xref: /linux/arch/arm64/lib/copy_from_user.S (revision 23d19ba06b9c5614d6457f5fed349ec8f6d4dac9)
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/asm-uaccess.h>
20#include <asm/assembler.h>
21#include <asm/cache.h>
22
23/*
24 * Copy from user space to a kernel buffer (alignment handled by the hardware)
25 *
26 * Parameters:
27 *	x0 - to
28 *	x1 - from
29 *	x2 - n
30 * Returns:
31 *	x0 - bytes not copied
32 */
33
34	.macro ldrb1 ptr, regB, val
35	uao_user_alternative 9998f, ldrb, ldtrb, \ptr, \regB, \val
36	.endm
37
38	.macro strb1 ptr, regB, val
39	strb \ptr, [\regB], \val
40	.endm
41
42	.macro ldrh1 ptr, regB, val
43	uao_user_alternative 9998f, ldrh, ldtrh, \ptr, \regB, \val
44	.endm
45
46	.macro strh1 ptr, regB, val
47	strh \ptr, [\regB], \val
48	.endm
49
50	.macro ldr1 ptr, regB, val
51	uao_user_alternative 9998f, ldr, ldtr, \ptr, \regB, \val
52	.endm
53
54	.macro str1 ptr, regB, val
55	str \ptr, [\regB], \val
56	.endm
57
58	.macro ldp1 ptr, regB, regC, val
59	uao_ldp 9998f, \ptr, \regB, \regC, \val
60	.endm
61
62	.macro stp1 ptr, regB, regC, val
63	stp \ptr, \regB, [\regC], \val
64	.endm
65
66end	.req	x5
67ENTRY(__arch_copy_from_user)
68	uaccess_enable_not_uao x3, x4, x5
69	add	end, x0, x2
70#include "copy_template.S"
71	uaccess_disable_not_uao x3, x4
72	mov	x0, #0				// Nothing to copy
73	ret
74ENDPROC(__arch_copy_from_user)
75EXPORT_SYMBOL(__arch_copy_from_user)
76
77	.section .fixup,"ax"
78	.align	2
799998:	sub	x0, end, dst			// bytes not copied
80	ret
81	.previous
82