• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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/bitops.h>
8 #include <linux/cpumask.h>
9 #include <linux/irqreturn.h>
10 #include <linux/irqnr.h>
11 #include <linux/hardirq.h>
12 #include <linux/irqflags.h>
13 #include <linux/hrtimer.h>
14 #include <linux/kref.h>
15 #include <linux/workqueue.h>
16 
17 #include <linux/atomic.h>
18 #include <asm/ptrace.h>
19 #include <asm/irq.h>
20 #include <asm/sections.h>
21 
22 /*
23  * These correspond to the IORESOURCE_IRQ_* defines in
24  * linux/ioport.h to select the interrupt line behaviour.  When
25  * requesting an interrupt without specifying a IRQF_TRIGGER, the
26  * setting should be assumed to be "as already configured", which
27  * may be as per machine or firmware initialisation.
28  */
29 #define IRQF_TRIGGER_NONE	0x00000000
30 #define IRQF_TRIGGER_RISING	0x00000001
31 #define IRQF_TRIGGER_FALLING	0x00000002
32 #define IRQF_TRIGGER_HIGH	0x00000004
33 #define IRQF_TRIGGER_LOW	0x00000008
34 #define IRQF_TRIGGER_MASK	(IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \
35 				 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)
36 #define IRQF_TRIGGER_PROBE	0x00000010
37 
38 /*
39  * These flags used only by the kernel as part of the
40  * irq handling routines.
41  *
42  * IRQF_SHARED - allow sharing the irq among several devices
43  * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
44  * IRQF_TIMER - Flag to mark this interrupt as timer interrupt
45  * IRQF_PERCPU - Interrupt is per cpu
46  * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing
47  * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is
48  *                registered first in a shared interrupt is considered for
49  *                performance reasons)
50  * IRQF_ONESHOT - Interrupt is not reenabled after the hardirq handler finished.
51  *                Used by threaded interrupts which need to keep the
52  *                irq line disabled until the threaded handler has been run.
53  * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend.  Does not guarantee
54  *                   that this interrupt will wake the system from a suspended
55  *                   state.  See Documentation/power/suspend-and-interrupts.rst
56  * IRQF_FORCE_RESUME - Force enable it on resume even if IRQF_NO_SUSPEND is set
57  * IRQF_NO_THREAD - Interrupt cannot be threaded
58  * IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device
59  *                resume time.
60  * IRQF_COND_SUSPEND - If the IRQ is shared with a NO_SUSPEND user, execute this
61  *                interrupt handler after suspending interrupts. For system
62  *                wakeup devices users need to implement wakeup detection in
63  *                their interrupt handlers.
64  */
65 #define IRQF_SHARED		0x00000080
66 #define IRQF_PROBE_SHARED	0x00000100
67 #define __IRQF_TIMER		0x00000200
68 #define IRQF_PERCPU		0x00000400
69 #define IRQF_NOBALANCING	0x00000800
70 #define IRQF_IRQPOLL		0x00001000
71 #define IRQF_ONESHOT		0x00002000
72 #define IRQF_NO_SUSPEND		0x00004000
73 #define IRQF_FORCE_RESUME	0x00008000
74 #define IRQF_NO_THREAD		0x00010000
75 #define IRQF_EARLY_RESUME	0x00020000
76 #define IRQF_COND_SUSPEND	0x00040000
77 
78 #define IRQF_TIMER		(__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD)
79 
80 /*
81  * These values can be returned by request_any_context_irq() and
82  * describe the context the interrupt will be run in.
