blob: dbc23e35fa065decbbeb4910f39d0153073f0c36 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Copyright (c) by Jaroslav Kysela <perex@suse.cz>
3 * Takashi Iwai <tiwai@suse.de>
4 *
5 * Generic memory allocators
6 *
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 *
22 */
23
24#include <linux/config.h>
25#include <linux/module.h>
26#include <linux/proc_fs.h>
27#include <linux/init.h>
28#include <linux/pci.h>
29#include <linux/slab.h>
30#include <linux/mm.h>
Takashi Iwaib6a96912005-05-30 18:27:03 +020031#include <asm/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include <linux/dma-mapping.h>
33#include <linux/moduleparam.h>
34#include <asm/semaphore.h>
35#include <sound/memalloc.h>
36#ifdef CONFIG_SBUS
37#include <asm/sbus.h>
38#endif
39
40
41MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>, Jaroslav Kysela <perex@suse.cz>");
42MODULE_DESCRIPTION("Memory allocator for ALSA system.");
43MODULE_LICENSE("GPL");
44
45
46#ifndef SNDRV_CARDS
47#define SNDRV_CARDS 8
48#endif
49
Linus Torvalds1da177e2005-04-16 15:20:36 -070050/*
51 */
52
53void *snd_malloc_sgbuf_pages(struct device *device,
54 size_t size, struct snd_dma_buffer *dmab,
55 size_t *res_size);
56int snd_free_sgbuf_pages(struct snd_dma_buffer *dmab);
57
58/*
59 */
60
61static DECLARE_MUTEX(list_mutex);
62static LIST_HEAD(mem_list_head);
63
64/* buffer preservation list */
65struct snd_mem_list {
66 struct snd_dma_buffer buffer;
67 unsigned int id;
68 struct list_head list;
69};
70
71/* id for pre-allocated buffers */
72#define SNDRV_DMA_DEVICE_UNUSED (unsigned int)-1
73
74#ifdef CONFIG_SND_DEBUG
75#define __ASTRING__(x) #x
76#define snd_assert(expr, args...) do {\
77 if (!(expr)) {\
78 printk(KERN_ERR "snd-malloc: BUG? (%s) (called from %p)\n", __ASTRING__(expr), __builtin_return_address(0));\
79 args;\
80 }\
81} while (0)
82#else
83#define snd_assert(expr, args...) /**/
84#endif
85
86/*
87 * Hacks
88 */
89
90#if defined(__i386__) || defined(__ppc__) || defined(__x86_64__)
91/*
92 * A hack to allocate large buffers via dma_alloc_coherent()
93 *
94 * since dma_alloc_coherent always tries GFP_DMA when the requested
95 * pci memory region is below 32bit, it happens quite often that even
96 * 2 order of pages cannot be allocated.
97 *
98 * so in the following, we allocate at first without dma_mask, so that
99 * allocation will be done without GFP_DMA. if the area doesn't match
100 * with the requested region, then realloate with the original dma_mask
101 * again.
102 *
103 * Really, we want to move this type of thing into dma_alloc_coherent()
104 * so dma_mask doesn't have to be messed with.
