Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2/* interrupt.h */
3#ifndef _LINUX_INTERRUPT_H
4#define _LINUX_INTERRUPT_H
5
6#include <linux/kernel.h>
7#include <linux/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 * @affinity: CPUs this irqaction is allowed to run on
113 * @next: pointer to the next irqaction for shared interrupts
114 * @irq: interrupt number
115 * @flags: flags (see IRQF_* above)
116 * @thread_fn: interrupt handler function for threaded interrupts
117 * @thread: thread pointer for threaded interrupts
118 * @secondary: pointer to secondary irqaction (force threading)
119 * @thread_flags: flags related to @thread
120 * @thread_mask: bitmask for keeping track of @thread activity
121 * @dir: pointer to the proc/irq/NN/name entry
122 */
123struct irqaction {
124 irq_handler_t handler;
125 union {
126 void *dev_id;
127 void __percpu *percpu_dev_id;
128 };
129 const struct cpumask *affinity;
130 struct irqaction *next;
131 irq_handler_t thread_fn;
132 struct task_struct *thread;
133 struct irqaction *secondary;
134 unsigned int irq;
135 unsigned int flags;
136 unsigned long thread_flags;
137 unsigned long thread_mask;
138 const char *name;
139 struct proc_dir_entry *dir;
140} ____cacheline_internodealigned_in_smp;
141
142extern irqreturn_t no_action(int cpl, void *dev_id);
143
144/*
145 * If a (PCI) device interrupt is not connected we set dev->irq to
146 * IRQ_NOTCONNECTED. This causes request_irq() to fail with -ENOTCONN, so we
147 * can distinguish that case from other error returns.
148 *
149 * 0x80000000 is guaranteed to be outside the available range of interrupts
150 * and easy to distinguish from other possible incorrect values.
151 */
152#define IRQ_NOTCONNECTED (1U << 31)
153
154extern int __must_check
155request_threaded_irq(unsigned int irq, irq_handler_t handler,
156 irq_handler_t thread_fn,
157 unsigned long flags, const char *name, void *dev);
158
159/**
160 * request_irq - Add a handler for an interrupt line
161 * @irq: The interrupt line to allocate
162 * @handler: Function to be called when the IRQ occurs.
163 * Primary handler for threaded interrupts
164 * If NULL, the default primary handler is installed
165 * @flags: Handling flags
166 * @name: Name of the device generating this interrupt
167 * @dev: A cookie passed to the handler function
168 *
169 * This call allocates an interrupt and establishes a handler; see
170 * the documentation for request_threaded_irq() for details.
171 */
172static inline int __must_check
173request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
174 const char *name, void *dev)
175{
176 return request_threaded_irq(irq, handler, NULL, flags | IRQF_COND_ONESHOT, name, dev);
177}
178
179extern int __must_check
180request_any_context_irq(unsigned int irq, irq_handler_t handler,
181 unsigned long flags, const char *name, void *dev_id);
182
183extern int __must_check
184request_percpu_irq_affinity(unsigned int irq, irq_handler_t handler, const char *devname,
185 const cpumask_t *affinity, void __percpu *percpu_dev_id);
186
187extern int __must_check
188request_nmi(unsigned int irq, irq_handler_t handler, unsigned long flags,
189 const char *name, void *dev);
190
191static inline int __must_check
192request_percpu_irq(unsigned int irq, irq_handler_t handler,
193 const char *devname, void __percpu *percpu_dev_id)
194{
195 return request_percpu_irq_affinity(irq, handler, devname,
196 NULL, percpu_dev_id);
197}
198
199extern int __must_check
200request_percpu_nmi(unsigned int irq, irq_handler_t handler, const char *name,
201 const struct cpumask *affinity, void __percpu *dev_id);
202
