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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 memmove.
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 __HAVE_ARCH_MEMMOVE
34#ifndef CONFIG_OPT_LIB_FUNCTION
35void *memmove(void *v_dst, const void *v_src, __kernel_size_t c)
36{
37 const char *src = v_src;
38 char *dst = v_dst;
39
40 if (!c)
41 return v_dst;
42
43 /* Use memcpy when source is higher than dest */
44 if (v_dst <= v_src)
45 return memcpy(v_dst, v_src, c);
46
47 /* copy backwards, from end to beginning */
48 src += c;
49 dst += c;
50
51 /* Simple, byte oriented memmove. */
52 while (c--)
53 *--dst = *--src;
54
55 return v_dst;
56}
57#else /* CONFIG_OPT_LIB_FUNCTION */
58void *memmove(void *v_dst, const void *v_src, __kernel_size_t c)
59{
60 const char *src = v_src;
61 char *dst = v_dst;
62 const uint32_t *i_src;
63 uint32_t *i_dst;
64
65 if (!c)
66 return v_dst;
67
68 /* Use memcpy when source is higher than dest */
69 if (v_dst <= v_src)
70 return memcpy(v_dst, v_src, c);
71
72 /* The following code tries to optimize the copy by using unsigned
73 * alignment. This will work fine if both source and destination are
74 * aligned on the same boundary. However, if they are aligned on
75 * different boundaries shifts will be necessary. This might result in
76 * bad performance on MicroBlaze systems without a barrel shifter.
77 */
78 /* FIXME this part needs more test */
79 /* Do a descending copy - this is a bit trickier! */
80 dst += c;
81 src += c;
82
83 if (c >= 4) {
84 unsigned value, buf_hold;
85
86 /* Align the destination to a word boundary. */
87 /* This is done in an endian independent manner. */
88
89 switch ((unsigned long)dst & 3) {
90 case 3:
91 *--dst = *--src;
92 --c;
93 case 2:
94 *--dst = *--src;
95 --c;
96 case 1:
97 *--dst = *--src;
98 --c;
99 }
100
101 i_dst = (void *)dst;
102 /* Choose a copy scheme based on the source */
103 /* alignment relative to dstination. */
104 switch ((unsigned long)src & 3) {
105 case 0x0: /* Both byte offsets are aligned */
106
107 i_src = (const void *)src;
108
109 for (; c >= 4; c -= 4)
110 *--i_dst = *--i_src;
111
112 src = (const void *)i_src;
113 break;
114 case 0x1: /* Unaligned - Off by 1 */
115 /* Word align the source */
116 i_src = (const void *) (((unsigned)src + 4) & ~3);
117#ifndef __MICROBLAZEEL__
118 /* Load the holding buffer */
119 buf_hold = *--i_src >> 24;
120
121 for (; c >= 4; c -= 4) {
122 value = *--i_src;
123 *--i_dst = buf_hold << 8 | value;
124 buf_hold = value >> 24;
125 }
126#else
127 /* Load the holding buffer */
128 buf_hold = (*--i_src & 0xFF) << 24;
129
130 for (; c >= 4; c -= 4) {
131 value = *--i_src;
132 *--i_dst = buf_hold |
133 ((value & 0xFFFFFF00) >> 8);
134 buf_hold = (value & 0xFF) << 24;
135 }
136#endif
137 /* Realign the source */
138 src = (const void *)i_src;
139 src += 1;
140 break;
141 case 0x2: /* Unaligned - Off by 2 */
142 /* Word align the source */
143 i_src = (const void *) (((unsigned)src + 4) & ~3);
144#ifndef __MICROBLAZEEL__
145 /* Load the holding buffer */
146 buf_hold = *--i_src >> 16;
147
148 for (; c >= 4; c -= 4) {
149 value = *--i_src;
150 *--i_dst = buf_hold << 16 | value;
151 buf_hold = value >> 16;
152 }
153#else
154 /* Load the holding buffer */
155 buf_hold = (*--i_src & 0xFFFF) << 16;
156
157 for (; c >= 4; c -= 4) {
158 value = *--i_src;
159 *--i_dst = buf_hold |
160 ((value & 0xFFFF0000) >> 16);
161 buf_hold = (value & 0xFFFF) << 16;
162 }
163#endif
164 /* Realign the source */
165 src = (const void *)i_src;
166 src += 2;
167 break;
168 case 0x3: /* Unaligned - Off by 3 */
169 /* Word align the source */
170 i_src = (const void *) (((unsigned)src + 4) & ~3);
171#ifndef __MICROBLAZEEL__
172 /* Load the holding buffer */
173 buf_hold = *--i_src >> 8;
174
175 for (; c >= 4; c -= 4) {
176 value = *--i_src;
177 *--i_dst = buf_hold << 24 | value;
178 buf_hold = value >> 8;
179 }
180#else
181 /* Load the holding buffer */
182 buf_hold = (*--i_src & 0xFFFFFF) << 8;
183
184 for (; c >= 4; c -= 4) {
185 value = *--i_src;
186 *--i_dst = buf_hold |
187 ((value & 0xFF000000) >> 24);
188 buf_hold = (value & 0xFFFFFF) << 8;
189 }
190#endif
191 /* Realign the source */
192 src = (const void *)i_src;
193 src += 3;
194 break;
195 }
196 dst = (void *)i_dst;
197 }
198
199 /* simple fast copy, ... unless a cache boundary is crossed */
200 /* Finish off any remaining bytes */
201 switch (c) {
202 case 4:
203 *--dst = *--src;
204 case 3:
205 *--dst = *--src;
206 case 2:
207 *--dst = *--src;
208 case 1:
209 *--dst = *--src;
210 }
211 return v_dst;
212}
213#endif /* CONFIG_OPT_LIB_FUNCTION */
214EXPORT_SYMBOL(memmove);
215#endif /* __HAVE_ARCH_MEMMOVE */
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 memmove.
