25d61578da
On SN, only allow one bit to be set in the smp_affinty mask when redirecting an interrupt. Currently setting multiple bits is allowed, but only the first bit is used in determining the CPU to redirect to. This has caused confusion among some customers. [akpm@linux-foundation.org: fixes] Signed-off-by: John Keller <jpk@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
164 lines
3.5 KiB
C
164 lines
3.5 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/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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#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 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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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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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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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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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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