xref: /openbmc/linux/arch/arm64/lib/copy_from_user.S (revision bb0eb050)
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/cache.h>
20#include <asm/asm-uaccess.h>
21
22/*
23 * Copy from user space to a kernel buffer (alignment handled by the hardware)
24 *
25 * Parameters:
26 *	x0 - to
27 *	x1 - from
28 *	x2 - n
29 * Returns:
30 *	x0 - bytes not copied
31 */
32
33	.macro ldrb1 ptr, regB, val
34	uao_user_alternative 9998f, ldrb, ldtrb, \ptr, \regB, \val
35	.endm
36
37	.macro strb1 ptr, regB, val
38	strb \ptr, [\regB], \val
39	.endm
40
41	.macro ldrh1 ptr, regB, val
42	uao_user_alternative 9998f, ldrh, ldtrh, \ptr, \regB, \val
43	.endm
44
45	.macro strh1 ptr, regB, val
46	strh \ptr, [\regB], \val
47	.endm
48
49	.macro ldr1 ptr, regB, val
50	uao_user_alternative 9998f, ldr, ldtr, \ptr, \regB, \val
51	.endm
52
53	.macro str1 ptr, regB, val
54	str \ptr, [\regB], \val
55	.endm
56
57	.macro ldp1 ptr, regB, regC, val
58	uao_ldp 9998f, \ptr, \regB, \regC, \val
59	.endm
60
61	.macro stp1 ptr, regB, regC, val
62	stp \ptr, \regB, [\regC], \val
63	.endm
64
65end	.req	x5
66ENTRY(__arch_copy_from_user)
67	uaccess_enable_not_uao x3, x4
68	add	end, x0, x2
69#include "copy_template.S"
70	uaccess_disable_not_uao x3
71	mov	x0, #0				// Nothing to copy
72	ret
73ENDPROC(__arch_copy_from_user)
74
75	.section .fixup,"ax"
76	.align	2
779998:	sub	x0, end, dst			// bytes not copied
78	ret
79	.previous
80