Linux kernel mirror (for testing)
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linux
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_ULL(nr) (ULL(1) << (nr))
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 (!defined(CONFIG_CC_IS_GCC) || CONFIG_GCC_VERSION >= 49000)
23#include <linux/build_bug.h>
24#define GENMASK_INPUT_CHECK(h, l) \
25 (BUILD_BUG_ON_ZERO(__builtin_choose_expr( \
26 __builtin_constant_p((l) > (h)), (l) > (h), 0)))
27#else
28/*
29 * BUILD_BUG_ON_ZERO is not available in h files included from asm files,
30 * disable the input check if that is the case.
31 */
32#define GENMASK_INPUT_CHECK(h, l) 0
33#endif
34
35#define __GENMASK(h, l) \
36 (((~UL(0)) - (UL(1) << (l)) + 1) & \
37 (~UL(0) >> (BITS_PER_LONG - 1 - (h))))
38#define GENMASK(h, l) \
39 (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
40
41#define __GENMASK_ULL(h, l) \
42 (((~ULL(0)) - (ULL(1) << (l)) + 1) & \
43 (~ULL(0) >> (BITS_PER_LONG_LONG - 1 - (h))))
44#define GENMASK_ULL(h, l) \
45 (GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l))
46
47#endif /* __LINUX_BITS_H */