105 */
106
107static void *snd_dma_hack_alloc_coherent(struct device *dev, size_t size,
108 dma_addr_t *dma_handle, int flags)
109{
110 void *ret;
111 u64 dma_mask, coherent_dma_mask;
112
113 if (dev == NULL || !dev->dma_mask)
114 return dma_alloc_coherent(dev, size, dma_handle, flags);
115 dma_mask = *dev->dma_mask;
116 coherent_dma_mask = dev->coherent_dma_mask;
117 *dev->dma_mask = 0xffffffff; /* do without masking */
118 dev->coherent_dma_mask = 0xffffffff; /* do without masking */
119 ret = dma_alloc_coherent(dev, size, dma_handle, flags);
120 *dev->dma_mask = dma_mask; /* restore */
121 dev->coherent_dma_mask = coherent_dma_mask; /* restore */
122 if (ret) {
123 /* obtained address is out of range? */
124 if (((unsigned long)*dma_handle + size - 1) & ~dma_mask) {
125 /* reallocate with the proper mask */
126 dma_free_coherent(dev, size, ret, *dma_handle);
127 ret = dma_alloc_coherent(dev, size, dma_handle, flags);
128 }
129 } else {
130 /* wish to success now with the proper mask... */
131 if (dma_mask != 0xffffffffUL) {
132 /* allocation with GFP_ATOMIC to avoid the long stall */
133 flags &= ~GFP_KERNEL;
134 flags |= GFP_ATOMIC;
135 ret = dma_alloc_coherent(dev, size, dma_handle, flags);
136 }
137 }
138 return ret;
139}
140
141/* redefine dma_alloc_coherent for some architectures */
142#undef dma_alloc_coherent
143#define dma_alloc_coherent snd_dma_hack_alloc_coherent
144
145#endif /* arch */
146
147#if ! defined(__arm__)
148#define NEED_RESERVE_PAGES
149#endif
150
151/*
152 *
153 * Generic memory allocators
154 *
155 */
156
157static long snd_allocated_pages; /* holding the number of allocated pages */
158
159static inline void inc_snd_pages(int order)
160{
161 snd_allocated_pages += 1 << order;
162}
163
164static inline void dec_snd_pages(int order)
165{
166 snd_allocated_pages -= 1 << order;
167}
168
169static void mark_pages(struct page *page, int order)
170{
171 struct page *last_page = page + (1 << order);
172 while (page < last_page)
173 SetPageReserved(page++);
174}
175
176static void unmark_pages(struct page *page, int order)
177{
178 struct page *last_page = page + (1 << order);
179 while (page < last_page)
180 ClearPageReserved(page++);
181}
182
183/**
184 * snd_malloc_pages - allocate pages with the given size
185 * @size: the size to allocate in bytes
186 * @gfp_flags: the allocation conditions, GFP_XXX
187 *
188 * Allocates the physically contiguous pages with the given size.
189 *
190 * Returns the pointer of the buffer, or NULL if no enoguh memory.
191 */
192void *snd_malloc_pages(size_t size, unsigned int gfp_flags)
193{
194 int pg;
195 void *res;
196
197 snd_assert(size > 0, return NULL);
198 snd_assert(gfp_flags != 0, return NULL);
199 pg = get_order(size);
200 if ((res = (void *) __get_free_pages(gfp_flags, pg)) != NULL) {
201 mark_pages(virt_to_page(res), pg);
202 inc_snd_pages(pg);
203 }
204 return res;
205}
206
207/**
208 * snd_free_pages - release the pages
209 * @ptr: the buffer pointer to release
210 * @size: the allocated buffer size
211 *
212 * Releases the buffer allocated via snd_malloc_pages().
213 */
214void snd_free_pages(void *ptr, size_t size)
215{
216 int pg;
217
218 if (ptr == NULL)
219 return;
220 pg = get_order(size);
221 dec_snd_pages(pg);
222 unmark_pages(virt_to_page(ptr), pg);
223 free_pages((unsigned long) ptr, pg);
224}
225
226/*
227 *
228 * Bus-specific memory allocators
229 *
230 */
231
232/* allocate the coherent DMA pages */
233static void *snd_malloc_dev_pages(struct device *dev, size_t size, dma_addr_t *dma)
234{
235 int pg;
236 void *res;
237 unsigned int gfp_flags;
238
239 snd_assert(size > 0, return NULL);
240 snd_assert(dma != NULL, return NULL);
241 pg = get_order(size);
242 gfp_flags = GFP_KERNEL
