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Subject[tip:x86/boot] x86, boot: Move memcmp() into string.h and string.c
Commit-ID:  fb4cac573ef6dce8d7543b68306566561c2e5725
Gitweb: http://git.kernel.org/tip/fb4cac573ef6dce8d7543b68306566561c2e5725
Author: Vivek Goyal <vgoyal@redhat.com>
AuthorDate: Tue, 18 Mar 2014 15:26:39 -0400
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Wed, 19 Mar 2014 15:44:04 -0700

x86, boot: Move memcmp() into string.h and string.c

Try to treat memcmp() in same way as memcpy() and memset(). Provide a
declaration in boot/string.h and by default user gets a memcmp() which
maps to builtin function.

Move optimized definition of memcmp() in boot/string.c. Now a user can
do #undef memcmp and link against string.c to use optimzied memcmp().

It also simplifies boot/compressed/string.c where we had to redefine
memcmp(). That extra definition is gone now.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Link: http://lkml.kernel.org/r/1395170800-11059-5-git-send-email-vgoyal@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/boot/boot.h | 8 --------
arch/x86/boot/compressed/string.c | 11 -----------
arch/x86/boot/string.c | 14 ++++++++++++++
arch/x86/boot/string.h | 2 ++
4 files changed, 16 insertions(+), 19 deletions(-)

diff --git a/arch/x86/boot/boot.h b/arch/x86/boot/boot.h
index bed9665..bd49ec6 100644
--- a/arch/x86/boot/boot.h
+++ b/arch/x86/boot/boot.h
@@ -177,14 +177,6 @@ static inline void wrgs32(u32 v, addr_t addr)
}

/* Note: these only return true/false, not a signed return value! */
-static inline int memcmp(const void *s1, const void *s2, size_t len)
-{
- u8 diff;
- asm("repe; cmpsb; setnz %0"
- : "=qm" (diff), "+D" (s1), "+S" (s2), "+c" (len));
- return diff;
-}
-
static inline int memcmp_fs(const void *s1, addr_t s2, size_t len)
{
u8 diff;
diff --git a/arch/x86/boot/compressed/string.c b/arch/x86/boot/compressed/string.c
index 3b5a82f..920b55e 100644
--- a/arch/x86/boot/compressed/string.c
+++ b/arch/x86/boot/compressed/string.c
@@ -1,15 +1,4 @@
#include "misc.h"
-
-/* Avoid intereference from any defines in string_32.h */
-#undef memcmp
-int memcmp(const void *s1, const void *s2, size_t len)
-{
- u8 diff;
- asm("repe; cmpsb; setnz %0"
- : "=qm" (diff), "+D" (s1), "+S" (s2), "+c" (len));
- return diff;
-}
-
#include "../string.c"

/* misc.h might pull in string_32.h which has a macro for memcpy. undef that */
diff --git a/arch/x86/boot/string.c b/arch/x86/boot/string.c
index 574dedf..5339040 100644
--- a/arch/x86/boot/string.c
+++ b/arch/x86/boot/string.c
@@ -14,6 +14,20 @@

#include "boot.h"

+/*
+ * This file gets included in compressed/string.c which might pull in
+ * string_32.h and which in turn maps memcmp to __builtin_memcmp(). Undo
+ * that first.
+ */
+#undef memcmp
+int memcmp(const void *s1, const void *s2, size_t len)
+{
+ u8 diff;
+ asm("repe; cmpsb; setnz %0"
+ : "=qm" (diff), "+D" (s1), "+S" (s2), "+c" (len));
+ return diff;
+}
+
int strcmp(const char *str1, const char *str2)
{
const unsigned char *s1 = (const unsigned char *)str1;
diff --git a/arch/x86/boot/string.h b/arch/x86/boot/string.h
index 10939d8..725e820 100644
--- a/arch/x86/boot/string.h
+++ b/arch/x86/boot/string.h
@@ -8,6 +8,7 @@

void *memcpy(void *dst, const void *src, size_t len);
void *memset(void *dst, int c, size_t len);
+int memcmp(const void *s1, const void *s2, size_t len);

/*
* Access builtin version by default. If one needs to use optimized version,
@@ -15,5 +16,6 @@ void *memset(void *dst, int c, size_t len);
*/
#define memcpy(d,s,l) __builtin_memcpy(d,s,l)
#define memset(d,c,l) __builtin_memset(d,c,l)
+#define memcmp __builtin_memcmp

#endif /* BOOT_STRING_H */

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