arch/mips/math-emu/cp1emu.c

   1 /*
   2  * cp1emu.c: a MIPS coprocessor 1 (FPU) instruction emulator
   3  *
   4  * MIPS floating point support
   5  * Copyright (C) 1994-2000 Algorithmics Ltd.
   6  *
   7  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
   8  * Copyright (C) 2000  MIPS Technologies, Inc.
   9  *
  10  *  This program is free software; you can distribute it and/or modify it
  11  *  under the terms of the GNU General Public License (Version 2) as
  12  *  published by the Free Software Foundation.
  13  *
  14  *  This program is distributed in the hope it will be useful, but WITHOUT
  15  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  16  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  17  *  for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License along
  20  *  with this program; if not, write to the Free Software Foundation, Inc.,
  21  *  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA.
  22  *
  23  * A complete emulator for MIPS coprocessor 1 instructions.  This is
  24  * required for #float(switch) or #float(trap), where it catches all
  25  * COP1 instructions via the "CoProcessor Unusable" exception.
  26  *
  27  * More surprisingly it is also required for #float(ieee), to help out
  28  * the hardware FPU at the boundaries of the IEEE-754 representation
  29  * (denormalised values, infinities, underflow, etc).  It is made
  30  * quite nasty because emulation of some non-COP1 instructions is
  31  * required, e.g. in branch delay slots.
  32  *
  33  * Note if you know that you won't have an FPU, then you'll get much
  34  * better performance by compiling with -msoft-float!
  35  */
  36 #include <linux/sched.h>
  37 #include <linux/debugfs.h>
  38 #include <linux/kconfig.h>
  39 #include <linux/percpu-defs.h>
  40 #include <linux/perf_event.h>
  41
  42 #include <asm/branch.h>
  43 #include <asm/inst.h>
  44 #include <asm/ptrace.h>
  45 #include <asm/signal.h>
  46 #include <asm/uaccess.h>
  47
  48 #include <asm/processor.h>
  49 #include <asm/fpu_emulator.h>
  50 #include <asm/fpu.h>
  51
  52 #include "ieee754.h"
  53
  54 /* Function which emulates a floating point instruction. */
  55
  56 static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *,
  57         mips_instruction);
  58
  59 static int fpux_emu(struct pt_regs *,
  60         struct mips_fpu_struct *, mips_instruction, void *__user *);
  61
  62 /* Control registers */
  63
  64 #define FPCREG_RID      0       /* $0  = revision id */
  65 #define FPCREG_CSR      31      /* $31 = csr */
  66
  67 /* Determine rounding mode from the RM bits of the FCSR */
  68 #define modeindex(v) ((v) & FPU_CSR_RM)
  69
  70 /* convert condition code register number to csr bit */
  71 static const unsigned int fpucondbit[8] = {
  72         FPU_CSR_COND0,
  73         FPU_CSR_COND1,
  74         FPU_CSR_COND2,
  75         FPU_CSR_COND3,
  76         FPU_CSR_COND4,
  77         FPU_CSR_COND5,
  78         FPU_CSR_COND6,
  79         FPU_CSR_COND7
  80 };
  81
  82 /* (microMIPS) Convert certain microMIPS instructions to MIPS32 format. */
  83 static const int sd_format[] = {16, 17, 0, 0, 0, 0, 0, 0};
  84 static const int sdps_format[] = {16, 17, 22, 0, 0, 0, 0, 0};
  85 static const int dwl_format[] = {17, 20, 21, 0, 0, 0, 0, 0};
  86 static const int swl_format[] = {16, 20, 21, 0, 0, 0, 0, 0};
  87
  88 /*
  89  * This functions translates a 32-bit microMIPS instruction
  90  * into a 32-bit MIPS32 instruction. Returns 0 on success
  91  * and SIGILL otherwise.
  92  */
  93 static int microMIPS32_to_MIPS32(union mips_instruction *insn_ptr)
  94 {
  95         union mips_instruction insn = *insn_ptr;
  96         union mips_instruction mips32_insn = insn;
  97         int func, fmt, op;
  98
  99         switch (insn.mm_i_format.opcode) {
 100         case mm_ldc132_op:
 101                 mips32_insn.mm_i_format.opcode = ldc1_op;
 102                 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
 103                 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
 104                 break;
 105         case mm_lwc132_op:
 106                 mips32_insn.mm_i_format.opcode = lwc1_op;
 107                 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
 108                 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
 109                 break;
 110         case mm_sdc132_op:
 111                 mips32_insn.mm_i_format.opcode = sdc1_op;
 112                 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
 113                 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
 114                 break;
 115         case mm_swc132_op:
 116                 mips32_insn.mm_i_format.opcode = swc1_op;
 117                 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
 118                 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
 119                 break;
 120         case mm_pool32i_op:
 121                 /* NOTE: offset is << by 1 if in microMIPS mode. */
 122                 if ((insn.mm_i_format.rt == mm_bc1f_op) ||
 123                     (insn.mm_i_format.rt == mm_bc1t_op)) {
 124                         mips32_insn.fb_format.opcode = cop1_op;
 125                         mips32_insn.fb_format.bc = bc_op;
 126                         mips32_insn.fb_format.flag =
 127                                 (insn.mm_i_format.rt == mm_bc1t_op) ? 1 : 0;
 128                 } else
 129                         return SIGILL;
 130                 break;
 131         case mm_pool32f_op:
 132                 switch (insn.mm_fp0_format.func) {
 133                 case mm_32f_01_op:
 134                 case mm_32f_11_op:
 135                 case mm_32f_02_op:
 136                 case mm_32f_12_op:
 137                 case mm_32f_41_op:
 138                 case mm_32f_51_op:
 139                 case mm_32f_42_op:
 140                 case mm_32f_52_op:
 141                         op = insn.mm_fp0_format.func;
 142                         if (op == mm_32f_01_op)
 143                                 func = madd_s_op;
 144                         else if (op == mm_32f_11_op)
 145                                 func = madd_d_op;
 146                         else if (op == mm_32f_02_op)
 147                                 func = nmadd_s_op;
 148                         else if (op == mm_32f_12_op)
 149                                 func = nmadd_d_op;
 150                         else if (op == mm_32f_41_op)
 151                                 func = msub_s_op;
 152                         else if (op == mm_32f_51_op)
 153                                 func = msub_d_op;
 154                         else if (op == mm_32f_42_op)
 155                                 func = nmsub_s_op;
 156                         else
 157                                 func = nmsub_d_op;
 158                         mips32_insn.fp6_format.opcode = cop1x_op;
 159                         mips32_insn.fp6_format.fr = insn.mm_fp6_format.fr;
 160                         mips32_insn.fp6_format.ft = insn.mm_fp6_format.ft;
 161                         mips32_insn.fp6_format.fs = insn.mm_fp6_format.fs;
 162                         mips32_insn.fp6_format.fd = insn.mm_fp6_format.fd;
 163                         mips32_insn.fp6_format.func = func;
 164                         break;
 165                 case mm_32f_10_op:
 166                         func = -1;      /* Invalid */
 167                         op = insn.mm_fp5_format.op & 0x7;
 168                         if (op == mm_ldxc1_op)
 169                                 func = ldxc1_op;
 170                         else if (op == mm_sdxc1_op)
 171                                 func = sdxc1_op;
 172                         else if (op == mm_lwxc1_op)
 173                                 func = lwxc1_op;
 174                         else if (op == mm_swxc1_op)
 175                                 func = swxc1_op;
 176
 177                         if (func != -1) {
 178                                 mips32_insn.r_format.opcode = cop1x_op;
 179                                 mips32_insn.r_format.rs =
 180                                         insn.mm_fp5_format.base;
 181                                 mips32_insn.r_format.rt =
 182                                         insn.mm_fp5_format.index;
 183                                 mips32_insn.r_format.rd = 0;
 184                                 mips32_insn.r_format.re = insn.mm_fp5_format.fd;
 185                                 mips32_insn.r_format.func = func;
 186                         } else
 187                                 return SIGILL;
 188                         break;
 189                 case mm_32f_40_op:
 190                         op = -1;        /* Invalid */
 191                         if (insn.mm_fp2_format.op == mm_fmovt_op)
 192                                 op = 1;
 193                         else if (insn.mm_fp2_format.op == mm_fmovf_op)
 194                                 op = 0;
 195                         if (op != -1) {
 196                                 mips32_insn.fp0_format.opcode = cop1_op;
 197                                 mips32_insn.fp0_format.fmt =
 198                                         sdps_format[insn.mm_fp2_format.fmt];
 199                                 mips32_insn.fp0_format.ft =
 200                                         (insn.mm_fp2_format.cc<<2) + op;
 201                                 mips32_insn.fp0_format.fs =
 202                                         insn.mm_fp2_format.fs;
 203                                 mips32_insn.fp0_format.fd =
 204                                         insn.mm_fp2_format.fd;
 205                                 mips32_insn.fp0_format.func = fmovc_op;
 206                         } else
 207                                 return SIGILL;
 208                         break;
 209                 case mm_32f_60_op:
 210                         func = -1;      /* Invalid */
 211                         if (insn.mm_fp0_format.op == mm_fadd_op)
 212                                 func = fadd_op;
 213                         else if (insn.mm_fp0_format.op == mm_fsub_op)
 214                                 func = fsub_op;
 215                         else if (insn.mm_fp0_format.op == mm_fmul_op)
 216                                 func = fmul_op;
 217                         else if (insn.mm_fp0_format.op == mm_fdiv_op)
 218                                 func = fdiv_op;
 219                         if (func != -1) {
 220                                 mips32_insn.fp0_format.opcode = cop1_op;
 221                                 mips32_insn.fp0_format.fmt =
 222                                         sdps_format[insn.mm_fp0_format.fmt];
 223                                 mips32_insn.fp0_format.ft =
 224                                         insn.mm_fp0_format.ft;
 225                                 mips32_insn.fp0_format.fs =
 226                                         insn.mm_fp0_format.fs;
 227                                 mips32_insn.fp0_format.fd =
 228                                         insn.mm_fp0_format.fd;
 229                                 mips32_insn.fp0_format.func = func;
 230                         } else
 231                                 return SIGILL;
 232                         break;
 233                 case mm_32f_70_op:
 234                         func = -1;      /* Invalid */
 235                         if (insn.mm_fp0_format.op == mm_fmovn_op)
 236                                 func = fmovn_op;
 237                         else if (insn.mm_fp0_format.op == mm_fmovz_op)
