[linux-2.6-block.git] / kernel / locking / lglock.c

/* See include/linux/lglock.h for description */
#include <linux/module.h>
#include <linux/lglock.h>
#include <linux/cpu.h>
#include <linux/string.h>

/*
 * Note there is no uninit, so lglocks cannot be defined in
 * modules (but it's fine to use them from there)
 * Could be added though, just undo lg_lock_init
 */

void lg_lock_init(struct lglock *lg, char *name)
{
	LOCKDEP_INIT_MAP(&lg->lock_dep_map, name, &lg->lock_key, 0);
}
EXPORT_SYMBOL(lg_lock_init);

void lg_local_lock(struct lglock *lg)
{
	arch_spinlock_t *lock;

	preempt_disable();
	lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
	lock = this_cpu_ptr(lg->lock);
	arch_spin_lock(lock);
}
EXPORT_SYMBOL(lg_local_lock);

void lg_local_unlock(struct lglock *lg)
{
	arch_spinlock_t *lock;

	lock_release(&lg->lock_dep_map, 1, _RET_IP_);
	lock = this_cpu_ptr(lg->lock);
	arch_spin_unlock(lock);
	preempt_enable();
}
EXPORT_SYMBOL(lg_local_unlock);

void lg_local_lock_cpu(struct lglock *lg, int cpu)
{
	arch_spinlock_t *lock;

	preempt_disable();
	lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
	lock = per_cpu_ptr(lg->lock, cpu);
	arch_spin_lock(lock);
}
EXPORT_SYMBOL(lg_local_lock_cpu);

void lg_local_unlock_cpu(struct lglock *lg, int cpu)
{
	arch_spinlock_t *lock;

	lock_release(&lg->lock_dep_map, 1, _RET_IP_);
	lock = per_cpu_ptr(lg->lock, cpu);
	arch_spin_unlock(lock);
	preempt_enable();
}
EXPORT_SYMBOL(lg_local_unlock_cpu);

void lg_double_lock(struct lglock *lg, int cpu1, int cpu2)
{
	BUG_ON(cpu1 == cpu2);

	/* lock in cpu order, just like lg_global_lock */
	if (cpu2 < cpu1)
		swap(cpu1, cpu2);

	preempt_disable();
	lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
	arch_spin_lock(per_cpu_ptr(lg->lock, cpu1));
	arch_spin_lock(per_cpu_ptr(lg->lock, cpu2));
}

void lg_double_unlock(struct lglock *lg, int cpu1, int cpu2)
{
	lock_release(&lg->lock_dep_map, 1, _RET_IP_);
	arch_spin_unlock(per_cpu_ptr(lg->lock, cpu1));
	arch_spin_unlock(per_cpu_ptr(lg->lock, cpu2));
	preempt_enable();
}

void lg_global_lock(struct lglock *lg)
{
	int i;

	preempt_disable();
	lock_acquire_exclusive(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
	for_each_possible_cpu(i) {
		arch_spinlock_t *lock;
		lock = per_cpu_ptr(lg->lock, i);
		arch_spin_lock(lock);
	}
}
EXPORT_SYMBOL(lg_global_lock);

void lg_global_unlock(struct lglock *lg)
{
	int i;

