ia64/linux-2.6.18-xen.hg

view kernel/irq/chip.c @ 912:dd42cdb0ab89

[IA64] Build blktap2 driver by default in x86 builds.

add CONFIG_XEN_BLKDEV_TAP2=y to buildconfigs/linux-defconfig_xen_ia64.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
author Isaku Yamahata <yamahata@valinux.co.jp>
date Mon Jun 29 12:09:16 2009 +0900 (2009-06-29)
parents 831230e53067
children
line source
1 /*
2 * linux/kernel/irq/chip.c
3 *
4 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
5 * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
6 *
7 * This file contains the core interrupt handling code, for irq-chip
8 * based architectures.
9 *
10 * Detailed information is available in Documentation/DocBook/genericirq
11 */
13 #include <linux/irq.h>
14 #include <linux/module.h>
15 #include <linux/interrupt.h>
16 #include <linux/kernel_stat.h>
18 #include "internals.h"
20 /**
21 * set_irq_chip - set the irq chip for an irq
22 * @irq: irq number
23 * @chip: pointer to irq chip description structure
24 */
25 int set_irq_chip(unsigned int irq, struct irq_chip *chip)
26 {
27 struct irq_desc *desc;
28 unsigned long flags;
30 if (irq >= NR_IRQS) {
31 printk(KERN_ERR "Trying to install chip for IRQ%d\n", irq);
32 WARN_ON(1);
33 return -EINVAL;
34 }
36 if (!chip)
37 chip = &no_irq_chip;
39 desc = irq_desc + irq;
40 spin_lock_irqsave(&desc->lock, flags);
41 irq_chip_set_defaults(chip);
42 desc->chip = chip;
43 /*
44 * For compatibility only:
45 */
46 desc->chip = chip;
47 spin_unlock_irqrestore(&desc->lock, flags);
49 return 0;
50 }
51 EXPORT_SYMBOL(set_irq_chip);
53 /**
54 * set_irq_type - set the irq type for an irq
55 * @irq: irq number
56 * @type: interrupt type - see include/linux/interrupt.h
57 */
58 int set_irq_type(unsigned int irq, unsigned int type)
59 {
60 struct irq_desc *desc;
61 unsigned long flags;
62 int ret = -ENXIO;
64 if (irq >= NR_IRQS) {
65 printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq);
66 return -ENODEV;
67 }
69 desc = irq_desc + irq;
70 if (desc->chip->set_type) {
71 spin_lock_irqsave(&desc->lock, flags);
72 ret = desc->chip->set_type(irq, type);
73 spin_unlock_irqrestore(&desc->lock, flags);
74 }
75 return ret;
76 }
77 EXPORT_SYMBOL(set_irq_type);
79 /**
80 * set_irq_data - set irq type data for an irq
81 * @irq: Interrupt number
82 * @data: Pointer to interrupt specific data
83 *
84 * Set the hardware irq controller data for an irq
85 */
86 int set_irq_data(unsigned int irq, void *data)
87 {
88 struct irq_desc *desc;
89 unsigned long flags;
91 if (irq >= NR_IRQS) {
92 printk(KERN_ERR
93 "Trying to install controller data for IRQ%d\n", irq);
94 return -EINVAL;
95 }
97 desc = irq_desc + irq;
98 spin_lock_irqsave(&desc->lock, flags);
99 desc->handler_data = data;
100 spin_unlock_irqrestore(&desc->lock, flags);
101 return 0;
102 }
103 EXPORT_SYMBOL(set_irq_data);
105 /**
106 * set_irq_chip_data - set irq chip data for an irq
107 * @irq: Interrupt number
108 * @data: Pointer to chip specific data
109 *
110 * Set the hardware irq chip data for an irq
111 */
112 int set_irq_chip_data(unsigned int irq, void *data)
113 {
114 struct irq_desc *desc = irq_desc + irq;
115 unsigned long flags;
117 if (irq >= NR_IRQS || !desc->chip) {
118 printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq);
