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         process_queued_cpu_work(cs);
  36
  37         switch (trapnr) {
  38         case EXCP_INTERRUPT:
  39             /* just indicate that signals should be handled asap */
  40             break;
  41
  42         case EXCP_DIV:
  43             /* Match kernel's handle_diverror_c(). */
  44             env->pc -= 4;
  45             force_sig_fault(TARGET_SIGFPE, TARGET_FPE_INTDIV, env->pc);
  46             break;
  47
  48         case EXCP_UNALIGN:
  49         case EXCP_UNALIGND:
  50             force_sig_fault(TARGET_SIGBUS, TARGET_BUS_ADRALN,
  51                             env->ctrl[CR_BADADDR]);
  52             break;
  53
  54         case EXCP_ILLEGAL:
  55         case EXCP_UNIMPL:
  56             /* Match kernel's handle_illegal_c(). */
  57             env->pc -= 4;
  58             force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLOPC, env->pc);
  59             break;
  60         case EXCP_SUPERI:
  61             /* Match kernel's handle_supervisor_instr(). */
  62             env->pc -= 4;
  63             force_sig_fault(TARGET_SIGILL, TARGET_ILL_PRVOPC, env->pc);
  64             break;
  65
  66         case EXCP_TRAP:
  67             switch (env->error_code) {
  68             case 0:
  69                 qemu_log_mask(CPU_LOG_INT, "\nSyscall\n");
  70
  71                 ret = do_syscall(env, env->regs[2],
  72                                  env->regs[4], env->regs[5], env->regs[6],
  73                                  env->regs[7], env->regs[8], env->regs[9],
  74                                  0, 0);
  75
  76                 if (ret == -QEMU_ESIGRETURN) {
  77                     /* rt_sigreturn has set all state. */
  78                     break;
  79                 }
  80                 if (ret == -QEMU_ERESTARTSYS) {
  81                     env->pc -= 4;
  82                     break;
  83                 }
  84                 /*
  85                  * See the code after translate_rc_and_ret: all negative
  86                  * values are errors (aided by userspace restricted to 2G),
  87                  * errno is returned positive in r2, and error indication
  88                  * is a boolean in r7.
  89                  */
  90                 env->regs[2] = abs(ret);
  91                 env->regs[7] = ret < 0;
  92                 break;
  93
  94             case 1:
  95                 qemu_log_mask(CPU_LOG_INT, "\nTrap 1\n");
  96                 force_sig_fault(TARGET_SIGUSR1, 0, env->pc);
  97                 break;
  98             case 2:
  99                 qemu_log_mask(CPU_LOG_INT, "\nTrap 2\n");
 100                 force_sig_fault(TARGET_SIGUSR2, 0, env->pc);
 101                 break;
 102             case 31:
 103                 qemu_log_mask(CPU_LOG_INT, "\nTrap 31\n");
 104                 /* Match kernel's breakpoint_c(). */
 105                 env->pc -= 4;
 106                 force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->pc);
 107                 break;
 108             default:
 109                 qemu_log_mask(CPU_LOG_INT, "\nTrap %d\n", env->error_code);
 110                 force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLTRP, env->pc);
 111                 break;
 112
 113             case 16: /* QEMU specific, for __kuser_cmpxchg */
 114                 {
 115                     abi_ptr g = env->regs[4];
 116                     uint32_t *h, n, o;
 117
 118                     if (g & 0x3) {
 119                         force_sig_fault(TARGET_SIGBUS, TARGET_BUS_ADRALN, g);
 120                         break;
 121                     }
 122                     ret = page_get_flags(g);
 123                     if (!(ret & PAGE_VALID)) {
 124                         force_sig_fault(TARGET_SIGSEGV, TARGET_SEGV_MAPERR, g);
 125                         break;
 126                     }
 127                     if (!(ret & PAGE_READ) || !(ret & PAGE_WRITE)) {
 128                         force_sig_fault(TARGET_SIGSEGV, TARGET_SEGV_ACCERR, g);
 129                         break;
 130                     }
 131                     h = g2h(cs, g);
 132                     o = env->regs[5];
 133                     n = env->regs[6];
 134                     env->regs[2] = qatomic_cmpxchg(h, o, n) - o;
 135                 }
 136                 break;
 137             }
 138             break;
 139
 140         case EXCP_DEBUG:
 141             force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->pc);
 142             break;
 143         default:
 144             EXCP_DUMP(env, "\nqemu: unhandled CPU exception %#x - aborting\n",
 145                      trapnr);
 146             abort();
 147         }
 148
 149         process_pending_signals(env);
 150     }
 151 }
 152
 153 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
 154 {
 155     env->regs[R_SP] = regs->sp;
 156     env->pc = regs->ea;
 157 }