	lock_release(&lg->lock_dep_map, 1, _RET_IP_);
	for_each_possible_cpu(i) {
		arch_spinlock_t *lock;
		lock = per_cpu_ptr(lg->lock, i);
		arch_spin_unlock(lock);
	}
	preempt_enable();
}
EXPORT_SYMBOL(lg_global_unlock);
Commit	Line	Data
eea62f83 AK	1	/* See include/linux/lglock.h for description */
	2	#include <linux/module.h>
	3	#include <linux/lglock.h>
	4	#include <linux/cpu.h>
	5	#include <linux/string.h>
	6
	7	/*
	8	* Note there is no uninit, so lglocks cannot be defined in
	9	* modules (but it's fine to use them from there)
	10	* Could be added though, just undo lg_lock_init
	11	*/
	12
	13	void lg_lock_init(struct lglock lg, char name)
	14	{
	15	LOCKDEP_INIT_MAP(&lg->lock_dep_map, name, &lg->lock_key, 0);
	16	}
	17	EXPORT_SYMBOL(lg_lock_init);
	18
	19	void lg_local_lock(struct lglock *lg)
	20	{
	21	arch_spinlock_t *lock;
	22
	23	preempt_disable();
c4be9cb4	24	lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
eea62f83 AK	25	lock = this_cpu_ptr(lg->lock);
	26	arch_spin_lock(lock);
	27	}
	28	EXPORT_SYMBOL(lg_local_lock);
	29
	30	void lg_local_unlock(struct lglock *lg)
	31	{
	32	arch_spinlock_t *lock;
	33
c4be9cb4	34	lock_release(&lg->lock_dep_map, 1, _RET_IP_);
eea62f83 AK	35	lock = this_cpu_ptr(lg->lock);
	36	arch_spin_unlock(lock);
	37	preempt_enable();
	38	}
	39	EXPORT_SYMBOL(lg_local_unlock);
	40
	41	void lg_local_lock_cpu(struct lglock *lg, int cpu)
	42	{
	43	arch_spinlock_t *lock;
	44
	45	preempt_disable();
c4be9cb4	46	lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
eea62f83 AK	47	lock = per_cpu_ptr(lg->lock, cpu);
	48	arch_spin_lock(lock);
	49	}
	50	EXPORT_SYMBOL(lg_local_lock_cpu);
	51
	52	void lg_local_unlock_cpu(struct lglock *lg, int cpu)
	53	{
	54	arch_spinlock_t *lock;
	55
c4be9cb4	56	lock_release(&lg->lock_dep_map, 1, _RET_IP_);
eea62f83 AK	57	lock = per_cpu_ptr(lg->lock, cpu);
	58	arch_spin_unlock(lock);
	59	preempt_enable();
	60	}
	61	EXPORT_SYMBOL(lg_local_unlock_cpu);
	62
b17718d0 PZ	63	void lg_double_lock(struct lglock *lg, int cpu1, int cpu2)
	64	{
	65	BUG_ON(cpu1 == cpu2);
	66
	67	/* lock in cpu order, just like lg_global_lock */
	68	if (cpu2 < cpu1)
	69	swap(cpu1, cpu2);
	70
	71	preempt_disable();
	72	lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
	73	arch_spin_lock(per_cpu_ptr(lg->lock, cpu1));
	74	arch_spin_lock(per_cpu_ptr(lg->lock, cpu2));
	75	}
	76
	77	void lg_double_unlock(struct lglock *lg, int cpu1, int cpu2)
	78	{
	79	lock_release(&lg->lock_dep_map, 1, _RET_IP_);
	80	arch_spin_unlock(per_cpu_ptr(lg->lock, cpu1));
	81	arch_spin_unlock(per_cpu_ptr(lg->lock, cpu2));
	82	preempt_enable();
	83	}
	84
eea62f83 AK	85	void lg_global_lock(struct lglock *lg)
	86	{
	87	int i;
	88
	89	preempt_disable();
c4be9cb4	90	lock_acquire_exclusive(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
eea62f83 AK	91	for_each_possible_cpu(i) {
	92	arch_spinlock_t *lock;
	93	lock = per_cpu_ptr(lg->lock, i);
	94	arch_spin_lock(lock);
	95	}
	96	}
	97	EXPORT_SYMBOL(lg_global_lock);
	98
	99	void lg_global_unlock(struct lglock *lg)
	100	{
	101	int i;
	102
c4be9cb4	103	lock_release(&lg->lock_dep_map, 1, _RET_IP_);
eea62f83 AK	104	for_each_possible_cpu(i) {
	105	arch_spinlock_t *lock;
	106	lock = per_cpu_ptr(lg->lock, i);
	107	arch_spin_unlock(lock);
	108	}
	109	preempt_enable();
	110	}
	111	EXPORT_SYMBOL(lg_global_unlock);