target-m68k/op_helper.c

   1 /*
   2  *  M68K helper routines
   3  *
   4  *  Copyright (c) 2007 CodeSourcery
   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, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20 #include "exec.h"
  21
  22 #if defined(CONFIG_USER_ONLY)
  23
  24 void do_interrupt(int is_hw)
  25 {
  26     env->exception_index = -1;
  27 }
  28
  29 #else
  30
  31 extern int semihosting_enabled;
  32
  33 #define MMUSUFFIX _mmu
  34 #ifdef __s390__
  35 # define GETPC() ((void*)((unsigned long)__builtin_return_address(0) & 0x7fffffffUL))
  36 #else
  37 # define GETPC() (__builtin_return_address(0))
  38 #endif
  39
  40 #define SHIFT 0
  41 #include "softmmu_template.h"
  42
  43 #define SHIFT 1
  44 #include "softmmu_template.h"
  45
  46 #define SHIFT 2
  47 #include "softmmu_template.h"
  48
  49 #define SHIFT 3
  50 #include "softmmu_template.h"
  51
  52 /* Try to fill the TLB and return an exception if error. If retaddr is
  53    NULL, it means that the function was called in C code (i.e. not
  54    from generated code or from helper.c) */
  55 /* XXX: fix it to restore all registers */
  56 void tlb_fill (target_ulong addr, int is_write, int mmu_idx, void *retaddr)
  57 {
  58     TranslationBlock *tb;
  59     CPUState *saved_env;
  60     unsigned long pc;
  61     int ret;
  62
  63     /* XXX: hack to restore env in all cases, even if not called from
  64        generated code */
  65     saved_env = env;
  66     env = cpu_single_env;
  67     ret = cpu_m68k_handle_mmu_fault(env, addr, is_write, mmu_idx, 1);
  68     if (__builtin_expect(ret, 0)) {
  69         if (retaddr) {
  70             /* now we have a real cpu fault */
  71             pc = (unsigned long)retaddr;
  72             tb = tb_find_pc(pc);
  73             if (tb) {
  74                 /* the PC is inside the translated code. It means that we have
  75                    a virtual CPU fault */
  76                 cpu_restore_state(tb, env, pc, NULL);
  77             }
  78         }
  79         cpu_loop_exit();
  80     }
  81     env = saved_env;
  82 }
  83
  84 static void do_rte(void)
  85 {
  86     uint32_t sp;
  87     uint32_t fmt;
  88
  89     sp = env->aregs[7];
  90     fmt = ldl_kernel(sp);
  91     env->pc = ldl_kernel(sp + 4);
  92     sp |= (fmt >> 28) & 3;
  93     env->sr = fmt & 0xffff;
  94     m68k_switch_sp(env);
  95     env->aregs[7] = sp + 8;
  96 }
  97
  98 void do_interrupt(int is_hw)
  99 {
 100     uint32_t sp;
 101     uint32_t fmt;
 102     uint32_t retaddr;
 103     uint32_t vector;
 104
 105     fmt = 0;
 106     retaddr = env->pc;
 107
 108     if (!is_hw) {
 109         switch (env->exception_index) {
 110         case EXCP_RTE:
 111             /* Return from an exception.  */
 112             do_rte();
 113             return;
 114         case EXCP_HALT_INSN:
 115             if (semihosting_enabled
 116                     && (env->sr & SR_S) != 0
 117                     && (env->pc & 3) == 0
 118                     && lduw_code(env->pc - 4) == 0x4e71
 119                     && ldl_code(env->pc) == 0x4e7bf000) {
 120                 env->pc += 4;
 121                 do_m68k_semihosting(env, env->dregs[0]);
 122                 return;
 123             }
 124             env->halted = 1;
 125             env->exception_index = EXCP_HLT;
 126             cpu_loop_exit();
 127             return;
 128         }
 129         if (env->exception_index >= EXCP_TRAP0
 130             && env->exception_index <= EXCP_TRAP15) {
 131             /* Move the PC after the trap instruction.  */
 132             retaddr += 2;
 133         }
 134     }
 135
 136     vector = env->exception_index << 2;
 137
 138     sp = env->aregs[7];
 139
 140     fmt |= 0x40000000;
 141     fmt |= (sp & 3) << 28;
 142     fmt |= vector << 16;
 143     fmt |= env->sr;
 144
 145     env->sr |= SR_S;
 146     if (is_hw) {
 147         env->sr = (env->sr & ~SR_I) | (env->pending_level << SR_I_SHIFT);
 148         env->sr &= ~SR_M;
 149     }
 150     m68k_switch_sp(env);
 151
 152     /* ??? This could cause MMU faults.  */
 153     sp &= ~3;
 154     sp -= 4;
 155     stl_kernel(sp, retaddr);
 156     sp -= 4;
 157     stl_kernel(sp, fmt);
 158     env->aregs[7] = sp;
 159     /* Jump to vector.  */
 160     env->pc = ldl_kernel(env->vbr + vector);
 161 }
 162
 163 #endif