arch/mips/math-emu/cp1emu.c

   1 /*
   2  * cp1emu.c: a MIPS coprocessor 1 (fpu) instruction emulator
   3  *
   4  * MIPS floating point support
   5  * Copyright (C) 1994-2000 Algorithmics Ltd.
   6  *
   7  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
   8  * Copyright (C) 2000  MIPS Technologies, Inc.
   9  *
  10  *  This program is free software; you can distribute it and/or modify it
  11  *  under the terms of the GNU General Public License (Version 2) as
  12  *  published by the Free Software Foundation.
  13  *
  14  *  This program is distributed in the hope it will be useful, but WITHOUT
  15  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  16  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  17  *  for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License along
  20  *  with this program; if not, write to the Free Software Foundation, Inc.,
  21  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  22  *
  23  * A complete emulator for MIPS coprocessor 1 instructions.  This is
  24  * required for #float(switch) or #float(trap), where it catches all
  25  * COP1 instructions via the "CoProcessor Unusable" exception.
  26  *
  27  * More surprisingly it is also required for #float(ieee), to help out
  28  * the hardware fpu at the boundaries of the IEEE-754 representation
  29  * (denormalised values, infinities, underflow, etc).  It is made
  30  * quite nasty because emulation of some non-COP1 instructions is
  31  * required, e.g. in branch delay slots.
  32  *
  33  * Note if you know that you won't have an fpu, then you'll get much
  34  * better performance by compiling with -msoft-float!
  35  */
  36 #include <linux/sched.h>
  37 #include <linux/module.h>
  38 #include <linux/debugfs.h>
  39 #include <linux/perf_event.h>
  40
  41 #include <asm/inst.h>
  42 #include <asm/bootinfo.h>
  43 #include <asm/processor.h>
  44 #include <asm/ptrace.h>
  45 #include <asm/signal.h>
  46 #include <asm/mipsregs.h>
  47 #include <asm/fpu_emulator.h>
  48 #include <asm/uaccess.h>
  49 #include <asm/branch.h>
  50
  51 #include "ieee754.h"
  52
  53 /* Strap kernel emulator for full MIPS IV emulation */
  54
  55 #ifdef __mips
  56 #undef __mips
  57 #endif
  58 #define __mips 4
  59
  60 /* Function which emulates a floating point instruction. */
  61
  62 static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *,
  63         mips_instruction);
  64
  65 #if __mips >= 4 && __mips != 32
  66 static int fpux_emu(struct pt_regs *,
  67         struct mips_fpu_struct *, mips_instruction, void *__user *);
  68 #endif
  69
  70 /* Further private data for which no space exists in mips_fpu_struct */
  71
  72 #ifdef CONFIG_DEBUG_FS
  73 DEFINE_PER_CPU(struct mips_fpu_emulator_stats, fpuemustats);
  74 #endif
  75
  76 /* Control registers */
  77
  78 #define FPCREG_RID      0       /* $0  = revision id */
  79 #define FPCREG_CSR      31      /* $31 = csr */
  80
  81 /* Determine rounding mode from the RM bits of the FCSR */
  82 #define modeindex(v) ((v) & FPU_CSR_RM)
  83
  84 /* Convert Mips rounding mode (0..3) to IEEE library modes. */
  85 static const unsigned char ieee_rm[4] = {
  86         [FPU_CSR_RN] = IEEE754_RN,
  87         [FPU_CSR_RZ] = IEEE754_RZ,
  88         [FPU_CSR_RU] = IEEE754_RU,
  89         [FPU_CSR_RD] = IEEE754_RD,
  90 };
  91 /* Convert IEEE library modes to Mips rounding mode (0..3). */
  92 static const unsigned char mips_rm[4] = {
  93         [IEEE754_RN] = FPU_CSR_RN,
  94         [IEEE754_RZ] = FPU_CSR_RZ,
  95         [IEEE754_RD] = FPU_CSR_RD,
  96         [IEEE754_RU] = FPU_CSR_RU,
  97 };
  98
  99 #if __mips >= 4
 100 /* convert condition code register number to csr bit */
 101 static const unsigned int fpucondbit[8] = {
 102         FPU_CSR_COND0,
 103         FPU_CSR_COND1,
 104         FPU_CSR_COND2,
 105         FPU_CSR_COND3,
 106         FPU_CSR_COND4,
 107         FPU_CSR_COND5,
 108         FPU_CSR_COND6,
 109         FPU_CSR_COND7
 110 };
 111 #endif
 112
 113
 114 /*
 115  * Redundant with logic already in kernel/branch.c,
 116  * embedded in compute_return_epc.  At some point,
 117  * a single subroutine should be used across both
 118  * modules.
 119  */
 120 static int isBranchInstr(mips_instruction * i)
 121 {
 122         switch (MIPSInst_OPCODE(*i)) {
 123         case spec_op:
 124                 switch (MIPSInst_FUNC(*i)) {
 125                 case jalr_op:
 126                 case jr_op:
 127                         return 1;
 128                 }
 129                 break;
 130
 131         case bcond_op:
 132                 switch (MIPSInst_RT(*i)) {
 133                 case bltz_op:
 134                 case bgez_op:
 135                 case bltzl_op:
 136                 case bgezl_op:
 137                 case bltzal_op:
 138                 case bgezal_op:
 139                 case bltzall_op:
 140                 case bgezall_op:
 141                         return 1;
 142                 }
 143                 break;
 144
 145         case j_op:
 146         case jal_op:
 147         case jalx_op:
 148         case beq_op:
 149         case bne_op:
 150         case blez_op:
 151         case bgtz_op:
 152         case beql_op:
 153         case bnel_op:
 154         case blezl_op:
 155         case bgtzl_op:
 156                 return 1;
 157
 158         case cop0_op:
 159         case cop1_op:
 160         case cop2_op:
 161         case cop1x_op:
 162                 if (MIPSInst_RS(*i) == bc_op)
 163                         return 1;
 164                 break;
 165         }
 166
 167         return 0;
 168 }
 169
 170 /*
 171  * In the Linux kernel, we support selection of FPR format on the
 172  * basis of the Status.FR bit.  If an FPU is not present, the FR bit
 173  * is hardwired to zero, which would imply a 32-bit FPU even for
 174  * 64-bit CPUs.  For 64-bit kernels with no FPU we use TIF_32BIT_REGS
 175  * as a proxy for the FR bit so that a 64-bit FPU is emulated.  In any
 176  * case, for a 32-bit kernel which uses the O32 MIPS ABI, only the
 177  * even FPRs are used (Status.FR = 0).
 178  */
 179 static inline int cop1_64bit(struct pt_regs *xcp)
 180 {
 181         if (cpu_has_fpu)
 182                 return xcp->cp0_status & ST0_FR;
 183 #ifdef CONFIG_64BIT
 184         return !test_thread_flag(TIF_32BIT_REGS);
 185 #else
 186         return 0;
 187 #endif
 188 }
 189
 190 #define SIFROMREG(si, x) ((si) = cop1_64bit(xcp) || !(x & 1) ? \
 191                         (int)ctx->fpr[x] : (int)(ctx->fpr[x & ~1] >> 32))
 192
 193 #define SITOREG(si, x)  (ctx->fpr[x & ~(cop1_64bit(xcp) == 0)] = \
 194                         cop1_64bit(xcp) || !(x & 1) ? \
 195                         ctx->fpr[x & ~1] >> 32 << 32 | (u32)(si) : \
 196                         ctx->fpr[x & ~1] << 32 >> 32 | (u64)(si) << 32)
 197
 198 #define DIFROMREG(di, x) ((di) = ctx->fpr[x & ~(cop1_64bit(xcp) == 0)])
 199 #define DITOREG(di, x)  (ctx->fpr[x & ~(cop1_64bit(xcp) == 0)] = (di))
 200
 201 #define SPFROMREG(sp, x) SIFROMREG((sp).bits, x)
 202 #define SPTOREG(sp, x)  SITOREG((sp).bits, x)
 203 #define DPFROMREG(dp, x)        DIFROMREG((dp).bits, x)
 204 #define DPTOREG(dp, x)  DITOREG((dp).bits, x)
 205
 206 /*
 207  * Emulate the single floating point instruction pointed at by EPC.
 208  * Two instructions if the instruction is in a branch delay slot.
 209  */
 210
 211 static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
 212                        void *__user *fault_addr)
 213 {
 214         mips_instruction ir;
 215         unsigned long emulpc, contpc;
 216         unsigned int cond;
 217
 218         if (!access_ok(VERIFY_READ, xcp->cp0_epc, sizeof(mips_instruction))) {
 219                 MIPS_FPU_EMU_INC_STATS(errors);
 220                 *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
 221                 return SIGBUS;
 222         }
 223         if (__get_user(ir, (mips_instruction __user *) xcp->cp0_epc)) {
 224                 MIPS_FPU_EMU_INC_STATS(errors);
 225                 *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
 226                 return SIGSEGV;
 227         }
 228
 229         /* XXX NEC Vr54xx bug workaround */
 230         if ((xcp->cp0_cause & CAUSEF_BD) && !isBranchInstr(&ir))
 231                 xcp->cp0_cause &= ~CAUSEF_BD;
 232
 233         if (xcp->cp0_cause & CAUSEF_BD) {
 234                 /*
 235                  * The instruction to be emulated is in a branch delay slot
 236                  * which means that we have to  emulate the branch instruction
 237                  * BEFORE we do the cop1 instruction.
 238                  *
 239                  * This branch could be a COP1 branch, but in that case we
 240                  * would have had a trap for that instruction, and would not
 241                  * come through this route.
 242                  *
 243                  * Linux MIPS branch emulator operates on context, updating the
 244                  * cp0_epc.
 245                  */
 246                 emulpc = xcp->cp0_epc + 4;      /* Snapshot emulation target */
 247
 248                 if (__compute_return_epc(xcp)) {
 249 #ifdef CP1DBG
 250                         printk("failed to emulate branch at %p\n",
 251                                 (void *) (xcp->cp0_epc));
 252 #endif
 253                         return SIGILL;
 254                 }
 255                 if (!access_ok(VERIFY_READ, emulpc, sizeof(mips_instruction))) {
 256                         MIPS_FPU_EMU_INC_STATS(errors);
 257                         *fault_addr = (mips_instruction __user *)emulpc;
 258                         return SIGBUS;
 259                 }
 260                 if (__get_user(ir, (mips_instruction __user *) emulpc)) {
 261                         MIPS_FPU_EMU_INC_STATS(errors);
 262                         *fault_addr = (mips_instruction __user *)emulpc;
 263                         return SIGSEGV;
 264                 }
 265                 /* __compute_return_epc() will have updated cp0_epc */
 266                 contpc = xcp->cp0_epc;
 267                 /* In order not to confuse ptrace() et al, tweak context */
 268                 xcp->cp0_epc = emulpc - 4;
 269         } else {
 270                 emulpc = xcp->cp0_epc;
 271                 contpc = xcp->cp0_epc + 4;
 272         }
 273
 274       emul:
 275         perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, xcp, 0);
 276         MIPS_FPU_EMU_INC_STATS(emulated);
 277         switch (MIPSInst_OPCODE(ir)) {
 278         case ldc1_op:{
 279                 u64 __user *va = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
 280                         MIPSInst_SIMM(ir));
 281                 u64 val;
 282
 283                 MIPS_FPU_EMU_INC_STATS(loads);
 284
 285                 if (!access_ok(VERIFY_READ, va, sizeof(u64))) {
 286                         MIPS_FPU_EMU_INC_STATS(errors);
 287                         *fault_addr = va;
 288                         return SIGBUS;
 289                 }
 290                 if (__get_user(val, va)) {
 291                         MIPS_FPU_EMU_INC_STATS(errors);
 292                         *fault_addr = va;
 293                         return SIGSEGV;
 294                 }
 295                 DITOREG(val, MIPSInst_RT(ir));
 296                 break;
 297         }
 298
 299         case sdc1_op:{
 300                 u64 __user *va = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
 301                         MIPSInst_SIMM(ir));
 302                 u64 val;
 303
 304                 MIPS_FPU_EMU_INC_STATS(stores);
 305                 DIFROMREG(val, MIPSInst_RT(ir));
 306                 if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) {
 307                         MIPS_FPU_EMU_INC_STATS(errors);
 308                         *fault_addr = va;
 309                         return SIGBUS;
 310                 }
 311                 if (__put_user(val, va)) {
 312                         MIPS_FPU_EMU_INC_STATS(errors);
 313                         *fault_addr = va;
 314                         return SIGSEGV;
 315                 }
 316                 break;
 317         }
 318
 319         case lwc1_op:{
 320                 u32 __user *va = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
 321                         MIPSInst_SIMM(ir));
 322                 u32 val;
 323
 324                 MIPS_FPU_EMU_INC_STATS(loads);
 325                 if (!access_ok(VERIFY_READ, va, sizeof(u32))) {
 326                         MIPS_FPU_EMU_INC_STATS(errors);
 327                         *fault_addr = va;
 328                         return SIGBUS;
 329                 }
 330                 if (__get_user(val, va)) {
 331                         MIPS_FPU_EMU_INC_STATS(errors);
 332                         *fault_addr = va;
 333                         return SIGSEGV;
 334                 }
 335                 SITOREG(val, MIPSInst_RT(ir));
 336                 break;
 337         }
 338
 339         case swc1_op:{
 340                 u32 __user *va = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
 341                         MIPSInst_SIMM(ir));
 342                 u32 val;
 343
 344                 MIPS_FPU_EMU_INC_STATS(stores);
 345                 SIFROMREG(val, MIPSInst_RT(ir));
 346                 if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) {
 347                         MIPS_FPU_EMU_INC_STATS(errors);
 348                         *fault_addr = va;
 349                         return SIGBUS;
 350                 }
 351                 if (__put_user(val, va)) {
 352                         MIPS_FPU_EMU_INC_STATS(errors);
 353                         *fault_addr = va;
 354                         return SIGSEGV;
 355                 }
 356                 break;
 357         }
 358
 359         case cop1_op:
 360                 switch (MIPSInst_RS(ir)) {
 361
 362 #if defined(__mips64)
 363                 case dmfc_op:
 364                         /* copregister fs -> gpr[rt] */
 365                         if (MIPSInst_RT(ir) != 0) {
 366                                 DIFROMREG(xcp->regs[MIPSInst_RT(ir)],
 367                                         MIPSInst_RD(ir));
 368                         }
 369                         break;
 370
 371                 case dmtc_op:
 372                         /* copregister fs <- rt */
 373                         DITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
 374                         break;
 375 #endif
 376
 377                 case mfc_op:
 378                         /* copregister rd -> gpr[rt] */
 379                         if (MIPSInst_RT(ir) != 0) {
 380                                 SIFROMREG(xcp->regs[MIPSInst_RT(ir)],
 381                                         MIPSInst_RD(ir));
 382                         }
 383                         break;
 384
 385                 case mtc_op:
 386                         /* copregister rd <- rt */
 387                         SITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
 388                         break;
 389
 390                 case cfc_op:{
 391                         /* cop control register rd -> gpr[rt] */
 392                         u32 value;
 393
 394                         if (MIPSInst_RD(ir) == FPCREG_CSR) {
 395                                 value = ctx->fcr31;
 396                                 value = (value & ~FPU_CSR_RM) |
 397                                         mips_rm[modeindex(value)];
 398 #ifdef CSRTRACE
 399                                 printk("%p gpr[%d]<-csr=%08x\n",
 400                                         (void *) (xcp->cp0_epc),
 401                                         MIPSInst_RT(ir), value);
 402 #endif
 403                         }
 404                         else if (MIPSInst_RD(ir) == FPCREG_RID)
 405                                 value = 0;
 406                         else
 407                                 value = 0;
 408                         if (MIPSInst_RT(ir))
 409                                 xcp->regs[MIPSInst_RT(ir)] = value;
 410                         break;
 411                 }
 412
 413                 case ctc_op:{
 414                         /* copregister rd <- rt */
 415                         u32 value;
 416
 417                         if (MIPSInst_RT(ir) == 0)
 418                                 value = 0;
 419                         else
 420                                 value = xcp->regs[MIPSInst_RT(ir)];
 421
 422                         /* we only have one writable control reg
 423                          */
 424                         if (MIPSInst_RD(ir) == FPCREG_CSR) {
 425 #ifdef CSRTRACE
 426                                 printk("%p gpr[%d]->csr=%08x\n",
 427                                         (void *) (xcp->cp0_epc),
 428                                         MIPSInst_RT(ir), value);
 429 #endif
 430
 431                                 /*
 432                                  * Don't write reserved bits,
 433                                  * and convert to ieee library modes
 434                                  */
 435                                 ctx->fcr31 = (value &
 436                                                 ~(FPU_CSR_RSVD | FPU_CSR_RM)) |
 437                                                 ieee_rm[modeindex(value)];
 438                         }
 439                         if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
 440                                 return SIGFPE;
 441                         }
 442                         break;
 443                 }
 444
 445                 case bc_op:{
 446                         int likely = 0;
 447
 448                         if (xcp->cp0_cause & CAUSEF_BD)
 449                                 return SIGILL;
 450
 451 #if __mips >= 4
 452                         cond = ctx->fcr31 & fpucondbit[MIPSInst_RT(ir) >> 2];
 453 #else
 454                         cond = ctx->fcr31 & FPU_CSR_COND;
 455 #endif
 456                         switch (MIPSInst_RT(ir) & 3) {
 457                         case bcfl_op:
 458                                 likely = 1;
 459                         case bcf_op:
 460                                 cond = !cond;
 461                                 break;
 462                         case bctl_op:
 463                                 likely = 1;
 464                         case bct_op:
 465                                 break;
 466                         default:
 467                                 /* thats an illegal instruction */
 468                                 return SIGILL;
 469                         }
 470
 471                         xcp->cp0_cause |= CAUSEF_BD;
 472                         if (cond) {
 473                                 /* branch taken: emulate dslot
 474                                  * instruction
 475                                  */
 476                                 xcp->cp0_epc += 4;
 477                                 contpc = (xcp->cp0_epc +
 478                                         (MIPSInst_SIMM(ir) << 2));
 479
 480                                 if (!access_ok(VERIFY_READ, xcp->cp0_epc,
 481                                                sizeof(mips_instruction))) {
 482                                         MIPS_FPU_EMU_INC_STATS(errors);
 483                                         *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
 484                                         return SIGBUS;
 485                                 }
 486                                 if (__get_user(ir,
 487                                     (mips_instruction __user *) xcp->cp0_epc)) {
 488                                         MIPS_FPU_EMU_INC_STATS(errors);
 489                                         *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
 490                                         return SIGSEGV;
 491                                 }
 492
 493                                 switch (MIPSInst_OPCODE(ir)) {
 494                                 case lwc1_op:
 495                                 case swc1_op:
 496 #if (__mips >= 2 || defined(__mips64))
 497                                 case ldc1_op:
 498                                 case sdc1_op:
 499 #endif
 500                                 case cop1_op:
 501 #if __mips >= 4 && __mips != 32
 502                                 case cop1x_op:
 503 #endif
 504                                         /* its one of ours */
 505                                         goto emul;
 506 #if __mips >= 4
 507                                 case spec_op:
 508                                         if (MIPSInst_FUNC(ir) == movc_op)
 509                                                 goto emul;
 510                                         break;
 511 #endif
 512                                 }
 513
 514                                 /*
 515                                  * Single step the non-cp1
 516                                  * instruction in the dslot
 517                                  */
 518                                 return mips_dsemul(xcp, ir, contpc);
 519                         }
 520                         else {
 521                                 /* branch not taken */
 522                                 if (likely) {
 523                                         /*
 524                                          * branch likely nullifies
 525                                          * dslot if not taken
 526                                          */
 527                                         xcp->cp0_epc += 4;
 528                                         contpc += 4;
 529                                         /*
 530                                          * else continue & execute
 531                                          * dslot as normal insn
 532                                          */
 533                                 }
 534                         }
 535                         break;
 536                 }
 537
 538                 default:
 539                         if (!(MIPSInst_RS(ir) & 0x10))
 540                                 return SIGILL;
 541                         {
 542                                 int sig;
 543
 544                                 /* a real fpu computation instruction */
 545                                 if ((sig = fpu_emu(xcp, ctx, ir)))
 546                                         return sig;
 547                         }
 548                 }
 549                 break;
 550
 551 #if __mips >= 4 && __mips != 32
 552         case cop1x_op:{
 553                 int sig = fpux_emu(xcp, ctx, ir, fault_addr);
 554                 if (sig)
 555                         return sig;
 556                 break;
 557         }
 558 #endif
 559
 560 #if __mips >= 4
 561         case spec_op:
 562                 if (MIPSInst_FUNC(ir) != movc_op)
 563                         return SIGILL;
 564                 cond = fpucondbit[MIPSInst_RT(ir) >> 2];
 565                 if (((ctx->fcr31 & cond) != 0) == ((MIPSInst_RT(ir) & 1) != 0))
 566                         xcp->regs[MIPSInst_RD(ir)] =
 567                                 xcp->regs[MIPSInst_RS(ir)];
 568                 break;
 569 #endif
 570
 571         default:
 572                 return SIGILL;
 573         }
 574
 575         /* we did it !! */
 576         xcp->cp0_epc = contpc;
 577         xcp->cp0_cause &= ~CAUSEF_BD;
 578
 579         return 0;
 580 }
 581
 582 /*
 583  * Conversion table from MIPS compare ops 48-63
 584  * cond = ieee754dp_cmp(x,y,IEEE754_UN,sig);
 585  */
 586 static const unsigned char cmptab[8] = {
 587         0,                      /* cmp_0 (sig) cmp_sf */
 588         IEEE754_CUN,            /* cmp_un (sig) cmp_ngle */
 589         IEEE754_CEQ,            /* cmp_eq (sig) cmp_seq */
 590         IEEE754_CEQ | IEEE754_CUN,      /* cmp_ueq (sig) cmp_ngl  */
 591         IEEE754_CLT,            /* cmp_olt (sig) cmp_lt */
 592         IEEE754_CLT | IEEE754_CUN,      /* cmp_ult (sig) cmp_nge */
 593         IEEE754_CLT | IEEE754_CEQ,      /* cmp_ole (sig) cmp_le */
 594         IEEE754_CLT | IEEE754_CEQ | IEEE754_CUN,        /* cmp_ule (sig) cmp_ngt */
 595 };
 596
 597
 598 #if __mips >= 4 && __mips != 32
 599
 600 /*
 601  * Additional MIPS4 instructions
 602  */
 603
 604 #define DEF3OP(name, p, f1, f2, f3) \
 605 static ieee754##p fpemu_##p##_##name(ieee754##p r, ieee754##p s, \
 606     ieee754##p t) \
 607 { \
 608         struct _ieee754_csr ieee754_csr_save; \
 609         s = f1(s, t); \
 610         ieee754_csr_save = ieee754_csr; \
 611         s = f2(s, r); \
 612         ieee754_csr_save.cx |= ieee754_csr.cx; \
 613         ieee754_csr_save.sx |= ieee754_csr.sx; \
 614         s = f3(s); \
 615         ieee754_csr.cx |= ieee754_csr_save.cx; \
 616         ieee754_csr.sx |= ieee754_csr_save.sx; \
 617         return s; \
 618 }
 619
 620 static ieee754dp fpemu_dp_recip(ieee754dp d)
 621 {
 622         return ieee754dp_div(ieee754dp_one(0), d);
 623 }
 624
 625 static ieee754dp fpemu_dp_rsqrt(ieee754dp d)
 626 {
 627         return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d));
 628 }
 629
 630 static ieee754sp fpemu_sp_recip(ieee754sp s)
 631 {
 632         return ieee754sp_div(ieee754sp_one(0), s);
 633 }
 634
 635 static ieee754sp fpemu_sp_rsqrt(ieee754sp s)
 636 {
 637         return ieee754sp_div(ieee754sp_one(0), ieee754sp_sqrt(s));
 638 }
 639
 640 DEF3OP(madd, sp, ieee754sp_mul, ieee754sp_add, );
 641 DEF3OP(msub, sp, ieee754sp_mul, ieee754sp_sub, );
 642 DEF3OP(nmadd, sp, ieee754sp_mul, ieee754sp_add, ieee754sp_neg);
 643 DEF3OP(nmsub, sp, ieee754sp_mul, ieee754sp_sub, ieee754sp_neg);
 644 DEF3OP(madd, dp, ieee754dp_mul, ieee754dp_add, );
 645 DEF3OP(msub, dp, ieee754dp_mul, ieee754dp_sub, );
 646 DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg);
 647 DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg);
 648
 649 static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
 650         mips_instruction ir, void *__user *fault_addr)
 651 {
 652         unsigned rcsr = 0;      /* resulting csr */
 653
 654         MIPS_FPU_EMU_INC_STATS(cp1xops);
 655
 656         switch (MIPSInst_FMA_FFMT(ir)) {
 657         case s_fmt:{            /* 0 */
 658
 659                 ieee754sp(*handler) (ieee754sp, ieee754sp, ieee754sp);
 660                 ieee754sp fd, fr, fs, ft;
 661                 u32 __user *va;
 662                 u32 val;
 663
 664                 switch (MIPSInst_FUNC(ir)) {
 665                 case lwxc1_op:
 666                         va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
 667                                 xcp->regs[MIPSInst_FT(ir)]);
 668
 669                         MIPS_FPU_EMU_INC_STATS(loads);
 670                         if (!access_ok(VERIFY_READ, va, sizeof(u32))) {
 671                                 MIPS_FPU_EMU_INC_STATS(errors);
 672                                 *fault_addr = va;
 673                                 return SIGBUS;
 674                         }
 675                         if (__get_user(val, va)) {
 676                                 MIPS_FPU_EMU_INC_STATS(errors);
 677                                 *fault_addr = va;
 678                                 return SIGSEGV;
 679                         }
 680                         SITOREG(val, MIPSInst_FD(ir));
 681                         break;
 682
 683                 case swxc1_op:
 684                         va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
 685                                 xcp->regs[MIPSInst_FT(ir)]);
 686
 687                         MIPS_FPU_EMU_INC_STATS(stores);
 688
 689                         SIFROMREG(val, MIPSInst_FS(ir));
 690                         if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) {
 691                                 MIPS_FPU_EMU_INC_STATS(errors);
 692                                 *fault_addr = va;
 693                                 return SIGBUS;
 694                         }
 695                         if (put_user(val, va)) {
 696                                 MIPS_FPU_EMU_INC_STATS(errors);
 697                                 *fault_addr = va;
 698                                 return SIGSEGV;
 699                         }
 700                         break;
 701
 702                 case madd_s_op:
 703                         handler = fpemu_sp_madd;
 704                         goto scoptop;
 705                 case msub_s_op:
 706                         handler = fpemu_sp_msub;
 707                         goto scoptop;
 708                 case nmadd_s_op:
 709                         handler = fpemu_sp_nmadd;
 710                         goto scoptop;
 711                 case nmsub_s_op:
 712                         handler = fpemu_sp_nmsub;
 713                         goto scoptop;
 714
 715                       scoptop:
 716                         SPFROMREG(fr, MIPSInst_FR(ir));
 717                         SPFROMREG(fs, MIPSInst_FS(ir));
 718                         SPFROMREG(ft, MIPSInst_FT(ir));
 719                         fd = (*handler) (fr, fs, ft);
 720                         SPTOREG(fd, MIPSInst_FD(ir));
 721
 722                       copcsr:
 723                         if (ieee754_cxtest(IEEE754_INEXACT))
 724                                 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
 725                         if (ieee754_cxtest(IEEE754_UNDERFLOW))
 726                                 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
 727                         if (ieee754_cxtest(IEEE754_OVERFLOW))
 728                                 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
 729                         if (ieee754_cxtest(IEEE754_INVALID_OPERATION))
 730                                 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
 731
 732                         ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
 733                         if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
 734                                 /*printk ("SIGFPE: fpu csr = %08x\n",
 735                                    ctx->fcr31); */
 736                                 return SIGFPE;
 737                         }
 738
 739                         break;
 740
 741                 default:
 742                         return SIGILL;
 743                 }
 744                 break;
 745         }
 746
 747         case d_fmt:{            /* 1 */
 748                 ieee754dp(*handler) (ieee754dp, ieee754dp, ieee754dp);
 749                 ieee754dp fd, fr, fs, ft;
 750                 u64 __user *va;
 751                 u64 val;
 752
 753                 switch (MIPSInst_FUNC(ir)) {
 754                 case ldxc1_op:
 755                         va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
 756                                 xcp->regs[MIPSInst_FT(ir)]);
 757
 758                         MIPS_FPU_EMU_INC_STATS(loads);
 759                         if (!access_ok(VERIFY_READ, va, sizeof(u64))) {
 760                                 MIPS_FPU_EMU_INC_STATS(errors);
 761                                 *fault_addr = va;
 762                                 return SIGBUS;
 763                         }
 764                         if (__get_user(val, va)) {
 765                                 MIPS_FPU_EMU_INC_STATS(errors);
 766                                 *fault_addr = va;
 767                                 return SIGSEGV;
 768                         }
 769                         DITOREG(val, MIPSInst_FD(ir));
 770                         break;
 771
 772                 case sdxc1_op:
 773                         va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
 774                                 xcp->regs[MIPSInst_FT(ir)]);
 775
 776                         MIPS_FPU_EMU_INC_STATS(stores);
 777                         DIFROMREG(val, MIPSInst_FS(ir));
 778                         if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) {
 779                                 MIPS_FPU_EMU_INC_STATS(errors);
 780                                 *fault_addr = va;
 781                                 return SIGBUS;
 782                         }
 783                         if (__put_user(val, va)) {
 784                                 MIPS_FPU_EMU_INC_STATS(errors);
 785                                 *fault_addr = va;
 786                                 return SIGSEGV;
 787                         }
 788                         break;
 789
 790                 case madd_d_op:
 791                         handler = fpemu_dp_madd;
 792                         goto dcoptop;
 793                 case msub_d_op:
 794                         handler = fpemu_dp_msub;
 795                         goto dcoptop;
 796                 case nmadd_d_op:
 797                         handler = fpemu_dp_nmadd;
 798                         goto dcoptop;
 799                 case nmsub_d_op:
 800                         handler = fpemu_dp_nmsub;
 801                         goto dcoptop;
 802
 803                       dcoptop:
 804                         DPFROMREG(fr, MIPSInst_FR(ir));
 805                         DPFROMREG(fs, MIPSInst_FS(ir));
 806                         DPFROMREG(ft, MIPSInst_FT(ir));
 807                         fd = (*handler) (fr, fs, ft);
 808                         DPTOREG(fd, MIPSInst_FD(ir));
 809                         goto copcsr;
 810
 811                 default:
 812                         return SIGILL;
 813                 }
 814                 break;
 815         }
 816
 817         case 0x7:               /* 7 */
 818                 if (MIPSInst_FUNC(ir) != pfetch_op) {
 819                         return SIGILL;
 820                 }
 821                 /* ignore prefx operation */
 822                 break;
 823
 824         default:
 825                 return SIGILL;
 826         }
 827
 828         return 0;
 829 }
 830 #endif
 831
 832
 833
 834 /*
 835  * Emulate a single COP1 arithmetic instruction.
