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v5.9
  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 */
 87enum {
 88	IRQC_IS_HARDIRQ	= 0,
 89	IRQC_IS_NESTED,
 90};
 91
 92typedef 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 */
110struct 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
126extern 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
138extern int __must_check
139request_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/**
144 * request_irq - Add a handler for an interrupt line
145 * @irq:	The interrupt line to allocate
146 * @handler:	Function to be called when the IRQ occurs.
147 *		Primary handler for threaded interrupts
148 *		If NULL, the default primary handler is installed
149 * @flags:	Handling flags
150 * @name:	Name of the device generating this interrupt
151 * @dev:	A cookie passed to the handler function
152 *
153 * This call allocates an interrupt and establishes a handler; see
154 * the documentation for request_threaded_irq() for details.
155 */
156static inline int __must_check
157request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
158	    const char *name, void *dev)
159{
160	return request_threaded_irq(irq, handler, NULL, flags, name, dev);
161}
162
163extern int __must_check
164request_any_context_irq(unsigned int irq, irq_handler_t handler,
165			unsigned long flags, const char *name, void *dev_id);
166
167extern int __must_check
168__request_percpu_irq(unsigned int irq, irq_handler_t handler,
169		     unsigned long flags, const char *devname,
170		     void __percpu *percpu_dev_id);
171
172extern int __must_check
173request_nmi(unsigned int irq, irq_handler_t handler, unsigned long flags,
174	    const char *name, void *dev);
175
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
176static inline int __must_check
177request_percpu_irq(unsigned int irq, irq_handler_t handler,
178		   const char *devname, void __percpu *percpu_dev_id)
179{
180	return __request_percpu_irq(irq, handler, 0,
181				    devname, percpu_dev_id);
182}
 
183
184extern int __must_check
185request_percpu_nmi(unsigned int irq, irq_handler_t handler,
186		   const char *devname, void __percpu *dev);
187
188extern const void *free_irq(unsigned int, void *);
189extern void free_percpu_irq(unsigned int, void __percpu *);
190
191extern const void *free_nmi(unsigned int irq, void *dev_id);
192extern void free_percpu_nmi(unsigned int irq, void __percpu *percpu_dev_id);
193
194struct device;
195
196extern int __must_check
197devm_request_threaded_irq(struct device *dev, unsigned int irq,
198			  irq_handler_t handler, irq_handler_t thread_fn,
199			  unsigned long irqflags, const char *devname,
200			  void *dev_id);
201
202static inline int __must_check
203devm_request_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
204		 unsigned long irqflags, const char *devname, void *dev_id)
205{
206	return devm_request_threaded_irq(dev, irq, handler, NULL, irqflags,
207					 devname, dev_id);
208}
209
210extern int __must_check
211devm_request_any_context_irq(struct device *dev, unsigned int irq,
212		 irq_handler_t handler, unsigned long irqflags,
213		 const char *devname, void *dev_id);
214
215extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
216
217/*
218 * On lockdep we dont want to enable hardirqs in hardirq
219 * context. Use local_irq_enable_in_hardirq() to annotate
220 * kernel code that has to do this nevertheless (pretty much
221 * the only valid case is for old/broken hardware that is
222 * insanely slow).
223 *
224 * NOTE: in theory this might break fragile code that relies
225 * on hardirq delivery - in practice we dont seem to have such
226 * places left. So the only effect should be slightly increased
227 * irqs-off latencies.
228 */
229#ifdef CONFIG_LOCKDEP
230# define local_irq_enable_in_hardirq()	do { } while (0)
231#else
232# define local_irq_enable_in_hardirq()	local_irq_enable()
233#endif
234
235extern void disable_irq_nosync(unsigned int irq);
236extern bool disable_hardirq(unsigned int irq);
237extern void disable_irq(unsigned int irq);
238extern void disable_percpu_irq(unsigned int irq);
239extern void enable_irq(unsigned int irq);
240extern void enable_percpu_irq(unsigned int irq, unsigned int type);
241extern bool irq_percpu_is_enabled(unsigned int irq);
242extern void irq_wake_thread(unsigned int irq, void *dev_id);
243
244extern void disable_nmi_nosync(unsigned int irq);
245extern void disable_percpu_nmi(unsigned int irq);
246extern void enable_nmi(unsigned int irq);
247extern void enable_percpu_nmi(unsigned int irq, unsigned int type);
248extern int prepare_percpu_nmi(unsigned int irq);
249extern void teardown_percpu_nmi(unsigned int irq);
250
251extern int irq_inject_interrupt(unsigned int irq);
252
253/* The following three functions are for the core kernel use only. */
 
254extern void suspend_device_irqs(void);
255extern void resume_device_irqs(void);
256extern void rearm_wake_irq(unsigned int irq);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
257
258/**
259 * struct irq_affinity_notify - context for notification of IRQ affinity changes
260 * @irq:		Interrupt to which notification applies
261 * @kref:		Reference count, for internal use
262 * @work:		Work item, for internal use
263 * @notify:		Function to be called on change.  This will be
264 *			called in process context.
265 * @release:		Function to be called on release.  This will be
266 *			called in process context.  Once registered, the
267 *			structure must only be freed when this function is
268 *			called or later.
269 */
270struct irq_affinity_notify {
271	unsigned int irq;
272	struct kref kref;
273	struct work_struct work;
274	void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
275	void (*release)(struct kref *ref);
276};
277
278#define	IRQ_AFFINITY_MAX_SETS  4
279
280/**
281 * struct irq_affinity - Description for automatic irq affinity assignements
282 * @pre_vectors:	Don't apply affinity to @pre_vectors at beginning of
283 *			the MSI(-X) vector space
284 * @post_vectors:	Don't apply affinity to @post_vectors at end of
285 *			the MSI(-X) vector space
286 * @nr_sets:		The number of interrupt sets for which affinity
287 *			spreading is required
288 * @set_size:		Array holding the size of each interrupt set
289 * @calc_sets:		Callback for calculating the number and size
290 *			of interrupt sets
291 * @priv:		Private data for usage by @calc_sets, usually a
292 *			pointer to driver/device specific data.
293 */
294struct irq_affinity {
295	unsigned int	pre_vectors;
296	unsigned int	post_vectors;
297	unsigned int	nr_sets;
298	unsigned int	set_size[IRQ_AFFINITY_MAX_SETS];
299	void		(*calc_sets)(struct irq_affinity *, unsigned int nvecs);
300	void		*priv;
301};
302
303/**
304 * struct irq_affinity_desc - Interrupt affinity descriptor
305 * @mask:	cpumask to hold the affinity assignment
306 * @is_managed: 1 if the interrupt is managed internally
307 */
308struct irq_affinity_desc {
309	struct cpumask	mask;
310	unsigned int	is_managed : 1;
311};
312
313#if defined(CONFIG_SMP)
314
315extern cpumask_var_t irq_default_affinity;
316
317/* Internal implementation. Use the helpers below */
318extern int __irq_set_affinity(unsigned int irq, const struct cpumask *cpumask,
319			      bool force);
320
321/**
322 * irq_set_affinity - Set the irq affinity of a given irq
323 * @irq:	Interrupt to set affinity
324 * @cpumask:	cpumask
325 *
326 * Fails if cpumask does not contain an online CPU
327 */
328static inline int
329irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
330{
331	return __irq_set_affinity(irq, cpumask, false);
332}
333
334/**
335 * irq_force_affinity - Force the irq affinity of a given irq
336 * @irq:	Interrupt to set affinity
337 * @cpumask:	cpumask
338 *
339 * Same as irq_set_affinity, but without checking the mask against
340 * online cpus.
341 *
342 * Solely for low level cpu hotplug code, where we need to make per
343 * cpu interrupts affine before the cpu becomes online.
344 */
345static inline int
346irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
347{
348	return __irq_set_affinity(irq, cpumask, true);
349}
350
351extern int irq_can_set_affinity(unsigned int irq);
352extern int irq_select_affinity(unsigned int irq);
353
354extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m);
355
356extern int
357irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
358
359struct irq_affinity_desc *
360irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd);
361
362unsigned int irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
363				       const struct irq_affinity *affd);
364
365#else /* CONFIG_SMP */
366
367static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
368{
369	return -EINVAL;
370}
371
372static inline int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
373{
374	return 0;
375}
376
377static inline int irq_can_set_affinity(unsigned int irq)
378{
379	return 0;
380}
381
382static inline int irq_select_affinity(unsigned int irq)  { return 0; }
383
384static inline int irq_set_affinity_hint(unsigned int irq,
385					const struct cpumask *m)
386{
387	return -EINVAL;
388}
 
389
390static inline int
391irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
392{
393	return 0;
394}
395
396static inline struct irq_affinity_desc *
397irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd)
398{
399	return NULL;
400}
401
402static inline unsigned int
403irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
404			  const struct irq_affinity *affd)
405{
406	return maxvec;
407}
408
409#endif /* CONFIG_SMP */
410
411/*
412 * Special lockdep variants of irq disabling/enabling.
413 * These should be used for locking constructs that
414 * know that a particular irq context which is disabled,
415 * and which is the only irq-context user of a lock,
416 * that it's safe to take the lock in the irq-disabled
417 * section without disabling hardirqs.
418 *
419 * On !CONFIG_LOCKDEP they are equivalent to the normal
420 * irq disable/enable methods.
421 */
422static inline void disable_irq_nosync_lockdep(unsigned int irq)
423{
424	disable_irq_nosync(irq);
425#ifdef CONFIG_LOCKDEP
426	local_irq_disable();
427#endif
428}
429
430static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
431{
432	disable_irq_nosync(irq);
433#ifdef CONFIG_LOCKDEP
434	local_irq_save(*flags);
435#endif
436}
437
438static inline void disable_irq_lockdep(unsigned int irq)
439{
440	disable_irq(irq);
441#ifdef CONFIG_LOCKDEP
442	local_irq_disable();
443#endif
444}
445
446static inline void enable_irq_lockdep(unsigned int irq)
447{
448#ifdef CONFIG_LOCKDEP
449	local_irq_enable();
450#endif
451	enable_irq(irq);
452}
453
454static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
455{
456#ifdef CONFIG_LOCKDEP
457	local_irq_restore(*flags);
458#endif
459	enable_irq(irq);
460}
461
462/* IRQ wakeup (PM) control: */
463extern int irq_set_irq_wake(unsigned int irq, unsigned int on);
464
465static inline int enable_irq_wake(unsigned int irq)
466{
467	return irq_set_irq_wake(irq, 1);
468}
469
470static inline int disable_irq_wake(unsigned int irq)
471{
472	return irq_set_irq_wake(irq, 0);
473}
474
 
