target-cris/op_helper.c

   1 /*
   2  *  CRIS helper routines
   3  *
   4  *  Copyright (c) 2007 AXIS Communications
   5  *  Written by Edgar E. Iglesias
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include "cpu.h"
  22 #include "mmu.h"
  23 #include "exec/helper-proto.h"
  24 #include "qemu/host-utils.h"
  25 #include "exec/cpu_ldst.h"
  26
  27 //#define CRIS_OP_HELPER_DEBUG
  28
  29
  30 #ifdef CRIS_OP_HELPER_DEBUG
  31 #define D(x) x
  32 #define D_LOG(...) qemu_log(__VA_ARGS__)
  33 #else
  34 #define D(x)
  35 #define D_LOG(...) do { } while (0)
  36 #endif
  37
  38 #if !defined(CONFIG_USER_ONLY)
  39 /* Try to fill the TLB and return an exception if error. If retaddr is
  40    NULL, it means that the function was called in C code (i.e. not
  41    from generated code or from helper.c) */
  42 void tlb_fill(CPUState *cs, target_ulong addr, int is_write, int mmu_idx,
  43               uintptr_t retaddr)
  44 {
  45     CRISCPU *cpu = CRIS_CPU(cs);
  46     CPUCRISState *env = &cpu->env;
  47     int ret;
  48
  49     D_LOG("%s pc=%x tpc=%x ra=%p\n", __func__,
  50           env->pc, env->pregs[PR_EDA], (void *)retaddr);
  51     ret = cris_cpu_handle_mmu_fault(cs, addr, is_write, mmu_idx);
  52     if (unlikely(ret)) {
  53         if (retaddr) {
  54             /* now we have a real cpu fault */
  55             if (cpu_restore_state(cs, retaddr)) {
  56                 /* Evaluate flags after retranslation.  */
  57                 helper_top_evaluate_flags(env);
  58             }
  59         }
  60         cpu_loop_exit(cs);
  61     }
  62 }
  63
  64 #endif
  65
  66 void helper_raise_exception(CPUCRISState *env, uint32_t index)
  67 {
  68     CPUState *cs = CPU(cris_env_get_cpu(env));
  69
  70     cs->exception_index = index;
  71     cpu_loop_exit(cs);
  72 }
  73
  74 void helper_tlb_flush_pid(CPUCRISState *env, uint32_t pid)
  75 {
  76 #if !defined(CONFIG_USER_ONLY)
  77         pid &= 0xff;
  78         if (pid != (env->pregs[PR_PID] & 0xff))
  79                 cris_mmu_flush_pid(env, env->pregs[PR_PID]);
  80 #endif
  81 }
  82
  83 void helper_spc_write(CPUCRISState *env, uint32_t new_spc)
  84 {
  85 #if !defined(CONFIG_USER_ONLY)
  86     CRISCPU *cpu = cris_env_get_cpu(env);
  87     CPUState *cs = CPU(cpu);
  88
  89     tlb_flush_page(cs, env->pregs[PR_SPC]);
  90     tlb_flush_page(cs, new_spc);
  91 #endif
  92 }
  93
  94 /* Used by the tlb decoder.  */
  95 #define EXTRACT_FIELD(src, start, end) \
  96             (((src) >> start) & ((1 << (end - start + 1)) - 1))
  97
  98 void helper_movl_sreg_reg(CPUCRISState *env, uint32_t sreg, uint32_t reg)
  99 {
 100 #if !defined(CONFIG_USER_ONLY)
 101     CRISCPU *cpu = cris_env_get_cpu(env);
 102 #endif
 103         uint32_t srs;
 104         srs = env->pregs[PR_SRS];
 105         srs &= 3;
 106         env->sregs[srs][sreg] = env->regs[reg];
 107
 108 #if !defined(CONFIG_USER_ONLY)
 109         if (srs == 1 || srs == 2) {
 110                 if (sreg == 6) {
 111                         /* Writes to tlb-hi write to mm_cause as a side
 112                            effect.  */
 113                         env->sregs[SFR_RW_MM_TLB_HI] = env->regs[reg];
 114                         env->sregs[SFR_R_MM_CAUSE] = env->regs[reg];
 115                 }
 116                 else if (sreg == 5) {
 117                         uint32_t set;
 118                         uint32_t idx;
 119                         uint32_t lo, hi;
 120                         uint32_t vaddr;
 121                         int tlb_v;
 122
 123                         idx = set = env->sregs[SFR_RW_MM_TLB_SEL];
 124                         set >>= 4;
 125                         set &= 3;
 126
 127                         idx &= 15;
 128                         /* We've just made a write to tlb_lo.  */
 129                         lo = env->sregs[SFR_RW_MM_TLB_LO];
 130                         /* Writes are done via r_mm_cause.  */
