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   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/debugfs.h>
  39
  40 #include <asm/inst.h>
  41 #include <asm/bootinfo.h>
  42 #include <asm/processor.h>
  43 #include <asm/ptrace.h>
  44 #include <asm/signal.h>
  45 #include <asm/mipsregs.h>
  46 #include <asm/fpu_emulator.h>
  47 #include <asm/uaccess.h>
  48 #include <asm/branch.h>
  49
  50 #include "ieee754.h"
  51
  52 /* Strap kernel emulator for full MIPS IV emulation */
  53
  54 #ifdef __mips
  55 #undef __mips
  56 #endif
  57 #define __mips 4
  58
  59 /* Function which emulates a floating point instruction. */
  60
  61 static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *,
  62         mips_instruction);
  63
  64 #if __mips >= 4 && __mips != 32
  65 static int fpux_emu(struct pt_regs *,
  66         struct mips_fpu_struct *, mips_instruction);
  67 #endif
  68
  69 /* Further private data for which no space exists in mips_fpu_struct */
  70
  71 struct mips_fpu_emulator_stats fpuemustats;
  72
  73 /* Control registers */
  74
  75 #define FPCREG_RID      0       /* $0  = revision id */
  76 #define FPCREG_CSR      31      /* $31 = csr */
  77
  78 /* Convert Mips rounding mode (0..3) to IEEE library modes. */
  79 static const unsigned char ieee_rm[4] = {
  80         [FPU_CSR_RN] = IEEE754_RN,
  81         [FPU_CSR_RZ] = IEEE754_RZ,
  82         [FPU_CSR_RU] = IEEE754_RU,
  83         [FPU_CSR_RD] = IEEE754_RD,
  84 };
  85 /* Convert IEEE library modes to Mips rounding mode (0..3). */
  86 static const unsigned char mips_rm[4] = {
  87         [IEEE754_RN] = FPU_CSR_RN,
  88         [IEEE754_RZ] = FPU_CSR_RZ,
  89         [IEEE754_RD] = FPU_CSR_RD,
  90         [IEEE754_RU] = FPU_CSR_RU,
  91 };
  92
  93 #if __mips >= 4
  94 /* convert condition code register number to csr bit */
  95 static const unsigned int fpucondbit[8] = {
  96         FPU_CSR_COND0,
  97         FPU_CSR_COND1,
  98         FPU_CSR_COND2,
  99         FPU_CSR_COND3,
 100         FPU_CSR_COND4,
 101         FPU_CSR_COND5,
 102         FPU_CSR_COND6,
 103         FPU_CSR_COND7
 104 };
 105 #endif
 106
 107
 108 /*
 109  * Redundant with logic already in kernel/branch.c,
 110  * embedded in compute_return_epc.  At some point,
 111  * a single subroutine should be used across both
 112  * modules.
 113  */
 114 static int isBranchInstr(mips_instruction * i)
 115 {
 116         switch (MIPSInst_OPCODE(*i)) {
 117         case spec_op:
 118                 switch (MIPSInst_FUNC(*i)) {
 119                 case jalr_op:
 120                 case jr_op:
 121                         return 1;
 122                 }
 123                 break;
 124
 125         case bcond_op:
 126                 switch (MIPSInst_RT(*i)) {
 127                 case bltz_op:
 128                 case bgez_op:
 129                 case bltzl_op:
 130                 case bgezl_op:
 131                 case bltzal_op:
 132                 case bgezal_op:
 133                 case bltzall_op:
 134                 case bgezall_op:
 135                         return 1;
 136                 }
 137                 break;
 138
 139         case j_op:
 140         case jal_op:
 141         case jalx_op:
 142         case beq_op:
 143         case bne_op:
 144         case blez_op:
 145         case bgtz_op:
 146         case beql_op:
 147         case bnel_op:
 148         case blezl_op:
 149         case bgtzl_op:
 150                 return 1;
 151
 152         case cop0_op:
 153         case cop1_op:
 154         case cop2_op:
 155         case cop1x_op:
 156                 if (MIPSInst_RS(*i) == bc_op)
 157                         return 1;
 158                 break;
 159         }
 160
 161         return 0;
 162 }
 163
 164 /*
 165  * In the Linux kernel, we support selection of FPR format on the
 166  * basis of the Status.FR bit.  This does imply that, if a full 32
 167  * FPRs are desired, there needs to be a flip-flop that can be written
 168  * to one at that bit position.  In any case, O32 MIPS ABI uses
 169  * only the even FPRs (Status.FR = 0).
 170  */
 171
 172 #define CP0_STATUS_FR_SUPPORT
 173
 174 #ifdef CP0_STATUS_FR_SUPPORT
 175 #define FR_BIT ST0_FR
 176 #else
 177 #define FR_BIT 0
 178 #endif
 179
 180 #define SIFROMREG(si, x) ((si) = \
 181                         (xcp->cp0_status & FR_BIT) || !(x & 1) ? \
 182                         (int)ctx->fpr[x] : \
 183                         (int)(ctx->fpr[x & ~1] >> 32 ))
 184 #define SITOREG(si, x)  (ctx->fpr[x & ~((xcp->cp0_status & FR_BIT) == 0)] = \
 185                         (xcp->cp0_status & FR_BIT) || !(x & 1) ? \
 186                         ctx->fpr[x & ~1] >> 32 << 32 | (u32)(si) : \
 187                         ctx->fpr[x & ~1] << 32 >> 32 | (u64)(si) << 32)
 188
 189 #define DIFROMREG(di, x) ((di) = \
 190                         ctx->fpr[x & ~((xcp->cp0_status & FR_BIT) == 0)])
 191 #define DITOREG(di, x)  (ctx->fpr[x & ~((xcp->cp0_status & FR_BIT) == 0)] \
 192                         = (di))
 193
 194 #define SPFROMREG(sp, x) SIFROMREG((sp).bits, x)
 195 #define SPTOREG(sp, x)  SITOREG((sp).bits, x)
 196 #define DPFROMREG(dp, x)        DIFROMREG((dp).bits, x)
 197 #define DPTOREG(dp, x)  DITOREG((dp).bits, x)
 198
 199 /*
 200  * Emulate the single floating point instruction pointed at by EPC.
