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/cleanup.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/cpumask_types.h>
16#include <linux/workqueue.h>
17#include <linux/jump_label.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 a 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.rst
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 * IRQF_NO_AUTOEN - Don't enable IRQ or NMI automatically when users request it.
67 * Users will enable it explicitly by enable_irq() or enable_nmi()
68 * later.
69 * IRQF_NO_DEBUG - Exclude from runnaway detection for IPI and similar handlers,
70 * depends on IRQF_PERCPU.
71 * IRQF_COND_ONESHOT - Agree to do IRQF_ONESHOT if already set for a shared
72 * interrupt.
73 */
74#define IRQF_SHARED 0x00000080
75#define IRQF_PROBE_SHARED 0x00000100
76#define __IRQF_TIMER 0x00000200
77#define IRQF_PERCPU 0x00000400
78#define IRQF_NOBALANCING 0x00000800
79#define IRQF_IRQPOLL 0x00001000
80#define IRQF_ONESHOT 0x00002000
81#define IRQF_NO_SUSPEND 0x00004000
82#define IRQF_FORCE_RESUME 0x00008000
83#define IRQF_NO_THREAD 0x00010000
84#define IRQF_EARLY_RESUME 0x00020000
85#define IRQF_COND_SUSPEND 0x00040000
86#define IRQF_NO_AUTOEN 0x00080000
87#define IRQF_NO_DEBUG 0x00100000
88#define IRQF_COND_ONESHOT 0x00200000
89
90#define IRQF_TIMER (__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD)
91
92/*
93 * These values can be returned by request_any_context_irq() and
94 * describe the context the interrupt will be run in.
95 *
96 * IRQC_IS_HARDIRQ - interrupt runs in hardirq context
97 * IRQC_IS_NESTED - interrupt runs in a nested threaded context
98 */
99enum {
100 IRQC_IS_HARDIRQ = 0,
101 IRQC_IS_NESTED,
102};
103
104typedef irqreturn_t (*irq_handler_t)(int, void *);
105
106/**
107 * struct irqaction - per interrupt action descriptor
108 * @handler: interrupt handler function
109 * @name: name of the device
110 * @dev_id: cookie to identify the device
111 * @percpu_dev_id: cookie to identify the device
112 * @next: pointer to the next irqaction for shared interrupts
113 * @irq: interrupt number
114 * @flags: flags (see IRQF_* above)
115 * @thread_fn: interrupt handler function for threaded interrupts
116 * @thread: thread pointer for threaded interrupts
117 * @secondary: pointer to secondary irqaction (force threading)
118 * @thread_flags: flags related to @thread
119 * @thread_mask: bitmask for keeping track of @thread activity
120 * @dir: pointer to the proc/irq/NN/name entry
121 */
122struct irqaction {
123 irq_handler_t handler;
124 void *dev_id;
125 void __percpu *percpu_dev_id;
126 struct irqaction *next;
127 irq_handler_t thread_fn;
128 struct task_struct *thread;
129 struct irqaction *secondary;
130 unsigned int irq;
131 unsigned int flags;
132 unsigned long thread_flags;
133 unsigned long thread_mask;
134 const char *name;
135 struct proc_dir_entry *dir;
136} ____cacheline_internodealigned_in_smp;
137
138extern irqreturn_t no_action(int cpl, void *dev_id);
139
140/*
141 * If a (PCI) device interrupt is not connected we set dev->irq to
142 * IRQ_NOTCONNECTED. This causes request_irq() to fail with -ENOTCONN, so we
143 * can distinguish that case from other error returns.
144 *
145 * 0x80000000 is guaranteed to be outside the available range of interrupts
146 * and easy to distinguish from other possible incorrect values.
147 */
148#define IRQ_NOTCONNECTED (1U << 31)
149
150extern int __must_check
151request_threaded_irq(unsigned int irq, irq_handler_t handler,
152 irq_handler_t thread_fn,
153 unsigned long flags, const char *name, void *dev);
154
155/**
156 * request_irq - Add a handler for an interrupt line
157 * @irq: The interrupt line to allocate
158 * @handler: Function to be called when the IRQ occurs.
