1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 *  linux/arch/arm/lib/putuser.S
4 *
5 *  Copyright (C) 2001 Russell King
6 *
7 *  Idea from x86 version, (C) Copyright 1998 Linus Torvalds
8 *
9 * These functions have a non-standard call interface to make
10 * them more efficient, especially as they return an error
11 * value in addition to the "real" return value.
12 *
13 * __put_user_X
14 *
15 * Inputs:	r0 contains the address
16 *		r1 contains the address limit, which must be preserved
17 *		r2, r3 contains the value
18 * Outputs:	r0 is the error code
19 *		lr corrupted
20 *
21 * No other registers must be altered.  (see <asm/uaccess.h>
22 * for specific ASM register usage).
23 *
24 * Note that ADDR_LIMIT is either 0 or 0xc0000000
25 * Note also that it is intended that __put_user_bad is not global.
26 */
27#include <linux/linkage.h>
28#include <asm/assembler.h>
29#include <asm/errno.h>
30#include <asm/domain.h>
31
32ENTRY(__put_user_1)
33	check_uaccess r0, 1, r1, ip, __put_user_bad
341: TUSER(strb)	r2, [r0]
35	mov	r0, #0
36	ret	lr
37ENDPROC(__put_user_1)
38
39ENTRY(__put_user_2)
40	check_uaccess r0, 2, r1, ip, __put_user_bad
41#if __LINUX_ARM_ARCH__ >= 6
42
432: TUSER(strh)	r2, [r0]
44
45#else
46
47	mov	ip, r2, lsr #8
48#ifndef __ARMEB__
492: TUSER(strb)	r2, [r0], #1
503: TUSER(strb)	ip, [r0]
51#else
522: TUSER(strb)	ip, [r0], #1
533: TUSER(strb)	r2, [r0]
54#endif
55
56#endif /* __LINUX_ARM_ARCH__ >= 6 */
57	mov	r0, #0
58	ret	lr
59ENDPROC(__put_user_2)
60
61ENTRY(__put_user_4)
62	check_uaccess r0, 4, r1, ip, __put_user_bad
634: TUSER(str)	r2, [r0]
64	mov	r0, #0
65	ret	lr
66ENDPROC(__put_user_4)
67
68ENTRY(__put_user_8)
69	check_uaccess r0, 8, r1, ip, __put_user_bad
70#ifdef CONFIG_THUMB2_KERNEL
715: TUSER(str)	r2, [r0]
726: TUSER(str)	r3, [r0, #4]
73#else
745: TUSER(str)	r2, [r0], #4
756: TUSER(str)	r3, [r0]
76#endif
77	mov	r0, #0
78	ret	lr
79ENDPROC(__put_user_8)
80
81__put_user_bad:
82	mov	r0, #-EFAULT
83	ret	lr
84ENDPROC(__put_user_bad)
85
86.pushsection __ex_table, "a"
87	.long	1b, __put_user_bad
88	.long	2b, __put_user_bad
89#if __LINUX_ARM_ARCH__ < 6
90	.long	3b, __put_user_bad
91#endif
92	.long	4b, __put_user_bad
93	.long	5b, __put_user_bad
94	.long	6b, __put_user_bad
95.popsection
96