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

/*
 * Read-Copy Update mechanism for mutual exclusion, the Bloatwatch edition.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, you can access it online at
 * http://www.gnu.org/licenses/gpl-2.0.html.
 *
 * Copyright IBM Corporation, 2008
 *
 * Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
 *
 * For detailed explanation of Read-Copy Update mechanism see -
 *		Documentation/RCU
 */
#ifndef __LINUX_TINY_H
#define __LINUX_TINY_H

#include <linux/ktime.h>

struct rcu_dynticks;
static inline int rcu_dynticks_snap(struct rcu_dynticks *rdtp)
{
	return 0;
}

/* Never flag non-existent other CPUs! */
static inline bool rcu_eqs_special_set(int cpu) { return false; }

static inline unsigned long get_state_synchronize_rcu(void)
{
	return 0;
}

static inline void cond_synchronize_rcu(unsigned long oldstate)
{
	might_sleep();
}

static inline unsigned long get_state_synchronize_sched(void)
{
	return 0;
}

static inline void cond_synchronize_sched(unsigned long oldstate)
{
	might_sleep();
}

extern void rcu_barrier_bh(void);
extern void rcu_barrier_sched(void);

static inline void synchronize_rcu_expedited(void)
{
	synchronize_sched();	/* Only one CPU, so pretty fast anyway!!! */
}

static inline void rcu_barrier(void)
{
	rcu_barrier_sched();  /* Only one CPU, so only one list of callbacks! */
}

static inline void synchronize_rcu_bh(void)
{
	synchronize_sched();
}

static inline void synchronize_rcu_bh_expedited(void)
{
	synchronize_sched();
}

static inline void synchronize_sched_expedited(void)
{
	synchronize_sched();
}

static inline void kfree_call_rcu(struct rcu_head *head,
				  rcu_callback_t func)
{
	call_rcu(head, func);
}

#define rcu_note_context_switch(preempt) \
	do { \
		rcu_sched_qs(); \
		rcu_tasks_qs(current); \
	} while (0)

static inline int rcu_needs_cpu(u64 basemono, u64 *nextevt)
{
	*nextevt = KTIME_MAX;
	return 0;
}

/*
 * Take advantage of the fact that there is only one CPU, which
 * allows us to ignore virtualization-based context switches.
 */
static inline void rcu_virt_note_context_switch(int cpu) { }
static inline void rcu_cpu_stall_reset(void) { }
static inline void rcu_idle_enter(void) { }
static inline void rcu_idle_exit(void) { }
static inline void rcu_irq_enter(void) { }
static inline void rcu_irq_exit_irqson(void) { }
static inline void rcu_irq_enter_irqson(void) { }
static inline void rcu_irq_exit(void) { }
static inline void exit_rcu(void) { }
#ifdef CONFIG_SRCU
void rcu_scheduler_starting(void);
#else /* #ifndef CONFIG_SRCU */
static inline void rcu_scheduler_starting(void) { }
#endif /* #else #ifndef CONFIG_SRCU */
static inline void rcu_end_inkernel_boot(void) { }
static inline bool rcu_is_watching(void) { return true; }

/* Avoid RCU read-side critical sections leaking across. */
static inline void rcu_all_qs(void) { barrier(); }

/* RCUtree hotplug events */
#define rcutree_prepare_cpu      NULL
#define rcutree_online_cpu       NULL
#define rcutree_offline_cpu      NULL
#define rcutree_dead_cpu         NULL
#define rcutree_dying_cpu        NULL
static inline void rcu_cpu_starting(unsigned int cpu) { }

