arm64: Change memcpy in kernel to use the copy template file

This converts the memcpy.S to use the copy template file. The copy
template file was based originally on the memcpy.S

Signed-off-by: Feng Kan <fkan@apm.com>
Signed-off-by: Balamurugan Shanmugam <bshanmugam@apm.com>
[catalin.marinas@arm.com: removed tmp3(w) .req statements as they are not used]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 193 insertions, 0 deletions

diff --git a/arch/arm64/lib/copy_template.S b/arch/arm64/lib/copy_template.S
new file mode 100644
index 000000000000..410fbdb8163f
--- /dev/null
+++ b/arch/arm64/lib/copy_template.S
@@ -0,0 +1,193 @@
+/*
+ * Copyright (C) 2013 ARM Ltd.
+ * Copyright (C) 2013 Linaro.
+ *
+ * This code is based on glibc cortex strings work originally authored by Linaro
+ * and re-licensed under GPLv2 for the Linux kernel. The original code can
+ * be found @
+ *
+ * http://bazaar.launchpad.net/~linaro-toolchain-dev/cortex-strings/trunk/
+ * files/head:/src/aarch64/
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+/*
+ * Copy a buffer from src to dest (alignment handled by the hardware)
+ *
+ * Parameters:
+ *	x0 - dest
+ *	x1 - src
+ *	x2 - n
+ * Returns:
+ *	x0 - dest
+ */
+dstin	.req	x0
+src	.req	x1
+count	.req	x2
+tmp1	.req	x3
+tmp1w	.req	w3
+tmp2	.req	x4
+tmp2w	.req	w4
+dst	.req	x6
+
+A_l	.req	x7
+A_h	.req	x8
+B_l	.req	x9
+B_h	.req	x10
+C_l	.req	x11
+C_h	.req	x12
+D_l	.req	x13
+D_h	.req	x14
+
+	mov	dst, dstin
+	cmp	count, #16
+	/*When memory length is less than 16, the accessed are not aligned.*/
+	b.lo	.Ltiny15
+
+	neg	tmp2, src
+	ands	tmp2, tmp2, #15/* Bytes to reach alignment. */
+	b.eq	.LSrcAligned
+	sub	count, count, tmp2
+	/*
+	* Copy the leading memory data from src to dst in an increasing
+	* address order.By this way,the risk of overwritting the source
+	* memory data is eliminated when the distance between src and
+	* dst is less than 16. The memory accesses here are alignment.
+	*/
+	tbz	tmp2, #0, 1f
+	ldrb1	tmp1w, src, #1
+	strb1	tmp1w, dst, #1
+1:
+	tbz	tmp2, #1, 2f
+	ldrh1	tmp1w, src, #2
+	strh1	tmp1w, dst, #2
+2:
+	tbz	tmp2, #2, 3f
+	ldr1	tmp1w, src, #4
+	str1	tmp1w, dst, #4
+3:
+	tbz	tmp2, #3, .LSrcAligned
+	ldr1	tmp1, src, #8
+	str1	tmp1, dst, #8
+
+.LSrcAligned:
+	cmp	count, #64
+	b.ge	.Lcpy_over64
+	/*
+	* Deal with small copies quickly by dropping straight into the
+	* exit block.
+	*/
+.Ltail63:
+	/*
+	* Copy up to 48 bytes of data. At this point we only need the
+	* bottom 6 bits of count to be accurate.
+	*/
+	ands	tmp1, count, #0x30
+	b.eq	.Ltiny15
+	cmp	tmp1w, #0x20
+	b.eq	1f
+	b.lt	2f
+	ldp1	A_l, A_h, src, #16
+	stp1	A_l, A_h, dst, #16
+1:
+	ldp1	A_l, A_h, src, #16
+	stp1	A_l, A_h, dst, #16
+2:
+	ldp1	A_l, A_h, src, #16
+	stp1	A_l, A_h, dst, #16
+.Ltiny15:
+	/*
+	* Prefer to break one ldp/stp into several load/store to access
+	* memory in an increasing address order,rather than to load/store 16
+	* bytes from (src-16) to (dst-16) and to backward the src to aligned
+	* address,which way is used in original cortex memcpy. If keeping
+	* the original memcpy process here, memmove need to satisfy the
+	* precondition that src address is at least 16 bytes bigger than dst
+	* address,otherwise some source data will be overwritten when memove
+	* call memcpy directly. To make memmove simpler and decouple the
+	* memcpy's dependency on memmove, withdrew the original process.
+	*/
+	tbz	count, #3, 1f
+	ldr1	tmp1, src, #8
+	str1	tmp1, dst, #8
+1:
+	tbz	count, #2, 2f
+	ldr1	tmp1w, src, #4
+	str1	tmp1w, dst, #4
+2:
+	tbz	count, #1, 3f
+	ldrh1	tmp1w, src, #2
+	strh1	tmp1w, dst, #2
+3:
+	tbz	count, #0, .Lexitfunc
+	ldrb1	tmp1w, src, #1
+	strb1	tmp1w, dst, #1
+
+	b	.Lexitfunc
+
+.Lcpy_over64:
+	subs	count, count, #128
+	b.ge	.Lcpy_body_large
+	/*
+	* Less than 128 bytes to copy, so handle 64 here and then jump
+	* to the tail.
+	*/
+	ldp1	A_l, A_h, src, #16
+	stp1	A_l, A_h, dst, #16
+	ldp1	B_l, B_h, src, #16
+	ldp1	C_l, C_h, src, #16
+	stp1	B_l, B_h, dst, #16
+	stp1	C_l, C_h, dst, #16
+	ldp1	D_l, D_h, src, #16
+	stp1	D_l, D_h, dst, #16
+
+	tst	count, #0x3f
+	b.ne	.Ltail63
+	b	.Lexitfunc
+
+	/*
+	* Critical loop.  Start at a new cache line boundary.  Assuming
+	* 64 bytes per line this ensures the entire loop is in one line.
+	*/
+	.p2align	L1_CACHE_SHIFT
+.Lcpy_body_large:
+	/* pre-get 64 bytes data. */
+	ldp1	A_l, A_h, src, #16
+	ldp1	B_l, B_h, src, #16
+	ldp1	C_l, C_h, src, #16
+	ldp1	D_l, D_h, src, #16
+1:
+	/*
+	* interlace the load of next 64 bytes data block with store of the last
+	* loaded 64 bytes data.
+	*/
+	stp1	A_l, A_h, dst, #16
+	ldp1	A_l, A_h, src, #16
+	stp1	B_l, B_h, dst, #16
+	ldp1	B_l, B_h, src, #16
+	stp1	C_l, C_h, dst, #16
+	ldp1	C_l, C_h, src, #16
+	stp1	D_l, D_h, dst, #16
+	ldp1	D_l, D_h, src, #16
+	subs	count, count, #64
+	b.ge	1b
+	stp1	A_l, A_h, dst, #16
+	stp1	B_l, B_h, dst, #16
+	stp1	C_l, C_h, dst, #16
+	stp1	D_l, D_h, dst, #16
+
+	tst	count, #0x3f
+	b.ne	.Ltail63
+.Lexitfunc: