Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2
3#ifndef _LINUX_WORDPART_H
4#define _LINUX_WORDPART_H
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
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
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
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
57#endif // _LINUX_WORDPART_H