 836  */
 837 static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
 838         mips_instruction ir)
 839 {
 840         int rfmt;               /* resulting format */
 841         unsigned rcsr = 0;      /* resulting csr */
 842         unsigned cond;
 843         union {
 844                 ieee754dp d;
 845                 ieee754sp s;
 846                 int w;
 847 #ifdef __mips64
 848                 s64 l;
 849 #endif
 850         } rv;                   /* resulting value */
 851
 852         MIPS_FPU_EMU_INC_STATS(cp1ops);
 853         switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) {
 854         case s_fmt:{            /* 0 */
 855                 union {
 856                         ieee754sp(*b) (ieee754sp, ieee754sp);
 857                         ieee754sp(*u) (ieee754sp);
 858                 } handler;
 859
 860                 switch (MIPSInst_FUNC(ir)) {
 861                         /* binary ops */
 862                 case fadd_op:
 863                         handler.b = ieee754sp_add;
 864                         goto scopbop;
 865                 case fsub_op:
 866                         handler.b = ieee754sp_sub;
 867                         goto scopbop;
 868                 case fmul_op:
 869                         handler.b = ieee754sp_mul;
 870                         goto scopbop;
 871                 case fdiv_op:
 872                         handler.b = ieee754sp_div;
 873                         goto scopbop;
 874
 875                         /* unary  ops */
 876 #if __mips >= 2 || defined(__mips64)
 877                 case fsqrt_op:
 878                         handler.u = ieee754sp_sqrt;
 879                         goto scopuop;
 880 #endif
 881 #if __mips >= 4 && __mips != 32
 882                 case frsqrt_op:
 883                         handler.u = fpemu_sp_rsqrt;
 884                         goto scopuop;
 885                 case frecip_op:
 886                         handler.u = fpemu_sp_recip;
 887                         goto scopuop;
 888 #endif
 889 #if __mips >= 4
 890                 case fmovc_op:
 891                         cond = fpucondbit[MIPSInst_FT(ir) >> 2];
 892                         if (((ctx->fcr31 & cond) != 0) !=
 893                                 ((MIPSInst_FT(ir) & 1) != 0))
 894                                 return 0;
 895                         SPFROMREG(rv.s, MIPSInst_FS(ir));
 896                         break;
 897                 case fmovz_op:
 898                         if (xcp->regs[MIPSInst_FT(ir)] != 0)
 899                                 return 0;
 900                         SPFROMREG(rv.s, MIPSInst_FS(ir));
 901                         break;
 902                 case fmovn_op:
 903                         if (xcp->regs[MIPSInst_FT(ir)] == 0)
 904                                 return 0;
 905                         SPFROMREG(rv.s, MIPSInst_FS(ir));
 906                         break;
 907 #endif
 908                 case fabs_op:
 909                         handler.u = ieee754sp_abs;
 910                         goto scopuop;
 911                 case fneg_op:
 912                         handler.u = ieee754sp_neg;
 913                         goto scopuop;
 914                 case fmov_op:
 915                         /* an easy one */
 916                         SPFROMREG(rv.s, MIPSInst_FS(ir));
 917                         goto copcsr;
 918
 919                         /* binary op on handler */
 920                       scopbop:
 921                         {
 922                                 ieee754sp fs, ft;
 923
 924                                 SPFROMREG(fs, MIPSInst_FS(ir));
 925                                 SPFROMREG(ft, MIPSInst_FT(ir));
 926
 927                                 rv.s = (*handler.b) (fs, ft);
 928                                 goto copcsr;
 929                         }
 930                       scopuop:
 931                         {
 932                                 ieee754sp fs;
 933
 934                                 SPFROMREG(fs, MIPSInst_FS(ir));
 935                                 rv.s = (*handler.u) (fs);
 936                                 goto copcsr;
 937                         }
 938                       copcsr:
 939                         if (ieee754_cxtest(IEEE754_INEXACT))
 940                                 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
 941                         if (ieee754_cxtest(IEEE754_UNDERFLOW))
 942                                 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
 943                         if (ieee754_cxtest(IEEE754_OVERFLOW))
 944                                 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
 945                         if (ieee754_cxtest(IEEE754_ZERO_DIVIDE))
 946                                 rcsr |= FPU_CSR_DIV_X | FPU_CSR_DIV_S;
 947                         if (ieee754_cxtest(IEEE754_INVALID_OPERATION))
 948                                 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
 949                         break;
 950
 951                         /* unary conv ops */
 952                 case fcvts_op:
 953                         return SIGILL;  /* not defined */
 954                 case fcvtd_op:{
 955                         ieee754sp fs;
 956
 957                         SPFROMREG(fs, MIPSInst_FS(ir));
 958                         rv.d = ieee754dp_fsp(fs);
 959                         rfmt = d_fmt;
 960                         goto copcsr;
 961                 }
 962                 case fcvtw_op:{
 963                         ieee754sp fs;
 964
 965                         SPFROMREG(fs, MIPSInst_FS(ir));
 966                         rv.w = ieee754sp_tint(fs);
 967                         rfmt = w_fmt;
 968                         goto copcsr;
 969                 }
 970
 971 #if __mips >= 2 || defined(__mips64)
 972                 case fround_op:
 973                 case ftrunc_op:
 974                 case fceil_op:
 975                 case ffloor_op:{
 976                         unsigned int oldrm = ieee754_csr.rm;
 977                         ieee754sp fs;
 978
 979                         SPFROMREG(fs, MIPSInst_FS(ir));
 980                         ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
 981                         rv.w = ieee754sp_tint(fs);
 982                         ieee754_csr.rm = oldrm;
 983                         rfmt = w_fmt;
 984                         goto copcsr;
 985                 }
 986 #endif /* __mips >= 2 */
 987
 988 #if defined(__mips64)
 989                 case fcvtl_op:{
 990                         ieee754sp fs;
 991
 992                         SPFROMREG(fs, MIPSInst_FS(ir));
 993                         rv.l = ieee754sp_tlong(fs);
 994                         rfmt = l_fmt;
 995                         goto copcsr;
 996                 }
 997
 998                 case froundl_op:
 999                 case ftruncl_op:
1000                 case fceill_op:
1001                 case ffloorl_op:{
1002                         unsigned int oldrm = ieee754_csr.rm;
1003                         ieee754sp fs;
1004
1005                         SPFROMREG(fs, MIPSInst_FS(ir));
1006                         ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
1007                         rv.l = ieee754sp_tlong(fs);
1008                         ieee754_csr.rm = oldrm;
1009                         rfmt = l_fmt;
1010                         goto copcsr;
1011                 }
1012 #endif /* defined(__mips64) */
1013
1014                 default:
1015                         if (MIPSInst_FUNC(ir) >= fcmp_op) {
1016                                 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
1017                                 ieee754sp fs, ft;
1018
1019                                 SPFROMREG(fs, MIPSInst_FS(ir));
1020                                 SPFROMREG(ft, MIPSInst_FT(ir));
1021                                 rv.w = ieee754sp_cmp(fs, ft,
1022                                         cmptab[cmpop & 0x7], cmpop & 0x8);
1023                                 rfmt = -1;
1024                                 if ((cmpop & 0x8) && ieee754_cxtest
1025                                         (IEEE754_INVALID_OPERATION))
1026                                         rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
1027                                 else
1028                                         goto copcsr;
1029
1030                         }
1031                         else {
1032                                 return SIGILL;
1033                         }
1034                         break;
1035                 }
1036                 break;
1037         }
1038
1039         case d_fmt:{
1040                 union {
1041                         ieee754dp(*b) (ieee754dp, ieee754dp);
1042                         ieee754dp(*u) (ieee754dp);
1043                 } handler;
