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  * http://www.algor.co.uk
   7  *
   8  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
   9  * Copyright (C) 2000  MIPS Technologies, Inc.
  10  *
  11  *  This program is free software; you can distribute it and/or modify it
  12  *  under the terms of the GNU General Public License (Version 2) as
  13  *  published by the Free Software Foundation.
  14  *
  15  *  This program is distributed in the hope it will be useful, but WITHOUT
  16  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  17  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  18  *  for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License along
  21  *  with this program; if not, write to the Free Software Foundation, Inc.,
  22  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  23  *
  24  * A complete emulator for MIPS coprocessor 1 instructions.  This is
  25  * required for #float(switch) or #float(trap), where it catches all
  26  * COP1 instructions via the "CoProcessor Unusable" exception.
  27  *
  28  * More surprisingly it is also required for #float(ieee), to help out
  29  * the hardware fpu at the boundaries of the IEEE-754 representation
  30  * (denormalised values, infinities, underflow, etc).  It is made
  31  * quite nasty because emulation of some non-COP1 instructions is
  32  * required, e.g. in branch delay slots.
  33  *
  34  * Note if you know that you won't have an fpu, then you'll get much
  35  * better performance by compiling with -msoft-float!
  36  */
  37 #include <linux/sched.h>
  38 #include <linux/module.h>
  39 #include <linux/debugfs.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);
  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 {
 213         mips_instruction ir;
 214         unsigned long emulpc, contpc;
 215         unsigned int cond;
 216
 217         if (get_user(ir, (mips_instruction __user *) xcp->cp0_epc)) {
 218                 MIPS_FPU_EMU_INC_STATS(errors);
 219                 return SIGBUS;
 220         }
 221
 222         /* XXX NEC Vr54xx bug workaround */
 223         if ((xcp->cp0_cause & CAUSEF_BD) && !isBranchInstr(&ir))
 224                 xcp->cp0_cause &= ~CAUSEF_BD;
 225
 226         if (xcp->cp0_cause & CAUSEF_BD) {
 227                 /*
 228                  * The instruction to be emulated is in a branch delay slot
 229                  * which means that we have to  emulate the branch instruction
 230                  * BEFORE we do the cop1 instruction.
 231                  *
 232                  * This branch could be a COP1 branch, but in that case we
 233                  * would have had a trap for that instruction, and would not
 234                  * come through this route.
 235                  *
 236                  * Linux MIPS branch emulator operates on context, updating the
 237                  * cp0_epc.
 238                  */
 239                 emulpc = xcp->cp0_epc + 4;      /* Snapshot emulation target */
 240
 241                 if (__compute_return_epc(xcp)) {
 242 #ifdef CP1DBG
 243                         printk("failed to emulate branch at %p\n",
 244                                 (void *) (xcp->cp0_epc));
 245 #endif
 246                         return SIGILL;
 247                 }
 248                 if (get_user(ir, (mips_instruction __user *) emulpc)) {
 249                         MIPS_FPU_EMU_INC_STATS(errors);
 250                         return SIGBUS;
 251                 }
 252                 /* __compute_return_epc() will have updated cp0_epc */
 253                 contpc = xcp->cp0_epc;
 254                 /* In order not to confuse ptrace() et al, tweak context */
 255                 xcp->cp0_epc = emulpc - 4;
 256         } else {
 257                 emulpc = xcp->cp0_epc;
 258                 contpc = xcp->cp0_epc + 4;
 259         }
 260
 261       emul:
 262         MIPS_FPU_EMU_INC_STATS(emulated);
 263         switch (MIPSInst_OPCODE(ir)) {
 264         case ldc1_op:{
 265                 u64 __user *va = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
 266                         MIPSInst_SIMM(ir));
 267                 u64 val;
 268
 269                 MIPS_FPU_EMU_INC_STATS(loads);
 270                 if (get_user(val, va)) {
 271                         MIPS_FPU_EMU_INC_STATS(errors);
 272                         return SIGBUS;
 273                 }
 274                 DITOREG(val, MIPSInst_RT(ir));
 275                 break;
 276         }
 277
 278         case sdc1_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(stores);
 284                 DIFROMREG(val, MIPSInst_RT(ir));
 285                 if (put_user(val, va)) {
 286                         MIPS_FPU_EMU_INC_STATS(errors);
 287                         return SIGBUS;
 288                 }
 289                 break;
 290         }
 291
 292         case lwc1_op:{
 293                 u32 __user *va = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
 294                         MIPSInst_SIMM(ir));
 295                 u32 val;
 296
 297                 MIPS_FPU_EMU_INC_STATS(loads);
 298                 if (get_user(val, va)) {
 299                         MIPS_FPU_EMU_INC_STATS(errors);
 300                         return SIGBUS;
 301                 }
 302                 SITOREG(val, MIPSInst_RT(ir));
 303                 break;
 304         }
 305
 306         case swc1_op:{
 307                 u32 __user *va = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
 308                         MIPSInst_SIMM(ir));
 309                 u32 val;
 310
 311                 MIPS_FPU_EMU_INC_STATS(stores);
 312                 SIFROMREG(val, MIPSInst_RT(ir));
 313                 if (put_user(val, va)) {
 314                         MIPS_FPU_EMU_INC_STATS(errors);
 315                         return SIGBUS;
 316                 }
 317                 break;
 318         }
 319
 320         case cop1_op:
 321                 switch (MIPSInst_RS(ir)) {
 322
 323 #if defined(__mips64)
 324                 case dmfc_op:
