[linux-block.git] / arch / parisc / include / asm / cmpxchg.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * forked from parisc asm/atomic.h which was:
 *	Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
 *	Copyright (C) 2006 Kyle McMartin <kyle@parisc-linux.org>
 */

#ifndef _ASM_PARISC_CMPXCHG_H_
#define _ASM_PARISC_CMPXCHG_H_

/* This should get optimized out since it's never called.
** Or get a link error if xchg is used "wrong".
*/
extern void __xchg_called_with_bad_pointer(void);

/* __xchg32/64 defined in arch/parisc/lib/bitops.c */
extern unsigned long __xchg8(char, char *);
extern unsigned long __xchg32(int, int *);
#ifdef CONFIG_64BIT
extern unsigned long __xchg64(unsigned long, unsigned long *);
#endif

/* optimizer better get rid of switch since size is a constant */
static inline unsigned long
__xchg(unsigned long x, __volatile__ void *ptr, int size)
{
	switch (size) {
#ifdef CONFIG_64BIT
	case 8: return __xchg64(x, (unsigned long *) ptr);
#endif
	case 4: return __xchg32((int) x, (int *) ptr);
	case 1: return __xchg8((char) x, (char *) ptr);
	}
	__xchg_called_with_bad_pointer();
	return x;
}

/*
** REVISIT - Abandoned use of LDCW in xchg() for now:
** o need to test sizeof(*ptr) to avoid clearing adjacent bytes
** o and while we are at it, could CONFIG_64BIT code use LDCD too?
**
**	if (__builtin_constant_p(x) && (x == NULL))
**		if (((unsigned long)p & 0xf) == 0)
**			return __ldcw(p);
*/
#define xchg(ptr, x) \
	((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))

/* bug catcher for when unsupported size is used - won't link */
extern void __cmpxchg_called_with_bad_pointer(void);

/* __cmpxchg_u32/u64 defined in arch/parisc/lib/bitops.c */
extern unsigned long __cmpxchg_u32(volatile unsigned int *m, unsigned int old,
				   unsigned int new_);
extern u64 __cmpxchg_u64(volatile u64 *ptr, u64 old, u64 new_);

/* don't worry...optimizer will get rid of most of this */
static inline unsigned long
__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size)
{
	switch (size) {
#ifdef CONFIG_64BIT
	case 8: return __cmpxchg_u64((u64 *)ptr, old, new_);
#endif
	case 4: return __cmpxchg_u32((unsigned int *)ptr,
				     (unsigned int)old, (unsigned int)new_);
	}
	__cmpxchg_called_with_bad_pointer();
	return old;
}

#define cmpxchg(ptr, o, n)						 \
({									 \
	__typeof__(*(ptr)) _o_ = (o);					 \
	__typeof__(*(ptr)) _n_ = (n);					 \
	(__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,	 \
				    (unsigned long)_n_, sizeof(*(ptr))); \
})

#include <asm-generic/cmpxchg-local.h>

static inline unsigned long __cmpxchg_local(volatile void *ptr,
				      unsigned long old,
				      unsigned long new_, int size)
{
	switch (size) {
#ifdef CONFIG_64BIT
	case 8:	return __cmpxchg_u64((u64 *)ptr, old, new_);
#endif
	case 4:	return __cmpxchg_u32(ptr, old, new_);
	default:
		return __cmpxchg_local_generic(ptr, old, new_, size);
	}
}

/*
 * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
 * them available.
 */
#define cmpxchg_local(ptr, o, n)					\
	((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o),	\
			(unsigned long)(n), sizeof(*(ptr))))
#ifdef CONFIG_64BIT
#define cmpxchg64_local(ptr, o, n)					\
({									\
	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
	cmpxchg_local((ptr), (o), (n));					\
})
#else
#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
#endif

#define cmpxchg64(ptr, o, n) __cmpxchg_u64(ptr, o, n)

