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 2.1 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 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 void helper_raise_exception(CPUMoxieState *env, int ex)
  30 {
  31     CPUState *cs = env_cpu(env);
  32
  33     cs->exception_index = ex;
  34     /* Stash the exception type.  */
  35     env->sregs[2] = ex;
  36     /* Stash the address where the exception occurred.  */
  37     cpu_restore_state(cs, GETPC(), true);
  38     env->sregs[5] = env->pc;
  39     /* Jump to the exception handline routine.  */
  40     env->pc = env->sregs[1];
  41     cpu_loop_exit(cs);
  42 }
  43
  44 uint32_t helper_div(CPUMoxieState *env, uint32_t a, uint32_t b)
  45 {
  46     if (unlikely(b == 0)) {
  47         helper_raise_exception(env, MOXIE_EX_DIV0);
  48         return 0;
  49     }
  50     if (unlikely(a == INT_MIN && b == -1)) {
  51         return INT_MIN;
  52     }
  53
  54     return (int32_t)a / (int32_t)b;
  55 }
  56
  57 uint32_t helper_udiv(CPUMoxieState *env, uint32_t a, uint32_t b)
  58 {
  59     if (unlikely(b == 0)) {
  60         helper_raise_exception(env, MOXIE_EX_DIV0);
  61         return 0;
  62     }
  63     return a / b;
  64 }
  65
  66 void helper_debug(CPUMoxieState *env)
  67 {
  68     CPUState *cs = env_cpu(env);
  69
  70     cs->exception_index = EXCP_DEBUG;
  71     cpu_loop_exit(cs);
  72 }
  73
  74 bool moxie_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
  75                         MMUAccessType access_type, int mmu_idx,
  76                         bool probe, uintptr_t retaddr)
  77 {
  78     MoxieCPU *cpu = MOXIE_CPU(cs);
  79     CPUMoxieState *env = &cpu->env;
  80     MoxieMMUResult res;
  81     int prot, miss;
  82
  83     address &= TARGET_PAGE_MASK;
  84     prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
  85     miss = moxie_mmu_translate(&res, env, address, access_type, mmu_idx);
  86     if (likely(!miss)) {
  87         tlb_set_page(cs, address, res.phy, prot, mmu_idx, TARGET_PAGE_SIZE);
  88         return true;
  89     }
  90     if (probe) {
  91         return false;
  92     }
  93
  94     cs->exception_index = MOXIE_EX_MMU_MISS;
  95     cpu_loop_exit_restore(cs, retaddr);
  96 }
  97
  98 void moxie_cpu_do_interrupt(CPUState *cs)
  99 {
 100     switch (cs->exception_index) {
 101     case MOXIE_EX_BREAK:
 102         break;
 103     default:
 104         break;
 105     }
 106 }
 107
 108 hwaddr moxie_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
 109 {
 110     MoxieCPU *cpu = MOXIE_CPU(cs);
 111     uint32_t phy = addr;
 112     MoxieMMUResult res;
 113     int miss;
 114
 115     miss = moxie_mmu_translate(&res, &cpu->env, addr, 0, 0);
 116     if (!miss) {
 117         phy = res.phy;
 118     }
 119     return phy;
 120 }