linux/kernel/irq/proc.c

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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/seq_file.h>
#include <linux/interrupt.h>
#include "internals.h"
static struct proc_dir_entry *root_irq_dir;
#ifdef CONFIG_SMP
static int irq_affinity_proc_show(struct seq_file *m, void *v)
{
struct irq_desc *desc = irq_to_desc((long)m->private);
cpumask_t *mask = &desc->affinity;
#ifdef CONFIG_GENERIC_PENDING_IRQ
if (desc->status & IRQ_MOVE_PENDING)
mask = &desc->pending_mask;
#endif
seq_cpumask(m, mask);
seq_putc(m, '\n');
return 0;
}
#ifndef is_affinity_mask_valid
#define is_affinity_mask_valid(val) 1
#endif
int no_irq_affinity;
static ssize_t irq_affinity_proc_write(struct file *file,
const char __user *buffer, size_t count, loff_t *pos)
{
unsigned int irq = (int)(long)PDE(file->f_path.dentry->d_inode)->data;
cpumask_t new_value;
int err;
if (!irq_to_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;
if (!is_affinity_mask_valid(new_value))
return -EINVAL;
/*
* 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.
*/
if (!cpus_intersects(new_value, cpu_online_map))
/* Special case for empty set - allow the architecture
code to set default SMP affinity. */
return irq_select_affinity(irq) ? -EINVAL : count;
irq_set_affinity(irq, new_value);
return count;
}
static int irq_affinity_proc_open(struct inode *inode, struct file *file)
{
return single_open(file, irq_affinity_proc_show, PDE(inode)->data);
}
static const struct file_operations irq_affinity_proc_fops = {
.open = irq_affinity_proc_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
.write = irq_affinity_proc_write,
};
static int default_affinity_show(struct seq_file *m, void *v)
{
seq_cpumask(m, &irq_default_affinity);
seq_putc(m, '\n');
return 0;
}
static ssize_t default_affinity_write(struct file *file,
const char __user *buffer, size_t count, loff_t *ppos)
{
cpumask_t new_value;
int err;
err = cpumask_parse_user(buffer, count, new_value);
if (err)
return err;
if (!is_affinity_mask_valid(new_value))
return -EINVAL;
/*
* 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.
*/
if (!cpus_intersects(new_value, cpu_online_map))
return -EINVAL;
irq_default_affinity = new_value;
return count;
}
static int default_affinity_open(struct inode *inode, struct file *file)
{
return single_open(file, default_affinity_show, NULL);
}
static const struct file_operations default_affinity_proc_fops = {
.open = default_affinity_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
.write = default_affinity_write,
};
#endif
static int irq_spurious_read(char *page, char **start, off_t off,
int count, int *eof, void *data)
{
struct irq_desc *desc = irq_to_desc((long) data);
return sprintf(page, "count %u\n"
"unhandled %u\n"
"last_unhandled %u ms\n",
desc->irq_count,
desc->irqs_unhandled,
jiffies_to_msecs(desc->last_unhandled));
}
#define MAX_NAMELEN 128
static int name_unique(unsigned int irq, struct irqaction *new_action)
{
struct irq_desc *desc = irq_to_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];
struct irq_desc *desc = irq_to_desc(irq);
if (!desc->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, desc->dir);
}
#undef MAX_NAMELEN
#define MAX_NAMELEN 10
void register_irq_proc(unsigned int irq, struct irq_desc *desc)
{
char name [MAX_NAMELEN];
struct proc_dir_entry *entry;
if (!root_irq_dir || (desc->chip == &no_irq_chip) || desc->dir)
return;
memset(name, 0, MAX_NAMELEN);
sprintf(name, "%d", irq);
/* create /proc/irq/1234 */
desc->dir = proc_mkdir(name, root_irq_dir);
#ifdef CONFIG_SMP
/* create /proc/irq/<irq>/smp_affinity */
proc_create_data("smp_affinity", 0600, desc->dir,
&irq_affinity_proc_fops, (void *)(long)irq);
#endif
entry = create_proc_entry("spurious", 0444, desc->dir);
if (entry) {
entry->data = (void *)(long)irq;
entry->read_proc = irq_spurious_read;
}
}
#undef MAX_NAMELEN
void unregister_handler_proc(unsigned int irq, struct irqaction *action)
{
if (action->dir) {
struct irq_desc *desc = irq_to_desc(irq);
remove_proc_entry(action->dir->name, desc->dir);
}
}
void register_default_affinity_proc(void)
{
#ifdef CONFIG_SMP
proc_create("irq/default_smp_affinity", 0600, NULL,
&default_affinity_proc_fops);
#endif
}
void init_irq_proc(void)
{
unsigned int irq;
struct irq_desc *desc;
/* create /proc/irq */
root_irq_dir = proc_mkdir("irq", NULL);
if (!root_irq_dir)
return;
register_default_affinity_proc();
/*
* Create entries for all existing IRQs.
*/
for_each_irq_desc(irq, desc)
register_irq_proc(irq, desc);
}