generic: add irq_desc in function in parameter
[linux-2.6.git] / kernel / irq / handle.c
1 /*
2  * linux/kernel/irq/handle.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.
8  *
9  * Detailed information is available in Documentation/DocBook/genericirq
10  *
11  */
12
13 #include <linux/irq.h>
14 #include <linux/module.h>
15 #include <linux/random.h>
16 #include <linux/interrupt.h>
17 #include <linux/kernel_stat.h>
18
19 #include "internals.h"
20
21 #ifdef CONFIG_TRACE_IRQFLAGS
22
23 /*
24  * lockdep: we want to handle all irq_desc locks as a single lock-class:
25  */
26 static struct lock_class_key irq_desc_lock_class;
27 #endif
28
29 /**
30  * handle_bad_irq - handle spurious and unhandled irqs
31  * @irq:       the interrupt number
32  * @desc:      description of the interrupt
33  *
34  * Handles spurious and unhandled IRQ's. It also prints a debugmessage.
35  */
36 void
37 handle_bad_irq(unsigned int irq, struct irq_desc *desc)
38 {
39         print_irq_desc(irq, desc);
40         kstat_irqs_this_cpu(desc)++;
41         ack_bad_irq(irq);
42 }
43
44 /*
45  * Linux has a controller-independent interrupt architecture.
46  * Every controller has a 'controller-template', that is used
47  * by the main code to do the right thing. Each driver-visible
48  * interrupt source is transparently wired to the appropriate
49  * controller. Thus drivers need not be aware of the
50  * interrupt-controller.
51  *
52  * The code is designed to be easily extended with new/different
53  * interrupt controllers, without having to do assembly magic or
54  * having to touch the generic code.
55  *
56  * Controller mappings for all interrupt sources:
57  */
58 int nr_irqs = NR_IRQS;
59 EXPORT_SYMBOL_GPL(nr_irqs);
60
61 #ifdef CONFIG_HAVE_DYN_ARRAY
62 static struct irq_desc irq_desc_init = {
63         .irq = -1U,
64         .status = IRQ_DISABLED,
65         .chip = &no_irq_chip,
66         .handle_irq = handle_bad_irq,
67         .depth = 1,
68         .lock = __SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
69 #ifdef CONFIG_SMP
70         .affinity = CPU_MASK_ALL
71 #endif
72 };
73
74
75 static void init_one_irq_desc(struct irq_desc *desc)
76 {
77         memcpy(desc, &irq_desc_init, sizeof(struct irq_desc));
78 #ifdef CONFIG_TRACE_IRQFLAGS
79         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
80 #endif
81 }
82
83 extern int after_bootmem;
84 extern void *__alloc_bootmem_nopanic(unsigned long size,
85                              unsigned long align,
86                              unsigned long goal);
87
88 static void init_kstat_irqs(struct irq_desc *desc, int nr_desc, int nr)
89 {
90         unsigned long bytes, total_bytes;
91         char *ptr;
92         int i;
93         unsigned long phys;
94
95         /* Compute how many bytes we need per irq and allocate them */
96         bytes = nr * sizeof(unsigned int);
97         total_bytes = bytes * nr_desc;
98         if (after_bootmem)
99                 ptr = kzalloc(total_bytes, GFP_ATOMIC);
100         else
101                 ptr = __alloc_bootmem_nopanic(total_bytes, PAGE_SIZE, 0);
102
103         if (!ptr)
104                 panic(" can not allocate kstat_irqs\n");
105
106         phys = __pa(ptr);
107         printk(KERN_DEBUG "kstat_irqs ==> [%#lx - %#lx]\n", phys, phys + total_bytes);
108
109         for (i = 0; i < nr_desc; i++) {
110                 desc[i].kstat_irqs = (unsigned int *)ptr;
111                 ptr += bytes;
112         }
113 }
114
115 static void __init init_work(void *data)
116 {
117         struct dyn_array *da = data;
118         int i;
119         struct  irq_desc *desc;
120
121         desc = *da->name;
122
123         for (i = 0; i < *da->nr; i++) {
124                 init_one_irq_desc(&desc[i]);
125 #ifndef CONFIG_HAVE_SPARSE_IRQ
126                 desc[i].irq = i;
127 #endif
128         }
129
130 #ifdef CONFIG_HAVE_SPARSE_IRQ
131         for (i = 1; i < *da->nr; i++)
132                 desc[i-1].next = &desc[i];
