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1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* interrupt.h */
3 #ifndef _LINUX_INTERRUPT_H
4 #define _LINUX_INTERRUPT_H
5 
6 #include <linux/kernel.h>
7 #include <linux/linkage.h>
8 #include <linux/bitops.h>
9 #include <linux/preempt.h>
10 #include <linux/cpumask.h>
11 #include <linux/irqreturn.h>
12 #include <linux/irqnr.h>
13 #include <linux/hardirq.h>
14 #include <linux/irqflags.h>
15 #include <linux/hrtimer.h>
16 #include <linux/kref.h>
17 #include <linux/workqueue.h>
18 
19 #include <linux/atomic.h>
20 #include <asm/ptrace.h>
21 #include <asm/irq.h>
22 #include <asm/sections.h>
23 
24 /*
25  * These correspond to the IORESOURCE_IRQ_* defines in
26  * linux/ioport.h to select the interrupt line behaviour.  When
27  * requesting an interrupt without specifying a IRQF_TRIGGER, the
28  * setting should be assumed to be "as already configured", which
29  * may be as per machine or firmware initialisation.
30  */
31 #define IRQF_TRIGGER_NONE	0x00000000
32 #define IRQF_TRIGGER_RISING	0x00000001
33 #define IRQF_TRIGGER_FALLING	0x00000002
34 #define IRQF_TRIGGER_HIGH	0x00000004
35 #define IRQF_TRIGGER_LOW	0x00000008
36 #define IRQF_TRIGGER_MASK	(IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \
37 				 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)
38 #define IRQF_TRIGGER_PROBE	0x00000010
39 
40 /*
41  * These flags used only by the kernel as part of the
42  * irq handling routines.
43  *
44  * IRQF_SHARED - allow sharing the irq among several devices
45  * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
46  * IRQF_TIMER - Flag to mark this interrupt as timer interrupt
47  * IRQF_PERCPU - Interrupt is per cpu
48  * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing
49  * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is
50  *                registered first in an shared interrupt is considered for
51  *                performance reasons)
52  * IRQF_ONESHOT - Interrupt is not reenabled after the hardirq handler finished.
53  *                Used by threaded interrupts which need to keep the
54  *                irq line disabled until the threaded handler has been run.
55  * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend.  Does not guarantee
56  *                   that this interrupt will wake the system from a suspended
57  *                   state.  See Documentation/power/suspend-and-interrupts.txt
58  * IRQF_FORCE_RESUME - Force enable it on resume even if IRQF_NO_SUSPEND is set
59  * IRQF_NO_THREAD - Interrupt cannot be threaded
60  * IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device
61  *                resume time.
62  * IRQF_COND_SUSPEND - If the IRQ is shared with a NO_SUSPEND user, execute this
63  *                interrupt handler after suspending interrupts. For system
64  *                wakeup devices users need to implement wakeup detection in
65  *                their interrupt handlers.
66  */
67 #define IRQF_SHARED		0x00000080
68 #define IRQF_PROBE_SHARED	0x00000100
69 #define __IRQF_TIMER		0x00000200
70 #define IRQF_PERCPU		0x00000400
71 #define IRQF_NOBALANCING	0x00000800
72 #define IRQF_IRQPOLL		0x00001000
73 #define IRQF_ONESHOT		0x00002000
74 #define IRQF_NO_SUSPEND		0x00004000
75 #define IRQF_FORCE_RESUME	0x00008000
76 #define IRQF_NO_THREAD		0x00010000
77 #define IRQF_EARLY_RESUME	0x00020000
78 #define IRQF_COND_SUSPEND	0x00040000
79 
80 #define IRQF_TIMER		(__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD)
81 
82 /*
83  * These values can be returned by request_any_context_irq() and
84  * describe the context the interrupt will be run in.
