endian: #define __BYTE_ORDER

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 <Joakim.Tjernlund@transmode.se>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/byteorder/little_endian.h b/include/linux/byteorder/little_endian.h
index 83195fb82962..f7f8ad13adb6 100644
--- 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>