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