1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __LINUX_BITS_H
3#define __LINUX_BITS_H
4
5#include <linux/const.h>
6#include <vdso/bits.h>
7#include <uapi/linux/bits.h>
8#include <asm/bitsperlong.h>
9
10#define BIT_MASK(nr)		(UL(1) << ((nr) % BITS_PER_LONG))
11#define BIT_WORD(nr)		((nr) / BITS_PER_LONG)
12#define BIT_ULL_MASK(nr)	(ULL(1) << ((nr) % BITS_PER_LONG_LONG))
13#define BIT_ULL_WORD(nr)	((nr) / BITS_PER_LONG_LONG)
14#define BITS_PER_BYTE		8
15
16/*
17 * Create a contiguous bitmask starting at bit position @l and ending at
18 * position @h. For example
19 * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
20 */
21#if !defined(__ASSEMBLY__)
22#include <linux/build_bug.h>
23#define GENMASK_INPUT_CHECK(h, l) \
24	(BUILD_BUG_ON_ZERO(__builtin_choose_expr( \
25		__is_constexpr((l) > (h)), (l) > (h), 0)))
26#else
27/*
28 * BUILD_BUG_ON_ZERO is not available in h files included from asm files,
29 * disable the input check if that is the case.
30 */
31#define GENMASK_INPUT_CHECK(h, l) 0
32#endif
33
34#define GENMASK(h, l) \
35	(GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
36#define GENMASK_ULL(h, l) \
37	(GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l))
38
39#endif	/* __LINUX_BITS_H */
40