133 #endif
134
135         /* init kstat_irqs, nr_cpu_ids is ready already */
136         init_kstat_irqs(desc, *da->nr, nr_cpu_ids);
137 }
138
139 #ifdef CONFIG_HAVE_SPARSE_IRQ
140 static int nr_irq_desc = 32;
141
142 static int __init parse_nr_irq_desc(char *arg)
143 {
144         if (arg)
145                 nr_irq_desc = simple_strtoul(arg, NULL, 0);
146         return 0;
147 }
148
149 early_param("nr_irq_desc", parse_nr_irq_desc);
150
151 struct irq_desc *sparse_irqs;
152 DEFINE_DYN_ARRAY(sparse_irqs, sizeof(struct irq_desc), nr_irq_desc, PAGE_SIZE, init_work);
153
154 struct irq_desc *__irq_to_desc(unsigned int irq)
155 {
156         struct irq_desc *desc;
157
158         BUG_ON(irq == -1U);
159
160         desc = &sparse_irqs[0];
161         while (desc) {
162                 if (desc->irq == irq)
163                         return desc;
164
165                 if (desc->irq == -1U)
166                         return NULL;
167
168                 desc = desc->next;
169         }
170         return NULL;
171 }
172 struct irq_desc *irq_to_desc(unsigned int irq)
173 {
174         struct irq_desc *desc, *desc_pri;
175         int i;
176         int count = 0;
177         unsigned long phys;
178         unsigned long total_bytes;
179
180         BUG_ON(irq == -1U);
181
182         desc_pri = desc = &sparse_irqs[0];
183         while (desc) {
184                 if (desc->irq == irq)
185                         return desc;
186
187                 if (desc->irq == -1U) {
188                         desc->irq = irq;
189                         return desc;
190                 }
191                 desc_pri = desc;
192                 desc = desc->next;
193                 count++;
194         }
195
196         /*
197          *  we run out of pre-allocate ones, allocate more
198          */
199         printk(KERN_DEBUG "try to get more irq_desc %d\n", nr_irq_desc);
200         {
201                 /* double check if some one mess up the list */
202                 struct irq_desc *desc;
203                 int count = 0;
204
205                 desc = &sparse_irqs[0];
206                 while (desc) {
207                         printk(KERN_DEBUG "found irq_desc for irq %d\n", desc->irq);
208                         if (desc->next)
209                                 printk(KERN_DEBUG "found irq_desc for irq %d and next will be irq %d\n", desc->irq, desc->next->irq);
210                         desc = desc->next;
211                         count++;
212                 }
213                 printk(KERN_DEBUG "all preallocted %d\n", count);
214         }
215
216         total_bytes = sizeof(struct irq_desc) * nr_irq_desc;
217         if (after_bootmem)
218                 desc = kzalloc(total_bytes, GFP_ATOMIC);
219         else
220                 desc = __alloc_bootmem_nopanic(total_bytes, PAGE_SIZE, 0);
221
222         if (!desc)
223                 panic("please boot with nr_irq_desc= %d\n", count * 2);
224
225         phys = __pa(desc);
226         printk(KERN_DEBUG "irq_desc ==> [%#lx - %#lx]\n", phys, phys + total_bytes);
227
228         for (i = 0; i < nr_irq_desc; i++)
229                 init_one_irq_desc(&desc[i]);
230
231         for (i = 1; i < nr_irq_desc; i++)
232                 desc[i-1].next = &desc[i];
233
234         /* init kstat_irqs, nr_cpu_ids is ready already */
235         init_kstat_irqs(desc, nr_irq_desc, nr_cpu_ids);
236
237         desc->irq = irq;
238         desc_pri->next = desc;
239         {
240                 /* double check if some one mess up the list */
241                 struct irq_desc *desc;
242                 int count = 0;
243
244                 desc = &sparse_irqs[0];
245                 while (desc) {
246                         printk(KERN_DEBUG "1 found irq_desc for irq %d\n", desc->irq);
247                         if (desc->next)
248                                 printk(KERN_DEBUG "1 found irq_desc for irq %d and next will be irq %d\n", desc->irq, desc->next->irq);
