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TOMOYO Linux Cross Reference
Linux/include/linux/interrupt.h

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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/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
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
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
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 /* The following three functions are for the core kernel use only. */
252 extern void suspend_device_irqs(void);
253 extern void resume_device_irqs(void);
254 extern void rearm_wake_irq(unsigned int irq);
255 
256 /**
257  * struct irq_affinity_notify - context for notification of IRQ affinity changes
258  * @irq:                Interrupt to which notification applies
259  * @kref:               Reference count, for internal use
260  * @work:               Work item, for internal use
261  * @notify:             Function to be called on change.  This will be
262  *                      called in process context.
263  * @release:            Function to be called on release.  This will be
264  *                      called in process context.  Once registered, the
265  *                      structure must only be freed when this function is
266  *                      called or later.
267  */
268 struct irq_affinity_notify {
269         unsigned int irq;
270         struct kref kref;
271         struct work_struct work;
272         void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
273         void (*release)(struct kref *ref);
274 };
275 
276 #define IRQ_AFFINITY_MAX_SETS  4
277 
278 /**
279  * struct irq_affinity - Description for automatic irq affinity assignements
280  * @pre_vectors:        Don't apply affinity to @pre_vectors at beginning of
281  *                      the MSI(-X) vector space
282  * @post_vectors:       Don't apply affinity to @post_vectors at end of
283  *                      the MSI(-X) vector space
284  * @nr_sets:            The number of interrupt sets for which affinity
285  *                      spreading is required
286  * @set_size:           Array holding the size of each interrupt set
287  * @calc_sets:          Callback for calculating the number and size
288  *                      of interrupt sets
289  * @priv:               Private data for usage by @calc_sets, usually a
290  *                      pointer to driver/device specific data.
291  */
292 struct irq_affinity {
293         unsigned int    pre_vectors;
294         unsigned int    post_vectors;
295         unsigned int    nr_sets;
296         unsigned int    set_size[IRQ_AFFINITY_MAX_SETS];
297         void            (*calc_sets)(struct irq_affinity *, unsigned int nvecs);
298         void            *priv;
299 };
300 
301 /**
302  * struct irq_affinity_desc - Interrupt affinity descriptor
303  * @mask:       cpumask to hold the affinity assignment
304  * @is_managed: 1 if the interrupt is managed internally
305  */
306 struct irq_affinity_desc {
307         struct cpumask  mask;
308         unsigned int    is_managed : 1;
309 };
310 
311 #if defined(CONFIG_SMP)
312 
313 extern cpumask_var_t irq_default_affinity;
314 
315 /* Internal implementation. Use the helpers below */
316 extern int __irq_set_affinity(unsigned int irq, const struct cpumask *cpumask,
317                               bool force);
318 
319 /**
320  * irq_set_affinity - Set the irq affinity of a given irq
321  * @irq:        Interrupt to set affinity
322  * @cpumask:    cpumask
323  *
324  * Fails if cpumask does not contain an online CPU
325  */
326 static inline int
327 irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
328 {
329         return __irq_set_affinity(irq, cpumask, false);
330 }
331 
332 /**
333  * irq_force_affinity - Force the irq affinity of a given irq
334  * @irq:        Interrupt to set affinity
335  * @cpumask:    cpumask
336  *
337  * Same as irq_set_affinity, but without checking the mask against
338  * online cpus.
339  *
340  * Solely for low level cpu hotplug code, where we need to make per
341  * cpu interrupts affine before the cpu becomes online.
