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1da177e4 LT |
1 | /* |
2 | * Digital Audio (PCM) abstract layer | |
3 | * Copyright (c) by Jaroslav Kysela <perex@suse.cz> | |
4 | * | |
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 <sound/driver.h> | |
23 | #include <asm/io.h> | |
24 | #include <linux/time.h> | |
25 | #include <linux/init.h> | |
26 | #include <linux/moduleparam.h> | |
27 | #include <sound/core.h> | |
28 | #include <sound/pcm.h> | |
29 | #include <sound/info.h> | |
30 | #include <sound/initval.h> | |
31 | ||
32 | static int preallocate_dma = 1; | |
33 | module_param(preallocate_dma, int, 0444); | |
34 | MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized."); | |
35 | ||
36 | static int maximum_substreams = 4; | |
37 | module_param(maximum_substreams, int, 0444); | |
38 | MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory."); | |
39 | ||
40 | static const size_t snd_minimum_buffer = 16384; | |
41 | ||
42 | ||
43 | /* | |
44 | * try to allocate as the large pages as possible. | |
45 | * stores the resultant memory size in *res_size. | |
46 | * | |
47 | * the minimum size is snd_minimum_buffer. it should be power of 2. | |
48 | */ | |
49 | static int preallocate_pcm_pages(snd_pcm_substream_t *substream, size_t size) | |
50 | { | |
51 | struct snd_dma_buffer *dmab = &substream->dma_buffer; | |
52 | int err; | |
53 | ||
54 | snd_assert(size > 0, return -EINVAL); | |
55 | ||
56 | /* already reserved? */ | |
57 | if (snd_dma_get_reserved_buf(dmab, substream->dma_buf_id) > 0) { | |
58 | if (dmab->bytes >= size) | |
59 | return 0; /* yes */ | |
60 | /* no, free the reserved block */ | |
61 | snd_dma_free_pages(dmab); | |
62 | dmab->bytes = 0; | |
63 | } | |
64 | ||
65 | do { | |
66 | if ((err = snd_dma_alloc_pages(dmab->dev.type, dmab->dev.dev, | |
67 | size, dmab)) < 0) { | |
68 | if (err != -ENOMEM) | |
69 | return err; /* fatal error */ | |
70 | } else | |
71 | return 0; | |
72 | size >>= 1; | |
73 | } while (size >= snd_minimum_buffer); | |
74 | dmab->bytes = 0; /* tell error */ | |
75 | return 0; | |
76 | } | |
77 | ||
78 | /* | |
79 | * release the preallocated buffer if not yet done. | |
80 | */ | |
81 | static void snd_pcm_lib_preallocate_dma_free(snd_pcm_substream_t *substream) | |
82 | { | |
83 | if (substream->dma_buffer.area == NULL) | |
84 | return; | |
85 | if (substream->dma_buf_id) | |
86 | snd_dma_reserve_buf(&substream->dma_buffer, substream->dma_buf_id); | |
87 | else | |
88 | snd_dma_free_pages(&substream->dma_buffer); | |
89 | substream->dma_buffer.area = NULL; | |
90 | } | |
91 | ||
92 | /** | |
93 | * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream. | |
94 | * @substream: the pcm substream instance | |
95 | * | |
96 | * Releases the pre-allocated buffer of the given substream. | |
97 | * | |
98 | * Returns zero if successful, or a negative error code on failure. | |
99 | */ | |
100 | int snd_pcm_lib_preallocate_free(snd_pcm_substream_t *substream) | |
101 | { | |
102 | snd_pcm_lib_preallocate_dma_free(substream); | |
103 | if (substream->proc_prealloc_entry) { | |
104 | snd_info_unregister(substream->proc_prealloc_entry); | |
105 | substream->proc_prealloc_entry = NULL; | |
106 | } | |
107 | return 0; | |
108 | } | |
109 | ||
110 | /** | |
111 | * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm | |
112 | * @pcm: the pcm instance | |
113 | * | |
114 | * Releases all the pre-allocated buffers on the given pcm. | |
115 | * | |
116 | * Returns zero if successful, or a negative error code on failure. | |
117 | */ | |
118 | int snd_pcm_lib_preallocate_free_for_all(snd_pcm_t *pcm) | |
119 | { | |
120 | snd_pcm_substream_t *substream; | |
121 | int stream; | |
122 | ||
123 | for (stream = 0; stream < 2; stream++) | |
124 | for (substream = pcm->streams[stream].substream; substream; substream = substream->next) | |
125 | snd_pcm_lib_preallocate_free(substream); | |
126 | return 0; | |
127 | } | |
128 | ||
129 | /* | |
130 | * read callback for prealloc proc file | |
131 | * | |
132 | * prints the current allocated size in kB. | |
133 | */ | |
134 | static void snd_pcm_lib_preallocate_proc_read(snd_info_entry_t *entry, | |
135 | snd_info_buffer_t *buffer) | |
136 | { | |
137 | snd_pcm_substream_t *substream = (snd_pcm_substream_t *)entry->private_data; | |
138 | snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024); | |
139 | } | |
140 | ||
141 | /* | |
142 | * write callback for prealloc proc file | |
143 | * | |
144 | * accepts the preallocation size in kB. | |
145 | */ | |
146 | static void snd_pcm_lib_preallocate_proc_write(snd_info_entry_t *entry, | |
147 | snd_info_buffer_t *buffer) | |
148 | { | |
149 | snd_pcm_substream_t *substream = (snd_pcm_substream_t *)entry->private_data; | |
150 | char line[64], str[64]; | |
151 | size_t size; | |
152 | struct snd_dma_buffer new_dmab; | |
153 | ||
154 | if (substream->runtime) { | |
155 | buffer->error = -EBUSY; | |
156 | return; | |
157 | } | |
158 | if (!snd_info_get_line(buffer, line, sizeof(line))) { | |
159 | snd_info_get_str(str, line, sizeof(str)); | |
160 | size = simple_strtoul(str, NULL, 10) * 1024; | |
161 | if ((size != 0 && size < 8192) || size > substream->dma_max) { | |
162 | buffer->error = -EINVAL; | |
163 | return; | |
164 | } | |
165 | if (substream->dma_buffer.bytes == size) | |
166 | return; | |
167 | memset(&new_dmab, 0, sizeof(new_dmab)); | |
168 | new_dmab.dev = substream->dma_buffer.dev; | |
169 | if (size > 0) { | |
170 | if (snd_dma_alloc_pages(substream->dma_buffer.dev.type, | |
171 | substream->dma_buffer.dev.dev, | |
172 | size, &new_dmab) < 0) { | |
173 | buffer->error = -ENOMEM; | |
174 | return; | |
175 | } | |
176 | substream->buffer_bytes_max = size; | |
177 | } else { | |
178 | substream->buffer_bytes_max = UINT_MAX; | |
179 | } | |
180 | if (substream->dma_buffer.area) | |
181 | snd_dma_free_pages(&substream->dma_buffer); | |
182 | substream->dma_buffer = new_dmab; | |
183 | } else { | |
184 | buffer->error = -EINVAL; | |
185 | } | |
186 | } | |
187 | ||
188 | /* | |
189 | * pre-allocate the buffer and create a proc file for the substream | |
190 | */ | |
191 | static int snd_pcm_lib_preallocate_pages1(snd_pcm_substream_t *substream, | |
192 | size_t size, size_t max) | |
193 | { | |
194 | snd_info_entry_t *entry; | |
195 | ||
196 | if (size > 0 && preallocate_dma && substream->number < maximum_substreams) | |
197 | preallocate_pcm_pages(substream, size); | |
198 | ||
199 | if (substream->dma_buffer.bytes > 0) | |
200 | substream->buffer_bytes_max = substream->dma_buffer.bytes; | |
201 | substream->dma_max = max; | |
