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Diffstat (limited to 'include/linux/wordpart.h')
-rw-r--r-- | include/linux/wordpart.h | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/include/linux/wordpart.h b/include/linux/wordpart.h new file mode 100644 index 000000000000..5a7b97bb7c95 --- /dev/null +++ b/include/linux/wordpart.h @@ -0,0 +1,57 @@ +/* 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 |