 238                                 func = fmovz_op;
 239                         if (func != -1) {
 240                                 mips32_insn.fp0_format.opcode = cop1_op;
 241                                 mips32_insn.fp0_format.fmt =
 242                                         sdps_format[insn.mm_fp0_format.fmt];
 243                                 mips32_insn.fp0_format.ft =
 244                                         insn.mm_fp0_format.ft;
 245                                 mips32_insn.fp0_format.fs =
 246                                         insn.mm_fp0_format.fs;
 247                                 mips32_insn.fp0_format.fd =
 248                                         insn.mm_fp0_format.fd;
 249                                 mips32_insn.fp0_format.func = func;
 250                         } else
 251                                 return SIGILL;
 252                         break;
 253                 case mm_32f_73_op:    /* POOL32FXF */
 254                         switch (insn.mm_fp1_format.op) {
 255                         case mm_movf0_op:
 256                         case mm_movf1_op:
 257                         case mm_movt0_op:
 258                         case mm_movt1_op:
 259                                 if ((insn.mm_fp1_format.op & 0x7f) ==
 260                                     mm_movf0_op)
 261                                         op = 0;
 262                                 else
 263                                         op = 1;
 264                                 mips32_insn.r_format.opcode = spec_op;
 265                                 mips32_insn.r_format.rs = insn.mm_fp4_format.fs;
 266                                 mips32_insn.r_format.rt =
 267                                         (insn.mm_fp4_format.cc << 2) + op;
 268                                 mips32_insn.r_format.rd = insn.mm_fp4_format.rt;
 269                                 mips32_insn.r_format.re = 0;
 270                                 mips32_insn.r_format.func = movc_op;
 271                                 break;
 272                         case mm_fcvtd0_op:
 273                         case mm_fcvtd1_op:
 274                         case mm_fcvts0_op:
 275                         case mm_fcvts1_op:
 276                                 if ((insn.mm_fp1_format.op & 0x7f) ==
 277                                     mm_fcvtd0_op) {
 278                                         func = fcvtd_op;
 279                                         fmt = swl_format[insn.mm_fp3_format.fmt];
 280                                 } else {
 281                                         func = fcvts_op;
 282                                         fmt = dwl_format[insn.mm_fp3_format.fmt];
 283                                 }
 284                                 mips32_insn.fp0_format.opcode = cop1_op;
 285                                 mips32_insn.fp0_format.fmt = fmt;
 286                                 mips32_insn.fp0_format.ft = 0;
 287                                 mips32_insn.fp0_format.fs =
 288                                         insn.mm_fp3_format.fs;
 289                                 mips32_insn.fp0_format.fd =
 290                                         insn.mm_fp3_format.rt;
 291                                 mips32_insn.fp0_format.func = func;
 292                                 break;
 293                         case mm_fmov0_op:
 294                         case mm_fmov1_op:
 295                         case mm_fabs0_op:
 296                         case mm_fabs1_op:
 297                         case mm_fneg0_op:
 298                         case mm_fneg1_op:
 299                                 if ((insn.mm_fp1_format.op & 0x7f) ==
 300                                     mm_fmov0_op)
 301                                         func = fmov_op;
 302                                 else if ((insn.mm_fp1_format.op & 0x7f) ==
 303                                          mm_fabs0_op)
 304                                         func = fabs_op;
 305                                 else
 306                                         func = fneg_op;
 307                                 mips32_insn.fp0_format.opcode = cop1_op;
 308                                 mips32_insn.fp0_format.fmt =
 309                                         sdps_format[insn.mm_fp3_format.fmt];
 310                                 mips32_insn.fp0_format.ft = 0;
 311                                 mips32_insn.fp0_format.fs =
 312                                         insn.mm_fp3_format.fs;
 313                                 mips32_insn.fp0_format.fd =
 314                                         insn.mm_fp3_format.rt;
 315                                 mips32_insn.fp0_format.func = func;
 316                                 break;
 317                         case mm_ffloorl_op:
 318                         case mm_ffloorw_op:
 319                         case mm_fceill_op:
 320                         case mm_fceilw_op:
 321                         case mm_ftruncl_op:
 322                         case mm_ftruncw_op:
 323                         case mm_froundl_op:
 324                         case mm_froundw_op:
 325                         case mm_fcvtl_op:
 326                         case mm_fcvtw_op:
 327                                 if (insn.mm_fp1_format.op == mm_ffloorl_op)
 328                                         func = ffloorl_op;
 329                                 else if (insn.mm_fp1_format.op == mm_ffloorw_op)
 330                                         func = ffloor_op;
 331                                 else if (insn.mm_fp1_format.op == mm_fceill_op)
 332                                         func = fceill_op;
 333                                 else if (insn.mm_fp1_format.op == mm_fceilw_op)
 334                                         func = fceil_op;
 335                                 else if (insn.mm_fp1_format.op == mm_ftruncl_op)
 336                                         func = ftruncl_op;
 337                                 else if (insn.mm_fp1_format.op == mm_ftruncw_op)
 338                                         func = ftrunc_op;
 339                                 else if (insn.mm_fp1_format.op == mm_froundl_op)
 340                                         func = froundl_op;
 341                                 else if (insn.mm_fp1_format.op == mm_froundw_op)
 342                                         func = fround_op;
 343                                 else if (insn.mm_fp1_format.op == mm_fcvtl_op)
 344                                         func = fcvtl_op;
 345                                 else
 346                                         func = fcvtw_op;
 347                                 mips32_insn.fp0_format.opcode = cop1_op;
 348                                 mips32_insn.fp0_format.fmt =
 349                                         sd_format[insn.mm_fp1_format.fmt];
 350                                 mips32_insn.fp0_format.ft = 0;
 351                                 mips32_insn.fp0_format.fs =
 352                                         insn.mm_fp1_format.fs;
 353                                 mips32_insn.fp0_format.fd =
 354                                         insn.mm_fp1_format.rt;
 355                                 mips32_insn.fp0_format.func = func;
 356                                 break;
 357                         case mm_frsqrt_op:
 358                         case mm_fsqrt_op:
 359                         case mm_frecip_op:
 360                                 if (insn.mm_fp1_format.op == mm_frsqrt_op)
 361                                         func = frsqrt_op;
 362                                 else if (insn.mm_fp1_format.op == mm_fsqrt_op)
 363                                         func = fsqrt_op;
 364                                 else
 365                                         func = frecip_op;
 366                                 mips32_insn.fp0_format.opcode = cop1_op;
 367                                 mips32_insn.fp0_format.fmt =
 368                                         sdps_format[insn.mm_fp1_format.fmt];
 369                                 mips32_insn.fp0_format.ft = 0;
 370                                 mips32_insn.fp0_format.fs =
 371                                         insn.mm_fp1_format.fs;
 372                                 mips32_insn.fp0_format.fd =
 373                                         insn.mm_fp1_format.rt;
 374                                 mips32_insn.fp0_format.func = func;
 375                                 break;
 376                         case mm_mfc1_op:
 377                         case mm_mtc1_op:
 378                         case mm_cfc1_op:
 379                         case mm_ctc1_op:
 380                         case mm_mfhc1_op:
 381                         case mm_mthc1_op:
 382                                 if (insn.mm_fp1_format.op == mm_mfc1_op)
 383                                         op = mfc_op;
 384                                 else if (insn.mm_fp1_format.op == mm_mtc1_op)
 385                                         op = mtc_op;
 386                                 else if (insn.mm_fp1_format.op == mm_cfc1_op)
 387                                         op = cfc_op;
 388                                 else if (insn.mm_fp1_format.op == mm_ctc1_op)
 389                                         op = ctc_op;
 390                                 else if (insn.mm_fp1_format.op == mm_mfhc1_op)
 391                                         op = mfhc_op;
 392                                 else
 393                                         op = mthc_op;
 394                                 mips32_insn.fp1_format.opcode = cop1_op;
 395                                 mips32_insn.fp1_format.op = op;
 396                                 mips32_insn.fp1_format.rt =
 397                                         insn.mm_fp1_format.rt;
 398                                 mips32_insn.fp1_format.fs =
 399                                         insn.mm_fp1_format.fs;
 400                                 mips32_insn.fp1_format.fd = 0;
 401                                 mips32_insn.fp1_format.func = 0;
 402                                 break;
 403                         default:
 404                                 return SIGILL;
 405                         }
 406                         break;
 407                 case mm_32f_74_op:      /* c.cond.fmt */
 408                         mips32_insn.fp0_format.opcode = cop1_op;
 409                         mips32_insn.fp0_format.fmt =
 410                                 sdps_format[insn.mm_fp4_format.fmt];
 411                         mips32_insn.fp0_format.ft = insn.mm_fp4_format.rt;
 412                         mips32_insn.fp0_format.fs = insn.mm_fp4_format.fs;
 413                         mips32_insn.fp0_format.fd = insn.mm_fp4_format.cc << 2;
 414                         mips32_insn.fp0_format.func =
 415                                 insn.mm_fp4_format.cond | MM_MIPS32_COND_FC;
 416                         break;
 417                 default:
 418                         return SIGILL;
 419                 }
 420                 break;
 421         default:
 422                 return SIGILL;
 423         }
 424
 425         *insn_ptr = mips32_insn;
 426         return 0;
 427 }
 428
 429 /*
 430  * Redundant with logic already in kernel/branch.c,
 431  * embedded in compute_return_epc.  At some point,
 432  * a single subroutine should be used across both
 433  * modules.
