linux-user/nios2/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(CPUNios2State *env)
  27 {
  28     CPUState *cs = env_cpu(env);
  29     target_siginfo_t info;
  30     int trapnr, ret;
  31
  32     for (;;) {
  33         cpu_exec_start(cs);
  34         trapnr = cpu_exec(cs);
  35         cpu_exec_end(cs);
  36
  37         switch (trapnr) {
  38         case EXCP_INTERRUPT:
  39             /* just indicate that signals should be handled asap */
  40             break;
  41
  42         case EXCP_TRAP:
  43             /*
  44              * TODO: This advance should be done in the translator, as
  45              * hardware produces an advanced pc as part of all exceptions.
  46              */
  47             env->regs[R_PC] += 4;
  48
  49             switch (env->error_code) {
  50             case 0:
  51                 qemu_log_mask(CPU_LOG_INT, "\nSyscall\n");
  52
  53                 ret = do_syscall(env, env->regs[2],
  54                                  env->regs[4], env->regs[5], env->regs[6],
  55                                  env->regs[7], env->regs[8], env->regs[9],
  56                                  0, 0);
  57
  58                 if (ret == -QEMU_ESIGRETURN) {
  59                     /* rt_sigreturn has set all state. */
  60                     break;
  61                 }
  62                 if (ret == -QEMU_ERESTARTSYS) {
  63                     env->regs[R_PC] -= 4;
  64                     break;
  65                 }
  66                 /*
  67                  * See the code after translate_rc_and_ret: all negative
  68                  * values are errors (aided by userspace restricted to 2G),
  69                  * errno is returned positive in r2, and error indication
  70                  * is a boolean in r7.
  71                  */
  72                 env->regs[2] = abs(ret);
  73                 env->regs[7] = ret < 0;
  74                 break;
  75
  76             case 1:
  77                 qemu_log_mask(CPU_LOG_INT, "\nTrap 1\n");
  78                 force_sig_fault(TARGET_SIGUSR1, 0, env->regs[R_PC]);
  79                 break;
  80             case 2:
  81                 qemu_log_mask(CPU_LOG_INT, "\nTrap 2\n");
  82                 force_sig_fault(TARGET_SIGUSR2, 0, env->regs[R_PC]);
  83                 break;
  84             case 31:
  85                 qemu_log_mask(CPU_LOG_INT, "\nTrap 31\n");
  86                 /* Match kernel's breakpoint_c(). */
  87                 env->regs[R_PC] -= 4;
  88                 force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->regs[R_PC]);
  89                 break;
  90             default:
  91                 qemu_log_mask(CPU_LOG_INT, "\nTrap %d\n", env->error_code);
  92                 force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLTRP,
  93                                 env->regs[R_PC]);
  94                 break;
  95
  96             case 16: /* QEMU specific, for __kuser_cmpxchg */
  97                 {
  98                     abi_ptr g = env->regs[4];
  99                     uint32_t *h, n, o;
 100
 101                     if (g & 0x3) {
 102                         force_sig_fault(TARGET_SIGBUS, TARGET_BUS_ADRALN, g);
 103                         break;
 104                     }
 105                     ret = page_get_flags(g);
 106                     if (!(ret & PAGE_VALID)) {
 107                         force_sig_fault(TARGET_SIGSEGV, TARGET_SEGV_MAPERR, g);
 108                         break;
 109                     }
 110                     if (!(ret & PAGE_READ) || !(ret & PAGE_WRITE)) {
 111                         force_sig_fault(TARGET_SIGSEGV, TARGET_SEGV_ACCERR, g);
 112                         break;
 113                     }
 114                     h = g2h(cs, g);
 115                     o = env->regs[5];
 116                     n = env->regs[6];
 117                     env->regs[2] = qatomic_cmpxchg(h, o, n) - o;
 118                 }
 119                 break;
 120             }
 121             break;
 122
 123         case EXCP_DEBUG:
 124             info.si_signo = TARGET_SIGTRAP;
 125             info.si_errno = 0;
 126             info.si_code = TARGET_TRAP_BRKPT;
 127             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
 128             break;
 129         case 0xaa:
 130             {
 131                 info.si_signo = TARGET_SIGSEGV;
 132                 info.si_errno = 0;
 133                 /* TODO: check env->error_code */
 134                 info.si_code = TARGET_SEGV_MAPERR;
 135                 info._sifields._sigfault._addr = env->regs[R_PC];
 136                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
 137             }
 138             break;
 139         default:
 140             EXCP_DUMP(env, "\nqemu: unhandled CPU exception %#x - aborting\n",
 141                      trapnr);
 142             abort();
 143         }
 144
 145         process_pending_signals(env);
 146     }
 147 }
 148
 149 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
 150 {
 151     env->regs[0] = 0;
 152     env->regs[1] = regs->r1;
 153     env->regs[2] = regs->r2;
 154     env->regs[3] = regs->r3;
 155     env->regs[4] = regs->r4;
 156     env->regs[5] = regs->r5;
 157     env->regs[6] = regs->r6;
 158     env->regs[7] = regs->r7;
 159     env->regs[8] = regs->r8;
 160     env->regs[9] = regs->r9;
 161     env->regs[10] = regs->r10;
 162     env->regs[11] = regs->r11;
 163     env->regs[12] = regs->r12;
 164     env->regs[13] = regs->r13;
 165     env->regs[14] = regs->r14;
 166     env->regs[15] = regs->r15;
 167     /* TODO: unsigned long  orig_r2; */
 168     env->regs[R_RA] = regs->ra;
 169     env->regs[R_FP] = regs->fp;
 170     env->regs[R_SP] = regs->sp;
 171     env->regs[R_GP] = regs->gp;
 172     env->regs[CR_ESTATUS] = regs->estatus;
 173     env->regs[R_PC] = regs->ea;
 174     /* TODO: unsigned long  orig_r7; */
 175 }