1 /* 2 * ARM helper routines 3 * 4 * Copyright (c) 2005-2007 CodeSourcery, LLC 5 * 6 * This library is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2.1 of the License, or (at your option) any later version. 10 * 11 * This library is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with this library; if not, see <http://www.gnu.org/licenses/>. 18 */ 19 #include "qemu/osdep.h" 20 #include "qemu/main-loop.h" 21 #include "cpu.h" 22 #include "exec/helper-proto.h" 23 #include "internals.h" 24 #include "cpu-features.h" 25 #include "exec/exec-all.h" 26 #include "exec/cpu_ldst.h" 27 #include "cpregs.h" 28 29 #define SIGNBIT (uint32_t)0x80000000 30 #define SIGNBIT64 ((uint64_t)1 << 63) 31 32 int exception_target_el(CPUARMState *env) 33 { 34 int target_el = MAX(1, arm_current_el(env)); 35 36 /* 37 * No such thing as secure EL1 if EL3 is aarch32, 38 * so update the target EL to EL3 in this case. 39 */ 40 if (arm_is_secure(env) && !arm_el_is_aa64(env, 3) && target_el == 1) { 41 target_el = 3; 42 } 43 44 return target_el; 45 } 46 47 void raise_exception(CPUARMState *env, uint32_t excp, 48 uint32_t syndrome, uint32_t target_el) 49 { 50 CPUState *cs = env_cpu(env); 51 52 if (target_el == 1 && (arm_hcr_el2_eff(env) & HCR_TGE)) { 53 /* 54 * Redirect NS EL1 exceptions to NS EL2. These are reported with 55 * their original syndrome register value, with the exception of 56 * SIMD/FP access traps, which are reported as uncategorized 57 * (see DDI0478C.a D1.10.4) 58 */ 59 target_el = 2; 60 if (syn_get_ec(syndrome) == EC_ADVSIMDFPACCESSTRAP) { 61 syndrome = syn_uncategorized(); 62 } 63 } 64 65 assert(!excp_is_internal(excp)); 66 cs->exception_index = excp; 67 env->exception.syndrome = syndrome; 68 env->exception.target_el = target_el; 69 cpu_loop_exit(cs); 70 } 71 72 void raise_exception_ra(CPUARMState *env, uint32_t excp, uint32_t syndrome, 73 uint32_t target_el, uintptr_t ra) 74 { 75 CPUState *cs = env_cpu(env); 76 77 /* 78 * restore_state_to_opc() will set env->exception.syndrome, so 79 * we must restore CPU state here before setting the syndrome 80 * the caller passed us, and cannot use cpu_loop_exit_restore(). 81 */ 82 cpu_restore_state(cs, ra); 83 raise_exception(env, excp, syndrome, target_el); 84 } 85 86 uint64_t HELPER(neon_tbl)(CPUARMState *env, uint32_t desc, 87 uint64_t ireg, uint64_t def) 88 { 89 uint64_t tmp, val = 0; 90 uint32_t maxindex = ((desc & 3) + 1) * 8; 91 uint32_t base_reg = desc >> 2; 92 uint32_t shift, index, reg; 93 94 for (shift = 0; shift < 64; shift += 8) { 95 index = (ireg >> shift) & 0xff; 96 if (index < maxindex) { 97 reg = base_reg + (index >> 3); 98 tmp = *aa32_vfp_dreg(env, reg); 99 tmp = ((tmp >> ((index & 7) << 3)) & 0xff) << shift; 100 } else { 101 tmp = def & (0xffull << shift); 102 } 103 val |= tmp; 104 } 105 return val; 106 } 107 108 void HELPER(v8m_stackcheck)(CPUARMState *env, uint32_t newvalue) 109 { 110 /* 111 * Perform the v8M stack limit check for SP updates from translated code, 112 * raising an exception if the limit is breached. 113 */ 114 if (newvalue < v7m_sp_limit(env)) { 115 /* 116 * Stack limit exceptions are a rare case, so rather than syncing 117 * PC/condbits before the call, we use raise_exception_ra() so 118 * that cpu_restore_state() will sort them out. 119 */ 120 raise_exception_ra(env, EXCP_STKOF, 0, 1, GETPC()); 121 } 122 } 123 124 /* Sign/zero extend */ 125 uint32_t HELPER(sxtb16)(uint32_t x) 126 { 127 uint32_t res; 128 res = (uint16_t)(int8_t)x; 129 res |= (uint32_t)(int8_t)(x >> 16) << 16; 130 return res; 131 } 132 133 static void handle_possible_div0_trap(CPUARMState *env, uintptr_t ra) 134 { 135 /* 136 * Take a division-by-zero exception if necessary; otherwise return 137 * to get the usual non-trapping division behaviour (result of 0) 138 */ 139 if (arm_feature(env, ARM_FEATURE_M) 140 && (env->v7m.ccr[env->v7m.secure] & R_V7M_CCR_DIV_0_TRP_MASK)) { 141 raise_exception_ra(env, EXCP_DIVBYZERO, 0, 1, ra); 142 } 143 } 144 145 uint32_t HELPER(uxtb16)(uint32_t x) 146 { 147 uint32_t res; 148 res = (uint16_t)(uint8_t)x; 149 res |= (uint32_t)(uint8_t)(x >> 16) << 16; 150 return res; 151 } 152 153 int32_t HELPER(sdiv)(CPUARMState *env, int32_t num, int32_t den) 154 { 155 if (den == 0) { 156 handle_possible_div0_trap(env, GETPC()); 157 return 0; 158 } 159 if (num == INT_MIN && den == -1) { 160 return INT_MIN; 161 } 162 return num / den; 