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1da177e4 LT |
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 | ||
1da177e4 LT |
22 | #include <linux/slab.h> |
23 | #include <linux/mm.h> | |
24 | #include <linux/vmalloc.h> | |
9d069dc0 | 25 | #include <linux/export.h> |
1da177e4 LT |
26 | #include <sound/memalloc.h> |
27 | ||
28 | ||
29 | /* table entries are align to 32 */ | |
30 | #define SGBUF_TBL_ALIGN 32 | |
7ab39926 | 31 | #define sgbuf_align_table(tbl) ALIGN((tbl), SGBUF_TBL_ALIGN) |
1da177e4 LT |
32 | |
33 | int snd_free_sgbuf_pages(struct snd_dma_buffer *dmab) | |
34 | { | |
35 | struct snd_sg_buf *sgbuf = dmab->private_data; | |
36 | struct snd_dma_buffer tmpb; | |
37 | int i; | |
38 | ||
39 | if (! sgbuf) | |
40 | return -EINVAL; | |
41 | ||
6af845e4 TI |
42 | if (dmab->area) |
43 | vunmap(dmab->area); | |
44 | dmab->area = NULL; | |
45 | ||
1da177e4 LT |
46 | tmpb.dev.type = SNDRV_DMA_TYPE_DEV; |
47 | tmpb.dev.dev = sgbuf->dev; | |
48 | for (i = 0; i < sgbuf->pages; i++) { | |
51e9f2e6 TI |
49 | if (!(sgbuf->table[i].addr & ~PAGE_MASK)) |
50 | continue; /* continuous pages */ | |
1da177e4 | 51 | tmpb.area = sgbuf->table[i].buf; |
51e9f2e6 TI |
52 | tmpb.addr = sgbuf->table[i].addr & PAGE_MASK; |
53 | tmpb.bytes = (sgbuf->table[i].addr & ~PAGE_MASK) << PAGE_SHIFT; | |
1da177e4 LT |
54 | snd_dma_free_pages(&tmpb); |
55 | } | |
1da177e4 LT |
56 | |
57 | kfree(sgbuf->table); | |
58 | kfree(sgbuf->page_table); | |
59 | kfree(sgbuf); | |
60 | dmab->private_data = NULL; | |
61 | ||
62 | return 0; | |
63 | } | |
64 | ||
51e9f2e6 TI |
65 | #define MAX_ALLOC_PAGES 32 |
66 | ||
1da177e4 LT |
67 | void *snd_malloc_sgbuf_pages(struct device *device, |
68 | size_t size, struct snd_dma_buffer *dmab, | |
69 | size_t *res_size) | |
70 | { | |
71 | struct snd_sg_buf *sgbuf; | |
51e9f2e6 | 72 | unsigned int i, pages, chunk, maxpages; |
1da177e4 | 73 | struct snd_dma_buffer tmpb; |
51e9f2e6 TI |
74 | struct snd_sg_page *table; |
75 | struct page **pgtable; | |
1da177e4 LT |
76 | |
77 | dmab->area = NULL; | |
78 | dmab->addr = 0; | |
59feddb2 | 79 | dmab->private_data = sgbuf = kzalloc(sizeof(*sgbuf), GFP_KERNEL); |
1da177e4 LT |
80 | if (! sgbuf) |
81 | return NULL; | |
1da177e4 LT |
82 | sgbuf->dev = device; |
83 | pages = snd_sgbuf_aligned_pages(size); | |
84 | sgbuf->tblsize = sgbuf_align_table(pages); | |
51e9f2e6 TI |
85 | table = kcalloc(sgbuf->tblsize, sizeof(*table), GFP_KERNEL); |
86 | if (!table) | |
1da177e4 | 87 | goto _failed; |
51e9f2e6 TI |
88 | sgbuf->table = table; |
89 | pgtable = kcalloc(sgbuf->tblsize, sizeof(*pgtable), GFP_KERNEL); | |
90 | if (!pgtable) | |
1da177e4 | 91 | goto _failed; |
51e9f2e6 | 92 | sgbuf->page_table = pgtable; |
1da177e4 | 93 | |
51e9f2e6 TI |
94 | /* allocate pages */ |
95 | maxpages = MAX_ALLOC_PAGES; | |
96 | while (pages > 0) { | |
97 | chunk = pages; | |
98 | /* don't be too eager to take a huge chunk */ | |
99 | if (chunk > maxpages) | |
100 | chunk = maxpages; | |
101 | chunk <<= PAGE_SHIFT; | |
102 | if (snd_dma_alloc_pages_fallback(SNDRV_DMA_TYPE_DEV, device, | |
103 | chunk, &tmpb) < 0) { | |
104 | if (!sgbuf->pages) | |
c810f903 | 105 | goto _failed; |
51e9f2e6 | 106 | if (!res_size) |
1da177e4 | 107 | goto _failed; |
51e9f2e6 | 108 | size = sgbuf->pages * PAGE_SIZE; |
1da177e4 LT |
109 | break; |
110 | } | |
51e9f2e6 TI |
111 | chunk = tmpb.bytes >> PAGE_SHIFT; |
112 | for (i = 0; i < chunk; i++) { | |
113 | table->buf = tmpb.area; | |
114 | table->addr = tmpb.addr; | |
115 | if (!i) | |
116 | table->addr |= chunk; /* mark head */ | |
117 | table++; | |
118 | *pgtable++ = virt_to_page(tmpb.area); | |
119 | tmpb.area += PAGE_SIZE; | |
120 | tmpb.addr += PAGE_SIZE; | |
121 | } | |
122 | sgbuf->pages += chunk; | |
123 | pages -= chunk; | |
124 | if (chunk < maxpages) | |
125 | maxpages = chunk; | |
1da177e4 LT |
126 | } |
127 | ||
128 | sgbuf->size = size; | |
129 | dmab->area = vmap(sgbuf->page_table, sgbuf->pages, VM_MAP, PAGE_KERNEL); | |
130 | if (! dmab->area) | |
131 | goto _failed; | |
51e9f2e6 TI |
132 | if (res_size) |
133 | *res_size = sgbuf->size; | |
1da177e4 LT |
134 | return dmab->area; |
135 | ||
136 | _failed: | |
137 | snd_free_sgbuf_pages(dmab); /* free the table */ | |
138 | return NULL; | |
139 | } | |
9d069dc0 TI |
140 | |
141 | /* | |
142 | * compute the max chunk size with continuous pages on sg-buffer | |
143 | */ | |
144 | unsigned int snd_sgbuf_get_chunk_size(struct snd_dma_buffer *dmab, | |
145 | unsigned int ofs, unsigned int size) | |
146 | { | |
147 | struct snd_sg_buf *sg = dmab->private_data; | |
148 | unsigned int start, end, pg; | |
149 | ||
150 | start = ofs >> PAGE_SHIFT; | |
151 | end = (ofs + size - 1) >> PAGE_SHIFT; | |
152 | /* check page continuity */ | |
153 | pg = sg->table[start].addr >> PAGE_SHIFT; | |
154 | for (;;) { | |
155 | start++; | |
156 | if (start > end) | |
157 | break; | |
158 | pg++; | |
159 | if ((sg->table[start].addr >> PAGE_SHIFT) != pg) | |
160 | return (start << PAGE_SHIFT) - ofs; | |
161 | } | |
162 | /* ok, all on continuous pages */ | |
163 | return size; | |
164 | } | |
165 | EXPORT_SYMBOL(snd_sgbuf_get_chunk_size); |