xref: /openbmc/linux/arch/arm/lib/putuser.S (revision 367b8112)
1/*
2 *  linux/arch/arm/lib/putuser.S
3 *
4 *  Copyright (C) 2001 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 *  Idea from x86 version, (C) Copyright 1998 Linus Torvalds
11 *
12 * These functions have a non-standard call interface to make
13 * them more efficient, especially as they return an error
14 * value in addition to the "real" return value.
15 *
16 * __put_user_X
17 *
18 * Inputs:	r0 contains the address
19 *		r2, r3 contains the value
20 * Outputs:	r0 is the error code
21 *		lr corrupted
22 *
23 * No other registers must be altered.  (see <asm/uaccess.h>
24 * for specific ASM register usage).
25 *
26 * Note that ADDR_LIMIT is either 0 or 0xc0000000
27 * Note also that it is intended that __put_user_bad is not global.
28 */
29#include <linux/linkage.h>
30#include <asm/errno.h>
31
32ENTRY(__put_user_1)
331:	strbt	r2, [r0]
34	mov	r0, #0
35	mov	pc, lr
36ENDPROC(__put_user_1)
37
38ENTRY(__put_user_2)
39	mov	ip, r2, lsr #8
40#ifndef __ARMEB__
412:	strbt	r2, [r0], #1
423:	strbt	ip, [r0]
43#else
442:	strbt	ip, [r0], #1
453:	strbt	r2, [r0]
46#endif
47	mov	r0, #0
48	mov	pc, lr
49ENDPROC(__put_user_2)
50
51ENTRY(__put_user_4)
524:	strt	r2, [r0]
53	mov	r0, #0
54	mov	pc, lr
55ENDPROC(__put_user_4)
56
57ENTRY(__put_user_8)
585:	strt	r2, [r0], #4
596:	strt	r3, [r0]
60	mov	r0, #0
61	mov	pc, lr
62ENDPROC(__put_user_8)
63
64__put_user_bad:
65	mov	r0, #-EFAULT
66	mov	pc, lr
67ENDPROC(__put_user_bad)
68
69.section __ex_table, "a"
70	.long	1b, __put_user_bad
71	.long	2b, __put_user_bad
72	.long	3b, __put_user_bad
73	.long	4b, __put_user_bad
74	.long	5b, __put_user_bad
75	.long	6b, __put_user_bad
76.previous
77