1 /* interrupt.h */
2 #ifndef _LINUX_INTERRUPT_H
3 #define _LINUX_INTERRUPT_H
4
5 #include <linux/kernel.h>
6 #include <linux/linkage.h>
7 #include <linux/bitops.h>
8 #include <linux/preempt.h>
9 #include <linux/cpumask.h>
10 #include <linux/irqreturn.h>
11 #include <linux/irqnr.h>
12 #include <linux/hardirq.h>
13 #include <linux/irqflags.h>
14 #include <linux/smp.h>
15 #include <linux/percpu.h>
16 #include <linux/hrtimer.h>
17 #include <linux/kref.h>
18 #include <linux/workqueue.h>
19
20 #include <linux/atomic.h>
21 #include <asm/ptrace.h>
22
23 /*
24 * These correspond to the IORESOURCE_IRQ_* defines in
25 * linux/ioport.h to select the interrupt line behaviour. When
26 * requesting an interrupt without specifying a IRQF_TRIGGER, the
27 * setting should be assumed to be "as already configured", which
28 * may be as per machine or firmware initialisation.
29 */
30 #define IRQF_TRIGGER_NONE 0x00000000
31 #define IRQF_TRIGGER_RISING 0x00000001
32 #define IRQF_TRIGGER_FALLING 0x00000002
33 #define IRQF_TRIGGER_HIGH 0x00000004
34 #define IRQF_TRIGGER_LOW 0x00000008
35 #define IRQF_TRIGGER_MASK (IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \
36 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)
37 #define IRQF_TRIGGER_PROBE 0x00000010
38
39 /*
40 * These flags used only by the kernel as part of the
41 * irq handling routines.
42 *
43 * IRQF_DISABLED - keep irqs disabled when calling the action handler.
44 * DEPRECATED. This flag is a NOOP and scheduled to be removed
45 * IRQF_SHARED - allow sharing the irq among several devices
46 * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
47 * IRQF_TIMER - Flag to mark this interrupt as timer interrupt
48 * IRQF_PERCPU - Interrupt is per cpu
49 * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing
50 * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is
51 * registered first in an shared interrupt is considered for
52 * performance reasons)
53 * IRQF_ONESHOT - Interrupt is not reenabled after the hardirq handler finished.
54 * Used by threaded interrupts which need to keep the
55 * irq line disabled until the threaded handler has been run.
56 * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend
57 * IRQF_FORCE_RESUME - Force enable it on resume even if IRQF_NO_SUSPEND is set
58 * IRQF_NO_THREAD - Interrupt cannot be threaded
59 * IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device
60 * resume time.
61 */
62 #define IRQF_DISABLED 0x00000020
63 #define IRQF_SHARED 0x00000080
64 #define IRQF_PROBE_SHARED 0x00000100
65 #define __IRQF_TIMER 0x00000200
66 #define IRQF_PERCPU 0x00000400
67 #define IRQF_NOBALANCING 0x00000800
68 #define IRQF_IRQPOLL 0x00001000
69 #define IRQF_ONESHOT 0x00002000
70 #define IRQF_NO_SUSPEND 0x00004000
71 #define IRQF_FORCE_RESUME 0x00008000
72 #define IRQF_NO_THREAD 0x00010000
73 #define IRQF_EARLY_RESUME 0x00020000
74
75 #define IRQF_TIMER (__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD)
76
77 /*
78 * These values can be returned by request_any_context_irq() and
79 * describe the context the interrupt will be run in.