159 * Primary handler for threaded interrupts
160 * If NULL, the default primary handler is installed
161 * @flags: Handling flags
162 * @name: Name of the device generating this interrupt
163 * @dev: A cookie passed to the handler function
164 *
165 * This call allocates an interrupt and establishes a handler; see
166 * the documentation for request_threaded_irq() for details.
167 */
168static inline int __must_check
169request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
170 const char *name, void *dev)
171{
172 return request_threaded_irq(irq, handler, NULL, flags: flags | IRQF_COND_ONESHOT, name, dev);
173}
174
175extern int __must_check
176request_any_context_irq(unsigned int irq, irq_handler_t handler,
177 unsigned long flags, const char *name, void *dev_id);
178
179extern int __must_check
180__request_percpu_irq(unsigned int irq, irq_handler_t handler,
181 unsigned long flags, const char *devname,
182 void __percpu *percpu_dev_id);
183
184extern int __must_check
185request_nmi(unsigned int irq, irq_handler_t handler, unsigned long flags,
186 const char *name, void *dev);
187
188static inline int __must_check
189request_percpu_irq(unsigned int irq, irq_handler_t handler,
190 const char *devname, void __percpu *percpu_dev_id)
191{
192 return __request_percpu_irq(irq, handler, flags: 0,
193 devname, percpu_dev_id);
194}
195
196extern int __must_check
197request_percpu_nmi(unsigned int irq, irq_handler_t handler,
198 const char *devname, void __percpu *dev);
199
200extern const void *free_irq(unsigned int, void *);
201extern void free_percpu_irq(unsigned int, void __percpu *);
202
203extern const void *free_nmi(unsigned int irq, void *dev_id);
204extern void free_percpu_nmi(unsigned int irq, void __percpu *percpu_dev_id);
205
206struct device;
207
208extern int __must_check
209devm_request_threaded_irq(struct device *dev, unsigned int irq,
210 irq_handler_t handler, irq_handler_t thread_fn,
211 unsigned long irqflags, const char *devname,
212 void *dev_id);
213
214static inline int __must_check
215devm_request_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
216 unsigned long irqflags, const char *devname, void *dev_id)
217{
218 return devm_request_threaded_irq(dev, irq, handler, NULL, irqflags,
219 devname, dev_id);
220}
221
222extern int __must_check
223devm_request_any_context_irq(struct device *dev, unsigned int irq,
224 irq_handler_t handler, unsigned long irqflags,
225 const char *devname, void *dev_id);
226
227extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
228
229bool irq_has_action(unsigned int irq);
230extern void disable_irq_nosync(unsigned int irq);
231extern bool disable_hardirq(unsigned int irq);
232extern void disable_irq(unsigned int irq);
233extern void disable_percpu_irq(unsigned int irq);
234extern void enable_irq(unsigned int irq);
235extern void enable_percpu_irq(unsigned int irq, unsigned int type);
236extern bool irq_percpu_is_enabled(unsigned int irq);
237extern void irq_wake_thread(unsigned int irq, void *dev_id);
238
239DEFINE_LOCK_GUARD_1(disable_irq, int,
240 disable_irq(*_T->lock), enable_irq(*_T->lock))
241
242extern void disable_nmi_nosync(unsigned int irq);
243extern void disable_percpu_nmi(unsigned int irq);
244extern void enable_nmi(unsigned int irq);
245extern void enable_percpu_nmi(unsigned int irq, unsigned int type);
246extern int prepare_percpu_nmi(unsigned int irq);
247extern void teardown_percpu_nmi(unsigned int irq);
248
249extern int irq_inject_interrupt(unsigned int irq);
250
251/* The following three functions are for the core kernel use only. */
252extern void suspend_device_irqs(void);
253extern void resume_device_irqs(void);
254extern void rearm_wake_irq(unsigned int irq);
255
256/**
257 * struct irq_affinity_notify - context for notification of IRQ affinity changes
258 * @irq: Interrupt to which notification applies
259 * @kref: Reference count, for internal use
260 * @work: Work item, for internal use
261 * @notify: Function to be called on change. This will be
262 * called in process context.
263 * @release: Function to be called on release. This will be
264 * called in process context. Once registered, the
265 * structure must only be freed when this function is
266 * called or later.
