[PATCH] powerpc: tiny memcpy_(to|from)io optimisation

[Albrecht Dreß]

This trivial patch changes memcpy_(to|from)io as to transfer as many 32-bit words as possible in 32-bit accesses (in the current solution, the last 32-bit word was transferred as 4 byte accesses).

Signed-off-by: Albrecht Dreß <albrecht.dr...@arcor.de>
---


@@ -161,7 +161,7 @@ void _memcpy_fromio(void *dest, const vo
                dest++;
                n--;
        }
-       while(n > 4) {
+       while(n >= 4) {
                *((u32 *)dest) = *((volatile u32 *)vsrc);
                eieio();
                vsrc += 4;
@@ -190,7 +190,7 @@ void _memcpy_toio(volatile void __iomem
                vdest++;
                n--;
        }
-       while(n > 4) {
+       while(n >= 4) {
                *((volatile u32 *)vdest) = *((volatile u32 *)src);
                src += 4;
                vdest += 4;

diff -urpN -X linux-2.6.29.1.orig/Documentation/dontdiff linux-2.6.29.1.orig/arch/powerpc/kernel/io.c linux-2.6.29.1/arch/powerpc/kernel/io.c --- linux-2.6.29.1.orig/arch/powerpc/kernel/io.c 2009-04-02 22:55:27.000000000 +0200 +++ linux-2.6.29.1/arch/powerpc/kernel/io.c 2009-05-27 11:36:09.000000000 +0200

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