target-arm/op_helper.c

   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 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 "cpu.h"
  20 #include "helper.h"
  21 #include "internals.h"
  22
  23 #define SIGNBIT (uint32_t)0x80000000
  24 #define SIGNBIT64 ((uint64_t)1 << 63)
  25
  26 static void raise_exception(CPUARMState *env, int tt)
  27 {
  28     ARMCPU *cpu = arm_env_get_cpu(env);
  29     CPUState *cs = CPU(cpu);
  30
  31     cs->exception_index = tt;
  32     cpu_loop_exit(cs);
  33 }
  34
  35 uint32_t HELPER(neon_tbl)(CPUARMState *env, uint32_t ireg, uint32_t def,
  36                           uint32_t rn, uint32_t maxindex)
  37 {
  38     uint32_t val;
  39     uint32_t tmp;
  40     int index;
  41     int shift;
  42     uint64_t *table;
  43     table = (uint64_t *)&env->vfp.regs[rn];
  44     val = 0;
  45     for (shift = 0; shift < 32; shift += 8) {
  46         index = (ireg >> shift) & 0xff;
  47         if (index < maxindex) {
  48             tmp = (table[index >> 3] >> ((index & 7) << 3)) & 0xff;
  49             val |= tmp << shift;
  50         } else {
  51             val |= def & (0xff << shift);
  52         }
  53     }
  54     return val;
  55 }
  56
  57 #if !defined(CONFIG_USER_ONLY)
  58
  59 #include "exec/softmmu_exec.h"
  60
  61 #define MMUSUFFIX _mmu
  62
  63 #define SHIFT 0
  64 #include "exec/softmmu_template.h"
  65
  66 #define SHIFT 1
  67 #include "exec/softmmu_template.h"
  68
  69 #define SHIFT 2
  70 #include "exec/softmmu_template.h"
  71
  72 #define SHIFT 3
  73 #include "exec/softmmu_template.h"
  74
  75 /* try to fill the TLB and return an exception if error. If retaddr is
  76  * NULL, it means that the function was called in C code (i.e. not
  77  * from generated code or from helper.c)
  78  */
  79 void tlb_fill(CPUState *cs, target_ulong addr, int is_write, int mmu_idx,
  80               uintptr_t retaddr)
  81 {
  82     int ret;
  83
  84     ret = arm_cpu_handle_mmu_fault(cs, addr, is_write, mmu_idx);
  85     if (unlikely(ret)) {
  86         ARMCPU *cpu = ARM_CPU(cs);
  87         CPUARMState *env = &cpu->env;
  88
  89         if (retaddr) {
  90             /* now we have a real cpu fault */
  91             cpu_restore_state(cs, retaddr);
  92         }
  93         raise_exception(env, cs->exception_index);
  94     }
  95 }
  96 #endif
  97
  98 uint32_t HELPER(add_setq)(CPUARMState *env, uint32_t a, uint32_t b)
  99 {
 100     uint32_t res = a + b;
 101     if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT))
 102         env->QF = 1;
 103     return res;
 104 }
 105
 106 uint32_t HELPER(add_saturate)(CPUARMState *env, uint32_t a, uint32_t b)
 107 {
 108     uint32_t res = a + b;
 109     if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT)) {
 110         env->QF = 1;
 111         res = ~(((int32_t)a >> 31) ^ SIGNBIT);
 112     }
 113     return res;
 114 }
 115
 116 uint32_t HELPER(sub_saturate)(CPUARMState *env, uint32_t a, uint32_t b)
 117 {
 118     uint32_t res = a - b;
 119     if (((res ^ a) & SIGNBIT) && ((a ^ b) & SIGNBIT)) {
 120         env->QF = 1;
 121         res = ~(((int32_t)a >> 31) ^ SIGNBIT);
 122     }
 123     return res;
 124 }
 125
 126 uint32_t HELPER(double_saturate)(CPUARMState *env, int32_t val)
 127 {
 128     uint32_t res;
