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 <asm/semaphore.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 #ifndef SNDRV_CARDS
  47 #define SNDRV_CARDS     8
  48 #endif
  49
  50 /*
  51  */
  52
  53 void *snd_malloc_sgbuf_pages(struct device *device,
  54                              size_t size, struct snd_dma_buffer *dmab,
  55                              size_t *res_size);
  56 int snd_free_sgbuf_pages(struct snd_dma_buffer *dmab);
  57
  58 /*
  59  */
  60
  61 static DECLARE_MUTEX(list_mutex);
  62 static LIST_HEAD(mem_list_head);
  63
  64 /* buffer preservation list */
  65 struct 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
 107 static void *snd_dma_hack_alloc_coherent(struct device *dev, size_t size,
 108                                          dma_addr_t *dma_handle,
 109                                          unsigned int __nocast flags)
 110 {
 111         void *ret;
 112         u64 dma_mask, coherent_dma_mask;
 113
 114         if (dev == NULL || !dev->dma_mask)
 115                 return dma_alloc_coherent(dev, size, dma_handle, flags);
 116         dma_mask = *dev->dma_mask;
 117         coherent_dma_mask = dev->coherent_dma_mask;
 118         *dev->dma_mask = 0xffffffff;    /* do without masking */
 119         dev->coherent_dma_mask = 0xffffffff;    /* do without masking */
 120         ret = dma_alloc_coherent(dev, size, dma_handle, flags);
 121         *dev->dma_mask = dma_mask;      /* restore */
 122         dev->coherent_dma_mask = coherent_dma_mask;     /* restore */
 123         if (ret) {
 124                 /* obtained address is out of range? */
 125                 if (((unsigned long)*dma_handle + size - 1) & ~dma_mask) {
 126                         /* reallocate with the proper mask */
 127                         dma_free_coherent(dev, size, ret, *dma_handle);
 128                         ret = dma_alloc_coherent(dev, size, dma_handle, flags);
 129                 }
 130         } else {
 131                 /* wish to success now with the proper mask... */
 132                 if (dma_mask != 0xffffffffUL) {
 133                         /* allocation with GFP_ATOMIC to avoid the long stall */
 134                         flags &= ~GFP_KERNEL;
 135                         flags |= GFP_ATOMIC;
 136                         ret = dma_alloc_coherent(dev, size, dma_handle, flags);
 137                 }
 138         }
 139         return ret;
 140 }
 141
 142 /* redefine dma_alloc_coherent for some architectures */
 143 #undef dma_alloc_coherent
 144 #define dma_alloc_coherent snd_dma_hack_alloc_coherent
 145
 146 #endif /* arch */
 147
 148 #if ! defined(__arm__)
 149 #define NEED_RESERVE_PAGES
 150 #endif
 151
 152 /*
 153  *
 154  *  Generic memory allocators
 155  *
 156  */
 157
 158 static long snd_allocated_pages; /* holding the number of allocated pages */
 159
 160 static inline void inc_snd_pages(int order)
 161 {
 162         snd_allocated_pages += 1 << order;
 163 }
 164
 165 static inline void dec_snd_pages(int order)
 166 {
 167         snd_allocated_pages -= 1 << order;
 168 }
 169
 170 static void mark_pages(struct page *page, int order)
 171 {
 172         struct page *last_page = page + (1 << order);
 173         while (page < last_page)
 174                 SetPageReserved(page++);
 175 }
 176
 177 static void unmark_pages(struct page *page, int order)
 178 {
 179         struct page *last_page = page + (1 << order);
 180         while (page < last_page)
 181                 ClearPageReserved(page++);
 182 }
 183
 184 /**
 185  * snd_malloc_pages - allocate pages with the given size
 186  * @size: the size to allocate in bytes
 187  * @gfp_flags: the allocation conditions, GFP_XXX
 188  *
 189  * Allocates the physically contiguous pages with the given size.
