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authorNicolas Pitre <nico@cam.org>2008-12-04 03:59:41 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2008-12-04 09:21:55 +0000
commit94fc7336646b392234c0fafea5d696d020c3677c (patch)
tree95137c3233bf0d4f07a52e8529122dfa284a5353 /arch/arm
parent82676d76252680fc035247fd4cfdb07ffce5db52 (diff)
[ARM] 5339/1: fix __fls() on ARM
Commit 0c65f459ce6c intended to fix truncation issues with fls() on ARMv5+ by renaming it to __fls() and wrapping it into a C function. However that didn't take into account the fact that __fls() already already had different semantics in the kernel. Let's move the __fls() code into fls() function directly, and redefine __fls() with the appropriate semantics. While at it, bring a generic __fls() definition for pre ARMv5 too. Signed-off-by: Nicolas Pitre <nico@marvell.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/include/asm/bitops.h16
1 files changed, 10 insertions, 6 deletions
diff --git a/arch/arm/include/asm/bitops.h b/arch/arm/include/asm/bitops.h
index 9a1db20e032..63a481fbbed 100644
--- a/arch/arm/include/asm/bitops.h
+++ b/arch/arm/include/asm/bitops.h
@@ -237,6 +237,7 @@ extern int _find_next_bit_be(const unsigned long *p, int size, int offset);
#if __LINUX_ARM_ARCH__ < 5
#include <asm-generic/bitops/ffz.h>
+#include <asm-generic/bitops/__fls.h>
#include <asm-generic/bitops/__ffs.h>
#include <asm-generic/bitops/fls.h>
#include <asm-generic/bitops/ffs.h>
@@ -277,16 +278,19 @@ static inline int constant_fls(int x)
* the clz instruction for much better code efficiency.
*/
-#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);
+ int ret;
+
+ if (__builtin_constant_p(x))
+ return constant_fls(x);
+
+ asm("clz\t%0, %1" : "=r" (ret) : "r" (x) : "cc");
+ ret = 32 - ret;
+ return ret;
}
+#define __fls(x) (fls(x) - 1)
#define ffs(x) ({ unsigned long __t = (x); fls(__t & -__t); })
#define __ffs(x) (ffs(x) - 1)
#define ffz(x) __ffs( ~(x) )