119 return -EINVAL;
120 }
122 spin_lock_irqsave(&desc->lock, flags);
123 desc->chip_data = data;
124 spin_unlock_irqrestore(&desc->lock, flags);
126 return 0;
127 }
128 EXPORT_SYMBOL(set_irq_chip_data);
130 /*
131 * default enable function
132 */
133 static void default_enable(unsigned int irq)
134 {
135 struct irq_desc *desc = irq_desc + irq;
137 desc->chip->unmask(irq);
138 desc->status &= ~IRQ_MASKED;
139 }
141 /*
142 * default disable function
143 */
144 static void default_disable(unsigned int irq)
145 {
146 struct irq_desc *desc = irq_desc + irq;
148 if (!(desc->status & IRQ_DELAYED_DISABLE))
149 irq_desc[irq].chip->mask(irq);
150 }
152 /*
153 * default startup function
154 */
155 static unsigned int default_startup(unsigned int irq)
156 {
157 irq_desc[irq].chip->enable(irq);
159 return 0;
160 }
162 /*
163 * Fixup enable/disable function pointers
164 */
165 void irq_chip_set_defaults(struct irq_chip *chip)
166 {
167 if (!chip->enable)
168 chip->enable = default_enable;
169 if (!chip->disable)
170 chip->disable = default_disable;
171 if (!chip->startup)
172 chip->startup = default_startup;
173 if (!chip->shutdown)
174 chip->shutdown = chip->disable;
175 if (!chip->name)
176 chip->name = chip->typename;
177 }
179 static inline void mask_ack_irq(struct irq_desc *desc, int irq)
180 {
181 if (desc->chip->mask_ack)
182 desc->chip->mask_ack(irq);
183 else {
184 desc->chip->mask(irq);
185 desc->chip->ack(irq);
186 }
187 }
189 /**
190 * handle_simple_irq - Simple and software-decoded IRQs.
191 * @irq: the interrupt number
192 * @desc: the interrupt description structure for this irq
193 * @regs: pointer to a register structure
194 *
195 * Simple interrupts are either sent from a demultiplexing interrupt
196 * handler or come from hardware, where no interrupt hardware control
197 * is necessary.
198 *
199 * Note: The caller is expected to handle the ack, clear, mask and
200 * unmask issues if necessary.
201 */
202 void fastcall
203 handle_simple_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs)
204 {
205 struct irqaction *action;
206 irqreturn_t action_ret;
207 const unsigned int cpu = smp_processor_id();
209 spin_lock(&desc->lock);
211 if (unlikely(desc->status & IRQ_INPROGRESS))
212 goto out_unlock;
213 desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
214 kstat_cpu(cpu).irqs[irq]++;
216 action = desc->action;
217 if (unlikely(!action || (desc->status & IRQ_DISABLED)))
218 goto out_unlock;
220 desc->status |= IRQ_INPROGRESS;
221 spin_unlock(&desc->lock);
223 action_ret = handle_IRQ_event(irq, regs, action);
224 if (!noirqdebug)
225 note_interrupt(irq, desc, action_ret, regs);
227 spin_lock(&desc->lock);
228 desc->status &= ~IRQ_INPROGRESS;
229 out_unlock:
230 spin_unlock(&desc->lock);
231 }
233 /**
234 * handle_level_irq - Level type irq handler
235 * @irq: the interrupt number
236 * @desc: the interrupt description structure for this irq
237 * @regs: pointer to a register structure
238 *
239 * Level type interrupts are active as long as the hardware line has
240 * the active level. This may require to mask the interrupt and unmask
241 * it after the associated handler has acknowledged the device, so the
242 * interrupt line is back to inactive.
