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     int trapnr, ret;
  30
  31     for (;;) {
  32         cpu_exec_start(cs);
  33         trapnr = cpu_exec(cs);
  34         cpu_exec_end(cs);
  35
  36         switch (trapnr) {
  37         case EXCP_INTERRUPT:
  38             /* just indicate that signals should be handled asap */
  39             break;
  40
  41         case EXCP_DIV:
  42             /* Match kernel's handle_diverror_c(). */
  43             env->pc -= 4;
  44             force_sig_fault(TARGET_SIGFPE, TARGET_FPE_INTDIV, env->pc);
  45             break;
  46
  47         case EXCP_UNALIGN:
  48         case EXCP_UNALIGND:
  49             force_sig_fault(TARGET_SIGBUS, TARGET_BUS_ADRALN,
  50                             env->ctrl[CR_BADADDR]);
  51             break;
  52
  53         case EXCP_ILLEGAL:
  54         case EXCP_UNIMPL:
  55             /* Match kernel's handle_illegal_c(). */
  56             env->pc -= 4;
  57             force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLOPC, env->pc);
  58             break;
  59         case EXCP_SUPERI:
  60             /* Match kernel's handle_supervisor_instr(). */
  61             env->pc -= 4;
  62             force_sig_fault(TARGET_SIGILL, TARGET_ILL_PRVOPC, env->pc);
  63             break;
  64
  65         case EXCP_TRAP:
  66             switch (env->error_code) {
  67             case 0:
  68                 qemu_log_mask(CPU_LOG_INT, "\nSyscall\n");
  69
  70                 ret = do_syscall(env, env->regs[2],
  71                                  env->regs[4], env->regs[5], env->regs[6],
  72                                  env->regs[7], env->regs[8], env->regs[9],
  73                                  0, 0);
  74
  75                 if (ret == -QEMU_ESIGRETURN) {
  76                     /* rt_sigreturn has set all state. */
  77                     break;
  78                 }
  79                 if (ret == -QEMU_ERESTARTSYS) {
  80                     env->pc -= 4;
  81                     break;
  82                 }
  83                 /*
  84                  * See the code after translate_rc_and_ret: all negative
  85                  * values are errors (aided by userspace restricted to 2G),
  86                  * errno is returned positive in r2, and error indication
  87                  * is a boolean in r7.
  88                  */
  89                 env->regs[2] = abs(ret);
  90                 env->regs[7] = ret < 0;
  91                 break;
  92
  93             case 1:
  94                 qemu_log_mask(CPU_LOG_INT, "\nTrap 1\n");
  95                 force_sig_fault(TARGET_SIGUSR1, 0, env->pc);
  96                 break;
  97             case 2:
  98                 qemu_log_mask(CPU_LOG_INT, "\nTrap 2\n");
  99                 force_sig_fault(TARGET_SIGUSR2, 0, env->pc);
 100                 break;
 101             case 31:
 102                 qemu_log_mask(CPU_LOG_INT, "\nTrap 31\n");
 103                 /* Match kernel's breakpoint_c(). */
 104                 env->pc -= 4;
 105                 force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->pc);
 106                 break;
 107             default:
 108                 qemu_log_mask(CPU_LOG_INT, "\nTrap %d\n", env->error_code);
 109                 force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLTRP, env->pc);
 110                 break;
 111
 112             case 16: /* QEMU specific, for __kuser_cmpxchg */
 113                 {
 114                     abi_ptr g = env->regs[4];
 115                     uint32_t *h, n, o;
 116
 117                     if (g & 0x3) {
 118                         force_sig_fault(TARGET_SIGBUS, TARGET_BUS_ADRALN, g);
 119                         break;
 120                     }
 121                     ret = page_get_flags(g);
 122                     if (!(ret & PAGE_VALID)) {
 123                         force_sig_fault(TARGET_SIGSEGV, TARGET_SEGV_MAPERR, g);
 124                         break;
 125                     }
 126                     if (!(ret & PAGE_READ) || !(ret & PAGE_WRITE)) {
 127                         force_sig_fault(TARGET_SIGSEGV, TARGET_SEGV_ACCERR, g);
 128                         break;
 129                     }
 130                     h = g2h(cs, g);
 131                     o = env->regs[5];
 132                     n = env->regs[6];
 133                     env->regs[2] = qatomic_cmpxchg(h, o, n) - o;
 134                 }
 135                 break;
 136             }
 137             break;
 138
 139         case EXCP_DEBUG:
 140             force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->pc);
 141             break;
 142         default:
 143             EXCP_DUMP(env, "\nqemu: unhandled CPU exception %#x - aborting\n",
 144                      trapnr);
 145             abort();
 146         }
 147
 148         process_pending_signals(env);
 149     }
 150 }
 151
 152 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
 153 {
 154     env->regs[R_SP] = regs->sp;
 155     env->pc = regs->ea;
 156 }