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 * IRQF_NO_AUTOEN - Don't enable IRQ or NMI automatically when users request it.
65 * Users will enable it explicitly by enable_irq() or enable_nmi()
66 * later.
67 */
68 #define IRQF_SHARED 0x00000080
69 #define IRQF_PROBE_SHARED 0x00000100
70 #define __IRQF_TIMER 0x00000200
71 #define IRQF_PERCPU 0x00000400
72 #define IRQF_NOBALANCING 0x00000800
73 #define IRQF_IRQPOLL 0x00001000
74 #define IRQF_ONESHOT 0x00002000
75 #define IRQF_NO_SUSPEND 0x00004000
76 #define IRQF_FORCE_RESUME 0x00008000
77 #define IRQF_NO_THREAD 0x00010000
78 #define IRQF_EARLY_RESUME 0x00020000
79 #define IRQF_COND_SUSPEND 0x00040000
80 #define IRQF_NO_AUTOEN 0x00080000
81
82 #define IRQF_TIMER (__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD)
83
84 /*
85 * These values can be returned by request_any_context_irq() and
86 * describe the context the interrupt will be run in.
87 *
88 * IRQC_IS_HARDIRQ - interrupt runs in hardirq context
89 * IRQC_IS_NESTED - interrupt runs in a nested threaded context
90 */
91 enum {
92 IRQC_IS_HARDIRQ = 0,
93 IRQC_IS_NESTED,
94 };
95
96 typedef irqreturn_t (*irq_handler_t)(int, void *);
97
98 /**
99 * struct irqaction - per interrupt action descriptor
100 * @handler: interrupt handler function
101 * @name: name of the device
102 * @dev_id: cookie to identify the device
103 * @percpu_dev_id: cookie to identify the device
104 * @next: pointer to the next irqaction for shared interrupts
105 * @irq: interrupt number
106 * @flags: flags (see IRQF_* above)
107 * @thread_fn: interrupt handler function for threaded interrupts
108 * @thread: thread pointer for threaded interrupts
109 * @secondary: pointer to secondary irqaction (force threading)
110 * @thread_flags: flags related to @thread
111 * @thread_mask: bitmask for keeping track of @thread activity
112 * @dir: pointer to the proc/irq/NN/name entry
113 */
114 struct irqaction {
115 irq_handler_t handler;
116 void *dev_id;
117 void __percpu *percpu_dev_id;
118 struct irqaction *next;
119 irq_handler_t thread_fn;
120 struct task_struct *thread;
121 struct irqaction *secondary;
122 unsigned int irq;
123 unsigned int flags;
124 unsigned long thread_flags;
125 unsigned long thread_mask;
126 const char *name;
127 struct proc_dir_entry *dir;
128 } ____cacheline_internodealigned_in_smp;
129
130 extern irqreturn_t no_action(int cpl, void *dev_id);
131
132 /*
133 * If a (PCI) device interrupt is not connected we set dev->irq to
134 * IRQ_NOTCONNECTED. This causes request_irq() to fail with -ENOTCONN, so we
135 * can distingiush that case from other error returns.
136 *
137 * 0x80000000 is guaranteed to be outside the available range of interrupts
138 * and easy to distinguish from other possible incorrect values.
139 */
140 #define IRQ_NOTCONNECTED (1U << 31)
141
142 extern int __must_check
143 request_threaded_irq(unsigned int irq, irq_handler_t handler,
144 irq_handler_t thread_fn,
145 unsigned long flags, const char *name, void *dev);
146
147 /**
148 * request_irq - Add a handler for an interrupt line
149 * @irq: The interrupt line to allocate
150 * @handler: Function to be called when the IRQ occurs.
151 * Primary handler for threaded interrupts
152 * If NULL, the default primary handler is installed
153 * @flags: Handling flags
154 * @name: Name of the device generating this interrupt
155 * @dev: A cookie passed to the handler function
156 *
157 * This call allocates an interrupt and establishes a handler; see
158 * the documentation for request_threaded_irq() for details.
