cacheable_memcpy uses dcbz instruction and is more efficient than
memcpy when the destination is in RAM
This patch renames memcpy as generic_memcpy, and defines memcpy as a
prolog to cacheable_memcpy. This prolog checks if the buffer is
in RAM. If not, it falls back to generic_memcpy()
On MPC885, we get approximatly 7% increase of the transfer rate
on an FTP reception
Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr>
---
arch/powerpc/lib/copy_32.S | 23 ++++++++++++++++-------
1 file changed, 16 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/lib/copy_32.S b/arch/powerpc/lib/copy_32.S
index d8a9a86..8f76d49 100644
--- a/arch/powerpc/lib/copy_32.S
+++ b/arch/powerpc/lib/copy_32.S
@@ -161,13 +161,27 @@ _GLOBAL(generic_memset)
* We only use this version if the source and dest don't overlap.
* -- paulus.
*/
+_GLOBAL(memmove)
+ cmplw 0,r3,r4
+ bgt backwards_memcpy
+ /* fall through */
+
+_GLOBAL(memcpy)
+ cmplwi r5,L1_CACHE_BYTES
+ blt- generic_memcpy
+ lis r8,max_pfn@ha
+ lwz r8,max_pfn@l(r8)
+ tophys (r9,r3)
+ srwi r9,r9,PAGE_SHIFT
+ cmplw r9,r8
+ bge- generic_memcpy
_GLOBAL(cacheable_memcpy)
add r7,r3,r5 /* test if the src & dst overlap */
add r8,r4,r5
cmplw 0,r4,r7
cmplw 1,r3,r8
crand 0,0,4 /* cr0.lt &= cr1.lt */
- blt memcpy /* if regions overlap */
+ blt generic_memcpy /* if regions overlap */
addi r4,r4,-4
addi r6,r3,-4
@@ -233,12 +247,7 @@ _GLOBAL(cacheable_memcpy)
bdnz 40b
65: blr
-_GLOBAL(memmove)
- cmplw 0,r3,r4
- bgt backwards_memcpy
- /* fall through */
-
-_GLOBAL(memcpy)
+_GLOBAL(generic_memcpy)
srwi. r7,r5,3
addi r6,r3,-4
addi r4,r4,-4
--
2.1.0
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