475/*
476 * irq_get_irqchip_state/irq_set_irqchip_state specific flags
477 */
478enum irqchip_irq_state {
479	IRQCHIP_STATE_PENDING,		/* Is interrupt pending? */
480	IRQCHIP_STATE_ACTIVE,		/* Is interrupt in progress? */
481	IRQCHIP_STATE_MASKED,		/* Is interrupt masked? */
482	IRQCHIP_STATE_LINE_LEVEL,	/* Is IRQ line high? */
483};
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
484
485extern int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
486				 bool *state);
487extern int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
488				 bool state);
489
490#ifdef CONFIG_IRQ_FORCED_THREADING
491# ifdef CONFIG_PREEMPT_RT
492#  define force_irqthreads	(true)
493# else
494extern bool force_irqthreads;
495# endif
496#else
497#define force_irqthreads	(0)
498#endif
499
500#ifndef local_softirq_pending
501
502#ifndef local_softirq_pending_ref
503#define local_softirq_pending_ref irq_stat.__softirq_pending
504#endif
505
506#define local_softirq_pending()	(__this_cpu_read(local_softirq_pending_ref))
507#define set_softirq_pending(x)	(__this_cpu_write(local_softirq_pending_ref, (x)))
508#define or_softirq_pending(x)	(__this_cpu_or(local_softirq_pending_ref, (x)))
509
510#endif /* local_softirq_pending */
511
512/* Some architectures might implement lazy enabling/disabling of
513 * interrupts. In some cases, such as stop_machine, we might want
514 * to ensure that after a local_irq_disable(), interrupts have
515 * really been disabled in hardware. Such architectures need to
516 * implement the following hook.
517 */
518#ifndef hard_irq_disable
519#define hard_irq_disable()	do { } while(0)
520#endif
521
522/* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
523   frequency threaded job scheduling. For almost all the purposes
524   tasklets are more than enough. F.e. all serial device BHs et
525   al. should be converted to tasklets, not to softirqs.
526 */
527
528enum
529{
530	HI_SOFTIRQ=0,
531	TIMER_SOFTIRQ,
532	NET_TX_SOFTIRQ,
533	NET_RX_SOFTIRQ,
534	BLOCK_SOFTIRQ,
535	IRQ_POLL_SOFTIRQ,
536	TASKLET_SOFTIRQ,
537	SCHED_SOFTIRQ,
538	HRTIMER_SOFTIRQ,
539	RCU_SOFTIRQ,    /* Preferable RCU should always be the last softirq */
540
541	NR_SOFTIRQS
542};
543
544#define SOFTIRQ_STOP_IDLE_MASK (~(1 << RCU_SOFTIRQ))
545
546/* map softirq index to softirq name. update 'softirq_to_name' in
547 * kernel/softirq.c when adding a new softirq.
548 */
549extern const char * const softirq_to_name[NR_SOFTIRQS];
550
551/* softirq mask and active fields moved to irq_cpustat_t in
552 * asm/hardirq.h to get better cache usage.  KAO
553 */
554
555struct softirq_action
556{
557	void	(*action)(struct softirq_action *);
558};
559
560asmlinkage void do_softirq(void);
561asmlinkage void __do_softirq(void);
562
563#ifdef __ARCH_HAS_DO_SOFTIRQ
564void do_softirq_own_stack(void);
565#else
566static inline void do_softirq_own_stack(void)
567{
568	__do_softirq();
569}
570#endif
571
572extern void open_softirq(int nr, void (*action)(struct softirq_action *));
573extern void softirq_init(void);
574extern void __raise_softirq_irqoff(unsigned int nr);
575
576extern void raise_softirq_irqoff(unsigned int nr);
577extern void raise_softirq(unsigned int nr);
578
 
 
 
 
 
 
 
 
 
579DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
580
581static inline struct task_struct *this_cpu_ksoftirqd(void)
582{
583	return this_cpu_read(ksoftirqd);
584}
585
586/* Tasklets --- multithreaded analogue of BHs.
 