85  *
86  * IRQC_IS_HARDIRQ - interrupt runs in hardirq context
87  * IRQC_IS_NESTED - interrupt runs in a nested threaded context
88  */
89 enum {
90 	IRQC_IS_HARDIRQ	= 0,
91 	IRQC_IS_NESTED,
92 };
93 
94 typedef irqreturn_t (*irq_handler_t)(int, void *);
95 
96 /**
97  * struct irqaction - per interrupt action descriptor
98  * @handler:	interrupt handler function
99  * @name:	name of the device
100  * @dev_id:	cookie to identify the device
101  * @percpu_dev_id:	cookie to identify the device
102  * @next:	pointer to the next irqaction for shared interrupts
103  * @irq:	interrupt number
104  * @flags:	flags (see IRQF_* above)
105  * @thread_fn:	interrupt handler function for threaded interrupts
106  * @thread:	thread pointer for threaded interrupts
107  * @secondary:	pointer to secondary irqaction (force threading)
108  * @thread_flags:	flags related to @thread
109  * @thread_mask:	bitmask for keeping track of @thread activity
110  * @dir:	pointer to the proc/irq/NN/name entry
111  */
112 struct irqaction {
113 	irq_handler_t		handler;
114 	void			*dev_id;
115 	void __percpu		*percpu_dev_id;
116 	struct irqaction	*next;
117 	irq_handler_t		thread_fn;
118 	struct task_struct	*thread;
119 	struct irqaction	*secondary;
120 	unsigned int		irq;
121 	unsigned int		flags;
122 	unsigned long		thread_flags;
123 	unsigned long		thread_mask;
124 	const char		*name;
125 	struct proc_dir_entry	*dir;
126 } ____cacheline_internodealigned_in_smp;
127 
128 extern irqreturn_t no_action(int cpl, void *dev_id);
129 
130 /*
131  * If a (PCI) device interrupt is not connected we set dev->irq to
132  * IRQ_NOTCONNECTED. This causes request_irq() to fail with -ENOTCONN, so we
133  * can distingiush that case from other error returns.
134  *
135  * 0x80000000 is guaranteed to be outside the available range of interrupts
136  * and easy to distinguish from other possible incorrect values.
137  */
138 #define IRQ_NOTCONNECTED	(1U << 31)
139 
140 extern int __must_check
141 request_threaded_irq(unsigned int irq, irq_handler_t handler,
142 		     irq_handler_t thread_fn,
143 		     unsigned long flags, const char *name, void *dev);
144 
145 static inline int __must_check
request_irq(unsigned int irq,irq_handler_t handler,unsigned long flags,const char * name,void * dev)146 request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
147 	    const char *name, void *dev)
148 {
149 	return request_threaded_irq(irq, handler, NULL, flags, name, dev);
150 }
151 
152 extern int __must_check
153 request_any_context_irq(unsigned int irq, irq_handler_t handler,
154 			unsigned long flags, const char *name, void *dev_id);
155 
156 extern int __must_check
157 __request_percpu_irq(unsigned int irq, irq_handler_t handler,
158 		     unsigned long flags, const char *devname,
159 		     void __percpu *percpu_dev_id);
160 
161 static inline int __must_check
request_percpu_irq(unsigned int irq,irq_handler_t handler,const char * devname,void __percpu * percpu_dev_id)162 request_percpu_irq(unsigned int irq, irq_handler_t handler,
163 		   const char *devname, void __percpu *percpu_dev_id)
164 {
165 	return __request_percpu_irq(irq, handler, 0,
166 				    devname, percpu_dev_id);
167 }
168 
169 extern const void *free_irq(unsigned int, void *);
170 extern void free_percpu_irq(unsigned int, void __percpu *);
171 
172 struct device;
173 
174 extern int __must_check
175 devm_request_threaded_irq(struct device *dev, unsigned int irq,
176 			  irq_handler_t handler, irq_handler_t thread_fn,
177 			  unsigned long irqflags, const char *devname,
178 			  void *dev_id);
179 
180 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)181 devm_request_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
182 		 unsigned long irqflags, const char *devname, void *dev_id)
183 {
184 	return devm_request_threaded_irq(dev, irq, handler, NULL, irqflags,
185 					 devname, dev_id);
186 }
187 
188 extern int __must_check
189 devm_request_any_context_irq(struct device *dev, unsigned int irq,
190 		 irq_handler_t handler, unsigned long irqflags,
191 		 const char *devname, void *dev_id);
192 
193 extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
194 
195 /*
196  * On lockdep we dont want to enable hardirqs in hardirq
197  * context. Use local_irq_enable_in_hardirq() to annotate
198  * kernel code that has to do this nevertheless (pretty much
199  * the only valid case is for old/broken hardware that is
200  * insanely slow).
