1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* interrupt.h */
3 #ifndef _LINUX_INTERRUPT_H
4 #define _LINUX_INTERRUPT_H
5
6 #include <linux/kernel.h>
7 #include <linux/bitops.h>
8 #include <linux/cpumask.h>
9 #include <linux/irqreturn.h>
10 #include <linux/irqnr.h>
11 #include <linux/hardirq.h>
12 #include <linux/irqflags.h>
13 #include <linux/hrtimer.h>
14 #include <linux/kref.h>
15 #include <linux/workqueue.h>
16
17 #include <linux/atomic.h>
18 #include <asm/ptrace.h>
19 #include <asm/irq.h>
20 #include <asm/sections.h>
21
22 /*
23 * These correspond to the IORESOURCE_IRQ_* defines in
24 * linux/ioport.h to select the interrupt line behaviour. When
25 * requesting an interrupt without specifying a IRQF_TRIGGER, the
26 * setting should be assumed to be "as already configured", which
27 * may be as per machine or firmware initialisation.
28 */
29 #define IRQF_TRIGGER_NONE 0x00000000
30 #define IRQF_TRIGGER_RISING 0x00000001
31 #define IRQF_TRIGGER_FALLING 0x00000002
32 #define IRQF_TRIGGER_HIGH 0x00000004
33 #define IRQF_TRIGGER_LOW 0x00000008
34 #define IRQF_TRIGGER_MASK (IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \
35 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)
36 #define IRQF_TRIGGER_PROBE 0x00000010
37
38 /*
39 * These flags used only by the kernel as part of the
40 * irq handling routines.
41 *
42 * IRQF_SHARED - allow sharing the irq among several devices
43 * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
44 * IRQF_TIMER - Flag to mark this interrupt as timer interrupt
45 * IRQF_PERCPU - Interrupt is per cpu
46 * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing
47 * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is
48 * registered first in a shared interrupt is considered for
49 * performance reasons)
50 * IRQF_ONESHOT - Interrupt is not reenabled after the hardirq handler finished.
51 * Used by threaded interrupts which need to keep the
52 * irq line disabled until the threaded handler has been run.
53 * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend. Does not guarantee
54 * that this interrupt will wake the system from a suspended
55 * state. See Documentation/power/suspend-and-interrupts.rst
56 * IRQF_FORCE_RESUME - Force enable it on resume even if IRQF_NO_SUSPEND is set
57 * IRQF_NO_THREAD - Interrupt cannot be threaded
58 * IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device
59 * resume time.
60 * IRQF_COND_SUSPEND - If the IRQ is shared with a NO_SUSPEND user, execute this
61 * interrupt handler after suspending interrupts. For system
62 * wakeup devices users need to implement wakeup detection in
63 * their interrupt handlers.
64 */
65 #define IRQF_SHARED 0x00000080
66 #define IRQF_PROBE_SHARED 0x00000100
67 #define __IRQF_TIMER 0x00000200
68 #define IRQF_PERCPU 0x00000400
69 #define IRQF_NOBALANCING 0x00000800
70 #define IRQF_IRQPOLL 0x00001000
71 #define IRQF_ONESHOT 0x00002000
72 #define IRQF_NO_SUSPEND 0x00004000
73 #define IRQF_FORCE_RESUME 0x00008000
74 #define IRQF_NO_THREAD 0x00010000
75 #define IRQF_EARLY_RESUME 0x00020000
76 #define IRQF_COND_SUSPEND 0x00040000
77
78 #define IRQF_TIMER (__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD)
79
80 /*
81 * These values can be returned by request_any_context_irq() and
82 * describe the context the interrupt will be run in.
