tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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)