243 | __GFP_NORETRY /* don't trigger OOM-killer */
244 | __GFP_NOWARN; /* no stack trace print - this call is non-critical */
245 res = dma_alloc_coherent(dev, PAGE_SIZE << pg, dma, gfp_flags);
246 if (res != NULL) {
247#ifdef NEED_RESERVE_PAGES
248 mark_pages(virt_to_page(res), pg); /* should be dma_to_page() */
249#endif
250 inc_snd_pages(pg);
251 }
252
253 return res;
254}
255
256/* free the coherent DMA pages */
257static void snd_free_dev_pages(struct device *dev, size_t size, void *ptr,
258 dma_addr_t dma)
259{
260 int pg;
261
262 if (ptr == NULL)
263 return;
264 pg = get_order(size);
265 dec_snd_pages(pg);
266#ifdef NEED_RESERVE_PAGES
267 unmark_pages(virt_to_page(ptr), pg); /* should be dma_to_page() */
268#endif
269 dma_free_coherent(dev, PAGE_SIZE << pg, ptr, dma);
270}
271
272#ifdef CONFIG_SBUS
273
274static void *snd_malloc_sbus_pages(struct device *dev, size_t size,
275 dma_addr_t *dma_addr)
276{
277 struct sbus_dev *sdev = (struct sbus_dev *)dev;
278 int pg;
279 void *res;
280
281 snd_assert(size > 0, return NULL);
282 snd_assert(dma_addr != NULL, return NULL);
283 pg = get_order(size);
284 res = sbus_alloc_consistent(sdev, PAGE_SIZE * (1 << pg), dma_addr);
285 if (res != NULL)
286 inc_snd_pages(pg);
287 return res;
288}
289
290static void snd_free_sbus_pages(struct device *dev, size_t size,
291 void *ptr, dma_addr_t dma_addr)
292{
293 struct sbus_dev *sdev = (struct sbus_dev *)dev;
294 int pg;
295
296 if (ptr == NULL)
297 return;
298 pg = get_order(size);
299 dec_snd_pages(pg);
300 sbus_free_consistent(sdev, PAGE_SIZE * (1 << pg), ptr, dma_addr);
301}
302
303#endif /* CONFIG_SBUS */
304
305/*
306 *
307 * ALSA generic memory management
308 *
309 */
310
311
312/**
313 * snd_dma_alloc_pages - allocate the buffer area according to the given type
314 * @type: the DMA buffer type
315 * @device: the device pointer
316 * @size: the buffer size to allocate
317 * @dmab: buffer allocation record to store the allocated data
318 *
319 * Calls the memory-allocator function for the corresponding
320 * buffer type.
321 *
322 * Returns zero if the buffer with the given size is allocated successfuly,
323 * other a negative value at error.
324 */
325int snd_dma_alloc_pages(int type, struct device *device, size_t size,
326 struct snd_dma_buffer *dmab)
327{
328 snd_assert(size > 0, return -ENXIO);
329 snd_assert(dmab != NULL, return -ENXIO);
330
331 dmab->dev.type = type;
332 dmab->dev.dev = device;
333 dmab->bytes = 0;
334 switch (type) {
335 case SNDRV_DMA_TYPE_CONTINUOUS:
336 dmab->area = snd_malloc_pages(size, (unsigned long)device);
337 dmab->addr = 0;
338 break;
339#ifdef CONFIG_SBUS
340 case SNDRV_DMA_TYPE_SBUS:
341 dmab->area = snd_malloc_sbus_pages(device, size, &dmab->addr);
342 break;
343#endif
344 case SNDRV_DMA_TYPE_DEV:
345 dmab->area = snd_malloc_dev_pages(device, size, &dmab->addr);
346 break;
347 case SNDRV_DMA_TYPE_DEV_SG:
348 snd_malloc_sgbuf_pages(device, size, dmab, NULL);
349 break;
350 default:
351 printk(KERN_ERR "snd-malloc: invalid device type %d\n", type);
352 dmab->area = NULL;
353 dmab->addr = 0;
354 return -ENXIO;
355 }
356 if (! dmab->area)
357 return -ENOMEM;
358 dmab->bytes = size;
359 return 0;
360}
361
362/**
363 * snd_dma_alloc_pages_fallback - allocate the buffer area according to the given type with fallback
364 * @type: the DMA buffer type
365 * @device: the device pointer
366 * @size: the buffer size to allocate
367 * @dmab: buffer allocation record to store the allocated data
368 *
369 * Calls the memory-allocator function for the corresponding
370 * buffer type. When no space is left, this function reduces the size and
371 * tries to allocate again. The size actually allocated is stored in
372 * res_size argument.