 434  */
 435 static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
 436                          unsigned long *contpc)
 437 {
 438         union mips_instruction insn = (union mips_instruction)dec_insn.insn;
 439         unsigned int fcr31;
 440         unsigned int bit = 0;
 441
 442         switch (insn.i_format.opcode) {
 443         case spec_op:
 444                 switch (insn.r_format.func) {
 445                 case jalr_op:
 446                         regs->regs[insn.r_format.rd] =
 447                                 regs->cp0_epc + dec_insn.pc_inc +
 448                                 dec_insn.next_pc_inc;
 449                         /* Fall through */
 450                 case jr_op:
 451                         *contpc = regs->regs[insn.r_format.rs];
 452                         return 1;
 453                 }
 454                 break;
 455         case bcond_op:
 456                 switch (insn.i_format.rt) {
 457                 case bltzal_op:
 458                 case bltzall_op:
 459                         regs->regs[31] = regs->cp0_epc +
 460                                 dec_insn.pc_inc +
 461                                 dec_insn.next_pc_inc;
 462                         /* Fall through */
 463                 case bltz_op:
 464                 case bltzl_op:
 465                         if ((long)regs->regs[insn.i_format.rs] < 0)
 466                                 *contpc = regs->cp0_epc +
 467                                         dec_insn.pc_inc +
 468                                         (insn.i_format.simmediate << 2);
 469                         else
 470                                 *contpc = regs->cp0_epc +
 471                                         dec_insn.pc_inc +
 472                                         dec_insn.next_pc_inc;
 473                         return 1;
 474                 case bgezal_op:
 475                 case bgezall_op:
 476                         regs->regs[31] = regs->cp0_epc +
 477                                 dec_insn.pc_inc +
 478                                 dec_insn.next_pc_inc;
 479                         /* Fall through */
 480                 case bgez_op:
 481                 case bgezl_op:
 482                         if ((long)regs->regs[insn.i_format.rs] >= 0)
 483                                 *contpc = regs->cp0_epc +
 484                                         dec_insn.pc_inc +
 485                                         (insn.i_format.simmediate << 2);
 486                         else
 487                                 *contpc = regs->cp0_epc +
 488                                         dec_insn.pc_inc +
 489                                         dec_insn.next_pc_inc;
 490                         return 1;
 491                 }
 492                 break;
 493         case jalx_op:
 494                 set_isa16_mode(bit);
 495         case jal_op:
 496                 regs->regs[31] = regs->cp0_epc +
 497                         dec_insn.pc_inc +
 498                         dec_insn.next_pc_inc;
 499                 /* Fall through */
 500         case j_op:
 501                 *contpc = regs->cp0_epc + dec_insn.pc_inc;
 502                 *contpc >>= 28;
 503                 *contpc <<= 28;
 504                 *contpc |= (insn.j_format.target << 2);
 505                 /* Set microMIPS mode bit: XOR for jalx. */
 506                 *contpc ^= bit;
 507                 return 1;
 508         case beq_op:
 509         case beql_op:
 510                 if (regs->regs[insn.i_format.rs] ==
 511                     regs->regs[insn.i_format.rt])
 512                         *contpc = regs->cp0_epc +
 513                                 dec_insn.pc_inc +
 514                                 (insn.i_format.simmediate << 2);
 515                 else
 516                         *contpc = regs->cp0_epc +
 517                                 dec_insn.pc_inc +
 518                                 dec_insn.next_pc_inc;
 519                 return 1;
 520         case bne_op:
 521         case bnel_op:
 522                 if (regs->regs[insn.i_format.rs] !=
 523                     regs->regs[insn.i_format.rt])
 524                         *contpc = regs->cp0_epc +
 525                                 dec_insn.pc_inc +
 526                                 (insn.i_format.simmediate << 2);
 527                 else
 528                         *contpc = regs->cp0_epc +
 529                                 dec_insn.pc_inc +
 530                                 dec_insn.next_pc_inc;
 531                 return 1;
 532         case blez_op:
 533         case blezl_op:
 534                 if ((long)regs->regs[insn.i_format.rs] <= 0)
 535                         *contpc = regs->cp0_epc +
 536                                 dec_insn.pc_inc +
 537                                 (insn.i_format.simmediate << 2);
 538                 else
 539                         *contpc = regs->cp0_epc +
 540                                 dec_insn.pc_inc +
 541                                 dec_insn.next_pc_inc;
 542                 return 1;
 543         case bgtz_op:
 544         case bgtzl_op:
 545                 if ((long)regs->regs[insn.i_format.rs] > 0)
 546                         *contpc = regs->cp0_epc +
 547                                 dec_insn.pc_inc +
 548                                 (insn.i_format.simmediate << 2);
 549                 else
 550                         *contpc = regs->cp0_epc +
 551                                 dec_insn.pc_inc +
 552                                 dec_insn.next_pc_inc;
 553                 return 1;
 554 #ifdef CONFIG_CPU_CAVIUM_OCTEON
 555         case lwc2_op: /* This is bbit0 on Octeon */
 556                 if ((regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) == 0)
 557                         *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
 558                 else
 559                         *contpc = regs->cp0_epc + 8;
 560                 return 1;
 561         case ldc2_op: /* This is bbit032 on Octeon */
 562                 if ((regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32))) == 0)
 563                         *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
 564                 else
 565                         *contpc = regs->cp0_epc + 8;
 566                 return 1;
 567         case swc2_op: /* This is bbit1 on Octeon */
 568                 if (regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt))
 569                         *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
 570                 else
 571                         *contpc = regs->cp0_epc + 8;
 572                 return 1;
 573         case sdc2_op: /* This is bbit132 on Octeon */
 574                 if (regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32)))
 575                         *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
 576                 else
 577                         *contpc = regs->cp0_epc + 8;
 578                 return 1;
 579 #endif
 580         case cop0_op:
 581         case cop1_op:
 582         case cop2_op:
 583         case cop1x_op:
 584                 if (insn.i_format.rs == bc_op) {
 585                         preempt_disable();
 586                         if (is_fpu_owner())
 587                                 fcr31 = read_32bit_cp1_register(CP1_STATUS);
 588                         else
 589                                 fcr31 = current->thread.fpu.fcr31;
 590                         preempt_enable();
 591
 592                         bit = (insn.i_format.rt >> 2);
 593                         bit += (bit != 0);
 594                         bit += 23;
 595                         switch (insn.i_format.rt & 3) {
 596                         case 0: /* bc1f */
 597                         case 2: /* bc1fl */
 598                                 if (~fcr31 & (1 << bit))
 599                                         *contpc = regs->cp0_epc +
 600                                                 dec_insn.pc_inc +
 601                                                 (insn.i_format.simmediate << 2);
 602                                 else
 603                                         *contpc = regs->cp0_epc +
 604                                                 dec_insn.pc_inc +
 605                                                 dec_insn.next_pc_inc;
 606                                 return 1;
 607                         case 1: /* bc1t */
 608                         case 3: /* bc1tl */
 609                                 if (fcr31 & (1 << bit))
 610                                         *contpc = regs->cp0_epc +
 611                                                 dec_insn.pc_inc +
 612                                                 (insn.i_format.simmediate << 2);
 613                                 else
 614                                         *contpc = regs->cp0_epc +
 615                                                 dec_insn.pc_inc +
 616                                                 dec_insn.next_pc_inc;
 617                                 return 1;
 618                         }
 619                 }
 620                 break;
 621         }
 622         return 0;
 623 }
 624
 625 /*
 626  * In the Linux kernel, we support selection of FPR format on the
 627  * basis of the Status.FR bit.  If an FPU is not present, the FR bit
 628  * is hardwired to zero, which would imply a 32-bit FPU even for
 629  * 64-bit CPUs so we rather look at TIF_32BIT_FPREGS.
 630  * FPU emu is slow and bulky and optimizing this function offers fairly
 631  * sizeable benefits so we try to be clever and make this function return
 632  * a constant whenever possible, that is on 64-bit kernels without O32
 633  * compatibility enabled and on 32-bit without 64-bit FPU support.
 634  */
 635 static inline int cop1_64bit(struct pt_regs *xcp)
 636 {
 637         if (config_enabled(CONFIG_64BIT) && !config_enabled(CONFIG_MIPS32_O32))
 638                 return 1;
 639         else if (config_enabled(CONFIG_32BIT) &&
 640                  !config_enabled(CONFIG_MIPS_O32_FP64_SUPPORT))
 641                 return 0;
 642
 643         return !test_thread_flag(TIF_32BIT_FPREGS);
 644 }
 645
 646 #define SIFROMREG(si, x)                                                \
 647 do {                                                                    \
 648         if (cop1_64bit(xcp))                                            \
 649                 (si) = (int)get_fpr32(&ctx->fpr[x], 0);                 \
 650         else                                                            \
 651                 (si) = (int)get_fpr32(&ctx->fpr[(x) & ~1], (x) & 1);    \
 652 } while (0)
 653
 654 #define SITOREG(si, x)                                                  \
 655 do {                                                                    \
 656         if (cop1_64bit(xcp)) {                                          \
 657                 unsigned i;                                             \
 658                 set_fpr32(&ctx->fpr[x], 0, si);                         \
 659                 for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val32); i++)     \
 660                         set_fpr32(&ctx->fpr[x], i, 0);                  \
 661         } else {                                                        \
 662                 set_fpr32(&ctx->fpr[(x) & ~1], (x) & 1, si);            \
 663         }                                                               \
 664 } while (0)
 665
 666 #define SIFROMHREG(si, x)       ((si) = (int)get_fpr32(&ctx->fpr[x], 1))
 667
 668 #define SITOHREG(si, x)                                                 \
 669 do {                                                                    \
 670         unsigned i;                                                     \
 671         set_fpr32(&ctx->fpr[x], 1, si);                                 \
 672         for (i = 2; i < ARRAY_SIZE(ctx->fpr[x].val32); i++)             \
 673                 set_fpr32(&ctx->fpr[x], i, 0);                          \
 674 } while (0)
 675
 676 #define DIFROMREG(di, x)                                                \
 677         ((di) = get_fpr64(&ctx->fpr[(x) & ~(cop1_64bit(xcp) == 0)], 0))
 678
 679 #define DITOREG(di, x)                                                  \
 680 do {                                                                    \
 681         unsigned fpr, i;                                                \
 682         fpr = (x) & ~(cop1_64bit(xcp) == 0);                            \
 683         set_fpr64(&ctx->fpr[fpr], 0, di);                               \
 684         for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val64); i++)             \
 685                 set_fpr64(&ctx->fpr[fpr], i, 0);                        \
 686 } while (0)
 687
 688 #define SPFROMREG(sp, x) SIFROMREG((sp).bits, x)
 689 #define SPTOREG(sp, x)  SITOREG((sp).bits, x)
 690 #define DPFROMREG(dp, x)        DIFROMREG((dp).bits, x)
 691 #define DPTOREG(dp, x)  DITOREG((dp).bits, x)
 692
 693 /*
 694  * Emulate the single floating point instruction pointed at by EPC.
