interrupt.h 9.54 KB
Newer Older
Linus Torvalds's avatar
Linus Torvalds committed
1
2
3
4
5
6
7
8
9
/* interrupt.h */
#ifndef _LINUX_INTERRUPT_H
#define _LINUX_INTERRUPT_H

#include <linux/kernel.h>
#include <linux/linkage.h>
#include <linux/bitops.h>
#include <linux/preempt.h>
#include <linux/cpumask.h>
10
#include <linux/irqreturn.h>
Linus Torvalds's avatar
Linus Torvalds committed
11
#include <linux/hardirq.h>
12
#include <linux/sched.h>
Linus Torvalds's avatar
Linus Torvalds committed
13
14
15
16
#include <asm/atomic.h>
#include <asm/ptrace.h>
#include <asm/system.h>

17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
/*
 * These correspond to the IORESOURCE_IRQ_* defines in
 * linux/ioport.h to select the interrupt line behaviour.  When
 * requesting an interrupt without specifying a IRQF_TRIGGER, the
 * setting should be assumed to be "as already configured", which
 * may be as per machine or firmware initialisation.
 */
#define IRQF_TRIGGER_NONE	0x00000000
#define IRQF_TRIGGER_RISING	0x00000001
#define IRQF_TRIGGER_FALLING	0x00000002
#define IRQF_TRIGGER_HIGH	0x00000004
#define IRQF_TRIGGER_LOW	0x00000008
#define IRQF_TRIGGER_MASK	(IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \
				 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)
#define IRQF_TRIGGER_PROBE	0x00000010

/*
 * These flags used only by the kernel as part of the
 * irq handling routines.
 *
 * IRQF_DISABLED - keep irqs disabled when calling the action handler
 * IRQF_SAMPLE_RANDOM - irq is used to feed the random generator
 * IRQF_SHARED - allow sharing the irq among several devices
 * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
 * IRQF_TIMER - Flag to mark this interrupt as timer interrupt
 */
#define IRQF_DISABLED		0x00000020
#define IRQF_SAMPLE_RANDOM	0x00000040
#define IRQF_SHARED		0x00000080
#define IRQF_PROBE_SHARED	0x00000100
#define IRQF_TIMER		0x00000200
48
#define IRQF_PERCPU		0x00000400
49
50
51
52
53
54
55
56
57

/*
 * Migration helpers. Scheduled for removal in 1/2007
 * Do not use for new code !
 */
#define SA_INTERRUPT		IRQF_DISABLED
#define SA_SAMPLE_RANDOM	IRQF_SAMPLE_RANDOM
#define SA_SHIRQ		IRQF_SHARED
#define SA_PROBEIRQ		IRQF_PROBE_SHARED
58
#define SA_PERCPU		IRQF_PERCPU
59
60
61
62
63
64
65

#define SA_TRIGGER_LOW		IRQF_TRIGGER_LOW
#define SA_TRIGGER_HIGH		IRQF_TRIGGER_HIGH
#define SA_TRIGGER_FALLING	IRQF_TRIGGER_FALLING
#define SA_TRIGGER_RISING	IRQF_TRIGGER_RISING
#define SA_TRIGGER_MASK		IRQF_TRIGGER_MASK

Linus Torvalds's avatar
Linus Torvalds committed
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
struct irqaction {
	irqreturn_t (*handler)(int, void *, struct pt_regs *);
	unsigned long flags;
	cpumask_t mask;
	const char *name;
	void *dev_id;
	struct irqaction *next;
	int irq;
	struct proc_dir_entry *dir;
};

extern irqreturn_t no_action(int cpl, void *dev_id, struct pt_regs *regs);
extern int request_irq(unsigned int,
		       irqreturn_t (*handler)(int, void *, struct pt_regs *),
		       unsigned long, const char *, void *);
extern void free_irq(unsigned int, void *);


#ifdef CONFIG_GENERIC_HARDIRQS
extern void disable_irq_nosync(unsigned int irq);
extern void disable_irq(unsigned int irq);
extern void enable_irq(unsigned int irq);
88
89
90
91
92
93
94
95
96
97
98
99
100
101

/* IRQ wakeup (PM) control: */
extern int set_irq_wake(unsigned int irq, unsigned int on);

static inline int enable_irq_wake(unsigned int irq)
{
	return set_irq_wake(irq, 1);
}

static inline int disable_irq_wake(unsigned int irq)
{
	return set_irq_wake(irq, 0);
}

Linus Torvalds's avatar
Linus Torvalds committed
102
103
#endif

104
105
106
107
108
#ifndef __ARCH_SET_SOFTIRQ_PENDING
#define set_softirq_pending(x) (local_softirq_pending() = (x))
#define or_softirq_pending(x)  (local_softirq_pending() |= (x))
#endif

Linus Torvalds's avatar
Linus Torvalds committed
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
/*
 * Temporary defines for UP kernels, until all code gets fixed.
 */
#ifndef CONFIG_SMP
static inline void __deprecated cli(void)
{
	local_irq_disable();
}
static inline void __deprecated sti(void)
{
	local_irq_enable();
}
static inline void __deprecated save_flags(unsigned long *x)
{
	local_save_flags(*x);
}
125
#define save_flags(x) save_flags(&x)
Linus Torvalds's avatar
Linus Torvalds committed
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
static inline void __deprecated restore_flags(unsigned long x)
{
	local_irq_restore(x);
}

static inline void __deprecated save_and_cli(unsigned long *x)
{
	local_irq_save(*x);
}
#define save_and_cli(x)	save_and_cli(&x)
#endif /* CONFIG_SMP */

/* SoftIRQ primitives.  */
#define local_bh_disable() \
		do { add_preempt_count(SOFTIRQ_OFFSET); barrier(); } while (0)
#define __local_bh_enable() \
		do { barrier(); sub_preempt_count(SOFTIRQ_OFFSET); } while (0)

extern void local_bh_enable(void);

/* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
   frequency threaded job scheduling. For almost all the purposes
   tasklets are more than enough. F.e. all serial device BHs et
   al. should be converted to tasklets, not to softirqs.
 */

enum
{
	HI_SOFTIRQ=0,
	TIMER_SOFTIRQ,
	NET_TX_SOFTIRQ,
	NET_RX_SOFTIRQ,
158
	BLOCK_SOFTIRQ,
Linus Torvalds's avatar
Linus Torvalds committed
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
	TASKLET_SOFTIRQ
};

/* softirq mask and active fields moved to irq_cpustat_t in
 * asm/hardirq.h to get better cache usage.  KAO
 */

struct softirq_action
{
	void	(*action)(struct softirq_action *);
	void	*data;
};

asmlinkage void do_softirq(void);
extern void open_softirq(int nr, void (*action)(struct softirq_action*), void *data);
extern void softirq_init(void);
175
#define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
Linus Torvalds's avatar
Linus Torvalds committed
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
extern void FASTCALL(raise_softirq_irqoff(unsigned int nr));
extern void FASTCALL(raise_softirq(unsigned int nr));


/* Tasklets --- multithreaded analogue of BHs.

   Main feature differing them of generic softirqs: tasklet
   is running only on one CPU simultaneously.

   Main feature differing them of BHs: different tasklets
   may be run simultaneously on different CPUs.

   Properties:
   * If tasklet_schedule() is called, then tasklet is guaranteed
     to be executed on some cpu at least once after this.
   * If the tasklet is already scheduled, but its excecution is still not
     started, it will be executed only once.
   * If this tasklet is already running on another CPU (or schedule is called
     from tasklet itself), it is rescheduled for later.
   * Tasklet is strictly serialized wrt itself, but not
     wrt another tasklets. If client needs some intertask synchronization,
     he makes it with spinlocks.
 */

struct tasklet_struct
{
	struct tasklet_struct *next;
	unsigned long state;
	atomic_t count;
	void (*func)(unsigned long);
	unsigned long data;
};

#define DECLARE_TASKLET(name, func, data) \
struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }

#define DECLARE_TASKLET_DISABLED(name, func, data) \
struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }


enum
{
	TASKLET_STATE_SCHED,	/* Tasklet is scheduled for execution */
	TASKLET_STATE_RUN	/* Tasklet is running (SMP only) */
};

#ifdef CONFIG_SMP
static inline int tasklet_trylock(struct tasklet_struct *t)
{
	return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
}

static inline void tasklet_unlock(struct tasklet_struct *t)
{
	smp_mb__before_clear_bit(); 
	clear_bit(TASKLET_STATE_RUN, &(t)->state);
}

static inline void tasklet_unlock_wait(struct tasklet_struct *t)
{
	while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
}
#else
#define tasklet_trylock(t) 1
#define tasklet_unlock_wait(t) do { } while (0)
#define tasklet_unlock(t) do { } while (0)
#endif

extern void FASTCALL(__tasklet_schedule(struct tasklet_struct *t));

static inline void tasklet_schedule(struct tasklet_struct *t)
{
	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
		__tasklet_schedule(t);
}

extern void FASTCALL(__tasklet_hi_schedule(struct tasklet_struct *t));

static inline void tasklet_hi_schedule(struct tasklet_struct *t)
{
	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
		__tasklet_hi_schedule(t);
}


static inline void tasklet_disable_nosync(struct tasklet_struct *t)
{
	atomic_inc(&t->count);
	smp_mb__after_atomic_inc();
}

static inline void tasklet_disable(struct tasklet_struct *t)
{
	tasklet_disable_nosync(t);
	tasklet_unlock_wait(t);
	smp_mb();
}

static inline void tasklet_enable(struct tasklet_struct *t)
{
	smp_mb__before_atomic_dec();
	atomic_dec(&t->count);
}

static inline void tasklet_hi_enable(struct tasklet_struct *t)
{
	smp_mb__before_atomic_dec();
	atomic_dec(&t->count);
}

extern void tasklet_kill(struct tasklet_struct *t);
extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
extern void tasklet_init(struct tasklet_struct *t,
			 void (*func)(unsigned long), unsigned long data);

/*
 * Autoprobing for irqs:
 *
 * probe_irq_on() and probe_irq_off() provide robust primitives
 * for accurate IRQ probing during kernel initialization.  They are
 * reasonably simple to use, are not "fooled" by spurious interrupts,
 * and, unlike other attempts at IRQ probing, they do not get hung on
 * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
 *
 * For reasonably foolproof probing, use them as follows:
 *
 * 1. clear and/or mask the device's internal interrupt.
 * 2. sti();
 * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
 * 4. enable the device and cause it to trigger an interrupt.
 * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
 * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
 * 7. service the device to clear its pending interrupt.
 * 8. loop again if paranoia is required.
 *
 * probe_irq_on() returns a mask of allocated irq's.
 *
 * probe_irq_off() takes the mask as a parameter,
 * and returns the irq number which occurred,
 * or zero if none occurred, or a negative irq number
 * if more than one irq occurred.
 */

#if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE) 
static inline unsigned long probe_irq_on(void)
{
	return 0;
}
static inline int probe_irq_off(unsigned long val)
{
	return 0;
}
static inline unsigned int probe_irq_mask(unsigned long val)
{
	return 0;
}
#else
extern unsigned long probe_irq_on(void);	/* returns 0 on failure */
extern int probe_irq_off(unsigned long);	/* returns 0 or negative on failure */
extern unsigned int probe_irq_mask(unsigned long);	/* returns mask of ISA interrupts */
#endif

#endif