203extern const void *free_irq(unsigned int, void *);
204extern void free_percpu_irq(unsigned int, void __percpu *);
205
206extern const void *free_nmi(unsigned int irq, void *dev_id);
207extern void free_percpu_nmi(unsigned int irq, void __percpu *percpu_dev_id);
208
209struct device;
210
211extern int __must_check
212devm_request_threaded_irq(struct device *dev, unsigned int irq,
213 irq_handler_t handler, irq_handler_t thread_fn,
214 unsigned long irqflags, const char *devname,
215 void *dev_id);
216
217static inline int __must_check
218devm_request_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
219 unsigned long irqflags, const char *devname, void *dev_id)
220{
221 return devm_request_threaded_irq(dev, irq, handler, NULL, irqflags | IRQF_COND_ONESHOT,
222 devname, dev_id);
223}
224
225extern int __must_check
226devm_request_any_context_irq(struct device *dev, unsigned int irq,
227 irq_handler_t handler, unsigned long irqflags,
228 const char *devname, void *dev_id);
229
230extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
231
232bool irq_has_action(unsigned int irq);
233extern void disable_irq_nosync(unsigned int irq);
234extern bool disable_hardirq(unsigned int irq);
235extern void disable_irq(unsigned int irq);
236extern void disable_percpu_irq(unsigned int irq);
237extern void enable_irq(unsigned int irq);
238extern void enable_percpu_irq(unsigned int irq, unsigned int type);
239extern bool irq_percpu_is_enabled(unsigned int irq);
240extern void irq_wake_thread(unsigned int irq, void *dev_id);
241
242DEFINE_LOCK_GUARD_1(disable_irq, int,
243 disable_irq(*_T->lock), enable_irq(*_T->lock))
244
245extern void disable_nmi_nosync(unsigned int irq);
246extern void disable_percpu_nmi(unsigned int irq);
247extern void enable_nmi(unsigned int irq);
248extern void enable_percpu_nmi(unsigned int irq, unsigned int type);
249extern int prepare_percpu_nmi(unsigned int irq);
250extern void teardown_percpu_nmi(unsigned int irq);
251
252extern int irq_inject_interrupt(unsigned int irq);
253
254/* The following three functions are for the core kernel use only. */
255extern void suspend_device_irqs(void);
256extern void resume_device_irqs(void);
257extern void rearm_wake_irq(unsigned int irq);
258
259/**
260 * struct irq_affinity_notify - context for notification of IRQ affinity changes
261 * @irq: Interrupt to which notification applies
262 * @kref: Reference count, for internal use
263 * @work: Work item, for internal use
264 * @notify: Function to be called on change. This will be
265 * called in process context.
266 * @release: Function to be called on release. This will be
267 * called in process context. Once registered, the
268 * structure must only be freed when this function is
269 * called or later.
270 */
271struct irq_affinity_notify {
272 unsigned int irq;
273 struct kref kref;
274 struct work_struct work;
275 void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
276 void (*release)(struct kref *ref);
277};
278
279#define IRQ_AFFINITY_MAX_SETS 4
280
281/**
282 * struct irq_affinity - Description for automatic irq affinity assignments
283 * @pre_vectors: Don't apply affinity to @pre_vectors at beginning of
284 * the MSI(-X) vector space
285 * @post_vectors: Don't apply affinity to @post_vectors at end of
286 * the MSI(-X) vector space
287 * @nr_sets: The number of interrupt sets for which affinity
288 * spreading is required
289 * @set_size: Array holding the size of each interrupt set
290 * @calc_sets: Callback for calculating the number and size
291 * of interrupt sets
292 * @priv: Private data for usage by @calc_sets, usually a
293 * pointer to driver/device specific data.
