xref: /openbmc/linux/sound/core/pcm_memory.c (revision 9fb29c73)
1 /*
2  *  Digital Audio (PCM) abstract layer
3  *  Copyright (c) by Jaroslav Kysela <perex@perex.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 <linux/io.h>
23 #include <linux/time.h>
24 #include <linux/init.h>
25 #include <linux/slab.h>
26 #include <linux/moduleparam.h>
27 #include <linux/vmalloc.h>
28 #include <linux/export.h>
29 #include <sound/core.h>
30 #include <sound/pcm.h>
31 #include <sound/info.h>
32 #include <sound/initval.h>
33 
34 static int preallocate_dma = 1;
35 module_param(preallocate_dma, int, 0444);
36 MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized.");
37 
38 static int maximum_substreams = 4;
39 module_param(maximum_substreams, int, 0444);
40 MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory.");
41 
42 static const size_t snd_minimum_buffer = 16384;
43 
44 
45 /*
46  * try to allocate as the large pages as possible.
47  * stores the resultant memory size in *res_size.
48  *
49  * the minimum size is snd_minimum_buffer.  it should be power of 2.
50  */
51 static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t size)
52 {
53 	struct snd_dma_buffer *dmab = &substream->dma_buffer;
54 	size_t orig_size = size;
55 	int err;
56 
57 	do {
58 		if ((err = snd_dma_alloc_pages(dmab->dev.type, dmab->dev.dev,
59 					       size, dmab)) < 0) {
60 			if (err != -ENOMEM)
61 				return err; /* fatal error */
62 		} else
63 			return 0;
64 		size >>= 1;
65 	} while (size >= snd_minimum_buffer);
66 	dmab->bytes = 0; /* tell error */
67 	pr_warn("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
68 		substream->pcm->card->number, substream->pcm->device,
69 		substream->stream ? 'c' : 'p', substream->number,
70 		substream->pcm->name, orig_size);
71 	return 0;
72 }
73 
74 /*
75  * release the preallocated buffer if not yet done.
76  */
77 static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream)
78 {
79 	if (substream->dma_buffer.area == NULL)
80 		return;
81 	snd_dma_free_pages(&substream->dma_buffer);
82 	substream->dma_buffer.area = NULL;
83 }
84 
85 /**
86  * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
87  * @substream: the pcm substream instance
88  *
89  * Releases the pre-allocated buffer of the given substream.
90  *
91  * Return: Zero if successful, or a negative error code on failure.
92  */
93 int snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
94 {
95 	snd_pcm_lib_preallocate_dma_free(substream);
96 #ifdef CONFIG_SND_VERBOSE_PROCFS
97 	snd_info_free_entry(substream->proc_prealloc_max_entry);
98 	substream->proc_prealloc_max_entry = NULL;
99 	snd_info_free_entry(substream->proc_prealloc_entry);
100 	substream->proc_prealloc_entry = NULL;
101 #endif
102 	return 0;
103 }
104 
105 /**
106  * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
107  * @pcm: the pcm instance
108  *
109  * Releases all the pre-allocated buffers on the given pcm.
110  *
111  * Return: Zero if successful, or a negative error code on failure.
112  */
113 int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
114 {
115 	struct snd_pcm_substream *substream;
116 	int stream;
117 
118 	for (stream = 0; stream < 2; stream++)
119 		for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
120 			snd_pcm_lib_preallocate_free(substream);
121 	return 0;
122 }
123 EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
124 
125 #ifdef CONFIG_SND_VERBOSE_PROCFS
126 /*
127  * read callback for prealloc proc file
128  *
129  * prints the current allocated size in kB.
130  */
131 static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
132 					      struct snd_info_buffer *buffer)
133 {
134 	struct snd_pcm_substream *substream = entry->private_data;
135 	snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
136 }
137 
138 /*
139  * read callback for prealloc_max proc file
140  *
141  * prints the maximum allowed size in kB.
142  */
143 static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
144 						  struct snd_info_buffer *buffer)
145 {
146 	struct snd_pcm_substream *substream = entry->private_data;
147 	snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
148 }
149 
150 /*
151  * write callback for prealloc proc file
152  *
153  * accepts the preallocation size in kB.
