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; 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 if (!cpus_intersects(new_value, cpu_online_map)) 66 /* Special case for empty set - allow the architecture 67 code to set default SMP affinity. */ 68 return irq_select_affinity(irq) ? -EINVAL : full_count; 69 70 irq_set_affinity(irq, new_value); 71 72 return full_count; 73 } 74 75 static int default_affinity_read(char *page, char **start, off_t off, 76 int count, int *eof, void *data) 77 { 78 int len = cpumask_scnprintf(page, count, irq_default_affinity); 79 if (count - len < 2) 80 return -EINVAL; 81 len += sprintf(page + len, "\n"); 82 return len; 83 } 84 85 static int default_affinity_write(struct file *file, const char __user *buffer, 86 unsigned long count, void *data) 87 { 88 unsigned int full_count = count, err; 89 cpumask_t new_value; 90 91 err = cpumask_parse_user(buffer, count, new_value); 92 if (err) 93 return err; 94 95 if (!is_affinity_mask_valid(new_value)) 96 return -EINVAL; 97 98 /* 99 * Do not allow disabling IRQs completely - it's a too easy 100 * way to make the system unusable accidentally :-) At least 101 * one online CPU still has to be targeted. 102 */ 103 if (!cpus_intersects(new_value, cpu_online_map)) 104 return -EINVAL; 105 106 irq_default_affinity = new_value; 107 108 return full_count; 109 } 110 #endif 111 112 static int irq_spurious_read(char *page, char **start, off_t off, 113 int count, int *eof, void *data) 114 { 115 struct irq_desc *d = &irq_desc[(long) data]; 116 return sprintf(page, "count %u\n" 117 "unhandled %u\n" 118 "last_unhandled %u ms\n", 119 d->irq_count, 120 d->irqs_unhandled, 121 jiffies_to_msecs(d->last_unhandled)); 122 } 123 124 #define MAX_NAMELEN 128 125 126 static int name_unique(unsigned int irq, struct irqaction *new_action) 127 { 128 struct irq_desc *desc = irq_desc + irq; 129 struct irqaction *action; 130 unsigned long flags; 131 int ret = 1; 132 133 spin_lock_irqsave(&desc->lock, flags); 134 for (action = desc->action ; action; action = action->next) { 135 if ((action != new_action) && action->name && 136 !strcmp(new_action->name, action->name)) { 137 ret = 0; 138 break; 139 } 140 } 141 spin_unlock_irqrestore(&desc->lock, flags); 142 return ret; 143 } 144 145 void register_handler_proc(unsigned int irq, struct irqaction *action) 146 { 147 char name [MAX_NAMELEN]; 148 149 if (!irq_desc[irq].dir || action->dir || !action->name || 150 !name_unique(irq, action)) 151 return; 152 153 memset(name, 0, MAX_NAMELEN); 154 snprintf(name, MAX_NAMELEN, "%s", action->name); 155 156 /* create /proc/irq/1234/handler/ */ 157 action->dir = proc_mkdir(name, irq_desc[irq].dir); 158 } 159 160 #undef MAX_NAMELEN 161 162 #define MAX_NAMELEN 10 163 164 void register_irq_proc(unsigned int irq) 165 { 166 char name [MAX_NAMELEN]; 167 struct proc_dir_entry *entry; 168 169 if (!root_irq_dir || 170 (irq_desc[irq].chip == &no_irq_chip) || 171 irq_desc[irq].dir) 172 return; 173 174 memset(name, 0, MAX_NAMELEN); 175 sprintf(name, "%d", irq); 176 177 /* create /proc/irq/1234 */ 178 irq_desc[irq].dir = proc_mkdir(name, root_irq_dir); 179 180 #ifdef CONFIG_SMP 181 { 182 /* create /proc/irq/<irq>/smp_affinity */ 183 entry = create_proc_entry("smp_affinity", 0600, irq_desc[irq].dir); 184 185 if (entry) { 186 entry->data = (void *)(long)irq; 187 entry->read_proc = irq_affinity_read_proc; 188 entry->write_proc = irq_affinity_write_proc; 189 } 190 } 191 #endif 192 193 entry = create_proc_entry("spurious", 0444, irq_desc[irq].dir); 194 if (entry) { 195 entry->data = (void *)(long)irq; 196 entry->read_proc = irq_spurious_read; 197 } 198 } 199 200 #undef MAX_NAMELEN 201 202 void unregister_handler_proc(unsigned int irq, struct irqaction *action) 203 { 204 if (action->dir) 205 remove_proc_entry(action->dir->name, irq_desc[irq].dir); 206 } 207 208 void register_default_affinity_proc(void) 209 { 210 #ifdef CONFIG_SMP 211 struct proc_dir_entry *entry; 212 213 /* create /proc/irq/default_smp_affinity */ 214 entry = create_proc_entry("default_smp_affinity", 0600, root_irq_dir); 215 if (entry) { 216 entry->data = NULL; 217 entry->read_proc = default_affinity_read; 218 entry->write_proc = default_affinity_write; 219 } 220 #endif 221 } 222 223 void init_irq_proc(void) 224 { 225 int i; 226 227 /* create /proc/irq */ 228 root_irq_dir = proc_mkdir("irq", NULL); 229 if (!root_irq_dir) 230 return; 231 232 register_default_affinity_proc(); 233 234 /* 235 * Create entries for all existing IRQs. 236 */ 237 for (i = 0; i < NR_IRQS; i++) 238 register_irq_proc(i); 239 } 240 241