From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 arch/blackfin/lib/memcpy.S | 124 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 124 insertions(+)
 create mode 100644 arch/blackfin/lib/memcpy.S

(limited to 'arch/blackfin/lib/memcpy.S')

diff --git a/arch/blackfin/lib/memcpy.S b/arch/blackfin/lib/memcpy.S
new file mode 100644
index 000000000..53cb3698a
--- /dev/null
+++ b/arch/blackfin/lib/memcpy.S
@@ -0,0 +1,124 @@
+/*
+ * internal version of memcpy(), issued by the compiler to copy blocks of
+ * data around. This is really memmove() - it has to be able to deal with
+ * possible overlaps, because that ambiguity is when the compiler gives up
+ * and calls a function. We have our own, internal version so that we get
+ * something we trust, even if the user has redefined the normal symbol.
+ *
+ * Copyright 2004-2009 Analog Devices Inc.
+ *
+ * Licensed under the Clear BSD license or the GPL-2 (or later)
+ */
+
+#include <linux/linkage.h>
+
+/* void *memcpy(void *dest, const void *src, size_t n);
+ * R0 = To Address (dest) (leave unchanged to form result)
+ * R1 = From Address (src)
+ * R2 = count
+ *
+ * Note: Favours word alignment
+ */
+
+#ifdef CONFIG_MEMCPY_L1
+.section .l1.text
+#else
+.text
+#endif
+
+.align 2
+
+ENTRY(_memcpy)
+	CC = R2 <=  0;	/* length not positive? */
+	IF CC JUMP .L_P1L2147483647;	/* Nothing to do */
+
+	P0 = R0 ;	/* dst*/
+	P1 = R1 ;	/* src*/
+	P2 = R2 ;	/* length */
+
+	/* check for overlapping data */
+	CC = R1 < R0;	/* src < dst */
+	IF !CC JUMP .Lno_overlap;
+	R3 = R1 + R2;
+	CC = R0 < R3;	/* and dst < src+len */
+	IF CC JUMP .Lhas_overlap;
+
+.Lno_overlap:
+	/* Check for aligned data.*/
+
+	R3 = R1 | R0;
+	R1 = 0x3;
+	R3 = R3 & R1;
+	CC = R3;	/* low bits set on either address? */
+	IF CC JUMP .Lnot_aligned;
+
+	/* Both addresses are word-aligned, so we can copy
+	at least part of the data using word copies.*/
+	P2 = P2 >> 2;
+	CC = P2 <= 2;
+	IF !CC JUMP .Lmore_than_seven;
+	/* less than eight bytes... */
+	P2 = R2;
+	LSETUP(.Lthree_start, .Lthree_end) LC0=P2;
+.Lthree_start:
+	R3 = B[P1++] (X);
+.Lthree_end:
+	B[P0++] = R3;
+
+	RTS;
+
+.Lmore_than_seven:
+	/* There's at least eight bytes to copy. */
+	P2 += -1;	/* because we unroll one iteration */
+	LSETUP(.Lword_loops, .Lword_loope) LC0=P2;
+	I1 = P1;
+	R3 = [I1++];
+#if ANOMALY_05000202
+.Lword_loops:
+	[P0++] = R3;
+.Lword_loope:
+	R3 = [I1++];
+#else
+.Lword_loops:
+.Lword_loope:
+	MNOP || [P0++] = R3 || R3 = [I1++];
+#endif
+	[P0++] = R3;
+	/* Any remaining bytes to copy? */
+	R3 = 0x3;
+	R3 = R2 & R3;
+	CC = R3 == 0;
+	P1 = I1;	/* in case there's something left, */
+	IF !CC JUMP .Lbytes_left;
+	RTS;
+.Lbytes_left:	P2 = R3;
+.Lnot_aligned:
+	/* From here, we're copying byte-by-byte. */
+	LSETUP (.Lbyte_start, .Lbyte_end) LC0=P2;
+.Lbyte_start:
+	R1 = B[P1++] (X);
+.Lbyte_end:
+	B[P0++] = R1;
+
+.L_P1L2147483647:
+	RTS;
+
+.Lhas_overlap:
+	/* Need to reverse the copying, because the
+	 * dst would clobber the src.
+	 * Don't bother to work out alignment for
+	 * the reverse case.
+	 */
+	P0 = P0 + P2;
+	P0 += -1;
+	P1 = P1 + P2;
+	P1 += -1;
+	LSETUP(.Lover_start, .Lover_end) LC0=P2;
+.Lover_start:
+	R1 = B[P1--] (X);
+.Lover_end:
+	B[P0--] = R1;
+
+	RTS;
+
+ENDPROC(_memcpy)
-- 
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