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
  26 //#define CRIS_OP_HELPER_DEBUG
  27
  28
  29 #ifdef CRIS_OP_HELPER_DEBUG
  30 #define D(x) x
  31 #define D_LOG(...) qemu_log(__VA_ARGS__)
  32 #else
  33 #define D(x)
  34 #define D_LOG(...) do { } while (0)
  35 #endif
  36
  37 #if !defined(CONFIG_USER_ONLY)
  38 #include "exec/softmmu_exec.h"
  39
  40 /* Try to fill the TLB and return an exception if error. If retaddr is
  41    NULL, it means that the function was called in C code (i.e. not
  42    from generated code or from helper.c) */
  43 void tlb_fill(CPUState *cs, target_ulong addr, int is_write, int mmu_idx,
  44               uintptr_t retaddr)
  45 {
  46     CRISCPU *cpu = CRIS_CPU(cs);
  47     CPUCRISState *env = &cpu->env;
  48     int ret;
  49
  50     D_LOG("%s pc=%x tpc=%x ra=%p\n", __func__,
  51           env->pc, env->pregs[PR_EDA], (void *)retaddr);
  52     ret = cris_cpu_handle_mmu_fault(cs, addr, is_write, mmu_idx);
  53     if (unlikely(ret)) {
  54         if (retaddr) {
  55             /* now we have a real cpu fault */
  56             if (cpu_restore_state(cs, retaddr)) {
  57                 /* Evaluate flags after retranslation.  */
  58                 helper_top_evaluate_flags(env);
  59             }
  60         }
  61         cpu_loop_exit(cs);
  62     }
  63 }
  64
  65 #endif
  66
  67 void helper_raise_exception(CPUCRISState *env, uint32_t index)
  68 {
  69     CPUState *cs = CPU(cris_env_get_cpu(env));
  70
  71     cs->exception_index = index;
  72     cpu_loop_exit(cs);
  73 }
  74
  75 void helper_tlb_flush_pid(CPUCRISState *env, uint32_t pid)
  76 {
  77 #if !defined(CONFIG_USER_ONLY)
  78         pid &= 0xff;
  79         if (pid != (env->pregs[PR_PID] & 0xff))
  80                 cris_mmu_flush_pid(env, env->pregs[PR_PID]);
  81 #endif
  82 }
  83
  84 void helper_spc_write(CPUCRISState *env, uint32_t new_spc)
  85 {
  86 #if !defined(CONFIG_USER_ONLY)
  87     CRISCPU *cpu = cris_env_get_cpu(env);
  88     CPUState *cs = CPU(cpu);
  89
  90     tlb_flush_page(cs, env->pregs[PR_SPC]);
  91     tlb_flush_page(cs, new_spc);
  92 #endif
  93 }
  94
  95 void helper_dump(uint32_t a0, uint32_t a1, uint32_t a2)
  96 {
  97         qemu_log("%s: a0=%x a1=%x\n", __func__, a0, a1);
  98 }
  99
 100 /* Used by the tlb decoder.  */
 101 #define EXTRACT_FIELD(src, start, end) \
 102             (((src) >> start) & ((1 << (end - start + 1)) - 1))
 103
 104 void helper_movl_sreg_reg(CPUCRISState *env, uint32_t sreg, uint32_t reg)
 105 {
 106 #if !defined(CONFIG_USER_ONLY)
 107     CRISCPU *cpu = cris_env_get_cpu(env);
 108 #endif
 109         uint32_t srs;
 110         srs = env->pregs[PR_SRS];
 111         srs &= 3;
 112         env->sregs[srs][sreg] = env->regs[reg];
 113
 114 #if !defined(CONFIG_USER_ONLY)
 115         if (srs == 1 || srs == 2) {
 116                 if (sreg == 6) {
 117                         /* Writes to tlb-hi write to mm_cause as a side
 118                            effect.  */
 119                         env->sregs[SFR_RW_MM_TLB_HI] = env->regs[reg];
 120                         env->sregs[SFR_R_MM_CAUSE] = env->regs[reg];
 121                 }
 122                 else if (sreg == 5) {
 123                         uint32_t set;
 124                         uint32_t idx;
 125                         uint32_t lo, hi;
 126                         uint32_t vaddr;
 127                         int tlb_v;
 128
 129                         idx = set = env->sregs[SFR_RW_MM_TLB_SEL];
 130                         set >>= 4;
 131                         set &= 3;
 132
 133                         idx &= 15;
 134                         /* We've just made a write to tlb_lo.  */
 135                         lo = env->sregs[SFR_RW_MM_TLB_LO];
 136                         /* Writes are done via r_mm_cause.  */
 137                         hi = env->sregs[SFR_R_MM_CAUSE];
 138