294 */
295struct irq_affinity {
296 unsigned int pre_vectors;
297 unsigned int post_vectors;
298 unsigned int nr_sets;
299 unsigned int set_size[IRQ_AFFINITY_MAX_SETS];
300 void (*calc_sets)(struct irq_affinity *, unsigned int nvecs);
301 void *priv;
302};
303
304/**
305 * struct irq_affinity_desc - Interrupt affinity descriptor
306 * @mask: cpumask to hold the affinity assignment
307 * @is_managed: 1 if the interrupt is managed internally
308 */
309struct irq_affinity_desc {
310 struct cpumask mask;
311 unsigned int is_managed : 1;
312};
313
314#if defined(CONFIG_SMP)
315
316extern cpumask_var_t irq_default_affinity;
317
318extern int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask);
319extern int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask);
320
321extern int irq_can_set_affinity(unsigned int irq);
322extern int irq_select_affinity(unsigned int irq);
323
324extern int __irq_apply_affinity_hint(unsigned int irq, const struct cpumask *m,
325 bool setaffinity);
326
327/**
328 * irq_update_affinity_hint - Update the affinity hint
329 * @irq: Interrupt to update
330 * @m: cpumask pointer (NULL to clear the hint)
331 *
332 * Updates the affinity hint, but does not change the affinity of the interrupt.
333 */
334static inline int
335irq_update_affinity_hint(unsigned int irq, const struct cpumask *m)
336{
337 return __irq_apply_affinity_hint(irq, m, false);
338}
339
340/**
341 * irq_set_affinity_and_hint - Update the affinity hint and apply the provided
342 * cpumask to the interrupt
343 * @irq: Interrupt to update
344 * @m: cpumask pointer (NULL to clear the hint)
345 *
346 * Updates the affinity hint and if @m is not NULL it applies it as the
347 * affinity of that interrupt.
348 */
349static inline int
350irq_set_affinity_and_hint(unsigned int irq, const struct cpumask *m)
351{
352 return __irq_apply_affinity_hint(irq, m, true);
353}
354
355/*
356 * Deprecated. Use irq_update_affinity_hint() or irq_set_affinity_and_hint()
357 * instead.
358 */
359static inline int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
360{
361 return irq_set_affinity_and_hint(irq, m);
362}
363
364extern int irq_update_affinity_desc(unsigned int irq,
365 struct irq_affinity_desc *affinity);
366
367extern int
368irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
369
370struct irq_affinity_desc *
371irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd);
372
373unsigned int irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
374 const struct irq_affinity *affd);
375
376#else /* CONFIG_SMP */
377
378static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
379{
380 return -EINVAL;
381}
382
383static inline int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
384{
385 return 0;
386}
387
388static inline int irq_can_set_affinity(unsigned int irq)
389{
390 return 0;
391}
392
393static inline int irq_select_affinity(unsigned int irq) { return 0; }
394
395static inline int irq_update_affinity_hint(unsigned int irq,
396 const struct cpumask *m)
397{
398 return -EINVAL;
399}
400
401static inline int irq_set_affinity_and_hint(unsigned int irq,
402 const struct cpumask *m)
403{
404 return -EINVAL;
405}
406
407static inline int irq_set_affinity_hint(unsigned int irq,
408 const struct cpumask *m)
409{
410 return -EINVAL;
411}
412
413static inline int irq_update_affinity_desc(unsigned int irq,
414 struct irq_affinity_desc *affinity)
415{
416 return -EINVAL;
417}
418
419static inline int
420irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
421{
422 return 0;
423}
424
425static inline struct irq_affinity_desc *
426irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd)
427{
428 return NULL;
429}
430
431static inline unsigned int
432irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
433 const struct irq_affinity *affd)
434{
435 return maxvec;
436}
437
438#endif /* CONFIG_SMP */
439
440/*
441 * Special lockdep variants of irq disabling/enabling.
442 * These should be used for locking constructs that
443 * know that a particular irq context which is disabled,
444 * and which is the only irq-context user of a lock,
445 * that it's safe to take the lock in the irq-disabled
446 * section without disabling hardirqs.
447 *
448 * On !CONFIG_LOCKDEP they are equivalent to the normal
449 * irq disable/enable methods.