159 */
160 static inline int __must_check
request_irq(unsigned int irq,irq_handler_t handler,unsigned long flags,const char * name,void * dev)161 request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
162 const char *name, void *dev)
163 {
164 return request_threaded_irq(irq, handler, NULL, flags, name, dev);
165 }
166
167 extern int __must_check
168 request_any_context_irq(unsigned int irq, irq_handler_t handler,
169 unsigned long flags, const char *name, void *dev_id);
170
171 extern int __must_check
172 __request_percpu_irq(unsigned int irq, irq_handler_t handler,
173 unsigned long flags, const char *devname,
174 void __percpu *percpu_dev_id);
175
176 extern int __must_check
177 request_nmi(unsigned int irq, irq_handler_t handler, unsigned long flags,
178 const char *name, void *dev);
179
180 static inline int __must_check
request_percpu_irq(unsigned int irq,irq_handler_t handler,const char * devname,void __percpu * percpu_dev_id)181 request_percpu_irq(unsigned int irq, irq_handler_t handler,
182 const char *devname, void __percpu *percpu_dev_id)
183 {
184 return __request_percpu_irq(irq, handler, 0,
185 devname, percpu_dev_id);
186 }
187
188 extern int __must_check
189 request_percpu_nmi(unsigned int irq, irq_handler_t handler,
190 const char *devname, void __percpu *dev);
191
192 extern const void *free_irq(unsigned int, void *);
193 extern void free_percpu_irq(unsigned int, void __percpu *);
194
195 extern const void *free_nmi(unsigned int irq, void *dev_id);
196 extern void free_percpu_nmi(unsigned int irq, void __percpu *percpu_dev_id);
197
198 struct device;
199
200 extern int __must_check
201 devm_request_threaded_irq(struct device *dev, unsigned int irq,
202 irq_handler_t handler, irq_handler_t thread_fn,
203 unsigned long irqflags, const char *devname,
204 void *dev_id);
205
206 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)207 devm_request_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
208 unsigned long irqflags, const char *devname, void *dev_id)
209 {
210 return devm_request_threaded_irq(dev, irq, handler, NULL, irqflags,
211 devname, dev_id);
212 }
213
214 extern int __must_check
215 devm_request_any_context_irq(struct device *dev, unsigned int irq,
216 irq_handler_t handler, unsigned long irqflags,
217 const char *devname, void *dev_id);
218
219 extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
220
221 /*
222 * On lockdep we dont want to enable hardirqs in hardirq
223 * context. Use local_irq_enable_in_hardirq() to annotate
224 * kernel code that has to do this nevertheless (pretty much
225 * the only valid case is for old/broken hardware that is
226 * insanely slow).
227 *
228 * NOTE: in theory this might break fragile code that relies
229 * on hardirq delivery - in practice we dont seem to have such
230 * places left. So the only effect should be slightly increased
231 * irqs-off latencies.
232 */
233 #ifdef CONFIG_LOCKDEP
234 # define local_irq_enable_in_hardirq() do { } while (0)
235 #else
236 # define local_irq_enable_in_hardirq() local_irq_enable()
237 #endif
238
239 extern void disable_irq_nosync(unsigned int irq);
240 extern bool disable_hardirq(unsigned int irq);
241 extern void disable_irq(unsigned int irq);
242 extern void disable_percpu_irq(unsigned int irq);
243 extern void enable_irq(unsigned int irq);
244 extern void enable_percpu_irq(unsigned int irq, unsigned int type);
245 extern bool irq_percpu_is_enabled(unsigned int irq);
246 extern void irq_wake_thread(unsigned int irq, void *dev_id);
247
248 extern void disable_nmi_nosync(unsigned int irq);
249 extern void disable_percpu_nmi(unsigned int irq);
250 extern void enable_nmi(unsigned int irq);
251 extern void enable_percpu_nmi(unsigned int irq, unsigned int type);
252 extern int prepare_percpu_nmi(unsigned int irq);
253 extern void teardown_percpu_nmi(unsigned int irq);
254
255 extern int irq_inject_interrupt(unsigned int irq);
256
257 /* The following three functions are for the core kernel use only. */
258 extern void suspend_device_irqs(void);
259 extern void resume_device_irqs(void);
260 extern void rearm_wake_irq(unsigned int irq);
261
262 /**
263 * struct irq_affinity_notify - context for notification of IRQ affinity changes
264 * @irq: Interrupt to which notification applies
265 * @kref: Reference count, for internal use
266 * @work: Work item, for internal use
267 * @notify: Function to be called on change. This will be
268 * called in process context.
