interrupt.c

/*
 * OpenRISC interrupt.
 *
 * Copyright (c) 2011-2012 Jia Liu <proljc@gmail.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */

#include "cpu.h"
#include "qemu-common.h"
#include "gdbstub.h"
#include "host-utils.h"
#ifndef CONFIG_USER_ONLY
#include "hw/loader.h"
#endif

void do_interrupt(CPUOpenRISCState *env)
{
#ifndef CONFIG_USER_ONLY
    if (env->flags & D_FLAG) { /* Delay Slot insn */
        env->flags &= ~D_FLAG;
        env->sr |= SR_DSX;
        if (env->exception_index == EXCP_TICK    ||
            env->exception_index == EXCP_INT     ||
            env->exception_index == EXCP_SYSCALL ||
            env->exception_index == EXCP_FPE) {
            env->epcr = env->jmp_pc;
        } else {
            env->epcr = env->pc - 4;
        }
    } else {
        if (env->exception_index == EXCP_TICK    ||
            env->exception_index == EXCP_INT     ||
            env->exception_index == EXCP_SYSCALL ||
            env->exception_index == EXCP_FPE) {
            env->epcr = env->npc;
        } else {
            env->epcr = env->pc;
        }
    }

    /* For machine-state changed between user-mode and supervisor mode,
       we need flush TLB when we enter&exit EXCP.  */
    tlb_flush(env, 1);

    env->esr = env->sr;
    env->sr &= ~SR_DME;
    env->sr &= ~SR_IME;
    env->sr |= SR_SM;
    env->sr &= ~SR_IEE;
    env->sr &= ~SR_TEE;
    env->tlb->cpu_openrisc_map_address_data = &cpu_openrisc_get_phys_nommu;
    env->tlb->cpu_openrisc_map_address_code = &cpu_openrisc_get_phys_nommu;

    if (env->exception_index > 0 && env->exception_index < EXCP_NR) {
        env->pc = (env->exception_index << 8);
    } else {
        cpu_abort(env, "Unhandled exception 0x%x\n", env->exception_index);
    }
#endif

    env->exception_index = -1;
}