163 } 164 165 uint32_t HELPER(udiv)(CPUARMState *env, uint32_t num, uint32_t den) 166 { 167 if (den == 0) { 168 handle_possible_div0_trap(env, GETPC()); 169 return 0; 170 } 171 return num / den; 172 } 173 174 uint32_t HELPER(rbit)(uint32_t x) 175 { 176 return revbit32(x); 177 } 178 179 uint32_t HELPER(add_setq)(CPUARMState *env, uint32_t a, uint32_t b) 180 { 181 uint32_t res = a + b; 182 if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT)) 183 env->QF = 1; 184 return res; 185 } 186 187 uint32_t HELPER(add_saturate)(CPUARMState *env, uint32_t a, uint32_t b) 188 { 189 uint32_t res = a + b; 190 if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT)) { 191 env->QF = 1; 192 res = ~(((int32_t)a >> 31) ^ SIGNBIT); 193 } 194 return res; 195 } 196 197 uint32_t HELPER(sub_saturate)(CPUARMState *env, uint32_t a, uint32_t b) 198 { 199 uint32_t res = a - b; 200 if (((res ^ a) & SIGNBIT) && ((a ^ b) & SIGNBIT)) { 201 env->QF = 1; 202 res = ~(((int32_t)a >> 31) ^ SIGNBIT); 203 } 204 return res; 205 } 206 207 uint32_t HELPER(add_usaturate)(CPUARMState *env, uint32_t a, uint32_t b) 208 { 209 uint32_t res = a + b; 210 if (res < a) { 211 env->QF = 1; 212 res = ~0; 213 } 214 return res; 215 } 216 217 uint32_t HELPER(sub_usaturate)(CPUARMState *env, uint32_t a, uint32_t b) 218 { 219 uint32_t res = a - b; 220 if (res > a) { 221 env->QF = 1; 222 res = 0; 223 } 224 return res; 225 } 226 227 /* Signed saturation. */ 228 static inline uint32_t do_ssat(CPUARMState *env, int32_t val, int shift) 229 { 230 int32_t top; 231 uint32_t mask; 232 233 top = val >> shift; 234 mask = (1u << shift) - 1; 235 if (top > 0) { 236 env->QF = 1; 237 return mask; 238 } else if (top < -1) { 239 env->QF = 1; 240 return ~mask; 241 } 242 return val; 243 } 244 245 /* Unsigned saturation. */ 246 static inline uint32_t do_usat(CPUARMState *env, int32_t val, int shift) 247 { 248 uint32_t max; 249 250 max = (1u << shift) - 1; 251 if (val < 0) { 252 env->QF = 1; 253 return 0; 254 } else if (val > max) { 255 env->QF = 1; 256 return max; 257 } 258 return val; 259 } 260 261 /* Signed saturate. */ 262 uint32_t HELPER(ssat)(CPUARMState *env, uint32_t x, uint32_t shift) 263 { 264 return do_ssat(env, x, shift); 265 } 266 267 /* Dual halfword signed saturate. */ 268 uint32_t HELPER(ssat16)(CPUARMState *env, uint32_t x, uint32_t shift) 269 { 270 uint32_t res; 271 272 res = (uint16_t)do_ssat(env, (int16_t)x, shift); 273 res |= do_ssat(env, ((int32_t)x) >> 16, shift) << 16; 274 return res; 275 } 276 277 /* Unsigned saturate. */ 278 uint32_t HELPER(usat)(CPUARMState *env, uint32_t x, uint32_t shift) 279 { 280 return do_usat(env, x, shift); 281 } 282 283 /* Dual halfword unsigned saturate. */ 284 uint32_t HELPER(usat16)(CPUARMState *env, uint32_t x, uint32_t shift) 285 { 286 uint32_t res; 287 288 res = (uint16_t)do_usat(env, (int16_t)x, shift); 289 res |= do_usat(env, ((int32_t)x) >> 16, shift) << 16; 290 return res; 291 } 292 293 void HELPER(setend)(CPUARMState *env) 294 { 295 env->uncached_cpsr ^= CPSR_E; 296 arm_rebuild_hflags(env); 297 } 298 299 void HELPER(check_bxj_trap)(CPUARMState *env, uint32_t rm) 300 { 301 /* 302 * Only called if in NS EL0 or EL1 for a BXJ for a v7A CPU; 303 * check if HSTR.TJDBX means we need to trap to EL2. 304 */ 305 if (env->cp15.hstr_el2 & HSTR_TJDBX) { 306 /* 307 * We know the condition code check passed, so take the IMPDEF 308 * choice to always report CV=1 COND 0xe 309 */ 310 uint32_t syn = syn_bxjtrap(1, 0xe, rm); 311 raise_exception_ra(env, EXCP_HYP_TRAP, syn, 2, GETPC()); 312 } 313 } 314 315 #ifndef CONFIG_USER_ONLY 316 /* Function checks whether WFx (WFI/WFE) instructions are set up to be trapped. 317 * The function returns the target EL (1-3) if the instruction is to be trapped; 318 * otherwise it returns 0 indicating it is not trapped. 319 */ 320 static inline int check_wfx_trap(CPUARMState *env, bool is_wfe) 321 { 322 int cur_el = arm_current_el(env); 323 uint64_t mask; 324 325 if (arm_feature(env, ARM_FEATURE_M)) { 326 /* M profile cores can never trap WFI/WFE. */ 327 return 0; 328 } 329 330 /* If we are currently in EL0 then we need to check if SCTLR is set up for 331 * WFx instructions being trapped to EL1. These trap bits don't exist in v7. 332 */ 333 if (cur_el < 1 && arm_feature(env, ARM_FEATURE_V8)) { 334 int target_el; 335 336 mask = is_wfe ? SCTLR_nTWE : SCTLR_nTWI; 337 if (arm_is_secure_below_el3(env) && !arm_el_is_aa64(env, 3)) { 338 /* Secure EL0 and Secure PL1 is at EL3 */ 339 target_el = 3; 340 } else { 341 target_el = 1; 342 } 343 344 if (!(env->cp15.sctlr_el[target_el] & mask)) { 345 return target_el; 346 } 347 } 348 349 /* We are not trapping to EL1; trap to EL2 if HCR_EL2 requires it 350 * No need for ARM_FEATURE check as if HCR_EL2 doesn't exist the 351 * bits will be zero indicating no trap. 352 */ 353 if (cur_el < 2) { 354 mask = is_wfe ? HCR_TWE : HCR_TWI; 355 if (arm_hcr_el2_eff(env) & mask) { 356 return 2; 357 } 358 } 359 360 /* We are not trapping to EL1 or EL2; trap to EL3 if SCR_EL3 requires it */ 361 if (cur_el < 3) { 362 mask = (is_wfe) ? SCR_TWE : SCR_TWI; 363 if (env->cp15.scr_el3 & mask) { 364 return 3; 365 } 366 } 367 368 return 0; 369 } 370 #endif 371 372 void HELPER(wfi)(CPUARMState *env, uint32_t insn_len) 373 { 374 #ifdef CONFIG_USER_ONLY 375 /* 376 * WFI in the user-mode emulator is technically permitted but not 377 * something any real-world code would do. AArch64 Linux kernels 378 * trap it via SCTRL_EL1.nTWI and make it an (expensive) NOP; 379 * AArch32 kernels don't trap it so it will delay a bit. 380 * For QEMU, make it NOP here, because trying to raise EXCP_HLT 381 * would trigger an abort. 382 */ 383 return; 384 #else 385 CPUState *cs = env_cpu(env); 386 int target_el = check_wfx_trap(env, false); 387 388 if (cpu_has_work(cs)) { 389 /* Don't bother to go into our "low power state" if 390 * we would just wake up immediately. 391 */ 392 return; 393 } 394 395 if (target_el) { 396 if (env->aarch64) { 397 env->pc -= insn_len; 398 } else { 399 env->regs[15] -= insn_len; 400 } 401 402 raise_exception(env, EXCP_UDEF, syn_wfx(1, 0xe, 0, insn_len == 2), 403 target_el); 404 } 405 406 cs->exception_index = EXCP_HLT; 407 cs->halted = 1; 408 cpu_loop_exit(cs); 409 #endif 410 } 411 412 void HELPER(wfit)(CPUARMState *env, uint64_t timeout) 413 { 414 #ifdef CONFIG_USER_ONLY 415 /* 416 * WFI in the user-mode emulator is technically permitted but not 417 * something any real-world code would do. AArch64 Linux kernels 418 * trap it via SCTRL_EL1.nTWI and make it an (expensive) NOP; 419 * AArch32 kernels don't trap it so it will delay a bit. 420 * For QEMU, make it NOP here, because trying to raise EXCP_HLT 421 * would trigger an abort. 422 */ 423 return; 424 #else 425 ARMCPU *cpu = env_archcpu(env); 426 CPUState *cs = env_cpu(env); 427 int target_el = check_wfx_trap(env, false); 428 /* The WFIT should time out when CNTVCT_EL0 >= the specified value. */ 429 uint64_t cntval = gt_get_countervalue(env); 430 uint64_t offset = gt_virt_cnt_offset(env); 431 uint64_t cntvct = cntval - offset; 432 uint64_t nexttick; 433 434 if (cpu_has_work(cs) || cntvct >= timeout) { 435 /* 436 * Don't bother to go into our "low power state" if 437 * we would just wake up immediately. 438 */ 439 return; 440 } 441 442 if (target_el) { 443 env->pc -= 4; 444 raise_exception(env, EXCP_UDEF, syn_wfx(1, 0xe, 0, false), 445 target_el); 446 } 447 448 if (uadd64_overflow(timeout, offset, &nexttick)) { 449 nexttick = UINT64_MAX; 450 } 451 if (nexttick > INT64_MAX / gt_cntfrq_period_ns(cpu)) { 452 /* 453 * If the timeout is too long for the signed 64-bit range 454 * of a QEMUTimer, let it expire early. 455 */ 456 timer_mod_ns(cpu->wfxt_timer, INT64_MAX); 457 } else { 458 timer_mod(cpu->wfxt_timer, nexttick); 459 } 460 cs->exception_index = EXCP_HLT; 461 cs->halted = 1; 462 cpu_loop_exit(cs); 463 #endif 464 } 465 466 void HELPER(wfe)(CPUARMState *env) 467 { 468 /* This is a hint instruction that is semantically different 469 * from YIELD even though we currently implement it identically. 470 * Don't actually halt the CPU, just yield back to top 471 * level loop. This is not going into a "low power state" 472 * (ie halting until some event occurs), so we never take 473 * a configurable trap to a different exception level. 474 */ 475 HELPER(yield)(env); 476 } 477 478 void HELPER(yield)(CPUARMState *env) 479 { 480 CPUState *cs = env_cpu(env); 481 482 /* This is a non-trappable hint instruction that generally indicates 483 * that the guest is currently busy-looping. Yield control back to the 484 * top level loop so that a more deserving VCPU has a chance to run. 485 */ 486 cs->exception_index = EXCP_YIELD; 487 cpu_loop_exit(cs); 488 } 489 490 /* Raise an internal-to-QEMU exception. This is limited to only 491 * those EXCP values which are special cases for QEMU to interrupt 492 * execution and not to be used for exceptions which are passed to 493 * the guest (those must all have syndrome information and thus should 494 * use exception_with_syndrome*). 495 */ 496 void HELPER(exception_internal)(CPUARMState *env, uint32_t excp) 497 { 498 CPUState *cs = env_cpu(env); 499 500 assert(excp_is_internal(excp)); 501 cs->exception_index = excp; 502 cpu_loop_exit(cs); 503 } 504 505 /* Raise an exception with the specified syndrome register value */ 506 void HELPER(exception_with_syndrome_el)(CPUARMState *env, uint32_t excp, 507 uint32_t syndrome, uint32_t target_el) 508 { 509 raise_exception(env, excp, syndrome, target_el); 510 } 511 512 /* 513 * Raise an exception with the specified syndrome register value 514 * to the default target el. 515 */ 516 void HELPER(exception_with_syndrome)(CPUARMState *env, uint32_t excp, 517 uint32_t syndrome) 518 { 519 raise_exception(env, excp, syndrome, exception_target_el(env)); 520 } 521 522 uint32_t HELPER(cpsr_read)(CPUARMState *env) 523 { 524 return cpsr_read(env) & ~CPSR_EXEC; 525 } 526 527 void HELPER(cpsr_write)(CPUARMState *env, uint32_t val, uint32_t mask) 528 { 529 cpsr_write(env, val, mask, CPSRWriteByInstr); 530 /* TODO: Not all cpsr bits are relevant to hflags. */ 531 arm_rebuild_hflags(env); 532 } 533 534 /* Write the CPSR for a 32-bit exception return */ 535 void HELPER(cpsr_write_eret)(CPUARMState *env, uint32_t val) 536 { 537 uint32_t mask; 538 539 bql_lock(); 540 arm_call_pre_el_change_hook(env_archcpu(env)); 541 bql_unlock(); 542 543 mask = aarch32_cpsr_valid_mask(env->features, &env_archcpu(env)->isar); 544 cpsr_write(env, val, mask, CPSRWriteExceptionReturn); 545 546 /* Generated code has already stored the new PC value, but 547 * without masking out its low bits, because which bits need 548 * masking depends on whether we're returning to Thumb or ARM 549 * state. Do the masking now. 550 */ 551 env->regs[15] &= (env->thumb ? ~1 : ~3); 552 arm_rebuild_hflags(env); 553 554 bql_lock(); 555 arm_call_el_change_hook(env_archcpu(env)); 556 bql_unlock(); 557 } 558 559 /* Access to user mode registers from privileged modes. */ 560 uint32_t HELPER(get_user_reg)(CPUARMState *env, uint32_t regno) 561 { 562 uint32_t val; 563 564 if (regno == 13) { 565 val = env->banked_r13[BANK_USRSYS]; 566 } else if (regno == 14) { 567 val = env->banked_r14[BANK_USRSYS]; 568 } else if (regno >= 8 569 && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) { 570 val = env->usr_regs[regno - 8]; 571 } else { 572 val = env->regs[regno]; 573 } 574 return val; 575 } 576 577 void HELPER(set_user_reg)(CPUARMState *env, uint32_t regno, uint32_t val) 578 { 579 if (regno == 13) { 580 env->banked_r13[BANK_USRSYS] = val; 581 } else if (regno == 14) { 582 env->banked_r14[BANK_USRSYS] = val; 583 } else if (regno >= 8 584 && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) { 585 env->usr_regs[regno - 8] = val; 586 } else { 587 env->regs[regno] = val; 588 } 589 } 590 591 void HELPER(set_r13_banked)(CPUARMState *env, uint32_t mode, uint32_t val) 592 { 593 if ((env->uncached_cpsr & CPSR_M) == mode) { 594 env->regs[13] = val; 595 } else { 596 env->banked_r13[bank_number(mode)] = val; 597 } 598 } 599 600 uint32_t HELPER(get_r13_banked)(CPUARMState *env, uint32_t mode) 601 { 602 if ((env->uncached_cpsr & CPSR_M) == ARM_CPU_MODE_SYS) { 603 /* SRS instruction is UNPREDICTABLE from System mode; we UNDEF. 604 * Other UNPREDICTABLE and UNDEF cases were caught at translate time. 605 */ 606 raise_exception(env, EXCP_UDEF, syn_uncategorized(), 607 exception_target_el(env)); 608 } 609 610 if ((env->uncached_cpsr & CPSR_M) == mode) { 611 return env->regs[13]; 612 } else { 613 return env->banked_r13[bank_number(mode)]; 614 } 615 } 616 617 static void msr_mrs_banked_exc_checks(CPUARMState *env, uint32_t tgtmode, 618 uint32_t regno) 619 { 620 /* Raise an exception if the requested access is one of the UNPREDICTABLE 621 * cases; otherwise return. This broadly corresponds to the pseudocode 622 * BankedRegisterAccessValid() and SPSRAccessValid(), 623 * except that we have already handled some cases at translate time. 624 */ 625 int curmode = env->uncached_cpsr & CPSR_M; 626 627 if (tgtmode == ARM_CPU_MODE_HYP) { 628 /* 629 * Handle Hyp target regs first because some are special cases 630 * which don't want the usual "not accessible from tgtmode" check. 631 */ 632 switch (regno) { 633 case 16 ... 17: /* ELR_Hyp, SPSR_Hyp */ 634 if (curmode != ARM_CPU_MODE_HYP && curmode != ARM_CPU_MODE_MON) { 635 goto undef; 636 } 637 break; 638 case 13: 639 if (curmode != ARM_CPU_MODE_MON) { 640 goto undef; 641 } 642 break; 643 default: 644 g_assert_not_reached(); 645 } 646 return; 647 } 648 649 if (curmode == tgtmode) { 650 goto undef; 651 } 652 653 if (tgtmode == ARM_CPU_MODE_USR) { 654 switch (regno) { 655 case 8 ... 12: 656 if (curmode != ARM_CPU_MODE_FIQ) { 657 goto undef; 658 } 659 break; 660 case 13: 661 if (curmode == ARM_CPU_MODE_SYS) { 662 goto undef; 663 } 664 break; 665 case 14: 666 if (curmode == ARM_CPU_MODE_HYP || curmode == ARM_CPU_MODE_SYS) { 667 goto undef; 668 } 669 break; 670 default: 671 break; 672 } 673 } 674 675 return; 676 677 undef: 678 raise_exception(env, EXCP_UDEF, syn_uncategorized(), 679 exception_target_el(env)); 680 } 681 682 void HELPER(msr_banked)(CPUARMState *env, uint32_t value, uint32_t tgtmode, 683 uint32_t regno) 684 { 685 msr_mrs_banked_exc_checks(env, tgtmode, regno); 686 687 switch (regno) { 688 case 16: /* SPSRs */ 689 if (tgtmode == (env->uncached_cpsr & CPSR_M)) { 690 /* Only happens for SPSR_Hyp access in Hyp mode */ 691 env->spsr = value; 692 } else { 693 env->banked_spsr[bank_number(tgtmode)] = value; 694 } 695 break; 696 case 17: /* ELR_Hyp */ 697 env->elr_el[2] = value; 698 break; 699 case 13: 700 env->banked_r13[bank_number(tgtmode)] = value; 701 break; 702 case 14: 703 env->banked_r14[r14_bank_number(tgtmode)] = value; 704 break; 705 case 8 ... 12: 706 switch (tgtmode) { 707 case ARM_CPU_MODE_USR: 708 env->usr_regs[regno - 8] = value; 709 break; 710 case ARM_CPU_MODE_FIQ: 711 env->fiq_regs[regno - 8] = value; 712 break; 713 default: 714 g_assert_not_reached(); 715 } 716 break; 717 default: 718 g_assert_not_reached(); 719 } 720 } 721 722 uint32_t HELPER(mrs_banked)(CPUARMState *env, uint32_t tgtmode, uint32_t regno) 723 { 724 msr_mrs_banked_exc_checks(env, tgtmode, regno); 725 726 switch (regno) { 727 case 16: /* SPSRs */ 728 if (tgtmode == (env->uncached_cpsr & CPSR_M)) { 729 /* Only happens for SPSR_Hyp access in Hyp mode */ 730 return env->spsr; 731 } else { 732 return env->banked_spsr[bank_number(tgtmode)]; 733 } 734 case 17: /* ELR_Hyp */ 735 return env->elr_el[2]; 736 case 13: 737 return env->banked_r13[bank_number(tgtmode)]; 738 case 14: 739 return env->banked_r14[r14_bank_number(tgtmode)]; 740 case 8 ... 12: 741 switch (tgtmode) { 742 case ARM_CPU_MODE_USR: 743 return env->usr_regs[regno - 8]; 744 case ARM_CPU_MODE_FIQ: 745 return env->fiq_regs[regno - 8]; 746 default: 747 g_assert_not_reached(); 748 } 749 default: 750 g_assert_not_reached(); 751 } 752 } 753 754 const void *HELPER(access_check_cp_reg)(CPUARMState *env, uint32_t key, 755 uint32_t syndrome, uint32_t isread) 756 { 757 ARMCPU *cpu = env_archcpu(env); 758 const ARMCPRegInfo *ri = get_arm_cp_reginfo(cpu->cp_regs, key); 759 CPAccessResult res = CP_ACCESS_OK; 760 int target_el; 761 762 assert(ri != NULL); 763 764 if (arm_feature(env, ARM_FEATURE_XSCALE) && ri->cp < 14 765 && extract32(env->cp15.c15_cpar, ri->cp, 1) == 0) { 766 res = CP_ACCESS_TRAP; 767 goto fail; 768 } 769 770 if (ri->accessfn) { 771 res = ri->accessfn(env, ri, isread); 772 } 773 774 /* 775 * If the access function indicates a trap from EL0 to EL1 then 776 * that always takes priority over the HSTR_EL2 trap. (If it indicates 777 * a trap to EL3, then the HSTR_EL2 trap takes priority; if it indicates 778 * a trap to EL2, then the syndrome is the same either way so we don't 779 * care whether technically the architecture says that HSTR_EL2 trap or 780 * the other trap takes priority. So we take the "check HSTR_EL2" path 781 * for all of those cases.) 782 */ 783 if (res != CP_ACCESS_OK && ((res & CP_ACCESS_EL_MASK) == 0) && 784 arm_current_el(env) == 0) { 785 goto fail; 786 } 787 788 /* 789 * HSTR_EL2 traps from EL1 are checked earlier, in generated code; 790 * we only need to check here for traps from EL0. 