 131                         hi = env->sregs[SFR_R_MM_CAUSE];
 132
 133                         vaddr = EXTRACT_FIELD(env->tlbsets[srs-1][set][idx].hi,
 134                                               13, 31);
 135                         vaddr <<= TARGET_PAGE_BITS;
 136                         tlb_v = EXTRACT_FIELD(env->tlbsets[srs-1][set][idx].lo,
 137                                             3, 3);
 138                         env->tlbsets[srs - 1][set][idx].lo = lo;
 139                         env->tlbsets[srs - 1][set][idx].hi = hi;
 140
 141                         D_LOG("tlb flush vaddr=%x v=%d pc=%x\n",
 142                                   vaddr, tlb_v, env->pc);
 143                         if (tlb_v) {
 144                 tlb_flush_page(CPU(cpu), vaddr);
 145                         }
 146                 }
 147         }
 148 #endif
 149 }
 150
 151 void helper_movl_reg_sreg(CPUCRISState *env, uint32_t reg, uint32_t sreg)
 152 {
 153         uint32_t srs;
 154         env->pregs[PR_SRS] &= 3;
 155         srs = env->pregs[PR_SRS];
 156
 157 #if !defined(CONFIG_USER_ONLY)
 158         if (srs == 1 || srs == 2)
 159         {
 160                 uint32_t set;
 161                 uint32_t idx;
 162                 uint32_t lo, hi;
 163
 164                 idx = set = env->sregs[SFR_RW_MM_TLB_SEL];
 165                 set >>= 4;
 166                 set &= 3;
 167                 idx &= 15;
 168
 169                 /* Update the mirror regs.  */
 170                 hi = env->tlbsets[srs - 1][set][idx].hi;
 171                 lo = env->tlbsets[srs - 1][set][idx].lo;
 172                 env->sregs[SFR_RW_MM_TLB_HI] = hi;
 173                 env->sregs[SFR_RW_MM_TLB_LO] = lo;
 174         }
 175 #endif
 176         env->regs[reg] = env->sregs[srs][sreg];
 177 }
 178
 179 static void cris_ccs_rshift(CPUCRISState *env)
 180 {
 181         uint32_t ccs;
 182
 183         /* Apply the ccs shift.  */
 184         ccs = env->pregs[PR_CCS];
 185         ccs = (ccs & 0xc0000000) | ((ccs & 0x0fffffff) >> 10);
 186         if (ccs & U_FLAG)
 187         {
 188                 /* Enter user mode.  */
 189                 env->ksp = env->regs[R_SP];
 190                 env->regs[R_SP] = env->pregs[PR_USP];
 191         }
 192
 193         env->pregs[PR_CCS] = ccs;
 194 }
 195
 196 void helper_rfe(CPUCRISState *env)
 197 {
 198         int rflag = env->pregs[PR_CCS] & R_FLAG;
 199
 200         D_LOG("rfe: erp=%x pid=%x ccs=%x btarget=%x\n",
 201                  env->pregs[PR_ERP], env->pregs[PR_PID],
 202                  env->pregs[PR_CCS],
 203                  env->btarget);
 204
 205         cris_ccs_rshift(env);
 206
 207         /* RFE sets the P_FLAG only if the R_FLAG is not set.  */
 208         if (!rflag)
 209                 env->pregs[PR_CCS] |= P_FLAG;
 210 }
 211
 212 void helper_rfn(CPUCRISState *env)
 213 {
 214         int rflag = env->pregs[PR_CCS] & R_FLAG;
 215
 216         D_LOG("rfn: erp=%x pid=%x ccs=%x btarget=%x\n",
 217                  env->pregs[PR_ERP], env->pregs[PR_PID],
 218                  env->pregs[PR_CCS],
 219                  env->btarget);
 220
 221         cris_ccs_rshift(env);
 222
 223         /* Set the P_FLAG only if the R_FLAG is not set.  */
 224         if (!rflag)
 225                 env->pregs[PR_CCS] |= P_FLAG;
 226
 227         /* Always set the M flag.  */
 228         env->pregs[PR_CCS] |= M_FLAG_V32;
 229 }
 230
 231 uint32_t helper_lz(uint32_t t0)
 232 {
 233         return clz32(t0);
 234 }
 235
 236 uint32_t helper_btst(CPUCRISState *env, uint32_t t0, uint32_t t1, uint32_t ccs)
 237 {
 238         /* FIXME: clean this up.  */
 239
 240         /* des ref:
 241            The N flag is set according to the selected bit in the dest reg.
 242            The Z flag is set if the selected bit and all bits to the right are
 243            zero.
 244            The X flag is cleared.
 245            Other flags are left untouched.