 139                         vaddr = EXTRACT_FIELD(env->tlbsets[srs-1][set][idx].hi,
 140                                               13, 31);
 141                         vaddr <<= TARGET_PAGE_BITS;
 142                         tlb_v = EXTRACT_FIELD(env->tlbsets[srs-1][set][idx].lo,
 143                                             3, 3);
 144                         env->tlbsets[srs - 1][set][idx].lo = lo;
 145                         env->tlbsets[srs - 1][set][idx].hi = hi;
 146
 147                         D_LOG("tlb flush vaddr=%x v=%d pc=%x\n",
 148                                   vaddr, tlb_v, env->pc);
 149                         if (tlb_v) {
 150                 tlb_flush_page(CPU(cpu), vaddr);
 151                         }
 152                 }
 153         }
 154 #endif
 155 }
 156
 157 void helper_movl_reg_sreg(CPUCRISState *env, uint32_t reg, uint32_t sreg)
 158 {
 159         uint32_t srs;
 160         env->pregs[PR_SRS] &= 3;
 161         srs = env->pregs[PR_SRS];
 162
 163 #if !defined(CONFIG_USER_ONLY)
 164         if (srs == 1 || srs == 2)
 165         {
 166                 uint32_t set;
 167                 uint32_t idx;
 168                 uint32_t lo, hi;
 169
 170                 idx = set = env->sregs[SFR_RW_MM_TLB_SEL];
 171                 set >>= 4;
 172                 set &= 3;
 173                 idx &= 15;
 174
 175                 /* Update the mirror regs.  */
 176                 hi = env->tlbsets[srs - 1][set][idx].hi;
 177                 lo = env->tlbsets[srs - 1][set][idx].lo;
 178                 env->sregs[SFR_RW_MM_TLB_HI] = hi;
 179                 env->sregs[SFR_RW_MM_TLB_LO] = lo;
 180         }
 181 #endif
 182         env->regs[reg] = env->sregs[srs][sreg];
 183 }
 184
 185 static void cris_ccs_rshift(CPUCRISState *env)
 186 {
 187         uint32_t ccs;
 188
 189         /* Apply the ccs shift.  */
 190         ccs = env->pregs[PR_CCS];
 191         ccs = (ccs & 0xc0000000) | ((ccs & 0x0fffffff) >> 10);
 192         if (ccs & U_FLAG)
 193         {
 194                 /* Enter user mode.  */
 195                 env->ksp = env->regs[R_SP];
 196                 env->regs[R_SP] = env->pregs[PR_USP];
 197         }
 198
 199         env->pregs[PR_CCS] = ccs;
 200 }
 201
 202 void helper_rfe(CPUCRISState *env)
 203 {
 204         int rflag = env->pregs[PR_CCS] & R_FLAG;
 205
 206         D_LOG("rfe: erp=%x pid=%x ccs=%x btarget=%x\n",
 207                  env->pregs[PR_ERP], env->pregs[PR_PID],
 208                  env->pregs[PR_CCS],
 209                  env->btarget);
 210
 211         cris_ccs_rshift(env);
 212
 213         /* RFE sets the P_FLAG only if the R_FLAG is not set.  */
 214         if (!rflag)
 215                 env->pregs[PR_CCS] |= P_FLAG;
 216 }
 217
 218 void helper_rfn(CPUCRISState *env)
 219 {
 220         int rflag = env->pregs[PR_CCS] & R_FLAG;
 221
 222         D_LOG("rfn: erp=%x pid=%x ccs=%x btarget=%x\n",
 223                  env->pregs[PR_ERP], env->pregs[PR_PID],
 224                  env->pregs[PR_CCS],
 225                  env->btarget);
 226
 227         cris_ccs_rshift(env);
 228
 229         /* Set the P_FLAG only if the R_FLAG is not set.  */
 230         if (!rflag)
 231                 env->pregs[PR_CCS] |= P_FLAG;
 232
 233         /* Always set the M flag.  */
 234         env->pregs[PR_CCS] |= M_FLAG_V32;
 235 }
 236
 237 uint32_t helper_lz(uint32_t t0)
 238 {
 239         return clz32(t0);
 240 }
 241
 242 uint32_t helper_btst(CPUCRISState *env, uint32_t t0, uint32_t t1, uint32_t ccs)
 243 {
 244         /* FIXME: clean this up.  */
 245
 246         /* des ref:
 247            The N flag is set according to the selected bit in the dest reg.
 248            The Z flag is set if the selected bit and all bits to the right are
 249            zero.
 250            The X flag is cleared.
 251            Other flags are left untouched.
 252            The destination reg is not affected.*/
