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interrupt.h
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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 {
87 };
88 
89 typedef irqreturn_t (*irq_handler_t)(int, void *);
90 
106 struct irqaction {
108  void *dev_id;
110  struct irqaction *next;
113  unsigned int irq;
114  unsigned int flags;
115  unsigned long thread_flags;
116  unsigned long thread_mask;
117  const char *name;
120 
121 extern irqreturn_t no_action(int cpl, void *dev_id);
122 
123 #ifdef CONFIG_GENERIC_HARDIRQS
124 extern int __must_check
125 request_threaded_irq(unsigned int irq, irq_handler_t handler,
126  irq_handler_t thread_fn,
127  unsigned long flags, const char *name, void *dev);
128 
129 static inline int __must_check
130 request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
131  const char *name, void *dev)
132 {
133  return request_threaded_irq(irq, handler, NULL, flags, name, dev);
134 }
135 
136 extern int __must_check
137 request_any_context_irq(unsigned int irq, irq_handler_t handler,
138  unsigned long flags, const char *name, void *dev_id);
139 
140 extern int __must_check
141 request_percpu_irq(unsigned int irq, irq_handler_t handler,
142  const char *devname, void __percpu *percpu_dev_id);
143 #else
144 
145 extern int __must_check
146 request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
147  const char *name, void *dev);
148 
149 /*
150  * Special function to avoid ifdeffery in kernel/irq/devres.c which
151  * gets magically built by GENERIC_HARDIRQS=n architectures (sparc,
152  * m68k). I really love these $@%#!* obvious Makefile references:
153  * ../../../kernel/irq/devres.o
154  */
155 static inline int __must_check
156 request_threaded_irq(unsigned int irq, irq_handler_t handler,
157  irq_handler_t thread_fn,
158  unsigned long flags, const char *name, void *dev)
159 {
160  return request_irq(irq, handler, flags, name, dev);
161 }
162 
163 static inline int __must_check
164 request_any_context_irq(unsigned int irq, irq_handler_t handler,
165  unsigned long flags, const char *name, void *dev_id)
166 {
167  return request_irq(irq, handler, flags, name, dev_id);
168 }
169 
170 static inline int __must_check
171 request_percpu_irq(unsigned int irq, irq_handler_t handler,
172  const char *devname, void __percpu *percpu_dev_id)
173 {
174  return request_irq(irq, handler, 0, devname, percpu_dev_id);
175 }
176 #endif
177 
178 extern void free_irq(unsigned int, void *);
179 extern void free_percpu_irq(unsigned int, void __percpu *);
180 
181 struct device;
182 
183 extern int __must_check
184 devm_request_threaded_irq(struct device *dev, unsigned int irq,
185  irq_handler_t handler, irq_handler_t thread_fn,
186  unsigned long irqflags, const char *devname,
187  void *dev_id);
188 
189 static inline int __must_check
190 devm_request_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
191  unsigned long irqflags, const char *devname, void *dev_id)
192 {
193  return devm_request_threaded_irq(dev, irq, handler, NULL, irqflags,
194  devname, dev_id);
195 }
196 
197 extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
198 
199 /*
200  * On lockdep we dont want to enable hardirqs in hardirq
201  * context. Use local_irq_enable_in_hardirq() to annotate
202  * kernel code that has to do this nevertheless (pretty much
203  * the only valid case is for old/broken hardware that is
204  * insanely slow).
205  *
206  * NOTE: in theory this might break fragile code that relies
207  * on hardirq delivery - in practice we dont seem to have such
208  * places left. So the only effect should be slightly increased
209  * irqs-off latencies.
