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Nicolas Pitrefadab092005-11-01 19:52:24 +00001/*
2 * linux/arch/arm/lib/copy_from_user.S
3 *
4 * Author: Nicolas Pitre
5 * Created: Sep 29, 2005
6 * Copyright: MontaVista Software, Inc.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include <linux/linkage.h>
14#include <asm/assembler.h>
15
16/*
17 * Prototype:
18 *
Russell King02fcb972006-06-21 14:44:52 +010019 * size_t __copy_from_user(void *to, const void *from, size_t n)
Nicolas Pitrefadab092005-11-01 19:52:24 +000020 *
21 * Purpose:
22 *
23 * copy a block to kernel memory from user memory
24 *
25 * Params:
26 *
27 * to = kernel memory
28 * from = user memory
29 * n = number of bytes to copy
30 *
31 * Return value:
32 *
33 * Number of bytes NOT copied.
34 */
35
Catalin Marinas8b592782009-07-24 12:32:57 +010036#ifndef CONFIG_THUMB2_KERNEL
37#define LDR1W_SHIFT 0
38#else
39#define LDR1W_SHIFT 1
40#endif
41#define STR1W_SHIFT 0
42
Nicolas Pitrefadab092005-11-01 19:52:24 +000043 .macro ldr1w ptr reg abort
Catalin Marinas8b592782009-07-24 12:32:57 +010044 ldrusr \reg, \ptr, 4, abort=\abort
Nicolas Pitrefadab092005-11-01 19:52:24 +000045 .endm
46
47 .macro ldr4w ptr reg1 reg2 reg3 reg4 abort
48 ldr1w \ptr, \reg1, \abort
49 ldr1w \ptr, \reg2, \abort
50 ldr1w \ptr, \reg3, \abort
51 ldr1w \ptr, \reg4, \abort
52 .endm
53
54 .macro ldr8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
55 ldr4w \ptr, \reg1, \reg2, \reg3, \reg4, \abort
56 ldr4w \ptr, \reg5, \reg6, \reg7, \reg8, \abort
57 .endm
58
59 .macro ldr1b ptr reg cond=al abort
Catalin Marinas8b592782009-07-24 12:32:57 +010060 ldrusr \reg, \ptr, 1, \cond, abort=\abort
Nicolas Pitrefadab092005-11-01 19:52:24 +000061 .endm
62
63 .macro str1w ptr reg abort
Catalin Marinas8b592782009-07-24 12:32:57 +010064 W(str) \reg, [\ptr], #4
Nicolas Pitrefadab092005-11-01 19:52:24 +000065 .endm
66
67 .macro str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
68 stmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8}
69 .endm
70
71 .macro str1b ptr reg cond=al abort
72 str\cond\()b \reg, [\ptr], #1
73 .endm
74
75 .macro enter reg1 reg2
76 mov r3, #0
77 stmdb sp!, {r0, r2, r3, \reg1, \reg2}
78 .endm
79
80 .macro exit reg1 reg2
81 add sp, sp, #8
82 ldmfd sp!, {r0, \reg1, \reg2}
83 .endm
84
85 .text
86
Russell King02fcb972006-06-21 14:44:52 +010087ENTRY(__copy_from_user)
Nicolas Pitrefadab092005-11-01 19:52:24 +000088
89#include "copy_template.S"
90
Catalin Marinas93ed3972008-08-28 11:22:32 +010091ENDPROC(__copy_from_user)
92
Nicolas Pitrefadab092005-11-01 19:52:24 +000093 .section .fixup,"ax"
94 .align 0
95 copy_abort_preamble
96 ldmfd sp!, {r1, r2}
97 sub r3, r0, r1
98 rsb r1, r3, r2
99 str r1, [sp]
100 bl __memzero
101 ldr r0, [sp], #4
102 copy_abort_end
103 .previous
104