1 | /* |
2 | * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu> |
3 | * Copyright (C) 2008-2009 PetaLogix |
4 | * Copyright (C) 2007 John Williams |
5 | * |
6 | * Reasonably optimised generic C-code for memset on Microblaze |
7 | * This is generic C code to do efficient, alignment-aware memcpy. |
8 | * |
9 | * It is based on demo code originally Copyright 2001 by Intel Corp, taken from |
10 | * http://www.embedded.com/showArticle.jhtml?articleID=19205567 |
11 | * |
12 | * Attempts were made, unsuccessfully, to contact the original |
13 | * author of this code (Michael Morrow, Intel). Below is the original |
14 | * copyright notice. |
15 | * |
16 | * This software has been developed by Intel Corporation. |
17 | * Intel specifically disclaims all warranties, express or |
18 | * implied, and all liability, including consequential and |
19 | * other indirect damages, for the use of this program, including |
20 | * liability for infringement of any proprietary rights, |
21 | * and including the warranties of merchantability and fitness |
22 | * for a particular purpose. Intel does not assume any |
23 | * responsibility for and errors which may appear in this program |
24 | * not any responsibility to update it. |
25 | */ |
26 | |
27 | #include <linux/export.h> |
28 | #include <linux/types.h> |
29 | #include <linux/stddef.h> |
30 | #include <linux/compiler.h> |
31 | #include <linux/string.h> |
32 | |
33 | #ifdef CONFIG_OPT_LIB_FUNCTION |
34 | void *memset(void *v_src, int c, __kernel_size_t n) |
35 | { |
36 | char *src = v_src; |
37 | uint32_t *i_src; |
38 | uint32_t w32 = 0; |
39 | |
40 | /* Truncate c to 8 bits */ |
41 | c = (c & 0xFF); |
42 | |
43 | if (unlikely(c)) { |
44 | /* Make a repeating word out of it */ |
45 | w32 = c; |
46 | w32 |= w32 << 8; |
47 | w32 |= w32 << 16; |
48 | } |
49 | |
50 | if (likely(n >= 4)) { |
51 | /* Align the destination to a word boundary */ |
52 | /* This is done in an endian independent manner */ |
53 | switch ((unsigned) src & 3) { |
54 | case 1: |
55 | *src++ = c; |
56 | --n; |
57 | fallthrough; |
58 | case 2: |
59 | *src++ = c; |
60 | --n; |
61 | fallthrough; |
62 | case 3: |
63 | *src++ = c; |
64 | --n; |
65 | } |
66 | |
67 | i_src = (void *)src; |
68 | |
69 | /* Do as many full-word copies as we can */ |
70 | for (; n >= 4; n -= 4) |
71 | *i_src++ = w32; |
72 | |
73 | src = (void *)i_src; |
74 | } |
75 | |
76 | /* Simple, byte oriented memset or the rest of count. */ |
77 | switch (n) { |
78 | case 3: |
79 | *src++ = c; |
80 | fallthrough; |
81 | case 2: |
82 | *src++ = c; |
83 | fallthrough; |
84 | case 1: |
85 | *src++ = c; |
86 | break; |
87 | default: |
88 | break; |
89 | } |
90 | |
91 | return v_src; |
92 | } |
93 | EXPORT_SYMBOL(memset); |
94 | #endif /* CONFIG_OPT_LIB_FUNCTION */ |
95 | |