[net-next-2.6.git] / include / asm-generic / cmpxchg-local.h

#ifndef __ASM_GENERIC_CMPXCHG_LOCAL_H
#define __ASM_GENERIC_CMPXCHG_LOCAL_H

#include <linux/types.h>

extern unsigned long wrong_size_cmpxchg(volatile void *ptr);

/*
 * Generic version of __cmpxchg_local (disables interrupts). Takes an unsigned
 * long parameter, supporting various types of architectures.
 */
static inline unsigned long __cmpxchg_local_generic(volatile void *ptr,
		unsigned long old, unsigned long new, int size)
{
	unsigned long flags, prev;

	/*
	 * Sanity checking, compile-time.
	 */
	if (size == 8 && sizeof(unsigned long) != 8)
		wrong_size_cmpxchg(ptr);

	local_irq_save(flags);
	switch (size) {
	case 1: prev = *(u8 *)ptr;
		if (prev == old)
			*(u8 *)ptr = (u8)new;
		break;
	case 2: prev = *(u16 *)ptr;
		if (prev == old)
			*(u16 *)ptr = (u16)new;
		break;
	case 4: prev = *(u32 *)ptr;
		if (prev == old)
			*(u32 *)ptr = (u32)new;
		break;
	case 8: prev = *(u64 *)ptr;
		if (prev == old)
			*(u64 *)ptr = (u64)new;
		break;
	default:
		wrong_size_cmpxchg(ptr);
	}
	local_irq_restore(flags);
	return prev;
}

/*
 * Generic version of __cmpxchg64_local. Takes an u64 parameter.
 */
static inline u64 __cmpxchg64_local_generic(volatile void *ptr,
		u64 old, u64 new)
{
	u64 prev;
	unsigned long flags;

	local_irq_save(flags);
	prev = *(u64 *)ptr;
	if (prev == old)
		*(u64 *)ptr = new;
	local_irq_restore(flags);
	return prev;
}

#endif
Commit	Line	Data
068fbad2 MD	1	#ifndef __ASM_GENERIC_CMPXCHG_LOCAL_H
	2	#define __ASM_GENERIC_CMPXCHG_LOCAL_H
	3
	4	#include <linux/types.h>
	5
	6	extern unsigned long wrong_size_cmpxchg(volatile void *ptr);
	7
	8	/*
	9	* Generic version of __cmpxchg_local (disables interrupts). Takes an unsigned
	10	* long parameter, supporting various types of architectures.
	11	*/
	12	static inline unsigned long __cmpxchg_local_generic(volatile void *ptr,
	13	unsigned long old, unsigned long new, int size)
	14	{
	15	unsigned long flags, prev;
	16
	17	/*
	18	* Sanity checking, compile-time.
	19	*/
	20	if (size == 8 && sizeof(unsigned long) != 8)
	21	wrong_size_cmpxchg(ptr);
	22
	23	local_irq_save(flags);
	24	switch (size) {
	25	case 1: prev = (u8 )ptr;
	26	if (prev == old)
	27	(u8 )ptr = (u8)new;
	28	break;
	29	case 2: prev = (u16 )ptr;
	30	if (prev == old)
	31	(u16 )ptr = (u16)new;
	32	break;
	33	case 4: prev = (u32 )ptr;
	34	if (prev == old)
	35	(u32 )ptr = (u32)new;
	36	break;
	37	case 8: prev = (u64 )ptr;
	38	if (prev == old)
	39	(u64 )ptr = (u64)new;
	40	break;
	41	default:
	42	wrong_size_cmpxchg(ptr);
	43	}
	44	local_irq_restore(flags);
	45	return prev;
	46	}
	47
	48	/*
	49	* Generic version of __cmpxchg64_local. Takes an u64 parameter.
	50	*/
	51	static inline u64 __cmpxchg64_local_generic(volatile void *ptr,
	52	u64 old, u64 new)
	53	{
	54	u64 prev;
	55	unsigned long flags;
	56
	57	local_irq_save(flags);
	58	prev = (u64 )ptr;
	59	if (prev == old)
	60	(u64 )ptr = new;
	61	local_irq_restore(flags);
	62	return prev;
	63	}
	64
65	#endif