342  */
343 static inline int
344 irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
345 {
346         return __irq_set_affinity(irq, cpumask, true);
347 }
348 
349 extern int irq_can_set_affinity(unsigned int irq);
350 extern int irq_select_affinity(unsigned int irq);
351 
352 extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m);
353 
354 extern int
355 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
356 
357 struct irq_affinity_desc *
358 irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd);
359 
360 unsigned int irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
361                                        const struct irq_affinity *affd);
362 
363 #else /* CONFIG_SMP */
364 
365 static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
366 {
367         return -EINVAL;
368 }
369 
370 static inline int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
371 {
372         return 0;
373 }
374 
375 static inline int irq_can_set_affinity(unsigned int irq)
376 {
377         return 0;
378 }
379 
380 static inline int irq_select_affinity(unsigned int irq)  { return 0; }
381 
382 static inline int irq_set_affinity_hint(unsigned int irq,
383                                         const struct cpumask *m)
384 {
385         return -EINVAL;
386 }
387 
388 static inline int
389 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
390 {
391         return 0;
392 }
393 
394 static inline struct irq_affinity_desc *
395 irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd)
396 {
397         return NULL;
398 }
399 
400 static inline unsigned int
401 irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
402                           const struct irq_affinity *affd)
403 {
404         return maxvec;
405 }
406 
407 #endif /* CONFIG_SMP */
408 
409 /*
410  * Special lockdep variants of irq disabling/enabling.
411  * These should be used for locking constructs that
412  * know that a particular irq context which is disabled,
413  * and which is the only irq-context user of a lock,
414  * that it's safe to take the lock in the irq-disabled
415  * section without disabling hardirqs.
416  *
417  * On !CONFIG_LOCKDEP they are equivalent to the normal
418  * irq disable/enable methods.
419  */
420 static inline void disable_irq_nosync_lockdep(unsigned int irq)
421 {
422         disable_irq_nosync(irq);
423 #ifdef CONFIG_LOCKDEP
424         local_irq_disable();
425 #endif
426 }
427 
428 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
429 {
430         disable_irq_nosync(irq);
431 #ifdef CONFIG_LOCKDEP
432         local_irq_save(*flags);
433 #endif
434 }
435 
436 static inline void disable_irq_lockdep(unsigned int irq)
437 {
438         disable_irq(irq);
439 #ifdef CONFIG_LOCKDEP
440         local_irq_disable();
441 #endif
442 }
443 
444 static inline void enable_irq_lockdep(unsigned int irq)
445 {
446 #ifdef CONFIG_LOCKDEP
447         local_irq_enable();
448 #endif
449         enable_irq(irq);
450 }
451 
452 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
453 {
454 #ifdef CONFIG_LOCKDEP
455         local_irq_restore(*flags);
456 #endif
457         enable_irq(irq);
458 }
459 
460 /* IRQ wakeup (PM) control: */
461 extern int irq_set_irq_wake(unsigned int irq, unsigned int on);
462 
463 static inline int enable_irq_wake(unsigned int irq)
464 {
465         return irq_set_irq_wake(irq, 1);
466 }
467 
468 static inline int disable_irq_wake(unsigned int irq)
469 {
470         return irq_set_irq_wake(irq, 0);
471 }
472 
473 /*
474  * irq_get_irqchip_state/irq_set_irqchip_state specific flags
475  */
476 enum irqchip_irq_state {
477         IRQCHIP_STATE_PENDING,          /* Is interrupt pending? */
478         IRQCHIP_STATE_ACTIVE,           /* Is interrupt in progress? */
479         IRQCHIP_STATE_MASKED,           /* Is interrupt masked? */
480         IRQCHIP_STATE_LINE_LEVEL,       /* Is IRQ line high? */
481 };
482 
483 extern int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
484                                  bool *state);
485 extern int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
486                                  bool state);
487 
488 #ifdef CONFIG_IRQ_FORCED_THREADING
489 # ifdef CONFIG_PREEMPT_RT
490 #  define force_irqthreads      (true)
491 # else
492 extern bool force_irqthreads;
493 # endif
494 #else
495 #define force_irqthreads        (0)
496 #endif
497 
498 #ifndef local_softirq_pending
499 
500 #ifndef local_softirq_pending_ref
501 #define local_softirq_pending_ref irq_stat.__softirq_pending
502 #endif
503 
504 #define local_softirq_pending() (__this_cpu_read(local_softirq_pending_ref))
505 #define set_softirq_pending(x)  (__this_cpu_write(local_softirq_pending_ref, (x)))
506 #define or_softirq_pending(x)   (__this_cpu_or(local_softirq_pending_ref, (x)))
507 
508 #endif /* local_softirq_pending */
509 
510 /* Some architectures might implement lazy enabling/disabling of
511  * interrupts. In some cases, such as stop_machine, we might want
512  * to ensure that after a local_irq_disable(), interrupts have
513  * really been disabled in hardware. Such architectures need to
514  * implement the following hook.