 325                         /* copregister fs -> gpr[rt] */
 326                         if (MIPSInst_RT(ir) != 0) {
 327                                 DIFROMREG(xcp->regs[MIPSInst_RT(ir)],
 328                                         MIPSInst_RD(ir));
 329                         }
 330                         break;
 331
 332                 case dmtc_op:
 333                         /* copregister fs <- rt */
 334                         DITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
 335                         break;
 336 #endif
 337
 338                 case mfc_op:
 339                         /* copregister rd -> gpr[rt] */
 340                         if (MIPSInst_RT(ir) != 0) {
 341                                 SIFROMREG(xcp->regs[MIPSInst_RT(ir)],
 342                                         MIPSInst_RD(ir));
 343                         }
 344                         break;
 345
 346                 case mtc_op:
 347                         /* copregister rd <- rt */
 348                         SITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
 349                         break;
 350
 351                 case cfc_op:{
 352                         /* cop control register rd -> gpr[rt] */
 353                         u32 value;
 354
 355                         if (MIPSInst_RD(ir) == FPCREG_CSR) {
 356                                 value = ctx->fcr31;
 357                                 value = (value & ~0x3) | mips_rm[value & 0x3];
 358 #ifdef CSRTRACE
 359                                 printk("%p gpr[%d]<-csr=%08x\n",
 360                                         (void *) (xcp->cp0_epc),
 361                                         MIPSInst_RT(ir), value);
 362 #endif
 363                         }
 364                         else if (MIPSInst_RD(ir) == FPCREG_RID)
 365                                 value = 0;
 366                         else
 367                                 value = 0;
 368                         if (MIPSInst_RT(ir))
 369                                 xcp->regs[MIPSInst_RT(ir)] = value;
 370                         break;
 371                 }
 372
 373                 case ctc_op:{
 374                         /* copregister rd <- rt */
 375                         u32 value;
 376
 377                         if (MIPSInst_RT(ir) == 0)
 378                                 value = 0;
 379                         else
 380                                 value = xcp->regs[MIPSInst_RT(ir)];
 381
 382                         /* we only have one writable control reg
 383                          */
 384                         if (MIPSInst_RD(ir) == FPCREG_CSR) {
 385 #ifdef CSRTRACE
 386                                 printk("%p gpr[%d]->csr=%08x\n",
 387                                         (void *) (xcp->cp0_epc),
 388                                         MIPSInst_RT(ir), value);
 389 #endif
 390
 391                                 /*
 392                                  * Don't write reserved bits,
 393                                  * and convert to ieee library modes
 394                                  */
 395                                 ctx->fcr31 = (value &
 396                                                 ~(FPU_CSR_RSVD | FPU_CSR_RM)) |
 397                                                 ieee_rm[modeindex(value)];
 398                         }
 399                         if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
 400                                 return SIGFPE;
 401                         }
 402                         break;
 403                 }
 404
 405                 case bc_op:{
 406                         int likely = 0;
 407
 408                         if (xcp->cp0_cause & CAUSEF_BD)
 409                                 return SIGILL;
 410
 411 #if __mips >= 4
 412                         cond = ctx->fcr31 & fpucondbit[MIPSInst_RT(ir) >> 2];
 413 #else
 414                         cond = ctx->fcr31 & FPU_CSR_COND;
 415 #endif
 416                         switch (MIPSInst_RT(ir) & 3) {
 417                         case bcfl_op:
 418                                 likely = 1;
 419                         case bcf_op:
 420                                 cond = !cond;
 421                                 break;
 422                         case bctl_op:
 423                                 likely = 1;
 424                         case bct_op:
 425                                 break;
 426                         default:
 427                                 /* thats an illegal instruction */
 428                                 return SIGILL;
 429                         }
 430
 431                         xcp->cp0_cause |= CAUSEF_BD;
 432                         if (cond) {
 433                                 /* branch taken: emulate dslot
 434                                  * instruction
 435                                  */
 436                                 xcp->cp0_epc += 4;
 437                                 contpc = (xcp->cp0_epc +
 438                                         (MIPSInst_SIMM(ir) << 2));
 439
 440                                 if (get_user(ir,
 441                                     (mips_instruction __user *) xcp->cp0_epc)) {
 442                                         MIPS_FPU_EMU_INC_STATS(errors);
 443                                         return SIGBUS;
 444                                 }
 445
 446                                 switch (MIPSInst_OPCODE(ir)) {
 447                                 case lwc1_op:
 448                                 case swc1_op:
 449 #if (__mips >= 2 || defined(__mips64))
 450                                 case ldc1_op:
 451                                 case sdc1_op:
 452 #endif
 453                                 case cop1_op:
 454 #if __mips >= 4 && __mips != 32
 455                                 case cop1x_op:
 456 #endif
 457                                         /* its one of ours */
 458                                         goto emul;
 459 #if __mips >= 4
