[deliverable/linux.git] / include / asm-generic / unaligned.h

#ifndef _ASM_GENERIC_UNALIGNED_H_
#define _ASM_GENERIC_UNALIGNED_H_

/*
 * For the benefit of those who are trying to port Linux to another
 * architecture, here are some C-language equivalents. 
 *
 * This is based almost entirely upon Richard Henderson's
 * asm-alpha/unaligned.h implementation.  Some comments were
 * taken from David Mosberger's asm-ia64/unaligned.h header.
 */

#include <linux/types.h>

/* 
 * The main single-value unaligned transfer routines.
 */
#define get_unaligned(ptr) \
	__get_unaligned((ptr), sizeof(*(ptr)))
#define put_unaligned(x,ptr) \
	((void)sizeof(*(ptr)=(x)),\
	__put_unaligned((__force __u64)(x), (ptr), sizeof(*(ptr))))

/*
 * This function doesn't actually exist.  The idea is that when
 * someone uses the macros below with an unsupported size (datatype),
 * the linker will alert us to the problem via an unresolved reference
 * error.
 */
extern void bad_unaligned_access_length(void) __attribute__((noreturn));

struct __una_u64 { __u64 x __attribute__((packed)); };
struct __una_u32 { __u32 x __attribute__((packed)); };
struct __una_u16 { __u16 x __attribute__((packed)); };

/*
 * Elemental unaligned loads 
 */

static inline __u64 __uldq(const __u64 *addr)
{
	const struct __una_u64 *ptr = (const struct __una_u64 *) addr;
	return ptr->x;
}

static inline __u32 __uldl(const __u32 *addr)
{
	const struct __una_u32 *ptr = (const struct __una_u32 *) addr;
	return ptr->x;
}

static inline __u16 __uldw(const __u16 *addr)
{
	const struct __una_u16 *ptr = (const struct __una_u16 *) addr;
	return ptr->x;
}

/*
 * Elemental unaligned stores 
 */

static inline void __ustq(__u64 val, __u64 *addr)
{
	struct __una_u64 *ptr = (struct __una_u64 *) addr;
	ptr->x = val;
}

static inline void __ustl(__u32 val, __u32 *addr)
{
	struct __una_u32 *ptr = (struct __una_u32 *) addr;
	ptr->x = val;
}

static inline void __ustw(__u16 val, __u16 *addr)
{
	struct __una_u16 *ptr = (struct __una_u16 *) addr;
	ptr->x = val;
}

#define __get_unaligned(ptr, size) ({		\
	const void *__gu_p = ptr;		\
	__u64 __val;				\
	switch (size) {				\
	case 1:					\
		__val = *(const __u8 *)__gu_p;	\
		break;				\
	case 2:					\
		__val = __uldw(__gu_p);		\
		break;				\
	case 4:					\
		__val = __uldl(__gu_p);		\
		break;				\
	case 8:					\
		__val = __uldq(__gu_p);		\
		break;				\
	default:				\
		bad_unaligned_access_length();	\
	};					\
	(__force __typeof__(*(ptr)))__val;	\
})

#define __put_unaligned(val, ptr, size)		\
({						\
	void *__gu_p = ptr;			\
	switch (size) {				\
	case 1:					\
		*(__u8 *)__gu_p = (__force __u8)val;		\
	        break;				\
	case 2:					\
		__ustw((__force __u16)val, __gu_p);		\
		break;				\
	case 4:					\
		__ustl((__force __u32)val, __gu_p);		\
		break;				\
	case 8:					\
		__ustq(val, __gu_p);		\
		break;				\
	default:				\
	    	bad_unaligned_access_length();	\
	};					\
	(void)0;				\
})