 201  * Two instructions if the instruction is in a branch delay slot.
 202  */
 203
 204 static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx)
 205 {
 206         mips_instruction ir;
 207         unsigned long emulpc, contpc;
 208         unsigned int cond;
 209
 210         if (get_user(ir, (mips_instruction __user *) xcp->cp0_epc)) {
 211                 fpuemustats.errors++;
 212                 return SIGBUS;
 213         }
 214
 215         /* XXX NEC Vr54xx bug workaround */
 216         if ((xcp->cp0_cause & CAUSEF_BD) && !isBranchInstr(&ir))
 217                 xcp->cp0_cause &= ~CAUSEF_BD;
 218
 219         if (xcp->cp0_cause & CAUSEF_BD) {
 220                 /*
 221                  * The instruction to be emulated is in a branch delay slot
 222                  * which means that we have to  emulate the branch instruction
 223                  * BEFORE we do the cop1 instruction.
 224                  *
 225                  * This branch could be a COP1 branch, but in that case we
 226                  * would have had a trap for that instruction, and would not
 227                  * come through this route.
 228                  *
 229                  * Linux MIPS branch emulator operates on context, updating the
 230                  * cp0_epc.
 231                  */
 232                 emulpc = xcp->cp0_epc + 4;      /* Snapshot emulation target */
 233
 234                 if (__compute_return_epc(xcp)) {
 235 #ifdef CP1DBG
 236                         printk("failed to emulate branch at %p\n",
 237                                 (void *) (xcp->cp0_epc));
 238 #endif
 239                         return SIGILL;
 240                 }
 241                 if (get_user(ir, (mips_instruction __user *) emulpc)) {
 242                         fpuemustats.errors++;
 243                         return SIGBUS;
 244                 }
 245                 /* __compute_return_epc() will have updated cp0_epc */
 246                 contpc = xcp->cp0_epc;
 247                 /* In order not to confuse ptrace() et al, tweak context */
 248                 xcp->cp0_epc = emulpc - 4;
 249         } else {
 250                 emulpc = xcp->cp0_epc;
 251                 contpc = xcp->cp0_epc + 4;
 252         }
 253
 254       emul:
 255         fpuemustats.emulated++;
 256         switch (MIPSInst_OPCODE(ir)) {
 257         case ldc1_op:{
 258                 u64 __user *va = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
 259                         MIPSInst_SIMM(ir));
 260                 u64 val;
 261
 262                 fpuemustats.loads++;
 263                 if (get_user(val, va)) {
 264                         fpuemustats.errors++;
 265                         return SIGBUS;
 266                 }
 267                 DITOREG(val, MIPSInst_RT(ir));
 268                 break;
 269         }
 270
 271         case sdc1_op:{
 272                 u64 __user *va = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
 273                         MIPSInst_SIMM(ir));
 274                 u64 val;
 275
 276                 fpuemustats.stores++;
 277                 DIFROMREG(val, MIPSInst_RT(ir));
 278                 if (put_user(val, va)) {
 279                         fpuemustats.errors++;
 280                         return SIGBUS;
 281                 }
 282                 break;
 283         }
 284
 285         case lwc1_op:{
 286                 u32 __user *va = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
 287                         MIPSInst_SIMM(ir));
 288                 u32 val;
 289
 290                 fpuemustats.loads++;
 291                 if (get_user(val, va)) {
 292                         fpuemustats.errors++;
 293                         return SIGBUS;
 294                 }
 295                 SITOREG(val, MIPSInst_RT(ir));
 296                 break;
 297         }
 298
 299         case swc1_op:{
 300                 u32 __user *va = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
 301                         MIPSInst_SIMM(ir));
 302                 u32 val;
 303
 304                 fpuemustats.stores++;
 305                 SIFROMREG(val, MIPSInst_RT(ir));
 306                 if (put_user(val, va)) {
 307                         fpuemustats.errors++;
 308                         return SIGBUS;
 309                 }
 310                 break;
 311         }
 312
 313         case cop1_op:
 314                 switch (MIPSInst_RS(ir)) {
 315
 316 #if defined(__mips64)
 317                 case dmfc_op:
 318                         /* copregister fs -> gpr[rt] */
 319                         if (MIPSInst_RT(ir) != 0) {
 320                                 DIFROMREG(xcp->regs[MIPSInst_RT(ir)],
 321                                         MIPSInst_RD(ir));
 322                         }
 323                         break;
 324
 325                 case dmtc_op:
 326                         /* copregister fs <- rt */
 327                         DITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
 328                         break;
 329 #endif
 330
 331                 case mfc_op:
 332                         /* copregister rd -> gpr[rt] */
 333                         if (MIPSInst_RT(ir) != 0) {
 334                                 SIFROMREG(xcp->regs[MIPSInst_RT(ir)],
 335                                         MIPSInst_RD(ir));
 336                         }
 337                         break;
 338
 339                 case mtc_op:
 340                         /* copregister rd <- rt */
 341                         SITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
 342                         break;
 343
 344                 case cfc_op:{
 345                         /* cop control register rd -> gpr[rt] */
 346                         u32 value;
 347
 348                         if (MIPSInst_RD(ir) == FPCREG_CSR) {
 349                                 value = ctx->fcr31;
 350                                 value = (value & ~0x3) | mips_rm[value & 0x3];
 351 #ifdef CSRTRACE
 352                                 printk("%p gpr[%d]<-csr=%08x\n",
 353                                         (void *) (xcp->cp0_epc),
 354                                         MIPSInst_RT(ir), value);
 355 #endif
 356                         }
 357                         else if (MIPSInst_RD(ir) == FPCREG_RID)
 358                                 value = 0;
 359                         else
 360                                 value = 0;
 361                         if (MIPSInst_RT(ir))
 362                                 xcp->regs[MIPSInst_RT(ir)] = value;
 363                         break;
 364                 }
 365
 366                 case ctc_op:{