 190  *
 191  * Returns the pointer of the buffer, or NULL if no enoguh memory.
 192  */
 193 void *snd_malloc_pages(size_t size, unsigned int gfp_flags)
 194 {
 195         int pg;
 196         void *res;
 197
 198         snd_assert(size > 0, return NULL);
 199         snd_assert(gfp_flags != 0, return NULL);
 200         pg = get_order(size);
 201         if ((res = (void *) __get_free_pages(gfp_flags, pg)) != NULL) {
 202                 mark_pages(virt_to_page(res), pg);
 203                 inc_snd_pages(pg);
 204         }
 205         return res;
 206 }
 207
 208 /**
 209  * snd_free_pages - release the pages
 210  * @ptr: the buffer pointer to release
 211  * @size: the allocated buffer size
 212  *
 213  * Releases the buffer allocated via snd_malloc_pages().
 214  */
 215 void snd_free_pages(void *ptr, size_t size)
 216 {
 217         int pg;
 218
 219         if (ptr == NULL)
 220                 return;
 221         pg = get_order(size);
 222         dec_snd_pages(pg);
 223         unmark_pages(virt_to_page(ptr), pg);
 224         free_pages((unsigned long) ptr, pg);
 225 }
 226
 227 /*
 228  *
 229  *  Bus-specific memory allocators
 230  *
 231  */
 232
 233 /* allocate the coherent DMA pages */
 234 static void *snd_malloc_dev_pages(struct device *dev, size_t size, dma_addr_t *dma)
 235 {
 236         int pg;
 237         void *res;
 238         unsigned int gfp_flags;
 239
 240         snd_assert(size > 0, return NULL);
 241         snd_assert(dma != NULL, return NULL);
 242         pg = get_order(size);
 243         gfp_flags = GFP_KERNEL
 244                 | __GFP_NORETRY /* don't trigger OOM-killer */
 245                 | __GFP_NOWARN; /* no stack trace print - this call is non-critical */
 246         res = dma_alloc_coherent(dev, PAGE_SIZE << pg, dma, gfp_flags);
 247         if (res != NULL) {
 248 #ifdef NEED_RESERVE_PAGES
 249                 mark_pages(virt_to_page(res), pg); /* should be dma_to_page() */
 250 #endif
 251                 inc_snd_pages(pg);
 252         }
 253
 254         return res;
 255 }
 256
 257 /* free the coherent DMA pages */
 258 static void snd_free_dev_pages(struct device *dev, size_t size, void *ptr,
 259                                dma_addr_t dma)
 260 {
 261         int pg;
 262
 263         if (ptr == NULL)
 264                 return;
 265         pg = get_order(size);
 266         dec_snd_pages(pg);
 267 #ifdef NEED_RESERVE_PAGES
 268         unmark_pages(virt_to_page(ptr), pg); /* should be dma_to_page() */
 269 #endif
 270         dma_free_coherent(dev, PAGE_SIZE << pg, ptr, dma);
 271 }
 272
 273 #ifdef CONFIG_SBUS
 274
 275 static void *snd_malloc_sbus_pages(struct device *dev, size_t size,
 276                                    dma_addr_t *dma_addr)
 277 {
 278         struct sbus_dev *sdev = (struct sbus_dev *)dev;
 279         int pg;
 280         void *res;
 281
 282         snd_assert(size > 0, return NULL);
 283         snd_assert(dma_addr != NULL, return NULL);
 284         pg = get_order(size);
 285         res = sbus_alloc_consistent(sdev, PAGE_SIZE * (1 << pg), dma_addr);
 286         if (res != NULL)
 287                 inc_snd_pages(pg);
 288         return res;
 289 }
 290
 291 static void snd_free_sbus_pages(struct device *dev, size_t size,
 292                                 void *ptr, dma_addr_t dma_addr)
 293 {
 294         struct sbus_dev *sdev = (struct sbus_dev *)dev;
 295         int pg;
 296
 297         if (ptr == NULL)
 298                 return;
 299         pg = get_order(size);
 300         dec_snd_pages(pg);
 301         sbus_free_consistent(sdev, PAGE_SIZE * (1 << pg), ptr, dma_addr);
 302 }
 303
 304 #endif /* CONFIG_SBUS */
 305
 306 /*
 307  *
 308  *  ALSA generic memory management
 309  *
 310  */
 311
 312
 313 /**
 314  * snd_dma_alloc_pages - allocate the buffer area according to the given type
 315  * @type: the DMA buffer type
 316  * @device: the device pointer
 317  * @size: the buffer size to allocate
 318  * @dmab: buffer allocation record to store the allocated data
 319  *
 320  * Calls the memory-allocator function for the corresponding
 321  * buffer type.