154  */
155 static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
156 					       struct snd_info_buffer *buffer)
157 {
158 	struct snd_pcm_substream *substream = entry->private_data;
159 	char line[64], str[64];
160 	size_t size;
161 	struct snd_dma_buffer new_dmab;
162 
163 	if (substream->runtime) {
164 		buffer->error = -EBUSY;
165 		return;
166 	}
167 	if (!snd_info_get_line(buffer, line, sizeof(line))) {
168 		snd_info_get_str(str, line, sizeof(str));
169 		size = simple_strtoul(str, NULL, 10) * 1024;
170 		if ((size != 0 && size < 8192) || size > substream->dma_max) {
171 			buffer->error = -EINVAL;
172 			return;
173 		}
174 		if (substream->dma_buffer.bytes == size)
175 			return;
176 		memset(&new_dmab, 0, sizeof(new_dmab));
177 		new_dmab.dev = substream->dma_buffer.dev;
178 		if (size > 0) {
179 			if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
180 						substream->dma_buffer.dev.dev,
181 						size, &new_dmab) < 0) {
182 				buffer->error = -ENOMEM;
183 				return;
184 			}
185 			substream->buffer_bytes_max = size;
186 		} else {
187 			substream->buffer_bytes_max = UINT_MAX;
188 		}
189 		if (substream->dma_buffer.area)
190 			snd_dma_free_pages(&substream->dma_buffer);
191 		substream->dma_buffer = new_dmab;
192 	} else {
193 		buffer->error = -EINVAL;
194 	}
195 }
196 
197 static inline void preallocate_info_init(struct snd_pcm_substream *substream)
198 {
199 	struct snd_info_entry *entry;
200 
201 	if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) {
202 		entry->c.text.read = snd_pcm_lib_preallocate_proc_read;
203 		entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
204 		entry->mode |= 0200;
205 		entry->private_data = substream;
206 		if (snd_info_register(entry) < 0) {
207 			snd_info_free_entry(entry);
208 			entry = NULL;
209 		}
210 	}
211 	substream->proc_prealloc_entry = entry;
212 	if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", substream->proc_root)) != NULL) {
213 		entry->c.text.read = snd_pcm_lib_preallocate_max_proc_read;
214 		entry->private_data = substream;
215 		if (snd_info_register(entry) < 0) {
216 			snd_info_free_entry(entry);
217 			entry = NULL;
218 		}
219 	}
220 	substream->proc_prealloc_max_entry = entry;
221 }
222 
223 #else /* !CONFIG_SND_VERBOSE_PROCFS */
224 #define preallocate_info_init(s)
225 #endif /* CONFIG_SND_VERBOSE_PROCFS */
226 
227 /*
228  * pre-allocate the buffer and create a proc file for the substream
229  */
230 static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
231 					  size_t size, size_t max)
232 {
233 
234 	if (size > 0 && preallocate_dma && substream->number < maximum_substreams)
235 		preallocate_pcm_pages(substream, size);
236 
237 	if (substream->dma_buffer.bytes > 0)
238 		substream->buffer_bytes_max = substream->dma_buffer.bytes;
239 	substream->dma_max = max;
240 	preallocate_info_init(substream);
241 	return 0;
242 }
243 
244 
245 /**
246  * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
247  * @substream: the pcm substream instance
248  * @type: DMA type (SNDRV_DMA_TYPE_*)
249  * @data: DMA type dependent data
250  * @size: the requested pre-allocation size in bytes
251  * @max: the max. allowed pre-allocation size
252  *
253  * Do pre-allocation for the given DMA buffer type.
254  *
255  * Return: Zero if successful, or a negative error code on failure.
256  */
257 int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
258 				  int type, struct device *data,
259 				  size_t size, size_t max)
260 {
261 	substream->dma_buffer.dev.type = type;
262 	substream->dma_buffer.dev.dev = data;
263 	return snd_pcm_lib_preallocate_pages1(substream, size, max);
264 }
265 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
266 
267 /**
268  * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
269  * @pcm: the pcm instance
270  * @type: DMA type (SNDRV_DMA_TYPE_*)
271  * @data: DMA type dependent data
272  * @size: the requested pre-allocation size in bytes
273  * @max: the max. allowed pre-allocation size
274  *
275  * Do pre-allocation to all substreams of the given pcm for the
276  * specified DMA type.
277  *
278  * Return: Zero if successful, or a negative error code on failure.
279  */
280 int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
281 					  int type, void *data,
282 					  size_t size, size_t max)
283 {
284 	struct snd_pcm_substream *substream;
285 	int stream, err;
286 
287 	for (stream = 0; stream < 2; stream++)
288 		for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
289 			if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0)
290 				return err;
291 	return 0;
292 }
293 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
294 
295 #ifdef CONFIG_SND_DMA_SGBUF
296 /**
297  * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
298  * @substream: the pcm substream instance
299  * @offset: the buffer offset
300  *
301  * Used as the page callback of PCM ops.
302  *
303  * Return: The page struct at the given buffer offset. %NULL on failure.