80 *
81 * IRQC_IS_HARDIRQ - interrupt runs in hardirq context
82 * IRQC_IS_NESTED - interrupt runs in a nested threaded context
83 */
84 enum {
85 IRQC_IS_HARDIRQ = 0,
86 IRQC_IS_NESTED,
87 };
88
89 typedef irqreturn_t (*irq_handler_t)(int, void *);
90
91 /**
92 * struct irqaction - per interrupt action descriptor
93 * @handler: interrupt handler function
94 * @name: name of the device
95 * @dev_id: cookie to identify the device
96 * @percpu_dev_id: cookie to identify the device
97 * @next: pointer to the next irqaction for shared interrupts
98 * @irq: interrupt number
99 * @flags: flags (see IRQF_* above)
100 * @thread_fn: interrupt handler function for threaded interrupts
101 * @thread: thread pointer for threaded interrupts
102 * @thread_flags: flags related to @thread
103 * @thread_mask: bitmask for keeping track of @thread activity
104 * @dir: pointer to the proc/irq/NN/name entry
105 */
106 struct irqaction {
107 irq_handler_t handler;
108 void *dev_id;
109 void __percpu *percpu_dev_id;
110 struct irqaction *next;
111 irq_handler_t thread_fn;
112 struct task_struct *thread;
113 unsigned int irq;
114 unsigned int flags;
115 unsigned long thread_flags;
116 unsigned long thread_mask;
117 const char *name;
118 struct proc_dir_entry *dir;
119 } ____cacheline_internodealigned_in_smp;
120
121 extern irqreturn_t no_action(int cpl, void *dev_id);
122
123 extern int __must_check
124 request_threaded_irq(unsigned int irq, irq_handler_t handler,
125 irq_handler_t thread_fn,
126 unsigned long flags, const char *name, void *dev);
127
128 static inline int __must_check
129 request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
130 const char *name, void *dev)
131 {
132 return request_threaded_irq(irq, handler, NULL, flags, name, dev);
133 }
134
135 extern int __must_check
136 request_any_context_irq(unsigned int irq, irq_handler_t handler,
137 unsigned long flags, const char *name, void *dev_id);
138
139 extern int __must_check
140 request_percpu_irq(unsigned int irq, irq_handler_t handler,
141 const char *devname, void __percpu *percpu_dev_id);
142
143 extern void free_irq(unsigned int, void *);
144 extern void free_percpu_irq(unsigned int, void __percpu *);
145
146 struct device;
147
148 extern int __must_check
149 devm_request_threaded_irq(struct device *dev, unsigned int irq,
150 irq_handler_t handler, irq_handler_t thread_fn,
151 unsigned long irqflags, const char *devname,
152 void *dev_id);
153
154 static inline int __must_check
155 devm_request_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
156 unsigned long irqflags, const char *devname, void *dev_id)
157 {
158 return devm_request_threaded_irq(dev, irq, handler, NULL, irqflags,
159 devname, dev_id);
160 }
161
162 extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
163
164 /*
165 * On lockdep we dont want to enable hardirqs in hardirq
166 * context. Use local_irq_enable_in_hardirq() to annotate
167 * kernel code that has to do this nevertheless (pretty much
168 * the only valid case is for old/broken hardware that is
169 * insanely slow).
170 *
171 * NOTE: in theory this might break fragile code that relies
172 * on hardirq delivery - in practice we dont seem to have such
173 * places left. So the only effect should be slightly increased
174 * irqs-off latencies.
175 */
176 #ifdef CONFIG_LOCKDEP
177 # define local_irq_enable_in_hardirq() do { } while (0)
178 #else
179 # define local_irq_enable_in_hardirq() local_irq_enable()
180 #endif
181
182 extern void disable_irq_nosync(unsigned int irq);
183 extern void disable_irq(unsigned int irq);
184 extern void disable_percpu_irq(unsigned int irq);
185 extern void enable_irq(unsigned int irq);
186 extern void enable_percpu_irq(unsigned int irq, unsigned int type);
187
188 /* The following three functions are for the core kernel use only. */
189 extern void suspend_device_irqs(void);
190 extern void resume_device_irqs(void);
191 #ifdef CONFIG_PM_SLEEP
192 extern int check_wakeup_irqs(void);
193 #else
194 static inline int check_wakeup_irqs(void) { return 0; }
195 #endif
196
197 #if defined(CONFIG_SMP)
198
199 extern cpumask_var_t irq_default_affinity;
200
201 /* Internal implementation. Use the helpers below */
202 extern int __irq_set_affinity(unsigned int irq, const struct cpumask *cpumask,
203 bool force);
204
205 /**
206 * irq_set_affinity - Set the irq affinity of a given irq
207 * @irq: Interrupt to set affinity
208 * @mask: cpumask
209 *
210 * Fails if cpumask does not contain an online CPU
211 */
212 static inline int
213 irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
214 {
215 return __irq_set_affinity(irq, cpumask, false);
216 }
217
218 /**
219 * irq_force_affinity - Force the irq affinity of a given irq
220 * @irq: Interrupt to set affinity
221 * @mask: cpumask
222 *
223 * Same as irq_set_affinity, but without checking the mask against
224 * online cpus.
225 *
226 * Solely for low level cpu hotplug code, where we need to make per
227 * cpu interrupts affine before the cpu becomes online.
228 */
229 static inline int
230 irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
231 {
232 return __irq_set_affinity(irq, cpumask, true);
233 }
234
235 extern int irq_can_set_affinity(unsigned int irq);
236 extern int irq_select_affinity(unsigned int irq);
237
238 extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m);
239
240 /**
241 * struct irq_affinity_notify - context for notification of IRQ affinity changes
242 * @irq: Interrupt to which notification applies
243 * @kref: Reference count, for internal use
244 * @work: Work item, for internal use
245 * @notify: Function to be called on change. This will be
246 * called in process context.
