sound/core/memalloc.c

   1 /*
   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>
  31 #include <asm/uaccess.h>
  32 #include <linux/dma-mapping.h>
  33 #include <linux/moduleparam.h>
  34 #include <linux/mutex.h>
  35 #include <sound/memalloc.h>
  36 #ifdef CONFIG_SBUS
  37 #include <asm/sbus.h>
  38 #endif
  39
  40
  41 MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>, Jaroslav Kysela <perex@suse.cz>");
  42 MODULE_DESCRIPTION("Memory allocator for ALSA system.");
  43 MODULE_LICENSE("GPL");
  44
  45
  46 /*
  47  */
  48
  49 void *snd_malloc_sgbuf_pages(struct device *device,
  50                              size_t size, struct snd_dma_buffer *dmab,
  51                              size_t *res_size);
  52 int snd_free_sgbuf_pages(struct snd_dma_buffer *dmab);
  53
  54 /*
  55  */
  56
  57 static DEFINE_MUTEX(list_mutex);
  58 static LIST_HEAD(mem_list_head);
  59
  60 /* buffer preservation list */
  61 struct snd_mem_list {
  62         struct snd_dma_buffer buffer;
  63         unsigned int id;
  64         struct list_head list;
  65 };
  66
  67 /* id for pre-allocated buffers */
  68 #define SNDRV_DMA_DEVICE_UNUSED (unsigned int)-1
  69
  70 #ifdef CONFIG_SND_DEBUG
  71 #define __ASTRING__(x) #x
  72 #define snd_assert(expr, args...) do {\
  73         if (!(expr)) {\
  74                 printk(KERN_ERR "snd-malloc: BUG? (%s) (called from %p)\n", __ASTRING__(expr), __builtin_return_address(0));\
  75                 args;\
  76         }\
  77 } while (0)
  78 #else
  79 #define snd_assert(expr, args...) /**/
  80 #endif
  81
  82 /*
  83  *  Hacks
  84  */
  85
  86 #if defined(__i386__)
  87 /*
  88  * A hack to allocate large buffers via dma_alloc_coherent()
  89  *
  90  * since dma_alloc_coherent always tries GFP_DMA when the requested
  91  * pci memory region is below 32bit, it happens quite often that even
  92  * 2 order of pages cannot be allocated.
  93  *
  94  * so in the following, we allocate at first without dma_mask, so that
  95  * allocation will be done without GFP_DMA.  if the area doesn't match
  96  * with the requested region, then realloate with the original dma_mask
  97  * again.
  98  *
  99  * Really, we want to move this type of thing into dma_alloc_coherent()
 100  * so dma_mask doesn't have to be messed with.
 101  */
 102
 103 static void *snd_dma_hack_alloc_coherent(struct device *dev, size_t size,
 104                                          dma_addr_t *dma_handle,
 105                                          gfp_t flags)
 106 {
 107         void *ret;
 108         u64 dma_mask, coherent_dma_mask;
 109
 110         if (dev == NULL || !dev->dma_mask)
 111                 return dma_alloc_coherent(dev, size, dma_handle, flags);
 112         dma_mask = *dev->dma_mask;
 113         coherent_dma_mask = dev->coherent_dma_mask;
 114         *dev->dma_mask = 0xffffffff;    /* do without masking */
 115         dev->coherent_dma_mask = 0xffffffff;    /* do without masking */
 116         ret = dma_alloc_coherent(dev, size, dma_handle, flags);
 117         *dev->dma_mask = dma_mask;      /* restore */
 118         dev->coherent_dma_mask = coherent_dma_mask;     /* restore */
 119         if (ret) {
 120                 /* obtained address is out of range? */
 121                 if (((unsigned long)*dma_handle + size - 1) & ~dma_mask) {
 122                         /* reallocate with the proper mask */
 123                         dma_free_coherent(dev, size, ret, *dma_handle);
 124                         ret = dma_alloc_coherent(dev, size, dma_handle, flags);
 125                 }
 126         } else {
 127                 /* wish to success now with the proper mask... */
 128                 if (dma_mask != 0xffffffffUL) {
 129                         /* allocation with GFP_ATOMIC to avoid the long stall */
 130                         flags &= ~GFP_KERNEL;
 131                         flags |= GFP_ATOMIC;
 132                         ret = dma_alloc_coherent(dev, size, dma_handle, flags);
 133                 }
 134         }
 135         return ret;
 136 }
 137
 138 /* redefine dma_alloc_coherent for some architectures */
 139 #undef dma_alloc_coherent
 140 #define dma_alloc_coherent snd_dma_hack_alloc_coherent
 141
 142 #endif /* arch */
 143
 144 /*
 145  *
 146  *  Generic memory allocators
 147  *
 148  */
 149
 150 static long snd_allocated_pages; /* holding the number of allocated pages */
 151
 152 static inline void inc_snd_pages(int order)
 153 {
 154         snd_allocated_pages += 1 << order;
 155 }
 156
 157 static inline void dec_snd_pages(int order)
 158 {
 159         snd_allocated_pages -= 1 << order;
 160 }
 161
 162 /**
 163  * snd_malloc_pages - allocate pages with the given size
 164  * @size: the size to allocate in bytes
 165  * @gfp_flags: the allocation conditions, GFP_XXX
 166  *
 167  * Allocates the physically contiguous pages with the given size.
 168  *
 169  * Returns the pointer of the buffer, or NULL if no enoguh memory.
 170  */
 171 void *snd_malloc_pages(size_t size, gfp_t gfp_flags)
 172 {
 173         int pg;
 174         void *res;
 175
 176         snd_assert(size > 0, return NULL);
 177         snd_assert(gfp_flags != 0, return NULL);
 178         gfp_flags |= __GFP_COMP;        /* compound page lets parts be mapped */
 179         pg = get_order(size);
 180         if ((res = (void *) __get_free_pages(gfp_flags, pg)) != NULL)
 181                 inc_snd_pages(pg);
 182         return res;
 183 }
 184
 185 /**
 186  * snd_free_pages - release the pages
 187  * @ptr: the buffer pointer to release
 188  * @size: the allocated buffer size
 189  *
 190  * Releases the buffer allocated via snd_malloc_pages().
 191  */
 192 void snd_free_pages(void *ptr, size_t size)
 193 {
 194         int pg;
 195
 196         if (ptr == NULL)
 197                 return;
 198         pg = get_order(size);
 199         dec_snd_pages(pg);
 200         free_pages((unsigned long) ptr, pg);
 201 }
 202
 203 /*
 204  *
 205  *  Bus-specific memory allocators
 206  *
 207  */
 208
 209 /* allocate the coherent DMA pages */
 210 static void *snd_malloc_dev_pages(struct device *dev, size_t size, dma_addr_t *dma)
 211 {
 212         int pg;
 213         void *res;
 214         gfp_t gfp_flags;
 215
 216         snd_assert(size > 0, return NULL);
 217         snd_assert(dma != NULL, return NULL);
 218         pg = get_order(size);
 219         gfp_flags = GFP_KERNEL
 220                 | __GFP_COMP    /* compound page lets parts be mapped */
 221                 | __GFP_NORETRY /* don't trigger OOM-killer */
 222                 | __GFP_NOWARN; /* no stack trace print - this call is non-critical */
 223         res = dma_alloc_coherent(dev, PAGE_SIZE << pg, dma, gfp_flags);
 224         if (res != NULL)
 225                 inc_snd_pages(pg);
 226
 227         return res;
 228 }
 229
 230 /* free the coherent DMA pages */
 231 static void snd_free_dev_pages(struct device *dev, size_t size, void *ptr,
 232                                dma_addr_t dma)
 233 {
 234         int pg;
 235
 236         if (ptr == NULL)
 237                 return;
 238         pg = get_order(size);
 239         dec_snd_pages(pg);
 240         dma_free_coherent(dev, PAGE_SIZE << pg, ptr, dma);
 241 }
 242
 243 #ifdef CONFIG_SBUS
 244
 245 static void *snd_malloc_sbus_pages(struct device *dev, size_t size,