 695  * Two instructions if the instruction is in a branch delay slot.
 696  */
 697
 698 static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
 699                 struct mm_decoded_insn dec_insn, void *__user *fault_addr)
 700 {
 701         unsigned long contpc = xcp->cp0_epc + dec_insn.pc_inc;
 702         unsigned int cond, cbit;
 703         mips_instruction ir;
 704         int likely, pc_inc;
 705         u32 __user *wva;
 706         u64 __user *dva;
 707         u32 value;
 708         u32 wval;
 709         u64 dval;
 710         int sig;
 711
 712         /*
 713          * These are giving gcc a gentle hint about what to expect in
 714          * dec_inst in order to do better optimization.
 715          */
 716         if (!cpu_has_mmips && dec_insn.micro_mips_mode)
 717                 unreachable();
 718
 719         /* XXX NEC Vr54xx bug workaround */
 720         if (delay_slot(xcp)) {
 721                 if (dec_insn.micro_mips_mode) {
 722                         if (!mm_isBranchInstr(xcp, dec_insn, &contpc))
 723                                 clear_delay_slot(xcp);
 724                 } else {
 725                         if (!isBranchInstr(xcp, dec_insn, &contpc))
 726                                 clear_delay_slot(xcp);
 727                 }
 728         }
 729
 730         if (delay_slot(xcp)) {
 731                 /*
 732                  * The instruction to be emulated is in a branch delay slot
 733                  * which means that we have to  emulate the branch instruction
 734                  * BEFORE we do the cop1 instruction.
 735                  *
 736                  * This branch could be a COP1 branch, but in that case we
 737                  * would have had a trap for that instruction, and would not
 738                  * come through this route.
 739                  *
 740                  * Linux MIPS branch emulator operates on context, updating the
 741                  * cp0_epc.
 742                  */
 743                 ir = dec_insn.next_insn;  /* process delay slot instr */
 744                 pc_inc = dec_insn.next_pc_inc;
 745         } else {
 746                 ir = dec_insn.insn;       /* process current instr */
 747                 pc_inc = dec_insn.pc_inc;
 748         }
 749
 750         /*
 751          * Since microMIPS FPU instructios are a subset of MIPS32 FPU
 752          * instructions, we want to convert microMIPS FPU instructions
 753          * into MIPS32 instructions so that we could reuse all of the
 754          * FPU emulation code.
 755          *
 756          * NOTE: We cannot do this for branch instructions since they
 757          *       are not a subset. Example: Cannot emulate a 16-bit
 758          *       aligned target address with a MIPS32 instruction.
 759          */
 760         if (dec_insn.micro_mips_mode) {
 761                 /*
 762                  * If next instruction is a 16-bit instruction, then it
 763                  * it cannot be a FPU instruction. This could happen
 764                  * since we can be called for non-FPU instructions.
 765                  */
 766                 if ((pc_inc == 2) ||
 767                         (microMIPS32_to_MIPS32((union mips_instruction *)&ir)
 768                          == SIGILL))
 769                         return SIGILL;
 770         }
 771
 772 emul:
 773         perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, xcp, 0);
 774         MIPS_FPU_EMU_INC_STATS(emulated);
 775         switch (MIPSInst_OPCODE(ir)) {
 776         case ldc1_op:
 777                 dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
 778                                      MIPSInst_SIMM(ir));
 779                 MIPS_FPU_EMU_INC_STATS(loads);
 780
 781                 if (!access_ok(VERIFY_READ, dva, sizeof(u64))) {
 782                         MIPS_FPU_EMU_INC_STATS(errors);
 783                         *fault_addr = dva;
 784                         return SIGBUS;
 785                 }
 786                 if (__get_user(dval, dva)) {
 787                         MIPS_FPU_EMU_INC_STATS(errors);
 788                         *fault_addr = dva;
 789                         return SIGSEGV;
 790                 }
 791                 DITOREG(dval, MIPSInst_RT(ir));
 792                 break;
 793
 794         case sdc1_op:
 795                 dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
 796                                       MIPSInst_SIMM(ir));
 797                 MIPS_FPU_EMU_INC_STATS(stores);
 798                 DIFROMREG(dval, MIPSInst_RT(ir));
 799                 if (!access_ok(VERIFY_WRITE, dva, sizeof(u64))) {
 800                         MIPS_FPU_EMU_INC_STATS(errors);
 801                         *fault_addr = dva;
 802                         return SIGBUS;
 803                 }
 804                 if (__put_user(dval, dva)) {
 805                         MIPS_FPU_EMU_INC_STATS(errors);
 806                         *fault_addr = dva;
 807                         return SIGSEGV;
 808                 }
 809                 break;
 810
 811         case lwc1_op:
 812                 wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
 813                                       MIPSInst_SIMM(ir));
 814                 MIPS_FPU_EMU_INC_STATS(loads);
 815                 if (!access_ok(VERIFY_READ, wva, sizeof(u32))) {
 816                         MIPS_FPU_EMU_INC_STATS(errors);
 817                         *fault_addr = wva;
 818                         return SIGBUS;
 819                 }
 820                 if (__get_user(wval, wva)) {
 821                         MIPS_FPU_EMU_INC_STATS(errors);
 822                         *fault_addr = wva;
 823                         return SIGSEGV;
 824                 }
 825                 SITOREG(wval, MIPSInst_RT(ir));
 826                 break;
 827
 828         case swc1_op:
 829                 wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
 830                                       MIPSInst_SIMM(ir));
 831                 MIPS_FPU_EMU_INC_STATS(stores);
 832                 SIFROMREG(wval, MIPSInst_RT(ir));
 833                 if (!access_ok(VERIFY_WRITE, wva, sizeof(u32))) {
 834                         MIPS_FPU_EMU_INC_STATS(errors);
 835                         *fault_addr = wva;
 836                         return SIGBUS;
 837                 }
 838                 if (__put_user(wval, wva)) {
 839                         MIPS_FPU_EMU_INC_STATS(errors);
 840                         *fault_addr = wva;
 841                         return SIGSEGV;
 842                 }
 843                 break;
 844
 845         case cop1_op:
 846                 switch (MIPSInst_RS(ir)) {
 847                 case dmfc_op:
 848                         if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
 849                                 return SIGILL;
 850
 851                         /* copregister fs -> gpr[rt] */
 852                         if (MIPSInst_RT(ir) != 0) {
 853                                 DIFROMREG(xcp->regs[MIPSInst_RT(ir)],
 854                                         MIPSInst_RD(ir));
 855                         }
 856                         break;
 857
 858                 case dmtc_op:
 859                         if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
 860                                 return SIGILL;
 861
 862                         /* copregister fs <- rt */
 863                         DITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
 864                         break;
 865
 866                 case mfhc_op:
 867                         if (!cpu_has_mips_r2)
 868                                 goto sigill;
 869
 870                         /* copregister rd -> gpr[rt] */
 871                         if (MIPSInst_RT(ir) != 0) {
 872                                 SIFROMHREG(xcp->regs[MIPSInst_RT(ir)],
 873                                         MIPSInst_RD(ir));
 874                         }
 875                         break;
 876
 877                 case mthc_op:
 878                         if (!cpu_has_mips_r2)
 879                                 goto sigill;
 880
 881                         /* copregister rd <- gpr[rt] */
 882                         SITOHREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
 883                         break;
 884
 885                 case mfc_op:
 886                         /* copregister rd -> gpr[rt] */
 887                         if (MIPSInst_RT(ir) != 0) {
 888                                 SIFROMREG(xcp->regs[MIPSInst_RT(ir)],
 889                                         MIPSInst_RD(ir));
 890                         }
 891                         break;
 892
 893                 case mtc_op:
 894                         /* copregister rd <- rt */
 895                         SITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
 896                         break;
 897
 898                 case cfc_op:
 899                         /* cop control register rd -> gpr[rt] */
 900                         if (MIPSInst_RD(ir) == FPCREG_CSR) {
 901                                 value = ctx->fcr31;
 902                                 value = (value & ~FPU_CSR_RM) | modeindex(value);
 903                                 pr_debug("%p gpr[%d]<-csr=%08x\n",
 904                                          (void *) (xcp->cp0_epc),
 905                                          MIPSInst_RT(ir), value);
 906                         }
 907                         else if (MIPSInst_RD(ir) == FPCREG_RID)
 908                                 value = 0;
 909                         else
 910                                 value = 0;
 911                         if (MIPSInst_RT(ir))
 912                                 xcp->regs[MIPSInst_RT(ir)] = value;
 913                         break;
 914
 915                 case ctc_op:
 916                         /* copregister rd <- rt */
 917                         if (MIPSInst_RT(ir) == 0)
 918                                 value = 0;
 919                         else
 920                                 value = xcp->regs[MIPSInst_RT(ir)];
 921
 922                         /* we only have one writable control reg
 923                          */
 924                         if (MIPSInst_RD(ir) == FPCREG_CSR) {
 925                                 pr_debug("%p gpr[%d]->csr=%08x\n",
 926                                          (void *) (xcp->cp0_epc),
 927                                          MIPSInst_RT(ir), value);
 928
 929                                 /*
 930                                  * Don't write reserved bits,
 931                                  * and convert to ieee library modes
 932                                  */
 933                                 ctx->fcr31 = (value & ~(FPU_CSR_RSVD | FPU_CSR_RM)) |
 934                                              modeindex(value);
 935                         }
 936                         if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
 937                                 return SIGFPE;
 938                         }
 939                         break;
 940
 941                 case bc_op:
 942                         if (delay_slot(xcp))
 943                                 return SIGILL;
 944
 945                         if (cpu_has_mips_4_5_r)
 946                                 cbit = fpucondbit[MIPSInst_RT(ir) >> 2];
 947                         else
 948                                 cbit = FPU_CSR_COND;
 949                         cond = ctx->fcr31 & cbit;
 950
 951                         likely = 0;
 952                         switch (MIPSInst_RT(ir) & 3) {
 953                         case bcfl_op:
 954                                 likely = 1;
 955                         case bcf_op:
 956                                 cond = !cond;
 957                                 break;
 958                         case bctl_op:
 959                                 likely = 1;
 960                         case bct_op:
 961                                 break;
 962                         default:
 963                                 /* thats an illegal instruction */
 964                                 return SIGILL;
 965                         }
 966
 967                         set_delay_slot(xcp);
 968                         if (cond) {
 969                                 /*
 970                                  * Branch taken: emulate dslot instruction
 971                                  */
 972                                 xcp->cp0_epc += dec_insn.pc_inc;
 973
 974                                 contpc = MIPSInst_SIMM(ir);
 975                                 ir = dec_insn.next_insn;
 976                                 if (dec_insn.micro_mips_mode) {
 977                                         contpc = (xcp->cp0_epc + (contpc << 1));
 978
 979                                         /* If 16-bit instruction, not FPU. */
 980                                         if ((dec_insn.next_pc_inc == 2) ||
 981                                                 (microMIPS32_to_MIPS32((union mips_instruction *)&ir) == SIGILL)) {
 982
 983                                                 /*
 984                                                  * Since this instruction will
 985                                                  * be put on the stack with
 986                                                  * 32-bit words, get around
 987                                                  * this problem by putting a
 988                                                  * NOP16 as the second one.
