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322ae8eb MS |
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 memcpy 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 | * | |
af901ca1 | 12 | * Attempts were made, unsuccessfully, to contact the original |
322ae8eb MS |
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/types.h> | |
28 | #include <linux/stddef.h> | |
29 | #include <linux/compiler.h> | |
30 | #include <linux/module.h> | |
31 | ||
32 | #include <linux/string.h> | |
33 | #include <asm/system.h> | |
34 | ||
35 | #ifdef __HAVE_ARCH_MEMCPY | |
93e2e851 | 36 | #ifndef CONFIG_OPT_LIB_FUNCTION |
322ae8eb MS |
37 | void *memcpy(void *v_dst, const void *v_src, __kernel_size_t c) |
38 | { | |
39 | const char *src = v_src; | |
40 | char *dst = v_dst; | |
93e2e851 | 41 | |
322ae8eb MS |
42 | /* Simple, byte oriented memcpy. */ |
43 | while (c--) | |
44 | *dst++ = *src++; | |
45 | ||
46 | return v_dst; | |
93e2e851 MS |
47 | } |
48 | #else /* CONFIG_OPT_LIB_FUNCTION */ | |
49 | void *memcpy(void *v_dst, const void *v_src, __kernel_size_t c) | |
50 | { | |
51 | const char *src = v_src; | |
52 | char *dst = v_dst; | |
53 | ||
322ae8eb MS |
54 | /* The following code tries to optimize the copy by using unsigned |
55 | * alignment. This will work fine if both source and destination are | |
56 | * aligned on the same boundary. However, if they are aligned on | |
57 | * different boundaries shifts will be necessary. This might result in | |
58 | * bad performance on MicroBlaze systems without a barrel shifter. | |
59 | */ | |
60 | const uint32_t *i_src; | |
61 | uint32_t *i_dst; | |
62 | ||
78ebfa88 | 63 | if (likely(c >= 4)) { |
322ae8eb MS |
64 | unsigned value, buf_hold; |
65 | ||
25985edc LDM |
66 | /* Align the destination to a word boundary. */ |
67 | /* This is done in an endian independent manner. */ | |
322ae8eb MS |
68 | switch ((unsigned long)dst & 3) { |
69 | case 1: | |
70 | *dst++ = *src++; | |
71 | --c; | |
72 | case 2: | |
73 | *dst++ = *src++; | |
74 | --c; | |
75 | case 3: | |
76 | *dst++ = *src++; | |
77 | --c; | |
78 | } | |
79 | ||
80 | i_dst = (void *)dst; | |
81 | ||
82 | /* Choose a copy scheme based on the source */ | |
25985edc | 83 | /* alignment relative to destination. */ |
322ae8eb MS |
84 | switch ((unsigned long)src & 3) { |
85 | case 0x0: /* Both byte offsets are aligned */ | |
86 | i_src = (const void *)src; | |
87 | ||
88 | for (; c >= 4; c -= 4) | |
89 | *i_dst++ = *i_src++; | |
90 | ||
91 | src = (const void *)i_src; | |
92 | break; | |
93 | case 0x1: /* Unaligned - Off by 1 */ | |
94 | /* Word align the source */ | |
95 | i_src = (const void *) ((unsigned)src & ~3); | |
1180b28c | 96 | #ifndef __MICROBLAZEEL__ |
322ae8eb MS |
97 | /* Load the holding buffer */ |
98 | buf_hold = *i_src++ << 8; | |
99 | ||
100 | for (; c >= 4; c -= 4) { | |
101 | value = *i_src++; | |
102 | *i_dst++ = buf_hold | value >> 24; | |