 246            The destination reg is not affected.*/
 247         unsigned int fz, sbit, bset, mask, masked_t0;
 248
 249         sbit = t1 & 31;
 250         bset = !!(t0 & (1 << sbit));
 251         mask = sbit == 31 ? -1 : (1 << (sbit + 1)) - 1;
 252         masked_t0 = t0 & mask;
 253         fz = !(masked_t0 | bset);
 254
 255         /* Clear the X, N and Z flags.  */
 256         ccs = ccs & ~(X_FLAG | N_FLAG | Z_FLAG);
 257         if (env->pregs[PR_VR] < 32)
 258                 ccs &= ~(V_FLAG | C_FLAG);
 259         /* Set the N and Z flags accordingly.  */
 260         ccs |= (bset << 3) | (fz << 2);
 261         return ccs;
 262 }
 263
 264 static inline uint32_t evaluate_flags_writeback(CPUCRISState *env,
 265                                                 uint32_t flags, uint32_t ccs)
 266 {
 267         unsigned int x, z, mask;
 268
 269         /* Extended arithmetics, leave the z flag alone.  */
 270         x = env->cc_x;
 271         mask = env->cc_mask | X_FLAG;
 272         if (x) {
 273                 z = flags & Z_FLAG;
 274                 mask = mask & ~z;
 275         }
 276         flags &= mask;
 277
 278         /* all insn clear the x-flag except setf or clrf.  */
 279         ccs &= ~mask;
 280         ccs |= flags;
 281         return ccs;
 282 }
 283
 284 uint32_t helper_evaluate_flags_muls(CPUCRISState *env,
 285                                     uint32_t ccs, uint32_t res, uint32_t mof)
 286 {
 287         uint32_t flags = 0;
 288         int64_t tmp;
 289         int dneg;
 290
 291         dneg = ((int32_t)res) < 0;
 292
 293         tmp = mof;
 294         tmp <<= 32;
 295         tmp |= res;
 296         if (tmp == 0)
 297                 flags |= Z_FLAG;
 298         else if (tmp < 0)
 299                 flags |= N_FLAG;
 300         if ((dneg && mof != -1)
 301             || (!dneg && mof != 0))
 302                 flags |= V_FLAG;
 303         return evaluate_flags_writeback(env, flags, ccs);
 304 }
 305
 306 uint32_t helper_evaluate_flags_mulu(CPUCRISState *env,
 307                                     uint32_t ccs, uint32_t res, uint32_t mof)
 308 {
 309         uint32_t flags = 0;
 310         uint64_t tmp;
 311
 312         tmp = mof;
 313         tmp <<= 32;
 314         tmp |= res;
 315         if (tmp == 0)
 316                 flags |= Z_FLAG;
 317         else if (tmp >> 63)
 318                 flags |= N_FLAG;
 319         if (mof)
 320                 flags |= V_FLAG;
 321
 322         return evaluate_flags_writeback(env, flags, ccs);
 323 }
 324
 325 uint32_t helper_evaluate_flags_mcp(CPUCRISState *env, uint32_t ccs,
 326                                    uint32_t src, uint32_t dst, uint32_t res)
 327 {
 328         uint32_t flags = 0;
 329
 330         src = src & 0x80000000;
 331         dst = dst & 0x80000000;
 332
 333         if ((res & 0x80000000L) != 0L)
 334         {
 335                 flags |= N_FLAG;
 336                 if (!src && !dst)
 337                         flags |= V_FLAG;
 338                 else if (src & dst)
 339                         flags |= R_FLAG;
 340         }
 341         else
 342         {
 343                 if (res == 0L)
 344                         flags |= Z_FLAG;
 345                 if (src & dst)
 346                         flags |= V_FLAG;
 347                 if (dst | src)
 348                         flags |= R_FLAG;
 349         }
 350
 351         return evaluate_flags_writeback(env, flags, ccs);
 352 }
 353
 354 uint32_t helper_evaluate_flags_alu_4(CPUCRISState *env, uint32_t ccs,
 355                                      uint32_t src, uint32_t dst, uint32_t res)
 356 {
 357         uint32_t flags = 0;
 358
 359         src = src & 0x80000000;
 360         dst = dst & 0x80000000;
 361
 362         if ((res & 0x80000000L) != 0L)
 363         {
 364                 flags |= N_FLAG;
 365                 if (!src && !dst)