83  *
84  * IRQC_IS_HARDIRQ - interrupt runs in hardirq context
85  * IRQC_IS_NESTED - interrupt runs in a nested threaded context
86  */
87 enum {
88 	IRQC_IS_HARDIRQ	= 0,
89 	IRQC_IS_NESTED,
90 };
91 
92 typedef irqreturn_t (*irq_handler_t)(int, void *);
93 
94 /**
95  * struct irqaction - per interrupt action descriptor
96  * @handler:	interrupt handler function
97  * @name:	name of the device
98  * @dev_id:	cookie to identify the device
99  * @percpu_dev_id:	cookie to identify the device
100  * @next:	pointer to the next irqaction for shared interrupts
101  * @irq:	interrupt number
102  * @flags:	flags (see IRQF_* above)
103  * @thread_fn:	interrupt handler function for threaded interrupts
104  * @thread:	thread pointer for threaded interrupts
105  * @secondary:	pointer to secondary irqaction (force threading)
106  * @thread_flags:	flags related to @thread
107  * @thread_mask:	bitmask for keeping track of @thread activity
108  * @dir:	pointer to the proc/irq/NN/name entry
109  */
110 struct irqaction {
111 	irq_handler_t		handler;
112 	void			*dev_id;
113 	void __percpu		*percpu_dev_id;
114 	struct irqaction	*next;
115 	irq_handler_t		thread_fn;
116 	struct task_struct	*thread;
117 	struct irqaction	*secondary;
118 	unsigned int		irq;
119 	unsigned int		flags;
120 	unsigned long		thread_flags;
121 	unsigned long		thread_mask;
122 	const char		*name;
123 	struct proc_dir_entry	*dir;
124 } ____cacheline_internodealigned_in_smp;
125 
126 extern irqreturn_t no_action(int cpl, void *dev_id);
127 
128 /*
129  * If a (PCI) device interrupt is not connected we set dev->irq to
130  * IRQ_NOTCONNECTED. This causes request_irq() to fail with -ENOTCONN, so we
131  * can distingiush that case from other error returns.
132  *
133  * 0x80000000 is guaranteed to be outside the available range of interrupts
134  * and easy to distinguish from other possible incorrect values.
135  */
136 #define IRQ_NOTCONNECTED	(1U << 31)
137 
138 extern int __must_check
139 request_threaded_irq(unsigned int irq, irq_handler_t handler,
140 		     irq_handler_t thread_fn,
141 		     unsigned long flags, const char *name, void *dev);
142 
143 static inline int __must_check
request_irq(unsigned int irq,irq_handler_t handler,unsigned long flags,const char * name,void * dev)144 request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
145 	    const char *name, void *dev)
146 {
147 	return request_threaded_irq(irq, handler, NULL, flags, name, dev);
148 }
149 
150 extern int __must_check
151 request_any_context_irq(unsigned int irq, irq_handler_t handler,
152 			unsigned long flags, const char *name, void *dev_id);
153 
154 extern int __must_check
155 __request_percpu_irq(unsigned int irq, irq_handler_t handler,
156 		     unsigned long flags, const char *devname,
157 		     void __percpu *percpu_dev_id);
158 
159 extern int __must_check
160 request_nmi(unsigned int irq, irq_handler_t handler, unsigned long flags,
161 	    const char *name, void *dev);
162 
163 static inline int __must_check
request_percpu_irq(unsigned int irq,irq_handler_t handler,const char * devname,void __percpu * percpu_dev_id)164 request_percpu_irq(unsigned int irq, irq_handler_t handler,
165 		   const char *devname, void __percpu *percpu_dev_id)
166 {
167 	return __request_percpu_irq(irq, handler, 0,
168 				    devname, percpu_dev_id);
169 }
170 
171 extern int __must_check
172 request_percpu_nmi(unsigned int irq, irq_handler_t handler,
173 		   const char *devname, void __percpu *dev);
174 
175 extern const void *free_irq(unsigned int, void *);
176 extern void free_percpu_irq(unsigned int, void __percpu *);
177 
178 extern const void *free_nmi(unsigned int irq, void *dev_id);
179 extern void free_percpu_nmi(unsigned int irq, void __percpu *percpu_dev_id);
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
devm_request_irq(struct device * dev,unsigned int irq,irq_handler_t handler,unsigned long irqflags,const char * devname,void * dev_id)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 int __must_check
198 devm_request_any_context_irq(struct device *dev, unsigned int irq,
199 		 irq_handler_t handler, unsigned long irqflags,
200 		 const char *devname, void *dev_id);
201 
202 extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
203 
204 /*
205  * On lockdep we dont want to enable hardirqs in hardirq
206  * context. Use local_irq_enable_in_hardirq() to annotate
207  * kernel code that has to do this nevertheless (pretty much
208  * the only valid case is for old/broken hardware that is
209  * insanely slow).