 460                                 case spec_op:
 461                                         if (MIPSInst_FUNC(ir) == movc_op)
 462                                                 goto emul;
 463                                         break;
 464 #endif
 465                                 }
 466
 467                                 /*
 468                                  * Single step the non-cp1
 469                                  * instruction in the dslot
 470                                  */
 471                                 return mips_dsemul(xcp, ir, contpc);
 472                         }
 473                         else {
 474                                 /* branch not taken */
 475                                 if (likely) {
 476                                         /*
 477                                          * branch likely nullifies
 478                                          * dslot if not taken
 479                                          */
 480                                         xcp->cp0_epc += 4;
 481                                         contpc += 4;
 482                                         /*
 483                                          * else continue & execute
 484                                          * dslot as normal insn
 485                                          */
 486                                 }
 487                         }
 488                         break;
 489                 }
 490
 491                 default:
 492                         if (!(MIPSInst_RS(ir) & 0x10))
 493                                 return SIGILL;
 494                         {
 495                                 int sig;
 496
 497                                 /* a real fpu computation instruction */
 498                                 if ((sig = fpu_emu(xcp, ctx, ir)))
 499                                         return sig;
 500                         }
 501                 }
 502                 break;
 503
 504 #if __mips >= 4 && __mips != 32
 505         case cop1x_op:{
 506                 int sig;
 507
 508                 if ((sig = fpux_emu(xcp, ctx, ir)))
 509                         return sig;
 510                 break;
 511         }
 512 #endif
 513
 514 #if __mips >= 4
 515         case spec_op:
 516                 if (MIPSInst_FUNC(ir) != movc_op)
 517                         return SIGILL;
 518                 cond = fpucondbit[MIPSInst_RT(ir) >> 2];
 519                 if (((ctx->fcr31 & cond) != 0) == ((MIPSInst_RT(ir) & 1) != 0))
 520                         xcp->regs[MIPSInst_RD(ir)] =
 521                                 xcp->regs[MIPSInst_RS(ir)];
 522                 break;
 523 #endif
 524
 525         default:
 526                 return SIGILL;
 527         }
 528
 529         /* we did it !! */
 530         xcp->cp0_epc = contpc;
 531         xcp->cp0_cause &= ~CAUSEF_BD;
 532
 533         return 0;
 534 }
 535
 536 /*
 537  * Conversion table from MIPS compare ops 48-63
 538  * cond = ieee754dp_cmp(x,y,IEEE754_UN,sig);
 539  */
 540 static const unsigned char cmptab[8] = {
 541         0,                      /* cmp_0 (sig) cmp_sf */
 542         IEEE754_CUN,            /* cmp_un (sig) cmp_ngle */
 543         IEEE754_CEQ,            /* cmp_eq (sig) cmp_seq */
 544         IEEE754_CEQ | IEEE754_CUN,      /* cmp_ueq (sig) cmp_ngl  */
 545         IEEE754_CLT,            /* cmp_olt (sig) cmp_lt */
 546         IEEE754_CLT | IEEE754_CUN,      /* cmp_ult (sig) cmp_nge */
 547         IEEE754_CLT | IEEE754_CEQ,      /* cmp_ole (sig) cmp_le */
 548         IEEE754_CLT | IEEE754_CEQ | IEEE754_CUN,        /* cmp_ule (sig) cmp_ngt */
 549 };
 550
 551
 552 #if __mips >= 4 && __mips != 32
 553
 554 /*
 555  * Additional MIPS4 instructions
 556  */
 557
 558 #define DEF3OP(name, p, f1, f2, f3) \
 559 static ieee754##p fpemu_##p##_##name(ieee754##p r, ieee754##p s, \
 560     ieee754##p t) \
 561 { \
 562         struct _ieee754_csr ieee754_csr_save; \
 563         s = f1(s, t); \
 564         ieee754_csr_save = ieee754_csr; \
 565         s = f2(s, r); \
 566         ieee754_csr_save.cx |= ieee754_csr.cx; \
 567         ieee754_csr_save.sx |= ieee754_csr.sx; \
 568         s = f3(s); \
 569         ieee754_csr.cx |= ieee754_csr_save.cx; \
 570         ieee754_csr.sx |= ieee754_csr_save.sx; \
 571         return s; \
 572 }
 573
 574 static ieee754dp fpemu_dp_recip(ieee754dp d)
 575 {
 576         return ieee754dp_div(ieee754dp_one(0), d);
 577 }
 578
 579 static ieee754dp fpemu_dp_rsqrt(ieee754dp d)
 580 {
 581         return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d));
 582 }
 583
 584 static ieee754sp fpemu_sp_recip(ieee754sp s)
 585 {
 586         return ieee754sp_div(ieee754sp_one(0), s);
 587 }
 588
 589 static ieee754sp fpemu_sp_rsqrt(ieee754sp s)
 590 {
 591         return ieee754sp_div(ieee754sp_one(0), ieee754sp_sqrt(s));
 592 }
 593
 594 DEF3OP(madd, sp, ieee754sp_mul, ieee754sp_add, );
 595 DEF3OP(msub, sp, ieee754sp_mul, ieee754sp_sub, );
 596 DEF3OP(nmadd, sp, ieee754sp_mul, ieee754sp_add, ieee754sp_neg);
 597 DEF3OP(nmsub, sp, ieee754sp_mul, ieee754sp_sub, ieee754sp_neg);
 598 DEF3OP(madd, dp, ieee754dp_mul, ieee754dp_add, );
 599 DEF3OP(msub, dp, ieee754dp_mul, ieee754dp_sub, );
 600 DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg);
 601 DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg);
 602
 603 static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
 604         mips_instruction ir)
 605 {
 606         unsigned rcsr = 0;      /* resulting csr */
 607
 608         MIPS_FPU_EMU_INC_STATS(cp1xops);
 609
 610         switch (MIPSInst_FMA_FFMT(ir)) {
 611         case s_fmt:{            /* 0 */
 612
 613                 ieee754sp(*handler) (ieee754sp, ieee754sp, ieee754sp);
 614                 ieee754sp fd, fr, fs, ft;
 615                 u32 __user *va;
 616                 u32 val;
 617
 618                 switch (MIPSInst_FUNC(ir)) {
 619                 case lwxc1_op:
 620                         va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