83 *
84 * IRQC_IS_HARDIRQ - interrupt runs in hardirq context
85 * IRQC_IS_NESTED - interrupt runs in a nested threaded context
86 */
87 enum {
88 IRQC_IS_HARDIRQ = 0,
89 IRQC_IS_NESTED,
90 };
91
92 typedef irqreturn_t (*irq_handler_t)(int, void *);
93
94 /**
95 * struct irqaction - per interrupt action descriptor
96 * @handler: interrupt handler function
97 * @name: name of the device
98 * @dev_id: cookie to identify the device
99 * @percpu_dev_id: cookie to identify the device
100 * @next: pointer to the next irqaction for shared interrupts
101 * @irq: interrupt number
102 * @flags: flags (see IRQF_* above)
103 * @thread_fn: interrupt handler function for threaded interrupts
104 * @thread: thread pointer for threaded interrupts
105 * @secondary: pointer to secondary irqaction (force threading)
106 * @thread_flags: flags related to @thread
107 * @thread_mask: bitmask for keeping track of @thread activity
108 * @dir: pointer to the proc/irq/NN/name entry
109 */
110 struct irqaction {
111 irq_handler_t handler;
112 void *dev_id;
113 void __percpu *percpu_dev_id;
114 struct irqaction *next;
115 irq_handler_t thread_fn;
116 struct task_struct *thread;
117 struct irqaction *secondary;
118 unsigned int irq;
119 unsigned int flags;
120 unsigned long thread_flags;
121 unsigned long thread_mask;
122 const char *name;
123 struct proc_dir_entry *dir;
124 } ____cacheline_internodealigned_in_smp;
125
126 extern irqreturn_t no_action(int cpl, void *dev_id);
127
128 /*
129 * If a (PCI) device interrupt is not connected we set dev->irq to
130 * IRQ_NOTCONNECTED. This causes request_irq() to fail with -ENOTCONN, so we
131 * can distingiush that case from other error returns.
132 *
133 * 0x80000000 is guaranteed to be outside the available range of interrupts
134 * and easy to distinguish from other possible incorrect values.
135 */
136 #define IRQ_NOTCONNECTED (1U << 31)
137
138 extern int __must_check
139 request_threaded_irq(unsigned int irq, irq_handler_t handler,
140 irq_handler_t thread_fn,
141 unsigned long flags, const char *name, void *dev);
142
143 /**
144 * request_irq - Add a handler for an interrupt line
145 * @irq: The interrupt line to allocate
146 * @handler: Function to be called when the IRQ occurs.
147 * Primary handler for threaded interrupts
148 * If NULL, the default primary handler is installed
149 * @flags: Handling flags
150 * @name: Name of the device generating this interrupt
151 * @dev: A cookie passed to the handler function
152 *
153 * This call allocates an interrupt and establishes a handler; see
154 * the documentation for request_threaded_irq() for details.
155 */
156 static inline int __must_check
request_irq(unsigned int irq,irq_handler_t handler,unsigned long flags,const char * name,void * dev)157 request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
158 const char *name, void *dev)
159 {
160 return request_threaded_irq(irq, handler, NULL, flags, name, dev);
161 }
162
163 extern int __must_check
164 request_any_context_irq(unsigned int irq, irq_handler_t handler,
165 unsigned long flags, const char *name, void *dev_id);
166
167 extern int __must_check
168 __request_percpu_irq(unsigned int irq, irq_handler_t handler,
169 unsigned long flags, const char *devname,
170 void __percpu *percpu_dev_id);
171
172 extern int __must_check
173 request_nmi(unsigned int irq, irq_handler_t handler, unsigned long flags,
174 const char *name, void *dev);
175
176 static inline int __must_check
request_percpu_irq(unsigned int irq,irq_handler_t handler,const char * devname,void __percpu * percpu_dev_id)177 request_percpu_irq(unsigned int irq, irq_handler_t handler,
178 const char *devname, void __percpu *percpu_dev_id)
179 {
180 return __request_percpu_irq(irq, handler, 0,
181 devname, percpu_dev_id);
182 }
183
184 extern int __must_check
185 request_percpu_nmi(unsigned int irq, irq_handler_t handler,
186 const char *devname, void __percpu *dev);
187
188 extern const void *free_irq(unsigned int, void *);
189 extern void free_percpu_irq(unsigned int, void __percpu *);
190
191 extern const void *free_nmi(unsigned int irq, void *dev_id);
192 extern void free_percpu_nmi(unsigned int irq, void __percpu *percpu_dev_id);
193
194 struct device;
195
196 extern int __must_check
197 devm_request_threaded_irq(struct device *dev, unsigned int irq,
198 irq_handler_t handler, irq_handler_t thread_fn,
199 unsigned long irqflags, const char *devname,
200 void *dev_id);
201
202 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)203 devm_request_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
204 unsigned long irqflags, const char *devname, void *dev_id)
205 {
206 return devm_request_threaded_irq(dev, irq, handler, NULL, irqflags,
207 devname, dev_id);
208 }
209
210 extern int __must_check
211 devm_request_any_context_irq(struct device *dev, unsigned int irq,
212 irq_handler_t handler, unsigned long irqflags,
213 const char *devname, void *dev_id);
214
215 extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
216
217 /*
218 * On lockdep we dont want to enable hardirqs in hardirq
219 * context. Use local_irq_enable_in_hardirq() to annotate
220 * kernel code that has to do this nevertheless (pretty much
221 * the only valid case is for old/broken hardware that is
222 * insanely slow).
