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/cpu-info.h> 49 #include <asm/processor.h> 50 #include <asm/fpu_emulator.h> 51 #include <asm/fpu.h> 52 #include <asm/mips-r2-to-r6-emul.h> 53 54 #include "ieee754.h" 55 56 /* Function which emulates a floating point instruction. */ 57 58 static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *, 59 mips_instruction); 60 61 static int fpux_emu(struct pt_regs *, 62 struct mips_fpu_struct *, mips_instruction, void *__user *); 63 64 /* Control registers */ 65 66 #define FPCREG_RID 0 /* $0 = revision id */ 67 #define FPCREG_FCCR 25 /* $25 = fccr */ 68 #define FPCREG_FEXR 26 /* $26 = fexr */ 69 #define FPCREG_FENR 28 /* $28 = fenr */ 70 #define FPCREG_CSR 31 /* $31 = csr */ 71 72 /* convert condition code register number to csr bit */ 73 const unsigned int fpucondbit[8] = { 74 FPU_CSR_COND, 75 FPU_CSR_COND1, 76 FPU_CSR_COND2, 77 FPU_CSR_COND3, 78 FPU_CSR_COND4, 79 FPU_CSR_COND5, 80 FPU_CSR_COND6, 81 FPU_CSR_COND7 82 }; 83 84 /* (microMIPS) Convert certain microMIPS instructions to MIPS32 format. */ 85 static const int sd_format[] = {16, 17, 0, 0, 0, 0, 0, 0}; 86 static const int sdps_format[] = {16, 17, 22, 0, 0, 0, 0, 0}; 87 static const int dwl_format[] = {17, 20, 21, 0, 0, 0, 0, 0}; 88 static const int swl_format[] = {16, 20, 21, 0, 0, 0, 0, 0}; 89 90 /* 91 * This functions translates a 32-bit microMIPS instruction 92 * into a 32-bit MIPS32 instruction. Returns 0 on success 93 * and SIGILL otherwise. 94 */ 95 static int microMIPS32_to_MIPS32(union mips_instruction *insn_ptr) 96 { 97 union mips_instruction insn = *insn_ptr; 98 union mips_instruction mips32_insn = insn; 99 int func, fmt, op; 100 101 switch (insn.mm_i_format.opcode) { 102 case mm_ldc132_op: 103 mips32_insn.mm_i_format.opcode = ldc1_op; 104 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs; 105 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt; 106 break; 107 case mm_lwc132_op: 108 mips32_insn.mm_i_format.opcode = lwc1_op; 109 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs; 110 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt; 111 break; 112 case mm_sdc132_op: 113 mips32_insn.mm_i_format.opcode = sdc1_op; 114 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs; 115 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt; 116 break; 117 case mm_swc132_op: 118 mips32_insn.mm_i_format.opcode = swc1_op; 119 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs; 120 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt; 121 break; 122 case mm_pool32i_op: 123 /* NOTE: offset is << by 1 if in microMIPS mode. */ 124 if ((insn.mm_i_format.rt == mm_bc1f_op) || 125 (insn.mm_i_format.rt == mm_bc1t_op)) { 126 mips32_insn.fb_format.opcode = cop1_op; 127 mips32_insn.fb_format.bc = bc_op; 128 mips32_insn.fb_format.flag = 129 (insn.mm_i_format.rt == mm_bc1t_op) ? 1 : 0; 130 } else 131 return SIGILL; 132 break; 133 case mm_pool32f_op: 134 switch (insn.mm_fp0_format.func) { 135 case mm_32f_01_op: 136 case mm_32f_11_op: 137 case mm_32f_02_op: 138 case mm_32f_12_op: 139 case mm_32f_41_op: 140 case mm_32f_51_op: 141 case mm_32f_42_op: 142 case mm_32f_52_op: 143 op = insn.mm_fp0_format.func; 144 if (op == mm_32f_01_op) 145 func = madd_s_op; 146 else if (op == mm_32f_11_op) 147 func = madd_d_op; 148 else if (op == mm_32f_02_op) 149 func = nmadd_s_op; 150 else if (op == mm_32f_12_op) 151 func = nmadd_d_op; 152 else if (op == mm_32f_41_op) 153 func = msub_s_op; 154 else if (op == mm_32f_51_op) 155 func = msub_d_op; 156 else if (op == mm_32f_42_op) 157 func = nmsub_s_op; 158 else 159 func = nmsub_d_op; 160 mips32_insn.fp6_format.opcode = cop1x_op; 161 mips32_insn.fp6_format.fr = insn.mm_fp6_format.fr; 162 mips32_insn.fp6_format.ft = insn.mm_fp6_format.ft; 163 mips32_insn.fp6_format.fs = insn.mm_fp6_format.fs; 164 mips32_insn.fp6_format.fd = insn.mm_fp6_format.fd; 165 mips32_insn.fp6_format.func = func; 166 break; 167 case mm_32f_10_op: 168 func = -1; /* Invalid */ 169 op = insn.mm_fp5_format.op & 0x7; 170 if (op == mm_ldxc1_op) 171 func = ldxc1_op; 172 else if (op == mm_sdxc1_op) 173 func = sdxc1_op; 174 else if (op == mm_lwxc1_op) 175 func = lwxc1_op; 176 else if (op == mm_swxc1_op) 177 func = swxc1_op; 178 179 if (func != -1) { 180 mips32_insn.r_format.opcode = cop1x_op; 181 mips32_insn.r_format.rs = 182 insn.mm_fp5_format.base; 183 mips32_insn.r_format.rt = 184 insn.mm_fp5_format.index; 185 mips32_insn.r_format.rd = 0; 186 mips32_insn.r_format.re = insn.mm_fp5_format.fd; 187 mips32_insn.r_format.func = func; 188 } else 189 return SIGILL; 190 break; 191 case mm_32f_40_op: 192 op = -1; /* Invalid */ 193 if (insn.mm_fp2_format.op == mm_fmovt_op) 194 op = 1; 195 else if (insn.mm_fp2_format.op == mm_fmovf_op) 196 op = 0; 197 if (op != -1) { 198 mips32_insn.fp0_format.opcode = cop1_op; 199 mips32_insn.fp0_format.fmt = 200 sdps_format[insn.mm_fp2_format.fmt]; 201 mips32_insn.fp0_format.ft = 202 (insn.mm_fp2_format.cc<<2) + op; 203 mips32_insn.fp0_format.fs = 204 insn.mm_fp2_format.fs; 205 mips32_insn.fp0_format.fd = 206 insn.mm_fp2_format.fd; 207 mips32_insn.fp0_format.func = fmovc_op; 208 } else 209 return SIGILL; 210 break; 211 case mm_32f_60_op: 212 func = -1; /* Invalid */ 213 if (insn.mm_fp0_format.op == mm_fadd_op) 214 func = fadd_op; 215 else if (insn.mm_fp0_format.op == mm_fsub_op) 216 func = fsub_op; 217 else if (insn.mm_fp0_format.op == mm_fmul_op) 218 func = fmul_op; 219 else if (insn.mm_fp0_format.op == mm_fdiv_op) 220 func = fdiv_op; 221 if (func != -1) { 222 mips32_insn.fp0_format.opcode = cop1_op; 223 mips32_insn.fp0_format.fmt = 224 sdps_format[insn.mm_fp0_format.fmt]; 225 mips32_insn.fp0_format.ft = 226 insn.mm_fp0_format.ft; 227 mips32_insn.fp0_format.fs = 228 insn.mm_fp0_format.fs; 229 mips32_insn.fp0_format.fd = 230 insn.mm_fp0_format.fd; 231 mips32_insn.fp0_format.func = func; 232 } else 233 return SIGILL; 234 break; 235 case mm_32f_70_op: 236 func = -1; /* Invalid */ 237 if (insn.mm_fp0_format.op == mm_fmovn_op) 238 func = fmovn_op; 239 else if (insn.mm_fp0_format.op == mm_fmovz_op) 240 func = fmovz_op; 241 if (func != -1) { 242 mips32_insn.fp0_format.opcode = cop1_op; 243 mips32_insn.fp0_format.fmt = 244 sdps_format[insn.mm_fp0_format.fmt]; 245 mips32_insn.fp0_format.ft = 246 insn.mm_fp0_format.ft; 247 mips32_insn.fp0_format.fs = 248 insn.mm_fp0_format.fs; 249 mips32_insn.fp0_format.fd = 250 insn.mm_fp0_format.fd; 251 mips32_insn.fp0_format.func = func; 252 } else 253 return SIGILL; 254 break; 255 case mm_32f_73_op: /* POOL32FXF */ 256 switch (insn.mm_fp1_format.op) { 257 case mm_movf0_op: 258 case mm_movf1_op: 259 case mm_movt0_op: 260 case mm_movt1_op: 261 if ((insn.mm_fp1_format.op & 0x7f) == 262 mm_movf0_op) 263 op = 0; 264 else 265 op = 1; 266 mips32_insn.r_format.opcode = spec_op; 267 mips32_insn.r_format.rs = insn.mm_fp4_format.fs; 268 mips32_insn.r_format.rt = 269 (insn.mm_fp4_format.cc << 2) + op; 270 mips32_insn.r_format.rd = insn.mm_fp4_format.rt; 271 mips32_insn.r_format.re = 0; 272 mips32_insn.r_format.func = movc_op; 273 break; 274 case mm_fcvtd0_op: 275 case mm_fcvtd1_op: 276 case mm_fcvts0_op: 277 case mm_fcvts1_op: 278 if ((insn.mm_fp1_format.op & 0x7f) == 279 mm_fcvtd0_op) { 280 func = fcvtd_op; 281 fmt = swl_format[insn.mm_fp3_format.fmt]; 282 } else { 283 func = fcvts_op; 284 fmt = dwl_format[insn.mm_fp3_format.fmt]; 285 } 286 mips32_insn.fp0_format.opcode = cop1_op; 287 mips32_insn.fp0_format.fmt = fmt; 288 mips32_insn.fp0_format.ft = 0; 289 mips32_insn.fp0_format.fs = 290 insn.mm_fp3_format.fs; 291 mips32_insn.fp0_format.fd = 292 insn.mm_fp3_format.rt; 293 mips32_insn.fp0_format.func = func; 294 break; 295 case mm_fmov0_op: 296 case mm_fmov1_op: 297 case mm_fabs0_op: 298 case mm_fabs1_op: 299 case mm_fneg0_op: 300 case mm_fneg1_op: 301 if ((insn.mm_fp1_format.op & 0x7f) == 302 mm_fmov0_op) 303 func = fmov_op; 304 else if ((insn.mm_fp1_format.op & 0x7f) == 305 mm_fabs0_op) 306 func = fabs_op; 307 else 308 func = fneg_op; 309 mips32_insn.fp0_format.opcode = cop1_op; 310 mips32_insn.fp0_format.fmt = 311 sdps_format[insn.mm_fp3_format.fmt]; 312 mips32_insn.fp0_format.ft = 0; 313 mips32_insn.fp0_format.fs = 314 insn.mm_fp3_format.fs; 315 mips32_insn.fp0_format.fd = 316 insn.mm_fp3_format.rt; 317 mips32_insn.fp0_format.func = func; 318 break; 319 case mm_ffloorl_op: 320 case mm_ffloorw_op: 