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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.

 */

/** @addtogroup mips32	

 * @{

 */

/** @file

 */

#include <arch/exception.h>

#include <arch/interrupt.h>

#include <arch/mm/tlb.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 <ddi/irq.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)

{

	fault_if_from_uspace(istate, "Unhandled exception %s.", exctable[n]);

	print_regdump(istate);

	panic("Unhandled exception %s.", exctable[n]);

}

static void reserved_instr_exception(int n, istate_t *istate)

{

	if (*((uint32_t *)istate->epc) == 0x7c03e83b) {

		ASSERT(THREAD);

		istate->epc += 4;

		istate->v1 = istate->k1;

	} else 

		unhandled_exception(n, istate);

}

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 {

		fault_if_from_uspace(istate, "Unhandled Coprocessor Unusable Exception.");

		panic("Unhandled Coprocessor Unusable Exception.");

	}

}

#endif

static void interrupt_exception(int n, istate_t *istate)

{

	uint32_t 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)) {

			irq_t *irq = irq_dispatch_and_lock(i);

			if (irq) {

				/*

				 * The IRQ handler was found.

				 */

				irq->handler(irq);

				spinlock_unlock(&irq->lock);

			} else {

				/*

				 * Spurious interrupt.

				 */

#ifdef CONFIG_DEBUG

				printf("cpu%u: spurious interrupt (inum=%d)\n",

				    CPU->id, i);

#endif

			}

		}

	}

}

/** 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);

}

/** @}

 */