467         case swl_op:
 468         case swr_op:
 469         case lb_op:
 470         case lbu_op:
 471         case sb_op:
 472                 goto sigbus;
 473
 474                 /*
 475                  * The remaining opcodes are the ones that are really of
 476                  * interest.
 477                  */
 478         case lh_op:
 479                 if (!access_ok(VERIFY_READ, addr, 2))
 480                         goto sigbus;
 481
 482                 LoadHW(addr, value, res);
 483                 if (res)
 484                         goto fault;
 485                 compute_return_epc(regs);
 486                 regs->regs[insn.i_format.rt] = value;
 487                 break;
 488
 489         case lw_op:
 490                 if (!access_ok(VERIFY_READ, addr, 4))
 491                         goto sigbus;
 492
 493                 LoadW(addr, value, res);
 494                 if (res)
 495                         goto fault;
 496                 compute_return_epc(regs);
 497                 regs->regs[insn.i_format.rt] = value;
 498                 break;
 499
 500         case lhu_op:
 501                 if (!access_ok(VERIFY_READ, addr, 2))
 502                         goto sigbus;
 503
 504                 LoadHWU(addr, value, res);
 505                 if (res)
 506                         goto fault;
 507                 compute_return_epc(regs);
 508                 regs->regs[insn.i_format.rt] = value;
 509                 break;
 510
 511         case lwu_op:
 512 #ifdef CONFIG_64BIT
 513                 /*
 514                  * A 32-bit kernel might be running on a 64-bit processor.  But
 515                  * if we're on a 32-bit processor and an i-cache incoherency
 516                  * or race makes us see a 64-bit instruction here the sdl/sdr
 517                  * would blow up, so for now we don't handle unaligned 64-bit
 518                  * instructions on 32-bit kernels.
 519                  */
 520                 if (!access_ok(VERIFY_READ, addr, 4))
 521                         goto sigbus;
 522
 523                 LoadWU(addr, value, res);
 524                 if (res)
 525                         goto fault;
 526                 compute_return_epc(regs);
 527                 regs->regs[insn.i_format.rt] = value;
 528                 break;
 529 #endif /* CONFIG_64BIT */
 530
 531                 /* Cannot handle 64-bit instructions in 32-bit kernel */
 532                 goto sigill;
 533
 534         case ld_op:
 535 #ifdef CONFIG_64BIT
 536                 /*
 537                  * A 32-bit kernel might be running on a 64-bit processor.  But
 538                  * if we're on a 32-bit processor and an i-cache incoherency
 539                  * or race makes us see a 64-bit instruction here the sdl/sdr
 540                  * would blow up, so for now we don't handle unaligned 64-bit
 541                  * instructions on 32-bit kernels.
 542                  */
 543                 if (!access_ok(VERIFY_READ, addr, 8))
 544                         goto sigbus;
 545
 546                 LoadDW(addr, value, res);
 547                 if (res)
 548                         goto fault;
 549                 compute_return_epc(regs);
 550                 regs->regs[insn.i_format.rt] = value;
 551                 break;
 552 #endif /* CONFIG_64BIT */
 553
 554                 /* Cannot handle 64-bit instructions in 32-bit kernel */
 555                 goto sigill;
 556
 557         case sh_op:
 558                 if (!access_ok(VERIFY_WRITE, addr, 2))
 559                         goto sigbus;
 560
 561                 compute_return_epc(regs);
 562                 value = regs->regs[insn.i_format.rt];
 563                 StoreHW(addr, value, res);
 564                 if (res)
 565                         goto fault;
 566                 break;
 567
 568         case sw_op:
 569                 if (!access_ok(VERIFY_WRITE, addr, 4))
 570                         goto sigbus;
 571
 572                 compute_return_epc(regs);
 573                 value = regs->regs[insn.i_format.rt];
 574                 StoreW(addr, value, res);
 575                 if (res)
 576                         goto fault;
 577                 break;
 578
 579         case sd_op:
 580 #ifdef CONFIG_64BIT
 581                 /*
 582                  * A 32-bit kernel might be running on a 64-bit processor.  But
 583                  * if we're on a 32-bit processor and an i-cache incoherency
 584                  * or race makes us see a 64-bit instruction here the sdl/sdr
 585                  * would blow up, so for now we don't handle unaligned 64-bit
 586                  * instructions on 32-bit kernels.
 587                  */
 588                 if (!access_ok(VERIFY_WRITE, addr, 8))
 589                         goto sigbus;
 590
 591                 compute_return_epc(regs);
 592                 value = regs->regs[insn.i_format.rt];
 593                 StoreDW(addr, value, res);
 594                 if (res)
 595                         goto fault;
 596                 break;
 597 #endif /* CONFIG_64BIT */
 598
 599                 /* Cannot handle 64-bit instructions in 32-bit kernel */
 600                 goto sigill;
 601
 602         case lwc1_op:
 603         case ldc1_op:
 604         case swc1_op:
 605         case sdc1_op:
 606                 die_if_kernel("Unaligned FP access in kernel code", regs);
 607                 BUG_ON(!used_math());
 608                 BUG_ON(!is_fpu_owner());
 609
 610                 lose_fpu(1);    /* Save FPU state for the emulator. */
 611                 res = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
 612                                                &fault_addr);
 613                 own_fpu(1);     /* Restore FPU state. */
 614
 615                 /* Signal if something went wrong. */
 616                 process_fpemu_return(res, fault_addr);
 617
 618                 if (res == 0)
 619                         break;
 620                 return;
 621
 622         /*
 623          * COP2 is available to implementor for application specific use.
