[linux-2.6-block.git] / include / linux / interrupt.h

/* 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>
#include <linux/irqreturn.h>
#include <linux/hardirq.h>
#include <linux/sched.h>
#include <linux/irqflags.h>
#include <asm/atomic.h>
#include <asm/ptrace.h>
#include <asm/system.h>

/*
 * 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
#define IRQF_PERCPU		0x00000400

/*
 * 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
#define SA_PERCPU		IRQF_PERCPU

#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

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 *);

/*
 * On lockdep we dont want to enable hardirqs in hardirq
 * context. Use local_irq_enable_in_hardirq() to annotate
 * kernel code that has to do this nevertheless (pretty much
 * the only valid case is for old/broken hardware that is
 * insanely slow).
 *
 * NOTE: in theory this might break fragile code that relies
 * on hardirq delivery - in practice we dont seem to have such
 * places left. So the only effect should be slightly increased
 * irqs-off latencies.
 */
#ifdef CONFIG_LOCKDEP
# define local_irq_enable_in_hardirq()	do { } while (0)
#else
# define local_irq_enable_in_hardirq()	local_irq_enable()
#endif

#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);

/*
 * Special lockdep variants of irq disabling/enabling.
 * These should be used for locking constructs that
 * know that a particular irq context which is disabled,
 * and which is the only irq-context user of a lock,
 * that it's safe to take the lock in the irq-disabled
 * section without disabling hardirqs.
 *
 * On !CONFIG_LOCKDEP they are equivalent to the normal
 * irq disable/enable methods.
 */
static inline void disable_irq_nosync_lockdep(unsigned int irq)
{
	disable_irq_nosync(irq);
#ifdef CONFIG_LOCKDEP
	local_irq_disable();
#endif
}

static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
{
	disable_irq_nosync(irq);
#ifdef CONFIG_LOCKDEP
	local_irq_save(*flags);
#endif
}

static inline void disable_irq_lockdep(unsigned int irq)
{
	disable_irq(irq);
#ifdef CONFIG_LOCKDEP
	local_irq_disable();
#endif
}

static inline void enable_irq_lockdep(unsigned int irq)
{
#ifdef CONFIG_LOCKDEP
	local_irq_enable();
#endif
	enable_irq(irq);
}

static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
{
#ifdef CONFIG_LOCKDEP
	local_irq_restore(*flags);
#endif
	enable_irq(irq);
}

/* 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);
}

#else /* !CONFIG_GENERIC_HARDIRQS */
/*
 * NOTE: non-genirq architectures, if they want to support the lock
 * validator need to define the methods below in their asm/irq.h
 * files, under an #ifdef CONFIG_LOCKDEP section.
 */
# ifndef CONFIG_LOCKDEP
#  define disable_irq_nosync_lockdep(irq)	disable_irq_nosync(irq)
#  define disable_irq_lockdep(irq)		disable_irq(irq)
#  define enable_irq_lockdep(irq)		enable_irq(irq)
# endif

#endif /* CONFIG_GENERIC_HARDIRQS */

#ifndef __ARCH_SET_SOFTIRQ_PENDING
#define set_softirq_pending(x) (local_softirq_pending() = (x))
#define or_softirq_pending(x)  (local_softirq_pending() |= (x))
#endif

/*
 * 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);
}
#define save_flags(x) save_flags(&x)
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 */

extern void local_bh_disable(void);
extern void __local_bh_enable(void);
extern void _local_bh_enable(void);
extern void local_bh_enable(void);
extern void local_bh_enable_ip(unsigned long ip);