247 * @release: Function to be called on release. This will be
248 * called in process context. Once registered, the
249 * structure must only be freed when this function is
250 * called or later.
251 */
252 struct irq_affinity_notify {
253 unsigned int irq;
254 struct kref kref;
255 struct work_struct work;
256 void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
257 void (*release)(struct kref *ref);
258 };
259
260 extern int
261 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
262
263 #else /* CONFIG_SMP */
264
265 static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
266 {
267 return -EINVAL;
268 }
269
270 static inline int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
271 {
272 return 0;
273 }
274
275 static inline int irq_can_set_affinity(unsigned int irq)
276 {
277 return 0;
278 }
279
280 static inline int irq_select_affinity(unsigned int irq) { return 0; }
281
282 static inline int irq_set_affinity_hint(unsigned int irq,
283 const struct cpumask *m)
284 {
285 return -EINVAL;
286 }
287 #endif /* CONFIG_SMP */
288
289 /*
290 * Special lockdep variants of irq disabling/enabling.
291 * These should be used for locking constructs that
292 * know that a particular irq context which is disabled,
293 * and which is the only irq-context user of a lock,
294 * that it's safe to take the lock in the irq-disabled
295 * section without disabling hardirqs.
296 *
297 * On !CONFIG_LOCKDEP they are equivalent to the normal
298 * irq disable/enable methods.
299 */
300 static inline void disable_irq_nosync_lockdep(unsigned int irq)
301 {
302 disable_irq_nosync(irq);
303 #ifdef CONFIG_LOCKDEP
304 local_irq_disable();
305 #endif
306 }
307
308 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
309 {
310 disable_irq_nosync(irq);
311 #ifdef CONFIG_LOCKDEP
312 local_irq_save(*flags);
313 #endif
314 }
315
316 static inline void disable_irq_lockdep(unsigned int irq)
317 {
318 disable_irq(irq);
319 #ifdef CONFIG_LOCKDEP
320 local_irq_disable();
321 #endif
322 }
323
324 static inline void enable_irq_lockdep(unsigned int irq)
325 {
326 #ifdef CONFIG_LOCKDEP
327 local_irq_enable();
328 #endif
329 enable_irq(irq);
330 }
331
332 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
333 {
334 #ifdef CONFIG_LOCKDEP
335 local_irq_restore(*flags);
336 #endif
337 enable_irq(irq);
338 }
339
340 /* IRQ wakeup (PM) control: */
341 extern int irq_set_irq_wake(unsigned int irq, unsigned int on);
342
343 static inline int enable_irq_wake(unsigned int irq)
344 {
345 return irq_set_irq_wake(irq, 1);
346 }
347
348 static inline int disable_irq_wake(unsigned int irq)
349 {
350 return irq_set_irq_wake(irq, 0);
351 }
352
353
354 #ifdef CONFIG_IRQ_FORCED_THREADING
355 extern bool force_irqthreads;
356 #else
357 #define force_irqthreads (0)
358 #endif
359
360 #ifndef __ARCH_SET_SOFTIRQ_PENDING
361 #define set_softirq_pending(x) (local_softirq_pending() = (x))
362 #define or_softirq_pending(x) (local_softirq_pending() |= (x))
363 #endif
364
365 /* Some architectures might implement lazy enabling/disabling of
366 * interrupts. In some cases, such as stop_machine, we might want
367 * to ensure that after a local_irq_disable(), interrupts have
368 * really been disabled in hardware. Such architectures need to
369 * implement the following hook.
370 */
371 #ifndef hard_irq_disable
372 #define hard_irq_disable() do { } while(0)
373 #endif
374
375 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
376 frequency threaded job scheduling. For almost all the purposes
377 tasklets are more than enough. F.e. all serial device BHs et
378 al. should be converted to tasklets, not to softirqs.
379 */
380
381 enum
382 {
383 HI_SOFTIRQ=0,
384 TIMER_SOFTIRQ,
385 NET_TX_SOFTIRQ,
386 NET_RX_SOFTIRQ,
387 BLOCK_SOFTIRQ,
388 BLOCK_IOPOLL_SOFTIRQ,
389 TASKLET_SOFTIRQ,
390 SCHED_SOFTIRQ,
391 HRTIMER_SOFTIRQ,
392 RCU_SOFTIRQ, /* Preferable RCU should always be the last softirq */
393
394 NR_SOFTIRQS
395 };
396
397 #define SOFTIRQ_STOP_IDLE_MASK (~(1 << RCU_SOFTIRQ))
398
399 /* map softirq index to softirq name. update 'softirq_to_name' in
400 * kernel/softirq.c when adding a new softirq.
