linux/arch/alpha/kernel/irq.c

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/*
* linux/arch/alpha/kernel/irq.c
*
* Copyright (C) 1995 Linus Torvalds
*
* This file contains the code used by various IRQ handling routines:
* asking for different IRQ's should be done through these routines
* instead of just grabbing them. Thus setups with different IRQ numbers
* shouldn't result in any weird surprises, and installing new handlers
* should be easier.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel_stat.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/ptrace.h>
#include <linux/interrupt.h>
#include <linux/random.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/profile.h>
#include <linux/bitops.h>
#include <asm/io.h>
#include <asm/uaccess.h>
volatile unsigned long irq_err_count;
DEFINE_PER_CPU(unsigned long, irq_pmi_count);
void ack_bad_irq(unsigned int irq)
{
irq_err_count++;
printk(KERN_CRIT "Unexpected IRQ trap at vector %u\n", irq);
}
#ifdef CONFIG_SMP
static char irq_user_affinity[NR_IRQS];
int irq_select_affinity(unsigned int irq)
{
struct irq_data *data = irq_get_irq_data(irq);
struct irq_chip *chip;
static int last_cpu;
int cpu = last_cpu + 1;
if (!data)
return 1;
chip = irq_data_get_irq_chip(data);
if (!chip->irq_set_affinity || irq_user_affinity[irq])
return 1;
while (!cpu_possible(cpu) ||
!cpumask_test_cpu(cpu, irq_default_affinity))
cpu = (cpu < (NR_CPUS-1) ? cpu + 1 : 0);
last_cpu = cpu;
cpumask_copy(data->affinity, cpumask_of(cpu));
chip->irq_set_affinity(data, cpumask_of(cpu), false);
return 0;
}
#endif /* CONFIG_SMP */
int arch_show_interrupts(struct seq_file *p, int prec)
{
int j;
#ifdef CONFIG_SMP
seq_puts(p, "IPI: ");
for_each_online_cpu(j)
seq_printf(p, "%10lu ", cpu_data[j].ipi_count);
seq_putc(p, '\n');
#endif
seq_puts(p, "PMI: ");
for_each_online_cpu(j)
seq_printf(p, "%10lu ", per_cpu(irq_pmi_count, j));
seq_puts(p, " Performance Monitoring\n");
seq_printf(p, "ERR: %10lu\n", irq_err_count);
return 0;
}
/*
* handle_irq handles all normal device IRQ's (the special
* SMP cross-CPU interrupts have their own specific
* handlers).
*/
#define MAX_ILLEGAL_IRQS 16
void
handle_irq(int irq)
{
/*
* We ack quickly, we don't want the irq controller
* thinking we're snobs just because some other CPU has
* disabled global interrupts (we have already done the
* INT_ACK cycles, it's too late to try to pretend to the
* controller that we aren't taking the interrupt).
*
* 0 return value means that this irq is already being
* handled by some other CPU. (or is disabled)
*/
static unsigned int illegal_count=0;
struct irq_desc *desc = irq_to_desc(irq);
if (!desc || ((unsigned) irq > ACTUAL_NR_IRQS &&
illegal_count < MAX_ILLEGAL_IRQS)) {
irq_err_count++;
illegal_count++;
printk(KERN_CRIT "device_interrupt: invalid interrupt %d\n",
irq);
return;
}
irq_enter();
generic_handle_irq_desc(irq, desc);
irq_exit();
}