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authorAndrew Morton <akpm@linux-foundation.org>2008-07-23 15:35:22 -0700
committerRussell King <rmk+kernel@arm.linux.org.uk>2008-07-26 15:23:25 +0100
commit0c65f459ce6c8bd873a61b3ae1e57858ab1debf3 (patch)
treefc0bfcedd17e63cfd7aca3a12d07a4c4da931070
parent[ARM] fix mode for board-yl-9200.c (diff)
downloadlinux-dev-0c65f459ce6c8bd873a61b3ae1e57858ab1debf3.tar.xz
linux-dev-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>
Diffstat (limited to '')
-rw-r--r--include/asm-arm/bitops.h9
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) )