From: Srinivas Kandagatla <[email protected]> This patch introduces BITS_MASK macro which creates a mask for a given lsb and msb bit locations. The usage of masks spread over mutiple bits is becoming very common for example with regmap_update_bits kind of apis. Having a common macro for this makes much sense and is clean and readable way to encode the mask rather than having an hex number for a mask.
Signed-off-by: Srinivas Kandagatla <[email protected]> --- include/linux/bitops.h | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/include/linux/bitops.h b/include/linux/bitops.h index a3b6b82..3ddce97 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -5,6 +5,7 @@ #ifdef __KERNEL__ #define BIT(nr) (1UL << (nr)) #define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG)) +#define BITS_MASK(lsb, msb) ((BIT(msb - lsb + 1) - 1) << lsb) #define BIT_WORD(nr) ((nr) / BITS_PER_LONG) #define BITS_PER_BYTE 8 #define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long)) -- 1.7.6.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