201  *
202  * NOTE: in theory this might break fragile code that relies
203  * on hardirq delivery - in practice we dont seem to have such
204  * places left. So the only effect should be slightly increased
205  * irqs-off latencies.
206  */
207 #ifdef CONFIG_LOCKDEP
208 # define local_irq_enable_in_hardirq()	do { } while (0)
209 #else
210 # define local_irq_enable_in_hardirq()	local_irq_enable()
211 #endif
212 
213 extern void disable_irq_nosync(unsigned int irq);
214 extern bool disable_hardirq(unsigned int irq);
215 extern void disable_irq(unsigned int irq);
216 extern void disable_percpu_irq(unsigned int irq);
217 extern void enable_irq(unsigned int irq);
218 extern void enable_percpu_irq(unsigned int irq, unsigned int type);
219 extern bool irq_percpu_is_enabled(unsigned int irq);
220 extern void irq_wake_thread(unsigned int irq, void *dev_id);
221 
222 /* The following three functions are for the core kernel use only. */
223 extern void suspend_device_irqs(void);
224 extern void resume_device_irqs(void);
225 
226 /**
227  * struct irq_affinity_notify - context for notification of IRQ affinity changes
228  * @irq:		Interrupt to which notification applies
229  * @kref:		Reference count, for internal use
230  * @work:		Work item, for internal use
231  * @notify:		Function to be called on change.  This will be
232  *			called in process context.
233  * @release:		Function to be called on release.  This will be
234  *			called in process context.  Once registered, the
235  *			structure must only be freed when this function is
236  *			called or later.
237  */
238 struct irq_affinity_notify {
239 	unsigned int irq;
240 	struct kref kref;
241 	struct work_struct work;
242 	void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
243 	void (*release)(struct kref *ref);
244 };
245 
246 /**
247  * struct irq_affinity - Description for automatic irq affinity assignements
248  * @pre_vectors:	Don't apply affinity to @pre_vectors at beginning of
249  *			the MSI(-X) vector space
250  * @post_vectors:	Don't apply affinity to @post_vectors at end of
251  *			the MSI(-X) vector space
252  */
253 struct irq_affinity {
254 	int	pre_vectors;
255 	int	post_vectors;
256 };
257 
258 #if defined(CONFIG_SMP)
259 
260 extern cpumask_var_t irq_default_affinity;
261 
262 /* Internal implementation. Use the helpers below */
263 extern int __irq_set_affinity(unsigned int irq, const struct cpumask *cpumask,
264 			      bool force);
265 
266 /**
267  * irq_set_affinity - Set the irq affinity of a given irq
268  * @irq:	Interrupt to set affinity
269  * @cpumask:	cpumask
270  *
271  * Fails if cpumask does not contain an online CPU
272  */
273 static inline int
irq_set_affinity(unsigned int irq,const struct cpumask * cpumask)274 irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
275 {
276 	return __irq_set_affinity(irq, cpumask, false);
277 }
278 
279 /**
280  * irq_force_affinity - Force the irq affinity of a given irq
281  * @irq:	Interrupt to set affinity
282  * @cpumask:	cpumask
283  *
284  * Same as irq_set_affinity, but without checking the mask against
285  * online cpus.
286  *
287  * Solely for low level cpu hotplug code, where we need to make per
288  * cpu interrupts affine before the cpu becomes online.
