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 <asm/bitsperlong.h>
8
9#define BIT_MASK(nr)		(UL(1) << ((nr) % BITS_PER_LONG))
10#define BIT_WORD(nr)		((nr) / BITS_PER_LONG)
11#define BIT_ULL_MASK(nr)	(ULL(1) << ((nr) % BITS_PER_LONG_LONG))
12#define BIT_ULL_WORD(nr)	((nr) / BITS_PER_LONG_LONG)
13#define BITS_PER_BYTE		8
14
15/*
16 * Create a contiguous bitmask starting at bit position @l and ending at
17 * position @h. For example
18 * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
19 */
20#if !defined(__ASSEMBLY__)
21#include <linux/build_bug.h>
22#define GENMASK_INPUT_CHECK(h, l) \
23	(BUILD_BUG_ON_ZERO(__builtin_choose_expr( \
24		__is_constexpr((l) > (h)), (l) > (h), 0)))
25#else
26/*
27 * BUILD_BUG_ON_ZERO is not available in h files included from asm files,
28 * disable the input check if that is the case.
29 */
30#define GENMASK_INPUT_CHECK(h, l) 0
31#endif
32
33#define __GENMASK(h, l) \
34	(((~UL(0)) - (UL(1) << (l)) + 1) & \
35	 (~UL(0) >> (BITS_PER_LONG - 1 - (h))))
36#define GENMASK(h, l) \
37	(GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
38
39#define __GENMASK_ULL(h, l) \
40	(((~ULL(0)) - (ULL(1) << (l)) + 1) & \
41	 (~ULL(0) >> (BITS_PER_LONG_LONG - 1 - (h))))
42#define GENMASK_ULL(h, l) \
43	(GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l))
44
45#endif	/* __LINUX_BITS_H */
46