 322  *
 323  * Returns zero if the buffer with the given size is allocated successfuly,
 324  * other a negative value at error.
 325  */
 326 int snd_dma_alloc_pages(int type, struct device *device, size_t size,
 327                         struct snd_dma_buffer *dmab)
 328 {
 329         snd_assert(size > 0, return -ENXIO);
 330         snd_assert(dmab != NULL, return -ENXIO);
 331
 332         dmab->dev.type = type;
 333         dmab->dev.dev = device;
 334         dmab->bytes = 0;
 335         switch (type) {
 336         case SNDRV_DMA_TYPE_CONTINUOUS:
 337                 dmab->area = snd_malloc_pages(size, (unsigned long)device);
 338                 dmab->addr = 0;
 339                 break;
 340 #ifdef CONFIG_SBUS
 341         case SNDRV_DMA_TYPE_SBUS:
 342                 dmab->area = snd_malloc_sbus_pages(device, size, &dmab->addr);
 343                 break;
 344 #endif
 345         case SNDRV_DMA_TYPE_DEV:
 346                 dmab->area = snd_malloc_dev_pages(device, size, &dmab->addr);
 347                 break;
 348         case SNDRV_DMA_TYPE_DEV_SG:
 349                 snd_malloc_sgbuf_pages(device, size, dmab, NULL);
 350                 break;
 351         default:
 352                 printk(KERN_ERR "snd-malloc: invalid device type %d\n", type);
 353                 dmab->area = NULL;
 354                 dmab->addr = 0;
 355                 return -ENXIO;
 356         }
 357         if (! dmab->area)
 358                 return -ENOMEM;
 359         dmab->bytes = size;
 360         return 0;
 361 }
 362
 363 /**
 364  * snd_dma_alloc_pages_fallback - allocate the buffer area according to the given type with fallback
 365  * @type: the DMA buffer type
 366  * @device: the device pointer
 367  * @size: the buffer size to allocate
 368  * @dmab: buffer allocation record to store the allocated data
 369  *
 370  * Calls the memory-allocator function for the corresponding
 371  * buffer type.  When no space is left, this function reduces the size and
 372  * tries to allocate again.  The size actually allocated is stored in
 373  * res_size argument.
 374  *
 375  * Returns zero if the buffer with the given size is allocated successfuly,
 376  * other a negative value at error.
 377  */
 378 int snd_dma_alloc_pages_fallback(int type, struct device *device, size_t size,
 379                                  struct snd_dma_buffer *dmab)
 380 {
 381         int err;
 382
 383         snd_assert(size > 0, return -ENXIO);
 384         snd_assert(dmab != NULL, return -ENXIO);
 385
 386         while ((err = snd_dma_alloc_pages(type, device, size, dmab)) < 0) {
 387                 if (err != -ENOMEM)
 388                         return err;
 389                 size >>= 1;
 390                 if (size <= PAGE_SIZE)
 391                         return -ENOMEM;
 392         }
 393         if (! dmab->area)
 394                 return -ENOMEM;
 395         return 0;
 396 }
 397
 398
 399 /**
 400  * snd_dma_free_pages - release the allocated buffer
 401  * @dmab: the buffer allocation record to release
 402  *
 403  * Releases the allocated buffer via snd_dma_alloc_pages().
