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