103 | buf_hold = value << 8; | |
104 | } | |
1180b28c MS |
105 | #else |
106 | /* Load the holding buffer */ | |
107 | buf_hold = (*i_src++ & 0xFFFFFF00) >>8; | |
322ae8eb | 108 | |
1180b28c MS |
109 | for (; c >= 4; c -= 4) { |
110 | value = *i_src++; | |
111 | *i_dst++ = buf_hold | ((value & 0xFF) << 24); | |
112 | buf_hold = (value & 0xFFFFFF00) >>8; | |
113 | } | |
114 | #endif | |
322ae8eb MS |
115 | /* Realign the source */ |
116 | src = (const void *)i_src; | |
117 | src -= 3; | |
118 | break; | |
119 | case 0x2: /* Unaligned - Off by 2 */ | |
120 | /* Word align the source */ | |
121 | i_src = (const void *) ((unsigned)src & ~3); | |
1180b28c | 122 | #ifndef __MICROBLAZEEL__ |
322ae8eb MS |
123 | /* Load the holding buffer */ |
124 | buf_hold = *i_src++ << 16; | |
125 | ||
126 | for (; c >= 4; c -= 4) { | |
127 | value = *i_src++; | |
128 | *i_dst++ = buf_hold | value >> 16; | |
129 | buf_hold = value << 16; | |
130 | } | |
1180b28c MS |
131 | #else |
132 | /* Load the holding buffer */ | |
133 | buf_hold = (*i_src++ & 0xFFFF0000 )>>16; | |
322ae8eb | 134 | |
1180b28c MS |
135 | for (; c >= 4; c -= 4) { |
136 | value = *i_src++; | |
137 | *i_dst++ = buf_hold | ((value & 0xFFFF)<<16); | |
138 | buf_hold = (value & 0xFFFF0000) >>16; | |
139 | } | |
140 | #endif | |
322ae8eb MS |
141 | /* Realign the source */ |
142 | src = (const void *)i_src; | |
143 | src -= 2; | |
144 | break; | |
145 | case 0x3: /* Unaligned - Off by 3 */ | |
146 | /* Word align the source */ | |
147 | i_src = (const void *) ((unsigned)src & ~3); | |
1180b28c | 148 | #ifndef __MICROBLAZEEL__ |
322ae8eb MS |
149 | /* Load the holding buffer */ |
150 | buf_hold = *i_src++ << 24; | |
151 | ||
152 | for (; c >= 4; c -= 4) { | |
153 | value = *i_src++; | |
154 | *i_dst++ = buf_hold | value >> 8; | |
155 | buf_hold = value << 24; | |
156 | } | |
1180b28c MS |
157 | #else |
158 | /* Load the holding buffer */ | |
159 | buf_hold = (*i_src++ & 0xFF000000) >> 24; | |
322ae8eb | 160 | |
1180b28c MS |
161 | for (; c >= 4; c -= 4) { |
162 | value = *i_src++; | |
163 | *i_dst++ = buf_hold | ((value & 0xFFFFFF) << 8); | |
164 | buf_hold = (value & 0xFF000000) >> 24; | |
165 | } | |
166 | #endif | |
322ae8eb MS |
167 | /* Realign the source */ |
168 | src = (const void *)i_src; | |
169 | src -= 1; | |
170 | break; | |
171 | } | |
172 | dst = (void *)i_dst; | |
173 | } | |
174 | ||
175 | /* Finish off any remaining bytes */ | |
25985edc | 176 | /* simple fast copy, ... unless a cache boundary is crossed */ |
322ae8eb MS |
177 | switch (c) { |
178 | case 3: | |
179 | *dst++ = *src++; | |
180 | case 2: | |
181 | *dst++ = *src++; | |
182 | case 1: | |
183 | *dst++ = *src++; | |
184 | } | |
185 | ||
186 | return v_dst; | |
322ae8eb | 187 | } |
93e2e851 | 188 | #endif /* CONFIG_OPT_LIB_FUNCTION */ |
322ae8eb MS |
189 | EXPORT_SYMBOL(memcpy); |
190 | #endif /* __HAVE_ARCH_MEMCPY */ |