aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/interrupt.h
blob: ff374ceface08d55c889c5698cdf6bcfda753655 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
/* interrupt.h */
#ifndef _LINUX_INTERRUPT_H
#define _LINUX_INTERRUPT_H

#include <linux/kernel.h>
#include <linux/linkage.h>
#include <linux/bitops.h>
#include <linux/preempt.h>
#include <linux/cpumask.h>
#include <linux/irqreturn.h>
#include <linux/irqnr.h>
#include <linux/hardirq.h>
#include <linux/sched.h>
#include <linux/irqflags.h>
#include <linux/smp.h>
#include <linux/percpu.h>

#include <asm/atomic.h>
#include <asm/ptrace.h>
#include <asm/system.h>

/*
 * These correspond to the IORESOURCE_IRQ_* defines in
 * linux/ioport.h to select the interrupt line behaviour.  When
 * requesting an interrupt without specifying a IRQF_TRIGGER, the
 * setting should be assumed to be "as already configured", which
 * may be as per machine or firmware initialisation.
 */
#define IRQF_TRIGGER_NONE	0x00000000
#define IRQF_TRIGGER_RISING	0x00000001
#define IRQF_TRIGGER_FALLING	0x00000002
#define IRQF_TRIGGER_HIGH	0x00000004
#define IRQF_TRIGGER_LOW	0x00000008
#define IRQF_TRIGGER_MASK	(IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \
				 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)
#define IRQF_TRIGGER_PROBE	0x00000010

/*
 * These flags used only by the kernel as part of the
 * irq handling routines.
 *
 * IRQF_DISABLED - keep irqs disabled when calling the action handler
 * IRQF_SAMPLE_RANDOM - irq is used to feed the random generator
 * IRQF_SHARED - allow sharing the irq among several devices
 * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
 * IRQF_TIMER - Flag to mark this interrupt as timer interrupt
 * IRQF_PERCPU - Interrupt is per cpu
 * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing
 * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is
 *                registered first in an shared interrupt is considered for
 *                performance reasons)
 */
#define IRQF_DISABLED		0x00000020
#define IRQF_SAMPLE_RANDOM	0x00000040
#define IRQF_SHARED		0x00000080
#define IRQF_PROBE_SHARED	0x00000100
#define IRQF_TIMER		0x00000200
#define IRQF_PERCPU		0x00000400
#define IRQF_NOBALANCING	0x00000800
#define IRQF_IRQPOLL		0x00001000

/*
 * Bits used by threaded handlers:
 * IRQTF_RUNTHREAD - signals that the interrupt handler thread should run
 * IRQTF_DIED      - handler thread died
 * IRQTF_WARNED    - warning "IRQ_WAKE_THREAD w/o thread_fn" has been printed
 */
enum {
	IRQTF_RUNTHREAD,
	IRQTF_DIED,
	IRQTF_WARNED,
};

typedef irqreturn_t (*irq_handler_t)(int, void *);

/**
 * struct irqaction - per interrupt action descriptor
 * @handler:	interrupt handler function
 * @flags:	flags (see IRQF_* above)
 * @mask:	no comment as it is useless and about to be removed
 * @name:	name of the device
 * @dev_id:	cookie to identify the device
 * @next:	pointer to the next irqaction for shared interrupts
 * @irq:	interrupt number
 * @dir:	pointer to the proc/irq/NN/name entry
 * @thread_fn:	interupt handler function for threaded interrupts
 * @thread:	thread pointer for threaded interrupts
 * @thread_flags:	flags related to @thread
 */
struct irqaction {
	irq_handler_t handler;
	unsigned long flags;
	cpumask_t mask;
	const char *name;
	void *dev_id;
	struct irqaction *next;
	int irq;
	struct proc_dir_entry *dir;
	irq_handler_t thread_fn;
	struct task_struct *thread;
	unsigned long thread_flags;
};

extern irqreturn_t no_action(int cpl, void *dev_id);

#ifdef CONFIG_GENERIC_HARDIRQS
extern int __must_check
request_threaded_irq(unsigned int irq, irq_handler_t handler,
		     irq_handler_t thread_fn,
		     unsigned long flags, const char *name, void *dev);

static inline int __must_check
request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
	    const char *name, void *dev)
{
	return request_threaded_irq(irq, handler, NULL, flags, name, dev);
}

extern void exit_irq_thread(void);
#else

extern int __must_check
request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
	    const char *name, void *dev);

