linux/arch/mips/math-emu/cp1emu.c
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   1/*
   2 * cp1emu.c: a MIPS coprocessor 1 (FPU) instruction emulator
   3 *
   4 * MIPS floating point support
   5 * Copyright (C) 1994-2000 Algorithmics Ltd.
   6 *
   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/percpu-defs.h>
  39#include <linux/perf_event.h>
  40
  41#include <asm/branch.h>
  42#include <asm/inst.h>
  43#include <asm/ptrace.h>
  44#include <asm/signal.h>
  45#include <linux/uaccess.h>
  46
  47#include <asm/cpu-info.h>
  48#include <asm/processor.h>
  49#include <asm/fpu_emulator.h>
  50#include <asm/fpu.h>
  51#include <asm/mips-r2-to-r6-emul.h>
  52
  53#include "ieee754.h"
  54
  55/* Function which emulates a floating point instruction. */
  56
  57static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *,
  58        mips_instruction);
  59
  60static int fpux_emu(struct pt_regs *,
  61        struct mips_fpu_struct *, mips_instruction, void *__user *);
  62
  63/* Control registers */
  64
  65#define FPCREG_RID      0       /* $0  = revision id */
  66#define FPCREG_FCCR     25      /* $25 = fccr */
  67#define FPCREG_FEXR     26      /* $26 = fexr */
  68#define FPCREG_FENR     28      /* $28 = fenr */
  69#define FPCREG_CSR      31      /* $31 = csr */
  70
  71/* convert condition code register number to csr bit */
  72const unsigned int fpucondbit[8] = {
  73        FPU_CSR_COND,
  74        FPU_CSR_COND1,
  75        FPU_CSR_COND2,
  76        FPU_CSR_COND3,
  77        FPU_CSR_COND4,
  78        FPU_CSR_COND5,
  79        FPU_CSR_COND6,
  80        FPU_CSR_COND7
  81};
  82
  83/* (microMIPS) Convert certain microMIPS instructions to MIPS32 format. */
  84static const int sd_format[] = {16, 17, 0, 0, 0, 0, 0, 0};
  85static const int sdps_format[] = {16, 17, 22, 0, 0, 0, 0, 0};
  86static const int dwl_format[] = {17, 20, 21, 0, 0, 0, 0, 0};
  87static const int swl_format[] = {16, 20, 21, 0, 0, 0, 0, 0};
  88
  89/*
  90 * This functions translates a 32-bit microMIPS instruction
  91 * into a 32-bit MIPS32 instruction. Returns 0 on success
  92 * and SIGILL otherwise.
  93 */
  94static int microMIPS32_to_MIPS32(union mips_instruction *insn_ptr)
  95{
  96        union mips_instruction insn = *insn_ptr;
  97        union mips_instruction mips32_insn = insn;
  98        int func, fmt, op;
  99
 100        switch (insn.mm_i_format.opcode) {
 101        case mm_ldc132_op:
 102                mips32_insn.mm_i_format.opcode = ldc1_op;
 103                mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
 104                mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
 105                break;
 106        case mm_lwc132_op:
 107                mips32_insn.mm_i_format.opcode = lwc1_op;
 108                mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
 109                mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
 110                break;
 111        case mm_sdc132_op:
 112                mips32_insn.mm_i_format.opcode = sdc1_op;
 113                mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
 114                mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
 115                break;
 116        case mm_swc132_op:
 117                mips32_insn.mm_i_format.opcode = swc1_op;
 118                mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
 119                mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
 120                break;
 121        case mm_pool32i_op:
 122                /* NOTE: offset is << by 1 if in microMIPS mode. */
 123                if ((insn.mm_i_format.rt == mm_bc1f_op) ||
 124                    (insn.mm_i_format.rt == mm_bc1t_op)) {
 125                        mips32_insn.fb_format.opcode = cop1_op;
 126                        mips32_insn.fb_format.bc = bc_op;
 127                        mips32_insn.fb_format.flag =
 128                                (insn.mm_i_format.rt == mm_bc1t_op) ? 1 : 0;
 129                } else
 130                        return SIGILL;
 131                break;
 132        case mm_pool32f_op:
 133                switch (insn.mm_fp0_format.func) {
 134                case mm_32f_01_op:
 135                case mm_32f_11_op:
 136                case mm_32f_02_op:
 137                case mm_32f_12_op:
 138                case mm_32f_41_op:
 139                case mm_32f_51_op:
 140                case mm_32f_42_op:
 141                case mm_32f_52_op:
 142                        op = insn.mm_fp0_format.func;
 143                        if (op == mm_32f_01_op)
 144                                func = madd_s_op;
 145                        else if (op == mm_32f_11_op)
 146                                func = madd_d_op;
 147                        else if (op == mm_32f_02_op)
 148                                func = nmadd_s_op;
 149                        else if (op == mm_32f_12_op)
 150                                func = nmadd_d_op;
 151                        else if (op == mm_32f_41_op)
 152                                func = msub_s_op;
 153                        else if (op == mm_32f_51_op)
 154                                func = msub_d_op;
 155                        else if (op == mm_32f_42_op)
 156                                func = nmsub_s_op;
 157                        else
 158                                func = nmsub_d_op;
 159                        mips32_insn.fp6_format.opcode = cop1x_op;
 160                        mips32_insn.fp6_format.fr = insn.mm_fp6_format.fr;
 161                        mips32_insn.fp6_format.ft = insn.mm_fp6_format.ft;
 162                        mips32_insn.fp6_format.fs = insn.mm_fp6_format.fs;
 163                        mips32_insn.fp6_format.fd = insn.mm_fp6_format.fd;
 164                        mips32_insn.fp6_format.func = func;
 165                        break;
 166                case mm_32f_10_op:
 167                        func = -1;      /* Invalid */
 168                        op = insn.mm_fp5_format.op & 0x7;
 169                        if (op == mm_ldxc1_op)
 170                                func = ldxc1_op;
 171                        else if (op == mm_sdxc1_op)
 172                                func = sdxc1_op;
 173                        else if (op == mm_lwxc1_op)
 174                                func = lwxc1_op;
 175                        else if (op == mm_swxc1_op)
 176                                func = swxc1_op;
 177
 178                        if (func != -1) {
 179                                mips32_insn.r_format.opcode = cop1x_op;
 180                                mips32_insn.r_format.rs =
 181                                        insn.mm_fp5_format.base;
 182                                mips32_insn.r_format.rt =
 183                                        insn.mm_fp5_format.index;
 184                                mips32_insn.r_format.rd = 0;
 185                                mips32_insn.r_format.re = insn.mm_fp5_format.fd;
 186                                mips32_insn.r_format.func = func;
 187                        } else
 188                                return SIGILL;
 189                        break;
 190                case mm_32f_40_op:
 191                        op = -1;        /* Invalid */
 192                        if (insn.mm_fp2_format.op == mm_fmovt_op)
 193                                op = 1;
 194                        else if (insn.mm_fp2_format.op == mm_fmovf_op)
 195                                op = 0;
 196                        if (op != -1) {
 197                                mips32_insn.fp0_format.opcode = cop1_op;
 198                                mips32_insn.fp0_format.fmt =
 199                                        sdps_format[insn.mm_fp2_format.fmt];
 200                                mips32_insn.fp0_format.ft =
 201                                        (insn.mm_fp2_format.cc<<2) + op;
 202                                mips32_insn.fp0_format.fs =
 203                                        insn.mm_fp2_format.fs;
 204                                mips32_insn.fp0_format.fd =
 205                                        insn.mm_fp2_format.fd;
 206                                mips32_insn.fp0_format.func = fmovc_op;
 207                        } else
 208                                return SIGILL;
 209                        break;
 210                case mm_32f_60_op:
 211                        func = -1;      /* Invalid */
 212                        if (insn.mm_fp0_format.op == mm_fadd_op)
 213                                func = fadd_op;
 214                        else if (insn.mm_fp0_format.op == mm_fsub_op)
 215                                func = fsub_op;
 216                        else if (insn.mm_fp0_format.op == mm_fmul_op)
 217                                func = fmul_op;
 218                        else if (insn.mm_fp0_format.op == mm_fdiv_op)
 219                                func = fdiv_op;
 220                        if (func != -1) {
 221                                mips32_insn.fp0_format.opcode = cop1_op;
 222                                mips32_insn.fp0_format.fmt =
 223                                        sdps_format[insn.mm_fp0_format.fmt];
 224                                mips32_insn.fp0_format.ft =
 225                                        insn.mm_fp0_format.ft;
 226                                mips32_insn.fp0_format.fs =
 227                                        insn.mm_fp0_format.fs;
 228                                mips32_insn.fp0_format.fd =
 229                                        insn.mm_fp0_format.fd;
 230                                mips32_insn.fp0_format.func = func;
 231                        } else
 232                                return SIGILL;
 233                        break;
 234                case mm_32f_70_op:
 235                        func = -1;      /* Invalid */
 236                        if (insn.mm_fp0_format.op == mm_fmovn_op)
 237                                func = fmovn_op;
 238                        else if (insn.mm_fp0_format.op == mm_fmovz_op)
 239                                func = fmovz_op;
 240                        if (func != -1) {
 241                                mips32_insn.fp0_format.opcode = cop1_op;
 242                                mips32_insn.fp0_format.fmt =
 243                                        sdps_format[insn.mm_fp0_format.fmt];
 244                                mips32_insn.fp0_format.ft =
 245                                        insn.mm_fp0_format.ft;
 246                                mips32_insn.fp0_format.fs =
 247                                        insn.mm_fp0_format.fs;
 248                                mips32_insn.fp0_format.fd =
 249                                        insn.mm_fp0_format.fd;
 250                                mips32_insn.fp0_format.func = func;
 251                        } else
 252                                return SIGILL;
 253                        break;
 254                case mm_32f_73_op:    /* POOL32FXF */
 255                        switch (insn.mm_fp1_format.op) {
 256                        case mm_movf0_op:
 257                        case mm_movf1_op:
 258                        case mm_movt0_op:
 259                        case mm_movt1_op:
 260                                if ((insn.mm_fp1_format.op & 0x7f) ==
 261                                    mm_movf0_op)
 262                                        op = 0;
 263                                else
 264                                        op = 1;
 265                                mips32_insn.r_format.opcode = spec_op;
 266                                mips32_insn.r_format.rs = insn.mm_fp4_format.fs;
 267                                mips32_insn.r_format.rt =
 268                                        (insn.mm_fp4_format.cc << 2) + op;
 269                                mips32_insn.r_format.rd = insn.mm_fp4_format.rt;
 270                                mips32_insn.r_format.re = 0;
 271                                mips32_insn.r_format.func = movc_op;
 272                                break;
 273                        case mm_fcvtd0_op:
 274                        case mm_fcvtd1_op:
 275                        case mm_fcvts0_op:
 276                        case mm_fcvts1_op:
 277                                if ((insn.mm_fp1_format.op & 0x7f) ==
 278                                    mm_fcvtd0_op) {
 279                                        func = fcvtd_op;
 280                                        fmt = swl_format[insn.mm_fp3_format.fmt];
 281                                } else {
 282                                        func = fcvts_op;
 283                                        fmt = dwl_format[insn.mm_fp3_format.fmt];
 284                                }
 285                                mips32_insn.fp0_format.opcode = cop1_op;
 286                                mips32_insn.fp0_format.fmt = fmt;
 287                                mips32_insn.fp0_format.ft = 0;
 288                                mips32_insn.fp0_format.fs =
 289                                        insn.mm_fp3_format.fs;
 290                                mips32_insn.fp0_format.fd =
 291                                        insn.mm_fp3_format.rt;
 292                                mips32_insn.fp0_format.func = func;
 293                                break;
 294                        case mm_fmov0_op:
 295                        case mm_fmov1_op:
 296                        case mm_fabs0_op:
 297                        case mm_fabs1_op:
 298                        case mm_fneg0_op:
 299                        case mm_fneg1_op:
 300                                if ((insn.mm_fp1_format.op & 0x7f) ==
 301                                    mm_fmov0_op)
 302                                        func = fmov_op;
 303                                else if ((insn.mm_fp1_format.op & 0x7f) ==
 304                                         mm_fabs0_op)
 305                                        func = fabs_op;
 306                                else
 307                                        func = fneg_op;
 308                                mips32_insn.fp0_format.opcode = cop1_op;
 309                                mips32_insn.fp0_format.fmt =
 310                                        sdps_format[insn.mm_fp3_format.fmt];
 311                                mips32_insn.fp0_format.ft = 0;
 312                                mips32_insn.fp0_format.fs =
