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