/* 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,
	BLOCK_SOFTIRQ,
	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);
#define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
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
Commit	Line	Data
1da177e4 LT	1	/* interrupt.h */
	2	#ifndef _LINUX_INTERRUPT_H
	3	#define _LINUX_INTERRUPT_H
	4
1da177e4 LT	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>
908dcecd	10	#include <linux/irqreturn.h>
1da177e4	11	#include <linux/hardirq.h>
f037360f	12	#include <linux/sched.h>
de30a2b3	13	#include <linux/irqflags.h>
1da177e4 LT	14	#include <asm/atomic.h>
	15	#include <asm/ptrace.h>
	16	#include <asm/system.h>
	17
6e213616 TG	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
284c6680	49	#define IRQF_PERCPU 0x00000400
6e213616 TG	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
284c6680	59	#define SA_PERCPU IRQF_PERCPU
6e213616 TG	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
1da177e4 LT	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
d7e9629d IM	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
1da177e4 LT	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);
ba9a2331	106
c01d403b IM	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	*/
	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
e8106b94 AV	126	static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
	127	{
	128	disable_irq_nosync(irq);
	129	#ifdef CONFIG_LOCKDEP
	130	local_irq_save(*flags);
	131	#endif
	132	}
	133
c01d403b IM	134	static inline void disable_irq_lockdep(unsigned int irq)
	135	{
	136	disable_irq(irq);
	137	#ifdef CONFIG_LOCKDEP
	138	local_irq_disable();
	139	#endif
	140	}
	141
	142	static inline void enable_irq_lockdep(unsigned int irq)
	143	{
	144	#ifdef CONFIG_LOCKDEP
	145	local_irq_enable();
	146	#endif
	147	enable_irq(irq);
	148	}
	149
e8106b94 AV	150	static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
	151	{
	152	#ifdef CONFIG_LOCKDEP
	153	local_irq_restore(*flags);
	154	#endif
	155	enable_irq(irq);
	156	}
	157
ba9a2331 TG	158	/* IRQ wakeup (PM) control: */
	159	extern int set_irq_wake(unsigned int irq, unsigned int on);
	160
	161	static inline int enable_irq_wake(unsigned int irq)
	162	{
	163	return set_irq_wake(irq, 1);
	164	}
	165
	166	static inline int disable_irq_wake(unsigned int irq)
	167	{
	168	return set_irq_wake(irq, 0);
	169	}
	170
c01d403b IM	171	#else /* !CONFIG_GENERIC_HARDIRQS */
	172	/*
	173	* NOTE: non-genirq architectures, if they want to support the lock
	174	* validator need to define the methods below in their asm/irq.h
	175	* files, under an #ifdef CONFIG_LOCKDEP section.
	176	*/
	177	# ifndef CONFIG_LOCKDEP
	178	# define disable_irq_nosync_lockdep(irq) disable_irq_nosync(irq)
	179	# define disable_irq_lockdep(irq) disable_irq(irq)
	180	# define enable_irq_lockdep(irq) enable_irq(irq)
	181	# endif
	182
	183	#endif /* CONFIG_GENERIC_HARDIRQS */
1da177e4	184
3f74478b AK	185	#ifndef __ARCH_SET_SOFTIRQ_PENDING
	186	#define set_softirq_pending(x) (local_softirq_pending() = (x))
	187	#define or_softirq_pending(x) (local_softirq_pending() \|= (x))
	188	#endif
	189
1da177e4 LT	190	/*
	191	* Temporary defines for UP kernels, until all code gets fixed.
	192	*/
	193	#ifndef CONFIG_SMP
	194	static inline void __deprecated cli(void)
	195	{
	196	local_irq_disable();
	197	}
	198	static inline void __deprecated sti(void)
	199	{
	200	local_irq_enable();
	201	}
	202	static inline void __deprecated save_flags(unsigned long *x)
	203	{
	204	local_save_flags(*x);
	205	}
ef9ceab2	206	#define save_flags(x) save_flags(&x)
1da177e4 LT	207	static inline void __deprecated restore_flags(unsigned long x)
	208	{
	209	local_irq_restore(x);
	210	}
	211
	212	static inline void __deprecated save_and_cli(unsigned long *x)
	213	{
	214	local_irq_save(*x);
	215	}
	216	#define save_and_cli(x) save_and_cli(&x)
	217	#endif /* CONFIG_SMP */
	218
de30a2b3 IM	219	extern void local_bh_disable(void);
	220	extern void __local_bh_enable(void);
	221	extern void _local_bh_enable(void);
1da177e4	222	extern void local_bh_enable(void);
de30a2b3	223	extern void local_bh_enable_ip(unsigned long ip);
1da177e4 LT	224
	225	/* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
	226	frequency threaded job scheduling. For almost all the purposes
	227	tasklets are more than enough. F.e. all serial device BHs et
	228	al. should be converted to tasklets, not to softirqs.
	229	*/
	230
	231	enum
	232	{
	233	HI_SOFTIRQ=0,
	234	TIMER_SOFTIRQ,
	235	NET_TX_SOFTIRQ,
	236	NET_RX_SOFTIRQ,
ff856bad	237	BLOCK_SOFTIRQ,
1da177e4 LT	238	TASKLET_SOFTIRQ
	239	};
	240
	241	/* softirq mask and active fields moved to irq_cpustat_t in
	242	* asm/hardirq.h to get better cache usage. KAO
	243	*/
	244
	245	struct softirq_action
	246	{
	247	void (action)(struct softirq_action );
	248	void *data;
	249	};
	250
	251	asmlinkage void do_softirq(void);
	252	extern void open_softirq(int nr, void (action)(struct softirq_action), void *data);
	253	extern void softirq_init(void);
3f74478b	254	#define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
1da177e4 LT	255	extern void FASTCALL(raise_softirq_irqoff(unsigned int nr));
	256	extern void FASTCALL(raise_softirq(unsigned int nr));
	257
	258