373 *
374 * Returns zero if the buffer with the given size is allocated successfuly,
375 * other a negative value at error.
376 */
377int snd_dma_alloc_pages_fallback(int type, struct device *device, size_t size,
378 struct snd_dma_buffer *dmab)
379{
380 int err;
381
382 snd_assert(size > 0, return -ENXIO);
383 snd_assert(dmab != NULL, return -ENXIO);
384
385 while ((err = snd_dma_alloc_pages(type, device, size, dmab)) < 0) {
386 if (err != -ENOMEM)
387 return err;
388 size >>= 1;
389 if (size <= PAGE_SIZE)
390 return -ENOMEM;
391 }
392 if (! dmab->area)
393 return -ENOMEM;
394 return 0;
395}
396
397
398/**
399 * snd_dma_free_pages - release the allocated buffer
400 * @dmab: the buffer allocation record to release
401 *
402 * Releases the allocated buffer via snd_dma_alloc_pages().
403 */
404void snd_dma_free_pages(struct snd_dma_buffer *dmab)
405{
406 switch (dmab->dev.type) {
407 case SNDRV_DMA_TYPE_CONTINUOUS:
408 snd_free_pages(dmab->area, dmab->bytes);
409 break;
410#ifdef CONFIG_SBUS
411 case SNDRV_DMA_TYPE_SBUS:
412 snd_free_sbus_pages(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);
413 break;
414#endif
415 case SNDRV_DMA_TYPE_DEV:
416 snd_free_dev_pages(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);
417 break;
418 case SNDRV_DMA_TYPE_DEV_SG:
419 snd_free_sgbuf_pages(dmab);
420 break;
421 default:
422 printk(KERN_ERR "snd-malloc: invalid device type %d\n", dmab->dev.type);
423 }
424}
425
426
427/**
428 * snd_dma_get_reserved - get the reserved buffer for the given device
429 * @dmab: the buffer allocation record to store
430 * @id: the buffer id
431 *
432 * Looks for the reserved-buffer list and re-uses if the same buffer
433 * is found in the list. When the buffer is found, it's removed from the free list.
434 *
435 * Returns the size of buffer if the buffer is found, or zero if not found.
436 */
437size_t snd_dma_get_reserved_buf(struct snd_dma_buffer *dmab, unsigned int id)
438{
439 struct list_head *p;
440 struct snd_mem_list *mem;
441
442 snd_assert(dmab, return 0);
443
444 down(&list_mutex);
445 list_for_each(p, &mem_list_head) {
446 mem = list_entry(p, struct snd_mem_list, list);
447 if (mem->id == id &&
Takashi Iwaib6a96912005-05-30 18:27:03 +0200448 (mem->buffer.dev.dev == NULL || dmab->dev.dev == NULL ||
449 ! memcmp(&mem->buffer.dev, &dmab->dev, sizeof(dmab->dev)))) {
450 struct device *dev = dmab->dev.dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451 list_del(p);
452 *dmab = mem->buffer;
Takashi Iwaib6a96912005-05-30 18:27:03 +0200453 if (dmab->dev.dev == NULL)
454 dmab->dev.dev = dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 kfree(mem);
456 up(&list_mutex);
457 return dmab->bytes;
458 }
459 }
460 up(&list_mutex);
461 return 0;
462}
463
464/**
465 * snd_dma_reserve_buf - reserve the buffer
466 * @dmab: the buffer to reserve
467 * @id: the buffer id
468 *
469 * Reserves the given buffer as a reserved buffer.
470 *
471 * Returns zero if successful, or a negative code at error.