 624          * It's up to applications to register a notifier chain and do
 625          * whatever they have to do, including possible sending of signals.
 626          */
 627         case lwc2_op:
 628                 cu2_notifier_call_chain(CU2_LWC2_OP, regs);
 629                 break;
 630
 631         case ldc2_op:
 632                 cu2_notifier_call_chain(CU2_LDC2_OP, regs);
 633                 break;
 634
 635         case swc2_op:
 636                 cu2_notifier_call_chain(CU2_SWC2_OP, regs);
 637                 break;
 638
 639         case sdc2_op:
 640                 cu2_notifier_call_chain(CU2_SDC2_OP, regs);
 641                 break;
 642
 643         default:
 644                 /*
 645                  * Pheeee...  We encountered an yet unknown instruction or
 646                  * cache coherence problem.  Die sucker, die ...
 647                  */
 648                 goto sigill;
 649         }
 650
 651 #ifdef CONFIG_DEBUG_FS
 652         unaligned_instructions++;
 653 #endif
 654
 655         return;
 656
 657 fault:
 658         /* roll back jump/branch */
 659         regs->cp0_epc = origpc;
 660         regs->regs[31] = orig31;
 661         /* Did we have an exception handler installed? */
 662         if (fixup_exception(regs))
 663                 return;
 664
 665         die_if_kernel("Unhandled kernel unaligned access", regs);
 666         force_sig(SIGSEGV, current);
 667
 668         return;
 669
 670 sigbus:
 671         die_if_kernel("Unhandled kernel unaligned access", regs);
 672         force_sig(SIGBUS, current);
 673
 674         return;
 675
 676 sigill:
 677         die_if_kernel
 678             ("Unhandled kernel unaligned access or invalid instruction", regs);
 679         force_sig(SIGILL, current);
 680 }
 681
 682 /* Recode table from 16-bit register notation to 32-bit GPR. */
 683 const int reg16to32[] = { 16, 17, 2, 3, 4, 5, 6, 7 };
 684
 685 /* Recode table from 16-bit STORE register notation to 32-bit GPR. */
 686 const int reg16to32st[] = { 0, 17, 2, 3, 4, 5, 6, 7 };
 687
 688 static void emulate_load_store_microMIPS(struct pt_regs *regs,
 689                                          void __user *addr)
 690 {
 691         unsigned long value;
 692         unsigned int res;
 693         int i;
 694         unsigned int reg = 0, rvar;
 695         unsigned long orig31;
 696         u16 __user *pc16;
 697         u16 halfword;
 698         unsigned int word;
 699         unsigned long origpc, contpc;
 700         union mips_instruction insn;
 701         struct mm_decoded_insn mminsn;
 702         void __user *fault_addr = NULL;
 703
 704         origpc = regs->cp0_epc;
 705         orig31 = regs->regs[31];
 706
 707         mminsn.micro_mips_mode = 1;
 708
 709         /*
 710          * This load never faults.
 711          */
 712         pc16 = (unsigned short __user *)msk_isa16_mode(regs->cp0_epc);
 713         __get_user(halfword, pc16);
 714         pc16++;
 715         contpc = regs->cp0_epc + 2;
 716         word = ((unsigned int)halfword << 16);
 717         mminsn.pc_inc = 2;
 718
 719         if (!mm_insn_16bit(halfword)) {
 720                 __get_user(halfword, pc16);
 721                 pc16++;
 722                 contpc = regs->cp0_epc + 4;
 723                 mminsn.pc_inc = 4;
 724                 word |= halfword;
 725         }
 726         mminsn.insn = word;
 727
 728         if (get_user(halfword, pc16))
 729                 goto fault;
 730         mminsn.next_pc_inc = 2;
 731         word = ((unsigned int)halfword << 16);
 732
 733         if (!mm_insn_16bit(halfword)) {
 734                 pc16++;
 735                 if (get_user(halfword, pc16))
 736                         goto fault;
 737                 mminsn.next_pc_inc = 4;
 738                 word |= halfword;
 739         }
 740         mminsn.next_insn = word;
 741
 742         insn = (union mips_instruction)(mminsn.insn);
 743         if (mm_isBranchInstr(regs, mminsn, &contpc))
 744                 insn = (union mips_instruction)(mminsn.next_insn);
 745
 746         /*  Parse instruction to find what to do */
 747
 748         switch (insn.mm_i_format.opcode) {
 749
 750         case mm_pool32a_op:
 751                 switch (insn.mm_x_format.func) {
 752                 case mm_lwxs_op:
 753                         reg = insn.mm_x_format.rd;
 754                         goto loadW;
 755                 }
 756
 757                 goto sigbus;
 758
 759         case mm_pool32b_op:
 760                 switch (insn.mm_m_format.func) {
 761                 case mm_lwp_func:
 762                         reg = insn.mm_m_format.rd;
 763                         if (reg == 31)
 764                                 goto sigbus;
 765
 766                         if (!access_ok(VERIFY_READ, addr, 8))
 767                                 goto sigbus;
 768
 769                         LoadW(addr, value, res);
 770                         if (res)
 771                                 goto fault;
 772                         regs->regs[reg] = value;
 773                         addr += 4;
 774                         LoadW(addr, value, res);
 775                         if (res)
 776                                 goto fault;
 777                         regs->regs[reg + 1] = value;
 778                         goto success;
 779
 780                 case mm_swp_func:
 781                         reg = insn.mm_m_format.rd;
 782                         if (reg == 31)
 783                                 goto sigbus;
 784
 785                         if (!access_ok(VERIFY_WRITE, addr, 8))
 786                                 goto sigbus;
 787
 788                         value = regs->regs[reg];
 789                         StoreW(addr, value, res);