	259	/* Tasklets --- multithreaded analogue of BHs.
	260
	261	Main feature differing them of generic softirqs: tasklet
	262	is running only on one CPU simultaneously.
	263
	264	Main feature differing them of BHs: different tasklets
	265	may be run simultaneously on different CPUs.
	266
	267	Properties:
	268	* If tasklet_schedule() is called, then tasklet is guaranteed
	269	to be executed on some cpu at least once after this.
	270	* If the tasklet is already scheduled, but its excecution is still not
	271	started, it will be executed only once.
	272	* If this tasklet is already running on another CPU (or schedule is called
	273	from tasklet itself), it is rescheduled for later.
	274	* Tasklet is strictly serialized wrt itself, but not
	275	wrt another tasklets. If client needs some intertask synchronization,
	276	he makes it with spinlocks.
	277	*/
	278
	279	struct tasklet_struct
	280	{
	281	struct tasklet_struct *next;
	282	unsigned long state;
	283	atomic_t count;
	284	void (*func)(unsigned long);
	285	unsigned long data;
	286	};
	287
	288	#define DECLARE_TASKLET(name, func, data) \
	289	struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
	290
	291	#define DECLARE_TASKLET_DISABLED(name, func, data) \
	292	struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
	293
	294
	295	enum
	296	{
	297	TASKLET_STATE_SCHED, /* Tasklet is scheduled for execution */
	298	TASKLET_STATE_RUN /* Tasklet is running (SMP only) */
	299	};
	300
	301	#ifdef CONFIG_SMP
	302	static inline int tasklet_trylock(struct tasklet_struct *t)
	303	{
	304	return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
	305	}
	306
	307	static inline void tasklet_unlock(struct tasklet_struct *t)
	308	{
	309	smp_mb__before_clear_bit();
	310	clear_bit(TASKLET_STATE_RUN, &(t)->state);
	311	}
	312
	313	static inline void tasklet_unlock_wait(struct tasklet_struct *t)
	314	{
	315	while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
	316	}
	317	#else
	318	#define tasklet_trylock(t) 1
319	#define tasklet_unlock_wait(t) do { } while (0)
320	#define tasklet_unlock(t) do { } while (0)
321	#endif
322
323	extern void FASTCALL(__tasklet_schedule(struct tasklet_struct *t));
324
325	static inline void tasklet_schedule(struct tasklet_struct *t)
326	{
327	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
328	__tasklet_schedule(t);
329	}
330
331	extern void FASTCALL(__tasklet_hi_schedule(struct tasklet_struct *t));
332
333	static inline void tasklet_hi_schedule(struct tasklet_struct *t)
334	{
335	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
336	__tasklet_hi_schedule(t);
337	}
338
339
340	static inline void tasklet_disable_nosync(struct tasklet_struct *t)
341	{
342	atomic_inc(&t->count);
343	smp_mb__after_atomic_inc();
344	}
345
346	static inline void tasklet_disable(struct tasklet_struct *t)
347	{
348	tasklet_disable_nosync(t);
349	tasklet_unlock_wait(t);
350	smp_mb();
351	}
352
353	static inline void tasklet_enable(struct tasklet_struct *t)
354	{
355	smp_mb__before_atomic_dec();
356	atomic_dec(&t->count);
357	}
358
359	static inline void tasklet_hi_enable(struct tasklet_struct *t)
360	{
361	smp_mb__before_atomic_dec();
362	atomic_dec(&t->count);
363	}
364
365	extern void tasklet_kill(struct tasklet_struct *t);
366	extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
367	extern void tasklet_init(struct tasklet_struct *t,
368	void (*func)(unsigned long), unsigned long data);
369
370	/*
371	* Autoprobing for irqs:
372	*
373	* probe_irq_on() and probe_irq_off() provide robust primitives
374	* for accurate IRQ probing during kernel initialization. They are
375	* reasonably simple to use, are not "fooled" by spurious interrupts,
376	* and, unlike other attempts at IRQ probing, they do not get hung on
377	* stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
378	*
379	* For reasonably foolproof probing, use them as follows:
380	*
381	* 1. clear and/or mask the device's internal interrupt.
382	* 2. sti();
383	* 3. irqs = probe_irq_on(); // "take over" all unassigned idle IRQs
384	* 4. enable the device and cause it to trigger an interrupt.
385	* 5. wait for the device to interrupt, using non-intrusive polling or a delay.
386	* 6. irq = probe_irq_off(irqs); // get IRQ number, 0=none, negative=multiple
387	* 7. service the device to clear its pending interrupt.
388	* 8. loop again if paranoia is required.
389	*
390	* probe_irq_on() returns a mask of allocated irq's.
391	*
392	* probe_irq_off() takes the mask as a parameter,
393	* and returns the irq number which occurred,
394	* or zero if none occurred, or a negative irq number
395	* if more than one irq occurred.
396	*/
397
398	#if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE)
399	static inline unsigned long probe_irq_on(void)
400	{
401	return 0;
402	}
403	static inline int probe_irq_off(unsigned long val)
404	{
405	return 0;
406	}
407	static inline unsigned int probe_irq_mask(unsigned long val)
408	{
409	return 0;
410	}
411	#else
412	extern unsigned long probe_irq_on(void); /* returns 0 on failure */
413	extern int probe_irq_off(unsigned long); /* returns 0 or negative on failure */
414	extern unsigned int probe_irq_mask(unsigned long); /* returns mask of ISA interrupts */
415	#endif
416
417	#endif