210  *
211  * NOTE: in theory this might break fragile code that relies
212  * on hardirq delivery - in practice we dont seem to have such
213  * places left. So the only effect should be slightly increased
214  * irqs-off latencies.
215  */
216 #ifdef CONFIG_LOCKDEP
217 # define local_irq_enable_in_hardirq()	do { } while (0)
218 #else
219 # define local_irq_enable_in_hardirq()	local_irq_enable()
220 #endif
221 
222 extern void disable_irq_nosync(unsigned int irq);
223 extern bool disable_hardirq(unsigned int irq);
224 extern void disable_irq(unsigned int irq);
225 extern void disable_percpu_irq(unsigned int irq);
226 extern void enable_irq(unsigned int irq);
227 extern void enable_percpu_irq(unsigned int irq, unsigned int type);
228 extern bool irq_percpu_is_enabled(unsigned int irq);
229 extern void irq_wake_thread(unsigned int irq, void *dev_id);
230 
231 extern void disable_nmi_nosync(unsigned int irq);
232 extern void disable_percpu_nmi(unsigned int irq);
233 extern void enable_nmi(unsigned int irq);
234 extern void enable_percpu_nmi(unsigned int irq, unsigned int type);
235 extern int prepare_percpu_nmi(unsigned int irq);
236 extern void teardown_percpu_nmi(unsigned int irq);
237 
238 /* The following three functions are for the core kernel use only. */
239 extern void suspend_device_irqs(void);
240 extern void resume_device_irqs(void);
241 extern void rearm_wake_irq(unsigned int irq);
242 
243 /**
244  * struct irq_affinity_notify - context for notification of IRQ affinity changes
245  * @irq:		Interrupt to which notification applies
246  * @kref:		Reference count, for internal use
247  * @work:		Work item, for internal use
248  * @notify:		Function to be called on change.  This will be
249  *			called in process context.
250  * @release:		Function to be called on release.  This will be
251  *			called in process context.  Once registered, the
252  *			structure must only be freed when this function is
253  *			called or later.
254  */
255 struct irq_affinity_notify {
256 	unsigned int irq;
257 	struct kref kref;
258 	struct work_struct work;
259 	void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
260 	void (*release)(struct kref *ref);
261 };
262 
263 #define	IRQ_AFFINITY_MAX_SETS  4
264 
265 /**
266  * struct irq_affinity - Description for automatic irq affinity assignements
267  * @pre_vectors:	Don't apply affinity to @pre_vectors at beginning of
268  *			the MSI(-X) vector space
269  * @post_vectors:	Don't apply affinity to @post_vectors at end of
270  *			the MSI(-X) vector space
271  * @nr_sets:		The number of interrupt sets for which affinity
272  *			spreading is required
273  * @set_size:		Array holding the size of each interrupt set
274  * @calc_sets:		Callback for calculating the number and size
275  *			of interrupt sets
276  * @priv:		Private data for usage by @calc_sets, usually a
277  *			pointer to driver/device specific data.