267 */
268struct irq_affinity_notify {
269 unsigned int irq;
270 struct kref kref;
271 struct work_struct work;
272 void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
273 void (*release)(struct kref *ref);
274};
275
276#define IRQ_AFFINITY_MAX_SETS 4
277
278/**
279 * struct irq_affinity - Description for automatic irq affinity assignments
280 * @pre_vectors: Don't apply affinity to @pre_vectors at beginning of
281 * the MSI(-X) vector space
282 * @post_vectors: Don't apply affinity to @post_vectors at end of
283 * the MSI(-X) vector space
284 * @nr_sets: The number of interrupt sets for which affinity
285 * spreading is required
286 * @set_size: Array holding the size of each interrupt set
287 * @calc_sets: Callback for calculating the number and size
288 * of interrupt sets
289 * @priv: Private data for usage by @calc_sets, usually a
290 * pointer to driver/device specific data.
291 */
292struct irq_affinity {
293 unsigned int pre_vectors;
294 unsigned int post_vectors;
295 unsigned int nr_sets;
296 unsigned int set_size[IRQ_AFFINITY_MAX_SETS];
297 void (*calc_sets)(struct irq_affinity *, unsigned int nvecs);
298 void *priv;
299};
300
301/**
302 * struct irq_affinity_desc - Interrupt affinity descriptor
303 * @mask: cpumask to hold the affinity assignment
304 * @is_managed: 1 if the interrupt is managed internally
305 */
306struct irq_affinity_desc {
307 struct cpumask mask;
308 unsigned int is_managed : 1;
309};
310
311#if defined(CONFIG_SMP)
312
313extern cpumask_var_t irq_default_affinity;
314
315extern int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask);
316extern int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask);
317
318extern int irq_can_set_affinity(unsigned int irq);
319extern int irq_select_affinity(unsigned int irq);
320
321extern int __irq_apply_affinity_hint(unsigned int irq, const struct cpumask *m,
322 bool setaffinity);
323
324/**
325 * irq_update_affinity_hint - Update the affinity hint
326 * @irq: Interrupt to update
327 * @m: cpumask pointer (NULL to clear the hint)
328 *
329 * Updates the affinity hint, but does not change the affinity of the interrupt.
330 */
331static inline int
332irq_update_affinity_hint(unsigned int irq, const struct cpumask *m)
333{
334 return __irq_apply_affinity_hint(irq, m, setaffinity: false);
335}
336
337/**
338 * irq_set_affinity_and_hint - Update the affinity hint and apply the provided
339 * cpumask to the interrupt
340 * @irq: Interrupt to update
341 * @m: cpumask pointer (NULL to clear the hint)
342 *
343 * Updates the affinity hint and if @m is not NULL it applies it as the
344 * affinity of that interrupt.
345 */
346static inline int
347irq_set_affinity_and_hint(unsigned int irq, const struct cpumask *m)
348{
349 return __irq_apply_affinity_hint(irq, m, setaffinity: true);
350}
351
352/*
353 * Deprecated. Use irq_update_affinity_hint() or irq_set_affinity_and_hint()
354 * instead.
355 */
356static inline int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
357{
358 return irq_set_affinity_and_hint(irq, m);
359}
360
361extern int irq_update_affinity_desc(unsigned int irq,
362 struct irq_affinity_desc *affinity);
363
364extern int
365irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
366
367struct irq_affinity_desc *
368irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd);
369
370unsigned int irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
371 const struct irq_affinity *affd);
372
373#else /* CONFIG_SMP */
374
375static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
376{
377 return -EINVAL;
378}
379
380static inline int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
381{
382 return 0;
383}
384
385static inline int irq_can_set_affinity(unsigned int irq)
386{
387 return 0;
388}
389
390static inline int irq_select_affinity(unsigned int irq) { return 0; }
391
392static inline int irq_update_affinity_hint(unsigned int irq,
393 const struct cpumask *m)
394{
395 return -EINVAL;
396}
397
398static inline int irq_set_affinity_and_hint(unsigned int irq,
399 const struct cpumask *m)
400{
401 return -EINVAL;
402}
403
404static inline int irq_set_affinity_hint(unsigned int irq,
405 const struct cpumask *m)
406{
407 return -EINVAL;
408}
409
410static inline int irq_update_affinity_desc(unsigned int irq,
411 struct irq_affinity_desc *affinity)
412{
413 return -EINVAL;
414}
415
416static inline int
417irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
418{
419 return 0;
420}
421
422static inline struct irq_affinity_desc *
423irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd)
424{
425 return NULL;
426}
427
428static inline unsigned int
429irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
430 const struct irq_affinity *affd)
431{
432 return maxvec;
433}
434
435#endif /* CONFIG_SMP */
436
437/*
438 * Special lockdep variants of irq disabling/enabling.