289  */
290 static inline int
irq_force_affinity(unsigned int irq,const struct cpumask * cpumask)291 irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
292 {
293 	return __irq_set_affinity(irq, cpumask, true);
294 }
295 
296 extern int irq_can_set_affinity(unsigned int irq);
297 extern int irq_select_affinity(unsigned int irq);
298 
299 extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m);
300 
301 extern int
302 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
303 
304 struct cpumask *irq_create_affinity_masks(int nvec, const struct irq_affinity *affd);
305 int irq_calc_affinity_vectors(int minvec, int maxvec, const struct irq_affinity *affd);
306 
307 #else /* CONFIG_SMP */
308 
irq_set_affinity(unsigned int irq,const struct cpumask * m)309 static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
310 {
311 	return -EINVAL;
312 }
313 
irq_force_affinity(unsigned int irq,const struct cpumask * cpumask)314 static inline int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
315 {
316 	return 0;
317 }
318 
irq_can_set_affinity(unsigned int irq)319 static inline int irq_can_set_affinity(unsigned int irq)
320 {
321 	return 0;
322 }
323 
irq_select_affinity(unsigned int irq)324 static inline int irq_select_affinity(unsigned int irq)  { return 0; }
325 
irq_set_affinity_hint(unsigned int irq,const struct cpumask * m)326 static inline int irq_set_affinity_hint(unsigned int irq,
327 					const struct cpumask *m)
328 {
329 	return -EINVAL;
330 }
331 
332 static inline int
irq_set_affinity_notifier(unsigned int irq,struct irq_affinity_notify * notify)333 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
334 {
335 	return 0;
336 }
337 
338 static inline struct cpumask *
irq_create_affinity_masks(int nvec,const struct irq_affinity * affd)339 irq_create_affinity_masks(int nvec, const struct irq_affinity *affd)
340 {
341 	return NULL;
342 }
343 
344 static inline int
irq_calc_affinity_vectors(int minvec,int maxvec,const struct irq_affinity * affd)345 irq_calc_affinity_vectors(int minvec, int maxvec, const struct irq_affinity *affd)
346 {
347 	return maxvec;
348 }
349 
350 #endif /* CONFIG_SMP */
351 
352 /*
353  * Special lockdep variants of irq disabling/enabling.
354  * These should be used for locking constructs that
355  * know that a particular irq context which is disabled,
356  * and which is the only irq-context user of a lock,
357  * that it's safe to take the lock in the irq-disabled
358  * section without disabling hardirqs.
359  *
360  * On !CONFIG_LOCKDEP they are equivalent to the normal
361  * irq disable/enable methods.
362  */
disable_irq_nosync_lockdep(unsigned int irq)363 static inline void disable_irq_nosync_lockdep(unsigned int irq)
364 {
365 	disable_irq_nosync(irq);
366 #ifdef CONFIG_LOCKDEP
367 	local_irq_disable();
368 #endif
369 }
370 
disable_irq_nosync_lockdep_irqsave(unsigned int irq,unsigned long * flags)371 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
372 {
373 	disable_irq_nosync(irq);
374 #ifdef CONFIG_LOCKDEP
375 	local_irq_save(*flags);
376 #endif
377 }
378 
disable_irq_lockdep(unsigned int irq)379 static inline void disable_irq_lockdep(unsigned int irq)
380 {
381 	disable_irq(irq);
382 #ifdef CONFIG_LOCKDEP
383 	local_irq_disable();
384 #endif
385 }
386 
enable_irq_lockdep(unsigned int irq)387 static inline void enable_irq_lockdep(unsigned int irq)
388 {
389 #ifdef CONFIG_LOCKDEP
390 	local_irq_enable();
391 #endif
392 	enable_irq(irq);
393 }
394 
enable_irq_lockdep_irqrestore(unsigned int irq,unsigned long * flags)395 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
396 {
397 #ifdef CONFIG_LOCKDEP
398 	local_irq_restore(*flags);
399 #endif