249                         desc = desc->next;
250                         count++;
251                 }
252                 printk(KERN_DEBUG "1 all preallocted %d\n", count);
253         }
254
255         return desc;
256 }
257 #else
258 struct irq_desc *irq_desc;
259 DEFINE_DYN_ARRAY(irq_desc, sizeof(struct irq_desc), nr_irqs, PAGE_SIZE, init_work);
260
261 #endif
262
263 #else
264
265 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
266         [0 ... NR_IRQS-1] = {
267                 .status = IRQ_DISABLED,
268                 .chip = &no_irq_chip,
269                 .handle_irq = handle_bad_irq,
270                 .depth = 1,
271                 .lock = __SPIN_LOCK_UNLOCKED(sparse_irqs->lock),
272 #ifdef CONFIG_SMP
273                 .affinity = CPU_MASK_ALL
274 #endif
275         }
276 };
277
278 #endif
279
280 #ifndef CONFIG_HAVE_SPARSE_IRQ
281 struct irq_desc *irq_to_desc(unsigned int irq)
282 {
283         if (irq < nr_irqs)
284                 return &irq_desc[irq];
285
286         return NULL;
287 }
288 struct irq_desc *__irq_to_desc(unsigned int irq)
289 {
290         return irq_to_desc(irq);
291 }
292 #endif
293
294 /*
295  * What should we do if we get a hw irq event on an illegal vector?
296  * Each architecture has to answer this themself.
297  */
298 static void ack_bad(unsigned int irq)
299 {
300         struct irq_desc *desc;
301
302         desc = irq_to_desc(irq);
303         print_irq_desc(irq, desc);
304         ack_bad_irq(irq);
305 }
306
307 /*
308  * NOP functions
309  */
310 static void noop(unsigned int irq)
311 {
312 }
313
314 static unsigned int noop_ret(unsigned int irq)
315 {
316         return 0;
317 }
318
319 /*
320  * Generic no controller implementation
321  */
322 struct irq_chip no_irq_chip = {
323         .name           = "none",
324         .startup        = noop_ret,
325         .shutdown       = noop,
326         .enable         = noop,
327         .disable        = noop,
328         .ack            = ack_bad,
329         .end            = noop,
330 };
331
332 /*
333  * Generic dummy implementation which can be used for
334  * real dumb interrupt sources
335  */
336 struct irq_chip dummy_irq_chip = {
337         .name           = "dummy",
338         .startup        = noop_ret,
339         .shutdown       = noop,
340         .enable         = noop,
341         .disable        = noop,
342         .ack            = noop,
343         .mask           = noop,
344         .unmask         = noop,
345         .end            = noop,
346 };
347
348 /*
349  * Special, empty irq handler:
350  */
351 irqreturn_t no_action(int cpl, void *dev_id)
352 {
353         return IRQ_NONE;
354 }
355
356 /**
357  * handle_IRQ_event - irq action chain handler
358  * @irq:        the interrupt number
359  * @action:     the interrupt action chain for this irq
360  *
361  * Handles the action chain of an irq event
362  */
363 irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action)
364 {
365         irqreturn_t ret, retval = IRQ_NONE;
366         unsigned int status = 0;
367
368         if (!(action->flags & IRQF_DISABLED))
369                 local_irq_enable_in_hardirq();
370
371         do {
372                 ret = action->handler(irq, action->dev_id);
373                 if (ret == IRQ_HANDLED)
374                         status |= action->flags;
375                 retval |= ret;
376                 action = action->next;
377         } while (action);
378
379         if (status & IRQF_SAMPLE_RANDOM)
380                 add_interrupt_randomness(irq);
381         local_irq_disable();
382
383         return retval;
384 }
385
386 #ifndef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ
387 /**
388  * __do_IRQ - original all in one highlevel IRQ handler
389  * @irq:        the interrupt number
390  *
391  * __do_IRQ handles all normal device IRQ's (the special
392  * SMP cross-CPU interrupts have their own specific
393  * handlers).