 404  */
 405 void snd_dma_free_pages(struct snd_dma_buffer *dmab)
 406 {
 407         switch (dmab->dev.type) {
 408         case SNDRV_DMA_TYPE_CONTINUOUS:
 409                 snd_free_pages(dmab->area, dmab->bytes);
 410                 break;
 411 #ifdef CONFIG_SBUS
 412         case SNDRV_DMA_TYPE_SBUS:
 413                 snd_free_sbus_pages(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);
 414                 break;
 415 #endif
 416         case SNDRV_DMA_TYPE_DEV:
 417                 snd_free_dev_pages(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);
 418                 break;
 419         case SNDRV_DMA_TYPE_DEV_SG:
 420                 snd_free_sgbuf_pages(dmab);
 421                 break;
 422         default:
 423                 printk(KERN_ERR "snd-malloc: invalid device type %d\n", dmab->dev.type);
 424         }
 425 }
 426
 427
 428 /**
 429  * snd_dma_get_reserved - get the reserved buffer for the given device
 430  * @dmab: the buffer allocation record to store
 431  * @id: the buffer id
 432  *
 433  * Looks for the reserved-buffer list and re-uses if the same buffer
 434  * is found in the list.  When the buffer is found, it's removed from the free list.
 435  *
 436  * Returns the size of buffer if the buffer is found, or zero if not found.
 437  */
 438 size_t snd_dma_get_reserved_buf(struct snd_dma_buffer *dmab, unsigned int id)
 439 {
 440         struct list_head *p;
 441         struct snd_mem_list *mem;
 442
 443         snd_assert(dmab, return 0);
 444
 445         down(&list_mutex);
 446         list_for_each(p, &mem_list_head) {
 447                 mem = list_entry(p, struct snd_mem_list, list);
 448                 if (mem->id == id &&
 449                     (mem->buffer.dev.dev == NULL || dmab->dev.dev == NULL ||
 450                      ! memcmp(&mem->buffer.dev, &dmab->dev, sizeof(dmab->dev)))) {
 451                         struct device *dev = dmab->dev.dev;
 452                         list_del(p);
 453                         *dmab = mem->buffer;
 454                         if (dmab->dev.dev == NULL)
 455                                 dmab->dev.dev = dev;
 456                         kfree(mem);
 457                         up(&list_mutex);
 458                         return dmab->bytes;
 459                 }
 460         }
 461         up(&list_mutex);
 462         return 0;
 463 }
 464
 465 /**
 466  * snd_dma_reserve_buf - reserve the buffer
 467  * @dmab: the buffer to reserve
 468  * @id: the buffer id
 469  *
 470  * Reserves the given buffer as a reserved buffer.
 471  *
 472  * Returns zero if successful, or a negative code at error.
