cp1emu.c revision a36d8225bceba4b7be47ade34d175945f85cffbc
1/* 2 * cp1emu.c: a MIPS coprocessor 1 (FPU) instruction emulator 3 * 4 * MIPS floating point support 5 * Copyright (C) 1994-2000 Algorithmics Ltd. 6 * 7 * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com 8 * Copyright (C) 2000 MIPS Technologies, Inc. 9 * 10 * This program is free software; you can distribute it and/or modify it 11 * under the terms of the GNU General Public License (Version 2) as 12 * published by the Free Software Foundation. 13 * 14 * This program is distributed in the hope it will be useful, but WITHOUT 15 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 16 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 17 * for more details. 18 * 19 * You should have received a copy of the GNU General Public License along 20 * with this program; if not, write to the Free Software Foundation, Inc., 21 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 22 * 23 * A complete emulator for MIPS coprocessor 1 instructions. This is 24 * required for #float(switch) or #float(trap), where it catches all 25 * COP1 instructions via the "CoProcessor Unusable" exception. 26 * 27 * More surprisingly it is also required for #float(ieee), to help out 28 * the hardware FPU at the boundaries of the IEEE-754 representation 29 * (denormalised values, infinities, underflow, etc). It is made 30 * quite nasty because emulation of some non-COP1 instructions is 31 * required, e.g. in branch delay slots. 32 * 33 * Note if you know that you won't have an FPU, then you'll get much 34 * better performance by compiling with -msoft-float! 35 */ 36#include <linux/sched.h> 37#include <linux/debugfs.h> 38#include <linux/kconfig.h> 39#include <linux/percpu-defs.h> 40#include <linux/perf_event.h> 41 42#include <asm/branch.h> 43#include <asm/inst.h> 44#include <asm/ptrace.h> 45#include <asm/signal.h> 46#include <asm/uaccess.h> 47 48#include <asm/processor.h> 49#include <asm/fpu_emulator.h> 50#include <asm/fpu.h> 51 52#include "ieee754.h" 53 54/* Function which emulates a floating point instruction. */ 55 56static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *, 57 mips_instruction); 58 59static int fpux_emu(struct pt_regs *, 60 struct mips_fpu_struct *, mips_instruction, void *__user *); 61 62/* Control registers */ 63 64#define FPCREG_RID 0 /* $0 = revision id */ 65#define FPCREG_CSR 31 /* $31 = csr */ 66 67/* Determine rounding mode from the RM bits of the FCSR */ 68#define modeindex(v) ((v) & FPU_CSR_RM) 69 70/* convert condition code register number to csr bit */ 71static const unsigned int fpucondbit[8] = { 72 FPU_CSR_COND0, 73 FPU_CSR_COND1, 74 FPU_CSR_COND2, 75 FPU_CSR_COND3, 76 FPU_CSR_COND4, 77 FPU_CSR_COND5, 78 FPU_CSR_COND6, 79 FPU_CSR_COND7 80}; 81 82/* (microMIPS) Convert certain microMIPS instructions to MIPS32 format. */ 83static const int sd_format[] = {16, 17, 0, 0, 0, 0, 0, 0}; 84static const int sdps_format[] = {16, 17, 22, 0, 0, 0, 0, 0}; 85static const int dwl_format[] = {17, 20, 21, 0, 0, 0, 0, 0}; 86static const int swl_format[] = {16, 20, 21, 0, 0, 0, 0, 0}; 87 88/* 89 * This functions translates a 32-bit microMIPS instruction 90 * into a 32-bit MIPS32 instruction. Returns 0 on success 91 * and SIGILL otherwise. 92 */ 93static int microMIPS32_to_MIPS32(union mips_instruction *insn_ptr) 94{ 95 union mips_instruction insn = *insn_ptr; 96 union mips_instruction mips32_insn = insn; 97 int func, fmt, op; 98 99 switch (insn.mm_i_format.opcode) { 100 case mm_ldc132_op: 101 mips32_insn.mm_i_format.opcode = ldc1_op; 102 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs; 103 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt; 104 break; 105 case mm_lwc132_op: 106 mips32_insn.mm_i_format.opcode = lwc1_op; 107 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs; 108 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt; 109 break; 110 case mm_sdc132_op: 111 mips32_insn.mm_i_format.opcode = sdc1_op; 112 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs; 113 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt; 114 break; 115 case mm_swc132_op: 116 mips32_insn.mm_i_format.opcode = swc1_op; 117 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs; 118 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt; 119 break; 120 case mm_pool32i_op: 121 /* NOTE: offset is << by 1 if in microMIPS mode. */ 122 if ((insn.mm_i_format.rt == mm_bc1f_op) || 123 (insn.mm_i_format.rt == mm_bc1t_op)) { 124 mips32_insn.fb_format.opcode = cop1_op; 125 mips32_insn.fb_format.bc = bc_op; 126 mips32_insn.fb_format.flag = 127 (insn.mm_i_format.rt == mm_bc1t_op) ? 1 : 0; 128 } else 129 return SIGILL; 130 break; 131 case mm_pool32f_op: 132 switch (insn.mm_fp0_format.func) { 133 case mm_32f_01_op: 134 case mm_32f_11_op: 135 case mm_32f_02_op: 136 case mm_32f_12_op: 137 case mm_32f_41_op: 138 case mm_32f_51_op: 139 case mm_32f_42_op: 140 case mm_32f_52_op: 141 op = insn.mm_fp0_format.func; 142 if (op == mm_32f_01_op) 143 func = madd_s_op; 144 else if (op == mm_32f_11_op) 145 func = madd_d_op; 146 else if (op == mm_32f_02_op) 147 func = nmadd_s_op; 148 else if (op == mm_32f_12_op) 149 func = nmadd_d_op; 150 else if (op == mm_32f_41_op) 151 func = msub_s_op; 152 else if (op == mm_32f_51_op) 153 func = msub_d_op; 154 else if (op == mm_32f_42_op) 155 func = nmsub_s_op; 156 else 157 func = nmsub_d_op; 158 mips32_insn.fp6_format.opcode = cop1x_op; 159 mips32_insn.fp6_format.fr = insn.mm_fp6_format.fr; 160 mips32_insn.fp6_format.ft = insn.mm_fp6_format.ft; 161 mips32_insn.fp6_format.fs = insn.mm_fp6_format.fs; 162 mips32_insn.fp6_format.fd = insn.mm_fp6_format.fd; 163 mips32_insn.fp6_format.func = func; 164 break; 165 case mm_32f_10_op: 166 func = -1; /* Invalid */ 167 op = insn.mm_fp5_format.op & 0x7; 168 if (op == mm_ldxc1_op) 169 func = ldxc1_op; 170 else if (op == mm_sdxc1_op) 171 func = sdxc1_op; 172 else if (op == mm_lwxc1_op) 173 func = lwxc1_op; 174 else if (op == mm_swxc1_op) 175 func = swxc1_op; 176 177 if (func != -1) { 178 mips32_insn.r_format.opcode = cop1x_op; 179 mips32_insn.r_format.rs = 180 insn.mm_fp5_format.base; 181 mips32_insn.r_format.rt = 182 insn.mm_fp5_format.index; 183 mips32_insn.r_format.rd = 0; 184 mips32_insn.r_format.re = insn.mm_fp5_format.fd; 185 mips32_insn.r_format.func = func; 186 } else 187 return SIGILL; 188 break; 189 case mm_32f_40_op: 190 op = -1; /* Invalid */ 191 if (insn.mm_fp2_format.op == mm_fmovt_op) 192 op = 1; 193 else if (insn.mm_fp2_format.op == mm_fmovf_op) 194 op = 0; 195 if (op != -1) { 196 mips32_insn.fp0_format.opcode = cop1_op; 197 mips32_insn.fp0_format.fmt = 198 sdps_format[insn.mm_fp2_format.fmt]; 199 mips32_insn.fp0_format.ft = 200 (insn.mm_fp2_format.cc<<2) + op; 201 mips32_insn.fp0_format.fs = 202 insn.mm_fp2_format.fs; 203 mips32_insn.fp0_format.fd = 204 insn.mm_fp2_format.fd; 205 mips32_insn.fp0_format.func = fmovc_op; 206 } else 207 return SIGILL; 208 break; 209 case mm_32f_60_op: 210 func = -1; /* Invalid */ 211 if (insn.mm_fp0_format.op == mm_fadd_op) 212 func = fadd_op; 213 else if (insn.mm_fp0_format.op == mm_fsub_op) 214 func = fsub_op; 215 else if (insn.mm_fp0_format.op == mm_fmul_op) 216 func = fmul_op; 217 else if (insn.mm_fp0_format.op == mm_fdiv_op) 218 func = fdiv_op; 219 if (func != -1) { 220 mips32_insn.fp0_format.opcode = cop1_op; 221 mips32_insn.fp0_format.fmt = 222 sdps_format[insn.mm_fp0_format.fmt]; 223 mips32_insn.fp0_format.ft = 224 insn.mm_fp0_format.ft; 225 mips32_insn.fp0_format.fs = 226 insn.mm_fp0_format.fs; 227 mips32_insn.fp0_format.fd = 228 insn.mm_fp0_format.fd; 229 mips32_insn.fp0_format.func = func; 230 } else 231 return SIGILL; 232 break; 233 case mm_32f_70_op: 234 func = -1; /* Invalid */ 235 if (insn.mm_fp0_format.op == mm_fmovn_op) 236 func = fmovn_op; 237 else if (insn.mm_fp0_format.op == mm_fmovz_op) 238 func = fmovz_op; 239 if (func != -1) { 240 mips32_insn.fp0_format.opcode = cop1_op; 241 mips32_insn.fp0_format.fmt = 242 sdps_format[insn.mm_fp0_format.fmt]; 243 mips32_insn.fp0_format.ft = 244 insn.mm_fp0_format.ft; 245 mips32_insn.fp0_format.fs = 246 insn.mm_fp0_format.fs; 247 mips32_insn.fp0_format.fd = 248 insn.mm_fp0_format.fd; 249 mips32_insn.fp0_format.func = func; 250 } else 251 return SIGILL; 252 break; 253 case mm_32f_73_op: /* POOL32FXF */ 254 switch (insn.mm_fp1_format.op) { 255 case mm_movf0_op: 256 case mm_movf1_op: 257 case mm_movt0_op: 258 case mm_movt1_op: 259 if ((insn.mm_fp1_format.op & 0x7f) == 260 mm_movf0_op) 261 op = 0; 262 else 263 op = 1; 264 mips32_insn.r_format.opcode = spec_op; 265 mips32_insn.r_format.rs = insn.mm_fp4_format.fs; 266 mips32_insn.r_format.rt = 267 (insn.mm_fp4_format.cc << 2) + op; 268 mips32_insn.r_format.rd = insn.mm_fp4_format.rt; 269 mips32_insn.r_format.re = 0; 270 mips32_insn.r_format.func = movc_op; 271 break; 272 case mm_fcvtd0_op: 273 case mm_fcvtd1_op: 274 case mm_fcvts0_op: 275 case mm_fcvts1_op: 276 if ((insn.mm_fp1_format.op & 0x7f) == 277 mm_fcvtd0_op) { 278 func = fcvtd_op; 279 fmt = swl_format[insn.mm_fp3_format.fmt]; 280 } else { 281 func = fcvts_op; 282 fmt = dwl_format[insn.mm_fp3_format.fmt]; 283 } 284 mips32_insn.fp0_format.opcode = cop1_op; 285 mips32_insn.fp0_format.fmt = fmt; 286 mips32_insn.fp0_format.ft = 0; 287 mips32_insn.fp0_format.fs = 288 insn.mm_fp3_format.fs; 289 mips32_insn.fp0_format.fd = 290 insn.mm_fp3_format.rt; 291 mips32_insn.fp0_format.func = func; 292 break; 293 case mm_fmov0_op: 294 case mm_fmov1_op: 295 case mm_fabs0_op: 296 case mm_fabs1_op: 297 case mm_fneg0_op: 298 case mm_fneg1_op: 299 if ((insn.mm_fp1_format.op & 0x7f) == 300 mm_fmov0_op) 301 func = fmov_op; 302 else if ((insn.mm_fp1_format.op & 0x7f) == 303 mm_fabs0_op) 304 func = fabs_op; 305 else 306 func = fneg_op; 307 mips32_insn.fp0_format.opcode = cop1_op; 308 mips32_insn.fp0_format.fmt = 309 sdps_format[insn.mm_fp3_format.fmt]; 310 mips32_insn.fp0_format.ft = 0; 311 mips32_insn.fp0_format.fs = 312 insn.mm_fp3_format.fs; 313 mips32_insn.fp0_format.fd = 314 insn.mm_fp3_format.rt; 315 mips32_insn.fp0_format.func = func; 316 break; 317 case mm_ffloorl_op: 318 case mm_ffloorw_op: 319 case mm_fceill_op: 320 case mm_fceilw_op: 321 case mm_ftruncl_op: 322 case mm_ftruncw_op: 323 case mm_froundl_op: 324 case mm_froundw_op: 325 case mm_fcvtl_op: 326 case mm_fcvtw_op: 327 if (insn.mm_fp1_format.op == mm_ffloorl_op) 328 func = ffloorl_op; 329 else if (insn.mm_fp1_format.op == mm_ffloorw_op) 330 func = ffloor_op; 331 else if (insn.mm_fp1_format.op == mm_fceill_op) 332 func = fceill_op; 333 else if (insn.mm_fp1_format.op == mm_fceilw_op) 334 func = fceil_op; 335 else if (insn.mm_fp1_format.op == mm_ftruncl_op) 336 func = ftruncl_op; 337 else if (insn.mm_fp1_format.op == mm_ftruncw_op) 338 func = ftrunc_op; 339 else if (insn.mm_fp1_format.op == mm_froundl_op) 340 func = froundl_op; 341 else if (insn.mm_fp1_format.op == mm_froundw_op) 342 func = fround_op; 343 else if (insn.mm_fp1_format.op == mm_fcvtl_op) 344 func = fcvtl_op; 345 else 346 func = fcvtw_op; 347 mips32_insn.fp0_format.opcode = cop1_op; 348 mips32_insn.fp0_format.fmt = 349 sd_format[insn.mm_fp1_format.fmt]; 350 mips32_insn.fp0_format.ft = 0; 351 mips32_insn.fp0_format.fs = 352 insn.mm_fp1_format.fs; 353 mips32_insn.fp0_format.fd = 354 insn.mm_fp1_format.rt; 355 mips32_insn.fp0_format.func = func; 356 break; 357 case mm_frsqrt_op: 358 case mm_fsqrt_op: 359 case mm_frecip_op: 360 if (insn.mm_fp1_format.op == mm_frsqrt_op) 361 func = frsqrt_op; 362 else if (insn.mm_fp1_format.op == mm_fsqrt_op) 363 func = fsqrt_op; 364 else 365 func = frecip_op; 366 mips32_insn.fp0_format.opcode = cop1_op; 367 mips32_insn.fp0_format.fmt = 368 sdps_format[insn.mm_fp1_format.fmt]; 369 mips32_insn.fp0_format.ft = 0; 370 mips32_insn.fp0_format.fs = 371 insn.mm_fp1_format.fs; 372 mips32_insn.fp0_format.fd = 373 insn.mm_fp1_format.rt; 374 mips32_insn.fp0_format.func = func; 375 break; 376 case mm_mfc1_op: 377 case mm_mtc1_op: 378 case mm_cfc1_op: 379 case mm_ctc1_op: 380 case mm_mfhc1_op: 381 case mm_mthc1_op: 382 if (insn.mm_fp1_format.op == mm_mfc1_op) 383 op = mfc_op; 384 else if (insn.mm_fp1_format.op == mm_mtc1_op) 385 op = mtc_op; 386 else if (insn.mm_fp1_format.op == mm_cfc1_op) 387 op = cfc_op; 388 else if (insn.mm_fp1_format.op == mm_ctc1_op) 389 op = ctc_op; 390 else if (insn.mm_fp1_format.op == mm_mfhc1_op) 391 op = mfhc_op; 392 else 393 op = mthc_op; 394 mips32_insn.fp1_format.opcode = cop1_op; 395 mips32_insn.fp1_format.op = op; 396 mips32_insn.fp1_format.rt = 397 insn.mm_fp1_format.rt; 398 mips32_insn.fp1_format.fs = 399 insn.mm_fp1_format.fs; 400 mips32_insn.fp1_format.fd = 0; 401 mips32_insn.fp1_format.func = 0; 402 break; 403 default: 404 return SIGILL; 405 } 406 break; 407 case mm_32f_74_op: /* c.cond.fmt */ 408 mips32_insn.fp0_format.opcode = cop1_op; 409 mips32_insn.fp0_format.fmt = 410 sdps_format[insn.mm_fp4_format.fmt]; 411 mips32_insn.fp0_format.ft = insn.mm_fp4_format.rt; 412 mips32_insn.fp0_format.fs = insn.mm_fp4_format.fs; 413 mips32_insn.fp0_format.fd = insn.mm_fp4_format.cc << 2; 414 mips32_insn.fp0_format.func = 415 insn.mm_fp4_format.cond | MM_MIPS32_COND_FC; 416 break; 417 default: 418 return SIGILL; 419 } 420 break; 421 default: 422 return SIGILL; 423 } 424 425 *insn_ptr = mips32_insn; 426 return 0; 427} 428 429/* 430 * Redundant with logic already in kernel/branch.c, 431 * embedded in compute_return_epc. At some point, 432 * a single subroutine should be used across both 433 * modules. 