From: Rob Herring rob.herring@calxeda.com
Add __ilog2 function for ARM. Needed for ahci.c
Signed-off-by: Rob Herring rob.herring@calxeda.com --- arch/arm/include/asm/bitops.h | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/arch/arm/include/asm/bitops.h b/arch/arm/include/asm/bitops.h index 270f163..0420182 100644 --- a/arch/arm/include/asm/bitops.h +++ b/arch/arm/include/asm/bitops.h @@ -106,6 +106,15 @@ static inline int test_bit(int nr, const void * addr) return ((unsigned char *) addr)[nr >> 3] & (1U << (nr & 7)); }
+extern __inline__ int __ilog2(unsigned int x) +{ + int ret; + + asm("clz\t%0, %1" : "=r" (ret) : "r" (x)); + ret = 31 - ret; + return ret; +} + /* * ffz = Find First Zero in word. Undefined if no zero exists, * so code should check against ~0UL first..