472 */
473int snd_dma_reserve_buf(struct snd_dma_buffer *dmab, unsigned int id)
474{
475 struct snd_mem_list *mem;
476
477 snd_assert(dmab, return -EINVAL);
478 mem = kmalloc(sizeof(*mem), GFP_KERNEL);
479 if (! mem)
480 return -ENOMEM;
481 down(&list_mutex);
482 mem->buffer = *dmab;
483 mem->id = id;
484 list_add_tail(&mem->list, &mem_list_head);
485 up(&list_mutex);
486 return 0;
487}
488
489/*
490 * purge all reserved buffers
491 */
492static void free_all_reserved_pages(void)
493{
494 struct list_head *p;
495 struct snd_mem_list *mem;
496
497 down(&list_mutex);
498 while (! list_empty(&mem_list_head)) {
499 p = mem_list_head.next;
500 mem = list_entry(p, struct snd_mem_list, list);
501 list_del(p);
502 snd_dma_free_pages(&mem->buffer);
503 kfree(mem);
504 }
505 up(&list_mutex);
506}
507
508
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509#ifdef CONFIG_PROC_FS
510/*
511 * proc file interface
512 */
Takashi Iwaib6a96912005-05-30 18:27:03 +0200513#define SND_MEM_PROC_FILE "driver/snd-page-alloc"
514struct proc_dir_entry *snd_mem_proc;
515
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516static int snd_mem_proc_read(char *page, char **start, off_t off,
517 int count, int *eof, void *data)
518{
519 int len = 0;
520 long pages = snd_allocated_pages >> (PAGE_SHIFT-12);
521 struct list_head *p;
522 struct snd_mem_list *mem;
523 int devno;
524 static char *types[] = { "UNKNOWN", "CONT", "DEV", "DEV-SG", "SBUS" };
525
526 down(&list_mutex);
527 len += snprintf(page + len, count - len,
528 "pages : %li bytes (%li pages per %likB)\n",
529 pages * PAGE_SIZE, pages, PAGE_SIZE / 1024);
530 devno = 0;
531 list_for_each(p, &mem_list_head) {
532 mem = list_entry(p, struct snd_mem_list, list);
533 devno++;
534 len += snprintf(page + len, count - len,
535 "buffer %d : ID %08x : type %s\n",
536 devno, mem->id, types[mem->buffer.dev.type]);
537 len += snprintf(page + len, count - len,
538 " addr = 0x%lx, size = %d bytes\n",
539 (unsigned long)mem->buffer.addr, (int)mem->buffer.bytes);
540 }
541 up(&list_mutex);
542 return len;
543}
Takashi Iwaib6a96912005-05-30 18:27:03 +0200544
545/* FIXME: for pci only - other bus? */
546#ifdef CONFIG_PCI
547#define gettoken(bufp) strsep(bufp, " \t\n")
548
549static int snd_mem_proc_write(struct file *file, const char __user *buffer,
550 unsigned long count, void *data)
551{
552 char buf[128];
553 char *token, *p;
554
555 if (count > ARRAY_SIZE(buf) - 1)
556 count = ARRAY_SIZE(buf) - 1;
557 if (copy_from_user(buf, buffer, count))
558 return -EFAULT;
559 buf[ARRAY_SIZE(buf) - 1] = '\0';
560
561 p = buf;
562 token = gettoken(&p);
563 if (! token || *token == '#')
564 return (int)count;
565 if (strcmp(token, "add") == 0) {
566 char *endp;
567 int vendor, device, size, buffers;
568 long mask;
569 int i, alloced;
570 struct pci_dev *pci;
571
572 if ((token = gettoken(&p)) == NULL ||
573 (vendor = simple_strtol(token, NULL, 0)) <= 0 ||
574 (token = gettoken(&p)) == NULL ||
575 (device = simple_strtol(token, NULL, 0)) <= 0 ||
576 (token = gettoken(&p)) == NULL ||
577 (mask = simple_strtol(token, NULL, 0)) < 0 ||
578 (token = gettoken(&p)) == NULL ||
579 (size = memparse(token, &endp)) < 64*1024 ||
580 size > 16*1024*1024 /* too big */ ||
