1 /* 2 * cp1emu.c: a MIPS coprocessor 1 (FPU) instruction emulator 3 * 4 * MIPS floating point support 5 * Copyright (C) 1994-2000 Algorithmics Ltd. 6 * 7 * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com 8 * Copyright (C) 2000 MIPS Technologies, Inc. 9 * 10 * This program is free software; you can distribute it and/or modify it 11 * under the terms of the GNU General Public License (Version 2) as 12 * published by the Free Software Foundation. 13 * 14 * This program is distributed in the hope it will be useful, but WITHOUT 15 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 16 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 17 * for more details. 18 * 19 * You should have received a copy of the GNU General Public License along 20 * with this program; if not, write to the Free Software Foundation, Inc., 21 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 22 * 23 * A complete emulator for MIPS coprocessor 1 instructions. This is 24 * required for #float(switch) or #float(trap), where it catches all 25 * COP1 instructions via the "CoProcessor Unusable" exception. 26 * 27 * More surprisingly it is also required for #float(ieee), to help out 28 * the hardware FPU at the boundaries of the IEEE-754 representation 29 * (denormalised values, infinities, underflow, etc). It is made 30 * quite nasty because emulation of some non-COP1 instructions is 31 * required, e.g. in branch delay slots. 32 * 33 * Note if you know that you won't have an FPU, then you'll get much 34 * better performance by compiling with -msoft-float! 35 */ 36 #include <linux/sched.h> 37 #include <linux/debugfs.h> 38 #include <linux/percpu-defs.h> 39 #include <linux/perf_event.h> 40 41 #include <asm/branch.h> 42 #include <asm/inst.h> 43 #include <asm/ptrace.h> 44 #include <asm/signal.h> 45 #include <linux/uaccess.h> 46 47 #include <asm/cpu-info.h> 48 #include <asm/processor.h> 49 #include <asm/fpu_emulator.h> 50 #include <asm/fpu.h> 51 #include <asm/mips-r2-to-r6-emul.h> 52 53 #include "ieee754.h" 54 55 /* Function which emulates a floating point instruction. */ 56 57 static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *, 58 mips_instruction); 59 60 static int fpux_emu(struct pt_regs *, 61 struct mips_fpu_struct *, mips_instruction, void *__user *); 62 63 /* Control registers */ 64 65 #define FPCREG_RID 0 /* $0 = revision id */ 66 #define FPCREG_FCCR 25 /* $25 = fccr */ 67 #define FPCREG_FEXR 26 /* $26 = fexr */ 68 #define FPCREG_FENR 28 /* $28 = fenr */ 69 #define FPCREG_CSR 31 /* $31 = csr */ 70 71 /* convert condition code register number to csr bit */ 72 const unsigned int fpucondbit[8] = { 73 FPU_CSR_COND, 74 FPU_CSR_COND1, 75 FPU_CSR_COND2, 76 FPU_CSR_COND3, 77 FPU_CSR_COND4, 78 FPU_CSR_COND5, 79 FPU_CSR_COND6, 80 FPU_CSR_COND7 81 }; 82 83 /* (microMIPS) Convert certain microMIPS instructions to MIPS32 format. */ 84 static const int sd_format[] = {16, 17, 0, 0, 0, 0, 0, 0}; 85 static const int sdps_format[] = {16, 17, 22, 0, 0, 0, 0, 0}; 86 static const int dwl_format[] = {17, 20, 21, 0, 0, 0, 0, 0}; 87 static const int swl_format[] = {16, 20, 21, 0, 0, 0, 0, 0}; 88 89 /* 90 * This functions translates a 32-bit microMIPS instruction 91 * into a 32-bit MIPS32 instruction. Returns 0 on success 92 * and SIGILL otherwise. 93 */ 94 static int microMIPS32_to_MIPS32(union mips_instruction *insn_ptr) 95 { 96 union mips_instruction insn = *insn_ptr; 97 union mips_instruction mips32_insn = insn; 98 int func, fmt, op; 99 100 switch (insn.mm_i_format.opcode) { 101 case mm_ldc132_op: 102 mips32_insn.mm_i_format.opcode = ldc1_op; 103 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs; 104 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt; 105 break; 106 case mm_lwc132_op: 107 mips32_insn.mm_i_format.opcode = lwc1_op; 108 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs; 109 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt; 110 break; 111 case mm_sdc132_op: 112 mips32_insn.mm_i_format.opcode = sdc1_op; 113 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs; 114 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt; 115 break; 116 case mm_swc132_op: 117 mips32_insn.mm_i_format.opcode = swc1_op; 118 mips32_insn.mm_i_format.rt = insn.mm_i_format.rs; 119 mips32_insn.mm_i_format.rs = insn.mm_i_format.rt; 120 break; 121 case mm_pool32i_op: 122 /* NOTE: offset is << by 1 if in microMIPS mode. */ 123 if ((insn.mm_i_format.rt == mm_bc1f_op) || 124 (insn.mm_i_format.rt == mm_bc1t_op)) { 125 mips32_insn.fb_format.opcode = cop1_op; 126 mips32_insn.fb_format.bc = bc_op; 127 mips32_insn.fb_format.flag = 128 (insn.mm_i_format.rt == mm_bc1t_op) ? 1 : 0; 129 } else 130 return SIGILL; 131 break; 132 case mm_pool32f_op: 133 switch (insn.mm_fp0_format.func) { 134 case mm_32f_01_op: 135 case mm_32f_11_op: 136 case mm_32f_02_op: 137 case mm_32f_12_op: 138 case mm_32f_41_op: 139 case mm_32f_51_op: 140 case mm_32f_42_op: 141 case mm_32f_52_op: 142 op = insn.mm_fp0_format.func; 143 if (op == mm_32f_01_op) 144 func = madd_s_op; 145 else if (op == mm_32f_11_op) 146 func = madd_d_op; 147 else if (op == mm_32f_02_op) 148 func = nmadd_s_op; 149 else if (op == mm_32f_12_op) 150 func = nmadd_d_op; 151 else if (op == mm_32f_41_op) 152 func = msub_s_op; 153 else if (op == mm_32f_51_op) 154 func = msub_d_op; 155 else if (op == mm_32f_42_op) 156 func = nmsub_s_op; 157 else 158 func = nmsub_d_op; 159 mips32_insn.fp6_format.opcode = cop1x_op; 160 mips32_insn.fp6_format.fr = insn.mm_fp6_format.fr; 161 mips32_insn.fp6_format.ft = insn.mm_fp6_format.ft; 162 mips32_insn.fp6_format.fs = insn.mm_fp6_format.fs; 163 mips32_insn.fp6_format.fd = insn.mm_fp6_format.fd; 164 mips32_insn.fp6_format.func = func; 165 break; 166 case mm_32f_10_op: 167 func = -1; /* Invalid */ 168 op = insn.mm_fp5_format.op & 0x7; 169 if (op == mm_ldxc1_op) 170 func = ldxc1_op; 171 else if (op == mm_sdxc1_op) 172 func = sdxc1_op; 173 else if (op == mm_lwxc1_op) 174 func = lwxc1_op; 175 else if (op == mm_swxc1_op) 176 func = swxc1_op; 177 178 if (func != -1) { 179 mips32_insn.r_format.opcode = cop1x_op; 180 mips32_insn.r_format.rs = 181 insn.mm_fp5_format.base; 182 mips32_insn.r_format.rt = 183 insn.mm_fp5_format.index; 184 mips32_insn.r_format.rd = 0; 185 mips32_insn.r_format.re = insn.mm_fp5_format.fd; 186 mips32_insn.r_format.func = func; 187 } else 188 return SIGILL; 189 break; 190 case mm_32f_40_op: 191 op = -1; /* Invalid */ 192 if (insn.mm_fp2_format.op == mm_fmovt_op) 193 op = 1; 194 else if (insn.mm_fp2_format.op == mm_fmovf_op) 195 op = 0; 196 if (op != -1) { 197 mips32_insn.fp0_format.opcode = cop1_op; 198 mips32_insn.fp0_format.fmt = 199 sdps_format[insn.mm_fp2_format.fmt]; 200 mips32_insn.fp0_format.ft = 201 (insn.mm_fp2_format.cc<<2) + op; 202 mips32_insn.fp0_format.fs = 203 insn.mm_fp2_format.fs; 204 mips32_insn.fp0_format.fd = 205 insn.mm_fp2_format.fd; 206 mips32_insn.fp0_format.func = fmovc_op; 207 } else 208 return SIGILL; 209 break; 210 case mm_32f_60_op: 211 func = -1; /* Invalid */ 212 if (insn.mm_fp0_format.op == mm_fadd_op) 213 func = fadd_op; 214 else if (insn.mm_fp0_format.op == mm_fsub_op) 215 func = fsub_op; 216 else if (insn.mm_fp0_format.op == mm_fmul_op) 217 func = fmul_op; 218 else if (insn.mm_fp0_format.op == mm_fdiv_op) 219 func = fdiv_op; 220 if (func != -1) { 221 mips32_insn.fp0_format.opcode = cop1_op; 222 mips32_insn.fp0_format.fmt = 223 sdps_format[insn.mm_fp0_format.fmt]; 224 mips32_insn.fp0_format.ft = 225 insn.mm_fp0_format.ft; 226 mips32_insn.fp0_format.fs = 227 insn.mm_fp0_format.fs; 228 mips32_insn.fp0_format.fd = 229 insn.mm_fp0_format.fd; 230 mips32_insn.fp0_format.func = func; 231 } else 232 return SIGILL; 233 break; 234 case mm_32f_70_op: 235 func = -1; /* Invalid */ 236 if (insn.mm_fp0_format.op == mm_fmovn_op) 237 func = fmovn_op; 238 else if (insn.mm_fp0_format.op == mm_fmovz_op) 239 func = fmovz_op; 240 if (func != -1) { 241 mips32_insn.fp0_format.opcode = cop1_op; 242 mips32_insn.fp0_format.fmt = 243 sdps_format[insn.mm_fp0_format.fmt]; 244 mips32_insn.fp0_format.ft = 245 insn.mm_fp0_format.ft; 246 mips32_insn.fp0_format.fs = 247 insn.mm_fp0_format.fs; 248 mips32_insn.fp0_format.fd = 249 insn.mm_fp0_format.fd; 250 mips32_insn.fp0_format.func = func; 251 } else 252 return SIGILL; 253 break; 254 case mm_32f_73_op: /* POOL32FXF */ 255 switch (insn.mm_fp1_format.op) { 256 case mm_movf0_op: 257 case mm_movf1_op: 258 case mm_movt0_op: 259 case mm_movt1_op: 260 if ((insn.mm_fp1_format.op & 0x7f) == 261 mm_movf0_op) 262 op = 0; 263 else 264 op = 1; 265 mips32_insn.r_format.opcode = spec_op; 266 mips32_insn.r_format.rs = insn.mm_fp4_format.fs; 267 mips32_insn.r_format.rt = 268 (insn.mm_fp4_format.cc << 2) + op; 269 mips32_insn.r_format.rd = insn.mm_fp4_format.rt; 270 mips32_insn.r_format.re = 0; 271 mips32_insn.r_format.func = movc_op; 272 break; 273 case mm_fcvtd0_op: 