 253         unsigned int fz, sbit, bset, mask, masked_t0;
 254
 255         sbit = t1 & 31;
 256         bset = !!(t0 & (1 << sbit));
 257         mask = sbit == 31 ? -1 : (1 << (sbit + 1)) - 1;
 258         masked_t0 = t0 & mask;
 259         fz = !(masked_t0 | bset);
 260
 261         /* Clear the X, N and Z flags.  */
 262         ccs = ccs & ~(X_FLAG | N_FLAG | Z_FLAG);
 263         if (env->pregs[PR_VR] < 32)
 264                 ccs &= ~(V_FLAG | C_FLAG);
 265         /* Set the N and Z flags accordingly.  */
 266         ccs |= (bset << 3) | (fz << 2);
 267         return ccs;
 268 }
 269
 270 static inline uint32_t evaluate_flags_writeback(CPUCRISState *env,
 271                                                 uint32_t flags, uint32_t ccs)
 272 {
 273         unsigned int x, z, mask;
 274
 275         /* Extended arithmetics, leave the z flag alone.  */
 276         x = env->cc_x;
 277         mask = env->cc_mask | X_FLAG;
 278         if (x) {
 279                 z = flags & Z_FLAG;
 280                 mask = mask & ~z;
 281         }
 282         flags &= mask;
 283
 284         /* all insn clear the x-flag except setf or clrf.  */
 285         ccs &= ~mask;
 286         ccs |= flags;
 287         return ccs;
 288 }
 289
 290 uint32_t helper_evaluate_flags_muls(CPUCRISState *env,
 291                                     uint32_t ccs, uint32_t res, uint32_t mof)
 292 {
 293         uint32_t flags = 0;
 294         int64_t tmp;
 295         int dneg;
 296
 297         dneg = ((int32_t)res) < 0;
 298
 299         tmp = mof;
 300         tmp <<= 32;
 301         tmp |= res;
 302         if (tmp == 0)
 303                 flags |= Z_FLAG;
 304         else if (tmp < 0)
 305                 flags |= N_FLAG;
 306         if ((dneg && mof != -1)
 307             || (!dneg && mof != 0))
 308                 flags |= V_FLAG;
 309         return evaluate_flags_writeback(env, flags, ccs);
 310 }
 311
 312 uint32_t helper_evaluate_flags_mulu(CPUCRISState *env,
 313                                     uint32_t ccs, uint32_t res, uint32_t mof)
 314 {
 315         uint32_t flags = 0;
 316         uint64_t tmp;
 317
 318         tmp = mof;
 319         tmp <<= 32;
 320         tmp |= res;
 321         if (tmp == 0)
 322                 flags |= Z_FLAG;
 323         else if (tmp >> 63)
 324                 flags |= N_FLAG;
 325         if (mof)
 326                 flags |= V_FLAG;
 327
 328         return evaluate_flags_writeback(env, flags, ccs);
 329 }
 330
 331 uint32_t helper_evaluate_flags_mcp(CPUCRISState *env, uint32_t ccs,
 332                                    uint32_t src, uint32_t dst, uint32_t res)
 333 {
 334         uint32_t flags = 0;
 335
 336         src = src & 0x80000000;
 337         dst = dst & 0x80000000;
 338
 339         if ((res & 0x80000000L) != 0L)
 340         {
 341                 flags |= N_FLAG;
 342                 if (!src && !dst)
 343                         flags |= V_FLAG;
 344                 else if (src & dst)
 345                         flags |= R_FLAG;
 346         }
 347         else
 348         {
 349                 if (res == 0L)
 350                         flags |= Z_FLAG;
 351                 if (src & dst)
 352                         flags |= V_FLAG;
 353                 if (dst | src)
 354                         flags |= R_FLAG;
 355         }
 356
 357         return evaluate_flags_writeback(env, flags, ccs);
 358 }
 359
 360 uint32_t helper_evaluate_flags_alu_4(CPUCRISState *env, uint32_t ccs,
 361                                      uint32_t src, uint32_t dst, uint32_t res)
 362 {
 363         uint32_t flags = 0;
 364
 365         src = src & 0x80000000;
 366         dst = dst & 0x80000000;
 367
 368         if ((res & 0x80000000L) != 0L)
 369         {
 370                 flags |= N_FLAG;
 371                 if (!src && !dst)
 372                         flags |= V_FLAG;
 373                 else if (src & dst)