 989                                                  */
 990                                                 if (dec_insn.next_pc_inc == 2)
 991                                                         ir = (ir & (~0xffff)) | MM_NOP16;
 992
 993                                                 /*
 994                                                  * Single step the non-CP1
 995                                                  * instruction in the dslot.
 996                                                  */
 997                                                 return mips_dsemul(xcp, ir, contpc);
 998                                         }
 999                                 } else
1000                                         contpc = (xcp->cp0_epc + (contpc << 2));
1001
1002                                 switch (MIPSInst_OPCODE(ir)) {
1003                                 case lwc1_op:
1004                                         goto emul;
1005
1006                                 case swc1_op:
1007                                         goto emul;
1008
1009                                 case ldc1_op:
1010                                 case sdc1_op:
1011                                         if (cpu_has_mips_2_3_4_5 ||
1012                                             cpu_has_mips64)
1013                                                 goto emul;
1014
1015                                         return SIGILL;
1016                                         goto emul;
1017
1018                                 case cop1_op:
1019                                         goto emul;
1020
1021                                 case cop1x_op:
1022                                         if (cpu_has_mips_4_5 || cpu_has_mips64 || cpu_has_mips32r2)
1023                                                 /* its one of ours */
1024                                                 goto emul;
1025
1026                                         return SIGILL;
1027
1028                                 case spec_op:
1029                                         if (!cpu_has_mips_4_5_r)
1030                                                 return SIGILL;
1031
1032                                         if (MIPSInst_FUNC(ir) == movc_op)
1033                                                 goto emul;
1034                                         break;
1035                                 }
1036
1037                                 /*
1038                                  * Single step the non-cp1
1039                                  * instruction in the dslot
1040                                  */
1041                                 return mips_dsemul(xcp, ir, contpc);
1042                         } else if (likely) {    /* branch not taken */
1043                                         /*
1044                                          * branch likely nullifies
1045                                          * dslot if not taken
1046                                          */
1047                                         xcp->cp0_epc += dec_insn.pc_inc;
1048                                         contpc += dec_insn.pc_inc;
1049                                         /*
1050                                          * else continue & execute
1051                                          * dslot as normal insn
1052                                          */
1053                                 }
1054                         break;
1055
1056                 default:
1057                         if (!(MIPSInst_RS(ir) & 0x10))
1058                                 return SIGILL;
1059
1060                         /* a real fpu computation instruction */
1061                         if ((sig = fpu_emu(xcp, ctx, ir)))
1062                                 return sig;
1063                 }
1064                 break;
1065
1066         case cop1x_op:
1067                 if (!cpu_has_mips_4_5 && !cpu_has_mips64 && !cpu_has_mips32r2)
1068                         return SIGILL;
1069
1070                 sig = fpux_emu(xcp, ctx, ir, fault_addr);
1071                 if (sig)
1072                         return sig;
1073                 break;
1074
1075         case spec_op:
1076                 if (!cpu_has_mips_4_5_r)
1077                         return SIGILL;
1078
1079                 if (MIPSInst_FUNC(ir) != movc_op)
1080                         return SIGILL;
1081                 cond = fpucondbit[MIPSInst_RT(ir) >> 2];
1082                 if (((ctx->fcr31 & cond) != 0) == ((MIPSInst_RT(ir) & 1) != 0))
1083                         xcp->regs[MIPSInst_RD(ir)] =
1084                                 xcp->regs[MIPSInst_RS(ir)];
1085                 break;
1086         default:
1087 sigill:
1088                 return SIGILL;
1089         }
1090
1091         /* we did it !! */
1092         xcp->cp0_epc = contpc;
1093         clear_delay_slot(xcp);
1094
1095         return 0;
1096 }
1097
1098 /*
1099  * Conversion table from MIPS compare ops 48-63
1100  * cond = ieee754dp_cmp(x,y,IEEE754_UN,sig);
1101  */
1102 static const unsigned char cmptab[8] = {
1103         0,                      /* cmp_0 (sig) cmp_sf */
1104         IEEE754_CUN,            /* cmp_un (sig) cmp_ngle */
1105         IEEE754_CEQ,            /* cmp_eq (sig) cmp_seq */
1106         IEEE754_CEQ | IEEE754_CUN,      /* cmp_ueq (sig) cmp_ngl  */
1107         IEEE754_CLT,            /* cmp_olt (sig) cmp_lt */
1108         IEEE754_CLT | IEEE754_CUN,      /* cmp_ult (sig) cmp_nge */
1109         IEEE754_CLT | IEEE754_CEQ,      /* cmp_ole (sig) cmp_le */
1110         IEEE754_CLT | IEEE754_CEQ | IEEE754_CUN,        /* cmp_ule (sig) cmp_ngt */
1111 };
1112
1113
1114 /*
1115  * Additional MIPS4 instructions
1116  */
1117
1118 #define DEF3OP(name, p, f1, f2, f3)                                     \
1119 static union ieee754##p fpemu_##p##_##name(union ieee754##p r,          \
1120         union ieee754##p s, union ieee754##p t)                         \
1121 {                                                                       \
1122         struct _ieee754_csr ieee754_csr_save;                           \
1123         s = f1(s, t);                                                   \
1124         ieee754_csr_save = ieee754_csr;                                 \
1125         s = f2(s, r);                                                   \
1126         ieee754_csr_save.cx |= ieee754_csr.cx;                          \
1127         ieee754_csr_save.sx |= ieee754_csr.sx;                          \
1128         s = f3(s);                                                      \
1129         ieee754_csr.cx |= ieee754_csr_save.cx;                          \
1130         ieee754_csr.sx |= ieee754_csr_save.sx;                          \
1131         return s;                                                       \
1132 }
1133
1134 static union ieee754dp fpemu_dp_recip(union ieee754dp d)
1135 {
1136         return ieee754dp_div(ieee754dp_one(0), d);
1137 }
1138
1139 static union ieee754dp fpemu_dp_rsqrt(union ieee754dp d)
1140 {
1141         return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d));
1142 }
1143
1144 static union ieee754sp fpemu_sp_recip(union ieee754sp s)
1145 {
1146         return ieee754sp_div(ieee754sp_one(0), s);
1147 }
1148
1149 static union ieee754sp fpemu_sp_rsqrt(union ieee754sp s)
1150 {
1151         return ieee754sp_div(ieee754sp_one(0), ieee754sp_sqrt(s));
1152 }
1153
1154 DEF3OP(madd, sp, ieee754sp_mul, ieee754sp_add, );
1155 DEF3OP(msub, sp, ieee754sp_mul, ieee754sp_sub, );
1156 DEF3OP(nmadd, sp, ieee754sp_mul, ieee754sp_add, ieee754sp_neg);
1157 DEF3OP(nmsub, sp, ieee754sp_mul, ieee754sp_sub, ieee754sp_neg);
1158 DEF3OP(madd, dp, ieee754dp_mul, ieee754dp_add, );
1159 DEF3OP(msub, dp, ieee754dp_mul, ieee754dp_sub, );
1160 DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg);
1161 DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg);
1162
1163 static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1164         mips_instruction ir, void *__user *fault_addr)
1165 {
1166         unsigned rcsr = 0;      /* resulting csr */
1167
1168         MIPS_FPU_EMU_INC_STATS(cp1xops);
1169
1170         switch (MIPSInst_FMA_FFMT(ir)) {
1171         case s_fmt:{            /* 0 */
1172
1173                 union ieee754sp(*handler) (union ieee754sp, union ieee754sp, union ieee754sp);
1174                 union ieee754sp fd, fr, fs, ft;
1175                 u32 __user *va;
1176                 u32 val;
1177
1178                 switch (MIPSInst_FUNC(ir)) {
1179                 case lwxc1_op:
1180                         va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1181                                 xcp->regs[MIPSInst_FT(ir)]);
1182
1183                         MIPS_FPU_EMU_INC_STATS(loads);
1184                         if (!access_ok(VERIFY_READ, va, sizeof(u32))) {
1185                                 MIPS_FPU_EMU_INC_STATS(errors);
1186                                 *fault_addr = va;
1187                                 return SIGBUS;
1188                         }
1189                         if (__get_user(val, va)) {
1190                                 MIPS_FPU_EMU_INC_STATS(errors);
1191                                 *fault_addr = va;
1192                                 return SIGSEGV;
1193                         }
