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 from user space to 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
23	.macro ldrb1 reg, ptr, val
24	user_ldst 9998f, ldtrb, \reg, \ptr, \val
25	.endm
26
27	.macro strb1 reg, ptr, val
28	strb \reg, [\ptr], \val
29	.endm
30
31	.macro ldrh1 reg, ptr, val
32	user_ldst 9997f, ldtrh, \reg, \ptr, \val
33	.endm
34
35	.macro strh1 reg, ptr, val
36	strh \reg, [\ptr], \val
37	.endm
38
39	.macro ldr1 reg, ptr, val
40	user_ldst 9997f, ldtr, \reg, \ptr, \val
41	.endm
42
43	.macro str1 reg, ptr, val
44	str \reg, [\ptr], \val
45	.endm
46
47	.macro ldp1 reg1, reg2, ptr, val
48	user_ldp 9997f, \reg1, \reg2, \ptr, \val
49	.endm
50
51	.macro stp1 reg1, reg2, ptr, val
52	stp \reg1, \reg2, [\ptr], \val
53	.endm
54
55end	.req	x5
56srcin	.req	x15
57SYM_FUNC_START(__arch_copy_from_user)
58	add	end, x0, x2
59	mov	srcin, x1
60#include "copy_template.S"
61	mov	x0, #0				// Nothing to copy
62	ret
63
64	// Exception fixups
659997:	cmp	dst, dstin
66	b.ne	9998f
67	// Before being absolutely sure we couldn't copy anything, try harder
68USER(9998f, ldtrb tmp1w, [srcin])
69	strb	tmp1w, [dst], #1
709998:	sub	x0, end, dst			// bytes not copied
71	ret
72SYM_FUNC_END(__arch_copy_from_user)
73EXPORT_SYMBOL(__arch_copy_from_user)
74