 790                         if (res)
 791                                 goto fault;
 792                         addr += 4;
 793                         value = regs->regs[reg + 1];
 794                         StoreW(addr, value, res);
 795                         if (res)
 796                                 goto fault;
 797                         goto success;
 798
 799                 case mm_ldp_func:
 800 #ifdef CONFIG_64BIT
 801                         reg = insn.mm_m_format.rd;
 802                         if (reg == 31)
 803                                 goto sigbus;
 804
 805                         if (!access_ok(VERIFY_READ, addr, 16))
 806                                 goto sigbus;
 807
 808                         LoadDW(addr, value, res);
 809                         if (res)
 810                                 goto fault;
 811                         regs->regs[reg] = value;
 812                         addr += 8;
 813                         LoadDW(addr, value, res);
 814                         if (res)
 815                                 goto fault;
 816                         regs->regs[reg + 1] = value;
 817                         goto success;
 818 #endif /* CONFIG_64BIT */
 819
 820                         goto sigill;
 821
 822                 case mm_sdp_func:
 823 #ifdef CONFIG_64BIT
 824                         reg = insn.mm_m_format.rd;
 825                         if (reg == 31)
 826                                 goto sigbus;
 827
 828                         if (!access_ok(VERIFY_WRITE, addr, 16))
 829                                 goto sigbus;
 830
 831                         value = regs->regs[reg];
 832                         StoreDW(addr, value, res);
 833                         if (res)
 834                                 goto fault;
 835                         addr += 8;
 836                         value = regs->regs[reg + 1];
 837                         StoreDW(addr, value, res);
 838                         if (res)
 839                                 goto fault;
 840                         goto success;
 841 #endif /* CONFIG_64BIT */
 842
 843                         goto sigill;
 844
 845                 case mm_lwm32_func:
 846                         reg = insn.mm_m_format.rd;
 847                         rvar = reg & 0xf;
 848                         if ((rvar > 9) || !reg)
 849                                 goto sigill;
 850                         if (reg & 0x10) {
 851                                 if (!access_ok
 852                                     (VERIFY_READ, addr, 4 * (rvar + 1)))
 853                                         goto sigbus;
 854                         } else {
 855                                 if (!access_ok(VERIFY_READ, addr, 4 * rvar))
 856                                         goto sigbus;
 857                         }
 858                         if (rvar == 9)
 859                                 rvar = 8;
 860                         for (i = 16; rvar; rvar--, i++) {
 861                                 LoadW(addr, value, res);
 862                                 if (res)
 863                                         goto fault;
 864                                 addr += 4;
 865                                 regs->regs[i] = value;
 866                         }
 867                         if ((reg & 0xf) == 9) {
 868                                 LoadW(addr, value, res);
 869                                 if (res)
 870                                         goto fault;
 871                                 addr += 4;
 872                                 regs->regs[30] = value;
 873                         }
 874                         if (reg & 0x10) {
 875                                 LoadW(addr, value, res);
 876                                 if (res)
 877                                         goto fault;
 878                                 regs->regs[31] = value;
 879                         }
 880                         goto success;
 881
 882                 case mm_swm32_func:
 883                         reg = insn.mm_m_format.rd;
 884                         rvar = reg & 0xf;
 885                         if ((rvar > 9) || !reg)
 886                                 goto sigill;
 887                         if (reg & 0x10) {
 888                                 if (!access_ok
 889                                     (VERIFY_WRITE, addr, 4 * (rvar + 1)))
 890                                         goto sigbus;
 891                         } else {
 892                                 if (!access_ok(VERIFY_WRITE, addr, 4 * rvar))
 893                                         goto sigbus;
 894                         }
 895                         if (rvar == 9)
 896                                 rvar = 8;
 897                         for (i = 16; rvar; rvar--, i++) {
 898                                 value = regs->regs[i];
 899                                 StoreW(addr, value, res);
 900                                 if (res)
 901                                         goto fault;
 902                                 addr += 4;
 903                         }
 904                         if ((reg & 0xf) == 9) {
 905                                 value = regs->regs[30];
 906                                 StoreW(addr, value, res);
 907                                 if (res)
 908                                         goto fault;
 909                                 addr += 4;
 910                         }
 911                         if (reg & 0x10) {
 912                                 value = regs->regs[31];
 913                                 StoreW(addr, value, res);
 914                                 if (res)
 915                                         goto fault;