 367                         /* copregister rd <- rt */
 368                         u32 value;
 369
 370                         if (MIPSInst_RT(ir) == 0)
 371                                 value = 0;
 372                         else
 373                                 value = xcp->regs[MIPSInst_RT(ir)];
 374
 375                         /* we only have one writable control reg
 376                          */
 377                         if (MIPSInst_RD(ir) == FPCREG_CSR) {
 378 #ifdef CSRTRACE
 379                                 printk("%p gpr[%d]->csr=%08x\n",
 380                                         (void *) (xcp->cp0_epc),
 381                                         MIPSInst_RT(ir), value);
 382 #endif
 383                                 value &= (FPU_CSR_FLUSH | FPU_CSR_ALL_E | FPU_CSR_ALL_S | 0x03);
 384                                 ctx->fcr31 &= ~(FPU_CSR_FLUSH | FPU_CSR_ALL_E | FPU_CSR_ALL_S | 0x03);
 385                                 /* convert to ieee library modes */
 386                                 ctx->fcr31 |= (value & ~0x3) | ieee_rm[value & 0x3];
 387                         }
 388                         if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
 389                                 return SIGFPE;
 390                         }
 391                         break;
 392                 }
 393
 394                 case bc_op:{
 395                         int likely = 0;
 396
 397                         if (xcp->cp0_cause & CAUSEF_BD)
 398                                 return SIGILL;
 399
 400 #if __mips >= 4
 401                         cond = ctx->fcr31 & fpucondbit[MIPSInst_RT(ir) >> 2];
 402 #else
 403                         cond = ctx->fcr31 & FPU_CSR_COND;
 404 #endif
 405                         switch (MIPSInst_RT(ir) & 3) {
 406                         case bcfl_op:
 407                                 likely = 1;
 408                         case bcf_op:
 409                                 cond = !cond;
 410                                 break;
 411                         case bctl_op:
 412                                 likely = 1;
 413                         case bct_op:
 414                                 break;
 415                         default:
 416                                 /* thats an illegal instruction */
 417                                 return SIGILL;
 418                         }
 419
 420                         xcp->cp0_cause |= CAUSEF_BD;
 421                         if (cond) {
 422                                 /* branch taken: emulate dslot
 423                                  * instruction
 424                                  */
 425                                 xcp->cp0_epc += 4;
 426                                 contpc = (xcp->cp0_epc +
 427                                         (MIPSInst_SIMM(ir) << 2));
 428
 429                                 if (get_user(ir,
 430                                     (mips_instruction __user *) xcp->cp0_epc)) {
 431                                         fpuemustats.errors++;
 432                                         return SIGBUS;
 433                                 }
 434
 435                                 switch (MIPSInst_OPCODE(ir)) {
 436                                 case lwc1_op:
 437                                 case swc1_op:
 438 #if (__mips >= 2 || defined(__mips64))
 439                                 case ldc1_op:
 440                                 case sdc1_op:
 441 #endif
 442                                 case cop1_op:
 443 #if __mips >= 4 && __mips != 32
 444                                 case cop1x_op:
 445 #endif
 446                                         /* its one of ours */
 447                                         goto emul;
 448 #if __mips >= 4
 449                                 case spec_op:
 450                                         if (MIPSInst_FUNC(ir) == movc_op)
 451                                                 goto emul;
 452                                         break;
 453 #endif
 454                                 }
 455
 456                                 /*
 457                                  * Single step the non-cp1
 458                                  * instruction in the dslot
 459                                  */
 460                                 return mips_dsemul(xcp, ir, contpc);
 461                         }
 462                         else {
 463                                 /* branch not taken */
 464                                 if (likely) {
 465                                         /*
 466                                          * branch likely nullifies
 467                                          * dslot if not taken
 468                                          */
 469                                         xcp->cp0_epc += 4;
 470                                         contpc += 4;
 471                                         /*
 472                                          * else continue & execute
 473                                          * dslot as normal insn
 474                                          */
 475                                 }
 476                         }
 477                         break;
 478                 }
 479
 480                 default:
 481                         if (!(MIPSInst_RS(ir) & 0x10))
 482                                 return SIGILL;
 483                         {
 484                                 int sig;
 485
 486                                 /* a real fpu computation instruction */
 487                                 if ((sig = fpu_emu(xcp, ctx, ir)))
 488                                         return sig;
 489                         }
 490                 }
 491                 break;
 492
 493 #if __mips >= 4 && __mips != 32
 494         case cop1x_op:{
 495                 int sig;
 496
 497                 if ((sig = fpux_emu(xcp, ctx, ir)))
 498                         return sig;
 499                 break;
 500         }
 501 #endif
 502
 503 #if __mips >= 4
 504         case spec_op:
 505                 if (MIPSInst_FUNC(ir) != movc_op)
 506                         return SIGILL;
 507                 cond = fpucondbit[MIPSInst_RT(ir) >> 2];
 508                 if (((ctx->fcr31 & cond) != 0) == ((MIPSInst_RT(ir) & 1) != 0))
 509                         xcp->regs[MIPSInst_RD(ir)] =
 510                                 xcp->regs[MIPSInst_RS(ir)];
 511                 break;
 512 #endif
 513
 514         default:
 515                 return SIGILL;
 516         }
 517
 518         /* we did it !! */
 519         xcp->cp0_epc = contpc;
 520         xcp->cp0_cause &= ~CAUSEF_BD;
 521
 522         return 0;
 523 }
 524