 129     if (val >= 0x40000000) {
 130         res = ~SIGNBIT;
 131         env->QF = 1;
 132     } else if (val <= (int32_t)0xc0000000) {
 133         res = SIGNBIT;
 134         env->QF = 1;
 135     } else {
 136         res = val << 1;
 137     }
 138     return res;
 139 }
 140
 141 uint32_t HELPER(add_usaturate)(CPUARMState *env, uint32_t a, uint32_t b)
 142 {
 143     uint32_t res = a + b;
 144     if (res < a) {
 145         env->QF = 1;
 146         res = ~0;
 147     }
 148     return res;
 149 }
 150
 151 uint32_t HELPER(sub_usaturate)(CPUARMState *env, uint32_t a, uint32_t b)
 152 {
 153     uint32_t res = a - b;
 154     if (res > a) {
 155         env->QF = 1;
 156         res = 0;
 157     }
 158     return res;
 159 }
 160
 161 /* Signed saturation.  */
 162 static inline uint32_t do_ssat(CPUARMState *env, int32_t val, int shift)
 163 {
 164     int32_t top;
 165     uint32_t mask;
 166
 167     top = val >> shift;
 168     mask = (1u << shift) - 1;
 169     if (top > 0) {
 170         env->QF = 1;
 171         return mask;
 172     } else if (top < -1) {
 173         env->QF = 1;
 174         return ~mask;
 175     }
 176     return val;
 177 }
 178
 179 /* Unsigned saturation.  */
 180 static inline uint32_t do_usat(CPUARMState *env, int32_t val, int shift)
 181 {
 182     uint32_t max;
 183
 184     max = (1u << shift) - 1;
 185     if (val < 0) {
 186         env->QF = 1;
 187         return 0;
 188     } else if (val > max) {
 189         env->QF = 1;
 190         return max;
 191     }
 192     return val;
 193 }
 194
 195 /* Signed saturate.  */
 196 uint32_t HELPER(ssat)(CPUARMState *env, uint32_t x, uint32_t shift)
 197 {
 198     return do_ssat(env, x, shift);
 199 }
 200
 201 /* Dual halfword signed saturate.  */
 202 uint32_t HELPER(ssat16)(CPUARMState *env, uint32_t x, uint32_t shift)
 203 {
 204     uint32_t res;
 205
 206     res = (uint16_t)do_ssat(env, (int16_t)x, shift);
 207     res |= do_ssat(env, ((int32_t)x) >> 16, shift) << 16;
 208     return res;
 209 }
 210
 211 /* Unsigned saturate.  */
 212 uint32_t HELPER(usat)(CPUARMState *env, uint32_t x, uint32_t shift)
 213 {
 214     return do_usat(env, x, shift);
 215 }
 216
 217 /* Dual halfword unsigned saturate.  */
 218 uint32_t HELPER(usat16)(CPUARMState *env, uint32_t x, uint32_t shift)
 219 {
 220     uint32_t res;
 221
 222     res = (uint16_t)do_usat(env, (int16_t)x, shift);
 223     res |= do_usat(env, ((int32_t)x) >> 16, shift) << 16;
 224     return res;
 225 }
 226
 227 void HELPER(wfi)(CPUARMState *env)
 228 {
 229     CPUState *cs = CPU(arm_env_get_cpu(env));
 230
 231     cs->exception_index = EXCP_HLT;
 232     cs->halted = 1;
 233     cpu_loop_exit(cs);
 234 }
 235
 236 void HELPER(wfe)(CPUARMState *env)
 237 {
 238     CPUState *cs = CPU(arm_env_get_cpu(env));
 239
 240     /* Don't actually halt the CPU, just yield back to top
 241      * level loop
 242      */
 243     cs->exception_index = EXCP_YIELD;
 244     cpu_loop_exit(cs);
 245 }
 246
 247 /* Raise an internal-to-QEMU exception. This is limited to only
 248  * those EXCP values which are special cases for QEMU to interrupt
 249  * execution and not to be used for exceptions which are passed to
 250  * the guest (those must all have syndrome information and thus should
 251  * use exception_with_syndrome).
