1/*
2 * Copyright (C) 2012 ARM Ltd.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
15 */
16
17#include <linux/linkage.h>
18#include <linux/const.h>
19#include <asm/assembler.h>
20#include <asm/page.h>
21#include <asm/cpufeature.h>
22#include <asm/alternative.h>
23
24/*
25 * Copy a page from src to dest (both are page aligned)
26 *
27 * Parameters:
28 *	x0 - dest
29 *	x1 - src
30 */
31ENTRY(copy_page)
32alternative_if ARM64_HAS_NO_HW_PREFETCH
33	// Prefetch three cache lines ahead.
34	prfm	pldl1strm, [x1, #128]
35	prfm	pldl1strm, [x1, #256]
36	prfm	pldl1strm, [x1, #384]
37alternative_else_nop_endif
38
39	ldp	x2, x3, [x1]
40	ldp	x4, x5, [x1, #16]
41	ldp	x6, x7, [x1, #32]
42	ldp	x8, x9, [x1, #48]
43	ldp	x10, x11, [x1, #64]
44	ldp	x12, x13, [x1, #80]
45	ldp	x14, x15, [x1, #96]
46	ldp	x16, x17, [x1, #112]
47
48	mov	x18, #(PAGE_SIZE - 128)
49	add	x1, x1, #128
501:
51	subs	x18, x18, #128
52
53alternative_if ARM64_HAS_NO_HW_PREFETCH
54	prfm	pldl1strm, [x1, #384]
55alternative_else_nop_endif
56
57	stnp	x2, x3, [x0]
58	ldp	x2, x3, [x1]
59	stnp	x4, x5, [x0, #16]
60	ldp	x4, x5, [x1, #16]
61	stnp	x6, x7, [x0, #32]
62	ldp	x6, x7, [x1, #32]
63	stnp	x8, x9, [x0, #48]
64	ldp	x8, x9, [x1, #48]
65	stnp	x10, x11, [x0, #64]
66	ldp	x10, x11, [x1, #64]
67	stnp	x12, x13, [x0, #80]
68	ldp	x12, x13, [x1, #80]
69	stnp	x14, x15, [x0, #96]
70	ldp	x14, x15, [x1, #96]
71	stnp	x16, x17, [x0, #112]
72	ldp	x16, x17, [x1, #112]
73
74	add	x0, x0, #128
75	add	x1, x1, #128
76
77	b.gt	1b
78
79	stnp	x2, x3, [x0]
80	stnp	x4, x5, [x0, #16]
81	stnp	x6, x7, [x0, #32]
82	stnp	x8, x9, [x0, #48]
83	stnp	x10, x11, [x0, #64]
84	stnp	x12, x13, [x0, #80]
85	stnp	x14, x15, [x0, #96]
86	stnp	x16, x17, [x0, #112]
87
88	ret
89ENDPROC(copy_page)
90