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 "qemu/log.h"
  22 #include "cpu.h"
  23 #include "exec/exec-all.h"
  24 #include "exec/gdbstub.h"
  25 #include "qemu/host-utils.h"
  26 #ifndef CONFIG_USER_ONLY
  27 #include "hw/loader.h"
  28 #endif
  29
  30 void openrisc_cpu_do_interrupt(CPUState *cs)
  31 {
  32     OpenRISCCPU *cpu = OPENRISC_CPU(cs);
  33     CPUOpenRISCState *env = &cpu->env;
  34     int exception = cs->exception_index;
  35
  36     env->epcr = env->pc;
  37     if (exception == EXCP_SYSCALL) {
  38         env->epcr += 4;
  39     }
  40     /* When we have an illegal instruction the error effective address
  41        shall be set to the illegal instruction address.  */
  42     if (exception == EXCP_ILLEGAL) {
  43         env->eear = env->pc;
  44     }
  45
  46     /* During exceptions esr is populared with the pre-exception sr.  */
  47     env->esr = cpu_get_sr(env);
  48     /* In parallel sr is updated to disable mmu, interrupts, timers and
  49        set the delay slot exception flag.  */
  50     env->sr &= ~SR_DME;
  51     env->sr &= ~SR_IME;
  52     env->sr |= SR_SM;
  53     env->sr &= ~SR_IEE;
  54     env->sr &= ~SR_TEE;
  55     env->pmr &= ~PMR_DME;
  56     env->pmr &= ~PMR_SME;
  57     env->lock_addr = -1;
  58
  59     /* Set/clear dsx to indicate if we are in a delay slot exception.  */
  60     if (env->dflag) {
  61         env->dflag = 0;
  62         env->sr |= SR_DSX;
  63         env->epcr -= 4;
  64     } else {
  65         env->sr &= ~SR_DSX;
  66     }
  67
  68     if (exception > 0 && exception < EXCP_NR) {
  69         static const char * const int_name[EXCP_NR] = {
  70             [EXCP_RESET]    = "RESET",
  71             [EXCP_BUSERR]   = "BUSERR (bus error)",
  72             [EXCP_DPF]      = "DFP (data protection fault)",
  73             [EXCP_IPF]      = "IPF (code protection fault)",
  74             [EXCP_TICK]     = "TICK (timer interrupt)",
  75             [EXCP_ALIGN]    = "ALIGN",
  76             [EXCP_ILLEGAL]  = "ILLEGAL",
  77             [EXCP_INT]      = "INT (device interrupt)",
  78             [EXCP_DTLBMISS] = "DTLBMISS (data tlb miss)",
  79             [EXCP_ITLBMISS] = "ITLBMISS (code tlb miss)",
  80             [EXCP_RANGE]    = "RANGE",
  81             [EXCP_SYSCALL]  = "SYSCALL",
  82             [EXCP_FPE]      = "FPE",
  83             [EXCP_TRAP]     = "TRAP",
  84         };
  85
  86         qemu_log_mask(CPU_LOG_INT, "INT: %s\n", int_name[exception]);
  87
  88         hwaddr vect_pc = exception << 8;
  89         if (env->cpucfgr & CPUCFGR_EVBARP) {
  90             vect_pc |= env->evbar;
  91         }
  92         if (env->sr & SR_EPH) {
  93             vect_pc |= 0xf0000000;
  94         }
  95         env->pc = vect_pc;
  96     } else {
  97         cpu_abort(cs, "Unhandled exception 0x%x\n", exception);
  98     }
  99
 100     cs->exception_index = -1;
 101 }
 102
 103 bool openrisc_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
 104 {
 105     OpenRISCCPU *cpu = OPENRISC_CPU(cs);
 106     CPUOpenRISCState *env = &cpu->env;
 107     int idx = -1;
 108
 109     if ((interrupt_request & CPU_INTERRUPT_HARD) && (env->sr & SR_IEE)) {
 110         idx = EXCP_INT;
 111     }
 112     if ((interrupt_request & CPU_INTERRUPT_TIMER) && (env->sr & SR_TEE)) {
 113         idx = EXCP_TICK;
 114     }
 115     if (idx >= 0) {
 116         cs->exception_index = idx;
 117         openrisc_cpu_do_interrupt(cs);
 118         return true;
 119     }
 120     return false;
 121 }