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