 374                         flags |= C_FLAG;
 375         }
 376         else
 377         {
 378                 if (res == 0L)
 379                         flags |= Z_FLAG;
 380                 if (src & dst)
 381                         flags |= V_FLAG;
 382                 if (dst | src)
 383                         flags |= C_FLAG;
 384         }
 385
 386         return evaluate_flags_writeback(env, flags, ccs);
 387 }
 388
 389 uint32_t helper_evaluate_flags_sub_4(CPUCRISState *env, uint32_t ccs,
 390                                      uint32_t src, uint32_t dst, uint32_t res)
 391 {
 392         uint32_t flags = 0;
 393
 394         src = (~src) & 0x80000000;
 395         dst = dst & 0x80000000;
 396
 397         if ((res & 0x80000000L) != 0L)
 398         {
 399                 flags |= N_FLAG;
 400                 if (!src && !dst)
 401                         flags |= V_FLAG;
 402                 else if (src & dst)
 403                         flags |= C_FLAG;
 404         }
 405         else
 406         {
 407                 if (res == 0L)
 408                         flags |= Z_FLAG;
 409                 if (src & dst)
 410                         flags |= V_FLAG;
 411                 if (dst | src)
 412                         flags |= C_FLAG;
 413         }
 414
 415         flags ^= C_FLAG;
 416         return evaluate_flags_writeback(env, flags, ccs);
 417 }
 418
 419 uint32_t helper_evaluate_flags_move_4(CPUCRISState *env,
 420                                       uint32_t ccs, uint32_t res)
 421 {
 422         uint32_t flags = 0;
 423
 424         if ((int32_t)res < 0)
 425                 flags |= N_FLAG;
 426         else if (res == 0L)
 427                 flags |= Z_FLAG;
 428
 429         return evaluate_flags_writeback(env, flags, ccs);
 430 }
 431 uint32_t helper_evaluate_flags_move_2(CPUCRISState *env,
 432                                       uint32_t ccs, uint32_t res)
 433 {
 434         uint32_t flags = 0;
 435
 436         if ((int16_t)res < 0L)
 437                 flags |= N_FLAG;
 438         else if (res == 0)
 439                 flags |= Z_FLAG;
 440
 441         return evaluate_flags_writeback(env, flags, ccs);
 442 }
 443
 444 /* TODO: This is expensive. We could split things up and only evaluate part of
 445    CCR on a need to know basis. For now, we simply re-evaluate everything.  */
 446 void helper_evaluate_flags(CPUCRISState *env)
 447 {
 448         uint32_t src, dst, res;
 449         uint32_t flags = 0;
 450
 451         src = env->cc_src;
 452         dst = env->cc_dest;
 453         res = env->cc_result;
 454
 455         if (env->cc_op == CC_OP_SUB || env->cc_op == CC_OP_CMP)
 456                 src = ~src;
 457
 458         /* Now, evaluate the flags. This stuff is based on
 459            Per Zander's CRISv10 simulator.  */
 460         switch (env->cc_size)
 461         {
 462                 case 1:
 463                         if ((res & 0x80L) != 0L)
 464                         {
 465                                 flags |= N_FLAG;
 466                                 if (((src & 0x80L) == 0L)
 467                                     && ((dst & 0x80L) == 0L))
 468                                 {
 469                                         flags |= V_FLAG;
 470                                 }
 471                                 else if (((src & 0x80L) != 0L)
 472                                          && ((dst & 0x80L) != 0L))
 473                                 {
 474                                         flags |= C_FLAG;
 475                                 }
 476                         }
 477                         else
 478                         {
 479                                 if ((res & 0xFFL) == 0L)
 480                                 {
 481                                         flags |= Z_FLAG;
 482                                 }