274 case mm_fcvtd1_op: 275 case mm_fcvts0_op: 276 case mm_fcvts1_op: 277 if ((insn.mm_fp1_format.op & 0x7f) == 278 mm_fcvtd0_op) { 279 func = fcvtd_op; 280 fmt = swl_format[insn.mm_fp3_format.fmt]; 281 } else { 282 func = fcvts_op; 283 fmt = dwl_format[insn.mm_fp3_format.fmt]; 284 } 285 mips32_insn.fp0_format.opcode = cop1_op; 286 mips32_insn.fp0_format.fmt = fmt; 287 mips32_insn.fp0_format.ft = 0; 288 mips32_insn.fp0_format.fs = 289 insn.mm_fp3_format.fs; 290 mips32_insn.fp0_format.fd = 291 insn.mm_fp3_format.rt; 292 mips32_insn.fp0_format.func = func; 293 break; 294 case mm_fmov0_op: 295 case mm_fmov1_op: 296 case mm_fabs0_op: 297 case mm_fabs1_op: 298 case mm_fneg0_op: 299 case mm_fneg1_op: 300 if ((insn.mm_fp1_format.op & 0x7f) == 301 mm_fmov0_op) 302 func = fmov_op; 303 else if ((insn.mm_fp1_format.op & 0x7f) == 304 mm_fabs0_op) 305 func = fabs_op; 306 else 307 func = fneg_op; 308 mips32_insn.fp0_format.opcode = cop1_op; 309 mips32_insn.fp0_format.fmt = 310 sdps_format[insn.mm_fp3_format.fmt]; 311 mips32_insn.fp0_format.ft = 0; 312 mips32_insn.fp0_format.fs = 313 insn.mm_fp3_format.fs; 314 mips32_insn.fp0_format.fd = 315 insn.mm_fp3_format.rt; 316 mips32_insn.fp0_format.func = func; 317 break; 318 case mm_ffloorl_op: 319 case mm_ffloorw_op: 320 case mm_fceill_op: 321 case mm_fceilw_op: 322 case mm_ftruncl_op: 323 case mm_ftruncw_op: 324 case mm_froundl_op: 325 case mm_froundw_op: 326 case mm_fcvtl_op: 327 case mm_fcvtw_op: 328 if (insn.mm_fp1_format.op == mm_ffloorl_op) 329 func = ffloorl_op; 330 else if (insn.mm_fp1_format.op == mm_ffloorw_op) 331 func = ffloor_op; 332 else if (insn.mm_fp1_format.op == mm_fceill_op) 333 func = fceill_op; 334 else if (insn.mm_fp1_format.op == mm_fceilw_op) 335 func = fceil_op; 336 else if (insn.mm_fp1_format.op == mm_ftruncl_op) 337 func = ftruncl_op; 338 else if (insn.mm_fp1_format.op == mm_ftruncw_op) 339 func = ftrunc_op; 340 else if (insn.mm_fp1_format.op == mm_froundl_op) 341 func = froundl_op; 342 else if (insn.mm_fp1_format.op == mm_froundw_op) 343 func = fround_op; 344 else if (insn.mm_fp1_format.op == mm_fcvtl_op) 345 func = fcvtl_op; 346 else 347 func = fcvtw_op; 348 mips32_insn.fp0_format.opcode = cop1_op; 349 mips32_insn.fp0_format.fmt = 350 sd_format[insn.mm_fp1_format.fmt]; 351 mips32_insn.fp0_format.ft = 0; 352 mips32_insn.fp0_format.fs = 353 insn.mm_fp1_format.fs; 354 mips32_insn.fp0_format.fd = 355 insn.mm_fp1_format.rt; 356 mips32_insn.fp0_format.func = func; 357 break; 358 case mm_frsqrt_op: 359 case mm_fsqrt_op: 360 case mm_frecip_op: 361 if (insn.mm_fp1_format.op == mm_frsqrt_op) 362 func = frsqrt_op; 363 else if (insn.mm_fp1_format.op == mm_fsqrt_op) 364 func = fsqrt_op; 365 else 366 func = frecip_op; 367 mips32_insn.fp0_format.opcode = cop1_op; 368 mips32_insn.fp0_format.fmt = 369 sdps_format[insn.mm_fp1_format.fmt]; 370 mips32_insn.fp0_format.ft = 0; 371 mips32_insn.fp0_format.fs = 372 insn.mm_fp1_format.fs; 373 mips32_insn.fp0_format.fd = 374 insn.mm_fp1_format.rt; 375 mips32_insn.fp0_format.func = func; 376 break; 377 case mm_mfc1_op: 378 case mm_mtc1_op: 379 case mm_cfc1_op: 380 case mm_ctc1_op: 381 case mm_mfhc1_op: 382 case mm_mthc1_op: 383 if (insn.mm_fp1_format.op == mm_mfc1_op) 384 op = mfc_op; 385 else if (insn.mm_fp1_format.op == mm_mtc1_op) 386 op = mtc_op; 387 else if (insn.mm_fp1_format.op == mm_cfc1_op) 388 op = cfc_op; 389 else if (insn.mm_fp1_format.op == mm_ctc1_op) 390 op = ctc_op; 391 else if (insn.mm_fp1_format.op == mm_mfhc1_op) 392 op = mfhc_op; 393 else 394 op = mthc_op; 395 mips32_insn.fp1_format.opcode = cop1_op; 396 mips32_insn.fp1_format.op = op; 397 mips32_insn.fp1_format.rt = 398 insn.mm_fp1_format.rt; 399 mips32_insn.fp1_format.fs = 400 insn.mm_fp1_format.fs; 401 mips32_insn.fp1_format.fd = 0; 402 mips32_insn.fp1_format.func = 0; 403 break; 404 default: 405 return SIGILL; 406 } 407 break; 408 case mm_32f_74_op: /* c.cond.fmt */ 409 mips32_insn.fp0_format.opcode = cop1_op; 410 mips32_insn.fp0_format.fmt = 411 sdps_format[insn.mm_fp4_format.fmt]; 412 mips32_insn.fp0_format.ft = insn.mm_fp4_format.rt; 413 mips32_insn.fp0_format.fs = insn.mm_fp4_format.fs; 414 mips32_insn.fp0_format.fd = insn.mm_fp4_format.cc << 2; 415 mips32_insn.fp0_format.func = 416 insn.mm_fp4_format.cond | MM_MIPS32_COND_FC; 417 break; 418 default: 419 return SIGILL; 420 } 421 break; 422 default: 423 return SIGILL; 424 } 425 426 *insn_ptr = mips32_insn; 427 return 0; 428 } 429 430 /* 431 * Redundant with logic already in kernel/branch.c, 432 * embedded in compute_return_epc. At some point, 433 * a single subroutine should be used across both 434 * modules. 435 */ 436 int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn, 437 unsigned long *contpc) 438 { 439 union mips_instruction insn = (union mips_instruction)dec_insn.insn; 440 unsigned int fcr31; 441 unsigned int bit = 0; 442 unsigned int bit0; 443 union fpureg *fpr; 444 445 switch (insn.i_format.opcode) { 446 case spec_op: 447 switch (insn.r_format.func) { 448 case jalr_op: 449 if (insn.r_format.rd != 0) { 450 regs->regs[insn.r_format.rd] = 451 regs->cp0_epc + dec_insn.pc_inc + 452 dec_insn.next_pc_inc; 453 } 454 /* Fall through */ 455 case jr_op: 456 /* For R6, JR already emulated in jalr_op */ 457 if (NO_R6EMU && insn.r_format.func == jr_op) 458 break; 459 *contpc = regs->regs[insn.r_format.rs]; 460 return 1; 461 } 462 break; 463 case bcond_op: 464 switch (insn.i_format.rt) { 465 case bltzal_op: 466 case bltzall_op: 467 if (NO_R6EMU && (insn.i_format.rs || 468 insn.i_format.rt == bltzall_op)) 469 break; 470 471 regs->regs[31] = regs->cp0_epc + 472 dec_insn.pc_inc + 473 dec_insn.next_pc_inc; 474 /* Fall through */ 475 case bltzl_op: 476 if (NO_R6EMU) 477 break; 478 case bltz_op: 479 if ((long)regs->regs[insn.i_format.rs] < 0) 480 *contpc = regs->cp0_epc + 481 dec_insn.pc_inc + 482 (insn.i_format.simmediate << 2); 483 else 484 *contpc = regs->cp0_epc + 485 dec_insn.pc_inc + 486 dec_insn.next_pc_inc; 487 return 1; 488 case bgezal_op: 489 case bgezall_op: 490 if (NO_R6EMU && (insn.i_format.rs || 491 insn.i_format.rt == bgezall_op)) 492 break; 493 494 regs->regs[31] = regs->cp0_epc + 495 dec_insn.pc_inc + 496 dec_insn.next_pc_inc; 497 /* Fall through */ 498 case bgezl_op: 499 if (NO_R6EMU) 500 break; 501 case bgez_op: 502 if ((long)regs->regs[insn.i_format.rs] >= 0) 503 *contpc = regs->cp0_epc + 504 dec_insn.pc_inc + 505 (insn.i_format.simmediate << 2); 506 else 507 *contpc = regs->cp0_epc + 508 dec_insn.pc_inc + 509 dec_insn.next_pc_inc; 510 return 1; 511 } 512 break; 513 case jalx_op: 514 set_isa16_mode(bit); 515 case jal_op: 516 regs->regs[31] = regs->cp0_epc + 517 dec_insn.pc_inc + 518 dec_insn.next_pc_inc; 519 /* Fall through */ 520 case j_op: 521 *contpc = regs->cp0_epc + dec_insn.pc_inc; 522 *contpc >>= 28; 523 *contpc <<= 28; 524 *contpc |= (insn.j_format.target << 2); 525 /* Set microMIPS mode bit: XOR for jalx. */ 526 *contpc ^= bit; 527 return 1; 528 case beql_op: 529 if (NO_R6EMU) 530 break; 531 case beq_op: 532 if (regs->regs[insn.i_format.rs] == 533 regs->regs[insn.i_format.rt]) 534 *contpc = regs->cp0_epc + 535 dec_insn.pc_inc + 536 (insn.i_format.simmediate << 2); 537 else 538 *contpc = regs->cp0_epc + 539 dec_insn.pc_inc + 540 dec_insn.next_pc_inc; 541 return 1; 542 case bnel_op: 543 if (NO_R6EMU) 544 break; 545 case bne_op: 546 if (regs->regs[insn.i_format.rs] != 547 regs->regs[insn.i_format.rt]) 548 *contpc = regs->cp0_epc + 549 dec_insn.pc_inc + 550 (insn.i_format.simmediate << 2); 551 else 552 *contpc = regs->cp0_epc + 553 dec_insn.pc_inc + 554 dec_insn.next_pc_inc; 555 return 1; 556 case blezl_op: 557 if (!insn.i_format.rt && NO_R6EMU) 558 break; 559 case blez_op: 560 561 /* 562 * Compact branches for R6 for the 563 * blez and blezl opcodes. 564 * BLEZ | rs = 0 | rt != 0 == BLEZALC 565 * BLEZ | rs = rt != 0 == BGEZALC 566 * BLEZ | rs != 0 | rt != 0 == BGEUC 567 * BLEZL | rs = 0 | rt != 0 == BLEZC 568 * BLEZL | rs = rt != 0 == BGEZC 569 * BLEZL | rs != 0 | rt != 0 == BGEC 570 * 571 * For real BLEZ{,L}, rt is always 0. 572 */ 573 if (cpu_has_mips_r6 && insn.i_format.rt) { 574 if ((insn.i_format.opcode == blez_op) && 575 ((!insn.i_format.rs && insn.i_format.rt) || 576 (insn.i_format.rs == insn.i_format.rt))) 577 regs->regs[31] = regs->cp0_epc + 578 dec_insn.pc_inc; 579 *contpc = regs->cp0_epc + dec_insn.pc_inc + 580 dec_insn.next_pc_inc; 581 582 return 1; 583 } 584 if ((long)regs->regs[insn.i_format.rs] <= 0) 585 *contpc = regs->cp0_epc + 586 dec_insn.pc_inc + 587 (insn.i_format.simmediate << 2); 588 else 589 *contpc = regs->cp0_epc + 590 dec_insn.pc_inc + 591 dec_insn.next_pc_inc; 592 return 1; 593 case bgtzl_op: 594 if (!insn.i_format.rt && NO_R6EMU) 595 break; 596 case bgtz_op: 597 /* 598 * Compact branches for R6 for the 599 * bgtz and bgtzl opcodes. 