439 * These should be used for locking constructs that
440 * know that a particular irq context which is disabled,
441 * and which is the only irq-context user of a lock,
442 * that it's safe to take the lock in the irq-disabled
443 * section without disabling hardirqs.
444 *
445 * On !CONFIG_LOCKDEP they are equivalent to the normal
446 * irq disable/enable methods.
447 */
448static inline void disable_irq_nosync_lockdep(unsigned int irq)
449{
450 disable_irq_nosync(irq);
451#if defined(CONFIG_LOCKDEP) && !defined(CONFIG_PREEMPT_RT)
452 local_irq_disable();
453#endif
454}
455
456static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
457{
458 disable_irq_nosync(irq);
459#if defined(CONFIG_LOCKDEP) && !defined(CONFIG_PREEMPT_RT)
460 local_irq_save(*flags);
461#endif
462}
463
464static inline void enable_irq_lockdep(unsigned int irq)
465{
466#if defined(CONFIG_LOCKDEP) && !defined(CONFIG_PREEMPT_RT)
467 local_irq_enable();
468#endif
469 enable_irq(irq);
470}
471
472static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
473{
474#if defined(CONFIG_LOCKDEP) && !defined(CONFIG_PREEMPT_RT)
475 local_irq_restore(*flags);
476#endif
477 enable_irq(irq);
478}
479
480/* IRQ wakeup (PM) control: */
481extern int irq_set_irq_wake(unsigned int irq, unsigned int on);
482
483static inline int enable_irq_wake(unsigned int irq)
484{
485 return irq_set_irq_wake(irq, on: 1);
486}
487
488static inline int disable_irq_wake(unsigned int irq)
489{
490 return irq_set_irq_wake(irq, on: 0);
491}
492
493/*
494 * irq_get_irqchip_state/irq_set_irqchip_state specific flags
495 */
496enum irqchip_irq_state {
497 IRQCHIP_STATE_PENDING, /* Is interrupt pending? */
498 IRQCHIP_STATE_ACTIVE, /* Is interrupt in progress? */
499 IRQCHIP_STATE_MASKED, /* Is interrupt masked? */
500 IRQCHIP_STATE_LINE_LEVEL, /* Is IRQ line high? */
501};
502
503extern int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
504 bool *state);
505extern int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
506 bool state);
507
508#ifdef CONFIG_IRQ_FORCED_THREADING
509# ifdef CONFIG_PREEMPT_RT
510# define force_irqthreads() (true)
511# else
512DECLARE_STATIC_KEY_FALSE(force_irqthreads_key);
513# define force_irqthreads() (static_branch_unlikely(&force_irqthreads_key))
514# endif
515#else
516#define force_irqthreads() (false)
517#endif
518
519#ifndef local_softirq_pending
520
521#ifndef local_softirq_pending_ref
522#define local_softirq_pending_ref irq_stat.__softirq_pending
523#endif
524
525#define local_softirq_pending() (__this_cpu_read(local_softirq_pending_ref))
526#define set_softirq_pending(x) (__this_cpu_write(local_softirq_pending_ref, (x)))
527#define or_softirq_pending(x) (__this_cpu_or(local_softirq_pending_ref, (x)))
528
529#endif /* local_softirq_pending */
530
531/* Some architectures might implement lazy enabling/disabling of
532 * interrupts. In some cases, such as stop_machine, we might want
533 * to ensure that after a local_irq_disable(), interrupts have
534 * really been disabled in hardware. Such architectures need to
535 * implement the following hook.
536 */
537#ifndef hard_irq_disable
538#define hard_irq_disable() do { } while(0)
539#endif
540
541/* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
542 frequency threaded job scheduling. For almost all the purposes
543 tasklets are more than enough. F.e. all serial device BHs et
544 al. should be converted to tasklets, not to softirqs.