/*
 * Special function to avoid ifdeffery in kernel/irq/devres.c which
 * gets magically built by GENERIC_HARDIRQS=n architectures (sparc,
 * m68k). I really love these $@%#!* obvious Makefile references:
 * ../../../kernel/irq/devres.o
 */
static inline int __must_check
request_threaded_irq(unsigned int irq, irq_handler_t handler,
		     irq_handler_t thread_fn,
		     unsigned long flags, const char *name, void *dev)
{
	return request_irq(irq, handler, flags, name, dev);
}

static inline void exit_irq_thread(void) { }
#endif

extern void free_irq(unsigned int, void *);

struct device;

extern int __must_check
devm_request_threaded_irq(struct device *dev, unsigned int irq,
			  irq_handler_t handler, irq_handler_t thread_fn,
			  unsigned long irqflags, const char *devname,
			  void *dev_id);

static inline int __must_check
devm_request_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
		 unsigned long irqflags, const char *devname, void *dev_id)
{
	return devm_request_threaded_irq(dev, irq, handler, NULL, irqflags,
					 devname, dev_id);
}

extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);

/*
 * On lockdep we dont want to enable hardirqs in hardirq
 * context. Use local_irq_enable_in_hardirq() to annotate
 * kernel code that has to do this nevertheless (pretty much
 * the only valid case is for old/broken hardware that is
 * insanely slow).
 *
 * NOTE: in theory this might break fragile code that relies
 * on hardirq delivery - in practice we dont seem to have such
 * places left. So the only effect should be slightly increased
 * irqs-off latencies.
 */
#ifdef CONFIG_LOCKDEP
# define local_irq_enable_in_hardirq()	do { } while (0)
#else
# define local_irq_enable_in_hardirq()	local_irq_enable()
#endif

extern void disable_irq_nosync(unsigned int irq);
extern void disable_irq(unsigned int irq);
extern void enable_irq(unsigned int irq);

/* The following three functions are for the core kernel use only. */
extern void suspend_device_irqs(void);
extern void resume_device_irqs(void);
#ifdef CONFIG_PM_SLEEP
extern int check_wakeup_irqs(void);
#else
static inline int check_wakeup_irqs(void) { return 0; }
#endif

#if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)

extern cpumask_var_t irq_default_affinity;

extern int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask);
extern int irq_can_set_affinity(unsigned int irq);
extern int irq_select_affinity(unsigned int irq);

#else /* CONFIG_SMP */

static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
{
	return -EINVAL;
}

static inline int irq_can_set_affinity(unsigned int irq)
{
	return 0;
}

static inline int irq_select_affinity(unsigned int irq)  { return 0; }

#endif /* CONFIG_SMP && CONFIG_GENERIC_HARDIRQS */

#ifdef CONFIG_GENERIC_HARDIRQS
/*
 * Special lockdep variants of irq disabling/enabling.
 * These should be used for locking constructs that
 * know that a particular irq context which is disabled,
 * and which is the only irq-context user of a lock,
 * that it's safe to take the lock in the irq-disabled
 * section without disabling hardirqs.
 *
 * On !CONFIG_LOCKDEP they are equivalent to the normal
 * irq disable/enable methods.
 */
static inline void disable_irq_nosync_lockdep(unsigned int irq)
{
	disable_irq_nosync(irq);
#ifdef CONFIG_LOCKDEP
	local_irq_disable();
#endif
}

static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
{
	disable_irq_nosync(irq);
#ifdef CONFIG_LOCKDEP
	local_irq_save(*flags);
#endif
}

static inline void disable_irq_lockdep(unsigned int irq)
{
	disable_irq(irq);
#ifdef CONFIG_LOCKDEP
	local_irq_disable();
#endif
}

static inline void enable_irq_lockdep(unsigned int irq)
{
#ifdef CONFIG_LOCKDEP
	local_irq_enable();
#endif
	enable_irq(irq);
}

static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
{
#ifdef CONFIG_LOCKDEP
	local_irq_restore(*flags);
#endif
	enable_irq(irq);
}

/* IRQ wakeup (PM) control: */
extern int set_irq_wake(unsigned int irq, unsigned int on);

static inline int enable_irq_wake(unsigned int irq)
{
	return set_irq_wake(irq, 1);
}

static inline int disable_irq_wake(unsigned int irq)
{
	return set_irq_wake(irq, 0);
}