 916                         }
 917                         goto success;
 918
 919                 case mm_ldm_func:
 920 #ifdef CONFIG_64BIT
 921                         reg = insn.mm_m_format.rd;
 922                         rvar = reg & 0xf;
 923                         if ((rvar > 9) || !reg)
 924                                 goto sigill;
 925                         if (reg & 0x10) {
 926                                 if (!access_ok
 927                                     (VERIFY_READ, addr, 8 * (rvar + 1)))
 928                                         goto sigbus;
 929                         } else {
 930                                 if (!access_ok(VERIFY_READ, addr, 8 * rvar))
 931                                         goto sigbus;
 932                         }
 933                         if (rvar == 9)
 934                                 rvar = 8;
 935
 936                         for (i = 16; rvar; rvar--, i++) {
 937                                 LoadDW(addr, value, res);
 938                                 if (res)
 939                                         goto fault;
 940                                 addr += 4;
 941                                 regs->regs[i] = value;
 942                         }
 943                         if ((reg & 0xf) == 9) {
 944                                 LoadDW(addr, value, res);
 945                                 if (res)
 946                                         goto fault;
 947                                 addr += 8;
 948                                 regs->regs[30] = value;
 949                         }
 950                         if (reg & 0x10) {
 951                                 LoadDW(addr, value, res);
 952                                 if (res)
 953                                         goto fault;
 954                                 regs->regs[31] = value;
 955                         }
 956                         goto success;
 957 #endif /* CONFIG_64BIT */
 958
 959                         goto sigill;
 960
 961                 case mm_sdm_func:
 962 #ifdef CONFIG_64BIT
 963                         reg = insn.mm_m_format.rd;
 964                         rvar = reg & 0xf;
 965                         if ((rvar > 9) || !reg)
 966                                 goto sigill;
 967                         if (reg & 0x10) {
 968                                 if (!access_ok
 969                                     (VERIFY_WRITE, addr, 8 * (rvar + 1)))
 970                                         goto sigbus;
 971                         } else {
 972                                 if (!access_ok(VERIFY_WRITE, addr, 8 * rvar))
 973                                         goto sigbus;
 974                         }
 975                         if (rvar == 9)
 976                                 rvar = 8;
 977
 978                         for (i = 16; rvar; rvar--, i++) {
 979                                 value = regs->regs[i];
 980                                 StoreDW(addr, value, res);
 981                                 if (res)
 982                                         goto fault;
 983                                 addr += 8;
 984                         }
 985                         if ((reg & 0xf) == 9) {
 986                                 value = regs->regs[30];
 987                                 StoreDW(addr, value, res);
 988                                 if (res)
 989                                         goto fault;
 990                                 addr += 8;
 991                         }
 992                         if (reg & 0x10) {
 993                                 value = regs->regs[31];
 994                                 StoreDW(addr, value, res);
 995                                 if (res)
 996                                         goto fault;
 997                         }
 998                         goto success;
 999 #endif /* CONFIG_64BIT */
1000
1001                         goto sigill;
1002
1003                         /*  LWC2, SWC2, LDC2, SDC2 are not serviced */
1004                 }
1005
1006                 goto sigbus;
1007
1008         case mm_pool32c_op:
1009                 switch (insn.mm_m_format.func) {
1010                 case mm_lwu_func:
1011                         reg = insn.mm_m_format.rd;
1012                         goto loadWU;
1013                 }
1014
1015                 /*  LL,SC,LLD,SCD are not serviced */
1016                 goto sigbus;
1017
1018         case mm_pool32f_op:
1019                 switch (insn.mm_x_format.func) {
1020                 case mm_lwxc1_func:
1021                 case mm_swxc1_func:
1022                 case mm_ldxc1_func:
1023                 case mm_sdxc1_func:
1024                         goto fpu_emul;
1025                 }
1026
1027                 goto sigbus;
1028
1029         case mm_ldc132_op:
1030         case mm_sdc132_op:
1031         case mm_lwc132_op:
1032         case mm_swc132_op:
1033 fpu_emul:
1034                 /* roll back jump/branch */
1035                 regs->cp0_epc = origpc;
1036                 regs->regs[31] = orig31;
1037
1038                 die_if_kernel("Unaligned FP access in kernel code", regs);
1039                 BUG_ON(!used_math());
1040                 BUG_ON(!is_fpu_owner());
1041
1042                 lose_fpu(1);    /* save the FPU state for the emulator */
1043                 res = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
1044                                                &fault_addr);
1045                 own_fpu(1);     /* restore FPU state */
1046
1047                 /* If something went wrong, signal */
1048                 process_fpemu_return(res, fault_addr);
1049
1050                 if (res == 0)