278  */
279 struct irq_affinity {
280 	unsigned int	pre_vectors;
281 	unsigned int	post_vectors;
282 	unsigned int	nr_sets;
283 	unsigned int	set_size[IRQ_AFFINITY_MAX_SETS];
284 	void		(*calc_sets)(struct irq_affinity *, unsigned int nvecs);
285 	void		*priv;
286 };
287 
288 /**
289  * struct irq_affinity_desc - Interrupt affinity descriptor
290  * @mask:	cpumask to hold the affinity assignment
291  * @is_managed: 1 if the interrupt is managed internally
292  */
293 struct irq_affinity_desc {
294 	struct cpumask	mask;
295 	unsigned int	is_managed : 1;
296 };
297 
298 #if defined(CONFIG_SMP)
299 
300 extern cpumask_var_t irq_default_affinity;
301 
302 /* Internal implementation. Use the helpers below */
303 extern int __irq_set_affinity(unsigned int irq, const struct cpumask *cpumask,
304 			      bool force);
305 
306 /**
307  * irq_set_affinity - Set the irq affinity of a given irq
308  * @irq:	Interrupt to set affinity
309  * @cpumask:	cpumask
310  *
311  * Fails if cpumask does not contain an online CPU
312  */
313 static inline int
irq_set_affinity(unsigned int irq,const struct cpumask * cpumask)314 irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
315 {
316 	return __irq_set_affinity(irq, cpumask, false);
317 }
318 
319 /**
320  * irq_force_affinity - Force the irq affinity of a given irq
321  * @irq:	Interrupt to set affinity
322  * @cpumask:	cpumask
323  *
324  * Same as irq_set_affinity, but without checking the mask against
325  * online cpus.
326  *
327  * Solely for low level cpu hotplug code, where we need to make per
328  * cpu interrupts affine before the cpu becomes online.
329  */
330 static inline int
irq_force_affinity(unsigned int irq,const struct cpumask * cpumask)331 irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
332 {
333 	return __irq_set_affinity(irq, cpumask, true);
334 }
335 
336 extern int irq_can_set_affinity(unsigned int irq);
337 extern int irq_select_affinity(unsigned int irq);
338 
339 extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m);
340 
341 extern int
342 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
343 
344 struct irq_affinity_desc *
345 irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd);
346 
347 unsigned int irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
348 				       const struct irq_affinity *affd);
349 
350 #else /* CONFIG_SMP */
351 
irq_set_affinity(unsigned int irq,const struct cpumask * m)352 static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
353 {
354 	return -EINVAL;
355 }
356 
irq_force_affinity(unsigned int irq,const struct cpumask * cpumask)357 static inline int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
358 {
359 	return 0;
360 }
361 
irq_can_set_affinity(unsigned int irq)362 static inline int irq_can_set_affinity(unsigned int irq)
363 {
364 	return 0;
365 }
366 
irq_select_affinity(unsigned int irq)367 static inline int irq_select_affinity(unsigned int irq)  { return 0; }
368 
irq_set_affinity_hint(unsigned int irq,const struct cpumask * m)369 static inline int irq_set_affinity_hint(unsigned int irq,
370 					const struct cpumask *m)
371 {
372 	return -EINVAL;
373 }
374 
375 static inline int
irq_set_affinity_notifier(unsigned int irq,struct irq_affinity_notify * notify)376 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
377 {
378 	return 0;
379 }
380 
381 static inline struct irq_affinity_desc *
irq_create_affinity_masks(unsigned int nvec,struct irq_affinity * affd)382 irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd)
383 {
384 	return NULL;
385 }
386 
387 static inline unsigned int
irq_calc_affinity_vectors(unsigned int minvec,unsigned int maxvec,const struct irq_affinity * affd)388 irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
389 			  const struct irq_affinity *affd)
390 {
391 	return maxvec;
392 }
393 
394 #endif /* CONFIG_SMP */
395 
396 /*
397  * Special lockdep variants of irq disabling/enabling.
398  * These should be used for locking constructs that
399  * know that a particular irq context which is disabled,
400  * and which is the only irq-context user of a lock,
401  * that it's safe to take the lock in the irq-disabled
402  * section without disabling hardirqs.
403  *
404  * On !CONFIG_LOCKDEP they are equivalent to the normal
405  * irq disable/enable methods.