600 * BGTZ | rs = 0 | rt != 0 == BGTZALC 601 * BGTZ | rs = rt != 0 == BLTZALC 602 * BGTZ | rs != 0 | rt != 0 == BLTUC 603 * BGTZL | rs = 0 | rt != 0 == BGTZC 604 * BGTZL | rs = rt != 0 == BLTZC 605 * BGTZL | rs != 0 | rt != 0 == BLTC 606 * 607 * *ZALC varint for BGTZ &&& rt != 0 608 * For real GTZ{,L}, rt is always 0. 609 */ 610 if (cpu_has_mips_r6 && insn.i_format.rt) { 611 if ((insn.i_format.opcode == blez_op) && 612 ((!insn.i_format.rs && insn.i_format.rt) || 613 (insn.i_format.rs == insn.i_format.rt))) 614 regs->regs[31] = regs->cp0_epc + 615 dec_insn.pc_inc; 616 *contpc = regs->cp0_epc + dec_insn.pc_inc + 617 dec_insn.next_pc_inc; 618 619 return 1; 620 } 621 622 if ((long)regs->regs[insn.i_format.rs] > 0) 623 *contpc = regs->cp0_epc + 624 dec_insn.pc_inc + 625 (insn.i_format.simmediate << 2); 626 else 627 *contpc = regs->cp0_epc + 628 dec_insn.pc_inc + 629 dec_insn.next_pc_inc; 630 return 1; 631 case pop10_op: 632 case pop30_op: 633 if (!cpu_has_mips_r6) 634 break; 635 if (insn.i_format.rt && !insn.i_format.rs) 636 regs->regs[31] = regs->cp0_epc + 4; 637 *contpc = regs->cp0_epc + dec_insn.pc_inc + 638 dec_insn.next_pc_inc; 639 640 return 1; 641 #ifdef CONFIG_CPU_CAVIUM_OCTEON 642 case lwc2_op: /* This is bbit0 on Octeon */ 643 if ((regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) == 0) 644 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2); 645 else 646 *contpc = regs->cp0_epc + 8; 647 return 1; 648 case ldc2_op: /* This is bbit032 on Octeon */ 649 if ((regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32))) == 0) 650 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2); 651 else 652 *contpc = regs->cp0_epc + 8; 653 return 1; 654 case swc2_op: /* This is bbit1 on Octeon */ 655 if (regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) 656 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2); 657 else 658 *contpc = regs->cp0_epc + 8; 659 return 1; 660 case sdc2_op: /* This is bbit132 on Octeon */ 661 if (regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32))) 662 *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2); 663 else 664 *contpc = regs->cp0_epc + 8; 665 return 1; 666 #else 667 case bc6_op: 668 /* 669 * Only valid for MIPS R6 but we can still end up 670 * here from a broken userland so just tell emulator 671 * this is not a branch and let it break later on. 672 */ 673 if (!cpu_has_mips_r6) 674 break; 675 *contpc = regs->cp0_epc + dec_insn.pc_inc + 676 dec_insn.next_pc_inc; 677 678 return 1; 679 case balc6_op: 680 if (!cpu_has_mips_r6) 681 break; 682 regs->regs[31] = regs->cp0_epc + 4; 683 *contpc = regs->cp0_epc + dec_insn.pc_inc + 684 dec_insn.next_pc_inc; 685 686 return 1; 687 case pop66_op: 688 if (!cpu_has_mips_r6) 689 break; 690 *contpc = regs->cp0_epc + dec_insn.pc_inc + 691 dec_insn.next_pc_inc; 692 693 return 1; 694 case pop76_op: 695 if (!cpu_has_mips_r6) 696 break; 697 if (!insn.i_format.rs) 698 regs->regs[31] = regs->cp0_epc + 4; 699 *contpc = regs->cp0_epc + dec_insn.pc_inc + 700 dec_insn.next_pc_inc; 701 702 return 1; 703 #endif 704 case cop0_op: 705 case cop1_op: 706 /* Need to check for R6 bc1nez and bc1eqz branches */ 707 if (cpu_has_mips_r6 && 708 ((insn.i_format.rs == bc1eqz_op) || 709 (insn.i_format.rs == bc1nez_op))) { 710 bit = 0; 711 fpr = ¤t->thread.fpu.fpr[insn.i_format.rt]; 712 bit0 = get_fpr32(fpr, 0) & 0x1; 713 switch (insn.i_format.rs) { 714 case bc1eqz_op: 715 bit = bit0 == 0; 716 break; 717 case bc1nez_op: 718 bit = bit0 != 0; 719 break; 720 } 721 if (bit) 722 *contpc = regs->cp0_epc + 723 dec_insn.pc_inc + 724 (insn.i_format.simmediate << 2); 725 else 726 *contpc = regs->cp0_epc + 727 dec_insn.pc_inc + 728 dec_insn.next_pc_inc; 729 730 return 1; 731 } 732 /* R2/R6 compatible cop1 instruction. Fall through */ 733 case cop2_op: 734 case cop1x_op: 735 if (insn.i_format.rs == bc_op) { 736 preempt_disable(); 737 if (is_fpu_owner()) 738 fcr31 = read_32bit_cp1_register(CP1_STATUS); 739 else 740 fcr31 = current->thread.fpu.fcr31; 741 preempt_enable(); 742 743 bit = (insn.i_format.rt >> 2); 744 bit += (bit != 0); 745 bit += 23; 746 switch (insn.i_format.rt & 3) { 747 case 0: /* bc1f */ 748 case 2: /* bc1fl */ 749 if (~fcr31 & (1 << bit)) 750 *contpc = regs->cp0_epc + 751 dec_insn.pc_inc + 752 (insn.i_format.simmediate << 2); 753 else 754 *contpc = regs->cp0_epc + 755 dec_insn.pc_inc + 756 dec_insn.next_pc_inc; 757 return 1; 758 case 1: /* bc1t */ 759 case 3: /* bc1tl */ 760 if (fcr31 & (1 << bit)) 761 *contpc = regs->cp0_epc + 762 dec_insn.pc_inc + 763 (insn.i_format.simmediate << 2); 764 else 765 *contpc = regs->cp0_epc + 766 dec_insn.pc_inc + 767 dec_insn.next_pc_inc; 768 return 1; 769 } 770 } 771 break; 772 } 773 return 0; 774 } 775 776 /* 777 * In the Linux kernel, we support selection of FPR format on the 778 * basis of the Status.FR bit. If an FPU is not present, the FR bit 779 * is hardwired to zero, which would imply a 32-bit FPU even for 780 * 64-bit CPUs so we rather look at TIF_32BIT_FPREGS. 781 * FPU emu is slow and bulky and optimizing this function offers fairly 782 * sizeable benefits so we try to be clever and make this function return 783 * a constant whenever possible, that is on 64-bit kernels without O32 784 * compatibility enabled and on 32-bit without 64-bit FPU support. 785 */ 786 static inline int cop1_64bit(struct pt_regs *xcp) 787 { 788 if (IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_MIPS32_O32)) 789 return 1; 790 else if (IS_ENABLED(CONFIG_32BIT) && 791 !IS_ENABLED(CONFIG_MIPS_O32_FP64_SUPPORT)) 792 return 0; 793 794 return !test_thread_flag(TIF_32BIT_FPREGS); 795 } 796 797 static inline bool hybrid_fprs(void) 798 { 799 return test_thread_flag(TIF_HYBRID_FPREGS); 800 } 801 802 #define SIFROMREG(si, x) \ 803 do { \ 804 if (cop1_64bit(xcp) && !hybrid_fprs()) \ 805 (si) = (int)get_fpr32(&ctx->fpr[x], 0); \ 806 else \ 807 (si) = (int)get_fpr32(&ctx->fpr[(x) & ~1], (x) & 1); \ 808 } while (0) 809 810 #define SITOREG(si, x) \ 811 do { \ 812 if (cop1_64bit(xcp) && !hybrid_fprs()) { \ 813 unsigned i; \ 814 set_fpr32(&ctx->fpr[x], 0, si); \ 815 for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val32); i++) \ 816 set_fpr32(&ctx->fpr[x], i, 0); \ 817 } else { \ 818 set_fpr32(&ctx->fpr[(x) & ~1], (x) & 1, si); \ 819 } \ 820 } while (0) 821 822 #define SIFROMHREG(si, x) ((si) = (int)get_fpr32(&ctx->fpr[x], 1)) 823 824 #define SITOHREG(si, x) \ 825 do { \ 826 unsigned i; \ 827 set_fpr32(&ctx->fpr[x], 1, si); \ 828 for (i = 2; i < ARRAY_SIZE(ctx->fpr[x].val32); i++) \ 829 set_fpr32(&ctx->fpr[x], i, 0); \ 830 } while (0) 831 832 #define DIFROMREG(di, x) \ 833 ((di) = get_fpr64(&ctx->fpr[(x) & ~(cop1_64bit(xcp) == 0)], 0)) 834 835 #define DITOREG(di, x) \ 836 do { \ 837 unsigned fpr, i; \ 838 fpr = (x) & ~(cop1_64bit(xcp) == 0); \ 839 set_fpr64(&ctx->fpr[fpr], 0, di); \ 840 for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val64); i++) \ 841 set_fpr64(&ctx->fpr[fpr], i, 0); \ 842 } while (0) 843 844 #define SPFROMREG(sp, x) SIFROMREG((sp).bits, x) 845 #define SPTOREG(sp, x) SITOREG((sp).bits, x) 846 #define DPFROMREG(dp, x) DIFROMREG((dp).bits, x) 847 #define DPTOREG(dp, x) DITOREG((dp).bits, x) 848 849 /* 850 * Emulate a CFC1 instruction. 851 */ 852 static inline void cop1_cfc(struct pt_regs *xcp, struct mips_fpu_struct *ctx, 853 mips_instruction ir) 854 { 855 u32 fcr31 = ctx->fcr31; 856 u32 value = 0; 857 858 switch (MIPSInst_RD(ir)) { 859 case FPCREG_CSR: 860 value = fcr31; 861 pr_debug("%p gpr[%d]<-csr=%08x\n", 862 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); 863 break; 864 865 case FPCREG_FENR: 866 if (!cpu_has_mips_r) 867 break; 868 value = (fcr31 >> (FPU_CSR_FS_S - MIPS_FENR_FS_S)) & 869 MIPS_FENR_FS; 870 value |= fcr31 & (FPU_CSR_ALL_E | FPU_CSR_RM); 871 pr_debug("%p gpr[%d]<-enr=%08x\n", 872 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); 873 break; 874 875 case FPCREG_FEXR: 876 if (!cpu_has_mips_r) 877 break; 878 value = fcr31 & (FPU_CSR_ALL_X | FPU_CSR_ALL_S); 879 pr_debug("%p gpr[%d]<-exr=%08x\n", 880 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); 881 break; 882 883 case FPCREG_FCCR: 884 if (!cpu_has_mips_r) 885 break; 886 value = (fcr31 >> (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) & 887 MIPS_FCCR_COND0; 888 value |= (fcr31 >> (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) & 889 (MIPS_FCCR_CONDX & ~MIPS_FCCR_COND0); 890 pr_debug("%p gpr[%d]<-ccr=%08x\n", 891 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); 892 break; 893 894 case FPCREG_RID: 895 value = boot_cpu_data.fpu_id; 896 break; 897 898 default: 899 break; 900 } 901 902 if (MIPSInst_RT(ir)) 903 xcp->regs[MIPSInst_RT(ir)] = value; 904 } 905 906 /* 907 * Emulate a CTC1 instruction. 