xref: /openbmc/linux/include/linux/bits.h (revision bbaf1ff0)
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