summaryrefslogtreecommitdiffstats
path: root/arch/microblaze/lib/uaccess_old.S
blob: d09f2dce648dcebf1e925f9e8c982af85b771ecc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
/*
 * Copyright (C) 2009 Michal Simek <monstr@monstr.eu>
 * Copyright (C) 2009 PetaLogix
 * Copyright (C) 2007 LynuxWorks, Inc.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#include <linux/errno.h>
#include <linux/linkage.h>

/*
 * int __strncpy_user(char *to, char *from, int len);
 *
 * Returns:
 *  -EFAULT  for an exception
 *  len      if we hit the buffer limit
 *  bytes copied
 */

	.text
.globl __strncpy_user;
.type  __strncpy_user, @function
.align 4;
__strncpy_user:

	/*
	 * r5 - to
	 * r6 - from
	 * r7 - len
	 * r3 - temp count
	 * r4 - temp val
	 */
	addik	r3,r7,0		/* temp_count = len */
	beqi	r3,3f
1:
	lbu	r4,r6,r0
	sb	r4,r5,r0

	addik	r3,r3,-1
	beqi	r3,2f		/* break on len */

	addik	r5,r5,1
	bneid	r4,1b
	addik	r6,r6,1		/* delay slot */
	addik	r3,r3,1		/* undo "temp_count--" */
2:
	rsubk	r3,r3,r7	/* temp_count = len - temp_count */
3:
	rtsd	r15,8
	nop
	.size   __strncpy_user, . - __strncpy_user

	.section	.fixup, "ax"
	.align	2
4:
	brid	3b
	addik	r3,r0, -EFAULT

	.section	__ex_table, "a"
	.word	1b,4b

/*
 * int __strnlen_user(char __user *str, int maxlen);
 *
 * Returns:
 *  0 on error
 *  maxlen + 1  if no NUL byte found within maxlen bytes
 *  size of the string (including NUL byte)
 */

	.text
.globl __strnlen_user;
.type  __strnlen_user, @function
.align 4;
__strnlen_user:
	addik	r3,r6,0
	beqi	r3,3f
1:
	lbu	r4,r5,r0
	beqid	r4,2f		/* break on NUL */
	addik	r3,r3,-1	/* delay slot */

	bneid	r3,1b
	addik	r5,r5,1		/* delay slot */

	addik	r3,r3,-1	/* for break on len */
2:
	rsubk	r3,r3,r6
3:
	rtsd	r15,8
	nop
	.size   __strnlen_user, . - __strnlen_user

	.section	.fixup,"ax"
4:
	brid	3b
	addk	r3,r0,r0

	.section	__ex_table,"a"
	.word	1b,4b

/*
 * int __copy_tofrom_user(char *to, char *from, int len)
 * Return:
 *   0 on success
 *   number of not copied bytes on error
 */
	.text
.globl __copy_tofrom_user;
.type  __copy_tofrom_user, @function
.align 4;
__copy_tofrom_user:
	/*
	 * r5 - to
	 * r6 - from
	 * r7, r3 - count
	 * r4 - tempval
	 */
	beqid	r7, 0f /* zero size is not likely */
	or	r3, r5, r6 /* find if is any to/from unaligned */
	or	r3, r3, r7 /* find if count is unaligned */
	andi	r3, r3, 0x3 /* mask last 3 bits */
	bneid	r3, bu1 /* if r3 is not zero then byte copying */
	or	r3, r0, r0

w1:	lw	r4, r6, r3 /* at least one 4 byte copy */
w2:	sw	r4, r5, r3
	addik	r7, r7, -4
	bneid	r7, w1
	addik	r3, r3, 4
	addik	r3, r7, 0
	rtsd	r15, 8
	nop

	.section	__ex_table,"a"
	.word	w1, 0f;
	.word	w2, 0f;
	.text

bu1:	lbu	r4,r6,r3
bu2:	sb	r4,r5,r3
	addik	r7,r7,-1
	bneid	r7,bu1
	addik	r3,r3,1		/* delay slot */
0:
	addik	r3,r7,0
	rtsd	r15,8
	nop
	.size   __copy_tofrom_user, . - __copy_tofrom_user

	.section	__ex_table,"a"
	.word	bu1, 0b;
	.word	bu2, 0b;
	.text