sound/pci/emu10k1/memory.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   4  *  Copyright (c) by Takashi Iwai <tiwai@suse.de>
   5  *
   6  *  EMU10K1 memory page allocation (PTB area)
   7  */
   8
   9 #include <linux/pci.h>
  10 #include <linux/gfp.h>
  11 #include <linux/time.h>
  12 #include <linux/mutex.h>
  13 #include <linux/export.h>
  14
  15 #include <sound/core.h>
  16 #include <sound/emu10k1.h>
  17
  18 /* page arguments of these two macros are Emu page (4096 bytes), not like
  19  * aligned pages in others
  20  */
  21 #define __set_ptb_entry(emu,page,addr) \
  22         (((__le32 *)(emu)->ptb_pages.area)[page] = \
  23          cpu_to_le32(((addr) << (emu->address_mode)) | (page)))
  24 #define __get_ptb_entry(emu, page) \
  25         (le32_to_cpu(((__le32 *)(emu)->ptb_pages.area)[page]))
  26
  27 #define UNIT_PAGES              (PAGE_SIZE / EMUPAGESIZE)
  28 #define MAX_ALIGN_PAGES0                (MAXPAGES0 / UNIT_PAGES)
  29 #define MAX_ALIGN_PAGES1                (MAXPAGES1 / UNIT_PAGES)
  30 /* get aligned page from offset address */
  31 #define get_aligned_page(offset)        ((offset) >> PAGE_SHIFT)
  32 /* get offset address from aligned page */
  33 #define aligned_page_offset(page)       ((page) << PAGE_SHIFT)
  34
  35 #if PAGE_SIZE == EMUPAGESIZE && !IS_ENABLED(CONFIG_DYNAMIC_DEBUG)
  36 /* fill PTB entrie(s) corresponding to page with addr */
  37 #define set_ptb_entry(emu,page,addr)    __set_ptb_entry(emu,page,addr)
  38 /* fill PTB entrie(s) corresponding to page with silence pointer */
  39 #define set_silent_ptb(emu,page)        __set_ptb_entry(emu,page,emu->silent_page.addr)
  40 #else
  41 /* fill PTB entries -- we need to fill UNIT_PAGES entries */
  42 static inline void set_ptb_entry(struct snd_emu10k1 *emu, int page, dma_addr_t addr)
  43 {
  44         int i;
  45         page *= UNIT_PAGES;
  46         for (i = 0; i < UNIT_PAGES; i++, page++) {
  47                 __set_ptb_entry(emu, page, addr);
  48                 dev_dbg(emu->card->dev, "mapped page %d to entry %.8x\n", page,
  49                         (unsigned int)__get_ptb_entry(emu, page));
  50                 addr += EMUPAGESIZE;
  51         }
  52 }
  53 static inline void set_silent_ptb(struct snd_emu10k1 *emu, int page)
  54 {
  55         int i;
  56         page *= UNIT_PAGES;
  57         for (i = 0; i < UNIT_PAGES; i++, page++) {
  58                 /* do not increment ptr */
  59                 __set_ptb_entry(emu, page, emu->silent_page.addr);
  60                 dev_dbg(emu->card->dev, "mapped silent page %d to entry %.8x\n",
  61                         page, (unsigned int)__get_ptb_entry(emu, page));
  62         }
  63 }
  64 #endif /* PAGE_SIZE */
  65
  66
  67 /*
  68  */
  69 static int synth_alloc_pages(struct snd_emu10k1 *hw, struct snd_emu10k1_memblk *blk);
  70 static int synth_free_pages(struct snd_emu10k1 *hw, struct snd_emu10k1_memblk *blk);
  71
  72 #define get_emu10k1_memblk(l,member)    list_entry(l, struct snd_emu10k1_memblk, member)
  73
  74
  75 /* initialize emu10k1 part */
  76 static void emu10k1_memblk_init(struct snd_emu10k1_memblk *blk)
  77 {
  78         blk->mapped_page = -1;
  79         INIT_LIST_HEAD(&blk->mapped_link);
  80         INIT_LIST_HEAD(&blk->mapped_order_link);
  81         blk->map_locked = 0;
  82
  83         blk->first_page = get_aligned_page(blk->mem.offset);
  84         blk->last_page = get_aligned_page(blk->mem.offset + blk->mem.size - 1);
  85         blk->pages = blk->last_page - blk->first_page + 1;
  86 }
  87
  88 /*
  89  * search empty region on PTB with the given size
  90  *
  91  * if an empty region is found, return the page and store the next mapped block
  92  * in nextp
  93  * if not found, return a negative error code.
