cacheable_memzero uses dcbz instruction and is more efficient than
memset(0) when the destination is in RAM
This patch renames memset as generic_memset, and defines memset
as a prolog to cacheable_memzero. This prolog checks if the byte
to set is 0 and if the buffer is in RAM. If not, it falls back to
generic_memcpy()
Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr>
---
arch/powerpc/lib/copy_32.S | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/lib/copy_32.S b/arch/powerpc/lib/copy_32.S
index cbca76c..d8a9a86 100644
--- a/arch/powerpc/lib/copy_32.S
+++ b/arch/powerpc/lib/copy_32.S
@@ -12,6 +12,7 @@
#include <asm/cache.h>
#include <asm/errno.h>
#include <asm/ppc_asm.h>
+#include <asm/page.h>
#define COPY_16_BYTES \
lwz r7,4(r4); \
@@ -74,6 +75,18 @@ CACHELINE_MASK = (L1_CACHE_BYTES-1)
* to set them to zero. This requires that the destination
* area is cacheable. -- paulus
*/
+_GLOBAL(memset)
+ cmplwi r4,0
+ bne- generic_memset
+ cmplwi r5,L1_CACHE_BYTES
+ blt- generic_memset
+ lis r8,max_pfn@ha
+ lwz r8,max_pfn@l(r8)
+ tophys (r9,r3)
+ srwi r9,r9,PAGE_SHIFT
+ cmplw r9,r8
+ bge- generic_memset
+ mr r4,r5
_GLOBAL(cacheable_memzero)
li r5,0
addi r6,r3,-4
@@ -116,7 +129,7 @@ _GLOBAL(cacheable_memzero)
bdnz 8b
blr
-_GLOBAL(memset)
+_GLOBAL(generic_memset)
rlwimi r4,r4,8,16,23
rlwimi r4,r4,16,0,15
addi r6,r3,-4
--
2.1.0
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