243 */
244 void fastcall
245 handle_level_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs)
246 {
247 unsigned int cpu = smp_processor_id();
248 struct irqaction *action;
249 irqreturn_t action_ret;
251 spin_lock(&desc->lock);
252 mask_ack_irq(desc, irq);
254 if (unlikely(desc->status & IRQ_INPROGRESS))
255 goto out_unlock;
256 desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
257 kstat_cpu(cpu).irqs[irq]++;
259 /*
260 * If its disabled or no action available
261 * keep it masked and get out of here
262 */
263 action = desc->action;
264 if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
265 desc->status |= IRQ_PENDING;
266 goto out_unlock;
267 }
269 desc->status |= IRQ_INPROGRESS;
270 desc->status &= ~IRQ_PENDING;
271 spin_unlock(&desc->lock);
273 action_ret = handle_IRQ_event(irq, regs, action);
274 if (!noirqdebug)
275 note_interrupt(irq, desc, action_ret, regs);
277 spin_lock(&desc->lock);
278 desc->status &= ~IRQ_INPROGRESS;
279 if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
280 desc->chip->unmask(irq);
281 out_unlock:
282 spin_unlock(&desc->lock);
283 }
285 /**
286 * handle_fasteoi_irq - irq handler for transparent controllers
287 * @irq: the interrupt number
288 * @desc: the interrupt description structure for this irq
289 * @regs: pointer to a register structure
290 *
291 * Only a single callback will be issued to the chip: an ->eoi()
292 * call when the interrupt has been serviced. This enables support
293 * for modern forms of interrupt handlers, which handle the flow
294 * details in hardware, transparently.
295 */
296 void fastcall
297 handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc,
298 struct pt_regs *regs)
299 {
300 unsigned int cpu = smp_processor_id();
301 struct irqaction *action;
302 irqreturn_t action_ret;
304 spin_lock(&desc->lock);
306 if (unlikely(desc->status & IRQ_INPROGRESS))
307 goto out;
309 desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
310 kstat_cpu(cpu).irqs[irq]++;
312 /*
313 * If its disabled or no action available
314 * keep it masked and get out of here
315 */
316 action = desc->action;
317 if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
318 desc->status |= IRQ_PENDING;
319 goto out;
320 }
322 desc->status |= IRQ_INPROGRESS;
323 desc->status &= ~IRQ_PENDING;
324 spin_unlock(&desc->lock);
326 action_ret = handle_IRQ_event(irq, regs, action);
327 if (!noirqdebug)
328 note_interrupt(irq, desc, action_ret, regs);
330 spin_lock(&desc->lock);
331 desc->status &= ~IRQ_INPROGRESS;
332 out:
333 desc->chip->eoi(irq);
335 spin_unlock(&desc->lock);
336 }
338 /**
339 * handle_edge_irq - edge type IRQ handler
340 * @irq: the interrupt number
341 * @desc: the interrupt description structure for this irq
342 * @regs: pointer to a register structure
343 *
344 * Interrupt occures on the falling and/or rising edge of a hardware
345 * signal. The occurence is latched into the irq controller hardware
346 * and must be acked in order to be reenabled. After the ack another
347 * interrupt can happen on the same source even before the first one
348 * is handled by the assosiacted event handler. If this happens it
349 * might be necessary to disable (mask) the interrupt depending on the
350 * controller hardware. This requires to reenable the interrupt inside
351 * of the loop which handles the interrupts which have arrived while
352 * the handler was running. If all pending interrupts are handled, the
353 * loop is left.
354 */
355 void fastcall
356 handle_edge_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs)
357 {
358 const unsigned int cpu = smp_processor_id();
360 spin_lock(&desc->lock);
362 desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
364 /*
365 * If we're currently running this IRQ, or its disabled,
366 * we shouldn't process the IRQ. Mark it pending, handle
367 * the necessary masking and go out
368 */
369 if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
370 !desc->action)) {
371 desc->status |= (IRQ_PENDING | IRQ_MASKED);
372 mask_ack_irq(desc, irq);
373 goto out_unlock;
374 }
376 kstat_cpu(cpu).irqs[irq]++;
378 /* Start handling the irq */
379 desc->chip->ack(irq);
381 /* Mark the IRQ currently in progress.*/
382 desc->status |= IRQ_INPROGRESS;
384 do {
385 struct irqaction *action = desc->action;
386 irqreturn_t action_ret;
388 if (unlikely(!action)) {
389 desc->chip->mask(irq);
390 goto out_unlock;
391 }
393 /*
394 * When another irq arrived while we were handling
395 * one, we could have masked the irq.
396 * Renable it, if it was not disabled in meantime.