406  */
disable_irq_nosync_lockdep(unsigned int irq)407 static inline void disable_irq_nosync_lockdep(unsigned int irq)
408 {
409 	disable_irq_nosync(irq);
410 #ifdef CONFIG_LOCKDEP
411 	local_irq_disable();
412 #endif
413 }
414 
disable_irq_nosync_lockdep_irqsave(unsigned int irq,unsigned long * flags)415 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
416 {
417 	disable_irq_nosync(irq);
418 #ifdef CONFIG_LOCKDEP
419 	local_irq_save(*flags);
420 #endif
421 }
422 
disable_irq_lockdep(unsigned int irq)423 static inline void disable_irq_lockdep(unsigned int irq)
424 {
425 	disable_irq(irq);
426 #ifdef CONFIG_LOCKDEP
427 	local_irq_disable();
428 #endif
429 }
430 
enable_irq_lockdep(unsigned int irq)431 static inline void enable_irq_lockdep(unsigned int irq)
432 {
433 #ifdef CONFIG_LOCKDEP
434 	local_irq_enable();
435 #endif
436 	enable_irq(irq);
437 }
438 
enable_irq_lockdep_irqrestore(unsigned int irq,unsigned long * flags)439 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
440 {
441 #ifdef CONFIG_LOCKDEP
442 	local_irq_restore(*flags);
443 #endif
444 	enable_irq(irq);
445 }
446 
447 /* IRQ wakeup (PM) control: */
448 extern int irq_set_irq_wake(unsigned int irq, unsigned int on);
449 
enable_irq_wake(unsigned int irq)450 static inline int enable_irq_wake(unsigned int irq)
451 {
452 	return irq_set_irq_wake(irq, 1);
453 }
454 
disable_irq_wake(unsigned int irq)455 static inline int disable_irq_wake(unsigned int irq)
456 {
457 	return irq_set_irq_wake(irq, 0);
458 }
459 
460 /*
461  * irq_get_irqchip_state/irq_set_irqchip_state specific flags
462  */
463 enum irqchip_irq_state {
464 	IRQCHIP_STATE_PENDING,		/* Is interrupt pending? */
465 	IRQCHIP_STATE_ACTIVE,		/* Is interrupt in progress? */
466 	IRQCHIP_STATE_MASKED,		/* Is interrupt masked? */
467 	IRQCHIP_STATE_LINE_LEVEL,	/* Is IRQ line high? */
468 };
469 
470 extern int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
471 				 bool *state);
472 extern int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
473 				 bool state);
474 
475 #ifdef CONFIG_IRQ_FORCED_THREADING
476 # ifdef CONFIG_PREEMPT_RT
477 #  define force_irqthreads	(true)
478 # else
479 extern bool force_irqthreads;
480 # endif
481 #else
482 #define force_irqthreads	(0)
483 #endif
484 
485 #ifndef local_softirq_pending
486 
487 #ifndef local_softirq_pending_ref
488 #define local_softirq_pending_ref irq_stat.__softirq_pending
489 #endif
490 
491 #define local_softirq_pending()	(__this_cpu_read(local_softirq_pending_ref))
492 #define set_softirq_pending(x)	(__this_cpu_write(local_softirq_pending_ref, (x)))
493 #define or_softirq_pending(x)	(__this_cpu_or(local_softirq_pending_ref, (x)))
494 
495 #endif /* local_softirq_pending */
496 
497 /* Some architectures might implement lazy enabling/disabling of
498  * interrupts. In some cases, such as stop_machine, we might want
499  * to ensure that after a local_irq_disable(), interrupts have
500  * really been disabled in hardware. Such architectures need to
501  * implement the following hook.
502  */
503 #ifndef hard_irq_disable
504 #define hard_irq_disable()	do { } while(0)
505 #endif
506 
507 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
508    frequency threaded job scheduling. For almost all the purposes
509    tasklets are more than enough. F.e. all serial device BHs et
510    al. should be converted to tasklets, not to softirqs.
511  */
512 
513 enum
514 {
515 	HI_SOFTIRQ=0,
516 	TIMER_SOFTIRQ,
517 	NET_TX_SOFTIRQ,
518 	NET_RX_SOFTIRQ,
519 	BLOCK_SOFTIRQ,
520 	IRQ_POLL_SOFTIRQ,
521 	TASKLET_SOFTIRQ,
522 	SCHED_SOFTIRQ,
523 	HRTIMER_SOFTIRQ, /* Unused, but kept as tools rely on the
524 			    numbering. Sigh! */
525 	RCU_SOFTIRQ,    /* Preferable RCU should always be the last softirq */
526 
527 	NR_SOFTIRQS
528 };
529 
530 #define SOFTIRQ_STOP_IDLE_MASK (~(1 << RCU_SOFTIRQ))
531 
532 /* map softirq index to softirq name. update 'softirq_to_name' in
533  * kernel/softirq.c when adding a new softirq.