394  *
395  * This is the original x86 implementation which is used for every
396  * interrupt type.
397  */
398 unsigned int __do_IRQ(unsigned int irq)
399 {
400         struct irq_desc *desc = irq_to_desc(irq);
401         struct irqaction *action;
402         unsigned int status;
403
404         kstat_irqs_this_cpu(desc)++;
405         if (CHECK_IRQ_PER_CPU(desc->status)) {
406                 irqreturn_t action_ret;
407
408                 /*
409                  * No locking required for CPU-local interrupts:
410                  */
411                 if (desc->chip->ack)
412                         desc->chip->ack(irq);
413                 if (likely(!(desc->status & IRQ_DISABLED))) {
414                         action_ret = handle_IRQ_event(irq, desc->action);
415                         if (!noirqdebug)
416                                 note_interrupt(irq, desc, action_ret);
417                 }
418                 desc->chip->end(irq);
419                 return 1;
420         }
421
422         spin_lock(&desc->lock);
423         if (desc->chip->ack)
424                 desc->chip->ack(irq);
425         /*
426          * REPLAY is when Linux resends an IRQ that was dropped earlier
427          * WAITING is used by probe to mark irqs that are being tested
428          */
429         status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING);
430         status |= IRQ_PENDING; /* we _want_ to handle it */
431
432         /*
433          * If the IRQ is disabled for whatever reason, we cannot
434          * use the action we have.
435          */
436         action = NULL;
437         if (likely(!(status & (IRQ_DISABLED | IRQ_INPROGRESS)))) {
438                 action = desc->action;
439                 status &= ~IRQ_PENDING; /* we commit to handling */
440                 status |= IRQ_INPROGRESS; /* we are handling it */
441         }
442         desc->status = status;
443
444         /*
445          * If there is no IRQ handler or it was disabled, exit early.
446          * Since we set PENDING, if another processor is handling
447          * a different instance of this same irq, the other processor
448          * will take care of it.
449          */
450         if (unlikely(!action))
451                 goto out;
452
453         /*
454          * Edge triggered interrupts need to remember
455          * pending events.
456          * This applies to any hw interrupts that allow a second
457          * instance of the same irq to arrive while we are in do_IRQ
458          * or in the handler. But the code here only handles the _second_
459          * instance of the irq, not the third or fourth. So it is mostly
460          * useful for irq hardware that does not mask cleanly in an
461          * SMP environment.
462          */
463         for (;;) {
464                 irqreturn_t action_ret;
465
466                 spin_unlock(&desc->lock);
467
468                 action_ret = handle_IRQ_event(irq, action);
469                 if (!noirqdebug)
470                         note_interrupt(irq, desc, action_ret);
471
472                 spin_lock(&desc->lock);
473                 if (likely(!(desc->status & IRQ_PENDING)))
474                         break;
475                 desc->status &= ~IRQ_PENDING;
476         }
477         desc->status &= ~IRQ_INPROGRESS;
478
479 out:
480         /*
481          * The ->end() handler has to deal with interrupts which got
482          * disabled while the handler was running.
483          */
484         desc->chip->end(irq);
485         spin_unlock(&desc->lock);
486
487         return 1;
488 }
489 #endif
490
491
492 #ifdef CONFIG_TRACE_IRQFLAGS
493 void early_init_irq_lock_class(void)
494 {
495 #ifndef CONFIG_HAVE_DYN_ARRAY
496         int i;
497
498         for (i = 0; i < nr_irqs; i++)
499                 lockdep_set_class(&irq_desc[i].lock, &irq_desc_lock_class);
500 #endif
501 }
502 #endif
503
504 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
505 {
506         struct irq_desc *desc = irq_to_desc(irq);
507         return desc->kstat_irqs[cpu];
508 }
509 EXPORT_SYMBOL(kstat_irqs_cpu);
510