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1 /* interrupt.h */
2 #ifndef _LINUX_INTERRUPT_H
3 #define _LINUX_INTERRUPT_H
4 
5 #include <linux/kernel.h>
6 #include <linux/linkage.h>
7 #include <linux/bitops.h>
8 #include <linux/preempt.h>
9 #include <linux/cpumask.h>
10 #include <linux/irqreturn.h>
11 #include <linux/irqnr.h>
12 #include <linux/hardirq.h>
13 #include <linux/sched.h>
14 #include <linux/irqflags.h>
15 #include <linux/smp.h>
16 #include <linux/percpu.h>
17 
18 #include <asm/atomic.h>
19 #include <asm/ptrace.h>
20 #include <asm/system.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_DISABLED - keep irqs disabled when calling the action handler
43  * IRQF_SAMPLE_RANDOM - irq is used to feed the random generator
44  * IRQF_SHARED - allow sharing the irq among several devices
45  * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
46  * IRQF_TIMER - Flag to mark this interrupt as timer interrupt
47  * IRQF_PERCPU - Interrupt is per cpu
48  * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing
49  * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is
50  *                registered first in an shared interrupt is considered for
51  *                performance reasons)
52  */
53 #define IRQF_DISABLED		0x00000020
54 #define IRQF_SAMPLE_RANDOM	0x00000040
55 #define IRQF_SHARED		0x00000080
56 #define IRQF_PROBE_SHARED	0x00000100
57 #define IRQF_TIMER		0x00000200
58 #define IRQF_PERCPU		0x00000400
59 #define IRQF_NOBALANCING	0x00000800
60 #define IRQF_IRQPOLL		0x00001000
61 
62 typedef irqreturn_t (*irq_handler_t)(int, void *);
63 
64 struct irqaction {
65 	irq_handler_t handler;
66 	unsigned long flags;
67 	cpumask_t mask;
68 	const char *name;
69 	void *dev_id;
70 	struct irqaction *next;
71 	int irq;
72 	struct proc_dir_entry *dir;
73 };
74 
75 extern irqreturn_t no_action(int cpl, void *dev_id);
76 extern int __must_check request_irq(unsigned int, irq_handler_t handler,
77 		       unsigned long, const char *, void *);
78 extern void free_irq(unsigned int, void *);
79 
80 struct device;
81 
82 extern int __must_check devm_request_irq(struct device *dev, unsigned int irq,
83 			    irq_handler_t handler, unsigned long irqflags,
84 			    const char *devname, void *dev_id);
85 extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
86 
87 /*
88  * On lockdep we dont want to enable hardirqs in hardirq
89  * context. Use local_irq_enable_in_hardirq() to annotate
90  * kernel code that has to do this nevertheless (pretty much
91  * the only valid case is for old/broken hardware that is
92  * insanely slow).
93  *
94  * NOTE: in theory this might break fragile code that relies
95  * on hardirq delivery - in practice we dont seem to have such
96  * places left. So the only effect should be slightly increased
97  * irqs-off latencies.
98  */
99 #ifdef CONFIG_LOCKDEP
100 # define local_irq_enable_in_hardirq()	do { } while (0)
101 #else
102 # define local_irq_enable_in_hardirq()	local_irq_enable()
103 #endif
104 
105 extern void disable_irq_nosync(unsigned int irq);
106 extern void disable_irq(unsigned int irq);
107 extern void enable_irq(unsigned int irq);
108 
109 #if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
110 
111 extern cpumask_var_t irq_default_affinity;
112 
113 extern int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask);
114 extern int irq_can_set_affinity(unsigned int irq);
115 extern int irq_select_affinity(unsigned int irq);
116 
117 #else /* CONFIG_SMP */
118 
irq_set_affinity(unsigned int irq,const struct cpumask * m)119 static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
120 {
121 	return -EINVAL;
122 }
123 
irq_can_set_affinity(unsigned int irq)124 static inline int irq_can_set_affinity(unsigned int irq)
125 {
126 	return 0;
127 }
128 
irq_select_affinity(unsigned int irq)129 static inline int irq_select_affinity(unsigned int irq)  { return 0; }
130 
131 #endif /* CONFIG_SMP && CONFIG_GENERIC_HARDIRQS */
132 
133 #ifdef CONFIG_GENERIC_HARDIRQS
134 /*
135  * Special lockdep variants of irq disabling/enabling.
