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1 : : // SPDX-License-Identifier: GPL-2.0-or-later
2 : : /*
3 : : * Digital Audio (PCM) abstract layer
4 : : * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 : : */
6 : :
7 : : #include <linux/io.h>
8 : : #include <linux/time.h>
9 : : #include <linux/init.h>
10 : : #include <linux/slab.h>
11 : : #include <linux/moduleparam.h>
12 : : #include <linux/vmalloc.h>
13 : : #include <linux/export.h>
14 : : #include <sound/core.h>
15 : : #include <sound/pcm.h>
16 : : #include <sound/info.h>
17 : : #include <sound/initval.h>
18 : :
19 : : static int preallocate_dma = 1;
20 : : module_param(preallocate_dma, int, 0444);
21 : : MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized.");
22 : :
23 : : static int maximum_substreams = 4;
24 : : module_param(maximum_substreams, int, 0444);
25 : : MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory.");
26 : :
27 : : static const size_t snd_minimum_buffer = 16384;
28 : :
29 : :
30 : : /*
31 : : * try to allocate as the large pages as possible.
32 : : * stores the resultant memory size in *res_size.
33 : : *
34 : : * the minimum size is snd_minimum_buffer. it should be power of 2.
35 : : */
36 : 1656 : static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t size)
37 : : {
38 : 1656 : struct snd_dma_buffer *dmab = &substream->dma_buffer;
39 : : size_t orig_size = size;
40 : : int err;
41 : :
42 : : do {
43 [ - + ]: 1656 : if ((err = snd_dma_alloc_pages(dmab->dev.type, dmab->dev.dev,
44 : : size, dmab)) < 0) {
45 [ # # ]: 0 : if (err != -ENOMEM)
46 : 0 : return err; /* fatal error */
47 : : } else
48 : : return 0;
49 : 0 : size >>= 1;
50 [ # # ]: 0 : } while (size >= snd_minimum_buffer);
51 : 0 : dmab->bytes = 0; /* tell error */
52 [ # # ]: 0 : pr_warn("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
53 : : substream->pcm->card->number, substream->pcm->device,
54 : : substream->stream ? 'c' : 'p', substream->number,
55 : : substream->pcm->name, orig_size);
56 : 0 : return 0;
57 : : }
58 : :
59 : : /*
60 : : * release the preallocated buffer if not yet done.
61 : : */
62 : : static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream)
63 : : {
64 [ # # # # ]: 0 : if (substream->dma_buffer.area == NULL)
65 : : return;
66 : 0 : snd_dma_free_pages(&substream->dma_buffer);
67 : 0 : substream->dma_buffer.area = NULL;
68 : : }
69 : :
70 : : /**
71 : : * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
72 : : * @substream: the pcm substream instance
73 : : *
74 : : * Releases the pre-allocated buffer of the given substream.
75 : : */
76 : 0 : void snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
77 : : {
78 : : snd_pcm_lib_preallocate_dma_free(substream);
79 : 0 : }
80 : :
81 : : /**
82 : : * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
83 : : * @pcm: the pcm instance
84 : : *
85 : : * Releases all the pre-allocated buffers on the given pcm.
86 : : */
87 : 0 : void snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
88 : : {
89 : : struct snd_pcm_substream *substream;
90 : : int stream;
91 : :
92 [ # # ]: 0 : for (stream = 0; stream < 2; stream++)
93 [ # # ]: 0 : for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
94 : : snd_pcm_lib_preallocate_free(substream);
95 : 0 : }
96 : : EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
97 : :
98 : : #ifdef CONFIG_SND_VERBOSE_PROCFS
99 : : /*
100 : : * read callback for prealloc proc file
101 : : *
102 : : * prints the current allocated size in kB.
103 : : */
104 : 0 : static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
105 : : struct snd_info_buffer *buffer)
106 : : {
107 : 0 : struct snd_pcm_substream *substream = entry->private_data;
108 : 0 : snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
109 : 0 : }
110 : :
111 : : /*
112 : : * read callback for prealloc_max proc file
113 : : *
114 : : * prints the maximum allowed size in kB.