 621                                 xcp->regs[MIPSInst_FT(ir)]);
 622
 623                         MIPS_FPU_EMU_INC_STATS(loads);
 624                         if (get_user(val, va)) {
 625                                 MIPS_FPU_EMU_INC_STATS(errors);
 626                                 return SIGBUS;
 627                         }
 628                         SITOREG(val, MIPSInst_FD(ir));
 629                         break;
 630
 631                 case swxc1_op:
 632                         va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
 633                                 xcp->regs[MIPSInst_FT(ir)]);
 634
 635                         MIPS_FPU_EMU_INC_STATS(stores);
 636
 637                         SIFROMREG(val, MIPSInst_FS(ir));
 638                         if (put_user(val, va)) {
 639                                 MIPS_FPU_EMU_INC_STATS(errors);
 640                                 return SIGBUS;
 641                         }
 642                         break;
 643
 644                 case madd_s_op:
 645                         handler = fpemu_sp_madd;
 646                         goto scoptop;
 647                 case msub_s_op:
 648                         handler = fpemu_sp_msub;
 649                         goto scoptop;
 650                 case nmadd_s_op:
 651                         handler = fpemu_sp_nmadd;
 652                         goto scoptop;
 653                 case nmsub_s_op:
 654                         handler = fpemu_sp_nmsub;
 655                         goto scoptop;
 656
 657                       scoptop:
 658                         SPFROMREG(fr, MIPSInst_FR(ir));
 659                         SPFROMREG(fs, MIPSInst_FS(ir));
 660                         SPFROMREG(ft, MIPSInst_FT(ir));
 661                         fd = (*handler) (fr, fs, ft);
 662                         SPTOREG(fd, MIPSInst_FD(ir));
 663
 664                       copcsr:
 665                         if (ieee754_cxtest(IEEE754_INEXACT))
 666                                 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
 667                         if (ieee754_cxtest(IEEE754_UNDERFLOW))
 668                                 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
 669                         if (ieee754_cxtest(IEEE754_OVERFLOW))
 670                                 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
 671                         if (ieee754_cxtest(IEEE754_INVALID_OPERATION))
 672                                 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
 673
 674                         ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
 675                         if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
 676                                 /*printk ("SIGFPE: fpu csr = %08x\n",
 677                                    ctx->fcr31); */
 678                                 return SIGFPE;
 679                         }
 680
 681                         break;
 682
 683                 default:
 684                         return SIGILL;
 685                 }
 686                 break;
 687         }
 688
 689         case d_fmt:{            /* 1 */
 690                 ieee754dp(*handler) (ieee754dp, ieee754dp, ieee754dp);
 691                 ieee754dp fd, fr, fs, ft;
 692                 u64 __user *va;
 693                 u64 val;
 694
 695                 switch (MIPSInst_FUNC(ir)) {
 696                 case ldxc1_op:
 697                         va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
 698                                 xcp->regs[MIPSInst_FT(ir)]);
 699
 700                         MIPS_FPU_EMU_INC_STATS(loads);
 701                         if (get_user(val, va)) {
 702                                 MIPS_FPU_EMU_INC_STATS(errors);
 703                                 return SIGBUS;
 704                         }
 705                         DITOREG(val, MIPSInst_FD(ir));
 706                         break;
 707
 708                 case sdxc1_op:
 709                         va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
 710                                 xcp->regs[MIPSInst_FT(ir)]);
 711
 712                         MIPS_FPU_EMU_INC_STATS(stores);
 713                         DIFROMREG(val, MIPSInst_FS(ir));
 714                         if (put_user(val, va)) {
 715                                 MIPS_FPU_EMU_INC_STATS(errors);
 716                                 return SIGBUS;
 717                         }
 718                         break;
 719
 720                 case madd_d_op:
 721                         handler = fpemu_dp_madd;
 722                         goto dcoptop;
 723                 case msub_d_op:
 724                         handler = fpemu_dp_msub;
 725                         goto dcoptop;
 726                 case nmadd_d_op:
 727                         handler = fpemu_dp_nmadd;
 728                         goto dcoptop;
 729                 case nmsub_d_op:
 730                         handler = fpemu_dp_nmsub;
 731                         goto dcoptop;
 732
 733                       dcoptop:
 734                         DPFROMREG(fr, MIPSInst_FR(ir));
 735                         DPFROMREG(fs, MIPSInst_FS(ir));
 736                         DPFROMREG(ft, MIPSInst_FT(ir));
 737                         fd = (*handler) (fr, fs, ft);
 738                         DPTOREG(fd, MIPSInst_FD(ir));
 739                         goto copcsr;
 740
 741                 default:
 742                         return SIGILL;
 743                 }
 744                 break;
 745         }
 746
 747         case 0x7:               /* 7 */
 748                 if (MIPSInst_FUNC(ir) != pfetch_op) {
 749                         return SIGILL;
 750                 }
 751                 /* ignore prefx operation */
 752                 break;
 753
 754         default:
 755                 return SIGILL;
 756         }
 757
 758         return 0;
 759 }
 760 #endif
 761
 762
 763
 764 /*
 765  * Emulate a single COP1 arithmetic instruction.
