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/*
* linux/kernel/irq/proc.c
*
* Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
*
* This file contains the /proc/irq/ handling code.
*/
#include <linux/irq.h>
#include <linux/proc_fs.h>
#include <linux/interrupt.h>
#include "internals.h"
static struct proc_dir_entry *root_irq_dir;
#ifdef CONFIG_SMP
static int irq_affinity_read_proc(char *page, char **start, off_t off,
int count, int *eof, void *data)
{
int len = cpumask_scnprintf(page, count, irq_desc[(long)data].affinity);
if (count - len < 2)
return -EINVAL;
len += sprintf(page + len, "\n");
return len;
}
int no_irq_affinity;
static int irq_affinity_write_proc(struct file *file, const char __user *buffer,
unsigned long count, void *data)
{
unsigned int irq = (int)(long)data, full_count = count, err;
cpumask_t new_value, tmp;
if (!irq_desc[irq].chip->set_affinity || no_irq_affinity ||
irq_balancing_disabled(irq))
return -EIO;
err = cpumask_parse_user(buffer, count, new_value);
if (err)
return err;
/*
* Do not allow disabling IRQs completely - it's a too easy
* way to make the system unusable accidentally :-) At least
* one online CPU still has to be targeted.
*/
cpus_and(tmp, new_value, cpu_online_map);
if (cpus_empty(tmp))
/* Special case for empty set - allow the architecture
code to set default SMP affinity. */
return select_smp_affinity(irq) ? -EINVAL : full_count;
irq_set_affinity(irq, new_value);
return full_count;
}
#endif
#define MAX_NAMELEN 128
static int name_unique(unsigned int irq, struct irqaction *new_action)
{
struct irq_desc *desc = irq_desc + irq;
struct irqaction *action;
unsigned long flags;
int ret = 1;
spin_lock_irqsave(&desc->lock, flags);
for (action = desc->action ; action; action = action->next) {
if ((action != new_action) && action->name &&
!strcmp(new_action->name, action->name)) {
ret = 0;
break;
}
}
spin_unlock_irqrestore(&desc->lock, flags);
return ret;
}
void register_handler_proc(unsigned int irq, struct irqaction *action)
{
char name [MAX_NAMELEN];
if (!irq_desc[irq].dir || action->dir || !action->name ||
!name_unique(irq, action))
return;
memset(name, 0, MAX_NAMELEN);
snprintf(name, MAX_NAMELEN, "%s", action->name);
/* create /proc/irq/1234/handler/ */
action->dir = proc_mkdir(name, irq_desc[irq].dir);
}
#undef MAX_NAMELEN
#define MAX_NAMELEN 10
void register_irq_proc(unsigned int irq)
{
char name [MAX_NAMELEN];
if (!root_irq_dir ||
(irq_desc[irq].chip == &no_irq_chip) ||
irq_desc[irq].dir)
return;
memset(name, 0, MAX_NAMELEN);
sprintf(name, "%d", irq);
/* create /proc/irq/1234 */
irq_desc[irq].dir = proc_mkdir(name, root_irq_dir);
#ifdef CONFIG_SMP
{
struct proc_dir_entry *entry;
/* create /proc/irq/<irq>/smp_affinity */
entry = create_proc_entry("smp_affinity", 0600, irq_desc[irq].dir);
if (entry) {
entry->data = (void *)(long)irq;
entry->read_proc = irq_affinity_read_proc;
entry->write_proc = irq_affinity_write_proc;
}
}
#endif
}
#undef MAX_NAMELEN
void unregister_handler_proc(unsigned int irq, struct irqaction *action)
{
if (action->dir)
remove_proc_entry(action->dir->name, irq_desc[irq].dir);
}
void init_irq_proc(void)
{
int i;
/* create /proc/irq */
root_irq_dir = proc_mkdir("irq", NULL);
if (!root_irq_dir)
return;
/*
* Create entries for all existing IRQs.
*/
for (i = 0; i < NR_IRQS; i++)
register_irq_proc(i);
}
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