400 	enable_irq(irq);
401 }
402 
403 /* IRQ wakeup (PM) control: */
404 extern int irq_set_irq_wake(unsigned int irq, unsigned int on);
405 
enable_irq_wake(unsigned int irq)406 static inline int enable_irq_wake(unsigned int irq)
407 {
408 	return irq_set_irq_wake(irq, 1);
409 }
410 
disable_irq_wake(unsigned int irq)411 static inline int disable_irq_wake(unsigned int irq)
412 {
413 	return irq_set_irq_wake(irq, 0);
414 }
415 
416 /*
417  * irq_get_irqchip_state/irq_set_irqchip_state specific flags
418  */
419 enum irqchip_irq_state {
420 	IRQCHIP_STATE_PENDING,		/* Is interrupt pending? */
421 	IRQCHIP_STATE_ACTIVE,		/* Is interrupt in progress? */
422 	IRQCHIP_STATE_MASKED,		/* Is interrupt masked? */
423 	IRQCHIP_STATE_LINE_LEVEL,	/* Is IRQ line high? */
424 };
425 
426 extern int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
427 				 bool *state);
428 extern int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
429 				 bool state);
430 
431 #ifdef CONFIG_IRQ_FORCED_THREADING
432 extern bool force_irqthreads;
433 #else
434 #define force_irqthreads	(0)
435 #endif
436 
437 #ifndef __ARCH_SET_SOFTIRQ_PENDING
438 #define set_softirq_pending(x) (local_softirq_pending() = (x))
439 #define or_softirq_pending(x)  (local_softirq_pending() |= (x))
440 #endif
441 
442 /* Some architectures might implement lazy enabling/disabling of
443  * interrupts. In some cases, such as stop_machine, we might want
444  * to ensure that after a local_irq_disable(), interrupts have
445  * really been disabled in hardware. Such architectures need to
446  * implement the following hook.
447  */
448 #ifndef hard_irq_disable
449 #define hard_irq_disable()	do { } while(0)
450 #endif
451 
452 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
453    frequency threaded job scheduling. For almost all the purposes
454    tasklets are more than enough. F.e. all serial device BHs et
455    al. should be converted to tasklets, not to softirqs.
456  */
457 
458 enum
459 {
460 	HI_SOFTIRQ=0,
461 	TIMER_SOFTIRQ,
462 	NET_TX_SOFTIRQ,
463 	NET_RX_SOFTIRQ,
464 	BLOCK_SOFTIRQ,
465 	IRQ_POLL_SOFTIRQ,
466 	TASKLET_SOFTIRQ,
467 	SCHED_SOFTIRQ,
468 	HRTIMER_SOFTIRQ, /* Unused, but kept as tools rely on the
469 			    numbering. Sigh! */
470 	RCU_SOFTIRQ,    /* Preferable RCU should always be the last softirq */
471 
472 	NR_SOFTIRQS
473 };
474 
475 #define SOFTIRQ_STOP_IDLE_MASK (~(1 << RCU_SOFTIRQ))
476 
477 /* map softirq index to softirq name. update 'softirq_to_name' in
478  * kernel/softirq.c when adding a new softirq.
479  */
480 extern const char * const softirq_to_name[NR_SOFTIRQS];
481 
482 /* softirq mask and active fields moved to irq_cpustat_t in
483  * asm/hardirq.h to get better cache usage.  KAO
484  */
485 
486 struct softirq_action
487 {
488 	void	(*action)(struct softirq_action *);
489 };
490 
491 asmlinkage void do_softirq(void);
492 asmlinkage void __do_softirq(void);
493 
494 #ifdef __ARCH_HAS_DO_SOFTIRQ
495 void do_softirq_own_stack(void);
496 #else
do_softirq_own_stack(void)497 static inline void do_softirq_own_stack(void)
498 {
499 	__do_softirq();
500 }
501 #endif
502 
503 extern void open_softirq(int nr, void (*action)(struct softirq_action *));
504 extern void softirq_init(void);
505 extern void __raise_softirq_irqoff(unsigned int nr);
506 
507 extern void raise_softirq_irqoff(unsigned int nr);
508 extern void raise_softirq(unsigned int nr);
509 
510 DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
511 
this_cpu_ksoftirqd(void)512 static inline struct task_struct *this_cpu_ksoftirqd(void)
513 {
514 	return this_cpu_read(ksoftirqd);
515 }
516 
517 /* Tasklets --- multithreaded analogue of BHs.