223 *
224 * NOTE: in theory this might break fragile code that relies
225 * on hardirq delivery - in practice we dont seem to have such
226 * places left. So the only effect should be slightly increased
227 * irqs-off latencies.
228 */
229 #ifdef CONFIG_LOCKDEP
230 # define local_irq_enable_in_hardirq() do { } while (0)
231 #else
232 # define local_irq_enable_in_hardirq() local_irq_enable()
233 #endif
234
235 extern void disable_irq_nosync(unsigned int irq);
236 extern bool disable_hardirq(unsigned int irq);
237 extern void disable_irq(unsigned int irq);
238 extern void disable_percpu_irq(unsigned int irq);
239 extern void enable_irq(unsigned int irq);
240 extern void enable_percpu_irq(unsigned int irq, unsigned int type);
241 extern bool irq_percpu_is_enabled(unsigned int irq);
242 extern void irq_wake_thread(unsigned int irq, void *dev_id);
243
244 extern void disable_nmi_nosync(unsigned int irq);
245 extern void disable_percpu_nmi(unsigned int irq);
246 extern void enable_nmi(unsigned int irq);
247 extern void enable_percpu_nmi(unsigned int irq, unsigned int type);
248 extern int prepare_percpu_nmi(unsigned int irq);
249 extern void teardown_percpu_nmi(unsigned int irq);
250
251 extern int irq_inject_interrupt(unsigned int irq);
252
253 /* The following three functions are for the core kernel use only. */
254 extern void suspend_device_irqs(void);
255 extern void resume_device_irqs(void);
256 extern void rearm_wake_irq(unsigned int irq);
257
258 /**
259 * struct irq_affinity_notify - context for notification of IRQ affinity changes
260 * @irq: Interrupt to which notification applies
261 * @kref: Reference count, for internal use
262 * @work: Work item, for internal use
263 * @notify: Function to be called on change. This will be
264 * called in process context.
265 * @release: Function to be called on release. This will be
266 * called in process context. Once registered, the
267 * structure must only be freed when this function is
268 * called or later.
269 */
270 struct irq_affinity_notify {
271 unsigned int irq;
272 struct kref kref;
273 struct work_struct work;
274 void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
275 void (*release)(struct kref *ref);
276 };
277
278 #define IRQ_AFFINITY_MAX_SETS 4
279
280 /**
281 * struct irq_affinity - Description for automatic irq affinity assignements
282 * @pre_vectors: Don't apply affinity to @pre_vectors at beginning of
283 * the MSI(-X) vector space
284 * @post_vectors: Don't apply affinity to @post_vectors at end of
285 * the MSI(-X) vector space
286 * @nr_sets: The number of interrupt sets for which affinity
287 * spreading is required
288 * @set_size: Array holding the size of each interrupt set
289 * @calc_sets: Callback for calculating the number and size
290 * of interrupt sets
291 * @priv: Private data for usage by @calc_sets, usually a
292 * pointer to driver/device specific data.
293 */
294 struct irq_affinity {
295 unsigned int pre_vectors;
296 unsigned int post_vectors;
297 unsigned int nr_sets;
298 unsigned int set_size[IRQ_AFFINITY_MAX_SETS];
299 void (*calc_sets)(struct irq_affinity *, unsigned int nvecs);
300 void *priv;
301 };
302
303 /**
304 * struct irq_affinity_desc - Interrupt affinity descriptor
305 * @mask: cpumask to hold the affinity assignment
306 * @is_managed: 1 if the interrupt is managed internally
307 */
308 struct irq_affinity_desc {
309 struct cpumask mask;
310 unsigned int is_managed : 1;
311 };
312
313 #if defined(CONFIG_SMP)
314
315 extern cpumask_var_t irq_default_affinity;
316
317 /* Internal implementation. Use the helpers below */
318 extern int __irq_set_affinity(unsigned int irq, const struct cpumask *cpumask,
319 bool force);
320
321 /**
322 * irq_set_affinity - Set the irq affinity of a given irq
323 * @irq: Interrupt to set affinity
324 * @cpumask: cpumask
325 *
326 * Fails if cpumask does not contain an online CPU
327 */
328 static inline int
irq_set_affinity(unsigned int irq,const struct cpumask * cpumask)329 irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
330 {
331 return __irq_set_affinity(irq, cpumask, false);
332 }
333
334 /**
335 * irq_force_affinity - Force the irq affinity of a given irq
336 * @irq: Interrupt to set affinity
337 * @cpumask: cpumask
338 *
339 * Same as irq_set_affinity, but without checking the mask against
340 * online cpus.