401 */
402 extern char *softirq_to_name[NR_SOFTIRQS];
403
404 /* softirq mask and active fields moved to irq_cpustat_t in
405 * asm/hardirq.h to get better cache usage. KAO
406 */
407
408 struct softirq_action
409 {
410 void (*action)(struct softirq_action *);
411 };
412
413 asmlinkage void do_softirq(void);
414 asmlinkage void __do_softirq(void);
415 extern void open_softirq(int nr, void (*action)(struct softirq_action *));
416 extern void softirq_init(void);
417 extern void __raise_softirq_irqoff(unsigned int nr);
418
419 extern void raise_softirq_irqoff(unsigned int nr);
420 extern void raise_softirq(unsigned int nr);
421
422 /* This is the worklist that queues up per-cpu softirq work.
423 *
424 * send_remote_sendirq() adds work to these lists, and
425 * the softirq handler itself dequeues from them. The queues
426 * are protected by disabling local cpu interrupts and they must
427 * only be accessed by the local cpu that they are for.
428 */
429 DECLARE_PER_CPU(struct list_head [NR_SOFTIRQS], softirq_work_list);
430
431 DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
432
433 static inline struct task_struct *this_cpu_ksoftirqd(void)
434 {
435 return this_cpu_read(ksoftirqd);
436 }
437
438 /* Try to send a softirq to a remote cpu. If this cannot be done, the
439 * work will be queued to the local cpu.
440 */
441 extern void send_remote_softirq(struct call_single_data *cp, int cpu, int softirq);
442
443 /* Like send_remote_softirq(), but the caller must disable local cpu interrupts
444 * and compute the current cpu, passed in as 'this_cpu'.
445 */
446 extern void __send_remote_softirq(struct call_single_data *cp, int cpu,
447 int this_cpu, int softirq);
448
449 /* Tasklets --- multithreaded analogue of BHs.
450
451 Main feature differing them of generic softirqs: tasklet
452 is running only on one CPU simultaneously.
453
454 Main feature differing them of BHs: different tasklets
455 may be run simultaneously on different CPUs.
456
457 Properties:
458 * If tasklet_schedule() is called, then tasklet is guaranteed
459 to be executed on some cpu at least once after this.
460 * If the tasklet is already scheduled, but its execution is still not
461 started, it will be executed only once.
462 * If this tasklet is already running on another CPU (or schedule is called
463 from tasklet itself), it is rescheduled for later.
464 * Tasklet is strictly serialized wrt itself, but not
465 wrt another tasklets. If client needs some intertask synchronization,
466 he makes it with spinlocks.
467 */
468
469 struct tasklet_struct
470 {
471 struct tasklet_struct *next;
472 unsigned long state;
473 atomic_t count;
474 void (*func)(unsigned long);
475 unsigned long data;
476 };
477
478 #define DECLARE_TASKLET(name, func, data) \
479 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
480
481 #define DECLARE_TASKLET_DISABLED(name, func, data) \
482 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
483
484
485 enum
486 {
487 TASKLET_STATE_SCHED, /* Tasklet is scheduled for execution */
488 TASKLET_STATE_RUN /* Tasklet is running (SMP only) */
489 };
490
491 #ifdef CONFIG_SMP
492 static inline int tasklet_trylock(struct tasklet_struct *t)
493 {
494 return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
495 }
496
497 static inline void tasklet_unlock(struct tasklet_struct *t)
498 {
499 smp_mb__before_clear_bit();
500 clear_bit(TASKLET_STATE_RUN, &(t)->state);
501 }
502
503 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
504 {
505 while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
506 }
507 #else
508 #define tasklet_trylock(t) 1
509 #define tasklet_unlock_wait(t) do { } while (0)
510 #define tasklet_unlock(t) do { } while (0)
511 #endif
512
513 extern void __tasklet_schedule(struct tasklet_struct *t);
514
515 static inline void tasklet_schedule(struct tasklet_struct *t)
516 {
517 if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
518 __tasklet_schedule(t);
519 }
520
521 extern void __tasklet_hi_schedule(struct tasklet_struct *t);
522
523 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
524 {
525 if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
526 __tasklet_hi_schedule(t);
527 }
528
529 extern void __tasklet_hi_schedule_first(struct tasklet_struct *t);
530
531 /*
532 * This version avoids touching any other tasklets. Needed for kmemcheck
533 * in order not to take any page faults while enqueueing this tasklet;
534 * consider VERY carefully whether you really need this or
535 * tasklet_hi_schedule()...
