ARM: 8187/1: add CONFIG_HAVE_ARCH_BITREVERSE to support rbit instruction
this change add CONFIG_HAVE_ARCH_BITREVERSE config option, so that we can use some architecture's bitrev hardware instruction to do bitrev operation. Introduce __constant_bitrev* macro for constant bitrev operation. Change __bitrev16() __bitrev32() to be inline function, don't need export symbol for these tiny functions. Signed-off-by: Yalin Wang <yalin.wang@sonymobile.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
parent
97bf6af1f9
commit
556d2f055b
3 changed files with 84 additions and 19 deletions
|
@ -3,14 +3,83 @@
|
|||
|
||||
#include <linux/types.h>
|
||||
|
||||
extern u8 const byte_rev_table[256];
|
||||
#ifdef CONFIG_HAVE_ARCH_BITREVERSE
|
||||
#include <asm/bitrev.h>
|
||||
|
||||
static inline u8 bitrev8(u8 byte)
|
||||
#define __bitrev32 __arch_bitrev32
|
||||
#define __bitrev16 __arch_bitrev16
|
||||
#define __bitrev8 __arch_bitrev8
|
||||
|
||||
#else
|
||||
extern u8 const byte_rev_table[256];
|
||||
static inline u8 __bitrev8(u8 byte)
|
||||
{
|
||||
return byte_rev_table[byte];
|
||||
}
|
||||
|
||||
extern u16 bitrev16(u16 in);
|
||||
extern u32 bitrev32(u32 in);
|
||||
static inline u16 __bitrev16(u16 x)
|
||||
{
|
||||
return (__bitrev8(x & 0xff) << 8) | __bitrev8(x >> 8);
|
||||
}
|
||||
|
||||
static inline u32 __bitrev32(u32 x)
|
||||
{
|
||||
return (__bitrev16(x & 0xffff) << 16) | __bitrev16(x >> 16);
|
||||
}
|
||||
|
||||
#endif /* CONFIG_HAVE_ARCH_BITREVERSE */
|
||||
|
||||
#define __constant_bitrev32(x) \
|
||||
({ \
|
||||
u32 __x = x; \
|
||||
__x = (__x >> 16) | (__x << 16); \
|
||||
__x = ((__x & (u32)0xFF00FF00UL) >> 8) | ((__x & (u32)0x00FF00FFUL) << 8); \
|
||||
__x = ((__x & (u32)0xF0F0F0F0UL) >> 4) | ((__x & (u32)0x0F0F0F0FUL) << 4); \
|
||||
__x = ((__x & (u32)0xCCCCCCCCUL) >> 2) | ((__x & (u32)0x33333333UL) << 2); \
|
||||
__x = ((__x & (u32)0xAAAAAAAAUL) >> 1) | ((__x & (u32)0x55555555UL) << 1); \
|
||||
__x; \
|
||||
})
|
||||
|
||||
#define __constant_bitrev16(x) \
|
||||
({ \
|
||||
u16 __x = x; \
|
||||
__x = (__x >> 8) | (__x << 8); \
|
||||
__x = ((__x & (u16)0xF0F0U) >> 4) | ((__x & (u16)0x0F0FU) << 4); \
|
||||
__x = ((__x & (u16)0xCCCCU) >> 2) | ((__x & (u16)0x3333U) << 2); \
|
||||
__x = ((__x & (u16)0xAAAAU) >> 1) | ((__x & (u16)0x5555U) << 1); \
|
||||
__x; \
|
||||
})
|
||||
|
||||
#define __constant_bitrev8(x) \
|
||||
({ \
|
||||
u8 __x = x; \
|
||||
__x = (__x >> 4) | (__x << 4); \
|
||||
__x = ((__x & (u8)0xCCU) >> 2) | ((__x & (u8)0x33U) << 2); \
|
||||
__x = ((__x & (u8)0xAAU) >> 1) | ((__x & (u8)0x55U) << 1); \
|
||||
__x; \
|
||||
})
|
||||
|
||||
#define bitrev32(x) \
|
||||
({ \
|
||||
u32 __x = x; \
|
||||
__builtin_constant_p(__x) ? \
|
||||
__constant_bitrev32(__x) : \
|
||||
__bitrev32(__x); \
|
||||
})
|
||||
|
||||
#define bitrev16(x) \
|
||||
({ \
|
||||
u16 __x = x; \
|
||||
__builtin_constant_p(__x) ? \
|
||||
__constant_bitrev16(__x) : \
|
||||
__bitrev16(__x); \
|
||||
})
|
||||
|
||||
#define bitrev8(x) \
|
||||
({ \
|
||||
u8 __x = x; \
|
||||
__builtin_constant_p(__x) ? \
|
||||
__constant_bitrev8(__x) : \
|
||||
__bitrev8(__x) ; \
|
||||
})
|
||||
#endif /* _LINUX_BITREV_H */
|
||||
|
|
|
@ -13,6 +13,15 @@ config RAID6_PQ
|
|||
config BITREVERSE
|
||||
tristate
|
||||
|
||||
config HAVE_ARCH_BITREVERSE
|
||||
boolean
|
||||
default n
|
||||
depends on BITREVERSE
|
||||
help
|
||||
This option provides an config for the architecture which have instruction
|
||||
can do bitreverse operation, we use the hardware instruction if the architecture
|
||||
have this capability.
|
||||
|
||||
config RATIONAL
|
||||
boolean
|
||||
|
||||
|
|
17
lib/bitrev.c
17
lib/bitrev.c
|
@ -1,3 +1,4 @@
|
|||
#ifndef CONFIG_HAVE_ARCH_BITREVERSE
|
||||
#include <linux/types.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/bitrev.h>
|
||||
|
@ -42,18 +43,4 @@ const u8 byte_rev_table[256] = {
|
|||
};
|
||||
EXPORT_SYMBOL_GPL(byte_rev_table);
|
||||
|
||||
u16 bitrev16(u16 x)
|
||||
{
|
||||
return (bitrev8(x & 0xff) << 8) | bitrev8(x >> 8);
|
||||
}
|
||||
EXPORT_SYMBOL(bitrev16);
|
||||
|
||||
/**
|
||||
* bitrev32 - reverse the order of bits in a u32 value
|
||||
* @x: value to be bit-reversed
|
||||
*/
|
||||
u32 bitrev32(u32 x)
|
||||
{
|
||||
return (bitrev16(x & 0xffff) << 16) | bitrev16(x >> 16);
|
||||
}
|
||||
EXPORT_SYMBOL(bitrev32);
|
||||
#endif /* CONFIG_HAVE_ARCH_BITREVERSE */
|
||||
|
|
Loading…
Reference in a new issue