Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/kernel/irq/manage.c |
| 3 | * |
Ingo Molnar | a34db9b | 2006-06-29 02:24:50 -0700 | [diff] [blame] | 4 | * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar |
| 5 | * Copyright (C) 2005-2006 Thomas Gleixner |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 6 | * |
| 7 | * This file contains driver APIs to the irq subsystem. |
| 8 | */ |
| 9 | |
| 10 | #include <linux/irq.h> |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/random.h> |
| 13 | #include <linux/interrupt.h> |
| 14 | |
| 15 | #include "internals.h" |
| 16 | |
| 17 | #ifdef CONFIG_SMP |
| 18 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | /** |
| 20 | * synchronize_irq - wait for pending IRQ handlers (on other CPUs) |
Randy Dunlap | 1e5d533 | 2005-11-07 01:01:06 -0800 | [diff] [blame] | 21 | * @irq: interrupt number to wait for |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | * |
| 23 | * This function waits for any pending IRQ handlers for this interrupt |
| 24 | * to complete before returning. If you use this function while |
| 25 | * holding a resource the IRQ handler may need you will deadlock. |
| 26 | * |
| 27 | * This function may be called - with care - from IRQ context. |
| 28 | */ |
| 29 | void synchronize_irq(unsigned int irq) |
| 30 | { |
| 31 | struct irq_desc *desc = irq_desc + irq; |
| 32 | |
Matthew Wilcox | c2b5a25 | 2005-11-03 07:51:18 -0700 | [diff] [blame] | 33 | if (irq >= NR_IRQS) |
| 34 | return; |
| 35 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | while (desc->status & IRQ_INPROGRESS) |
| 37 | cpu_relax(); |
| 38 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | EXPORT_SYMBOL(synchronize_irq); |
| 40 | |
| 41 | #endif |
| 42 | |
| 43 | /** |
| 44 | * disable_irq_nosync - disable an irq without waiting |
| 45 | * @irq: Interrupt to disable |
| 46 | * |
| 47 | * Disable the selected interrupt line. Disables and Enables are |
| 48 | * nested. |
| 49 | * Unlike disable_irq(), this function does not ensure existing |
| 50 | * instances of the IRQ handler have completed before returning. |
| 51 | * |
| 52 | * This function may be called from IRQ context. |
| 53 | */ |
| 54 | void disable_irq_nosync(unsigned int irq) |
| 55 | { |
Ingo Molnar | 34ffdb7 | 2006-06-29 02:24:40 -0700 | [diff] [blame] | 56 | struct irq_desc *desc = irq_desc + irq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | unsigned long flags; |
| 58 | |
Matthew Wilcox | c2b5a25 | 2005-11-03 07:51:18 -0700 | [diff] [blame] | 59 | if (irq >= NR_IRQS) |
| 60 | return; |
| 61 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | spin_lock_irqsave(&desc->lock, flags); |
| 63 | if (!desc->depth++) { |
| 64 | desc->status |= IRQ_DISABLED; |
Ingo Molnar | d1bef4e | 2006-06-29 02:24:36 -0700 | [diff] [blame] | 65 | desc->chip->disable(irq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | } |
| 67 | spin_unlock_irqrestore(&desc->lock, flags); |
| 68 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | EXPORT_SYMBOL(disable_irq_nosync); |
| 70 | |
| 71 | /** |
| 72 | * disable_irq - disable an irq and wait for completion |
| 73 | * @irq: Interrupt to disable |
| 74 | * |
| 75 | * Disable the selected interrupt line. Enables and Disables are |
| 76 | * nested. |
| 77 | * This function waits for any pending IRQ handlers for this interrupt |
| 78 | * to complete before returning. If you use this function while |
| 79 | * holding a resource the IRQ handler may need you will deadlock. |
| 80 | * |