450 */
451static inline void disable_irq_nosync_lockdep(unsigned int irq)
452{
453 disable_irq_nosync(irq);
454#if defined(CONFIG_LOCKDEP) && !defined(CONFIG_PREEMPT_RT)
455 local_irq_disable();
456#endif
457}
458
459static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
460{
461 disable_irq_nosync(irq);
462#if defined(CONFIG_LOCKDEP) && !defined(CONFIG_PREEMPT_RT)
463 local_irq_save(*flags);
464#endif
465}
466
467static inline void enable_irq_lockdep(unsigned int irq)
468{
469#if defined(CONFIG_LOCKDEP) && !defined(CONFIG_PREEMPT_RT)
470 local_irq_enable();
471#endif
472 enable_irq(irq);
473}
474
475static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
476{
477#if defined(CONFIG_LOCKDEP) && !defined(CONFIG_PREEMPT_RT)
478 local_irq_restore(*flags);
479#endif
480 enable_irq(irq);
481}
482
483/* IRQ wakeup (PM) control: */
484extern int irq_set_irq_wake(unsigned int irq, unsigned int on);
485
486static inline int enable_irq_wake(unsigned int irq)
487{
488 return irq_set_irq_wake(irq, 1);
489}
490
491static inline int disable_irq_wake(unsigned int irq)
492{
493 return irq_set_irq_wake(irq, 0);
494}
495
496/*
497 * irq_get_irqchip_state/irq_set_irqchip_state specific flags
498 */
499enum irqchip_irq_state {
500 IRQCHIP_STATE_PENDING, /* Is interrupt pending? */
501 IRQCHIP_STATE_ACTIVE, /* Is interrupt in progress? */
502 IRQCHIP_STATE_MASKED, /* Is interrupt masked? */
503 IRQCHIP_STATE_LINE_LEVEL, /* Is IRQ line high? */
504};
505
506extern int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
507 bool *state);
508extern int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
509 bool state);
510
511#ifdef CONFIG_IRQ_FORCED_THREADING
512# ifdef CONFIG_PREEMPT_RT
513# define force_irqthreads() (true)
514# else
515DECLARE_STATIC_KEY_FALSE(force_irqthreads_key);
516# define force_irqthreads() (static_branch_unlikely(&force_irqthreads_key))
517# endif
518#else
519#define force_irqthreads() (false)
520#endif
521
522#ifndef local_softirq_pending
523
524#ifndef local_softirq_pending_ref
525#define local_softirq_pending_ref irq_stat.__softirq_pending
526#endif
527
528#define local_softirq_pending() (__this_cpu_read(local_softirq_pending_ref))
529#define set_softirq_pending(x) (__this_cpu_write(local_softirq_pending_ref, (x)))
530#define or_softirq_pending(x) (__this_cpu_or(local_softirq_pending_ref, (x)))
531
532#endif /* local_softirq_pending */
533
534/* Some architectures might implement lazy enabling/disabling of
535 * interrupts. In some cases, such as stop_machine, we might want
536 * to ensure that after a local_irq_disable(), interrupts have
537 * really been disabled in hardware. Such architectures need to
538 * implement the following hook.
539 */
540#ifndef hard_irq_disable
541#define hard_irq_disable() do { } while(0)
542#endif
543
544/* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
545 frequency threaded job scheduling. For almost all the purposes
546 tasklets are more than enough. F.e. all serial device BHs et
547 al. should be converted to tasklets, not to softirqs.
548 */
549
550enum
551{
552 HI_SOFTIRQ=0,
553 TIMER_SOFTIRQ,
554 NET_TX_SOFTIRQ,
555 NET_RX_SOFTIRQ,
556 BLOCK_SOFTIRQ,
557 IRQ_POLL_SOFTIRQ,
558 TASKLET_SOFTIRQ,
559 SCHED_SOFTIRQ,
560 HRTIMER_SOFTIRQ,
561 RCU_SOFTIRQ, /* Preferable RCU should always be the last softirq */
562
563 NR_SOFTIRQS
564};
565
566/*
567 * The following vectors can be safely ignored after ksoftirqd is parked:
568 *
569 * _ RCU:
570 * 1) rcutree_migrate_callbacks() migrates the queue.