536 */
537 static inline void tasklet_hi_schedule_first(struct tasklet_struct *t)
538 {
539 if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
540 __tasklet_hi_schedule_first(t);
541 }
542
543
544 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
545 {
546 atomic_inc(&t->count);
547 smp_mb__after_atomic_inc();
548 }
549
550 static inline void tasklet_disable(struct tasklet_struct *t)
551 {
552 tasklet_disable_nosync(t);
553 tasklet_unlock_wait(t);
554 smp_mb();
555 }
556
557 static inline void tasklet_enable(struct tasklet_struct *t)
558 {
559 smp_mb__before_atomic_dec();
560 atomic_dec(&t->count);
561 }
562
563 static inline void tasklet_hi_enable(struct tasklet_struct *t)
564 {
565 smp_mb__before_atomic_dec();
566 atomic_dec(&t->count);
567 }
568
569 extern void tasklet_kill(struct tasklet_struct *t);
570 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
571 extern void tasklet_init(struct tasklet_struct *t,
572 void (*func)(unsigned long), unsigned long data);
573
574 struct tasklet_hrtimer {
575 struct hrtimer timer;
576 struct tasklet_struct tasklet;
577 enum hrtimer_restart (*function)(struct hrtimer *);
578 };
579
580 extern void
581 tasklet_hrtimer_init(struct tasklet_hrtimer *ttimer,
582 enum hrtimer_restart (*function)(struct hrtimer *),
583 clockid_t which_clock, enum hrtimer_mode mode);
584
585 static inline
586 int tasklet_hrtimer_start(struct tasklet_hrtimer *ttimer, ktime_t time,
587 const enum hrtimer_mode mode)
588 {
589 return hrtimer_start(&ttimer->timer, time, mode);
590 }
591
592 static inline
593 void tasklet_hrtimer_cancel(struct tasklet_hrtimer *ttimer)
594 {
595 hrtimer_cancel(&ttimer->timer);
596 tasklet_kill(&ttimer->tasklet);
597 }
598
599 /*
600 * Autoprobing for irqs:
601 *
602 * probe_irq_on() and probe_irq_off() provide robust primitives
603 * for accurate IRQ probing during kernel initialization. They are
604 * reasonably simple to use, are not "fooled" by spurious interrupts,
605 * and, unlike other attempts at IRQ probing, they do not get hung on
606 * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
607 *
608 * For reasonably foolproof probing, use them as follows:
609 *
610 * 1. clear and/or mask the device's internal interrupt.
611 * 2. sti();
612 * 3. irqs = probe_irq_on(); // "take over" all unassigned idle IRQs
613 * 4. enable the device and cause it to trigger an interrupt.
614 * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
615 * 6. irq = probe_irq_off(irqs); // get IRQ number, 0=none, negative=multiple
616 * 7. service the device to clear its pending interrupt.
617 * 8. loop again if paranoia is required.
618 *
619 * probe_irq_on() returns a mask of allocated irq's.
620 *
621 * probe_irq_off() takes the mask as a parameter,
622 * and returns the irq number which occurred,
623 * or zero if none occurred, or a negative irq number
624 * if more than one irq occurred.
625 */
626
627 #if !defined(CONFIG_GENERIC_IRQ_PROBE)
628 static inline unsigned long probe_irq_on(void)
629 {
630 return 0;
631 }
632 static inline int probe_irq_off(unsigned long val)
633 {
634 return 0;
635 }
636 static inline unsigned int probe_irq_mask(unsigned long val)
637 {
638 return 0;
639 }
640 #else
641 extern unsigned long probe_irq_on(void); /* returns 0 on failure */
642 extern int probe_irq_off(unsigned long); /* returns 0 or negative on failure */
643 extern unsigned int probe_irq_mask(unsigned long); /* returns mask of ISA interrupts */
644 #endif
645
646 #ifdef CONFIG_PROC_FS
647 /* Initialize /proc/irq/ */
648 extern void init_irq_proc(void);
649 #else
650 static inline void init_irq_proc(void)
651 {
652 }
653 #endif
654
655 struct seq_file;
656 int show_interrupts(struct seq_file *p, void *v);
657 int arch_show_interrupts(struct seq_file *p, int prec);
658
659 extern int early_irq_init(void);
660 extern int arch_probe_nr_irqs(void);
661 extern int arch_early_irq_init(void);
662
663 #endif
664
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