 366                         flags |= V_FLAG;
 367                 else if (src & dst)
 368                         flags |= C_FLAG;
 369         }
 370         else
 371         {
 372                 if (res == 0L)
 373                         flags |= Z_FLAG;
 374                 if (src & dst)
 375                         flags |= V_FLAG;
 376                 if (dst | src)
 377                         flags |= C_FLAG;
 378         }
 379
 380         return evaluate_flags_writeback(env, flags, ccs);
 381 }
 382
 383 uint32_t helper_evaluate_flags_sub_4(CPUCRISState *env, uint32_t ccs,
 384                                      uint32_t src, uint32_t dst, uint32_t res)
 385 {
 386         uint32_t flags = 0;
 387
 388         src = (~src) & 0x80000000;
 389         dst = dst & 0x80000000;
 390
 391         if ((res & 0x80000000L) != 0L)
 392         {
 393                 flags |= N_FLAG;
 394                 if (!src && !dst)
 395                         flags |= V_FLAG;
 396                 else if (src & dst)
 397                         flags |= C_FLAG;
 398         }
 399         else
 400         {
 401                 if (res == 0L)
 402                         flags |= Z_FLAG;
 403                 if (src & dst)
 404                         flags |= V_FLAG;
 405                 if (dst | src)
 406                         flags |= C_FLAG;
 407         }
 408
 409         flags ^= C_FLAG;
 410         return evaluate_flags_writeback(env, flags, ccs);
 411 }
 412
 413 uint32_t helper_evaluate_flags_move_4(CPUCRISState *env,
 414                                       uint32_t ccs, uint32_t res)
 415 {
 416         uint32_t flags = 0;
 417
 418         if ((int32_t)res < 0)
 419                 flags |= N_FLAG;
 420         else if (res == 0L)
 421                 flags |= Z_FLAG;
 422
 423         return evaluate_flags_writeback(env, flags, ccs);
 424 }
 425 uint32_t helper_evaluate_flags_move_2(CPUCRISState *env,
 426                                       uint32_t ccs, uint32_t res)
 427 {
 428         uint32_t flags = 0;
 429
 430         if ((int16_t)res < 0L)
 431                 flags |= N_FLAG;
 432         else if (res == 0)
 433                 flags |= Z_FLAG;
 434
 435         return evaluate_flags_writeback(env, flags, ccs);
 436 }
 437
 438 /* TODO: This is expensive. We could split things up and only evaluate part of
 439    CCR on a need to know basis. For now, we simply re-evaluate everything.  */
 440 void helper_evaluate_flags(CPUCRISState *env)
 441 {
 442         uint32_t src, dst, res;
 443         uint32_t flags = 0;
 444
 445         src = env->cc_src;
 446         dst = env->cc_dest;
 447         res = env->cc_result;
 448
 449         if (env->cc_op == CC_OP_SUB || env->cc_op == CC_OP_CMP)
 450                 src = ~src;
 451
 452         /* Now, evaluate the flags. This stuff is based on
 453            Per Zander's CRISv10 simulator.  */
 454         switch (env->cc_size)
 455         {
 456                 case 1:
 457                         if ((res & 0x80L) != 0L)
 458                         {
 459                                 flags |= N_FLAG;
 460                                 if (((src & 0x80L) == 0L)
 461                                     && ((dst & 0x80L) == 0L))
 462                                 {
 463                                         flags |= V_FLAG;
 464                                 }
 465                                 else if (((src & 0x80L) != 0L)
 466                                          && ((dst & 0x80L) != 0L))
 467                                 {
 468                                         flags |= C_FLAG;
 469                                 }
 470                         }
 471                         else
 472                         {
 473                                 if ((res & 0xFFL) == 0L)
 474                                 {
 475                                         flags |= Z_FLAG;
 476                                 }