| 81 | * This function may be called - with care - from IRQ context. |
| 82 | */ |
| 83 | void disable_irq(unsigned int irq) |
| 84 | { |
Ingo Molnar | 34ffdb7 | 2006-06-29 02:24:40 -0700 | [diff] [blame] | 85 | struct irq_desc *desc = irq_desc + irq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 86 | |
Matthew Wilcox | c2b5a25 | 2005-11-03 07:51:18 -0700 | [diff] [blame] | 87 | if (irq >= NR_IRQS) |
| 88 | return; |
| 89 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | disable_irq_nosync(irq); |
| 91 | if (desc->action) |
| 92 | synchronize_irq(irq); |
| 93 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | EXPORT_SYMBOL(disable_irq); |
| 95 | |
| 96 | /** |
| 97 | * enable_irq - enable handling of an irq |
| 98 | * @irq: Interrupt to enable |
| 99 | * |
| 100 | * Undoes the effect of one call to disable_irq(). If this |
| 101 | * matches the last disable, processing of interrupts on this |
| 102 | * IRQ line is re-enabled. |
| 103 | * |
| 104 | * This function may be called from IRQ context. |
| 105 | */ |
| 106 | void enable_irq(unsigned int irq) |
| 107 | { |
Ingo Molnar | 34ffdb7 | 2006-06-29 02:24:40 -0700 | [diff] [blame] | 108 | struct irq_desc *desc = irq_desc + irq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | unsigned long flags; |
| 110 | |
Matthew Wilcox | c2b5a25 | 2005-11-03 07:51:18 -0700 | [diff] [blame] | 111 | if (irq >= NR_IRQS) |
| 112 | return; |
| 113 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | spin_lock_irqsave(&desc->lock, flags); |
| 115 | switch (desc->depth) { |
| 116 | case 0: |
Bjorn Helgaas | e8c4b9d | 2006-07-01 04:35:45 -0700 | [diff] [blame] | 117 | printk(KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | WARN_ON(1); |
| 119 | break; |
| 120 | case 1: { |
Thomas Gleixner | 3418d72 | 2006-06-29 02:24:49 -0700 | [diff] [blame] | 121 | unsigned int status = desc->status & ~IRQ_DISABLED; |
| 122 | |
| 123 | /* Prevent probing on this irq: */ |
| 124 | desc->status = status | IRQ_NOPROBE; |
Thomas Gleixner | a4633adc | 2006-06-29 02:24:48 -0700 | [diff] [blame] | 125 | check_irq_resend(desc, irq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | /* fall-through */ |
| 127 | } |
| 128 | default: |
| 129 | desc->depth--; |
| 130 | } |
| 131 | spin_unlock_irqrestore(&desc->lock, flags); |
| 132 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | EXPORT_SYMBOL(enable_irq); |
| 134 | |
Thomas Gleixner | ba9a233 | 2006-06-29 02:24:55 -0700 | [diff] [blame] | 135 | /** |
| 136 | * set_irq_wake - control irq power management wakeup |
| 137 | * @irq: interrupt to control |
| 138 | * @on: enable/disable power management wakeup |
| 139 | * |
| 140 | * Enable/disable power management wakeup mode |
| 141 | */ |
| 142 | int set_irq_wake(unsigned int irq, unsigned int on) |
| 143 | { |
| 144 | struct irq_desc *desc = irq_desc + irq; |
| 145 | unsigned long flags; |
| 146 | int ret = -ENXIO; |
| 147 | |
| 148 | spin_lock_irqsave(&desc->lock, flags); |
| 149 | if (desc->chip->set_wake) |
| 150 | ret = desc->chip->set_wake(irq, on); |
| 151 | spin_unlock_irqrestore(&desc->lock, flags); |
| 152 | return ret; |
| 153 | } |
| 154 | EXPORT_SYMBOL(set_irq_wake); |
| 155 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | /* |
| 157 | * Internal function that tells the architecture code whether a |
| 158 | * particular irq has been exclusively allocated or is available |
| 159 | * for driver use. |
| 160 | */ |
| 161 | int can_request_irq(unsigned int irq, unsigned long irqflags) |
| 162 | { |
