1/*
2 *  linux/arch/arm/lib/getuser.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 them more
13 * efficient, especially as they return an error value in addition to
14 * the "real" return value.
15 *
16 * __get_user_X
17 *
18 * Inputs:	r0 contains the address
19 * Outputs:	r0 is the error code
20 *		r2, r3 contains the zero-extended value
21 *		lr corrupted
22 *
23 * No other registers must be altered.  (see include/asm-arm/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 __get_user_bad is not global.
28 */
29#include <asm/errno.h>
30
31	.global	__get_user_1
32__get_user_1:
331:	ldrbt	r2, [r0]
34	mov	r0, #0
35	mov	pc, lr
36
37	.global	__get_user_2
38__get_user_2:
392:	ldrbt	r2, [r0], #1
403:	ldrbt	r3, [r0]
41#ifndef __ARMEB__
42	orr	r2, r2, r3, lsl #8
43#else
44	orr	r2, r3, r2, lsl #8
45#endif
46	mov	r0, #0
47	mov	pc, lr
48
49	.global	__get_user_4
50__get_user_4:
514:	ldrt	r2, [r0]
52	mov	r0, #0
53	mov	pc, lr
54
55__get_user_bad:
56	mov	r2, #0
57	mov	r0, #-EFAULT
58	mov	pc, lr
59
60.section __ex_table, "a"
61	.long	1b, __get_user_bad
62	.long	2b, __get_user_bad
63	.long	3b, __get_user_bad
64	.long	4b, __get_user_bad
65.previous
66