202 | if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) { | |
203 | entry->c.text.read_size = 64; | |
204 | entry->c.text.read = snd_pcm_lib_preallocate_proc_read; | |
205 | entry->c.text.write_size = 64; | |
206 | entry->c.text.write = snd_pcm_lib_preallocate_proc_write; | |
bd7bf042 | 207 | entry->mode |= S_IWUSR; |
1da177e4 LT |
208 | entry->private_data = substream; |
209 | if (snd_info_register(entry) < 0) { | |
210 | snd_info_free_entry(entry); | |
211 | entry = NULL; | |
212 | } | |
213 | } | |
214 | substream->proc_prealloc_entry = entry; | |
215 | return 0; | |
216 | } | |
217 | ||
218 | ||
219 | /** | |
220 | * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type | |
221 | * @substream: the pcm substream instance | |
222 | * @type: DMA type (SNDRV_DMA_TYPE_*) | |
223 | * @data: DMA type dependant data | |
224 | * @size: the requested pre-allocation size in bytes | |
225 | * @max: the max. allowed pre-allocation size | |
226 | * | |
227 | * Do pre-allocation for the given DMA buffer type. | |
228 | * | |
229 | * When substream->dma_buf_id is set, the function tries to look for | |
230 | * the reserved buffer, and the buffer is not freed but reserved at | |
231 | * destruction time. The dma_buf_id must be unique for all systems | |
232 | * (in the same DMA buffer type) e.g. using snd_dma_pci_buf_id(). | |
233 | * | |
234 | * Returns zero if successful, or a negative error code on failure. | |
235 | */ | |
236 | int snd_pcm_lib_preallocate_pages(snd_pcm_substream_t *substream, | |
237 | int type, struct device *data, | |
238 | size_t size, size_t max) | |
239 | { | |
240 | substream->dma_buffer.dev.type = type; | |
241 | substream->dma_buffer.dev.dev = data; | |
242 | return snd_pcm_lib_preallocate_pages1(substream, size, max); | |
243 | } | |
244 | ||
245 | /** | |
246 | * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continous memory type (all substreams) | |
df8db936 | 247 | * @pcm: the pcm instance |
1da177e4 LT |
248 | * @type: DMA type (SNDRV_DMA_TYPE_*) |
249 | * @data: DMA type dependant data | |
250 | * @size: the requested pre-allocation size in bytes | |
251 | * @max: the max. allowed pre-allocation size | |
252 | * | |
253 | * Do pre-allocation to all substreams of the given pcm for the | |
254 | * specified DMA type. | |
255 | * | |
256 | * Returns zero if successful, or a negative error code on failure. | |
257 | */ | |
258 | int snd_pcm_lib_preallocate_pages_for_all(snd_pcm_t *pcm, | |
259 | int type, void *data, | |
260 | size_t size, size_t max) | |
261 | { | |
262 | snd_pcm_substream_t *substream; | |
263 | int stream, err; | |
264 | ||
265 | for (stream = 0; stream < 2; stream++) | |
266 | for (substream = pcm->streams[stream].substream; substream; substream = substream->next) | |
267 | if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0) | |
268 | return err; | |
269 | return 0; | |
270 | } | |
271 | ||
272 | /** | |
273 | * snd_pcm_sgbuf_ops_page - get the page struct at the given offset | |
274 | * @substream: the pcm substream instance | |
275 | * @offset: the buffer offset | |
276 | * | |
277 | * Returns the page struct at the given buffer offset. | |
278 | * Used as the page callback of PCM ops. | |
279 | */ | |
280 | struct page *snd_pcm_sgbuf_ops_page(snd_pcm_substream_t *substream, unsigned long offset) | |
