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| author | Andrew Morton <akpm@linux-foundation.org> | 2008-07-24 00:35:22 +0200 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2008-07-26 16:23:25 +0200 |
| commit | 0c65f459ce6c8bd873a61b3ae1e57858ab1debf3 (patch) | |
| tree | fc0bfcedd17e63cfd7aca3a12d07a4c4da931070 | |
| parent | [ARM] fix mode for board-yl-9200.c (diff) | |
| download | linux-0c65f459ce6c8bd873a61b3ae1e57858ab1debf3.tar.xz linux-0c65f459ce6c8bd873a61b3ae1e57858ab1debf3.zip | |
[ARM] fix fls() for 64-bit arguments
arm's fls() is implemented as a macro, causing it to misbehave when passed
64-bit arguments. Fix.
Cc: Nickolay Vinogradov <nickolay@protei.ru>
Tested-by: Krzysztof Halasa <khc@pm.waw.pl>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | include/asm-arm/bitops.h | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/include/asm-arm/bitops.h b/include/asm-arm/bitops.h index 5c60bfc1a84d..9a1db20e032a 100644 --- a/include/asm-arm/bitops.h +++ b/include/asm-arm/bitops.h @@ -277,9 +277,16 @@ static inline int constant_fls(int x) * the clz instruction for much better code efficiency. */ -#define fls(x) \ +#define __fls(x) \ ( __builtin_constant_p(x) ? constant_fls(x) : \ ({ int __r; asm("clz\t%0, %1" : "=r"(__r) : "r"(x) : "cc"); 32-__r; }) ) + +/* Implement fls() in C so that 64-bit args are suitably truncated */ +static inline int fls(int x) +{ + return __fls(x); +} + #define ffs(x) ({ unsigned long __t = (x); fls(__t & -__t); }) #define __ffs(x) (ffs(x) - 1) #define ffz(x) __ffs( ~(x) ) |