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