target-moxie/helper.c

   1 /*
   2  *  Moxie helper routines.
   3  *
   4  *  Copyright (c) 2008, 2009, 2010, 2013 Anthony Green
   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 General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <stdio.h>
  21 #include <string.h>
  22 #include <assert.h>
  23
  24 #include "config.h"
  25 #include "cpu.h"
  26 #include "mmu.h"
  27 #include "exec/exec-all.h"
  28 #include "exec/cpu_ldst.h"
  29 #include "qemu/host-utils.h"
  30 #include "exec/helper-proto.h"
  31
  32 /* Try to fill the TLB and return an exception if error. If retaddr is
  33    NULL, it means that the function was called in C code (i.e. not
  34    from generated code or from helper.c) */
  35 void tlb_fill(CPUState *cs, target_ulong addr, int is_write, int mmu_idx,
  36               uintptr_t retaddr)
  37 {
  38     int ret;
  39
  40     ret = moxie_cpu_handle_mmu_fault(cs, addr, is_write, mmu_idx);
  41     if (unlikely(ret)) {
  42         if (retaddr) {
  43             cpu_restore_state(cs, retaddr);
  44         }
  45     }
  46     cpu_loop_exit(cs);
  47 }
  48
  49 void helper_raise_exception(CPUMoxieState *env, int ex)
  50 {
  51     CPUState *cs = CPU(moxie_env_get_cpu(env));
  52
  53     cs->exception_index = ex;
  54     /* Stash the exception type.  */
  55     env->sregs[2] = ex;
  56     /* Stash the address where the exception occurred.  */
  57     cpu_restore_state(cs, GETPC());
  58     env->sregs[5] = env->pc;
  59     /* Jump the the exception handline routine.  */
  60     env->pc = env->sregs[1];
  61     cpu_loop_exit(cs);
  62 }
  63
  64 uint32_t helper_div(CPUMoxieState *env, uint32_t a, uint32_t b)
  65 {
  66     if (unlikely(b == 0)) {
  67         helper_raise_exception(env, MOXIE_EX_DIV0);
  68         return 0;
  69     }
  70     if (unlikely(a == INT_MIN && b == -1)) {
  71         return INT_MIN;
  72     }
  73
  74     return (int32_t)a / (int32_t)b;
  75 }
  76
  77 uint32_t helper_udiv(CPUMoxieState *env, uint32_t a, uint32_t b)
  78 {
  79     if (unlikely(b == 0)) {
  80         helper_raise_exception(env, MOXIE_EX_DIV0);
  81         return 0;
  82     }
  83     return a / b;
  84 }
  85
  86 void helper_debug(CPUMoxieState *env)
  87 {
  88     CPUState *cs = CPU(moxie_env_get_cpu(env));
  89
  90     cs->exception_index = EXCP_DEBUG;
  91     cpu_loop_exit(cs);
  92 }
  93
  94 #if defined(CONFIG_USER_ONLY)
  95
  96 void moxie_cpu_do_interrupt(CPUState *cs)
  97 {
  98     CPUState *cs = CPU(moxie_env_get_cpu(env));
  99
 100     cs->exception_index = -1;
 101 }
 102
 103 int moxie_cpu_handle_mmu_fault(CPUState *cs, vaddr address,
 104                                int rw, int mmu_idx)
 105 {
 106     MoxieCPU *cpu = MOXIE_CPU(cs);
 107
 108     cs->exception_index = 0xaa;
 109     cpu->env.debug1 = address;
 110     cpu_dump_state(cs, stderr, fprintf, 0);
 111     return 1;
 112 }
 113
 114 #else /* !CONFIG_USER_ONLY */
 115
 116 int moxie_cpu_handle_mmu_fault(CPUState *cs, vaddr address,
 117                                int rw, int mmu_idx)
 118 {
 119     MoxieCPU *cpu = MOXIE_CPU(cs);
 120     CPUMoxieState *env = &cpu->env;
 121     MoxieMMUResult res;
 122     int prot, miss;
 123     target_ulong phy;
 124     int r = 1;
 125
 126     address &= TARGET_PAGE_MASK;
 127     prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
 128     miss = moxie_mmu_translate(&res, env, address, rw, mmu_idx);
 129     if (miss) {
 130         /* handle the miss.  */
 131         phy = 0;
 132         cs->exception_index = MOXIE_EX_MMU_MISS;
 133     } else {
 134         phy = res.phy;
 135         r = 0;
 136     }
 137     tlb_set_page(cs, address, phy, prot, mmu_idx, TARGET_PAGE_SIZE);
 138     return r;
 139 }
 140
 141
 142 void moxie_cpu_do_interrupt(CPUState *cs)
 143 {
 144     switch (cs->exception_index) {
 145     case MOXIE_EX_BREAK:
 146         break;
 147     default:
 148         break;
 149     }
 150 }
 151
 152 hwaddr moxie_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
 153 {
 154     MoxieCPU *cpu = MOXIE_CPU(cs);
 155     uint32_t phy = addr;
 156     MoxieMMUResult res;
 157     int miss;
 158
 159     miss = moxie_mmu_translate(&res, &cpu->env, addr, 0, 0);
 160     if (!miss) {
 161         phy = res.phy;
 162     }
 163     return phy;
 164 }
 165 #endif