434 */ 435static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn, 436 unsigned long *contpc) 437{ 438 union mips_instruction insn = (union mips_instruction)dec_insn.insn; 439 unsigned int fcr31; 440 unsigned int bit = 0; 441 442 switch (insn.i_format.opcode) { 443 case spec_op: 444 switch (insn.r_format.func) { 445 case jalr_op: 446 regs->regs[insn.r_format.rd] = 447 regs->cp0_epc + dec_insn.pc_inc + 448 dec_insn.next_pc_inc; 449 /* Fall through */ 450 case jr_op: 451 *contpc = regs->regs[insn.r_format.rs]; 452 return 1; 453 } 454 break; 455 case bcond_op: 456 switch (insn.i_format.rt) { 457 case bltzal_op: 458 case bltzall_op: 459 regs->regs[31] = regs->cp0_epc + 460 dec_insn.pc_inc + 461 dec_insn.next_pc_inc; 462 /* Fall through */ 463 case bltz_op: 464 case bltzl_op: 465 if ((long)regs->regs[insn.i_format.rs] < 0) 466 *contpc = regs->cp0_epc + 467 dec_insn.pc_inc + 468 (insn.i_format.simmediate << 2); 469 else 470 *contpc = regs->cp0_epc + 471 dec_insn.pc_inc + 472 dec_insn.next_pc_inc; 473 return 1; 474 case bgezal_op: 475 case bgezall_op: 476 regs->regs[31] = regs->cp0_epc + 477 dec_insn.pc_inc + 478 dec_insn.next_pc_inc; 479 /* Fall through */ 480 case bgez_op: 481 case bgezl_op: 482 if ((long)regs->regs[insn.i_format.rs] >= 0) 483 *contpc = regs->cp0_epc + 484 dec_insn.pc_inc + 485 (insn.i_format.simmediate << 2); 486 else 487 *contpc = regs->cp0_epc + 488 dec_insn.pc_inc + 489 dec_insn.next_pc_inc; 490 return 1; 491 } 492 break; 493 case jalx_op: 494 set_isa16_mode(bit); 495 case jal_op: 496 regs->regs[31] = regs->cp0_epc + 497 dec_insn.pc_inc + 498 dec_insn.next_pc_inc; 499 /* Fall through */ 500 case j_op: 501 *contpc = regs->cp0_epc + dec_insn.pc_inc; 502 *contpc >>= 28; 503 *contpc <<= 28; 504 *contpc |= (insn.j_format.target << 2); 505 /* Set microMIPS mode bit: XOR for jalx. */ 506 *contpc ^= bit; 507 return 1; 508 case beq_op: 509 case beql_op: 510 if (regs->regs[insn.i_format.rs] == 511 regs->regs[insn.i_format.rt]) 512 *contpc = regs->cp0_epc + 513 dec_insn.pc_inc + 514 (insn.i_format.simmediate << 2); 515 else 516 *contpc = regs->cp0_epc + 517 dec_insn.pc_inc + 518 dec_insn.next_pc_inc; 519 return 1; 520 case bne_op: 521 case bnel_op: 522 if (regs->regs[insn.i_format.rs] != 523 regs->regs[insn.i_format.rt]) 524 *contpc = regs->cp0_epc + 525 dec_insn.pc_inc + 526 (insn.i_format.simmediate << 2); 527 else 528 *contpc = regs->cp0_epc + 529 dec_insn.pc_inc + 530 dec_insn.next_pc_inc; 531 return 1; 532 case blez_op: 533 case blezl_op: 534 if ((long)regs->regs[insn.i_format.rs] <= 0) 535 *contpc = regs->cp0_epc + 536 dec_insn.pc_inc + 537 (insn.i_format.simmediate << 2); 538 else 539 *contpc = regs->cp0_epc + 540 dec_insn.pc_inc + 541 dec_insn.next_pc_inc; 542 return 1; 543 case bgtz_op: 544 case bgtzl_op: 545 if ((long)regs->regs[insn.i_format.rs] > 0) 546 *contpc = regs->cp0_epc + 547 dec_insn.pc_inc + 548 (insn.i_format.simmediate << 2); 549 else 550 *contpc = regs->cp0_epc + 551 dec_insn.pc_inc + 552 dec_insn.next_pc_inc; 553 return 1; 554#ifdef CONFIG_CPU_CAVIUM_OCTEON 555 case lwc2_op: /* This is bbit0 on Octeon */ 556 if ((regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) == 0) 557 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2); 558 else 559 *contpc = regs->cp0_epc + 8; 560 return 1; 561 case ldc2_op: /* This is bbit032 on Octeon */ 562 if ((regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32))) == 0) 563 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2); 564 else 565 *contpc = regs->cp0_epc + 8; 566 return 1; 567 case swc2_op: /* This is bbit1 on Octeon */ 568 if (regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) 569 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2); 570 else 571 *contpc = regs->cp0_epc + 8; 572 return 1; 573 case sdc2_op: /* This is bbit132 on Octeon */ 574 if (regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32))) 575 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2); 576 else 577 *contpc = regs->cp0_epc + 8; 578 return 1; 579#endif 580 case cop0_op: 581 case cop1_op: 582 case cop2_op: 583 case cop1x_op: 584 if (insn.i_format.rs == bc_op) { 585 preempt_disable(); 586 if (is_fpu_owner()) 587 asm volatile( 588 ".set push\n" 589 "\t.set mips1\n" 590 "\tcfc1\t%0,$31\n" 591 "\t.set pop" : "=r" (fcr31)); 592 else 593 fcr31 = current->thread.fpu.fcr31; 594 preempt_enable(); 595 596 bit = (insn.i_format.rt >> 2); 597 bit += (bit != 0); 598 bit += 23; 599 switch (insn.i_format.rt & 3) { 600 case 0: /* bc1f */ 601 case 2: /* bc1fl */ 602 if (~fcr31 & (1 << bit)) 603 *contpc = regs->cp0_epc + 604 dec_insn.pc_inc + 605 (insn.i_format.simmediate << 2); 606 else 607 *contpc = regs->cp0_epc + 608 dec_insn.pc_inc + 609 dec_insn.next_pc_inc; 610 return 1; 611 case 1: /* bc1t */ 612 case 3: /* bc1tl */ 613 if (fcr31 & (1 << bit)) 614 *contpc = regs->cp0_epc + 615 dec_insn.pc_inc + 616 (insn.i_format.simmediate << 2); 617 else 618 *contpc = regs->cp0_epc + 619 dec_insn.pc_inc + 620 dec_insn.next_pc_inc; 621 return 1; 622 } 623 } 624 break; 625 } 626 return 0; 627} 628 629/* 630 * In the Linux kernel, we support selection of FPR format on the 631 * basis of the Status.FR bit. If an FPU is not present, the FR bit 632 * is hardwired to zero, which would imply a 32-bit FPU even for 633 * 64-bit CPUs so we rather look at TIF_32BIT_FPREGS. 634 * FPU emu is slow and bulky and optimizing this function offers fairly 635 * sizeable benefits so we try to be clever and make this function return 636 * a constant whenever possible, that is on 64-bit kernels without O32 637 * compatibility enabled and on 32-bit without 64-bit FPU support. 