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bitops: Introduce a more generic BITMASK macro

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This patch is back-porting the generic _portion_ of
10ef6b0dff to 3.10

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
This commit is contained in:
Mathieu Poirier 2014-12-09 14:38:21 -07:00
parent 54d37488ba
commit bfab9062c7
1 changed files with 8 additions and 0 deletions
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8
include/linux/bitops.h
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@ -10,6 +10,14 @@
#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
#endif
/*
* Create a contiguous bitmask starting at bit position @l and ending at
* position @h. For example
* GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
*/
#define GENMASK(h, l) (((U32_C(1) << ((h) - (l) + 1)) - 1) << (l))
#define GENMASK_ULL(h, l) (((U64_C(1) << ((h) - (l) + 1)) - 1) << (l))
extern unsigned int __sw_hweight8(unsigned int w);
extern unsigned int __sw_hweight16(unsigned int w);
extern unsigned int __sw_hweight32(unsigned int w);