 313                                        insn.mm_fp3_format.fs;
 314                                mips32_insn.fp0_format.fd =
 315                                        insn.mm_fp3_format.rt;
 316                                mips32_insn.fp0_format.func = func;
 317                                break;
 318                        case mm_ffloorl_op:
 319                        case mm_ffloorw_op:
 320                        case mm_fceill_op:
 321                        case mm_fceilw_op:
 322                        case mm_ftruncl_op:
 323                        case mm_ftruncw_op:
 324                        case mm_froundl_op:
 325                        case mm_froundw_op:
 326                        case mm_fcvtl_op:
 327                        case mm_fcvtw_op:
 328                                if (insn.mm_fp1_format.op == mm_ffloorl_op)
 329                                        func = ffloorl_op;
 330                                else if (insn.mm_fp1_format.op == mm_ffloorw_op)
 331                                        func = ffloor_op;
 332                                else if (insn.mm_fp1_format.op == mm_fceill_op)
 333                                        func = fceill_op;
 334                                else if (insn.mm_fp1_format.op == mm_fceilw_op)
 335                                        func = fceil_op;
 336                                else if (insn.mm_fp1_format.op == mm_ftruncl_op)
 337                                        func = ftruncl_op;
 338                                else if (insn.mm_fp1_format.op == mm_ftruncw_op)
 339                                        func = ftrunc_op;
 340                                else if (insn.mm_fp1_format.op == mm_froundl_op)
 341                                        func = froundl_op;
 342                                else if (insn.mm_fp1_format.op == mm_froundw_op)
 343                                        func = fround_op;
 344                                else if (insn.mm_fp1_format.op == mm_fcvtl_op)
 345                                        func = fcvtl_op;
 346                                else
 347                                        func = fcvtw_op;
 348                                mips32_insn.fp0_format.opcode = cop1_op;
 349                                mips32_insn.fp0_format.fmt =
 350                                        sd_format[insn.mm_fp1_format.fmt];
 351                                mips32_insn.fp0_format.ft = 0;
 352                                mips32_insn.fp0_format.fs =
 353                                        insn.mm_fp1_format.fs;
 354                                mips32_insn.fp0_format.fd =
 355                                        insn.mm_fp1_format.rt;
 356                                mips32_insn.fp0_format.func = func;
 357                                break;
 358                        case mm_frsqrt_op:
 359                        case mm_fsqrt_op:
 360                        case mm_frecip_op:
 361                                if (insn.mm_fp1_format.op == mm_frsqrt_op)
 362                                        func = frsqrt_op;
 363                                else if (insn.mm_fp1_format.op == mm_fsqrt_op)
 364                                        func = fsqrt_op;
 365                                else
 366                                        func = frecip_op;
 367                                mips32_insn.fp0_format.opcode = cop1_op;
 368                                mips32_insn.fp0_format.fmt =
 369                                        sdps_format[insn.mm_fp1_format.fmt];
 370                                mips32_insn.fp0_format.ft = 0;
 371                                mips32_insn.fp0_format.fs =
 372                                        insn.mm_fp1_format.fs;
 373                                mips32_insn.fp0_format.fd =
 374                                        insn.mm_fp1_format.rt;
 375                                mips32_insn.fp0_format.func = func;
 376                                break;
 377                        case mm_mfc1_op:
 378                        case mm_mtc1_op:
 379                        case mm_cfc1_op:
 380                        case mm_ctc1_op:
 381                        case mm_mfhc1_op:
 382                        case mm_mthc1_op:
 383                                if (insn.mm_fp1_format.op == mm_mfc1_op)
 384                                        op = mfc_op;
 385                                else if (insn.mm_fp1_format.op == mm_mtc1_op)
 386                                        op = mtc_op;
 387                                else if (insn.mm_fp1_format.op == mm_cfc1_op)
 388                                        op = cfc_op;
 389                                else if (insn.mm_fp1_format.op == mm_ctc1_op)
 390                                        op = ctc_op;
 391                                else if (insn.mm_fp1_format.op == mm_mfhc1_op)
 392                                        op = mfhc_op;
 393                                else
 394                                        op = mthc_op;
 395                                mips32_insn.fp1_format.opcode = cop1_op;
 396                                mips32_insn.fp1_format.op = op;
 397                                mips32_insn.fp1_format.rt =
 398                                        insn.mm_fp1_format.rt;
 399                                mips32_insn.fp1_format.fs =
 400                                        insn.mm_fp1_format.fs;
 401                                mips32_insn.fp1_format.fd = 0;
 402                                mips32_insn.fp1_format.func = 0;
 403                                break;
 404                        default:
 405                                return SIGILL;
 406                        }
 407                        break;
 408                case mm_32f_74_op:      /* c.cond.fmt */
 409                        mips32_insn.fp0_format.opcode = cop1_op;
 410                        mips32_insn.fp0_format.fmt =
 411                                sdps_format[insn.mm_fp4_format.fmt];
 412                        mips32_insn.fp0_format.ft = insn.mm_fp4_format.rt;
 413                        mips32_insn.fp0_format.fs = insn.mm_fp4_format.fs;
 414                        mips32_insn.fp0_format.fd = insn.mm_fp4_format.cc << 2;
 415                        mips32_insn.fp0_format.func =
 416                                insn.mm_fp4_format.cond | MM_MIPS32_COND_FC;
 417                        break;
 418                default:
 419                        return SIGILL;
 420                }
 421                break;
 422        default:
 423                return SIGILL;
 424        }
 425
 426        *insn_ptr = mips32_insn;
 427        return 0;
 428}
 429
 430/*
 431 * Redundant with logic already in kernel/branch.c,
 432 * embedded in compute_return_epc.  At some point,
 433 * a single subroutine should be used across both
 434 * modules.
 435 */
 436int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
 437                  unsigned long *contpc)
 438{
 439        union mips_instruction insn = (union mips_instruction)dec_insn.insn;
 440        unsigned int fcr31;
 441        unsigned int bit = 0;
 442
 443        switch (insn.i_format.opcode) {
 444        case spec_op:
 445                switch (insn.r_format.func) {
 446                case jalr_op:
 447                        if (insn.r_format.rd != 0) {
 448                                regs->regs[insn.r_format.rd] =
 449                                        regs->cp0_epc + dec_insn.pc_inc +
 450                                        dec_insn.next_pc_inc;
 451                        }
 452                        /* Fall through */
 453                case jr_op:
 454                        /* For R6, JR already emulated in jalr_op */
 455                        if (NO_R6EMU && insn.r_format.func == jr_op)
 456                                break;
 457                        *contpc = regs->regs[insn.r_format.rs];
 458                        return 1;
 459                }
 460                break;
 461        case bcond_op:
 462                switch (insn.i_format.rt) {
 463                case bltzal_op:
 464                case bltzall_op:
 465                        if (NO_R6EMU && (insn.i_format.rs ||
 466                            insn.i_format.rt == bltzall_op))
 467                                break;
 468
 469                        regs->regs[31] = regs->cp0_epc +
 470                                dec_insn.pc_inc +
 471                                dec_insn.next_pc_inc;
 472                        /* Fall through */
 473                case bltzl_op:
 474                        if (NO_R6EMU)
 475                                break;
 476                case bltz_op:
 477                        if ((long)regs->regs[insn.i_format.rs] < 0)
 478                                *contpc = regs->cp0_epc +
 479                                        dec_insn.pc_inc +
 480                                        (insn.i_format.simmediate << 2);
 481                        else
 482                                *contpc = regs->cp0_epc +
 483                                        dec_insn.pc_inc +
 484                                        dec_insn.next_pc_inc;
 485                        return 1;
 486                case bgezal_op:
 487                case bgezall_op:
 488                        if (NO_R6EMU && (insn.i_format.rs ||
 489                            insn.i_format.rt == bgezall_op))
 490                                break;
 491
 492                        regs->regs[31] = regs->cp0_epc +
 493                                dec_insn.pc_inc +
 494                                dec_insn.next_pc_inc;
 495                        /* Fall through */
 496                case bgezl_op:
 497                        if (NO_R6EMU)
 498                                break;
 499                case bgez_op:
 500                        if ((long)regs->regs[insn.i_format.rs] >= 0)
 501                                *contpc = regs->cp0_epc +
 502                                        dec_insn.pc_inc +
 503                                        (insn.i_format.simmediate << 2);
 504                        else
 505                                *contpc = regs->cp0_epc +
 506                                        dec_insn.pc_inc +
 507                                        dec_insn.next_pc_inc;
 508                        return 1;
 509                }
 510                break;
 511        case jalx_op:
 512                set_isa16_mode(bit);
 513        case jal_op:
 514                regs->regs[31] = regs->cp0_epc +
 515                        dec_insn.pc_inc +
 516                        dec_insn.next_pc_inc;
 517                /* Fall through */
 518        case j_op:
 519                *contpc = regs->cp0_epc + dec_insn.pc_inc;
 520                *contpc >>= 28;
 521                *contpc <<= 28;
 522                *contpc |= (insn.j_format.target << 2);
 523                /* Set microMIPS mode bit: XOR for jalx. */
 524                *contpc ^= bit;
 525                return 1;
 526        case beql_op:
 527                if (NO_R6EMU)
 528                        break;
 529        case beq_op:
 530                if (regs->regs[insn.i_format.rs] ==
 531                    regs->regs[insn.i_format.rt])
 532                        *contpc = regs->cp0_epc +
 533                                dec_insn.pc_inc +
 534                                (insn.i_format.simmediate << 2);
 535                else
 536                        *contpc = regs->cp0_epc +
 537                                dec_insn.pc_inc +
 538                                dec_insn.next_pc_inc;
 539                return 1;
 540        case bnel_op:
 541                if (NO_R6EMU)
 542                        break;
 543        case bne_op:
 544                if (regs->regs[insn.i_format.rs] !=
 545                    regs->regs[insn.i_format.rt])
 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        case blezl_op:
 555                if (!insn.i_format.rt && NO_R6EMU)
 556                        break;
 557        case blez_op:
 558
 559                /*
 560                 * Compact branches for R6 for the
 561                 * blez and blezl opcodes.
 562                 * BLEZ  | rs = 0 | rt != 0  == BLEZALC
 563                 * BLEZ  | rs = rt != 0      == BGEZALC
 564                 * BLEZ  | rs != 0 | rt != 0 == BGEUC
 565                 * BLEZL | rs = 0 | rt != 0  == BLEZC
 566                 * BLEZL | rs = rt != 0      == BGEZC
 567                 * BLEZL | rs != 0 | rt != 0 == BGEC
 568                 *
 569                 * For real BLEZ{,L}, rt is always 0.
 570                 */
 571                if (cpu_has_mips_r6 && insn.i_format.rt) {
 572                        if ((insn.i_format.opcode == blez_op) &&
 573                            ((!insn.i_format.rs && insn.i_format.rt) ||
 574                             (insn.i_format.rs == insn.i_format.rt)))
 575                                regs->regs[31] = regs->cp0_epc +
 576                                        dec_insn.pc_inc;
 577                        *contpc = regs->cp0_epc + dec_insn.pc_inc +
 578                                dec_insn.next_pc_inc;
 579
 580                        return 1;
 581                }
 582                if ((long)regs->regs[insn.i_format.rs] <= 0)
 583                        *contpc = regs->cp0_epc +
 584                                dec_insn.pc_inc +
 585                                (insn.i_format.simmediate << 2);
 586                else
 587                        *contpc = regs->cp0_epc +
 588                                dec_insn.pc_inc +
 589                                dec_insn.next_pc_inc;
 590                return 1;
 591        case bgtzl_op:
 592                if (!insn.i_format.rt && NO_R6EMU)
 593                        break;
 594        case bgtz_op:
 595                /*
 596                 * Compact branches for R6 for the
 597                 * bgtz and bgtzl opcodes.
 598                 * BGTZ  | rs = 0 | rt != 0  == BGTZALC
 599                 * BGTZ  | rs = rt != 0      == BLTZALC
 600                 * BGTZ  | rs != 0 | rt != 0 == BLTUC
 601                 * BGTZL | rs = 0 | rt != 0  == BGTZC
 602                 * BGTZL | rs = rt != 0      == BLTZC
 603                 * BGTZL | rs != 0 | rt != 0 == BLTC
 604                 *
 605                 * *ZALC varint for BGTZ &&& rt != 0
 606                 * For real GTZ{,L}, rt is always 0.
