target-microblaze/op_helper.c

   1 /*
   2  *  Microblaze helper routines.
   3  *
   4  *  Copyright (c) 2009 Edgar E. Iglesias <edgar.iglesias@gmail.com>.
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA  02110-1301 USA
  19  */
  20
  21 #include <assert.h>
  22 #include "exec.h"
  23 #include "helper.h"
  24 #include "host-utils.h"
  25
  26 #define D(x)
  27
  28 #if !defined(CONFIG_USER_ONLY)
  29 #define MMUSUFFIX _mmu
  30 #define SHIFT 0
  31 #include "softmmu_template.h"
  32 #define SHIFT 1
  33 #include "softmmu_template.h"
  34 #define SHIFT 2
  35 #include "softmmu_template.h"
  36 #define SHIFT 3
  37 #include "softmmu_template.h"
  38
  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 /* XXX: fix it to restore all registers */
  43 void tlb_fill (target_ulong addr, int is_write, int mmu_idx, void *retaddr)
  44 {
  45     TranslationBlock *tb;
  46     CPUState *saved_env;
  47     unsigned long pc;
  48     int ret;
  49
  50     /* XXX: hack to restore env in all cases, even if not called from
  51        generated code */
  52     saved_env = env;
  53     env = cpu_single_env;
  54
  55     ret = cpu_mb_handle_mmu_fault(env, addr, is_write, mmu_idx, 1);
  56     if (unlikely(ret)) {
  57         if (retaddr) {
  58             /* now we have a real cpu fault */
  59             pc = (unsigned long)retaddr;
  60             tb = tb_find_pc(pc);
  61             if (tb) {
  62                 /* the PC is inside the translated code. It means that we have
  63                    a virtual CPU fault */
  64                 cpu_restore_state(tb, env, pc, NULL);
  65             }
  66         }
  67         cpu_loop_exit();
  68     }
  69     env = saved_env;
  70 }
  71 #endif
  72
  73 void helper_raise_exception(uint32_t index)
  74 {
  75     env->exception_index = index;
  76     cpu_loop_exit();
  77 }
  78
  79 void helper_debug(void)
  80 {
  81     int i;
  82
  83     qemu_log("PC=%8.8x\n", env->sregs[SR_PC]);
  84     for (i = 0; i < 32; i++) {
  85         qemu_log("r%2.2d=%8.8x ", i, env->regs[i]);
  86         if ((i + 1) % 4 == 0)
  87             qemu_log("\n");
  88     }
  89     qemu_log("\n\n");
  90 }
  91
  92 static inline uint32_t compute_carry(uint32_t a, uint32_t b, uint32_t cin)
  93 {
  94     uint32_t cout = 0;
  95
  96     if ((b == ~0) && cin)
  97         cout = 1;
  98     else if ((~0 - a) < (b + cin))
  99         cout = 1;
 100     return cout;
 101 }
 102
 103 uint32_t helper_cmp(uint32_t a, uint32_t b)
 104 {
 105     uint32_t t;
 106
 107     t = b + ~a + 1;
 108     if ((b & 0x80000000) ^ (a & 0x80000000))
 109         t = (t & 0x7fffffff) | (b & 0x80000000);
 110     return t;
 111 }
 112
 113 uint32_t helper_cmpu(uint32_t a, uint32_t b)
 114 {
 115     uint32_t t;
 116
 117     t = b + ~a + 1;
 118     if ((b & 0x80000000) ^ (a & 0x80000000))
 119         t = (t & 0x7fffffff) | (a & 0x80000000);
 120     return t;
 121 }
 122
 123 uint32_t helper_addkc(uint32_t a, uint32_t b, uint32_t k, uint32_t c)
 124 {
 125     uint32_t d, cf = 0, ncf;
 126
 127     if (c)
 128         cf = env->sregs[SR_MSR] >> 31;
 129     assert(cf == 0 || cf == 1);
 130     d = a + b + cf;
 131
 132     if (!k) {
 133         ncf = compute_carry(a, b, cf);
 134         assert(ncf == 0 || ncf == 1);
 135         if (ncf)
 136             env->sregs[SR_MSR] |= MSR_C | MSR_CC;
 137         else
 138             env->sregs[SR_MSR] &= ~(MSR_C | MSR_CC);
 139     }
 140     D(qemu_log("%x = %x + %x cf=%d ncf=%d k=%d c=%d\n",
 141                d, a, b, cf, ncf, k, c));
 142     return d;
 143 }
 144
 145 uint32_t helper_subkc(uint32_t a, uint32_t b, uint32_t k, uint32_t c)
 146 {
 147     uint32_t d, cf = 1, ncf;
 148
 149     if (c)
 150         cf = env->sregs[SR_MSR] >> 31;
 151     assert(cf == 0 || cf == 1);
 152     d = b + ~a + cf;
 153
 154     if (!k) {
 155         ncf = compute_carry(b, ~a, cf);
 156         assert(ncf == 0 || ncf == 1);
 157         if (ncf)
 158             env->sregs[SR_MSR] |= MSR_C | MSR_CC;
 159         else
 160             env->sregs[SR_MSR] &= ~(MSR_C | MSR_CC);
 161     }
 162     D(qemu_log("%x = %x + %x cf=%d ncf=%d k=%d c=%d\n",
 163                d, a, b, cf, ncf, k, c));
 164     return d;
 165 }
 166
 167 static inline int div_prepare(uint32_t a, uint32_t b)
 168 {
 169     if (b == 0) {
 170         env->sregs[SR_MSR] |= MSR_DZ;
 171         /* FIXME: Raise the div by zero exception.  */
 172         return 0;
 173     }
 174     env->sregs[SR_MSR] &= ~MSR_DZ;
 175     return 1;
 176 }
 177
 178 uint32_t helper_divs(uint32_t a, uint32_t b)
 179 {
 180     if (!div_prepare(a, b))
 181         return 0;
 182     return (int32_t)a / (int32_t)b;
 183 }
 184
 185 uint32_t helper_divu(uint32_t a, uint32_t b)
 186 {
 187     if (!div_prepare(a, b))
 188         return 0;
 189     return a / b;
 190 }
 191
 192 uint32_t helper_pcmpbf(uint32_t a, uint32_t b)
 193 {
 194     unsigned int i;
 195     uint32_t mask = 0xff000000;
 196
 197     for (i = 0; i < 4; i++) {
 198         if ((a & mask) == (b & mask))
 199             return i + 1;
 200         mask >>= 8;
 201     }
 202     return 0;
 203 }
 204
 205 #if !defined(CONFIG_USER_ONLY)
 206 /* Writes/reads to the MMU's special regs end up here.  */
 207 uint32_t helper_mmu_read(uint32_t rn)
 208 {
 209     return mmu_read(env, rn);
 210 }
 211
 212 void helper_mmu_write(uint32_t rn, uint32_t v)
 213 {
 214     mmu_write(env, rn, v);
 215 }
 216 #endif