diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/bitops.h | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/include/linux/bitops.h b/include/linux/bitops.h index 7b4011f..1b2e491 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -2,6 +2,7 @@ #define _LINUX_BITOPS_H #include <asm/types.h> +#include <linux/compiler.h> #define BIT(nr) (1UL << (nr)) #define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG)) @@ -139,6 +140,32 @@ static inline unsigned int generic_hweight8(unsigned int w) # define fls generic_fls #endif +static inline unsigned fls_long(unsigned long l) +{ + if (sizeof(l) == 4) + return fls(l); + return fls64(l); +} + +/** + * __ffs64 - find first set bit in a 64 bit word + * @word: The 64 bit word + * + * On 64 bit arches this is a synomyn for __ffs + * The result is not defined if no bits are set, so check that @word + * is non-zero before calling this. + */ +static inline unsigned long __ffs64(u64 word) +{ +#if BITS_PER_LONG == 32 + if (((u32)word) == 0UL) + return __ffs((u32)(word >> 32)) + 32; +#elif BITS_PER_LONG != 64 +#error BITS_PER_LONG not 32 or 64 +#endif + return __ffs((unsigned long)word); +} + /** * __set_bit - Set a bit in memory * @nr: the bit to set |