1/*
2 *  linux/arch/arm26/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/asm-offsets.h>
30#include <asm/thread_info.h>
31#include <asm/errno.h>
32
33        .global __get_user_1
34__get_user_1:
35        bic     r1, sp, #0x1f00
36        bic     r1, r1, #0x00ff
37        str     lr, [sp, #-4]!
38        ldr     r1, [r1, #TI_ADDR_LIMIT]
39        sub     r1, r1, #1
40        cmp     r0, r1
41        bge     __get_user_bad
42        cmp     r0, #0x02000000
431:      ldrlsbt r1, [r0]
44        ldrgeb  r1, [r0]
45        mov     r0, #0
46        ldmfd   sp!, {pc}^
47
48        .global __get_user_2
49__get_user_2:
50        bic     r2, sp, #0x1f00
51        bic     r2, r2, #0x00ff
52        str     lr, [sp, #-4]!
53        ldr     r2, [r2, #TI_ADDR_LIMIT]
54        sub     r2, r2, #2
55        cmp     r0, r2
56        bge     __get_user_bad
57        cmp     r0, #0x02000000
582:      ldrlsbt r1, [r0], #1
593:      ldrlsbt r2, [r0]
60        ldrgeb  r1, [r0], #1
61        ldrgeb  r2, [r0]
62        orr     r1, r1, r2, lsl #8
63        mov     r0, #0
64        ldmfd   sp!, {pc}^
65
66        .global __get_user_4
67__get_user_4:
68        bic     r1, sp, #0x1f00
69        bic     r1, r1, #0x00ff
70        str     lr, [sp, #-4]!
71        ldr     r1, [r1, #TI_ADDR_LIMIT]
72        sub     r1, r1, #4
73        cmp     r0, r1
74        bge     __get_user_bad
75        cmp     r0, #0x02000000
764:      ldrlst  r1, [r0]
77        ldrge   r1, [r0]
78        mov     r0, #0
79        ldmfd   sp!, {pc}^
80
81        .global __get_user_8
82__get_user_8:
83        bic     r2, sp, #0x1f00
84        bic     r2, r2, #0x00ff
85        str     lr, [sp, #-4]!
86        ldr     r2, [r2, #TI_ADDR_LIMIT]
87        sub     r2, r2, #8
88        cmp     r0, r2
89        bge     __get_user_bad_8
90        cmp     r0, #0x02000000
915:      ldrlst  r1, [r0], #4
926:      ldrlst  r2, [r0]
93        ldrge   r1, [r0], #4
94        ldrge   r2, [r0]
95        mov     r0, #0
96        ldmfd   sp!, {pc}^
97
98__get_user_bad_8:
99        mov     r2, #0
100__get_user_bad:
101        mov     r1, #0
102        mov     r0, #-EFAULT
103        ldmfd   sp!, {pc}^
104
105.section __ex_table, "a"
106	.long	1b, __get_user_bad
107	.long	2b, __get_user_bad
108	.long	3b, __get_user_bad
109	.long	4b, __get_user_bad
110	.long	5b, __get_user_bad_8
111	.long	6b, __get_user_bad_8
112.previous
113