515  */
516 #ifndef hard_irq_disable
517 #define hard_irq_disable()      do { } while(0)
518 #endif
519 
520 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
521    frequency threaded job scheduling. For almost all the purposes
522    tasklets are more than enough. F.e. all serial device BHs et
523    al. should be converted to tasklets, not to softirqs.
524  */
525 
526 enum
527 {
528         HI_SOFTIRQ=0,
529         TIMER_SOFTIRQ,
530         NET_TX_SOFTIRQ,
531         NET_RX_SOFTIRQ,
532         BLOCK_SOFTIRQ,
533         IRQ_POLL_SOFTIRQ,
534         TASKLET_SOFTIRQ,
535         SCHED_SOFTIRQ,
536         HRTIMER_SOFTIRQ,
537         RCU_SOFTIRQ,    /* Preferable RCU should always be the last softirq */
538 
539         NR_SOFTIRQS
540 };
541 
542 #define SOFTIRQ_STOP_IDLE_MASK (~(1 << RCU_SOFTIRQ))
543 
544 /* map softirq index to softirq name. update 'softirq_to_name' in
545  * kernel/softirq.c when adding a new softirq.
546  */
547 extern const char * const softirq_to_name[NR_SOFTIRQS];
548 
549 /* softirq mask and active fields moved to irq_cpustat_t in
550  * asm/hardirq.h to get better cache usage.  KAO
551  */
552 
553 struct softirq_action
554 {
555         void    (*action)(struct softirq_action *);
556 };
557 
558 asmlinkage void do_softirq(void);
559 asmlinkage void __do_softirq(void);
560 
561 #ifdef __ARCH_HAS_DO_SOFTIRQ
562 void do_softirq_own_stack(void);
563 #else
564 static inline void do_softirq_own_stack(void)
565 {
566         __do_softirq();
567 }
568 #endif
569 
570 extern void open_softirq(int nr, void (*action)(struct softirq_action *));
571 extern void softirq_init(void);
572 extern void __raise_softirq_irqoff(unsigned int nr);
573 
574 extern void raise_softirq_irqoff(unsigned int nr);
575 extern void raise_softirq(unsigned int nr);
576 
577 DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
578 
579 static inline struct task_struct *this_cpu_ksoftirqd(void)
580 {
581         return this_cpu_read(ksoftirqd);
582 }
583 
584 /* Tasklets --- multithreaded analogue of BHs.
585 
586    Main feature differing them of generic softirqs: tasklet
587    is running only on one CPU simultaneously.
588 
589    Main feature differing them of BHs: different tasklets
590    may be run simultaneously on different CPUs.
591 
592    Properties:
593    * If tasklet_schedule() is called, then tasklet is guaranteed
594      to be executed on some cpu at least once after this.
595    * If the tasklet is already scheduled, but its execution is still not
596      started, it will be executed only once.
597    * If this tasklet is already running on another CPU (or schedule is called
598      from tasklet itself), it is rescheduled for later.
599    * Tasklet is strictly serialized wrt itself, but not
600      wrt another tasklets. If client needs some intertask synchronization,
601      he makes it with spinlocks.