#endif /* _ASM_PARISC_CMPXCHG_H_ */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
9e5228ce PG	2	/*
	3	* forked from parisc asm/atomic.h which was:
	4	* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
	5	* Copyright (C) 2006 Kyle McMartin <kyle@parisc-linux.org>
	6	*/
	7
	8	#ifndef _ASM_PARISC_CMPXCHG_H_
	9	#define _ASM_PARISC_CMPXCHG_H_
	10
	11	/* This should get optimized out since it's never called.
	12	** Or get a link error if xchg is used "wrong".
	13	*/
	14	extern void __xchg_called_with_bad_pointer(void);
	15
	16	/* __xchg32/64 defined in arch/parisc/lib/bitops.c */
	17	extern unsigned long __xchg8(char, char *);
	18	extern unsigned long __xchg32(int, int *);
	19	#ifdef CONFIG_64BIT
	20	extern unsigned long __xchg64(unsigned long, unsigned long *);
	21	#endif
	22
	23	/* optimizer better get rid of switch since size is a constant */
	24	static inline unsigned long
	25	__xchg(unsigned long x, __volatile__ void *ptr, int size)
	26	{
	27	switch (size) {
	28	#ifdef CONFIG_64BIT
	29	case 8: return __xchg64(x, (unsigned long *) ptr);
	30	#endif
	31	case 4: return __xchg32((int) x, (int *) ptr);
	32	case 1: return __xchg8((char) x, (char *) ptr);
	33	}
	34	__xchg_called_with_bad_pointer();
	35	return x;
	36	}
	37
	38	/*
	39	** REVISIT - Abandoned use of LDCW in xchg() for now:
	40	** o need to test sizeof(*ptr) to avoid clearing adjacent bytes
	41	** o and while we are at it, could CONFIG_64BIT code use LDCD too?
	42	**
	43	** if (__builtin_constant_p(x) && (x == NULL))
	44	** if (((unsigned long)p & 0xf) == 0)
	45	** return __ldcw(p);
	46	*/
	47	#define xchg(ptr, x) \
	48	((__typeof__((ptr)))__xchg((unsigned long)(x), (ptr), sizeof((ptr))))
	49
9e5228ce PG	50	/* bug catcher for when unsupported size is used - won't link */
	51	extern void __cmpxchg_called_with_bad_pointer(void);
	52
	53	/* __cmpxchg_u32/u64 defined in arch/parisc/lib/bitops.c */
	54	extern unsigned long __cmpxchg_u32(volatile unsigned int *m, unsigned int old,
	55	unsigned int new_);
54b66800	56	extern u64 __cmpxchg_u64(volatile u64 *ptr, u64 old, u64 new_);
9e5228ce PG	57
	58	/* don't worry...optimizer will get rid of most of this */
	59	static inline unsigned long
	60	__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size)
	61	{
	62	switch (size) {
	63	#ifdef CONFIG_64BIT
54b66800	64	case 8: return __cmpxchg_u64((u64 *)ptr, old, new_);
9e5228ce PG	65	#endif
	66	case 4: return __cmpxchg_u32((unsigned int *)ptr,
	67	(unsigned int)old, (unsigned int)new_);
	68	}
	69	__cmpxchg_called_with_bad_pointer();
	70	return old;
	71	}
	72
	73	#define cmpxchg(ptr, o, n) \
	74	({ \
	75	__typeof__(*(ptr)) _o_ = (o); \
	76	__typeof__(*(ptr)) _n_ = (n); \
	77	(__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
	78	(unsigned long)_n_, sizeof(*(ptr))); \
	79	})
	80
	81	#include <asm-generic/cmpxchg-local.h>
	82
	83	static inline unsigned long __cmpxchg_local(volatile void *ptr,
	84	unsigned long old,
	85	unsigned long new_, int size)
	86	{
	87	switch (size) {
	88	#ifdef CONFIG_64BIT
54b66800	89	case 8: return __cmpxchg_u64((u64 *)ptr, old, new_);
9e5228ce PG	90	#endif
	91	case 4: return __cmpxchg_u32(ptr, old, new_);
	92	default:
	93	return __cmpxchg_local_generic(ptr, old, new_, size);
	94	}
	95	}
	96
	97	/*
	98	* cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
	99	* them available.
	100	*/
	101	#define cmpxchg_local(ptr, o, n) \
	102	((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
	103	(unsigned long)(n), sizeof(*(ptr))))
	104	#ifdef CONFIG_64BIT
	105	#define cmpxchg64_local(ptr, o, n) \
	106	({ \
	107	BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
	108	cmpxchg_local((ptr), (o), (n)); \
	109	})
	110	#else
	111	#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
	112	#endif
	113
54b66800 HD	114	#define cmpxchg64(ptr, o, n) __cmpxchg_u64(ptr, o, n)
54b66800 HD	115
9e5228ce	116	#endif /* _ASM_PARISC_CMPXCHG_H_ */