269 * @release: Function to be called on release. This will be
270 * called in process context. Once registered, the
271 * structure must only be freed when this function is
272 * called or later.
273 */
274 struct irq_affinity_notify {
275 unsigned int irq;
276 struct kref kref;
277 struct work_struct work;
278 void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
279 void (*release)(struct kref *ref);
280 };
281
282 #define IRQ_AFFINITY_MAX_SETS 4
283
284 /**
285 * struct irq_affinity - Description for automatic irq affinity assignements
286 * @pre_vectors: Don't apply affinity to @pre_vectors at beginning of
287 * the MSI(-X) vector space
288 * @post_vectors: Don't apply affinity to @post_vectors at end of
289 * the MSI(-X) vector space
290 * @nr_sets: The number of interrupt sets for which affinity
291 * spreading is required
292 * @set_size: Array holding the size of each interrupt set
293 * @calc_sets: Callback for calculating the number and size
294 * of interrupt sets
295 * @priv: Private data for usage by @calc_sets, usually a
296 * pointer to driver/device specific data.
297 */
298 struct irq_affinity {
299 unsigned int pre_vectors;
300 unsigned int post_vectors;
301 unsigned int nr_sets;
302 unsigned int set_size[IRQ_AFFINITY_MAX_SETS];
303 void (*calc_sets)(struct irq_affinity *, unsigned int nvecs);
304 void *priv;
305 };
306
307 /**
308 * struct irq_affinity_desc - Interrupt affinity descriptor
309 * @mask: cpumask to hold the affinity assignment
310 * @is_managed: 1 if the interrupt is managed internally
311 */
312 struct irq_affinity_desc {
313 struct cpumask mask;
314 unsigned int is_managed : 1;
315 };
316
317 #if defined(CONFIG_SMP)
318
319 extern cpumask_var_t irq_default_affinity;
320
321 /* Internal implementation. Use the helpers below */
322 extern int __irq_set_affinity(unsigned int irq, const struct cpumask *cpumask,
323 bool force);
324
325 /**
326 * irq_set_affinity - Set the irq affinity of a given irq
327 * @irq: Interrupt to set affinity
328 * @cpumask: cpumask
329 *
330 * Fails if cpumask does not contain an online CPU
331 */
332 static inline int
irq_set_affinity(unsigned int irq,const struct cpumask * cpumask)333 irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
334 {
335 return __irq_set_affinity(irq, cpumask, false);
336 }
337
338 /**
339 * irq_force_affinity - Force the irq affinity of a given irq
340 * @irq: Interrupt to set affinity
341 * @cpumask: cpumask
342 *
343 * Same as irq_set_affinity, but without checking the mask against
344 * online cpus.
345 *
346 * Solely for low level cpu hotplug code, where we need to make per
347 * cpu interrupts affine before the cpu becomes online.