 
 
587
588   This API is deprecated. Please consider using threaded IRQs instead:
589   https://lore.kernel.org/lkml/20200716081538.2sivhkj4hcyrusem@linutronix.de
 
 
 
 
 
590
591   Main feature differing them of generic softirqs: tasklet
592   is running only on one CPU simultaneously.
593
594   Main feature differing them of BHs: different tasklets
595   may be run simultaneously on different CPUs.
596
597   Properties:
598   * If tasklet_schedule() is called, then tasklet is guaranteed
599     to be executed on some cpu at least once after this.
600   * If the tasklet is already scheduled, but its execution is still not
601     started, it will be executed only once.
602   * If this tasklet is already running on another CPU (or schedule is called
603     from tasklet itself), it is rescheduled for later.
604   * Tasklet is strictly serialized wrt itself, but not
605     wrt another tasklets. If client needs some intertask synchronization,
606     he makes it with spinlocks.
607 */
608
609struct tasklet_struct
610{
611	struct tasklet_struct *next;
612	unsigned long state;
613	atomic_t count;
614	bool use_callback;
615	union {
616		void (*func)(unsigned long data);
617		void (*callback)(struct tasklet_struct *t);
618	};
619	unsigned long data;
620};
621
622#define DECLARE_TASKLET(name, _callback)		\
623struct tasklet_struct name = {				\
624	.count = ATOMIC_INIT(0),			\
625	.callback = _callback,				\
626	.use_callback = true,				\
627}
628
629#define DECLARE_TASKLET_DISABLED(name, _callback)	\
630struct tasklet_struct name = {				\
631	.count = ATOMIC_INIT(1),			\
632	.callback = _callback,				\
633	.use_callback = true,				\
634}
635
636#define from_tasklet(var, callback_tasklet, tasklet_fieldname)	\
637	container_of(callback_tasklet, typeof(*var), tasklet_fieldname)
638
639#define DECLARE_TASKLET_OLD(name, _func)		\
640struct tasklet_struct name = {				\
641	.count = ATOMIC_INIT(0),			\
642	.func = _func,					\
643}
644
645#define DECLARE_TASKLET_DISABLED_OLD(name, _func)	\
646struct tasklet_struct name = {				\
647	.count = ATOMIC_INIT(1),			\
648	.func = _func,					\
649}
650
651enum
652{
653	TASKLET_STATE_SCHED,	/* Tasklet is scheduled for execution */
654	TASKLET_STATE_RUN	/* Tasklet is running (SMP only) */
655};
656
657#ifdef CONFIG_SMP
658static inline int tasklet_trylock(struct tasklet_struct *t)
659{
660	return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
661}
662
663static inline void tasklet_unlock(struct tasklet_struct *t)
664{
665	smp_mb__before_atomic();
666	clear_bit(TASKLET_STATE_RUN, &(t)->state);
667}
668
669static inline void tasklet_unlock_wait(struct tasklet_struct *t)
670{
671	while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
672}
673#else
674#define tasklet_trylock(t) 1
675#define tasklet_unlock_wait(t) do { } while (0)
676#define tasklet_unlock(t) do { } while (0)
677#endif
678
679extern void __tasklet_schedule(struct tasklet_struct *t);
680
681static inline void tasklet_schedule(struct tasklet_struct *t)
682{
683	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
684		__tasklet_schedule(t);
685}
686
687extern void __tasklet_hi_schedule(struct tasklet_struct *t);
688
689static inline void tasklet_hi_schedule(struct tasklet_struct *t)
690{
691	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
692		__tasklet_hi_schedule(t);
693}
694
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
695static inline void tasklet_disable_nosync(struct tasklet_struct *t)
696{
697	atomic_inc(&t->count);
698	smp_mb__after_atomic();
699}
700
701static inline void tasklet_disable(struct tasklet_struct *t)
702{
703	tasklet_disable_nosync(t);
704	tasklet_unlock_wait(t);
705	smp_mb();
706}
707
708static inline void tasklet_enable(struct tasklet_struct *t)
709{
710	smp_mb__before_atomic();
 
 
 
 
 
