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authorIngo Molnar <mingo@elte.hu>2009-01-10 12:04:41 +0100
committerIngo Molnar <mingo@elte.hu>2009-01-10 12:04:41 +0100
commitb17304245f0db0ac69b795c411407808f3f2796d (patch)
tree63ed3915d9295bd08f640bf25c322064ba787fad /arch/x86/include/asm/swab.h
parentbzip2/lzma: centralize format detection (diff)
parentMerge git://git.kernel.org/pub/scm/linux/kernel/git/arjan/linux-2.6-async-2 (diff)
downloadlinux-b17304245f0db0ac69b795c411407808f3f2796d.tar.xz
linux-b17304245f0db0ac69b795c411407808f3f2796d.zip
Merge branch 'linus' into x86/setup-lzma
Conflicts: init/do_mounts_rd.c
Diffstat (limited to 'arch/x86/include/asm/swab.h')
-rw-r--r--arch/x86/include/asm/swab.h61
1 files changed, 61 insertions, 0 deletions
diff --git a/arch/x86/include/asm/swab.h b/arch/x86/include/asm/swab.h
new file mode 100644
index 000000000000..306d4178ffc9
--- /dev/null
+++ b/arch/x86/include/asm/swab.h
@@ -0,0 +1,61 @@
+#ifndef _ASM_X86_SWAB_H
+#define _ASM_X86_SWAB_H
+
+#include <asm/types.h>
+#include <linux/compiler.h>
+
+static inline __attribute_const__ __u32 __arch_swab32(__u32 val)
+{
+#ifdef __i386__
+# ifdef CONFIG_X86_BSWAP
+ asm("bswap %0" : "=r" (val) : "0" (val));
+# else
+ asm("xchgb %b0,%h0\n\t" /* swap lower bytes */
+ "rorl $16,%0\n\t" /* swap words */
+ "xchgb %b0,%h0" /* swap higher bytes */
+ : "=q" (val)
+ : "0" (val));
+# endif
+
+#else /* __i386__ */
+ asm("bswapl %0"
+ : "=r" (val)
+ : "0" (val));
+#endif
+ return val;
+}
+#define __arch_swab32 __arch_swab32
+
+static inline __attribute_const__ __u64 __arch_swab64(__u64 val)
+{
+#ifdef __i386__
+ union {
+ struct {
+ __u32 a;
+ __u32 b;
+ } s;
+ __u64 u;
+ } v;
+ v.u = val;
+# ifdef CONFIG_X86_BSWAP
+ asm("bswapl %0 ; bswapl %1 ; xchgl %0,%1"
+ : "=r" (v.s.a), "=r" (v.s.b)
+ : "0" (v.s.a), "1" (v.s.b));
+# else
+ v.s.a = __arch_swab32(v.s.a);
+ v.s.b = __arch_swab32(v.s.b);
+ asm("xchgl %0,%1"
+ : "=r" (v.s.a), "=r" (v.s.b)
+ : "0" (v.s.a), "1" (v.s.b));
+# endif
+ return v.u;
+#else /* __i386__ */
+ asm("bswapq %0"
+ : "=r" (val)
+ : "0" (val));
+ return val;
+#endif
+}
+#define __arch_swab64 __arch_swab64
+
+#endif /* _ASM_X86_SWAB_H */