 607                 */
 608                if (cpu_has_mips_r6 && insn.i_format.rt) {
 609                        if ((insn.i_format.opcode == blez_op) &&
 610                            ((!insn.i_format.rs && insn.i_format.rt) ||
 611                             (insn.i_format.rs == insn.i_format.rt)))
 612                                regs->regs[31] = regs->cp0_epc +
 613                                        dec_insn.pc_inc;
 614                        *contpc = regs->cp0_epc + dec_insn.pc_inc +
 615                                dec_insn.next_pc_inc;
 616
 617                        return 1;
 618                }
 619
 620                if ((long)regs->regs[insn.i_format.rs] > 0)
 621                        *contpc = regs->cp0_epc +
 622                                dec_insn.pc_inc +
 623                                (insn.i_format.simmediate << 2);
 624                else
 625                        *contpc = regs->cp0_epc +
 626                                dec_insn.pc_inc +
 627                                dec_insn.next_pc_inc;
 628                return 1;
 629        case pop10_op:
 630        case pop30_op:
 631                if (!cpu_has_mips_r6)
 632                        break;
 633                if (insn.i_format.rt && !insn.i_format.rs)
 634                        regs->regs[31] = regs->cp0_epc + 4;
 635                *contpc = regs->cp0_epc + dec_insn.pc_inc +
 636                        dec_insn.next_pc_inc;
 637
 638                return 1;
 639#ifdef CONFIG_CPU_CAVIUM_OCTEON
 640        case lwc2_op: /* This is bbit0 on Octeon */
 641                if ((regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) == 0)
 642                        *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
 643                else
 644                        *contpc = regs->cp0_epc + 8;
 645                return 1;
 646        case ldc2_op: /* This is bbit032 on Octeon */
 647                if ((regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32))) == 0)
 648                        *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
 649                else
 650                        *contpc = regs->cp0_epc + 8;
 651                return 1;
 652        case swc2_op: /* This is bbit1 on Octeon */
 653                if (regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt))
 654                        *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
 655                else
 656                        *contpc = regs->cp0_epc + 8;
 657                return 1;
 658        case sdc2_op: /* This is bbit132 on Octeon */
 659                if (regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32)))
 660                        *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
 661                else
 662                        *contpc = regs->cp0_epc + 8;
 663                return 1;
 664#else
 665        case bc6_op:
 666                /*
 667                 * Only valid for MIPS R6 but we can still end up
 668                 * here from a broken userland so just tell emulator
 669                 * this is not a branch and let it break later on.
 670                 */
 671                if  (!cpu_has_mips_r6)
 672                        break;
 673                *contpc = regs->cp0_epc + dec_insn.pc_inc +
 674                        dec_insn.next_pc_inc;
 675
 676                return 1;
 677        case balc6_op:
 678                if (!cpu_has_mips_r6)
 679                        break;
 680                regs->regs[31] = regs->cp0_epc + 4;
 681                *contpc = regs->cp0_epc + dec_insn.pc_inc +
 682                        dec_insn.next_pc_inc;
 683
 684                return 1;
 685        case pop66_op:
 686                if (!cpu_has_mips_r6)
 687                        break;
 688                *contpc = regs->cp0_epc + dec_insn.pc_inc +
 689                        dec_insn.next_pc_inc;
 690
 691                return 1;
 692        case pop76_op:
 693                if (!cpu_has_mips_r6)
 694                        break;
 695                if (!insn.i_format.rs)
 696                        regs->regs[31] = regs->cp0_epc + 4;
 697                *contpc = regs->cp0_epc + dec_insn.pc_inc +
 698                        dec_insn.next_pc_inc;
 699
 700                return 1;
 701#endif
 702        case cop0_op:
 703        case cop1_op:
 704                /* Need to check for R6 bc1nez and bc1eqz branches */
 705                if (cpu_has_mips_r6 &&
 706                    ((insn.i_format.rs == bc1eqz_op) ||
 707                     (insn.i_format.rs == bc1nez_op))) {
 708                        bit = 0;
 709                        switch (insn.i_format.rs) {
 710                        case bc1eqz_op:
 711                                if (get_fpr32(&current->thread.fpu.fpr[insn.i_format.rt], 0) & 0x1)
 712                                    bit = 1;
 713                                break;
 714                        case bc1nez_op:
 715                                if (!(get_fpr32(&current->thread.fpu.fpr[insn.i_format.rt], 0) & 0x1))
 716                                    bit = 1;
 717                                break;
 718                        }
 719                        if (bit)
 720                                *contpc = regs->cp0_epc +
 721                                        dec_insn.pc_inc +
 722                                        (insn.i_format.simmediate << 2);
 723                        else
 724                                *contpc = regs->cp0_epc +
 725                                        dec_insn.pc_inc +
 726                                        dec_insn.next_pc_inc;
 727
 728                        return 1;
 729                }
 730                /* R2/R6 compatible cop1 instruction. Fall through */
 731        case cop2_op:
 732        case cop1x_op:
 733                if (insn.i_format.rs == bc_op) {
 734                        preempt_disable();
 735                        if (is_fpu_owner())
 736                                fcr31 = read_32bit_cp1_register(CP1_STATUS);
 737                        else
 738                                fcr31 = current->thread.fpu.fcr31;
 739                        preempt_enable();
 740
 741                        bit = (insn.i_format.rt >> 2);
 742                        bit += (bit != 0);
 743                        bit += 23;
 744                        switch (insn.i_format.rt & 3) {
 745                        case 0: /* bc1f */
 746                        case 2: /* bc1fl */
 747                                if (~fcr31 & (1 << bit))
 748                                        *contpc = regs->cp0_epc +
 749                                                dec_insn.pc_inc +
 750                                                (insn.i_format.simmediate << 2);
 751                                else
 752                                        *contpc = regs->cp0_epc +
 753                                                dec_insn.pc_inc +
 754                                                dec_insn.next_pc_inc;
 755                                return 1;
 756                        case 1: /* bc1t */
 757                        case 3: /* bc1tl */
 758                                if (fcr31 & (1 << bit))
 759                                        *contpc = regs->cp0_epc +
 760                                                dec_insn.pc_inc +
 761                                                (insn.i_format.simmediate << 2);
 762                                else
 763                                        *contpc = regs->cp0_epc +
 764                                                dec_insn.pc_inc +
 765                                                dec_insn.next_pc_inc;
 766                                return 1;
 767                        }
 768                }
 769                break;
 770        }
 771        return 0;
 772}
 773
 774/*
 775 * In the Linux kernel, we support selection of FPR format on the
 776 * basis of the Status.FR bit.  If an FPU is not present, the FR bit
 777 * is hardwired to zero, which would imply a 32-bit FPU even for
 778 * 64-bit CPUs so we rather look at TIF_32BIT_FPREGS.
 779 * FPU emu is slow and bulky and optimizing this function offers fairly
 780 * sizeable benefits so we try to be clever and make this function return
 781 * a constant whenever possible, that is on 64-bit kernels without O32
 782 * compatibility enabled and on 32-bit without 64-bit FPU support.
 783 */
 784static inline int cop1_64bit(struct pt_regs *xcp)
 785{
 786        if (IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_MIPS32_O32))
 787                return 1;
 788        else if (IS_ENABLED(CONFIG_32BIT) &&
 789                 !IS_ENABLED(CONFIG_MIPS_O32_FP64_SUPPORT))
 790                return 0;
 791
 792        return !test_thread_flag(TIF_32BIT_FPREGS);
 793}
 794
 795static inline bool hybrid_fprs(void)
 796{
 797        return test_thread_flag(TIF_HYBRID_FPREGS);
 798}
 799
 800#define SIFROMREG(si, x)                                                \
 801do {                                                                    \
 802        if (cop1_64bit(xcp) && !hybrid_fprs())                          \
 803                (si) = (int)get_fpr32(&ctx->fpr[x], 0);                 \
 804        else                                                            \
 805                (si) = (int)get_fpr32(&ctx->fpr[(x) & ~1], (x) & 1);    \
 806} while (0)
 807
 808#define SITOREG(si, x)                                                  \
 809do {                                                                    \
 810        if (cop1_64bit(xcp) && !hybrid_fprs()) {                        \
 811                unsigned i;                                             \
 812                set_fpr32(&ctx->fpr[x], 0, si);                         \
 813                for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val32); i++)     \
 814                        set_fpr32(&ctx->fpr[x], i, 0);                  \
 815        } else {                                                        \
 816                set_fpr32(&ctx->fpr[(x) & ~1], (x) & 1, si);            \
 817        }                                                               \
 818} while (0)
 819
 820#define SIFROMHREG(si, x)       ((si) = (int)get_fpr32(&ctx->fpr[x], 1))
 821
 822#define SITOHREG(si, x)                                                 \
 823do {                                                                    \
 824        unsigned i;                                                     \
 825        set_fpr32(&ctx->fpr[x], 1, si);                                 \
 826        for (i = 2; i < ARRAY_SIZE(ctx->fpr[x].val32); i++)             \
 827                set_fpr32(&ctx->fpr[x], i, 0);                          \
 828} while (0)
 829
 830#define DIFROMREG(di, x)                                                \
 831        ((di) = get_fpr64(&ctx->fpr[(x) & ~(cop1_64bit(xcp) == 0)], 0))
 832
 833#define DITOREG(di, x)                                                  \
 834do {                                                                    \
 835        unsigned fpr, i;                                                \
 836        fpr = (x) & ~(cop1_64bit(xcp) == 0);                            \
 837        set_fpr64(&ctx->fpr[fpr], 0, di);                               \
 838        for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val64); i++)             \
 839                set_fpr64(&ctx->fpr[fpr], i, 0);                        \
 840} while (0)
 841
 842#define SPFROMREG(sp, x) SIFROMREG((sp).bits, x)
 843#define SPTOREG(sp, x)  SITOREG((sp).bits, x)
 844#define DPFROMREG(dp, x)        DIFROMREG((dp).bits, x)
 845#define DPTOREG(dp, x)  DITOREG((dp).bits, x)
 846
 847/*
 848 * Emulate a CFC1 instruction.
 849 */
 850static inline void cop1_cfc(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
 851                            mips_instruction ir)
 852{
 853        u32 fcr31 = ctx->fcr31;
 854        u32 value = 0;
 855
 856        switch (MIPSInst_RD(ir)) {
 857        case FPCREG_CSR:
 858                value = fcr31;
 859                pr_debug("%p gpr[%d]<-csr=%08x\n",
 860                         (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
 861                break;
 862
 863        case FPCREG_FENR:
 864                if (!cpu_has_mips_r)
 865                        break;
 866                value = (fcr31 >> (FPU_CSR_FS_S - MIPS_FENR_FS_S)) &
 867                        MIPS_FENR_FS;
 868                value |= fcr31 & (FPU_CSR_ALL_E | FPU_CSR_RM);
 869                pr_debug("%p gpr[%d]<-enr=%08x\n",
 870                         (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
 871                break;
 872
 873        case FPCREG_FEXR:
 874                if (!cpu_has_mips_r)
 875                        break;
 876                value = fcr31 & (FPU_CSR_ALL_X | FPU_CSR_ALL_S);
 877                pr_debug("%p gpr[%d]<-exr=%08x\n",
 878                         (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
 879                break;
 880
 881        case FPCREG_FCCR:
 882                if (!cpu_has_mips_r)
 883                        break;
 884                value = (fcr31 >> (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) &
 885                        MIPS_FCCR_COND0;
 886                value |= (fcr31 >> (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) &
 887                         (MIPS_FCCR_CONDX & ~MIPS_FCCR_COND0);
 888                pr_debug("%p gpr[%d]<-ccr=%08x\n",
 889                         (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
 890                break;
 891
 892        case FPCREG_RID:
 893                value = boot_cpu_data.fpu_id;
 894                break;
 895
 896        default:
 897                break;
 898        }
 899
 900        if (MIPSInst_RT(ir))
 901                xcp->regs[MIPSInst_RT(ir)] = value;
 902}
 903
 904/*
 905 * Emulate a CTC1 instruction.