281 | { | |
282 | struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream); | |
283 | ||
284 | unsigned int idx = offset >> PAGE_SHIFT; | |
285 | if (idx >= (unsigned int)sgbuf->pages) | |
286 | return NULL; | |
287 | return sgbuf->page_table[idx]; | |
288 | } | |
289 | ||
290 | /** | |
291 | * snd_pcm_lib_malloc_pages - allocate the DMA buffer | |
292 | * @substream: the substream to allocate the DMA buffer to | |
293 | * @size: the requested buffer size in bytes | |
294 | * | |
295 | * Allocates the DMA buffer on the BUS type given earlier to | |
296 | * snd_pcm_lib_preallocate_xxx_pages(). | |
297 | * | |
298 | * Returns 1 if the buffer is changed, 0 if not changed, or a negative | |
299 | * code on failure. | |
300 | */ | |
301 | int snd_pcm_lib_malloc_pages(snd_pcm_substream_t *substream, size_t size) | |
302 | { | |
303 | snd_pcm_runtime_t *runtime; | |
304 | struct snd_dma_buffer *dmab = NULL; | |
305 | ||
306 | snd_assert(substream->dma_buffer.dev.type != SNDRV_DMA_TYPE_UNKNOWN, return -EINVAL); | |
307 | snd_assert(substream != NULL, return -EINVAL); | |
308 | runtime = substream->runtime; | |
309 | snd_assert(runtime != NULL, return -EINVAL); | |
310 | ||
311 | if (runtime->dma_buffer_p) { | |
312 | /* perphaps, we might free the large DMA memory region | |
313 | to save some space here, but the actual solution | |
314 | costs us less time */ | |
315 | if (runtime->dma_buffer_p->bytes >= size) { | |
316 | runtime->dma_bytes = size; | |
317 | return 0; /* ok, do not change */ | |
318 | } | |
319 | snd_pcm_lib_free_pages(substream); | |
320 | } | |
321 | if (substream->dma_buffer.area != NULL && substream->dma_buffer.bytes >= size) { | |
322 | dmab = &substream->dma_buffer; /* use the pre-allocated buffer */ | |
323 | } else { | |
324 | dmab = kcalloc(1, sizeof(*dmab), GFP_KERNEL); | |
325 | if (! dmab) | |
326 | return -ENOMEM; | |
327 | dmab->dev = substream->dma_buffer.dev; | |
328 | if (snd_dma_alloc_pages(substream->dma_buffer.dev.type, | |
329 | substream->dma_buffer.dev.dev, | |
330 | size, dmab) < 0) { | |
331 | kfree(dmab); | |
332 | return -ENOMEM; | |
333 | } | |
334 | } | |
335 | snd_pcm_set_runtime_buffer(substream, dmab); | |
336 | runtime->dma_bytes = size; | |
337 | return 1; /* area was changed */ | |
338 | } | |
339 | ||
340 | /** | |
341 | * snd_pcm_lib_free_pages - release the allocated DMA buffer. | |
342 | * @substream: the substream to release the DMA buffer | |
343 | * | |
344 | * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages(). | |
345 | * | |
346 | * Returns zero if successful, or a negative error code on failure. | |
347 | */ | |
348 | int snd_pcm_lib_free_pages(snd_pcm_substream_t *substream) | |
349 | { | |
350 | snd_pcm_runtime_t *runtime; | |
351 | ||
352 | snd_assert(substream != NULL, return -EINVAL); | |
353 | runtime = substream->runtime; | |
354 | snd_assert(runtime != NULL, return -EINVAL); | |
355 | if (runtime->dma_area == NULL) | |
356 | return 0; | |
357 | if (runtime->dma_buffer_p != &substream->dma_buffer) { | |
358 | /* it's a newly allocated buffer. release it now. */ | |
359 | snd_dma_free_pages(runtime->dma_buffer_p); | |
360 | kfree(runtime->dma_buffer_p); | |
361 | } | |
362 | snd_pcm_set_runtime_buffer(substream, NULL); | |
363 | return 0; | |
364 | } |