 477                                 if (((src & 0x80L) != 0L)
 478                                     && ((dst & 0x80L) != 0L))
 479                                 {
 480                                         flags |= V_FLAG;
 481                                 }
 482                                 if ((dst & 0x80L) != 0L
 483                                     || (src & 0x80L) != 0L)
 484                                 {
 485                                         flags |= C_FLAG;
 486                                 }
 487                         }
 488                         break;
 489                 case 2:
 490                         if ((res & 0x8000L) != 0L)
 491                         {
 492                                 flags |= N_FLAG;
 493                                 if (((src & 0x8000L) == 0L)
 494                                     && ((dst & 0x8000L) == 0L))
 495                                 {
 496                                         flags |= V_FLAG;
 497                                 }
 498                                 else if (((src & 0x8000L) != 0L)
 499                                          && ((dst & 0x8000L) != 0L))
 500                                 {
 501                                         flags |= C_FLAG;
 502                                 }
 503                         }
 504                         else
 505                         {
 506                                 if ((res & 0xFFFFL) == 0L)
 507                                 {
 508                                         flags |= Z_FLAG;
 509                                 }
 510                                 if (((src & 0x8000L) != 0L)
 511                                     && ((dst & 0x8000L) != 0L))
 512                                 {
 513                                         flags |= V_FLAG;
 514                                 }
 515                                 if ((dst & 0x8000L) != 0L
 516                                     || (src & 0x8000L) != 0L)
 517                                 {
 518                                         flags |= C_FLAG;
 519                                 }
 520                         }
 521                         break;
 522                 case 4:
 523                         if ((res & 0x80000000L) != 0L)
 524                         {
 525                                 flags |= N_FLAG;
 526                                 if (((src & 0x80000000L) == 0L)
 527                                     && ((dst & 0x80000000L) == 0L))
 528                                 {
 529                                         flags |= V_FLAG;
 530                                 }
 531                                 else if (((src & 0x80000000L) != 0L) &&
 532                                          ((dst & 0x80000000L) != 0L))
 533                                 {
 534                                         flags |= C_FLAG;
 535                                 }
 536                         }
 537                         else
 538                         {
 539                                 if (res == 0L)
 540                                         flags |= Z_FLAG;
 541                                 if (((src & 0x80000000L) != 0L)
 542                                     && ((dst & 0x80000000L) != 0L))
 543                                         flags |= V_FLAG;
 544                                 if ((dst & 0x80000000L) != 0L
 545                                     || (src & 0x80000000L) != 0L)
 546                                         flags |= C_FLAG;
 547                         }
 548                         break;
 549                 default:
 550                         break;
 551         }
 552
 553         if (env->cc_op == CC_OP_SUB || env->cc_op == CC_OP_CMP)
 554                 flags ^= C_FLAG;
 555
 556         env->pregs[PR_CCS] = evaluate_flags_writeback(env, flags,