210  */
211 #ifdef CONFIG_LOCKDEP
212 # define local_irq_enable_in_hardirq() do { } while (0)
213 #else
214 # define local_irq_enable_in_hardirq() local_irq_enable()
215 #endif
216 
217 extern void disable_irq_nosync(unsigned int irq);
218 extern void disable_irq(unsigned int irq);
219 extern void disable_percpu_irq(unsigned int irq);
220 extern void enable_irq(unsigned int irq);
221 extern void enable_percpu_irq(unsigned int irq, unsigned int type);
222 
223 /* The following three functions are for the core kernel use only. */
224 #ifdef CONFIG_GENERIC_HARDIRQS
225 extern void suspend_device_irqs(void);
226 extern void resume_device_irqs(void);
227 #ifdef CONFIG_PM_SLEEP
228 extern int check_wakeup_irqs(void);
229 #else
230 static inline int check_wakeup_irqs(void) { return 0; }
231 #endif
232 #else
233 static inline void suspend_device_irqs(void) { };
234 static inline void resume_device_irqs(void) { };
235 static inline int check_wakeup_irqs(void) { return 0; }
236 #endif
237 
238 #if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
239 
240 extern cpumask_var_t irq_default_affinity;
241 
242 extern int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask);
243 extern int irq_can_set_affinity(unsigned int irq);
244 extern int irq_select_affinity(unsigned int irq);
245 
246 extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m);
247 
260 struct irq_affinity_notify {
261  unsigned int irq;
262  struct kref kref;
263  struct work_struct work;
264  void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
265  void (*release)(struct kref *ref);
266 };
267 
268 extern int
269 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
270 
271 static inline void irq_run_affinity_notifiers(void)
272 {
274 }
275 
276 #else /* CONFIG_SMP */
277 
278 static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
279 {
280  return -EINVAL;
281 }
282 
283 static inline int irq_can_set_affinity(unsigned int irq)
284 {
285  return 0;
286 }
287 
288 static inline int irq_select_affinity(unsigned int irq) { return 0; }
289 
290 static inline int irq_set_affinity_hint(unsigned int irq,
291  const struct cpumask *m)
292 {
293  return -EINVAL;
294 }
295 #endif /* CONFIG_SMP && CONFIG_GENERIC_HARDIRQS */
296 
297 #ifdef CONFIG_GENERIC_HARDIRQS
298 /*
299  * Special lockdep variants of irq disabling/enabling.
300  * These should be used for locking constructs that
301  * know that a particular irq context which is disabled,
302  * and which is the only irq-context user of a lock,
303  * that it's safe to take the lock in the irq-disabled
304  * section without disabling hardirqs.
305  *
306  * On !CONFIG_LOCKDEP they are equivalent to the normal
307  * irq disable/enable methods.
308  */
309 static inline void disable_irq_nosync_lockdep(unsigned int irq)
310 {
311  disable_irq_nosync(irq);
312 #ifdef CONFIG_LOCKDEP
314 #endif
315 }
316 
317 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
318 {
319  disable_irq_nosync(irq);
320 #ifdef CONFIG_LOCKDEP
321  local_irq_save(*flags);
322 #endif
323 }
324 
325 static inline void disable_irq_lockdep(unsigned int irq)
326 {
327  disable_irq(irq);
328 #ifdef CONFIG_LOCKDEP
330 #endif
331 }
332 
333 static inline void enable_irq_lockdep(unsigned int irq)
334 {
335 #ifdef CONFIG_LOCKDEP
337 #endif
338  enable_irq(irq);
339 }
340 
341 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
342 {
343 #ifdef CONFIG_LOCKDEP
344  local_irq_restore(*flags);
345 #endif
346  enable_irq(irq);
347 }
348 
349 /* IRQ wakeup (PM) control: */
350 extern int irq_set_irq_wake(unsigned int irq, unsigned int on);
351 
352 static inline int enable_irq_wake(unsigned int irq)
353 {
354  return irq_set_irq_wake(irq, 1);
355 }
356 
357 static inline int disable_irq_wake(unsigned int irq)
358 {
359  return irq_set_irq_wake(irq, 0);
360 }
361 
362 #else /* !CONFIG_GENERIC_HARDIRQS */
363 /*
364  * NOTE: non-genirq architectures, if they want to support the lock
365  * validator need to define the methods below in their asm/irq.h
366  * files, under an #ifdef CONFIG_LOCKDEP section.
367  */
368 #ifndef CONFIG_LOCKDEP
369 # define disable_irq_nosync_lockdep(irq) disable_irq_nosync(irq)
370 # define disable_irq_nosync_lockdep_irqsave(irq, flags) \
371  disable_irq_nosync(irq)
372 # define disable_irq_lockdep(irq) disable_irq(irq)
373 # define enable_irq_lockdep(irq) enable_irq(irq)
374 # define enable_irq_lockdep_irqrestore(irq, flags) \
375  enable_irq(irq)
376 # endif
377 
378 static inline int enable_irq_wake(unsigned int irq)
379 {
380  return 0;
381 }
382 
383 static inline int disable_irq_wake(unsigned int irq)
384 {
385  return 0;
386 }
387 #endif /* CONFIG_GENERIC_HARDIRQS */
388 
389 
390 #ifdef CONFIG_IRQ_FORCED_THREADING
391 extern bool force_irqthreads;
392 #else
393 #define force_irqthreads (0)
394 #endif
395 
396 #ifndef __ARCH_SET_SOFTIRQ_PENDING
397 #define set_softirq_pending(x) (local_softirq_pending() = (x))
398 #define or_softirq_pending(x) (local_softirq_pending() |= (x))
399 #endif
400 
401 /* Some architectures might implement lazy enabling/disabling of
402  * interrupts. In some cases, such as stop_machine, we might want
403  * to ensure that after a local_irq_disable(), interrupts have
404  * really been disabled in hardware. Such architectures need to
405  * implement the following hook.
