xref: /openbmc/linux/arch/arm64/lib/copy_to_user.S (revision 9cfc5c90)
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
19#include <asm/alternative.h>
20#include <asm/assembler.h>
21#include <asm/cache.h>
22#include <asm/cpufeature.h>
23#include <asm/sysreg.h>
24
25/*
26 * Copy to user space from a kernel buffer (alignment handled by the hardware)
27 *
28 * Parameters:
29 *	x0 - to
30 *	x1 - from
31 *	x2 - n
32 * Returns:
33 *	x0 - bytes not copied
34 */
35	.macro ldrb1 ptr, regB, val
36	ldrb  \ptr, [\regB], \val
37	.endm
38
39	.macro strb1 ptr, regB, val
40	USER(9998f, strb \ptr, [\regB], \val)
41	.endm
42
43	.macro ldrh1 ptr, regB, val
44	ldrh  \ptr, [\regB], \val
45	.endm
46
47	.macro strh1 ptr, regB, val
48	USER(9998f, strh \ptr, [\regB], \val)
49	.endm
50
51	.macro ldr1 ptr, regB, val
52	ldr \ptr, [\regB], \val
53	.endm
54
55	.macro str1 ptr, regB, val
56	USER(9998f, str \ptr, [\regB], \val)
57	.endm
58
59	.macro ldp1 ptr, regB, regC, val
60	ldp \ptr, \regB, [\regC], \val
61	.endm
62
63	.macro stp1 ptr, regB, regC, val
64	USER(9998f, stp \ptr, \regB, [\regC], \val)
65	.endm
66
67end	.req	x5
68ENTRY(__copy_to_user)
69ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_HAS_PAN, \
70	    CONFIG_ARM64_PAN)
71	add	end, x0, x2
72#include "copy_template.S"
73ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_HAS_PAN, \
74	    CONFIG_ARM64_PAN)
75	mov	x0, #0
76	ret
77ENDPROC(__copy_to_user)
78
79	.section .fixup,"ax"
80	.align	2
819998:	sub	x0, end, dst			// bytes not copied
82	ret
83	.previous
84