linux-user/alpha/cpu_loop.c

   1 /*
   2  *  qemu user cpu loop
   3  *
   4  *  Copyright (c) 2003-2008 Fabrice Bellard
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program 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
  14  *  GNU 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 #include "qemu.h"
  22 #include "user-internals.h"
  23 #include "cpu_loop-common.h"
  24 #include "signal-common.h"
  25
  26 void cpu_loop(CPUAlphaState *env)
  27 {
  28     CPUState *cs = env_cpu(env);
  29     int trapnr, si_code;
  30     abi_long sysret;
  31
  32     while (1) {
  33         bool arch_interrupt = true;
  34
  35         cpu_exec_start(cs);
  36         trapnr = cpu_exec(cs);
  37         cpu_exec_end(cs);
  38         process_queued_cpu_work(cs);
  39
  40         switch (trapnr) {
  41         case EXCP_RESET:
  42             fprintf(stderr, "Reset requested. Exit\n");
  43             exit(EXIT_FAILURE);
  44             break;
  45         case EXCP_MCHK:
  46             fprintf(stderr, "Machine check exception. Exit\n");
  47             exit(EXIT_FAILURE);
  48             break;
  49         case EXCP_SMP_INTERRUPT:
  50         case EXCP_CLK_INTERRUPT:
  51         case EXCP_DEV_INTERRUPT:
  52             fprintf(stderr, "External interrupt. Exit\n");
  53             exit(EXIT_FAILURE);
  54             break;
  55         case EXCP_OPCDEC:
  56         do_sigill:
  57             force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLOPC, env->pc);
  58             break;
  59         case EXCP_ARITH:
  60             force_sig_fault(TARGET_SIGFPE, TARGET_FPE_FLTINV, env->pc);
  61             break;
  62         case EXCP_FEN:
  63             /* No-op.  Linux simply re-enables the FPU.  */
  64             break;
  65         case EXCP_CALL_PAL:
  66             switch (env->error_code) {
  67             case 0x80:
  68                 /* BPT */
  69                 goto do_sigtrap_brkpt;
  70             case 0x81:
  71                 /* BUGCHK */
  72                 goto do_sigtrap_unk;
  73             case 0x83:
  74                 /* CALLSYS */
  75                 trapnr = env->ir[IR_V0];
  76                 sysret = do_syscall(env, trapnr,
  77                                     env->ir[IR_A0], env->ir[IR_A1],
  78                                     env->ir[IR_A2], env->ir[IR_A3],
  79                                     env->ir[IR_A4], env->ir[IR_A5],
  80                                     0, 0);
  81                 if (sysret == -QEMU_ERESTARTSYS) {
  82                     env->pc -= 4;
  83                     break;
  84                 }
  85                 if (sysret == -QEMU_ESIGRETURN) {
  86                     break;
  87                 }
  88                 /* Syscall writes 0 to V0 to bypass error check, similar
  89                    to how this is handled internal to Linux kernel.
  90                    (Ab)use trapnr temporarily as boolean indicating error.  */
  91                 trapnr = (env->ir[IR_V0] != 0 && sysret < 0);
  92                 env->ir[IR_V0] = (trapnr ? -sysret : sysret);
  93                 env->ir[IR_A3] = trapnr;
  94                 break;
  95             case 0x86:
  96                 /* IMB */
  97                 /* ??? We can probably elide the code using page_unprotect
  98                    that is checking for self-modifying code.  Instead we
  99                    could simply call tb_flush here.  Until we work out the
 100                    changes required to turn off the extra write protection,
 101                    this can be a no-op.  */
 102                 break;
 103             case 0x9E:
 104                 /* RDUNIQUE */
 105                 /* Handled in the translator for usermode.  */
 106                 abort();
 107             case 0x9F:
 108                 /* WRUNIQUE */
 109                 /* Handled in the translator for usermode.  */
 110                 abort();
 111             case 0xAA:
 112                 /* GENTRAP */
 113                 switch (env->ir[IR_A0]) {
 114                 case TARGET_GEN_INTOVF:
 115                     si_code = TARGET_FPE_INTOVF;
 116                     break;
 117                 case TARGET_GEN_INTDIV:
 118                     si_code = TARGET_FPE_INTDIV;
 119                     break;
 120                 case TARGET_GEN_FLTOVF:
 121                     si_code = TARGET_FPE_FLTOVF;
 122                     break;
 123                 case TARGET_GEN_FLTUND:
 124                     si_code = TARGET_FPE_FLTUND;
 125                     break;
 126                 case TARGET_GEN_FLTINV:
 127                     si_code = TARGET_FPE_FLTINV;
 128                     break;
 129                 case TARGET_GEN_FLTINE:
 130                     si_code = TARGET_FPE_FLTRES;
 131                     break;
 132                 case TARGET_GEN_ROPRAND:
 133                     si_code = TARGET_FPE_FLTUNK;
 134                     break;
 135                 default:
 136                     goto do_sigtrap_unk;
 137                 }
 138                 force_sig_fault(TARGET_SIGFPE, si_code, env->pc);
 139                 break;
 140             default:
 141                 goto do_sigill;
 142             }
 143             break;
 144         case EXCP_DEBUG:
 145         do_sigtrap_brkpt:
 146             force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->pc);
 147             break;
 148         do_sigtrap_unk:
 149             force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_UNK, env->pc);
 150             break;
 151         case EXCP_INTERRUPT:
 152             /* Just indicate that signals should be handled asap.  */
 153             break;
 154         case EXCP_ATOMIC:
 155             cpu_exec_step_atomic(cs);
 156             arch_interrupt = false;
 157             break;
 158         default:
 159             fprintf(stderr, "Unhandled trap: 0x%x\n", trapnr);
 160             cpu_dump_state(cs, stderr, 0);
 161             exit(EXIT_FAILURE);
 162         }
 163         process_pending_signals (env);
 164
 165         /* Most of the traps imply a transition through PALcode, which
 166            implies an REI instruction has been executed.  Which means
 167            that RX and LOCK_ADDR should be cleared.  But there are a
 168            few exceptions for traps internal to QEMU.  */
 169         if (arch_interrupt) {
 170             env->flags &= ~ENV_FLAG_RX_FLAG;
 171             env->lock_addr = -1;
 172         }
 173     }
 174 }
 175
 176 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
 177 {
 178     int i;
 179
 180     for(i = 0; i < 28; i++) {
 181         env->ir[i] = ((abi_ulong *)regs)[i];
 182     }
 183     env->ir[IR_SP] = regs->usp;
 184     env->pc = regs->pc;
 185 }