[mirror_ubuntu-bionic-kernel.git] / include / asm-x86 / cmpxchg_64.h

#ifndef __ASM_CMPXCHG_H
#define __ASM_CMPXCHG_H

#include <asm/alternative.h> /* Provides LOCK_PREFIX */

#define xchg(ptr, v) ((__typeof__(*(ptr)))__xchg((unsigned long)(v), \
						 (ptr), sizeof(*(ptr))))

#define __xg(x) ((volatile long *)(x))

static inline void set_64bit(volatile unsigned long *ptr, unsigned long val)
{
	*ptr = val;
}

#define _set_64bit set_64bit

/*
 * Note: no "lock" prefix even on SMP: xchg always implies lock anyway
 * Note 2: xchg has side effect, so that attribute volatile is necessary,
 *	  but generally the primitive is invalid, *ptr is output argument. --ANK
 */
static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
				   int size)
{
	switch (size) {
	case 1:
		asm volatile("xchgb %b0,%1"
			     : "=q" (x)
			     : "m" (*__xg(ptr)), "0" (x)
			     : "memory");
		break;
	case 2:
		asm volatile("xchgw %w0,%1"
			     : "=r" (x)
			     : "m" (*__xg(ptr)), "0" (x)
			     : "memory");
		break;
	case 4:
		asm volatile("xchgl %k0,%1"
			     : "=r" (x)
			     : "m" (*__xg(ptr)), "0" (x)
			     : "memory");
		break;
	case 8:
		asm volatile("xchgq %0,%1"
			     : "=r" (x)
			     : "m" (*__xg(ptr)), "0" (x)
			     : "memory");
		break;
	}
	return x;
}

/*
 * Atomic compare and exchange.  Compare OLD with MEM, if identical,
 * store NEW in MEM.  Return the initial value in MEM.  Success is
 * indicated by comparing RETURN with OLD.
 */

#define __HAVE_ARCH_CMPXCHG 1

static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
				      unsigned long new, int size)
{
	unsigned long prev;
	switch (size) {
	case 1:
		asm volatile(LOCK_PREFIX "cmpxchgb %b1,%2"
			     : "=a"(prev)
			     : "q"(new), "m"(*__xg(ptr)), "0"(old)
			     : "memory");
		return prev;
	case 2:
		asm volatile(LOCK_PREFIX "cmpxchgw %w1,%2"
			     : "=a"(prev)
			     : "r"(new), "m"(*__xg(ptr)), "0"(old)
			     : "memory");
		return prev;
	case 4:
		asm volatile(LOCK_PREFIX "cmpxchgl %k1,%2"
			     : "=a"(prev)
			     : "r"(new), "m"(*__xg(ptr)), "0"(old)
			     : "memory");
		return prev;
	case 8:
		asm volatile(LOCK_PREFIX "cmpxchgq %1,%2"
			     : "=a"(prev)
			     : "r"(new), "m"(*__xg(ptr)), "0"(old)
			     : "memory");
		return prev;
	}
	return old;
}

static inline unsigned long __cmpxchg_local(volatile void *ptr,
					    unsigned long old,
					    unsigned long new, int size)
{
	unsigned long prev;
	switch (size) {
	case 1:
		asm volatile("cmpxchgb %b1,%2"
			     : "=a"(prev)
			     : "q"(new), "m"(*__xg(ptr)), "0"(old)
			     : "memory");
		return prev;
	case 2:
		asm volatile("cmpxchgw %w1,%2"
			     : "=a"(prev)
			     : "r"(new), "m"(*__xg(ptr)), "0"(old)
			     : "memory");
		return prev;
	case 4:
		asm volatile("cmpxchgl %k1,%2"
			     : "=a"(prev)
			     : "r"(new), "m"(*__xg(ptr)), "0"(old)
			     : "memory");
		return prev;
	case 8:
		asm volatile("cmpxchgq %1,%2"
			     : "=a"(prev)
			     : "r"(new), "m"(*__xg(ptr)), "0"(old)
			     : "memory");
		return prev;
	}
	return old;
}

#define cmpxchg(ptr, o, n)						\
	((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o),	\
				       (unsigned long)(n), sizeof(*(ptr))))
#define cmpxchg64(ptr, o, n)						\
({									\
	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
	cmpxchg((ptr), (o), (n));					\
})
#define cmpxchg_local(ptr, o, n)					\
	((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o),	\
					     (unsigned long)(n),	\
					     sizeof(*(ptr))))
#define cmpxchg64_local(ptr, o, n)					\
({									\
	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
	cmpxchg_local((ptr), (o), (n));					\
})