406  */
407 #ifndef hard_irq_disable
408 #define hard_irq_disable() do { } while(0)
409 #endif
410 
411 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
412  frequency threaded job scheduling. For almost all the purposes
413  tasklets are more than enough. F.e. all serial device BHs et
414  al. should be converted to tasklets, not to softirqs.
415  */
416 
417 enum
418 {
428  RCU_SOFTIRQ, /* Preferable RCU should always be the last softirq */
429 
431 };
432 
433 #define SOFTIRQ_STOP_IDLE_MASK (~(1 << RCU_SOFTIRQ))
434 
435 /* map softirq index to softirq name. update 'softirq_to_name' in
436  * kernel/softirq.c when adding a new softirq.
437  */
438 extern char *softirq_to_name[NR_SOFTIRQS];
439 
440 /* softirq mask and active fields moved to irq_cpustat_t in
441  * asm/hardirq.h to get better cache usage. KAO
442  */
443 
445 {
446  void (*action)(struct softirq_action *);
447 };
448 
449 asmlinkage void do_softirq(void);
450 asmlinkage void __do_softirq(void);
451 extern void open_softirq(int nr, void (*action)(struct softirq_action *));
452 extern void softirq_init(void);
453 extern void __raise_softirq_irqoff(unsigned int nr);
454 
455 extern void raise_softirq_irqoff(unsigned int nr);
456 extern void raise_softirq(unsigned int nr);
457 
458 /* This is the worklist that queues up per-cpu softirq work.
459  *
460  * send_remote_sendirq() adds work to these lists, and
461  * the softirq handler itself dequeues from them. The queues
462  * are protected by disabling local cpu interrupts and they must
463  * only be accessed by the local cpu that they are for.
464  */
465 DECLARE_PER_CPU(struct list_head [NR_SOFTIRQS], softirq_work_list);
466 
467 DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
468 
469 static inline struct task_struct *this_cpu_ksoftirqd(void)
470 {
471  return this_cpu_read(ksoftirqd);
472 }
473 
474 /* Try to send a softirq to a remote cpu. If this cannot be done, the
475  * work will be queued to the local cpu.
476  */
477 extern void send_remote_softirq(struct call_single_data *cp, int cpu, int softirq);
478 
479 /* Like send_remote_softirq(), but the caller must disable local cpu interrupts
480  * and compute the current cpu, passed in as 'this_cpu'.
481  */
482 extern void __send_remote_softirq(struct call_single_data *cp, int cpu,
483  int this_cpu, int softirq);
484 
485 /* Tasklets --- multithreaded analogue of BHs.
486 
487  Main feature differing them of generic softirqs: tasklet
488  is running only on one CPU simultaneously.
489 
490  Main feature differing them of BHs: different tasklets
491  may be run simultaneously on different CPUs.
492 
493  Properties:
494  * If tasklet_schedule() is called, then tasklet is guaranteed
495  to be executed on some cpu at least once after this.
496  * If the tasklet is already scheduled, but its execution is still not
497  started, it will be executed only once.
498  * If this tasklet is already running on another CPU (or schedule is called
499  from tasklet itself), it is rescheduled for later.
500  * Tasklet is strictly serialized wrt itself, but not
501  wrt another tasklets. If client needs some intertask synchronization,
502  he makes it with spinlocks.
503  */
504 
506 {
508  unsigned long state;
510  void (*func)(unsigned long);
511  unsigned long data;
512 };
513 
514 #define DECLARE_TASKLET(name, func, data) \
515 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
516 
517 #define DECLARE_TASKLET_DISABLED(name, func, data) \
518 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
519 
520 
521 enum
522 {
523  TASKLET_STATE_SCHED, /* Tasklet is scheduled for execution */
524  TASKLET_STATE_RUN /* Tasklet is running (SMP only) */
525 };
526 
527 #ifdef CONFIG_SMP
528 static inline int tasklet_trylock(struct tasklet_struct *t)
529 {
530  return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
531 }
532 
533 static inline void tasklet_unlock(struct tasklet_struct *t)
534 {
537 }
538 
539 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
540 {
541  while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
542 }
543 #else
544 #define tasklet_trylock(t) 1
545 #define tasklet_unlock_wait(t) do { } while (0)
546 #define tasklet_unlock(t) do { } while (0)
547 #endif
548 
549 extern void __tasklet_schedule(struct tasklet_struct *t);
550 
551 static inline void tasklet_schedule(struct tasklet_struct *t)
552 {
555 }
556 
557 extern void __tasklet_hi_schedule(struct tasklet_struct *t);
558 
559 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
560 {
563 }
564 
565 extern void __tasklet_hi_schedule_first(struct tasklet_struct *t);
566 
567 /*
568  * This version avoids touching any other tasklets. Needed for kmemcheck
569  * in order not to take any page faults while enqueueing this tasklet;
570  * consider VERY carefully whether you really need this or
571  * tasklet_hi_schedule()...