 
711	atomic_dec(&t->count);
712}
713
714extern void tasklet_kill(struct tasklet_struct *t);
715extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
716extern void tasklet_init(struct tasklet_struct *t,
717			 void (*func)(unsigned long), unsigned long data);
718extern void tasklet_setup(struct tasklet_struct *t,
719			  void (*callback)(struct tasklet_struct *));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
720
721/*
722 * Autoprobing for irqs:
723 *
724 * probe_irq_on() and probe_irq_off() provide robust primitives
725 * for accurate IRQ probing during kernel initialization.  They are
726 * reasonably simple to use, are not "fooled" by spurious interrupts,
727 * and, unlike other attempts at IRQ probing, they do not get hung on
728 * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
729 *
730 * For reasonably foolproof probing, use them as follows:
731 *
732 * 1. clear and/or mask the device's internal interrupt.
733 * 2. sti();
734 * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
735 * 4. enable the device and cause it to trigger an interrupt.
736 * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
737 * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
738 * 7. service the device to clear its pending interrupt.
739 * 8. loop again if paranoia is required.
740 *
741 * probe_irq_on() returns a mask of allocated irq's.
742 *
743 * probe_irq_off() takes the mask as a parameter,
744 * and returns the irq number which occurred,
745 * or zero if none occurred, or a negative irq number
746 * if more than one irq occurred.
747 */
748
749#if !defined(CONFIG_GENERIC_IRQ_PROBE) 
750static inline unsigned long probe_irq_on(void)
751{
752	return 0;
753}
754static inline int probe_irq_off(unsigned long val)
755{
756	return 0;
757}
758static inline unsigned int probe_irq_mask(unsigned long val)
759{
760	return 0;
761}
762#else
763extern unsigned long probe_irq_on(void);	/* returns 0 on failure */
764extern int probe_irq_off(unsigned long);	/* returns 0 or negative on failure */
765extern unsigned int probe_irq_mask(unsigned long);	/* returns mask of ISA interrupts */
766#endif
767
768#ifdef CONFIG_PROC_FS
769/* Initialize /proc/irq/ */
770extern void init_irq_proc(void);
771#else
772static inline void init_irq_proc(void)
773{
774}
775#endif
776
777#ifdef CONFIG_IRQ_TIMINGS
778void irq_timings_enable(void);
779void irq_timings_disable(void);
780u64 irq_timings_next_event(u64 now);
781#endif
782
783struct seq_file;
784int show_interrupts(struct seq_file *p, void *v);
785int arch_show_interrupts(struct seq_file *p, int prec);
786
787extern int early_irq_init(void);
788extern int arch_probe_nr_irqs(void);
789extern int arch_early_irq_init(void);
790
791/*
792 * We want to know which function is an entrypoint of a hardirq or a softirq.
793 */
794#ifndef __irq_entry
795# define __irq_entry	 __attribute__((__section__(".irqentry.text")))
796#endif
797
798#define __softirq_entry  __attribute__((__section__(".softirqentry.text")))
799
800#endif
v3.5.6
 
  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_SAMPLE_RANDOM - irq is used to feed the random generator
 46 * IRQF_SHARED - allow sharing the irq among several devices
 47 * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
 48 * IRQF_TIMER - Flag to mark this interrupt as timer interrupt
 49 * IRQF_PERCPU - Interrupt is per cpu
 50 * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing
 51 * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is
 52 *                registered first in an shared interrupt is considered for
 53 *                performance reasons)
 54 * IRQF_ONESHOT - Interrupt is not reenabled after the hardirq handler finished.
 55 *                Used by threaded interrupts which need to keep the
 56 *                irq line disabled until the threaded handler has been run.
 57 * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend
 
 
 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 */
 63#define IRQF_DISABLED		0x00000020
 64#define IRQF_SAMPLE_RANDOM	0x00000040
 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
 77#define IRQF_TIMER		(__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD)
 78
 79/*
 80 * These values can be returned by request_any_context_irq() and
 81 * describe the context the interrupt will be run in.
 82 *
 83 * IRQC_IS_HARDIRQ - interrupt runs in hardirq context
 84 * IRQC_IS_NESTED - interrupt runs in a nested threaded context
 85 */
 86enum {
 87	IRQC_IS_HARDIRQ	= 0,
 88	IRQC_IS_NESTED,
 89};
 90
 91typedef irqreturn_t (*irq_handler_t)(int, void *);
 92
 93/**
 94 * struct irqaction - per interrupt action descriptor
 95 * @handler:	interrupt handler function
 96 * @name:	name of the device
 97 * @dev_id:	cookie to identify the device
 98 * @percpu_dev_id:	cookie to identify the device
 99 * @next:	pointer to the next irqaction for shared interrupts
100 * @irq:	interrupt number
101 * @flags:	flags (see IRQF_* above)
102 * @thread_fn:	interrupt handler function for threaded interrupts
103 * @thread:	thread pointer for threaded interrupts
 
104 * @thread_flags:	flags related to @thread
105 * @thread_mask:	bitmask for keeping track of @thread activity
106 * @dir:	pointer to the proc/irq/NN/name entry
107 */
108struct irqaction {
109	irq_handler_t		handler;
110	void			*dev_id;
111	void __percpu		*percpu_dev_id;
112	struct irqaction	*next;
113	irq_handler_t		thread_fn;
114	struct task_struct	*thread;
 
115	unsigned int		irq;
116	unsigned int		flags;
117	unsigned long		thread_flags;
118	unsigned long		thread_mask;
119	const char		*name;
120	struct proc_dir_entry	*dir;
121} ____cacheline_internodealigned_in_smp;
122
123extern irqreturn_t no_action(int cpl, void *dev_id);
124
125#ifdef CONFIG_GENERIC_HARDIRQS
 
 
 
 
 
 
 
 
 
126extern int __must_check
127request_threaded_irq(unsigned int irq, irq_handler_t handler,
128		     irq_handler_t thread_fn,
129		     unsigned long flags, const char *name, void *dev);
130
 
 
 
 
 
 
 
 
 