534  */
535 extern const char * const softirq_to_name[NR_SOFTIRQS];
536 
537 /* softirq mask and active fields moved to irq_cpustat_t in
538  * asm/hardirq.h to get better cache usage.  KAO
539  */
540 
541 struct softirq_action
542 {
543 	void	(*action)(struct softirq_action *);
544 };
545 
546 asmlinkage void do_softirq(void);
547 asmlinkage void __do_softirq(void);
548 
549 #ifdef __ARCH_HAS_DO_SOFTIRQ
550 void do_softirq_own_stack(void);
551 #else
do_softirq_own_stack(void)552 static inline void do_softirq_own_stack(void)
553 {
554 	__do_softirq();
555 }
556 #endif
557 
558 extern void open_softirq(int nr, void (*action)(struct softirq_action *));
559 extern void softirq_init(void);
560 extern void __raise_softirq_irqoff(unsigned int nr);
561 
562 extern void raise_softirq_irqoff(unsigned int nr);
563 extern void raise_softirq(unsigned int nr);
564 
565 DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
566 
this_cpu_ksoftirqd(void)567 static inline struct task_struct *this_cpu_ksoftirqd(void)
568 {
569 	return this_cpu_read(ksoftirqd);
570 }
571 
572 /* Tasklets --- multithreaded analogue of BHs.
573 
574    Main feature differing them of generic softirqs: tasklet
575    is running only on one CPU simultaneously.
576 
577    Main feature differing them of BHs: different tasklets
578    may be run simultaneously on different CPUs.
579 
580    Properties:
581    * If tasklet_schedule() is called, then tasklet is guaranteed
582      to be executed on some cpu at least once after this.
583    * If the tasklet is already scheduled, but its execution is still not
584      started, it will be executed only once.
585    * If this tasklet is already running on another CPU (or schedule is called
586      from tasklet itself), it is rescheduled for later.
587    * Tasklet is strictly serialized wrt itself, but not
588      wrt another tasklets. If client needs some intertask synchronization,
589      he makes it with spinlocks.
590  */
591 
592 struct tasklet_struct
593 {
594 	struct tasklet_struct *next;
595 	unsigned long state;
596 	atomic_t count;
597 	void (*func)(unsigned long);
598 	unsigned long data;
599 };
600 
601 #define DECLARE_TASKLET(name, func, data) \
602 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
603 
604 #define DECLARE_TASKLET_DISABLED(name, func, data) \
605 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
606 
607 
608 enum
609 {
610 	TASKLET_STATE_SCHED,	/* Tasklet is scheduled for execution */
611 	TASKLET_STATE_RUN	/* Tasklet is running (SMP only) */
612 };
613 
614 #ifdef CONFIG_SMP
tasklet_trylock(struct tasklet_struct * t)615 static inline int tasklet_trylock(struct tasklet_struct *t)
616 {
617 	return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
618 }
619 
tasklet_unlock(struct tasklet_struct * t)620 static inline void tasklet_unlock(struct tasklet_struct *t)
621 {
622 	smp_mb__before_atomic();
623 	clear_bit(TASKLET_STATE_RUN, &(t)->state);
624 }
625 
tasklet_unlock_wait(struct tasklet_struct * t)626 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
627 {
628 	while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
629 }
630 #else
631 #define tasklet_trylock(t) 1
632 #define tasklet_unlock_wait(t) do { } while (0)
633 #define tasklet_unlock(t) do { } while (0)
634 #endif
635 
636 extern void __tasklet_schedule(struct tasklet_struct *t);
637 
tasklet_schedule(struct tasklet_struct * t)638 static inline void tasklet_schedule(struct tasklet_struct *t)
639 {
640 	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
641 		__tasklet_schedule(t);
642 }
643 
644 extern void __tasklet_hi_schedule(struct tasklet_struct *t);
645 