321 case mm_fceill_op: 322 case mm_fceilw_op: 323 case mm_ftruncl_op: 324 case mm_ftruncw_op: 325 case mm_froundl_op: 326 case mm_froundw_op: 327 case mm_fcvtl_op: 328 case mm_fcvtw_op: 329 if (insn.mm_fp1_format.op == mm_ffloorl_op) 330 func = ffloorl_op; 331 else if (insn.mm_fp1_format.op == mm_ffloorw_op) 332 func = ffloor_op; 333 else if (insn.mm_fp1_format.op == mm_fceill_op) 334 func = fceill_op; 335 else if (insn.mm_fp1_format.op == mm_fceilw_op) 336 func = fceil_op; 337 else if (insn.mm_fp1_format.op == mm_ftruncl_op) 338 func = ftruncl_op; 339 else if (insn.mm_fp1_format.op == mm_ftruncw_op) 340 func = ftrunc_op; 341 else if (insn.mm_fp1_format.op == mm_froundl_op) 342 func = froundl_op; 343 else if (insn.mm_fp1_format.op == mm_froundw_op) 344 func = fround_op; 345 else if (insn.mm_fp1_format.op == mm_fcvtl_op) 346 func = fcvtl_op; 347 else 348 func = fcvtw_op; 349 mips32_insn.fp0_format.opcode = cop1_op; 350 mips32_insn.fp0_format.fmt = 351 sd_format[insn.mm_fp1_format.fmt]; 352 mips32_insn.fp0_format.ft = 0; 353 mips32_insn.fp0_format.fs = 354 insn.mm_fp1_format.fs; 355 mips32_insn.fp0_format.fd = 356 insn.mm_fp1_format.rt; 357 mips32_insn.fp0_format.func = func; 358 break; 359 case mm_frsqrt_op: 360 case mm_fsqrt_op: 361 case mm_frecip_op: 362 if (insn.mm_fp1_format.op == mm_frsqrt_op) 363 func = frsqrt_op; 364 else if (insn.mm_fp1_format.op == mm_fsqrt_op) 365 func = fsqrt_op; 366 else 367 func = frecip_op; 368 mips32_insn.fp0_format.opcode = cop1_op; 369 mips32_insn.fp0_format.fmt = 370 sdps_format[insn.mm_fp1_format.fmt]; 371 mips32_insn.fp0_format.ft = 0; 372 mips32_insn.fp0_format.fs = 373 insn.mm_fp1_format.fs; 374 mips32_insn.fp0_format.fd = 375 insn.mm_fp1_format.rt; 376 mips32_insn.fp0_format.func = func; 377 break; 378 case mm_mfc1_op: 379 case mm_mtc1_op: 380 case mm_cfc1_op: 381 case mm_ctc1_op: 382 case mm_mfhc1_op: 383 case mm_mthc1_op: 384 if (insn.mm_fp1_format.op == mm_mfc1_op) 385 op = mfc_op; 386 else if (insn.mm_fp1_format.op == mm_mtc1_op) 387 op = mtc_op; 388 else if (insn.mm_fp1_format.op == mm_cfc1_op) 389 op = cfc_op; 390 else if (insn.mm_fp1_format.op == mm_ctc1_op) 391 op = ctc_op; 392 else if (insn.mm_fp1_format.op == mm_mfhc1_op) 393 op = mfhc_op; 394 else 395 op = mthc_op; 396 mips32_insn.fp1_format.opcode = cop1_op; 397 mips32_insn.fp1_format.op = op; 398 mips32_insn.fp1_format.rt = 399 insn.mm_fp1_format.rt; 400 mips32_insn.fp1_format.fs = 401 insn.mm_fp1_format.fs; 402 mips32_insn.fp1_format.fd = 0; 403 mips32_insn.fp1_format.func = 0; 404 break; 405 default: 406 return SIGILL; 407 } 408 break; 409 case mm_32f_74_op: /* c.cond.fmt */ 410 mips32_insn.fp0_format.opcode = cop1_op; 411 mips32_insn.fp0_format.fmt = 412 sdps_format[insn.mm_fp4_format.fmt]; 413 mips32_insn.fp0_format.ft = insn.mm_fp4_format.rt; 414 mips32_insn.fp0_format.fs = insn.mm_fp4_format.fs; 415 mips32_insn.fp0_format.fd = insn.mm_fp4_format.cc << 2; 416 mips32_insn.fp0_format.func = 417 insn.mm_fp4_format.cond | MM_MIPS32_COND_FC; 418 break; 419 default: 420 return SIGILL; 421 } 422 break; 423 default: 424 return SIGILL; 425 } 426 427 *insn_ptr = mips32_insn; 428 return 0; 429 } 430 431 /* 432 * Redundant with logic already in kernel/branch.c, 433 * embedded in compute_return_epc. At some point, 434 * a single subroutine should be used across both 435 * modules. 436 */ 437 static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn, 438 unsigned long *contpc) 439 { 440 union mips_instruction insn = (union mips_instruction)dec_insn.insn; 441 unsigned int fcr31; 442 unsigned int bit = 0; 443 444 switch (insn.i_format.opcode) { 445 case spec_op: 446 switch (insn.r_format.func) { 447 case jalr_op: 448 regs->regs[insn.r_format.rd] = 449 regs->cp0_epc + dec_insn.pc_inc + 450 dec_insn.next_pc_inc; 451 /* Fall through */ 452 case jr_op: 453 /* For R6, JR already emulated in jalr_op */ 454 if (NO_R6EMU && insn.r_format.func == jr_op) 455 break; 456 *contpc = regs->regs[insn.r_format.rs]; 457 return 1; 458 } 459 break; 460 case bcond_op: 461 switch (insn.i_format.rt) { 462 case bltzal_op: 463 case bltzall_op: 464 if (NO_R6EMU && (insn.i_format.rs || 465 insn.i_format.rt == bltzall_op)) 466 break; 467 468 regs->regs[31] = regs->cp0_epc + 469 dec_insn.pc_inc + 470 dec_insn.next_pc_inc; 471 /* Fall through */ 472 case bltzl_op: 473 if (NO_R6EMU) 474 break; 475 case bltz_op: 476 if ((long)regs->regs[insn.i_format.rs] < 0) 477 *contpc = regs->cp0_epc + 478 dec_insn.pc_inc + 479 (insn.i_format.simmediate << 2); 480 else 481 *contpc = regs->cp0_epc + 482 dec_insn.pc_inc + 483 dec_insn.next_pc_inc; 484 return 1; 485 case bgezal_op: 486 case bgezall_op: 487 if (NO_R6EMU && (insn.i_format.rs || 488 insn.i_format.rt == bgezall_op)) 489 break; 490 491 regs->regs[31] = regs->cp0_epc + 492 dec_insn.pc_inc + 493 dec_insn.next_pc_inc; 494 /* Fall through */ 495 case bgezl_op: 496 if (NO_R6EMU) 497 break; 498 case bgez_op: 499 if ((long)regs->regs[insn.i_format.rs] >= 0) 500 *contpc = regs->cp0_epc + 501 dec_insn.pc_inc + 502 (insn.i_format.simmediate << 2); 503 else 504 *contpc = regs->cp0_epc + 505 dec_insn.pc_inc + 506 dec_insn.next_pc_inc; 507 return 1; 508 } 509 break; 510 case jalx_op: 511 set_isa16_mode(bit); 512 case jal_op: 513 regs->regs[31] = regs->cp0_epc + 514 dec_insn.pc_inc + 515 dec_insn.next_pc_inc; 516 /* Fall through */ 517 case j_op: 518 *contpc = regs->cp0_epc + dec_insn.pc_inc; 519 *contpc >>= 28; 520 *contpc <<= 28; 521 *contpc |= (insn.j_format.target << 2); 522 /* Set microMIPS mode bit: XOR for jalx. */ 523 *contpc ^= bit; 524 return 1; 525 case beql_op: 526 if (NO_R6EMU) 527 break; 528 case beq_op: 529 if (regs->regs[insn.i_format.rs] == 530 regs->regs[insn.i_format.rt]) 531 *contpc = regs->cp0_epc + 532 dec_insn.pc_inc + 533 (insn.i_format.simmediate << 2); 534 else 535 *contpc = regs->cp0_epc + 536 dec_insn.pc_inc + 537 dec_insn.next_pc_inc; 538 return 1; 539 case bnel_op: 540 if (NO_R6EMU) 541 break; 542 case bne_op: 543 if (regs->regs[insn.i_format.rs] != 544 regs->regs[insn.i_format.rt]) 545 *contpc = regs->cp0_epc + 546 dec_insn.pc_inc + 547 (insn.i_format.simmediate << 2); 548 else 549 *contpc = regs->cp0_epc + 550 dec_insn.pc_inc + 551 dec_insn.next_pc_inc; 552 return 1; 553 case blezl_op: 554 if (!insn.i_format.rt && NO_R6EMU) 555 break; 556 case blez_op: 557 558 /* 559 * Compact branches for R6 for the 560 * blez and blezl opcodes. 561 * BLEZ | rs = 0 | rt != 0 == BLEZALC 562 * BLEZ | rs = rt != 0 == BGEZALC 563 * BLEZ | rs != 0 | rt != 0 == BGEUC 564 * BLEZL | rs = 0 | rt != 0 == BLEZC 565 * BLEZL | rs = rt != 0 == BGEZC 566 * BLEZL | rs != 0 | rt != 0 == BGEC 567 * 568 * For real BLEZ{,L}, rt is always 0. 569 */ 570 if (cpu_has_mips_r6 && insn.i_format.rt) { 571 if ((insn.i_format.opcode == blez_op) && 572 ((!insn.i_format.rs && insn.i_format.rt) || 573 (insn.i_format.rs == insn.i_format.rt))) 574 regs->regs[31] = regs->cp0_epc + 575 dec_insn.pc_inc; 576 *contpc = regs->cp0_epc + dec_insn.pc_inc + 577 dec_insn.next_pc_inc; 578 579 return 1; 580 } 581 if ((long)regs->regs[insn.i_format.rs] <= 0) 582 *contpc = regs->cp0_epc + 583 dec_insn.pc_inc + 584 (insn.i_format.simmediate << 2); 585 else 586 *contpc = regs->cp0_epc + 587 dec_insn.pc_inc + 588 dec_insn.next_pc_inc; 589 return 1; 590 case bgtzl_op: 591 if (!insn.i_format.rt && NO_R6EMU) 592 break; 593 case bgtz_op: 594 /* 595 * Compact branches for R6 for the 596 * bgtz and bgtzl opcodes. 597 * BGTZ | rs = 0 | rt != 0 == BGTZALC 598 * BGTZ | rs = rt != 0 == BLTZALC 599 * BGTZ | rs != 0 | rt != 0 == BLTUC 600 * BGTZL | rs = 0 | rt != 0 == BGTZC 601 * BGTZL | rs = rt != 0 == BLTZC 602 * BGTZL | rs != 0 | rt != 0 == BLTC 603 * 604 * *ZALC varint for BGTZ &&& rt != 0 605 * For real GTZ{,L}, rt is always 0. 