1194                         SITOREG(val, MIPSInst_FD(ir));
1195                         break;
1196
1197                 case swxc1_op:
1198                         va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1199                                 xcp->regs[MIPSInst_FT(ir)]);
1200
1201                         MIPS_FPU_EMU_INC_STATS(stores);
1202
1203                         SIFROMREG(val, MIPSInst_FS(ir));
1204                         if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) {
1205                                 MIPS_FPU_EMU_INC_STATS(errors);
1206                                 *fault_addr = va;
1207                                 return SIGBUS;
1208                         }
1209                         if (put_user(val, va)) {
1210                                 MIPS_FPU_EMU_INC_STATS(errors);
1211                                 *fault_addr = va;
1212                                 return SIGSEGV;
1213                         }
1214                         break;
1215
1216                 case madd_s_op:
1217                         handler = fpemu_sp_madd;
1218                         goto scoptop;
1219                 case msub_s_op:
1220                         handler = fpemu_sp_msub;
1221                         goto scoptop;
1222                 case nmadd_s_op:
1223                         handler = fpemu_sp_nmadd;
1224                         goto scoptop;
1225                 case nmsub_s_op:
1226                         handler = fpemu_sp_nmsub;
1227                         goto scoptop;
1228
1229                       scoptop:
1230                         SPFROMREG(fr, MIPSInst_FR(ir));
1231                         SPFROMREG(fs, MIPSInst_FS(ir));
1232                         SPFROMREG(ft, MIPSInst_FT(ir));
1233                         fd = (*handler) (fr, fs, ft);
1234                         SPTOREG(fd, MIPSInst_FD(ir));
1235
1236                       copcsr:
1237                         if (ieee754_cxtest(IEEE754_INEXACT)) {
1238                                 MIPS_FPU_EMU_INC_STATS(ieee754_inexact);
1239                                 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
1240                         }
1241                         if (ieee754_cxtest(IEEE754_UNDERFLOW)) {
1242                                 MIPS_FPU_EMU_INC_STATS(ieee754_underflow);
1243                                 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
1244                         }
1245                         if (ieee754_cxtest(IEEE754_OVERFLOW)) {
1246                                 MIPS_FPU_EMU_INC_STATS(ieee754_overflow);
1247                                 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
1248                         }
1249                         if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) {
1250                                 MIPS_FPU_EMU_INC_STATS(ieee754_invalidop);
1251                                 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
1252                         }
1253
1254                         ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
1255                         if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1256                                 /*printk ("SIGFPE: FPU csr = %08x\n",
1257                                    ctx->fcr31); */
1258                                 return SIGFPE;
1259                         }
1260
1261                         break;
1262
1263                 default:
1264                         return SIGILL;
1265                 }
1266                 break;
1267         }
1268
1269         case d_fmt:{            /* 1 */
1270                 union ieee754dp(*handler) (union ieee754dp, union ieee754dp, union ieee754dp);
1271                 union ieee754dp fd, fr, fs, ft;
1272                 u64 __user *va;
1273                 u64 val;
1274
1275                 switch (MIPSInst_FUNC(ir)) {
1276                 case ldxc1_op:
1277                         va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1278                                 xcp->regs[MIPSInst_FT(ir)]);
1279
1280                         MIPS_FPU_EMU_INC_STATS(loads);
1281                         if (!access_ok(VERIFY_READ, va, sizeof(u64))) {
1282                                 MIPS_FPU_EMU_INC_STATS(errors);
1283                                 *fault_addr = va;
1284                                 return SIGBUS;
1285                         }
1286                         if (__get_user(val, va)) {
1287                                 MIPS_FPU_EMU_INC_STATS(errors);
1288                                 *fault_addr = va;
1289                                 return SIGSEGV;
1290                         }
1291                         DITOREG(val, MIPSInst_FD(ir));
1292                         break;
1293
1294                 case sdxc1_op:
1295                         va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1296                                 xcp->regs[MIPSInst_FT(ir)]);
1297
1298                         MIPS_FPU_EMU_INC_STATS(stores);
1299                         DIFROMREG(val, MIPSInst_FS(ir));
1300                         if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) {
1301                                 MIPS_FPU_EMU_INC_STATS(errors);
1302                                 *fault_addr = va;
1303                                 return SIGBUS;
1304                         }
1305                         if (__put_user(val, va)) {
1306                                 MIPS_FPU_EMU_INC_STATS(errors);
1307                                 *fault_addr = va;
1308                                 return SIGSEGV;
1309                         }
1310                         break;
1311
1312                 case madd_d_op:
1313                         handler = fpemu_dp_madd;
1314                         goto dcoptop;
1315                 case msub_d_op:
1316                         handler = fpemu_dp_msub;
1317                         goto dcoptop;
1318                 case nmadd_d_op:
1319                         handler = fpemu_dp_nmadd;
1320                         goto dcoptop;
1321                 case nmsub_d_op:
1322                         handler = fpemu_dp_nmsub;
1323                         goto dcoptop;
1324
1325                       dcoptop:
1326                         DPFROMREG(fr, MIPSInst_FR(ir));
1327                         DPFROMREG(fs, MIPSInst_FS(ir));
1328                         DPFROMREG(ft, MIPSInst_FT(ir));
1329                         fd = (*handler) (fr, fs, ft);
1330                         DPTOREG(fd, MIPSInst_FD(ir));
1331                         goto copcsr;
1332
1333                 default:
1334                         return SIGILL;
1335                 }
1336                 break;
1337         }
1338
1339         case 0x3:
1340                 if (MIPSInst_FUNC(ir) != pfetch_op)
1341                         return SIGILL;
1342
1343                 /* ignore prefx operation */
1344                 break;
1345
1346         default:
1347                 return SIGILL;
1348         }
1349
1350         return 0;
1351 }
1352
1353
1354
1355 /*
1356  * Emulate a single COP1 arithmetic instruction.
1357  */
1358 static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1359         mips_instruction ir)
1360 {
1361         int rfmt;               /* resulting format */
1362         unsigned rcsr = 0;      /* resulting csr */
1363         unsigned int oldrm;
1364         unsigned int cbit;
1365         unsigned cond;
1366         union {
1367                 union ieee754dp d;
1368                 union ieee754sp s;
1369                 int w;
1370                 s64 l;
1371         } rv;                   /* resulting value */
1372         u64 bits;
1373
1374         MIPS_FPU_EMU_INC_STATS(cp1ops);
1375         switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) {
1376         case s_fmt: {           /* 0 */
1377                 union {
1378                         union ieee754sp(*b) (union ieee754sp, union ieee754sp);
1379                         union ieee754sp(*u) (union ieee754sp);
1380                 } handler;
1381                 union ieee754sp fs, ft;
1382
1383                 switch (MIPSInst_FUNC(ir)) {
1384                         /* binary ops */
1385                 case fadd_op:
1386                         handler.b = ieee754sp_add;
1387                         goto scopbop;
1388                 case fsub_op:
1389                         handler.b = ieee754sp_sub;
1390                         goto scopbop;
1391                 case fmul_op:
1392                         handler.b = ieee754sp_mul;
1393                         goto scopbop;
1394                 case fdiv_op:
1395                         handler.b = ieee754sp_div;
1396                         goto scopbop;
1397
1398                         /* unary  ops */
1399                 case fsqrt_op:
1400                         if (!cpu_has_mips_4_5_r)
1401                                 return SIGILL;
1402
1403                         handler.u = ieee754sp_sqrt;
1404                         goto scopuop;
1405
1406                 /*
1407                  * Note that on some MIPS IV implementations such as the
1408                  * R5000 and R8000 the FSQRT and FRECIP instructions do not
1409                  * achieve full IEEE-754 accuracy - however this emulator does.
