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 *		r1, r2 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/constants.h>
30
31	.global	__get_user_1
32__get_user_1:
33	bic	r1, sp, #0x1f00
34	bic	r1, r1, #0x00ff
35	ldr	r1, [r1, #TSK_ADDR_LIMIT]
36	sub	r1, r1, #1
37	cmp	r0, r1
381:	ldrlsbt	r1, [r0]
39	movls	r0, #0
40	movls	pc, lr
41	b	__get_user_bad
42
43	.global	__get_user_2
44__get_user_2:
45	bic	r2, sp, #0x1f00
46	bic	r2, r2, #0x00ff
47	ldr	r2, [r2, #TSK_ADDR_LIMIT]
48	sub	r2, r2, #2
49	cmp	r0, r2
502:	ldrlsbt	r1, [r0], #1
513:	ldrlsbt	r2, [r0]
52	orrls	r1, r1, r2, lsl #8
53	movls	r0, #0
54	movls	pc, lr
55	b	__get_user_bad
56
57	.global	__get_user_4
58__get_user_4:
59	bic	r1, sp, #0x1f00
60	bic	r1, r1, #0x00ff
61	ldr	r1, [r1, #TSK_ADDR_LIMIT]
62	sub	r1, r1, #4
63	cmp	r0, r1
644:	ldrlst	r1, [r0]
65	movls	r0, #0
66	movls	pc, lr
67	b	__get_user_bad
68
69	.global	__get_user_8
70__get_user_8:
71	bic	r2, sp, #0x1f00
72	bic	r2, r2, #0x00ff
73	ldr	r2, [r2, #TSK_ADDR_LIMIT]
74	sub	r2, r2, #8
75	cmp	r0, r2
765:	ldrlst	r1, [r0], #4
776:	ldrlst	r2, [r0]
78	movls	r0, #0
79	movls	pc, lr
80
81	/* fall through */
82
83__get_user_bad_8:
84	mov	r2, #0
85__get_user_bad:
86	mov	r1, #0
87	mov	r0, #-14
88	mov	pc, lr
89
90.section __ex_table, "a"
91	.long	1b, __get_user_bad
92	.long	2b, __get_user_bad
93	.long	3b, __get_user_bad
94	.long	4b, __get_user_bad
95	.long	5b, __get_user_bad_8
96	.long	6b, __get_user_bad_8
97.previous
98