 246                                    dma_addr_t *dma_addr)
 247 {
 248         struct sbus_dev *sdev = (struct sbus_dev *)dev;
 249         int pg;
 250         void *res;
 251
 252         snd_assert(size > 0, return NULL);
 253         snd_assert(dma_addr != NULL, return NULL);
 254         pg = get_order(size);
 255         res = sbus_alloc_consistent(sdev, PAGE_SIZE * (1 << pg), dma_addr);
 256         if (res != NULL)
 257                 inc_snd_pages(pg);
 258         return res;
 259 }
 260
 261 static void snd_free_sbus_pages(struct device *dev, size_t size,
 262                                 void *ptr, dma_addr_t dma_addr)
 263 {
 264         struct sbus_dev *sdev = (struct sbus_dev *)dev;
 265         int pg;
 266
 267         if (ptr == NULL)
 268                 return;
 269         pg = get_order(size);
 270         dec_snd_pages(pg);
 271         sbus_free_consistent(sdev, PAGE_SIZE * (1 << pg), ptr, dma_addr);
 272 }
 273
 274 #endif /* CONFIG_SBUS */
 275
 276 /*
 277  *
 278  *  ALSA generic memory management
 279  *
 280  */
 281
 282
 283 /**
 284  * snd_dma_alloc_pages - allocate the buffer area according to the given type
 285  * @type: the DMA buffer type
 286  * @device: the device pointer
 287  * @size: the buffer size to allocate
 288  * @dmab: buffer allocation record to store the allocated data
 289  *
 290  * Calls the memory-allocator function for the corresponding
 291  * buffer type.
 292  *
 293  * Returns zero if the buffer with the given size is allocated successfuly,
 294  * other a negative value at error.
 295  */
 296 int snd_dma_alloc_pages(int type, struct device *device, size_t size,
 297                         struct snd_dma_buffer *dmab)
 298 {
 299         snd_assert(size > 0, return -ENXIO);
 300         snd_assert(dmab != NULL, return -ENXIO);
 301
 302         dmab->dev.type = type;
 303         dmab->dev.dev = device;
 304         dmab->bytes = 0;
 305         switch (type) {
 306         case SNDRV_DMA_TYPE_CONTINUOUS:
 307                 dmab->area = snd_malloc_pages(size, (unsigned long)device);
 308                 dmab->addr = 0;
 309                 break;
 310 #ifdef CONFIG_SBUS
 311         case SNDRV_DMA_TYPE_SBUS:
 312                 dmab->area = snd_malloc_sbus_pages(device, size, &dmab->addr);
 313                 break;
 314 #endif
 315         case SNDRV_DMA_TYPE_DEV:
 316                 dmab->area = snd_malloc_dev_pages(device, size, &dmab->addr);
 317                 break;
 318         case SNDRV_DMA_TYPE_DEV_SG:
 319                 snd_malloc_sgbuf_pages(device, size, dmab, NULL);
 320                 break;
 321         default:
 322                 printk(KERN_ERR "snd-malloc: invalid device type %d\n", type);
 323                 dmab->area = NULL;
 324                 dmab->addr = 0;
 325                 return -ENXIO;
 326         }
 327         if (! dmab->area)
 328                 return -ENOMEM;
 329         dmab->bytes = size;
 330         return 0;
 331 }
 332
 333 /**
 334  * snd_dma_alloc_pages_fallback - allocate the buffer area according to the given type with fallback
 335  * @type: the DMA buffer type
 336  * @device: the device pointer
 337  * @size: the buffer size to allocate
 338  * @dmab: buffer allocation record to store the allocated data
 339  *
 340  * Calls the memory-allocator function for the corresponding
 341  * buffer type.  When no space is left, this function reduces the size and
 342  * tries to allocate again.  The size actually allocated is stored in
 343  * res_size argument.
 344  *
 345  * Returns zero if the buffer with the given size is allocated successfuly,
 346  * other a negative value at error.
