/*
 * Copyright (c) 2001-2004 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 kernel_ia32_interrupt
 * @{
 */
/** @file
 */

#include <arch/interrupt.h>
#include <assert.h>
#include <syscall/syscall.h>
#include <stdio.h>
#include <debug.h>
#include <panic.h>
#include <genarch/drivers/i8259/i8259.h>
#include <halt.h>
#include <cpu.h>
#include <arch/asm.h>
#include <mm/tlb.h>
#include <mm/as.h>
#include <arch.h>
#include <proc/thread.h>
#include <proc/task.h>
#include <synch/spinlock.h>
#include <arch/ddi/ddi.h>
#include <ipc/sysipc.h>
#include <interrupt.h>
#include <ddi/irq.h>
#include <symtab.h>
#include <stacktrace.h>
#include <proc/task.h>

/*
 * Interrupt and exception dispatching.
 */

void (*disable_irqs_function)(uint16_t irqmask) = NULL;
void (*enable_irqs_function)(uint16_t irqmask) = NULL;
void (*eoi_function)(unsigned int) = NULL;
const char *irqs_info = NULL;

void istate_decode(istate_t *istate)
{
	printf("cs =%0#10" PRIx32 "\teip=%0#10" PRIx32 "\t"
	    "efl=%0#10" PRIx32 "\terr=%0#10" PRIx32 "\n",
	    istate->cs, istate->eip, istate->eflags, istate->error_word);

	printf("ds =%0#10" PRIx32 "\tes =%0#10" PRIx32 "\t"
	    "fs =%0#10" PRIx32 "\tgs =%0#10" PRIx32 "\n",
	    istate->ds, istate->es, istate->fs, istate->gs);

	if (istate_from_uspace(istate))
		printf("ss =%0#10" PRIx32 "\n", istate->ss);

	printf("eax=%0#10" PRIx32 "\tebx=%0#10" PRIx32 "\t"
	    "ecx=%0#10" PRIx32 "\tedx=%0#10" PRIx32 "\n",
	    istate->eax, istate->ebx, istate->ecx, istate->edx);

	printf("esi=%0#10" PRIx32 "\tedi=%0#10" PRIx32 "\t"
	    "ebp=%0#10" PRIx32 "\tesp=%0#10" PRIx32 "\n",
	    istate->esi, istate->edi, istate->ebp,
	    istate_from_uspace(istate) ? istate->esp :
	    (uint32_t) &istate->esp);
}

static void trap_virtual_eoi(unsigned int inum)
{
	if (eoi_function)
		eoi_function(inum);
	else
		panic("No eoi_function.");

}

static void null_interrupt(unsigned int n, istate_t *istate)
{
	fault_if_from_uspace(istate, "Unserviced interrupt: %u.", n);
	panic_badtrap(istate, n, "Unserviced interrupt: %u.", n);
}

static void de_fault(unsigned int n, istate_t *istate)
{
	fault_if_from_uspace(istate, "Divide error.");
	panic_badtrap(istate, n, "Divide error.");
}

static void db_exception(unsigned int n, istate_t *istate)
{
	/*
	 * We need to provide at least an empty handler that does not panic
	 * if the exception appears to come from the kernel because the
	 * userspace can inject a kernel-level #DB after e.g. the SYSENTER
	 * instruction if the EFLAGS.TF is set.
	 */
}

/** General Protection Fault. */
static void gp_fault(unsigned int n __attribute__((unused)), istate_t *istate)
{
	if (TASK) {
		irq_spinlock_lock(&TASK->lock, false);
		size_t ver = TASK->arch.iomapver;
		irq_spinlock_unlock(&TASK->lock, false);

		if (CPU->arch.iomapver_copy != ver) {
			/*
			 * This fault can be caused by an early access
			 * to I/O port because of an out-dated
			 * I/O Permission bitmap installed on CPU.
			 * Install the fresh copy and restart
			 * the instruction.
			 */
			io_perm_bitmap_install();
			return;
		}
		fault_if_from_uspace(istate, "General protection fault.");
	}
	panic_badtrap(istate, n, "General protection fault.");
}

static void ss_fault(unsigned int n __attribute__((unused)), istate_t *istate)
{
	fault_if_from_uspace(istate, "Stack fault.");
	panic_badtrap(istate, n, "Stack fault.");
}

static void simd_fp_exception(unsigned int n __attribute__((unused)), istate_t *istate)
{
	uint32_t mxcsr;
	asm volatile (
	    "stmxcsr %[mxcsr]\n"
	    : [mxcsr] "=m" (mxcsr)
	);

