diff options
| author | Mathieu Poirier <mathieu.poirier@linaro.org> | 2014-12-09 14:38:21 -0700 |
|---|---|---|
| committer | Mathieu Poirier <mathieu.poirier@linaro.org> | 2014-12-22 10:49:12 -0700 |
| commit | bfab9062c7be44b3a255d478bda5d4a7a3dba7e2 (patch) | |
| tree | 84a02dbf8602a2fe926131b0d34deb53a36adc44 | |
| parent | 54d37488baccb0b31610458ac9833591b76de1e4 (diff) | |
bitops: Introduce a more generic BITMASK macro
This patch is back-porting the generic _portion_ of
10ef6b0dffe404bcc54e94cb2ca1a5b18445a66b to 3.10
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
| -rw-r--r-- | include/linux/bitops.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/bitops.h b/include/linux/bitops.h index a3b6b82108b9..bd0c4598d03b 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -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); |