tasklet_hi_schedule(struct tasklet_struct * t)646 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
647 {
648 	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
649 		__tasklet_hi_schedule(t);
650 }
651 
tasklet_disable_nosync(struct tasklet_struct * t)652 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
653 {
654 	atomic_inc(&t->count);
655 	smp_mb__after_atomic();
656 }
657 
tasklet_disable(struct tasklet_struct * t)658 static inline void tasklet_disable(struct tasklet_struct *t)
659 {
660 	tasklet_disable_nosync(t);
661 	tasklet_unlock_wait(t);
662 	smp_mb();
663 }
664 
tasklet_enable(struct tasklet_struct * t)665 static inline void tasklet_enable(struct tasklet_struct *t)
666 {
667 	smp_mb__before_atomic();
668 	atomic_dec(&t->count);
669 }
670 
671 extern void tasklet_kill(struct tasklet_struct *t);
672 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
673 extern void tasklet_init(struct tasklet_struct *t,
674 			 void (*func)(unsigned long), unsigned long data);
675 
676 /*
677  * Autoprobing for irqs:
678  *
679  * probe_irq_on() and probe_irq_off() provide robust primitives
680  * for accurate IRQ probing during kernel initialization.  They are
681  * reasonably simple to use, are not "fooled" by spurious interrupts,
682  * and, unlike other attempts at IRQ probing, they do not get hung on
683  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
684  *
685  * For reasonably foolproof probing, use them as follows:
686  *
687  * 1. clear and/or mask the device's internal interrupt.
688  * 2. sti();
689  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
690  * 4. enable the device and cause it to trigger an interrupt.
691  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
692  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
693  * 7. service the device to clear its pending interrupt.
694  * 8. loop again if paranoia is required.
695  *
696  * probe_irq_on() returns a mask of allocated irq's.
697  *
698  * probe_irq_off() takes the mask as a parameter,
699  * and returns the irq number which occurred,
700  * or zero if none occurred, or a negative irq number
701  * if more than one irq occurred.
702  */
703 
704 #if !defined(CONFIG_GENERIC_IRQ_PROBE)
probe_irq_on(void)705 static inline unsigned long probe_irq_on(void)
706 {
707 	return 0;
708 }
probe_irq_off(unsigned long val)709 static inline int probe_irq_off(unsigned long val)
710 {
711 	return 0;
712 }
probe_irq_mask(unsigned long val)713 static inline unsigned int probe_irq_mask(unsigned long val)
714 {
715 	return 0;
716 }
717 #else
718 extern unsigned long probe_irq_on(void);	/* returns 0 on failure */
719 extern int probe_irq_off(unsigned long);	/* returns 0 or negative on failure */
720 extern unsigned int probe_irq_mask(unsigned long);	/* returns mask of ISA interrupts */
721 #endif
722 
723 #ifdef CONFIG_PROC_FS
724 /* Initialize /proc/irq/ */
725 extern void init_irq_proc(void);
726 #else
init_irq_proc(void)727 static inline void init_irq_proc(void)
728 {
729 }
730 #endif
731 
732 #ifdef CONFIG_IRQ_TIMINGS
733 void irq_timings_enable(void);
734 void irq_timings_disable(void);
735 u64 irq_timings_next_event(u64 now);
736 #endif
737 
738 struct seq_file;
739 int show_interrupts(struct seq_file *p, void *v);
740 int arch_show_interrupts(struct seq_file *p, int prec);
741 
742 extern int early_irq_init(void);
743 extern int arch_probe_nr_irqs(void);
744 extern int arch_early_irq_init(void);
745 
746 /*
747  * We want to know which function is an entrypoint of a hardirq or a softirq.
748  */
749 #define __irq_entry		 __attribute__((__section__(".irqentry.text")))
750 #define __softirq_entry  \
751 	__attribute__((__section__(".softirqentry.text")))
752 
753 #endif
754