 
 
 
 
131static inline int __must_check
132request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
133	    const char *name, void *dev)
134{
135	return request_threaded_irq(irq, handler, NULL, flags, name, dev);
136}
137
138extern int __must_check
139request_any_context_irq(unsigned int irq, irq_handler_t handler,
140			unsigned long flags, const char *name, void *dev_id);
141
142extern int __must_check
143request_percpu_irq(unsigned int irq, irq_handler_t handler,
144		   const char *devname, void __percpu *percpu_dev_id);
145#else
146
147extern int __must_check
148request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
149	    const char *name, void *dev);
150
151/*
152 * Special function to avoid ifdeffery in kernel/irq/devres.c which
153 * gets magically built by GENERIC_HARDIRQS=n architectures (sparc,
154 * m68k). I really love these $@%#!* obvious Makefile references:
155 * ../../../kernel/irq/devres.o
156 */
157static inline int __must_check
158request_threaded_irq(unsigned int irq, irq_handler_t handler,
159		     irq_handler_t thread_fn,
160		     unsigned long flags, const char *name, void *dev)
161{
162	return request_irq(irq, handler, flags, name, dev);
163}
164
165static inline int __must_check
166request_any_context_irq(unsigned int irq, irq_handler_t handler,
167			unsigned long flags, const char *name, void *dev_id)
168{
169	return request_irq(irq, handler, flags, name, dev_id);
170}
171
172static inline int __must_check
173request_percpu_irq(unsigned int irq, irq_handler_t handler,
174		   const char *devname, void __percpu *percpu_dev_id)
175{
176	return request_irq(irq, handler, 0, devname, percpu_dev_id);
 
177}
178#endif
179
180extern void free_irq(unsigned int, void *);
 
 
 
 
181extern void free_percpu_irq(unsigned int, void __percpu *);
182
 
 
 
183struct device;
184
185extern int __must_check
186devm_request_threaded_irq(struct device *dev, unsigned int irq,
187			  irq_handler_t handler, irq_handler_t thread_fn,
188			  unsigned long irqflags, const char *devname,
189			  void *dev_id);
190
191static inline int __must_check
192devm_request_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
193		 unsigned long irqflags, const char *devname, void *dev_id)
194{
195	return devm_request_threaded_irq(dev, irq, handler, NULL, irqflags,
196					 devname, dev_id);
197}
198
 
 
 
 
 
199extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
200
201/*
202 * On lockdep we dont want to enable hardirqs in hardirq
203 * context. Use local_irq_enable_in_hardirq() to annotate
204 * kernel code that has to do this nevertheless (pretty much
205 * the only valid case is for old/broken hardware that is
206 * insanely slow).
207 *
208 * NOTE: in theory this might break fragile code that relies
209 * on hardirq delivery - in practice we dont seem to have such
210 * places left. So the only effect should be slightly increased
211 * irqs-off latencies.
212 */
213#ifdef CONFIG_LOCKDEP
214# define local_irq_enable_in_hardirq()	do { } while (0)
215#else
216# define local_irq_enable_in_hardirq()	local_irq_enable()
217#endif
218
219extern void disable_irq_nosync(unsigned int irq);
 
220extern void disable_irq(unsigned int irq);
221extern void disable_percpu_irq(unsigned int irq);
222extern void enable_irq(unsigned int irq);
223extern void enable_percpu_irq(unsigned int irq, unsigned int type);
 
 
 
 
 
 
 
 
 
 
 
224
225/* The following three functions are for the core kernel use only. */
226#ifdef CONFIG_GENERIC_HARDIRQS
227extern void suspend_device_irqs(void);
228extern void resume_device_irqs(void);
229#ifdef CONFIG_PM_SLEEP
230extern int check_wakeup_irqs(void);
231#else
232static inline int check_wakeup_irqs(void) { return 0; }
233#endif
234#else
235static inline void suspend_device_irqs(void) { };
236static inline void resume_device_irqs(void) { };
237static inline int check_wakeup_irqs(void) { return 0; }
238#endif
239
240#if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
241
242extern cpumask_var_t irq_default_affinity;
243
244extern int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask);
245extern int irq_can_set_affinity(unsigned int irq);
246extern int irq_select_affinity(unsigned int irq);
247
248extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m);
249
250/**
251 * struct irq_affinity_notify - context for notification of IRQ affinity changes
252 * @irq:		Interrupt to which notification applies
253 * @kref:		Reference count, for internal use
254 * @work:		Work item, for internal use
255 * @notify:		Function to be called on change.  This will be
256 *			called in process context.
257 * @release:		Function to be called on release.  This will be
258 *			called in process context.  Once registered, the
259 *			structure must only be freed when this function is
260 *			called or later.
261 */
262struct irq_affinity_notify {
263	unsigned int irq;
264	struct kref kref;
265	struct work_struct work;
266	void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
267	void (*release)(struct kref *ref);
268};
269
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
270extern int
271irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
272
273static inline void irq_run_affinity_notifiers(void)
274{
275	flush_scheduled_work();
276}
 