606 */ 607 if (cpu_has_mips_r6 && insn.i_format.rt) { 608 if ((insn.i_format.opcode == blez_op) && 609 ((!insn.i_format.rs && insn.i_format.rt) || 610 (insn.i_format.rs == insn.i_format.rt))) 611 regs->regs[31] = regs->cp0_epc + 612 dec_insn.pc_inc; 613 *contpc = regs->cp0_epc + dec_insn.pc_inc + 614 dec_insn.next_pc_inc; 615 616 return 1; 617 } 618 619 if ((long)regs->regs[insn.i_format.rs] > 0) 620 *contpc = regs->cp0_epc + 621 dec_insn.pc_inc + 622 (insn.i_format.simmediate << 2); 623 else 624 *contpc = regs->cp0_epc + 625 dec_insn.pc_inc + 626 dec_insn.next_pc_inc; 627 return 1; 628 case cbcond0_op: 629 case cbcond1_op: 630 if (!cpu_has_mips_r6) 631 break; 632 if (insn.i_format.rt && !insn.i_format.rs) 633 regs->regs[31] = regs->cp0_epc + 4; 634 *contpc = regs->cp0_epc + dec_insn.pc_inc + 635 dec_insn.next_pc_inc; 636 637 return 1; 638 #ifdef CONFIG_CPU_CAVIUM_OCTEON 639 case lwc2_op: /* This is bbit0 on Octeon */ 640 if ((regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) == 0) 641 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2); 642 else 643 *contpc = regs->cp0_epc + 8; 644 return 1; 645 case ldc2_op: /* This is bbit032 on Octeon */ 646 if ((regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32))) == 0) 647 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2); 648 else 649 *contpc = regs->cp0_epc + 8; 650 return 1; 651 case swc2_op: /* This is bbit1 on Octeon */ 652 if (regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) 653 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2); 654 else 655 *contpc = regs->cp0_epc + 8; 656 return 1; 657 case sdc2_op: /* This is bbit132 on Octeon */ 658 if (regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32))) 659 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2); 660 else 661 *contpc = regs->cp0_epc + 8; 662 return 1; 663 #else 664 case bc6_op: 665 /* 666 * Only valid for MIPS R6 but we can still end up 667 * here from a broken userland so just tell emulator 668 * this is not a branch and let it break later on. 669 */ 670 if (!cpu_has_mips_r6) 671 break; 672 *contpc = regs->cp0_epc + dec_insn.pc_inc + 673 dec_insn.next_pc_inc; 674 675 return 1; 676 case balc6_op: 677 if (!cpu_has_mips_r6) 678 break; 679 regs->regs[31] = regs->cp0_epc + 4; 680 *contpc = regs->cp0_epc + dec_insn.pc_inc + 681 dec_insn.next_pc_inc; 682 683 return 1; 684 case beqzcjic_op: 685 if (!cpu_has_mips_r6) 686 break; 687 *contpc = regs->cp0_epc + dec_insn.pc_inc + 688 dec_insn.next_pc_inc; 689 690 return 1; 691 case bnezcjialc_op: 692 if (!cpu_has_mips_r6) 693 break; 694 if (!insn.i_format.rs) 695 regs->regs[31] = regs->cp0_epc + 4; 696 *contpc = regs->cp0_epc + dec_insn.pc_inc + 697 dec_insn.next_pc_inc; 698 699 return 1; 700 #endif 701 case cop0_op: 702 case cop1_op: 703 /* Need to check for R6 bc1nez and bc1eqz branches */ 704 if (cpu_has_mips_r6 && 705 ((insn.i_format.rs == bc1eqz_op) || 706 (insn.i_format.rs == bc1nez_op))) { 707 bit = 0; 708 switch (insn.i_format.rs) { 709 case bc1eqz_op: 710 if (get_fpr32(¤t->thread.fpu.fpr[insn.i_format.rt], 0) & 0x1) 711 bit = 1; 712 break; 713 case bc1nez_op: 714 if (!(get_fpr32(¤t->thread.fpu.fpr[insn.i_format.rt], 0) & 0x1)) 715 bit = 1; 716 break; 717 } 718 if (bit) 719 *contpc = regs->cp0_epc + 720 dec_insn.pc_inc + 721 (insn.i_format.simmediate << 2); 722 else 723 *contpc = regs->cp0_epc + 724 dec_insn.pc_inc + 725 dec_insn.next_pc_inc; 726 727 return 1; 728 } 729 /* R2/R6 compatible cop1 instruction. Fall through */ 730 case cop2_op: 731 case cop1x_op: 732 if (insn.i_format.rs == bc_op) { 733 preempt_disable(); 734 if (is_fpu_owner()) 735 fcr31 = read_32bit_cp1_register(CP1_STATUS); 736 else 737 fcr31 = current->thread.fpu.fcr31; 738 preempt_enable(); 739 740 bit = (insn.i_format.rt >> 2); 741 bit += (bit != 0); 742 bit += 23; 743 switch (insn.i_format.rt & 3) { 744 case 0: /* bc1f */ 745 case 2: /* bc1fl */ 746 if (~fcr31 & (1 << bit)) 747 *contpc = regs->cp0_epc + 748 dec_insn.pc_inc + 749 (insn.i_format.simmediate << 2); 750 else 751 *contpc = regs->cp0_epc + 752 dec_insn.pc_inc + 753 dec_insn.next_pc_inc; 754 return 1; 755 case 1: /* bc1t */ 756 case 3: /* bc1tl */ 757 if (fcr31 & (1 << bit)) 758 *contpc = regs->cp0_epc + 759 dec_insn.pc_inc + 760 (insn.i_format.simmediate << 2); 761 else 762 *contpc = regs->cp0_epc + 763 dec_insn.pc_inc + 764 dec_insn.next_pc_inc; 765 return 1; 766 } 767 } 768 break; 769 } 770 return 0; 771 } 772 773 /* 774 * In the Linux kernel, we support selection of FPR format on the 775 * basis of the Status.FR bit. If an FPU is not present, the FR bit 776 * is hardwired to zero, which would imply a 32-bit FPU even for 777 * 64-bit CPUs so we rather look at TIF_32BIT_FPREGS. 778 * FPU emu is slow and bulky and optimizing this function offers fairly 779 * sizeable benefits so we try to be clever and make this function return 780 * a constant whenever possible, that is on 64-bit kernels without O32 781 * compatibility enabled and on 32-bit without 64-bit FPU support. 782 */ 783 static inline int cop1_64bit(struct pt_regs *xcp) 784 { 785 if (config_enabled(CONFIG_64BIT) && !config_enabled(CONFIG_MIPS32_O32)) 786 return 1; 787 else if (config_enabled(CONFIG_32BIT) && 788 !config_enabled(CONFIG_MIPS_O32_FP64_SUPPORT)) 789 return 0; 790 791 return !test_thread_flag(TIF_32BIT_FPREGS); 792 } 793 794 static inline bool hybrid_fprs(void) 795 { 796 return test_thread_flag(TIF_HYBRID_FPREGS); 797 } 798 799 #define SIFROMREG(si, x) \ 800 do { \ 801 if (cop1_64bit(xcp) && !hybrid_fprs()) \ 802 (si) = (int)get_fpr32(&ctx->fpr[x], 0); \ 803 else \ 804 (si) = (int)get_fpr32(&ctx->fpr[(x) & ~1], (x) & 1); \ 805 } while (0) 806 807 #define SITOREG(si, x) \ 808 do { \ 809 if (cop1_64bit(xcp) && !hybrid_fprs()) { \ 810 unsigned i; \ 811 set_fpr32(&ctx->fpr[x], 0, si); \ 812 for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val32); i++) \ 813 set_fpr32(&ctx->fpr[x], i, 0); \ 814 } else { \ 815 set_fpr32(&ctx->fpr[(x) & ~1], (x) & 1, si); \ 816 } \ 817 } while (0) 818 819 #define SIFROMHREG(si, x) ((si) = (int)get_fpr32(&ctx->fpr[x], 1)) 820 821 #define SITOHREG(si, x) \ 822 do { \ 823 unsigned i; \ 824 set_fpr32(&ctx->fpr[x], 1, si); \ 825 for (i = 2; i < ARRAY_SIZE(ctx->fpr[x].val32); i++) \ 826 set_fpr32(&ctx->fpr[x], i, 0); \ 827 } while (0) 828 829 #define DIFROMREG(di, x) \ 830 ((di) = get_fpr64(&ctx->fpr[(x) & ~(cop1_64bit(xcp) == 0)], 0)) 831 832 #define DITOREG(di, x) \ 833 do { \ 834 unsigned fpr, i; \ 835 fpr = (x) & ~(cop1_64bit(xcp) == 0); \ 836 set_fpr64(&ctx->fpr[fpr], 0, di); \ 837 for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val64); i++) \ 838 set_fpr64(&ctx->fpr[fpr], i, 0); \ 839 } while (0) 840 841 #define SPFROMREG(sp, x) SIFROMREG((sp).bits, x) 842 #define SPTOREG(sp, x) SITOREG((sp).bits, x) 843 #define DPFROMREG(dp, x) DIFROMREG((dp).bits, x) 844 #define DPTOREG(dp, x) DITOREG((dp).bits, x) 845 846 /* 847 * Emulate a CFC1 instruction. 848 */ 849 static inline void cop1_cfc(struct pt_regs *xcp, struct mips_fpu_struct *ctx, 850 mips_instruction ir) 851 { 852 u32 fcr31 = ctx->fcr31; 853 u32 value = 0; 854 855 switch (MIPSInst_RD(ir)) { 856 case FPCREG_CSR: 857 value = fcr31; 858 pr_debug("%p gpr[%d]<-csr=%08x\n", 859 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); 860 break; 861 862 case FPCREG_FENR: 863 if (!cpu_has_mips_r) 864 break; 865 value = (fcr31 >> (FPU_CSR_FS_S - MIPS_FENR_FS_S)) & 866 MIPS_FENR_FS; 867 value |= fcr31 & (FPU_CSR_ALL_E | FPU_CSR_RM); 868 pr_debug("%p gpr[%d]<-enr=%08x\n", 869 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); 870 break; 871 872 case FPCREG_FEXR: 873 if (!cpu_has_mips_r) 874 break; 875 value = fcr31 & (FPU_CSR_ALL_X | FPU_CSR_ALL_S); 876 pr_debug("%p gpr[%d]<-exr=%08x\n", 877 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); 878 break; 879 880 case FPCREG_FCCR: 881 if (!cpu_has_mips_r) 882 break; 883 value = (fcr31 >> (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) & 884 MIPS_FCCR_COND0; 885 value |= (fcr31 >> (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) & 886 (MIPS_FCCR_CONDX & ~MIPS_FCCR_COND0); 887 pr_debug("%p gpr[%d]<-ccr=%08x\n", 888 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); 889 break; 890 891 case FPCREG_RID: 892 value = boot_cpu_data.fpu_id; 893 break; 894 895 default: 896 break; 897 } 898 899 if (MIPSInst_RT(ir)) 900 xcp->regs[MIPSInst_RT(ir)] = value; 901 } 902 903 /* 904 * Emulate a CTC1 instruction. 