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