| 163 | struct irqaction *action; |
| 164 | |
Thomas Gleixner | 6550c77 | 2006-06-29 02:24:49 -0700 | [diff] [blame] | 165 | if (irq >= NR_IRQS || irq_desc[irq].status & IRQ_NOREQUEST) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | return 0; |
| 167 | |
| 168 | action = irq_desc[irq].action; |
| 169 | if (action) |
| 170 | if (irqflags & action->flags & SA_SHIRQ) |
| 171 | action = NULL; |
| 172 | |
| 173 | return !action; |
| 174 | } |
| 175 | |
Thomas Gleixner | 6a6de9e | 2006-06-29 02:24:51 -0700 | [diff] [blame] | 176 | void compat_irq_chip_set_default_handler(struct irq_desc *desc) |
| 177 | { |
| 178 | /* |
| 179 | * If the architecture still has not overriden |
| 180 | * the flow handler then zap the default. This |
| 181 | * should catch incorrect flow-type setting. |
| 182 | */ |
| 183 | if (desc->handle_irq == &handle_bad_irq) |
| 184 | desc->handle_irq = NULL; |
| 185 | } |
| 186 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | /* |
| 188 | * Internal function to register an irqaction - typically used to |
| 189 | * allocate special interrupts that are part of the architecture. |
| 190 | */ |
Ingo Molnar | 06fcb0c | 2006-06-29 02:24:40 -0700 | [diff] [blame] | 191 | int setup_irq(unsigned int irq, struct irqaction *new) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 192 | { |
| 193 | struct irq_desc *desc = irq_desc + irq; |
| 194 | struct irqaction *old, **p; |
| 195 | unsigned long flags; |
| 196 | int shared = 0; |
| 197 | |
Matthew Wilcox | c2b5a25 | 2005-11-03 07:51:18 -0700 | [diff] [blame] | 198 | if (irq >= NR_IRQS) |
| 199 | return -EINVAL; |
| 200 | |
Ingo Molnar | f1c2662 | 2006-06-29 02:24:57 -0700 | [diff] [blame] | 201 | if (desc->chip == &no_irq_chip) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | return -ENOSYS; |
| 203 | /* |
| 204 | * Some drivers like serial.c use request_irq() heavily, |
| 205 | * so we have to be careful not to interfere with a |
| 206 | * running system. |
| 207 | */ |
| 208 | if (new->flags & SA_SAMPLE_RANDOM) { |
| 209 | /* |
| 210 | * This function might sleep, we want to call it first, |
| 211 | * outside of the atomic block. |
| 212 | * Yes, this might clear the entropy pool if the wrong |
| 213 | * driver is attempted to be loaded, without actually |
| 214 | * installing a new handler, but is this really a problem, |
| 215 | * only the sysadmin is able to do this. |
| 216 | */ |
| 217 | rand_initialize_irq(irq); |
| 218 | } |
| 219 | |
| 220 | /* |
| 221 | * The following block of code has to be executed atomically |
| 222 | */ |
Ingo Molnar | 06fcb0c | 2006-06-29 02:24:40 -0700 | [diff] [blame] | 223 | spin_lock_irqsave(&desc->lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 224 | p = &desc->action; |
Ingo Molnar | 06fcb0c | 2006-06-29 02:24:40 -0700 | [diff] [blame] | 225 | old = *p; |
| 226 | if (old) { |
Thomas Gleixner | e76de9f | 2006-06-29 02:24:56 -0700 | [diff] [blame] | 227 | /* |
| 228 | * Can't share interrupts unless both agree to and are |
| 229 | * the same type (level, edge, polarity). So both flag |
| 230 | * fields must have SA_SHIRQ set and the bits which |
| 231 | * set the trigger type must match. |
| 232 | */ |
| 233 | if (!((old->flags & new->flags) & SA_SHIRQ) || |
| 234 | ((old->flags ^ new->flags) & SA_TRIGGER_MASK)) |
Dimitri Sivanich | f516342 | 2006-03-25 03:08:23 -0800 | [diff] [blame] | 235 | goto mismatch; |
| 236 | |
Ingo Molnar | 0d7012a | 2006-06-29 02:24:43 -0700 | [diff] [blame] | 237 | #if defined(CONFIG_IRQ_PER_CPU) && defined(SA_PERCPU_IRQ) |