905 */ 906 static inline void cop1_ctc(struct pt_regs *xcp, struct mips_fpu_struct *ctx, 907 mips_instruction ir) 908 { 909 u32 fcr31 = ctx->fcr31; 910 u32 value; 911 u32 mask; 912 913 if (MIPSInst_RT(ir) == 0) 914 value = 0; 915 else 916 value = xcp->regs[MIPSInst_RT(ir)]; 917 918 switch (MIPSInst_RD(ir)) { 919 case FPCREG_CSR: 920 pr_debug("%p gpr[%d]->csr=%08x\n", 921 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); 922 923 /* Preserve read-only bits. */ 924 mask = boot_cpu_data.fpu_msk31; 925 fcr31 = (value & ~mask) | (fcr31 & mask); 926 break; 927 928 case FPCREG_FENR: 929 if (!cpu_has_mips_r) 930 break; 931 pr_debug("%p gpr[%d]->enr=%08x\n", 932 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); 933 fcr31 &= ~(FPU_CSR_FS | FPU_CSR_ALL_E | FPU_CSR_RM); 934 fcr31 |= (value << (FPU_CSR_FS_S - MIPS_FENR_FS_S)) & 935 FPU_CSR_FS; 936 fcr31 |= value & (FPU_CSR_ALL_E | FPU_CSR_RM); 937 break; 938 939 case FPCREG_FEXR: 940 if (!cpu_has_mips_r) 941 break; 942 pr_debug("%p gpr[%d]->exr=%08x\n", 943 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); 944 fcr31 &= ~(FPU_CSR_ALL_X | FPU_CSR_ALL_S); 945 fcr31 |= value & (FPU_CSR_ALL_X | FPU_CSR_ALL_S); 946 break; 947 948 case FPCREG_FCCR: 949 if (!cpu_has_mips_r) 950 break; 951 pr_debug("%p gpr[%d]->ccr=%08x\n", 952 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); 953 fcr31 &= ~(FPU_CSR_CONDX | FPU_CSR_COND); 954 fcr31 |= (value << (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) & 955 FPU_CSR_COND; 956 fcr31 |= (value << (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) & 957 FPU_CSR_CONDX; 958 break; 959 960 default: 961 break; 962 } 963 964 ctx->fcr31 = fcr31; 965 } 966 967 /* 968 * Emulate the single floating point instruction pointed at by EPC. 969 * Two instructions if the instruction is in a branch delay slot. 970 */ 971 972 static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx, 973 struct mm_decoded_insn dec_insn, void *__user *fault_addr) 974 { 975 unsigned long contpc = xcp->cp0_epc + dec_insn.pc_inc; 976 unsigned int cond, cbit; 977 mips_instruction ir; 978 int likely, pc_inc; 979 u32 __user *wva; 980 u64 __user *dva; 981 u32 wval; 982 u64 dval; 983 int sig; 984 985 /* 986 * These are giving gcc a gentle hint about what to expect in 987 * dec_inst in order to do better optimization. 988 */ 989 if (!cpu_has_mmips && dec_insn.micro_mips_mode) 990 unreachable(); 991 992 /* XXX NEC Vr54xx bug workaround */ 993 if (delay_slot(xcp)) { 994 if (dec_insn.micro_mips_mode) { 995 if (!mm_isBranchInstr(xcp, dec_insn, &contpc)) 996 clear_delay_slot(xcp); 997 } else { 998 if (!isBranchInstr(xcp, dec_insn, &contpc)) 999 clear_delay_slot(xcp); 1000 } 1001 } 1002 1003 if (delay_slot(xcp)) { 1004 /* 1005 * The instruction to be emulated is in a branch delay slot 1006 * which means that we have to emulate the branch instruction 1007 * BEFORE we do the cop1 instruction. 1008 * 1009 * This branch could be a COP1 branch, but in that case we 1010 * would have had a trap for that instruction, and would not 1011 * come through this route. 1012 * 1013 * Linux MIPS branch emulator operates on context, updating the 1014 * cp0_epc. 1015 */ 1016 ir = dec_insn.next_insn; /* process delay slot instr */ 1017 pc_inc = dec_insn.next_pc_inc; 1018 } else { 1019 ir = dec_insn.insn; /* process current instr */ 1020 pc_inc = dec_insn.pc_inc; 1021 } 1022 1023 /* 1024 * Since microMIPS FPU instructios are a subset of MIPS32 FPU 1025 * instructions, we want to convert microMIPS FPU instructions 1026 * into MIPS32 instructions so that we could reuse all of the 1027 * FPU emulation code. 1028 * 1029 * NOTE: We cannot do this for branch instructions since they 1030 * are not a subset. Example: Cannot emulate a 16-bit 1031 * aligned target address with a MIPS32 instruction. 1032 */ 1033 if (dec_insn.micro_mips_mode) { 1034 /* 1035 * If next instruction is a 16-bit instruction, then it 1036 * it cannot be a FPU instruction. This could happen 1037 * since we can be called for non-FPU instructions. 1038 */ 1039 if ((pc_inc == 2) || 1040 (microMIPS32_to_MIPS32((union mips_instruction *)&ir) 1041 == SIGILL)) 1042 return SIGILL; 1043 } 1044 1045 emul: 1046 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, xcp, 0); 1047 MIPS_FPU_EMU_INC_STATS(emulated); 1048 switch (MIPSInst_OPCODE(ir)) { 1049 case ldc1_op: 1050 dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] + 1051 MIPSInst_SIMM(ir)); 1052 MIPS_FPU_EMU_INC_STATS(loads); 1053 1054 if (!access_ok(VERIFY_READ, dva, sizeof(u64))) { 1055 MIPS_FPU_EMU_INC_STATS(errors); 1056 *fault_addr = dva; 1057 return SIGBUS; 1058 } 1059 if (__get_user(dval, dva)) { 1060 MIPS_FPU_EMU_INC_STATS(errors); 1061 *fault_addr = dva; 1062 return SIGSEGV; 1063 } 1064 DITOREG(dval, MIPSInst_RT(ir)); 1065 break; 1066 1067 case sdc1_op: 1068 dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] + 1069 MIPSInst_SIMM(ir)); 1070 MIPS_FPU_EMU_INC_STATS(stores); 1071 DIFROMREG(dval, MIPSInst_RT(ir)); 1072 if (!access_ok(VERIFY_WRITE, dva, sizeof(u64))) { 1073 MIPS_FPU_EMU_INC_STATS(errors); 1074 *fault_addr = dva; 1075 return SIGBUS; 1076 } 1077 if (__put_user(dval, dva)) { 1078 MIPS_FPU_EMU_INC_STATS(errors); 1079 *fault_addr = dva; 1080 return SIGSEGV; 1081 } 1082 break; 1083 1084 case lwc1_op: 1085 wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] + 1086 MIPSInst_SIMM(ir)); 1087 MIPS_FPU_EMU_INC_STATS(loads); 1088 if (!access_ok(VERIFY_READ, wva, sizeof(u32))) { 1089 MIPS_FPU_EMU_INC_STATS(errors); 1090 *fault_addr = wva; 1091 return SIGBUS; 1092 } 1093 if (__get_user(wval, wva)) { 1094 MIPS_FPU_EMU_INC_STATS(errors); 1095 *fault_addr = wva; 1096 return SIGSEGV; 1097 } 1098 SITOREG(wval, MIPSInst_RT(ir)); 1099 break; 1100 1101 case swc1_op: 1102 wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] + 1103 MIPSInst_SIMM(ir)); 1104 MIPS_FPU_EMU_INC_STATS(stores); 1105 SIFROMREG(wval, MIPSInst_RT(ir)); 1106 if (!access_ok(VERIFY_WRITE, wva, sizeof(u32))) { 1107 MIPS_FPU_EMU_INC_STATS(errors); 1108 *fault_addr = wva; 1109 return SIGBUS; 1110 } 1111 if (__put_user(wval, wva)) { 1112 MIPS_FPU_EMU_INC_STATS(errors); 1113 *fault_addr = wva; 1114 return SIGSEGV; 1115 } 1116 break; 1117 1118 case cop1_op: 1119 switch (MIPSInst_RS(ir)) { 1120 case dmfc_op: 1121 if (!cpu_has_mips_3_4_5 && !cpu_has_mips64) 1122 return SIGILL; 1123 1124 /* copregister fs -> gpr[rt] */ 1125 if (MIPSInst_RT(ir) != 0) { 1126 DIFROMREG(xcp->regs[MIPSInst_RT(ir)], 1127 MIPSInst_RD(ir)); 1128 } 1129 break; 1130 1131 case dmtc_op: 1132 if (!cpu_has_mips_3_4_5 && !cpu_has_mips64) 1133 return SIGILL; 1134 1135 /* copregister fs <- rt */ 1136 DITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir)); 1137 break; 1138 1139 case mfhc_op: 1140 if (!cpu_has_mips_r2_r6) 1141 goto sigill; 1142 1143 /* copregister rd -> gpr[rt] */ 1144 if (MIPSInst_RT(ir) != 0) { 1145 SIFROMHREG(xcp->regs[MIPSInst_RT(ir)], 1146 MIPSInst_RD(ir)); 1147 } 1148 break; 1149 1150 case mthc_op: 1151 if (!cpu_has_mips_r2_r6) 1152 goto sigill; 1153 1154 /* copregister rd <- gpr[rt] */ 1155 SITOHREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir)); 1156 break; 1157 1158 case mfc_op: 1159 /* copregister rd -> gpr[rt] */ 1160 if (MIPSInst_RT(ir) != 0) { 1161 SIFROMREG(xcp->regs[MIPSInst_RT(ir)], 1162 MIPSInst_RD(ir)); 1163 } 1164 break; 1165 1166 case mtc_op: 1167 /* copregister rd <- rt */ 1168 SITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir)); 1169 break; 1170 1171 case cfc_op: 1172 /* cop control register rd -> gpr[rt] */ 1173 cop1_cfc(xcp, ctx, ir); 1174 break; 1175 1176 case ctc_op: 1177 /* copregister rd <- rt */ 1178 cop1_ctc(xcp, ctx, ir); 1179 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) { 1180 return SIGFPE; 1181 } 1182 break; 1183 1184 case bc1eqz_op: 1185 case bc1nez_op: 1186 if (!cpu_has_mips_r6 || delay_slot(xcp)) 1187 return SIGILL; 1188 1189 cond = likely = 0; 1190 switch (MIPSInst_RS(ir)) { 1191 case bc1eqz_op: 1192 if (get_fpr32(¤t->thread.fpu.fpr[MIPSInst_RT(ir)], 0) & 0x1) 1193 cond = 1; 1194 break; 1195 case bc1nez_op: 1196 if (!(get_fpr32(¤t->thread.fpu.fpr[MIPSInst_RT(ir)], 0) & 0x1)) 1197 cond = 1; 1198 break; 1199 } 1200 goto branch_common; 1201 1202 case bc_op: 1203 if (delay_slot(xcp)) 1204 return SIGILL; 1205 1206 if (cpu_has_mips_4_5_r) 1207 cbit = fpucondbit[MIPSInst_RT(ir) >> 2]; 1208 else 1209 cbit = FPU_CSR_COND; 1210 cond = ctx->fcr31 & cbit; 1211 1212 likely = 0; 1213 switch (MIPSInst_RT(ir) & 3) { 1214 case bcfl_op: 1215 if (cpu_has_mips_2_3_4_5_r) 1216 likely = 1; 1217 /* Fall through */ 1218 case bcf_op: 1219 cond = !cond; 1220 break; 1221 case bctl_op: 1222 if (cpu_has_mips_2_3_4_5_r) 1223 likely = 1; 1224 /* Fall through */ 1225 case bct_op: 1226 break; 1227 } 1228 branch_common: 1229 set_delay_slot(xcp); 1230 if (cond) { 1231 /* 1232 * Branch taken: emulate dslot instruction 1233 */ 1234 unsigned long bcpc; 1235 1236 /* 1237 * Remember EPC at the branch to point back 1238 * at so that any delay-slot instruction 1239 * signal is not silently ignored. 