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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/hardirq.h>
12 #include <linux/sched.h>
13 #include <linux/irqflags.h>
14 #include <asm/atomic.h>
15 #include <asm/ptrace.h>
16 #include <asm/system.h>
17 
18 /*
19  * These correspond to the IORESOURCE_IRQ_* defines in
20  * linux/ioport.h to select the interrupt line behaviour.  When
21  * requesting an interrupt without specifying a IRQF_TRIGGER, the
22  * setting should be assumed to be "as already configured", which
23  * may be as per machine or firmware initialisation.
24  */
25 #define IRQF_TRIGGER_NONE	0x00000000
26 #define IRQF_TRIGGER_RISING	0x00000001
27 #define IRQF_TRIGGER_FALLING	0x00000002
28 #define IRQF_TRIGGER_HIGH	0x00000004
29 #define IRQF_TRIGGER_LOW	0x00000008
30 #define IRQF_TRIGGER_MASK	(IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \
31 				 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)
32 #define IRQF_TRIGGER_PROBE	0x00000010
33 
34 /*
35  * These flags used only by the kernel as part of the
36  * irq handling routines.
37  *
38  * IRQF_DISABLED - keep irqs disabled when calling the action handler
39  * IRQF_SAMPLE_RANDOM - irq is used to feed the random generator
40  * IRQF_SHARED - allow sharing the irq among several devices
41  * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
42  * IRQF_TIMER - Flag to mark this interrupt as timer interrupt
43  */
44 #define IRQF_DISABLED		0x00000020
45 #define IRQF_SAMPLE_RANDOM	0x00000040
46 #define IRQF_SHARED		0x00000080
47 #define IRQF_PROBE_SHARED	0x00000100
48 #define IRQF_TIMER		0x00000200
49 #define IRQF_PERCPU		0x00000400
50 
51 /*
52  * Migration helpers. Scheduled for removal in 1/2007
53  * Do not use for new code !
54  */
55 #define SA_INTERRUPT		IRQF_DISABLED
56 #define SA_SAMPLE_RANDOM	IRQF_SAMPLE_RANDOM
57 #define SA_SHIRQ		IRQF_SHARED
58 #define SA_PROBEIRQ		IRQF_PROBE_SHARED
59 #define SA_PERCPU		IRQF_PERCPU
60 
61 #define SA_TRIGGER_LOW		IRQF_TRIGGER_LOW
62 #define SA_TRIGGER_HIGH		IRQF_TRIGGER_HIGH
63 #define SA_TRIGGER_FALLING	IRQF_TRIGGER_FALLING
64 #define SA_TRIGGER_RISING	IRQF_TRIGGER_RISING
65 #define SA_TRIGGER_MASK		IRQF_TRIGGER_MASK
66 
67 struct irqaction {
68 	irqreturn_t (*handler)(int, void *, struct pt_regs *);
69 	unsigned long flags;
70 	cpumask_t mask;
71 	const char *name;
72 	void *dev_id;
73 	struct irqaction *next;
74 	int irq;
75 	struct proc_dir_entry *dir;
76 };
77 
78 extern irqreturn_t no_action(int cpl, void *dev_id, struct pt_regs *regs);
79 extern int request_irq(unsigned int,
80 		       irqreturn_t (*handler)(int, void *, struct pt_regs *),
81 		       unsigned long, const char *, void *);
82 extern void free_irq(unsigned int, void *);
83 
84 /*
85  * On lockdep we dont want to enable hardirqs in hardirq
86  * context. Use local_irq_enable_in_hardirq() to annotate
87  * kernel code that has to do this nevertheless (pretty much
88  * the only valid case is for old/broken hardware that is
89  * insanely slow).
90  *
91  * NOTE: in theory this might break fragile code that relies
92  * on hardirq delivery - in practice we dont seem to have such
93  * places left. So the only effect should be slightly increased
94  * irqs-off latencies.
95  */
96 #ifdef CONFIG_LOCKDEP
97 # define local_irq_enable_in_hardirq()	do { } while (0)
98 #else
99 # define local_irq_enable_in_hardirq()	local_irq_enable()
100 #endif
101 
102 #ifdef CONFIG_GENERIC_HARDIRQS
103 extern void disable_irq_nosync(unsigned int irq);
104 extern void disable_irq(unsigned int irq);
105 extern void enable_irq(unsigned int irq);
106 
107 /*
108  * Special lockdep variants of irq disabling/enabling.
109  * These should be used for locking constructs that
110  * know that a particular irq context which is disabled,
111  * and which is the only irq-context user of a lock,
112  * that it's safe to take the lock in the irq-disabled
113  * section without disabling hardirqs.
114  *
115  * On !CONFIG_LOCKDEP they are equivalent to the normal
116  * irq disable/enable methods.
