irq: add irq_desc_without_new
[linux-2.6] / 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         total_bytes = sizeof(struct irq_desc) * nr_irq_desc;
202         if (after_bootmem)
203                 desc = kzalloc(total_bytes, GFP_ATOMIC);
204         else
205                 desc = __alloc_bootmem_nopanic(total_bytes, PAGE_SIZE, 0);
206
207         if (!desc)
208                 panic("please boot with nr_irq_desc= %d\n", count * 2);
209
210         phys = __pa(desc);
211         printk(KERN_DEBUG "irq_desc ==> [%#lx - %#lx]\n", phys, phys + total_bytes);
212
213         for (i = 0; i < nr_irq_desc; i++)
214                 init_one_irq_desc(&desc[i]);
215
216         for (i = 1; i < nr_irq_desc; i++)
217                 desc[i-1].next = &desc[i];
218
219         /* init kstat_irqs, nr_cpu_ids is ready already */
220         init_kstat_irqs(desc, nr_irq_desc, nr_cpu_ids);
221
222         desc->irq = irq;
223         desc_pri->next = desc;
224
225         return desc;
226 }
227 #else
228 struct irq_desc *irq_desc;
229 DEFINE_DYN_ARRAY(irq_desc, sizeof(struct irq_desc), nr_irqs, PAGE_SIZE, init_work);
230
231 #endif
232
233 #else
234
235 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
236         [0 ... NR_IRQS-1] = {
237                 .status = IRQ_DISABLED,
238                 .chip = &no_irq_chip,
239                 .handle_irq = handle_bad_irq,
240                 .depth = 1,
241                 .lock = __SPIN_LOCK_UNLOCKED(sparse_irqs->lock),
242 #ifdef CONFIG_SMP
243                 .affinity = CPU_MASK_ALL
244 #endif
245         }
246 };
247
248 #endif
249
250 #ifndef CONFIG_HAVE_SPARSE_IRQ
251 struct irq_desc *irq_to_desc(unsigned int irq)
252 {
253         if (irq < nr_irqs)
254                 return &irq_desc[irq];
255
256         return NULL;
257 }
258 struct irq_desc *__irq_to_desc(unsigned int irq)
259 {
260         return irq_to_desc(irq);
261 }
262 #endif
263
264 /*
265  * What should we do if we get a hw irq event on an illegal vector?
266  * Each architecture has to answer this themself.
267  */
268 static void ack_bad(unsigned int irq)
269 {
270         struct irq_desc *desc;
271
272         desc = irq_to_desc(irq);
273         print_irq_desc(irq, desc);
274         ack_bad_irq(irq);
275 }
276
277 /*
278  * NOP functions
279  */
280 static void noop(unsigned int irq)
281 {
282 }
283
284 static unsigned int noop_ret(unsigned int irq)
285 {
286         return 0;
287 }
288
289 /*
290  * Generic no controller implementation
291  */
292 struct irq_chip no_irq_chip = {
293         .name           = "none",
294         .startup        = noop_ret,
295         .shutdown       = noop,
296         .enable         = noop,
297         .disable        = noop,
298         .ack            = ack_bad,
299         .end            = noop,
300 };
301
302 /*
303  * Generic dummy implementation which can be used for
304  * real dumb interrupt sources
305  */
306 struct irq_chip dummy_irq_chip = {
307         .name           = "dummy",
308         .startup        = noop_ret,
309         .shutdown       = noop,
310         .enable         = noop,
311         .disable        = noop,
312         .ack            = noop,
313         .mask           = noop,
314         .unmask         = noop,
315         .end            = noop,
316 };
317
318 /*
319  * Special, empty irq handler:
320  */
321 irqreturn_t no_action(int cpl, void *dev_id)
322 {
323         return IRQ_NONE;
324 }
325
326 /**
327  * handle_IRQ_event - irq action chain handler
328  * @irq:        the interrupt number
329  * @action:     the interrupt action chain for this irq
330  *
331  * Handles the action chain of an irq event
332  */
333 irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action)
334 {
335         irqreturn_t ret, retval = IRQ_NONE;
336         unsigned int status = 0;
337
338         if (!(action->flags & IRQF_DISABLED))
339                 local_irq_enable_in_hardirq();
340
341         do {
342                 ret = action->handler(irq, action->dev_id);
343                 if (ret == IRQ_HANDLED)
344                         status |= action->flags;
345                 retval |= ret;
346                 action = action->next;
347         } while (action);
348
349         if (status & IRQF_SAMPLE_RANDOM)
350                 add_interrupt_randomness(irq);
351         local_irq_disable();
352
353         return retval;
354 }
355
356 #ifndef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ
357 /**
358  * __do_IRQ - original all in one highlevel IRQ handler
359  * @irq:        the interrupt number
360  *
361  * __do_IRQ handles all normal device IRQ's (the special
362  * SMP cross-CPU interrupts have their own specific
363  * handlers).
