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, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <assert.h>
  21 #include "exec.h"
  22 #include "helper.h"
  23 #include "host-utils.h"
  24
  25 #define D(x)
  26
  27 #if !defined(CONFIG_USER_ONLY)
  28 #define MMUSUFFIX _mmu
  29 #define SHIFT 0
  30 #include "softmmu_template.h"
  31 #define SHIFT 1
  32 #include "softmmu_template.h"
  33 #define SHIFT 2
  34 #include "softmmu_template.h"
  35 #define SHIFT 3
  36 #include "softmmu_template.h"
  37
  38 /* Try to fill the TLB and return an exception if error. If retaddr is
  39    NULL, it means that the function was called in C code (i.e. not
  40    from generated code or from helper.c) */
  41 /* XXX: fix it to restore all registers */
  42 void tlb_fill (target_ulong addr, int is_write, int mmu_idx, void *retaddr)
  43 {
  44     TranslationBlock *tb;
  45     CPUState *saved_env;
  46     unsigned long pc;
  47     int ret;
  48
  49     /* XXX: hack to restore env in all cases, even if not called from
  50        generated code */
  51     saved_env = env;
  52     env = cpu_single_env;
  53
  54     ret = cpu_mb_handle_mmu_fault(env, addr, is_write, mmu_idx, 1);
  55     if (unlikely(ret)) {
  56         if (retaddr) {
  57             /* now we have a real cpu fault */
  58             pc = (unsigned long)retaddr;
  59             tb = tb_find_pc(pc);
  60             if (tb) {
  61                 /* the PC is inside the translated code. It means that we have
  62                    a virtual CPU fault */
  63                 cpu_restore_state(tb, env, pc, NULL);
  64             }
  65         }
  66         cpu_loop_exit();
  67     }
  68     env = saved_env;
  69 }
  70 #endif
  71
  72 void helper_raise_exception(uint32_t index)
  73 {
  74     env->exception_index = index;
  75     cpu_loop_exit();
  76 }
  77
  78 void helper_debug(void)
  79 {
  80     int i;
  81
  82     qemu_log("PC=%8.8x\n", env->sregs[SR_PC]);
  83     for (i = 0; i < 32; i++) {
  84         qemu_log("r%2.2d=%8.8x ", i, env->regs[i]);
  85         if ((i + 1) % 4 == 0)
  86             qemu_log("\n");
  87     }
  88     qemu_log("\n\n");
  89 }
  90
  91 static inline uint32_t compute_carry(uint32_t a, uint32_t b, uint32_t cin)
  92 {
  93     uint32_t cout = 0;
  94
  95     if ((b == ~0) && cin)
  96         cout = 1;
  97     else if ((~0 - a) < (b + cin))
  98         cout = 1;
  99     return cout;
 100 }
 101
 102 uint32_t helper_cmp(uint32_t a, uint32_t b)
 103 {
 104     uint32_t t;
 105
 106     t = b + ~a + 1;
 107     if ((b & 0x80000000) ^ (a & 0x80000000))
 108         t = (t & 0x7fffffff) | (b & 0x80000000);
 109     return t;
 110 }
 111
 112 uint32_t helper_cmpu(uint32_t a, uint32_t b)
 113 {
 114     uint32_t t;
 115
 116     t = b + ~a + 1;
 117     if ((b & 0x80000000) ^ (a & 0x80000000))
 118         t = (t & 0x7fffffff) | (a & 0x80000000);
 119     return t;
 120 }
 121
 122 uint32_t helper_addkc(uint32_t a, uint32_t b, uint32_t k, uint32_t c)
 123 {
 124     uint32_t d, cf = 0, ncf;
 125
 126     if (c)
 127         cf = env->sregs[SR_MSR] >> 31;
 128     assert(cf == 0 || cf == 1);
 129     d = a + b + cf;
 130
 131     if (!k) {
 132         ncf = compute_carry(a, b, cf);
 133         assert(ncf == 0 || ncf == 1);
 134         if (ncf)
 135             env->sregs[SR_MSR] |= MSR_C | MSR_CC;
 136         else
 137             env->sregs[SR_MSR] &= ~(MSR_C | MSR_CC);
 138     }
 139     D(qemu_log("%x = %x + %x cf=%d ncf=%d k=%d c=%d\n",
 140                d, a, b, cf, ncf, k, c));
 141     return d;
 142 }
 143
 144 uint32_t helper_subkc(uint32_t a, uint32_t b, uint32_t k, uint32_t c)
 145 {
 146     uint32_t d, cf = 1, ncf;
 147
 148     if (c)
 149         cf = env->sregs[SR_MSR] >> 31;
 150     assert(cf == 0 || cf == 1);
 151     d = b + ~a + cf;
 152
 153     if (!k) {
 154         ncf = compute_carry(b, ~a, cf);
 155         assert(ncf == 0 || ncf == 1);
 156         if (ncf)
 157             env->sregs[SR_MSR] |= MSR_C | MSR_CC;
 158         else
 159             env->sregs[SR_MSR] &= ~(MSR_C | MSR_CC);
 160     }
 161     D(qemu_log("%x = %x + %x cf=%d ncf=%d k=%d c=%d\n",
 162                d, a, b, cf, ncf, k, c));
 163     return d;
 164 }
 165
 166 static inline int div_prepare(uint32_t a, uint32_t b)
 167 {
 168     if (b == 0) {
 169         env->sregs[SR_MSR] |= MSR_DZ;
 170         /* FIXME: Raise the div by zero exception.  */
 171         return 0;
 172     }
 173     env->sregs[SR_MSR] &= ~MSR_DZ;
 174     return 1;
 175 }
 176
 177 uint32_t helper_divs(uint32_t a, uint32_t b)
 178 {
 179     if (!div_prepare(a, b))
 180         return 0;
 181     return (int32_t)a / (int32_t)b;
 182 }
 183
 184 uint32_t helper_divu(uint32_t a, uint32_t b)
 185 {
 186     if (!div_prepare(a, b))
 187         return 0;
 188     return a / b;
 189 }
 190
 191 uint32_t helper_pcmpbf(uint32_t a, uint32_t b)
 192 {
 193     unsigned int i;
 194     uint32_t mask = 0xff000000;
 195
 196     for (i = 0; i < 4; i++) {
 197         if ((a & mask) == (b & mask))
 198             return i + 1;
 199         mask >>= 8;
 200     }
 201     return 0;
 202 }
 203
 204 #if !defined(CONFIG_USER_ONLY)
 205 /* Writes/reads to the MMU's special regs end up here.  */
 206 uint32_t helper_mmu_read(uint32_t rn)
 207 {
 208     return mmu_read(env, rn);
 209 }
 210
 211 void helper_mmu_write(uint32_t rn, uint32_t v)
 212 {
 213     mmu_write(env, rn, v);
 214 }
 215 #endif