1051                         goto success;
1052                 return;
1053
1054         case mm_lh32_op:
1055                 reg = insn.mm_i_format.rt;
1056                 goto loadHW;
1057
1058         case mm_lhu32_op:
1059                 reg = insn.mm_i_format.rt;
1060                 goto loadHWU;
1061
1062         case mm_lw32_op:
1063                 reg = insn.mm_i_format.rt;
1064                 goto loadW;
1065
1066         case mm_sh32_op:
1067                 reg = insn.mm_i_format.rt;
1068                 goto storeHW;
1069
1070         case mm_sw32_op:
1071                 reg = insn.mm_i_format.rt;
1072                 goto storeW;
1073
1074         case mm_ld32_op:
1075                 reg = insn.mm_i_format.rt;
1076                 goto loadDW;
1077
1078         case mm_sd32_op:
1079                 reg = insn.mm_i_format.rt;
1080                 goto storeDW;
1081
1082         case mm_pool16c_op:
1083                 switch (insn.mm16_m_format.func) {
1084                 case mm_lwm16_op:
1085                         reg = insn.mm16_m_format.rlist;
1086                         rvar = reg + 1;
1087                         if (!access_ok(VERIFY_READ, addr, 4 * rvar))
1088                                 goto sigbus;
1089
1090                         for (i = 16; rvar; rvar--, i++) {
1091                                 LoadW(addr, value, res);
1092                                 if (res)
1093                                         goto fault;
1094                                 addr += 4;
1095                                 regs->regs[i] = value;
1096                         }
1097                         LoadW(addr, value, res);
1098                         if (res)
1099                                 goto fault;
1100                         regs->regs[31] = value;
1101
1102                         goto success;
1103
1104                 case mm_swm16_op:
1105                         reg = insn.mm16_m_format.rlist;
1106                         rvar = reg + 1;
1107                         if (!access_ok(VERIFY_WRITE, addr, 4 * rvar))
1108                                 goto sigbus;
1109
1110                         for (i = 16; rvar; rvar--, i++) {
1111                                 value = regs->regs[i];
1112                                 StoreW(addr, value, res);
1113                                 if (res)
1114                                         goto fault;
1115                                 addr += 4;
1116                         }
1117                         value = regs->regs[31];
1118                         StoreW(addr, value, res);
1119                         if (res)
1120                                 goto fault;
1121
1122                         goto success;
1123
1124                 }
1125
1126                 goto sigbus;
1127
1128         case mm_lhu16_op:
1129                 reg = reg16to32[insn.mm16_rb_format.rt];
1130                 goto loadHWU;
1131
1132         case mm_lw16_op:
1133                 reg = reg16to32[insn.mm16_rb_format.rt];
1134                 goto loadW;
1135
1136         case mm_sh16_op:
1137                 reg = reg16to32st[insn.mm16_rb_format.rt];
1138                 goto storeHW;
1139
1140         case mm_sw16_op:
1141                 reg = reg16to32st[insn.mm16_rb_format.rt];
1142                 goto storeW;
1143
1144         case mm_lwsp16_op:
1145                 reg = insn.mm16_r5_format.rt;
1146                 goto loadW;
1147
1148         case mm_swsp16_op:
1149                 reg = insn.mm16_r5_format.rt;
1150                 goto storeW;
1151
1152         case mm_lwgp16_op:
1153                 reg = reg16to32[insn.mm16_r3_format.rt];
1154                 goto loadW;
1155
1156         default:
1157                 goto sigill;
1158         }
1159
1160 loadHW:
1161         if (!access_ok(VERIFY_READ, addr, 2))
1162                 goto sigbus;
1163
1164         LoadHW(addr, value, res);
1165         if (res)
1166                 goto fault;
1167         regs->regs[reg] = value;
1168         goto success;
1169
1170 loadHWU:
1171         if (!access_ok(VERIFY_READ, addr, 2))
1172                 goto sigbus;
1173
1174         LoadHWU(addr, value, res);
1175         if (res)
1176                 goto fault;
1177         regs->regs[reg] = value;
1178         goto success;
1179
1180 loadW:
1181         if (!access_ok(VERIFY_READ, addr, 4))
1182                 goto sigbus;
1183
1184         LoadW(addr, value, res);
1185         if (res)
1186                 goto fault;
1187         regs->regs[reg] = value;
1188         goto success;
1189
1190 loadWU:
1191 #ifdef CONFIG_64BIT
1192         /*
1193          * A 32-bit kernel might be running on a 64-bit processor.  But
1194          * if we're on a 32-bit processor and an i-cache incoherency
1195          * or race makes us see a 64-bit instruction here the sdl/sdr
1196          * would blow up, so for now we don't handle unaligned 64-bit
1197          * instructions on 32-bit kernels.
1198          */
1199         if (!access_ok(VERIFY_READ, addr, 4))
1200                 goto sigbus;
1201
1202         LoadWU(addr, value, res);
1203         if (res)
1204                 goto fault;
1205         regs->regs[reg] = value;
1206         goto success;
1207 #endif /* CONFIG_64BIT */
1208
1209         /* Cannot handle 64-bit instructions in 32-bit kernel */
1210         goto sigill;
1211
1212 loadDW:
1213 #ifdef CONFIG_64BIT
1214         /*
1215          * A 32-bit kernel might be running on a 64-bit processor.  But
1216          * if we're on a 32-bit processor and an i-cache incoherency
1217          * or race makes us see a 64-bit instruction here the sdl/sdr
1218          * would blow up, so for now we don't handle unaligned 64-bit
1219          * instructions on 32-bit kernels.