364  *
365  * This is the original x86 implementation which is used for every
366  * interrupt type.
367  */
368 unsigned int __do_IRQ(unsigned int irq)
369 {
370         struct irq_desc *desc = irq_to_desc(irq);
371         struct irqaction *action;
372         unsigned int status;
373
374         kstat_irqs_this_cpu(desc)++;
375         if (CHECK_IRQ_PER_CPU(desc->status)) {
376                 irqreturn_t action_ret;
377
378                 /*
379                  * No locking required for CPU-local interrupts:
380                  */
381                 if (desc->chip->ack)
382                         desc->chip->ack(irq);
383                 if (likely(!(desc->status & IRQ_DISABLED))) {
384                         action_ret = handle_IRQ_event(irq, desc->action);
385                         if (!noirqdebug)
386                                 note_interrupt(irq, desc, action_ret);
387                 }
388                 desc->chip->end(irq);
389                 return 1;
390         }
391
392         spin_lock(&desc->lock);
393         if (desc->chip->ack)
394                 desc->chip->ack(irq);
395         /*
396          * REPLAY is when Linux resends an IRQ that was dropped earlier
397          * WAITING is used by probe to mark irqs that are being tested
398          */
399         status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING);
400         status |= IRQ_PENDING; /* we _want_ to handle it */
401
402         /*
403          * If the IRQ is disabled for whatever reason, we cannot
404          * use the action we have.
405          */
406         action = NULL;
407         if (likely(!(status & (IRQ_DISABLED | IRQ_INPROGRESS)))) {
408                 action = desc->action;
409                 status &= ~IRQ_PENDING; /* we commit to handling */
410                 status |= IRQ_INPROGRESS; /* we are handling it */
411         }
412         desc->status = status;
413
414         /*
415          * If there is no IRQ handler or it was disabled, exit early.
416          * Since we set PENDING, if another processor is handling
417          * a different instance of this same irq, the other processor
418          * will take care of it.
419          */
420         if (unlikely(!action))
421                 goto out;
422
423         /*
424          * Edge triggered interrupts need to remember
425          * pending events.
426          * This applies to any hw interrupts that allow a second
427          * instance of the same irq to arrive while we are in do_IRQ
428          * or in the handler. But the code here only handles the _second_
429          * instance of the irq, not the third or fourth. So it is mostly
430          * useful for irq hardware that does not mask cleanly in an
431          * SMP environment.
432          */
433         for (;;) {
434                 irqreturn_t action_ret;
435
436                 spin_unlock(&desc->lock);
437
438                 action_ret = handle_IRQ_event(irq, action);
439                 if (!noirqdebug)
440                         note_interrupt(irq, desc, action_ret);
441
442                 spin_lock(&desc->lock);
443                 if (likely(!(desc->status & IRQ_PENDING)))
444                         break;
445                 desc->status &= ~IRQ_PENDING;
446         }
447         desc->status &= ~IRQ_INPROGRESS;
448
449 out:
450         /*
451          * The ->end() handler has to deal with interrupts which got
452          * disabled while the handler was running.
453          */
454         desc->chip->end(irq);
455         spin_unlock(&desc->lock);
456
457         return 1;
458 }
459 #endif
460
461
462 #ifdef CONFIG_TRACE_IRQFLAGS
463 void early_init_irq_lock_class(void)
464 {
465 #ifndef CONFIG_HAVE_DYN_ARRAY
466         int i;
467
468         for (i = 0; i < nr_irqs; i++)
469                 lockdep_set_class(&irq_desc[i].lock, &irq_desc_lock_class);
470 #endif
471 }
472 #endif
473
474 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
475 {
476         struct irq_desc *desc = irq_to_desc(irq);
477         return desc->kstat_irqs[cpu];
478 }
479 EXPORT_SYMBOL(kstat_irqs_cpu);
480