v4.19.13 snapshot.
diff --git a/arch/arm/lib/memchr.S b/arch/arm/lib/memchr.S
new file mode 100644
index 0000000..74a5bed
--- /dev/null
+++ b/arch/arm/lib/memchr.S
@@ -0,0 +1,26 @@
+/*
+ * 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 <linux/linkage.h>
+#include <asm/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
+ ret lr
+ENDPROC(memchr)