[Xen-devel] [PATCH v2 07/17] xen: arm32: add optimised memchr routine

[Ian Campbell <ian.campbell@xxxxxxxxxx>]

This isn't used enough to be critical, but it completes the set of mem*.

Taken from Linux v3.14-rc7.

Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
Acked-by: Julien Grall <julien.grall@xxxxxxxxxx>
---
 xen/arch/arm/arm32/lib/Makefile |    2 +-
 xen/arch/arm/arm32/lib/memchr.S |   28 ++++++++++++++++++++++++++++
 xen/include/asm-arm/string.h    |    3 +++
 3 files changed, 32 insertions(+), 1 deletion(-)
 create mode 100644 xen/arch/arm/arm32/lib/memchr.S

diff --git a/xen/arch/arm/arm32/lib/Makefile b/xen/arch/arm/arm32/lib/Makefile
index 4cf41f4..fa4e241 100644
--- a/xen/arch/arm/arm32/lib/Makefile
+++ b/xen/arch/arm/arm32/lib/Makefile
@@ -1,4 +1,4 @@
-obj-y += memcpy.o memmove.o memset.o memzero.o
+obj-y += memcpy.o memmove.o memset.o memchr.o memzero.o
 obj-y += findbit.o setbit.o
 obj-y += setbit.o clearbit.o changebit.o
 obj-y += testsetbit.o testclearbit.o testchangebit.o
diff --git a/xen/arch/arm/arm32/lib/memchr.S b/xen/arch/arm/arm32/lib/memchr.S
new file mode 100644
index 0000000..fd64ed8
--- /dev/null
+++ b/xen/arch/arm/arm32/lib/memchr.S
@@ -0,0 +1,28 @@
+/*
+ *  linux/arch/arm/lib/memchr.S
+ *
+ *  Copyright (C) 1995-2000 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ *  ASM optimised string functions
+ */
+
+#include <xen/config.h>
+
+#include "assembler.h"
+
+       .text
+       .align  5
+ENTRY(memchr)
+1:     subs    r2, r2, #1
+       bmi     2f
+       ldrb    r3, [r0], #1
+       teq     r3, r1
+       bne     1b
+       sub     r0, r0, #1
+2:     movne   r0, #0
+       mov     pc, lr
+ENDPROC(memchr)
diff --git a/xen/include/asm-arm/string.h b/xen/include/asm-arm/string.h
index abfa9d2..2c9f4f7 100644
--- a/xen/include/asm-arm/string.h
+++ b/xen/include/asm-arm/string.h
@@ -14,6 +14,9 @@ extern void *memmove(void *dest, const void *src, size_t n);
 #define __HAVE_ARCH_MEMSET
 extern void * memset(void *, int, __kernel_size_t);
 
+#define __HAVE_ARCH_MEMCHR
+extern void * memchr(const void *, int, __kernel_size_t);
+
 extern void __memzero(void *ptr, __kernel_size_t n);
 
 #define memset(p,v,n)                                                   \
-- 
1.7.10.4


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