endian: #define __BYTE_ORDER

Joakim Tjernlund · torvalds · commit b3b77c8caef1 · 2010-05-25T08:07:02.000-07:00
Linux does not define __BYTE_ORDER in its endian header files which makes
some header files bend backwards to get at the current endian.  Lets
#define __BYTE_ORDER in big_endian.h/litte_endian.h to make it easier for
header files that are used in user space too.

In userspace the convention is that

  1. _both_ __LITTLE_ENDIAN and __BIG_ENDIAN are defined,
  2. you have to test for e.g. __BYTE_ORDER == __BIG_ENDIAN.

Signed-off-by: Joakim Tjernlund &lt;Joakim.Tjernlund@transmode.se&gt;
Cc: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
diff --git a/arch/alpha/math-emu/sfp-util.h b/arch/alpha/math-emu/sfp-util.h
@@ -28,8 +28,3 @@ extern unsigned long __udiv_qrnnd (unsigned long *, unsigned long,
 #define UDIV_NEEDS_NORMALIZATION 1  
 
 #define abort()			goto bad_insn
-
-#ifndef __LITTLE_ENDIAN
-#define __LITTLE_ENDIAN -1
-#endif
-#define __BYTE_ORDER __LITTLE_ENDIAN
diff --git a/arch/powerpc/include/asm/sfp-machine.h b/arch/powerpc/include/asm/sfp-machine.h
@@ -353,12 +353,6 @@
 #define abort()								\
 	return 0
 
-#ifdef __BIG_ENDIAN
-#define __BYTE_ORDER __BIG_ENDIAN
-#else
-#define __BYTE_ORDER __LITTLE_ENDIAN
-#endif
-
 /* Exception flags. */
 #define EFLAG_INVALID		(1 << (31 - 2))
 #define EFLAG_OVERFLOW		(1 << (31 - 3))
diff --git a/arch/s390/include/asm/sfp-util.h b/arch/s390/include/asm/sfp-util.h
@@ -73,5 +73,3 @@ extern unsigned long __udiv_qrnnd (unsigned int *, unsigned int,
 #define UDIV_NEEDS_NORMALIZATION 0
 
 #define abort() return 0
-
-#define __BYTE_ORDER __BIG_ENDIAN
diff --git a/arch/sh/math-emu/sfp-util.h b/arch/sh/math-emu/sfp-util.h
@@ -66,7 +66,3 @@
   } while (0)
 
 #define abort()	return 0
-
-#define __BYTE_ORDER __LITTLE_ENDIAN
-
-
diff --git a/arch/sparc/math-emu/sfp-util_32.h b/arch/sparc/math-emu/sfp-util_32.h
@@ -107,9 +107,3 @@
 
 #define abort()								\
 	return 0
-
-#ifdef __BIG_ENDIAN
-#define __BYTE_ORDER __BIG_ENDIAN
-#else
-#define __BYTE_ORDER __LITTLE_ENDIAN
-#endif
diff --git a/arch/sparc/math-emu/sfp-util_64.h b/arch/sparc/math-emu/sfp-util_64.h
@@ -112,9 +112,3 @@
 
 #define abort() \
 	return 0
-
-#ifdef __BIG_ENDIAN
-#define __BYTE_ORDER __BIG_ENDIAN
-#else
-#define __BYTE_ORDER __LITTLE_ENDIAN
-#endif
diff --git a/arch/x86/boot/compressed/relocs.c b/arch/x86/boot/compressed/relocs.c
@@ -195,11 +195,11 @@ static const char *sym_name(const char *sym_strtab, Elf32_Sym *sym)
 
 
 
-#if BYTE_ORDER == LITTLE_ENDIAN
+#if __BYTE_ORDER == __LITTLE_ENDIAN
 #define le16_to_cpu(val) (val)
 #define le32_to_cpu(val) (val)
 #endif
-#if BYTE_ORDER == BIG_ENDIAN
+#if __BYTE_ORDER == __BIG_ENDIAN
 #define le16_to_cpu(val) bswap_16(val)
 #define le32_to_cpu(val) bswap_32(val)
 #endif
diff --git a/include/linux/byteorder/big_endian.h b/include/linux/byteorder/big_endian.h
@@ -7,6 +7,9 @@
 #ifndef __BIG_ENDIAN_BITFIELD
 #define __BIG_ENDIAN_BITFIELD
 #endif
+#ifndef __BYTE_ORDER
+#define __BYTE_ORDER __BIG_ENDIAN
+#endif
 
 #include <linux/types.h>
 #include <linux/swab.h>
diff --git a/include/linux/byteorder/little_endian.h b/include/linux/byteorder/little_endian.h
@@ -7,6 +7,9 @@
 #ifndef __LITTLE_ENDIAN_BITFIELD
 #define __LITTLE_ENDIAN_BITFIELD
 #endif
+#ifndef __BYTE_ORDER
+#define __BYTE_ORDER __LITTLE_ENDIAN
+#endif
 
 #include <linux/types.h>
 #include <linux/swab.h>
