x86_64: rename irq_desc/irq_desc_alloc
[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_alloc(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                         printk(KERN_DEBUG "found new irq_desc for irq %d\n", desc->irq);
190                         return desc;
191                 }
192                 desc_pri = desc;
193                 desc = desc->next;
194                 count++;
195         }
196
197         /*
198          *  we run out of pre-allocate ones, allocate more
199          */
200         printk(KERN_DEBUG "try to get more irq_desc %d\n", nr_irq_desc);
201         {
202                 /* double check if some one mess up the list */
203                 struct irq_desc *desc;
204                 int count = 0;
205
206                 desc = &sparse_irqs[0];
207                 while (desc) {
208                         printk(KERN_DEBUG "found irq_desc for irq %d\n", desc->irq);
209                         if (desc->next)
210                                 printk(KERN_DEBUG "found irq_desc for irq %d and next will be irq %d\n", desc->irq, desc->next->irq);
211                         desc = desc->next;
212                         count++;
213                 }
214                 printk(KERN_DEBUG "all preallocted %d\n", count);
215         }
216
217         total_bytes = sizeof(struct irq_desc) * nr_irq_desc;
218         if (after_bootmem)
219                 desc = kzalloc(total_bytes, GFP_ATOMIC);
220         else
221                 desc = __alloc_bootmem_nopanic(total_bytes, PAGE_SIZE, 0);
222
223         if (!desc)
224                 panic("please boot with nr_irq_desc= %d\n", count * 2);
225
226         phys = __pa(desc);
227         printk(KERN_DEBUG "irq_desc ==> [%#lx - %#lx]\n", phys, phys + total_bytes);
228
229         for (i = 0; i < nr_irq_desc; i++)
230                 init_one_irq_desc(&desc[i]);
231
232         for (i = 1; i < nr_irq_desc; i++)
233                 desc[i-1].next = &desc[i];
234
235         /* init kstat_irqs, nr_cpu_ids is ready already */
236         init_kstat_irqs(desc, nr_irq_desc, nr_cpu_ids);
237
238         desc->irq = irq;
239         desc_pri->next = desc;
240         printk(KERN_DEBUG "1 found new irq_desc for irq %d and pri will be irq %d\n", desc->irq, desc_pri->irq);
241
242         return desc;
243 }
244 #else
245 struct irq_desc *irq_desc;
246 DEFINE_DYN_ARRAY(irq_desc, sizeof(struct irq_desc), nr_irqs, PAGE_SIZE, init_work);
247
248 #endif
249
250 #else
251
252 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
253         [0 ... NR_IRQS-1] = {
254                 .status = IRQ_DISABLED,
255                 .chip = &no_irq_chip,
256                 .handle_irq = handle_bad_irq,
257                 .depth = 1,
258                 .lock = __SPIN_LOCK_UNLOCKED(sparse_irqs->lock),
259 #ifdef CONFIG_SMP
260                 .affinity = CPU_MASK_ALL
261 #endif
262         }
263 };
264
265 #endif
266
267 #ifndef CONFIG_HAVE_SPARSE_IRQ
268 struct irq_desc *irq_to_desc(unsigned int irq)
269 {
270         if (irq < nr_irqs)
271                 return &irq_desc[irq];
272
273         return NULL;
274 }
275 struct irq_desc *irq_to_desc_alloc(unsigned int irq)
276 {
277         return irq_to_desc(irq);
278 }
279 #endif
280
281 /*
282  * What should we do if we get a hw irq event on an illegal vector?
283  * Each architecture has to answer this themself.
284  */
285 static void ack_bad(unsigned int irq)
286 {
287         struct irq_desc *desc;
288
289         desc = irq_to_desc(irq);
290         print_irq_desc(irq, desc);
291         ack_bad_irq(irq);
292 }
293
294 /*
295  * NOP functions
296  */
297 static void noop(unsigned int irq)
298 {
299 }
300
301 static unsigned int noop_ret(unsigned int irq)
302 {
303         return 0;
304 }
305
306 /*
307  * Generic no controller implementation
308  */
309 struct irq_chip no_irq_chip = {
310         .name           = "none",
311         .startup        = noop_ret,
312         .shutdown       = noop,
313         .enable         = noop,
314         .disable        = noop,
315         .ack            = ack_bad,
316         .end            = noop,
317 };
318
319 /*
320  * Generic dummy implementation which can be used for
321  * real dumb interrupt sources
322  */
323 struct irq_chip dummy_irq_chip = {
324         .name           = "dummy",
325         .startup        = noop_ret,
326         .shutdown       = noop,
327         .enable         = noop,
328         .disable        = noop,
329         .ack            = noop,
330         .mask           = noop,
331         .unmask         = noop,
332         .end            = noop,
333 };
334
335 /*
336  * Special, empty irq handler:
337  */
338 irqreturn_t no_action(int cpl, void *dev_id)
339 {
340         return IRQ_NONE;
341 }
342
343 /**
344  * handle_IRQ_event - irq action chain handler
345  * @irq:        the interrupt number
346  * @action:     the interrupt action chain for this irq
347  *
348  * Handles the action chain of an irq event
349  */
350 irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action)
351 {
352         irqreturn_t ret, retval = IRQ_NONE;
353         unsigned int status = 0;
354
355         if (!(action->flags & IRQF_DISABLED))
356                 local_irq_enable_in_hardirq();
357
358         do {
359                 ret = action->handler(irq, action->dev_id);
360                 if (ret == IRQ_HANDLED)
361                         status |= action->flags;
362                 retval |= ret;
363                 action = action->next;
364         } while (action);
365
366         if (status & IRQF_SAMPLE_RANDOM)
367                 add_interrupt_randomness(irq);
368         local_irq_disable();
369
370         return retval;
371 }
372
373 #ifndef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ
374 /**
375  * __do_IRQ - original all in one highlevel IRQ handler
376  * @irq:        the interrupt number
377  *
378  * __do_IRQ handles all normal device IRQ's (the special
379  * SMP cross-CPU interrupts have their own specific
380  * handlers).