	fault_if_from_uspace(istate, "SIMD FP exception(19), MXCSR=%#0" PRIx32 ".",
	    mxcsr);
	panic_badtrap(istate, n, "SIMD FP exception");
}

static void nm_fault(unsigned int n __attribute__((unused)),
    istate_t *istate __attribute__((unused)))
{
#ifdef CONFIG_FPU_LAZY
	scheduler_fpu_lazy_request();
#else
	fault_if_from_uspace(istate, "FPU fault.");
	panic_badtrap(istate, n, "FPU fault.");
#endif
}

#ifdef CONFIG_SMP
static void tlb_shootdown_ipi(unsigned int n __attribute__((unused)),
    istate_t *istate __attribute__((unused)))
{
	trap_virtual_eoi(0);
	tlb_shootdown_ipi_recv();
}
#endif

/** Handler of IRQ exceptions */
static void irq_interrupt(unsigned int n, istate_t *istate __attribute__((unused)))
{
	assert(n >= IVT_IRQBASE);

	unsigned int inum = n - IVT_IRQBASE;
	bool ack = false;
	assert(inum < IRQ_COUNT);
	assert(inum != IRQ_PIC1);

	irq_t *irq = irq_dispatch_and_lock(inum);
	if (irq) {
		/*
		 * The IRQ handler was found.
		 */

		if (irq->preack) {
			/* Send EOI before processing the interrupt */
			trap_virtual_eoi(inum);
			ack = true;
		}
		irq->handler(irq);
		irq_spinlock_unlock(&irq->lock, false);
	} else {
#ifdef CONFIG_DEBUG
		log(LF_ARCH, LVL_DEBUG, "cpu%u: unhandled IRQ %u", CPU->id,
		    inum);
#endif
	}

	if (!ack)
		trap_virtual_eoi(inum);
}

static void pic_spurious(unsigned int n, istate_t *istate)
{
	unsigned int inum = n - IVT_IRQBASE;
	if (!pic_is_spurious(inum)) {
		/* This is actually not a spurious IRQ, so proceed as usual. */
		irq_interrupt(n, istate);
		return;
	}
	pic_handle_spurious(n);
#ifdef CONFIG_DEBUG
	log(LF_ARCH, LVL_DEBUG, "cpu%u: PIC spurious interrupt %u", CPU->id,
	    inum);
#endif
}

void interrupt_init(void)
{
	unsigned int i;

	for (i = 0; i < IVT_ITEMS; i++)
		exc_register(i, "null", false, (iroutine_t) null_interrupt);

	for (i = 0; i < IRQ_COUNT; i++) {
		if ((i != IRQ_PIC0_SPUR) && (i != IRQ_PIC1_SPUR) &&
		    (i != IRQ_PIC1))
			exc_register(IVT_IRQBASE + i, "irq", true,
			    (iroutine_t) irq_interrupt);
	}

	exc_register(VECTOR_DE, "de_fault", true, (iroutine_t) de_fault);
	exc_register(VECTOR_DB, "db_exc", true, (iroutine_t) db_exception);
	exc_register(VECTOR_NM, "nm_fault", true, (iroutine_t) nm_fault);
	exc_register(VECTOR_SS, "ss_fault", true, (iroutine_t) ss_fault);
	exc_register(VECTOR_GP, "gp_fault", true, (iroutine_t) gp_fault);
	exc_register(VECTOR_XM, "simd_fp", true, (iroutine_t) simd_fp_exception);
	exc_register(VECTOR_PIC0_SPUR, "pic0_spurious", true,
	    (iroutine_t) pic_spurious);
	exc_register(VECTOR_PIC1_SPUR, "pic1_spurious", true,
	    (iroutine_t) pic_spurious);

#ifdef CONFIG_SMP
	exc_register(VECTOR_TLB_SHOOTDOWN_IPI, "tlb_shootdown", true,
	    (iroutine_t) tlb_shootdown_ipi);
#endif
}

void trap_virtual_enable_irqs(uint16_t irqmask)
{
	if (enable_irqs_function)
		enable_irqs_function(irqmask);
	else
		panic("No enable_irqs_function.");
}

void trap_virtual_disable_irqs(uint16_t irqmask)
{
	if (disable_irqs_function)
		disable_irqs_function(irqmask);
	else
		panic("No disable_irqs_function.");
}

/** @}
 */
