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![Alexey Dobriyan](/assets/img/avatar_default.png)
Switch /proc/irq/*/smp_affinity , /proc/irq/default_smp_affinity to seq_files. cat(1) reads with 1024 chunks by default, with high enough NR_CPUS, there will be -EINVAL. As side effect, there are now two less users of the ->read_proc interface. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Paul Jackson <pj@sgi.com> Cc: Mike Travis <travis@sgi.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
246 lines
5.5 KiB
C
246 lines
5.5 KiB
C
/*
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* linux/kernel/irq/proc.c
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*
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* Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
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*
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* This file contains the /proc/irq/ handling code.
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*/
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#include <linux/irq.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/interrupt.h>
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#include "internals.h"
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static struct proc_dir_entry *root_irq_dir;
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#ifdef CONFIG_SMP
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static int irq_affinity_proc_show(struct seq_file *m, void *v)
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{
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struct irq_desc *desc = irq_desc + (long)m->private;
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cpumask_t *mask = &desc->affinity;
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#ifdef CONFIG_GENERIC_PENDING_IRQ
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if (desc->status & IRQ_MOVE_PENDING)
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mask = &desc->pending_mask;
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#endif
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seq_cpumask(m, mask);
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seq_putc(m, '\n');
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return 0;
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}
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#ifndef is_affinity_mask_valid
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#define is_affinity_mask_valid(val) 1
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#endif
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int no_irq_affinity;
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static ssize_t irq_affinity_proc_write(struct file *file,
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const char __user *buffer, size_t count, loff_t *pos)
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{
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unsigned int irq = (int)(long)PDE(file->f_path.dentry->d_inode)->data;
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cpumask_t new_value;
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int err;
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if (!irq_desc[irq].chip->set_affinity || no_irq_affinity ||
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irq_balancing_disabled(irq))
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return -EIO;
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err = cpumask_parse_user(buffer, count, new_value);
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if (err)
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return err;
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if (!is_affinity_mask_valid(new_value))
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return -EINVAL;
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/*
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* Do not allow disabling IRQs completely - it's a too easy
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* way to make the system unusable accidentally :-) At least
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* one online CPU still has to be targeted.
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*/
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if (!cpus_intersects(new_value, cpu_online_map))
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/* Special case for empty set - allow the architecture
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code to set default SMP affinity. */
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return irq_select_affinity(irq) ? -EINVAL : count;
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irq_set_affinity(irq, new_value);
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return count;
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}
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static int irq_affinity_proc_open(struct inode *inode, struct file *file)
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{
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return single_open(file, irq_affinity_proc_show, PDE(inode)->data);
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}
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static const struct file_operations irq_affinity_proc_fops = {
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.open = irq_affinity_proc_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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.write = irq_affinity_proc_write,
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};
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static int default_affinity_show(struct seq_file *m, void *v)
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{
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seq_cpumask(m, &irq_default_affinity);
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seq_putc(m, '\n');
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return 0;
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}
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static ssize_t default_affinity_write(struct file *file,
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const char __user *buffer, size_t count, loff_t *ppos)
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{
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cpumask_t new_value;
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int err;
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err = cpumask_parse_user(buffer, count, new_value);
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if (err)
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return err;
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if (!is_affinity_mask_valid(new_value))
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return -EINVAL;
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/*
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* Do not allow disabling IRQs completely - it's a too easy
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* way to make the system unusable accidentally :-) At least
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* one online CPU still has to be targeted.
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*/
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if (!cpus_intersects(new_value, cpu_online_map))
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return -EINVAL;
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irq_default_affinity = new_value;
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return count;
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}
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static int default_affinity_open(struct inode *inode, struct file *file)
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{
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return single_open(file, default_affinity_show, NULL);
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}
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static const struct file_operations default_affinity_proc_fops = {
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.open = default_affinity_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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.write = default_affinity_write,
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};
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#endif
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static int irq_spurious_read(char *page, char **start, off_t off,
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int count, int *eof, void *data)
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{
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struct irq_desc *d = &irq_desc[(long) data];
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return sprintf(page, "count %u\n"
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"unhandled %u\n"
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"last_unhandled %u ms\n",
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d->irq_count,
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d->irqs_unhandled,
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jiffies_to_msecs(d->last_unhandled));
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}
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#define MAX_NAMELEN 128
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static int name_unique(unsigned int irq, struct irqaction *new_action)
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{
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struct irq_desc *desc = irq_desc + irq;
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struct irqaction *action;
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unsigned long flags;
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int ret = 1;
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spin_lock_irqsave(&desc->lock, flags);
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for (action = desc->action ; action; action = action->next) {
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if ((action != new_action) && action->name &&
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!strcmp(new_action->name, action->name)) {
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ret = 0;
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break;
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}
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}
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spin_unlock_irqrestore(&desc->lock, flags);
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return ret;
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}
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void register_handler_proc(unsigned int irq, struct irqaction *action)
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{
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char name [MAX_NAMELEN];
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if (!irq_desc[irq].dir || action->dir || !action->name ||
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!name_unique(irq, action))
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return;
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memset(name, 0, MAX_NAMELEN);
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snprintf(name, MAX_NAMELEN, "%s", action->name);
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/* create /proc/irq/1234/handler/ */
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action->dir = proc_mkdir(name, irq_desc[irq].dir);
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}
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#undef MAX_NAMELEN
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#define MAX_NAMELEN 10
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void register_irq_proc(unsigned int irq)
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{
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char name [MAX_NAMELEN];
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struct proc_dir_entry *entry;
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if (!root_irq_dir ||
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(irq_desc[irq].chip == &no_irq_chip) ||
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irq_desc[irq].dir)
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return;
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memset(name, 0, MAX_NAMELEN);
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sprintf(name, "%d", irq);
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/* create /proc/irq/1234 */
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irq_desc[irq].dir = proc_mkdir(name, root_irq_dir);
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#ifdef CONFIG_SMP
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/* create /proc/irq/<irq>/smp_affinity */
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proc_create_data("smp_affinity", 0600, irq_desc[irq].dir,
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&irq_affinity_proc_fops, (void *)(long)irq);
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#endif
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entry = create_proc_entry("spurious", 0444, irq_desc[irq].dir);
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if (entry) {
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entry->data = (void *)(long)irq;
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entry->read_proc = irq_spurious_read;
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}
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}
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#undef MAX_NAMELEN
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void unregister_handler_proc(unsigned int irq, struct irqaction *action)
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{
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if (action->dir)
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remove_proc_entry(action->dir->name, irq_desc[irq].dir);
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}
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void register_default_affinity_proc(void)
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{
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#ifdef CONFIG_SMP
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proc_create("irq/default_smp_affinity", 0600, NULL,
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&default_affinity_proc_fops);
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#endif
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}
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void init_irq_proc(void)
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{
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int i;
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/* create /proc/irq */
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root_irq_dir = proc_mkdir("irq", NULL);
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if (!root_irq_dir)
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return;
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register_default_affinity_proc();
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/*
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* Create entries for all existing IRQs.
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*/
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for (i = 0; i < NR_IRQS; i++)
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register_irq_proc(i);
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}
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