 525 /*
 526  * Conversion table from MIPS compare ops 48-63
 527  * cond = ieee754dp_cmp(x,y,IEEE754_UN,sig);
 528  */
 529 static const unsigned char cmptab[8] = {
 530         0,                      /* cmp_0 (sig) cmp_sf */
 531         IEEE754_CUN,            /* cmp_un (sig) cmp_ngle */
 532         IEEE754_CEQ,            /* cmp_eq (sig) cmp_seq */
 533         IEEE754_CEQ | IEEE754_CUN,      /* cmp_ueq (sig) cmp_ngl  */
 534         IEEE754_CLT,            /* cmp_olt (sig) cmp_lt */
 535         IEEE754_CLT | IEEE754_CUN,      /* cmp_ult (sig) cmp_nge */
 536         IEEE754_CLT | IEEE754_CEQ,      /* cmp_ole (sig) cmp_le */
 537         IEEE754_CLT | IEEE754_CEQ | IEEE754_CUN,        /* cmp_ule (sig) cmp_ngt */
 538 };
 539
 540
 541 #if __mips >= 4 && __mips != 32
 542
 543 /*
 544  * Additional MIPS4 instructions
 545  */
 546
 547 #define DEF3OP(name, p, f1, f2, f3) \
 548 static ieee754##p fpemu_##p##_##name(ieee754##p r, ieee754##p s, \
 549     ieee754##p t) \
 550 { \
 551         struct _ieee754_csr ieee754_csr_save; \
 552         s = f1(s, t); \
 553         ieee754_csr_save = ieee754_csr; \
 554         s = f2(s, r); \
 555         ieee754_csr_save.cx |= ieee754_csr.cx; \
 556         ieee754_csr_save.sx |= ieee754_csr.sx; \
 557         s = f3(s); \
 558         ieee754_csr.cx |= ieee754_csr_save.cx; \
 559         ieee754_csr.sx |= ieee754_csr_save.sx; \
 560         return s; \
 561 }
 562
 563 static ieee754dp fpemu_dp_recip(ieee754dp d)
 564 {
 565         return ieee754dp_div(ieee754dp_one(0), d);
 566 }
 567
 568 static ieee754dp fpemu_dp_rsqrt(ieee754dp d)
 569 {
 570         return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d));
 571 }
 572
 573 static ieee754sp fpemu_sp_recip(ieee754sp s)
 574 {
 575         return ieee754sp_div(ieee754sp_one(0), s);
 576 }
 577
 578 static ieee754sp fpemu_sp_rsqrt(ieee754sp s)
 579 {
 580         return ieee754sp_div(ieee754sp_one(0), ieee754sp_sqrt(s));
 581 }
 582
 583 DEF3OP(madd, sp, ieee754sp_mul, ieee754sp_add, );
 584 DEF3OP(msub, sp, ieee754sp_mul, ieee754sp_sub, );
 585 DEF3OP(nmadd, sp, ieee754sp_mul, ieee754sp_add, ieee754sp_neg);
 586 DEF3OP(nmsub, sp, ieee754sp_mul, ieee754sp_sub, ieee754sp_neg);
 587 DEF3OP(madd, dp, ieee754dp_mul, ieee754dp_add, );
 588 DEF3OP(msub, dp, ieee754dp_mul, ieee754dp_sub, );
 589 DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg);
 590 DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg);
 591
 592 static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
 593         mips_instruction ir)
 594 {
 595         unsigned rcsr = 0;      /* resulting csr */
 596
 597         fpuemustats.cp1xops++;
 598
 599         switch (MIPSInst_FMA_FFMT(ir)) {
 600         case s_fmt:{            /* 0 */
 601
 602                 ieee754sp(*handler) (ieee754sp, ieee754sp, ieee754sp);
 603                 ieee754sp fd, fr, fs, ft;
 604                 u32 __user *va;
 605                 u32 val;
 606
 607                 switch (MIPSInst_FUNC(ir)) {
 608                 case lwxc1_op:
 609                         va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
 610                                 xcp->regs[MIPSInst_FT(ir)]);
 611
 612                         fpuemustats.loads++;
 613                         if (get_user(val, va)) {
 614                                 fpuemustats.errors++;
 615                                 return SIGBUS;
 616                         }
 617                         SITOREG(val, MIPSInst_FD(ir));
 618                         break;
 619
 620                 case swxc1_op:
 621                         va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
 622                                 xcp->regs[MIPSInst_FT(ir)]);
 623
 624                         fpuemustats.stores++;
 625
 626                         SIFROMREG(val, MIPSInst_FS(ir));
 627                         if (put_user(val, va)) {
 628                                 fpuemustats.errors++;
 629                                 return SIGBUS;
 630                         }
 631                         break;
 632
 633                 case madd_s_op:
 634                         handler = fpemu_sp_madd;
 635                         goto scoptop;
 636                 case msub_s_op:
 637                         handler = fpemu_sp_msub;
 638                         goto scoptop;
 639                 case nmadd_s_op:
 640                         handler = fpemu_sp_nmadd;
 641                         goto scoptop;
 642                 case nmsub_s_op:
 643                         handler = fpemu_sp_nmsub;
 644                         goto scoptop;
 645
 646                       scoptop:
 647                         SPFROMREG(fr, MIPSInst_FR(ir));
 648                         SPFROMREG(fs, MIPSInst_FS(ir));
 649                         SPFROMREG(ft, MIPSInst_FT(ir));
 650                         fd = (*handler) (fr, fs, ft);
 651                         SPTOREG(fd, MIPSInst_FD(ir));
 652
 653                       copcsr:
 654                         if (ieee754_cxtest(IEEE754_INEXACT))
 655                                 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
 656                         if (ieee754_cxtest(IEEE754_UNDERFLOW))
 657                                 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
 658                         if (ieee754_cxtest(IEEE754_OVERFLOW))
 659                                 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
 660                         if (ieee754_cxtest(IEEE754_INVALID_OPERATION))
 661                                 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
 662
 663                         ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
 664                         if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
 665                                 /*printk ("SIGFPE: fpu csr = %08x\n",
 666                                    ctx->fcr31); */
 667                                 return SIGFPE;
 668                         }
 669
 670                         break;
 671
 672                 default:
 673                         return SIGILL;
 674                 }
 675                 break;
 676         }
 677
 678         case d_fmt:{            /* 1 */
 679                 ieee754dp(*handler) (ieee754dp, ieee754dp, ieee754dp);
 680                 ieee754dp fd, fr, fs, ft;
 681                 u64 __user *va;
 682                 u64 val;
 683
 684                 switch (MIPSInst_FUNC(ir)) {
 685                 case ldxc1_op:
 686                         va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
 687                                 xcp->regs[MIPSInst_FT(ir)]);
 688
 689                         fpuemustats.loads++;