 483                                 if (((src & 0x80L) != 0L)
 484                                     && ((dst & 0x80L) != 0L))
 485                                 {
 486                                         flags |= V_FLAG;
 487                                 }
 488                                 if ((dst & 0x80L) != 0L
 489                                     || (src & 0x80L) != 0L)
 490                                 {
 491                                         flags |= C_FLAG;
 492                                 }
 493                         }
 494                         break;
 495                 case 2:
 496                         if ((res & 0x8000L) != 0L)
 497                         {
 498                                 flags |= N_FLAG;
 499                                 if (((src & 0x8000L) == 0L)
 500                                     && ((dst & 0x8000L) == 0L))
 501                                 {
 502                                         flags |= V_FLAG;
 503                                 }
 504                                 else if (((src & 0x8000L) != 0L)
 505                                          && ((dst & 0x8000L) != 0L))
 506                                 {
 507                                         flags |= C_FLAG;
 508                                 }
 509                         }
 510                         else
 511                         {
 512                                 if ((res & 0xFFFFL) == 0L)
 513                                 {
 514                                         flags |= Z_FLAG;
 515                                 }
 516                                 if (((src & 0x8000L) != 0L)
 517                                     && ((dst & 0x8000L) != 0L))
 518                                 {
 519                                         flags |= V_FLAG;
 520                                 }
 521                                 if ((dst & 0x8000L) != 0L
 522                                     || (src & 0x8000L) != 0L)
 523                                 {
 524                                         flags |= C_FLAG;
 525                                 }
 526                         }
 527                         break;
 528                 case 4:
 529                         if ((res & 0x80000000L) != 0L)
 530                         {
 531                                 flags |= N_FLAG;
 532                                 if (((src & 0x80000000L) == 0L)
 533                                     && ((dst & 0x80000000L) == 0L))
 534                                 {
 535                                         flags |= V_FLAG;
 536                                 }
 537                                 else if (((src & 0x80000000L) != 0L) &&
 538                                          ((dst & 0x80000000L) != 0L))
 539                                 {
 540                                         flags |= C_FLAG;
 541                                 }
 542                         }
 543                         else
 544                         {
 545                                 if (res == 0L)
 546                                         flags |= Z_FLAG;
 547                                 if (((src & 0x80000000L) != 0L)
 548                                     && ((dst & 0x80000000L) != 0L))
 549                                         flags |= V_FLAG;
 550                                 if ((dst & 0x80000000L) != 0L
 551                                     || (src & 0x80000000L) != 0L)
 552                                         flags |= C_FLAG;
 553                         }
 554                         break;
 555                 default:
 556                         break;
 557         }
 558
 559         if (env->cc_op == CC_OP_SUB || env->cc_op == CC_OP_CMP)
 560                 flags ^= C_FLAG;
 561
 562         env->pregs[PR_CCS] = evaluate_flags_writeback(env, flags,