115 : : */
116 : 0 : static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
117 : : struct snd_info_buffer *buffer)
118 : : {
119 : 0 : struct snd_pcm_substream *substream = entry->private_data;
120 : 0 : snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
121 : 0 : }
122 : :
123 : : /*
124 : : * write callback for prealloc proc file
125 : : *
126 : : * accepts the preallocation size in kB.
127 : : */
128 : 0 : static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
129 : : struct snd_info_buffer *buffer)
130 : : {
131 : 0 : struct snd_pcm_substream *substream = entry->private_data;
132 : : char line[64], str[64];
133 : : size_t size;
134 : : struct snd_dma_buffer new_dmab;
135 : :
136 [ # # ]: 0 : if (substream->runtime) {
137 : 0 : buffer->error = -EBUSY;
138 : 0 : return;
139 : : }
140 [ # # ]: 0 : if (!snd_info_get_line(buffer, line, sizeof(line))) {
141 : 0 : snd_info_get_str(str, line, sizeof(str));
142 : 0 : size = simple_strtoul(str, NULL, 10) * 1024;
143 [ # # # # ]: 0 : if ((size != 0 && size < 8192) || size > substream->dma_max) {
144 : 0 : buffer->error = -EINVAL;
145 : 0 : return;
146 : : }
147 [ # # ]: 0 : if (substream->dma_buffer.bytes == size)
148 : : return;
149 : 0 : memset(&new_dmab, 0, sizeof(new_dmab));
150 : 0 : new_dmab.dev = substream->dma_buffer.dev;
151 [ # # ]: 0 : if (size > 0) {
152 [ # # ]: 0 : if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
153 : : substream->dma_buffer.dev.dev,
154 : : size, &new_dmab) < 0) {
155 : 0 : buffer->error = -ENOMEM;
156 : 0 : return;
157 : : }
158 : 0 : substream->buffer_bytes_max = size;
159 : : } else {
160 : 0 : substream->buffer_bytes_max = UINT_MAX;
161 : : }
162 [ # # ]: 0 : if (substream->dma_buffer.area)
163 : 0 : snd_dma_free_pages(&substream->dma_buffer);
164 : 0 : substream->dma_buffer = new_dmab;
165 : : } else {
166 : 0 : buffer->error = -EINVAL;
167 : : }
168 : : }
169 : :
170 : 1656 : static inline void preallocate_info_init(struct snd_pcm_substream *substream)
171 : : {
172 : : struct snd_info_entry *entry;
173 : :
174 : 1656 : entry = snd_info_create_card_entry(substream->pcm->card, "prealloc",
175 : : substream->proc_root);
176 [ + - ]: 1656 : if (entry) {
177 : : snd_info_set_text_ops(entry, substream,
178 : : snd_pcm_lib_preallocate_proc_read);
179 : 1656 : entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
180 : 1656 : entry->mode |= 0200;
181 : : }
182 : 1656 : entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max",
183 : : substream->proc_root);
184 [ + - ]: 1656 : if (entry)
185 : : snd_info_set_text_ops(entry, substream,
186 : : snd_pcm_lib_preallocate_max_proc_read);
187 : 1656 : }
188 : :
189 : : #else /* !CONFIG_SND_VERBOSE_PROCFS */
190 : : #define preallocate_info_init(s)
191 : : #endif /* CONFIG_SND_VERBOSE_PROCFS */
192 : :
193 : : /*
194 : : * pre-allocate the buffer and create a proc file for the substream
195 : : */
196 : 1656 : static void snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
197 : : size_t size, size_t max)
198 : : {
199 : :
200 [ + - + - : 1656 : if (size > 0 && preallocate_dma && substream->number < maximum_substreams)
+ - ]
201 : 1656 : preallocate_pcm_pages(substream, size);
202 : :
203 [ + - ]: 1656 : if (substream->dma_buffer.bytes > 0)
204 : 1656 : substream->buffer_bytes_max = substream->dma_buffer.bytes;
205 : 1656 : substream->dma_max = max;
206 : 1656 : preallocate_info_init(substream);
207 : 1656 : }
208 : :
209 : :
210 : : /**
211 : : * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
212 : : * @substream: the pcm substream instance
213 : : * @type: DMA type (SNDRV_DMA_TYPE_*)
214 : : * @data: DMA type dependent data
215 : : * @size: the requested pre-allocation size in bytes
216 : : * @max: the max. allowed pre-allocation size
217 : : *
218 : : * Do pre-allocation for the given DMA buffer type.
