irq.c
/*
* linux/arch/xtensa/kernel/irq.c
*
* Xtensa built-in interrupt controller and some generic functions copied
* from i386.
*
* Copyright (C) 2002 - 2006 Tensilica, Inc.
* Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
*
*
* Chris Zankel <chris@zankel.net>
* Kevin Chea
*
*/
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kernel_stat.h>
#include <asm/uaccess.h>
#include <asm/platform.h>
static unsigned int cached_irq_mask;
atomic_t irq_err_count;
/*
* do_IRQ handles all normal device IRQ's (the special
* SMP cross-CPU interrupts have their own specific
* handlers).
*/
asmlinkage void do_IRQ(int irq, struct pt_regs *regs)
{
struct pt_regs *old_regs = set_irq_regs(regs);
if (irq >= NR_IRQS) {
printk(KERN_EMERG "%s: cannot handle IRQ %d\n",
__func__, irq);
}
irq_enter();
#ifdef CONFIG_DEBUG_STACKOVERFLOW
/* Debugging check for stack overflow: is there less than 1KB free? */
{
unsigned long sp;
__asm__ __volatile__ ("mov %0, a1\n" : "=a" (sp));
sp &= THREAD_SIZE - 1;
if (unlikely(sp < (sizeof(thread_info) + 1024)))
printk("Stack overflow in do_IRQ: %ld\n",
sp - sizeof(struct thread_info));
}
#endif
generic_handle_irq(irq);
irq_exit();
set_irq_regs(old_regs);
}
int arch_show_interrupts(struct seq_file *p, int prec)
{
seq_printf(p, "%*s: ", prec, "ERR");
seq_printf(p, "%10u\n", atomic_read(&irq_err_count));
return 0;
}
static void xtensa_irq_mask(struct irq_data *d)
{
cached_irq_mask &= ~(1 << d->irq);
set_sr (cached_irq_mask, INTENABLE);
}
static void xtensa_irq_unmask(struct irq_data *d)
{
cached_irq_mask |= 1 << d->irq;
set_sr (cached_irq_mask, INTENABLE);
}
static void xtensa_irq_enable(struct irq_data *d)
{
variant_irq_enable(d->irq);
xtensa_irq_unmask(d->irq);
}
static void xtensa_irq_disable(struct irq_data *d)
{
xtensa_irq_mask(d->irq);
variant_irq_disable(d->irq);
}
static void xtensa_irq_ack(struct irq_data *d)
{
set_sr(1 << d->irq, INTCLEAR);
}
static int xtensa_irq_retrigger(struct irq_data *d)
{
set_sr (1 << d->irq, INTSET);
return 1;
}
static struct irq_chip xtensa_irq_chip = {
.name = "xtensa",
.irq_enable = xtensa_irq_enable,
.irq_disable = xtensa_irq_disable,
.irq_mask = xtensa_irq_mask,
.irq_unmask = xtensa_irq_unmask,
.irq_ack = xtensa_irq_ack,
.irq_retrigger = xtensa_irq_retrigger,
};
void __init init_IRQ(void)
{
int index;
for (index = 0; index < XTENSA_NR_IRQS; index++) {
int mask = 1 << index;
if (mask & XCHAL_INTTYPE_MASK_SOFTWARE)
irq_set_chip_and_handler(index, &xtensa_irq_chip,
handle_simple_irq);
else if (mask & XCHAL_INTTYPE_MASK_EXTERN_EDGE)
irq_set_chip_and_handler(index, &xtensa_irq_chip,
handle_edge_irq);
else if (mask & XCHAL_INTTYPE_MASK_EXTERN_LEVEL)
irq_set_chip_and_handler(index, &xtensa_irq_chip,
handle_level_irq);
else if (mask & XCHAL_INTTYPE_MASK_TIMER)
irq_set_chip_and_handler(index, &xtensa_irq_chip,
handle_edge_irq);
else /* XCHAL_INTTYPE_MASK_WRITE_ERROR */
/* XCHAL_INTTYPE_MASK_NMI */
irq_set_chip_and_handler(index, &xtensa_irq_chip,
handle_level_irq);
}
cached_irq_mask = 0;
variant_init_irq();
}