 766  */
 767 static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
 768         mips_instruction ir)
 769 {
 770         int rfmt;               /* resulting format */
 771         unsigned rcsr = 0;      /* resulting csr */
 772         unsigned cond;
 773         union {
 774                 ieee754dp d;
 775                 ieee754sp s;
 776                 int w;
 777 #ifdef __mips64
 778                 s64 l;
 779 #endif
 780         } rv;                   /* resulting value */
 781
 782         MIPS_FPU_EMU_INC_STATS(cp1ops);
 783         switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) {
 784         case s_fmt:{            /* 0 */
 785                 union {
 786                         ieee754sp(*b) (ieee754sp, ieee754sp);
 787                         ieee754sp(*u) (ieee754sp);
 788                 } handler;
 789
 790                 switch (MIPSInst_FUNC(ir)) {
 791                         /* binary ops */
 792                 case fadd_op:
 793                         handler.b = ieee754sp_add;
 794                         goto scopbop;
 795                 case fsub_op:
 796                         handler.b = ieee754sp_sub;
 797                         goto scopbop;
 798                 case fmul_op:
 799                         handler.b = ieee754sp_mul;
 800                         goto scopbop;
 801                 case fdiv_op:
 802                         handler.b = ieee754sp_div;
 803                         goto scopbop;
 804
 805                         /* unary  ops */
 806 #if __mips >= 2 || defined(__mips64)
 807                 case fsqrt_op:
 808                         handler.u = ieee754sp_sqrt;
 809                         goto scopuop;
 810 #endif
 811 #if __mips >= 4 && __mips != 32
 812                 case frsqrt_op:
 813                         handler.u = fpemu_sp_rsqrt;
 814                         goto scopuop;
 815                 case frecip_op:
 816                         handler.u = fpemu_sp_recip;
 817                         goto scopuop;
 818 #endif
 819 #if __mips >= 4
 820                 case fmovc_op:
 821                         cond = fpucondbit[MIPSInst_FT(ir) >> 2];
 822                         if (((ctx->fcr31 & cond) != 0) !=
 823                                 ((MIPSInst_FT(ir) & 1) != 0))
 824                                 return 0;
 825                         SPFROMREG(rv.s, MIPSInst_FS(ir));
 826                         break;
 827                 case fmovz_op:
 828                         if (xcp->regs[MIPSInst_FT(ir)] != 0)
 829                                 return 0;
 830                         SPFROMREG(rv.s, MIPSInst_FS(ir));
 831                         break;
 832                 case fmovn_op:
 833                         if (xcp->regs[MIPSInst_FT(ir)] == 0)
 834                                 return 0;
 835                         SPFROMREG(rv.s, MIPSInst_FS(ir));
 836                         break;
 837 #endif
 838                 case fabs_op:
 839                         handler.u = ieee754sp_abs;
 840                         goto scopuop;
 841                 case fneg_op:
 842                         handler.u = ieee754sp_neg;
 843                         goto scopuop;
 844                 case fmov_op:
 845                         /* an easy one */
 846                         SPFROMREG(rv.s, MIPSInst_FS(ir));
 847                         goto copcsr;
 848
 849                         /* binary op on handler */
 850                       scopbop:
 851                         {
 852                                 ieee754sp fs, ft;
 853
 854                                 SPFROMREG(fs, MIPSInst_FS(ir));
 855                                 SPFROMREG(ft, MIPSInst_FT(ir));
 856
 857                                 rv.s = (*handler.b) (fs, ft);
 858                                 goto copcsr;
 859                         }
 860                       scopuop:
 861                         {
 862                                 ieee754sp fs;
 863
 864                                 SPFROMREG(fs, MIPSInst_FS(ir));
 865                                 rv.s = (*handler.u) (fs);
 866                                 goto copcsr;
 867                         }
 868                       copcsr:
 869                         if (ieee754_cxtest(IEEE754_INEXACT))
 870                                 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
 871                         if (ieee754_cxtest(IEEE754_UNDERFLOW))
 872                                 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
 873                         if (ieee754_cxtest(IEEE754_OVERFLOW))
 874                                 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
 875                         if (ieee754_cxtest(IEEE754_ZERO_DIVIDE))
 876                                 rcsr |= FPU_CSR_DIV_X | FPU_CSR_DIV_S;
 877                         if (ieee754_cxtest(IEEE754_INVALID_OPERATION))
 878                                 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
 879                         break;
 880
 881                         /* unary conv ops */
 882                 case fcvts_op:
 883                         return SIGILL;  /* not defined */
 884                 case fcvtd_op:{
 885                         ieee754sp fs;
 886
 887                         SPFROMREG(fs, MIPSInst_FS(ir));
 888                         rv.d = ieee754dp_fsp(fs);
 889                         rfmt = d_fmt;
 890                         goto copcsr;
 891                 }
 892                 case fcvtw_op:{
 893                         ieee754sp fs;
 894
 895                         SPFROMREG(fs, MIPSInst_FS(ir));
 896                         rv.w = ieee754sp_tint(fs);
 897                         rfmt = w_fmt;
 898                         goto copcsr;
 899                 }
 900
 901 #if __mips >= 2 || defined(__mips64)
 902                 case fround_op:
 903                 case ftrunc_op:
