1 /* 2 * linux/kernel/irq/proc.c 3 * 4 * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar 5 * 6 * This file contains the /proc/irq/ handling code. 7 */ 8 9 #include <linux/irq.h> 10 #include <linux/proc_fs.h> 11 #include <linux/interrupt.h> 12 13 #include "internals.h" 14 15 static struct proc_dir_entry *root_irq_dir; 16 17 #ifdef CONFIG_SMP 18 19 static int irq_affinity_read_proc(char *page, char **start, off_t off, 20 int count, int *eof, void *data) 21 { 22 struct irq_desc *desc = irq_desc + (long)data; 23 cpumask_t *mask = &desc->affinity; 24 int len; 25 26 #ifdef CONFIG_GENERIC_PENDING_IRQ 27 if (desc->status & IRQ_MOVE_PENDING) 28 mask = &desc->pending_mask; 29 #endif 30 len = cpumask_scnprintf(page, count, *mask); 31 32 if (count - len < 2) 33 return -EINVAL; 34 len += sprintf(page + len, "\n"); 35 return len; 36 } 37 38 #ifndef is_affinity_mask_valid 39 #define is_affinity_mask_valid(val) 1 40 #endif 41 42 int no_irq_affinity; 43 static int irq_affinity_write_proc(struct file *file, const char __user *buffer, 44 unsigned long count, void *data) 45 { 46 unsigned int irq = (int)(long)data, full_count = count, err; 47 cpumask_t new_value, tmp; 48 49 if (!irq_desc[irq].chip->set_affinity || no_irq_affinity || 50 irq_balancing_disabled(irq)) 51 return -EIO; 52 53 err = cpumask_parse_user(buffer, count, new_value); 54 if (err) 55 return err; 56 57 if (!is_affinity_mask_valid(new_value)) 58 return -EINVAL; 59 60 /* 61 * Do not allow disabling IRQs completely - it's a too easy 62 * way to make the system unusable accidentally :-) At least 63 * one online CPU still has to be targeted. 64 */ 65 cpus_and(tmp, new_value, cpu_online_map); 66 if (cpus_empty(tmp)) 67 /* Special case for empty set - allow the architecture 68 code to set default SMP affinity. */ 69 return select_smp_affinity(irq) ? -EINVAL : full_count; 70 71 irq_set_affinity(irq, new_value); 72 73 return full_count; 74 } 75 76 #endif 77 78 static int irq_spurious_read(char *page, char **start, off_t off, 79 int count, int *eof, void *data) 80 { 81 struct irq_desc *d = &irq_desc[(long) data]; 82 return sprintf(page, "count %u\n" 83 "unhandled %u\n" 84 "last_unhandled %u ms\n", 85 d->irq_count, 86 d->irqs_unhandled, 87 jiffies_to_msecs(d->last_unhandled)); 88 } 89 90 #define MAX_NAMELEN 128 91 92 static int name_unique(unsigned int irq, struct irqaction *new_action) 93 { 94 struct irq_desc *desc = irq_desc + irq; 95 struct irqaction *action; 96 unsigned long flags; 97 int ret = 1; 98 99 spin_lock_irqsave(&desc->lock, flags); 100 for (action = desc->action ; action; action = action->next) { 101 if ((action != new_action) && action->name && 102 !strcmp(new_action->name, action->name)) { 103 ret = 0; 104 break; 105 } 106 } 107 spin_unlock_irqrestore(&desc->lock, flags); 108 return ret; 109 } 110 111 void register_handler_proc(unsigned int irq, struct irqaction *action) 112 { 113 char name [MAX_NAMELEN]; 114 115 if (!irq_desc[irq].dir || action->dir || !action->name || 116 !name_unique(irq, action)) 117 return; 118 119 memset(name, 0, MAX_NAMELEN); 120 snprintf(name, MAX_NAMELEN, "%s", action->name); 121 122 /* create /proc/irq/1234/handler/ */ 123 action->dir = proc_mkdir(name, irq_desc[irq].dir); 124 } 125 126 #undef MAX_NAMELEN 127 128 #define MAX_NAMELEN 10 129 130 void register_irq_proc(unsigned int irq) 131 { 132 char name [MAX_NAMELEN]; 133 struct proc_dir_entry *entry; 134 135 if (!root_irq_dir || 136 (irq_desc[irq].chip == &no_irq_chip) || 137 irq_desc[irq].dir) 138 return; 139 140 memset(name, 0, MAX_NAMELEN); 141 sprintf(name, "%d", irq); 142 143 /* create /proc/irq/1234 */ 144 irq_desc[irq].dir = proc_mkdir(name, root_irq_dir); 145 146 #ifdef CONFIG_SMP 147 { 148 /* create /proc/irq/<irq>/smp_affinity */ 149 entry = create_proc_entry("smp_affinity", 0600, irq_desc[irq].dir); 150 151 if (entry) { 152 entry->data = (void *)(long)irq; 153 entry->read_proc = irq_affinity_read_proc; 154 entry->write_proc = irq_affinity_write_proc; 155 } 156 } 157 #endif 158 159 entry = create_proc_entry("spurious", 0444, irq_desc[irq].dir); 160 if (entry) { 161 entry->data = (void *)(long)irq; 162 entry->read_proc = irq_spurious_read; 163 } 164 } 165 166 #undef MAX_NAMELEN 167 168 void unregister_handler_proc(unsigned int irq, struct irqaction *action) 169 { 170 if (action->dir) 171 remove_proc_entry(action->dir->name, irq_desc[irq].dir); 172 } 173 174 void init_irq_proc(void) 175 { 176 int i; 177 178 /* create /proc/irq */ 179 root_irq_dir = proc_mkdir("irq", NULL); 180 if (!root_irq_dir) 181 return; 182 183 /* 184 * Create entries for all existing IRQs. 185 */ 186 for (i = 0; i < NR_IRQS; i++) 187 register_irq_proc(i); 188 } 189 190