791 */ 792 if (!is_a64(env) && arm_current_el(env) == 0 && ri->cp == 15 && 793 arm_is_el2_enabled(env) && 794 (arm_hcr_el2_eff(env) & (HCR_E2H | HCR_TGE)) != (HCR_E2H | HCR_TGE)) { 795 uint32_t mask = 1 << ri->crn; 796 797 if (ri->type & ARM_CP_64BIT) { 798 mask = 1 << ri->crm; 799 } 800 801 /* T4 and T14 are RES0 */ 802 mask &= ~((1 << 4) | (1 << 14)); 803 804 if (env->cp15.hstr_el2 & mask) { 805 res = CP_ACCESS_TRAP_EL2; 806 goto fail; 807 } 808 } 809 810 /* 811 * Fine-grained traps also are lower priority than undef-to-EL1, 812 * higher priority than trap-to-EL3, and we don't care about priority 813 * order with other EL2 traps because the syndrome value is the same. 814 */ 815 if (arm_fgt_active(env, arm_current_el(env))) { 816 uint64_t trapword = 0; 817 unsigned int idx = FIELD_EX32(ri->fgt, FGT, IDX); 818 unsigned int bitpos = FIELD_EX32(ri->fgt, FGT, BITPOS); 819 bool rev = FIELD_EX32(ri->fgt, FGT, REV); 820 bool trapbit; 821 822 if (ri->fgt & FGT_EXEC) { 823 assert(idx < ARRAY_SIZE(env->cp15.fgt_exec)); 824 trapword = env->cp15.fgt_exec[idx]; 825 } else if (isread && (ri->fgt & FGT_R)) { 826 assert(idx < ARRAY_SIZE(env->cp15.fgt_read)); 827 trapword = env->cp15.fgt_read[idx]; 828 } else if (!isread && (ri->fgt & FGT_W)) { 829 assert(idx < ARRAY_SIZE(env->cp15.fgt_write)); 830 trapword = env->cp15.fgt_write[idx]; 831 } 832 833 trapbit = extract64(trapword, bitpos, 1); 834 if (trapbit != rev) { 835 res = CP_ACCESS_TRAP_EL2; 836 goto fail; 837 } 838 } 839 840 if (likely(res == CP_ACCESS_OK)) { 841 return ri; 842 } 843 844 fail: 845 switch (res & ~CP_ACCESS_EL_MASK) { 846 case CP_ACCESS_TRAP: 847 break; 848 case CP_ACCESS_TRAP_UNCATEGORIZED: 849 /* Only CP_ACCESS_TRAP traps are direct to a specified EL */ 850 assert((res & CP_ACCESS_EL_MASK) == 0); 851 if (cpu_isar_feature(aa64_ids, cpu) && isread && 852 arm_cpreg_in_idspace(ri)) { 853 /* 854 * FEAT_IDST says this should be reported as EC_SYSTEMREGISTERTRAP, 855 * not EC_UNCATEGORIZED 856 */ 857 break; 858 } 859 syndrome = syn_uncategorized(); 860 break; 861 default: 862 g_assert_not_reached(); 863 } 864 865 target_el = res & CP_ACCESS_EL_MASK; 866 switch (target_el) { 867 case 0: 868 target_el = exception_target_el(env); 869 break; 870 case 2: 871 assert(arm_current_el(env) != 3); 872 assert(arm_is_el2_enabled(env)); 873 break; 874 case 3: 875 assert(arm_feature(env, ARM_FEATURE_EL3)); 876 break; 877 default: 878 /* No "direct" traps to EL1 */ 879 g_assert_not_reached(); 880 } 881 882 raise_exception(env, EXCP_UDEF, syndrome, target_el); 883 } 884 885 const void *HELPER(lookup_cp_reg)(CPUARMState *env, uint32_t key) 886 { 887 ARMCPU *cpu = env_archcpu(env); 888 const ARMCPRegInfo *ri = get_arm_cp_reginfo(cpu->cp_regs, key); 889 890 assert(ri != NULL); 891 return ri; 892 } 893 894 /* 895 * Test for HCR_EL2.TIDCP at EL1. 896 * Since implementation defined registers are rare, and within QEMU 897 * most of them are no-op, do not waste HFLAGS space for this and 898 * always use a helper. 899 */ 900 void HELPER(tidcp_el1)(CPUARMState *env, uint32_t syndrome) 901 { 902 if (arm_hcr_el2_eff(env) & HCR_TIDCP) { 903 raise_exception_ra(env, EXCP_UDEF, syndrome, 2, GETPC()); 904 } 905 } 906 907 /* 908 * Similarly, for FEAT_TIDCP1 at EL0. 909 * We have already checked for the presence of the feature. 910 */ 911 void HELPER(tidcp_el0)(CPUARMState *env, uint32_t syndrome) 912 { 913 /* See arm_sctlr(), but we also need the sctlr el. */ 914 ARMMMUIdx mmu_idx = arm_mmu_idx_el(env, 0); 915 int target_el = mmu_idx == ARMMMUIdx_E20_0 ? 2 : 1; 916 917 /* 918 * The bit is not valid unless the target el is aa64, but since the 919 * bit test is simpler perform that first and check validity after. 920 */ 921 if ((env->cp15.sctlr_el[target_el] & SCTLR_TIDCP) 922 && arm_el_is_aa64(env, target_el)) { 923 raise_exception_ra(env, EXCP_UDEF, syndrome, target_el, GETPC()); 924 } 925 } 926 927 void HELPER(set_cp_reg)(CPUARMState *env, const void *rip, uint32_t value) 928 { 929 const ARMCPRegInfo *ri = rip; 930 931 if (ri->type & ARM_CP_IO) { 932 bql_lock(); 933 ri->writefn(env, ri, value); 934 bql_unlock(); 935 } else { 936 ri->writefn(env, ri, value); 937 } 938 } 939 940 uint32_t HELPER(get_cp_reg)(CPUARMState *env, const void *rip) 941 { 942 const ARMCPRegInfo *ri = rip; 943 uint32_t res; 944 945 if (ri->type & ARM_CP_IO) { 946 bql_lock(); 947 res = ri->readfn(env, ri); 948 bql_unlock(); 949 } else { 950 res = ri->readfn(env, ri); 951 } 952 953 return res; 954 } 955 956 void HELPER(set_cp_reg64)(CPUARMState *env, const void *rip, uint64_t value) 957 { 958 const ARMCPRegInfo *ri = rip; 959 960 if (ri->type & ARM_CP_IO) { 961 bql_lock(); 962 