348 */
349 static inline int
irq_force_affinity(unsigned int irq,const struct cpumask * cpumask)350 irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
351 {
352 return __irq_set_affinity(irq, cpumask, true);
353 }
354
355 extern int irq_can_set_affinity(unsigned int irq);
356 extern int irq_select_affinity(unsigned int irq);
357
358 extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m);
359
360 extern int
361 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
362
363 struct irq_affinity_desc *
364 irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd);
365
366 unsigned int irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
367 const struct irq_affinity *affd);
368
369 #else /* CONFIG_SMP */
370
irq_set_affinity(unsigned int irq,const struct cpumask * m)371 static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
372 {
373 return -EINVAL;
374 }
375
irq_force_affinity(unsigned int irq,const struct cpumask * cpumask)376 static inline int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
377 {
378 return 0;
379 }
380
irq_can_set_affinity(unsigned int irq)381 static inline int irq_can_set_affinity(unsigned int irq)
382 {
383 return 0;
384 }
385
irq_select_affinity(unsigned int irq)386 static inline int irq_select_affinity(unsigned int irq) { return 0; }
387
irq_set_affinity_hint(unsigned int irq,const struct cpumask * m)388 static inline int irq_set_affinity_hint(unsigned int irq,
389 const struct cpumask *m)
390 {
391 return -EINVAL;
392 }
393
394 static inline int
irq_set_affinity_notifier(unsigned int irq,struct irq_affinity_notify * notify)395 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
396 {
397 return 0;
398 }
399
400 static inline struct irq_affinity_desc *
irq_create_affinity_masks(unsigned int nvec,struct irq_affinity * affd)401 irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd)
402 {
403 return NULL;
404 }
405
406 static inline unsigned int
irq_calc_affinity_vectors(unsigned int minvec,unsigned int maxvec,const struct irq_affinity * affd)407 irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
408 const struct irq_affinity *affd)
409 {
410 return maxvec;
411 }
412
413 #endif /* CONFIG_SMP */
414
415 /*
416 * Special lockdep variants of irq disabling/enabling.
417 * These should be used for locking constructs that
418 * know that a particular irq context which is disabled,
419 * and which is the only irq-context user of a lock,
420 * that it's safe to take the lock in the irq-disabled
421 * section without disabling hardirqs.
422 *
423 * On !CONFIG_LOCKDEP they are equivalent to the normal
424 * irq disable/enable methods.
425 */
disable_irq_nosync_lockdep(unsigned int irq)426 static inline void disable_irq_nosync_lockdep(unsigned int irq)
427 {
428 disable_irq_nosync(irq);
429 #ifdef CONFIG_LOCKDEP
430 local_irq_disable();
431 #endif
432 }
433
disable_irq_nosync_lockdep_irqsave(unsigned int irq,unsigned long * flags)434 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
435 {
436 disable_irq_nosync(irq);
437 #ifdef CONFIG_LOCKDEP
438 local_irq_save(*flags);
439 #endif
440 }
441
disable_irq_lockdep(unsigned int irq)442 static inline void disable_irq_lockdep(unsigned int irq)
443 {
444 disable_irq(irq);
445 #ifdef CONFIG_LOCKDEP
446 local_irq_disable();
447 #endif
448 }
449
enable_irq_lockdep(unsigned int irq)450 static inline void enable_irq_lockdep(unsigned int irq)
451 {
452 #ifdef CONFIG_LOCKDEP
453 local_irq_enable();
454 #endif
455 enable_irq(irq);
456 }
457
enable_irq_lockdep_irqrestore(unsigned int irq,unsigned long * flags)458 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
459 {
460 #ifdef CONFIG_LOCKDEP
461 local_irq_restore(*flags);
462 #endif
463 enable_irq(irq);
464 }
465
466 /* IRQ wakeup (PM) control: */
467 extern int irq_set_irq_wake(unsigned int irq, unsigned int on);
468
enable_irq_wake(unsigned int irq)469 static inline int enable_irq_wake(unsigned int irq)