Dimitri Sivanich | f516342 | 2006-03-25 03:08:23 -0800 | [diff] [blame] | 238 | /* All handlers must agree on per-cpuness */ |
Bjorn Helgaas | 17311c0 | 2006-07-01 04:35:44 -0700 | [diff] [blame] | 239 | if ((old->flags & SA_PERCPU_IRQ) != |
| 240 | (new->flags & SA_PERCPU_IRQ)) |
Dimitri Sivanich | f516342 | 2006-03-25 03:08:23 -0800 | [diff] [blame] | 241 | goto mismatch; |
| 242 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 243 | |
| 244 | /* add new interrupt at end of irq queue */ |
| 245 | do { |
| 246 | p = &old->next; |
| 247 | old = *p; |
| 248 | } while (old); |
| 249 | shared = 1; |
| 250 | } |
| 251 | |
| 252 | *p = new; |
Ingo Molnar | 0d7012a | 2006-06-29 02:24:43 -0700 | [diff] [blame] | 253 | #if defined(CONFIG_IRQ_PER_CPU) && defined(SA_PERCPU_IRQ) |
Dimitri Sivanich | f516342 | 2006-03-25 03:08:23 -0800 | [diff] [blame] | 254 | if (new->flags & SA_PERCPU_IRQ) |
| 255 | desc->status |= IRQ_PER_CPU; |
| 256 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 257 | if (!shared) { |
Thomas Gleixner | 6a6de9e | 2006-06-29 02:24:51 -0700 | [diff] [blame] | 258 | irq_chip_set_defaults(desc->chip); |
Thomas Gleixner | e76de9f | 2006-06-29 02:24:56 -0700 | [diff] [blame] | 259 | |
| 260 | /* Setup the type (level, edge polarity) if configured: */ |
| 261 | if (new->flags & SA_TRIGGER_MASK) { |
| 262 | if (desc->chip && desc->chip->set_type) |
| 263 | desc->chip->set_type(irq, |
| 264 | new->flags & SA_TRIGGER_MASK); |
| 265 | else |
| 266 | /* |
| 267 | * SA_TRIGGER_* but the PIC does not support |
| 268 | * multiple flow-types? |
| 269 | */ |
Bjorn Helgaas | e8c4b9d | 2006-07-01 04:35:45 -0700 | [diff] [blame] | 270 | printk(KERN_WARNING "No SA_TRIGGER set_type " |
| 271 | "function for IRQ %d (%s)\n", irq, |
| 272 | desc->chip ? desc->chip->name : |
| 273 | "unknown"); |
Thomas Gleixner | e76de9f | 2006-06-29 02:24:56 -0700 | [diff] [blame] | 274 | } else |
| 275 | compat_irq_chip_set_default_handler(desc); |
Thomas Gleixner | 6a6de9e | 2006-06-29 02:24:51 -0700 | [diff] [blame] | 276 | |
Thomas Gleixner | 94d39e1 | 2006-06-29 02:24:50 -0700 | [diff] [blame] | 277 | desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING | |
| 278 | IRQ_INPROGRESS); |
| 279 | |
| 280 | if (!(desc->status & IRQ_NOAUTOEN)) { |
| 281 | desc->depth = 0; |
| 282 | desc->status &= ~IRQ_DISABLED; |
| 283 | if (desc->chip->startup) |
| 284 | desc->chip->startup(irq); |
| 285 | else |
| 286 | desc->chip->enable(irq); |
Thomas Gleixner | e76de9f | 2006-06-29 02:24:56 -0700 | [diff] [blame] | 287 | } else |
| 288 | /* Undo nested disables: */ |
| 289 | desc->depth = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 290 | } |
Ingo Molnar | 06fcb0c | 2006-06-29 02:24:40 -0700 | [diff] [blame] | 291 | spin_unlock_irqrestore(&desc->lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 292 | |
| 293 | new->irq = irq; |
| 294 | register_irq_proc(irq); |
| 295 | new->dir = NULL; |
| 296 | register_handler_proc(irq, new); |
| 297 | |
| 298 | return 0; |
Dimitri Sivanich | f516342 | 2006-03-25 03:08:23 -0800 | [diff] [blame] | 299 | |
| 300 | mismatch: |
| 301 | spin_unlock_irqrestore(&desc->lock, flags); |
Andrew Morton | 13e87ec | 2006-04-27 18:39:18 -0700 | [diff] [blame] | 302 | if (!(new->flags & SA_PROBEIRQ)) { |
Bjorn Helgaas | e8c4b9d | 2006-07-01 04:35:45 -0700 | [diff] [blame] | 303 | printk(KERN_ERR "IRQ handler type mismatch for IRQ %d\n", irq); |
Andrew Morton | 13e87ec | 2006-04-27 18:39:18 -0700 | [diff] [blame] | 304 | dump_stack(); |