341 *
342 * Solely for low level cpu hotplug code, where we need to make per
343 * cpu interrupts affine before the cpu becomes online.
344 */
345 static inline int
irq_force_affinity(unsigned int irq,const struct cpumask * cpumask)346 irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
347 {
348 return __irq_set_affinity(irq, cpumask, true);
349 }
350
351 extern int irq_can_set_affinity(unsigned int irq);
352 extern int irq_select_affinity(unsigned int irq);
353
354 extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m);
355
356 extern int
357 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
358
359 struct irq_affinity_desc *
360 irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd);
361
362 unsigned int irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
363 const struct irq_affinity *affd);
364
365 #else /* CONFIG_SMP */
366
irq_set_affinity(unsigned int irq,const struct cpumask * m)367 static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
368 {
369 return -EINVAL;
370 }
371
irq_force_affinity(unsigned int irq,const struct cpumask * cpumask)372 static inline int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
373 {
374 return 0;
375 }
376
irq_can_set_affinity(unsigned int irq)377 static inline int irq_can_set_affinity(unsigned int irq)
378 {
379 return 0;
380 }
381
irq_select_affinity(unsigned int irq)382 static inline int irq_select_affinity(unsigned int irq) { return 0; }
383
irq_set_affinity_hint(unsigned int irq,const struct cpumask * m)384 static inline int irq_set_affinity_hint(unsigned int irq,
385 const struct cpumask *m)
386 {
387 return -EINVAL;
388 }
389
390 static inline int
irq_set_affinity_notifier(unsigned int irq,struct irq_affinity_notify * notify)391 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
392 {
393 return 0;
394 }
395
396 static inline struct irq_affinity_desc *
irq_create_affinity_masks(unsigned int nvec,struct irq_affinity * affd)397 irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd)
398 {
399 return NULL;
400 }
401
402 static inline unsigned int
irq_calc_affinity_vectors(unsigned int minvec,unsigned int maxvec,const struct irq_affinity * affd)403 irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
404 const struct irq_affinity *affd)
405 {
406 return maxvec;
407 }
408
409 #endif /* CONFIG_SMP */
410
411 /*
412 * Special lockdep variants of irq disabling/enabling.
413 * These should be used for locking constructs that
414 * know that a particular irq context which is disabled,
415 * and which is the only irq-context user of a lock,
416 * that it's safe to take the lock in the irq-disabled
417 * section without disabling hardirqs.
418 *
419 * On !CONFIG_LOCKDEP they are equivalent to the normal
420 * irq disable/enable methods.
