diff options
| author |   Robert P. J. Day <rpjday@mindspring.com> | 2007-01-30 06:06:00 -0500 |
|---|---|---|
| committer |   Paul Mackerras <paulus@samba.org> | 2007-02-07 14:03:19 +1100 |
| commit | 63c2f782e8f6aafbc11b14b2cb291b3dc9fc217d (patch) | |
| tree | cbcd1f138a886529ec62a21c5dd4b2c87581058d | |
| parent | [POWERPC] MPIC: support more than 256 sources (diff) | |
| download | linux-dev-63c2f782e8f6aafbc11b14b2cb291b3dc9fc217d.tar.xz linux-dev-63c2f782e8f6aafbc11b14b2cb291b3dc9fc217d.zip | |
[POWERPC] Add "is_power_of_2" checking to log2.h.
Add the inline function "is_power_of_2()" to log2.h, where the value
zero is *not* considered to be a power of two.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
| -rw-r--r-- | arch/powerpc/mm/pgtable_32.c | 5 | ||||
| -rw-r--r-- | arch/ppc/mm/pgtable.c | 5 | ||||
| -rw-r--r-- | arch/ppc/syslib/ppc85xx_rio.c | 2 | ||||
| -rw-r--r-- | drivers/net/gianfar_ethtool.c | 2 | ||||
| -rw-r--r-- | include/linux/log2.h | 11 |
5 files changed, 13 insertions, 12 deletions
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c index 1891dbeeb8e9..bd02272bcb0f 100644 --- a/arch/powerpc/mm/pgtable_32.c +++ b/arch/powerpc/mm/pgtable_32.c @@ -294,11 +294,8 @@ void __init mapin_ram(void) } } -/* is x a power of 2? */ -#define is_power_of_2(x) ((x) != 0 && (((x) & ((x) - 1)) == 0)) - /* is x a power of 4? */ -#define is_power_of_4(x) ((x) != 0 && (((x) & (x-1)) == 0) && (ffs(x) & 1)) +#define is_power_of_4(x) is_power_of_2(x) && (ffs(x) & 1)) /* * Set up a mapping for a block of I/O. diff --git a/arch/ppc/mm/pgtable.c b/arch/ppc/mm/pgtable.c index 354a9408f024..82b06a1ef95d 100644 --- a/arch/ppc/mm/pgtable.c +++ b/arch/ppc/mm/pgtable.c @@ -313,11 +313,8 @@ void __init mapin_ram(void) } } -/* is x a power of 2? */ -#define is_power_of_2(x) ((x) != 0 && (((x) & ((x) - 1)) == 0)) - /* is x a power of 4? */ -#define is_power_of_4(x) ((x) != 0 && (((x) & (x-1)) == 0) && (ffs(x) & 1)) +#define is_power_of_4(x) is_power_of_2(x) && (ffs(x) & 1)) /* * Set up a mapping for a block of I/O. diff --git a/arch/ppc/syslib/ppc85xx_rio.c b/arch/ppc/syslib/ppc85xx_rio.c index 05b0e9415085..2b097800cdd9 100644 --- a/arch/ppc/syslib/ppc85xx_rio.c +++ b/arch/ppc/syslib/ppc85xx_rio.c @@ -59,8 +59,6 @@ #define DBELL_TID(x) (*(u8 *)(x + DOORBELL_TID_OFFSET)) #define DBELL_INF(x) (*(u16 *)(x + DOORBELL_INFO_OFFSET)) -#define is_power_of_2(x) (((x) & ((x) - 1)) == 0) - struct rio_atmu_regs { u32 rowtar; u32 pad1; diff --git a/drivers/net/gianfar_ethtool.c b/drivers/net/gianfar_ethtool.c index 6d71bea5e900..0d6943d67096 100644 --- a/drivers/net/gianfar_ethtool.c +++ b/drivers/net/gianfar_ethtool.c @@ -42,8 +42,6 @@ #include "gianfar.h" -#define is_power_of_2(x) ((x) != 0 && (((x) & ((x) - 1)) == 0)) - extern void gfar_start(struct net_device *dev); extern int gfar_clean_rx_ring(struct net_device *dev, int rx_work_limit); diff --git a/include/linux/log2.h b/include/linux/log2.h index d02e1a547a7e..99922bedfcc9 100644 --- a/include/linux/log2.h +++ b/include/linux/log2.h @@ -44,6 +44,17 @@ int __ilog2_u64(u64 n) #endif /* + * Determine whether some value is a power of two, where zero is + * *not* considered a power of two. + */ + +static inline __attribute__((const)) +bool is_power_of_2(unsigned long n) +{ + return (n != 0 && ((n & (n - 1)) == 0)); +} + +/* * round up to nearest power of two */ static inline __attribute__((const)) |