 252  */
 253 void HELPER(exception_internal)(CPUARMState *env, uint32_t excp)
 254 {
 255     CPUState *cs = CPU(arm_env_get_cpu(env));
 256
 257     assert(excp_is_internal(excp));
 258     cs->exception_index = excp;
 259     cpu_loop_exit(cs);
 260 }
 261
 262 /* Raise an exception with the specified syndrome register value */
 263 void HELPER(exception_with_syndrome)(CPUARMState *env, uint32_t excp,
 264                                      uint32_t syndrome)
 265 {
 266     CPUState *cs = CPU(arm_env_get_cpu(env));
 267
 268     assert(!excp_is_internal(excp));
 269     cs->exception_index = excp;
 270     env->exception.syndrome = syndrome;
 271     cpu_loop_exit(cs);
 272 }
 273
 274 uint32_t HELPER(cpsr_read)(CPUARMState *env)
 275 {
 276     return cpsr_read(env) & ~CPSR_EXEC;
 277 }
 278
 279 void HELPER(cpsr_write)(CPUARMState *env, uint32_t val, uint32_t mask)
 280 {
 281     cpsr_write(env, val, mask);
 282 }
 283
 284 /* Access to user mode registers from privileged modes.  */
 285 uint32_t HELPER(get_user_reg)(CPUARMState *env, uint32_t regno)
 286 {
 287     uint32_t val;
 288
 289     if (regno == 13) {
 290         val = env->banked_r13[0];
 291     } else if (regno == 14) {
 292         val = env->banked_r14[0];
 293     } else if (regno >= 8
 294                && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
 295         val = env->usr_regs[regno - 8];
 296     } else {
 297         val = env->regs[regno];
 298     }
 299     return val;
 300 }
 301
 302 void HELPER(set_user_reg)(CPUARMState *env, uint32_t regno, uint32_t val)
 303 {
 304     if (regno == 13) {
 305         env->banked_r13[0] = val;
 306     } else if (regno == 14) {
 307         env->banked_r14[0] = val;
 308     } else if (regno >= 8
 309                && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
 310         env->usr_regs[regno - 8] = val;
 311     } else {
 312         env->regs[regno] = val;
 313     }
 314 }
 315
 316 void HELPER(access_check_cp_reg)(CPUARMState *env, void *rip, uint32_t syndrome)
 317 {
 318     const ARMCPRegInfo *ri = rip;
 319     switch (ri->accessfn(env, ri)) {
 320     case CP_ACCESS_OK:
 321         return;
 322     case CP_ACCESS_TRAP:
 323         env->exception.syndrome = syndrome;
 324         break;
 325     case CP_ACCESS_TRAP_UNCATEGORIZED:
 326         env->exception.syndrome = syn_uncategorized();
 327         break;
 328     default:
 329         g_assert_not_reached();
 330     }
 331     raise_exception(env, EXCP_UDEF);
 332 }
 333
 334 void HELPER(set_cp_reg)(CPUARMState *env, void *rip, uint32_t value)
 335 {
 336     const ARMCPRegInfo *ri = rip;
 337
 338     ri->writefn(env, ri, value);
 339 }
 340
 341 uint32_t HELPER(get_cp_reg)(CPUARMState *env, void *rip)
 342 {
 343     const ARMCPRegInfo *ri = rip;
 344
 345     return ri->readfn(env, ri);
 346 }
 347
 348 void HELPER(set_cp_reg64)(CPUARMState *env, void *rip, uint64_t value)
 349 {
 350     const ARMCPRegInfo *ri = rip;
 351
 352     ri->writefn(env, ri, value);
 353 }
 354
 355 uint64_t HELPER(get_cp_reg64)(CPUARMState *env, void *rip)
 356 {
 357     const ARMCPRegInfo *ri = rip;
 358
 359     return ri->readfn(env, ri);
 360 }
 361
 362 void HELPER(msr_i_pstate)(CPUARMState *env, uint32_t op, uint32_t imm)
 363 {
 364     /* MSR_i to update PSTATE. This is OK from EL0 only if UMA is set.
 365      * Note that SPSel is never OK from EL0; we rely on handle_msr_i()
 366      * to catch that case at translate time.