 347  */
 348 int snd_dma_alloc_pages_fallback(int type, struct device *device, size_t size,
 349                                  struct snd_dma_buffer *dmab)
 350 {
 351         int err;
 352
 353         snd_assert(size > 0, return -ENXIO);
 354         snd_assert(dmab != NULL, return -ENXIO);
 355
 356         while ((err = snd_dma_alloc_pages(type, device, size, dmab)) < 0) {
 357                 if (err != -ENOMEM)
 358                         return err;
 359                 size >>= 1;
 360                 if (size <= PAGE_SIZE)
 361                         return -ENOMEM;
 362         }
 363         if (! dmab->area)
 364                 return -ENOMEM;
 365         return 0;
 366 }
 367
 368
 369 /**
 370  * snd_dma_free_pages - release the allocated buffer
 371  * @dmab: the buffer allocation record to release
 372  *
 373  * Releases the allocated buffer via snd_dma_alloc_pages().
 374  */
 375 void snd_dma_free_pages(struct snd_dma_buffer *dmab)
 376 {
 377         switch (dmab->dev.type) {
 378         case SNDRV_DMA_TYPE_CONTINUOUS:
 379                 snd_free_pages(dmab->area, dmab->bytes);
 380                 break;
 381 #ifdef CONFIG_SBUS
 382         case SNDRV_DMA_TYPE_SBUS:
 383                 snd_free_sbus_pages(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);
 384                 break;
 385 #endif
 386         case SNDRV_DMA_TYPE_DEV:
 387                 snd_free_dev_pages(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);
 388                 break;
 389         case SNDRV_DMA_TYPE_DEV_SG:
 390                 snd_free_sgbuf_pages(dmab);
 391                 break;
 392         default:
 393                 printk(KERN_ERR "snd-malloc: invalid device type %d\n", dmab->dev.type);
 394         }
 395 }
 396
 397
 398 /**
 399  * snd_dma_get_reserved - get the reserved buffer for the given device
 400  * @dmab: the buffer allocation record to store
 401  * @id: the buffer id
 402  *
 403  * Looks for the reserved-buffer list and re-uses if the same buffer
 404  * is found in the list.  When the buffer is found, it's removed from the free list.
 405  *
 406  * Returns the size of buffer if the buffer is found, or zero if not found.
 407  */
 408 size_t snd_dma_get_reserved_buf(struct snd_dma_buffer *dmab, unsigned int id)
 409 {
 410         struct list_head *p;
 411         struct snd_mem_list *mem;
 412
 413         snd_assert(dmab, return 0);
 414
 415         mutex_lock(&list_mutex);
 416         list_for_each(p, &mem_list_head) {
 417                 mem = list_entry(p, struct snd_mem_list, list);
 418                 if (mem->id == id &&
 419                     (mem->buffer.dev.dev == NULL || dmab->dev.dev == NULL ||
 420                      ! memcmp(&mem->buffer.dev, &dmab->dev, sizeof(dmab->dev)))) {
 421                         struct device *dev = dmab->dev.dev;
 422                         list_del(p);
 423                         *dmab = mem->buffer;
 424                         if (dmab->dev.dev == NULL)
 425                                 dmab->dev.dev = dev;
 426                         kfree(mem);
 427                         mutex_unlock(&list_mutex);
 428                         return dmab->bytes;
 429                 }
 430         }
 431         mutex_unlock(&list_mutex);
 432         return 0;
 433 }
 434
 435 /**
 436  * snd_dma_reserve_buf - reserve the buffer
 437  * @dmab: the buffer to reserve
 438  * @id: the buffer id
 439  *
 440  * Reserves the given buffer as a reserved buffer.
 441  *
 442  * Returns zero if successful, or a negative code at error.
