[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / asm-generic / cmpxchg-local.h

#ifndef __ASM_GENERIC_CMPXCHG_LOCAL_H
#define __ASM_GENERIC_CMPXCHG_LOCAL_H

#include <linux/types.h>
#include <linux/irqflags.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);

	raw_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);
	}
	raw_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;

	raw_local_irq_save(flags);
	prev = *(u64 *)ptr;
	if (prev == old)
		*(u64 *)ptr = new;
	raw_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>
df9ee292	5	#include <linux/irqflags.h>
068fbad2 MD	6
	7	extern unsigned long wrong_size_cmpxchg(volatile void *ptr);
	8
	9	/*
	10	* Generic version of __cmpxchg_local (disables interrupts). Takes an unsigned
	11	* long parameter, supporting various types of architectures.
	12	*/
	13	static inline unsigned long __cmpxchg_local_generic(volatile void *ptr,
	14	unsigned long old, unsigned long new, int size)
	15	{
	16	unsigned long flags, prev;
	17
	18	/*
	19	* Sanity checking, compile-time.
	20	*/
	21	if (size == 8 && sizeof(unsigned long) != 8)
	22	wrong_size_cmpxchg(ptr);
	23
5042afe7	24	raw_local_irq_save(flags);
068fbad2 MD	25	switch (size) {
	26	case 1: prev = (u8 )ptr;
	27	if (prev == old)
	28	(u8 )ptr = (u8)new;
	29	break;
	30	case 2: prev = (u16 )ptr;
	31	if (prev == old)
	32	(u16 )ptr = (u16)new;
	33	break;
	34	case 4: prev = (u32 )ptr;
	35	if (prev == old)
	36	(u32 )ptr = (u32)new;
	37	break;
	38	case 8: prev = (u64 )ptr;
	39	if (prev == old)
	40	(u64 )ptr = (u64)new;
	41	break;
	42	default:
	43	wrong_size_cmpxchg(ptr);
	44	}
5042afe7	45	raw_local_irq_restore(flags);
068fbad2 MD	46	return prev;
	47	}
	48
	49	/*
	50	* Generic version of __cmpxchg64_local. Takes an u64 parameter.
	51	*/
	52	static inline u64 __cmpxchg64_local_generic(volatile void *ptr,
	53	u64 old, u64 new)
	54	{
	55	u64 prev;
	56	unsigned long flags;
	57
5042afe7	58	raw_local_irq_save(flags);
068fbad2 MD	59	prev = (u64 )ptr;
	60	if (prev == old)
	61	(u64 )ptr = new;
5042afe7	62	raw_local_irq_restore(flags);
068fbad2 MD	63	return prev;
	64	}
	65
	66	#endif