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-common.h"
  22 #include "qemu.h"
  23 #include "user-internals.h"
  24 #include "cpu_loop-common.h"
  25 #include "signal-common.h"
  26
  27 void cpu_loop(CPUAlphaState *env)
  28 {
  29     CPUState *cs = env_cpu(env);
  30     int trapnr, si_code;
  31     abi_long sysret;
  32
  33     while (1) {
  34         bool arch_interrupt = true;
  35
  36         cpu_exec_start(cs);
  37         trapnr = cpu_exec(cs);
  38         cpu_exec_end(cs);
  39         process_queued_cpu_work(cs);
  40
  41         switch (trapnr) {
  42         case EXCP_RESET:
  43             fprintf(stderr, "Reset requested. Exit\n");
  44             exit(EXIT_FAILURE);
  45             break;
  46         case EXCP_MCHK:
  47             fprintf(stderr, "Machine check exception. Exit\n");
  48             exit(EXIT_FAILURE);
  49             break;
  50         case EXCP_SMP_INTERRUPT:
  51         case EXCP_CLK_INTERRUPT:
  52         case EXCP_DEV_INTERRUPT:
  53             fprintf(stderr, "External interrupt. Exit\n");
  54             exit(EXIT_FAILURE);
  55             break;
  56         case EXCP_OPCDEC:
  57         do_sigill:
  58             force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLOPC, env->pc);
  59             break;
  60         case EXCP_ARITH:
  61             force_sig_fault(TARGET_SIGFPE, TARGET_FPE_FLTINV, env->pc);
  62             break;
  63         case EXCP_FEN:
  64             /* No-op.  Linux simply re-enables the FPU.  */
  65             break;
  66         case EXCP_CALL_PAL:
  67             switch (env->error_code) {
  68             case 0x80:
  69                 /* BPT */
  70                 goto do_sigtrap_brkpt;
  71             case 0x81:
  72                 /* BUGCHK */
  73                 goto do_sigtrap_unk;
  74             case 0x83:
  75                 /* CALLSYS */
  76                 trapnr = env->ir[IR_V0];
  77                 sysret = do_syscall(env, trapnr,
  78                                     env->ir[IR_A0], env->ir[IR_A1],
  79                                     env->ir[IR_A2], env->ir[IR_A3],
  80                                     env->ir[IR_A4], env->ir[IR_A5],
  81                                     0, 0);
  82                 if (sysret == -QEMU_ERESTARTSYS) {
  83                     env->pc -= 4;
  84                     break;
  85                 }
  86                 if (sysret == -QEMU_ESIGRETURN) {
  87                     break;
  88                 }
  89                 /* Syscall writes 0 to V0 to bypass error check, similar
  90                    to how this is handled internal to Linux kernel.
  91                    (Ab)use trapnr temporarily as boolean indicating error.  */
  92                 trapnr = (env->ir[IR_V0] != 0 && sysret < 0);
  93                 env->ir[IR_V0] = (trapnr ? -sysret : sysret);
  94                 env->ir[IR_A3] = trapnr;
  95                 break;
  96             case 0x86:
  97                 /* IMB */
  98                 /* ??? We can probably elide the code using page_unprotect
  99                    that is checking for self-modifying code.  Instead we
 100                    could simply call tb_flush here.  Until we work out the
 101                    changes required to turn off the extra write protection,
 102                    this can be a no-op.  */
 103                 break;
 104             case 0x9E:
 105                 /* RDUNIQUE */
 106                 /* Handled in the translator for usermode.  */
 107                 abort();
 108             case 0x9F:
 109                 /* WRUNIQUE */
 110                 /* Handled in the translator for usermode.  */
 111                 abort();
 112             case 0xAA:
 113                 /* GENTRAP */
 114                 switch (env->ir[IR_A0]) {
 115                 case TARGET_GEN_INTOVF:
 116                     si_code = TARGET_FPE_INTOVF;
 117                     break;
 118                 case TARGET_GEN_INTDIV:
 119                     si_code = TARGET_FPE_INTDIV;
 120                     break;
 121                 case TARGET_GEN_FLTOVF:
 122                     si_code = TARGET_FPE_FLTOVF;
 123                     break;
 124                 case TARGET_GEN_FLTUND:
 125                     si_code = TARGET_FPE_FLTUND;
 126                     break;
 127                 case TARGET_GEN_FLTINV:
 128                     si_code = TARGET_FPE_FLTINV;
 129                     break;
 130                 case TARGET_GEN_FLTINE:
 131                     si_code = TARGET_FPE_FLTRES;
 132                     break;
 133                 case TARGET_GEN_ROPRAND:
 134                     si_code = TARGET_FPE_FLTUNK;
 135                     break;
 136                 default:
 137                     goto do_sigtrap_unk;
 138                 }
 139                 force_sig_fault(TARGET_SIGFPE, si_code, env->pc);
 140                 break;
 141             default:
 142                 goto do_sigill;
 143             }
 144             break;
 145         case EXCP_DEBUG:
 146         do_sigtrap_brkpt:
 147             force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->pc);
 148             break;
 149         do_sigtrap_unk:
 150             force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_UNK, env->pc);
 151             break;
 152         case EXCP_INTERRUPT:
 153             /* Just indicate that signals should be handled asap.  */
 154             break;
 155         case EXCP_ATOMIC:
 156             cpu_exec_step_atomic(cs);
 157             arch_interrupt = false;
 158             break;
 159         default:
 160             fprintf(stderr, "Unhandled trap: 0x%x\n", trapnr);
 161             cpu_dump_state(cs, stderr, 0);
 162             exit(EXIT_FAILURE);
 163         }
 164         process_pending_signals (env);
 165
 166         /* Most of the traps imply a transition through PALcode, which
 167            implies an REI instruction has been executed.  Which means
 168            that RX and LOCK_ADDR should be cleared.  But there are a
 169            few exceptions for traps internal to QEMU.  */
 170         if (arch_interrupt) {
 171             env->flags &= ~ENV_FLAG_RX_FLAG;
 172             env->lock_addr = -1;
 173         }
 174     }
 175 }
 176
 177 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
 178 {
 179     int i;
 180
 181     for(i = 0; i < 28; i++) {
 182         env->ir[i] = ((abi_ulong *)regs)[i];
 183     }
 184     env->ir[IR_SP] = regs->usp;
 185     env->pc = regs->pc;
 186 }