908 */ 909 static inline void cop1_ctc(struct pt_regs *xcp, struct mips_fpu_struct *ctx, 910 mips_instruction ir) 911 { 912 u32 fcr31 = ctx->fcr31; 913 u32 value; 914 u32 mask; 915 916 if (MIPSInst_RT(ir) == 0) 917 value = 0; 918 else 919 value = xcp->regs[MIPSInst_RT(ir)]; 920 921 switch (MIPSInst_RD(ir)) { 922 case FPCREG_CSR: 923 pr_debug("%p gpr[%d]->csr=%08x\n", 924 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); 925 926 /* Preserve read-only bits. */ 927 mask = boot_cpu_data.fpu_msk31; 928 fcr31 = (value & ~mask) | (fcr31 & mask); 929 break; 930 931 case FPCREG_FENR: 932 if (!cpu_has_mips_r) 933 break; 934 pr_debug("%p gpr[%d]->enr=%08x\n", 935 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); 936 fcr31 &= ~(FPU_CSR_FS | FPU_CSR_ALL_E | FPU_CSR_RM); 937 fcr31 |= (value << (FPU_CSR_FS_S - MIPS_FENR_FS_S)) & 938 FPU_CSR_FS; 939 fcr31 |= value & (FPU_CSR_ALL_E | FPU_CSR_RM); 940 break; 941 942 case FPCREG_FEXR: 943 if (!cpu_has_mips_r) 944 break; 945 pr_debug("%p gpr[%d]->exr=%08x\n", 946 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); 947 fcr31 &= ~(FPU_CSR_ALL_X | FPU_CSR_ALL_S); 948 fcr31 |= value & (FPU_CSR_ALL_X | FPU_CSR_ALL_S); 949 break; 950 951 case FPCREG_FCCR: 952 if (!cpu_has_mips_r) 953 break; 954 pr_debug("%p gpr[%d]->ccr=%08x\n", 955 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); 956 fcr31 &= ~(FPU_CSR_CONDX | FPU_CSR_COND); 957 fcr31 |= (value << (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) & 958 FPU_CSR_COND; 959 fcr31 |= (value << (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) & 960 FPU_CSR_CONDX; 961 break; 962 963 default: 964 break; 965 } 966 967 ctx->fcr31 = fcr31; 968 } 969 970 /* 971 * Emulate the single floating point instruction pointed at by EPC. 972 * Two instructions if the instruction is in a branch delay slot. 973 */ 974 975 static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx, 976 struct mm_decoded_insn dec_insn, void *__user *fault_addr) 977 { 978 unsigned long contpc = xcp->cp0_epc + dec_insn.pc_inc; 979 unsigned int cond, cbit, bit0; 980 mips_instruction ir; 981 int likely, pc_inc; 982 union fpureg *fpr; 983 u32 __user *wva; 984 u64 __user *dva; 985 u32 wval; 986 u64 dval; 987 int sig; 988 989 /* 990 * These are giving gcc a gentle hint about what to expect in 991 * dec_inst in order to do better optimization. 992 */ 993 if (!cpu_has_mmips && dec_insn.micro_mips_mode) 994 unreachable(); 995 996 /* XXX NEC Vr54xx bug workaround */ 997 if (delay_slot(xcp)) { 998 if (dec_insn.micro_mips_mode) { 999 if (!mm_isBranchInstr(xcp, dec_insn, &contpc)) 1000 clear_delay_slot(xcp); 1001 } else { 1002 if (!isBranchInstr(xcp, dec_insn, &contpc)) 1003 clear_delay_slot(xcp); 1004 } 1005 } 1006 1007 if (delay_slot(xcp)) { 1008 /* 1009 * The instruction to be emulated is in a branch delay slot 1010 * which means that we have to emulate the branch instruction 1011 * BEFORE we do the cop1 instruction. 1012 * 1013 * This branch could be a COP1 branch, but in that case we 1014 * would have had a trap for that instruction, and would not 1015 * come through this route. 1016 * 1017 * Linux MIPS branch emulator operates on context, updating the 1018 * cp0_epc. 1019 */ 1020 ir = dec_insn.next_insn; /* process delay slot instr */ 1021 pc_inc = dec_insn.next_pc_inc; 1022 } else { 1023 ir = dec_insn.insn; /* process current instr */ 1024 pc_inc = dec_insn.pc_inc; 1025 } 1026 1027 /* 1028 * Since microMIPS FPU instructios are a subset of MIPS32 FPU 1029 * instructions, we want to convert microMIPS FPU instructions 1030 * into MIPS32 instructions so that we could reuse all of the 1031 * FPU emulation code. 1032 * 1033 * NOTE: We cannot do this for branch instructions since they 1034 * are not a subset. Example: Cannot emulate a 16-bit 1035 * aligned target address with a MIPS32 instruction. 1036 */ 1037 if (dec_insn.micro_mips_mode) { 1038 /* 1039 * If next instruction is a 16-bit instruction, then it 1040 * it cannot be a FPU instruction. This could happen 1041 * since we can be called for non-FPU instructions. 1042 */ 1043 if ((pc_inc == 2) || 1044 (microMIPS32_to_MIPS32((union mips_instruction *)&ir) 1045 == SIGILL)) 1046 return SIGILL; 1047 } 1048 1049 emul: 1050 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, xcp, 0); 1051 MIPS_FPU_EMU_INC_STATS(emulated); 1052 switch (MIPSInst_OPCODE(ir)) { 1053 case ldc1_op: 1054 dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] + 1055 MIPSInst_SIMM(ir)); 1056 MIPS_FPU_EMU_INC_STATS(loads); 1057 1058 if (!access_ok(VERIFY_READ, dva, sizeof(u64))) { 1059 MIPS_FPU_EMU_INC_STATS(errors); 1060 *fault_addr = dva; 1061 return SIGBUS; 1062 } 1063 if (__get_user(dval, dva)) { 1064 MIPS_FPU_EMU_INC_STATS(errors); 1065 *fault_addr = dva; 1066 return SIGSEGV; 1067 } 1068 DITOREG(dval, MIPSInst_RT(ir)); 1069 break; 1070 1071 case sdc1_op: 1072 dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] + 1073 MIPSInst_SIMM(ir)); 1074 MIPS_FPU_EMU_INC_STATS(stores); 1075 DIFROMREG(dval, MIPSInst_RT(ir)); 1076 if (!access_ok(VERIFY_WRITE, dva, sizeof(u64))) { 1077 MIPS_FPU_EMU_INC_STATS(errors); 1078 *fault_addr = dva; 1079 return SIGBUS; 1080 } 1081 if (__put_user(dval, dva)) { 1082 MIPS_FPU_EMU_INC_STATS(errors); 1083 *fault_addr = dva; 1084 return SIGSEGV; 1085 } 1086 break; 1087 1088 case lwc1_op: 1089 wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] + 1090 MIPSInst_SIMM(ir)); 1091 MIPS_FPU_EMU_INC_STATS(loads); 1092 if (!access_ok(VERIFY_READ, wva, sizeof(u32))) { 1093 MIPS_FPU_EMU_INC_STATS(errors); 1094 *fault_addr = wva; 1095 return SIGBUS; 1096 } 1097 if (__get_user(wval, wva)) { 1098 MIPS_FPU_EMU_INC_STATS(errors); 1099 *fault_addr = wva; 1100 return SIGSEGV; 1101 } 1102 SITOREG(wval, MIPSInst_RT(ir)); 1103 break; 1104 1105 case swc1_op: 1106 wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] + 1107 MIPSInst_SIMM(ir)); 1108 MIPS_FPU_EMU_INC_STATS(stores); 1109 SIFROMREG(wval, MIPSInst_RT(ir)); 1110 if (!access_ok(VERIFY_WRITE, wva, sizeof(u32))) { 1111 MIPS_FPU_EMU_INC_STATS(errors); 1112 *fault_addr = wva; 1113 return SIGBUS; 1114 } 1115 if (__put_user(wval, wva)) { 1116 MIPS_FPU_EMU_INC_STATS(errors); 1117 *fault_addr = wva; 1118 return SIGSEGV; 1119 } 1120 break; 1121 1122 case cop1_op: 1123 switch (MIPSInst_RS(ir)) { 1124 case dmfc_op: 1125 if (!cpu_has_mips_3_4_5 && !cpu_has_mips64) 1126 return SIGILL; 1127 1128 /* copregister fs -> gpr[rt] */ 1129 if (MIPSInst_RT(ir) != 0) { 1130 DIFROMREG(xcp->regs[MIPSInst_RT(ir)], 1131 MIPSInst_RD(ir)); 1132 } 1133 break; 1134 1135 case dmtc_op: 1136 if (!cpu_has_mips_3_4_5 && !cpu_has_mips64) 1137 return SIGILL; 1138 1139 /* copregister fs <- rt */ 1140 DITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir)); 1141 break; 1142 1143 case mfhc_op: 1144 if (!cpu_has_mips_r2_r6) 1145 return SIGILL; 1146 1147 /* copregister rd -> gpr[rt] */ 1148 if (MIPSInst_RT(ir) != 0) { 1149 SIFROMHREG(xcp->regs[MIPSInst_RT(ir)], 1150 MIPSInst_RD(ir)); 1151 } 1152 break; 1153 1154 case mthc_op: 1155 if (!cpu_has_mips_r2_r6) 1156 return SIGILL; 1157 1158 /* copregister rd <- gpr[rt] */ 1159 SITOHREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir)); 1160 break; 1161 1162 case mfc_op: 1163 /* copregister rd -> gpr[rt] */ 1164 if (MIPSInst_RT(ir) != 0) { 1165 SIFROMREG(xcp->regs[MIPSInst_RT(ir)], 1166 MIPSInst_RD(ir)); 1167 } 1168 break; 1169 1170 case mtc_op: 1171 /* copregister rd <- rt */ 1172 SITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir)); 1173 break; 1174 1175 case cfc_op: 1176 /* cop control register rd -> gpr[rt] */ 1177 cop1_cfc(xcp, ctx, ir); 1178 break; 1179 1180 case ctc_op: 1181 /* copregister rd <- rt */ 1182 cop1_ctc(xcp, ctx, ir); 1183 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) { 1184 return SIGFPE; 1185 } 1186 break; 1187 1188 case bc1eqz_op: 1189 case bc1nez_op: 1190 if (!cpu_has_mips_r6 || delay_slot(xcp)) 1191 return SIGILL; 1192 1193 cond = likely = 0; 1194 fpr = ¤t->thread.fpu.fpr[MIPSInst_RT(ir)]; 1195 bit0 = get_fpr32(fpr, 0) & 0x1; 1196 switch (MIPSInst_RS(ir)) { 1197 case bc1eqz_op: 1198 cond = bit0 == 0; 1199 break; 1200 case bc1nez_op: 1201 cond = bit0 != 0; 1202 break; 1203 } 1204 goto branch_common; 1205 1206 case bc_op: 1207 if (delay_slot(xcp)) 1208 return SIGILL; 1209 1210 if (cpu_has_mips_4_5_r) 1211 cbit = fpucondbit[MIPSInst_RT(ir) >> 2]; 1212 else 1213 cbit = FPU_CSR_COND; 1214 cond = ctx->fcr31 & cbit; 1215 1216 likely = 0; 1217 switch (MIPSInst_RT(ir) & 3) { 1218 case bcfl_op: 1219 if (cpu_has_mips_2_3_4_5_r) 1220 likely = 1; 1221 /* Fall through */ 1222 case bcf_op: 1223 cond = !cond; 1224 break; 1225 case bctl_op: 1226 if (cpu_has_mips_2_3_4_5_r) 1227 likely = 1; 1228 /* Fall through */ 1229 case bct_op: 1230 break; 1231 } 1232 branch_common: 1233 set_delay_slot(xcp); 1234 if (cond) { 1235 /* 1236 * Branch taken: emulate dslot instruction 1237 */ 1238 unsigned long bcpc; 1239 1240 /* 1241 * Remember EPC at the branch to point back 1242 * at so that any delay-slot instruction 1243 * signal is not silently ignored. 