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
|
/*
* 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 memset 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>
#ifdef __HAVE_ARCH_MEMSET
#ifndef CONFIG_OPT_LIB_FUNCTION
void *memset(void *v_src, int c, __kernel_size_t n)
{
char *src = v_src;
/* Truncate c to 8 bits */
c = (c & 0xFF);
/* Simple, byte oriented memset or the rest of count. */
while (n--)
*src++ = c;
return v_src;
}
#else /* CONFIG_OPT_LIB_FUNCTION */
void *memset(void *v_src, int c, __kernel_size_t n)
{
char *src = v_src;
uint32_t *i_src;
uint32_t w32 = 0;
/* Truncate c to 8 bits */
c = (c & 0xFF);
if (unlikely(c)) {
/* Make a repeating word out of it */
w32 = c;
w32 |= w32 << 8;
w32 |= w32 << 16;
}
if (likely(n >= 4)) {
/* Align the destination to a word boundary */
/* This is done in an endian independant manner */
switch ((unsigned) src & 3) {
case 1:
*src++ = c;
--n;
case 2:
*src++ = c;
--n;
case 3:
*src++ = c;
--n;
}
i_src = (void *)src;
/* Do as many full-word copies as we can */
for (; n >= 4; n -= 4)
*i_src++ = w32;
src = (void *)i_src;
}
/* Simple, byte oriented memset or the rest of count. */
while (n--)
*src++ = c;
return v_src;
}
#endif /* CONFIG_OPT_LIB_FUNCTION */
EXPORT_SYMBOL(memset);
#endif /* __HAVE_ARCH_MEMSET */
|