572  */
573 static inline void tasklet_hi_schedule_first(struct tasklet_struct *t)
574 {
577 }
578 
579 
580 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
581 {
582  atomic_inc(&t->count);
584 }
585 
586 static inline void tasklet_disable(struct tasklet_struct *t)
587 {
588  tasklet_disable_nosync(t);
590  smp_mb();
591 }
592 
593 static inline void tasklet_enable(struct tasklet_struct *t)
594 {
596  atomic_dec(&t->count);
597 }
598 
599 static inline void tasklet_hi_enable(struct tasklet_struct *t)
600 {
602  atomic_dec(&t->count);
603 }
604 
605 extern void tasklet_kill(struct tasklet_struct *t);
606 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
607 extern void tasklet_init(struct tasklet_struct *t,
608  void (*func)(unsigned long), unsigned long data);
609 
611  struct hrtimer timer;
613  enum hrtimer_restart (*function)(struct hrtimer *);
614 };
615 
616 extern void
618  enum hrtimer_restart (*function)(struct hrtimer *),
619  clockid_t which_clock, enum hrtimer_mode mode);
620 
621 static inline
622 int tasklet_hrtimer_start(struct tasklet_hrtimer *ttimer, ktime_t time,
623  const enum hrtimer_mode mode)
624 {
625  return hrtimer_start(&ttimer->timer, time, mode);
626 }
627 
628 static inline
629 void tasklet_hrtimer_cancel(struct tasklet_hrtimer *ttimer)
630 {
631  hrtimer_cancel(&ttimer->timer);
632  tasklet_kill(&ttimer->tasklet);
633 }
634 
635 /*
636  * Autoprobing for irqs:
637  *
638  * probe_irq_on() and probe_irq_off() provide robust primitives
639  * for accurate IRQ probing during kernel initialization. They are
640  * reasonably simple to use, are not "fooled" by spurious interrupts,
641  * and, unlike other attempts at IRQ probing, they do not get hung on
642  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
643  *
644  * For reasonably foolproof probing, use them as follows:
645  *
646  * 1. clear and/or mask the device's internal interrupt.
647  * 2. sti();
648  * 3. irqs = probe_irq_on(); // "take over" all unassigned idle IRQs
649  * 4. enable the device and cause it to trigger an interrupt.
650  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
651  * 6. irq = probe_irq_off(irqs); // get IRQ number, 0=none, negative=multiple
652  * 7. service the device to clear its pending interrupt.
653  * 8. loop again if paranoia is required.
654  *
655  * probe_irq_on() returns a mask of allocated irq's.
656  *
657  * probe_irq_off() takes the mask as a parameter,
658  * and returns the irq number which occurred,
659  * or zero if none occurred, or a negative irq number
660  * if more than one irq occurred.
661  */
662 
663 #if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE)
664 static inline unsigned long probe_irq_on(void)
665 {
666  return 0;
667 }
668 static inline int probe_irq_off(unsigned long val)
669 {
670  return 0;
671 }
672 static inline unsigned int probe_irq_mask(unsigned long val)
673 {
674  return 0;
675 }
676 #else
677 extern unsigned long probe_irq_on(void); /* returns 0 on failure */
678 extern int probe_irq_off(unsigned long); /* returns 0 or negative on failure */
679 extern unsigned int probe_irq_mask(unsigned long); /* returns mask of ISA interrupts */
680 #endif
681 
682 #ifdef CONFIG_PROC_FS
683 /* Initialize /proc/irq/ */
684 extern void init_irq_proc(void);
685 #else
686 static inline void init_irq_proc(void)
687 {
688 }
689 #endif
690 
691 struct seq_file;
692 int show_interrupts(struct seq_file *p, void *v);
693 int arch_show_interrupts(struct seq_file *p, int prec);
694 
695 extern int early_irq_init(void);
696 extern int arch_probe_nr_irqs(void);
697 extern int arch_early_irq_init(void);
698 
699 #endif