Unaligned stores take alignment exceptions on POWER7 running in little-endian.
This is a dumb little-endian base memcpy that prevents unaligned stores.
It is replaced by the VMX memcpy at boot.
Signed-off-by: Philippe Bergheaud <fe...@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/string.h | 4 ----
arch/powerpc/kernel/ppc_ksyms.c | 2 --
arch/powerpc/lib/Makefile | 2 --
arch/powerpc/lib/memcpy_64.S | 19 +++++++++++++++++++
4 files changed, 19 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/include/asm/string.h
b/arch/powerpc/include/asm/string.h
index 0dffad6..e40010a 100644
--- a/arch/powerpc/include/asm/string.h
+++ b/arch/powerpc/include/asm/string.h
@@ -10,9 +10,7 @@
#define __HAVE_ARCH_STRNCMP
#define __HAVE_ARCH_STRCAT
#define __HAVE_ARCH_MEMSET
-#ifdef __BIG_ENDIAN__
#define __HAVE_ARCH_MEMCPY
-#endif
#define __HAVE_ARCH_MEMMOVE
#define __HAVE_ARCH_MEMCMP
#define __HAVE_ARCH_MEMCHR
@@ -24,9 +22,7 @@ extern int strcmp(const char *,const char *);
extern int strncmp(const char *, const char *, __kernel_size_t);
extern char * strcat(char *, const char *);
extern void * memset(void *,int,__kernel_size_t);
-#ifdef __BIG_ENDIAN__
extern void * memcpy(void *,const void *,__kernel_size_t);
-#endif
extern void * memmove(void *,const void *,__kernel_size_t);
extern int memcmp(const void *,const void *,__kernel_size_t);
extern void * memchr(const void *,int,__kernel_size_t);
diff --git a/arch/powerpc/kernel/ppc_ksyms.c b/arch/powerpc/kernel/ppc_ksyms.c
index 526ad5c..0c2dd60 100644
--- a/arch/powerpc/kernel/ppc_ksyms.c
+++ b/arch/powerpc/kernel/ppc_ksyms.c
@@ -147,9 +147,7 @@ EXPORT_SYMBOL(__ucmpdi2);
#endif
long long __bswapdi2(long long);
EXPORT_SYMBOL(__bswapdi2);
-#ifdef __BIG_ENDIAN__
EXPORT_SYMBOL(memcpy);
-#endif
EXPORT_SYMBOL(memset);
EXPORT_SYMBOL(memmove);
EXPORT_SYMBOL(memcmp);
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index 5310132..6670361 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -23,9 +23,7 @@ obj-y += checksum_$(CONFIG_WORD_SIZE).o
obj-$(CONFIG_PPC64) += checksum_wrappers_64.o
endif
-ifeq ($(CONFIG_CPU_LITTLE_ENDIAN),)
obj-$(CONFIG_PPC64) += memcpy_power7.o memcpy_64.o
-endif
obj-$(CONFIG_PPC_EMULATE_SSTEP) += sstep.o ldstfp.o
diff --git a/arch/powerpc/lib/memcpy_64.S b/arch/powerpc/lib/memcpy_64.S
index d2bbbc8..358cf74 100644
--- a/arch/powerpc/lib/memcpy_64.S
+++ b/arch/powerpc/lib/memcpy_64.S
@@ -12,10 +12,28 @@
.align 7
_GLOBAL(memcpy)
BEGIN_FTR_SECTION
+#ifdef __LITTLE_ENDIAN__
+ cmpdi cr7,r5,0 /* dumb little-endian memcpy */
+#else
std r3,48(r1) /* save destination pointer for return value */
+#endif
FTR_SECTION_ELSE
b memcpy_power7
ALT_FTR_SECTION_END_IFCLR(CPU_FTR_VMX_COPY)
+#ifdef __LITTLE_ENDIAN__
+ addi r5,r5,-1
+ addi r9,r3,-1
+ add r5,r3,r5
+ subf r5,r9,r5
+ addi r4,r4,-1
+ mtctr r5
+ beqlr cr7
+1:
+ lbzu r10,1(r4)
+ stbu r10,1(r9)
+ bdnz 1b
+ blr
+#else
PPC_MTOCRF(0x01,r5)
cmpldi cr1,r5,16
neg r6,r3 # LS 3 bits = # bytes to 8-byte dest bdry
@@ -201,3 +219,4 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
stb r0,0(r3)
4: ld r3,48(r1) /* return dest pointer */
blr
+#endif
--
1.7.10.4
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