1244 */ 1245 bcpc = xcp->cp0_epc; 1246 xcp->cp0_epc += dec_insn.pc_inc; 1247 1248 contpc = MIPSInst_SIMM(ir); 1249 ir = dec_insn.next_insn; 1250 if (dec_insn.micro_mips_mode) { 1251 contpc = (xcp->cp0_epc + (contpc << 1)); 1252 1253 /* If 16-bit instruction, not FPU. */ 1254 if ((dec_insn.next_pc_inc == 2) || 1255 (microMIPS32_to_MIPS32((union mips_instruction *)&ir) == SIGILL)) { 1256 1257 /* 1258 * Since this instruction will 1259 * be put on the stack with 1260 * 32-bit words, get around 1261 * this problem by putting a 1262 * NOP16 as the second one. 1263 */ 1264 if (dec_insn.next_pc_inc == 2) 1265 ir = (ir & (~0xffff)) | MM_NOP16; 1266 1267 /* 1268 * Single step the non-CP1 1269 * instruction in the dslot. 1270 */ 1271 sig = mips_dsemul(xcp, ir, 1272 bcpc, contpc); 1273 if (sig < 0) 1274 break; 1275 if (sig) 1276 xcp->cp0_epc = bcpc; 1277 /* 1278 * SIGILL forces out of 1279 * the emulation loop. 1280 */ 1281 return sig ? sig : SIGILL; 1282 } 1283 } else 1284 contpc = (xcp->cp0_epc + (contpc << 2)); 1285 1286 switch (MIPSInst_OPCODE(ir)) { 1287 case lwc1_op: 1288 case swc1_op: 1289 goto emul; 1290 1291 case ldc1_op: 1292 case sdc1_op: 1293 if (cpu_has_mips_2_3_4_5_r) 1294 goto emul; 1295 1296 goto bc_sigill; 1297 1298 case cop1_op: 1299 goto emul; 1300 1301 case cop1x_op: 1302 if (cpu_has_mips_4_5_64_r2_r6) 1303 /* its one of ours */ 1304 goto emul; 1305 1306 goto bc_sigill; 1307 1308 case spec_op: 1309 switch (MIPSInst_FUNC(ir)) { 1310 case movc_op: 1311 if (cpu_has_mips_4_5_r) 1312 goto emul; 1313 1314 goto bc_sigill; 1315 } 1316 break; 1317 1318 bc_sigill: 1319 xcp->cp0_epc = bcpc; 1320 return SIGILL; 1321 } 1322 1323 /* 1324 * Single step the non-cp1 1325 * instruction in the dslot 1326 */ 1327 sig = mips_dsemul(xcp, ir, bcpc, contpc); 1328 if (sig < 0) 1329 break; 1330 if (sig) 1331 xcp->cp0_epc = bcpc; 1332 /* SIGILL forces out of the emulation loop. */ 1333 return sig ? sig : SIGILL; 1334 } else if (likely) { /* branch not taken */ 1335 /* 1336 * branch likely nullifies 1337 * dslot if not taken 1338 */ 1339 xcp->cp0_epc += dec_insn.pc_inc; 1340 contpc += dec_insn.pc_inc; 1341 /* 1342 * else continue & execute 1343 * dslot as normal insn 1344 */ 1345 } 1346 break; 1347 1348 default: 1349 if (!(MIPSInst_RS(ir) & 0x10)) 1350 return SIGILL; 1351 1352 /* a real fpu computation instruction */ 1353 if ((sig = fpu_emu(xcp, ctx, ir))) 1354 return sig; 1355 } 1356 break; 1357 1358 case cop1x_op: 1359 if (!cpu_has_mips_4_5_64_r2_r6) 1360 return SIGILL; 1361 1362 sig = fpux_emu(xcp, ctx, ir, fault_addr); 1363 if (sig) 1364 return sig; 1365 break; 1366 1367 case spec_op: 1368 if (!cpu_has_mips_4_5_r) 1369 return SIGILL; 1370 1371 if (MIPSInst_FUNC(ir) != movc_op) 1372 return SIGILL; 1373 cond = fpucondbit[MIPSInst_RT(ir) >> 2]; 1374 if (((ctx->fcr31 & cond) != 0) == ((MIPSInst_RT(ir) & 1) != 0)) 1375 xcp->regs[MIPSInst_RD(ir)] = 1376 xcp->regs[MIPSInst_RS(ir)]; 1377 break; 1378 default: 1379 return SIGILL; 1380 } 1381 1382 /* we did it !! */ 1383 xcp->cp0_epc = contpc; 1384 clear_delay_slot(xcp); 1385 1386 return 0; 1387 } 1388 1389 /* 1390 * Conversion table from MIPS compare ops 48-63 1391 * cond = ieee754dp_cmp(x,y,IEEE754_UN,sig); 1392 */ 1393 static const unsigned char cmptab[8] = { 1394 0, /* cmp_0 (sig) cmp_sf */ 1395 IEEE754_CUN, /* cmp_un (sig) cmp_ngle */ 1396 IEEE754_CEQ, /* cmp_eq (sig) cmp_seq */ 1397 IEEE754_CEQ | IEEE754_CUN, /* cmp_ueq (sig) cmp_ngl */ 1398 IEEE754_CLT, /* cmp_olt (sig) cmp_lt */ 1399 IEEE754_CLT | IEEE754_CUN, /* cmp_ult (sig) cmp_nge */ 1400 IEEE754_CLT | IEEE754_CEQ, /* cmp_ole (sig) cmp_le */ 1401 IEEE754_CLT | IEEE754_CEQ | IEEE754_CUN, /* cmp_ule (sig) cmp_ngt */ 1402 }; 1403 1404 static const unsigned char negative_cmptab[8] = { 1405 0, /* Reserved */ 1406 IEEE754_CLT | IEEE754_CGT | IEEE754_CEQ, 1407 IEEE754_CLT | IEEE754_CGT | IEEE754_CUN, 1408 IEEE754_CLT | IEEE754_CGT, 1409 /* Reserved */ 1410 }; 1411 1412 1413 /* 1414 * Additional MIPS4 instructions 1415 */ 1416 1417 #define DEF3OP(name, p, f1, f2, f3) \ 1418 static union ieee754##p fpemu_##p##_##name(union ieee754##p r, \ 1419 union ieee754##p s, union ieee754##p t) \ 1420 { \ 1421 struct _ieee754_csr ieee754_csr_save; \ 1422 s = f1(s, t); \ 1423 ieee754_csr_save = ieee754_csr; \ 1424 s = f2(s, r); \ 1425 ieee754_csr_save.cx |= ieee754_csr.cx; \ 1426 ieee754_csr_save.sx |= ieee754_csr.sx; \ 1427 s = f3(s); \ 1428 ieee754_csr.cx |= ieee754_csr_save.cx; \ 1429 ieee754_csr.sx |= ieee754_csr_save.sx; \ 1430 return s; \ 1431 } 1432 1433 static union ieee754dp fpemu_dp_recip(union ieee754dp d) 1434 { 1435 return ieee754dp_div(ieee754dp_one(0), d); 1436 } 1437 1438 static union ieee754dp fpemu_dp_rsqrt(union ieee754dp d) 1439 { 1440 return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d)); 1441 } 1442 1443 static union ieee754sp fpemu_sp_recip(union ieee754sp s) 1444 { 1445 return ieee754sp_div(ieee754sp_one(0), s); 1446 } 1447 1448 static union ieee754sp fpemu_sp_rsqrt(union ieee754sp s) 1449 { 1450 return ieee754sp_div(ieee754sp_one(0), ieee754sp_sqrt(s)); 1451 } 1452 1453 DEF3OP(madd, sp, ieee754sp_mul, ieee754sp_add, ); 1454 DEF3OP(msub, sp, ieee754sp_mul, ieee754sp_sub, ); 1455 DEF3OP(nmadd, sp, ieee754sp_mul, ieee754sp_add, ieee754sp_neg); 1456 DEF3OP(nmsub, sp, ieee754sp_mul, ieee754sp_sub, ieee754sp_neg); 1457 DEF3OP(madd, dp, ieee754dp_mul, ieee754dp_add, ); 1458 DEF3OP(msub, dp, ieee754dp_mul, ieee754dp_sub, ); 1459 DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg); 1460 DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg); 1461 1462 static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx, 1463 mips_instruction ir, void *__user *fault_addr) 1464 { 1465 unsigned rcsr = 0; /* resulting csr */ 1466 1467 MIPS_FPU_EMU_INC_STATS(cp1xops); 1468 1469 switch (MIPSInst_FMA_FFMT(ir)) { 1470 case s_fmt:{ /* 0 */ 1471 1472 union ieee754sp(*handler) (union ieee754sp, union ieee754sp, union ieee754sp); 1473 union ieee754sp fd, fr, fs, ft; 1474 u32 __user *va; 1475 u32 val; 1476 1477 switch (MIPSInst_FUNC(ir)) { 1478 case lwxc1_op: 1479 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] + 1480 xcp->regs[MIPSInst_FT(ir)]); 1481 1482 MIPS_FPU_EMU_INC_STATS(loads); 1483 if (!access_ok(VERIFY_READ, va, sizeof(u32))) { 1484 MIPS_FPU_EMU_INC_STATS(errors); 1485 *fault_addr = va; 1486 return SIGBUS; 1487 } 1488 if (__get_user(val, va)) { 1489 MIPS_FPU_EMU_INC_STATS(errors); 1490 *fault_addr = va; 1491 return SIGSEGV; 1492 } 1493 SITOREG(val, MIPSInst_FD(ir)); 1494 break; 1495 1496 case swxc1_op: 1497 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] + 1498 xcp->regs[MIPSInst_FT(ir)]); 1499 1500 MIPS_FPU_EMU_INC_STATS(stores); 1501 1502 SIFROMREG(val, MIPSInst_FS(ir)); 1503 if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) { 1504 MIPS_FPU_EMU_INC_STATS(errors); 1505 *fault_addr = va; 1506 return SIGBUS; 1507 } 1508 if (put_user(val, va)) { 1509 MIPS_FPU_EMU_INC_STATS(errors); 1510 *fault_addr = va; 1511 return SIGSEGV; 1512 } 1513 break; 1514 1515 case madd_s_op: 1516 handler = fpemu_sp_madd; 1517 goto scoptop; 1518 case msub_s_op: 1519 handler = fpemu_sp_msub; 1520 goto scoptop; 1521 case nmadd_s_op: 1522 handler = fpemu_sp_nmadd; 1523 goto scoptop; 1524 case nmsub_s_op: 1525 handler = fpemu_sp_nmsub; 1526 goto scoptop; 1527 1528 scoptop: 1529 SPFROMREG(fr, MIPSInst_FR(ir)); 1530 SPFROMREG(fs, MIPSInst_FS(ir)); 1531 SPFROMREG(ft, MIPSInst_FT(ir)); 1532 fd = (*handler) (fr, fs, ft); 1533 SPTOREG(fd, MIPSInst_FD(ir)); 1534 1535 copcsr: 1536 if (ieee754_cxtest(IEEE754_INEXACT)) { 1537 MIPS_FPU_EMU_INC_STATS(ieee754_inexact); 1538 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S; 1539 } 1540 if (ieee754_cxtest(IEEE754_UNDERFLOW)) { 1541 MIPS_FPU_EMU_INC_STATS(ieee754_underflow); 1542 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S; 1543 } 1544 if (ieee754_cxtest(IEEE754_OVERFLOW)) { 1545 MIPS_FPU_EMU_INC_STATS(ieee754_overflow); 1546 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S; 1547 } 1548 if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) { 1549 MIPS_FPU_EMU_INC_STATS(ieee754_invalidop); 1550 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S; 1551 } 1552 1553 ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr; 1554 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) { 1555 /*printk ("SIGFPE: FPU csr = %08x\n", 1556 ctx->fcr31); */ 1557 return SIGFPE; 1558 } 1559 1560 break; 1561 1562 default: 1563 return SIGILL; 1564 } 1565 break; 1566 } 1567 1568 case d_fmt:{ /* 1 */ 1569 union ieee754dp(*handler) (union ieee754dp, union ieee754dp, union ieee754dp); 1570 union ieee754dp fd, fr, fs, ft; 1571 u64 __user *va; 1572 u64 val; 1573 1574 switch (MIPSInst_FUNC(ir)) { 1575 case ldxc1_op: 1576 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] + 1577 xcp->regs[MIPSInst_FT(ir)]); 1578 1579 MIPS_FPU_EMU_INC_STATS(loads); 