545 */
546
547enum
548{
549 HI_SOFTIRQ=0,
550 TIMER_SOFTIRQ,
551 NET_TX_SOFTIRQ,
552 NET_RX_SOFTIRQ,
553 BLOCK_SOFTIRQ,
554 IRQ_POLL_SOFTIRQ,
555 TASKLET_SOFTIRQ,
556 SCHED_SOFTIRQ,
557 HRTIMER_SOFTIRQ,
558 RCU_SOFTIRQ, /* Preferable RCU should always be the last softirq */
559
560 NR_SOFTIRQS
561};
562
563/*
564 * The following vectors can be safely ignored after ksoftirqd is parked:
565 *
566 * _ RCU:
567 * 1) rcutree_migrate_callbacks() migrates the queue.
568 * 2) rcutree_report_cpu_dead() reports the final quiescent states.
569 *
570 * _ IRQ_POLL: irq_poll_cpu_dead() migrates the queue
571 *
572 * _ (HR)TIMER_SOFTIRQ: (hr)timers_dead_cpu() migrates the queue
573 */
574#define SOFTIRQ_HOTPLUG_SAFE_MASK (BIT(TIMER_SOFTIRQ) | BIT(IRQ_POLL_SOFTIRQ) |\
575 BIT(HRTIMER_SOFTIRQ) | BIT(RCU_SOFTIRQ))
576
577
578/* map softirq index to softirq name. update 'softirq_to_name' in
579 * kernel/softirq.c when adding a new softirq.
580 */
581extern const char * const softirq_to_name[NR_SOFTIRQS];
582
583/* softirq mask and active fields moved to irq_cpustat_t in
584 * asm/hardirq.h to get better cache usage. KAO
585 */
586
587struct softirq_action
588{
589 void (*action)(void);
590};
591
592asmlinkage void do_softirq(void);
593asmlinkage void __do_softirq(void);
594
595#ifdef CONFIG_PREEMPT_RT
596extern void do_softirq_post_smp_call_flush(unsigned int was_pending);
597#else
598static inline void do_softirq_post_smp_call_flush(unsigned int unused)
599{
600 do_softirq();
601}
602#endif
603
604extern void open_softirq(int nr, void (*action)(void));
605extern void softirq_init(void);
606extern void __raise_softirq_irqoff(unsigned int nr);
607
608extern void raise_softirq_irqoff(unsigned int nr);
609extern void raise_softirq(unsigned int nr);
610
611/*
612 * With forced-threaded interrupts enabled a raised softirq is deferred to
613 * ksoftirqd unless it can be handled within the threaded interrupt. This
614 * affects timer_list timers and hrtimers which are explicitly marked with
615 * HRTIMER_MODE_SOFT.
616 * With PREEMPT_RT enabled more hrtimers are moved to softirq for processing
617 * which includes all timers which are not explicitly marked HRTIMER_MODE_HARD.
618 * Userspace controlled timers (like the clock_nanosleep() interface) is divided
619 * into two categories: Tasks with elevated scheduling policy including
620 * SCHED_{FIFO|RR|DL} and the remaining scheduling policy. The tasks with the
621 * elevated scheduling policy are woken up directly from the HARDIRQ while all
622 * other wake ups are delayed to softirq and so to ksoftirqd.
623 *
624 * The ksoftirqd runs at SCHED_OTHER policy at which it should remain since it
625 * handles the softirq in an overloaded situation (not handled everything
626 * within its last run).
627 * If the timers are handled at SCHED_OTHER priority then they competes with all
628 * other SCHED_OTHER tasks for CPU resources are possibly delayed.
629 * Moving timers softirqs to a low priority SCHED_FIFO thread instead ensures
630 * that timer are performed before scheduling any SCHED_OTHER thread.
