771ee3b04e
Provide funtions to: - check, whether an interrupt can set the affinity - pin the interrupt to a given cpu Necessary for the ability to setup clocksources more flexible (e.g. use the different HPET channels per CPU) [akpm@osdl.org: alpha build fix] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: john stultz <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
150 lines
3.2 KiB
C
150 lines
3.2 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/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_read_proc(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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int len = cpumask_scnprintf(page, count, irq_desc[(long)data].affinity);
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if (count - len < 2)
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return -EINVAL;
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len += sprintf(page + len, "\n");
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return len;
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}
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int no_irq_affinity;
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static int irq_affinity_write_proc(struct file *file, const char __user *buffer,
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unsigned long count, void *data)
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{
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unsigned int irq = (int)(long)data, full_count = count, err;
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cpumask_t new_value, tmp;
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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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/*
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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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cpus_and(tmp, new_value, cpu_online_map);
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if (cpus_empty(tmp))
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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 select_smp_affinity(irq) ? -EINVAL : full_count;
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irq_set_affinity(irq, new_value);
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return full_count;
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}
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#endif
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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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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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return 0;
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return 1;
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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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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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{
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struct proc_dir_entry *entry;
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/* create /proc/irq/<irq>/smp_affinity */
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entry = create_proc_entry("smp_affinity", 0600, 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_affinity_read_proc;
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entry->write_proc = irq_affinity_write_proc;
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}
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}
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#endif
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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 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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/*
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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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