1580 if (!access_ok(VERIFY_READ, va, sizeof(u64))) { 1581 MIPS_FPU_EMU_INC_STATS(errors); 1582 *fault_addr = va; 1583 return SIGBUS; 1584 } 1585 if (__get_user(val, va)) { 1586 MIPS_FPU_EMU_INC_STATS(errors); 1587 *fault_addr = va; 1588 return SIGSEGV; 1589 } 1590 DITOREG(val, MIPSInst_FD(ir)); 1591 break; 1592 1593 case sdxc1_op: 1594 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] + 1595 xcp->regs[MIPSInst_FT(ir)]); 1596 1597 MIPS_FPU_EMU_INC_STATS(stores); 1598 DIFROMREG(val, MIPSInst_FS(ir)); 1599 if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) { 1600 MIPS_FPU_EMU_INC_STATS(errors); 1601 *fault_addr = va; 1602 return SIGBUS; 1603 } 1604 if (__put_user(val, va)) { 1605 MIPS_FPU_EMU_INC_STATS(errors); 1606 *fault_addr = va; 1607 return SIGSEGV; 1608 } 1609 break; 1610 1611 case madd_d_op: 1612 handler = fpemu_dp_madd; 1613 goto dcoptop; 1614 case msub_d_op: 1615 handler = fpemu_dp_msub; 1616 goto dcoptop; 1617 case nmadd_d_op: 1618 handler = fpemu_dp_nmadd; 1619 goto dcoptop; 1620 case nmsub_d_op: 1621 handler = fpemu_dp_nmsub; 1622 goto dcoptop; 1623 1624 dcoptop: 1625 DPFROMREG(fr, MIPSInst_FR(ir)); 1626 DPFROMREG(fs, MIPSInst_FS(ir)); 1627 DPFROMREG(ft, MIPSInst_FT(ir)); 1628 fd = (*handler) (fr, fs, ft); 1629 DPTOREG(fd, MIPSInst_FD(ir)); 1630 goto copcsr; 1631 1632 default: 1633 return SIGILL; 1634 } 1635 break; 1636 } 1637 1638 case 0x3: 1639 if (MIPSInst_FUNC(ir) != pfetch_op) 1640 return SIGILL; 1641 1642 /* ignore prefx operation */ 1643 break; 1644 1645 default: 1646 return SIGILL; 1647 } 1648 1649 return 0; 1650 } 1651 1652 1653 1654 /* 1655 * Emulate a single COP1 arithmetic instruction. 1656 */ 1657 static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx, 1658 mips_instruction ir) 1659 { 1660 int rfmt; /* resulting format */ 1661 unsigned rcsr = 0; /* resulting csr */ 1662 unsigned int oldrm; 1663 unsigned int cbit; 1664 unsigned cond; 1665 union { 1666 union ieee754dp d; 1667 union ieee754sp s; 1668 int w; 1669 s64 l; 1670 } rv; /* resulting value */ 1671 u64 bits; 1672 1673 MIPS_FPU_EMU_INC_STATS(cp1ops); 1674 switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) { 1675 case s_fmt: { /* 0 */ 1676 union { 1677 union ieee754sp(*b) (union ieee754sp, union ieee754sp); 1678 union ieee754sp(*u) (union ieee754sp); 1679 } handler; 1680 union ieee754sp fd, fs, ft; 1681 1682 switch (MIPSInst_FUNC(ir)) { 1683 /* binary ops */ 1684 case fadd_op: 1685 handler.b = ieee754sp_add; 1686 goto scopbop; 1687 case fsub_op: 1688 handler.b = ieee754sp_sub; 1689 goto scopbop; 1690 case fmul_op: 1691 handler.b = ieee754sp_mul; 1692 goto scopbop; 1693 case fdiv_op: 1694 handler.b = ieee754sp_div; 1695 goto scopbop; 1696 1697 /* unary ops */ 1698 case fsqrt_op: 1699 if (!cpu_has_mips_2_3_4_5_r) 1700 return SIGILL; 1701 1702 handler.u = ieee754sp_sqrt; 1703 goto scopuop; 1704 1705 /* 1706 * Note that on some MIPS IV implementations such as the 1707 * R5000 and R8000 the FSQRT and FRECIP instructions do not 1708 * achieve full IEEE-754 accuracy - however this emulator does. 1709 */ 1710 case frsqrt_op: 1711 if (!cpu_has_mips_4_5_64_r2_r6) 1712 return SIGILL; 1713 1714 handler.u = fpemu_sp_rsqrt; 1715 goto scopuop; 1716 1717 case frecip_op: 1718 if (!cpu_has_mips_4_5_64_r2_r6) 1719 return SIGILL; 1720 1721 handler.u = fpemu_sp_recip; 1722 goto scopuop; 1723 1724 case fmovc_op: 1725 if (!cpu_has_mips_4_5_r) 1726 return SIGILL; 1727 1728 cond = fpucondbit[MIPSInst_FT(ir) >> 2]; 1729 if (((ctx->fcr31 & cond) != 0) != 1730 ((MIPSInst_FT(ir) & 1) != 0)) 1731 return 0; 1732 SPFROMREG(rv.s, MIPSInst_FS(ir)); 1733 break; 1734 1735 case fmovz_op: 1736 if (!cpu_has_mips_4_5_r) 1737 return SIGILL; 1738 1739 if (xcp->regs[MIPSInst_FT(ir)] != 0) 1740 return 0; 1741 SPFROMREG(rv.s, MIPSInst_FS(ir)); 1742 break; 1743 1744 case fmovn_op: 1745 if (!cpu_has_mips_4_5_r) 1746 return SIGILL; 1747 1748 if (xcp->regs[MIPSInst_FT(ir)] == 0) 1749 return 0; 1750 SPFROMREG(rv.s, MIPSInst_FS(ir)); 1751 break; 1752 1753 case fseleqz_op: 1754 if (!cpu_has_mips_r6) 1755 return SIGILL; 1756 1757 SPFROMREG(rv.s, MIPSInst_FT(ir)); 1758 if (rv.w & 0x1) 1759 rv.w = 0; 1760 else 1761 SPFROMREG(rv.s, MIPSInst_FS(ir)); 1762 break; 1763 1764 case fselnez_op: 1765 if (!cpu_has_mips_r6) 1766 return SIGILL; 1767 1768 SPFROMREG(rv.s, MIPSInst_FT(ir)); 1769 if (rv.w & 0x1) 1770 SPFROMREG(rv.s, MIPSInst_FS(ir)); 1771 else 1772 rv.w = 0; 1773 break; 1774 1775 case fmaddf_op: { 1776 union ieee754sp ft, fs, fd; 1777 1778 if (!cpu_has_mips_r6) 1779 return SIGILL; 1780 1781 SPFROMREG(ft, MIPSInst_FT(ir)); 1782 SPFROMREG(fs, MIPSInst_FS(ir)); 1783 SPFROMREG(fd, MIPSInst_FD(ir)); 1784 rv.s = ieee754sp_maddf(fd, fs, ft); 1785 break; 1786 } 1787 1788 case fmsubf_op: { 1789 union ieee754sp ft, fs, fd; 1790 1791 if (!cpu_has_mips_r6) 1792 return SIGILL; 1793 1794 SPFROMREG(ft, MIPSInst_FT(ir)); 1795 SPFROMREG(fs, MIPSInst_FS(ir)); 1796 SPFROMREG(fd, MIPSInst_FD(ir)); 1797 rv.s = ieee754sp_msubf(fd, fs, ft); 1798 break; 1799 } 1800 1801 case frint_op: { 1802 union ieee754sp fs; 1803 1804 if (!cpu_has_mips_r6) 1805 return SIGILL; 1806 1807 SPFROMREG(fs, MIPSInst_FS(ir)); 1808 rv.l = ieee754sp_tlong(fs); 1809 rv.s = ieee754sp_flong(rv.l); 1810 goto copcsr; 1811 } 1812 1813 case fclass_op: { 1814 union ieee754sp fs; 1815 1816 if (!cpu_has_mips_r6) 1817 return SIGILL; 1818 1819 SPFROMREG(fs, MIPSInst_FS(ir)); 1820 rv.w = ieee754sp_2008class(fs); 1821 rfmt = w_fmt; 1822 break; 1823 } 1824 1825 case fmin_op: { 1826 union ieee754sp fs, ft; 1827 1828 if (!cpu_has_mips_r6) 1829 return SIGILL; 1830 1831 SPFROMREG(ft, MIPSInst_FT(ir)); 1832 SPFROMREG(fs, MIPSInst_FS(ir)); 1833 rv.s = ieee754sp_fmin(fs, ft); 1834 break; 1835 } 1836 1837 case fmina_op: { 1838 union ieee754sp fs, ft; 1839 1840 if (!cpu_has_mips_r6) 1841 return SIGILL; 1842 1843 SPFROMREG(ft, MIPSInst_FT(ir)); 1844 SPFROMREG(fs, MIPSInst_FS(ir)); 1845 rv.s = ieee754sp_fmina(fs, ft); 1846 break; 1847 } 1848 1849 case fmax_op: { 1850 union ieee754sp fs, ft; 1851 1852 if (!cpu_has_mips_r6) 1853 return SIGILL; 1854 1855 SPFROMREG(ft, MIPSInst_FT(ir)); 1856 SPFROMREG(fs, MIPSInst_FS(ir)); 1857 rv.s = ieee754sp_fmax(fs, ft); 1858 break; 1859 } 1860 1861 case fmaxa_op: { 1862 union ieee754sp fs, ft; 1863 1864 if (!cpu_has_mips_r6) 1865 return SIGILL; 1866 1867 SPFROMREG(ft, MIPSInst_FT(ir)); 1868 SPFROMREG(fs, MIPSInst_FS(ir)); 1869 rv.s = ieee754sp_fmaxa(fs, ft); 1870 break; 1871 } 1872 1873 case fabs_op: 1874 handler.u = ieee754sp_abs; 1875 goto scopuop; 1876 1877 case fneg_op: 1878 handler.u = ieee754sp_neg; 1879 goto scopuop; 1880 1881 case fmov_op: 1882 /* an easy one */ 1883 SPFROMREG(rv.s, MIPSInst_FS(ir)); 1884 goto copcsr; 1885 1886 /* binary op on handler */ 1887 scopbop: 1888 SPFROMREG(fs, MIPSInst_FS(ir)); 1889 SPFROMREG(ft, MIPSInst_FT(ir)); 1890 1891 rv.s = (*handler.b) (fs, ft); 1892 goto copcsr; 1893 scopuop: 1894 SPFROMREG(fs, MIPSInst_FS(ir)); 1895 rv.s = (*handler.u) (fs); 1896 goto copcsr; 1897 copcsr: 1898 if (ieee754_cxtest(IEEE754_INEXACT)) { 1899 MIPS_FPU_EMU_INC_STATS(ieee754_inexact); 1900 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S; 1901 } 1902 if (ieee754_cxtest(IEEE754_UNDERFLOW)) { 1903 MIPS_FPU_EMU_INC_STATS(ieee754_underflow); 1904 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S; 1905 } 1906 if (ieee754_cxtest(IEEE754_OVERFLOW)) { 1907 MIPS_FPU_EMU_INC_STATS(ieee754_overflow); 1908 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S; 1909 } 1910 if (ieee754_cxtest(IEEE754_ZERO_DIVIDE)) { 1911 MIPS_FPU_EMU_INC_STATS(ieee754_zerodiv); 1912 rcsr |= FPU_CSR_DIV_X | FPU_CSR_DIV_S; 1913 } 1914 if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) { 1915 MIPS_FPU_EMU_INC_STATS(ieee754_invalidop); 1916 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S; 1917 } 1918 break; 1919 1920 /* unary conv ops */ 1921 case fcvts_op: 1922 return SIGILL; /* not defined */ 1923 1924 case fcvtd_op: 1925 SPFROMREG(fs, MIPSInst_FS(ir)); 1926 rv.d = ieee754dp_fsp(fs); 1927 rfmt = d_fmt; 1928 goto copcsr; 1929 1930 case fcvtw_op: 1931 SPFROMREG(fs, MIPSInst_FS(ir)); 1932 rv.w = ieee754sp_tint(fs); 1933 rfmt = w_fmt; 1934 goto copcsr; 1935 1936 case fround_op: 1937 case ftrunc_op: 1938 case fceil_op: 1939 case ffloor_op: 1940 if (!cpu_has_mips_2_3_4_5_r) 1941 return SIGILL; 1942 1943 oldrm = ieee754_csr.rm; 1944 SPFROMREG(fs, MIPSInst_FS(ir)); 1945 ieee754_csr.rm = MIPSInst_FUNC(ir); 1946 rv.w = ieee754sp_tint(fs); 1947 ieee754_csr.rm = oldrm; 1948 rfmt = w_fmt; 1949 goto copcsr; 1950 1951 case fsel_op: 1952 if (!cpu_has_mips_r6) 1953 return SIGILL; 1954 1955 SPFROMREG(fd, MIPSInst_FD(ir)); 1956 if (fd.bits & 0x1) 1957 SPFROMREG(rv.s, MIPSInst_FT(ir)); 1958 else 1959 SPFROMREG(rv.s, MIPSInst_FS(ir)); 1960 break; 1961 1962 case fcvtl_op: 1963 if (!cpu_has_mips_3_4_5_64_r2_r6) 1964 return SIGILL; 1965 1966 