 906 */
 907static inline void cop1_ctc(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
 908                            mips_instruction ir)
 909{
 910        u32 fcr31 = ctx->fcr31;
 911        u32 value;
 912        u32 mask;
 913
 914        if (MIPSInst_RT(ir) == 0)
 915                value = 0;
 916        else
 917                value = xcp->regs[MIPSInst_RT(ir)];
 918
 919        switch (MIPSInst_RD(ir)) {
 920        case FPCREG_CSR:
 921                pr_debug("%p gpr[%d]->csr=%08x\n",
 922                         (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
 923
 924                /* Preserve read-only bits.  */
 925                mask = boot_cpu_data.fpu_msk31;
 926                fcr31 = (value & ~mask) | (fcr31 & mask);
 927                break;
 928
 929        case FPCREG_FENR:
 930                if (!cpu_has_mips_r)
 931                        break;
 932                pr_debug("%p gpr[%d]->enr=%08x\n",
 933                         (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
 934                fcr31 &= ~(FPU_CSR_FS | FPU_CSR_ALL_E | FPU_CSR_RM);
 935                fcr31 |= (value << (FPU_CSR_FS_S - MIPS_FENR_FS_S)) &
 936                         FPU_CSR_FS;
 937                fcr31 |= value & (FPU_CSR_ALL_E | FPU_CSR_RM);
 938                break;
 939
 940        case FPCREG_FEXR:
 941                if (!cpu_has_mips_r)
 942                        break;
 943                pr_debug("%p gpr[%d]->exr=%08x\n",
 944                         (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
 945                fcr31 &= ~(FPU_CSR_ALL_X | FPU_CSR_ALL_S);
 946                fcr31 |= value & (FPU_CSR_ALL_X | FPU_CSR_ALL_S);
 947                break;
 948
 949        case FPCREG_FCCR:
 950                if (!cpu_has_mips_r)
 951                        break;
 952                pr_debug("%p gpr[%d]->ccr=%08x\n",
 953                         (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
 954                fcr31 &= ~(FPU_CSR_CONDX | FPU_CSR_COND);
 955                fcr31 |= (value << (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) &
 956                         FPU_CSR_COND;
 957                fcr31 |= (value << (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) &
 958                         FPU_CSR_CONDX;
 959                break;
 960
 961        default:
 962                break;
 963        }
 964
 965        ctx->fcr31 = fcr31;
 966}
 967
 968/*
 969 * Emulate the single floating point instruction pointed at by EPC.
 970 * Two instructions if the instruction is in a branch delay slot.
 971 */
 972
 973static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
 974                struct mm_decoded_insn dec_insn, void *__user *fault_addr)
 975{
 976        unsigned long contpc = xcp->cp0_epc + dec_insn.pc_inc;
 977        unsigned int cond, cbit, bit0;
 978        mips_instruction ir;
 979        int likely, pc_inc;
 980        union fpureg *fpr;
 981        u32 __user *wva;
 982        u64 __user *dva;
 983        u32 wval;
 984        u64 dval;
 985        int sig;
 986
 987        /*
 988         * These are giving gcc a gentle hint about what to expect in
 989         * dec_inst in order to do better optimization.
 990         */
 991        if (!cpu_has_mmips && dec_insn.micro_mips_mode)
 992                unreachable();
 993
 994        /* XXX NEC Vr54xx bug workaround */
 995        if (delay_slot(xcp)) {
 996                if (dec_insn.micro_mips_mode) {
 997                        if (!mm_isBranchInstr(xcp, dec_insn, &contpc))
 998                                clear_delay_slot(xcp);
 999                } else {
1000                        if (!isBranchInstr(xcp, dec_insn, &contpc))
1001                                clear_delay_slot(xcp);
1002                }
1003        }
1004
1005        if (delay_slot(xcp)) {
1006                /*
1007                 * The instruction to be emulated is in a branch delay slot
1008                 * which means that we have to  emulate the branch instruction
1009                 * BEFORE we do the cop1 instruction.
1010                 *
1011                 * This branch could be a COP1 branch, but in that case we
1012                 * would have had a trap for that instruction, and would not
1013                 * come through this route.
1014                 *
1015                 * Linux MIPS branch emulator operates on context, updating the
1016                 * cp0_epc.
1017                 */
1018                ir = dec_insn.next_insn;  /* process delay slot instr */
1019                pc_inc = dec_insn.next_pc_inc;
1020        } else {
1021                ir = dec_insn.insn;       /* process current instr */
1022                pc_inc = dec_insn.pc_inc;
1023        }
1024
1025        /*
1026         * Since microMIPS FPU instructios are a subset of MIPS32 FPU
1027         * instructions, we want to convert microMIPS FPU instructions
1028         * into MIPS32 instructions so that we could reuse all of the
1029         * FPU emulation code.
1030         *
1031         * NOTE: We cannot do this for branch instructions since they
1032         *       are not a subset. Example: Cannot emulate a 16-bit
1033         *       aligned target address with a MIPS32 instruction.
1034         */
1035        if (dec_insn.micro_mips_mode) {
1036                /*
1037                 * If next instruction is a 16-bit instruction, then it
1038                 * it cannot be a FPU instruction. This could happen
1039                 * since we can be called for non-FPU instructions.
1040                 */
1041                if ((pc_inc == 2) ||
1042                        (microMIPS32_to_MIPS32((union mips_instruction *)&ir)
1043                         == SIGILL))
1044                        return SIGILL;
1045        }
1046
1047emul:
1048        perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, xcp, 0);
1049        MIPS_FPU_EMU_INC_STATS(emulated);
1050        switch (MIPSInst_OPCODE(ir)) {
1051        case ldc1_op:
1052                dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1053                                     MIPSInst_SIMM(ir));
1054                MIPS_FPU_EMU_INC_STATS(loads);
1055
1056                if (!access_ok(VERIFY_READ, dva, sizeof(u64))) {
1057                        MIPS_FPU_EMU_INC_STATS(errors);
1058                        *fault_addr = dva;
1059                        return SIGBUS;
1060                }
1061                if (__get_user(dval, dva)) {
1062                        MIPS_FPU_EMU_INC_STATS(errors);
1063                        *fault_addr = dva;
1064                        return SIGSEGV;
1065                }
1066                DITOREG(dval, MIPSInst_RT(ir));
1067                break;
1068
1069        case sdc1_op:
1070                dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1071                                      MIPSInst_SIMM(ir));
1072                MIPS_FPU_EMU_INC_STATS(stores);
1073                DIFROMREG(dval, MIPSInst_RT(ir));
1074                if (!access_ok(VERIFY_WRITE, dva, sizeof(u64))) {
1075                        MIPS_FPU_EMU_INC_STATS(errors);
1076                        *fault_addr = dva;
1077                        return SIGBUS;
1078                }
1079                if (__put_user(dval, dva)) {
1080                        MIPS_FPU_EMU_INC_STATS(errors);
1081                        *fault_addr = dva;
1082                        return SIGSEGV;
1083                }
1084                break;
1085
1086        case lwc1_op:
1087                wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1088                                      MIPSInst_SIMM(ir));
1089                MIPS_FPU_EMU_INC_STATS(loads);
1090                if (!access_ok(VERIFY_READ, wva, sizeof(u32))) {
1091                        MIPS_FPU_EMU_INC_STATS(errors);
1092                        *fault_addr = wva;
1093                        return SIGBUS;
1094                }
1095                if (__get_user(wval, wva)) {
1096                        MIPS_FPU_EMU_INC_STATS(errors);
1097                        *fault_addr = wva;
1098                        return SIGSEGV;
1099                }
1100                SITOREG(wval, MIPSInst_RT(ir));
1101                break;
1102
1103        case swc1_op:
1104                wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
1105                                      MIPSInst_SIMM(ir));
1106                MIPS_FPU_EMU_INC_STATS(stores);
1107                SIFROMREG(wval, MIPSInst_RT(ir));
1108                if (!access_ok(VERIFY_WRITE, wva, sizeof(u32))) {
1109                        MIPS_FPU_EMU_INC_STATS(errors);
1110                        *fault_addr = wva;
1111                        return SIGBUS;
1112                }
1113                if (__put_user(wval, wva)) {
1114                        MIPS_FPU_EMU_INC_STATS(errors);
1115                        *fault_addr = wva;
1116                        return SIGSEGV;
1117                }
1118                break;
1119
1120        case cop1_op:
1121                switch (MIPSInst_RS(ir)) {
1122                case dmfc_op:
1123                        if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
1124                                return SIGILL;
1125
1126                        /* copregister fs -> gpr[rt] */
1127                        if (MIPSInst_RT(ir) != 0) {
1128                                DIFROMREG(xcp->regs[MIPSInst_RT(ir)],
1129                                        MIPSInst_RD(ir));
1130                        }
1131                        break;
1132
1133                case dmtc_op:
1134                        if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
1135                                return SIGILL;
1136
1137                        /* copregister fs <- rt */
1138                        DITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
1139                        break;
1140
1141                case mfhc_op:
1142                        if (!cpu_has_mips_r2_r6)
1143                                goto sigill;
1144
1145                        /* copregister rd -> gpr[rt] */
1146                        if (MIPSInst_RT(ir) != 0) {
1147                                SIFROMHREG(xcp->regs[MIPSInst_RT(ir)],
1148                                        MIPSInst_RD(ir));
1149                        }
1150                        break;
1151
1152                case mthc_op:
1153                        if (!cpu_has_mips_r2_r6)
1154                                goto sigill;
1155
1156                        /* copregister rd <- gpr[rt] */
1157                        SITOHREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
1158                        break;
1159
1160                case mfc_op:
1161                        /* copregister rd -> gpr[rt] */
1162                        if (MIPSInst_RT(ir) != 0) {
1163                                SIFROMREG(xcp->regs[MIPSInst_RT(ir)],
1164                                        MIPSInst_RD(ir));
1165                        }
1166                        break;
1167
1168                case mtc_op:
1169                        /* copregister rd <- rt */
1170                        SITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
1171                        break;
1172
1173                case cfc_op:
1174                        /* cop control register rd -> gpr[rt] */
1175                        cop1_cfc(xcp, ctx, ir);
1176                        break;
1177
1178                case ctc_op:
1179                        /* copregister rd <- rt */
1180                        cop1_ctc(xcp, ctx, ir);
1181                        if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1182                                return SIGFPE;
1183                        }
1184                        break;
1185
1186                case bc1eqz_op:
1187                case bc1nez_op:
1188                        if (!cpu_has_mips_r6 || delay_slot(xcp))
1189                                return SIGILL;
1190
1191                        cond = likely = 0;
1192                        fpr = &current->thread.fpu.fpr[MIPSInst_RT(ir)];
1193                        bit0 = get_fpr32(fpr, 0) & 0x1;
1194                        switch (MIPSInst_RS(ir)) {
1195                        case bc1eqz_op:
1196                                cond = bit0 == 0;
1197                                break;
1198                        case bc1nez_op:
1199                                cond = bit0 != 0;
1200                                break;
1201                        }
1202                        goto branch_common;
1203
1204                case bc_op:
1205                        if (delay_slot(xcp))
1206                                return SIGILL;
1207
1208                        if (cpu_has_mips_4_5_r)
1209                                cbit = fpucondbit[MIPSInst_RT(ir) >> 2];
1210                        else
1211                                cbit = FPU_CSR_COND;
1212                        cond = ctx->fcr31 & cbit;
1213
1214                        likely = 0;
1215                        switch (MIPSInst_RT(ir) & 3) {
1216                        case bcfl_op:
1217                                if (cpu_has_mips_2_3_4_5_r)
1218                                        likely = 1;
1219                                /* Fall through */
1220                        case bcf_op:
1221                                cond = !cond;
1222                                break;
1223                        case bctl_op:
1224                                if (cpu_has_mips_2_3_4_5_r)
1225                                        likely = 1;
1226                                /* Fall through */
1227                        case bct_op:
1228                                break;
1229                        }
1230branch_common:
1231                        set_delay_slot(xcp);
1232                        if (cond) {
1233                                /*
1234                                 * Branch taken: emulate dslot instruction
1235                                 */
1236                                unsigned long bcpc;
1237
1238                                /*
1239                                 * Remember EPC at the branch to point back
1240                                 * at so that any delay-slot instruction
1241                                 * signal is not silently ignored.
1242                                 */
1243                                bcpc = xcp->cp0_epc;
1244                                xcp->cp0_epc += dec_insn.pc_inc;
1245
1246                                contpc = MIPSInst_SIMM(ir);
1247                                ir = dec_insn.next_insn;
1248                                if (dec_insn.micro_mips_mode) {
1249                                        contpc = (xcp->cp0_epc + (contpc << 1));
1250
1251                                        /* If 16-bit instruction, not FPU. */
1252                                        if ((dec_insn.next_pc_inc == 2) ||
1253                                                (microMIPS32_to_MIPS32((union mips_instruction *)&ir) == SIGILL)) {
1254
1255                                                /*
1256                                                 * Since this instruction will
1257                                                 * be put on the stack with
1258                                                 * 32-bit words, get around
1259                                                 * this problem by putting a
1260                                                 * NOP16 as the second one.