421 */
disable_irq_nosync_lockdep(unsigned int irq)422 static inline void disable_irq_nosync_lockdep(unsigned int irq)
423 {
424 disable_irq_nosync(irq);
425 #ifdef CONFIG_LOCKDEP
426 local_irq_disable();
427 #endif
428 }
429
disable_irq_nosync_lockdep_irqsave(unsigned int irq,unsigned long * flags)430 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
431 {
432 disable_irq_nosync(irq);
433 #ifdef CONFIG_LOCKDEP
434 local_irq_save(*flags);
435 #endif
436 }
437
disable_irq_lockdep(unsigned int irq)438 static inline void disable_irq_lockdep(unsigned int irq)
439 {
440 disable_irq(irq);
441 #ifdef CONFIG_LOCKDEP
442 local_irq_disable();
443 #endif
444 }
445
enable_irq_lockdep(unsigned int irq)446 static inline void enable_irq_lockdep(unsigned int irq)
447 {
448 #ifdef CONFIG_LOCKDEP
449 local_irq_enable();
450 #endif
451 enable_irq(irq);
452 }
453
enable_irq_lockdep_irqrestore(unsigned int irq,unsigned long * flags)454 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
455 {
456 #ifdef CONFIG_LOCKDEP
457 local_irq_restore(*flags);
458 #endif
459 enable_irq(irq);
460 }
461
462 /* IRQ wakeup (PM) control: */
463 extern int irq_set_irq_wake(unsigned int irq, unsigned int on);
464
enable_irq_wake(unsigned int irq)465 static inline int enable_irq_wake(unsigned int irq)
466 {
467 return irq_set_irq_wake(irq, 1);
468 }
469
disable_irq_wake(unsigned int irq)470 static inline int disable_irq_wake(unsigned int irq)
471 {
472 return irq_set_irq_wake(irq, 0);
473 }
474
475 /*
476 * irq_get_irqchip_state/irq_set_irqchip_state specific flags
477 */
478 enum irqchip_irq_state {
479 IRQCHIP_STATE_PENDING, /* Is interrupt pending? */
480 IRQCHIP_STATE_ACTIVE, /* Is interrupt in progress? */
481 IRQCHIP_STATE_MASKED, /* Is interrupt masked? */
482 IRQCHIP_STATE_LINE_LEVEL, /* Is IRQ line high? */
483 };
484
485 extern int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
486 bool *state);
487 extern int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
488 bool state);
489
490 #ifdef CONFIG_IRQ_FORCED_THREADING
491 # ifdef CONFIG_PREEMPT_RT
492 # define force_irqthreads (true)
493 # else
494 extern bool force_irqthreads;
495 # endif
496 #else
497 #define force_irqthreads (0)
498 #endif
499
500 #ifndef local_softirq_pending
501
502 #ifndef local_softirq_pending_ref
503 #define local_softirq_pending_ref irq_stat.__softirq_pending
504 #endif
505
506 #define local_softirq_pending() (__this_cpu_read(local_softirq_pending_ref))
507 #define set_softirq_pending(x) (__this_cpu_write(local_softirq_pending_ref, (x)))
508 #define or_softirq_pending(x) (__this_cpu_or(local_softirq_pending_ref, (x)))
509
510 #endif /* local_softirq_pending */
511
512 /* Some architectures might implement lazy enabling/disabling of
513 * interrupts. In some cases, such as stop_machine, we might want
514 * to ensure that after a local_irq_disable(), interrupts have
515 * really been disabled in hardware. Such architectures need to
516 * implement the following hook.
517 */
518 #ifndef hard_irq_disable
519 #define hard_irq_disable() do { } while(0)
520 #endif
521
522 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
523 frequency threaded job scheduling. For almost all the purposes
524 tasklets are more than enough. F.e. all serial device BHs et
525 al. should be converted to tasklets, not to softirqs.
526 */
527
528 enum
529 {
530 HI_SOFTIRQ=0,
531 TIMER_SOFTIRQ,
532 NET_TX_SOFTIRQ,
533 NET_RX_SOFTIRQ,
534 BLOCK_SOFTIRQ,
535 IRQ_POLL_SOFTIRQ,
536 TASKLET_SOFTIRQ,
537 SCHED_SOFTIRQ,
538 HRTIMER_SOFTIRQ,
539 RCU_SOFTIRQ, /* Preferable RCU should always be the last softirq */
540
541 NR_SOFTIRQS
542 };
543
544 #define SOFTIRQ_STOP_IDLE_MASK (~(1 << RCU_SOFTIRQ))
545 /* Softirq's where the handling might be long: */
546 #define LONG_SOFTIRQ_MASK ((1 << NET_TX_SOFTIRQ) | \
547 (1 << NET_RX_SOFTIRQ) | \
548 (1 << BLOCK_SOFTIRQ) | \
549 (1 << IRQ_POLL_SOFTIRQ) | \
550 (1 << TASKLET_SOFTIRQ))
551
552 /* map softirq index to softirq name. update 'softirq_to_name' in
553 * kernel/softirq.c when adding a new softirq.