 690                         if (get_user(val, va)) {
 691                                 fpuemustats.errors++;
 692                                 return SIGBUS;
 693                         }
 694                         DITOREG(val, MIPSInst_FD(ir));
 695                         break;
 696
 697                 case sdxc1_op:
 698                         va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
 699                                 xcp->regs[MIPSInst_FT(ir)]);
 700
 701                         fpuemustats.stores++;
 702                         DIFROMREG(val, MIPSInst_FS(ir));
 703                         if (put_user(val, va)) {
 704                                 fpuemustats.errors++;
 705                                 return SIGBUS;
 706                         }
 707                         break;
 708
 709                 case madd_d_op:
 710                         handler = fpemu_dp_madd;
 711                         goto dcoptop;
 712                 case msub_d_op:
 713                         handler = fpemu_dp_msub;
 714                         goto dcoptop;
 715                 case nmadd_d_op:
 716                         handler = fpemu_dp_nmadd;
 717                         goto dcoptop;
 718                 case nmsub_d_op:
 719                         handler = fpemu_dp_nmsub;
 720                         goto dcoptop;
 721
 722                       dcoptop:
 723                         DPFROMREG(fr, MIPSInst_FR(ir));
 724                         DPFROMREG(fs, MIPSInst_FS(ir));
 725                         DPFROMREG(ft, MIPSInst_FT(ir));
 726                         fd = (*handler) (fr, fs, ft);
 727                         DPTOREG(fd, MIPSInst_FD(ir));
 728                         goto copcsr;
 729
 730                 default:
 731                         return SIGILL;
 732                 }
 733                 break;
 734         }
 735
 736         case 0x7:               /* 7 */
 737                 if (MIPSInst_FUNC(ir) != pfetch_op) {
 738                         return SIGILL;
 739                 }
 740                 /* ignore prefx operation */
 741                 break;
 742
 743         default:
 744                 return SIGILL;
 745         }
 746
 747         return 0;
 748 }
 749 #endif
 750
 751
 752
 753 /*
 754  * Emulate a single COP1 arithmetic instruction.
 755  */
 756 static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
 757         mips_instruction ir)
 758 {
 759         int rfmt;               /* resulting format */
 760         unsigned rcsr = 0;      /* resulting csr */
 761         unsigned cond;
 762         union {
 763                 ieee754dp d;
 764                 ieee754sp s;
 765                 int w;
 766 #ifdef __mips64
 767                 s64 l;
 768 #endif
 769         } rv;                   /* resulting value */
 770
 771         fpuemustats.cp1ops++;
 772         switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) {
 773         case s_fmt:{            /* 0 */
 774                 union {
 775                         ieee754sp(*b) (ieee754sp, ieee754sp);
 776                         ieee754sp(*u) (ieee754sp);
 777                 } handler;
 778
 779                 switch (MIPSInst_FUNC(ir)) {
 780                         /* binary ops */
 781                 case fadd_op:
 782                         handler.b = ieee754sp_add;
 783                         goto scopbop;
 784                 case fsub_op:
 785                         handler.b = ieee754sp_sub;
 786                         goto scopbop;
 787                 case fmul_op:
 788                         handler.b = ieee754sp_mul;
 789                         goto scopbop;
 790                 case fdiv_op:
 791                         handler.b = ieee754sp_div;
 792                         goto scopbop;
 793
 794                         /* unary  ops */
 795 #if __mips >= 2 || defined(__mips64)
 796                 case fsqrt_op:
 797                         handler.u = ieee754sp_sqrt;
 798                         goto scopuop;
 799 #endif
 800 #if __mips >= 4 && __mips != 32
 801                 case frsqrt_op:
 802                         handler.u = fpemu_sp_rsqrt;
 803                         goto scopuop;
 804                 case frecip_op:
 805                         handler.u = fpemu_sp_recip;
 806                         goto scopuop;
 807 #endif
 808 #if __mips >= 4
 809                 case fmovc_op:
 810                         cond = fpucondbit[MIPSInst_FT(ir) >> 2];
 811                         if (((ctx->fcr31 & cond) != 0) !=
 812                                 ((MIPSInst_FT(ir) & 1) != 0))
 813                                 return 0;
 814                         SPFROMREG(rv.s, MIPSInst_FS(ir));
 815                         break;
 816                 case fmovz_op:
 817                         if (xcp->regs[MIPSInst_FT(ir)] != 0)
 818                                 return 0;
 819                         SPFROMREG(rv.s, MIPSInst_FS(ir));
 820                         break;
 821                 case fmovn_op:
 822                         if (xcp->regs[MIPSInst_FT(ir)] == 0)
 823                                 return 0;
 824                         SPFROMREG(rv.s, MIPSInst_FS(ir));
 825                         break;
 826 #endif
 827                 case fabs_op:
 828                         handler.u = ieee754sp_abs;
 829                         goto scopuop;
 830                 case fneg_op:
 831                         handler.u = ieee754sp_neg;
 832                         goto scopuop;
 833                 case fmov_op:
 834                         /* an easy one */
 835                         SPFROMREG(rv.s, MIPSInst_FS(ir));
 836                         goto copcsr;
 837
 838                         /* binary op on handler */
 839                       scopbop:
 840                         {
 841                                 ieee754sp fs, ft;
 842
 843                                 SPFROMREG(fs, MIPSInst_FS(ir));
 844                                 SPFROMREG(ft, MIPSInst_FT(ir));
 845
 846                                 rv.s = (*handler.b) (fs, ft);
 847                                 goto copcsr;
 848                         }
 849                       scopuop:
 850                         {
 851                                 ieee754sp fs;
 852
 853                                 SPFROMREG(fs, MIPSInst_FS(ir));
 854                                 rv.s = (*handler.u) (fs);
 855                                 goto copcsr;
 856                         }
 857                       copcsr:
 858                         if (ieee754_cxtest(IEEE754_INEXACT))
 859                                 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