638 */ 639static inline int cop1_64bit(struct pt_regs *xcp) 640{ 641 if (config_enabled(CONFIG_64BIT) && !config_enabled(CONFIG_MIPS32_O32)) 642 return 1; 643 else if (config_enabled(CONFIG_32BIT) && 644 !config_enabled(CONFIG_MIPS_O32_FP64_SUPPORT)) 645 return 0; 646 647 return !test_thread_flag(TIF_32BIT_FPREGS); 648} 649 650#define SIFROMREG(si, x) \ 651do { \ 652 if (cop1_64bit(xcp)) \ 653 (si) = get_fpr32(&ctx->fpr[x], 0); \ 654 else \ 655 (si) = get_fpr32(&ctx->fpr[(x) & ~1], (x) & 1); \ 656} while (0) 657 658#define SITOREG(si, x) \ 659do { \ 660 if (cop1_64bit(xcp)) { \ 661 unsigned i; \ 662 set_fpr32(&ctx->fpr[x], 0, si); \ 663 for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val32); i++) \ 664 set_fpr32(&ctx->fpr[x], i, 0); \ 665 } else { \ 666 set_fpr32(&ctx->fpr[(x) & ~1], (x) & 1, si); \ 667 } \ 668} while (0) 669 670#define SIFROMHREG(si, x) ((si) = get_fpr32(&ctx->fpr[x], 1)) 671 672#define SITOHREG(si, x) \ 673do { \ 674 unsigned i; \ 675 set_fpr32(&ctx->fpr[x], 1, si); \ 676 for (i = 2; i < ARRAY_SIZE(ctx->fpr[x].val32); i++) \ 677 set_fpr32(&ctx->fpr[x], i, 0); \ 678} while (0) 679 680#define DIFROMREG(di, x) \ 681 ((di) = get_fpr64(&ctx->fpr[(x) & ~(cop1_64bit(xcp) == 0)], 0)) 682 683#define DITOREG(di, x) \ 684do { \ 685 unsigned fpr, i; \ 686 fpr = (x) & ~(cop1_64bit(xcp) == 0); \ 687 set_fpr64(&ctx->fpr[fpr], 0, di); \ 688 for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val64); i++) \ 689 set_fpr64(&ctx->fpr[fpr], i, 0); \ 690} while (0) 691 692#define SPFROMREG(sp, x) SIFROMREG((sp).bits, x) 693#define SPTOREG(sp, x) SITOREG((sp).bits, x) 694#define DPFROMREG(dp, x) DIFROMREG((dp).bits, x) 695#define DPTOREG(dp, x) DITOREG((dp).bits, x) 696 697/* 698 * Emulate the single floating point instruction pointed at by EPC. 699 * Two instructions if the instruction is in a branch delay slot. 700 */ 701 702static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx, 703 struct mm_decoded_insn dec_insn, void *__user *fault_addr) 704{ 705 unsigned long contpc = xcp->cp0_epc + dec_insn.pc_inc; 706 unsigned int cond, cbit; 707 mips_instruction ir; 708 int likely, pc_inc; 709 u32 __user *wva; 710 u64 __user *dva; 711 u32 value; 712 u32 wval; 713 u64 dval; 714 int sig; 715 716 /* 717 * These are giving gcc a gentle hint about what to expect in 718 * dec_inst in order to do better optimization. 719 */ 720 if (!cpu_has_mmips && dec_insn.micro_mips_mode) 721 unreachable(); 722 723 /* XXX NEC Vr54xx bug workaround */ 724 if (delay_slot(xcp)) { 725 if (dec_insn.micro_mips_mode) { 726 if (!mm_isBranchInstr(xcp, dec_insn, &contpc)) 727 clear_delay_slot(xcp); 728 } else { 729 if (!isBranchInstr(xcp, dec_insn, &contpc)) 730 clear_delay_slot(xcp); 731 } 732 } 733 734 if (delay_slot(xcp)) { 735 /* 736 * The instruction to be emulated is in a branch delay slot 737 * which means that we have to emulate the branch instruction 738 * BEFORE we do the cop1 instruction. 739 * 740 * This branch could be a COP1 branch, but in that case we 741 * would have had a trap for that instruction, and would not 742 * come through this route. 743 * 744 * Linux MIPS branch emulator operates on context, updating the 745 * cp0_epc. 746 */ 747 ir = dec_insn.next_insn; /* process delay slot instr */ 748 pc_inc = dec_insn.next_pc_inc; 749 } else { 750 ir = dec_insn.insn; /* process current instr */ 751 pc_inc = dec_insn.pc_inc; 752 } 753 754 /* 755 * Since microMIPS FPU instructios are a subset of MIPS32 FPU 756 * instructions, we want to convert microMIPS FPU instructions 757 * into MIPS32 instructions so that we could reuse all of the 758 * FPU emulation code. 759 * 760 * NOTE: We cannot do this for branch instructions since they 761 * are not a subset. Example: Cannot emulate a 16-bit 762 * aligned target address with a MIPS32 instruction. 763 */ 764 if (dec_insn.micro_mips_mode) { 765 /* 766 * If next instruction is a 16-bit instruction, then it 767 * it cannot be a FPU instruction. This could happen 768 * since we can be called for non-FPU instructions. 769 */ 770 if ((pc_inc == 2) || 771 (microMIPS32_to_MIPS32((union mips_instruction *)&ir) 772 == SIGILL)) 773 return SIGILL; 774 } 775 776emul: 777 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, xcp, 0); 778 MIPS_FPU_EMU_INC_STATS(emulated); 779 switch (MIPSInst_OPCODE(ir)) { 780 case ldc1_op: 781 dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] + 782 MIPSInst_SIMM(ir)); 783 MIPS_FPU_EMU_INC_STATS(loads); 784 785 if (!access_ok(VERIFY_READ, dva, sizeof(u64))) { 786 MIPS_FPU_EMU_INC_STATS(errors); 787 *fault_addr = dva; 788 return SIGBUS; 789 } 790 if (__get_user(dval, dva)) { 791 MIPS_FPU_EMU_INC_STATS(errors); 792 *fault_addr = dva; 793 return SIGSEGV; 794 } 795 DITOREG(dval, MIPSInst_RT(ir)); 796 break; 797 798 case sdc1_op: 799 dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] + 800 MIPSInst_SIMM(ir)); 801 MIPS_FPU_EMU_INC_STATS(stores); 802 DIFROMREG(dval, MIPSInst_RT(ir)); 803 if (!access_ok(VERIFY_WRITE, dva, sizeof(u64))) { 804 MIPS_FPU_EMU_INC_STATS(errors); 805 *fault_addr = dva; 806 return SIGBUS; 807 } 808 if (__put_user(dval, dva)) { 809 MIPS_FPU_EMU_INC_STATS(errors); 810 *fault_addr = dva; 811 return SIGSEGV; 812 } 813 break; 814 815 case lwc1_op: 816 wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] + 817 MIPSInst_SIMM(ir)); 818 MIPS_FPU_EMU_INC_STATS(loads); 819 if (!access_ok(VERIFY_READ, wva, sizeof(u32))) { 820 MIPS_FPU_EMU_INC_STATS(errors); 821 *fault_addr = wva; 822 return SIGBUS; 823 } 824 if (__get_user(wval, wva)) { 825 MIPS_FPU_EMU_INC_STATS(errors); 826 *fault_addr = wva; 827 return SIGSEGV; 828 } 829 SITOREG(wval, MIPSInst_RT(ir)); 830 break; 831 832 case swc1_op: 833 wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] + 834 MIPSInst_SIMM(ir)); 835 MIPS_FPU_EMU_INC_STATS(stores); 836 SIFROMREG(wval, MIPSInst_RT(ir)); 837 if (!access_ok(VERIFY_WRITE, wva, sizeof(u32))) { 838 MIPS_FPU_EMU_INC_STATS(errors); 839 *fault_addr = wva; 840 return SIGBUS; 841 } 842 if (__put_user(wval, wva)) { 843 MIPS_FPU_EMU_INC_STATS(errors); 844 *fault_addr = wva; 845 return SIGSEGV; 846 } 847 break; 848 849 case cop1_op: 850 switch (MIPSInst_RS(ir)) { 851 case dmfc_op: 852 if (!cpu_has_mips_3_4_5 && !cpu_has_mips64) 853 return SIGILL; 854 855 /* copregister fs -> gpr[rt] */ 856 if (MIPSInst_RT(ir) != 0) { 857 DIFROMREG(xcp->regs[MIPSInst_RT(ir)], 858 MIPSInst_RD(ir)); 859 } 860 break; 861 862 case dmtc_op: 863 if (!cpu_has_mips_3_4_5 && !cpu_has_mips64) 864 return SIGILL; 865 866 /* copregister fs <- rt */ 867 DITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir)); 868 break; 869 870 case mfhc_op: 871 if (!cpu_has_mips_r2) 872 goto sigill; 873 874 /* copregister rd -> gpr[rt] */ 875 if (MIPSInst_RT(ir) != 0) { 876 SIFROMHREG(xcp->regs[MIPSInst_RT(ir)], 877 MIPSInst_RD(ir)); 878 } 879 break; 880 881 case mthc_op: 882 if (!cpu_has_mips_r2) 883 goto sigill; 884 885 /* copregister rd <- gpr[rt] */ 886 SITOHREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir)); 887 break; 888 889 case mfc_op: 890 /* copregister rd -> gpr[rt] */ 891 if (MIPSInst_RT(ir) != 0) { 892 SIFROMREG(xcp->regs[MIPSInst_RT(ir)], 893 MIPSInst_RD(ir)); 894 } 895 break; 896 897 case mtc_op: 898 /* copregister rd <- rt */ 899 SITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir)); 900 break; 901 902 case cfc_op: 903 /* cop control