136  * These should be used for locking constructs that
137  * know that a particular irq context which is disabled,
138  * and which is the only irq-context user of a lock,
139  * that it's safe to take the lock in the irq-disabled
140  * section without disabling hardirqs.
141  *
142  * On !CONFIG_LOCKDEP they are equivalent to the normal
143  * irq disable/enable methods.
144  */
disable_irq_nosync_lockdep(unsigned int irq)145 static inline void disable_irq_nosync_lockdep(unsigned int irq)
146 {
147 	disable_irq_nosync(irq);
148 #ifdef CONFIG_LOCKDEP
149 	local_irq_disable();
150 #endif
151 }
152 
disable_irq_nosync_lockdep_irqsave(unsigned int irq,unsigned long * flags)153 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
154 {
155 	disable_irq_nosync(irq);
156 #ifdef CONFIG_LOCKDEP
157 	local_irq_save(*flags);
158 #endif
159 }
160 
disable_irq_lockdep(unsigned int irq)161 static inline void disable_irq_lockdep(unsigned int irq)
162 {
163 	disable_irq(irq);
164 #ifdef CONFIG_LOCKDEP
165 	local_irq_disable();
166 #endif
167 }
168 
enable_irq_lockdep(unsigned int irq)169 static inline void enable_irq_lockdep(unsigned int irq)
170 {
171 #ifdef CONFIG_LOCKDEP
172 	local_irq_enable();
173 #endif
174 	enable_irq(irq);
175 }
176 
enable_irq_lockdep_irqrestore(unsigned int irq,unsigned long * flags)177 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
178 {
179 #ifdef CONFIG_LOCKDEP
180 	local_irq_restore(*flags);
181 #endif
182 	enable_irq(irq);
183 }
184 
185 /* IRQ wakeup (PM) control: */
186 extern int set_irq_wake(unsigned int irq, unsigned int on);
187 
enable_irq_wake(unsigned int irq)188 static inline int enable_irq_wake(unsigned int irq)
189 {
190 	return set_irq_wake(irq, 1);
191 }
192 
disable_irq_wake(unsigned int irq)193 static inline int disable_irq_wake(unsigned int irq)
194 {
195 	return set_irq_wake(irq, 0);
196 }
197 
198 #else /* !CONFIG_GENERIC_HARDIRQS */
199 /*
200  * NOTE: non-genirq architectures, if they want to support the lock
201  * validator need to define the methods below in their asm/irq.h
202  * files, under an #ifdef CONFIG_LOCKDEP section.
203  */
204 #ifndef CONFIG_LOCKDEP
205 #  define disable_irq_nosync_lockdep(irq)	disable_irq_nosync(irq)
206 #  define disable_irq_nosync_lockdep_irqsave(irq, flags) \
207 						disable_irq_nosync(irq)
208 #  define disable_irq_lockdep(irq)		disable_irq(irq)
209 #  define enable_irq_lockdep(irq)		enable_irq(irq)
210 #  define enable_irq_lockdep_irqrestore(irq, flags) \
211 						enable_irq(irq)
212 # endif
213 
enable_irq_wake(unsigned int irq)214 static inline int enable_irq_wake(unsigned int irq)
215 {
216 	return 0;
217 }
218 
disable_irq_wake(unsigned int irq)219 static inline int disable_irq_wake(unsigned int irq)
220 {
221 	return 0;
222 }
223 #endif /* CONFIG_GENERIC_HARDIRQS */
224 
225 #ifndef __ARCH_SET_SOFTIRQ_PENDING
226 #define set_softirq_pending(x) (local_softirq_pending() = (x))
227 #define or_softirq_pending(x)  (local_softirq_pending() |= (x))
228 #endif
229 
230 /* Some architectures might implement lazy enabling/disabling of
231  * interrupts. In some cases, such as stop_machine, we might want
232  * to ensure that after a local_irq_disable(), interrupts have
233  * really been disabled in hardware. Such architectures need to
234  * implement the following hook.