 904                 case fceil_op:
 905                 case ffloor_op:{
 906                         unsigned int oldrm = ieee754_csr.rm;
 907                         ieee754sp fs;
 908
 909                         SPFROMREG(fs, MIPSInst_FS(ir));
 910                         ieee754_csr.rm = ieee_rm[MIPSInst_FUNC(ir) & 0x3];
 911                         rv.w = ieee754sp_tint(fs);
 912                         ieee754_csr.rm = oldrm;
 913                         rfmt = w_fmt;
 914                         goto copcsr;
 915                 }
 916 #endif /* __mips >= 2 */
 917
 918 #if defined(__mips64)
 919                 case fcvtl_op:{
 920                         ieee754sp fs;
 921
 922                         SPFROMREG(fs, MIPSInst_FS(ir));
 923                         rv.l = ieee754sp_tlong(fs);
 924                         rfmt = l_fmt;
 925                         goto copcsr;
 926                 }
 927
 928                 case froundl_op:
 929                 case ftruncl_op:
 930                 case fceill_op:
 931                 case ffloorl_op:{
 932                         unsigned int oldrm = ieee754_csr.rm;
 933                         ieee754sp fs;
 934
 935                         SPFROMREG(fs, MIPSInst_FS(ir));
 936                         ieee754_csr.rm = ieee_rm[MIPSInst_FUNC(ir) & 0x3];
 937                         rv.l = ieee754sp_tlong(fs);
 938                         ieee754_csr.rm = oldrm;
 939                         rfmt = l_fmt;
 940                         goto copcsr;
 941                 }
 942 #endif /* defined(__mips64) */
 943
 944                 default:
 945                         if (MIPSInst_FUNC(ir) >= fcmp_op) {
 946                                 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
 947                                 ieee754sp fs, ft;
 948
 949                                 SPFROMREG(fs, MIPSInst_FS(ir));
 950                                 SPFROMREG(ft, MIPSInst_FT(ir));
 951                                 rv.w = ieee754sp_cmp(fs, ft,
 952                                         cmptab[cmpop & 0x7], cmpop & 0x8);
 953                                 rfmt = -1;
 954                                 if ((cmpop & 0x8) && ieee754_cxtest
 955                                         (IEEE754_INVALID_OPERATION))
 956                                         rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
 957                                 else
 958                                         goto copcsr;
 959
 960                         }
 961                         else {
 962                                 return SIGILL;
 963                         }
 964                         break;
 965                 }
 966                 break;
 967         }
 968
 969         case d_fmt:{
 970                 union {
 971                         ieee754dp(*b) (ieee754dp, ieee754dp);
 972                         ieee754dp(*u) (ieee754dp);
 973                 } handler;
 974
 975                 switch (MIPSInst_FUNC(ir)) {
 976                         /* binary ops */
 977                 case fadd_op:
 978                         handler.b = ieee754dp_add;
 979                         goto dcopbop;
 980                 case fsub_op:
 981                         handler.b = ieee754dp_sub;
 982                         goto dcopbop;
 983                 case fmul_op:
 984                         handler.b = ieee754dp_mul;
 985                         goto dcopbop;
 986                 case fdiv_op:
 987                         handler.b = ieee754dp_div;
 988                         goto dcopbop;
 989
 990                         /* unary  ops */
 991 #if __mips >= 2 || defined(__mips64)
 992                 case fsqrt_op:
 993                         handler.u = ieee754dp_sqrt;
 994                         goto dcopuop;
 995 #endif
 996 #if __mips >= 4 && __mips != 32
 997                 case frsqrt_op:
 998                         handler.u = fpemu_dp_rsqrt;
 999                         goto dcopuop;
1000                 case frecip_op:
1001                         handler.u = fpemu_dp_recip;
1002                         goto dcopuop;
1003 #endif
1004 #if __mips >= 4
1005                 case fmovc_op:
1006                         cond = fpucondbit[MIPSInst_FT(ir) >> 2];
1007                         if (((ctx->fcr31 & cond) != 0) !=
1008                                 ((MIPSInst_FT(ir) & 1) != 0))
1009                                 return 0;
1010                         DPFROMREG(rv.d, MIPSInst_FS(ir));
1011                         break;
1012                 case fmovz_op:
1013                         if (xcp->regs[MIPSInst_FT(ir)] != 0)
1014                                 return 0;
1015                         DPFROMREG(rv.d, MIPSInst_FS(ir));
1016                         break;
1017                 case fmovn_op:
1018                         if (xcp->regs[MIPSInst_FT(ir)] == 0)
1019                                 return 0;
1020                         DPFROMREG(rv.d, MIPSInst_FS(ir));
1021                         break;
1022 #endif
1023                 case fabs_op:
1024                         handler.u = ieee754dp_abs;
1025                         goto dcopuop;
1026
1027                 case fneg_op:
1028                         handler.u = ieee754dp_neg;
1029                         goto dcopuop;
1030
1031                 case fmov_op:
1032                         /* an easy one */
1033                         DPFROMREG(rv.d, MIPSInst_FS(ir));
1034                         goto copcsr;
1035
1036                         /* binary op on handler */
1037                       dcopbop:{
1038                                 ieee754dp fs, ft;
1039
1040                                 DPFROMREG(fs, MIPSInst_FS(ir));
1041                                 DPFROMREG(ft, MIPSInst_FT(ir));
1042
1043                                 rv.d = (*handler.b) (fs, ft);
1044                                 goto copcsr;