554 */
555 extern const char * const softirq_to_name[NR_SOFTIRQS];
556
557 /* softirq mask and active fields moved to irq_cpustat_t in
558 * asm/hardirq.h to get better cache usage. KAO
559 */
560
561 struct softirq_action
562 {
563 void (*action)(struct softirq_action *);
564 };
565
566 asmlinkage void do_softirq(void);
567 asmlinkage void __do_softirq(void);
568
569 #ifdef __ARCH_HAS_DO_SOFTIRQ
570 void do_softirq_own_stack(void);
571 #else
do_softirq_own_stack(void)572 static inline void do_softirq_own_stack(void)
573 {
574 __do_softirq();
575 }
576 #endif
577
578 extern void open_softirq(int nr, void (*action)(struct softirq_action *));
579 extern void softirq_init(void);
580 extern void __raise_softirq_irqoff(unsigned int nr);
581
582 extern void raise_softirq_irqoff(unsigned int nr);
583 extern void raise_softirq(unsigned int nr);
584
585 DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
586 DECLARE_PER_CPU(__u32, active_softirqs);
587
this_cpu_ksoftirqd(void)588 static inline struct task_struct *this_cpu_ksoftirqd(void)
589 {
590 return this_cpu_read(ksoftirqd);
591 }
592
593 /* Tasklets --- multithreaded analogue of BHs.
594
595 This API is deprecated. Please consider using threaded IRQs instead:
596 https://lore.kernel.org/lkml/20200716081538.2sivhkj4hcyrusem@linutronix.de
597
598 Main feature differing them of generic softirqs: tasklet
599 is running only on one CPU simultaneously.
600
601 Main feature differing them of BHs: different tasklets
602 may be run simultaneously on different CPUs.
603
604 Properties:
605 * If tasklet_schedule() is called, then tasklet is guaranteed
606 to be executed on some cpu at least once after this.
607 * If the tasklet is already scheduled, but its execution is still not
608 started, it will be executed only once.
609 * If this tasklet is already running on another CPU (or schedule is called
610 from tasklet itself), it is rescheduled for later.
611 * Tasklet is strictly serialized wrt itself, but not
612 wrt another tasklets. If client needs some intertask synchronization,
613 he makes it with spinlocks.
614 */
615
616 struct tasklet_struct
617 {
618 struct tasklet_struct *next;
619 unsigned long state;
620 atomic_t count;
621 bool use_callback;
622 union {
623 void (*func)(unsigned long data);
624 void (*callback)(struct tasklet_struct *t);
625 };
626 unsigned long data;
627 };
628
629 #define DECLARE_TASKLET(name, _callback) \
630 struct tasklet_struct name = { \
631 .count = ATOMIC_INIT(0), \
632 .callback = _callback, \
633 .use_callback = true, \
634 }
635
636 #define DECLARE_TASKLET_DISABLED(name, _callback) \
637 struct tasklet_struct name = { \
638 .count = ATOMIC_INIT(1), \
639 .callback = _callback, \
640 .use_callback = true, \
641 }
642
643 #define from_tasklet(var, callback_tasklet, tasklet_fieldname) \
644 container_of(callback_tasklet, typeof(*var), tasklet_fieldname)
645
646 #define DECLARE_TASKLET_OLD(name, _func) \
647 struct tasklet_struct name = { \
648 .count = ATOMIC_INIT(0), \
649 .func = _func, \
650 }
651
652 #define DECLARE_TASKLET_DISABLED_OLD(name, _func) \
653 struct tasklet_struct name = { \
654 .count = ATOMIC_INIT(1), \
655 .func = _func, \
656 }
657
658 enum
659 {
660 TASKLET_STATE_SCHED, /* Tasklet is scheduled for execution */
661 TASKLET_STATE_RUN /* Tasklet is running (SMP only) */
662 };
663
664 #ifdef CONFIG_SMP
tasklet_trylock(struct tasklet_struct * t)665 static inline int tasklet_trylock(struct tasklet_struct *t)
666 {
667 return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
668 }
669
tasklet_unlock(struct tasklet_struct * t)670 static inline void tasklet_unlock(struct tasklet_struct *t)
671 {
672 smp_mb__before_atomic();
673 clear_bit(TASKLET_STATE_RUN, &(t)->state);
674 }
675
tasklet_unlock_wait(struct tasklet_struct * t)676 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
677 {
678 while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
679 }
680 #else
681 #define tasklet_trylock(t) 1
682 #define tasklet_unlock_wait(t) do { } while (0)
683 #define tasklet_unlock(t) do { } while (0)
684 #endif
685
686 extern void __tasklet_schedule(struct tasklet_struct *t);