571 * 2) rcutree_report_cpu_dead() reports the final quiescent states.
572 *
573 * _ IRQ_POLL: irq_poll_cpu_dead() migrates the queue
574 *
575 * _ (HR)TIMER_SOFTIRQ: (hr)timers_dead_cpu() migrates the queue
576 */
577#define SOFTIRQ_HOTPLUG_SAFE_MASK (BIT(TIMER_SOFTIRQ) | BIT(IRQ_POLL_SOFTIRQ) |\
578 BIT(HRTIMER_SOFTIRQ) | BIT(RCU_SOFTIRQ))
579
580
581/* map softirq index to softirq name. update 'softirq_to_name' in
582 * kernel/softirq.c when adding a new softirq.
583 */
584extern const char * const softirq_to_name[NR_SOFTIRQS];
585
586/* softirq mask and active fields moved to irq_cpustat_t in
587 * asm/hardirq.h to get better cache usage. KAO
588 */
589
590struct softirq_action
591{
592 void (*action)(void);
593};
594
595asmlinkage void do_softirq(void);
596asmlinkage void __do_softirq(void);
597
598#ifdef CONFIG_PREEMPT_RT
599extern void do_softirq_post_smp_call_flush(unsigned int was_pending);
600#else
601static inline void do_softirq_post_smp_call_flush(unsigned int unused)
602{
603 do_softirq();
604}
605#endif
606
607extern void open_softirq(int nr, void (*action)(void));
608extern void softirq_init(void);
609extern void __raise_softirq_irqoff(unsigned int nr);
610
611extern void raise_softirq_irqoff(unsigned int nr);
612extern void raise_softirq(unsigned int nr);
613
614/*
615 * With forced-threaded interrupts enabled a raised softirq is deferred to
616 * ksoftirqd unless it can be handled within the threaded interrupt. This
617 * affects timer_list timers and hrtimers which are explicitly marked with
618 * HRTIMER_MODE_SOFT.
619 * With PREEMPT_RT enabled more hrtimers are moved to softirq for processing
620 * which includes all timers which are not explicitly marked HRTIMER_MODE_HARD.
621 * Userspace controlled timers (like the clock_nanosleep() interface) is divided
622 * into two categories: Tasks with elevated scheduling policy including
623 * SCHED_{FIFO|RR|DL} and the remaining scheduling policy. The tasks with the
624 * elevated scheduling policy are woken up directly from the HARDIRQ while all
625 * other wake ups are delayed to softirq and so to ksoftirqd.
626 *
627 * The ksoftirqd runs at SCHED_OTHER policy at which it should remain since it
628 * handles the softirq in an overloaded situation (not handled everything
629 * within its last run).
630 * If the timers are handled at SCHED_OTHER priority then they competes with all
631 * other SCHED_OTHER tasks for CPU resources are possibly delayed.
632 * Moving timers softirqs to a low priority SCHED_FIFO thread instead ensures
633 * that timer are performed before scheduling any SCHED_OTHER thread.
634 */
635DECLARE_PER_CPU(struct task_struct *, ktimerd);
636DECLARE_PER_CPU(unsigned long, pending_timer_softirq);
637void raise_ktimers_thread(unsigned int nr);
638
639static inline unsigned int local_timers_pending_force_th(void)
640{
641 return __this_cpu_read(pending_timer_softirq);
642}
643
644static inline void raise_timer_softirq(unsigned int nr)
645{
646 lockdep_assert_in_irq();
647 if (force_irqthreads())
648 raise_ktimers_thread(nr);
649 else
650 __raise_softirq_irqoff(nr);
651}
652
653static inline unsigned int local_timers_pending(void)
654{
655 if (force_irqthreads())
656 return local_timers_pending_force_th();
657 else
658 return local_softirq_pending();
659}
660
661DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
662
663static inline struct task_struct *this_cpu_ksoftirqd(void)
664{
665 return this_cpu_read(ksoftirqd);
666}
667
668/* Tasklets --- multithreaded analogue of BHs.