#endif /* _ASM_GENERIC_UNALIGNED_H */
Commit	Line	Data
1da177e4 LT	1	#ifndef _ASM_GENERIC_UNALIGNED_H_
	2	#define _ASM_GENERIC_UNALIGNED_H_
	3
	4	/*
	5	* For the benefit of those who are trying to port Linux to another
	6	* architecture, here are some C-language equivalents.
	7	*
	8	* This is based almost entirely upon Richard Henderson's
	9	* asm-alpha/unaligned.h implementation. Some comments were
	10	* taken from David Mosberger's asm-ia64/unaligned.h header.
	11	*/
	12
	13	#include <linux/types.h>
	14
	15	/*
	16	* The main single-value unaligned transfer routines.
	17	*/
	18	#define get_unaligned(ptr) \
eed74dfc	19	__get_unaligned((ptr), sizeof(*(ptr)))
1da177e4	20	#define put_unaligned(x,ptr) \
d37c6e1b AV	21	((void)sizeof(*(ptr)=(x)),\
d37c6e1b AV	22	__put_unaligned((__force __u64)(x), (ptr), sizeof(*(ptr))))
1da177e4 LT	23
	24	/*
	25	* This function doesn't actually exist. The idea is that when
	26	* someone uses the macros below with an unsupported size (datatype),
	27	* the linker will alert us to the problem via an unresolved reference
	28	* error.
	29	*/
	30	extern void bad_unaligned_access_length(void) __attribute__((noreturn));
	31
	32	struct __una_u64 { __u64 x __attribute__((packed)); };
	33	struct __una_u32 { __u32 x __attribute__((packed)); };
	34	struct __una_u16 { __u16 x __attribute__((packed)); };
	35
	36	/*
	37	* Elemental unaligned loads
	38	*/
	39
eed74dfc	40	static inline __u64 __uldq(const __u64 *addr)
1da177e4 LT	41	{
	42	const struct __una_u64 ptr = (const struct __una_u64 ) addr;
	43	return ptr->x;
	44	}
	45
eed74dfc	46	static inline __u32 __uldl(const __u32 *addr)
1da177e4 LT	47	{
	48	const struct __una_u32 ptr = (const struct __una_u32 ) addr;
	49	return ptr->x;
	50	}
	51
eed74dfc	52	static inline __u16 __uldw(const __u16 *addr)
1da177e4 LT	53	{
	54	const struct __una_u16 ptr = (const struct __una_u16 ) addr;
	55	return ptr->x;
	56	}
	57
	58	/*
	59	* Elemental unaligned stores
	60	*/
	61
	62	static inline void __ustq(__u64 val, __u64 *addr)
	63	{
	64	struct __una_u64 ptr = (struct __una_u64 ) addr;
	65	ptr->x = val;
	66	}
	67
	68	static inline void __ustl(__u32 val, __u32 *addr)
	69	{
	70	struct __una_u32 ptr = (struct __una_u32 ) addr;
	71	ptr->x = val;
	72	}
	73
	74	static inline void __ustw(__u16 val, __u16 *addr)
	75	{
	76	struct __una_u16 ptr = (struct __una_u16 ) addr;
	77	ptr->x = val;
	78	}
	79
3106dbcd AV	80	#define __get_unaligned(ptr, size) ({ \
3106dbcd AV	81	const void *__gu_p = ptr; \
937472b0	82	__u64 __val; \
3106dbcd AV	83	switch (size) { \
3106dbcd AV	84	case 1: \
937472b0	85	__val = (const __u8 )__gu_p; \
3106dbcd AV	86	break; \
3106dbcd AV	87	case 2: \
937472b0	88	__val = __uldw(__gu_p); \
3106dbcd AV	89	break; \
3106dbcd AV	90	case 4: \
937472b0	91	__val = __uldl(__gu_p); \
3106dbcd AV	92	break; \
3106dbcd AV	93	case 8: \
937472b0	94	__val = __uldq(__gu_p); \
3106dbcd AV	95	break; \
	96	default: \
	97	bad_unaligned_access_length(); \
	98	}; \
937472b0	99	(__force __typeof__(*(ptr)))__val; \
3106dbcd AV	100	})
	101
	102	#define __put_unaligned(val, ptr, size) \
d37c6e1b	103	({ \
3106dbcd AV	104	void *__gu_p = ptr; \
	105	switch (size) { \
	106	case 1: \
d37c6e1b	107	(__u8 )__gu_p = (__force __u8)val; \
3106dbcd AV	108	break; \
3106dbcd AV	109	case 2: \
d37c6e1b	110	__ustw((__force __u16)val, __gu_p); \
3106dbcd AV	111	break; \
3106dbcd AV	112	case 4: \
d37c6e1b	113	__ustl((__force __u32)val, __gu_p); \
3106dbcd AV	114	break; \
	115	case 8: \
	116	__ustq(val, __gu_p); \
	117	break; \
	118	default: \
	119	bad_unaligned_access_length(); \
	120	}; \
d37c6e1b AV	121	(void)0; \
d37c6e1b AV	122	})
1da177e4 LT	123
1da177e4 LT	124	#endif /* _ASM_GENERIC_UNALIGNED_H */