219 : : */
220 : 0 : void snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
221 : : int type, struct device *data,
222 : : size_t size, size_t max)
223 : : {
224 : 1656 : substream->dma_buffer.dev.type = type;
225 : 1656 : substream->dma_buffer.dev.dev = data;
226 : 1656 : snd_pcm_lib_preallocate_pages1(substream, size, max);
227 : 0 : }
228 : : EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
229 : :
230 : : /**
231 : : * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
232 : : * @pcm: the pcm instance
233 : : * @type: DMA type (SNDRV_DMA_TYPE_*)
234 : : * @data: DMA type dependent data
235 : : * @size: the requested pre-allocation size in bytes
236 : : * @max: the max. allowed pre-allocation size
237 : : *
238 : : * Do pre-allocation to all substreams of the given pcm for the
239 : : * specified DMA type.
240 : : */
241 : 414 : void snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
242 : : int type, void *data,
243 : : size_t size, size_t max)
244 : : {
245 : : struct snd_pcm_substream *substream;
246 : : int stream;
247 : :
248 [ + + ]: 1242 : for (stream = 0; stream < 2; stream++)
249 [ + + ]: 2484 : for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
250 : : snd_pcm_lib_preallocate_pages(substream, type, data, size, max);
251 : 414 : }
252 : : EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
253 : :
254 : : #ifdef CONFIG_SND_DMA_SGBUF
255 : : /**
256 : : * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
257 : : * @substream: the pcm substream instance
258 : : * @offset: the buffer offset
259 : : *
260 : : * Used as the page callback of PCM ops.
261 : : *
262 : : * Return: The page struct at the given buffer offset. %NULL on failure.
263 : : */
264 : : struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset)
265 : : {
266 : : struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
267 : :
268 : : unsigned int idx = offset >> PAGE_SHIFT;
269 : : if (idx >= (unsigned int)sgbuf->pages)
270 : : return NULL;
271 : : return sgbuf->page_table[idx];
272 : : }
273 : : EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
274 : : #endif /* CONFIG_SND_DMA_SGBUF */
275 : :
276 : : /**
277 : : * snd_pcm_lib_malloc_pages - allocate the DMA buffer
278 : : * @substream: the substream to allocate the DMA buffer to
279 : : * @size: the requested buffer size in bytes
280 : : *
281 : : * Allocates the DMA buffer on the BUS type given earlier to
282 : : * snd_pcm_lib_preallocate_xxx_pages().
283 : : *
284 : : * Return: 1 if the buffer is changed, 0 if not changed, or a negative
285 : : * code on failure.
286 : : */
287 : 0 : int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
288 : : {
289 : : struct snd_pcm_runtime *runtime;
290 : : struct snd_dma_buffer *dmab = NULL;
291 : :
292 [ # # # # : 0 : if (PCM_RUNTIME_CHECK(substream))
# # ]
293 : : return -EINVAL;
294 [ # # ]: 0 : if (snd_BUG_ON(substream->dma_buffer.dev.type ==
295 : : SNDRV_DMA_TYPE_UNKNOWN))
296 : : return -EINVAL;
297 : 0 : runtime = substream->runtime;
298 : :
299 [ # # ]: 0 : if (runtime->dma_buffer_p) {
300 : : /* perphaps, we might free the large DMA memory region
301 : : to save some space here, but the actual solution
302 : : costs us less time */
303 [ # # ]: 0 : if (runtime->dma_buffer_p->bytes >= size) {
304 : 0 : runtime->dma_bytes = size;
305 : 0 : return 0; /* ok, do not change */
306 : : }
307 : 0 : snd_pcm_lib_free_pages(substream);
308 : : }
309 [ # # # # ]: 0 : if (substream->dma_buffer.area != NULL &&
310 : 0 : substream->dma_buffer.bytes >= size) {
311 : 0 : dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
312 : : } else {
313 : 0 : dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
314 [ # # ]: 0 : if (! dmab)
315 : : return -ENOMEM;
316 : 0 : dmab->dev = substream->dma_buffer.dev;
317 [ # # ]: 0 : if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
318 : : substream->dma_buffer.dev.dev,
319 : : size, dmab) < 0) {
320 : 0 : kfree(dmab);
321 : 0 : return -ENOMEM;
322 : : }
323 : : }
324 : : snd_pcm_set_runtime_buffer(substream, dmab);
325 : 0 : runtime->dma_bytes = size;
326 : 0 : return 1; /* area was changed */
327 : : }
328 : : EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
329 : :
330 : : /**
331 : : * snd_pcm_lib_free_pages - release the allocated DMA buffer.