1410                  */
1411                 case frsqrt_op:
1412                         if (!cpu_has_mips_4_5_r2)
1413                                 return SIGILL;
1414
1415                         handler.u = fpemu_sp_rsqrt;
1416                         goto scopuop;
1417
1418                 case frecip_op:
1419                         if (!cpu_has_mips_4_5_r2)
1420                                 return SIGILL;
1421
1422                         handler.u = fpemu_sp_recip;
1423                         goto scopuop;
1424
1425                 case fmovc_op:
1426                         if (!cpu_has_mips_4_5_r)
1427                                 return SIGILL;
1428
1429                         cond = fpucondbit[MIPSInst_FT(ir) >> 2];
1430                         if (((ctx->fcr31 & cond) != 0) !=
1431                                 ((MIPSInst_FT(ir) & 1) != 0))
1432                                 return 0;
1433                         SPFROMREG(rv.s, MIPSInst_FS(ir));
1434                         break;
1435
1436                 case fmovz_op:
1437                         if (!cpu_has_mips_4_5_r)
1438                                 return SIGILL;
1439
1440                         if (xcp->regs[MIPSInst_FT(ir)] != 0)
1441                                 return 0;
1442                         SPFROMREG(rv.s, MIPSInst_FS(ir));
1443                         break;
1444
1445                 case fmovn_op:
1446                         if (!cpu_has_mips_4_5_r)
1447                                 return SIGILL;
1448
1449                         if (xcp->regs[MIPSInst_FT(ir)] == 0)
1450                                 return 0;
1451                         SPFROMREG(rv.s, MIPSInst_FS(ir));
1452                         break;
1453
1454                 case fabs_op:
1455                         handler.u = ieee754sp_abs;
1456                         goto scopuop;
1457
1458                 case fneg_op:
1459                         handler.u = ieee754sp_neg;
1460                         goto scopuop;
1461
1462                 case fmov_op:
1463                         /* an easy one */
1464                         SPFROMREG(rv.s, MIPSInst_FS(ir));
1465                         goto copcsr;
1466
1467                         /* binary op on handler */
1468 scopbop:
1469                         SPFROMREG(fs, MIPSInst_FS(ir));
1470                         SPFROMREG(ft, MIPSInst_FT(ir));
1471
1472                         rv.s = (*handler.b) (fs, ft);
1473                         goto copcsr;
1474 scopuop:
1475                         SPFROMREG(fs, MIPSInst_FS(ir));
1476                         rv.s = (*handler.u) (fs);
1477                         goto copcsr;
1478 copcsr:
1479                         if (ieee754_cxtest(IEEE754_INEXACT)) {
1480                                 MIPS_FPU_EMU_INC_STATS(ieee754_inexact);
1481                                 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
1482                         }
1483                         if (ieee754_cxtest(IEEE754_UNDERFLOW)) {
1484                                 MIPS_FPU_EMU_INC_STATS(ieee754_underflow);
1485                                 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
1486                         }
1487                         if (ieee754_cxtest(IEEE754_OVERFLOW)) {
1488                                 MIPS_FPU_EMU_INC_STATS(ieee754_overflow);
1489                                 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
1490                         }
1491                         if (ieee754_cxtest(IEEE754_ZERO_DIVIDE)) {
1492                                 MIPS_FPU_EMU_INC_STATS(ieee754_zerodiv);
1493                                 rcsr |= FPU_CSR_DIV_X | FPU_CSR_DIV_S;
1494                         }
1495                         if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) {
1496                                 MIPS_FPU_EMU_INC_STATS(ieee754_invalidop);
1497                                 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
1498                         }
1499                         break;
1500
1501                         /* unary conv ops */
1502                 case fcvts_op:
1503                         return SIGILL;  /* not defined */
1504
1505                 case fcvtd_op:
1506                         SPFROMREG(fs, MIPSInst_FS(ir));
1507                         rv.d = ieee754dp_fsp(fs);
1508                         rfmt = d_fmt;
1509                         goto copcsr;
1510
1511                 case fcvtw_op:
1512                         SPFROMREG(fs, MIPSInst_FS(ir));
1513                         rv.w = ieee754sp_tint(fs);
1514                         rfmt = w_fmt;
1515                         goto copcsr;
1516
1517                 case fround_op:
1518                 case ftrunc_op:
1519                 case fceil_op:
1520                 case ffloor_op:
1521                         if (!cpu_has_mips_2_3_4_5 && !cpu_has_mips64)
1522                                 return SIGILL;
1523
1524                         oldrm = ieee754_csr.rm;
1525                         SPFROMREG(fs, MIPSInst_FS(ir));
1526                         ieee754_csr.rm = modeindex(MIPSInst_FUNC(ir));
1527                         rv.w = ieee754sp_tint(fs);
1528                         ieee754_csr.rm = oldrm;
1529                         rfmt = w_fmt;
1530                         goto copcsr;
1531
1532                 case fcvtl_op:
1533                         if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
1534                                 return SIGILL;
1535
1536                         SPFROMREG(fs, MIPSInst_FS(ir));
1537                         rv.l = ieee754sp_tlong(fs);
1538                         rfmt = l_fmt;
1539                         goto copcsr;
1540
1541                 case froundl_op:
1542                 case ftruncl_op:
1543                 case fceill_op:
1544                 case ffloorl_op:
1545                         if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
1546                                 return SIGILL;
1547
1548                         oldrm = ieee754_csr.rm;
1549                         SPFROMREG(fs, MIPSInst_FS(ir));
1550                         ieee754_csr.rm = modeindex(MIPSInst_FUNC(ir));
1551                         rv.l = ieee754sp_tlong(fs);
1552                         ieee754_csr.rm = oldrm;
1553                         rfmt = l_fmt;
1554                         goto copcsr;
1555
1556                 default:
1557                         if (MIPSInst_FUNC(ir) >= fcmp_op) {
1558                                 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
1559                                 union ieee754sp fs, ft;
1560
1561                                 SPFROMREG(fs, MIPSInst_FS(ir));
1562                                 SPFROMREG(ft, MIPSInst_FT(ir));
1563                                 rv.w = ieee754sp_cmp(fs, ft,
1564                                         cmptab[cmpop & 0x7], cmpop & 0x8);
1565                                 rfmt = -1;
1566                                 if ((cmpop & 0x8) && ieee754_cxtest
1567                                         (IEEE754_INVALID_OPERATION))
1568                                         rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
1569                                 else
1570                                         goto copcsr;
1571
1572                         } else
1573                                 return SIGILL;
1574                         break;
1575                 }
1576                 break;
1577         }
1578
1579         case d_fmt: {
1580                 union ieee754dp fs, ft;
1581                 union {
1582                         union ieee754dp(*b) (union ieee754dp, union ieee754dp);
1583                         union ieee754dp(*u) (union ieee754dp);
1584                 } handler;
1585
1586                 switch (MIPSInst_FUNC(ir)) {
1587                         /* binary ops */
1588                 case fadd_op:
1589                         handler.b = ieee754dp_add;
1590                         goto dcopbop;
1591                 case fsub_op:
1592                         handler.b = ieee754dp_sub;
1593                         goto dcopbop;
1594                 case fmul_op:
1595                         handler.b = ieee754dp_mul;
1596                         goto dcopbop;
1597                 case fdiv_op:
1598                         handler.b = ieee754dp_div;
1599                         goto dcopbop;
1600
1601                         /* unary  ops */
1602                 case fsqrt_op:
1603                         if (!cpu_has_mips_2_3_4_5_r)
1604                                 return SIGILL;
1605
1606                         handler.u = ieee754dp_sqrt;
1607                         goto dcopuop;
1608                 /*
1609                  * Note that on some MIPS IV implementations such as the
1610                  * R5000 and R8000 the FSQRT and FRECIP instructions do not
1611                  * achieve full IEEE-754 accuracy - however this emulator does.