1045                         }
1046                       dcopuop:{
1047                                 ieee754dp fs;
1048
1049                                 DPFROMREG(fs, MIPSInst_FS(ir));
1050                                 rv.d = (*handler.u) (fs);
1051                                 goto copcsr;
1052                         }
1053
1054                         /* unary conv ops */
1055                 case fcvts_op:{
1056                         ieee754dp fs;
1057
1058                         DPFROMREG(fs, MIPSInst_FS(ir));
1059                         rv.s = ieee754sp_fdp(fs);
1060                         rfmt = s_fmt;
1061                         goto copcsr;
1062                 }
1063                 case fcvtd_op:
1064                         return SIGILL;  /* not defined */
1065
1066                 case fcvtw_op:{
1067                         ieee754dp fs;
1068
1069                         DPFROMREG(fs, MIPSInst_FS(ir));
1070                         rv.w = ieee754dp_tint(fs);      /* wrong */
1071                         rfmt = w_fmt;
1072                         goto copcsr;
1073                 }
1074
1075 #if __mips >= 2 || defined(__mips64)
1076                 case fround_op:
1077                 case ftrunc_op:
1078                 case fceil_op:
1079                 case ffloor_op:{
1080                         unsigned int oldrm = ieee754_csr.rm;
1081                         ieee754dp fs;
1082
1083                         DPFROMREG(fs, MIPSInst_FS(ir));
1084                         ieee754_csr.rm = ieee_rm[MIPSInst_FUNC(ir) & 0x3];
1085                         rv.w = ieee754dp_tint(fs);
1086                         ieee754_csr.rm = oldrm;
1087                         rfmt = w_fmt;
1088                         goto copcsr;
1089                 }
1090 #endif
1091
1092 #if defined(__mips64)
1093                 case fcvtl_op:{
1094                         ieee754dp fs;
1095
1096                         DPFROMREG(fs, MIPSInst_FS(ir));
1097                         rv.l = ieee754dp_tlong(fs);
1098                         rfmt = l_fmt;
1099                         goto copcsr;
1100                 }
1101
1102                 case froundl_op:
1103                 case ftruncl_op:
1104                 case fceill_op:
1105                 case ffloorl_op:{
1106                         unsigned int oldrm = ieee754_csr.rm;
1107                         ieee754dp fs;
1108
1109                         DPFROMREG(fs, MIPSInst_FS(ir));
1110                         ieee754_csr.rm = ieee_rm[MIPSInst_FUNC(ir) & 0x3];
1111                         rv.l = ieee754dp_tlong(fs);
1112                         ieee754_csr.rm = oldrm;
1113                         rfmt = l_fmt;
1114                         goto copcsr;
1115                 }
1116 #endif /* __mips >= 3 */
1117
1118                 default:
1119                         if (MIPSInst_FUNC(ir) >= fcmp_op) {
1120                                 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
1121                                 ieee754dp fs, ft;
1122
1123                                 DPFROMREG(fs, MIPSInst_FS(ir));
1124                                 DPFROMREG(ft, MIPSInst_FT(ir));
1125                                 rv.w = ieee754dp_cmp(fs, ft,
1126                                         cmptab[cmpop & 0x7], cmpop & 0x8);
1127                                 rfmt = -1;
1128                                 if ((cmpop & 0x8)
1129                                         &&
1130                                         ieee754_cxtest
1131                                         (IEEE754_INVALID_OPERATION))
1132                                         rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
1133                                 else
1134                                         goto copcsr;
1135
1136                         }
1137                         else {
1138                                 return SIGILL;
1139                         }
1140                         break;
1141                 }
1142                 break;
1143         }
1144
1145         case w_fmt:{
1146                 ieee754sp fs;
1147
1148                 switch (MIPSInst_FUNC(ir)) {
1149                 case fcvts_op:
1150                         /* convert word to single precision real */
1151                         SPFROMREG(fs, MIPSInst_FS(ir));
1152                         rv.s = ieee754sp_fint(fs.bits);
1153                         rfmt = s_fmt;
1154                         goto copcsr;
1155                 case fcvtd_op:
1156                         /* convert word to double precision real */
1157                         SPFROMREG(fs, MIPSInst_FS(ir));
1158                         rv.d = ieee754dp_fint(fs.bits);
1159                         rfmt = d_fmt;
1160                         goto copcsr;
1161                 default:
1162                         return SIGILL;
1163                 }
1164                 break;
1165         }
1166
1167 #if defined(__mips64)
1168         case l_fmt:{
1169                 switch (MIPSInst_FUNC(ir)) {
1170                 case fcvts_op:
1171                         /* convert long to single precision real */
1172                         rv.s = ieee754sp_flong(ctx->fpr[MIPSInst_FS(ir)]);
1173                         rfmt = s_fmt;
1174                         goto copcsr;
1175                 case fcvtd_op:
1176                         /* convert long to double precision real */
1177                         rv.d = ieee754dp_flong(ctx->fpr[MIPSInst_FS(ir)]);
1178                         rfmt = d_fmt;
1179                         goto copcsr;
1180                 default:
1181                         return SIGILL;
1182                 }
1183                 break;
1184         }
1185 #endif
1186
1187         default:
1188                 return SIGILL;
1189         }
1190
1191         /*
1192          * Update the fpu CSR register for this operation.
