1 files changed, 85 insertions, 0 deletions
diff --git a/arch/blackfin/lib/strncpy.S b/arch/blackfin/lib/strncpy.S
new file mode 100644
index 00000000000..f3931d50b4a
--- /dev/null
+++ b/arch/blackfin/lib/strncpy.S
@@ -0,0 +1,85 @@
+/*
+ * Copyright 2005-2010 Analog Devices Inc.
+ *
+ * Licensed under the ADI BSD license or the GPL-2 (or later)
+ */
+
+#include <linux/linkage.h>
+#include <asm/context.S>
+
+/* void *strncpy(char *dest, const char *src, size_t n);
+ * R0 = address (dest)
+ * R1 = address (src)
+ * R2 = size
+ * Returns a pointer (R0) to the destination string dest
+ *  we do this by not changing R0
+ */
+
+#ifdef CONFIG_STRNCPY_L1
+.section .l1.text
+#else
+.text
+#endif
+
+.align 2
+
+ENTRY(_strncpy)
+	CC = R2 == 0;
+	if CC JUMP 4f;
+
+	P2 = R2 ;       /* size */
+	P0 = R0 ;       /* dst*/
+	P1 = R1 ;       /* src*/
+
+	LSETUP (1f, 2f) LC0 = P2;
+1:
+	R1 = B [P1++] (Z);
+	B [P0++] = R1;
+	CC = R1 == 0;
+2:
+	if CC jump 3f;
+
+	RTS;
+
+	/* if src is shorter than n, we need to null pad bytes in dest
+	 * but, we can get here when the last byte is zero, and we don't
+	 * want to copy an extra byte at the end, so we need to check
+	 */
+3:
+	R2 = LC0;
+	CC = R2
+	if ! CC jump 6f;
+
+	/* if the required null padded portion is small, do it here, rather than
+	 * handling the overhead of memset (which is OK when things are big).
+	 */
+	R3 = 0x20;
+	CC = R2 < R3;
+	IF CC jump 4f;
+
+	R2 += -1;
+
+	/* Set things up for memset
+	 * R0 = address
+	 * R1 = filler byte (this case it's zero, set above)
+	 * R2 = count (set above)
+	 */
+
+	I1 = R0;
+	R0 = RETS;
+	I0 = R0;
+	R0 = P0;
+	pseudo_long_call _memset, p0;
+	R0 = I0;
+	RETS = R0;
+	R0 = I1;
+	RTS;
+
+4:
+	LSETUP(5f, 5f) LC0;
+5:
+	B [P0++] = R1;
+6:
+	RTS;
+
+ENDPROC(_strncpy)