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 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 "cpu.h"
  21 #include "qemu-common.h"
  22 #include "exec/gdbstub.h"
  23 #include "qemu/host-utils.h"
  24 #ifndef CONFIG_USER_ONLY
  25 #include "hw/loader.h"
  26 #endif
  27
  28 void openrisc_cpu_do_interrupt(CPUState *cs)
  29 {
  30 #ifndef CONFIG_USER_ONLY
  31     OpenRISCCPU *cpu = OPENRISC_CPU(cs);
  32     CPUOpenRISCState *env = &cpu->env;
  33
  34     env->epcr = env->pc;
  35     if (env->flags & D_FLAG) {
  36         env->flags &= ~D_FLAG;
  37         env->sr |= SR_DSX;
  38         env->epcr -= 4;
  39     }
  40     if (cs->exception_index == EXCP_SYSCALL) {
  41         env->epcr += 4;
  42     }
  43
  44     /* For machine-state changed between user-mode and supervisor mode,
  45        we need flush TLB when we enter&exit EXCP.  */
  46     tlb_flush(cs, 1);
  47
  48     env->esr = env->sr;
  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->tlb->cpu_openrisc_map_address_data = &cpu_openrisc_get_phys_nommu;
  55     env->tlb->cpu_openrisc_map_address_code = &cpu_openrisc_get_phys_nommu;
  56
  57     if (cs->exception_index > 0 && cs->exception_index < EXCP_NR) {
  58         env->pc = (cs->exception_index << 8);
  59     } else {
  60         cpu_abort(cs, "Unhandled exception 0x%x\n", cs->exception_index);
  61     }
  62 #endif
  63
  64     cs->exception_index = -1;
  65 }
  66
  67 bool openrisc_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
  68 {
  69     OpenRISCCPU *cpu = OPENRISC_CPU(cs);
  70     CPUOpenRISCState *env = &cpu->env;
  71     int idx = -1;
  72
  73     if ((interrupt_request & CPU_INTERRUPT_HARD) && (env->sr & SR_IEE)) {
  74         idx = EXCP_INT;
  75     }
  76     if ((interrupt_request & CPU_INTERRUPT_TIMER) && (env->sr & SR_TEE)) {
  77         idx = EXCP_TICK;
  78     }
  79     if (idx >= 0) {
  80         cs->exception_index = idx;
  81         openrisc_cpu_do_interrupt(cs);
  82         return true;
  83     }
  84     return false;
  85 }