1193          * If an exception is required, generate a tidy SIGFPE exception,
1194          * without updating the result register.
1195          * Note: cause exception bits do not accumulate, they are rewritten
1196          * for each op; only the flag/sticky bits accumulate.
1197          */
1198         ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
1199         if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1200                 /*printk ("SIGFPE: fpu csr = %08x\n",ctx->fcr31); */
1201                 return SIGFPE;
1202         }
1203
1204         /*
1205          * Now we can safely write the result back to the register file.
1206          */
1207         switch (rfmt) {
1208         case -1:{
1209 #if __mips >= 4
1210                 cond = fpucondbit[MIPSInst_FD(ir) >> 2];
1211 #else
1212                 cond = FPU_CSR_COND;
1213 #endif
1214                 if (rv.w)
1215                         ctx->fcr31 |= cond;
1216                 else
1217                         ctx->fcr31 &= ~cond;
1218                 break;
1219         }
1220         case d_fmt:
1221                 DPTOREG(rv.d, MIPSInst_FD(ir));
1222                 break;
1223         case s_fmt:
1224                 SPTOREG(rv.s, MIPSInst_FD(ir));
1225                 break;
1226         case w_fmt:
1227                 SITOREG(rv.w, MIPSInst_FD(ir));
1228                 break;
1229 #if defined(__mips64)
1230         case l_fmt:
1231                 DITOREG(rv.l, MIPSInst_FD(ir));
1232                 break;
1233 #endif
1234         default:
1235                 return SIGILL;
1236         }
1237
1238         return 0;
1239 }
1240
1241 int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1242         int has_fpu)
1243 {
1244         unsigned long oldepc, prevepc;
1245         mips_instruction insn;
1246         int sig = 0;
1247
1248         oldepc = xcp->cp0_epc;
1249         do {
1250                 prevepc = xcp->cp0_epc;
1251
1252                 if (get_user(insn, (mips_instruction __user *) xcp->cp0_epc)) {
1253                         MIPS_FPU_EMU_INC_STATS(errors);
1254                         return SIGBUS;
1255                 }
1256                 if (insn == 0)
1257                         xcp->cp0_epc += 4;      /* skip nops */
1258                 else {
1259                         /*
1260                          * The 'ieee754_csr' is an alias of
1261                          * ctx->fcr31.  No need to copy ctx->fcr31 to
1262                          * ieee754_csr.  But ieee754_csr.rm is ieee
1263                          * library modes. (not mips rounding mode)
1264                          */
1265                         /* convert to ieee library modes */
1266                         ieee754_csr.rm = ieee_rm[ieee754_csr.rm];
1267                         sig = cop1Emulate(xcp, ctx);
1268                         /* revert to mips rounding mode */
1269                         ieee754_csr.rm = mips_rm[ieee754_csr.rm];
1270                 }
1271
1272                 if (has_fpu)
1273                         break;
1274                 if (sig)
1275                         break;
1276
1277                 cond_resched();
1278         } while (xcp->cp0_epc > prevepc);
1279
1280         /* SIGILL indicates a non-fpu instruction */
1281         if (sig == SIGILL && xcp->cp0_epc != oldepc)
1282                 /* but if epc has advanced, then ignore it */
1283                 sig = 0;
1284
1285         return sig;
1286 }
1287
1288 #ifdef CONFIG_DEBUG_FS
1289
1290 static int fpuemu_stat_get(void *data, u64 *val)
1291 {
1292         int cpu;
1293         unsigned long sum = 0;
1294         for_each_online_cpu(cpu) {
1295                 struct mips_fpu_emulator_stats *ps;
1296                 local_t *pv;
1297                 ps = &per_cpu(fpuemustats, cpu);
1298                 pv = (void *)ps + (unsigned long)data;
1299                 sum += local_read(pv);
1300         }
1301         *val = sum;
1302         return 0;
1303 }
1304 DEFINE_SIMPLE_ATTRIBUTE(fops_fpuemu_stat, fpuemu_stat_get, NULL, "%llu\n");
1305
1306 extern struct dentry *mips_debugfs_dir;
1307 static int __init debugfs_fpuemu(void)
1308 {
1309         struct dentry *d, *dir;
1310
1311         if (!mips_debugfs_dir)
1312                 return -ENODEV;
1313         dir = debugfs_create_dir("fpuemustats", mips_debugfs_dir);
1314         if (!dir)
1315                 return -ENOMEM;
1316
1317 #define FPU_STAT_CREATE(M)                                              \
1318         do {                                                            \
1319                 d = debugfs_create_file(#M , S_IRUGO, dir,              \
1320                         (void *)offsetof(struct mips_fpu_emulator_stats, M), \
1321                         &fops_fpuemu_stat);                             \
1322                 if (!d)                                                 \
1323                         return -ENOMEM;                                 \
1324         } while (0)
1325
1326         FPU_STAT_CREATE(emulated);
1327         FPU_STAT_CREATE(loads);
1328         FPU_STAT_CREATE(stores);
1329         FPU_STAT_CREATE(cp1ops);
1330         FPU_STAT_CREATE(cp1xops);
1331         FPU_STAT_CREATE(errors);
1332
1333         return 0;
1334 }
1335 __initcall(debugfs_fpuemu);
1336 #endif