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