 473  */
 474 int snd_dma_reserve_buf(struct snd_dma_buffer *dmab, unsigned int id)
 475 {
 476         struct snd_mem_list *mem;
 477
 478         snd_assert(dmab, return -EINVAL);
 479         mem = kmalloc(sizeof(*mem), GFP_KERNEL);
 480         if (! mem)
 481                 return -ENOMEM;
 482         down(&list_mutex);
 483         mem->buffer = *dmab;
 484         mem->id = id;
 485         list_add_tail(&mem->list, &mem_list_head);
 486         up(&list_mutex);
 487         return 0;
 488 }
 489
 490 /*
 491  * purge all reserved buffers
 492  */
 493 static void free_all_reserved_pages(void)
 494 {
 495         struct list_head *p;
 496         struct snd_mem_list *mem;
 497
 498         down(&list_mutex);
 499         while (! list_empty(&mem_list_head)) {
 500                 p = mem_list_head.next;
 501                 mem = list_entry(p, struct snd_mem_list, list);
 502                 list_del(p);
 503                 snd_dma_free_pages(&mem->buffer);
 504                 kfree(mem);
 505         }
 506         up(&list_mutex);
 507 }
 508
 509
 510 #ifdef CONFIG_PROC_FS
 511 /*
 512  * proc file interface
 513  */
 514 #define SND_MEM_PROC_FILE       "driver/snd-page-alloc"
 515 struct proc_dir_entry *snd_mem_proc;
 516
 517 static int snd_mem_proc_read(char *page, char **start, off_t off,
 518                              int count, int *eof, void *data)
 519 {
 520         int len = 0;
 521         long pages = snd_allocated_pages >> (PAGE_SHIFT-12);
 522         struct list_head *p;
 523         struct snd_mem_list *mem;
 524         int devno;
 525         static char *types[] = { "UNKNOWN", "CONT", "DEV", "DEV-SG", "SBUS" };
 526
 527         down(&list_mutex);
 528         len += snprintf(page + len, count - len,
 529                         "pages  : %li bytes (%li pages per %likB)\n",
 530                         pages * PAGE_SIZE, pages, PAGE_SIZE / 1024);
 531         devno = 0;
 532         list_for_each(p, &mem_list_head) {
 533                 mem = list_entry(p, struct snd_mem_list, list);
 534                 devno++;
 535                 len += snprintf(page + len, count - len,
 536                                 "buffer %d : ID %08x : type %s\n",
 537                                 devno, mem->id, types[mem->buffer.dev.type]);
 538                 len += snprintf(page + len, count - len,
 539                                 "  addr = 0x%lx, size = %d bytes\n",
 540                                 (unsigned long)mem->buffer.addr, (int)mem->buffer.bytes);
 541         }
 542         up(&list_mutex);
 543         return len;
 544 }
 545
 546 /* FIXME: for pci only - other bus? */
 547 #ifdef CONFIG_PCI
 548 #define gettoken(bufp) strsep(bufp, " \t\n")
 549
 550 static int snd_mem_proc_write(struct file *file, const char __user *buffer,
 551                               unsigned long count, void *data)
 552 {
 553         char buf[128];
 554         char *token, *p;
 555
 556         if (count > ARRAY_SIZE(buf) - 1)
 557                 count = ARRAY_SIZE(buf) - 1;
 558         if (copy_from_user(buf, buffer, count))
 559                 return -EFAULT;
 560         buf[ARRAY_SIZE(buf) - 1] = '\0';
 561
 562         p = buf;
 563         token = gettoken(&p);
 564         if (! token || *token == '#')
 565                 return (int)count;
 566         if (strcmp(token, "add") == 0) {
 567                 char *endp;
 568                 int vendor, device, size, buffers;
 569                 long mask;
 570                 int i, alloced;
 571                 struct pci_dev *pci;
 572
 573                 if ((token = gettoken(&p)) == NULL ||
 574                     (vendor = simple_strtol(token, NULL, 0)) <= 0 ||
 575                     (token = gettoken(&p)) == NULL ||
 576                     (device = simple_strtol(token, NULL, 0)) <= 0 ||
 577                     (token = gettoken(&p)) == NULL ||
 578                     (mask = simple_strtol(token, NULL, 0)) < 0 ||
 579                     (token = gettoken(&p)) == NULL ||
 580                     (size = memparse(token, &endp)) < 64*1024 ||
 581                     size > 16*1024*1024 /* too big */ ||
 582                     (token = gettoken(&p)) == NULL ||
 583                     (buffers = simple_strtol(token, NULL, 0)) <= 0 ||