register rd -> gpr[rt] */ 904 if (MIPSInst_RD(ir) == FPCREG_CSR) { 905 value = ctx->fcr31; 906 value = (value & ~FPU_CSR_RM) | modeindex(value); 907 pr_debug("%p gpr[%d]<-csr=%08x\n", 908 (void *) (xcp->cp0_epc), 909 MIPSInst_RT(ir), value); 910 } 911 else if (MIPSInst_RD(ir) == FPCREG_RID) 912 value = 0; 913 else 914 value = 0; 915 if (MIPSInst_RT(ir)) 916 xcp->regs[MIPSInst_RT(ir)] = value; 917 break; 918 919 case ctc_op: 920 /* copregister rd <- rt */ 921 if (MIPSInst_RT(ir) == 0) 922 value = 0; 923 else 924 value = xcp->regs[MIPSInst_RT(ir)]; 925 926 /* we only have one writable control reg 927 */ 928 if (MIPSInst_RD(ir) == FPCREG_CSR) { 929 pr_debug("%p gpr[%d]->csr=%08x\n", 930 (void *) (xcp->cp0_epc), 931 MIPSInst_RT(ir), value); 932 933 /* 934 * Don't write reserved bits, 935 * and convert to ieee library modes 936 */ 937 ctx->fcr31 = (value & ~(FPU_CSR_RSVD | FPU_CSR_RM)) | 938 modeindex(value); 939 } 940 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) { 941 return SIGFPE; 942 } 943 break; 944 945 case bc_op: 946 if (delay_slot(xcp)) 947 return SIGILL; 948 949 if (cpu_has_mips_4_5_r) 950 cbit = fpucondbit[MIPSInst_RT(ir) >> 2]; 951 else 952 cbit = FPU_CSR_COND; 953 cond = ctx->fcr31 & cbit; 954 955 likely = 0; 956 switch (MIPSInst_RT(ir) & 3) { 957 case bcfl_op: 958 likely = 1; 959 case bcf_op: 960 cond = !cond; 961 break; 962 case bctl_op: 963 likely = 1; 964 case bct_op: 965 break; 966 default: 967 /* thats an illegal instruction */ 968 return SIGILL; 969 } 970 971 set_delay_slot(xcp); 972 if (cond) { 973 /* 974 * Branch taken: emulate dslot instruction 975 */ 976 xcp->cp0_epc += dec_insn.pc_inc; 977 978 contpc = MIPSInst_SIMM(ir); 979 ir = dec_insn.next_insn; 980 if (dec_insn.micro_mips_mode) { 981 contpc = (xcp->cp0_epc + (contpc << 1)); 982 983 /* If 16-bit instruction, not FPU. */ 984 if ((dec_insn.next_pc_inc == 2) || 985 (microMIPS32_to_MIPS32((union mips_instruction *)&ir) == SIGILL)) { 986 987 /* 988 * Since this instruction will 989 * be put on the stack with 990 * 32-bit words, get around 991 * this problem by putting a 992 * NOP16 as the second one. 993 */ 994 if (dec_insn.next_pc_inc == 2) 995 ir = (ir & (~0xffff)) | MM_NOP16; 996 997 /* 998 * Single step the non-CP1 999 * instruction in the dslot. 1000 */ 1001 return mips_dsemul(xcp, ir, contpc); 1002 } 1003 } else 1004 contpc = (xcp->cp0_epc + (contpc << 2)); 1005 1006 switch (MIPSInst_OPCODE(ir)) { 1007 case lwc1_op: 1008 goto emul; 1009 1010 case swc1_op: 1011 goto emul; 1012 1013 case ldc1_op: 1014 case sdc1_op: 1015 if (cpu_has_mips_2_3_4_5 || 1016 cpu_has_mips64) 1017 goto emul; 1018 1019 return SIGILL; 1020 goto emul; 1021 1022 case cop1_op: 1023 goto emul; 1024 1025 case cop1x_op: 1026 if (cpu_has_mips_4_5 || cpu_has_mips64) 1027 /* its one of ours */ 1028 goto emul; 1029 1030 return SIGILL; 1031 1032 case spec_op: 1033 if (!cpu_has_mips_4_5_r) 1034 return SIGILL; 1035 1036 if (MIPSInst_FUNC(ir) == movc_op) 1037 goto emul; 1038 break; 1039 } 1040 1041 /* 1042 * Single step the non-cp1 1043 * instruction in the dslot 1044 */ 1045 return mips_dsemul(xcp, ir, contpc); 1046 } else if (likely) { /* branch not taken */ 1047 /* 1048 * branch likely nullifies 1049 * dslot if not taken 1050 */ 1051 xcp->cp0_epc += dec_insn.pc_inc; 1052 contpc += dec_insn.pc_inc; 1053 /* 1054 * else continue & execute 1055 * dslot as normal insn 1056 */ 1057 } 1058 break; 1059 1060 default: 1061 if (!(MIPSInst_RS(ir) & 0x10)) 1062 return SIGILL; 1063 1064 /* a real fpu computation instruction */ 1065 if ((sig = fpu_emu(xcp, ctx, ir))) 1066 return sig; 1067 } 1068 break; 1069 1070 case cop1x_op: 1071 if (!cpu_has_mips_4_5 && !cpu_has_mips64) 1072 return SIGILL; 1073 1074 sig = fpux_emu(xcp, ctx, ir, fault_addr); 1075 if (sig) 1076 return sig; 1077 break; 1078 1079 case spec_op: 1080 if (!cpu_has_mips_4_5_r) 1081 return SIGILL; 1082 1083 if (MIPSInst_FUNC(ir) != movc_op) 1084 return SIGILL; 1085 cond = fpucondbit[MIPSInst_RT(ir) >> 2]; 1086 if (((ctx->fcr31 & cond) != 0) == ((MIPSInst_RT(ir) & 1) != 0)) 1087 xcp->regs[MIPSInst_RD(ir)] = 1088 xcp->regs[MIPSInst_RS(ir)]; 1089 break; 1090 default: 1091sigill: 1092 return SIGILL; 1093 } 1094 1095 /* we did it !! */ 1096 xcp->cp0_epc = contpc; 1097 clear_delay_slot(xcp); 1098 1099 return 0; 1100} 1101 1102/* 1103 * Conversion table from MIPS compare ops 48-63 1104 * cond = ieee754dp_cmp(x,y,IEEE754_UN,sig); 1105 */ 1106static const unsigned char cmptab[8] = { 1107 0, /* cmp_0 (sig) cmp_sf */ 1108 IEEE754_CUN, /* cmp_un (sig) cmp_ngle */ 1109 IEEE754_CEQ, /* cmp_eq (sig) cmp_seq */ 1110 IEEE754_CEQ | IEEE754_CUN, /* cmp_ueq (sig) cmp_ngl */ 1111 IEEE754_CLT, /* cmp_olt (sig) cmp_lt */ 1112 IEEE754_CLT | IEEE754_CUN, /* cmp_ult (sig) cmp_nge */ 1113 IEEE754_CLT | IEEE754_CEQ, /* cmp_ole (sig) cmp_le */ 1114 IEEE754_CLT | IEEE754_CEQ | IEEE754_CUN, /* cmp_ule (sig) cmp_ngt */ 1115}; 1116 1117 1118/* 1119 * Additional MIPS4 instructions 1120 */ 1121 1122#define DEF3OP(name, p, f1, f2, f3) \ 1123static union ieee754##p fpemu_##p##_##name(union ieee754##p r, \ 1124 union ieee754##p s, union ieee754##p t) \ 1125{ \ 1126 struct _ieee754_csr ieee754_csr_save; \ 1127 s = f1(s, t); \ 1128 ieee754_csr_save = ieee754_csr; \ 1129 s = f2(s, r); \ 1130 ieee754_csr_save.cx |= ieee754_csr.cx; \ 1131 ieee754_csr_save.sx |= ieee754_csr.sx; \ 1132 s = f3(s); \ 1133 ieee754_csr.cx |= ieee754_csr_save.cx; \ 1134 ieee754_csr.sx |= ieee754_csr_save.sx; \ 1135 return s; \ 1136} 1137 1138static union ieee754dp fpemu_dp_recip(union ieee754dp d) 1139{ 1140 return ieee754dp_div(ieee754dp_one(0), d); 1141} 1142 1143static union ieee754dp fpemu_dp_rsqrt(union ieee754dp d) 1144{ 1145 return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d)); 1146} 1147 1148static union ieee754sp fpemu_sp_recip(union ieee754sp s) 1149{ 1150 return ieee754sp_div(ieee754sp_one(0), s); 1151} 1152 1153static union ieee754sp fpemu_sp_rsqrt(union ieee754sp s) 1154{ 1155 return ieee754sp_div(ieee754sp_one(0), ieee754sp_sqrt(s)); 1156} 1157 1158DEF3OP(madd, sp, ieee754sp_mul, ieee754sp_add, ); 1159DEF3OP(msub, sp, ieee754sp_mul, ieee754sp_sub, ); 1160DEF3OP(nmadd, sp, ieee754sp_mul, ieee754sp_add, ieee754sp_neg); 1161DEF3OP(nmsub, sp, ieee754sp_mul, ieee754sp_sub, ieee754sp_neg); 1162DEF3OP(madd, dp, ieee754dp_mul, ieee754dp_add, ); 1163DEF3OP(msub, dp, ieee754dp_mul, ieee754dp_sub, ); 1164DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg); 1165DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg); 1166 1167static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx, 1168 mips_instruction ir, void *__user *fault_addr) 1169{ 1170 unsigned rcsr = 0; /* resulting csr */ 1171 1172 MIPS_FPU_EMU_INC_STATS(cp1xops); 1173 1174 switch (MIPSInst_FMA_FFMT(ir)) { 1175 case s_fmt:{ /* 0 */ 1176 1177 union ieee754sp(*handler) (union ieee754sp, union ieee754sp, union ieee754sp); 1178 union ieee754sp fd, fr, fs, ft; 1179 u32 __user *va; 1180 u32 val; 1181 1182 switch (MIPSInst_FUNC(ir)) { 1183 case lwxc1_op: 1184 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] + 1185 xcp->regs[MIPSInst_FT(ir)]); 1186 1187 MIPS_FPU_EMU_INC_STATS(loads); 1188 if (!access_ok(VERIFY_READ, va, sizeof(u32))) { 1189 MIPS_FPU_EMU_INC_STATS(errors); 1190 *fault_addr = va; 1191 return SIGBUS; 1192 } 1193 if (__get_user(val, va)) { 1194 MIPS_FPU_EMU_INC_STATS(errors); 1195 *fault_addr = va; 1196 return SIGSEGV; 1197 } 1198 SITOREG(val, MIPSInst_FD(ir)); 1199 break; 1200 1201 case swxc1_op: 1202 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] + 1203 xcp->regs[MIPSInst_FT(ir)]); 1204 1205 MIPS_FPU_EMU_INC_STATS(stores); 1206 1207 SIFROMREG(val, MIPSInst_FS(ir)); 1208 if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) { 1209 MIPS_FPU_EMU_INC_STATS(errors); 1210 *fault_addr = va; 1211 return SIGBUS; 1212 } 1213 if (put_user(val, va)) { 1214 MIPS_FPU_EMU_INC_STATS(errors); 1215 *fault_addr = va; 1216 return SIGSEGV; 1217 } 1218 break; 1219 1220 case madd_s_op: 1221 handler = fpemu_sp_madd; 1222 goto scoptop; 1223 case msub_s_op: 1224 handler = fpemu_sp_msub; 1225 goto scoptop; 1226 case nmadd_s_op: 1227 handler = fpemu_sp_nmadd; 1228 goto scoptop; 1229 case nmsub_s_op: 1230 handler = fpemu_sp_nmsub; 1231 goto scoptop; 1232 1233 scoptop: 1234 SPFROMREG(fr, MIPSInst_FR(ir)); 1235 SPFROMREG(fs, MIPSInst_FS(ir)); 1236 SPFROMREG(ft, MIPSInst_FT(ir)); 1237 fd = (*handler) (fr, fs, ft); 1238 SPTOREG(fd, MIPSInst_FD(ir)); 1239 1240 copcsr: 1241 if (ieee754_cxtest(IEEE754_INEXACT)) { 1242 MIPS_FPU_EMU_INC_STATS(ieee754_inexact); 1243 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S; 1244 } 1245 if (ieee754_cxtest(IEEE754_UNDERFLOW)) { 1246 MIPS_FPU_EMU_INC_STATS(ieee754_underflow); 1247 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S; 1248 } 1249 if (ieee754_cxtest(IEEE754_OVERFLOW)) { 1250 MIPS_FPU_EMU_INC_STATS(ieee754_overflow); 1251 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S; 1252 } 1253 if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) { 1254 MIPS_FPU_EMU_INC_STATS(ieee754_invalidop); 1255 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S; 1256 } 1257 1258 ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr; 1259 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) { 1260 /*printk ("SIGFPE: FPU csr = %08x\n", 1261 ctx->fcr31); */ 1262 return SIGFPE; 1263 } 1264 1265 break; 1266 1267 default: 1268 return SIGILL; 1269 } 1270 break; 1271 } 1272 1273 case d_fmt:{ /* 1 */ 1274 union ieee754dp(*handler) (union ieee754dp, union ieee754dp, union ieee754dp); 1275 union ieee754dp fd, fr, fs, ft; 1276 u64 __user *va; 1277 u64 val; 1278 1279 switch (MIPSInst_FUNC(ir)) { 1280 case ldxc1_op: 1281 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] + 1282 xcp->regs[MIPSInst_FT(ir)]); 1283 1284 MIPS_FPU_EMU_INC_STATS(loads); 1285 if (!access_ok(VERIFY_READ, va, sizeof(u64))) { 1286 MIPS_FPU_EMU_INC_STATS(errors); 1287 *fault_addr = va; 1288 return SIGBUS; 1289 } 1290 if (__get_user(val, va)) { 1291 MIPS_FPU_EMU_INC_STATS(errors); 1292 *fault_addr = va; 1293 return SIGSEGV; 1294 } 1295 DITOREG(val, MIPSInst_FD(ir)); 1296 break; 1297 1298 case sdxc1_op: 1299 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] + 1300 xcp->regs[MIPSInst_FT(ir)]); 1301 1302 MIPS_FPU_EMU_INC_STATS(stores); 1303 DIFROMREG(val, MIPSInst_FS(ir)); 1304 if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) { 1305 MIPS_FPU_EMU_INC_STATS(errors); 1306 *fault_addr = va; 1307 return SIGBUS; 1308 } 1309 if (__put_user(val, va)) { 1310 MIPS_FPU_EMU_INC_STATS(errors); 1311 *fault_addr = va; 1312 return SIGSEGV; 1313 } 1314 break; 1315 1316 case madd_d_op: 1317 handler = fpemu_dp_madd; 1318 goto dcoptop; 1319 case msub_d_op: 1320 handler = fpemu_dp_msub; 1321 goto dcoptop; 1322 case nmadd_d_op: 1323 handler = fpemu_dp_nmadd; 1324 goto dcoptop; 1325 case nmsub_d_op: 1326 handler = fpemu_dp_nmsub; 1327 goto dcoptop; 1328 1329 dcoptop: 1330 DPFROMREG(fr, MIPSInst_FR(ir)); 1331 DPFROMREG(fs, MIPSInst_FS(ir)); 1332 DPFROMREG(ft, MIPSInst_FT(ir)); 1333 fd = (*handler) (fr, fs, ft); 1334 DPTOREG(fd, MIPSInst_FD(ir)); 1335 goto copcsr; 1336 1337 default: 1338 return SIGILL; 1339 } 1340 break; 1341 } 1342 1343 case 0x3: 1344 if (MIPSInst_FUNC(ir) != pfetch_op) 1345 return SIGILL; 1346 1347 /* ignore prefx operation */ 1348 break; 1349 1350 default: 1351 return SIGILL; 1352 } 1353 1354 return 0; 1355} 1356 1357 1358 1359/* 1360 * Emulate a single COP1 arithmetic instruction. 1361 */ 1362static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx, 1363 mips_instruction ir) 1364{ 1365 int rfmt; /* resulting format */ 1366 unsigned rcsr = 0; /* resulting csr */ 1367 unsigned int oldrm; 1368 unsigned int cbit; 1369 unsigned cond; 1370 union { 1371 union ieee754dp d; 1372 union ieee754sp s; 1373 int w; 1374 s64 l; 1375 } rv; /* resulting value */ 1376 u64 bits; 1377 1378 MIPS_FPU_EMU_INC_STATS(cp1ops); 1379 switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) { 1380 case s_fmt: { /* 0 */ 1381 union { 1382 union ieee754sp(*b) (union ieee754sp, union ieee754sp); 1383 union ieee754sp(*u) (union ieee754sp); 1384 } handler; 1385 union ieee754sp fs, ft; 1386 1387 switch (MIPSInst_FUNC(ir)) { 1388 /* binary ops */ 1389 case fadd_op: 1390 handler.b = ieee754sp_add; 1391 goto scopbop; 1392 case fsub_op: 1393 handler.b = ieee754sp_sub; 1394 goto scopbop; 1395 case fmul_op: 1396 handler.b = ieee754sp_mul; 1397 goto scopbop; 1398 case fdiv_op: 1399 handler.b = ieee754sp_div; 1400 goto scopbop; 1401 1402 /* unary ops */ 1403 case fsqrt_op: 1404 if (!cpu_has_mips_4_5_r) 1405 return SIGILL; 1406 1407 handler.u = ieee754sp_sqrt; 1408 goto scopuop; 1409 1410 /* 1411 * Note that on some MIPS IV implementations such as the 1412 * R5000 and R8000 the FSQRT and FRECIP instructions do not 1413 * achieve full IEEE-754 accuracy - however this emulator does. 1414 */ 1415 case frsqrt_op: 1416 if (!cpu_has_mips_4_5_r2) 1417 return SIGILL; 1418 1419 handler.u = fpemu_sp_rsqrt; 1420 goto scopuop; 1421 1422 case frecip_op: 1423 if (!cpu_has_mips_4_5_r2) 1424 return SIGILL; 1425 1426 handler.u = fpemu_sp_recip; 1427 goto scopuop; 1428 1429 case fmovc_op: 1430 if (!cpu_has_mips_4_5_r) 1431 return SIGILL; 1432 1433 cond = fpucondbit[MIPSInst_FT(ir) >> 2]; 1434 if (((ctx->fcr31 & cond) != 0) != 1435 ((MIPSInst_FT(ir) & 1) != 0)) 1436 return 0; 1437 SPFROMREG(rv.s, MIPSInst_FS(ir)); 1438 break; 1439 1440 case fmovz_op: 1441 if (!cpu_has_mips_4_5_r) 1442 return SIGILL; 1443 1444 if (xcp->regs[MIPSInst_FT(ir)] != 0) 1445 return 0; 1446 SPFROMREG(rv.s, MIPSInst_FS(ir)); 1447 break; 1448 1449 case fmovn_op: 1450 if (!cpu_has_mips_4_5_r) 1451 return SIGILL; 1452 1453 if (xcp->regs[MIPSInst_FT(ir)] == 0) 1454 return 0; 1455 SPFROMREG(rv.s, MIPSInst_FS(ir)); 1456 break; 1457 1458 case fabs_op: 1459 handler.u = ieee754sp_abs; 1460 goto scopuop; 1461 1462 case fneg_op: 1463 handler.u = ieee754sp_neg; 1464 goto scopuop; 1465 1466 case fmov_op: 1467 /* an easy one */ 1468 SPFROMREG(rv.s, MIPSInst_FS(ir)); 1469 goto copcsr; 1470 1471 /* binary op on handler */ 1472scopbop: 1473 SPFROMREG(fs, MIPSInst_FS(ir)); 1474 SPFROMREG(ft, MIPSInst_FT(ir)); 1475 1476 rv.s = (*handler.b) (fs, ft); 1477 goto copcsr; 1478scopuop: 1479 SPFROMREG(fs, MIPSInst_FS(ir)); 1480 rv.s = (*handler.u) (fs); 1481 goto copcsr; 1482copcsr: 1483 if (ieee754_cxtest(IEEE754_INEXACT)) { 1484 MIPS_FPU_EMU_INC_STATS(ieee754_inexact); 1485 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S; 1486 } 1487 if (ieee754_cxtest(IEEE754_UNDERFLOW)) { 1488 MIPS_FPU_EMU_INC_STATS(ieee754_underflow); 1489 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S; 1490 } 1491 if (ieee754_cxtest(IEEE754_OVERFLOW)) { 1492 MIPS_FPU_EMU_INC_STATS(ieee754_overflow); 1493 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S; 1494 } 1495 if (ieee754_cxtest(IEEE754_ZERO_DIVIDE)) { 1496 MIPS_FPU_EMU_INC_STATS(ieee754_zerodiv); 1497 rcsr |= FPU_CSR_DIV_X | FPU_CSR_DIV_S; 1498 } 1499 if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) { 1500 MIPS_FPU_EMU_INC_STATS(ieee754_invalidop); 1501 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S; 1502 } 1503 break; 1504 1505 /* unary conv ops */ 1506 case fcvts_op: 1507 return SIGILL; /* not defined */ 1508 1509 case fcvtd_op: 1510 SPFROMREG(fs, MIPSInst_FS(ir)); 1511 rv.d = ieee754dp_fsp(fs); 1512 rfmt = d_fmt; 1513 goto copcsr; 1514 1515 case fcvtw_op: 1516 SPFROMREG(fs, MIPSInst_FS(ir)); 1517 rv.w = ieee754sp_tint(fs); 1518 rfmt = w_fmt; 1519 goto copcsr; 1520 1521 case fround_op: 1522 case ftrunc_op: 1523 case fceil_op: 1524 case ffloor_op: 1525 if (!cpu_has_mips_2_3_4_5 && !cpu_has_mips64) 1526 return SIGILL; 1527 1528 oldrm = ieee754_csr.rm; 1529 SPFROMREG(fs, MIPSInst_FS(ir)); 1530 ieee754_csr.rm = modeindex(MIPSInst_FUNC(ir)); 1531 rv.w = ieee754sp_tint(fs); 1532 ieee754_csr.rm = oldrm; 1533 rfmt = w_fmt; 1534 goto copcsr; 1535 1536 case fcvtl_op: 1537 if (!cpu_has_mips_3_4_5 && !cpu_has_mips64) 1538 return SIGILL; 1539 1540 SPFROMREG(fs, MIPSInst_FS(ir)); 1541 rv.l = ieee754sp_tlong(fs); 1542 rfmt = l_fmt; 1543 goto copcsr; 1544 1545 case froundl_op: 1546 case ftruncl_op: 1547 case fceill_op: 1548 case ffloorl_op: 1549 if (!cpu_has_mips_3_4_5 && !cpu_has_mips64) 1550 return SIGILL; 1551 1552 oldrm = ieee754_csr.rm; 1553 SPFROMREG(fs, MIPSInst_FS(ir)); 1554 ieee754_csr.rm = modeindex(MIPSInst_FUNC(ir)); 1555 rv.l = ieee754sp_tlong(fs); 1556 ieee754_csr.rm = oldrm; 1557 rfmt = l_fmt; 1558 goto copcsr; 1559 1560 default: 1561 if (MIPSInst_FUNC(ir) >= fcmp_op) { 1562 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op; 1563 union ieee754sp fs, ft; 1564 1565 SPFROMREG(fs, MIPSInst_FS(ir)); 1566 SPFROMREG(ft, MIPSInst_FT(ir)); 1567 rv.w = ieee754sp_cmp(fs, ft, 1568 cmptab[cmpop & 0x7], cmpop & 0x8); 1569 rfmt = -1; 1570 if ((cmpop & 0x8) && ieee754_cxtest 1571 (IEEE754_INVALID_OPERATION)) 1572 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S; 1573 else 1574 goto copcsr; 1575 1576 } else 1577 return SIGILL; 1578 break; 1579 } 1580 break; 1581 } 1582 1583 case d_fmt: { 1584 union ieee754dp fs, ft; 1585 union { 1586 union ieee754dp(*b) (union ieee754dp, union ieee754dp); 1587 union ieee754dp(*u) (union ieee754dp); 1588 } handler; 1589 1590 switch (MIPSInst_FUNC(ir)) { 1591 /* binary ops */ 1592 case fadd_op: 1593 handler.b = ieee754dp_add; 1594 goto dcopbop; 1595 case fsub_op: 1596 handler.b = ieee754dp_sub; 1597 goto dcopbop; 1598 case fmul_op: 1599 handler.b = ieee754dp_mul; 1600 goto dcopbop; 1601 case fdiv_op: 1602 handler.b = ieee754dp_div; 1603 goto dcopbop; 1604 1605 /* unary ops */ 1606 case fsqrt_op: 1607 if (!cpu_has_mips_2_3_4_5_r) 1608 return SIGILL; 1609 1610 handler.u = ieee754dp_sqrt; 1611 goto dcopuop; 1612 /* 1613 * Note that on some MIPS IV implementations such as the 1614 * R5000 and R8000 the FSQRT and FRECIP instructions do not 1615 * achieve full IEEE-754 accuracy - however this emulator does. 1616 */ 1617 case frsqrt_op: 1618 if (!cpu_has_mips_4_5_r2) 1619 return SIGILL; 1620 1621 handler.u = fpemu_dp_rsqrt; 1622 goto dcopuop; 1623 case frecip_op: 1624 if (!cpu_has_mips_4_5_r2) 1625 return SIGILL; 1626 1627 handler.u = fpemu_dp_recip; 1628 goto dcopuop; 1629 case fmovc_op: 1630 if (!cpu_has_mips_4_5_r) 1631 return SIGILL; 1632 1633 cond = fpucondbit[MIPSInst_FT(ir) >> 2]; 1634 if (((ctx->fcr31 & cond) != 0) != 1635 ((MIPSInst_FT(ir) & 1) != 0)) 1636 return 0; 1637 DPFROMREG(rv.d, MIPSInst_FS(ir)); 1638 break; 1639 case fmovz_op: 1640 if (!cpu_has_mips_4_5_r) 1641 return SIGILL; 1642 1643 if (xcp->regs[MIPSInst_FT(ir)] != 0) 1644 return 0; 1645 DPFROMREG(rv.d, MIPSInst_FS(ir)); 1646 break; 1647 case fmovn_op: 1648 if (!cpu_has_mips_4_5_r) 1649 return SIGILL; 1650 1651 if (xcp->regs[MIPSInst_FT(ir)] == 0) 1652 return 0; 1653 DPFROMREG(rv.d, MIPSInst_FS(ir)); 1654 break; 1655 case fabs_op: 1656 handler.u = ieee754dp_abs; 1657 goto dcopuop; 1658 1659 case fneg_op: 1660 handler.u = ieee754dp_neg; 1661 goto dcopuop; 1662 1663 case fmov_op: 1664 /* an easy one */ 1665 DPFROMREG(rv.d, MIPSInst_FS(ir)); 1666 goto copcsr; 1667 1668 /* binary op on handler */ 1669dcopbop: 1670 DPFROMREG(fs, MIPSInst_FS(ir)); 1671 DPFROMREG(ft, MIPSInst_FT(ir)); 1672 1673 rv.d = (*handler.b) (fs, ft); 1674 goto copcsr; 1675dcopuop: 1676 DPFROMREG(fs, MIPSInst_FS(ir)); 1677 rv.d = (*handler.u) (fs); 1678 goto copcsr; 1679 1680 /* 1681 * unary conv ops 1682 */ 1683 case fcvts_op: 1684 DPFROMREG(fs, MIPSInst_FS(ir)); 1685 rv.s = ieee754sp_fdp(fs); 1686 rfmt = s_fmt; 1687 goto copcsr; 1688 1689 case fcvtd_op: 1690 return SIGILL; /* not defined */ 1691 1692 case fcvtw_op: 1693 DPFROMREG(fs, MIPSInst_FS(ir)); 1694 rv.w = ieee754dp_tint(fs); /* wrong */ 1695 rfmt = w_fmt; 1696 goto copcsr; 1697 1698 case fround_op: 1699 case ftrunc_op: 1700 case fceil_op: 1701 case ffloor_op: 1702 if (!cpu_has_mips_2_3_4_5_r) 