/* * 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_var_t new_value; int err; if (!irq_to_desc(irq)->chip->set_affinity || no_irq_affinity || irq_balancing_disabled(irq)) return -EIO; if (!alloc_cpumask_var(&new_value, GFP_KERNEL)) return -ENOMEM; err = cpumask_parse_user(buffer, count, new_value); if (err) goto free_cpumask; if (!is_affinity_mask_valid(*new_value)) { err = -EINVAL; goto free_cpumask; } /* * 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 (!cpumask_intersects(new_value, cpu_online_mask)) { /* Special case for empty set - allow the architecture code to set default SMP affinity. */ err = irq_select_affinity_usr(irq) ? -EINVAL : count; } else { irq_set_affinity(irq, new_value); err = count; } free_cpumask: free_cpumask_var(new_value); return err; } 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); } } static 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); }