xref: /openbmc/linux/arch/arm64/lib/copy_to_user.S (revision 03638e62)
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (C) 2012 ARM Ltd.
4 */
5
6#include <linux/linkage.h>
7
8#include <asm/asm-uaccess.h>
9#include <asm/assembler.h>
10#include <asm/cache.h>
11
12/*
13 * Copy to user space from a kernel buffer (alignment handled by the hardware)
14 *
15 * Parameters:
16 *	x0 - to
17 *	x1 - from
18 *	x2 - n
19 * Returns:
20 *	x0 - bytes not copied
21 */
22	.macro ldrb1 ptr, regB, val
23	ldrb  \ptr, [\regB], \val
24	.endm
25
26	.macro strb1 ptr, regB, val
27	uao_user_alternative 9998f, strb, sttrb, \ptr, \regB, \val
28	.endm
29
30	.macro ldrh1 ptr, regB, val
31	ldrh  \ptr, [\regB], \val
32	.endm
33
34	.macro strh1 ptr, regB, val
35	uao_user_alternative 9998f, strh, sttrh, \ptr, \regB, \val
36	.endm
37
38	.macro ldr1 ptr, regB, val
39	ldr \ptr, [\regB], \val
40	.endm
41
42	.macro str1 ptr, regB, val
43	uao_user_alternative 9998f, str, sttr, \ptr, \regB, \val
44	.endm
45
46	.macro ldp1 ptr, regB, regC, val
47	ldp \ptr, \regB, [\regC], \val
48	.endm
49
50	.macro stp1 ptr, regB, regC, val
51	uao_stp 9998f, \ptr, \regB, \regC, \val
52	.endm
53
54end	.req	x5
55ENTRY(__arch_copy_to_user)
56	uaccess_enable_not_uao x3, x4, x5
57	add	end, x0, x2
58#include "copy_template.S"
59	uaccess_disable_not_uao x3, x4
60	mov	x0, #0
61	ret
62ENDPROC(__arch_copy_to_user)
63EXPORT_SYMBOL(__arch_copy_to_user)
64
65	.section .fixup,"ax"
66	.align	2
679998:	sub	x0, end, dst			// bytes not copied
68	ret
69	.previous
70