235  */
236 #ifndef hard_irq_disable
237 #define hard_irq_disable()	do { } while(0)
238 #endif
239 
240 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
241    frequency threaded job scheduling. For almost all the purposes
242    tasklets are more than enough. F.e. all serial device BHs et
243    al. should be converted to tasklets, not to softirqs.
244  */
245 
246 enum
247 {
248 	HI_SOFTIRQ=0,
249 	TIMER_SOFTIRQ,
250 	NET_TX_SOFTIRQ,
251 	NET_RX_SOFTIRQ,
252 	BLOCK_SOFTIRQ,
253 	TASKLET_SOFTIRQ,
254 	SCHED_SOFTIRQ,
255 	HRTIMER_SOFTIRQ,
256 	RCU_SOFTIRQ,	/* Preferable RCU should always be the last softirq */
257 
258 	NR_SOFTIRQS
259 };
260 
261 /* softirq mask and active fields moved to irq_cpustat_t in
262  * asm/hardirq.h to get better cache usage.  KAO
263  */
264 
265 struct softirq_action
266 {
267 	void	(*action)(struct softirq_action *);
268 };
269 
270 asmlinkage void do_softirq(void);
271 asmlinkage void __do_softirq(void);
272 extern void open_softirq(int nr, void (*action)(struct softirq_action *));
273 extern void softirq_init(void);
274 #define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
275 extern void raise_softirq_irqoff(unsigned int nr);
276 extern void raise_softirq(unsigned int nr);
277 
278 /* This is the worklist that queues up per-cpu softirq work.
279  *
280  * send_remote_sendirq() adds work to these lists, and
281  * the softirq handler itself dequeues from them.  The queues
282  * are protected by disabling local cpu interrupts and they must
283  * only be accessed by the local cpu that they are for.
284  */
285 DECLARE_PER_CPU(struct list_head [NR_SOFTIRQS], softirq_work_list);
286 
287 /* Try to send a softirq to a remote cpu.  If this cannot be done, the
288  * work will be queued to the local cpu.
289  */
290 extern void send_remote_softirq(struct call_single_data *cp, int cpu, int softirq);
291 
292 /* Like send_remote_softirq(), but the caller must disable local cpu interrupts
293  * and compute the current cpu, passed in as 'this_cpu'.
294  */
295 extern void __send_remote_softirq(struct call_single_data *cp, int cpu,
296 				  int this_cpu, int softirq);
297 
298 /* Tasklets --- multithreaded analogue of BHs.
299 
300    Main feature differing them of generic softirqs: tasklet
301    is running only on one CPU simultaneously.
302 
303    Main feature differing them of BHs: different tasklets
304    may be run simultaneously on different CPUs.
305 
306    Properties:
307    * If tasklet_schedule() is called, then tasklet is guaranteed
308      to be executed on some cpu at least once after this.
309    * If the tasklet is already scheduled, but its excecution is still not
310      started, it will be executed only once.
311    * If this tasklet is already running on another CPU (or schedule is called
312      from tasklet itself), it is rescheduled for later.
313    * Tasklet is strictly serialized wrt itself, but not
314      wrt another tasklets. If client needs some intertask synchronization,
315      he makes it with spinlocks.