332 : : * @substream: the substream to release the DMA buffer
333 : : *
334 : : * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
335 : : *
336 : : * Return: Zero if successful, or a negative error code on failure.
337 : : */
338 : 0 : int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
339 : : {
340 : : struct snd_pcm_runtime *runtime;
341 : :
342 [ # # # # : 0 : if (PCM_RUNTIME_CHECK(substream))
# # ]
343 : : return -EINVAL;
344 : 0 : runtime = substream->runtime;
345 [ # # ]: 0 : if (runtime->dma_area == NULL)
346 : : return 0;
347 [ # # ]: 0 : if (runtime->dma_buffer_p != &substream->dma_buffer) {
348 : : /* it's a newly allocated buffer. release it now. */
349 : 0 : snd_dma_free_pages(runtime->dma_buffer_p);
350 : 0 : kfree(runtime->dma_buffer_p);
351 : : }
352 : : snd_pcm_set_runtime_buffer(substream, NULL);
353 : 0 : return 0;
354 : : }
355 : : EXPORT_SYMBOL(snd_pcm_lib_free_pages);
356 : :
357 : 0 : int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
358 : : size_t size, gfp_t gfp_flags)
359 : : {
360 : : struct snd_pcm_runtime *runtime;
361 : :
362 [ # # # # : 0 : if (PCM_RUNTIME_CHECK(substream))
# # ]
363 : : return -EINVAL;
364 : 0 : runtime = substream->runtime;
365 [ # # ]: 0 : if (runtime->dma_area) {
366 [ # # ]: 0 : if (runtime->dma_bytes >= size)
367 : : return 0; /* already large enough */
368 : 0 : vfree(runtime->dma_area);
369 : : }
370 : 0 : runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL);
371 [ # # ]: 0 : if (!runtime->dma_area)
372 : : return -ENOMEM;
373 : 0 : runtime->dma_bytes = size;
374 : 0 : return 1;
375 : : }
376 : : EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
377 : :
378 : : /**
379 : : * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
380 : : * @substream: the substream with a buffer allocated by
381 : : * snd_pcm_lib_alloc_vmalloc_buffer()
382 : : *
383 : : * Return: Zero if successful, or a negative error code on failure.
384 : : */
385 : 0 : int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
386 : : {
387 : : struct snd_pcm_runtime *runtime;
388 : :
389 [ # # # # : 0 : if (PCM_RUNTIME_CHECK(substream))
# # ]
390 : : return -EINVAL;
391 : 0 : runtime = substream->runtime;
392 : 0 : vfree(runtime->dma_area);
393 : 0 : runtime->dma_area = NULL;
394 : 0 : return 0;
395 : : }
396 : : EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
397 : :
398 : : /**
399 : : * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
400 : : * @substream: the substream with a buffer allocated by
401 : : * snd_pcm_lib_alloc_vmalloc_buffer()
402 : : * @offset: offset in the buffer
403 : : *
404 : : * This function is to be used as the page callback in the PCM ops.
405 : : *
406 : : * Return: The page struct, or %NULL on failure.
407 : : */
408 : 0 : struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
409 : : unsigned long offset)
410 : : {
411 : 0 : return vmalloc_to_page(substream->runtime->dma_area + offset);
412 : : }
413 : : EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);
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