ri->writefn(env, ri, value); 963 bql_unlock(); 964 } else { 965 ri->writefn(env, ri, value); 966 } 967 } 968 969 uint64_t HELPER(get_cp_reg64)(CPUARMState *env, const void *rip) 970 { 971 const ARMCPRegInfo *ri = rip; 972 uint64_t res; 973 974 if (ri->type & ARM_CP_IO) { 975 bql_lock(); 976 res = ri->readfn(env, ri); 977 bql_unlock(); 978 } else { 979 res = ri->readfn(env, ri); 980 } 981 982 return res; 983 } 984 985 void HELPER(pre_hvc)(CPUARMState *env) 986 { 987 ARMCPU *cpu = env_archcpu(env); 988 int cur_el = arm_current_el(env); 989 /* FIXME: Use actual secure state. */ 990 bool secure = false; 991 bool undef; 992 993 if (arm_is_psci_call(cpu, EXCP_HVC)) { 994 /* If PSCI is enabled and this looks like a valid PSCI call then 995 * that overrides the architecturally mandated HVC behaviour. 996 */ 997 return; 998 } 999 1000 if (!arm_feature(env, ARM_FEATURE_EL2)) { 1001 /* If EL2 doesn't exist, HVC always UNDEFs */ 1002 undef = true; 1003 } else if (arm_feature(env, ARM_FEATURE_EL3)) { 1004 /* EL3.HCE has priority over EL2.HCD. */ 1005 undef = !(env->cp15.scr_el3 & SCR_HCE); 1006 } else { 1007 undef = env->cp15.hcr_el2 & HCR_HCD; 1008 } 1009 1010 /* In ARMv7 and ARMv8/AArch32, HVC is undef in secure state. 1011 * For ARMv8/AArch64, HVC is allowed in EL3. 1012 * Note that we've already trapped HVC from EL0 at translation 1013 * time. 1014 */ 1015 if (secure && (!is_a64(env) || cur_el == 1)) { 1016 undef = true; 1017 } 1018 1019 if (undef) { 1020 raise_exception(env, EXCP_UDEF, syn_uncategorized(), 1021 exception_target_el(env)); 1022 } 1023 } 1024 1025 void HELPER(pre_smc)(CPUARMState *env, uint32_t syndrome) 1026 { 1027 ARMCPU *cpu = env_archcpu(env); 1028 int cur_el = arm_current_el(env); 1029 bool secure = arm_is_secure(env); 1030 bool smd_flag = env->cp15.scr_el3 & SCR_SMD; 1031 1032 /* 1033 * SMC behaviour is summarized in the following table. 1034 * This helper handles the "Trap to EL2" and "Undef insn" cases. 1035 * The "Trap to EL3" and "PSCI call" cases are handled in the exception 1036 * helper. 1037 * 1038 * -> ARM_FEATURE_EL3 and !SMD 1039 * HCR_TSC && NS EL1 !HCR_TSC || !NS EL1 1040 * 1041 * Conduit SMC, valid call Trap to EL2 PSCI Call 1042 * Conduit SMC, inval call Trap to EL2 Trap to EL3 1043 * Conduit not SMC Trap to EL2 Trap to EL3 1044 * 1045 * 1046 * -> ARM_FEATURE_EL3 and SMD 1047 * HCR_TSC && NS EL1 !HCR_TSC || !NS EL1 1048 * 1049 * Conduit SMC, valid call Trap to EL2 PSCI Call 1050 * Conduit SMC, inval call Trap to EL2 Undef insn 1051 * Conduit not SMC Trap to EL2 Undef insn 1052 * 1053 * 1054 * -> !ARM_FEATURE_EL3 1055 * HCR_TSC && NS EL1 !HCR_TSC || !NS EL1 1056 * 1057 * Conduit SMC, valid call Trap to EL2 PSCI Call 1058 * Conduit SMC, inval call Trap to EL2 Undef insn 1059 * Conduit not SMC Undef or trap[1] Undef insn 1060 * 1061 * [1] In this case: 1062 * - if HCR_EL2.NV == 1 we must trap to EL2 1063 * - if HCR_EL2.NV == 0 then newer architecture revisions permit 1064 * AArch64 (but not AArch32) to trap to EL2 as an IMPDEF choice 1065 * - otherwise we must UNDEF 1066 * We take the IMPDEF choice to always UNDEF if HCR_EL2.NV == 0. 1067 */ 1068 1069 /* On ARMv8 with EL3 AArch64, SMD applies to both S and NS state. 1070 * On ARMv8 with EL3 AArch32, or ARMv7 with the Virtualization 1071 * extensions, SMD only applies to NS state. 1072 * On ARMv7 without the Virtualization extensions, the SMD bit 1073 * doesn't exist, but we forbid the guest to set it to 1 in scr_write(), 1074 * so we need not special case this here. 1075 */ 1076 bool smd = arm_feature(env, ARM_FEATURE_AARCH64) ? smd_flag 1077 : smd_flag && !secure; 1078 1079 if (!arm_feature(env, ARM_FEATURE_EL3) && 1080 !(arm_hcr_el2_eff(env) & HCR_NV) && 1081 cpu->psci_conduit != QEMU_PSCI_CONDUIT_SMC) { 1082 /* 1083 * If we have no EL3 then traditionally SMC always UNDEFs and can't be 1084 * trapped to EL2. For nested virtualization, SMC can be trapped to 1085 * the outer hypervisor. PSCI-via-SMC is a sort of ersatz EL3 1086 * firmware within QEMU, and we want an EL2 guest to be able 1087 * to forbid its EL1 from making PSCI calls into QEMU's 1088 * "firmware" via HCR.TSC, so for these purposes treat 1089 * PSCI-via-SMC as implying an EL3. 1090 * This handles the very last line of the previous table. 