 557                                                       env->pregs[PR_CCS]);
 558 }
 559
 560 void helper_top_evaluate_flags(CPUCRISState *env)
 561 {
 562         switch (env->cc_op)
 563         {
 564                 case CC_OP_MCP:
 565                         env->pregs[PR_CCS] = helper_evaluate_flags_mcp(env,
 566                                         env->pregs[PR_CCS], env->cc_src,
 567                                         env->cc_dest, env->cc_result);
 568                         break;
 569                 case CC_OP_MULS:
 570                         env->pregs[PR_CCS] = helper_evaluate_flags_muls(env,
 571                                         env->pregs[PR_CCS], env->cc_result,
 572                                         env->pregs[PR_MOF]);
 573                         break;
 574                 case CC_OP_MULU:
 575                         env->pregs[PR_CCS] = helper_evaluate_flags_mulu(env,
 576                                         env->pregs[PR_CCS], env->cc_result,
 577                                         env->pregs[PR_MOF]);
 578                         break;
 579                 case CC_OP_MOVE:
 580                 case CC_OP_AND:
 581                 case CC_OP_OR:
 582                 case CC_OP_XOR:
 583                 case CC_OP_ASR:
 584                 case CC_OP_LSR:
 585                 case CC_OP_LSL:
 586                 switch (env->cc_size)
 587                 {
 588                         case 4:
 589                                 env->pregs[PR_CCS] =
 590                                         helper_evaluate_flags_move_4(env,
 591                                                         env->pregs[PR_CCS],
 592                                                         env->cc_result);
 593                                 break;
 594                         case 2:
 595                                 env->pregs[PR_CCS] =
 596                                         helper_evaluate_flags_move_2(env,
 597                                                         env->pregs[PR_CCS],
 598                                                         env->cc_result);
 599                                 break;
 600                         default:
 601                                 helper_evaluate_flags(env);
 602                                 break;
 603                 }
 604                 break;
 605                 case CC_OP_FLAGS:
 606                         /* live.  */
 607                         break;
 608                 case CC_OP_SUB:
 609                 case CC_OP_CMP:
 610                         if (env->cc_size == 4)
 611                                 env->pregs[PR_CCS] =
 612                                         helper_evaluate_flags_sub_4(env,
 613                                                 env->pregs[PR_CCS],
 614                                                 env->cc_src, env->cc_dest,
 615                                                 env->cc_result);
 616                         else
 617                                 helper_evaluate_flags(env);
 618                         break;
 619                 default:
 620                 {
 621                         switch (env->cc_size)
 622                         {
 623                         case 4:
 624                                 env->pregs[PR_CCS] =
 625                                         helper_evaluate_flags_alu_4(env,
 626                                                 env->pregs[PR_CCS],
 627                                                 env->cc_src, env->cc_dest,
 628                                                 env->cc_result);
 629                                 break;
 630                         default:
 631                                 helper_evaluate_flags(env);
 632                                 break;
 633                         }
 634                 }
 635                 break;
 636         }
 637 }