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authorHarvey Harrison <harvey.harrison@gmail.com>2009-01-06 17:56:30 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-06 21:10:28 -0500
commitaf8e24e96facfd42eb12d13c8120e3e95de40aba (patch)
tree2c29e2311dd66cd333ad911cddc3ebc80ecb3a0c /arch/arm
parentdd8b72c0cc118196984f1bd23beed545d5087872 (diff)
arm: introduce asm/swab.h
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/include/asm/Kbuild1
-rw-r--r--arch/arm/include/asm/byteorder.h33
-rw-r--r--arch/arm/include/asm/swab.h50
3 files changed, 52 insertions, 32 deletions
diff --git a/arch/arm/include/asm/Kbuild b/arch/arm/include/asm/Kbuild
index 73237bd130a2..43b0b2ba392f 100644
--- a/arch/arm/include/asm/Kbuild
+++ b/arch/arm/include/asm/Kbuild
@@ -1,3 +1,4 @@
1include include/asm-generic/Kbuild.asm 1include include/asm-generic/Kbuild.asm
2 2
3unifdef-y += hwcap.h 3unifdef-y += hwcap.h
4unifdef-y += swab.h
diff --git a/arch/arm/include/asm/byteorder.h b/arch/arm/include/asm/byteorder.h
index 4fbfb22f65a0..c02b6fc28e1a 100644
--- a/arch/arm/include/asm/byteorder.h
+++ b/arch/arm/include/asm/byteorder.h
@@ -15,38 +15,7 @@
15#ifndef __ASM_ARM_BYTEORDER_H 15#ifndef __ASM_ARM_BYTEORDER_H
16#define __ASM_ARM_BYTEORDER_H 16#define __ASM_ARM_BYTEORDER_H
17 17
18#include <linux/compiler.h> 18#include <asm/swab.h>
19#include <asm/types.h>
20
21static inline __attribute_const__ __u32 ___arch__swab32(__u32 x)
22{
23 __u32 t;
24
25#ifndef __thumb__
26 if (!__builtin_constant_p(x)) {
27 /*
28 * The compiler needs a bit of a hint here to always do the
29 * right thing and not screw it up to different degrees
30 * depending on the gcc version.
31 */
32 asm ("eor\t%0, %1, %1, ror #16" : "=r" (t) : "r" (x));
33 } else
34#endif
35 t = x ^ ((x << 16) | (x >> 16)); /* eor r1,r0,r0,ror #16 */
36
37 x = (x << 24) | (x >> 8); /* mov r0,r0,ror #8 */
38 t &= ~0x00FF0000; /* bic r1,r1,#0x00FF0000 */
39 x ^= (t >> 8); /* eor r0,r0,r1,lsr #8 */
40
41 return x;
42}
43
44#define __arch__swab32(x) ___arch__swab32(x)
45
46#if !defined(__STRICT_ANSI__) || defined(__KERNEL__)
47# define __BYTEORDER_HAS_U64__
48# define __SWAB_64_THRU_32__
49#endif
50 19
51#ifdef __ARMEB__ 20#ifdef __ARMEB__
52#include <linux/byteorder/big_endian.h> 21#include <linux/byteorder/big_endian.h>
diff --git a/arch/arm/include/asm/swab.h b/arch/arm/include/asm/swab.h
new file mode 100644
index 000000000000..27a689be0856
--- /dev/null
+++ b/arch/arm/include/asm/swab.h
@@ -0,0 +1,50 @@
1/*
2 * arch/arm/include/asm/byteorder.h
3 *
4 * ARM Endian-ness. In little endian mode, the data bus is connected such
5 * that byte accesses appear as:
6 * 0 = d0...d7, 1 = d8...d15, 2 = d16...d23, 3 = d24...d31
7 * and word accesses (data or instruction) appear as:
8 * d0...d31
9 *
10 * When in big endian mode, byte accesses appear as:
11 * 0 = d24...d31, 1 = d16...d23, 2 = d8...d15, 3 = d0...d7
12 * and word accesses (data or instruction) appear as:
13 * d0...d31
14 */
15#ifndef __ASM_ARM_SWAB_H
16#define __ASM_ARM_SWAB_H
17
18#include <linux/compiler.h>
19#include <asm/types.h>
20
21#if !defined(__STRICT_ANSI__) || defined(__KERNEL__)
22# define __SWAB_64_THRU_32__
23#endif
24
25static inline __attribute_const__ __u32 __arch_swab32(__u32 x)
26{
27 __u32 t;
28
29#ifndef __thumb__
30 if (!__builtin_constant_p(x)) {
31 /*
32 * The compiler needs a bit of a hint here to always do the
33 * right thing and not screw it up to different degrees
34 * depending on the gcc version.
35 */
36 asm ("eor\t%0, %1, %1, ror #16" : "=r" (t) : "r" (x));
37 } else
38#endif
39 t = x ^ ((x << 16) | (x >> 16)); /* eor r1,r0,r0,ror #16 */
40
41 x = (x << 24) | (x >> 8); /* mov r0,r0,ror #8 */
42 t &= ~0x00FF0000; /* bic r1,r1,#0x00FF0000 */
43 x ^= (t >> 8); /* eor r0,r0,r1,lsr #8 */
44
45 return x;
46}
47#define __arch_swab32 __arch_swab32
48
49#endif
50