1220          */
1221         if (!access_ok(VERIFY_READ, addr, 8))
1222                 goto sigbus;
1223
1224         LoadDW(addr, value, res);
1225         if (res)
1226                 goto fault;
1227         regs->regs[reg] = value;
1228         goto success;
1229 #endif /* CONFIG_64BIT */
1230
1231         /* Cannot handle 64-bit instructions in 32-bit kernel */
1232         goto sigill;
1233
1234 storeHW:
1235         if (!access_ok(VERIFY_WRITE, addr, 2))
1236                 goto sigbus;
1237
1238         value = regs->regs[reg];
1239         StoreHW(addr, value, res);
1240         if (res)
1241                 goto fault;
1242         goto success;
1243
1244 storeW:
1245         if (!access_ok(VERIFY_WRITE, addr, 4))
1246                 goto sigbus;
1247
1248         value = regs->regs[reg];
1249         StoreW(addr, value, res);
1250         if (res)
1251                 goto fault;
1252         goto success;
1253
1254 storeDW:
1255 #ifdef CONFIG_64BIT
1256         /*
1257          * A 32-bit kernel might be running on a 64-bit processor.  But
1258          * if we're on a 32-bit processor and an i-cache incoherency
1259          * or race makes us see a 64-bit instruction here the sdl/sdr
1260          * would blow up, so for now we don't handle unaligned 64-bit
1261          * instructions on 32-bit kernels.
1262          */
1263         if (!access_ok(VERIFY_WRITE, addr, 8))
1264                 goto sigbus;
1265
1266         value = regs->regs[reg];
1267         StoreDW(addr, value, res);
1268         if (res)
1269                 goto fault;
1270         goto success;
1271 #endif /* CONFIG_64BIT */
1272
1273         /* Cannot handle 64-bit instructions in 32-bit kernel */
1274         goto sigill;
1275
1276 success:
1277         regs->cp0_epc = contpc; /* advance or branch */
1278
1279 #ifdef CONFIG_DEBUG_FS
1280         unaligned_instructions++;
1281 #endif
1282         return;
1283
1284 fault:
1285         /* roll back jump/branch */
1286         regs->cp0_epc = origpc;
1287         regs->regs[31] = orig31;
1288         /* Did we have an exception handler installed? */
1289         if (fixup_exception(regs))
1290                 return;
1291
1292         die_if_kernel("Unhandled kernel unaligned access", regs);
1293         force_sig(SIGSEGV, current);
1294
1295         return;
1296
1297 sigbus:
1298         die_if_kernel("Unhandled kernel unaligned access", regs);
1299         force_sig(SIGBUS, current);
1300
1301         return;
1302
1303 sigill:
1304         die_if_kernel
1305             ("Unhandled kernel unaligned access or invalid instruction", regs);
1306         force_sig(SIGILL, current);
1307 }
1308
1309 static void emulate_load_store_MIPS16e(struct pt_regs *regs, void __user * addr)
1310 {
1311         unsigned long value;
1312         unsigned int res;
1313         int reg;
1314         unsigned long orig31;
1315         u16 __user *pc16;
1316         unsigned long origpc;
1317         union mips16e_instruction mips16inst, oldinst;
1318
1319         origpc = regs->cp0_epc;
1320         orig31 = regs->regs[31];
1321         pc16 = (unsigned short __user *)msk_isa16_mode(origpc);
1322         /*
1323          * This load never faults.
1324          */
1325         __get_user(mips16inst.full, pc16);
1326         oldinst = mips16inst;
1327
1328         /* skip EXTEND instruction */
1329         if (mips16inst.ri.opcode == MIPS16e_extend_op) {
1330                 pc16++;
1331                 __get_user(mips16inst.full, pc16);
1332         } else if (delay_slot(regs)) {
1333                 /*  skip jump instructions */
1334                 /*  JAL/JALX are 32 bits but have OPCODE in first short int */
1335                 if (mips16inst.ri.opcode == MIPS16e_jal_op)
1336                         pc16++;
1337                 pc16++;
1338                 if (get_user(mips16inst.full, pc16))
1339                         goto sigbus;
1340         }
1341
1342         switch (mips16inst.ri.opcode) {
1343         case MIPS16e_i64_op:    /* I64 or RI64 instruction */
1344                 switch (mips16inst.i64.func) {  /* I64/RI64 func field check */
1345                 case MIPS16e_ldpc_func:
1346                 case MIPS16e_ldsp_func:
1347                         reg = reg16to32[mips16inst.ri64.ry];
1348                         goto loadDW;
1349
1350                 case MIPS16e_sdsp_func:
1351                         reg = reg16to32[mips16inst.ri64.ry];
1352                         goto writeDW;
1353
1354                 case MIPS16e_sdrasp_func:
1355                         reg = 29;       /* GPRSP */
1356                         goto writeDW;
1357                 }
1358
1359                 goto sigbus;
1360
1361         case MIPS16e_swsp_op:
1362         case MIPS16e_lwpc_op:
1363         case MIPS16e_lwsp_op:
1364                 reg = reg16to32[mips16inst.ri.rx];
1365                 break;
1366
1367         case MIPS16e_i8_op:
1368                 if (mips16inst.i8.func != MIPS16e_swrasp_func)
1369                         goto sigbus;
1370                 reg = 29;       /* GPRSP */
