summaryrefslogtreecommitdiff
path: root/arch/nios2/mm/uaccess.c
blob: 34f10af8ea4028a865506c4a6b479d2bf633a1a5 (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
/*
 * 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.
 *
 * Copyright (C) 2009, Wind River Systems Inc
 * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
 */

#include <linux/export.h>
#include <linux/uaccess.h>

asm(".global	raw_copy_from_user\n"
	"   .type raw_copy_from_user, @function\n"
	"raw_copy_from_user:\n"
	"   movi  r2,7\n"
	"   mov   r3,r4\n"
	"   bge   r2,r6,1f\n"
	"   xor   r2,r4,r5\n"
	"   andi  r2,r2,3\n"
	"   movi  r7,3\n"
	"   beq   r2,zero,4f\n"
	"1: addi  r6,r6,-1\n"
	"   movi  r2,-1\n"
	"   beq   r6,r2,3f\n"
	"   mov   r7,r2\n"
	"2: ldbu  r2,0(r5)\n"
	"   addi  r6,r6,-1\n"
	"   addi  r5,r5,1\n"
	"   stb   r2,0(r3)\n"
	"   addi  r3,r3,1\n"
	"   bne   r6,r7,2b\n"
	"3:\n"
	"   addi  r2,r6,1\n"
	"   ret\n"
	"13:mov   r2,r6\n"
	"   ret\n"
	"4: andi  r2,r4,1\n"
	"   cmpeq r2,r2,zero\n"
	"   beq   r2,zero,7f\n"
	"5: andi  r2,r3,2\n"
	"   beq   r2,zero,6f\n"
	"9: ldhu  r2,0(r5)\n"
	"   addi  r6,r6,-2\n"
	"   addi  r5,r5,2\n"
	"   sth   r2,0(r3)\n"
	"   addi  r3,r3,2\n"
	"6: bge   r7,r6,1b\n"
	"10:ldw   r2,0(r5)\n"
	"   addi  r6,r6,-4\n"
	"   addi  r5,r5,4\n"
	"   stw   r2,0(r3)\n"
	"   addi  r3,r3,4\n"
	"   br    6b\n"
	"7: ldbu  r2,0(r5)\n"
	"   addi  r6,r6,-1\n"
	"   addi  r5,r5,1\n"
	"   addi  r3,r4,1\n"
	"   stb   r2,0(r4)\n"
	"   br    5b\n"
	".section __ex_table,\"a\"\n"
	".word 2b,3b\n"
	".word 9b,13b\n"
	".word 10b,13b\n"
	".word 7b,13b\n"
	".previous\n"
	);
EXPORT_SYMBOL(raw_copy_from_user);

asm(
	"   .global raw_copy_to_user\n"
	"   .type raw_copy_to_user, @function\n"
	"raw_copy_to_user:\n"
	"   movi  r2,7\n"
	"   mov   r3,r4\n"
	"   bge   r2,r6,1f\n"
	"   xor   r2,r4,r5\n"
	"   andi  r2,r2,3\n"
	"   movi  r7,3\n"
	"   beq   r2,zero,4f\n"
	/* Bail if we try to copy zero bytes  */
	"1: addi  r6,r6,-1\n"
	"   movi  r2,-1\n"
	"   beq   r6,r2,3f\n"
	/* Copy byte by byte for small copies and if src^dst != 0 */
	"   mov   r7,r2\n"
	"2: ldbu  r2,0(r5)\n"
	"   addi  r5,r5,1\n"
	"9: stb   r2,0(r3)\n"
	"   addi  r6,r6,-1\n"
	"   addi  r3,r3,1\n"
	"   bne   r6,r7,2b\n"
	"3: addi  r2,r6,1\n"
	"   ret\n"
	"13:mov   r2,r6\n"
	"   ret\n"
	/*  If 'to' is an odd address byte copy */
	"4: andi  r2,r4,1\n"
	"   cmpeq r2,r2,zero\n"
	"   beq   r2,zero,7f\n"
	/* If 'to' is not divideable by four copy halfwords */
	"5: andi  r2,r3,2\n"
	"   beq   r2,zero,6f\n"
	"   ldhu  r2,0(r5)\n"
	"   addi  r5,r5,2\n"
	"10:sth   r2,0(r3)\n"
	"   addi  r6,r6,-2\n"
	"   addi  r3,r3,2\n"
	/* Copy words */
	"6: bge   r7,r6,1b\n"
	"   ldw   r2,0(r5)\n"
	"   addi  r5,r5,4\n"
	"11:stw   r2,0(r3)\n"
	"   addi  r6,r6,-4\n"
	"   addi  r3,r3,4\n"
	"   br    6b\n"
	/* Copy remaining bytes */
	"7: ldbu  r2,0(r5)\n"
	"   addi  r5,r5,1\n"
	"   addi  r3,r4,1\n"
	"12: stb  r2,0(r4)\n"
	"   addi  r6,r6,-1\n"
	"   br    5b\n"
	".section __ex_table,\"a\"\n"
	".word 9b,3b\n"
	".word 10b,13b\n"
	".word 11b,13b\n"
	".word 12b,13b\n"
	".previous\n");
EXPORT_SYMBOL(raw_copy_to_user);