diff options
Diffstat (limited to 'kernel/irq/proc.c')
-rw-r--r-- | kernel/irq/proc.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c new file mode 100644 index 000000000000..85d08daa6600 --- /dev/null +++ b/kernel/irq/proc.c @@ -0,0 +1,159 @@ +/* + * 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/interrupt.h> + +static struct proc_dir_entry *root_irq_dir, *irq_dir[NR_IRQS]; + +#ifdef CONFIG_SMP + +/* + * The /proc/irq/<irq>/smp_affinity values: + */ +static struct proc_dir_entry *smp_affinity_entry[NR_IRQS]; + +void __attribute__((weak)) +proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val) +{ + irq_affinity[irq] = mask_val; + irq_desc[irq].handler->set_affinity(irq, mask_val); +} + +static int irq_affinity_read_proc(char *page, char **start, off_t off, + int count, int *eof, void *data) +{ + int len = cpumask_scnprintf(page, count, irq_affinity[(long)data]); + + if (count - len < 2) + return -EINVAL; + len += sprintf(page + len, "\n"); + return len; +} + +int no_irq_affinity; +static int irq_affinity_write_proc(struct file *file, const char __user *buffer, + unsigned long count, void *data) +{ + unsigned int irq = (int)(long)data, full_count = count, err; + cpumask_t new_value, tmp; + + if (!irq_desc[irq].handler->set_affinity || no_irq_affinity) + return -EIO; + + err = cpumask_parse(buffer, count, new_value); + if (err) + return err; + + /* + * 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. + */ + cpus_and(tmp, new_value, cpu_online_map); + if (cpus_empty(tmp)) + return -EINVAL; + + proc_set_irq_affinity(irq, new_value); + + return full_count; +} + +#endif + +#define MAX_NAMELEN 128 + +static int name_unique(unsigned int irq, struct irqaction *new_action) +{ + struct irq_desc *desc = irq_desc + irq; + struct irqaction *action; + + for (action = desc->action ; action; action = action->next) + if ((action != new_action) && action->name && + !strcmp(new_action->name, action->name)) + return 0; + return 1; +} + +void register_handler_proc(unsigned int irq, struct irqaction *action) +{ + char name [MAX_NAMELEN]; + + if (!irq_dir[irq] || 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, irq_dir[irq]); +} + +#undef MAX_NAMELEN + +#define MAX_NAMELEN 10 + +void register_irq_proc(unsigned int irq) +{ + char name [MAX_NAMELEN]; + + if (!root_irq_dir || + (irq_desc[irq].handler == &no_irq_type) || + irq_dir[irq]) + return; + + memset(name, 0, MAX_NAMELEN); + sprintf(name, "%d", irq); + + /* create /proc/irq/1234 */ + irq_dir[irq] = proc_mkdir(name, root_irq_dir); + +#ifdef CONFIG_SMP + { + struct proc_dir_entry *entry; + + /* create /proc/irq/<irq>/smp_affinity */ + entry = create_proc_entry("smp_affinity", 0600, irq_dir[irq]); + + if (entry) { + entry->nlink = 1; + entry->data = (void *)(long)irq; + entry->read_proc = irq_affinity_read_proc; + entry->write_proc = irq_affinity_write_proc; + } + smp_affinity_entry[irq] = entry; + } +#endif +} + +#undef MAX_NAMELEN + +void unregister_handler_proc(unsigned int irq, struct irqaction *action) +{ + if (action->dir) + remove_proc_entry(action->dir->name, irq_dir[irq]); +} + +void init_irq_proc(void) +{ + int i; + + /* create /proc/irq */ + root_irq_dir = proc_mkdir("irq", NULL); + if (!root_irq_dir) + return; + + /* + * Create entries for all existing IRQs. + */ + for (i = 0; i < NR_IRQS; i++) + register_irq_proc(i); +} + |