 367      */
 368     if (arm_current_pl(env) == 0 && !(env->cp15.c1_sys & SCTLR_UMA)) {
 369         raise_exception(env, EXCP_UDEF);
 370     }
 371
 372     switch (op) {
 373     case 0x05: /* SPSel */
 374         update_spsel(env, imm);
 375         break;
 376     case 0x1e: /* DAIFSet */
 377         env->daif |= (imm << 6) & PSTATE_DAIF;
 378         break;
 379     case 0x1f: /* DAIFClear */
 380         env->daif &= ~((imm << 6) & PSTATE_DAIF);
 381         break;
 382     default:
 383         g_assert_not_reached();
 384     }
 385 }
 386
 387 void HELPER(exception_return)(CPUARMState *env)
 388 {
 389     uint32_t spsr = env->banked_spsr[0];
 390     int new_el, i;
 391
 392     if (env->pstate & PSTATE_SP) {
 393         env->sp_el[1] = env->xregs[31];
 394     } else {
 395         env->sp_el[0] = env->xregs[31];
 396     }
 397
 398     env->exclusive_addr = -1;
 399
 400     if (spsr & PSTATE_nRW) {
 401         env->aarch64 = 0;
 402         new_el = 0;
 403         env->uncached_cpsr = 0x10;
 404         cpsr_write(env, spsr, ~0);
 405         for (i = 0; i < 15; i++) {
 406             env->regs[i] = env->xregs[i];
 407         }
 408
 409         env->regs[15] = env->elr_el1 & ~0x1;
 410     } else {
 411         new_el = extract32(spsr, 2, 2);
 412         if (new_el > 1) {
 413             /* Return to unimplemented EL */
 414             goto illegal_return;
 415         }
 416         if (extract32(spsr, 1, 1)) {
 417             /* Return with reserved M[1] bit set */
 418             goto illegal_return;
 419         }
 420         if (new_el == 0 && (spsr & PSTATE_SP)) {
 421             /* Return to EL0 with M[0] bit set */
 422             goto illegal_return;
 423         }
 424         env->aarch64 = 1;
 425         pstate_write(env, spsr);
 426         env->xregs[31] = env->sp_el[new_el];
 427         env->pc = env->elr_el1;
 428     }
 429
 430     return;
 431
 432 illegal_return:
 433     /* Illegal return events of various kinds have architecturally
 434      * mandated behaviour:
 435      * restore NZCV and DAIF from SPSR_ELx
 436      * set PSTATE.IL
 437      * restore PC from ELR_ELx
 438      * no change to exception level, execution state or stack pointer
 439      */
 440     env->pstate |= PSTATE_IL;
 441     env->pc = env->elr_el1;
 442     spsr &= PSTATE_NZCV | PSTATE_DAIF;
 443     spsr |= pstate_read(env) & ~(PSTATE_NZCV | PSTATE_DAIF);
 444     pstate_write(env, spsr);
 445 }
 446
 447 /* ??? Flag setting arithmetic is awkward because we need to do comparisons.
 448    The only way to do that in TCG is a conditional branch, which clobbers
 449    all our temporaries.  For now implement these as helper functions.  */
 450
 451 /* Similarly for variable shift instructions.  */
 452
 453 uint32_t HELPER(shl_cc)(CPUARMState *env, uint32_t x, uint32_t i)
 454 {
 455     int shift = i & 0xff;
 456     if (shift >= 32) {
 457         if (shift == 32)
 458             env->CF = x & 1;
 459         else
 460             env->CF = 0;
 461         return 0;
 462     } else if (shift != 0) {
 463         env->CF = (x >> (32 - shift)) & 1;
 464         return x << shift;
 465     }
 466     return x;
 467 }
 468
 469 uint32_t HELPER(shr_cc)(CPUARMState *env, uint32_t x, uint32_t i)
 470 {
 471     int shift = i & 0xff;
 472     if (shift >= 32) {
 473         if (shift == 32)
 474             env->CF = (x >> 31) & 1;
 475         else
 476             env->CF = 0;
 477         return 0;
 478     } else if (shift != 0) {
 479         env->CF = (x >> (shift - 1)) & 1;
 480         return x >> shift;
 481     }
 482     return x;
 483 }
 484
 485 uint32_t HELPER(sar_cc)(CPUARMState *env, uint32_t x, uint32_t i)
 486 {
 487     int shift = i & 0xff;
 488     if (shift >= 32) {
 489         env->CF = (x >> 31) & 1;
 490         return (int32_t)x >> 31;
 491     } else if (shift != 0) {
 492         env->CF = (x >> (shift - 1)) & 1;
 493         return (int32_t)x >> shift;
 494     }
 495     return x;
 496 }
 497
 498 uint32_t HELPER(ror_cc)(CPUARMState *env, uint32_t x, uint32_t i)
 499 {
 500     int shift1, shift;
 501     shift1 = i & 0xff;
 502     shift = shift1 & 0x1f;
 503     if (shift == 0) {
 504         if (shift1 != 0)
 505             env->CF = (x >> 31) & 1;
 506         return x;
 507     } else {
 508         env->CF = (x >> (shift - 1)) & 1;
 509         return ((uint32_t)x >> shift) | (x << (32 - shift));
 510     }
 511 }