diff options
| author | Angelo Dureghello <angelo@sysam.it> | 2018-08-04 23:02:56 +0200 |
|---|---|---|
| committer | Angelo Dureghello <angelo@sysam.it> | 2018-09-16 00:01:13 +0200 |
| commit | faae49543a0b366087cb733c26f8c581b17abe82 (patch) | |
| tree | d695c1badfaa25d5332f51bae7509980c4b5a1d1 /arch/m68k | |
| parent | a1ed3a83be63bfc6e817854b29c9c0572a86bea7 (diff) | |
m68k: fix multiple memory accesses on swap operations
On a
u32 val = __sw32(*addr);
multiple memory accesses are not welcome, since "addr" may
be an IO peripheral register address.
This patch changes __sw16/32 to perform a single memory
access for the source value.
Signed-off-by: Angelo Dureghello <angelo@sysam.it>
Diffstat (limited to 'arch/m68k')
| -rw-r--r-- | arch/m68k/include/asm/byteorder.h | 34 |
1 files changed, 20 insertions, 14 deletions
diff --git a/arch/m68k/include/asm/byteorder.h b/arch/m68k/include/asm/byteorder.h index eb03b6a053..9179622250 100644 --- a/arch/m68k/include/asm/byteorder.h +++ b/arch/m68k/include/asm/byteorder.h @@ -10,21 +10,28 @@ #include <asm/types.h> #ifdef __GNUC__ -#define __sw16(x) \ - ((__u16)( \ - (((__u16)(x) & (__u16)0x00ffU) << 8) | \ - (((__u16)(x) & (__u16)0xff00U) >> 8) )) -#define __sw32(x) \ - ((__u32)( \ - (((__u32)(x)) << 24) | \ - (((__u32)(x) & (__u32)0x0000ff00UL) << 8) | \ - (((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \ - (((__u32)(x)) >> 24) )) + +static inline __u32 __sw32(__u32 x) +{ + __u32 v = x; + + return v << 24 | + (v & (__u32)0x0000ff00UL) << 8 | + (v & (__u32)0x00ff0000UL) >> 8 | + v >> 24; +} + +static inline __u16 __sw16(__u16 x) +{ + __u16 v = x; + + return (v & (__u16)0x00ffU) << 8 | + (v & (__u16)0xff00U) >> 8; +} static __inline__ unsigned ld_le16(const volatile unsigned short *addr) { - unsigned result = *addr; - return __sw16(result); + return __sw16(*addr); } static __inline__ void st_le16(volatile unsigned short *addr, @@ -35,8 +42,7 @@ static __inline__ void st_le16(volatile unsigned short *addr, static __inline__ unsigned ld_le32(const volatile unsigned *addr) { - unsigned result = *addr; - return __sw32(result); + return __sw32(*addr); } static __inline__ void st_le32(volatile unsigned *addr, const unsigned val) |