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1 | /* |
2 | * Scatter-Gather buffer |
3 | * |
4 | * Copyright (c) by Takashi Iwai <tiwai@suse.de> |
5 | * |
6 | * This program is free software; you can redistribute it and/or modify |
7 | * it under the terms of the GNU General Public License as published by |
8 | * the Free Software Foundation; either version 2 of the License, or |
9 | * (at your option) any later version. |
10 | * |
11 | * This program is distributed in the hope that it will be useful, |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
14 | * GNU General Public License for more details. |
15 | * |
16 | * You should have received a copy of the GNU General Public License |
17 | * along with this program; if not, write to the Free Software |
18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
19 | * |
20 | */ |
21 | |
22 | #include <linux/slab.h> |
23 | #include <linux/mm.h> |
24 | #include <linux/vmalloc.h> |
25 | #include <sound/memalloc.h> |
26 | |
27 | |
28 | /* table entries are align to 32 */ |
29 | #define SGBUF_TBL_ALIGN 32 |
30 | #define sgbuf_align_table(tbl) ALIGN((tbl), SGBUF_TBL_ALIGN) |
31 | |
32 | int snd_free_sgbuf_pages(struct snd_dma_buffer *dmab) |
33 | { |
34 | struct snd_sg_buf *sgbuf = dmab->private_data; |
35 | struct snd_dma_buffer tmpb; |
36 | int i; |
37 | |
38 | if (! sgbuf) |
39 | return -EINVAL; |
40 | |
41 | if (dmab->area) |
42 | vunmap(dmab->area); |
43 | dmab->area = NULL; |
44 | |
45 | tmpb.dev.type = SNDRV_DMA_TYPE_DEV; |
46 | tmpb.dev.dev = sgbuf->dev; |
47 | for (i = 0; i < sgbuf->pages; i++) { |
48 | if (!(sgbuf->table[i].addr & ~PAGE_MASK)) |
49 | continue; /* continuous pages */ |
50 | tmpb.area = sgbuf->table[i].buf; |
51 | tmpb.addr = sgbuf->table[i].addr & PAGE_MASK; |
52 | tmpb.bytes = (sgbuf->table[i].addr & ~PAGE_MASK) << PAGE_SHIFT; |
53 | snd_dma_free_pages(&tmpb); |
54 | } |
55 | |
56 | kfree(sgbuf->table); |
57 | kfree(sgbuf->page_table); |
58 | kfree(sgbuf); |
59 | dmab->private_data = NULL; |
60 | |
61 | return 0; |
62 | } |
63 | |
64 | #define MAX_ALLOC_PAGES 32 |
65 | |
66 | void *snd_malloc_sgbuf_pages(struct device *device, |
67 | size_t size, struct snd_dma_buffer *dmab, |
68 | size_t *res_size) |
69 | { |
70 | struct snd_sg_buf *sgbuf; |
71 | unsigned int i, pages, chunk, maxpages; |
72 | struct snd_dma_buffer tmpb; |
73 | struct snd_sg_page *table; |
74 | struct page **pgtable; |
75 | |
76 | dmab->area = NULL; |
77 | dmab->addr = 0; |
78 | dmab->private_data = sgbuf = kzalloc(sizeof(*sgbuf), GFP_KERNEL); |
79 | if (! sgbuf) |
80 | return NULL; |
81 | sgbuf->dev = device; |
82 | pages = snd_sgbuf_aligned_pages(size); |
83 | sgbuf->tblsize = sgbuf_align_table(pages); |
84 | table = kcalloc(sgbuf->tblsize, sizeof(*table), GFP_KERNEL); |
85 | if (!table) |
86 | goto _failed; |
87 | sgbuf->table = table; |
88 | pgtable = kcalloc(sgbuf->tblsize, sizeof(*pgtable), GFP_KERNEL); |
89 | if (!pgtable) |
90 | goto _failed; |
91 | sgbuf->page_table = pgtable; |
92 | |
93 | /* allocate pages */ |
94 | maxpages = MAX_ALLOC_PAGES; |
95 | while (pages > 0) { |
96 | chunk = pages; |
97 | /* don't be too eager to take a huge chunk */ |
98 | if (chunk > maxpages) |
99 | chunk = maxpages; |
100 | chunk <<= PAGE_SHIFT; |
101 | if (snd_dma_alloc_pages_fallback(SNDRV_DMA_TYPE_DEV, device, |
102 | chunk, &tmpb) < 0) { |
103 | if (!sgbuf->pages) |
104 | return NULL; |
105 | if (!res_size) |
106 | goto _failed; |
107 | size = sgbuf->pages * PAGE_SIZE; |
108 | break; |
109 | } |
110 | chunk = tmpb.bytes >> PAGE_SHIFT; |
111 | for (i = 0; i < chunk; i++) { |
112 | table->buf = tmpb.area; |
113 | table->addr = tmpb.addr; |
114 | if (!i) |
115 | table->addr |= chunk; /* mark head */ |
116 | table++; |
117 | *pgtable++ = virt_to_page(tmpb.area); |
118 | tmpb.area += PAGE_SIZE; |
119 | tmpb.addr += PAGE_SIZE; |
120 | } |
121 | sgbuf->pages += chunk; |
122 | pages -= chunk; |
123 | if (chunk < maxpages) |
124 | maxpages = chunk; |
125 | } |
126 | |
127 | sgbuf->size = size; |
128 | dmab->area = vmap(sgbuf->page_table, sgbuf->pages, VM_MAP, PAGE_KERNEL); |
129 | if (! dmab->area) |
130 | goto _failed; |
131 | if (res_size) |
132 | *res_size = sgbuf->size; |
133 | return dmab->area; |
134 | |
135 | _failed: |
136 | snd_free_sgbuf_pages(dmab); /* free the table */ |
137 | return NULL; |
138 | } |
139 |
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Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9