1240 */ 1241 bcpc = xcp->cp0_epc; 1242 xcp->cp0_epc += dec_insn.pc_inc; 1243 1244 contpc = MIPSInst_SIMM(ir); 1245 ir = dec_insn.next_insn; 1246 if (dec_insn.micro_mips_mode) { 1247 contpc = (xcp->cp0_epc + (contpc << 1)); 1248 1249 /* If 16-bit instruction, not FPU. */ 1250 if ((dec_insn.next_pc_inc == 2) || 1251 (microMIPS32_to_MIPS32((union mips_instruction *)&ir) == SIGILL)) { 1252 1253 /* 1254 * Since this instruction will 1255 * be put on the stack with 1256 * 32-bit words, get around 1257 * this problem by putting a 1258 * NOP16 as the second one. 1259 */ 1260 if (dec_insn.next_pc_inc == 2) 1261 ir = (ir & (~0xffff)) | MM_NOP16; 1262 1263 /* 1264 * Single step the non-CP1 1265 * instruction in the dslot. 1266 */ 1267 sig = mips_dsemul(xcp, ir, 1268 contpc); 1269 if (sig) 1270 xcp->cp0_epc = bcpc; 1271 /* 1272 * SIGILL forces out of 1273 * the emulation loop. 1274 */ 1275 return sig ? sig : SIGILL; 1276 } 1277 } else 1278 contpc = (xcp->cp0_epc + (contpc << 2)); 1279 1280 switch (MIPSInst_OPCODE(ir)) { 1281 case lwc1_op: 1282 case swc1_op: 1283 goto emul; 1284 1285 case ldc1_op: 1286 case sdc1_op: 1287 if (cpu_has_mips_2_3_4_5_r) 1288 goto emul; 1289 1290 goto bc_sigill; 1291 1292 case cop1_op: 1293 goto emul; 1294 1295 case cop1x_op: 1296 if (cpu_has_mips_4_5_64_r2_r6) 1297 /* its one of ours */ 1298 goto emul; 1299 1300 goto bc_sigill; 1301 1302 case spec_op: 1303 switch (MIPSInst_FUNC(ir)) { 1304 case movc_op: 1305 if (cpu_has_mips_4_5_r) 1306 goto emul; 1307 1308 goto bc_sigill; 1309 } 1310 break; 1311 1312 bc_sigill: 1313 xcp->cp0_epc = bcpc; 1314 return SIGILL; 1315 } 1316 1317 /* 1318 * Single step the non-cp1 1319 * instruction in the dslot 1320 */ 1321 sig = mips_dsemul(xcp, ir, contpc); 1322 if (sig) 1323 xcp->cp0_epc = bcpc; 1324 /* SIGILL forces out of the emulation loop. */ 1325 return sig ? sig : SIGILL; 1326 } else if (likely) { /* branch not taken */ 1327 /* 1328 * branch likely nullifies 1329 * dslot if not taken 1330 */ 1331 xcp->cp0_epc += dec_insn.pc_inc; 1332 contpc += dec_insn.pc_inc; 1333 /* 1334 * else continue & execute 1335 * dslot as normal insn 1336 */ 1337 } 1338 break; 1339 1340 default: 1341 if (!(MIPSInst_RS(ir) & 0x10)) 1342 return SIGILL; 1343 1344 /* a real fpu computation instruction */ 1345 if ((sig = fpu_emu(xcp, ctx, ir))) 1346 return sig; 1347 } 1348 break; 1349 1350 case cop1x_op: 1351 if (!cpu_has_mips_4_5_64_r2_r6) 1352 return SIGILL; 1353 1354 sig = fpux_emu(xcp, ctx, ir, fault_addr); 1355 if (sig) 1356 return sig; 1357 break; 1358 1359 case spec_op: 1360 if (!cpu_has_mips_4_5_r) 1361 return SIGILL; 1362 1363 if (MIPSInst_FUNC(ir) != movc_op) 1364 return SIGILL; 1365 cond = fpucondbit[MIPSInst_RT(ir) >> 2]; 1366 if (((ctx->fcr31 & cond) != 0) == ((MIPSInst_RT(ir) & 1) != 0)) 1367 xcp->regs[MIPSInst_RD(ir)] = 1368 xcp->regs[MIPSInst_RS(ir)]; 1369 break; 1370 default: 1371 sigill: 1372 return SIGILL; 1373 } 1374 1375 /* we did it !! */ 1376 xcp->cp0_epc = contpc; 1377 clear_delay_slot(xcp); 1378 1379 return 0; 1380 } 1381 1382 /* 1383 * Conversion table from MIPS compare ops 48-63 1384 * cond = ieee754dp_cmp(x,y,IEEE754_UN,sig); 1385 */ 1386 static const unsigned char cmptab[8] = { 1387 0, /* cmp_0 (sig) cmp_sf */ 1388 IEEE754_CUN, /* cmp_un (sig) cmp_ngle */ 1389 IEEE754_CEQ, /* cmp_eq (sig) cmp_seq */ 1390 IEEE754_CEQ | IEEE754_CUN, /* cmp_ueq (sig) cmp_ngl */ 1391 IEEE754_CLT, /* cmp_olt (sig) cmp_lt */ 1392 IEEE754_CLT | IEEE754_CUN, /* cmp_ult (sig) cmp_nge */ 1393 IEEE754_CLT | IEEE754_CEQ, /* cmp_ole (sig) cmp_le */ 1394 IEEE754_CLT | IEEE754_CEQ | IEEE754_CUN, /* cmp_ule (sig) cmp_ngt */ 1395 }; 1396 1397 static const unsigned char negative_cmptab[8] = { 1398 0, /* Reserved */ 1399 IEEE754_CLT | IEEE754_CGT | IEEE754_CEQ, 1400 IEEE754_CLT | IEEE754_CGT | IEEE754_CUN, 1401 IEEE754_CLT | IEEE754_CGT, 1402 /* Reserved */ 1403 }; 1404 1405 1406 /* 1407 * Additional MIPS4 instructions 1408 */ 1409 1410 #define DEF3OP(name, p, f1, f2, f3) \ 1411 static union ieee754##p fpemu_##p##_##name(union ieee754##p r, \ 1412 union ieee754##p s, union ieee754##p t) \ 1413 { \ 1414 struct _ieee754_csr ieee754_csr_save; \ 1415 s = f1(s, t); \ 1416 ieee754_csr_save = ieee754_csr; \ 1417 s = f2(s, r); \ 1418 ieee754_csr_save.cx |= ieee754_csr.cx; \ 1419 ieee754_csr_save.sx |= ieee754_csr.sx; \ 1420 s = f3(s); \ 1421 ieee754_csr.cx |= ieee754_csr_save.cx; \ 1422 ieee754_csr.sx |= ieee754_csr_save.sx; \ 1423 return s; \ 1424 } 1425 1426 static union ieee754dp fpemu_dp_recip(union ieee754dp d) 1427 { 1428 return ieee754dp_div(ieee754dp_one(0), d); 1429 } 1430 1431 static union ieee754dp fpemu_dp_rsqrt(union ieee754dp d) 1432 { 1433 return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d)); 1434 } 1435 1436 static union ieee754sp fpemu_sp_recip(union ieee754sp s) 1437 { 1438 return ieee754sp_div(ieee754sp_one(0), s); 1439 } 1440 1441 static union ieee754sp fpemu_sp_rsqrt(union ieee754sp s) 1442 { 1443 return ieee754sp_div(ieee754sp_one(0), ieee754sp_sqrt(s)); 1444 } 1445 1446 DEF3OP(madd, sp, ieee754sp_mul, ieee754sp_add, ); 1447 DEF3OP(msub, sp, ieee754sp_mul, ieee754sp_sub, ); 1448 DEF3OP(nmadd, sp, ieee754sp_mul, ieee754sp_add, ieee754sp_neg); 1449 DEF3OP(nmsub, sp, ieee754sp_mul, ieee754sp_sub, ieee754sp_neg); 1450 DEF3OP(madd, dp, ieee754dp_mul, ieee754dp_add, ); 1451 DEF3OP(msub, dp, ieee754dp_mul, ieee754dp_sub, ); 1452 DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg); 1453 DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg); 1454 1455 static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx, 1456 mips_instruction ir, void *__user *fault_addr) 1457 { 1458 unsigned rcsr = 0; /* resulting csr */ 1459 1460 MIPS_FPU_EMU_INC_STATS(cp1xops); 1461 1462 switch (MIPSInst_FMA_FFMT(ir)) { 1463 case s_fmt:{ /* 0 */ 1464 1465 union ieee754sp(*handler) (union ieee754sp, union ieee754sp, union ieee754sp); 1466 union ieee754sp fd, fr, fs, ft; 1467 u32 __user *va; 1468 u32 val; 1469 1470 switch (MIPSInst_FUNC(ir)) { 1471 case lwxc1_op: 1472 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] + 1473 xcp->regs[MIPSInst_FT(ir)]); 1474 1475 MIPS_FPU_EMU_INC_STATS(loads); 1476 if (!access_ok(VERIFY_READ, va, sizeof(u32))) { 1477 MIPS_FPU_EMU_INC_STATS(errors); 1478 *fault_addr = va; 1479 return SIGBUS; 1480 } 1481 if (__get_user(val, va)) { 1482 MIPS_FPU_EMU_INC_STATS(errors); 1483 *fault_addr = va; 1484 return SIGSEGV; 1485 } 1486 SITOREG(val, MIPSInst_FD(ir)); 1487 break; 1488 1489 case swxc1_op: 1490 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] + 1491 xcp->regs[MIPSInst_FT(ir)]); 1492 1493 MIPS_FPU_EMU_INC_STATS(stores); 1494 1495 SIFROMREG(val, MIPSInst_FS(ir)); 1496 if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) { 1497 MIPS_FPU_EMU_INC_STATS(errors); 1498 *fault_addr = va; 1499 return SIGBUS; 1500 } 1501 if (put_user(val, va)) { 1502 MIPS_FPU_EMU_INC_STATS(errors); 1503 *fault_addr = va; 1504 return SIGSEGV; 1505 } 1506 break; 1507 1508 case madd_s_op: 1509 handler = fpemu_sp_madd; 1510 goto scoptop; 1511 case msub_s_op: 1512 handler = fpemu_sp_msub; 1513 goto scoptop; 1514 case nmadd_s_op: 1515 handler = fpemu_sp_nmadd; 1516 goto scoptop; 1517 case nmsub_s_op: 1518 handler = fpemu_sp_nmsub; 1519 goto scoptop; 1520 1521 scoptop: 1522 SPFROMREG(fr, MIPSInst_FR(ir)); 1523 SPFROMREG(fs, MIPSInst_FS(ir)); 1524 SPFROMREG(ft, MIPSInst_FT(ir)); 1525 fd = (*handler) (fr, fs, ft); 1526 SPTOREG(fd, MIPSInst_FD(ir)); 1527 1528 copcsr: 1529 if (ieee754_cxtest(IEEE754_INEXACT)) { 1530 MIPS_FPU_EMU_INC_STATS(ieee754_inexact); 1531 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S; 1532 } 1533 if (ieee754_cxtest(IEEE754_UNDERFLOW)) { 1534 MIPS_FPU_EMU_INC_STATS(ieee754_underflow); 1535 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S; 1536 } 1537 if (ieee754_cxtest(IEEE754_OVERFLOW)) { 1538 MIPS_FPU_EMU_INC_STATS(ieee754_overflow); 1539 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S; 1540 } 1541 if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) { 1542 MIPS_FPU_EMU_INC_STATS(ieee754_invalidop); 1543 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S; 