 443  */
 444 int snd_dma_reserve_buf(struct snd_dma_buffer *dmab, unsigned int id)
 445 {
 446         struct snd_mem_list *mem;
 447
 448         snd_assert(dmab, return -EINVAL);
 449         mem = kmalloc(sizeof(*mem), GFP_KERNEL);
 450         if (! mem)
 451                 return -ENOMEM;
 452         mutex_lock(&list_mutex);
 453         mem->buffer = *dmab;
 454         mem->id = id;
 455         list_add_tail(&mem->list, &mem_list_head);
 456         mutex_unlock(&list_mutex);
 457         return 0;
 458 }
 459
 460 /*
 461  * purge all reserved buffers
 462  */
 463 static void free_all_reserved_pages(void)
 464 {
 465         struct list_head *p;
 466         struct snd_mem_list *mem;
 467
 468         mutex_lock(&list_mutex);
 469         while (! list_empty(&mem_list_head)) {
 470                 p = mem_list_head.next;
 471                 mem = list_entry(p, struct snd_mem_list, list);
 472                 list_del(p);
 473                 snd_dma_free_pages(&mem->buffer);
 474                 kfree(mem);
 475         }
 476         mutex_unlock(&list_mutex);
 477 }
 478
 479
 480 #ifdef CONFIG_PROC_FS
 481 /*
 482  * proc file interface
 483  */
 484 #define SND_MEM_PROC_FILE       "driver/snd-page-alloc"
 485 static struct proc_dir_entry *snd_mem_proc;
 486
 487 static int snd_mem_proc_read(char *page, char **start, off_t off,
 488                              int count, int *eof, void *data)
 489 {
 490         int len = 0;
 491         long pages = snd_allocated_pages >> (PAGE_SHIFT-12);
 492         struct list_head *p;
 493         struct snd_mem_list *mem;
 494         int devno;
 495         static char *types[] = { "UNKNOWN", "CONT", "DEV", "DEV-SG", "SBUS" };
 496
 497         mutex_lock(&list_mutex);
 498         len += snprintf(page + len, count - len,
 499                         "pages  : %li bytes (%li pages per %likB)\n",
 500                         pages * PAGE_SIZE, pages, PAGE_SIZE / 1024);
 501         devno = 0;
 502         list_for_each(p, &mem_list_head) {
 503                 mem = list_entry(p, struct snd_mem_list, list);
 504                 devno++;
 505                 len += snprintf(page + len, count - len,
 506                                 "buffer %d : ID %08x : type %s\n",
 507                                 devno, mem->id, types[mem->buffer.dev.type]);
 508                 len += snprintf(page + len, count - len,
 509                                 "  addr = 0x%lx, size = %d bytes\n",
 510                                 (unsigned long)mem->buffer.addr, (int)mem->buffer.bytes);
 511         }
 512         mutex_unlock(&list_mutex);
 513         return len;
 514 }
 515
 516 /* FIXME: for pci only - other bus? */
 517 #ifdef CONFIG_PCI
 518 #define gettoken(bufp) strsep(bufp, " \t\n")
 519
 520 static int snd_mem_proc_write(struct file *file, const char __user *buffer,
 521                               unsigned long count, void *data)
 522 {
 523         char buf[128];
 524         char *token, *p;
 525
 526         if (count > ARRAY_SIZE(buf) - 1)
 527                 count = ARRAY_SIZE(buf) - 1;
 528         if (copy_from_user(buf, buffer, count))
 529                 return -EFAULT;
 530         buf[ARRAY_SIZE(buf) - 1] = '\0';
 531
 532         p = buf;
 533         token = gettoken(&p);
 534         if (! token || *token == '#')
 535                 return (int)count;
 536         if (strcmp(token, "add") == 0) {
 537                 char *endp;
 538                 int vendor, device, size, buffers;
 539                 long mask;
 540                 int i, alloced;
 541                 struct pci_dev *pci;
 542
 543                 if ((token = gettoken(&p)) == NULL ||
 544                     (vendor = simple_strtol(token, NULL, 0)) <= 0 ||
 545                     (token = gettoken(&p)) == NULL ||
 546                     (device = simple_strtol(token, NULL, 0)) <= 0 ||
 547                     (token = gettoken(&p)) == NULL ||
 548                     (mask = simple_strtol(token, NULL, 0)) < 0 ||
 549                     (token = gettoken(&p)) == NULL ||
 550                     (size = memparse(token, &endp)) < 64*1024 ||
 551                     size > 16*1024*1024 /* too big */ ||
 552                     (token = gettoken(&p)) == NULL ||
 553                     (buffers = simple_strtol(token, NULL, 0)) <= 0 ||