#endif
Commit	Line	Data
a436ed9c JD	1	#ifndef __ASM_CMPXCHG_H
	2	#define __ASM_CMPXCHG_H
	3
	4	#include <asm/alternative.h> /* Provides LOCK_PREFIX */
	5
e52da357 JP	6	#define xchg(ptr, v) ((__typeof__(*(ptr)))__xchg((unsigned long)(v), \
e52da357 JP	7	(ptr), sizeof(*(ptr))))
a436ed9c JD	8
	9	#define __xg(x) ((volatile long *)(x))
	10
	11	static inline void set_64bit(volatile unsigned long *ptr, unsigned long val)
	12	{
	13	*ptr = val;
	14	}
	15
	16	#define _set_64bit set_64bit
	17
	18	/*
	19	* Note: no "lock" prefix even on SMP: xchg always implies lock anyway
	20	* Note 2: xchg has side effect, so that attribute volatile is necessary,
	21	* but generally the primitive is invalid, *ptr is output argument. --ANK
	22	*/
e52da357 JP	23	static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
e52da357 JP	24	int size)
a436ed9c JD	25	{
a436ed9c JD	26	switch (size) {
e52da357 JP	27	case 1:
	28	asm volatile("xchgb %b0,%1"
	29	: "=q" (x)
	30	: "m" (*__xg(ptr)), "0" (x)
	31	: "memory");
	32	break;
	33	case 2:
	34	asm volatile("xchgw %w0,%1"
	35	: "=r" (x)
	36	: "m" (*__xg(ptr)), "0" (x)
	37	: "memory");
	38	break;
	39	case 4:
	40	asm volatile("xchgl %k0,%1"
	41	: "=r" (x)
	42	: "m" (*__xg(ptr)), "0" (x)
	43	: "memory");
	44	break;
	45	case 8:
	46	asm volatile("xchgq %0,%1"
	47	: "=r" (x)
	48	: "m" (*__xg(ptr)), "0" (x)
	49	: "memory");
	50	break;
a436ed9c JD	51	}
	52	return x;
	53	}
	54
	55	/*
	56	* Atomic compare and exchange. Compare OLD with MEM, if identical,
	57	* store NEW in MEM. Return the initial value in MEM. Success is
	58	* indicated by comparing RETURN with OLD.
	59	*/
	60
	61	#define __HAVE_ARCH_CMPXCHG 1
	62
	63	static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
	64	unsigned long new, int size)
	65	{
	66	unsigned long prev;
	67	switch (size) {
	68	case 1:
e52da357 JP	69	asm volatile(LOCK_PREFIX "cmpxchgb %b1,%2"
	70	: "=a"(prev)
	71	: "q"(new), "m"(*__xg(ptr)), "0"(old)
	72	: "memory");
a436ed9c JD	73	return prev;
a436ed9c JD	74	case 2:
e52da357 JP	75	asm volatile(LOCK_PREFIX "cmpxchgw %w1,%2"
	76	: "=a"(prev)
	77	: "r"(new), "m"(*__xg(ptr)), "0"(old)
	78	: "memory");
a436ed9c JD	79	return prev;
a436ed9c JD	80	case 4:
e52da357 JP	81	asm volatile(LOCK_PREFIX "cmpxchgl %k1,%2"
	82	: "=a"(prev)
	83	: "r"(new), "m"(*__xg(ptr)), "0"(old)
	84	: "memory");
a436ed9c JD	85	return prev;
a436ed9c JD	86	case 8:
e52da357 JP	87	asm volatile(LOCK_PREFIX "cmpxchgq %1,%2"
	88	: "=a"(prev)
	89	: "r"(new), "m"(*__xg(ptr)), "0"(old)
	90	: "memory");
a436ed9c JD	91	return prev;
	92	}
	93	return old;
	94	}
	95
	96	static inline unsigned long __cmpxchg_local(volatile void *ptr,
e52da357 JP	97	unsigned long old,
e52da357 JP	98	unsigned long new, int size)
a436ed9c JD	99	{
	100	unsigned long prev;
	101	switch (size) {
	102	case 1:
e52da357 JP	103	asm volatile("cmpxchgb %b1,%2"
	104	: "=a"(prev)
	105	: "q"(new), "m"(*__xg(ptr)), "0"(old)
	106	: "memory");
a436ed9c JD	107	return prev;
a436ed9c JD	108	case 2:
e52da357 JP	109	asm volatile("cmpxchgw %w1,%2"
	110	: "=a"(prev)
	111	: "r"(new), "m"(*__xg(ptr)), "0"(old)
	112	: "memory");
a436ed9c JD	113	return prev;
a436ed9c JD	114	case 4:
e52da357 JP	115	asm volatile("cmpxchgl %k1,%2"
	116	: "=a"(prev)
	117	: "r"(new), "m"(*__xg(ptr)), "0"(old)
	118	: "memory");
a436ed9c JD	119	return prev;
a436ed9c JD	120	case 8:
e52da357 JP	121	asm volatile("cmpxchgq %1,%2"
	122	: "=a"(prev)
	123	: "r"(new), "m"(*__xg(ptr)), "0"(old)
	124	: "memory");
a436ed9c JD	125	return prev;
	126	}
	127	return old;
	128	}
	129
32f49eab MD	130	#define cmpxchg(ptr, o, n) \
32f49eab MD	131	((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o), \
e52da357	132	(unsigned long)(n), sizeof(*(ptr))))
32f49eab	133	#define cmpxchg64(ptr, o, n) \
e52da357	134	({ \
32f49eab MD	135	BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
32f49eab MD	136	cmpxchg((ptr), (o), (n)); \
e52da357	137	})
32f49eab MD	138	#define cmpxchg_local(ptr, o, n) \
32f49eab MD	139	((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
e52da357 JP	140	(unsigned long)(n), \
e52da357 JP	141	sizeof(*(ptr))))
32f49eab	142	#define cmpxchg64_local(ptr, o, n) \
e52da357	143	({ \
32f49eab MD	144	BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
32f49eab MD	145	cmpxchg_local((ptr), (o), (n)); \
e52da357	146	})
a436ed9c JD	147
a436ed9c JD	148	#endif