381  *
382  * This is the original x86 implementation which is used for every
383  * interrupt type.
384  */
385 unsigned int __do_IRQ(unsigned int irq)
386 {
387         struct irq_desc *desc = irq_to_desc(irq);
388         struct irqaction *action;
389         unsigned int status;
390
391         kstat_irqs_this_cpu(desc)++;
392         if (CHECK_IRQ_PER_CPU(desc->status)) {
393                 irqreturn_t action_ret;
394
395                 /*
396                  * No locking required for CPU-local interrupts:
397                  */
398                 if (desc->chip->ack)
399                         desc->chip->ack(irq);
400                 if (likely(!(desc->status & IRQ_DISABLED))) {
401                         action_ret = handle_IRQ_event(irq, desc->action);
402                         if (!noirqdebug)
403                                 note_interrupt(irq, desc, action_ret);
404                 }
405                 desc->chip->end(irq);
406                 return 1;
407         }
408
409         spin_lock(&desc->lock);
410         if (desc->chip->ack)
411                 desc->chip->ack(irq);
412         /*
413          * REPLAY is when Linux resends an IRQ that was dropped earlier
414          * WAITING is used by probe to mark irqs that are being tested
415          */
416         status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING);
417         status |= IRQ_PENDING; /* we _want_ to handle it */
418
419         /*
420          * If the IRQ is disabled for whatever reason, we cannot
421          * use the action we have.
422          */
423         action = NULL;
424         if (likely(!(status & (IRQ_DISABLED | IRQ_INPROGRESS)))) {
425                 action = desc->action;
426                 status &= ~IRQ_PENDING; /* we commit to handling */
427                 status |= IRQ_INPROGRESS; /* we are handling it */
428         }
429         desc->status = status;
430
431         /*
432          * If there is no IRQ handler or it was disabled, exit early.
433          * Since we set PENDING, if another processor is handling
434          * a different instance of this same irq, the other processor
435          * will take care of it.
436          */
437         if (unlikely(!action))
438                 goto out;
439
440         /*
441          * Edge triggered interrupts need to remember
442          * pending events.
443          * This applies to any hw interrupts that allow a second
444          * instance of the same irq to arrive while we are in do_IRQ
445          * or in the handler. But the code here only handles the _second_
446          * instance of the irq, not the third or fourth. So it is mostly
447          * useful for irq hardware that does not mask cleanly in an
448          * SMP environment.
449          */
450         for (;;) {
451                 irqreturn_t action_ret;
452
453                 spin_unlock(&desc->lock);
454
455                 action_ret = handle_IRQ_event(irq, action);
456                 if (!noirqdebug)
457                         note_interrupt(irq, desc, action_ret);
458
459                 spin_lock(&desc->lock);
460                 if (likely(!(desc->status & IRQ_PENDING)))
461                         break;
462                 desc->status &= ~IRQ_PENDING;
463         }
464         desc->status &= ~IRQ_INPROGRESS;
465
466 out:
467         /*
468          * The ->end() handler has to deal with interrupts which got
469          * disabled while the handler was running.
470          */
471         desc->chip->end(irq);
472         spin_unlock(&desc->lock);
473
474         return 1;
475 }
476 #endif
477
478
479 #ifdef CONFIG_TRACE_IRQFLAGS
480 void early_init_irq_lock_class(void)
481 {
482 #ifndef CONFIG_HAVE_DYN_ARRAY
483         int i;
484
485         for (i = 0; i < nr_irqs; i++)
486                 lockdep_set_class(&irq_desc[i].lock, &irq_desc_lock_class);
487 #endif
488 }
489 #endif
490
491 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
492 {
493         struct irq_desc *desc = irq_to_desc(irq);
494         return desc->kstat_irqs[cpu];
495 }
496 EXPORT_SYMBOL(kstat_irqs_cpu);
497