1371                 break;
1372
1373         default:
1374                 reg = reg16to32[mips16inst.rri.ry];
1375                 break;
1376         }
1377
1378         switch (mips16inst.ri.opcode) {
1379
1380         case MIPS16e_lb_op:
1381         case MIPS16e_lbu_op:
1382         case MIPS16e_sb_op:
1383                 goto sigbus;
1384
1385         case MIPS16e_lh_op:
1386                 if (!access_ok(VERIFY_READ, addr, 2))
1387                         goto sigbus;
1388
1389                 LoadHW(addr, value, res);
1390                 if (res)
1391                         goto fault;
1392                 MIPS16e_compute_return_epc(regs, &oldinst);
1393                 regs->regs[reg] = value;
1394                 break;
1395
1396         case MIPS16e_lhu_op:
1397                 if (!access_ok(VERIFY_READ, addr, 2))
1398                         goto sigbus;
1399
1400                 LoadHWU(addr, value, res);
1401                 if (res)
1402                         goto fault;
1403                 MIPS16e_compute_return_epc(regs, &oldinst);
1404                 regs->regs[reg] = value;
1405                 break;
1406
1407         case MIPS16e_lw_op:
1408         case MIPS16e_lwpc_op:
1409         case MIPS16e_lwsp_op:
1410                 if (!access_ok(VERIFY_READ, addr, 4))
1411                         goto sigbus;
1412
1413                 LoadW(addr, value, res);
1414                 if (res)
1415                         goto fault;
1416                 MIPS16e_compute_return_epc(regs, &oldinst);
1417                 regs->regs[reg] = value;
1418                 break;
1419
1420         case MIPS16e_lwu_op:
1421 #ifdef CONFIG_64BIT
1422                 /*
1423                  * A 32-bit kernel might be running on a 64-bit processor.  But
1424                  * if we're on a 32-bit processor and an i-cache incoherency
1425                  * or race makes us see a 64-bit instruction here the sdl/sdr
1426                  * would blow up, so for now we don't handle unaligned 64-bit
1427                  * instructions on 32-bit kernels.
1428                  */
1429                 if (!access_ok(VERIFY_READ, addr, 4))
1430                         goto sigbus;
1431
1432                 LoadWU(addr, value, res);
1433                 if (res)
1434                         goto fault;
1435                 MIPS16e_compute_return_epc(regs, &oldinst);
1436                 regs->regs[reg] = value;
1437                 break;
1438 #endif /* CONFIG_64BIT */
1439
1440                 /* Cannot handle 64-bit instructions in 32-bit kernel */
1441                 goto sigill;
1442
1443         case MIPS16e_ld_op:
1444 loadDW:
1445 #ifdef CONFIG_64BIT
1446                 /*
1447                  * A 32-bit kernel might be running on a 64-bit processor.  But
1448                  * if we're on a 32-bit processor and an i-cache incoherency
1449                  * or race makes us see a 64-bit instruction here the sdl/sdr
1450                  * would blow up, so for now we don't handle unaligned 64-bit
1451                  * instructions on 32-bit kernels.
1452                  */
1453                 if (!access_ok(VERIFY_READ, addr, 8))
1454                         goto sigbus;
1455
1456                 LoadDW(addr, value, res);
1457                 if (res)
1458                         goto fault;
1459                 MIPS16e_compute_return_epc(regs, &oldinst);
1460                 regs->regs[reg] = value;
1461                 break;
1462 #endif /* CONFIG_64BIT */
1463
1464                 /* Cannot handle 64-bit instructions in 32-bit kernel */
1465                 goto sigill;
1466
1467         case MIPS16e_sh_op:
1468                 if (!access_ok(VERIFY_WRITE, addr, 2))
1469                         goto sigbus;
1470
1471                 MIPS16e_compute_return_epc(regs, &oldinst);
1472                 value = regs->regs[reg];
1473                 StoreHW(addr, value, res);
1474                 if (res)
1475                         goto fault;
1476                 break;
1477
1478         case MIPS16e_sw_op:
1479         case MIPS16e_swsp_op:
1480         case MIPS16e_i8_op:     /* actually - MIPS16e_swrasp_func */
1481                 if (!access_ok(VERIFY_WRITE, addr, 4))
1482                         goto sigbus;
1483
1484                 MIPS16e_compute_return_epc(regs, &oldinst);
1485                 value = regs->regs[reg];
1486                 StoreW(addr, value, res);
1487                 if (res)
1488                         goto fault;
1489                 break;
1490
1491         case MIPS16e_sd_op:
1492 writeDW:
1493 #ifdef CONFIG_64BIT
1494                 /*
1495                  * A 32-bit kernel might be running on a 64-bit processor.  But
1496                  * if we're on a 32-bit processor and an i-cache incoherency
1497                  * or race makes us see a 64-bit instruction here the sdl/sdr
1498                  * would blow up, so for now we don't handle unaligned 64-bit
1499                  * instructions on 32-bit kernels.