581 (token = gettoken(&p)) == NULL ||
582 (buffers = simple_strtol(token, NULL, 0)) <= 0 ||
583 buffers > 4) {
584 printk(KERN_ERR "snd-page-alloc: invalid proc write format\n");
585 return (int)count;
586 }
587 vendor &= 0xffff;
588 device &= 0xffff;
589
590 alloced = 0;
591 pci = NULL;
592 while ((pci = pci_find_device(vendor, device, pci)) != NULL) {
593 if (mask > 0 && mask < 0xffffffff) {
594 if (pci_set_dma_mask(pci, mask) < 0 ||
595 pci_set_consistent_dma_mask(pci, mask) < 0) {
596 printk(KERN_ERR "snd-page-alloc: cannot set DMA mask %lx for pci %04x:%04x\n", mask, vendor, device);
597 return (int)count;
598 }
599 }
600 for (i = 0; i < buffers; i++) {
601 struct snd_dma_buffer dmab;
602 memset(&dmab, 0, sizeof(dmab));
603 if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, snd_dma_pci_data(pci),
604 size, &dmab) < 0) {
605 printk(KERN_ERR "snd-page-alloc: cannot allocate buffer pages (size = %d)\n", size);
606 return (int)count;
607 }
608 snd_dma_reserve_buf(&dmab, snd_dma_pci_buf_id(pci));
609 }
610 alloced++;
611 }
612 if (! alloced) {
613 for (i = 0; i < buffers; i++) {
614 struct snd_dma_buffer dmab;
615 memset(&dmab, 0, sizeof(dmab));
616 /* FIXME: We can allocate only in ZONE_DMA
617 * without a device pointer!
618 */
619 if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, NULL,
620 size, &dmab) < 0) {
621 printk(KERN_ERR "snd-page-alloc: cannot allocate buffer pages (size = %d)\n", size);
622 break;
623 }
624 snd_dma_reserve_buf(&dmab, (unsigned int)((vendor << 16) | device));
625 }
626 }
627 } else if (strcmp(token, "erase") == 0)
628 /* FIXME: need for releasing each buffer chunk? */
629 free_all_reserved_pages();
630 else
631 printk(KERN_ERR "snd-page-alloc: invalid proc cmd\n");
632 return (int)count;
633}
634#endif /* CONFIG_PCI */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635#endif /* CONFIG_PROC_FS */
636
637/*
638 * module entry
639 */
640
641static int __init snd_mem_init(void)
642{
643#ifdef CONFIG_PROC_FS
Takashi Iwaib6a96912005-05-30 18:27:03 +0200644 snd_mem_proc = create_proc_entry(SND_MEM_PROC_FILE, 0644, NULL);
645 if (snd_mem_proc) {
646 snd_mem_proc->read_proc = snd_mem_proc_read;
647#ifdef CONFIG_PCI
648 snd_mem_proc->write_proc = snd_mem_proc_write;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649#endif
Takashi Iwaib6a96912005-05-30 18:27:03 +0200650 }
651#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652 return 0;
653}
654
655static void __exit snd_mem_exit(void)
656{
Takashi Iwaib6a96912005-05-30 18:27:03 +0200657 if (snd_mem_proc)
658 remove_proc_entry(SND_MEM_PROC_FILE, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659 free_all_reserved_pages();
660 if (snd_allocated_pages > 0)
661 printk(KERN_ERR "snd-malloc: Memory leak? pages not freed = %li\n", snd_allocated_pages);
662}
663
664
665module_init(snd_mem_init)
666module_exit(snd_mem_exit)
667
668
669/*
670 * exports
671 */
672EXPORT_SYMBOL(snd_dma_alloc_pages);
673EXPORT_SYMBOL(snd_dma_alloc_pages_fallback);
674EXPORT_SYMBOL(snd_dma_free_pages);
675
676EXPORT_SYMBOL(snd_dma_get_reserved_buf);
677EXPORT_SYMBOL(snd_dma_reserve_buf);
678
679EXPORT_SYMBOL(snd_malloc_pages);
680EXPORT_SYMBOL(snd_free_pages);