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op_helper.c (15548B)


      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 }