SPFROMREG(fs, MIPSInst_FS(ir)); 1967 rv.l = ieee754sp_tlong(fs); 1968 rfmt = l_fmt; 1969 goto copcsr; 1970 1971 case froundl_op: 1972 case ftruncl_op: 1973 case fceill_op: 1974 case ffloorl_op: 1975 if (!cpu_has_mips_3_4_5_64_r2_r6) 1976 return SIGILL; 1977 1978 oldrm = ieee754_csr.rm; 1979 SPFROMREG(fs, MIPSInst_FS(ir)); 1980 ieee754_csr.rm = MIPSInst_FUNC(ir); 1981 rv.l = ieee754sp_tlong(fs); 1982 ieee754_csr.rm = oldrm; 1983 rfmt = l_fmt; 1984 goto copcsr; 1985 1986 default: 1987 if (!NO_R6EMU && MIPSInst_FUNC(ir) >= fcmp_op) { 1988 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op; 1989 union ieee754sp fs, ft; 1990 1991 SPFROMREG(fs, MIPSInst_FS(ir)); 1992 SPFROMREG(ft, MIPSInst_FT(ir)); 1993 rv.w = ieee754sp_cmp(fs, ft, 1994 cmptab[cmpop & 0x7], cmpop & 0x8); 1995 rfmt = -1; 1996 if ((cmpop & 0x8) && ieee754_cxtest 1997 (IEEE754_INVALID_OPERATION)) 1998 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S; 1999 else 2000 goto copcsr; 2001 2002 } else 2003 return SIGILL; 2004 break; 2005 } 2006 break; 2007 } 2008 2009 case d_fmt: { 2010 union ieee754dp fd, fs, ft; 2011 union { 2012 union ieee754dp(*b) (union ieee754dp, union ieee754dp); 2013 union ieee754dp(*u) (union ieee754dp); 2014 } handler; 2015 2016 switch (MIPSInst_FUNC(ir)) { 2017 /* binary ops */ 2018 case fadd_op: 2019 handler.b = ieee754dp_add; 2020 goto dcopbop; 2021 case fsub_op: 2022 handler.b = ieee754dp_sub; 2023 goto dcopbop; 2024 case fmul_op: 2025 handler.b = ieee754dp_mul; 2026 goto dcopbop; 2027 case fdiv_op: 2028 handler.b = ieee754dp_div; 2029 goto dcopbop; 2030 2031 /* unary ops */ 2032 case fsqrt_op: 2033 if (!cpu_has_mips_2_3_4_5_r) 2034 return SIGILL; 2035 2036 handler.u = ieee754dp_sqrt; 2037 goto dcopuop; 2038 /* 2039 * Note that on some MIPS IV implementations such as the 2040 * R5000 and R8000 the FSQRT and FRECIP instructions do not 2041 * achieve full IEEE-754 accuracy - however this emulator does. 2042 */ 2043 case frsqrt_op: 2044 if (!cpu_has_mips_4_5_64_r2_r6) 2045 return SIGILL; 2046 2047 handler.u = fpemu_dp_rsqrt; 2048 goto dcopuop; 2049 case frecip_op: 2050 if (!cpu_has_mips_4_5_64_r2_r6) 2051 return SIGILL; 2052 2053 handler.u = fpemu_dp_recip; 2054 goto dcopuop; 2055 case fmovc_op: 2056 if (!cpu_has_mips_4_5_r) 2057 return SIGILL; 2058 2059 cond = fpucondbit[MIPSInst_FT(ir) >> 2]; 2060 if (((ctx->fcr31 & cond) != 0) != 2061 ((MIPSInst_FT(ir) & 1) != 0)) 2062 return 0; 2063 DPFROMREG(rv.d, MIPSInst_FS(ir)); 2064 break; 2065 case fmovz_op: 2066 if (!cpu_has_mips_4_5_r) 2067 return SIGILL; 2068 2069 if (xcp->regs[MIPSInst_FT(ir)] != 0) 2070 return 0; 2071 DPFROMREG(rv.d, MIPSInst_FS(ir)); 2072 break; 2073 case fmovn_op: 2074 if (!cpu_has_mips_4_5_r) 2075 return SIGILL; 2076 2077 if (xcp->regs[MIPSInst_FT(ir)] == 0) 2078 return 0; 2079 DPFROMREG(rv.d, MIPSInst_FS(ir)); 2080 break; 2081 2082 case fseleqz_op: 2083 if (!cpu_has_mips_r6) 2084 return SIGILL; 2085 2086 DPFROMREG(rv.d, MIPSInst_FT(ir)); 2087 if (rv.l & 0x1) 2088 rv.l = 0; 2089 else 2090 DPFROMREG(rv.d, MIPSInst_FS(ir)); 2091 break; 2092 2093 case fselnez_op: 2094 if (!cpu_has_mips_r6) 2095 return SIGILL; 2096 2097 DPFROMREG(rv.d, MIPSInst_FT(ir)); 2098 if (rv.l & 0x1) 2099 DPFROMREG(rv.d, MIPSInst_FS(ir)); 2100 else 2101 rv.l = 0; 2102 break; 2103 2104 case fmaddf_op: { 2105 union ieee754dp ft, fs, fd; 2106 2107 if (!cpu_has_mips_r6) 2108 return SIGILL; 2109 2110 DPFROMREG(ft, MIPSInst_FT(ir)); 2111 DPFROMREG(fs, MIPSInst_FS(ir)); 2112 DPFROMREG(fd, MIPSInst_FD(ir)); 2113 rv.d = ieee754dp_maddf(fd, fs, ft); 2114 break; 2115 } 2116 2117 case fmsubf_op: { 2118 union ieee754dp ft, fs, fd; 2119 2120 if (!cpu_has_mips_r6) 2121 return SIGILL; 2122 2123 DPFROMREG(ft, MIPSInst_FT(ir)); 2124 DPFROMREG(fs, MIPSInst_FS(ir)); 2125 DPFROMREG(fd, MIPSInst_FD(ir)); 2126 rv.d = ieee754dp_msubf(fd, fs, ft); 2127 break; 2128 } 2129 2130 case frint_op: { 2131 union ieee754dp fs; 2132 2133 if (!cpu_has_mips_r6) 2134 return SIGILL; 2135 2136 DPFROMREG(fs, MIPSInst_FS(ir)); 2137 rv.l = ieee754dp_tlong(fs); 2138 rv.d = ieee754dp_flong(rv.l); 2139 goto copcsr; 2140 } 2141 2142 case fclass_op: { 2143 union ieee754dp fs; 2144 2145 if (!cpu_has_mips_r6) 2146 return SIGILL; 2147 2148 DPFROMREG(fs, MIPSInst_FS(ir)); 2149 rv.w = ieee754dp_2008class(fs); 2150 rfmt = w_fmt; 2151 break; 2152 } 2153 2154 case fmin_op: { 2155 union ieee754dp fs, ft; 2156 2157 if (!cpu_has_mips_r6) 2158 return SIGILL; 2159 2160 DPFROMREG(ft, MIPSInst_FT(ir)); 2161 DPFROMREG(fs, MIPSInst_FS(ir)); 2162 rv.d = ieee754dp_fmin(fs, ft); 2163 break; 2164 } 2165 2166 case fmina_op: { 2167 union ieee754dp fs, ft; 2168 2169 if (!cpu_has_mips_r6) 2170 return SIGILL; 2171 2172 DPFROMREG(ft, MIPSInst_FT(ir)); 2173 DPFROMREG(fs, MIPSInst_FS(ir)); 2174 rv.d = ieee754dp_fmina(fs, ft); 2175 break; 2176 } 2177 2178 case fmax_op: { 2179 union ieee754dp fs, ft; 2180 2181 if (!cpu_has_mips_r6) 2182 return SIGILL; 2183 2184 DPFROMREG(ft, MIPSInst_FT(ir)); 2185 DPFROMREG(fs, MIPSInst_FS(ir)); 2186 rv.d = ieee754dp_fmax(fs, ft); 2187 break; 2188 } 2189 2190 case fmaxa_op: { 2191 union ieee754dp fs, ft; 2192 2193 if (!cpu_has_mips_r6) 2194 return SIGILL; 2195 2196 DPFROMREG(ft, MIPSInst_FT(ir)); 2197 DPFROMREG(fs, MIPSInst_FS(ir)); 2198 rv.d = ieee754dp_fmaxa(fs, ft); 2199 break; 2200 } 2201 2202 case fabs_op: 2203 handler.u = ieee754dp_abs; 2204 goto dcopuop; 2205 2206 case fneg_op: 2207 handler.u = ieee754dp_neg; 2208 goto dcopuop; 2209 2210 case fmov_op: 2211 /* an easy one */ 2212 DPFROMREG(rv.d, MIPSInst_FS(ir)); 2213 goto copcsr; 2214 2215 /* binary op on handler */ 2216 dcopbop: 2217 DPFROMREG(fs, MIPSInst_FS(ir)); 2218 DPFROMREG(ft, MIPSInst_FT(ir)); 2219 2220 rv.d = (*handler.b) (fs, ft); 2221 goto copcsr; 2222 dcopuop: 2223 DPFROMREG(fs, MIPSInst_FS(ir)); 2224 rv.d = (*handler.u) (fs); 2225 goto copcsr; 2226 2227 /* 2228 * unary conv ops 2229 */ 2230 case fcvts_op: 2231 DPFROMREG(fs, MIPSInst_FS(ir)); 2232 rv.s = ieee754sp_fdp(fs); 2233 rfmt = s_fmt; 2234 goto copcsr; 2235 2236 case fcvtd_op: 2237 return SIGILL; /* not defined */ 2238 2239 case fcvtw_op: 2240 DPFROMREG(fs, MIPSInst_FS(ir)); 2241 rv.w = ieee754dp_tint(fs); /* wrong */ 2242 rfmt = w_fmt; 2243 goto copcsr; 2244 2245 case fround_op: 2246 case ftrunc_op: 2247 case fceil_op: 2248 case ffloor_op: 2249 if (!cpu_has_mips_2_3_4_5_r) 2250 return SIGILL; 2251 2252 oldrm = ieee754_csr.rm; 2253 DPFROMREG(fs, MIPSInst_FS(ir)); 2254 ieee754_csr.rm = MIPSInst_FUNC(ir); 2255 rv.w = ieee754dp_tint(fs); 2256 ieee754_csr.rm = oldrm; 2257 rfmt = w_fmt; 2258 goto copcsr; 2259 2260 case fsel_op: 2261 if (!cpu_has_mips_r6) 2262 return SIGILL; 2263 2264 DPFROMREG(fd, MIPSInst_FD(ir)); 2265 if (fd.bits & 0x1) 2266 DPFROMREG(rv.d, MIPSInst_FT(ir)); 2267 else 2268 DPFROMREG(rv.d, MIPSInst_FS(ir)); 2269 break; 2270 2271 case fcvtl_op: 2272 if (!cpu_has_mips_3_4_5_64_r2_r6) 2273 return SIGILL; 2274 2275 DPFROMREG(fs, MIPSInst_FS(ir)); 2276 rv.l = ieee754dp_tlong(fs); 2277 rfmt = l_fmt; 2278 goto copcsr; 2279 2280 case froundl_op: 2281 case ftruncl_op: 2282 case fceill_op: 2283 case ffloorl_op: 2284 if (!cpu_has_mips_3_4_5_64_r2_r6) 2285 return SIGILL; 2286 2287 oldrm = ieee754_csr.rm; 2288 DPFROMREG(fs, MIPSInst_FS(ir)); 2289 ieee754_csr.rm = MIPSInst_FUNC(ir); 2290 rv.l = ieee754dp_tlong(fs); 2291 ieee754_csr.rm = oldrm; 2292 rfmt = l_fmt; 2293 goto copcsr; 2294 2295 default: 2296 if (!NO_R6EMU && MIPSInst_FUNC(ir) >= fcmp_op) { 2297 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op; 2298 union ieee754dp fs, ft; 2299 2300 DPFROMREG(fs, MIPSInst_FS(ir)); 2301 DPFROMREG(ft, MIPSInst_FT(ir)); 2302 rv.w = ieee754dp_cmp(fs, ft, 2303 cmptab[cmpop & 0x7], cmpop & 0x8); 2304 rfmt = -1; 2305 if ((cmpop & 0x8) 2306 && 2307 ieee754_cxtest 2308 (IEEE754_INVALID_OPERATION)) 2309 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S; 2310 else 2311 goto copcsr; 2312 2313 } 2314 else { 2315 return SIGILL; 2316 } 2317 break; 2318 } 2319 break; 2320 } 2321 2322 case w_fmt: { 2323 union ieee754dp fs; 2324 2325 switch (MIPSInst_FUNC(ir)) { 2326 case fcvts_op: 2327 /* convert word to single precision real */ 2328 SPFROMREG(fs, MIPSInst_FS(ir)); 2329 rv.s = ieee754sp_fint(fs.bits); 2330 rfmt = s_fmt; 2331 goto copcsr; 2332 case fcvtd_op: 2333 /* convert word to double precision real */ 2334 SPFROMREG(fs, MIPSInst_FS(ir)); 2335 rv.d = ieee754dp_fint(fs.bits); 2336 rfmt = d_fmt; 2337 goto copcsr; 2338 default: { 2339 /* Emulating the new CMP.condn.fmt R6 instruction */ 2340 #define CMPOP_MASK 0x7 2341 #define SIGN_BIT (0x1 << 3) 2342 #define PREDICATE_BIT (0x1 << 4) 2343 2344 int cmpop = MIPSInst_FUNC(ir) & CMPOP_MASK; 2345 int sig = MIPSInst_FUNC(ir) & SIGN_BIT; 2346 union ieee754sp fs, ft; 2347 2348 /* This is an R6 only instruction */ 2349 if (!cpu_has_mips_r6 || 2350 (MIPSInst_FUNC(ir) & 0x20)) 2351 return SIGILL; 2352 2353 /* fmt is w_fmt for single precision so fix it */ 2354 rfmt = s_fmt; 2355 /* default to false */ 2356 rv.w = 0; 2357 2358 /* CMP.condn.S */ 2359 SPFROMREG(fs, MIPSInst_FS(ir)); 2360 SPFROMREG(ft, MIPSInst_FT(ir)); 2361 2362 /* positive predicates */ 2363 if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) { 2364 if (ieee754sp_cmp(fs, ft, cmptab[cmpop], 2365 sig)) 2366 rv.w = -1; /* true, all 1s */ 2367 if ((sig) && 2368 ieee754_cxtest(IEEE754_INVALID_OPERATION)) 2369 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S; 2370 else 2371 goto copcsr; 2372 } else { 2373 /* negative predicates */ 2374 switch (cmpop) { 2375 case 1: 2376 case 2: 2377 case 3: 2378 if (ieee754sp_cmp(fs, ft, 2379 negative_cmptab[cmpop], 2380 sig)) 2381 rv.w = -1; /* true, all 1s */ 2382 if (sig && 2383 ieee754_cxtest(IEEE754_INVALID_OPERATION)) 2384 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S; 2385 else 2386 goto copcsr; 2387 break; 2388 default: 2389 /* Reserved R6 ops */ 2390 pr_err("Reserved MIPS R6 CMP.condn.S operation\n"); 2391 return SIGILL; 2392 } 2393 } 2394 break; 2395 } 2396 } 2397 } 2398 2399 case l_fmt: 2400 2401 if (!cpu_has_mips_3_4_5_64_r2_r6) 2402 return SIGILL; 2403 2404 DIFROMREG(bits, MIPSInst_FS(ir)); 2405 2406 switch (MIPSInst_FUNC(ir)) { 2407 case fcvts_op: 2408 /* convert long to single precision real */ 2409 rv.s = ieee754sp_flong(bits); 2410 rfmt = s_fmt; 2411 goto copcsr; 2412 case fcvtd_op: 2413 /* convert long to double precision real */ 2414 rv.d = ieee754dp_flong(bits); 2415 rfmt = d_fmt; 2416 goto copcsr; 2417 default: { 2418 /* Emulating the new CMP.condn.fmt R6 instruction */ 2419 int cmpop = MIPSInst_FUNC(ir) & CMPOP_MASK; 2420 int sig = MIPSInst_FUNC(ir) & SIGN_BIT; 2421 union ieee754dp fs, ft; 2422 2423 if (!cpu_has_mips_r6 || 2424 (MIPSInst_FUNC(ir) & 0x20)) 2425 return SIGILL; 2426 2427 /* fmt is l_fmt for double precision so fix it */ 2428 rfmt = d_fmt; 2429 /* default to false */ 2430 rv.l = 0; 2431 2432 /* CMP.condn.D */ 2433 DPFROMREG(fs, MIPSInst_FS(ir)); 2434 DPFROMREG(ft, MIPSInst_FT(ir)); 2435 2436 /* positive predicates */ 2437 if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) { 2438 if (ieee754dp_cmp(fs, ft, 2439 cmptab[cmpop], sig)) 2440 rv.l = -1LL; /* true, all 1s */ 2441 if (sig && 2442 ieee754_cxtest(IEEE754_INVALID_OPERATION)) 2443 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S; 2444 else 2445 goto copcsr; 2446 } else { 2447 /* negative predicates */ 2448 switch (cmpop) { 2449 case 1: 2450 case 2: 2451 case 3: 2452 if (ieee754dp_cmp(fs, ft, 2453 negative_cmptab[cmpop], 2454 sig)) 2455 rv.l = -1LL; /* true, all 1s */ 2456 if (sig && 2457 ieee754_cxtest(IEEE754_INVALID_OPERATION)) 2458 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S; 2459 else 2460 goto copcsr; 2461 break; 2462 default: 2463 /* Reserved R6 ops */ 2464 pr_err("Reserved MIPS R6 CMP.condn.D operation\n"); 2465 return SIGILL; 2466 } 2467 } 2468 break; 2469 } 2470 } 2471 default: 2472 return SIGILL; 2473 } 2474 2475 /* 2476 * Update the fpu CSR register for this operation. 2477 * If an exception is required, generate a tidy SIGFPE exception, 2478 * without updating the result register. 2479 * Note: cause exception bits do not accumulate, they are rewritten 2480 * for each op; only the flag/sticky bits accumulate. 2481 */ 2482 ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr; 2483 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) { 2484 /*printk ("SIGFPE: FPU csr = %08x\n",ctx->fcr31); */ 2485 return SIGFPE; 2486 } 2487 2488 /* 2489 * Now we can safely write the result back to the register file. 2490 */ 2491 switch (rfmt) { 2492 case -1: 2493 2494 if (cpu_has_mips_4_5_r) 2495 cbit = fpucondbit[MIPSInst_FD(ir) >> 2]; 2496 else 2497 cbit = FPU_CSR_COND; 2498 if (rv.w) 2499 ctx->fcr31 |= cbit; 2500 else 2501 ctx->fcr31 &= ~cbit; 2502 break; 2503 2504 case d_fmt: 2505 DPTOREG(rv.d, MIPSInst_FD(ir)); 2506 break; 2507 case s_fmt: 2508 SPTOREG(rv.s, MIPSInst_FD(ir)); 2509 break; 2510 case w_fmt: 2511 SITOREG(rv.w, MIPSInst_FD(ir)); 2512 break; 2513 case l_fmt: 2514 if (!cpu_has_mips_3_4_5_64_r2_r6) 2515 return SIGILL; 2516 2517 DITOREG(rv.l, MIPSInst_FD(ir)); 2518 break; 2519 default: 2520 return SIGILL; 2521 } 2522 2523 return 0; 2524 } 2525 2526 /* 2527 * Emulate FPU instructions. 2528 * 2529 * If we use FPU hardware, then we have been typically called to handle 2530 * an unimplemented operation, such as where an operand is a NaN or 2531 * denormalized. In that case exit the emulation loop after a single 2532 * iteration so as to let hardware execute any subsequent instructions. 2533 * 2534 * If we have no FPU hardware or it has been disabled, then continue 2535 * emulating floating-point instructions until one of these conditions 2536 * has occurred: 2537 * 2538 * - a non-FPU instruction has been encountered, 2539 * 2540 * - an attempt to emulate has ended with a signal, 2541 * 2542 * - the ISA mode has been switched. 2543 * 2544 * We need to terminate the emulation loop if we got switched to the 2545 * MIPS16 mode, whether supported or not, so that we do not attempt 2546 * to emulate a MIPS16 instruction as a regular MIPS FPU instruction. 2547 * Similarly if we got switched to the microMIPS mode and only the 2548 * regular MIPS mode is supported, so that we do not attempt to emulate 2549 * a microMIPS instruction as a regular MIPS FPU instruction. Or if 2550 * we got switched to the regular MIPS mode and only the microMIPS mode 2551 * is supported, so that we do not attempt to emulate a regular MIPS 2552 * instruction that should cause an Address Error exception instead. 2553 * For simplicity we always terminate upon an ISA mode switch. 2554 */ 2555 int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx, 2556 int has_fpu, void *__user *fault_addr) 2557 { 2558 unsigned long oldepc, prevepc; 2559 struct mm_decoded_insn dec_insn; 2560 u16 instr[4]; 2561 u16 *instr_ptr; 2562 int sig = 0; 2563 2564 oldepc = xcp->cp0_epc; 2565 do { 2566 prevepc = xcp->cp0_epc; 2567 2568 if (get_isa16_mode(prevepc) && cpu_has_mmips) { 2569 /* 2570 * Get next 2 microMIPS instructions and convert them 2571 * into 32-bit instructions. 2572 */ 2573 if ((get_user(instr[0], (u16 __user *)msk_isa16_mode(xcp->cp0_epc))) || 2574 (get_user(instr[1], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 2))) || 2575 (get_user(instr[2], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 4))) || 2576 (get_user(instr[3], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 6)))) { 2577 MIPS_FPU_EMU_INC_STATS(errors); 2578 return SIGBUS; 2579 } 2580 instr_ptr = instr; 2581 2582 /* Get first instruction. */ 2583 if (mm_insn_16bit(*instr_ptr)) { 2584 /* Duplicate the half-word. */ 2585 dec_insn.insn = (*instr_ptr << 16) | 2586 (*instr_ptr); 2587 /* 16-bit instruction. */ 2588 dec_insn.pc_inc = 2; 2589 instr_ptr += 1; 2590 } else { 2591 dec_insn.insn = (*instr_ptr << 16) | 2592 *(instr_ptr+1); 2593 /* 32-bit instruction. */ 2594 dec_insn.pc_inc = 4; 2595 instr_ptr += 2; 2596 } 2597 /* Get second instruction. */ 2598 if (mm_insn_16bit(*instr_ptr)) { 2599 /* Duplicate the half-word. */ 2600 dec_insn.next_insn = (*instr_ptr << 16) | 2601 (*instr_ptr); 2602 /* 16-bit instruction. */ 2603 dec_insn.next_pc_inc = 2; 2604 } else { 2605 dec_insn.next_insn = (*instr_ptr << 16) | 2606 *(instr_ptr+1); 2607 /* 32-bit instruction. */ 2608 dec_insn.next_pc_inc = 4; 2609 } 2610 dec_insn.micro_mips_mode = 1; 2611 } else { 2612 if ((get_user(dec_insn.insn, 2613 (mips_instruction __user *) xcp->cp0_epc)) || 2614 (get_user(dec_insn.next_insn, 2615 (mips_instruction __user *)(xcp->cp0_epc+4)))) { 2616 MIPS_FPU_EMU_INC_STATS(errors); 2617 return SIGBUS; 2618 } 2619 dec_insn.pc_inc = 4; 2620 dec_insn.next_pc_inc = 4; 2621 dec_insn.micro_mips_mode = 0; 2622 } 2623 2624 if ((dec_insn.insn == 0) || 2625 ((dec_insn.pc_inc == 2) && 2626 ((dec_insn.insn & 0xffff) == MM_NOP16))) 2627 xcp->cp0_epc += dec_insn.pc_inc; /* Skip NOPs */ 2628 else { 2629 /* 2630 * The 'ieee754_csr' is an alias of ctx->fcr31. 2631 * No need to copy ctx->fcr31 to ieee754_csr. 2632 */ 2633 sig = cop1Emulate(xcp, ctx, dec_insn, fault_addr); 2634 } 2635 2636 if (has_fpu) 2637 break; 2638 if (sig) 2639 break; 2640 /* 2641 * We have to check for the ISA bit explicitly here, 2642 * because `get_isa16_mode' may return 0 if support 2643 * for code compression has been globally disabled, 2644 * or otherwise we may produce the wrong signal or 2645 * even proceed successfully where we must not. 2646 */ 2647 if ((xcp->cp0_epc ^ prevepc) & 0x1) 2648 break; 2649 2650 cond_resched(); 2651 } while (xcp->cp0_epc > prevepc); 2652 2653 /* SIGILL indicates a non-fpu instruction */ 2654 if (sig == SIGILL && xcp->cp0_epc != oldepc) 2655 /* but if EPC has advanced, then ignore it */ 2656 sig = 0; 2657 2658 return sig; 2659 } 2660