518 
519    Main feature differing them of generic softirqs: tasklet
520    is running only on one CPU simultaneously.
521 
522    Main feature differing them of BHs: different tasklets
523    may be run simultaneously on different CPUs.
524 
525    Properties:
526    * If tasklet_schedule() is called, then tasklet is guaranteed
527      to be executed on some cpu at least once after this.
528    * If the tasklet is already scheduled, but its execution is still not
529      started, it will be executed only once.
530    * If this tasklet is already running on another CPU (or schedule is called
531      from tasklet itself), it is rescheduled for later.
532    * Tasklet is strictly serialized wrt itself, but not
533      wrt another tasklets. If client needs some intertask synchronization,
534      he makes it with spinlocks.
535  */
536 
537 struct tasklet_struct
538 {
539 	struct tasklet_struct *next;
540 	unsigned long state;
541 	atomic_t count;
542 	void (*func)(unsigned long);
543 	unsigned long data;
544 };
545 
546 #define DECLARE_TASKLET(name, func, data) \
547 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
548 
549 #define DECLARE_TASKLET_DISABLED(name, func, data) \
550 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
551 
552 
553 enum
554 {
555 	TASKLET_STATE_SCHED,	/* Tasklet is scheduled for execution */
556 	TASKLET_STATE_RUN	/* Tasklet is running (SMP only) */
557 };
558 
559 #ifdef CONFIG_SMP
tasklet_trylock(struct tasklet_struct * t)560 static inline int tasklet_trylock(struct tasklet_struct *t)
561 {
562 	return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
563 }
564 
tasklet_unlock(struct tasklet_struct * t)565 static inline void tasklet_unlock(struct tasklet_struct *t)
566 {
567 	smp_mb__before_atomic();
568 	clear_bit(TASKLET_STATE_RUN, &(t)->state);
569 }
570 
tasklet_unlock_wait(struct tasklet_struct * t)571 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
572 {
573 	while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
574 }
575 #else
576 #define tasklet_trylock(t) 1
577 #define tasklet_unlock_wait(t) do { } while (0)
578 #define tasklet_unlock(t) do { } while (0)
579 #endif
580 
581 extern void __tasklet_schedule(struct tasklet_struct *t);
582 
tasklet_schedule(struct tasklet_struct * t)583 static inline void tasklet_schedule(struct tasklet_struct *t)
584 {
585 	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
586 		__tasklet_schedule(t);
587 }
588 
589 extern void __tasklet_hi_schedule(struct tasklet_struct *t);
590 
tasklet_hi_schedule(struct tasklet_struct * t)591 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
592 {
593 	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
594 		__tasklet_hi_schedule(t);
595 }
596 
tasklet_disable_nosync(struct tasklet_struct * t)597 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
598 {
599 	atomic_inc(&t->count);
600 	smp_mb__after_atomic();
601 }
602 
tasklet_disable(struct tasklet_struct * t)603 static inline void tasklet_disable(struct tasklet_struct *t)
604 {
605 	tasklet_disable_nosync(t);
606 	tasklet_unlock_wait(t);
607 	smp_mb();
608 }
609 
tasklet_enable(struct tasklet_struct * t)610 static inline void tasklet_enable(struct tasklet_struct *t)
611 {
612 	smp_mb__before_atomic();
613 	atomic_dec(&t->count);
614 }
615 
616 extern void tasklet_kill(struct tasklet_struct *t);
617 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
618 extern void tasklet_init(struct tasklet_struct *t,
619 			 void (*func)(unsigned long), unsigned long data);
620 
621 struct tasklet_hrtimer {