631 */
632DECLARE_PER_CPU(struct task_struct *, ktimerd);
633DECLARE_PER_CPU(unsigned long, pending_timer_softirq);
634void raise_ktimers_thread(unsigned int nr);
635
636static inline unsigned int local_timers_pending_force_th(void)
637{
638 return __this_cpu_read(pending_timer_softirq);
639}
640
641static inline void raise_timer_softirq(unsigned int nr)
642{
643 lockdep_assert_in_irq();
644 if (force_irqthreads())
645 raise_ktimers_thread(nr);
646 else
647 __raise_softirq_irqoff(nr);
648}
649
650static inline unsigned int local_timers_pending(void)
651{
652 if (force_irqthreads())
653 return local_timers_pending_force_th();
654 else
655 return local_softirq_pending();
656}
657
658DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
659
660static inline struct task_struct *this_cpu_ksoftirqd(void)
661{
662 return this_cpu_read(ksoftirqd);
663}
664
665/* Tasklets --- multithreaded analogue of BHs.
666
667 This API is deprecated. Please consider using threaded IRQs instead:
668 https://lore.kernel.org/lkml/20200716081538.2sivhkj4hcyrusem@linutronix.de
669
670 Main feature differing them of generic softirqs: tasklet
671 is running only on one CPU simultaneously.
672
673 Main feature differing them of BHs: different tasklets
674 may be run simultaneously on different CPUs.
675
676 Properties:
677 * If tasklet_schedule() is called, then tasklet is guaranteed
678 to be executed on some cpu at least once after this.
679 * If the tasklet is already scheduled, but its execution is still not
680 started, it will be executed only once.
681 * If this tasklet is already running on another CPU (or schedule is called
682 from tasklet itself), it is rescheduled for later.
683 * Tasklet is strictly serialized wrt itself, but not
684 wrt another tasklets. If client needs some intertask synchronization,
685 he makes it with spinlocks.
686 */
687
688struct tasklet_struct
689{
690 struct tasklet_struct *next;
691 unsigned long state;
692 atomic_t count;
693 bool use_callback;
694 union {
695 void (*func)(unsigned long data);
696 void (*callback)(struct tasklet_struct *t);
697 };
698 unsigned long data;
699};
700
701#define DECLARE_TASKLET(name, _callback) \
702struct tasklet_struct name = { \
703 .count = ATOMIC_INIT(0), \
704 .callback = _callback, \
705 .use_callback = true, \
706}
707
708#define DECLARE_TASKLET_DISABLED(name, _callback) \
709struct tasklet_struct name = { \
710 .count = ATOMIC_INIT(1), \
711 .callback = _callback, \
712 .use_callback = true, \
713}
714
715#define from_tasklet(var, callback_tasklet, tasklet_fieldname) \
716 container_of(callback_tasklet, typeof(*var), tasklet_fieldname)
717
718#define DECLARE_TASKLET_OLD(name, _func) \
719struct tasklet_struct name = { \
720 .count = ATOMIC_INIT(0), \
721 .func = _func, \
722}
723
724#define DECLARE_TASKLET_DISABLED_OLD(name, _func) \
725struct tasklet_struct name = { \
726 .count = ATOMIC_INIT(1), \
727 .func = _func, \
728}
729
730enum
731{
732 TASKLET_STATE_SCHED, /* Tasklet is scheduled for execution */
733 TASKLET_STATE_RUN /* Tasklet is running (SMP only) */
734};
735
736#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT)
737static inline int tasklet_trylock(struct tasklet_struct *t)
738{
739 return !test_and_set_bit(nr: TASKLET_STATE_RUN, addr: &(t)->state);
740}
741
742void tasklet_unlock(struct tasklet_struct *t);
743void tasklet_unlock_wait(struct tasklet_struct *t);
744void tasklet_unlock_spin_wait(struct tasklet_struct *t);
745
746#else
747static inline int tasklet_trylock(struct tasklet_struct *t) { return 1; }
748static inline void tasklet_unlock(struct tasklet_struct *t) { }
749static inline void tasklet_unlock_wait(struct tasklet_struct *t) { }
750static inline void tasklet_unlock_spin_wait(struct tasklet_struct *t) { }
751#endif
752
753extern void __tasklet_schedule(struct tasklet_struct *t);
754
755static inline void tasklet_schedule(struct tasklet_struct *t)
756{
757 if (!test_and_set_bit(nr: TASKLET_STATE_SCHED, addr: &t->state))
758 __tasklet_schedule(t);
759}
760
761extern void __tasklet_hi_schedule(struct tasklet_struct *t);
762
763static inline void tasklet_hi_schedule(struct tasklet_struct *t)
764{
765 if (!test_and_set_bit(nr: TASKLET_STATE_SCHED, addr: &t->state))
766 __tasklet_hi_schedule(t);
767}
768
769static inline void tasklet_disable_nosync(struct tasklet_struct *t)
770{
771 atomic_inc(v: &t->count);
772 smp_mb__after_atomic();
773}
774
775/*
776 * Do not use in new code. Disabling tasklets from atomic contexts is
777 * error prone and should be avoided.
