diff options
author | Ingo Molnar <mingo@elte.hu> | 2009-04-29 14:46:59 +0200 |
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committer | Ingo Molnar <mingo@elte.hu> | 2009-04-29 14:47:05 +0200 |
commit | e7fd5d4b3d240f42c30a9e3d20a4689c4d3a795a (patch) | |
tree | 4ba588631dd8189a818a91c9e3976526071178b6 /include/linux/bitops.h | |
parent | 1130b0296184bc21806225fd06d533515a99d2db (diff) | |
parent | 56a50adda49b2020156616c4eb15353e0f9ad7de (diff) |
Merge branch 'linus' into perfcounters/core
Merge reason: This brach was on -rc1, refresh it to almost-rc4 to pick up
the latest upstream fixes.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/bitops.h')
-rw-r--r-- | include/linux/bitops.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/bitops.h b/include/linux/bitops.h index 61829139795a..c05a29cb9bb2 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -112,6 +112,25 @@ static inline unsigned fls_long(unsigned long 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); +} + #ifdef __KERNEL__ #ifdef CONFIG_GENERIC_FIND_FIRST_BIT |