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