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b660df3c MV |
1 | /* |
2 | * Generic bounce buffer implementation | |
3 | * | |
4 | * Copyright (C) 2012 Marek Vasut <marex@denx.de> | |
5 | * | |
6 | * See file CREDITS for list of people who contributed to this | |
7 | * project. | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License as | |
11 | * published by the Free Software Foundation; either version 2 of | |
12 | * the License, or (at your option) any later version. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public License | |
20 | * along with this program; if not, write to the Free Software | |
21 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, | |
22 | * MA 02111-1307 USA | |
23 | */ | |
24 | ||
25 | #include <common.h> | |
26 | #include <malloc.h> | |
27 | #include <errno.h> | |
28 | #include <bouncebuf.h> | |
29 | ||
30 | static int addr_aligned(void *data, size_t len) | |
31 | { | |
32 | const ulong align_mask = ARCH_DMA_MINALIGN - 1; | |
33 | ||
34 | /* Check if start is aligned */ | |
35 | if ((ulong)data & align_mask) { | |
36 | debug("Unaligned start address %p\n", data); | |
37 | return 0; | |
38 | } | |
39 | ||
40 | data += len; | |
41 | ||
42 | /* Check if end is aligned */ | |
43 | if ((ulong)data & align_mask) { | |
44 | debug("Unaligned end address %p\n", data); | |
45 | return 0; | |
46 | } | |
47 | ||
48 | /* Aligned */ | |
49 | return 1; | |
50 | } | |
51 | ||
52 | int bounce_buffer_start(void **data, size_t len, void **backup, uint8_t flags) | |
53 | { | |
54 | void *tmp; | |
55 | size_t alen; | |
56 | ||
57 | if (addr_aligned(*data, len)) { | |
58 | *backup = NULL; | |
59 | return 0; | |
60 | } | |
61 | ||
62 | alen = roundup(len, ARCH_DMA_MINALIGN); | |
63 | tmp = memalign(ARCH_DMA_MINALIGN, alen); | |
64 | ||
65 | if (!tmp) | |
66 | return -ENOMEM; | |
67 | ||
68 | if (flags & GEN_BB_READ) | |
69 | memcpy(tmp, *data, len); | |
70 | ||
71 | *backup = *data; | |
72 | *data = tmp; | |
73 | ||
74 | return 0; | |
75 | } | |
76 | ||
77 | int bounce_buffer_stop(void **data, size_t len, void **backup, uint8_t flags) | |
78 | { | |
79 | void *tmp = *data; | |
80 | ||
81 | /* The buffer was already aligned, since "backup" is NULL. */ | |
82 | if (!*backup) | |
83 | return 0; | |
84 | ||
85 | if (flags & GEN_BB_WRITE) | |
86 | memcpy(*backup, *data, len); | |
87 | ||
88 | *data = *backup; | |
89 | free(tmp); | |
90 | ||
91 | return 0; | |
92 | } |