1261                                                 */
1262                                                if (dec_insn.next_pc_inc == 2)
1263                                                        ir = (ir & (~0xffff)) | MM_NOP16;
1264
1265                                                /*
1266                                                 * Single step the non-CP1
1267                                                 * instruction in the dslot.
1268                                                 */
1269                                                sig = mips_dsemul(xcp, ir,
1270                                                                  bcpc, contpc);
1271                                                if (sig < 0)
1272                                                        break;
1273                                                if (sig)
1274                                                        xcp->cp0_epc = bcpc;
1275                                                /*
1276                                                 * SIGILL forces out of
1277                                                 * the emulation loop.
1278                                                 */
1279                                                return sig ? sig : SIGILL;
1280                                        }
1281                                } else
1282                                        contpc = (xcp->cp0_epc + (contpc << 2));
1283
1284                                switch (MIPSInst_OPCODE(ir)) {
1285                                case lwc1_op:
1286                                case swc1_op:
1287                                        goto emul;
1288
1289                                case ldc1_op:
1290                                case sdc1_op:
1291                                        if (cpu_has_mips_2_3_4_5_r)
1292                                                goto emul;
1293
1294                                        goto bc_sigill;
1295
1296                                case cop1_op:
1297                                        goto emul;
1298
1299                                case cop1x_op:
1300                                        if (cpu_has_mips_4_5_64_r2_r6)
1301                                                /* its one of ours */
1302                                                goto emul;
1303
1304                                        goto bc_sigill;
1305
1306                                case spec_op:
1307                                        switch (MIPSInst_FUNC(ir)) {
1308                                        case movc_op:
1309                                                if (cpu_has_mips_4_5_r)
1310                                                        goto emul;
1311
1312                                                goto bc_sigill;
1313                                        }
1314                                        break;
1315
1316                                bc_sigill:
1317                                        xcp->cp0_epc = bcpc;
1318                                        return SIGILL;
1319                                }
1320
1321                                /*
1322                                 * Single step the non-cp1
1323                                 * instruction in the dslot
1324                                 */
1325                                sig = mips_dsemul(xcp, ir, bcpc, contpc);
1326                                if (sig < 0)
1327                                        break;
1328                                if (sig)
1329                                        xcp->cp0_epc = bcpc;
1330                                /* SIGILL forces out of the emulation loop.  */
1331                                return sig ? sig : SIGILL;
1332                        } else if (likely) {    /* branch not taken */
1333                                /*
1334                                 * branch likely nullifies
1335                                 * dslot if not taken
1336                                 */
1337                                xcp->cp0_epc += dec_insn.pc_inc;
1338                                contpc += dec_insn.pc_inc;
1339                                /*
1340                                 * else continue & execute
1341                                 * dslot as normal insn
1342                                 */
1343                        }
1344                        break;
1345
1346                default:
1347                        if (!(MIPSInst_RS(ir) & 0x10))
1348                                return SIGILL;
1349
1350                        /* a real fpu computation instruction */
1351                        if ((sig = fpu_emu(xcp, ctx, ir)))
1352                                return sig;
1353                }
1354                break;
1355
1356        case cop1x_op:
1357                if (!cpu_has_mips_4_5_64_r2_r6)
1358                        return SIGILL;
1359
1360                sig = fpux_emu(xcp, ctx, ir, fault_addr);
1361                if (sig)
1362                        return sig;
1363                break;
1364
1365        case spec_op:
1366                if (!cpu_has_mips_4_5_r)
1367                        return SIGILL;
1368
1369                if (MIPSInst_FUNC(ir) != movc_op)
1370                        return SIGILL;
1371                cond = fpucondbit[MIPSInst_RT(ir) >> 2];
1372                if (((ctx->fcr31 & cond) != 0) == ((MIPSInst_RT(ir) & 1) != 0))
1373                        xcp->regs[MIPSInst_RD(ir)] =
1374                                xcp->regs[MIPSInst_RS(ir)];
1375                break;
1376        default:
1377sigill:
1378                return SIGILL;
1379        }
1380
1381        /* we did it !! */
1382        xcp->cp0_epc = contpc;
1383        clear_delay_slot(xcp);
1384
1385        return 0;
1386}
1387
1388/*
1389 * Conversion table from MIPS compare ops 48-63
1390 * cond = ieee754dp_cmp(x,y,IEEE754_UN,sig);
1391 */
1392static const unsigned char cmptab[8] = {
1393        0,                      /* cmp_0 (sig) cmp_sf */
1394        IEEE754_CUN,            /* cmp_un (sig) cmp_ngle */
1395        IEEE754_CEQ,            /* cmp_eq (sig) cmp_seq */
1396        IEEE754_CEQ | IEEE754_CUN,      /* cmp_ueq (sig) cmp_ngl  */
1397        IEEE754_CLT,            /* cmp_olt (sig) cmp_lt */
1398        IEEE754_CLT | IEEE754_CUN,      /* cmp_ult (sig) cmp_nge */
1399        IEEE754_CLT | IEEE754_CEQ,      /* cmp_ole (sig) cmp_le */
1400        IEEE754_CLT | IEEE754_CEQ | IEEE754_CUN,        /* cmp_ule (sig) cmp_ngt */
1401};
1402
1403static const unsigned char negative_cmptab[8] = {
1404        0, /* Reserved */
1405        IEEE754_CLT | IEEE754_CGT | IEEE754_CEQ,
1406        IEEE754_CLT | IEEE754_CGT | IEEE754_CUN,
1407        IEEE754_CLT | IEEE754_CGT,
1408        /* Reserved */
1409};
1410
1411
1412/*
1413 * Additional MIPS4 instructions
1414 */
1415
1416#define DEF3OP(name, p, f1, f2, f3)                                     \
1417static union ieee754##p fpemu_##p##_##name(union ieee754##p r,          \
1418        union ieee754##p s, union ieee754##p t)                         \
1419{                                                                       \
1420        struct _ieee754_csr ieee754_csr_save;                           \
1421        s = f1(s, t);                                                   \
1422        ieee754_csr_save = ieee754_csr;                                 \
1423        s = f2(s, r);                                                   \
1424        ieee754_csr_save.cx |= ieee754_csr.cx;                          \
1425        ieee754_csr_save.sx |= ieee754_csr.sx;                          \
1426        s = f3(s);                                                      \
1427        ieee754_csr.cx |= ieee754_csr_save.cx;                          \
1428        ieee754_csr.sx |= ieee754_csr_save.sx;                          \
1429        return s;                                                       \
1430}
1431
1432static union ieee754dp fpemu_dp_recip(union ieee754dp d)
1433{
1434        return ieee754dp_div(ieee754dp_one(0), d);
1435}
1436
1437static union ieee754dp fpemu_dp_rsqrt(union ieee754dp d)
1438{
1439        return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d));
1440}
1441
1442static union ieee754sp fpemu_sp_recip(union ieee754sp s)
1443{
1444        return ieee754sp_div(ieee754sp_one(0), s);
1445}
1446
1447static union ieee754sp fpemu_sp_rsqrt(union ieee754sp s)
1448{
1449        return ieee754sp_div(ieee754sp_one(0), ieee754sp_sqrt(s));
1450}
1451
1452DEF3OP(madd, sp, ieee754sp_mul, ieee754sp_add, );
1453DEF3OP(msub, sp, ieee754sp_mul, ieee754sp_sub, );
1454DEF3OP(nmadd, sp, ieee754sp_mul, ieee754sp_add, ieee754sp_neg);
1455DEF3OP(nmsub, sp, ieee754sp_mul, ieee754sp_sub, ieee754sp_neg);
1456DEF3OP(madd, dp, ieee754dp_mul, ieee754dp_add, );
1457DEF3OP(msub, dp, ieee754dp_mul, ieee754dp_sub, );
1458DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg);
1459DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg);
1460
1461static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1462        mips_instruction ir, void *__user *fault_addr)
1463{
1464        unsigned rcsr = 0;      /* resulting csr */
1465
1466        MIPS_FPU_EMU_INC_STATS(cp1xops);
1467
1468        switch (MIPSInst_FMA_FFMT(ir)) {
1469        case s_fmt:{            /* 0 */
1470
1471                union ieee754sp(*handler) (union ieee754sp, union ieee754sp, union ieee754sp);
1472                union ieee754sp fd, fr, fs, ft;
1473                u32 __user *va;
1474                u32 val;
1475
1476                switch (MIPSInst_FUNC(ir)) {
1477                case lwxc1_op:
1478                        va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1479                                xcp->regs[MIPSInst_FT(ir)]);
1480
1481                        MIPS_FPU_EMU_INC_STATS(loads);
1482                        if (!access_ok(VERIFY_READ, va, sizeof(u32))) {
1483                                MIPS_FPU_EMU_INC_STATS(errors);
1484                                *fault_addr = va;
1485                                return SIGBUS;
1486                        }
1487                        if (__get_user(val, va)) {
1488                                MIPS_FPU_EMU_INC_STATS(errors);
1489                                *fault_addr = va;
1490                                return SIGSEGV;
1491                        }
1492                        SITOREG(val, MIPSInst_FD(ir));
1493                        break;
1494
1495                case swxc1_op:
1496                        va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1497                                xcp->regs[MIPSInst_FT(ir)]);
1498
1499                        MIPS_FPU_EMU_INC_STATS(stores);
1500
1501                        SIFROMREG(val, MIPSInst_FS(ir));
1502                        if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) {
1503                                MIPS_FPU_EMU_INC_STATS(errors);
1504                                *fault_addr = va;
1505                                return SIGBUS;
1506                        }
1507                        if (put_user(val, va)) {
1508                                MIPS_FPU_EMU_INC_STATS(errors);
1509                                *fault_addr = va;
1510                                return SIGSEGV;
1511                        }
1512                        break;
1513
1514                case madd_s_op:
1515                        handler = fpemu_sp_madd;
1516                        goto scoptop;
1517                case msub_s_op:
1518                        handler = fpemu_sp_msub;
1519                        goto scoptop;
1520                case nmadd_s_op:
1521                        handler = fpemu_sp_nmadd;
1522                        goto scoptop;
1523                case nmsub_s_op:
1524                        handler = fpemu_sp_nmsub;
1525                        goto scoptop;
1526
1527                      scoptop:
1528                        SPFROMREG(fr, MIPSInst_FR(ir));
1529                        SPFROMREG(fs, MIPSInst_FS(ir));
1530                        SPFROMREG(ft, MIPSInst_FT(ir));
1531                        fd = (*handler) (fr, fs, ft);
1532                        SPTOREG(fd, MIPSInst_FD(ir));
1533
1534                      copcsr:
1535                        if (ieee754_cxtest(IEEE754_INEXACT)) {
1536                                MIPS_FPU_EMU_INC_STATS(ieee754_inexact);
1537                                rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
1538                        }
1539                        if (ieee754_cxtest(IEEE754_UNDERFLOW)) {
1540                                MIPS_FPU_EMU_INC_STATS(ieee754_underflow);
1541                                rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
1542                        }
1543                        if (ieee754_cxtest(IEEE754_OVERFLOW)) {
1544                                MIPS_FPU_EMU_INC_STATS(ieee754_overflow);
1545                                rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
1546                        }
1547                        if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) {
1548                                MIPS_FPU_EMU_INC_STATS(ieee754_invalidop);
1549                                rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
1550                        }
1551
1552                        ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
1553                        if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1554                                /*printk ("SIGFPE: FPU csr = %08x\n",
1555                                   ctx->fcr31); */
1556                                return SIGFPE;
1557                        }
1558
1559                        break;
1560
1561                default:
1562                        return SIGILL;
1563                }
1564                break;
1565        }
1566
1567        case d_fmt:{            /* 1 */
1568                union ieee754dp(*handler) (union ieee754dp, union ieee754dp, union ieee754dp);
1569                union ieee754dp fd, fr, fs, ft;
1570                u64 __user *va;
1571                u64 val;
1572
1573                switch (MIPSInst_FUNC(ir)) {
1574                case ldxc1_op:
1575                        va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1576                                xcp->regs[MIPSInst_FT(ir)]);
1577
1578                        MIPS_FPU_EMU_INC_STATS(loads);
1579                        if (!access_ok(VERIFY_READ, va, sizeof(u64))) {
1580                                MIPS_FPU_EMU_INC_STATS(errors);
1581                                *fault_addr = va;
1582                                return SIGBUS;
1583                        }
1584                        if (__get_user(val, va)) {
1585                                MIPS_FPU_EMU_INC_STATS(errors);
1586                                *fault_addr = va;
1587                                return SIGSEGV;
1588                        }
1589                        DITOREG(val, MIPSInst_FD(ir));
1590                        break;
1591
1592                case sdxc1_op:
1593                        va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
1594                                xcp->regs[MIPSInst_FT(ir)]);
1595
1596                        MIPS_FPU_EMU_INC_STATS(stores);
1597                        DIFROMREG(val, MIPSInst_FS(ir));
1598                        if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) {
1599                                MIPS_FPU_EMU_INC_STATS(errors);
1600                                *fault_addr = va;
1601                                return SIGBUS;
1602                        }
1603                        if (__put_user(val, va)) {
1604                                MIPS_FPU_EMU_INC_STATS(errors);
1605                                *fault_addr = va;
1606                                return SIGSEGV;
1607                        }
1608                        break;
1609
1610                case madd_d_op:
1611                        handler = fpemu_dp_madd;
1612                        goto dcoptop;
1613                case msub_d_op:
1614                        handler = fpemu_dp_msub;
1615                        goto dcoptop;
1616                case nmadd_d_op:
1617                        handler = fpemu_dp_nmadd;
1618                        goto dcoptop;
1619                case nmsub_d_op:
1620                        handler = fpemu_dp_nmsub;
1621                        goto dcoptop;
1622
1623                      dcoptop:
1624                        DPFROMREG(fr, MIPSInst_FR(ir));
1625                        DPFROMREG(fs, MIPSInst_FS(ir));
1626                        DPFROMREG(ft, MIPSInst_FT(ir));
1627                        fd = (*handler) (fr, fs, ft);
1628                        DPTOREG(fd, MIPSInst_FD(ir));
1629                        goto copcsr;
1630
1631                default:
1632                        return SIGILL;
1633                }
1634                break;
1635        }
1636
1637        case 0x3:
1638                if (MIPSInst_FUNC(ir) != pfetch_op)
1639                        return SIGILL;
1640
1641                /* ignore prefx operation */
1642                break;
1643
1644        default:
1645                return SIGILL;
1646        }
1647
1648        return 0;
1649}
1650
1651
1652
1653/*
1654 * Emulate a single COP1 arithmetic instruction.
