[linux-2.6-block.git] / arch / ia64 / include / uapi / asm / cmpxchg.h

#ifndef _ASM_IA64_CMPXCHG_H
#define _ASM_IA64_CMPXCHG_H

/*
 * Compare/Exchange, forked from asm/intrinsics.h
 * which was:
 *
 *	Copyright (C) 2002-2003 Hewlett-Packard Co
 *	David Mosberger-Tang <davidm@hpl.hp.com>
 */

#ifndef __ASSEMBLY__

#include <linux/types.h>
/* include compiler specific intrinsics */
#include <asm/ia64regs.h>
#ifdef __INTEL_COMPILER
# include <asm/intel_intrin.h>
#else
# include <asm/gcc_intrin.h>
#endif

/*
 * This function doesn't exist, so you'll get a linker error if
 * something tries to do an invalid xchg().
 */
extern void ia64_xchg_called_with_bad_pointer(void);

#define __xchg(x, ptr, size)						\
({									\
	unsigned long __xchg_result;					\
									\
	switch (size) {							\
	case 1:								\
		__xchg_result = ia64_xchg1((__u8 *)ptr, x);		\
		break;							\
									\
	case 2:								\
		__xchg_result = ia64_xchg2((__u16 *)ptr, x);		\
		break;							\
									\
	case 4:								\
		__xchg_result = ia64_xchg4((__u32 *)ptr, x);		\
		break;							\
									\
	case 8:								\
		__xchg_result = ia64_xchg8((__u64 *)ptr, x);		\
		break;							\
	default:							\
		ia64_xchg_called_with_bad_pointer();			\
	}								\
	__xchg_result;							\
})

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

/*
 * 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.
 */

/*
 * This function doesn't exist, so you'll get a linker error
 * if something tries to do an invalid cmpxchg().
 */
extern long ia64_cmpxchg_called_with_bad_pointer(void);

#define ia64_cmpxchg(sem, ptr, old, new, size)				\
({									\
	__u64 _o_, _r_;							\
									\
	switch (size) {							\
	case 1:								\
		_o_ = (__u8) (long) (old);				\
		break;							\
	case 2:								\
		_o_ = (__u16) (long) (old);				\
		break;							\
	case 4:								\
		_o_ = (__u32) (long) (old);				\
		break;							\
	case 8:								\
		_o_ = (__u64) (long) (old);				\
		break;							\
	default:							\
		break;							\
	}								\
	switch (size) {							\
	case 1:								\
		_r_ = ia64_cmpxchg1_##sem((__u8 *) ptr, new, _o_);	\
		break;							\
									\
	case 2:								\
		_r_ = ia64_cmpxchg2_##sem((__u16 *) ptr, new, _o_);	\
		break;							\
									\
	case 4:								\
		_r_ = ia64_cmpxchg4_##sem((__u32 *) ptr, new, _o_);	\
		break;							\
									\
	case 8:								\
		_r_ = ia64_cmpxchg8_##sem((__u64 *) ptr, new, _o_);	\
		break;							\
									\
	default:							\
		_r_ = ia64_cmpxchg_called_with_bad_pointer();		\
		break;							\
	}								\
	(__typeof__(old)) _r_;						\
})

#define cmpxchg_acq(ptr, o, n)	\
	ia64_cmpxchg(acq, (ptr), (o), (n), sizeof(*(ptr)))
#define cmpxchg_rel(ptr, o, n)	\
	ia64_cmpxchg(rel, (ptr), (o), (n), sizeof(*(ptr)))

/*
 * Worse still - early processor implementations actually just ignored
 * the acquire/release and did a full fence all the time.  Unfortunately
 * this meant a lot of badly written code that used .acq when they really
 * wanted .rel became legacy out in the wild - so when we made a cpu
 * that strictly did the .acq or .rel ... all that code started breaking - so
 * we had to back-pedal and keep the "legacy" behavior of a full fence :-(
 */

/* for compatibility with other platforms: */
#define cmpxchg(ptr, o, n)	cmpxchg_acq((ptr), (o), (n))
#define cmpxchg64(ptr, o, n)	cmpxchg_acq((ptr), (o), (n))

#define cmpxchg_local		cmpxchg
#define cmpxchg64_local		cmpxchg64

#ifdef CONFIG_IA64_DEBUG_CMPXCHG
# define CMPXCHG_BUGCHECK_DECL	int _cmpxchg_bugcheck_count = 128;
# define CMPXCHG_BUGCHECK(v)						\
do {									\
	if (_cmpxchg_bugcheck_count-- <= 0) {				\
		void *ip;						\
		extern int printk(const char *fmt, ...);		\
		ip = (void *) ia64_getreg(_IA64_REG_IP);		\
		printk("CMPXCHG_BUGCHECK: stuck at %p on word %p\n", ip, (v));\
		break;							\
	}								\
} while (0)
#else /* !CONFIG_IA64_DEBUG_CMPXCHG */
# define CMPXCHG_BUGCHECK_DECL
# define CMPXCHG_BUGCHECK(v)
#endif /* !CONFIG_IA64_DEBUG_CMPXCHG */