687
tasklet_schedule(struct tasklet_struct * t)688 static inline void tasklet_schedule(struct tasklet_struct *t)
689 {
690 if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
691 __tasklet_schedule(t);
692 }
693
694 extern void __tasklet_hi_schedule(struct tasklet_struct *t);
695
tasklet_hi_schedule(struct tasklet_struct * t)696 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
697 {
698 if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
699 __tasklet_hi_schedule(t);
700 }
701
tasklet_disable_nosync(struct tasklet_struct * t)702 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
703 {
704 atomic_inc(&t->count);
705 smp_mb__after_atomic();
706 }
707
tasklet_disable(struct tasklet_struct * t)708 static inline void tasklet_disable(struct tasklet_struct *t)
709 {
710 tasklet_disable_nosync(t);
711 tasklet_unlock_wait(t);
712 smp_mb();
713 }
714
tasklet_enable(struct tasklet_struct * t)715 static inline void tasklet_enable(struct tasklet_struct *t)
716 {
717 smp_mb__before_atomic();
718 atomic_dec(&t->count);
719 }
720
721 extern void tasklet_kill(struct tasklet_struct *t);
722 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
723 extern void tasklet_init(struct tasklet_struct *t,
724 void (*func)(unsigned long), unsigned long data);
725 extern void tasklet_setup(struct tasklet_struct *t,
726 void (*callback)(struct tasklet_struct *));
727
728 /*
729 * Autoprobing for irqs:
730 *
731 * probe_irq_on() and probe_irq_off() provide robust primitives
732 * for accurate IRQ probing during kernel initialization. They are
733 * reasonably simple to use, are not "fooled" by spurious interrupts,
734 * and, unlike other attempts at IRQ probing, they do not get hung on
735 * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
736 *
737 * For reasonably foolproof probing, use them as follows:
738 *
739 * 1. clear and/or mask the device's internal interrupt.
740 * 2. sti();
741 * 3. irqs = probe_irq_on(); // "take over" all unassigned idle IRQs
742 * 4. enable the device and cause it to trigger an interrupt.
743 * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
744 * 6. irq = probe_irq_off(irqs); // get IRQ number, 0=none, negative=multiple
745 * 7. service the device to clear its pending interrupt.
746 * 8. loop again if paranoia is required.
747 *
748 * probe_irq_on() returns a mask of allocated irq's.
749 *
750 * probe_irq_off() takes the mask as a parameter,
751 * and returns the irq number which occurred,
752 * or zero if none occurred, or a negative irq number
753 * if more than one irq occurred.
754 */
755
756 #if !defined(CONFIG_GENERIC_IRQ_PROBE)
probe_irq_on(void)757 static inline unsigned long probe_irq_on(void)
758 {
759 return 0;
760 }
probe_irq_off(unsigned long val)761 static inline int probe_irq_off(unsigned long val)
762 {
763 return 0;
764 }
probe_irq_mask(unsigned long val)765 static inline unsigned int probe_irq_mask(unsigned long val)
766 {
767 return 0;
768 }
769 #else
770 extern unsigned long probe_irq_on(void); /* returns 0 on failure */
771 extern int probe_irq_off(unsigned long); /* returns 0 or negative on failure */
772 extern unsigned int probe_irq_mask(unsigned long); /* returns mask of ISA interrupts */
773 #endif
774
775 #ifdef CONFIG_PROC_FS
776 /* Initialize /proc/irq/ */
777 extern void init_irq_proc(void);
778 #else
init_irq_proc(void)779 static inline void init_irq_proc(void)
780 {
781 }
782 #endif
783
784 #ifdef CONFIG_IRQ_TIMINGS
785 void irq_timings_enable(void);
786 void irq_timings_disable(void);
787 u64 irq_timings_next_event(u64 now);
788 #endif
789
790 struct seq_file;
791 int show_interrupts(struct seq_file *p, void *v);
792 int arch_show_interrupts(struct seq_file *p, int prec);
793
794 extern int early_irq_init(void);
795 extern int arch_probe_nr_irqs(void);
796 extern int arch_early_irq_init(void);
797
798 /*
799 * We want to know which function is an entrypoint of a hardirq or a softirq.
800 */
801 #ifndef __irq_entry
802 # define __irq_entry __section(".irqentry.text")
803 #endif
804
805 #define __softirq_entry __section(".softirqentry.text")
806
807 #endif
808