 860                         if (ieee754_cxtest(IEEE754_UNDERFLOW))
 861                                 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
 862                         if (ieee754_cxtest(IEEE754_OVERFLOW))
 863                                 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
 864                         if (ieee754_cxtest(IEEE754_ZERO_DIVIDE))
 865                                 rcsr |= FPU_CSR_DIV_X | FPU_CSR_DIV_S;
 866                         if (ieee754_cxtest(IEEE754_INVALID_OPERATION))
 867                                 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
 868                         break;
 869
 870                         /* unary conv ops */
 871                 case fcvts_op:
 872                         return SIGILL;  /* not defined */
 873                 case fcvtd_op:{
 874                         ieee754sp fs;
 875
 876                         SPFROMREG(fs, MIPSInst_FS(ir));
 877                         rv.d = ieee754dp_fsp(fs);
 878                         rfmt = d_fmt;
 879                         goto copcsr;
 880                 }
 881                 case fcvtw_op:{
 882                         ieee754sp fs;
 883
 884                         SPFROMREG(fs, MIPSInst_FS(ir));
 885                         rv.w = ieee754sp_tint(fs);
 886                         rfmt = w_fmt;
 887                         goto copcsr;
 888                 }
 889
 890 #if __mips >= 2 || defined(__mips64)
 891                 case fround_op:
 892                 case ftrunc_op:
 893                 case fceil_op:
 894                 case ffloor_op:{
 895                         unsigned int oldrm = ieee754_csr.rm;
 896                         ieee754sp fs;
 897
 898                         SPFROMREG(fs, MIPSInst_FS(ir));
 899                         ieee754_csr.rm = ieee_rm[MIPSInst_FUNC(ir) & 0x3];
 900                         rv.w = ieee754sp_tint(fs);
 901                         ieee754_csr.rm = oldrm;
 902                         rfmt = w_fmt;
 903                         goto copcsr;
 904                 }
 905 #endif /* __mips >= 2 */
 906
 907 #if defined(__mips64)
 908                 case fcvtl_op:{
 909                         ieee754sp fs;
 910
 911                         SPFROMREG(fs, MIPSInst_FS(ir));
 912                         rv.l = ieee754sp_tlong(fs);
 913                         rfmt = l_fmt;
 914                         goto copcsr;
 915                 }
 916
 917                 case froundl_op:
 918                 case ftruncl_op:
 919                 case fceill_op:
 920                 case ffloorl_op:{
 921                         unsigned int oldrm = ieee754_csr.rm;
 922                         ieee754sp fs;
 923
 924                         SPFROMREG(fs, MIPSInst_FS(ir));
 925                         ieee754_csr.rm = ieee_rm[MIPSInst_FUNC(ir) & 0x3];
 926                         rv.l = ieee754sp_tlong(fs);
 927                         ieee754_csr.rm = oldrm;
 928                         rfmt = l_fmt;
 929                         goto copcsr;
 930                 }
 931 #endif /* defined(__mips64) */
 932
 933                 default:
 934                         if (MIPSInst_FUNC(ir) >= fcmp_op) {
 935                                 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
 936                                 ieee754sp fs, ft;
 937
 938                                 SPFROMREG(fs, MIPSInst_FS(ir));
 939                                 SPFROMREG(ft, MIPSInst_FT(ir));
 940                                 rv.w = ieee754sp_cmp(fs, ft,
 941                                         cmptab[cmpop & 0x7], cmpop & 0x8);
 942                                 rfmt = -1;
 943                                 if ((cmpop & 0x8) && ieee754_cxtest
 944                                         (IEEE754_INVALID_OPERATION))
 945                                         rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
 946                                 else
 947                                         goto copcsr;
 948
 949                         }
 950                         else {
 951                                 return SIGILL;
 952                         }
 953                         break;
 954                 }
 955                 break;
 956         }
 957
 958         case d_fmt:{
 959                 union {
 960                         ieee754dp(*b) (ieee754dp, ieee754dp);
 961                         ieee754dp(*u) (ieee754dp);
 962                 } handler;
 963
 964                 switch (MIPSInst_FUNC(ir)) {
 965                         /* binary ops */
 966                 case fadd_op:
 967                         handler.b = ieee754dp_add;
 968                         goto dcopbop;
 969                 case fsub_op:
 970                         handler.b = ieee754dp_sub;
 971                         goto dcopbop;
 972                 case fmul_op:
 973                         handler.b = ieee754dp_mul;
 974                         goto dcopbop;
 975                 case fdiv_op:
 976                         handler.b = ieee754dp_div;
 977                         goto dcopbop;
 978
 979                         /* unary  ops */
 980 #if __mips >= 2 || defined(__mips64)
 981                 case fsqrt_op:
 982                         handler.u = ieee754dp_sqrt;
 983                         goto dcopuop;
 984 #endif
 985 #if __mips >= 4 && __mips != 32
 986                 case frsqrt_op:
 987                         handler.u = fpemu_dp_rsqrt;
 988                         goto dcopuop;
 989                 case frecip_op:
 990                         handler.u = fpemu_dp_recip;
 991                         goto dcopuop;
 992 #endif
 993 #if __mips >= 4
 994                 case fmovc_op:
 995                         cond = fpucondbit[MIPSInst_FT(ir) >> 2];
 996                         if (((ctx->fcr31 & cond) != 0) !=
 997                                 ((MIPSInst_FT(ir) & 1) != 0))
 998                                 return 0;
 999                         DPFROMREG(rv.d, MIPSInst_FS(ir));
1000                         break;
1001                 case fmovz_op:
1002                         if (xcp->regs[MIPSInst_FT(ir)] != 0)
1003                                 return 0;
1004                         DPFROMREG(rv.d, MIPSInst_FS(ir));
1005                         break;
1006                 case fmovn_op:
1007                         if (xcp->regs[MIPSInst_FT(ir)] == 0)
1008                                 return 0;
1009                         DPFROMREG(rv.d, MIPSInst_FS(ir));
1010                         break;
1011 #endif
1012                 case fabs_op:
1013                         handler.u = ieee754dp_abs;