1544 } 1545 1546 ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr; 1547 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) { 1548 /*printk ("SIGFPE: FPU csr = %08x\n", 1549 ctx->fcr31); */ 1550 return SIGFPE; 1551 } 1552 1553 break; 1554 1555 default: 1556 return SIGILL; 1557 } 1558 break; 1559 } 1560 1561 case d_fmt:{ /* 1 */ 1562 union ieee754dp(*handler) (union ieee754dp, union ieee754dp, union ieee754dp); 1563 union ieee754dp fd, fr, fs, ft; 1564 u64 __user *va; 1565 u64 val; 1566 1567 switch (MIPSInst_FUNC(ir)) { 1568 case ldxc1_op: 1569 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] + 1570 xcp->regs[MIPSInst_FT(ir)]); 1571 1572 MIPS_FPU_EMU_INC_STATS(loads); 1573 if (!access_ok(VERIFY_READ, va, sizeof(u64))) { 1574 MIPS_FPU_EMU_INC_STATS(errors); 1575 *fault_addr = va; 1576 return SIGBUS; 1577 } 1578 if (__get_user(val, va)) { 1579 MIPS_FPU_EMU_INC_STATS(errors); 1580 *fault_addr = va; 1581 return SIGSEGV; 1582 } 1583 DITOREG(val, MIPSInst_FD(ir)); 1584 break; 1585 1586 case sdxc1_op: 1587 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] + 1588 xcp->regs[MIPSInst_FT(ir)]); 1589 1590 MIPS_FPU_EMU_INC_STATS(stores); 1591 DIFROMREG(val, MIPSInst_FS(ir)); 1592 if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) { 1593 MIPS_FPU_EMU_INC_STATS(errors); 1594 *fault_addr = va; 1595 return SIGBUS; 1596 } 1597 if (__put_user(val, va)) { 1598 MIPS_FPU_EMU_INC_STATS(errors); 1599 *fault_addr = va; 1600 return SIGSEGV; 1601 } 1602 break; 1603 1604 case madd_d_op: 1605 handler = fpemu_dp_madd; 1606 goto dcoptop; 1607 case msub_d_op: 1608 handler = fpemu_dp_msub; 1609 goto dcoptop; 1610 case nmadd_d_op: 1611 handler = fpemu_dp_nmadd; 1612 goto dcoptop; 1613 case nmsub_d_op: 1614 handler = fpemu_dp_nmsub; 1615 goto dcoptop; 1616 1617 dcoptop: 1618 DPFROMREG(fr, MIPSInst_FR(ir)); 1619 DPFROMREG(fs, MIPSInst_FS(ir)); 1620 DPFROMREG(ft, MIPSInst_FT(ir)); 1621 fd = (*handler) (fr, fs, ft); 1622 DPTOREG(fd, MIPSInst_FD(ir)); 1623 goto copcsr; 1624 1625 default: 1626 return SIGILL; 1627 } 1628 break; 1629 } 1630 1631 case 0x3: 1632 if (MIPSInst_FUNC(ir) != pfetch_op) 1633 return SIGILL; 1634 1635 /* ignore prefx operation */ 1636 break; 1637 1638 default: 1639 return SIGILL; 1640 } 1641 1642 return 0; 1643 } 1644 1645 1646 1647 /* 1648 * Emulate a single COP1 arithmetic instruction. 1649 */ 1650 static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx, 1651 mips_instruction ir) 1652 { 1653 int rfmt; /* resulting format */ 1654 unsigned rcsr = 0; /* resulting csr */ 1655 unsigned int oldrm; 1656 unsigned int cbit; 1657 unsigned cond; 1658 union { 1659 union ieee754dp d; 1660 union ieee754sp s; 1661 int w; 1662 s64 l; 1663 } rv; /* resulting value */ 1664 u64 bits; 1665 1666 MIPS_FPU_EMU_INC_STATS(cp1ops); 1667 switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) { 1668 case s_fmt: { /* 0 */ 1669 union { 1670 union ieee754sp(*b) (union ieee754sp, union ieee754sp); 1671 union ieee754sp(*u) (union ieee754sp); 1672 } handler; 1673 union ieee754sp fs, ft; 1674 1675 switch (MIPSInst_FUNC(ir)) { 1676 /* binary ops */ 1677 case fadd_op: 1678 handler.b = ieee754sp_add; 1679 goto scopbop; 1680 case fsub_op: 1681 handler.b = ieee754sp_sub; 1682 goto scopbop; 1683 case fmul_op: 1684 handler.b = ieee754sp_mul; 1685 goto scopbop; 1686 case fdiv_op: 1687 handler.b = ieee754sp_div; 1688 goto scopbop; 1689 1690 /* unary ops */ 1691 case fsqrt_op: 1692 if (!cpu_has_mips_2_3_4_5_r) 1693 return SIGILL; 1694 1695 handler.u = ieee754sp_sqrt; 1696 goto scopuop; 1697 1698 /* 1699 * Note that on some MIPS IV implementations such as the 1700 * R5000 and R8000 the FSQRT and FRECIP instructions do not 1701 * achieve full IEEE-754 accuracy - however this emulator does. 1702 */ 1703 case frsqrt_op: 1704 if (!cpu_has_mips_4_5_64_r2_r6) 1705 return SIGILL; 1706 1707 handler.u = fpemu_sp_rsqrt; 1708 goto scopuop; 1709 1710 case frecip_op: 1711 if (!cpu_has_mips_4_5_64_r2_r6) 1712 return SIGILL; 1713 1714 handler.u = fpemu_sp_recip; 1715 goto scopuop; 1716 1717 case fmovc_op: 1718 if (!cpu_has_mips_4_5_r) 1719 return SIGILL; 1720 1721 cond = fpucondbit[MIPSInst_FT(ir) >> 2]; 1722 if (((ctx->fcr31 & cond) != 0) != 1723 ((MIPSInst_FT(ir) & 1) != 0)) 1724 return 0; 1725 SPFROMREG(rv.s, MIPSInst_FS(ir)); 1726 break; 1727 1728 case fmovz_op: 1729 if (!cpu_has_mips_4_5_r) 1730 return SIGILL; 1731 1732 if (xcp->regs[MIPSInst_FT(ir)] != 0) 1733 return 0; 1734 SPFROMREG(rv.s, MIPSInst_FS(ir)); 1735 break; 1736 1737 case fmovn_op: 1738 if (!cpu_has_mips_4_5_r) 1739 return SIGILL; 1740 1741 if (xcp->regs[MIPSInst_FT(ir)] == 0) 1742 return 0; 1743 SPFROMREG(rv.s, MIPSInst_FS(ir)); 1744 break; 1745 1746 case fseleqz_op: 1747 if (!cpu_has_mips_r6) 1748 return SIGILL; 1749 1750 SPFROMREG(rv.s, MIPSInst_FT(ir)); 1751 if (rv.w & 0x1) 1752 rv.w = 0; 1753 else 1754 SPFROMREG(rv.s, MIPSInst_FS(ir)); 1755 break; 1756 1757 case fselnez_op: 1758 if (!cpu_has_mips_r6) 1759 return SIGILL; 1760 1761 SPFROMREG(rv.s, MIPSInst_FT(ir)); 1762 if (rv.w & 0x1) 1763 SPFROMREG(rv.s, MIPSInst_FS(ir)); 1764 else 1765 rv.w = 0; 1766 break; 1767 1768 case fmaddf_op: { 1769 union ieee754sp ft, fs, fd; 1770 1771 if (!cpu_has_mips_r6) 1772 return SIGILL; 1773 1774 SPFROMREG(ft, MIPSInst_FT(ir)); 1775 SPFROMREG(fs, MIPSInst_FS(ir)); 1776 SPFROMREG(fd, MIPSInst_FD(ir)); 1777 rv.s = ieee754sp_maddf(fd, fs, ft); 1778 break; 1779 } 1780 1781 case fmsubf_op: { 1782 union ieee754sp ft, fs, fd; 1783 1784 if (!cpu_has_mips_r6) 1785 return SIGILL; 1786 1787 SPFROMREG(ft, MIPSInst_FT(ir)); 1788 SPFROMREG(fs, MIPSInst_FS(ir)); 1789 SPFROMREG(fd, MIPSInst_FD(ir)); 1790 rv.s = ieee754sp_msubf(fd, fs, ft); 1791 break; 1792 } 1793 1794 case frint_op: { 1795 union ieee754sp fs; 1796 1797 if (!cpu_has_mips_r6) 1798 return SIGILL; 1799 1800 SPFROMREG(fs, MIPSInst_FS(ir)); 1801 rv.l = ieee754sp_tlong(fs); 1802 rv.s = ieee754sp_flong(rv.l); 1803 goto copcsr; 1804 } 1805 1806 case fclass_op: { 1807 union ieee754sp fs; 1808 1809 if (!cpu_has_mips_r6) 1810 return SIGILL; 1811 1812 SPFROMREG(fs, MIPSInst_FS(ir)); 1813 rv.w = ieee754sp_2008class(fs); 1814 rfmt = w_fmt; 1815 break; 1816 } 1817 1818 case fmin_op: { 1819 union ieee754sp fs, ft; 1820 1821 if (!cpu_has_mips_r6) 1822 return SIGILL; 1823 1824 SPFROMREG(ft, MIPSInst_FT(ir)); 1825 SPFROMREG(fs, MIPSInst_FS(ir)); 1826 rv.s = ieee754sp_fmin(fs, ft); 1827 break; 1828 } 1829 1830 case fmina_op: { 1831 union ieee754sp fs, ft; 1832 1833 if (!cpu_has_mips_r6) 1834 return SIGILL; 1835 1836 SPFROMREG(ft, MIPSInst_FT(ir)); 1837 SPFROMREG(fs, MIPSInst_FS(ir)); 1838 rv.s = ieee754sp_fmina(fs, ft); 1839 break; 1840 } 1841 1842 case fmax_op: { 1843 union ieee754sp fs, ft; 1844 1845 if (!cpu_has_mips_r6) 1846 return SIGILL; 1847 1848 SPFROMREG(ft, MIPSInst_FT(ir)); 1849 SPFROMREG(fs, MIPSInst_FS(ir)); 1850 rv.s = ieee754sp_fmax(fs, ft); 1851 break; 1852 } 1853 1854 case fmaxa_op: { 1855 union ieee754sp fs, ft; 1856 1857 if (!cpu_has_mips_r6) 1858 return SIGILL; 1859 1860 SPFROMREG(ft, MIPSInst_FT(ir)); 1861 SPFROMREG(fs, MIPSInst_FS(ir)); 1862 rv.s = ieee754sp_fmaxa(fs, ft); 1863 break; 1864 } 1865 1866 case fabs_op: 1867 handler.u = ieee754sp_abs; 1868 goto scopuop; 1869 1870 case fneg_op: 1871 handler.u = ieee754sp_neg; 1872 goto scopuop; 1873 1874 case fmov_op: 1875 /* an easy one */ 1876 SPFROMREG(rv.s, MIPSInst_FS(ir)); 1877 goto copcsr; 1878 1879 /* binary op on handler */ 1880 scopbop: 1881 SPFROMREG(fs, MIPSInst_FS(ir)); 1882 SPFROMREG(ft, MIPSInst_FT(ir)); 1883 1884 rv.s = (*handler.b) (fs, ft); 1885 goto copcsr; 1886 scopuop: 1887 SPFROMREG(fs, MIPSInst_FS(ir)); 1888 rv.s = (*handler.u) (fs); 1889 goto copcsr; 1890 copcsr: 1891 if (ieee754_cxtest(IEEE754_INEXACT)) { 1892 MIPS_FPU_EMU_INC_STATS(ieee754_inexact); 1893 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S; 1894 } 1895 if (ieee754_cxtest(IEEE754_UNDERFLOW)) { 1896 MIPS_FPU_EMU_INC_STATS(ieee754_underflow); 1897 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S; 1898 } 1899 if (ieee754_cxtest(IEEE754_OVERFLOW)) { 1900 MIPS_FPU_EMU_INC_STATS(ieee754_overflow); 1901 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S; 1902 } 1903 if (ieee754_cxtest(IEEE754_ZERO_DIVIDE)) { 1904 MIPS_FPU_EMU_INC_STATS(ieee754_zerodiv); 1905 rcsr |= FPU_CSR_DIV_X | FPU_CSR_DIV_S; 1906 } 