117  */
disable_irq_nosync_lockdep(unsigned int irq)118 static inline void disable_irq_nosync_lockdep(unsigned int irq)
119 {
120 	disable_irq_nosync(irq);
121 #ifdef CONFIG_LOCKDEP
122 	local_irq_disable();
123 #endif
124 }
125 
disable_irq_lockdep(unsigned int irq)126 static inline void disable_irq_lockdep(unsigned int irq)
127 {
128 	disable_irq(irq);
129 #ifdef CONFIG_LOCKDEP
130 	local_irq_disable();
131 #endif
132 }
133 
enable_irq_lockdep(unsigned int irq)134 static inline void enable_irq_lockdep(unsigned int irq)
135 {
136 #ifdef CONFIG_LOCKDEP
137 	local_irq_enable();
138 #endif
139 	enable_irq(irq);
140 }
141 
142 /* IRQ wakeup (PM) control: */
143 extern int set_irq_wake(unsigned int irq, unsigned int on);
144 
enable_irq_wake(unsigned int irq)145 static inline int enable_irq_wake(unsigned int irq)
146 {
147 	return set_irq_wake(irq, 1);
148 }
149 
disable_irq_wake(unsigned int irq)150 static inline int disable_irq_wake(unsigned int irq)
151 {
152 	return set_irq_wake(irq, 0);
153 }
154 
155 #else /* !CONFIG_GENERIC_HARDIRQS */
156 /*
157  * NOTE: non-genirq architectures, if they want to support the lock
158  * validator need to define the methods below in their asm/irq.h
159  * files, under an #ifdef CONFIG_LOCKDEP section.
160  */
161 # ifndef CONFIG_LOCKDEP
162 #  define disable_irq_nosync_lockdep(irq)	disable_irq_nosync(irq)
163 #  define disable_irq_lockdep(irq)		disable_irq(irq)
164 #  define enable_irq_lockdep(irq)		enable_irq(irq)
165 # endif
166 
167 #endif /* CONFIG_GENERIC_HARDIRQS */
168 
169 #ifndef __ARCH_SET_SOFTIRQ_PENDING
170 #define set_softirq_pending(x) (local_softirq_pending() = (x))
171 #define or_softirq_pending(x)  (local_softirq_pending() |= (x))
172 #endif
173 
174 /*
175  * Temporary defines for UP kernels, until all code gets fixed.
176  */
177 #ifndef CONFIG_SMP
cli(void)178 static inline void __deprecated cli(void)
179 {
180 	local_irq_disable();
181 }
sti(void)182 static inline void __deprecated sti(void)
183 {
184 	local_irq_enable();
185 }
save_flags(unsigned long * x)186 static inline void __deprecated save_flags(unsigned long *x)
187 {
188 	local_save_flags(*x);
189 }
190 #define save_flags(x) save_flags(&x)
restore_flags(unsigned long x)191 static inline void __deprecated restore_flags(unsigned long x)
192 {
193 	local_irq_restore(x);
194 }
195 
save_and_cli(unsigned long * x)196 static inline void __deprecated save_and_cli(unsigned long *x)
197 {
198 	local_irq_save(*x);
199 }
200 #define save_and_cli(x)	save_and_cli(&x)
201 #endif /* CONFIG_SMP */
202 
203 extern void local_bh_disable(void);
204 extern void __local_bh_enable(void);
205 extern void _local_bh_enable(void);
206 extern void local_bh_enable(void);
207 extern void local_bh_enable_ip(unsigned long ip);
208 
209 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
210    frequency threaded job scheduling. For almost all the purposes
211    tasklets are more than enough. F.e. all serial device BHs et
212    al. should be converted to tasklets, not to softirqs.
213  */
214 
215 enum
216 {
217 	HI_SOFTIRQ=0,
218 	TIMER_SOFTIRQ,
219 	NET_TX_SOFTIRQ,
220 	NET_RX_SOFTIRQ,
221 	BLOCK_SOFTIRQ,
222 	TASKLET_SOFTIRQ
223 };
224 
225 /* softirq mask and active fields moved to irq_cpustat_t in
226  * asm/hardirq.h to get better cache usage.  KAO
227  */
228 
229 struct softirq_action
230 {
231 	void	(*action)(struct softirq_action *);
232 	void	*data;
233 };
234 
235 asmlinkage void do_softirq(void);
236 extern void open_softirq(int nr, void (*action)(struct softirq_action*), void *data);
237 extern void softirq_init(void);
238 #define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
239 extern void FASTCALL(raise_softirq_irqoff(unsigned int nr));
240 extern void FASTCALL(raise_softirq(unsigned int nr));
241 
242 
243 /* Tasklets --- multithreaded analogue of BHs.
244 
245    Main feature differing them of generic softirqs: tasklet
246    is running only on one CPU simultaneously.
247 
248    Main feature differing them of BHs: different tasklets
249    may be run simultaneously on different CPUs.
250 
251    Properties:
252    * If tasklet_schedule() is called, then tasklet is guaranteed
253      to be executed on some cpu at least once after this.
254    * If the tasklet is already scheduled, but its excecution is still not
255      started, it will be executed only once.
256    * If this tasklet is already running on another CPU (or schedule is called
257      from tasklet itself), it is rescheduled for later.
