[linux-2.6-block.git] / include / linux / wordpart.h

/* SPDX-License-Identifier: GPL-2.0 */

#ifndef _LINUX_WORDPART_H
#define _LINUX_WORDPART_H

/**
 * upper_32_bits - return bits 32-63 of a number
 * @n: the number we're accessing
 *
 * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
 * the "right shift count >= width of type" warning when that quantity is
 * 32-bits.
 */
#define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))

/**
 * lower_32_bits - return bits 0-31 of a number
 * @n: the number we're accessing
 */
#define lower_32_bits(n) ((u32)((n) & 0xffffffff))

/**
 * upper_16_bits - return bits 16-31 of a number
 * @n: the number we're accessing
 */
#define upper_16_bits(n) ((u16)((n) >> 16))

/**
 * lower_16_bits - return bits 0-15 of a number
 * @n: the number we're accessing
 */
#define lower_16_bits(n) ((u16)((n) & 0xffff))

/**
 * REPEAT_BYTE - repeat the value @x multiple times as an unsigned long value
 * @x: value to repeat
 *
 * NOTE: @x is not checked for > 0xff; larger values produce odd results.
 */
#define REPEAT_BYTE(x)	((~0ul / 0xff) * (x))

/**
 * REPEAT_BYTE_U32 - repeat the value @x multiple times as a u32 value
 * @x: value to repeat
 *
 * NOTE: @x is not checked for > 0xff; larger values produce odd results.
 */
#define REPEAT_BYTE_U32(x)	lower_32_bits(REPEAT_BYTE(x))

/* Set bits in the first 'n' bytes when loaded from memory */
#ifdef __LITTLE_ENDIAN
#  define aligned_byte_mask(n) ((1UL << 8*(n))-1)
#else
#  define aligned_byte_mask(n) (~0xffUL << (BITS_PER_LONG - 8 - 8*(n)))
#endif

#endif // _LINUX_WORDPART_H
Commit	Line	Data
66a5c40f TH	1	/* SPDX-License-Identifier: GPL-2.0 */
	2
	3	#ifndef _LINUX_WORDPART_H
	4	#define _LINUX_WORDPART_H
adeb0436 AS	5
	6	/**
	7	* upper_32_bits - return bits 32-63 of a number
	8	* @n: the number we're accessing
	9	*
	10	* A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
	11	* the "right shift count >= width of type" warning when that quantity is
	12	* 32-bits.
	13	*/
	14	#define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
	15
	16	/**
	17	* lower_32_bits - return bits 0-31 of a number
	18	* @n: the number we're accessing
	19	*/
	20	#define lower_32_bits(n) ((u32)((n) & 0xffffffff))
	21
	22	/**
	23	* upper_16_bits - return bits 16-31 of a number
	24	* @n: the number we're accessing
	25	*/
	26	#define upper_16_bits(n) ((u16)((n) >> 16))
	27
	28	/**
	29	* lower_16_bits - return bits 0-15 of a number
	30	* @n: the number we're accessing
	31	*/
	32	#define lower_16_bits(n) ((u16)((n) & 0xffff))
	33
66a5c40f TH	34	/**
	35	* REPEAT_BYTE - repeat the value @x multiple times as an unsigned long value
	36	* @x: value to repeat
	37	*
	38	* NOTE: @x is not checked for > 0xff; larger values produce odd results.
	39	*/
	40	#define REPEAT_BYTE(x) ((~0ul / 0xff) * (x))
	41
118d777c MR	42	/**
	43	* REPEAT_BYTE_U32 - repeat the value @x multiple times as a u32 value
	44	* @x: value to repeat
	45	*
	46	* NOTE: @x is not checked for > 0xff; larger values produce odd results.
	47	*/
	48	#define REPEAT_BYTE_U32(x) lower_32_bits(REPEAT_BYTE(x))
	49
9f2c2d6b AS	50	/* Set bits in the first 'n' bytes when loaded from memory */
	51	#ifdef __LITTLE_ENDIAN
	52	# define aligned_byte_mask(n) ((1UL << 8*(n))-1)
	53	#else
	54	# define aligned_byte_mask(n) (~0xffUL << (BITS_PER_LONG - 8 - 8*(n)))
	55	#endif
	56
66a5c40f	57	#endif // _LINUX_WORDPART_H