470 {
471 return irq_set_irq_wake(irq, 1);
472 }
473
disable_irq_wake(unsigned int irq)474 static inline int disable_irq_wake(unsigned int irq)
475 {
476 return irq_set_irq_wake(irq, 0);
477 }
478
479 /*
480 * irq_get_irqchip_state/irq_set_irqchip_state specific flags
481 */
482 enum irqchip_irq_state {
483 IRQCHIP_STATE_PENDING, /* Is interrupt pending? */
484 IRQCHIP_STATE_ACTIVE, /* Is interrupt in progress? */
485 IRQCHIP_STATE_MASKED, /* Is interrupt masked? */
486 IRQCHIP_STATE_LINE_LEVEL, /* Is IRQ line high? */
487 };
488
489 extern int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
490 bool *state);
491 extern int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
492 bool state);
493
494 #ifdef CONFIG_IRQ_FORCED_THREADING
495 # ifdef CONFIG_PREEMPT_RT
496 # define force_irqthreads (true)
497 # else
498 extern bool force_irqthreads;
499 # endif
500 #else
501 #define force_irqthreads (0)
502 #endif
503
504 #ifndef local_softirq_pending
505
506 #ifndef local_softirq_pending_ref
507 #define local_softirq_pending_ref irq_stat.__softirq_pending
508 #endif
509
510 #define local_softirq_pending() (__this_cpu_read(local_softirq_pending_ref))
511 #define set_softirq_pending(x) (__this_cpu_write(local_softirq_pending_ref, (x)))
512 #define or_softirq_pending(x) (__this_cpu_or(local_softirq_pending_ref, (x)))
513
514 #endif /* local_softirq_pending */
515
516 /* Some architectures might implement lazy enabling/disabling of
517 * interrupts. In some cases, such as stop_machine, we might want
518 * to ensure that after a local_irq_disable(), interrupts have
519 * really been disabled in hardware. Such architectures need to
520 * implement the following hook.
521 */
522 #ifndef hard_irq_disable
523 #define hard_irq_disable() do { } while(0)
524 #endif
525
526 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
527 frequency threaded job scheduling. For almost all the purposes
528 tasklets are more than enough. F.e. all serial device BHs et
529 al. should be converted to tasklets, not to softirqs.
530 */
531
532 enum
533 {
534 HI_SOFTIRQ=0,
535 TIMER_SOFTIRQ,
536 NET_TX_SOFTIRQ,
537 NET_RX_SOFTIRQ,
538 BLOCK_SOFTIRQ,
539 IRQ_POLL_SOFTIRQ,
540 TASKLET_SOFTIRQ,
541 SCHED_SOFTIRQ,
542 HRTIMER_SOFTIRQ,
543 RCU_SOFTIRQ, /* Preferable RCU should always be the last softirq */
544
545 NR_SOFTIRQS
546 };
547
548 #define SOFTIRQ_STOP_IDLE_MASK (~(1 << RCU_SOFTIRQ))
549 /* Softirq's where the handling might be long: */
550 #define LONG_SOFTIRQ_MASK ((1 << NET_TX_SOFTIRQ) | \
551 (1 << NET_RX_SOFTIRQ) | \
552 (1 << BLOCK_SOFTIRQ) | \
553 (1 << IRQ_POLL_SOFTIRQ) | \
554 (1 << TASKLET_SOFTIRQ))
555
556 /* map softirq index to softirq name. update 'softirq_to_name' in
557 * kernel/softirq.c when adding a new softirq.
558 */
559 extern const char * const softirq_to_name[NR_SOFTIRQS];
560
561 /* softirq mask and active fields moved to irq_cpustat_t in
562 * asm/hardirq.h to get better cache usage. KAO
563 */
564
565 struct softirq_action
566 {
567 void (*action)(struct softirq_action *);
568 };
569
570 asmlinkage void do_softirq(void);
571 asmlinkage void __do_softirq(void);
572
573 #ifdef __ARCH_HAS_DO_SOFTIRQ
574 void do_softirq_own_stack(void);
575 #else
do_softirq_own_stack(void)576 static inline void do_softirq_own_stack(void)
577 {
578 __do_softirq();
579 }
580 #endif
581
582 extern void open_softirq(int nr, void (*action)(struct softirq_action *));
583 extern void softirq_init(void);
584 extern void __raise_softirq_irqoff(unsigned int nr);
585
586 extern void raise_softirq_irqoff(unsigned int nr);
587 extern void raise_softirq(unsigned int nr);
588
589 DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
590 DECLARE_PER_CPU(__u32, active_softirqs);
591
this_cpu_ksoftirqd(void)592 static inline struct task_struct *this_cpu_ksoftirqd(void)
593 {
594 return this_cpu_read(ksoftirqd);
595 }
596
597 /* Tasklets --- multithreaded analogue of BHs.
