xref: /openbmc/linux/include/linux/bits.h (revision 04b3c795)
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 */
48