258    * Tasklet is strictly serialized wrt itself, but not
259      wrt another tasklets. If client needs some intertask synchronization,
260      he makes it with spinlocks.
261  */
262 
263 struct tasklet_struct
264 {
265 	struct tasklet_struct *next;
266 	unsigned long state;
267 	atomic_t count;
268 	void (*func)(unsigned long);
269 	unsigned long data;
270 };
271 
272 #define DECLARE_TASKLET(name, func, data) \
273 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
274 
275 #define DECLARE_TASKLET_DISABLED(name, func, data) \
276 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
277 
278 
279 enum
280 {
281 	TASKLET_STATE_SCHED,	/* Tasklet is scheduled for execution */
282 	TASKLET_STATE_RUN	/* Tasklet is running (SMP only) */
283 };
284 
285 #ifdef CONFIG_SMP
tasklet_trylock(struct tasklet_struct * t)286 static inline int tasklet_trylock(struct tasklet_struct *t)
287 {
288 	return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
289 }
290 
tasklet_unlock(struct tasklet_struct * t)291 static inline void tasklet_unlock(struct tasklet_struct *t)
292 {
293 	smp_mb__before_clear_bit();
294 	clear_bit(TASKLET_STATE_RUN, &(t)->state);
295 }
296 
tasklet_unlock_wait(struct tasklet_struct * t)297 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
298 {
299 	while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
300 }
301 #else
302 #define tasklet_trylock(t) 1
303 #define tasklet_unlock_wait(t) do { } while (0)
304 #define tasklet_unlock(t) do { } while (0)
305 #endif
306 
307 extern void FASTCALL(__tasklet_schedule(struct tasklet_struct *t));
308 
tasklet_schedule(struct tasklet_struct * t)309 static inline void tasklet_schedule(struct tasklet_struct *t)
310 {
311 	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
312 		__tasklet_schedule(t);
313 }
314 
315 extern void FASTCALL(__tasklet_hi_schedule(struct tasklet_struct *t));
316 
tasklet_hi_schedule(struct tasklet_struct * t)317 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
318 {
319 	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
320 		__tasklet_hi_schedule(t);
321 }
322 
323 
tasklet_disable_nosync(struct tasklet_struct * t)324 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
325 {
326 	atomic_inc(&t->count);
327 	smp_mb__after_atomic_inc();
328 }
329 
tasklet_disable(struct tasklet_struct * t)330 static inline void tasklet_disable(struct tasklet_struct *t)
331 {
332 	tasklet_disable_nosync(t);
333 	tasklet_unlock_wait(t);
334 	smp_mb();
335 }
336 
tasklet_enable(struct tasklet_struct * t)337 static inline void tasklet_enable(struct tasklet_struct *t)
338 {
339 	smp_mb__before_atomic_dec();
340 	atomic_dec(&t->count);
341 }
342 
tasklet_hi_enable(struct tasklet_struct * t)343 static inline void tasklet_hi_enable(struct tasklet_struct *t)
344 {
345 	smp_mb__before_atomic_dec();
346 	atomic_dec(&t->count);
347 }
348 
349 extern void tasklet_kill(struct tasklet_struct *t);
350 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
351 extern void tasklet_init(struct tasklet_struct *t,
352 			 void (*func)(unsigned long), unsigned long data);
353 
354 /*
355  * Autoprobing for irqs:
356  *
357  * probe_irq_on() and probe_irq_off() provide robust primitives
358  * for accurate IRQ probing during kernel initialization.  They are
359  * reasonably simple to use, are not "fooled" by spurious interrupts,
360  * and, unlike other attempts at IRQ probing, they do not get hung on
361  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
362  *
363  * For reasonably foolproof probing, use them as follows:
364  *
365  * 1. clear and/or mask the device's internal interrupt.
366  * 2. sti();
367  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
368  * 4. enable the device and cause it to trigger an interrupt.
369  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
370  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
371  * 7. service the device to clear its pending interrupt.
372  * 8. loop again if paranoia is required.
373  *
374  * probe_irq_on() returns a mask of allocated irq's.
375  *
376  * probe_irq_off() takes the mask as a parameter,
377  * and returns the irq number which occurred,
378  * or zero if none occurred, or a negative irq number
379  * if more than one irq occurred.
380  */
381 
382 #if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE)
probe_irq_on(void)383 static inline unsigned long probe_irq_on(void)
384 {
385 	return 0;
386 }
probe_irq_off(unsigned long val)387 static inline int probe_irq_off(unsigned long val)
388 {
389 	return 0;
390 }
probe_irq_mask(unsigned long val)391 static inline unsigned int probe_irq_mask(unsigned long val)
392 {
393 	return 0;
394 }
395 #else
396 extern unsigned long probe_irq_on(void);	/* returns 0 on failure */
397 extern int probe_irq_off(unsigned long);	/* returns 0 or negative on failure */
398 extern unsigned int probe_irq_mask(unsigned long);	/* returns mask of ISA interrupts */
399 #endif
400 
401 #endif
402