669
670 This API is deprecated. Please consider using threaded IRQs instead:
671 https://lore.kernel.org/lkml/20200716081538.2sivhkj4hcyrusem@linutronix.de
672
673 Main feature differing them of generic softirqs: tasklet
674 is running only on one CPU simultaneously.
675
676 Main feature differing them of BHs: different tasklets
677 may be run simultaneously on different CPUs.
678
679 Properties:
680 * If tasklet_schedule() is called, then tasklet is guaranteed
681 to be executed on some cpu at least once after this.
682 * If the tasklet is already scheduled, but its execution is still not
683 started, it will be executed only once.
684 * If this tasklet is already running on another CPU (or schedule is called
685 from tasklet itself), it is rescheduled for later.
686 * Tasklet is strictly serialized wrt itself, but not
687 wrt another tasklets. If client needs some intertask synchronization,
688 he makes it with spinlocks.
689 */
690
691struct tasklet_struct
692{
693 struct tasklet_struct *next;
694 unsigned long state;
695 atomic_t count;
696 bool use_callback;
697 union {
698 void (*func)(unsigned long data);
699 void (*callback)(struct tasklet_struct *t);
700 };
701 unsigned long data;
702};
703
704#define DECLARE_TASKLET(name, _callback) \
705struct tasklet_struct name = { \
706 .count = ATOMIC_INIT(0), \
707 .callback = _callback, \
708 .use_callback = true, \
709}
710
711#define DECLARE_TASKLET_DISABLED(name, _callback) \
712struct tasklet_struct name = { \
713 .count = ATOMIC_INIT(1), \
714 .callback = _callback, \
715 .use_callback = true, \
716}
717
718#define from_tasklet(var, callback_tasklet, tasklet_fieldname) \
719 container_of(callback_tasklet, typeof(*var), tasklet_fieldname)
720
721#define DECLARE_TASKLET_OLD(name, _func) \
722struct tasklet_struct name = { \
723 .count = ATOMIC_INIT(0), \
724 .func = _func, \
725}
726
727#define DECLARE_TASKLET_DISABLED_OLD(name, _func) \
728struct tasklet_struct name = { \
729 .count = ATOMIC_INIT(1), \
730 .func = _func, \
731}
732
733enum
734{
735 TASKLET_STATE_SCHED, /* Tasklet is scheduled for execution */
736 TASKLET_STATE_RUN /* Tasklet is running (SMP only) */
737};
738
739#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT)
740static inline int tasklet_trylock(struct tasklet_struct *t)
741{
742 return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
743}
744
745void tasklet_unlock(struct tasklet_struct *t);
746void tasklet_unlock_wait(struct tasklet_struct *t);
747void tasklet_unlock_spin_wait(struct tasklet_struct *t);
748
749#else
750static inline int tasklet_trylock(struct tasklet_struct *t) { return 1; }
751static inline void tasklet_unlock(struct tasklet_struct *t) { }
752static inline void tasklet_unlock_wait(struct tasklet_struct *t) { }
753static inline void tasklet_unlock_spin_wait(struct tasklet_struct *t) { }
754#endif
755
756extern void __tasklet_schedule(struct tasklet_struct *t);
757
758static inline void tasklet_schedule(struct tasklet_struct *t)
759{
760 if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
761 __tasklet_schedule(t);
762}
763
764extern void __tasklet_hi_schedule(struct tasklet_struct *t);
765
766static inline void tasklet_hi_schedule(struct tasklet_struct *t)
767{
768 if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
769 __tasklet_hi_schedule(t);
770}
771
772static inline void tasklet_disable_nosync(struct tasklet_struct *t)
773{
774 atomic_inc(&t->count);
775 smp_mb__after_atomic();
776}
777
778/*
779 * Do not use in new code. Disabling tasklets from atomic contexts is
780 * error prone and should be avoided.
