[ARM] Fix byte order macros for Thumb

The byte order functions are visible to userspace.  Unfortunately,
__arch_swab32() contains an assembly instruction which is invalid when
compiling for Thumb.  This reverts to the C version when compiling for
Thumb.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/include/asm-arm/byteorder.h b/include/asm-arm/byteorder.h
index 17eaf8bdf0925a7b0146df2d6e35f8ac08cf3484..e6f7fcdc73b0299524b1e3b6a6b83eb9f360424f 100644 (file)
--- a/include/asm-arm/byteorder.h
+++ b/include/asm-arm/byteorder.h
@@ -22,16 +22,18 @@ static inline __attribute_const__ __u32 ___arch__swab32(__u32 x)
 {
        __u32 t;
 
-       if (__builtin_constant_p(x)) {
-               t = x ^ ((x << 16) | (x >> 16)); /* eor r1,r0,r0,ror #16 */
-       } else {
+#ifndef __thumb__
+       if (!__builtin_constant_p(x)) {
                /*
                 * The compiler needs a bit of a hint here to always do the
                 * right thing and not screw it up to different degrees
                 * depending on the gcc version.
                 */
                asm ("eor\t%0, %1, %1, ror #16" : "=r" (t) : "r" (x));
-       }
+       } else
+#endif
+               t = x ^ ((x << 16) | (x >> 16)); /* eor r1,r0,r0,ror #16 */
+
        x = (x << 24) | (x >> 8);               /* mov r0,r0,ror #8      */
        t &= ~0x00FF0000;                       /* bic r1,r1,#0x00FF0000 */
        x ^= (t >> 8);                          /* eor r0,r0,r1,lsr #8   */