1907 if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) { 1908 MIPS_FPU_EMU_INC_STATS(ieee754_invalidop); 1909 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S; 1910 } 1911 break; 1912 1913 /* unary conv ops */ 1914 case fcvts_op: 1915 return SIGILL; /* not defined */ 1916 1917 case fcvtd_op: 1918 SPFROMREG(fs, MIPSInst_FS(ir)); 1919 rv.d = ieee754dp_fsp(fs); 1920 rfmt = d_fmt; 1921 goto copcsr; 1922 1923 case fcvtw_op: 1924 SPFROMREG(fs, MIPSInst_FS(ir)); 1925 rv.w = ieee754sp_tint(fs); 1926 rfmt = w_fmt; 1927 goto copcsr; 1928 1929 case fround_op: 1930 case ftrunc_op: 1931 case fceil_op: 1932 case ffloor_op: 1933 if (!cpu_has_mips_2_3_4_5_r) 1934 return SIGILL; 1935 1936 oldrm = ieee754_csr.rm; 1937 SPFROMREG(fs, MIPSInst_FS(ir)); 1938 ieee754_csr.rm = MIPSInst_FUNC(ir); 1939 rv.w = ieee754sp_tint(fs); 1940 ieee754_csr.rm = oldrm; 1941 rfmt = w_fmt; 1942 goto copcsr; 1943 1944 case fcvtl_op: 1945 if (!cpu_has_mips_3_4_5_64_r2_r6) 1946 return SIGILL; 1947 1948 SPFROMREG(fs, MIPSInst_FS(ir)); 1949 rv.l = ieee754sp_tlong(fs); 1950 rfmt = l_fmt; 1951 goto copcsr; 1952 1953 case froundl_op: 1954 case ftruncl_op: 1955 case fceill_op: 1956 case ffloorl_op: 1957 if (!cpu_has_mips_3_4_5_64_r2_r6) 1958 return SIGILL; 1959 1960 oldrm = ieee754_csr.rm; 1961 SPFROMREG(fs, MIPSInst_FS(ir)); 1962 ieee754_csr.rm = MIPSInst_FUNC(ir); 1963 rv.l = ieee754sp_tlong(fs); 1964 ieee754_csr.rm = oldrm; 1965 rfmt = l_fmt; 1966 goto copcsr; 1967 1968 default: 1969 if (!NO_R6EMU && MIPSInst_FUNC(ir) >= fcmp_op) { 1970 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op; 1971 union ieee754sp fs, ft; 1972 1973 SPFROMREG(fs, MIPSInst_FS(ir)); 1974 SPFROMREG(ft, MIPSInst_FT(ir)); 1975 rv.w = ieee754sp_cmp(fs, ft, 1976 cmptab[cmpop & 0x7], cmpop & 0x8); 1977 rfmt = -1; 1978 if ((cmpop & 0x8) && ieee754_cxtest 1979 (IEEE754_INVALID_OPERATION)) 1980 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S; 1981 else 1982 goto copcsr; 1983 1984 } else 1985 return SIGILL; 1986 break; 1987 } 1988 break; 1989 } 1990 1991 case d_fmt: { 1992 union ieee754dp fs, ft; 1993 union { 1994 union ieee754dp(*b) (union ieee754dp, union ieee754dp); 1995 union ieee754dp(*u) (union ieee754dp); 1996 } handler; 1997 1998 switch (MIPSInst_FUNC(ir)) { 1999 /* binary ops */ 2000 case fadd_op: 2001 handler.b = ieee754dp_add; 2002 goto dcopbop; 2003 case fsub_op: 2004 handler.b = ieee754dp_sub; 2005 goto dcopbop; 2006 case fmul_op: 2007 handler.b = ieee754dp_mul; 2008 goto dcopbop; 2009 case fdiv_op: 2010 handler.b = ieee754dp_div; 2011 goto dcopbop; 2012 2013 /* unary ops */ 2014 case fsqrt_op: 2015 if (!cpu_has_mips_2_3_4_5_r) 2016 return SIGILL; 2017 2018 handler.u = ieee754dp_sqrt; 2019 goto dcopuop; 2020 /* 2021 * Note that on some MIPS IV implementations such as the 2022 * R5000 and R8000 the FSQRT and FRECIP instructions do not 2023 * achieve full IEEE-754 accuracy - however this emulator does. 2024 */ 2025 case frsqrt_op: 2026 if (!cpu_has_mips_4_5_64_r2_r6) 2027 return SIGILL; 2028 2029 handler.u = fpemu_dp_rsqrt; 2030 goto dcopuop; 2031 case frecip_op: 2032 if (!cpu_has_mips_4_5_64_r2_r6) 2033 return SIGILL; 2034 2035 handler.u = fpemu_dp_recip; 2036 goto dcopuop; 2037 case fmovc_op: 2038 if (!cpu_has_mips_4_5_r) 2039 return SIGILL; 2040 2041 cond = fpucondbit[MIPSInst_FT(ir) >> 2]; 2042 if (((ctx->fcr31 & cond) != 0) != 2043 ((MIPSInst_FT(ir) & 1) != 0)) 2044 return 0; 2045 DPFROMREG(rv.d, MIPSInst_FS(ir)); 2046 break; 2047 case fmovz_op: 2048 if (!cpu_has_mips_4_5_r) 2049 return SIGILL; 2050 2051 if (xcp->regs[MIPSInst_FT(ir)] != 0) 2052 return 0; 2053 DPFROMREG(rv.d, MIPSInst_FS(ir)); 2054 break; 2055 case fmovn_op: 2056 if (!cpu_has_mips_4_5_r) 2057 return SIGILL; 2058 2059 if (xcp->regs[MIPSInst_FT(ir)] == 0) 2060 return 0; 2061 DPFROMREG(rv.d, MIPSInst_FS(ir)); 2062 break; 2063 2064 case fseleqz_op: 2065 if (!cpu_has_mips_r6) 2066 return SIGILL; 2067 2068 DPFROMREG(rv.d, MIPSInst_FT(ir)); 2069 if (rv.l & 0x1) 2070 rv.l = 0; 2071 else 2072 DPFROMREG(rv.d, MIPSInst_FS(ir)); 2073 break; 2074 2075 case fselnez_op: 2076 if (!cpu_has_mips_r6) 2077 return SIGILL; 2078 2079 DPFROMREG(rv.d, MIPSInst_FT(ir)); 2080 if (rv.l & 0x1) 2081 DPFROMREG(rv.d, MIPSInst_FS(ir)); 2082 else 2083 rv.l = 0; 2084 break; 2085 2086 case fmaddf_op: { 2087 union ieee754dp ft, fs, fd; 2088 2089 if (!cpu_has_mips_r6) 2090 return SIGILL; 2091 2092 DPFROMREG(ft, MIPSInst_FT(ir)); 2093 DPFROMREG(fs, MIPSInst_FS(ir)); 2094 DPFROMREG(fd, MIPSInst_FD(ir)); 2095 rv.d = ieee754dp_maddf(fd, fs, ft); 2096 break; 2097 } 2098 2099 case fmsubf_op: { 2100 union ieee754dp ft, fs, fd; 2101 2102 if (!cpu_has_mips_r6) 2103 return SIGILL; 2104 2105 DPFROMREG(ft, MIPSInst_FT(ir)); 2106 DPFROMREG(fs, MIPSInst_FS(ir)); 2107 DPFROMREG(fd, MIPSInst_FD(ir)); 2108 rv.d = ieee754dp_msubf(fd, fs, ft); 2109 break; 2110 } 2111 2112 case frint_op: { 2113 union ieee754dp fs; 2114 2115 if (!cpu_has_mips_r6) 2116 return SIGILL; 2117 2118 DPFROMREG(fs, MIPSInst_FS(ir)); 2119 rv.l = ieee754dp_tlong(fs); 2120 rv.d = ieee754dp_flong(rv.l); 2121 goto copcsr; 2122 } 2123 2124 case fclass_op: { 2125 union ieee754dp fs; 2126 2127 if (!cpu_has_mips_r6) 2128 return SIGILL; 2129 2130 DPFROMREG(fs, MIPSInst_FS(ir)); 2131 rv.w = ieee754dp_2008class(fs); 2132 rfmt = w_fmt; 2133 break; 2134 } 2135 2136 case fmin_op: { 2137 union ieee754dp fs, ft; 2138 2139 if (!cpu_has_mips_r6) 2140 return SIGILL; 2141 2142 DPFROMREG(ft, MIPSInst_FT(ir)); 2143 DPFROMREG(fs, MIPSInst_FS(ir)); 2144 rv.d = ieee754dp_fmin(fs, ft); 2145 break; 2146 } 2147 2148 case fmina_op: { 2149 union ieee754dp fs, ft; 2150 2151 if (!cpu_has_mips_r6) 2152 return SIGILL; 2153 2154 DPFROMREG(ft, MIPSInst_FT(ir)); 2155 DPFROMREG(fs, MIPSInst_FS(ir)); 2156 rv.d = ieee754dp_fmina(fs, ft); 2157 break; 2158 } 2159 2160 case fmax_op: { 2161 union ieee754dp fs, ft; 2162 2163 if (!cpu_has_mips_r6) 2164 return SIGILL; 2165 2166 DPFROMREG(ft, MIPSInst_FT(ir)); 2167 DPFROMREG(fs, MIPSInst_FS(ir)); 2168 rv.d = ieee754dp_fmax(fs, ft); 2169 break; 2170 } 2171 2172 case fmaxa_op: { 2173 union ieee754dp fs, ft; 2174 2175 if (!cpu_has_mips_r6) 2176 return SIGILL; 2177 2178 DPFROMREG(ft, MIPSInst_FT(ir)); 2179 DPFROMREG(fs, MIPSInst_FS(ir)); 2180 rv.d = ieee754dp_fmaxa(fs, ft); 2181 break; 2182 } 2183 2184 case fabs_op: 2185 handler.u = ieee754dp_abs; 2186 goto dcopuop; 2187 2188 case fneg_op: 2189 handler.u = ieee754dp_neg; 2190 goto dcopuop; 2191 2192 case fmov_op: 2193 /* an easy one */ 2194 DPFROMREG(rv.d, MIPSInst_FS(ir)); 2195 goto copcsr; 2196 2197 /* binary op on handler */ 2198 dcopbop: 2199 DPFROMREG(fs, MIPSInst_FS(ir)); 2200 DPFROMREG(ft, MIPSInst_FT(ir)); 2201 2202 rv.d = (*handler.b) (fs, ft); 2203 goto copcsr; 2204 dcopuop: 2205 DPFROMREG(fs, MIPSInst_FS(ir)); 2206 rv.d = (*handler.u) (fs); 2207 goto copcsr; 2208 2209 /* 2210 * unary conv ops 2211 */ 2212 case fcvts_op: 2213 DPFROMREG(fs, MIPSInst_FS(ir)); 2214 rv.s = ieee754sp_fdp(fs); 2215 rfmt = s_fmt; 2216 goto copcsr; 2217 2218 case fcvtd_op: 2219 return SIGILL; /* not defined */ 2220 2221 case fcvtw_op: 2222 DPFROMREG(fs, MIPSInst_FS(ir)); 2223 rv.w = ieee754dp_tint(fs); /* wrong */ 2224 rfmt = w_fmt; 2225 goto copcsr; 2226 2227 case fround_op: 2228 case ftrunc_op: 2229 case fceil_op: 2230 case ffloor_op: 2231 if (!cpu_has_mips_2_3_4_5_r) 2232 return SIGILL; 2233 2234 oldrm = ieee754_csr.rm; 2235 DPFROMREG(fs, MIPSInst_FS(ir)); 2236 ieee754_csr.rm = MIPSInst_FUNC(ir); 2237 rv.w = ieee754dp_tint(fs); 2238 ieee754_csr.rm = oldrm; 2239 rfmt = w_fmt; 2240 goto copcsr; 2241 2242 case fcvtl_op: 2243 if (!cpu_has_mips_3_4_5_64_r2_r6) 2244 return SIGILL; 2245 2246 DPFROMREG(fs, MIPSInst_FS(ir)); 2247 rv.l = ieee754dp_tlong(fs); 2248 rfmt = l_fmt; 2249 goto copcsr; 2250 2251 case froundl_op: 2252 case ftruncl_op: 2253 case fceill_op: 2254 case ffloorl_op: 2255 if (!cpu_has_mips_3_4_5_64_r2_r6) 2256 return SIGILL; 2257 2258 oldrm = ieee754_csr.rm; 2259 DPFROMREG(fs, MIPSInst_FS(ir)); 2260 ieee754_csr.rm = MIPSInst_FUNC(ir); 2261 rv.l = ieee754dp_tlong(fs); 2262 ieee754_csr.rm = oldrm; 2263 rfmt = l_fmt; 2264 goto copcsr; 2265 2266 default: 2267 if (!NO_R6EMU && MIPSInst_FUNC(ir) >= fcmp_op) { 2268 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op; 2269 union ieee754dp fs, ft; 2270 2271 DPFROMREG(fs, MIPSInst_FS(ir)); 2272 