778 */
779static inline void tasklet_disable_in_atomic(struct tasklet_struct *t)
780{
781 tasklet_disable_nosync(t);
782 tasklet_unlock_spin_wait(t);
783 smp_mb();
784}
785
786static inline void tasklet_disable(struct tasklet_struct *t)
787{
788 tasklet_disable_nosync(t);
789 tasklet_unlock_wait(t);
790 smp_mb();
791}
792
793static inline void tasklet_enable(struct tasklet_struct *t)
794{
795 smp_mb__before_atomic();
796 atomic_dec(v: &t->count);
797}
798
799extern void tasklet_kill(struct tasklet_struct *t);
800extern void tasklet_init(struct tasklet_struct *t,
801 void (*func)(unsigned long), unsigned long data);
802extern void tasklet_setup(struct tasklet_struct *t,
803 void (*callback)(struct tasklet_struct *));
804
805/*
806 * Autoprobing for irqs:
807 *
808 * probe_irq_on() and probe_irq_off() provide robust primitives
809 * for accurate IRQ probing during kernel initialization. They are
810 * reasonably simple to use, are not "fooled" by spurious interrupts,
811 * and, unlike other attempts at IRQ probing, they do not get hung on
812 * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
813 *
814 * For reasonably foolproof probing, use them as follows:
815 *
816 * 1. clear and/or mask the device's internal interrupt.
817 * 2. sti();
818 * 3. irqs = probe_irq_on(); // "take over" all unassigned idle IRQs
819 * 4. enable the device and cause it to trigger an interrupt.
820 * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
821 * 6. irq = probe_irq_off(irqs); // get IRQ number, 0=none, negative=multiple
822 * 7. service the device to clear its pending interrupt.
823 * 8. loop again if paranoia is required.
824 *
825 * probe_irq_on() returns a mask of allocated irq's.
826 *
827 * probe_irq_off() takes the mask as a parameter,
828 * and returns the irq number which occurred,
829 * or zero if none occurred, or a negative irq number
830 * if more than one irq occurred.
831 */
832
833#if !defined(CONFIG_GENERIC_IRQ_PROBE)
834static inline unsigned long probe_irq_on(void)
835{
836 return 0;
837}
838static inline int probe_irq_off(unsigned long val)
839{
840 return 0;
841}
842static inline unsigned int probe_irq_mask(unsigned long val)
843{
844 return 0;
845}
846#else
847extern unsigned long probe_irq_on(void); /* returns 0 on failure */
848extern int probe_irq_off(unsigned long); /* returns 0 or negative on failure */
849extern unsigned int probe_irq_mask(unsigned long); /* returns mask of ISA interrupts */
850#endif
851
852#ifdef CONFIG_PROC_FS
853/* Initialize /proc/irq/ */
854extern void init_irq_proc(void);
855#else
856static inline void init_irq_proc(void)
857{
858}
859#endif
860
861#ifdef CONFIG_IRQ_TIMINGS
862void irq_timings_enable(void);
863void irq_timings_disable(void);
864u64 irq_timings_next_event(u64 now);
865#endif
866
867struct seq_file;
868int show_interrupts(struct seq_file *p, void *v);
869int arch_show_interrupts(struct seq_file *p, int prec);
870
871extern int early_irq_init(void);
872extern int arch_probe_nr_irqs(void);
873extern int arch_early_irq_init(void);
874
875/*
876 * We want to know which function is an entrypoint of a hardirq or a softirq.
877 */
878#ifndef __irq_entry
879# define __irq_entry __section(".irqentry.text")
880#endif
881
882#define __softirq_entry __section(".softirqentry.text")
883
884#endif
885

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source code of linux/include/linux/interrupt.h