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