 563                                                       env->pregs[PR_CCS]);
 564 }
 565
 566 void helper_top_evaluate_flags(CPUCRISState *env)
 567 {
 568         switch (env->cc_op)
 569         {
 570                 case CC_OP_MCP:
 571                         env->pregs[PR_CCS] = helper_evaluate_flags_mcp(env,
 572                                         env->pregs[PR_CCS], env->cc_src,
 573                                         env->cc_dest, env->cc_result);
 574                         break;
 575                 case CC_OP_MULS:
 576                         env->pregs[PR_CCS] = helper_evaluate_flags_muls(env,
 577                                         env->pregs[PR_CCS], env->cc_result,
 578                                         env->pregs[PR_MOF]);
 579                         break;
 580                 case CC_OP_MULU:
 581                         env->pregs[PR_CCS] = helper_evaluate_flags_mulu(env,
 582                                         env->pregs[PR_CCS], env->cc_result,
 583                                         env->pregs[PR_MOF]);
 584                         break;
 585                 case CC_OP_MOVE:
 586                 case CC_OP_AND:
 587                 case CC_OP_OR:
 588                 case CC_OP_XOR:
 589                 case CC_OP_ASR:
 590                 case CC_OP_LSR:
 591                 case CC_OP_LSL:
 592                 switch (env->cc_size)
 593                 {
 594                         case 4:
 595                                 env->pregs[PR_CCS] =
 596                                         helper_evaluate_flags_move_4(env,
 597                                                         env->pregs[PR_CCS],
 598                                                         env->cc_result);
 599                                 break;
 600                         case 2:
 601                                 env->pregs[PR_CCS] =
 602                                         helper_evaluate_flags_move_2(env,
 603                                                         env->pregs[PR_CCS],
 604                                                         env->cc_result);
 605                                 break;
 606                         default:
 607                                 helper_evaluate_flags(env);
 608                                 break;
 609                 }
 610                 break;
 611                 case CC_OP_FLAGS:
 612                         /* live.  */
 613                         break;
 614                 case CC_OP_SUB:
 615                 case CC_OP_CMP:
 616                         if (env->cc_size == 4)
 617                                 env->pregs[PR_CCS] =
 618                                         helper_evaluate_flags_sub_4(env,
 619                                                 env->pregs[PR_CCS],
 620                                                 env->cc_src, env->cc_dest,
 621                                                 env->cc_result);
 622                         else
 623                                 helper_evaluate_flags(env);
 624                         break;
 625                 default:
 626                 {
 627                         switch (env->cc_size)
 628                         {
 629                         case 4:
 630                                 env->pregs[PR_CCS] =
 631                                         helper_evaluate_flags_alu_4(env,
 632                                                 env->pregs[PR_CCS],
 633                                                 env->cc_src, env->cc_dest,
 634                                                 env->cc_result);
 635                                 break;
 636                         default:
 637                                 helper_evaluate_flags(env);
 638                                 break;
 639                         }
 640                 }
 641                 break;
 642         }
 643 }