277
278#else /* CONFIG_SMP */
279
280static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
281{
282	return -EINVAL;
283}
284
 
 
 
 
 
285static inline int irq_can_set_affinity(unsigned int irq)
286{
287	return 0;
288}
289
290static inline int irq_select_affinity(unsigned int irq)  { return 0; }
291
292static inline int irq_set_affinity_hint(unsigned int irq,
293					const struct cpumask *m)
294{
295	return -EINVAL;
296}
297#endif /* CONFIG_SMP && CONFIG_GENERIC_HARDIRQS */
298
299#ifdef CONFIG_GENERIC_HARDIRQS
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
300/*
301 * Special lockdep variants of irq disabling/enabling.
302 * These should be used for locking constructs that
303 * know that a particular irq context which is disabled,
304 * and which is the only irq-context user of a lock,
305 * that it's safe to take the lock in the irq-disabled
306 * section without disabling hardirqs.
307 *
308 * On !CONFIG_LOCKDEP they are equivalent to the normal
309 * irq disable/enable methods.
310 */
311static inline void disable_irq_nosync_lockdep(unsigned int irq)
312{
313	disable_irq_nosync(irq);
314#ifdef CONFIG_LOCKDEP
315	local_irq_disable();
316#endif
317}
318
319static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
320{
321	disable_irq_nosync(irq);
322#ifdef CONFIG_LOCKDEP
323	local_irq_save(*flags);
324#endif
325}
326
327static inline void disable_irq_lockdep(unsigned int irq)
328{
329	disable_irq(irq);
330#ifdef CONFIG_LOCKDEP
331	local_irq_disable();
332#endif
333}
334
335static inline void enable_irq_lockdep(unsigned int irq)
336{
337#ifdef CONFIG_LOCKDEP
338	local_irq_enable();
339#endif
340	enable_irq(irq);
341}
342
343static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
344{
345#ifdef CONFIG_LOCKDEP
346	local_irq_restore(*flags);
347#endif
348	enable_irq(irq);
349}
350
351/* IRQ wakeup (PM) control: */
352extern int irq_set_irq_wake(unsigned int irq, unsigned int on);
353
354static inline int enable_irq_wake(unsigned int irq)
355{
356	return irq_set_irq_wake(irq, 1);
357}
358
359static inline int disable_irq_wake(unsigned int irq)
360{
361	return irq_set_irq_wake(irq, 0);
362}
363
364#else /* !CONFIG_GENERIC_HARDIRQS */
365/*
366 * NOTE: non-genirq architectures, if they want to support the lock
367 * validator need to define the methods below in their asm/irq.h
368 * files, under an #ifdef CONFIG_LOCKDEP section.
369 */
370#ifndef CONFIG_LOCKDEP
371#  define disable_irq_nosync_lockdep(irq)	disable_irq_nosync(irq)
372#  define disable_irq_nosync_lockdep_irqsave(irq, flags) \
373						disable_irq_nosync(irq)
374#  define disable_irq_lockdep(irq)		disable_irq(irq)
375#  define enable_irq_lockdep(irq)		enable_irq(irq)
376#  define enable_irq_lockdep_irqrestore(irq, flags) \
377						enable_irq(irq)
378# endif
379
380static inline int enable_irq_wake(unsigned int irq)
381{
382	return 0;
383}
384
385static inline int disable_irq_wake(unsigned int irq)
386{
387	return 0;
388}
389#endif /* CONFIG_GENERIC_HARDIRQS */
390
 
 
 
 
391
392#ifdef CONFIG_IRQ_FORCED_THREADING
 
 
 
393extern bool force_irqthreads;
 
394#else
395#define force_irqthreads	(0)
396#endif
397
398#ifndef __ARCH_SET_SOFTIRQ_PENDING
399#define set_softirq_pending(x) (local_softirq_pending() = (x))
400#define or_softirq_pending(x)  (local_softirq_pending() |= (x))
 
401#endif
402
 
 
 
 
 
 
403/* Some architectures might implement lazy enabling/disabling of
404 * interrupts. In some cases, such as stop_machine, we might want
405 * to ensure that after a local_irq_disable(), interrupts have
406 * really been disabled in hardware. Such architectures need to
407 * implement the following hook.
408 */
409#ifndef hard_irq_disable
410#define hard_irq_disable()	do { } while(0)
411#endif
412
413/* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
414   frequency threaded job scheduling. For almost all the purposes
415   tasklets are more than enough. F.e. all serial device BHs et
416   al. should be converted to tasklets, not to softirqs.
417 */
418
419enum
420{
421	HI_SOFTIRQ=0,
422	TIMER_SOFTIRQ,
423	NET_TX_SOFTIRQ,
424	NET_RX_SOFTIRQ,
425	BLOCK_SOFTIRQ,
426	BLOCK_IOPOLL_SOFTIRQ,
427	TASKLET_SOFTIRQ,
428	SCHED_SOFTIRQ,
429	HRTIMER_SOFTIRQ,
430	RCU_SOFTIRQ,    /* Preferable RCU should always be the last softirq */
431
432	NR_SOFTIRQS
433};
434
 