1655 */
1656static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
1657        mips_instruction ir)
1658{
1659        int rfmt;               /* resulting format */
1660        unsigned rcsr = 0;      /* resulting csr */
1661        unsigned int oldrm;
1662        unsigned int cbit;
1663        unsigned cond;
1664        union {
1665                union ieee754dp d;
1666                union ieee754sp s;
1667                int w;
1668                s64 l;
1669        } rv;                   /* resulting value */
1670        u64 bits;
1671
1672        MIPS_FPU_EMU_INC_STATS(cp1ops);
1673        switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) {
1674        case s_fmt: {           /* 0 */
1675                union {
1676                        union ieee754sp(*b) (union ieee754sp, union ieee754sp);
1677                        union ieee754sp(*u) (union ieee754sp);
1678                } handler;
1679                union ieee754sp fd, fs, ft;
1680
1681                switch (MIPSInst_FUNC(ir)) {
1682                        /* binary ops */
1683                case fadd_op:
1684                        handler.b = ieee754sp_add;
1685                        goto scopbop;
1686                case fsub_op:
1687                        handler.b = ieee754sp_sub;
1688                        goto scopbop;
1689                case fmul_op:
1690                        handler.b = ieee754sp_mul;
1691                        goto scopbop;
1692                case fdiv_op:
1693                        handler.b = ieee754sp_div;
1694                        goto scopbop;
1695
1696                        /* unary  ops */
1697                case fsqrt_op:
1698                        if (!cpu_has_mips_2_3_4_5_r)
1699                                return SIGILL;
1700
1701                        handler.u = ieee754sp_sqrt;
1702                        goto scopuop;
1703
1704                /*
1705                 * Note that on some MIPS IV implementations such as the
1706                 * R5000 and R8000 the FSQRT and FRECIP instructions do not
1707                 * achieve full IEEE-754 accuracy - however this emulator does.
1708                 */
1709                case frsqrt_op:
1710                        if (!cpu_has_mips_4_5_64_r2_r6)
1711                                return SIGILL;
1712
1713                        handler.u = fpemu_sp_rsqrt;
1714                        goto scopuop;
1715
1716                case frecip_op:
1717                        if (!cpu_has_mips_4_5_64_r2_r6)
1718                                return SIGILL;
1719
1720                        handler.u = fpemu_sp_recip;
1721                        goto scopuop;
1722
1723                case fmovc_op:
1724                        if (!cpu_has_mips_4_5_r)
1725                                return SIGILL;
1726
1727                        cond = fpucondbit[MIPSInst_FT(ir) >> 2];
1728                        if (((ctx->fcr31 & cond) != 0) !=
1729                                ((MIPSInst_FT(ir) & 1) != 0))
1730                                return 0;
1731                        SPFROMREG(rv.s, MIPSInst_FS(ir));
1732                        break;
1733
1734                case fmovz_op:
1735                        if (!cpu_has_mips_4_5_r)
1736                                return SIGILL;
1737
1738                        if (xcp->regs[MIPSInst_FT(ir)] != 0)
1739                                return 0;
1740                        SPFROMREG(rv.s, MIPSInst_FS(ir));
1741                        break;
1742
1743                case fmovn_op:
1744                        if (!cpu_has_mips_4_5_r)
1745                                return SIGILL;
1746
1747                        if (xcp->regs[MIPSInst_FT(ir)] == 0)
1748                                return 0;
1749                        SPFROMREG(rv.s, MIPSInst_FS(ir));
1750                        break;
1751
1752                case fseleqz_op:
1753                        if (!cpu_has_mips_r6)
1754                                return SIGILL;
1755
1756                        SPFROMREG(rv.s, MIPSInst_FT(ir));
1757                        if (rv.w & 0x1)
1758                                rv.w = 0;
1759                        else
1760                                SPFROMREG(rv.s, MIPSInst_FS(ir));
1761                        break;
1762
1763                case fselnez_op:
1764                        if (!cpu_has_mips_r6)
1765                                return SIGILL;
1766
1767                        SPFROMREG(rv.s, MIPSInst_FT(ir));
1768                        if (rv.w & 0x1)
1769                                SPFROMREG(rv.s, MIPSInst_FS(ir));
1770                        else
1771                                rv.w = 0;
1772                        break;
1773
1774                case fmaddf_op: {
1775                        union ieee754sp ft, fs, fd;
1776
1777                        if (!cpu_has_mips_r6)
1778                                return SIGILL;
1779
1780                        SPFROMREG(ft, MIPSInst_FT(ir));
1781                        SPFROMREG(fs, MIPSInst_FS(ir));
1782                        SPFROMREG(fd, MIPSInst_FD(ir));
1783                        rv.s = ieee754sp_maddf(fd, fs, ft);
1784                        break;
1785                }
1786
1787                case fmsubf_op: {
1788                        union ieee754sp ft, fs, fd;
1789
1790                        if (!cpu_has_mips_r6)
1791                                return SIGILL;
1792
1793                        SPFROMREG(ft, MIPSInst_FT(ir));
1794                        SPFROMREG(fs, MIPSInst_FS(ir));
1795                        SPFROMREG(fd, MIPSInst_FD(ir));
1796                        rv.s = ieee754sp_msubf(fd, fs, ft);
1797                        break;
1798                }
1799
1800                case frint_op: {
1801                        union ieee754sp fs;
1802
1803                        if (!cpu_has_mips_r6)
1804                                return SIGILL;
1805
1806                        SPFROMREG(fs, MIPSInst_FS(ir));
1807                        rv.l = ieee754sp_tlong(fs);
1808                        rv.s = ieee754sp_flong(rv.l);
1809                        goto copcsr;
1810                }
1811
1812                case fclass_op: {
1813                        union ieee754sp fs;
1814
1815                        if (!cpu_has_mips_r6)
1816                                return SIGILL;
1817
1818                        SPFROMREG(fs, MIPSInst_FS(ir));
1819                        rv.w = ieee754sp_2008class(fs);
1820                        rfmt = w_fmt;
1821                        break;
1822                }
1823
1824                case fmin_op: {
1825                        union ieee754sp fs, ft;
1826
1827                        if (!cpu_has_mips_r6)
1828                                return SIGILL;
1829
1830                        SPFROMREG(ft, MIPSInst_FT(ir));
1831                        SPFROMREG(fs, MIPSInst_FS(ir));
1832                        rv.s = ieee754sp_fmin(fs, ft);
1833                        break;
1834                }
1835
1836                case fmina_op: {
1837                        union ieee754sp fs, ft;
1838
1839                        if (!cpu_has_mips_r6)
1840                                return SIGILL;
1841
1842                        SPFROMREG(ft, MIPSInst_FT(ir));
1843                        SPFROMREG(fs, MIPSInst_FS(ir));
1844                        rv.s = ieee754sp_fmina(fs, ft);
1845                        break;
1846                }
1847
1848                case fmax_op: {
1849                        union ieee754sp fs, ft;
1850
1851                        if (!cpu_has_mips_r6)
1852                                return SIGILL;
1853
1854                        SPFROMREG(ft, MIPSInst_FT(ir));
1855                        SPFROMREG(fs, MIPSInst_FS(ir));
1856                        rv.s = ieee754sp_fmax(fs, ft);
1857                        break;
1858                }
1859
1860                case fmaxa_op: {
1861                        union ieee754sp fs, ft;
1862
1863                        if (!cpu_has_mips_r6)
1864                                return SIGILL;
1865
1866                        SPFROMREG(ft, MIPSInst_FT(ir));
1867                        SPFROMREG(fs, MIPSInst_FS(ir));
1868                        rv.s = ieee754sp_fmaxa(fs, ft);
1869                        break;
1870                }
1871
1872                case fabs_op:
1873                        handler.u = ieee754sp_abs;
1874                        goto scopuop;
1875
1876                case fneg_op:
1877                        handler.u = ieee754sp_neg;
1878                        goto scopuop;
1879
1880                case fmov_op:
1881                        /* an easy one */
1882                        SPFROMREG(rv.s, MIPSInst_FS(ir));
1883                        goto copcsr;
1884
1885                        /* binary op on handler */
1886scopbop:
1887                        SPFROMREG(fs, MIPSInst_FS(ir));
1888                        SPFROMREG(ft, MIPSInst_FT(ir));
1889
1890                        rv.s = (*handler.b) (fs, ft);
1891                        goto copcsr;
1892scopuop:
1893                        SPFROMREG(fs, MIPSInst_FS(ir));
1894                        rv.s = (*handler.u) (fs);
1895                        goto copcsr;
1896copcsr:
1897                        if (ieee754_cxtest(IEEE754_INEXACT)) {
1898                                MIPS_FPU_EMU_INC_STATS(ieee754_inexact);
1899                                rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
1900                        }
1901                        if (ieee754_cxtest(IEEE754_UNDERFLOW)) {
1902                                MIPS_FPU_EMU_INC_STATS(ieee754_underflow);
1903                                rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
1904                        }
1905                        if (ieee754_cxtest(IEEE754_OVERFLOW)) {
1906                                MIPS_FPU_EMU_INC_STATS(ieee754_overflow);
1907                                rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
1908                        }
1909                        if (ieee754_cxtest(IEEE754_ZERO_DIVIDE)) {
1910                                MIPS_FPU_EMU_INC_STATS(ieee754_zerodiv);
1911                                rcsr |= FPU_CSR_DIV_X | FPU_CSR_DIV_S;
1912                        }
1913                        if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) {
1914                                MIPS_FPU_EMU_INC_STATS(ieee754_invalidop);
1915                                rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
1916                        }
1917                        break;
1918
1919                        /* unary conv ops */
1920                case fcvts_op:
1921                        return SIGILL;  /* not defined */
1922
1923                case fcvtd_op:
1924                        SPFROMREG(fs, MIPSInst_FS(ir));
1925                        rv.d = ieee754dp_fsp(fs);
1926                        rfmt = d_fmt;
1927                        goto copcsr;
1928
1929                case fcvtw_op:
1930                        SPFROMREG(fs, MIPSInst_FS(ir));
1931                        rv.w = ieee754sp_tint(fs);
1932                        rfmt = w_fmt;
1933                        goto copcsr;
1934
1935                case fround_op:
1936                case ftrunc_op:
1937                case fceil_op:
1938                case ffloor_op:
1939                        if (!cpu_has_mips_2_3_4_5_r)
1940                                return SIGILL;
1941
1942                        oldrm = ieee754_csr.rm;
1943                        SPFROMREG(fs, MIPSInst_FS(ir));
1944                        ieee754_csr.rm = MIPSInst_FUNC(ir);
1945                        rv.w = ieee754sp_tint(fs);
1946                        ieee754_csr.rm = oldrm;
1947                        rfmt = w_fmt;
1948                        goto copcsr;
1949
1950                case fsel_op:
1951                        if (!cpu_has_mips_r6)
1952                                return SIGILL;
1953
1954                        SPFROMREG(fd, MIPSInst_FD(ir));
1955                        if (fd.bits & 0x1)
1956                                SPFROMREG(rv.s, MIPSInst_FT(ir));
1957                        else
1958                                SPFROMREG(rv.s, MIPSInst_FS(ir));
1959                        break;
1960
1961                case fcvtl_op:
1962                        if (!cpu_has_mips_3_4_5_64_r2_r6)
1963                                return SIGILL;
1964
1965                        SPFROMREG(fs, MIPSInst_FS(ir));
1966                        rv.l = ieee754sp_tlong(fs);
1967                        rfmt = l_fmt;
1968                        goto copcsr;
1969
1970                case froundl_op:
1971                case ftruncl_op:
1972                case fceill_op:
1973                case ffloorl_op:
1974                        if (!cpu_has_mips_3_4_5_64_r2_r6)
1975                                return SIGILL;
1976
1977                        oldrm = ieee754_csr.rm;
1978                        SPFROMREG(fs, MIPSInst_FS(ir));
1979                        ieee754_csr.rm = MIPSInst_FUNC(ir);
1980                        rv.l = ieee754sp_tlong(fs);
1981                        ieee754_csr.rm = oldrm;
1982                        rfmt = l_fmt;
1983                        goto copcsr;
1984
1985                default:
1986                        if (!NO_R6EMU && MIPSInst_FUNC(ir) >= fcmp_op) {
1987                                unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
1988                                union ieee754sp fs, ft;
1989
1990                                SPFROMREG(fs, MIPSInst_FS(ir));
1991                                SPFROMREG(ft, MIPSInst_FT(ir));
1992                                rv.w = ieee754sp_cmp(fs, ft,
1993                                        cmptab[cmpop & 0x7], cmpop & 0x8);
1994                                rfmt = -1;
1995                                if ((cmpop & 0x8) && ieee754_cxtest
1996                                        (IEEE754_INVALID_OPERATION))
1997                                        rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
1998                                else
1999                                        goto copcsr;
2000
2001                        } else
2002                                return SIGILL;
2003                        break;
2004                }
2005                break;
2006        }
2007
2008        case d_fmt: {
2009                union ieee754dp fd, fs, ft;
2010                union {
2011                        union ieee754dp(*b) (union ieee754dp, union ieee754dp);
2012                        union ieee754dp(*u) (union ieee754dp);
2013                } handler;
2014
2015                switch (MIPSInst_FUNC(ir)) {
2016                        /* binary ops */
2017                case fadd_op:
2018                        handler.b = ieee754dp_add;
2019                        goto dcopbop;
2020                case fsub_op:
2021                        handler.b = ieee754dp_sub;
2022                        goto dcopbop;
2023                case fmul_op:
2024                        handler.b = ieee754dp_mul;
2025                        goto dcopbop;
2026                case fdiv_op:
2027                        handler.b = ieee754dp_div;
2028                        goto dcopbop;
2029
2030                        /* unary  ops */
2031                case fsqrt_op:
2032                        if (!cpu_has_mips_2_3_4_5_r)
2033                                return SIGILL;
2034
2035                        handler.u = ieee754dp_sqrt;
2036                        goto dcopuop;
2037                /*
2038                 * Note that on some MIPS IV implementations such as the
2039                 * R5000 and R8000 the FSQRT and FRECIP instructions do not
2040                 * achieve full IEEE-754 accuracy - however this emulator does.