| 305 | } |
Dimitri Sivanich | f516342 | 2006-03-25 03:08:23 -0800 | [diff] [blame] | 306 | return -EBUSY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 307 | } |
| 308 | |
| 309 | /** |
| 310 | * free_irq - free an interrupt |
| 311 | * @irq: Interrupt line to free |
| 312 | * @dev_id: Device identity to free |
| 313 | * |
| 314 | * Remove an interrupt handler. The handler is removed and if the |
| 315 | * interrupt line is no longer in use by any driver it is disabled. |
| 316 | * On a shared IRQ the caller must ensure the interrupt is disabled |
| 317 | * on the card it drives before calling this function. The function |
| 318 | * does not return until any executing interrupts for this IRQ |
| 319 | * have completed. |
| 320 | * |
| 321 | * This function must not be called from interrupt context. |
| 322 | */ |
| 323 | void free_irq(unsigned int irq, void *dev_id) |
| 324 | { |
| 325 | struct irq_desc *desc; |
| 326 | struct irqaction **p; |
| 327 | unsigned long flags; |
| 328 | |
Ingo Molnar | cd7b24b | 2006-03-26 01:36:54 -0800 | [diff] [blame] | 329 | WARN_ON(in_interrupt()); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 330 | if (irq >= NR_IRQS) |
| 331 | return; |
| 332 | |
| 333 | desc = irq_desc + irq; |
Ingo Molnar | 06fcb0c | 2006-06-29 02:24:40 -0700 | [diff] [blame] | 334 | spin_lock_irqsave(&desc->lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | p = &desc->action; |
| 336 | for (;;) { |
Ingo Molnar | 06fcb0c | 2006-06-29 02:24:40 -0700 | [diff] [blame] | 337 | struct irqaction *action = *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 338 | |
| 339 | if (action) { |
| 340 | struct irqaction **pp = p; |
| 341 | |
| 342 | p = &action->next; |
| 343 | if (action->dev_id != dev_id) |
| 344 | continue; |
| 345 | |
| 346 | /* Found it - now remove it from the list of entries */ |
| 347 | *pp = action->next; |
Paolo 'Blaisorblade' Giarrusso | dbce706 | 2005-06-21 17:16:19 -0700 | [diff] [blame] | 348 | |
Paolo 'Blaisorblade' Giarrusso | b77d6ad | 2005-06-21 17:16:24 -0700 | [diff] [blame] | 349 | /* Currently used only by UML, might disappear one day.*/ |
| 350 | #ifdef CONFIG_IRQ_RELEASE_METHOD |
Ingo Molnar | d1bef4e | 2006-06-29 02:24:36 -0700 | [diff] [blame] | 351 | if (desc->chip->release) |
| 352 | desc->chip->release(irq, dev_id); |
Paolo 'Blaisorblade' Giarrusso | b77d6ad | 2005-06-21 17:16:24 -0700 | [diff] [blame] | 353 | #endif |
Paolo 'Blaisorblade' Giarrusso | dbce706 | 2005-06-21 17:16:19 -0700 | [diff] [blame] | 354 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 355 | if (!desc->action) { |
| 356 | desc->status |= IRQ_DISABLED; |
Ingo Molnar | d1bef4e | 2006-06-29 02:24:36 -0700 | [diff] [blame] | 357 | if (desc->chip->shutdown) |
| 358 | desc->chip->shutdown(irq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 359 | else |
Ingo Molnar | d1bef4e | 2006-06-29 02:24:36 -0700 | [diff] [blame] | 360 | desc->chip->disable(irq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | } |
Ingo Molnar | 06fcb0c | 2006-06-29 02:24:40 -0700 | [diff] [blame] | 362 | spin_unlock_irqrestore(&desc->lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 363 | unregister_handler_proc(irq, action); |
| 364 | |
| 365 | /* Make sure it's not being used on another CPU */ |
| 366 | synchronize_irq(irq); |
| 367 | kfree(action); |
| 368 | return; |
| 369 | } |
Bjorn Helgaas | e8c4b9d | 2006-07-01 04:35:45 -0700 | [diff] [blame] | 370 | printk(KERN_ERR "Trying to free already-free IRQ %d\n", irq); |
