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authorSrikant Patnaik2015-01-11 12:28:04 +0530
committerSrikant Patnaik2015-01-11 12:28:04 +0530
commit871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch)
tree8718f573808810c2a1e8cb8fb6ac469093ca2784 /arch/alpha/include/asm/swab.h
parent9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff)
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure.
Diffstat (limited to 'arch/alpha/include/asm/swab.h')
-rw-r--r--arch/alpha/include/asm/swab.h42
1 files changed, 42 insertions, 0 deletions
diff --git a/arch/alpha/include/asm/swab.h b/arch/alpha/include/asm/swab.h
new file mode 100644
index 00000000..4d682b16
--- /dev/null
+++ b/arch/alpha/include/asm/swab.h
@@ -0,0 +1,42 @@
+#ifndef _ALPHA_SWAB_H
+#define _ALPHA_SWAB_H
+
+#include <linux/types.h>
+#include <linux/compiler.h>
+#include <asm/compiler.h>
+
+#ifdef __GNUC__
+
+static inline __attribute_const__ __u32 __arch_swab32(__u32 x)
+{
+ /*
+ * Unfortunately, we can't use the 6 instruction sequence
+ * on ev6 since the latency of the UNPKBW is 3, which is
+ * pretty hard to hide. Just in case a future implementation
+ * has a lower latency, here's the sequence (also by Mike Burrows)
+ *
+ * UNPKBW a0, v0 v0: 00AA00BB00CC00DD
+ * SLL v0, 24, a0 a0: BB00CC00DD000000
+ * BIS v0, a0, a0 a0: BBAACCBBDDCC00DD
+ * EXTWL a0, 6, v0 v0: 000000000000BBAA
+ * ZAP a0, 0xf3, a0 a0: 00000000DDCC0000
+ * ADDL a0, v0, v0 v0: ssssssssDDCCBBAA
+ */
+
+ __u64 t0, t1, t2, t3;
+
+ t0 = __kernel_inslh(x, 7); /* t0 : 0000000000AABBCC */
+ t1 = __kernel_inswl(x, 3); /* t1 : 000000CCDD000000 */
+ t1 |= t0; /* t1 : 000000CCDDAABBCC */
+ t2 = t1 >> 16; /* t2 : 0000000000CCDDAA */
+ t0 = t1 & 0xFF00FF00; /* t0 : 00000000DD00BB00 */
+ t3 = t2 & 0x00FF00FF; /* t3 : 0000000000CC00AA */
+ t1 = t0 + t3; /* t1 : ssssssssDDCCBBAA */
+
+ return t1;
+}
+#define __arch_swab32 __arch_swab32
+
+#endif /* __GNUC__ */
+
+#endif /* _ALPHA_SWAB_H */