1014                         goto dcopuop;
1015
1016                 case fneg_op:
1017                         handler.u = ieee754dp_neg;
1018                         goto dcopuop;
1019
1020                 case fmov_op:
1021                         /* an easy one */
1022                         DPFROMREG(rv.d, MIPSInst_FS(ir));
1023                         goto copcsr;
1024
1025                         /* binary op on handler */
1026                       dcopbop:{
1027                                 ieee754dp fs, ft;
1028
1029                                 DPFROMREG(fs, MIPSInst_FS(ir));
1030                                 DPFROMREG(ft, MIPSInst_FT(ir));
1031
1032                                 rv.d = (*handler.b) (fs, ft);
1033                                 goto copcsr;
1034                         }
1035                       dcopuop:{
1036                                 ieee754dp fs;
1037
1038                                 DPFROMREG(fs, MIPSInst_FS(ir));
1039                                 rv.d = (*handler.u) (fs);
1040                                 goto copcsr;
1041                         }
1042
1043                         /* unary conv ops */
1044                 case fcvts_op:{
1045                         ieee754dp fs;
1046
1047                         DPFROMREG(fs, MIPSInst_FS(ir));
1048                         rv.s = ieee754sp_fdp(fs);
1049                         rfmt = s_fmt;
1050                         goto copcsr;
1051                 }
1052                 case fcvtd_op:
1053                         return SIGILL;  /* not defined */
1054
1055                 case fcvtw_op:{
1056                         ieee754dp fs;
1057
1058                         DPFROMREG(fs, MIPSInst_FS(ir));
1059                         rv.w = ieee754dp_tint(fs);      /* wrong */
1060                         rfmt = w_fmt;
1061                         goto copcsr;
1062                 }
1063
1064 #if __mips >= 2 || defined(__mips64)
1065                 case fround_op:
1066                 case ftrunc_op:
1067                 case fceil_op:
1068                 case ffloor_op:{
1069                         unsigned int oldrm = ieee754_csr.rm;
1070                         ieee754dp fs;
1071
1072                         DPFROMREG(fs, MIPSInst_FS(ir));
1073                         ieee754_csr.rm = ieee_rm[MIPSInst_FUNC(ir) & 0x3];
1074                         rv.w = ieee754dp_tint(fs);
1075                         ieee754_csr.rm = oldrm;
1076                         rfmt = w_fmt;
1077                         goto copcsr;
1078                 }
1079 #endif
1080
1081 #if defined(__mips64)
1082                 case fcvtl_op:{
1083                         ieee754dp fs;
1084
1085                         DPFROMREG(fs, MIPSInst_FS(ir));
1086                         rv.l = ieee754dp_tlong(fs);
1087                         rfmt = l_fmt;
1088                         goto copcsr;
1089                 }
1090
1091                 case froundl_op:
1092                 case ftruncl_op:
1093                 case fceill_op:
1094                 case ffloorl_op:{
1095                         unsigned int oldrm = ieee754_csr.rm;
1096                         ieee754dp fs;
1097
1098                         DPFROMREG(fs, MIPSInst_FS(ir));
1099                         ieee754_csr.rm = ieee_rm[MIPSInst_FUNC(ir) & 0x3];
1100                         rv.l = ieee754dp_tlong(fs);
1101                         ieee754_csr.rm = oldrm;
1102                         rfmt = l_fmt;
1103                         goto copcsr;
1104                 }
1105 #endif /* __mips >= 3 */
1106
1107                 default:
1108                         if (MIPSInst_FUNC(ir) >= fcmp_op) {
1109                                 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
1110                                 ieee754dp fs, ft;
1111
1112                                 DPFROMREG(fs, MIPSInst_FS(ir));
1113                                 DPFROMREG(ft, MIPSInst_FT(ir));
1114                                 rv.w = ieee754dp_cmp(fs, ft,
1115                                         cmptab[cmpop & 0x7], cmpop & 0x8);
1116                                 rfmt = -1;
1117                                 if ((cmpop & 0x8)
1118                                         &&
1119                                         ieee754_cxtest
1120                                         (IEEE754_INVALID_OPERATION))
1121                                         rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
1122                                 else
1123                                         goto copcsr;
1124
1125                         }
1126                         else {
1127                                 return SIGILL;
1128                         }
1129                         break;
1130                 }
1131                 break;
1132         }
1133
1134         case w_fmt:{
1135                 ieee754sp fs;
1136
1137                 switch (MIPSInst_FUNC(ir)) {
1138                 case fcvts_op:
1139                         /* convert word to single precision real */
1140                         SPFROMREG(fs, MIPSInst_FS(ir));
1141                         rv.s = ieee754sp_fint(fs.bits);
1142                         rfmt = s_fmt;
1143                         goto copcsr;
1144                 case fcvtd_op:
1145                         /* convert word to double precision real */
1146                         SPFROMREG(fs, MIPSInst_FS(ir));
1147                         rv.d = ieee754dp_fint(fs.bits);
1148                         rfmt = d_fmt;
1149                         goto copcsr;
1150                 default:
1151                         return SIGILL;
1152                 }
1153                 break;
1154         }
1155
1156 #if defined(__mips64)
1157         case l_fmt:{
1158                 switch (MIPSInst_FUNC(ir)) {
1159                 case fcvts_op:
1160                         /* convert long to single precision real */
1161                         rv.s = ieee754sp_flong(ctx->fpr[MIPSInst_FS(ir)]);
1162                         rfmt = s_fmt;
1163                         goto copcsr;
1164                 case fcvtd_op:
1165                         /* convert long to double precision real */
1166                         rv.d = ieee754dp_flong(ctx->fpr[MIPSInst_FS(ir)]);
1167                         rfmt = d_fmt;
1168                         goto copcsr;
1169                 default:
1170                         return SIGILL;
1171                 }
1172                 break;
1173         }
1174 #endif
1175
1176         default:
1177                 return SIGILL;
1178         }
1179
1180         /*
1181          * Update the fpu CSR register for this operation.
