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