xref: /openbmc/linux/arch/arm/lib/copy_to_user.S (revision 384740dc)
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	.macro ldr1w ptr reg abort
37	ldr \reg, [\ptr], #4
38	.endm
39
40	.macro ldr4w ptr reg1 reg2 reg3 reg4 abort
41	ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4}
42	.endm
43
44	.macro ldr8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
45	ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8}
46	.endm
47
48	.macro ldr1b ptr reg cond=al abort
49	ldr\cond\()b \reg, [\ptr], #1
50	.endm
51
52	.macro str1w ptr reg abort
53100:	strt \reg, [\ptr], #4
54	.section __ex_table, "a"
55	.long 100b, \abort
56	.previous
57	.endm
58
59	.macro str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
60	str1w \ptr, \reg1, \abort
61	str1w \ptr, \reg2, \abort
62	str1w \ptr, \reg3, \abort
63	str1w \ptr, \reg4, \abort
64	str1w \ptr, \reg5, \abort
65	str1w \ptr, \reg6, \abort
66	str1w \ptr, \reg7, \abort
67	str1w \ptr, \reg8, \abort
68	.endm
69
70	.macro str1b ptr reg cond=al abort
71100:	str\cond\()bt \reg, [\ptr], #1
72	.section __ex_table, "a"
73	.long 100b, \abort
74	.previous
75	.endm
76
77	.macro enter reg1 reg2
78	mov	r3, #0
79	stmdb	sp!, {r0, r2, r3, \reg1, \reg2}
80	.endm
81
82	.macro exit reg1 reg2
83	add	sp, sp, #8
84	ldmfd	sp!, {r0, \reg1, \reg2}
85	.endm
86
87	.text
88
89ENTRY(__copy_to_user)
90
91#include "copy_template.S"
92
93	.section .fixup,"ax"
94	.align 0
95	copy_abort_preamble
96	ldmfd	sp!, {r1, r2, r3}
97	sub	r0, r0, r1
98	rsb	r0, r0, r2
99	copy_abort_end
100	.previous
101
102