target/openrisc/interrupt.c

   1 /*
   2  * OpenRISC interrupt.
   3  *
   4  * Copyright (c) 2011-2012 Jia Liu <proljc@gmail.com>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library 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 GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "qemu/osdep.h"
  21 #include "cpu.h"
  22 #include "exec/exec-all.h"
  23 #include "exec/gdbstub.h"
  24 #include "qemu/host-utils.h"
  25 #ifndef CONFIG_USER_ONLY
  26 #include "hw/loader.h"
  27 #endif
  28
  29 void openrisc_cpu_do_interrupt(CPUState *cs)
  30 {
  31     OpenRISCCPU *cpu = OPENRISC_CPU(cs);
  32     CPUOpenRISCState *env = &cpu->env;
  33     int exception = cs->exception_index;
  34
  35     env->epcr = env->pc;
  36     if (exception == EXCP_SYSCALL) {
  37         env->epcr += 4;
  38     }
  39     /* When we have an illegal instruction the error effective address
  40        shall be set to the illegal instruction address.  */
  41     if (exception == EXCP_ILLEGAL) {
  42         env->eear = env->pc;
  43     }
  44
  45     /* During exceptions esr is populared with the pre-exception sr.  */
  46     env->esr = cpu_get_sr(env);
  47     /* In parallel sr is updated to disable mmu, interrupts, timers and
  48        set the delay slot exception flag.  */
  49     env->sr &= ~SR_DME;
  50     env->sr &= ~SR_IME;
  51     env->sr |= SR_SM;
  52     env->sr &= ~SR_IEE;
  53     env->sr &= ~SR_TEE;
  54     env->pmr &= ~PMR_DME;
  55     env->pmr &= ~PMR_SME;
  56     env->lock_addr = -1;
  57
  58     /* Set/clear dsx to indicate if we are in a delay slot exception.  */
  59     if (env->dflag) {
  60         env->dflag = 0;
  61         env->sr |= SR_DSX;
  62         env->epcr -= 4;
  63     } else {
  64         env->sr &= ~SR_DSX;
  65     }
  66
  67     if (exception > 0 && exception < EXCP_NR) {
  68         static const char * const int_name[EXCP_NR] = {
  69             [EXCP_RESET]    = "RESET",
  70             [EXCP_BUSERR]   = "BUSERR (bus error)",
  71             [EXCP_DPF]      = "DFP (data protection fault)",
  72             [EXCP_IPF]      = "IPF (code protection fault)",
  73             [EXCP_TICK]     = "TICK (timer interrupt)",
  74             [EXCP_ALIGN]    = "ALIGN",
  75             [EXCP_ILLEGAL]  = "ILLEGAL",
  76             [EXCP_INT]      = "INT (device interrupt)",
  77             [EXCP_DTLBMISS] = "DTLBMISS (data tlb miss)",
  78             [EXCP_ITLBMISS] = "ITLBMISS (code tlb miss)",
  79             [EXCP_RANGE]    = "RANGE",
  80             [EXCP_SYSCALL]  = "SYSCALL",
  81             [EXCP_FPE]      = "FPE",
  82             [EXCP_TRAP]     = "TRAP",
  83         };
  84
  85         qemu_log_mask(CPU_LOG_INT, "INT: %s\n", int_name[exception]);
  86
  87         hwaddr vect_pc = exception << 8;
  88         if (env->cpucfgr & CPUCFGR_EVBARP) {
  89             vect_pc |= env->evbar;
  90         }
  91         if (env->sr & SR_EPH) {
  92             vect_pc |= 0xf0000000;
  93         }
  94         env->pc = vect_pc;
  95     } else {
  96         cpu_abort(cs, "Unhandled exception 0x%x\n", exception);
  97     }
  98
  99     cs->exception_index = -1;
 100 }
 101
 102 bool openrisc_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
 103 {
 104     OpenRISCCPU *cpu = OPENRISC_CPU(cs);
 105     CPUOpenRISCState *env = &cpu->env;
 106     int idx = -1;
 107
 108     if ((interrupt_request & CPU_INTERRUPT_HARD) && (env->sr & SR_IEE)) {
 109         idx = EXCP_INT;
 110     }
 111     if ((interrupt_request & CPU_INTERRUPT_TIMER) && (env->sr & SR_TEE)) {
 112         idx = EXCP_TICK;
 113     }
 114     if (idx >= 0) {
 115         cs->exception_index = idx;
 116         openrisc_cpu_do_interrupt(cs);
 117         return true;
 118     }
 119     return false;
 120 }