1182          * If an exception is required, generate a tidy SIGFPE exception,
1183          * without updating the result register.
1184          * Note: cause exception bits do not accumulate, they are rewritten
1185          * for each op; only the flag/sticky bits accumulate.
1186          */
1187         ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
1188         if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1189                 /*printk ("SIGFPE: fpu csr = %08x\n",ctx->fcr31); */
1190                 return SIGFPE;
1191         }
1192
1193         /*
1194          * Now we can safely write the result back to the register file.
1195          */
1196         switch (rfmt) {
1197         case -1:{
1198 #if __mips >= 4
1199                 cond = fpucondbit[MIPSInst_FD(ir) >> 2];
1200 #else
1201                 cond = FPU_CSR_COND;
1202 #endif
1203                 if (rv.w)
1204                         ctx->fcr31 |= cond;
1205                 else
1206                         ctx->fcr31 &= ~cond;
1207                 break;
1208         }
1209         case d_fmt:
1210                 DPTOREG(rv.d, MIPSInst_FD(ir));
1211                 break;
1212         case s_fmt:
1213                 SPTOREG(rv.s, MIPSInst_FD(ir));
1214                 break;
1215         case w_fmt:
1216                 SITOREG(rv.w, MIPSInst_FD(ir));
1217                 break;
1218 #if defined(__mips64)
1219         case l_fmt:
1220                 DITOREG(rv.l, MIPSInst_FD(ir));
1221                 break;
1222 #endif
1223         default:
1224                 return SIGILL;
1225         }
1226
1227         return 0;
1228 }
1229
1230 int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1231         int has_fpu)
1232 {
1233         unsigned long oldepc, prevepc;
1234         mips_instruction insn;
1235         int sig = 0;
1236
1237         oldepc = xcp->cp0_epc;
1238         do {
1239                 prevepc = xcp->cp0_epc;
1240
1241                 if (get_user(insn, (mips_instruction __user *) xcp->cp0_epc)) {
1242                         fpuemustats.errors++;
1243                         return SIGBUS;
1244                 }
1245                 if (insn == 0)
1246                         xcp->cp0_epc += 4;      /* skip nops */
1247                 else {
1248                         /*
1249                          * The 'ieee754_csr' is an alias of
1250                          * ctx->fcr31.  No need to copy ctx->fcr31 to
1251                          * ieee754_csr.  But ieee754_csr.rm is ieee
1252                          * library modes. (not mips rounding mode)
1253                          */
1254                         /* convert to ieee library modes */
1255                         ieee754_csr.rm = ieee_rm[ieee754_csr.rm];
1256                         sig = cop1Emulate(xcp, ctx);
1257                         /* revert to mips rounding mode */
1258                         ieee754_csr.rm = mips_rm[ieee754_csr.rm];
1259                 }
1260
1261                 if (has_fpu)
1262                         break;
1263                 if (sig)
1264                         break;
1265
1266                 cond_resched();
1267         } while (xcp->cp0_epc > prevepc);
1268
1269         /* SIGILL indicates a non-fpu instruction */
1270         if (sig == SIGILL && xcp->cp0_epc != oldepc)
1271                 /* but if epc has advanced, then ignore it */
1272                 sig = 0;
1273
1274         return sig;
1275 }
1276
1277 #ifdef CONFIG_DEBUG_FS
1278 extern struct dentry *mips_debugfs_dir;
1279 static int __init debugfs_fpuemu(void)
1280 {
1281         struct dentry *d, *dir;
1282         int i;
1283         static struct {
1284                 const char *name;
1285                 unsigned int *v;
1286         } vars[] __initdata = {
1287                 { "emulated", &fpuemustats.emulated },
1288                 { "loads",    &fpuemustats.loads },
1289                 { "stores",   &fpuemustats.stores },
1290                 { "cp1ops",   &fpuemustats.cp1ops },
1291                 { "cp1xops",  &fpuemustats.cp1xops },
1292                 { "errors",   &fpuemustats.errors },
1293         };
1294
1295         if (!mips_debugfs_dir)
1296                 return -ENODEV;
1297         dir = debugfs_create_dir("fpuemustats", mips_debugfs_dir);
1298         if (!dir)
1299                 return -ENOMEM;
1300         for (i = 0; i < ARRAY_SIZE(vars); i++) {
1301                 d = debugfs_create_u32(vars[i].name, S_IRUGO, dir, vars[i].v);
1302                 if (!d)
1303                         return -ENOMEM;
1304         }
1305         return 0;
1306 }
1307 __initcall(debugfs_fpuemu);
1308 #endif