602  */
603 
604 struct tasklet_struct
605 {
606         struct tasklet_struct *next;
607         unsigned long state;
608         atomic_t count;
609         void (*func)(unsigned long);
610         unsigned long data;
611 };
612 
613 #define DECLARE_TASKLET(name, func, data) \
614 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
615 
616 #define DECLARE_TASKLET_DISABLED(name, func, data) \
617 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
618 
619 
620 enum
621 {
622         TASKLET_STATE_SCHED,    /* Tasklet is scheduled for execution */
623         TASKLET_STATE_RUN       /* Tasklet is running (SMP only) */
624 };
625 
626 #ifdef CONFIG_SMP
627 static inline int tasklet_trylock(struct tasklet_struct *t)
628 {
629         return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
630 }
631 
632 static inline void tasklet_unlock(struct tasklet_struct *t)
633 {
634         smp_mb__before_atomic();
635         clear_bit(TASKLET_STATE_RUN, &(t)->state);
636 }
637 
638 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
639 {
640         while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
641 }
642 #else
643 #define tasklet_trylock(t) 1
644 #define tasklet_unlock_wait(t) do { } while (0)
645 #define tasklet_unlock(t) do { } while (0)
646 #endif
647 
648 extern void __tasklet_schedule(struct tasklet_struct *t);
649 
650 static inline void tasklet_schedule(struct tasklet_struct *t)
651 {
652         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
653                 __tasklet_schedule(t);
654 }
655 
656 extern void __tasklet_hi_schedule(struct tasklet_struct *t);
657 
658 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
659 {
660         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
661                 __tasklet_hi_schedule(t);
662 }
663 
664 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
665 {
666         atomic_inc(&t->count);
667         smp_mb__after_atomic();
668 }
669 
670 static inline void tasklet_disable(struct tasklet_struct *t)
671 {
672         tasklet_disable_nosync(t);
673         tasklet_unlock_wait(t);
674         smp_mb();
675 }
676 
677 static inline void tasklet_enable(struct tasklet_struct *t)
678 {
679         smp_mb__before_atomic();
680         atomic_dec(&t->count);
681 }
682 
683 extern void tasklet_kill(struct tasklet_struct *t);
684 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
685 extern void tasklet_init(struct tasklet_struct *t,
686                          void (*func)(unsigned long), unsigned long data);
687 
688 /*
689  * Autoprobing for irqs:
690  *
691  * probe_irq_on() and probe_irq_off() provide robust primitives
692  * for accurate IRQ probing during kernel initialization.  They are
693  * reasonably simple to use, are not "fooled" by spurious interrupts,
694  * and, unlike other attempts at IRQ probing, they do not get hung on
695  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
696  *
697  * For reasonably foolproof probing, use them as follows:
698  *
699  * 1. clear and/or mask the device's internal interrupt.
700  * 2. sti();
701  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
702  * 4. enable the device and cause it to trigger an interrupt.
703  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
704  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
705  * 7. service the device to clear its pending interrupt.
706  * 8. loop again if paranoia is required.
707  *
708  * probe_irq_on() returns a mask of allocated irq's.
709  *
710  * probe_irq_off() takes the mask as a parameter,
711  * and returns the irq number which occurred,
712  * or zero if none occurred, or a negative irq number
713  * if more than one irq occurred.
714  */
715 
716 #if !defined(CONFIG_GENERIC_IRQ_PROBE) 
717 static inline unsigned long probe_irq_on(void)
718 {
719         return 0;
720 }
721 static inline int probe_irq_off(unsigned long val)
722 {
723         return 0;
724 }
725 static inline unsigned int probe_irq_mask(unsigned long val)
726 {
727         return 0;
728 }
729 #else
730 extern unsigned long probe_irq_on(void);        /* returns 0 on failure */
731 extern int probe_irq_off(unsigned long);        /* returns 0 or negative on failure */
732 extern unsigned int probe_irq_mask(unsigned long);      /* returns mask of ISA interrupts */
733 #endif
734 
735 #ifdef CONFIG_PROC_FS
736 /* Initialize /proc/irq/ */
737 extern void init_irq_proc(void);
738 #else
739 static inline void init_irq_proc(void)
740 {
741 }
742 #endif
743 
744 #ifdef CONFIG_IRQ_TIMINGS
745 void irq_timings_enable(void);
746 void irq_timings_disable(void);
747 u64 irq_timings_next_event(u64 now);
748 #endif
749 
750 struct seq_file;
751 int show_interrupts(struct seq_file *p, void *v);
752 int arch_show_interrupts(struct seq_file *p, int prec);
753 
754 extern int early_irq_init(void);
755 extern int arch_probe_nr_irqs(void);
756 extern int arch_early_irq_init(void);
757 
758 /*
759  * We want to know which function is an entrypoint of a hardirq or a softirq.
760  */
761 #define __irq_entry              __attribute__((__section__(".irqentry.text")))
762 #define __softirq_entry  \
763         __attribute__((__section__(".softirqentry.text")))
764 
765 #endif
766 

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