xref: /openbmc/linux/arch/arm/lib/copy_to_user.S (revision b6dcefde) 
1/*
2 *  linux/arch/arm/lib/copy_to_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 *
19 *	size_t __copy_to_user(void *to, const void *from, size_t n)
20 *
21 * Purpose:
22 *
23 *	copy a block to user memory from kernel memory
24 *
25 * Params:
26 *
27 *	to = user memory
28 *	from = kernel memory
29 *	n = number of bytes to copy
30 *
31 * Return value:
32 *
33 *	Number of bytes NOT copied.
34 */
35
36#define LDR1W_SHIFT	0
37#ifndef CONFIG_THUMB2_KERNEL
38#define STR1W_SHIFT	0
39#else
40#define STR1W_SHIFT	1
41#endif
42
43	.macro ldr1w ptr reg abort
44	W(ldr) \reg, [\ptr], #4
45	.endm
46
47	.macro ldr4w ptr reg1 reg2 reg3 reg4 abort
48	ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4}
49	.endm
50
51	.macro ldr8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
52	ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8}
53	.endm
54
55	.macro ldr1b ptr reg cond=al abort
56	ldr\cond\()b \reg, [\ptr], #1
57	.endm
58
59	.macro str1w ptr reg abort
60	strusr	\reg, \ptr, 4, abort=\abort
61	.endm
62
63	.macro str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
64	str1w \ptr, \reg1, \abort
65	str1w \ptr, \reg2, \abort
66	str1w \ptr, \reg3, \abort
67	str1w \ptr, \reg4, \abort
68	str1w \ptr, \reg5, \abort
69	str1w \ptr, \reg6, \abort
70	str1w \ptr, \reg7, \abort
71	str1w \ptr, \reg8, \abort
72	.endm
73
74	.macro str1b ptr reg cond=al abort
75	strusr	\reg, \ptr, 1, \cond, abort=\abort
76	.endm
77
78	.macro enter reg1 reg2
79	mov	r3, #0
80	stmdb	sp!, {r0, r2, r3, \reg1, \reg2}
81	.endm
82
83	.macro exit reg1 reg2
84	add	sp, sp, #8
85	ldmfd	sp!, {r0, \reg1, \reg2}
86	.endm
87
88	.text
89
90ENTRY(__copy_to_user_std)
91WEAK(__copy_to_user)
92
93#include "copy_template.S"
94
95ENDPROC(__copy_to_user)
96
97	.section .fixup,"ax"
98	.align 0
99	copy_abort_preamble
100	ldmfd	sp!, {r1, r2, r3}
101	sub	r0, r0, r1
102	rsb	r0, r0, r2
103	copy_abort_end
104	.previous
105
106