#else /* !CONFIG_GENERIC_HARDIRQS */
/*
 * NOTE: non-genirq architectures, if they want to support the lock
 * validator need to define the methods below in their asm/irq.h
 * files, under an #ifdef CONFIG_LOCKDEP section.
 */
#ifndef CONFIG_LOCKDEP
#  define disable_irq_nosync_lockdep(irq)	disable_irq_nosync(irq)
#  define disable_irq_nosync_lockdep_irqsave(irq, flags) \
						disable_irq_nosync(irq)
#  define disable_irq_lockdep(irq)		disable_irq(irq)
#  define enable_irq_lockdep(irq)		enable_irq(irq)
#  define enable_irq_lockdep_irqrestore(irq, flags) \
						enable_irq(irq)
# endif

static inline int enable_irq_wake(unsigned int irq)
{
	return 0;
}

static inline int disable_irq_wake(unsigned int irq)
{
	return 0;
}
#endif /* CONFIG_GENERIC_HARDIRQS */

#ifndef __ARCH_SET_SOFTIRQ_PENDING
#define set_softirq_pending(x) (local_softirq_pending() = (x))
#define or_softirq_pending(x)  (local_softirq_pending() |= (x))
#endif

/* Some architectures might implement lazy enabling/disabling of
 * interrupts. In some cases, such as stop_machine, we might want
 * to ensure that after a local_irq_disable(), interrupts have
 * really been disabled in hardware. Such architectures need to
 * implement the following hook.
 */
#ifndef hard_irq_disable
#define hard_irq_disable()	do { } while(0)
#endif

/* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
   frequency threaded job scheduling. For almost all the purposes
   tasklets are more than enough. F.e. all serial device BHs et
   al. should be converted to tasklets, not to softirqs.
 */

enum
{
	HI_SOFTIRQ=0,
	TIMER_SOFTIRQ,
	NET_TX_SOFTIRQ,
	NET_RX_SOFTIRQ,
	BLOCK_SOFTIRQ,
	TASKLET_SOFTIRQ,
	SCHED_SOFTIRQ,
	HRTIMER_SOFTIRQ,
	RCU_SOFTIRQ,	/* Preferable RCU should always be the last softirq */

	NR_SOFTIRQS
};

/* map softirq index to softirq name. update 'softirq_to_name' in
 * kernel/softirq.c when adding a new softirq.
 */
extern char *softirq_to_name[NR_SOFTIRQS];

/* softirq mask and active fields moved to irq_cpustat_t in
 * asm/hardirq.h to get better cache usage.  KAO
 */

struct softirq_action
{
	void	(*action)(struct softirq_action *);
};

asmlinkage void do_softirq(void);
asmlinkage void __do_softirq(void);
extern void open_softirq(int nr, void (*action)(struct softirq_action *));
extern void softirq_init(void);
#define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
extern void raise_softirq_irqoff(unsigned int nr);
extern void raise_softirq(unsigned int nr);
extern void wakeup_softirqd(void);

/* This is the worklist that queues up per-cpu softirq work.
 *
 * send_remote_sendirq() adds work to these lists, and
 * the softirq handler itself dequeues from them.  The queues
 * are protected by disabling local cpu interrupts and they must
 * only be accessed by the local cpu that they are for.
 */
DECLARE_PER_CPU(struct list_head [NR_SOFTIRQS], softirq_work_list);

/* Try to send a softirq to a remote cpu.  If this cannot be done, the
 * work will be queued to the local cpu.
 */
extern void send_remote_softirq(struct call_single_data *cp, int cpu, int softirq);

/* Like send_remote_softirq(), but the caller must disable local cpu interrupts
 * and compute the current cpu, passed in as 'this_cpu'.
 */
extern void __send_remote_softirq(struct call_single_data *cp, int cpu,
				  int this_cpu, int softirq);

/* Tasklets --- multithreaded analogue of BHs.

   Main feature differing them of generic softirqs: tasklet
   is running only on one CPU simultaneously.

   Main feature differing them of BHs: different tasklets
   may be run simultaneously on different CPUs.

