Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 441ff855 authored by H. Peter Anvin's avatar H. Peter Anvin Committed by Russell King
Browse files

[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: default avatarH. Peter Anvin <hpa@zytor.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 5e642387

include/asm-arm/byteorder.h

+6 −4
Original line number Original line Diff line number Diff line
@@ -22,16 +22,18 @@ static inline __attribute_const__ __u32 ___arch__swab32(__u32 x) 
{

{

	__u32 t;

	__u32 t;





	if (__builtin_constant_p(x)) {

#ifndef __thumb__

		t = x ^ ((x << 16) | (x >> 16)); /* eor r1,r0,r0,ror #16 */

	if (!__builtin_constant_p(x)) {

	} else {

		/*

		/*

		 * The compiler needs a bit of a hint here to always do the

		 * The compiler needs a bit of a hint here to always do the

		 * right thing and not screw it up to different degrees

		 * right thing and not screw it up to different degrees

		 * depending on the gcc version.

		 * depending on the gcc version.

		 */

		 */

		asm ("eor\t%0, %1, %1, ror #16" : "=r" (t) : "r" (x));

		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      */

	x = (x << 24) | (x >> 8);		/* mov r0,r0,ror #8      */

	t &= ~0x00FF0000;			/* bic r1,r1,#0x00FF0000 */

	t &= ~0x00FF0000;			/* bic r1,r1,#0x00FF0000 */

	x ^= (t >> 8);				/* eor r0,r0,r1,lsr #8   */

	x ^= (t >> 8);				/* eor r0,r0,r1,lsr #8   */