397 */
398 if (unlikely((desc->status &
399 (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
400 (IRQ_PENDING | IRQ_MASKED))) {
401 desc->chip->unmask(irq);
402 desc->status &= ~IRQ_MASKED;
403 }
405 desc->status &= ~IRQ_PENDING;
406 spin_unlock(&desc->lock);
407 action_ret = handle_IRQ_event(irq, regs, action);
408 if (!noirqdebug)
409 note_interrupt(irq, desc, action_ret, regs);
410 spin_lock(&desc->lock);
412 } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
414 desc->status &= ~IRQ_INPROGRESS;
415 out_unlock:
416 spin_unlock(&desc->lock);
417 }
419 #ifdef CONFIG_SMP
420 /**
421 * handle_percpu_IRQ - Per CPU local irq handler
422 * @irq: the interrupt number
423 * @desc: the interrupt description structure for this irq
424 * @regs: pointer to a register structure
425 *
426 * Per CPU interrupts on SMP machines without locking requirements
427 */
428 void fastcall
429 handle_percpu_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs)
430 {
431 irqreturn_t action_ret;
433 kstat_this_cpu.irqs[irq]++;
435 if (desc->chip->ack)
436 desc->chip->ack(irq);
438 action_ret = handle_IRQ_event(irq, regs, desc->action);
439 if (!noirqdebug)
440 note_interrupt(irq, desc, action_ret, regs);
442 if (desc->chip->eoi)
443 desc->chip->eoi(irq);
444 }
446 #endif /* CONFIG_SMP */
448 void
449 __set_irq_handler(unsigned int irq,
450 void fastcall (*handle)(unsigned int, irq_desc_t *,
451 struct pt_regs *),
452 int is_chained)
453 {
454 struct irq_desc *desc;
455 unsigned long flags;
457 if (irq >= NR_IRQS) {
458 printk(KERN_ERR
459 "Trying to install type control for IRQ%d\n", irq);
460 return;
461 }
463 desc = irq_desc + irq;
465 if (!handle)
466 handle = handle_bad_irq;
468 if (desc->chip == &no_irq_chip) {
469 printk(KERN_WARNING "Trying to install %sinterrupt handler "
470 "for IRQ%d\n", is_chained ? "chained " : " ", irq);
471 /*
472 * Some ARM implementations install a handler for really dumb
473 * interrupt hardware without setting an irq_chip. This worked
474 * with the ARM no_irq_chip but the check in setup_irq would
475 * prevent us to setup the interrupt at all. Switch it to
476 * dummy_irq_chip for easy transition.
477 */
478 desc->chip = &dummy_irq_chip;
479 }
481 spin_lock_irqsave(&desc->lock, flags);
483 /* Uninstall? */
484 if (handle == handle_bad_irq) {
485 if (desc->chip != &no_irq_chip) {
486 desc->chip->mask(irq);
487 desc->chip->ack(irq);
488 }
489 desc->status |= IRQ_DISABLED;
490 desc->depth = 1;
491 }
492 desc->handle_irq = handle;
494 if (handle != handle_bad_irq && is_chained) {
495 desc->status &= ~IRQ_DISABLED;
496 desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
497 desc->depth = 0;
498 desc->chip->unmask(irq);
499 }
500 spin_unlock_irqrestore(&desc->lock, flags);
501 }
503 void
504 set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
505 void fastcall (*handle)(unsigned int,
506 struct irq_desc *,
507 struct pt_regs *))
508 {
509 set_irq_chip(irq, chip);
510 __set_irq_handler(irq, handle, 0);
511 }
513 /*
514 * Get a descriptive string for the highlevel handler, for
515 * /proc/interrupts output:
516 */
517 const char *
518 handle_irq_name(void fastcall (*handle)(unsigned int, struct irq_desc *,
519 struct pt_regs *))
520 {
521 if (handle == handle_level_irq)
522 return "level ";
523 if (handle == handle_fasteoi_irq)
524 return "fasteoi";
525 if (handle == handle_edge_irq)
526 return "edge ";
527 if (handle == handle_simple_irq)
528 return "simple ";
529 #ifdef CONFIG_SMP
530 if (handle == handle_percpu_irq)
531 return "percpu ";
532 #endif
533 if (handle == handle_bad_irq)
534 return "bad ";
536 return NULL;
537 }