304  */
305 struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset)
306 {
307 	struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
308 
309 	unsigned int idx = offset >> PAGE_SHIFT;
310 	if (idx >= (unsigned int)sgbuf->pages)
311 		return NULL;
312 	return sgbuf->page_table[idx];
313 }
314 EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
315 #endif /* CONFIG_SND_DMA_SGBUF */
316 
317 /**
318  * snd_pcm_lib_malloc_pages - allocate the DMA buffer
319  * @substream: the substream to allocate the DMA buffer to
320  * @size: the requested buffer size in bytes
321  *
322  * Allocates the DMA buffer on the BUS type given earlier to
323  * snd_pcm_lib_preallocate_xxx_pages().
324  *
325  * Return: 1 if the buffer is changed, 0 if not changed, or a negative
326  * code on failure.
327  */
328 int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
329 {
330 	struct snd_pcm_runtime *runtime;
331 	struct snd_dma_buffer *dmab = NULL;
332 
333 	if (PCM_RUNTIME_CHECK(substream))
334 		return -EINVAL;
335 	if (snd_BUG_ON(substream->dma_buffer.dev.type ==
336 		       SNDRV_DMA_TYPE_UNKNOWN))
337 		return -EINVAL;
338 	runtime = substream->runtime;
339 
340 	if (runtime->dma_buffer_p) {
341 		/* perphaps, we might free the large DMA memory region
342 		   to save some space here, but the actual solution
343 		   costs us less time */
344 		if (runtime->dma_buffer_p->bytes >= size) {
345 			runtime->dma_bytes = size;
346 			return 0;	/* ok, do not change */
347 		}
348 		snd_pcm_lib_free_pages(substream);
349 	}
350 	if (substream->dma_buffer.area != NULL &&
351 	    substream->dma_buffer.bytes >= size) {
352 		dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
353 	} else {
354 		dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
355 		if (! dmab)
356 			return -ENOMEM;
357 		dmab->dev = substream->dma_buffer.dev;
358 		if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
359 					substream->dma_buffer.dev.dev,
360 					size, dmab) < 0) {
361 			kfree(dmab);
362 			return -ENOMEM;
363 		}
364 	}
365 	snd_pcm_set_runtime_buffer(substream, dmab);
366 	runtime->dma_bytes = size;
367 	return 1;			/* area was changed */
368 }
369 EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
370 
371 /**
372  * snd_pcm_lib_free_pages - release the allocated DMA buffer.
373  * @substream: the substream to release the DMA buffer
374  *
375  * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
376  *
377  * Return: Zero if successful, or a negative error code on failure.
378  */
379 int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
380 {
381 	struct snd_pcm_runtime *runtime;
382 
383 	if (PCM_RUNTIME_CHECK(substream))
384 		return -EINVAL;
385 	runtime = substream->runtime;
386 	if (runtime->dma_area == NULL)
387 		return 0;
388 	if (runtime->dma_buffer_p != &substream->dma_buffer) {
389 		/* it's a newly allocated buffer.  release it now. */
390 		snd_dma_free_pages(runtime->dma_buffer_p);
391 		kfree(runtime->dma_buffer_p);
392 	}
393 	snd_pcm_set_runtime_buffer(substream, NULL);
394 	return 0;
395 }
396 EXPORT_SYMBOL(snd_pcm_lib_free_pages);
397 
398 int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
399 				      size_t size, gfp_t gfp_flags)
400 {
401 	struct snd_pcm_runtime *runtime;
402 
403 	if (PCM_RUNTIME_CHECK(substream))
404 		return -EINVAL;
405 	runtime = substream->runtime;
406 	if (runtime->dma_area) {
407 		if (runtime->dma_bytes >= size)
408 			return 0; /* already large enough */
409 		vfree(runtime->dma_area);
410 	}
411 	runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL);
412 	if (!runtime->dma_area)
413 		return -ENOMEM;
414 	runtime->dma_bytes = size;
415 	return 1;
416 }
417 EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
418 
419 /**
420  * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
421  * @substream: the substream with a buffer allocated by
422  *	snd_pcm_lib_alloc_vmalloc_buffer()
423  *
424  * Return: Zero if successful, or a negative error code on failure.
425  */
426 int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
427 {
428 	struct snd_pcm_runtime *runtime;
429 
430 	if (PCM_RUNTIME_CHECK(substream))
431 		return -EINVAL;
432 	runtime = substream->runtime;
433 	vfree(runtime->dma_area);
434 	runtime->dma_area = NULL;
435 	return 0;
436 }
437 EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
438 
439 /**
440  * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
441  * @substream: the substream with a buffer allocated by
442  *	snd_pcm_lib_alloc_vmalloc_buffer()
443  * @offset: offset in the buffer
444  *
445  * This function is to be used as the page callback in the PCM ops.
446  *
447  * Return: The page struct, or %NULL on failure.
448  */
449 struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
450 					  unsigned long offset)
451 {
452 	return vmalloc_to_page(substream->runtime->dma_area + offset);
453 }
454 EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);
455