DPFROMREG(ft, MIPSInst_FT(ir)); 2273 rv.w = ieee754dp_cmp(fs, ft, 2274 cmptab[cmpop & 0x7], cmpop & 0x8); 2275 rfmt = -1; 2276 if ((cmpop & 0x8) 2277 && 2278 ieee754_cxtest 2279 (IEEE754_INVALID_OPERATION)) 2280 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S; 2281 else 2282 goto copcsr; 2283 2284 } 2285 else { 2286 return SIGILL; 2287 } 2288 break; 2289 } 2290 break; 2291 } 2292 2293 case w_fmt: { 2294 union ieee754dp fs; 2295 2296 switch (MIPSInst_FUNC(ir)) { 2297 case fcvts_op: 2298 /* convert word to single precision real */ 2299 SPFROMREG(fs, MIPSInst_FS(ir)); 2300 rv.s = ieee754sp_fint(fs.bits); 2301 rfmt = s_fmt; 2302 goto copcsr; 2303 case fcvtd_op: 2304 /* convert word to double precision real */ 2305 SPFROMREG(fs, MIPSInst_FS(ir)); 2306 rv.d = ieee754dp_fint(fs.bits); 2307 rfmt = d_fmt; 2308 goto copcsr; 2309 default: { 2310 /* Emulating the new CMP.condn.fmt R6 instruction */ 2311 #define CMPOP_MASK 0x7 2312 #define SIGN_BIT (0x1 << 3) 2313 #define PREDICATE_BIT (0x1 << 4) 2314 2315 int cmpop = MIPSInst_FUNC(ir) & CMPOP_MASK; 2316 int sig = MIPSInst_FUNC(ir) & SIGN_BIT; 2317 union ieee754sp fs, ft; 2318 2319 /* This is an R6 only instruction */ 2320 if (!cpu_has_mips_r6 || 2321 (MIPSInst_FUNC(ir) & 0x20)) 2322 return SIGILL; 2323 2324 /* fmt is w_fmt for single precision so fix it */ 2325 rfmt = s_fmt; 2326 /* default to false */ 2327 rv.w = 0; 2328 2329 /* CMP.condn.S */ 2330 SPFROMREG(fs, MIPSInst_FS(ir)); 2331 SPFROMREG(ft, MIPSInst_FT(ir)); 2332 2333 /* positive predicates */ 2334 if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) { 2335 if (ieee754sp_cmp(fs, ft, cmptab[cmpop], 2336 sig)) 2337 rv.w = -1; /* true, all 1s */ 2338 if ((sig) && 2339 ieee754_cxtest(IEEE754_INVALID_OPERATION)) 2340 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S; 2341 else 2342 goto copcsr; 2343 } else { 2344 /* negative predicates */ 2345 switch (cmpop) { 2346 case 1: 2347 case 2: 2348 case 3: 2349 if (ieee754sp_cmp(fs, ft, 2350 negative_cmptab[cmpop], 2351 sig)) 2352 rv.w = -1; /* true, all 1s */ 2353 if (sig && 2354 ieee754_cxtest(IEEE754_INVALID_OPERATION)) 2355 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S; 2356 else 2357 goto copcsr; 2358 break; 2359 default: 2360 /* Reserved R6 ops */ 2361 pr_err("Reserved MIPS R6 CMP.condn.S operation\n"); 2362 return SIGILL; 2363 } 2364 } 2365 break; 2366 } 2367 } 2368 } 2369 2370 case l_fmt: 2371 2372 if (!cpu_has_mips_3_4_5_64_r2_r6) 2373 return SIGILL; 2374 2375 DIFROMREG(bits, MIPSInst_FS(ir)); 2376 2377 switch (MIPSInst_FUNC(ir)) { 2378 case fcvts_op: 2379 /* convert long to single precision real */ 2380 rv.s = ieee754sp_flong(bits); 2381 rfmt = s_fmt; 2382 goto copcsr; 2383 case fcvtd_op: 2384 /* convert long to double precision real */ 2385 rv.d = ieee754dp_flong(bits); 2386 rfmt = d_fmt; 2387 goto copcsr; 2388 default: { 2389 /* Emulating the new CMP.condn.fmt R6 instruction */ 2390 int cmpop = MIPSInst_FUNC(ir) & CMPOP_MASK; 2391 int sig = MIPSInst_FUNC(ir) & SIGN_BIT; 2392 union ieee754dp fs, ft; 2393 2394 if (!cpu_has_mips_r6 || 2395 (MIPSInst_FUNC(ir) & 0x20)) 2396 return SIGILL; 2397 2398 /* fmt is l_fmt for double precision so fix it */ 2399 rfmt = d_fmt; 2400 /* default to false */ 2401 rv.l = 0; 2402 2403 /* CMP.condn.D */ 2404 DPFROMREG(fs, MIPSInst_FS(ir)); 2405 DPFROMREG(ft, MIPSInst_FT(ir)); 2406 2407 /* positive predicates */ 2408 if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) { 2409 if (ieee754dp_cmp(fs, ft, 2410 cmptab[cmpop], sig)) 2411 rv.l = -1LL; /* true, all 1s */ 2412 if (sig && 2413 ieee754_cxtest(IEEE754_INVALID_OPERATION)) 2414 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S; 2415 else 2416 goto copcsr; 2417 } else { 2418 /* negative predicates */ 2419 switch (cmpop) { 2420 case 1: 2421 case 2: 2422 case 3: 2423 if (ieee754dp_cmp(fs, ft, 2424 negative_cmptab[cmpop], 2425 sig)) 2426 rv.l = -1LL; /* true, all 1s */ 2427 if (sig && 2428 ieee754_cxtest(IEEE754_INVALID_OPERATION)) 2429 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S; 2430 else 2431 goto copcsr; 2432 break; 2433 default: 2434 /* Reserved R6 ops */ 2435 pr_err("Reserved MIPS R6 CMP.condn.D operation\n"); 2436 return SIGILL; 2437 } 2438 } 2439 break; 2440 } 2441 } 2442 default: 2443 return SIGILL; 2444 } 2445 2446 /* 2447 * Update the fpu CSR register for this operation. 2448 * If an exception is required, generate a tidy SIGFPE exception, 2449 * without updating the result register. 2450 * Note: cause exception bits do not accumulate, they are rewritten 2451 * for each op; only the flag/sticky bits accumulate. 2452 */ 2453 ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr; 2454 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) { 2455 /*printk ("SIGFPE: FPU csr = %08x\n",ctx->fcr31); */ 2456 return SIGFPE; 2457 } 2458 2459 /* 2460 * Now we can safely write the result back to the register file. 2461 */ 2462 switch (rfmt) { 2463 case -1: 2464 2465 if (cpu_has_mips_4_5_r) 2466 cbit = fpucondbit[MIPSInst_FD(ir) >> 2]; 2467 else 2468 cbit = FPU_CSR_COND; 2469 if (rv.w) 2470 ctx->fcr31 |= cbit; 2471 else 2472 ctx->fcr31 &= ~cbit; 2473 break; 2474 2475 case d_fmt: 2476 DPTOREG(rv.d, MIPSInst_FD(ir)); 2477 break; 2478 case s_fmt: 2479 SPTOREG(rv.s, MIPSInst_FD(ir)); 2480 break; 2481 case w_fmt: 2482 SITOREG(rv.w, MIPSInst_FD(ir)); 2483 break; 2484 case l_fmt: 2485 if (!cpu_has_mips_3_4_5_64_r2_r6) 2486 return SIGILL; 2487 2488 DITOREG(rv.l, MIPSInst_FD(ir)); 2489 break; 2490 default: 2491 return SIGILL; 2492 } 2493 2494 return 0; 2495 } 2496 2497 int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx, 2498 int has_fpu, void *__user *fault_addr) 2499 { 2500 unsigned long oldepc, prevepc; 2501 struct mm_decoded_insn dec_insn; 2502 u16 instr[4]; 2503 u16 *instr_ptr; 2504 int sig = 0; 2505 2506 oldepc = xcp->cp0_epc; 2507 do { 2508 prevepc = xcp->cp0_epc; 2509 2510 if (get_isa16_mode(prevepc) && cpu_has_mmips) { 2511 /* 2512 * Get next 2 microMIPS instructions and convert them 2513 * into 32-bit instructions. 2514 */ 2515 if ((get_user(instr[0], (u16 __user *)msk_isa16_mode(xcp->cp0_epc))) || 2516 (get_user(instr[1], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 2))) || 2517 (get_user(instr[2], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 4))) || 2518 (get_user(instr[3], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 6)))) { 2519 MIPS_FPU_EMU_INC_STATS(errors); 2520 return SIGBUS; 2521 } 2522 instr_ptr = instr; 2523 2524 /* Get first instruction. */ 2525 if (mm_insn_16bit(*instr_ptr)) { 2526 /* Duplicate the half-word. */ 2527 dec_insn.insn = (*instr_ptr << 16) | 2528 (*instr_ptr); 2529 /* 16-bit instruction. */ 2530 dec_insn.pc_inc = 2; 2531 instr_ptr += 1; 2532 } else { 2533 dec_insn.insn = (*instr_ptr << 16) | 2534 *(instr_ptr+1); 2535 /* 32-bit instruction. */ 2536 dec_insn.pc_inc = 4; 2537 instr_ptr += 2; 2538 } 2539 /* Get second instruction. */ 2540 if (mm_insn_16bit(*instr_ptr)) { 2541 /* Duplicate the half-word. */ 2542 dec_insn.next_insn = (*instr_ptr << 16) | 2543 (*instr_ptr); 2544 /* 16-bit instruction. */ 2545 dec_insn.next_pc_inc = 2; 2546 } else { 2547 dec_insn.next_insn = (*instr_ptr << 16) | 2548 *(instr_ptr+1); 2549 /* 32-bit instruction. */ 2550 dec_insn.next_pc_inc = 4; 2551 } 2552 dec_insn.micro_mips_mode = 1; 2553 } else { 2554 if ((get_user(dec_insn.insn, 2555 (mips_instruction __user *) xcp->cp0_epc)) || 2556 (get_user(dec_insn.next_insn, 2557 (mips_instruction __user *)(xcp->cp0_epc+4)))) { 2558 MIPS_FPU_EMU_INC_STATS(errors); 2559 return SIGBUS; 2560 } 2561 dec_insn.pc_inc = 4; 2562 dec_insn.next_pc_inc = 4; 2563 dec_insn.micro_mips_mode = 0; 2564 } 2565 2566 if ((dec_insn.insn == 0) || 2567 ((dec_insn.pc_inc == 2) && 2568 ((dec_insn.insn & 0xffff) == MM_NOP16))) 2569 xcp->cp0_epc += dec_insn.pc_inc; /* Skip NOPs */ 2570 else { 2571 /* 2572 * The 'ieee754_csr' is an alias of ctx->fcr31. 2573 * No need to copy ctx->fcr31 to ieee754_csr. 2574 */ 2575 sig = cop1Emulate(xcp, ctx, dec_insn, fault_addr); 2576 } 2577 2578 if (has_fpu) 2579 break; 2580 if (sig) 2581 break; 2582 2583 cond_resched(); 2584 } while (xcp->cp0_epc > prevepc); 2585 2586 /* SIGILL indicates a non-fpu instruction */ 2587 if (sig == SIGILL && xcp->cp0_epc != oldepc) 2588 /* but if EPC has advanced, then ignore it */ 2589 sig = 0; 2590 2591 return sig; 2592 } 2593