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powerpc: tiny memcpy_(to|from)io optimisation

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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.dress@arcor.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This commit is contained in:
Albrecht Dreß
2009-11-04 16:43:12 -07:00
committed by Grant Likely
parent 5cc17d7e01
commit a22c65f81a
1 changed files with 2 additions and 2 deletions
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4
arch/powerpc/kernel/io.c
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@@ -161,7 +161,7 @@ void _memcpy_fromio(void *dest, const volatile void __iomem *src,
dest++; dest++;
n--; n--;
} }
while(n > 4) { while(n >= 4) {
*((u32 *)dest) = *((volatile u32 *)vsrc); *((u32 *)dest) = *((volatile u32 *)vsrc);
eieio(); eieio();
vsrc += 4; vsrc += 4;
@@ -190,7 +190,7 @@ void _memcpy_toio(volatile void __iomem *dest, const void *src, unsigned long n)
vdest++; vdest++;
n--; n--;
} }
while(n > 4) { while(n >= 4) {
*((volatile u32 *)vdest) = *((volatile u32 *)src); *((volatile u32 *)vdest) = *((volatile u32 *)src);
src += 4; src += 4;
vdest += 4; vdest += 4;