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