622 	struct hrtimer		timer;
623 	struct tasklet_struct	tasklet;
624 	enum hrtimer_restart	(*function)(struct hrtimer *);
625 };
626 
627 extern void
628 tasklet_hrtimer_init(struct tasklet_hrtimer *ttimer,
629 		     enum hrtimer_restart (*function)(struct hrtimer *),
630 		     clockid_t which_clock, enum hrtimer_mode mode);
631 
632 static inline
tasklet_hrtimer_start(struct tasklet_hrtimer * ttimer,ktime_t time,const enum hrtimer_mode mode)633 void tasklet_hrtimer_start(struct tasklet_hrtimer *ttimer, ktime_t time,
634 			   const enum hrtimer_mode mode)
635 {
636 	hrtimer_start(&ttimer->timer, time, mode);
637 }
638 
639 static inline
tasklet_hrtimer_cancel(struct tasklet_hrtimer * ttimer)640 void tasklet_hrtimer_cancel(struct tasklet_hrtimer *ttimer)
641 {
642 	hrtimer_cancel(&ttimer->timer);
643 	tasklet_kill(&ttimer->tasklet);
644 }
645 
646 /*
647  * Autoprobing for irqs:
648  *
649  * probe_irq_on() and probe_irq_off() provide robust primitives
650  * for accurate IRQ probing during kernel initialization.  They are
651  * reasonably simple to use, are not "fooled" by spurious interrupts,
652  * and, unlike other attempts at IRQ probing, they do not get hung on
653  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
654  *
655  * For reasonably foolproof probing, use them as follows:
656  *
657  * 1. clear and/or mask the device's internal interrupt.
658  * 2. sti();
659  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
660  * 4. enable the device and cause it to trigger an interrupt.
661  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
662  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
663  * 7. service the device to clear its pending interrupt.
664  * 8. loop again if paranoia is required.
665  *
666  * probe_irq_on() returns a mask of allocated irq's.
667  *
668  * probe_irq_off() takes the mask as a parameter,
669  * and returns the irq number which occurred,
670  * or zero if none occurred, or a negative irq number
671  * if more than one irq occurred.
672  */
673 
674 #if !defined(CONFIG_GENERIC_IRQ_PROBE)
probe_irq_on(void)675 static inline unsigned long probe_irq_on(void)
676 {
677 	return 0;
678 }
probe_irq_off(unsigned long val)679 static inline int probe_irq_off(unsigned long val)
680 {
681 	return 0;
682 }
probe_irq_mask(unsigned long val)683 static inline unsigned int probe_irq_mask(unsigned long val)
684 {
685 	return 0;
686 }
687 #else
688 extern unsigned long probe_irq_on(void);	/* returns 0 on failure */
689 extern int probe_irq_off(unsigned long);	/* returns 0 or negative on failure */
690 extern unsigned int probe_irq_mask(unsigned long);	/* returns mask of ISA interrupts */
691 #endif
692 
693 #ifdef CONFIG_PROC_FS
694 /* Initialize /proc/irq/ */
695 extern void init_irq_proc(void);
696 #else
init_irq_proc(void)697 static inline void init_irq_proc(void)
698 {
699 }
700 #endif
701 
702 #ifdef CONFIG_IRQ_TIMINGS
703 void irq_timings_enable(void);
704 void irq_timings_disable(void);
705 u64 irq_timings_next_event(u64 now);
706 #endif
707 
708 struct seq_file;
709 int show_interrupts(struct seq_file *p, void *v);
710 int arch_show_interrupts(struct seq_file *p, int prec);
711 
712 extern int early_irq_init(void);
713 extern int arch_probe_nr_irqs(void);
714 extern int arch_early_irq_init(void);
715 
716 /*
717  * We want to know which function is an entrypoint of a hardirq or a softirq.
718  */
719 #define __irq_entry		 __attribute__((__section__(".irqentry.text")))
720 #define __softirq_entry  \
721 	__attribute__((__section__(".softirqentry.text")))
722 
723 #endif
724