598
599 This API is deprecated. Please consider using threaded IRQs instead:
600 https://lore.kernel.org/lkml/20200716081538.2sivhkj4hcyrusem@linutronix.de
601
602 Main feature differing them of generic softirqs: tasklet
603 is running only on one CPU simultaneously.
604
605 Main feature differing them of BHs: different tasklets
606 may be run simultaneously on different CPUs.
607
608 Properties:
609 * If tasklet_schedule() is called, then tasklet is guaranteed
610 to be executed on some cpu at least once after this.
611 * If the tasklet is already scheduled, but its execution is still not
612 started, it will be executed only once.
613 * If this tasklet is already running on another CPU (or schedule is called
614 from tasklet itself), it is rescheduled for later.
615 * Tasklet is strictly serialized wrt itself, but not
616 wrt another tasklets. If client needs some intertask synchronization,
617 he makes it with spinlocks.
618 */
619
620 struct tasklet_struct
621 {
622 struct tasklet_struct *next;
623 unsigned long state;
624 atomic_t count;
625 bool use_callback;
626 union {
627 void (*func)(unsigned long data);
628 void (*callback)(struct tasklet_struct *t);
629 };
630 unsigned long data;
631 };
632
633 #define DECLARE_TASKLET(name, _callback) \
634 struct tasklet_struct name = { \
635 .count = ATOMIC_INIT(0), \
636 .callback = _callback, \
637 .use_callback = true, \
638 }
639
640 #define DECLARE_TASKLET_DISABLED(name, _callback) \
641 struct tasklet_struct name = { \
642 .count = ATOMIC_INIT(1), \
643 .callback = _callback, \
644 .use_callback = true, \
645 }
646
647 #define from_tasklet(var, callback_tasklet, tasklet_fieldname) \
648 container_of(callback_tasklet, typeof(*var), tasklet_fieldname)
649
650 #define DECLARE_TASKLET_OLD(name, _func) \
651 struct tasklet_struct name = { \
652 .count = ATOMIC_INIT(0), \
653 .func = _func, \
654 }
655
656 #define DECLARE_TASKLET_DISABLED_OLD(name, _func) \
657 struct tasklet_struct name = { \
658 .count = ATOMIC_INIT(1), \
659 .func = _func, \
660 }
661
662 enum
663 {
664 TASKLET_STATE_SCHED, /* Tasklet is scheduled for execution */
665 TASKLET_STATE_RUN /* Tasklet is running (SMP only) */
666 };
667
668 #ifdef CONFIG_SMP
tasklet_trylock(struct tasklet_struct * t)669 static inline int tasklet_trylock(struct tasklet_struct *t)
670 {
671 return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
672 }
673
tasklet_unlock(struct tasklet_struct * t)674 static inline void tasklet_unlock(struct tasklet_struct *t)
675 {
676 smp_mb__before_atomic();
677 clear_bit(TASKLET_STATE_RUN, &(t)->state);
678 }
679
tasklet_unlock_wait(struct tasklet_struct * t)680 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
681 {
682 while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
683 }
684 #else
685 #define tasklet_trylock(t) 1
686 #define tasklet_unlock_wait(t) do { } while (0)
687 #define tasklet_unlock(t) do { } while (0)
688 #endif
689
690 extern void __tasklet_schedule(struct tasklet_struct *t);
691
tasklet_schedule(struct tasklet_struct * t)692 static inline void tasklet_schedule(struct tasklet_struct *t)
693 {
694 if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
695 __tasklet_schedule(t);
696 }
697
698 extern void __tasklet_hi_schedule(struct tasklet_struct *t);
699
tasklet_hi_schedule(struct tasklet_struct * t)700 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
701 {
702 if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
703 __tasklet_hi_schedule(t);
704 }
705
tasklet_disable_nosync(struct tasklet_struct * t)706 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