#endif /* __LINUX_RCUTINY_H */
Commit	Line	Data
	1	/*
	2	* Read-Copy Update mechanism for mutual exclusion, the Bloatwatch edition.
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2 of the License, or
	7	* (at your option) any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, you can access it online at
	16	* http://www.gnu.org/licenses/gpl-2.0.html.
	17	*
	18	* Copyright IBM Corporation, 2008
	19	*
	20	* Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
	21	*
	22	* For detailed explanation of Read-Copy Update mechanism see -
	23	* Documentation/RCU
	24	*/
	25	#ifndef __LINUX_TINY_H
	26	#define __LINUX_TINY_H
	27
	28	#include <linux/ktime.h>
	29
	30	struct rcu_dynticks;
	31	static inline int rcu_dynticks_snap(struct rcu_dynticks *rdtp)
	32	{
	33	return 0;
	34	}
	35
	36	/* Never flag non-existent other CPUs! */
	37	static inline bool rcu_eqs_special_set(int cpu) { return false; }
	38
	39	static inline unsigned long get_state_synchronize_rcu(void)
	40	{
	41	return 0;
	42	}
	43
	44	static inline void cond_synchronize_rcu(unsigned long oldstate)
	45	{
	46	might_sleep();
	47	}
	48
	49	static inline unsigned long get_state_synchronize_sched(void)
	50	{
	51	return 0;
	52	}
	53
	54	static inline void cond_synchronize_sched(unsigned long oldstate)
	55	{
	56	might_sleep();
	57	}
	58
	59	extern void rcu_barrier_bh(void);
	60	extern void rcu_barrier_sched(void);
	61
	62	static inline void synchronize_rcu_expedited(void)
	63	{
	64	synchronize_sched(); /* Only one CPU, so pretty fast anyway!!! */
	65	}
	66
	67	static inline void rcu_barrier(void)
	68	{
	69	rcu_barrier_sched(); /* Only one CPU, so only one list of callbacks! */
	70	}
	71
	72	static inline void synchronize_rcu_bh(void)
	73	{
	74	synchronize_sched();
	75	}
	76
	77	static inline void synchronize_rcu_bh_expedited(void)
	78	{
	79	synchronize_sched();
	80	}
	81
	82	static inline void synchronize_sched_expedited(void)
	83	{
	84	synchronize_sched();
	85	}
	86
	87	static inline void kfree_call_rcu(struct rcu_head *head,
	88	rcu_callback_t func)
	89	{
	90	call_rcu(head, func);
	91	}
	92
	93	#define rcu_note_context_switch(preempt) \
	94	do { \
	95	rcu_sched_qs(); \
	96	rcu_tasks_qs(current); \
	97	} while (0)
	98
	99	static inline int rcu_needs_cpu(u64 basemono, u64 *nextevt)
	100	{
	101	*nextevt = KTIME_MAX;
	102	return 0;
	103	}
	104
	105	/*
	106	* Take advantage of the fact that there is only one CPU, which
	107	* allows us to ignore virtualization-based context switches.
	108	*/
	109	static inline void rcu_virt_note_context_switch(int cpu) { }
	110	static inline void rcu_cpu_stall_reset(void) { }
	111	static inline void rcu_idle_enter(void) { }
	112	static inline void rcu_idle_exit(void) { }
	113	static inline void rcu_irq_enter(void) { }
	114	static inline void rcu_irq_exit_irqson(void) { }
	115	static inline void rcu_irq_enter_irqson(void) { }
	116	static inline void rcu_irq_exit(void) { }
	117	static inline void exit_rcu(void) { }
	118	#ifdef CONFIG_SRCU
	119	void rcu_scheduler_starting(void);
	120	#else /* #ifndef CONFIG_SRCU */
	121	static inline void rcu_scheduler_starting(void) { }
	122	#endif /* #else #ifndef CONFIG_SRCU */
	123	static inline void rcu_end_inkernel_boot(void) { }
	124	static inline bool rcu_is_watching(void) { return true; }
	125
	126	/* Avoid RCU read-side critical sections leaking across. */
	127	static inline void rcu_all_qs(void) { barrier(); }
	128
	129	/* RCUtree hotplug events */
	130	#define rcutree_prepare_cpu NULL
	131	#define rcutree_online_cpu NULL
	132	#define rcutree_offline_cpu NULL
	133	#define rcutree_dead_cpu NULL
	134	#define rcutree_dying_cpu NULL
	135	static inline void rcu_cpu_starting(unsigned int cpu) { }
	136
	137	#endif /* __LINUX_RCUTINY_H */