[POWERPC] Add hand-coded assembly strcmp

We have an assembly version of strncmp for the bootwrapper, but not
for the kernel, so we end up using the C version in the kernel.  This
takes the strncmp code from the bootup and copies it to the kernel
proper, adding two instructions so it copes correctly with len==0.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

3 files changed, 17 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/ppc_ksyms.c b/arch/powerpc/kernel/ppc_ksyms.c
index a722ede726db..5a4c76eada48 100644
--- a/arch/powerpc/kernel/ppc_ksyms.c
+++ b/arch/powerpc/kernel/ppc_ksyms.c
@@ -78,6 +78,7 @@ EXPORT_SYMBOL(strncpy);
 EXPORT_SYMBOL(strcat);
 EXPORT_SYMBOL(strlen);
 EXPORT_SYMBOL(strcmp);
+EXPORT_SYMBOL(strncmp);
 
 EXPORT_SYMBOL(csum_partial);
 EXPORT_SYMBOL(csum_partial_copy_generic);
diff --git a/arch/powerpc/lib/string.S b/arch/powerpc/lib/string.S
index c4c622d8e6ac..49eb1f1a2bb4 100644
--- a/arch/powerpc/lib/string.S
+++ b/arch/powerpc/lib/string.S
@@ -75,6 +75,20 @@ _GLOBAL(strcmp)
         beq     1b
         blr
 
+_GLOBAL(strncmp)
+        PPC_LCMPI r5,0
+        beqlr
+        mtctr   r5
+        addi    r5,r3,-1
+        addi    r4,r4,-1
+1:      lbzu    r3,1(r5)
+        cmpwi   1,r3,0
+        lbzu    r0,1(r4)
+        subf.   r3,r0,r3
+        beqlr   1
+        bdnzt   eq,1b
+        blr
+
 _GLOBAL(strlen)
         addi    r4,r3,-1
 1:      lbzu    r0,1(r4)
diff --git a/include/asm-powerpc/string.h b/include/asm-powerpc/string.h
index aa40f92c298d..e40010abcaf1 100644
--- a/include/asm-powerpc/string.h
+++ b/include/asm-powerpc/string.h
@@ -7,6 +7,7 @@
 #define __HAVE_ARCH_STRNCPY
 #define __HAVE_ARCH_STRLEN
 #define __HAVE_ARCH_STRCMP
+#define __HAVE_ARCH_STRNCMP
 #define __HAVE_ARCH_STRCAT
 #define __HAVE_ARCH_MEMSET
 #define __HAVE_ARCH_MEMCPY
@@ -18,6 +19,7 @@ extern char * strcpy(char *,const char *);
 extern char * strncpy(char *,const char *, __kernel_size_t);
 extern __kernel_size_t strlen(const char *);
 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);
 extern void * memcpy(void *,const void *,__kernel_size_t);