Ingo Molnar | 06fcb0c | 2006-06-29 02:24:40 -0700 | [diff] [blame] | 371 | spin_unlock_irqrestore(&desc->lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | return; |
| 373 | } |
| 374 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | EXPORT_SYMBOL(free_irq); |
| 376 | |
| 377 | /** |
| 378 | * request_irq - allocate an interrupt line |
| 379 | * @irq: Interrupt line to allocate |
| 380 | * @handler: Function to be called when the IRQ occurs |
| 381 | * @irqflags: Interrupt type flags |
| 382 | * @devname: An ascii name for the claiming device |
| 383 | * @dev_id: A cookie passed back to the handler function |
| 384 | * |
| 385 | * This call allocates interrupt resources and enables the |
| 386 | * interrupt line and IRQ handling. From the point this |
| 387 | * call is made your handler function may be invoked. Since |
| 388 | * your handler function must clear any interrupt the board |
| 389 | * raises, you must take care both to initialise your hardware |
| 390 | * and to set up the interrupt handler in the right order. |
| 391 | * |
| 392 | * Dev_id must be globally unique. Normally the address of the |
| 393 | * device data structure is used as the cookie. Since the handler |
| 394 | * receives this value it makes sense to use it. |
| 395 | * |
| 396 | * If your interrupt is shared you must pass a non NULL dev_id |
| 397 | * as this is required when freeing the interrupt. |
| 398 | * |
| 399 | * Flags: |
| 400 | * |
| 401 | * SA_SHIRQ Interrupt is shared |
| 402 | * SA_INTERRUPT Disable local interrupts while processing |
| 403 | * SA_SAMPLE_RANDOM The interrupt can be used for entropy |
| 404 | * |
| 405 | */ |
| 406 | int request_irq(unsigned int irq, |
| 407 | irqreturn_t (*handler)(int, void *, struct pt_regs *), |
Ingo Molnar | 06fcb0c | 2006-06-29 02:24:40 -0700 | [diff] [blame] | 408 | unsigned long irqflags, const char *devname, void *dev_id) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | { |
Ingo Molnar | 06fcb0c | 2006-06-29 02:24:40 -0700 | [diff] [blame] | 410 | struct irqaction *action; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 411 | int retval; |
| 412 | |
| 413 | /* |
| 414 | * Sanity-check: shared interrupts must pass in a real dev-ID, |
| 415 | * otherwise we'll have trouble later trying to figure out |
| 416 | * which interrupt is which (messes up the interrupt freeing |
| 417 | * logic etc). |
| 418 | */ |
| 419 | if ((irqflags & SA_SHIRQ) && !dev_id) |
| 420 | return -EINVAL; |
| 421 | if (irq >= NR_IRQS) |
| 422 | return -EINVAL; |
Thomas Gleixner | 6550c77 | 2006-06-29 02:24:49 -0700 | [diff] [blame] | 423 | if (irq_desc[irq].status & IRQ_NOREQUEST) |
| 424 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 425 | if (!handler) |
| 426 | return -EINVAL; |
| 427 | |
| 428 | action = kmalloc(sizeof(struct irqaction), GFP_ATOMIC); |
| 429 | if (!action) |
| 430 | return -ENOMEM; |
| 431 | |
| 432 | action->handler = handler; |
| 433 | action->flags = irqflags; |
| 434 | cpus_clear(action->mask); |
| 435 | action->name = devname; |
| 436 | action->next = NULL; |
| 437 | action->dev_id = dev_id; |
| 438 | |
Ivan Kokshaysky | eee4526 | 2006-01-06 00:12:21 -0800 | [diff] [blame] | 439 | select_smp_affinity(irq); |
| 440 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 441 | retval = setup_irq(irq, action); |
| 442 | if (retval) |
| 443 | kfree(action); |
| 444 | |
| 445 | return retval; |
| 446 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 447 | EXPORT_SYMBOL(request_irq); |
| 448 | |