1091 */ 1092 raise_exception(env, EXCP_UDEF, syn_uncategorized(), 1093 exception_target_el(env)); 1094 } 1095 1096 if (cur_el == 1 && (arm_hcr_el2_eff(env) & HCR_TSC)) { 1097 /* In NS EL1, HCR controlled routing to EL2 has priority over SMD. 1098 * We also want an EL2 guest to be able to forbid its EL1 from 1099 * making PSCI calls into QEMU's "firmware" via HCR.TSC. 1100 * This handles all the "Trap to EL2" cases of the previous table. 1101 */ 1102 raise_exception(env, EXCP_HYP_TRAP, syndrome, 2); 1103 } 1104 1105 /* Catch the two remaining "Undef insn" cases of the previous table: 1106 * - PSCI conduit is SMC but we don't have a valid PCSI call, 1107 * - We don't have EL3 or SMD is set. 1108 */ 1109 if (!arm_is_psci_call(cpu, EXCP_SMC) && 1110 (smd || !arm_feature(env, ARM_FEATURE_EL3))) { 1111 raise_exception(env, EXCP_UDEF, syn_uncategorized(), 1112 exception_target_el(env)); 1113 } 1114 } 1115 1116 /* ??? Flag setting arithmetic is awkward because we need to do comparisons. 1117 The only way to do that in TCG is a conditional branch, which clobbers 1118 all our temporaries. For now implement these as helper functions. */ 1119 1120 /* Similarly for variable shift instructions. */ 1121 1122 uint32_t HELPER(shl_cc)(CPUARMState *env, uint32_t x, uint32_t i) 1123 { 1124 int shift = i & 0xff; 1125 if (shift >= 32) { 1126 if (shift == 32) 1127 env->CF = x & 1; 1128 else 1129 env->CF = 0; 1130 return 0; 1131 } else if (shift != 0) { 1132 env->CF = (x >> (32 - shift)) & 1; 1133 return x << shift; 1134 } 1135 return x; 1136 } 1137 1138 uint32_t HELPER(shr_cc)(CPUARMState *env, uint32_t x, uint32_t i) 1139 { 1140 int shift = i & 0xff; 1141 if (shift >= 32) { 1142 if (shift == 32) 1143 env->CF = (x >> 31) & 1; 1144 else 1145 env->CF = 0; 1146 return 0; 1147 } else if (shift != 0) { 1148 env->CF = (x >> (shift - 1)) & 1; 1149 return x >> shift; 1150 } 1151 return x; 1152 } 1153 1154 uint32_t HELPER(sar_cc)(CPUARMState *env, uint32_t x, uint32_t i) 1155 { 1156 int shift = i & 0xff; 1157 if (shift >= 32) { 1158 env->CF = (x >> 31) & 1; 1159 return (int32_t)x >> 31; 1160 } else if (shift != 0) { 1161 env->CF = (x >> (shift - 1)) & 1; 1162 return (int32_t)x >> shift; 1163 } 1164 return x; 1165 } 1166 1167 uint32_t HELPER(ror_cc)(CPUARMState *env, uint32_t x, uint32_t i) 1168 { 1169 int shift1, shift; 1170 shift1 = i & 0xff; 1171 shift = shift1 & 0x1f; 1172 if (shift == 0) { 1173 if (shift1 != 0) 1174 env->CF = (x >> 31) & 1; 1175 return x; 1176 } else { 1177 env->CF = (x >> (shift - 1)) & 1; 1178 return ((uint32_t)x >> shift) | (x << (32 - shift)); 1179 } 1180 } 1181 1182 void HELPER(probe_access)(CPUARMState *env, target_ulong ptr, 1183 uint32_t access_type, uint32_t mmu_idx, 1184 uint32_t size) 1185 { 1186 uint32_t in_page = -((uint32_t)ptr | TARGET_PAGE_SIZE); 1187 uintptr_t ra = GETPC(); 1188 1189 if (likely(size <= in_page)) { 1190 probe_access(env, ptr, size, access_type, mmu_idx, ra); 1191 } else { 1192 probe_access(env, ptr, in_page, access_type, mmu_idx, ra); 1193 probe_access(env, ptr + in_page, size - in_page, 1194 access_type, mmu_idx, ra); 1195 } 1196 } 1197 1198 /* 1199 * This function corresponds to AArch64.vESBOperation(). 1200 * Note that the AArch32 version is not functionally different. 1201 */ 1202 void HELPER(vesb)(CPUARMState *env) 1203 { 1204 /* 1205 * The EL2Enabled() check is done inside arm_hcr_el2_eff, 1206 * and will return HCR_EL2.VSE == 0, so nothing happens. 1207 */ 1208 uint64_t hcr = arm_hcr_el2_eff(env); 1209 bool enabled = !(hcr & HCR_TGE) && (hcr & HCR_AMO); 1210 bool pending = enabled && (hcr & HCR_VSE); 1211 bool masked = (env->daif & PSTATE_A); 1212 1213 /* If VSE pending and masked, defer the exception. */ 1214 if (pending && masked) { 1215 uint32_t syndrome; 1216 1217 if (arm_el_is_aa64(env, 1)) { 1218 /* Copy across IDS and ISS from VSESR. */ 1219 syndrome = env->cp15.vsesr_el2 & 0x1ffffff; 1220 } else { 1221 ARMMMUFaultInfo fi = { .type = ARMFault_AsyncExternal }; 1222 1223 if (extended_addresses_enabled(env)) { 1224 syndrome = arm_fi_to_lfsc(&fi); 1225 } else { 1226 syndrome = arm_fi_to_sfsc(&fi); 1227 } 1228 /* Copy across AET and ExT from VSESR. */ 1229 syndrome |= env->cp15.vsesr_el2 & 0xd000; 1230 } 1231 1232 /* Set VDISR_EL2.A along with the syndrome. */ 1233 env->cp15.vdisr_el2 = syndrome | (1u << 31); 1234 1235 /* Clear pending virtual SError */ 1236 env->cp15.hcr_el2 &= ~HCR_VSE; 1237 cpu_reset_interrupt(env_cpu(env), CPU_INTERRUPT_VSERR); 1238 } 1239 } 1240