2041                 */
2042                case frsqrt_op:
2043                        if (!cpu_has_mips_4_5_64_r2_r6)
2044                                return SIGILL;
2045
2046                        handler.u = fpemu_dp_rsqrt;
2047                        goto dcopuop;
2048                case frecip_op:
2049                        if (!cpu_has_mips_4_5_64_r2_r6)
2050                                return SIGILL;
2051
2052                        handler.u = fpemu_dp_recip;
2053                        goto dcopuop;
2054                case fmovc_op:
2055                        if (!cpu_has_mips_4_5_r)
2056                                return SIGILL;
2057
2058                        cond = fpucondbit[MIPSInst_FT(ir) >> 2];
2059                        if (((ctx->fcr31 & cond) != 0) !=
2060                                ((MIPSInst_FT(ir) & 1) != 0))
2061                                return 0;
2062                        DPFROMREG(rv.d, MIPSInst_FS(ir));
2063                        break;
2064                case fmovz_op:
2065                        if (!cpu_has_mips_4_5_r)
2066                                return SIGILL;
2067
2068                        if (xcp->regs[MIPSInst_FT(ir)] != 0)
2069                                return 0;
2070                        DPFROMREG(rv.d, MIPSInst_FS(ir));
2071                        break;
2072                case fmovn_op:
2073                        if (!cpu_has_mips_4_5_r)
2074                                return SIGILL;
2075
2076                        if (xcp->regs[MIPSInst_FT(ir)] == 0)
2077                                return 0;
2078                        DPFROMREG(rv.d, MIPSInst_FS(ir));
2079                        break;
2080
2081                case fseleqz_op:
2082                        if (!cpu_has_mips_r6)
2083                                return SIGILL;
2084
2085                        DPFROMREG(rv.d, MIPSInst_FT(ir));
2086                        if (rv.l & 0x1)
2087                                rv.l = 0;
2088                        else
2089                                DPFROMREG(rv.d, MIPSInst_FS(ir));
2090                        break;
2091
2092                case fselnez_op:
2093                        if (!cpu_has_mips_r6)
2094                                return SIGILL;
2095
2096                        DPFROMREG(rv.d, MIPSInst_FT(ir));
2097                        if (rv.l & 0x1)
2098                                DPFROMREG(rv.d, MIPSInst_FS(ir));
2099                        else
2100                                rv.l = 0;
2101                        break;
2102
2103                case fmaddf_op: {
2104                        union ieee754dp ft, fs, fd;
2105
2106                        if (!cpu_has_mips_r6)
2107                                return SIGILL;
2108
2109                        DPFROMREG(ft, MIPSInst_FT(ir));
2110                        DPFROMREG(fs, MIPSInst_FS(ir));
2111                        DPFROMREG(fd, MIPSInst_FD(ir));
2112                        rv.d = ieee754dp_maddf(fd, fs, ft);
2113                        break;
2114                }
2115
2116                case fmsubf_op: {
2117                        union ieee754dp ft, fs, fd;
2118
2119                        if (!cpu_has_mips_r6)
2120                                return SIGILL;
2121
2122                        DPFROMREG(ft, MIPSInst_FT(ir));
2123                        DPFROMREG(fs, MIPSInst_FS(ir));
2124                        DPFROMREG(fd, MIPSInst_FD(ir));
2125                        rv.d = ieee754dp_msubf(fd, fs, ft);
2126                        break;
2127                }
2128
2129                case frint_op: {
2130                        union ieee754dp fs;
2131
2132                        if (!cpu_has_mips_r6)
2133                                return SIGILL;
2134
2135                        DPFROMREG(fs, MIPSInst_FS(ir));
2136                        rv.l = ieee754dp_tlong(fs);
2137                        rv.d = ieee754dp_flong(rv.l);
2138                        goto copcsr;
2139                }
2140
2141                case fclass_op: {
2142                        union ieee754dp fs;
2143
2144                        if (!cpu_has_mips_r6)
2145                                return SIGILL;
2146
2147                        DPFROMREG(fs, MIPSInst_FS(ir));
2148                        rv.w = ieee754dp_2008class(fs);
2149                        rfmt = w_fmt;
2150                        break;
2151                }
2152
2153                case fmin_op: {
2154                        union ieee754dp fs, ft;
2155
2156                        if (!cpu_has_mips_r6)
2157                                return SIGILL;
2158
2159                        DPFROMREG(ft, MIPSInst_FT(ir));
2160                        DPFROMREG(fs, MIPSInst_FS(ir));
2161                        rv.d = ieee754dp_fmin(fs, ft);
2162                        break;
2163                }
2164
2165                case fmina_op: {
2166                        union ieee754dp fs, ft;
2167
2168                        if (!cpu_has_mips_r6)
2169                                return SIGILL;
2170
2171                        DPFROMREG(ft, MIPSInst_FT(ir));
2172                        DPFROMREG(fs, MIPSInst_FS(ir));
2173                        rv.d = ieee754dp_fmina(fs, ft);
2174                        break;
2175                }
2176
2177                case fmax_op: {
2178                        union ieee754dp fs, ft;
2179
2180                        if (!cpu_has_mips_r6)
2181                                return SIGILL;
2182
2183                        DPFROMREG(ft, MIPSInst_FT(ir));
2184                        DPFROMREG(fs, MIPSInst_FS(ir));
2185                        rv.d = ieee754dp_fmax(fs, ft);
2186                        break;
2187                }
2188
2189                case fmaxa_op: {
2190                        union ieee754dp fs, ft;
2191
2192                        if (!cpu_has_mips_r6)
2193                                return SIGILL;
2194
2195                        DPFROMREG(ft, MIPSInst_FT(ir));
2196                        DPFROMREG(fs, MIPSInst_FS(ir));
2197                        rv.d = ieee754dp_fmaxa(fs, ft);
2198                        break;
2199                }
2200
2201                case fabs_op:
2202                        handler.u = ieee754dp_abs;
2203                        goto dcopuop;
2204
2205                case fneg_op:
2206                        handler.u = ieee754dp_neg;
2207                        goto dcopuop;
2208
2209                case fmov_op:
2210                        /* an easy one */
2211                        DPFROMREG(rv.d, MIPSInst_FS(ir));
2212                        goto copcsr;
2213
2214                        /* binary op on handler */
2215dcopbop:
2216                        DPFROMREG(fs, MIPSInst_FS(ir));
2217                        DPFROMREG(ft, MIPSInst_FT(ir));
2218
2219                        rv.d = (*handler.b) (fs, ft);
2220                        goto copcsr;
2221dcopuop:
2222                        DPFROMREG(fs, MIPSInst_FS(ir));
2223                        rv.d = (*handler.u) (fs);
2224                        goto copcsr;
2225
2226                /*
2227                 * unary conv ops
2228                 */
2229                case fcvts_op:
2230                        DPFROMREG(fs, MIPSInst_FS(ir));
2231                        rv.s = ieee754sp_fdp(fs);
2232                        rfmt = s_fmt;
2233                        goto copcsr;
2234
2235                case fcvtd_op:
2236                        return SIGILL;  /* not defined */
2237
2238                case fcvtw_op:
2239                        DPFROMREG(fs, MIPSInst_FS(ir));
2240                        rv.w = ieee754dp_tint(fs);      /* wrong */
2241                        rfmt = w_fmt;
2242                        goto copcsr;
2243
2244                case fround_op:
2245                case ftrunc_op:
2246                case fceil_op:
2247                case ffloor_op:
2248                        if (!cpu_has_mips_2_3_4_5_r)
2249                                return SIGILL;
2250
2251                        oldrm = ieee754_csr.rm;
2252                        DPFROMREG(fs, MIPSInst_FS(ir));
2253                        ieee754_csr.rm = MIPSInst_FUNC(ir);
2254                        rv.w = ieee754dp_tint(fs);
2255                        ieee754_csr.rm = oldrm;
2256                        rfmt = w_fmt;
2257                        goto copcsr;
2258
2259                case fsel_op:
2260                        if (!cpu_has_mips_r6)
2261                                return SIGILL;
2262
2263                        DPFROMREG(fd, MIPSInst_FD(ir));
2264                        if (fd.bits & 0x1)
2265                                DPFROMREG(rv.d, MIPSInst_FT(ir));
2266                        else
2267                                DPFROMREG(rv.d, MIPSInst_FS(ir));
2268                        break;
2269
2270                case fcvtl_op:
2271                        if (!cpu_has_mips_3_4_5_64_r2_r6)
2272                                return SIGILL;
2273
2274                        DPFROMREG(fs, MIPSInst_FS(ir));
2275                        rv.l = ieee754dp_tlong(fs);
2276                        rfmt = l_fmt;
2277                        goto copcsr;
2278
2279                case froundl_op:
2280                case ftruncl_op:
2281                case fceill_op:
2282                case ffloorl_op:
2283                        if (!cpu_has_mips_3_4_5_64_r2_r6)
2284                                return SIGILL;
2285
2286                        oldrm = ieee754_csr.rm;
2287                        DPFROMREG(fs, MIPSInst_FS(ir));
2288                        ieee754_csr.rm = MIPSInst_FUNC(ir);
2289                        rv.l = ieee754dp_tlong(fs);
2290                        ieee754_csr.rm = oldrm;
2291                        rfmt = l_fmt;
2292                        goto copcsr;
2293
2294                default:
2295                        if (!NO_R6EMU && MIPSInst_FUNC(ir) >= fcmp_op) {
2296                                unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
2297                                union ieee754dp fs, ft;
2298
2299                                DPFROMREG(fs, MIPSInst_FS(ir));
2300                                DPFROMREG(ft, MIPSInst_FT(ir));
2301                                rv.w = ieee754dp_cmp(fs, ft,
2302                                        cmptab[cmpop & 0x7], cmpop & 0x8);
2303                                rfmt = -1;
2304                                if ((cmpop & 0x8)
2305                                        &&
2306                                        ieee754_cxtest
2307                                        (IEEE754_INVALID_OPERATION))
2308                                        rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2309                                else
2310                                        goto copcsr;
2311
2312                        }
2313                        else {
2314                                return SIGILL;
2315                        }
2316                        break;
2317                }
2318                break;
2319        }
2320
2321        case w_fmt: {
2322                union ieee754dp fs;
2323
2324                switch (MIPSInst_FUNC(ir)) {
2325                case fcvts_op:
2326                        /* convert word to single precision real */
2327                        SPFROMREG(fs, MIPSInst_FS(ir));
2328                        rv.s = ieee754sp_fint(fs.bits);
2329                        rfmt = s_fmt;
2330                        goto copcsr;
2331                case fcvtd_op:
2332                        /* convert word to double precision real */
2333                        SPFROMREG(fs, MIPSInst_FS(ir));
2334                        rv.d = ieee754dp_fint(fs.bits);
2335                        rfmt = d_fmt;
2336                        goto copcsr;
2337                default: {
2338                        /* Emulating the new CMP.condn.fmt R6 instruction */
2339#define CMPOP_MASK      0x7
2340#define SIGN_BIT        (0x1 << 3)
2341#define PREDICATE_BIT   (0x1 << 4)
2342
2343                        int cmpop = MIPSInst_FUNC(ir) & CMPOP_MASK;
2344                        int sig = MIPSInst_FUNC(ir) & SIGN_BIT;
2345                        union ieee754sp fs, ft;
2346
2347                        /* This is an R6 only instruction */
2348                        if (!cpu_has_mips_r6 ||
2349                            (MIPSInst_FUNC(ir) & 0x20))
2350                                return SIGILL;
2351
2352                        /* fmt is w_fmt for single precision so fix it */