1044
1045                 switch (MIPSInst_FUNC(ir)) {
1046                         /* binary ops */
1047                 case fadd_op:
1048                         handler.b = ieee754dp_add;
1049                         goto dcopbop;
1050                 case fsub_op:
1051                         handler.b = ieee754dp_sub;
1052                         goto dcopbop;
1053                 case fmul_op:
1054                         handler.b = ieee754dp_mul;
1055                         goto dcopbop;
1056                 case fdiv_op:
1057                         handler.b = ieee754dp_div;
1058                         goto dcopbop;
1059
1060                         /* unary  ops */
1061 #if __mips >= 2 || defined(__mips64)
1062                 case fsqrt_op:
1063                         handler.u = ieee754dp_sqrt;
1064                         goto dcopuop;
1065 #endif
1066 #if __mips >= 4 && __mips != 32
1067                 case frsqrt_op:
1068                         handler.u = fpemu_dp_rsqrt;
1069                         goto dcopuop;
1070                 case frecip_op:
1071                         handler.u = fpemu_dp_recip;
1072                         goto dcopuop;
1073 #endif
1074 #if __mips >= 4
1075                 case fmovc_op:
1076                         cond = fpucondbit[MIPSInst_FT(ir) >> 2];
1077                         if (((ctx->fcr31 & cond) != 0) !=
1078                                 ((MIPSInst_FT(ir) & 1) != 0))
1079                                 return 0;
1080                         DPFROMREG(rv.d, MIPSInst_FS(ir));
1081                         break;
1082                 case fmovz_op:
1083                         if (xcp->regs[MIPSInst_FT(ir)] != 0)
1084                                 return 0;
1085                         DPFROMREG(rv.d, MIPSInst_FS(ir));
1086                         break;
1087                 case fmovn_op:
1088                         if (xcp->regs[MIPSInst_FT(ir)] == 0)
1089                                 return 0;
1090                         DPFROMREG(rv.d, MIPSInst_FS(ir));
1091                         break;
1092 #endif
1093                 case fabs_op:
1094                         handler.u = ieee754dp_abs;
1095                         goto dcopuop;
1096
1097                 case fneg_op:
1098                         handler.u = ieee754dp_neg;
1099                         goto dcopuop;
1100
1101                 case fmov_op:
1102                         /* an easy one */
1103                         DPFROMREG(rv.d, MIPSInst_FS(ir));
1104                         goto copcsr;
1105
1106                         /* binary op on handler */
1107                       dcopbop:{
1108                                 ieee754dp fs, ft;
1109
1110                                 DPFROMREG(fs, MIPSInst_FS(ir));
1111                                 DPFROMREG(ft, MIPSInst_FT(ir));
1112
1113                                 rv.d = (*handler.b) (fs, ft);
1114                                 goto copcsr;
1115                         }
1116                       dcopuop:{
1117                                 ieee754dp fs;
1118
1119                                 DPFROMREG(fs, MIPSInst_FS(ir));
1120                                 rv.d = (*handler.u) (fs);
1121                                 goto copcsr;
1122                         }
1123
1124                         /* unary conv ops */
1125                 case fcvts_op:{
1126                         ieee754dp fs;
1127
1128                         DPFROMREG(fs, MIPSInst_FS(ir));
1129                         rv.s = ieee754sp_fdp(fs);
1130                         rfmt = s_fmt;
1131                         goto copcsr;
1132                 }
1133                 case fcvtd_op:
1134                         return SIGILL;  /* not defined */
1135
1136                 case fcvtw_op:{
1137                         ieee754dp fs;
1138
1139                         DPFROMREG(fs, MIPSInst_FS(ir));
1140                         rv.w = ieee754dp_tint(fs);      /* wrong */
1141                         rfmt = w_fmt;
1142                         goto copcsr;
1143                 }
1144
1145 #if __mips >= 2 || defined(__mips64)
1146                 case fround_op:
1147                 case ftrunc_op:
1148                 case fceil_op:
1149                 case ffloor_op:{
1150                         unsigned int oldrm = ieee754_csr.rm;
1151                         ieee754dp fs;
1152
1153                         DPFROMREG(fs, MIPSInst_FS(ir));
1154                         ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
1155                         rv.w = ieee754dp_tint(fs);
1156                         ieee754_csr.rm = oldrm;
1157                         rfmt = w_fmt;
1158                         goto copcsr;
1159                 }
1160 #endif
1161
1162 #if defined(__mips64)
1163                 case fcvtl_op:{
1164                         ieee754dp fs;
1165
1166                         DPFROMREG(fs, MIPSInst_FS(ir));
1167                         rv.l = ieee754dp_tlong(fs);
1168                         rfmt = l_fmt;
1169                         goto copcsr;
1170                 }
1171
1172                 case froundl_op:
1173                 case ftruncl_op:
1174                 case fceill_op:
1175                 case ffloorl_op:{
1176                         unsigned int oldrm = ieee754_csr.rm;
1177                         ieee754dp fs;
1178
1179                         DPFROMREG(fs, MIPSInst_FS(ir));
1180                         ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
1181                         rv.l = ieee754dp_tlong(fs);
1182                         ieee754_csr.rm = oldrm;
1183                         rfmt = l_fmt;
1184                         goto copcsr;
1185                 }
1186 #endif /* __mips >= 3 */
1187
1188                 default:
1189                         if (MIPSInst_FUNC(ir) >= fcmp_op) {
1190                                 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
1191                                 ieee754dp fs, ft;
1192
1193                                 DPFROMREG(fs, MIPSInst_FS(ir));
1194                                 DPFROMREG(ft, MIPSInst_FT(ir));
1195                                 rv.w = ieee754dp_cmp(fs, ft,
1196                                         cmptab[cmpop & 0x7], cmpop & 0x8);
1197                                 rfmt = -1;
1198                                 if ((cmpop & 0x8)
1199                                         &&
1200                                         ieee754_cxtest
1201                                         (IEEE754_INVALID_OPERATION))
1202                                         rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
1203                                 else
1204                                         goto copcsr;
1205
1206                         }
1207                         else {
1208                                 return SIGILL;
1209                         }
1210                         break;
1211                 }
1212                 break;
1213         }
1214
1215         case w_fmt:{
1216                 ieee754sp fs;
1217
1218                 switch (MIPSInst_FUNC(ir)) {
1219                 case fcvts_op:
1220                         /* convert word to single precision real */
1221                         SPFROMREG(fs, MIPSInst_FS(ir));
1222                         rv.s = ieee754sp_fint(fs.bits);
1223                         rfmt = s_fmt;
1224                         goto copcsr;
1225                 case fcvtd_op:
1226                         /* convert word to double precision real */
1227                         SPFROMREG(fs, MIPSInst_FS(ir));
1228                         rv.d = ieee754dp_fint(fs.bits);
1229                         rfmt = d_fmt;
1230                         goto copcsr;
1231                 default:
1232                         return SIGILL;
1233                 }
1234                 break;
1235         }
1236
1237 #if defined(__mips64)
1238         case l_fmt:{
1239                 switch (MIPSInst_FUNC(ir)) {
1240                 case fcvts_op:
1241                         /* convert long to single precision real */
1242                         rv.s = ieee754sp_flong(ctx->fpr[MIPSInst_FS(ir)]);
1243                         rfmt = s_fmt;
1244                         goto copcsr;
1245                 case fcvtd_op:
1246                         /* convert long to double precision real */
1247                         rv.d = ieee754dp_flong(ctx->fpr[MIPSInst_FS(ir)]);
1248                         rfmt = d_fmt;
1249                         goto copcsr;
1250                 default:
1251                         return SIGILL;
1252                 }
1253                 break;
1254         }
1255 #endif
1256
1257         default:
1258                 return SIGILL;
1259         }
1260
1261         /*
1262          * Update the fpu CSR register for this operation.