 
435/* map softirq index to softirq name. update 'softirq_to_name' in
436 * kernel/softirq.c when adding a new softirq.
437 */
438extern 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
444struct softirq_action
445{
446	void	(*action)(struct softirq_action *);
447};
448
449asmlinkage void do_softirq(void);
450asmlinkage void __do_softirq(void);
 
 
 
 
 
 
 
 
 
 
451extern void open_softirq(int nr, void (*action)(struct softirq_action *));
452extern void softirq_init(void);
453extern void __raise_softirq_irqoff(unsigned int nr);
454
455extern void raise_softirq_irqoff(unsigned int nr);
456extern 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 */
465DECLARE_PER_CPU(struct list_head [NR_SOFTIRQS], softirq_work_list);
466
467DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
468
469static 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 */
477extern 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 */
482extern 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
505struct tasklet_struct
506{
507	struct tasklet_struct *next;
508	unsigned long state;
509	atomic_t count;
510	void (*func)(unsigned long);
 
 
 
 
511	unsigned long data;
512};
513
514#define DECLARE_TASKLET(name, func, data) \
515struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
 
 
 
 
 
 
 
 
 
 
 
516
517#define DECLARE_TASKLET_DISABLED(name, func, data) \
518struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
 
 
 
 
 
 
519
 
 
 
 
 
520
521enum
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
528static inline int tasklet_trylock(struct tasklet_struct *t)
529{
530	return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
531}
532
533static inline void tasklet_unlock(struct tasklet_struct *t)
534{
535	smp_mb__before_clear_bit(); 
536	clear_bit(TASKLET_STATE_RUN, &(t)->state);
537}
538
539static 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
549extern void __tasklet_schedule(struct tasklet_struct *t);
550
551static inline void tasklet_schedule(struct tasklet_struct *t)
552{
553	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
554		__tasklet_schedule(t);
555}
556
557extern void __tasklet_hi_schedule(struct tasklet_struct *t);
558
559static inline void tasklet_hi_schedule(struct tasklet_struct *t)
560{
561	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
562		__tasklet_hi_schedule(t);
563}
564
565extern 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 */
573static inline void tasklet_hi_schedule_first(struct tasklet_struct *t)
574{
575	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
576		__tasklet_hi_schedule_first(t);
577}
578
579
580static inline void tasklet_disable_nosync(struct tasklet_struct *t)
581{
582	atomic_inc(&t->count);
583	smp_mb__after_atomic_inc();
584}
585
586static inline void tasklet_disable(struct tasklet_struct *t)
587{
588	tasklet_disable_nosync(t);
589	tasklet_unlock_wait(t);
590	smp_mb();
591}
592
593static inline void tasklet_enable(struct tasklet_struct *t)
594{
595	smp_mb__before_atomic_dec();
596	atomic_dec(&t->count);
597}
598
599static inline void tasklet_hi_enable(struct tasklet_struct *t)
600{
601	smp_mb__before_atomic_dec();
602	atomic_dec(&t->count);
603}
604
605extern void tasklet_kill(struct tasklet_struct *t);
606extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
607extern void tasklet_init(struct tasklet_struct *t,
608			 void (*func)(unsigned long), unsigned long data);
609
610struct tasklet_hrtimer {
611	struct hrtimer		timer;
612	struct tasklet_struct	tasklet;
613	enum hrtimer_restart	(*function)(struct hrtimer *);
614};
615
616extern void
617tasklet_hrtimer_init(struct tasklet_hrtimer *ttimer,
618		     enum hrtimer_restart (*function)(struct hrtimer *),
619		     clockid_t which_clock, enum hrtimer_mode mode);
620
621static inline
622int 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
628static inline
629void 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) 
664static inline unsigned long probe_irq_on(void)
665{
666	return 0;
667}
668static inline int probe_irq_off(unsigned long val)
669{
670	return 0;
671}
672static inline unsigned int probe_irq_mask(unsigned long val)
673{
674	return 0;
675}
676#else
677extern unsigned long probe_irq_on(void);	/* returns 0 on failure */
678extern int probe_irq_off(unsigned long);	/* returns 0 or negative on failure */
679extern unsigned int probe_irq_mask(unsigned long);	/* returns mask of ISA interrupts */
680#endif
681
682#ifdef CONFIG_PROC_FS
683/* Initialize /proc/irq/ */
684extern void init_irq_proc(void);
685#else
686static inline void init_irq_proc(void)
687{
688}
689#endif
690
 
 
 
 
 
 
691struct seq_file;
692int show_interrupts(struct seq_file *p, void *v);
693int arch_show_interrupts(struct seq_file *p, int prec);
694
695extern int early_irq_init(void);
696extern int arch_probe_nr_irqs(void);
697extern int arch_early_irq_init(void);
 
 
 
 
 
 
 
 
 
698
699#endif