 554                     buffers > 4) {
 555                         printk(KERN_ERR "snd-page-alloc: invalid proc write format\n");
 556                         return (int)count;
 557                 }
 558                 vendor &= 0xffff;
 559                 device &= 0xffff;
 560
 561                 alloced = 0;
 562                 pci = NULL;
 563                 while ((pci = pci_get_device(vendor, device, pci)) != NULL) {
 564                         if (mask > 0 && mask < 0xffffffff) {
 565                                 if (pci_set_dma_mask(pci, mask) < 0 ||
 566                                     pci_set_consistent_dma_mask(pci, mask) < 0) {
 567                                         printk(KERN_ERR "snd-page-alloc: cannot set DMA mask %lx for pci %04x:%04x\n", mask, vendor, device);
 568                                         return (int)count;
 569                                 }
 570                         }
 571                         for (i = 0; i < buffers; i++) {
 572                                 struct snd_dma_buffer dmab;
 573                                 memset(&dmab, 0, sizeof(dmab));
 574                                 if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, snd_dma_pci_data(pci),
 575                                                         size, &dmab) < 0) {
 576                                         printk(KERN_ERR "snd-page-alloc: cannot allocate buffer pages (size = %d)\n", size);
 577                                         pci_dev_put(pci);
 578                                         return (int)count;
 579                                 }
 580                                 snd_dma_reserve_buf(&dmab, snd_dma_pci_buf_id(pci));
 581                         }
 582                         alloced++;
 583                 }
 584                 if (! alloced) {
 585                         for (i = 0; i < buffers; i++) {
 586                                 struct snd_dma_buffer dmab;
 587                                 memset(&dmab, 0, sizeof(dmab));
 588                                 /* FIXME: We can allocate only in ZONE_DMA
 589                                  * without a device pointer!
 590                                  */
 591                                 if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, NULL,
 592                                                         size, &dmab) < 0) {
 593                                         printk(KERN_ERR "snd-page-alloc: cannot allocate buffer pages (size = %d)\n", size);
 594                                         break;
 595                                 }
 596                                 snd_dma_reserve_buf(&dmab, (unsigned int)((vendor << 16) | device));
 597                         }
 598                 }
 599         } else if (strcmp(token, "erase") == 0)
 600                 /* FIXME: need for releasing each buffer chunk? */
 601                 free_all_reserved_pages();
 602         else
 603                 printk(KERN_ERR "snd-page-alloc: invalid proc cmd\n");
 604         return (int)count;
 605 }
 606 #endif /* CONFIG_PCI */
 607 #endif /* CONFIG_PROC_FS */
 608
 609 /*
 610  * module entry
 611  */
 612
 613 static int __init snd_mem_init(void)
 614 {
 615 #ifdef CONFIG_PROC_FS
 616         snd_mem_proc = create_proc_entry(SND_MEM_PROC_FILE, 0644, NULL);
 617         if (snd_mem_proc) {
 618                 snd_mem_proc->read_proc = snd_mem_proc_read;
 619 #ifdef CONFIG_PCI
 620                 snd_mem_proc->write_proc = snd_mem_proc_write;
 621 #endif
 622         }
 623 #endif
 624         return 0;
 625 }
 626
 627 static void __exit snd_mem_exit(void)
 628 {
 629         remove_proc_entry(SND_MEM_PROC_FILE, NULL);
 630         free_all_reserved_pages();
 631         if (snd_allocated_pages > 0)
 632                 printk(KERN_ERR "snd-malloc: Memory leak?  pages not freed = %li\n", snd_allocated_pages);
 633 }
 634
 635
 636 module_init(snd_mem_init)
 637 module_exit(snd_mem_exit)
 638
 639
 640 /*
 641  * exports
 642  */
 643 EXPORT_SYMBOL(snd_dma_alloc_pages);
 644 EXPORT_SYMBOL(snd_dma_alloc_pages_fallback);
 645 EXPORT_SYMBOL(snd_dma_free_pages);
 646
 647 EXPORT_SYMBOL(snd_dma_get_reserved_buf);
 648 EXPORT_SYMBOL(snd_dma_reserve_buf);
 649
 650 EXPORT_SYMBOL(snd_malloc_pages);
 651 EXPORT_SYMBOL(snd_free_pages);