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 *		r1 contains the address limit, which must be preserved
20 * Outputs:	r0 is the error code
21 *		r2, r3 contains the zero-extended value
22 *		lr corrupted
23 *
24 * No other registers must be altered.  (see <asm/uaccess.h>
25 * for specific ASM register usage).
26 *
27 * Note that ADDR_LIMIT is either 0 or 0xc0000000.
28 * Note also that it is intended that __get_user_bad is not global.
29 */
30#include <linux/linkage.h>
31#include <asm/assembler.h>
32#include <asm/errno.h>
33#include <asm/domain.h>
34
35ENTRY(__get_user_1)
36	check_uaccess r0, 1, r1, r2, __get_user_bad
371: TUSER(ldrb)	r2, [r0]
38	mov	r0, #0
39	ret	lr
40ENDPROC(__get_user_1)
41
42ENTRY(__get_user_2)
43	check_uaccess r0, 2, r1, r2, __get_user_bad
44#ifdef CONFIG_CPU_USE_DOMAINS
45rb	.req	ip
462:	ldrbt	r2, [r0], #1
473:	ldrbt	rb, [r0], #0
48#else
49rb	.req	r0
502:	ldrb	r2, [r0]
513:	ldrb	rb, [r0, #1]
52#endif
53#ifndef __ARMEB__
54	orr	r2, r2, rb, lsl #8
55#else
56	orr	r2, rb, r2, lsl #8
57#endif
58	mov	r0, #0
59	ret	lr
60ENDPROC(__get_user_2)
61
62ENTRY(__get_user_4)
63	check_uaccess r0, 4, r1, r2, __get_user_bad
644: TUSER(ldr)	r2, [r0]
65	mov	r0, #0
66	ret	lr
67ENDPROC(__get_user_4)
68
69ENTRY(__get_user_8)
70	check_uaccess r0, 8, r1, r2, __get_user_bad
71#ifdef CONFIG_THUMB2_KERNEL
725: TUSER(ldr)	r2, [r0]
736: TUSER(ldr)	r3, [r0, #4]
74#else
755: TUSER(ldr)	r2, [r0], #4
766: TUSER(ldr)	r3, [r0]
77#endif
78	mov	r0, #0
79	ret	lr
80ENDPROC(__get_user_8)
81
82#ifdef __ARMEB__
83ENTRY(__get_user_32t_8)
84	check_uaccess r0, 8, r1, r2, __get_user_bad
85#ifdef CONFIG_CPU_USE_DOMAINS
86	add	r0, r0, #4
877:	ldrt	r2, [r0]
88#else
897:	ldr	r2, [r0, #4]
90#endif
91	mov	r0, #0
92	ret	lr
93ENDPROC(__get_user_32t_8)
94
95ENTRY(__get_user_64t_1)
96	check_uaccess r0, 1, r1, r2, __get_user_bad8
978: TUSER(ldrb)	r3, [r0]
98	mov	r0, #0
99	ret	lr
100ENDPROC(__get_user_64t_1)
101
102ENTRY(__get_user_64t_2)
103	check_uaccess r0, 2, r1, r2, __get_user_bad8
104#ifdef CONFIG_CPU_USE_DOMAINS
105rb	.req	ip
1069:	ldrbt	r3, [r0], #1
10710:	ldrbt	rb, [r0], #0
108#else
109rb	.req	r0
1109:	ldrb	r3, [r0]
11110:	ldrb	rb, [r0, #1]
112#endif
113	orr	r3, rb, r3, lsl #8
114	mov	r0, #0
115	ret	lr
116ENDPROC(__get_user_64t_2)
117
118ENTRY(__get_user_64t_4)
119	check_uaccess r0, 4, r1, r2, __get_user_bad8
12011: TUSER(ldr)	r3, [r0]
121	mov	r0, #0
122	ret	lr
123ENDPROC(__get_user_64t_4)
124#endif
125
126__get_user_bad8:
127	mov	r3, #0
128__get_user_bad:
129	mov	r2, #0
130	mov	r0, #-EFAULT
131	ret	lr
132ENDPROC(__get_user_bad)
133ENDPROC(__get_user_bad8)
134
135.pushsection __ex_table, "a"
136	.long	1b, __get_user_bad
137	.long	2b, __get_user_bad
138	.long	3b, __get_user_bad
139	.long	4b, __get_user_bad
140	.long	5b, __get_user_bad8
141	.long	6b, __get_user_bad8
142#ifdef __ARMEB__
143	.long   7b, __get_user_bad
144	.long	8b, __get_user_bad8
145	.long	9b, __get_user_bad8
146	.long	10b, __get_user_bad8
147	.long	11b, __get_user_bad8
148#endif
149.popsection
150