From 962749af67b145c57917bfbff3c303ebd7d5988c Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Sat, 25 Mar 2006 03:08:01 -0800 Subject: [PATCH] [PATCH] roundup_pow_of_two() 64-bit fix fls() takes an integer, so roundup_pow_of_two() is busted for ulongs larger than 2^32-1. Fix this by implementing and using fls_long(). (Why does roundup_pow_of_two() return a long?) (Why is roundup_pow_of_two() __attribute_const__ whereas long_log2() is __attribute_pure__?) (Why does long_log2() suck so much? Because we were missing fls_long()?) Cc: Roland Dreier Cc: "Chen, Kenneth W" Cc: John Hawkes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/bitops.h | 7 +++++++ include/linux/kernel.h | 5 +++-- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/include/linux/bitops.h b/include/linux/bitops.h index 208650b..f17525a 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -175,4 +175,11 @@ static inline __u32 ror32(__u32 word, unsigned int shift) return (word >> shift) | (word << (32 - shift)); } +static inline unsigned fls_long(unsigned long l) +{ + if (sizeof(l) == 4) + return fls(l); + return fls64(l); +} + #endif diff --git a/include/linux/kernel.h b/include/linux/kernel.h index bb6e7dd..03d6cfa 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -154,9 +154,10 @@ static inline int __attribute_pure__ long_log2(unsigned long x) return r; } -static inline unsigned long __attribute_const__ roundup_pow_of_two(unsigned long x) +static inline unsigned long +__attribute_const__ roundup_pow_of_two(unsigned long x) { - return (1UL << fls(x - 1)); + return 1UL << fls_long(x - 1); } extern int printk_ratelimit(void); -- 2.7.4