1263          * If an exception is required, generate a tidy SIGFPE exception,
1264          * without updating the result register.
1265          * Note: cause exception bits do not accumulate, they are rewritten
1266          * for each op; only the flag/sticky bits accumulate.
1267          */
1268         ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
1269         if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1270                 /*printk ("SIGFPE: fpu csr = %08x\n",ctx->fcr31); */
1271                 return SIGFPE;
1272         }
1273
1274         /*
1275          * Now we can safely write the result back to the register file.
1276          */
1277         switch (rfmt) {
1278         case -1:{
1279 #if __mips >= 4
1280                 cond = fpucondbit[MIPSInst_FD(ir) >> 2];
1281 #else
1282                 cond = FPU_CSR_COND;
1283 #endif
1284                 if (rv.w)
1285                         ctx->fcr31 |= cond;
1286                 else
1287                         ctx->fcr31 &= ~cond;
1288                 break;
1289         }
1290         case d_fmt:
1291                 DPTOREG(rv.d, MIPSInst_FD(ir));
1292                 break;
1293         case s_fmt:
1294                 SPTOREG(rv.s, MIPSInst_FD(ir));
1295                 break;
1296         case w_fmt:
1297                 SITOREG(rv.w, MIPSInst_FD(ir));
1298                 break;
1299 #if defined(__mips64)
1300         case l_fmt:
1301                 DITOREG(rv.l, MIPSInst_FD(ir));
1302                 break;
1303 #endif
1304         default:
1305                 return SIGILL;
1306         }
1307
1308         return 0;
1309 }
1310
1311 int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1312         int has_fpu, void *__user *fault_addr)
1313 {
1314         unsigned long oldepc, prevepc;
1315         mips_instruction insn;
1316         int sig = 0;
1317
1318         oldepc = xcp->cp0_epc;
1319         do {
1320                 prevepc = xcp->cp0_epc;
1321
1322                 if (!access_ok(VERIFY_READ, xcp->cp0_epc, sizeof(mips_instruction))) {
1323                         MIPS_FPU_EMU_INC_STATS(errors);
1324                         *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
1325                         return SIGBUS;
1326                 }
1327                 if (__get_user(insn, (mips_instruction __user *) xcp->cp0_epc)) {
1328                         MIPS_FPU_EMU_INC_STATS(errors);
1329                         *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
1330                         return SIGSEGV;
1331                 }
1332                 if (insn == 0)
1333                         xcp->cp0_epc += 4;      /* skip nops */
1334                 else {
1335                         /*
1336                          * The 'ieee754_csr' is an alias of
1337                          * ctx->fcr31.  No need to copy ctx->fcr31 to
1338                          * ieee754_csr.  But ieee754_csr.rm is ieee
1339                          * library modes. (not mips rounding mode)
1340                          */
1341                         /* convert to ieee library modes */
1342                         ieee754_csr.rm = ieee_rm[ieee754_csr.rm];
1343                         sig = cop1Emulate(xcp, ctx, fault_addr);
1344                         /* revert to mips rounding mode */
1345                         ieee754_csr.rm = mips_rm[ieee754_csr.rm];
1346                 }
1347
1348                 if (has_fpu)
1349                         break;
1350                 if (sig)
1351                         break;
1352
1353                 cond_resched();
1354         } while (xcp->cp0_epc > prevepc);
1355
1356         /* SIGILL indicates a non-fpu instruction */
1357         if (sig == SIGILL && xcp->cp0_epc != oldepc)
1358                 /* but if epc has advanced, then ignore it */
1359                 sig = 0;
1360
1361         return sig;
1362 }
1363
1364 #ifdef CONFIG_DEBUG_FS
1365
1366 static int fpuemu_stat_get(void *data, u64 *val)
1367 {
1368         int cpu;
1369         unsigned long sum = 0;
1370         for_each_online_cpu(cpu) {
1371                 struct mips_fpu_emulator_stats *ps;
1372                 local_t *pv;
1373                 ps = &per_cpu(fpuemustats, cpu);
1374                 pv = (void *)ps + (unsigned long)data;
1375                 sum += local_read(pv);
1376         }
1377         *val = sum;
1378         return 0;
1379 }
1380 DEFINE_SIMPLE_ATTRIBUTE(fops_fpuemu_stat, fpuemu_stat_get, NULL, "%llu\n");
1381
1382 extern struct dentry *mips_debugfs_dir;
1383 static int __init debugfs_fpuemu(void)
1384 {
1385         struct dentry *d, *dir;
1386
1387         if (!mips_debugfs_dir)
1388                 return -ENODEV;
1389         dir = debugfs_create_dir("fpuemustats", mips_debugfs_dir);
1390         if (!dir)
1391                 return -ENOMEM;
1392
1393 #define FPU_STAT_CREATE(M)                                              \
1394         do {                                                            \
1395                 d = debugfs_create_file(#M , S_IRUGO, dir,              \
1396                         (void *)offsetof(struct mips_fpu_emulator_stats, M), \
1397                         &fops_fpuemu_stat);                             \
1398                 if (!d)                                                 \
1399                         return -ENOMEM;                                 \
1400         } while (0)
1401
1402         FPU_STAT_CREATE(emulated);
1403         FPU_STAT_CREATE(loads);
1404         FPU_STAT_CREATE(stores);
1405         FPU_STAT_CREATE(cp1ops);
1406         FPU_STAT_CREATE(cp1xops);
1407         FPU_STAT_CREATE(errors);
1408
1409         return 0;
1410 }
1411 __initcall(debugfs_fpuemu);
1412 #endif