#endif /* !__ASSEMBLY__ */

#endif /* _ASM_IA64_CMPXCHG_H */
Commit	Line	Data
85f8f775 PG	1	#ifndef _ASM_IA64_CMPXCHG_H
	2	#define _ASM_IA64_CMPXCHG_H
	3
	4	/*
	5	* Compare/Exchange, forked from asm/intrinsics.h
	6	* which was:
	7	*
	8	* Copyright (C) 2002-2003 Hewlett-Packard Co
	9	* David Mosberger-Tang <davidm@hpl.hp.com>
	10	*/
	11
	12	#ifndef __ASSEMBLY__
	13
	14	#include <linux/types.h>
	15	/* include compiler specific intrinsics */
	16	#include <asm/ia64regs.h>
	17	#ifdef __INTEL_COMPILER
	18	# include <asm/intel_intrin.h>
	19	#else
	20	# include <asm/gcc_intrin.h>
	21	#endif
	22
	23	/*
	24	* This function doesn't exist, so you'll get a linker error if
	25	* something tries to do an invalid xchg().
	26	*/
	27	extern void ia64_xchg_called_with_bad_pointer(void);
	28
	29	#define __xchg(x, ptr, size) \
	30	({ \
	31	unsigned long __xchg_result; \
	32	\
	33	switch (size) { \
	34	case 1: \
	35	__xchg_result = ia64_xchg1((__u8 *)ptr, x); \
	36	break; \
	37	\
	38	case 2: \
	39	__xchg_result = ia64_xchg2((__u16 *)ptr, x); \
	40	break; \
	41	\
	42	case 4: \
	43	__xchg_result = ia64_xchg4((__u32 *)ptr, x); \
	44	break; \
	45	\
	46	case 8: \
	47	__xchg_result = ia64_xchg8((__u64 *)ptr, x); \
	48	break; \
	49	default: \
	50	ia64_xchg_called_with_bad_pointer(); \
	51	} \
	52	__xchg_result; \
	53	})
	54
	55	#define xchg(ptr, x) \
	56	((__typeof__((ptr))) __xchg((unsigned long) (x), (ptr), sizeof((ptr))))
	57
	58	/*
	59	* Atomic compare and exchange. Compare OLD with MEM, if identical,
	60	* store NEW in MEM. Return the initial value in MEM. Success is
	61	* indicated by comparing RETURN with OLD.
	62	*/
	63
85f8f775 PG	64	/*
	65	* This function doesn't exist, so you'll get a linker error
	66	* if something tries to do an invalid cmpxchg().
	67	*/
	68	extern long ia64_cmpxchg_called_with_bad_pointer(void);
	69
	70	#define ia64_cmpxchg(sem, ptr, old, new, size) \
	71	({ \
	72	__u64 _o_, _r_; \
	73	\
	74	switch (size) { \
	75	case 1: \
	76	_o_ = (__u8) (long) (old); \
	77	break; \
	78	case 2: \
	79	_o_ = (__u16) (long) (old); \
	80	break; \
	81	case 4: \
	82	_o_ = (__u32) (long) (old); \
	83	break; \
	84	case 8: \
	85	_o_ = (__u64) (long) (old); \
	86	break; \
	87	default: \
	88	break; \
	89	} \
	90	switch (size) { \
	91	case 1: \
	92	_r_ = ia64_cmpxchg1_##sem((__u8 *) ptr, new, _o_); \
	93	break; \
	94	\
	95	case 2: \
	96	_r_ = ia64_cmpxchg2_##sem((__u16 *) ptr, new, _o_); \
	97	break; \
	98	\
	99	case 4: \
	100	_r_ = ia64_cmpxchg4_##sem((__u32 *) ptr, new, _o_); \
	101	break; \
	102	\
	103	case 8: \
	104	_r_ = ia64_cmpxchg8_##sem((__u64 *) ptr, new, _o_); \
	105	break; \
	106	\
	107	default: \
	108	_r_ = ia64_cmpxchg_called_with_bad_pointer(); \
	109	break; \
	110	} \
	111	(__typeof__(old)) _r_; \
	112	})
	113
	114	#define cmpxchg_acq(ptr, o, n) \
	115	ia64_cmpxchg(acq, (ptr), (o), (n), sizeof(*(ptr)))
	116	#define cmpxchg_rel(ptr, o, n) \
	117	ia64_cmpxchg(rel, (ptr), (o), (n), sizeof(*(ptr)))
	118
e4f9bfb3 PZ	119	/*
	120	* Worse still - early processor implementations actually just ignored
	121	* the acquire/release and did a full fence all the time. Unfortunately
	122	* this meant a lot of badly written code that used .acq when they really
	123	* wanted .rel became legacy out in the wild - so when we made a cpu
	124	* that strictly did the .acq or .rel ... all that code started breaking - so
	125	* we had to back-pedal and keep the "legacy" behavior of a full fence :-(
	126	*/
	127
85f8f775 PG	128	/* for compatibility with other platforms: */
	129	#define cmpxchg(ptr, o, n) cmpxchg_acq((ptr), (o), (n))
	130	#define cmpxchg64(ptr, o, n) cmpxchg_acq((ptr), (o), (n))
	131
	132	#define cmpxchg_local cmpxchg
	133	#define cmpxchg64_local cmpxchg64
	134
	135	#ifdef CONFIG_IA64_DEBUG_CMPXCHG
	136	# define CMPXCHG_BUGCHECK_DECL int _cmpxchg_bugcheck_count = 128;
	137	# define CMPXCHG_BUGCHECK(v) \
	138	do { \
	139	if (_cmpxchg_bugcheck_count-- <= 0) { \
	140	void *ip; \
	141	extern int printk(const char *fmt, ...); \
	142	ip = (void *) ia64_getreg(_IA64_REG_IP); \
	143	printk("CMPXCHG_BUGCHECK: stuck at %p on word %p\n", ip, (v));\
	144	break; \
	145	} \
	146	} while (0)
	147	#else /* !CONFIG_IA64_DEBUG_CMPXCHG */
	148	# define CMPXCHG_BUGCHECK_DECL
	149	# define CMPXCHG_BUGCHECK(v)
	150	#endif /* !CONFIG_IA64_DEBUG_CMPXCHG */
	151
	152	#endif /* !__ASSEMBLY__ */
	153
	154	#endif /* _ASM_IA64_CMPXCHG_H */