1500                  */
1501                 if (!access_ok(VERIFY_WRITE, addr, 8))
1502                         goto sigbus;
1503
1504                 MIPS16e_compute_return_epc(regs, &oldinst);
1505                 value = regs->regs[reg];
1506                 StoreDW(addr, value, res);
1507                 if (res)
1508                         goto fault;
1509                 break;
1510 #endif /* CONFIG_64BIT */
1511
1512                 /* Cannot handle 64-bit instructions in 32-bit kernel */
1513                 goto sigill;
1514
1515         default:
1516                 /*
1517                  * Pheeee...  We encountered an yet unknown instruction or
1518                  * cache coherence problem.  Die sucker, die ...
1519                  */
1520                 goto sigill;
1521         }
1522
1523 #ifdef CONFIG_DEBUG_FS
1524         unaligned_instructions++;
1525 #endif
1526
1527         return;
1528
1529 fault:
1530         /* roll back jump/branch */
1531         regs->cp0_epc = origpc;
1532         regs->regs[31] = orig31;
1533         /* Did we have an exception handler installed? */
1534         if (fixup_exception(regs))
1535                 return;
1536
1537         die_if_kernel("Unhandled kernel unaligned access", regs);
1538         force_sig(SIGSEGV, current);
1539
1540         return;
1541
1542 sigbus:
1543         die_if_kernel("Unhandled kernel unaligned access", regs);
1544         force_sig(SIGBUS, current);
1545
1546         return;
1547
1548 sigill:
1549         die_if_kernel
1550             ("Unhandled kernel unaligned access or invalid instruction", regs);
1551         force_sig(SIGILL, current);
1552 }
1553
1554 asmlinkage void do_ade(struct pt_regs *regs)
1555 {
1556         enum ctx_state prev_state;
1557         unsigned int __user *pc;
1558         mm_segment_t seg;
1559
1560         prev_state = exception_enter();
1561         perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS,
1562                         1, regs, regs->cp0_badvaddr);
1563         /*
1564          * Did we catch a fault trying to load an instruction?
1565          */
1566         if (regs->cp0_badvaddr == regs->cp0_epc)
1567                 goto sigbus;
1568
1569         if (user_mode(regs) && !test_thread_flag(TIF_FIXADE))
1570                 goto sigbus;
1571         if (unaligned_action == UNALIGNED_ACTION_SIGNAL)
1572                 goto sigbus;
1573
1574         /*
1575          * Do branch emulation only if we didn't forward the exception.
1576          * This is all so but ugly ...
1577          */
1578
1579         /*
1580          * Are we running in microMIPS mode?
1581          */
1582         if (get_isa16_mode(regs->cp0_epc)) {
1583                 /*
1584                  * Did we catch a fault trying to load an instruction in
1585                  * 16-bit mode?
1586                  */
1587                 if (regs->cp0_badvaddr == msk_isa16_mode(regs->cp0_epc))
1588                         goto sigbus;
1589                 if (unaligned_action == UNALIGNED_ACTION_SHOW)
1590                         show_registers(regs);
1591
1592                 if (cpu_has_mmips) {
1593                         seg = get_fs();
1594                         if (!user_mode(regs))
1595                                 set_fs(KERNEL_DS);
1596                         emulate_load_store_microMIPS(regs,
1597                                 (void __user *)regs->cp0_badvaddr);
1598                         set_fs(seg);
1599
1600                         return;
1601                 }
1602
1603                 if (cpu_has_mips16) {
1604                         seg = get_fs();
1605                         if (!user_mode(regs))
1606                                 set_fs(KERNEL_DS);
1607                         emulate_load_store_MIPS16e(regs,
1608                                 (void __user *)regs->cp0_badvaddr);
1609                         set_fs(seg);
1610
1611                         return;
1612         }
1613
1614                 goto sigbus;
1615         }
1616
1617         if (unaligned_action == UNALIGNED_ACTION_SHOW)
1618                 show_registers(regs);
1619         pc = (unsigned int __user *)exception_epc(regs);
1620
1621         seg = get_fs();
1622         if (!user_mode(regs))
1623                 set_fs(KERNEL_DS);
1624         emulate_load_store_insn(regs, (void __user *)regs->cp0_badvaddr, pc);
1625         set_fs(seg);
1626
1627         return;
1628
1629 sigbus:
1630         die_if_kernel("Kernel unaligned instruction access", regs);
1631         force_sig(SIGBUS, current);
1632
1633         /*
1634          * XXX On return from the signal handler we should advance the epc
1635          */
1636         exception_exit(prev_state);
1637 }
1638
1639 #ifdef CONFIG_DEBUG_FS
1640 extern struct dentry *mips_debugfs_dir;
1641 static int __init debugfs_unaligned(void)
1642 {
1643         struct dentry *d;
1644
1645         if (!mips_debugfs_dir)
1646                 return -ENODEV;
1647         d = debugfs_create_u32("unaligned_instructions", S_IRUGO,
1648                                mips_debugfs_dir, &unaligned_instructions);
1649         if (!d)
1650                 return -ENOMEM;
1651         d = debugfs_create_u32("unaligned_action", S_IRUGO | S_IWUSR,
1652                                mips_debugfs_dir, &unaligned_action);
1653         if (!d)
1654                 return -ENOMEM;
1655         return 0;
1656 }
1657 __initcall(debugfs_unaligned);
1658 #endif