[RFC PATCH 09/18] powerpc/boot: define byteswapping routines for little endian
From: Cédric Le Goater <hidden>
Date: 2014-02-07 15:59:53
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
These are not the most efficient versions of swab but the wrapper does not do much byte swapping. On a big endian cpu, these routines are a no-op. Signed-off-by: Cédric Le Goater <redacted> --- arch/powerpc/boot/of.h | 7 +++++++ arch/powerpc/boot/swab.h | 29 +++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+) create mode 100644 arch/powerpc/boot/swab.h
diff --git a/arch/powerpc/boot/of.h b/arch/powerpc/boot/of.h
index bf228fea3517..fc71848f6962 100644
--- a/arch/powerpc/boot/of.h
+++ b/arch/powerpc/boot/of.h@@ -1,6 +1,8 @@ #ifndef _PPC_BOOT_OF_H_ #define _PPC_BOOT_OF_H_ +#include "swab.h" + typedef void *phandle; typedef u32 ihandle;
@@ -21,7 +23,12 @@ void of_console_init(void); typedef u32 __be32; +#ifdef __LITTLE_ENDIAN__ +#define cpu_to_be32(x) swab32(x) +#define be32_to_cpu(x) swab32(x) +#else #define cpu_to_be32(x) (x) #define be32_to_cpu(x) (x) +#endif #endif /* _PPC_BOOT_OF_H_ */
diff --git a/arch/powerpc/boot/swab.h b/arch/powerpc/boot/swab.h
new file mode 100644
index 000000000000..d0e1431084ca
--- /dev/null
+++ b/arch/powerpc/boot/swab.h@@ -0,0 +1,29 @@ +#ifndef _PPC_BOOT_SWAB_H_ +#define _PPC_BOOT_SWAB_H_ + +static inline u16 swab16(u16 x) +{ + return ((x & (u16)0x00ffU) << 8) | + ((x & (u16)0xff00U) >> 8); +} + +static inline u32 swab32(u32 x) +{ + return ((x & (u32)0x000000ffUL) << 24) | + ((x & (u32)0x0000ff00UL) << 8) | + ((x & (u32)0x00ff0000UL) >> 8) | + ((x & (u32)0xff000000UL) >> 24); +} + +static inline u64 swab64(u64 x) +{ + return (u64)((x & (u64)0x00000000000000ffULL) << 56) | + (u64)((x & (u64)0x000000000000ff00ULL) << 40) | + (u64)((x & (u64)0x0000000000ff0000ULL) << 24) | + (u64)((x & (u64)0x00000000ff000000ULL) << 8) | + (u64)((x & (u64)0x000000ff00000000ULL) >> 8) | + (u64)((x & (u64)0x0000ff0000000000ULL) >> 24) | + (u64)((x & (u64)0x00ff000000000000ULL) >> 40) | + (u64)((x & (u64)0xff00000000000000ULL) >> 56); +} +#endif /* _PPC_BOOT_SWAB_H_ */
--
1.7.10.4