 584                     buffers > 4) {
 585                         printk(KERN_ERR "snd-page-alloc: invalid proc write format\n");
 586                         return (int)count;
 587                 }
 588                 vendor &= 0xffff;
 589                 device &= 0xffff;
 590
 591                 alloced = 0;
 592                 pci = NULL;
 593                 while ((pci = pci_find_device(vendor, device, pci)) != NULL) {
 594                         if (mask > 0 && mask < 0xffffffff) {
 595                                 if (pci_set_dma_mask(pci, mask) < 0 ||
 596                                     pci_set_consistent_dma_mask(pci, mask) < 0) {
 597                                         printk(KERN_ERR "snd-page-alloc: cannot set DMA mask %lx for pci %04x:%04x\n", mask, vendor, device);
 598                                         return (int)count;
 599                                 }
 600                         }
 601                         for (i = 0; i < buffers; i++) {
 602                                 struct snd_dma_buffer dmab;
 603                                 memset(&dmab, 0, sizeof(dmab));
 604                                 if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, snd_dma_pci_data(pci),
 605                                                         size, &dmab) < 0) {
 606                                         printk(KERN_ERR "snd-page-alloc: cannot allocate buffer pages (size = %d)\n", size);
 607                                         return (int)count;
 608                                 }
 609                                 snd_dma_reserve_buf(&dmab, snd_dma_pci_buf_id(pci));
 610                         }
 611                         alloced++;
 612                 }
 613                 if (! alloced) {
 614                         for (i = 0; i < buffers; i++) {
 615                                 struct snd_dma_buffer dmab;
 616                                 memset(&dmab, 0, sizeof(dmab));
 617                                 /* FIXME: We can allocate only in ZONE_DMA
 618                                  * without a device pointer!
 619                                  */
 620                                 if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, NULL,
 621                                                         size, &dmab) < 0) {
 622                                         printk(KERN_ERR "snd-page-alloc: cannot allocate buffer pages (size = %d)\n", size);
 623                                         break;
 624                                 }
 625                                 snd_dma_reserve_buf(&dmab, (unsigned int)((vendor << 16) | device));
 626                         }
 627                 }
 628         } else if (strcmp(token, "erase") == 0)
 629                 /* FIXME: need for releasing each buffer chunk? */
 630                 free_all_reserved_pages();
 631         else
 632                 printk(KERN_ERR "snd-page-alloc: invalid proc cmd\n");
 633         return (int)count;
 634 }
 635 #endif /* CONFIG_PCI */
 636 #endif /* CONFIG_PROC_FS */
 637
 638 /*
 639  * module entry
 640  */
 641
 642 static int __init snd_mem_init(void)
 643 {
 644 #ifdef CONFIG_PROC_FS
 645         snd_mem_proc = create_proc_entry(SND_MEM_PROC_FILE, 0644, NULL);
 646         if (snd_mem_proc) {
 647                 snd_mem_proc->read_proc = snd_mem_proc_read;
 648 #ifdef CONFIG_PCI
 649                 snd_mem_proc->write_proc = snd_mem_proc_write;
 650 #endif
 651         }
 652 #endif
 653         return 0;
 654 }
 655
 656 static void __exit snd_mem_exit(void)
 657 {
 658         if (snd_mem_proc)
 659                 remove_proc_entry(SND_MEM_PROC_FILE, NULL);
 660         free_all_reserved_pages();
 661         if (snd_allocated_pages > 0)
 662                 printk(KERN_ERR "snd-malloc: Memory leak?  pages not freed = %li\n", snd_allocated_pages);
 663 }
 664
 665
 666 module_init(snd_mem_init)
 667 module_exit(snd_mem_exit)
 668
 669
 670 /*
 671  * exports
 672  */
 673 EXPORT_SYMBOL(snd_dma_alloc_pages);
 674 EXPORT_SYMBOL(snd_dma_alloc_pages_fallback);
 675 EXPORT_SYMBOL(snd_dma_free_pages);
 676
 677 EXPORT_SYMBOL(snd_dma_get_reserved_buf);
 678 EXPORT_SYMBOL(snd_dma_reserve_buf);
 679
 680 EXPORT_SYMBOL(snd_malloc_pages);
 681 EXPORT_SYMBOL(snd_free_pages);