1612                  */
1613                 case frsqrt_op:
1614                         if (!cpu_has_mips_4_5_r2)
1615                                 return SIGILL;
1616
1617                         handler.u = fpemu_dp_rsqrt;
1618                         goto dcopuop;
1619                 case frecip_op:
1620                         if (!cpu_has_mips_4_5_r2)
1621                                 return SIGILL;
1622
1623                         handler.u = fpemu_dp_recip;
1624                         goto dcopuop;
1625                 case fmovc_op:
1626                         if (!cpu_has_mips_4_5_r)
1627                                 return SIGILL;
1628
1629                         cond = fpucondbit[MIPSInst_FT(ir) >> 2];
1630                         if (((ctx->fcr31 & cond) != 0) !=
1631                                 ((MIPSInst_FT(ir) & 1) != 0))
1632                                 return 0;
1633                         DPFROMREG(rv.d, MIPSInst_FS(ir));
1634                         break;
1635                 case fmovz_op:
1636                         if (!cpu_has_mips_4_5_r)
1637                                 return SIGILL;
1638
1639                         if (xcp->regs[MIPSInst_FT(ir)] != 0)
1640                                 return 0;
1641                         DPFROMREG(rv.d, MIPSInst_FS(ir));
1642                         break;
1643                 case fmovn_op:
1644                         if (!cpu_has_mips_4_5_r)
1645                                 return SIGILL;
1646
1647                         if (xcp->regs[MIPSInst_FT(ir)] == 0)
1648                                 return 0;
1649                         DPFROMREG(rv.d, MIPSInst_FS(ir));
1650                         break;
1651                 case fabs_op:
1652                         handler.u = ieee754dp_abs;
1653                         goto dcopuop;
1654
1655                 case fneg_op:
1656                         handler.u = ieee754dp_neg;
1657                         goto dcopuop;
1658
1659                 case fmov_op:
1660                         /* an easy one */
1661                         DPFROMREG(rv.d, MIPSInst_FS(ir));
1662                         goto copcsr;
1663
1664                         /* binary op on handler */
1665 dcopbop:
1666                         DPFROMREG(fs, MIPSInst_FS(ir));
1667                         DPFROMREG(ft, MIPSInst_FT(ir));
1668
1669                         rv.d = (*handler.b) (fs, ft);
1670                         goto copcsr;
1671 dcopuop:
1672                         DPFROMREG(fs, MIPSInst_FS(ir));
1673                         rv.d = (*handler.u) (fs);
1674                         goto copcsr;
1675
1676                 /*
1677                  * unary conv ops
1678                  */
1679                 case fcvts_op:
1680                         DPFROMREG(fs, MIPSInst_FS(ir));
1681                         rv.s = ieee754sp_fdp(fs);
1682                         rfmt = s_fmt;
1683                         goto copcsr;
1684
1685                 case fcvtd_op:
1686                         return SIGILL;  /* not defined */
1687
1688                 case fcvtw_op:
1689                         DPFROMREG(fs, MIPSInst_FS(ir));
1690                         rv.w = ieee754dp_tint(fs);      /* wrong */
1691                         rfmt = w_fmt;
1692                         goto copcsr;
1693
1694                 case fround_op:
1695                 case ftrunc_op:
1696                 case fceil_op:
1697                 case ffloor_op:
1698                         if (!cpu_has_mips_2_3_4_5_r)
1699                                 return SIGILL;
1700
1701                         oldrm = ieee754_csr.rm;
1702                         DPFROMREG(fs, MIPSInst_FS(ir));
1703                         ieee754_csr.rm = modeindex(MIPSInst_FUNC(ir));
1704                         rv.w = ieee754dp_tint(fs);
1705                         ieee754_csr.rm = oldrm;
1706                         rfmt = w_fmt;
1707                         goto copcsr;
1708
1709                 case fcvtl_op:
1710                         if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
1711                                 return SIGILL;
1712
1713                         DPFROMREG(fs, MIPSInst_FS(ir));
1714                         rv.l = ieee754dp_tlong(fs);
1715                         rfmt = l_fmt;
1716                         goto copcsr;
1717
1718                 case froundl_op:
1719                 case ftruncl_op:
1720                 case fceill_op:
1721                 case ffloorl_op:
1722                         if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
1723                                 return SIGILL;
1724
1725                         oldrm = ieee754_csr.rm;
1726                         DPFROMREG(fs, MIPSInst_FS(ir));
1727                         ieee754_csr.rm = modeindex(MIPSInst_FUNC(ir));
1728                         rv.l = ieee754dp_tlong(fs);
1729                         ieee754_csr.rm = oldrm;
1730                         rfmt = l_fmt;
1731                         goto copcsr;
1732
1733                 default:
1734                         if (MIPSInst_FUNC(ir) >= fcmp_op) {
1735                                 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
1736                                 union ieee754dp fs, ft;
1737
1738                                 DPFROMREG(fs, MIPSInst_FS(ir));
1739                                 DPFROMREG(ft, MIPSInst_FT(ir));
1740                                 rv.w = ieee754dp_cmp(fs, ft,
1741                                         cmptab[cmpop & 0x7], cmpop & 0x8);
1742                                 rfmt = -1;
1743                                 if ((cmpop & 0x8)
1744                                         &&
1745                                         ieee754_cxtest
1746                                         (IEEE754_INVALID_OPERATION))
1747                                         rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
1748                                 else
1749                                         goto copcsr;
1750
1751                         }
1752                         else {
1753                                 return SIGILL;
1754                         }
1755                         break;
1756                 }
1757                 break;
1758
1759         case w_fmt:
1760                 switch (MIPSInst_FUNC(ir)) {
1761                 case fcvts_op:
1762                         /* convert word to single precision real */
1763                         SPFROMREG(fs, MIPSInst_FS(ir));
1764                         rv.s = ieee754sp_fint(fs.bits);
1765                         rfmt = s_fmt;
1766                         goto copcsr;
1767                 case fcvtd_op:
1768                         /* convert word to double precision real */
1769                         SPFROMREG(fs, MIPSInst_FS(ir));
1770                         rv.d = ieee754dp_fint(fs.bits);
1771                         rfmt = d_fmt;
1772                         goto copcsr;
1773                 default:
1774                         return SIGILL;
1775                 }
1776                 break;
1777         }
1778
1779         case l_fmt:
1780
1781                 if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
1782                         return SIGILL;
1783
1784                 DIFROMREG(bits, MIPSInst_FS(ir));
1785
1786                 switch (MIPSInst_FUNC(ir)) {
1787                 case fcvts_op:
1788                         /* convert long to single precision real */
1789                         rv.s = ieee754sp_flong(bits);
1790                         rfmt = s_fmt;
1791                         goto copcsr;
1792                 case fcvtd_op:
1793                         /* convert long to double precision real */
1794                         rv.d = ieee754dp_flong(bits);
1795                         rfmt = d_fmt;
1796                         goto copcsr;
1797                 default:
1798                         return SIGILL;
1799                 }
1800                 break;
1801
1802         default:
1803                 return SIGILL;
1804         }
1805
1806         /*
1807          * Update the fpu CSR register for this operation.
1808          * If an exception is required, generate a tidy SIGFPE exception,
1809          * without updating the result register.
1810          * Note: cause exception bits do not accumulate, they are rewritten
1811          * for each op; only the flag/sticky bits accumulate.
1812          */
1813         ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
1814         if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1815                 /*printk ("SIGFPE: FPU csr = %08x\n",ctx->fcr31); */
1816                 return SIGFPE;
1817         }
1818
1819         /*
1820          * Now we can safely write the result back to the register file.
1821          */
1822         switch (rfmt) {
1823         case -1:
1824
1825                 if (cpu_has_mips_4_5_r)
1826                         cbit = fpucondbit[MIPSInst_FD(ir) >> 2];
1827                 else
1828                         cbit = FPU_CSR_COND;
1829                 if (rv.w)
1830                         ctx->fcr31 |= cbit;
1831                 else
1832                         ctx->fcr31 &= ~cbit;
1833                 break;
1834
1835         case d_fmt:
1836                 DPTOREG(rv.d, MIPSInst_FD(ir));
1837                 break;
1838         case s_fmt:
1839                 SPTOREG(rv.s, MIPSInst_FD(ir));
1840                 break;
1841         case w_fmt:
1842                 SITOREG(rv.w, MIPSInst_FD(ir));
1843                 break;
1844         case l_fmt:
1845                 if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
1846                         return SIGILL;
1847
1848                 DITOREG(rv.l, MIPSInst_FD(ir));
1849                 break;
1850         default:
1851                 return SIGILL;
1852         }
1853
1854         return 0;
1855 }
1856
1857 int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1858         int has_fpu, void *__user *fault_addr)
1859 {
1860         unsigned long oldepc, prevepc;
1861         struct mm_decoded_insn dec_insn;
1862         u16 instr[4];
1863         u16 *instr_ptr;
1864         int sig = 0;
1865
1866         oldepc = xcp->cp0_epc;
1867         do {
1868                 prevepc = xcp->cp0_epc;
1869
1870                 if (get_isa16_mode(prevepc) && cpu_has_mmips) {
1871                         /*
1872                          * Get next 2 microMIPS instructions and convert them
1873                          * into 32-bit instructions.
1874                          */
1875                         if ((get_user(instr[0], (u16 __user *)msk_isa16_mode(xcp->cp0_epc))) ||
1876                             (get_user(instr[1], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 2))) ||
1877                             (get_user(instr[2], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 4))) ||
1878                             (get_user(instr[3], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 6)))) {
1879                                 MIPS_FPU_EMU_INC_STATS(errors);
1880                                 return SIGBUS;
1881                         }
1882                         instr_ptr = instr;
1883
1884                         /* Get first instruction. */
1885                         if (mm_insn_16bit(*instr_ptr)) {
1886                                 /* Duplicate the half-word. */
1887                                 dec_insn.insn = (*instr_ptr << 16) |
1888                                         (*instr_ptr);
1889                                 /* 16-bit instruction. */
1890                                 dec_insn.pc_inc = 2;
1891                                 instr_ptr += 1;
1892                         } else {
1893                                 dec_insn.insn = (*instr_ptr << 16) |
1894                                         *(instr_ptr+1);
1895                                 /* 32-bit instruction. */
1896                                 dec_insn.pc_inc = 4;
1897                                 instr_ptr += 2;
1898                         }
1899                         /* Get second instruction. */
1900                         if (mm_insn_16bit(*instr_ptr)) {
1901                                 /* Duplicate the half-word. */
1902                                 dec_insn.next_insn = (*instr_ptr << 16) |
1903                                         (*instr_ptr);
1904                                 /* 16-bit instruction. */
1905                                 dec_insn.next_pc_inc = 2;
1906                         } else {
1907                                 dec_insn.next_insn = (*instr_ptr << 16) |
1908                                         *(instr_ptr+1);
1909                                 /* 32-bit instruction. */
1910                                 dec_insn.next_pc_inc = 4;
1911                         }
1912                         dec_insn.micro_mips_mode = 1;
1913                 } else {
1914                         if ((get_user(dec_insn.insn,
1915                             (mips_instruction __user *) xcp->cp0_epc)) ||
1916                             (get_user(dec_insn.next_insn,
1917                             (mips_instruction __user *)(xcp->cp0_epc+4)))) {
1918                                 MIPS_FPU_EMU_INC_STATS(errors);
1919                                 return SIGBUS;
1920                         }
1921                         dec_insn.pc_inc = 4;
1922                         dec_insn.next_pc_inc = 4;
1923                         dec_insn.micro_mips_mode = 0;
1924                 }
1925
1926                 if ((dec_insn.insn == 0) ||
1927                    ((dec_insn.pc_inc == 2) &&
1928                    ((dec_insn.insn & 0xffff) == MM_NOP16)))
1929                         xcp->cp0_epc += dec_insn.pc_inc;        /* Skip NOPs */
1930                 else {
1931                         /*
1932                          * The 'ieee754_csr' is an alias of
1933                          * ctx->fcr31.  No need to copy ctx->fcr31 to
1934                          * ieee754_csr.  But ieee754_csr.rm is ieee
1935                          * library modes. (not mips rounding mode)
1936                          */
1937                         sig = cop1Emulate(xcp, ctx, dec_insn, fault_addr);
1938                 }
1939
1940                 if (has_fpu)
1941                         break;
1942                 if (sig)
1943                         break;
1944
1945                 cond_resched();
1946         } while (xcp->cp0_epc > prevepc);
1947
1948         /* SIGILL indicates a non-fpu instruction */
1949         if (sig == SIGILL && xcp->cp0_epc != oldepc)
1950                 /* but if EPC has advanced, then ignore it */
1951                 sig = 0;
1952
1953         return sig;
1954 }