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/*

 * Copyright (C) 2003-2004 Jakub Jermar

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * - Redistributions of source code must retain the above copyright

 *   notice, this list of conditions and the following disclaimer.

 * - Redistributions in binary form must reproduce the above copyright

 *   notice, this list of conditions and the following disclaimer in the

 *   documentation and/or other materials provided with the distribution.

 * - The name of the author may not be used to endorse or promote products

 *   derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include <arch/exception.h>

#include <arch/interrupt.h>

#include <panic.h>

#include <arch/cp0.h>

#include <arch/types.h>

#include <arch.h>

#include <debug.h>

#include <proc/thread.h>

#include <symtab.h>

#include <print.h>

#include <interrupt.h>

#include <func.h>

#include <console/kconsole.h>

#include <arch/debugger.h>

static char * exctable[] = {

    "Interrupt","TLB Modified","TLB Invalid","TLB Invalid Store",

        "Address Error - load/instr. fetch",

        "Address Error - store",

        "Bus Error - fetch instruction",

        "Bus Error - data reference",

        "Syscall",

        "BreakPoint",

        "Reserved Instruction",

        "Coprocessor Unusable",

        "Arithmetic Overflow",

        "Trap",

        "Virtual Coherency - instruction",

        "Floating Point",

        NULL, NULL, NULL, NULL, NULL, NULL, NULL,

        "WatchHi/WatchLo", /* 23 */

        NULL, NULL, NULL, NULL, NULL, NULL, NULL,

        "Virtual Coherency - data",

};

static void print_regdump(istate_t *istate)

{

    char *pcsymbol = "";

    char *rasymbol = "";

    char *s = get_symtab_entry(istate->epc);

    if (s)

        pcsymbol = s;

    s = get_symtab_entry(istate->ra);

    if (s)

        rasymbol = s;

    printf("PC: %X(%s) RA: %X(%s), SP(%P)\n",istate->epc,pcsymbol,

           istate->ra,rasymbol, istate->sp);

}

static void unhandled_exception(int n, istate_t *istate)

{

    print_regdump(istate);

    panic("unhandled exception %s\n", exctable[n]);

}

static void reserved_instr_exception(int n, istate_t *istate)

{

    if (*((__u32 *)istate->epc) == 0x7c03e83b) {

        ASSERT(THREAD);

        istate->epc += 4;

        istate->v1 = istate->k1;

    } else {

        print_regdump(istate);

        panic("reserved instruction");

    }

}

static void breakpoint_exception(int n, istate_t *istate)

{

#ifdef CONFIG_DEBUG

    debugger_bpoint(istate);

#else

    /* it is necessary to not re-execute BREAK instruction after

       returning from Exception handler

       (see page 138 in R4000 Manual for more information) */

    istate->epc += 4;

#endif

}

static void tlbmod_exception(int n, istate_t *istate)

{

    tlb_modified(istate);

}

static void tlbinv_exception(int n, istate_t *istate)

{

    tlb_invalid(istate);

}

#ifdef CONFIG_FPU_LAZY

static void cpuns_exception(int n, istate_t *istate)

{

    if (cp0_cause_coperr(cp0_cause_read()) == fpu_cop_id)

        scheduler_fpu_lazy_request();

    else

        panic("unhandled Coprocessor Unusable Exception\n");

}

#endif

static void interrupt_exception(int n, istate_t *istate)

{

    __u32 cause;

    int i;

    /* decode interrupt number and process the interrupt */

    cause = (cp0_cause_read() >> 8) &0xff;

    for (i = 0; i < 8; i++)

        if (cause & (1 << i))

            exc_dispatch(i+INT_OFFSET, istate);

}

/** Handle syscall userspace call */

static void syscall_exception(int n, istate_t *istate)

{

    panic("Syscall is handled through shortcut");

}

void exception_init(void)

{

    int i;

    /* Clear exception table */

    for (i=0;i < IVT_ITEMS; i++)

        exc_register(i, "undef", (iroutine) unhandled_exception);

    exc_register(EXC_Bp, "bkpoint", (iroutine) breakpoint_exception);

    exc_register(EXC_RI, "resinstr", (iroutine) reserved_instr_exception);

    exc_register(EXC_Mod, "tlb_mod", (iroutine) tlbmod_exception);

    exc_register(EXC_TLBL, "tlbinvl", (iroutine) tlbinv_exception);

    exc_register(EXC_TLBS, "tlbinvl", (iroutine) tlbinv_exception);

    exc_register(EXC_Int, "interrupt", (iroutine) interrupt_exception);

#ifdef CONFIG_FPU_LAZY

    exc_register(EXC_CpU, "cpunus", (iroutine) cpuns_exception);

#endif

    exc_register(EXC_Sys, "syscall", (iroutine) syscall_exception);

}