xref: /openbmc/linux/arch/arm/lib/copy_to_user.S (revision 3fba7e23) 
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#include <asm/unwind.h>
16
17/*
18 * Prototype:
19 *
20 *	size_t arm_copy_to_user(void *to, const void *from, size_t n)
21 *
22 * Purpose:
23 *
24 *	copy a block to user memory from kernel memory
25 *
26 * Params:
27 *
28 *	to = user memory
29 *	from = kernel memory
30 *	n = number of bytes to copy
31 *
32 * Return value:
33 *
34 *	Number of bytes NOT copied.
35 */
36
37#define LDR1W_SHIFT	0
38#ifndef CONFIG_THUMB2_KERNEL
39#define STR1W_SHIFT	0
40#else
41#define STR1W_SHIFT	1
42#endif
43
44	.macro ldr1w ptr reg abort
45	W(ldr) \reg, [\ptr], #4
46	.endm
47
48	.macro ldr4w ptr reg1 reg2 reg3 reg4 abort
49	ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4}
50	.endm
51
52	.macro ldr8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
53	ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8}
54	.endm
55
56	.macro ldr1b ptr reg cond=al abort
57	ldr\cond\()b \reg, [\ptr], #1
58	.endm
59
60	.macro str1w ptr reg abort
61	strusr	\reg, \ptr, 4, abort=\abort
62	.endm
63
64	.macro str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
65	str1w \ptr, \reg1, \abort
66	str1w \ptr, \reg2, \abort
67	str1w \ptr, \reg3, \abort
68	str1w \ptr, \reg4, \abort
69	str1w \ptr, \reg5, \abort
70	str1w \ptr, \reg6, \abort
71	str1w \ptr, \reg7, \abort
72	str1w \ptr, \reg8, \abort
73	.endm
74
75	.macro str1b ptr reg cond=al abort
76	strusr	\reg, \ptr, 1, \cond, abort=\abort
77	.endm
78
79	.macro enter reg1 reg2
80	mov	r3, #0
81	stmdb	sp!, {r0, r2, r3, \reg1, \reg2}
82	.endm
83
84	.macro usave reg1 reg2
85	UNWIND(	.save {r0, r2, r3, \reg1, \reg2}	)
86	.endm
87
88	.macro exit reg1 reg2
89	add	sp, sp, #8
90	ldmfd	sp!, {r0, \reg1, \reg2}
91	.endm
92
93	.text
94
95ENTRY(__copy_to_user_std)
96WEAK(arm_copy_to_user)
97
98#include "copy_template.S"
99
100ENDPROC(arm_copy_to_user)
101ENDPROC(__copy_to_user_std)
102
103	.pushsection .text.fixup,"ax"
104	.align 0
105	copy_abort_preamble
106	ldmfd	sp!, {r1, r2, r3}
107	sub	r0, r0, r1
108	rsb	r0, r0, r2
109	copy_abort_end
110	.popsection
111
112