2 * linux/kernel/irq/proc.c
4 * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
6 * This file contains the /proc/irq/ handling code.
10 #include <linux/proc_fs.h>
11 #include <linux/interrupt.h>
13 #include "internals.h"
15 static struct proc_dir_entry *root_irq_dir;
19 static int irq_affinity_read_proc(char *page, char **start, off_t off,
20 int count, int *eof, void *data)
22 int len = cpumask_scnprintf(page, count, irq_desc[(long)data].affinity);
26 len += sprintf(page + len, "\n");
31 static int irq_affinity_write_proc(struct file *file, const char __user *buffer,
32 unsigned long count, void *data)
34 unsigned int irq = (int)(long)data, full_count = count, err;
35 cpumask_t new_value, tmp;
37 if (!irq_desc[irq].chip->set_affinity || no_irq_affinity ||
38 irq_balancing_disabled(irq))
41 err = cpumask_parse_user(buffer, count, new_value);
46 * Do not allow disabling IRQs completely - it's a too easy
47 * way to make the system unusable accidentally :-) At least
48 * one online CPU still has to be targeted.
50 cpus_and(tmp, new_value, cpu_online_map);
52 /* Special case for empty set - allow the architecture
53 code to set default SMP affinity. */
54 return select_smp_affinity(irq) ? -EINVAL : full_count;
56 irq_set_affinity(irq, new_value);
63 #define MAX_NAMELEN 128
65 static int name_unique(unsigned int irq, struct irqaction *new_action)
67 struct irq_desc *desc = irq_desc + irq;
68 struct irqaction *action;
72 spin_lock_irqsave(&desc->lock, flags);
73 for (action = desc->action ; action; action = action->next) {
74 if ((action != new_action) && action->name &&
75 !strcmp(new_action->name, action->name)) {
80 spin_unlock_irqrestore(&desc->lock, flags);
84 void register_handler_proc(unsigned int irq, struct irqaction *action)
86 char name [MAX_NAMELEN];
88 if (!irq_desc[irq].dir || action->dir || !action->name ||
89 !name_unique(irq, action))
92 memset(name, 0, MAX_NAMELEN);
93 snprintf(name, MAX_NAMELEN, "%s", action->name);
95 /* create /proc/irq/1234/handler/ */
96 action->dir = proc_mkdir(name, irq_desc[irq].dir);
101 #define MAX_NAMELEN 10
103 void register_irq_proc(unsigned int irq)
105 char name [MAX_NAMELEN];
108 (irq_desc[irq].chip == &no_irq_chip) ||
112 memset(name, 0, MAX_NAMELEN);
113 sprintf(name, "%d", irq);
115 /* create /proc/irq/1234 */
116 irq_desc[irq].dir = proc_mkdir(name, root_irq_dir);
120 struct proc_dir_entry *entry;
122 /* create /proc/irq/<irq>/smp_affinity */
123 entry = create_proc_entry("smp_affinity", 0600, irq_desc[irq].dir);
126 entry->data = (void *)(long)irq;
127 entry->read_proc = irq_affinity_read_proc;
128 entry->write_proc = irq_affinity_write_proc;
136 void unregister_handler_proc(unsigned int irq, struct irqaction *action)
139 remove_proc_entry(action->dir->name, irq_desc[irq].dir);
142 void init_irq_proc(void)
146 /* create /proc/irq */
147 root_irq_dir = proc_mkdir("irq", NULL);
152 * Create entries for all existing IRQs.
154 for (i = 0; i < NR_IRQS; i++)
155 register_irq_proc(i);