781 */
782static inline void tasklet_disable_in_atomic(struct tasklet_struct *t)
783{
784 tasklet_disable_nosync(t);
785 tasklet_unlock_spin_wait(t);
786 smp_mb();
787}
788
789static inline void tasklet_disable(struct tasklet_struct *t)
790{
791 tasklet_disable_nosync(t);
792 tasklet_unlock_wait(t);
793 smp_mb();
794}
795
796static inline void tasklet_enable(struct tasklet_struct *t)
797{
798 smp_mb__before_atomic();
799 atomic_dec(&t->count);
800}
801
802extern void tasklet_kill(struct tasklet_struct *t);
803extern void tasklet_init(struct tasklet_struct *t,
804 void (*func)(unsigned long), unsigned long data);
805extern void tasklet_setup(struct tasklet_struct *t,
806 void (*callback)(struct tasklet_struct *));
807
808/*
809 * Autoprobing for irqs:
810 *
811 * probe_irq_on() and probe_irq_off() provide robust primitives
812 * for accurate IRQ probing during kernel initialization. They are
813 * reasonably simple to use, are not "fooled" by spurious interrupts,
814 * and, unlike other attempts at IRQ probing, they do not get hung on
815 * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
816 *
817 * For reasonably foolproof probing, use them as follows:
818 *
819 * 1. clear and/or mask the device's internal interrupt.
820 * 2. sti();
821 * 3. irqs = probe_irq_on(); // "take over" all unassigned idle IRQs
822 * 4. enable the device and cause it to trigger an interrupt.
823 * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
824 * 6. irq = probe_irq_off(irqs); // get IRQ number, 0=none, negative=multiple
825 * 7. service the device to clear its pending interrupt.
826 * 8. loop again if paranoia is required.
827 *
828 * probe_irq_on() returns a mask of allocated irq's.
829 *
830 * probe_irq_off() takes the mask as a parameter,
831 * and returns the irq number which occurred,
832 * or zero if none occurred, or a negative irq number
833 * if more than one irq occurred.
834 */
835
836#if !defined(CONFIG_GENERIC_IRQ_PROBE)
837static inline unsigned long probe_irq_on(void)
838{
839 return 0;
840}
841static inline int probe_irq_off(unsigned long val)
842{
843 return 0;
844}
845static inline unsigned int probe_irq_mask(unsigned long val)
846{
847 return 0;
848}
849#else
850extern unsigned long probe_irq_on(void); /* returns 0 on failure */
851extern int probe_irq_off(unsigned long); /* returns 0 or negative on failure */
852extern unsigned int probe_irq_mask(unsigned long); /* returns mask of ISA interrupts */
853#endif
854
855#ifdef CONFIG_PROC_FS
856/* Initialize /proc/irq/ */
857extern void init_irq_proc(void);
858#else
859static inline void init_irq_proc(void)
860{
861}
862#endif
863
864struct seq_file;
865int show_interrupts(struct seq_file *p, void *v);
866int arch_show_interrupts(struct seq_file *p, int prec);
867
868extern int early_irq_init(void);
869extern int arch_probe_nr_irqs(void);
870extern int arch_early_irq_init(void);
871
872/*
873 * We want to know which function is an entrypoint of a hardirq or a softirq.
874 */
875#ifndef __irq_entry
876# define __irq_entry __section(".irqentry.text")
877#endif
878
879#define __softirq_entry __section(".softirqentry.text")
880
881#endif