316  */
317 
318 struct tasklet_struct
319 {
320 	struct tasklet_struct *next;
321 	unsigned long state;
322 	atomic_t count;
323 	void (*func)(unsigned long);
324 	unsigned long data;
325 };
326 
327 #define DECLARE_TASKLET(name, func, data) \
328 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
329 
330 #define DECLARE_TASKLET_DISABLED(name, func, data) \
331 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
332 
333 
334 enum
335 {
336 	TASKLET_STATE_SCHED,	/* Tasklet is scheduled for execution */
337 	TASKLET_STATE_RUN	/* Tasklet is running (SMP only) */
338 };
339 
340 #ifdef CONFIG_SMP
tasklet_trylock(struct tasklet_struct * t)341 static inline int tasklet_trylock(struct tasklet_struct *t)
342 {
343 	return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
344 }
345 
tasklet_unlock(struct tasklet_struct * t)346 static inline void tasklet_unlock(struct tasklet_struct *t)
347 {
348 	smp_mb__before_clear_bit();
349 	clear_bit(TASKLET_STATE_RUN, &(t)->state);
350 }
351 
tasklet_unlock_wait(struct tasklet_struct * t)352 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
353 {
354 	while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
355 }
356 #else
357 #define tasklet_trylock(t) 1
358 #define tasklet_unlock_wait(t) do { } while (0)
359 #define tasklet_unlock(t) do { } while (0)
360 #endif
361 
362 extern void __tasklet_schedule(struct tasklet_struct *t);
363 
tasklet_schedule(struct tasklet_struct * t)364 static inline void tasklet_schedule(struct tasklet_struct *t)
365 {
366 	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
367 		__tasklet_schedule(t);
368 }
369 
370 extern void __tasklet_hi_schedule(struct tasklet_struct *t);
371 
tasklet_hi_schedule(struct tasklet_struct * t)372 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
373 {
374 	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
375 		__tasklet_hi_schedule(t);
376 }
377 
378 
tasklet_disable_nosync(struct tasklet_struct * t)379 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
380 {
381 	atomic_inc(&t->count);
382 	smp_mb__after_atomic_inc();
383 }
384 
tasklet_disable(struct tasklet_struct * t)385 static inline void tasklet_disable(struct tasklet_struct *t)
386 {
387 	tasklet_disable_nosync(t);
388 	tasklet_unlock_wait(t);
389 	smp_mb();
390 }
391 
tasklet_enable(struct tasklet_struct * t)392 static inline void tasklet_enable(struct tasklet_struct *t)
393 {
394 	smp_mb__before_atomic_dec();
395 	atomic_dec(&t->count);
396 }
397 
tasklet_hi_enable(struct tasklet_struct * t)398 static inline void tasklet_hi_enable(struct tasklet_struct *t)
399 {
400 	smp_mb__before_atomic_dec();
401 	atomic_dec(&t->count);
402 }
403 
404 extern void tasklet_kill(struct tasklet_struct *t);
405 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
406 extern void tasklet_init(struct tasklet_struct *t,
407 			 void (*func)(unsigned long), unsigned long data);
408 
409 /*
410  * Autoprobing for irqs:
411  *
412  * probe_irq_on() and probe_irq_off() provide robust primitives
413  * for accurate IRQ probing during kernel initialization.  They are
414  * reasonably simple to use, are not "fooled" by spurious interrupts,
415  * and, unlike other attempts at IRQ probing, they do not get hung on
416  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
417  *
418  * For reasonably foolproof probing, use them as follows:
419  *
420  * 1. clear and/or mask the device's internal interrupt.
421  * 2. sti();
422  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
423  * 4. enable the device and cause it to trigger an interrupt.
424  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
425  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
426  * 7. service the device to clear its pending interrupt.
427  * 8. loop again if paranoia is required.
428  *
429  * probe_irq_on() returns a mask of allocated irq's.
430  *
431  * probe_irq_off() takes the mask as a parameter,
432  * and returns the irq number which occurred,
433  * or zero if none occurred, or a negative irq number
434  * if more than one irq occurred.
435  */
436 
437 #if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE)
probe_irq_on(void)438 static inline unsigned long probe_irq_on(void)
439 {
440 	return 0;
441 }
probe_irq_off(unsigned long val)442 static inline int probe_irq_off(unsigned long val)
443 {
444 	return 0;
445 }
probe_irq_mask(unsigned long val)446 static inline unsigned int probe_irq_mask(unsigned long val)
447 {
448 	return 0;
449 }
450 #else
451 extern unsigned long probe_irq_on(void);	/* returns 0 on failure */
452 extern int probe_irq_off(unsigned long);	/* returns 0 or negative on failure */
453 extern unsigned int probe_irq_mask(unsigned long);	/* returns mask of ISA interrupts */
454 #endif
455 
456 #ifdef CONFIG_PROC_FS
457 /* Initialize /proc/irq/ */
458 extern void init_irq_proc(void);
459 #else
init_irq_proc(void)460 static inline void init_irq_proc(void)
461 {
462 }
463 #endif
464 
465 int show_interrupts(struct seq_file *p, void *v);
466 
467 struct irq_desc;
468 
469 extern int early_irq_init(void);
470 extern int arch_early_irq_init(void);
471 extern int arch_init_chip_data(struct irq_desc *desc, int cpu);
472 
473 #endif
474