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
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
|
/*
* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2008-2009 PetaLogix
* Copyright (C) 2007 John Williams
*
* Reasonably optimised generic C-code for memcpy on Microblaze
* This is generic C code to do efficient, alignment-aware memcpy.
*
* It is based on demo code originally Copyright 2001 by Intel Corp, taken from
* http://www.embedded.com/showArticle.jhtml?articleID=19205567
*
* Attempts were made, unsuccessfully, to contact the original
* author of this code (Michael Morrow, Intel). Below is the original
* copyright notice.
*
* This software has been developed by Intel Corporation.
* Intel specifically disclaims all warranties, express or
* implied, and all liability, including consequential and
* other indirect damages, for the use of this program, including
* liability for infringement of any proprietary rights,
* and including the warranties of merchantability and fitness
* for a particular purpose. Intel does not assume any
* responsibility for and errors which may appear in this program
* not any responsibility to update it.
*/
#include <linux/types.h>
#include <linux/stddef.h>
#include <linux/compiler.h>
#include <linux/module.h>
#include <linux/string.h>
#include <asm/system.h>
#ifdef __HAVE_ARCH_MEMCPY
#ifndef CONFIG_OPT_LIB_FUNCTION
void *memcpy(void *v_dst, const void *v_src, __kernel_size_t c)
{
const char *src = v_src;
char *dst = v_dst;
/* Simple, byte oriented memcpy. */
while (c--)
*dst++ = *src++;
return v_dst;
}
#else /* CONFIG_OPT_LIB_FUNCTION */
void *memcpy(void *v_dst, const void *v_src, __kernel_size_t c)
{
const char *src = v_src;
char *dst = v_dst;
/* The following code tries to optimize the copy by using unsigned
* alignment. This will work fine if both source and destination are
* aligned on the same boundary. However, if they are aligned on
* different boundaries shifts will be necessary. This might result in
* bad performance on MicroBlaze systems without a barrel shifter.
*/
const uint32_t *i_src;
uint32_t *i_dst;
if (likely(c >= 4)) {
unsigned value, buf_hold;
/* Align the dstination to a word boundry. */
/* This is done in an endian independant manner. */
switch ((unsigned long)dst & 3) {
case 1:
*dst++ = *src++;
--c;
case 2:
*dst++ = *src++;
--c;
case 3:
*dst++ = *src++;
--c;
}
i_dst = (void *)dst;
/* Choose a copy scheme based on the source */
/* alignment relative to dstination. */
switch ((unsigned long)src & 3) {
case 0x0: /* Both byte offsets are aligned */
i_src = (const void *)src;
for (; c >= 4; c -= 4)
*i_dst++ = *i_src++;
src = (const void *)i_src;
break;
case 0x1: /* Unaligned - Off by 1 */
/* Word align the source */
i_src = (const void *) ((unsigned)src & ~3);
#ifndef __MICROBLAZEEL__
/* Load the holding buffer */
buf_hold = *i_src++ << 8;
for (; c >= 4; c -= 4) {
value = *i_src++;
*i_dst++ = buf_hold | value >> 24;
buf_hold = value << 8;
}
#else
/* Load the holding buffer */
buf_hold = (*i_src++ & 0xFFFFFF00) >>8;
for (; c >= 4; c -= 4) {
value = *i_src++;
*i_dst++ = buf_hold | ((value & 0xFF) << 24);
buf_hold = (value & 0xFFFFFF00) >>8;
}
#endif
/* Realign the source */
src = (const void *)i_src;
src -= 3;
break;
case 0x2: /* Unaligned - Off by 2 */
/* Word align the source */
i_src = (const void *) ((unsigned)src & ~3);
#ifndef __MICROBLAZEEL__
/* Load the holding buffer */
buf_hold = *i_src++ << 16;
for (; c >= 4; c -= 4) {
value = *i_src++;
*i_dst++ = buf_hold | value >> 16;
buf_hold = value << 16;
}
#else
/* Load the holding buffer */
buf_hold = (*i_src++ & 0xFFFF0000 )>>16;
for (; c >= 4; c -= 4) {
value = *i_src++;
*i_dst++ = buf_hold | ((value & 0xFFFF)<<16);
buf_hold = (value & 0xFFFF0000) >>16;
}
#endif
/* Realign the source */
src = (const void *)i_src;
src -= 2;
break;
case 0x3: /* Unaligned - Off by 3 */
/* Word align the source */
i_src = (const void *) ((unsigned)src & ~3);
#ifndef __MICROBLAZEEL__
/* Load the holding buffer */
buf_hold = *i_src++ << 24;
for (; c >= 4; c -= 4) {
value = *i_src++;
*i_dst++ = buf_hold | value >> 8;
buf_hold = value << 24;
}
#else
/* Load the holding buffer */
buf_hold = (*i_src++ & 0xFF000000) >> 24;
for (; c >= 4; c -= 4) {
value = *i_src++;
*i_dst++ = buf_hold | ((value & 0xFFFFFF) << 8);
buf_hold = (value & 0xFF000000) >> 24;
}
#endif
/* Realign the source */
src = (const void *)i_src;
src -= 1;
break;
}
dst = (void *)i_dst;
}
/* Finish off any remaining bytes */
/* simple fast copy, ... unless a cache boundry is crossed */
switch (c) {
case 3:
*dst++ = *src++;
case 2:
*dst++ = *src++;
case 1:
*dst++ = *src++;
}
return v_dst;
}
#endif /* CONFIG_OPT_LIB_FUNCTION */
EXPORT_SYMBOL(memcpy);
#endif /* __HAVE_ARCH_MEMCPY */
|