   Properties:
   * If tasklet_schedule() is called, then tasklet is guaranteed
     to be executed on some cpu at least once after this.
   * If the tasklet is already scheduled, but its excecution is still not
     started, it will be executed only once.
   * If this tasklet is already running on another CPU (or schedule is called
     from tasklet itself), it is rescheduled for later.
   * Tasklet is strictly serialized wrt itself, but not
     wrt another tasklets. If client needs some intertask synchronization,
     he makes it with spinlocks.
 */

struct tasklet_struct
{
	struct tasklet_struct *next;
	unsigned long state;
	atomic_t count;
	void (*func)(unsigned long);
	unsigned long data;
};

#define DECLARE_TASKLET(name, func, data) \
struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }

#define DECLARE_TASKLET_DISABLED(name, func, data) \
struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }


enum
{
	TASKLET_STATE_SCHED,	/* Tasklet is scheduled for execution */
	TASKLET_STATE_RUN	/* Tasklet is running (SMP only) */
};

#ifdef CONFIG_SMP
static inline int tasklet_trylock(struct tasklet_struct *t)
{
	return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
}

static inline void tasklet_unlock(struct tasklet_struct *t)
{
	smp_mb__before_clear_bit(); 
	clear_bit(TASKLET_STATE_RUN, &(t)->state);
}

static inline void tasklet_unlock_wait(struct tasklet_struct *t)
{
	while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
}
#else
#define tasklet_trylock(t) 1
#define tasklet_unlock_wait(t) do { } while (0)
#define tasklet_unlock(t) do { } while (0)
#endif

extern void __tasklet_schedule(struct tasklet_struct *t);

static inline void tasklet_schedule(struct tasklet_struct *t)
{
	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
		__tasklet_schedule(t);
}

extern void __tasklet_hi_schedule(struct tasklet_struct *t);

static inline void tasklet_hi_schedule(struct tasklet_struct *t)
{
	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
		__tasklet_hi_schedule(t);
}


static inline void tasklet_disable_nosync(struct tasklet_struct *t)
{
	atomic_inc(&t->count);
	smp_mb__after_atomic_inc();
}

static inline void tasklet_disable(struct tasklet_struct *t)
{
	tasklet_disable_nosync(t);
	tasklet_unlock_wait(t);
	smp_mb();
}

static inline void tasklet_enable(struct tasklet_struct *t)
{
	smp_mb__before_atomic_dec();
	atomic_dec(&t->count);
}

static inline void tasklet_hi_enable(struct tasklet_struct *t)
{
	smp_mb__before_atomic_dec();
	atomic_dec(&t->count);
}

extern void tasklet_kill(struct tasklet_struct *t);
extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
extern void tasklet_init(struct tasklet_struct *t,
			 void (*func)(unsigned long), unsigned long data);

/*
 * Autoprobing for irqs:
 *
 * probe_irq_on() and probe_irq_off() provide robust primitives
 * for accurate IRQ probing during kernel initialization.  They are
 * reasonably simple to use, are not "fooled" by spurious interrupts,
 * and, unlike other attempts at IRQ probing, they do not get hung on
 * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
 *
 * For reasonably foolproof probing, use them as follows:
 *
 * 1. clear and/or mask the device's internal interrupt.
 * 2. sti();
 * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
 * 4. enable the device and cause it to trigger an interrupt.
 * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
 * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
 * 7. service the device to clear its pending interrupt.
 * 8. loop again if paranoia is required.
 *
 * probe_irq_on() returns a mask of allocated irq's.
 *
 * probe_irq_off() takes the mask as a parameter,
 * and returns the irq number which occurred,
 * or zero if none occurred, or a negative irq number
 * if more than one irq occurred.
 */

#if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE) 
static inline unsigned long probe_irq_on(void)
{
	return 0;
}
static inline int probe_irq_off(unsigned long val)
{
	return 0;
}
static inline unsigned int probe_irq_mask(unsigned long val)
{
	return 0;
}
#else
extern unsigned long probe_irq_on(void);	/* returns 0 on failure */
extern int probe_irq_off(unsigned long);	/* returns 0 or negative on failure */
extern unsigned int probe_irq_mask(unsigned long);	/* returns mask of ISA interrupts */
#endif

#ifdef CONFIG_PROC_FS
/* Initialize /proc/irq/ */
extern void init_irq_proc(void);
#else
static inline void init_irq_proc(void)
{
}
#endif

#if defined(CONFIG_GENERIC_HARDIRQS) && defined(CONFIG_DEBUG_SHIRQ)
extern void debug_poll_all_shared_irqs(void);
#else
static inline void debug_poll_all_shared_irqs(void) { }
#endif

int show_interrupts(struct seq_file *p, void *v);

struct irq_desc;

extern int early_irq_init(void);
extern int arch_probe_nr_irqs(void);
extern int arch_early_irq_init(void);
extern int arch_init_chip_data(struct irq_desc *desc, int node);

#endif