707 {
708 atomic_inc(&t->count);
709 smp_mb__after_atomic();
710 }
711
tasklet_disable(struct tasklet_struct * t)712 static inline void tasklet_disable(struct tasklet_struct *t)
713 {
714 tasklet_disable_nosync(t);
715 tasklet_unlock_wait(t);
716 smp_mb();
717 }
718
tasklet_enable(struct tasklet_struct * t)719 static inline void tasklet_enable(struct tasklet_struct *t)
720 {
721 smp_mb__before_atomic();
722 atomic_dec(&t->count);
723 }
724
725 extern void tasklet_kill(struct tasklet_struct *t);
726 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
727 extern void tasklet_init(struct tasklet_struct *t,
728 void (*func)(unsigned long), unsigned long data);
729 extern void tasklet_setup(struct tasklet_struct *t,
730 void (*callback)(struct tasklet_struct *));
731
732 /*
733 * Autoprobing for irqs:
734 *
735 * probe_irq_on() and probe_irq_off() provide robust primitives
736 * for accurate IRQ probing during kernel initialization. They are
737 * reasonably simple to use, are not "fooled" by spurious interrupts,
738 * and, unlike other attempts at IRQ probing, they do not get hung on
739 * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
740 *
741 * For reasonably foolproof probing, use them as follows:
742 *
743 * 1. clear and/or mask the device's internal interrupt.
744 * 2. sti();
745 * 3. irqs = probe_irq_on(); // "take over" all unassigned idle IRQs
746 * 4. enable the device and cause it to trigger an interrupt.
747 * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
748 * 6. irq = probe_irq_off(irqs); // get IRQ number, 0=none, negative=multiple
749 * 7. service the device to clear its pending interrupt.
750 * 8. loop again if paranoia is required.
751 *
752 * probe_irq_on() returns a mask of allocated irq's.
753 *
754 * probe_irq_off() takes the mask as a parameter,
755 * and returns the irq number which occurred,
756 * or zero if none occurred, or a negative irq number
757 * if more than one irq occurred.
758 */
759
760 #if !defined(CONFIG_GENERIC_IRQ_PROBE)
probe_irq_on(void)761 static inline unsigned long probe_irq_on(void)
762 {
763 return 0;
764 }
probe_irq_off(unsigned long val)765 static inline int probe_irq_off(unsigned long val)
766 {
767 return 0;
768 }
probe_irq_mask(unsigned long val)769 static inline unsigned int probe_irq_mask(unsigned long val)
770 {
771 return 0;
772 }
773 #else
774 extern unsigned long probe_irq_on(void); /* returns 0 on failure */
775 extern int probe_irq_off(unsigned long); /* returns 0 or negative on failure */
776 extern unsigned int probe_irq_mask(unsigned long); /* returns mask of ISA interrupts */
777 #endif
778
779 #ifdef CONFIG_PROC_FS
780 /* Initialize /proc/irq/ */
781 extern void init_irq_proc(void);
782 #else
init_irq_proc(void)783 static inline void init_irq_proc(void)
784 {
785 }
786 #endif
787
788 #ifdef CONFIG_IRQ_TIMINGS
789 void irq_timings_enable(void);
790 void irq_timings_disable(void);
791 u64 irq_timings_next_event(u64 now);
792 #endif
793
794 struct seq_file;
795 int show_interrupts(struct seq_file *p, void *v);
796 int arch_show_interrupts(struct seq_file *p, int prec);
797
798 extern int early_irq_init(void);
799 extern int arch_probe_nr_irqs(void);
800 extern int arch_early_irq_init(void);
801
802 /*
803 * We want to know which function is an entrypoint of a hardirq or a softirq.
804 */
805 #ifndef __irq_entry
806 # define __irq_entry __section(".irqentry.text")
807 #endif
808
809 #define __softirq_entry __section(".softirqentry.text")
810
811 #endif
812