2353                        rfmt = s_fmt;
2354                        /* default to false */
2355                        rv.w = 0;
2356
2357                        /* CMP.condn.S */
2358                        SPFROMREG(fs, MIPSInst_FS(ir));
2359                        SPFROMREG(ft, MIPSInst_FT(ir));
2360
2361                        /* positive predicates */
2362                        if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2363                                if (ieee754sp_cmp(fs, ft, cmptab[cmpop],
2364                                                  sig))
2365                                    rv.w = -1; /* true, all 1s */
2366                                if ((sig) &&
2367                                    ieee754_cxtest(IEEE754_INVALID_OPERATION))
2368                                        rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2369                                else
2370                                        goto copcsr;
2371                        } else {
2372                                /* negative predicates */
2373                                switch (cmpop) {
2374                                case 1:
2375                                case 2:
2376                                case 3:
2377                                        if (ieee754sp_cmp(fs, ft,
2378                                                          negative_cmptab[cmpop],
2379                                                          sig))
2380                                                rv.w = -1; /* true, all 1s */
2381                                        if (sig &&
2382                                            ieee754_cxtest(IEEE754_INVALID_OPERATION))
2383                                                rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2384                                        else
2385                                                goto copcsr;
2386                                        break;
2387                                default:
2388                                        /* Reserved R6 ops */
2389                                        pr_err("Reserved MIPS R6 CMP.condn.S operation\n");
2390                                        return SIGILL;
2391                                }
2392                        }
2393                        break;
2394                        }
2395                }
2396        }
2397
2398        case l_fmt:
2399
2400                if (!cpu_has_mips_3_4_5_64_r2_r6)
2401                        return SIGILL;
2402
2403                DIFROMREG(bits, MIPSInst_FS(ir));
2404
2405                switch (MIPSInst_FUNC(ir)) {
2406                case fcvts_op:
2407                        /* convert long to single precision real */
2408                        rv.s = ieee754sp_flong(bits);
2409                        rfmt = s_fmt;
2410                        goto copcsr;
2411                case fcvtd_op:
2412                        /* convert long to double precision real */
2413                        rv.d = ieee754dp_flong(bits);
2414                        rfmt = d_fmt;
2415                        goto copcsr;
2416                default: {
2417                        /* Emulating the new CMP.condn.fmt R6 instruction */
2418                        int cmpop = MIPSInst_FUNC(ir) & CMPOP_MASK;
2419                        int sig = MIPSInst_FUNC(ir) & SIGN_BIT;
2420                        union ieee754dp fs, ft;
2421
2422                        if (!cpu_has_mips_r6 ||
2423                            (MIPSInst_FUNC(ir) & 0x20))
2424                                return SIGILL;
2425
2426                        /* fmt is l_fmt for double precision so fix it */
2427                        rfmt = d_fmt;
2428                        /* default to false */
2429                        rv.l = 0;
2430
2431                        /* CMP.condn.D */
2432                        DPFROMREG(fs, MIPSInst_FS(ir));
2433                        DPFROMREG(ft, MIPSInst_FT(ir));
2434
2435                        /* positive predicates */
2436                        if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) {
2437                                if (ieee754dp_cmp(fs, ft,
2438                                                  cmptab[cmpop], sig))
2439                                    rv.l = -1LL; /* true, all 1s */
2440                                if (sig &&
2441                                    ieee754_cxtest(IEEE754_INVALID_OPERATION))
2442                                        rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2443                                else
2444                                        goto copcsr;
2445                        } else {
2446                                /* negative predicates */
2447                                switch (cmpop) {
2448                                case 1:
2449                                case 2:
2450                                case 3:
2451                                        if (ieee754dp_cmp(fs, ft,
2452                                                          negative_cmptab[cmpop],
2453                                                          sig))
2454                                                rv.l = -1LL; /* true, all 1s */
2455                                        if (sig &&
2456                                            ieee754_cxtest(IEEE754_INVALID_OPERATION))
2457                                                rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
2458                                        else
2459                                                goto copcsr;
2460                                        break;
2461                                default:
2462                                        /* Reserved R6 ops */
2463                                        pr_err("Reserved MIPS R6 CMP.condn.D operation\n");
2464                                        return SIGILL;
2465                                }
2466                        }
2467                        break;
2468                        }
2469                }
2470        default:
2471                return SIGILL;
2472        }
2473
2474        /*
2475         * Update the fpu CSR register for this operation.
2476         * If an exception is required, generate a tidy SIGFPE exception,
2477         * without updating the result register.
2478         * Note: cause exception bits do not accumulate, they are rewritten
2479         * for each op; only the flag/sticky bits accumulate.
2480         */
2481        ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
2482        if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
2483                /*printk ("SIGFPE: FPU csr = %08x\n",ctx->fcr31); */
2484                return SIGFPE;
2485        }
2486
2487        /*
2488         * Now we can safely write the result back to the register file.
2489         */
2490        switch (rfmt) {
2491        case -1:
2492
2493                if (cpu_has_mips_4_5_r)
2494                        cbit = fpucondbit[MIPSInst_FD(ir) >> 2];
2495                else
2496                        cbit = FPU_CSR_COND;
2497                if (rv.w)
2498                        ctx->fcr31 |= cbit;
2499                else
2500                        ctx->fcr31 &= ~cbit;
2501                break;
2502
2503        case d_fmt:
2504                DPTOREG(rv.d, MIPSInst_FD(ir));
2505                break;
2506        case s_fmt:
2507                SPTOREG(rv.s, MIPSInst_FD(ir));
2508                break;
2509        case w_fmt:
2510                SITOREG(rv.w, MIPSInst_FD(ir));
2511                break;
2512        case l_fmt:
2513                if (!cpu_has_mips_3_4_5_64_r2_r6)
2514                        return SIGILL;
2515
2516                DITOREG(rv.l, MIPSInst_FD(ir));
2517                break;
2518        default:
2519                return SIGILL;
2520        }
2521
2522        return 0;
2523}
2524
2525int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
2526        int has_fpu, void *__user *fault_addr)
2527{
2528        unsigned long oldepc, prevepc;
2529        struct mm_decoded_insn dec_insn;
2530        u16 instr[4];
2531        u16 *instr_ptr;
2532        int sig = 0;
2533
2534        oldepc = xcp->cp0_epc;
2535        do {
2536                prevepc = xcp->cp0_epc;
2537
2538                if (get_isa16_mode(prevepc) && cpu_has_mmips) {
2539                        /*
2540                         * Get next 2 microMIPS instructions and convert them
2541                         * into 32-bit instructions.
2542                         */
2543                        if ((get_user(instr[0], (u16 __user *)msk_isa16_mode(xcp->cp0_epc))) ||
2544                            (get_user(instr[1], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 2))) ||
2545                            (get_user(instr[2], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 4))) ||
2546                            (get_user(instr[3], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 6)))) {
2547                                MIPS_FPU_EMU_INC_STATS(errors);
2548                                return SIGBUS;
2549                        }
2550                        instr_ptr = instr;
2551
2552                        /* Get first instruction. */
2553                        if (mm_insn_16bit(*instr_ptr)) {
2554                                /* Duplicate the half-word. */
2555                                dec_insn.insn = (*instr_ptr << 16) |
2556                                        (*instr_ptr);
2557                                /* 16-bit instruction. */
2558                                dec_insn.pc_inc = 2;
2559                                instr_ptr += 1;
2560                        } else {
2561                                dec_insn.insn = (*instr_ptr << 16) |
2562                                        *(instr_ptr+1);
2563                                /* 32-bit instruction. */
2564                                dec_insn.pc_inc = 4;
2565                                instr_ptr += 2;
2566                        }
2567                        /* Get second instruction. */
2568                        if (mm_insn_16bit(*instr_ptr)) {
2569                                /* Duplicate the half-word. */
2570                                dec_insn.next_insn = (*instr_ptr << 16) |
2571                                        (*instr_ptr);
2572                                /* 16-bit instruction. */
2573                                dec_insn.next_pc_inc = 2;
2574                        } else {
2575                                dec_insn.next_insn = (*instr_ptr << 16) |
2576                                        *(instr_ptr+1);
2577                                /* 32-bit instruction. */
2578                                dec_insn.next_pc_inc = 4;
2579                        }
2580                        dec_insn.micro_mips_mode = 1;
2581                } else {
2582                        if ((get_user(dec_insn.insn,
2583                            (mips_instruction __user *) xcp->cp0_epc)) ||
2584                            (get_user(dec_insn.next_insn,
2585                            (mips_instruction __user *)(xcp->cp0_epc+4)))) {
2586                                MIPS_FPU_EMU_INC_STATS(errors);
2587                                return SIGBUS;
2588                        }
2589                        dec_insn.pc_inc = 4;
2590                        dec_insn.next_pc_inc = 4;
2591                        dec_insn.micro_mips_mode = 0;
2592                }
2593
2594                if ((dec_insn.insn == 0) ||
2595                   ((dec_insn.pc_inc == 2) &&
2596                   ((dec_insn.insn & 0xffff) == MM_NOP16)))
2597                        xcp->cp0_epc += dec_insn.pc_inc;        /* Skip NOPs */
2598                else {
2599                        /*
2600                         * The 'ieee754_csr' is an alias of ctx->fcr31.
2601                         * No need to copy ctx->fcr31 to ieee754_csr.
2602                         */
2603                        sig = cop1Emulate(xcp, ctx, dec_insn, fault_addr);
2604                }
2605
2606                if (has_fpu)
2607                        break;
2608                if (sig)
2609                        break;
2610
2611                cond_resched();
2612        } while (xcp->cp0_epc > prevepc);
2613
2614        /* SIGILL indicates a non-fpu instruction */
2615        if (sig == SIGILL && xcp->cp0_epc != oldepc)
2616                /* but if EPC has advanced, then ignore it */
2617                sig = 0;
2618
2619        return sig;
2620}
2621