1703 return SIGILL; 1704 1705 oldrm = ieee754_csr.rm; 1706 DPFROMREG(fs, MIPSInst_FS(ir)); 1707 ieee754_csr.rm = modeindex(MIPSInst_FUNC(ir)); 1708 rv.w = ieee754dp_tint(fs); 1709 ieee754_csr.rm = oldrm; 1710 rfmt = w_fmt; 1711 goto copcsr; 1712 1713 case fcvtl_op: 1714 if (!cpu_has_mips_3_4_5 && !cpu_has_mips64) 1715 return SIGILL; 1716 1717 DPFROMREG(fs, MIPSInst_FS(ir)); 1718 rv.l = ieee754dp_tlong(fs); 1719 rfmt = l_fmt; 1720 goto copcsr; 1721 1722 case froundl_op: 1723 case ftruncl_op: 1724 case fceill_op: 1725 case ffloorl_op: 1726 if (!cpu_has_mips_3_4_5 && !cpu_has_mips64) 1727 return SIGILL; 1728 1729 oldrm = ieee754_csr.rm; 1730 DPFROMREG(fs, MIPSInst_FS(ir)); 1731 ieee754_csr.rm = modeindex(MIPSInst_FUNC(ir)); 1732 rv.l = ieee754dp_tlong(fs); 1733 ieee754_csr.rm = oldrm; 1734 rfmt = l_fmt; 1735 goto copcsr; 1736 1737 default: 1738 if (MIPSInst_FUNC(ir) >= fcmp_op) { 1739 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op; 1740 union ieee754dp fs, ft; 1741 1742 DPFROMREG(fs, MIPSInst_FS(ir)); 1743 DPFROMREG(ft, MIPSInst_FT(ir)); 1744 rv.w = ieee754dp_cmp(fs, ft, 1745 cmptab[cmpop & 0x7], cmpop & 0x8); 1746 rfmt = -1; 1747 if ((cmpop & 0x8) 1748 && 1749 ieee754_cxtest 1750 (IEEE754_INVALID_OPERATION)) 1751 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S; 1752 else 1753 goto copcsr; 1754 1755 } 1756 else { 1757 return SIGILL; 1758 } 1759 break; 1760 } 1761 break; 1762 1763 case w_fmt: 1764 switch (MIPSInst_FUNC(ir)) { 1765 case fcvts_op: 1766 /* convert word to single precision real */ 1767 SPFROMREG(fs, MIPSInst_FS(ir)); 1768 rv.s = ieee754sp_fint(fs.bits); 1769 rfmt = s_fmt; 1770 goto copcsr; 1771 case fcvtd_op: 1772 /* convert word to double precision real */ 1773 SPFROMREG(fs, MIPSInst_FS(ir)); 1774 rv.d = ieee754dp_fint(fs.bits); 1775 rfmt = d_fmt; 1776 goto copcsr; 1777 default: 1778 return SIGILL; 1779 } 1780 break; 1781 } 1782 1783 case l_fmt: 1784 1785 if (!cpu_has_mips_3_4_5 && !cpu_has_mips64) 1786 return SIGILL; 1787 1788 DIFROMREG(bits, MIPSInst_FS(ir)); 1789 1790 switch (MIPSInst_FUNC(ir)) { 1791 case fcvts_op: 1792 /* convert long to single precision real */ 1793 rv.s = ieee754sp_flong(bits); 1794 rfmt = s_fmt; 1795 goto copcsr; 1796 case fcvtd_op: 1797 /* convert long to double precision real */ 1798 rv.d = ieee754dp_flong(bits); 1799 rfmt = d_fmt; 1800 goto copcsr; 1801 default: 1802 return SIGILL; 1803 } 1804 break; 1805 1806 default: 1807 return SIGILL; 1808 } 1809 1810 /* 1811 * Update the fpu CSR register for this operation. 1812 * If an exception is required, generate a tidy SIGFPE exception, 1813 * without updating the result register. 1814 * Note: cause exception bits do not accumulate, they are rewritten 1815 * for each op; only the flag/sticky bits accumulate. 1816 */ 1817 ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr; 1818 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) { 1819 /*printk ("SIGFPE: FPU csr = %08x\n",ctx->fcr31); */ 1820 return SIGFPE; 1821 } 1822 1823 /* 1824 * Now we can safely write the result back to the register file. 1825 */ 1826 switch (rfmt) { 1827 case -1: 1828 1829 if (cpu_has_mips_4_5_r) 1830 cbit = fpucondbit[MIPSInst_RT(ir) >> 2]; 1831 else 1832 cbit = FPU_CSR_COND; 1833 if (rv.w) 1834 ctx->fcr31 |= cbit; 1835 else 1836 ctx->fcr31 &= ~cbit; 1837 break; 1838 1839 case d_fmt: 1840 DPTOREG(rv.d, MIPSInst_FD(ir)); 1841 break; 1842 case s_fmt: 1843 SPTOREG(rv.s, MIPSInst_FD(ir)); 1844 break; 1845 case w_fmt: 1846 SITOREG(rv.w, MIPSInst_FD(ir)); 1847 break; 1848 case l_fmt: 1849 if (!cpu_has_mips_3_4_5 && !cpu_has_mips64) 1850 return SIGILL; 1851 1852 DITOREG(rv.l, MIPSInst_FD(ir)); 1853 break; 1854 default: 1855 return SIGILL; 1856 } 1857 1858 return 0; 1859} 1860 1861int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx, 1862 int has_fpu, void *__user *fault_addr) 1863{ 1864 unsigned long oldepc, prevepc; 1865 struct mm_decoded_insn dec_insn; 1866 u16 instr[4]; 1867 u16 *instr_ptr; 1868 int sig = 0; 1869 1870 oldepc = xcp->cp0_epc; 1871 do { 1872 prevepc = xcp->cp0_epc; 1873 1874 if (get_isa16_mode(prevepc) && cpu_has_mmips) { 1875 /* 1876 * Get next 2 microMIPS instructions and convert them 1877 * into 32-bit instructions. 1878 */ 1879 if ((get_user(instr[0], (u16 __user *)msk_isa16_mode(xcp->cp0_epc))) || 1880 (get_user(instr[1], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 2))) || 1881 (get_user(instr[2], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 4))) || 1882 (get_user(instr[3], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 6)))) { 1883 MIPS_FPU_EMU_INC_STATS(errors); 1884 return SIGBUS; 1885 } 1886 instr_ptr = instr; 1887 1888 /* Get first instruction. */ 1889 if (mm_insn_16bit(*instr_ptr)) { 1890 /* Duplicate the half-word. */ 1891 dec_insn.insn = (*instr_ptr << 16) | 1892 (*instr_ptr); 1893 /* 16-bit instruction. */ 1894 dec_insn.pc_inc = 2; 1895 instr_ptr += 1; 1896 } else { 1897 dec_insn.insn = (*instr_ptr << 16) | 1898 *(instr_ptr+1); 1899 /* 32-bit instruction. */ 1900 dec_insn.pc_inc = 4; 1901 instr_ptr += 2; 1902 } 1903 /* Get second instruction. */ 1904 if (mm_insn_16bit(*instr_ptr)) { 1905 /* Duplicate the half-word. */ 1906 dec_insn.next_insn = (*instr_ptr << 16) | 1907 (*instr_ptr); 1908 /* 16-bit instruction. */ 1909 dec_insn.next_pc_inc = 2; 1910 } else { 1911 dec_insn.next_insn = (*instr_ptr << 16) | 1912 *(instr_ptr+1); 1913 /* 32-bit instruction. */ 1914 dec_insn.next_pc_inc = 4; 1915 } 1916 dec_insn.micro_mips_mode = 1; 1917 } else { 1918 if ((get_user(dec_insn.insn, 1919 (mips_instruction __user *) xcp->cp0_epc)) || 1920 (get_user(dec_insn.next_insn, 1921 (mips_instruction __user *)(xcp->cp0_epc+4)))) { 1922 MIPS_FPU_EMU_INC_STATS(errors); 1923 return SIGBUS; 1924 } 1925 dec_insn.pc_inc = 4; 1926 dec_insn.next_pc_inc = 4; 1927 dec_insn.micro_mips_mode = 0; 1928 } 1929 1930 if ((dec_insn.insn == 0) || 1931 ((dec_insn.pc_inc == 2) && 1932 ((dec_insn.insn & 0xffff) == MM_NOP16))) 1933 xcp->cp0_epc += dec_insn.pc_inc; /* Skip NOPs */ 1934 else { 1935 /* 1936 * The 'ieee754_csr' is an alias of 1937 * ctx->fcr31. No need to copy ctx->fcr31 to 1938 * ieee754_csr. But ieee754_csr.rm is ieee 1939 * library modes. (not mips rounding mode) 1940 */ 1941 sig = cop1Emulate(xcp, ctx, dec_insn, fault_addr); 1942 } 1943 1944 if (has_fpu) 1945 break; 1946 if (sig) 1947 break; 1948 1949 cond_resched(); 1950 } while (xcp->cp0_epc > prevepc); 1951 1952 /* SIGILL indicates a non-fpu instruction */ 1953 if (sig == SIGILL && xcp->cp0_epc != oldepc) 1954 /* but if EPC has advanced, then ignore it */ 1955 sig = 0; 1956 1957 return sig; 1958} 1959