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
34void *memmove(void *v_dst, const void *v_src, __kernel_size_t c)
35{
36 const char *src = v_src;
37 char *dst = v_dst;
38 const uint32_t *i_src;
39 uint32_t *i_dst;
40
41 if (!c)
42 return v_dst;
43
44 /* Use memcpy when source is higher than dest */
45 if (v_dst <= v_src)
46 return memcpy(v_dst, v_src, c);
47
48 /* The following code tries to optimize the copy by using unsigned
49 * alignment. This will work fine if both source and destination are
50 * aligned on the same boundary. However, if they are aligned on
51 * different boundaries shifts will be necessary. This might result in
52 * bad performance on MicroBlaze systems without a barrel shifter.
53 */
54 /* FIXME this part needs more test */
55 /* Do a descending copy - this is a bit trickier! */
56 dst += c;
57 src += c;
58
59 if (c >= 4) {
60 unsigned value, buf_hold;
61
62 /* Align the destination to a word boundary. */
63 /* This is done in an endian independent manner. */
64
65 switch ((unsigned long)dst & 3) {
66 case 3:
67 *--dst = *--src;
68 --c;
69 fallthrough;
70 case 2:
71 *--dst = *--src;
72 --c;
73 fallthrough;
74 case 1:
75 *--dst = *--src;
76 --c;
77 }
78
79 i_dst = (void *)dst;
80 /* Choose a copy scheme based on the source */
81 /* alignment relative to destination. */
82 switch ((unsigned long)src & 3) {
83 case 0x0: /* Both byte offsets are aligned */
84
85 i_src = (const void *)src;
86
87 for (; c >= 4; c -= 4)
88 *--i_dst = *--i_src;
89
90 src = (const void *)i_src;
91 break;
92 case 0x1: /* Unaligned - Off by 1 */
93 /* Word align the source */
94 i_src = (const void *) (((unsigned)src + 4) & ~3);
95#ifndef __MICROBLAZEEL__
96 /* Load the holding buffer */
97 buf_hold = *--i_src >> 24;
98
99 for (; c >= 4; c -= 4) {
100 value = *--i_src;
101 *--i_dst = buf_hold << 8 | value;
102 buf_hold = value >> 24;
103 }
104#else
105 /* Load the holding buffer */
106 buf_hold = (*--i_src & 0xFF) << 24;
107
108 for (; c >= 4; c -= 4) {
109 value = *--i_src;
110 *--i_dst = buf_hold |
111 ((value & 0xFFFFFF00) >> 8);
112 buf_hold = (value & 0xFF) << 24;
113 }
114#endif
115 /* Realign the source */
116 src = (const void *)i_src;
117 src += 1;
118 break;
119 case 0x2: /* Unaligned - Off by 2 */
120 /* Word align the source */
121 i_src = (const void *) (((unsigned)src + 4) & ~3);
122#ifndef __MICROBLAZEEL__
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 << 16 | value;
129 buf_hold = value >> 16;
130 }
131#else
132 /* Load the holding buffer */
133 buf_hold = (*--i_src & 0xFFFF) << 16;
134
135 for (; c >= 4; c -= 4) {
136 value = *--i_src;
137 *--i_dst = buf_hold |
138 ((value & 0xFFFF0000) >> 16);
139 buf_hold = (value & 0xFFFF) << 16;
140 }
141#endif
142 /* Realign the source */
143 src = (const void *)i_src;
144 src += 2;
145 break;
146 case 0x3: /* Unaligned - Off by 3 */
147 /* Word align the source */
148 i_src = (const void *) (((unsigned)src + 4) & ~3);
149#ifndef __MICROBLAZEEL__
150 /* Load the holding buffer */
151 buf_hold = *--i_src >> 8;
152
153 for (; c >= 4; c -= 4) {
154 value = *--i_src;
155 *--i_dst = buf_hold << 24 | value;
156 buf_hold = value >> 8;
157 }
158#else
159 /* Load the holding buffer */
160 buf_hold = (*--i_src & 0xFFFFFF) << 8;
161
162 for (; c >= 4; c -= 4) {
163 value = *--i_src;
164 *--i_dst = buf_hold |
165 ((value & 0xFF000000) >> 24);
166 buf_hold = (value & 0xFFFFFF) << 8;
167 }
168#endif
169 /* Realign the source */
170 src = (const void *)i_src;
171 src += 3;
172 break;
173 }
174 dst = (void *)i_dst;
175 }
176
177 /* simple fast copy, ... unless a cache boundary is crossed */
178 /* Finish off any remaining bytes */
179 switch (c) {
180 case 4:
181 *--dst = *--src;
182 fallthrough;
183 case 3:
184 *--dst = *--src;
185 fallthrough;
186 case 2:
187 *--dst = *--src;
188 fallthrough;
189 case 1:
190 *--dst = *--src;
191 }
192 return v_dst;
193}
194EXPORT_SYMBOL(memmove);
195#endif /* CONFIG_OPT_LIB_FUNCTION */