  94  */
  95 static int search_empty_map_area(struct snd_emu10k1 *emu, int npages, struct list_head **nextp)
  96 {
  97         int page = 1, found_page = -ENOMEM;
  98         int max_size = npages;
  99         int size;
 100         struct list_head *candidate = &emu->mapped_link_head;
 101         struct list_head *pos;
 102
 103         list_for_each (pos, &emu->mapped_link_head) {
 104                 struct snd_emu10k1_memblk *blk = get_emu10k1_memblk(pos, mapped_link);
 105                 if (blk->mapped_page < 0)
 106                         continue;
 107                 size = blk->mapped_page - page;
 108                 if (size == npages) {
 109                         *nextp = pos;
 110                         return page;
 111                 }
 112                 else if (size > max_size) {
 113                         /* we look for the maximum empty hole */
 114                         max_size = size;
 115                         candidate = pos;
 116                         found_page = page;
 117                 }
 118                 page = blk->mapped_page + blk->pages;
 119         }
 120         size = (emu->address_mode ? MAX_ALIGN_PAGES1 : MAX_ALIGN_PAGES0) - page;
 121         if (size >= max_size) {
 122                 *nextp = pos;
 123                 return page;
 124         }
 125         *nextp = candidate;
 126         return found_page;
 127 }
 128
 129 /*
 130  * map a memory block onto emu10k1's PTB
 131  *
 132  * call with memblk_lock held
 133  */
 134 static int map_memblk(struct snd_emu10k1 *emu, struct snd_emu10k1_memblk *blk)
 135 {
 136         int page, pg;
 137         struct list_head *next;
 138
 139         page = search_empty_map_area(emu, blk->pages, &next);
 140         if (page < 0) /* not found */
 141                 return page;
 142         if (page == 0) {
 143                 dev_err(emu->card->dev, "trying to map zero (reserved) page\n");
 144                 return -EINVAL;
 145         }
 146         /* insert this block in the proper position of mapped list */
 147         list_add_tail(&blk->mapped_link, next);
 148         /* append this as a newest block in order list */
 149         list_add_tail(&blk->mapped_order_link, &emu->mapped_order_link_head);
 150         blk->mapped_page = page;
 151         /* fill PTB */
 152         for (pg = blk->first_page; pg <= blk->last_page; pg++) {
 153                 set_ptb_entry(emu, page, emu->page_addr_table[pg]);
 154                 page++;
 155         }
 156         return 0;
 157 }
 158
 159 /*
 160  * unmap the block
 161  * return the size of resultant empty pages
 162  *
 163  * call with memblk_lock held
 164  */
 165 static int unmap_memblk(struct snd_emu10k1 *emu, struct snd_emu10k1_memblk *blk)
 166 {
 167         int start_page, end_page, mpage, pg;
 168         struct list_head *p;
 169         struct snd_emu10k1_memblk *q;
 170
 171         /* calculate the expected size of empty region */
 172         if ((p = blk->mapped_link.prev) != &emu->mapped_link_head) {
 173                 q = get_emu10k1_memblk(p, mapped_link);
 174                 start_page = q->mapped_page + q->pages;
 175         } else
 176                 start_page = 1;
 177         if ((p = blk->mapped_link.next) != &emu->mapped_link_head) {
 178                 q = get_emu10k1_memblk(p, mapped_link);
 179                 end_page = q->mapped_page;
 180         } else
 181                 end_page = (emu->address_mode ? MAX_ALIGN_PAGES1 : MAX_ALIGN_PAGES0);
 182
 183         /* remove links */
 184         list_del(&blk->mapped_link);
 185         list_del(&blk->mapped_order_link);
 186         /* clear PTB */
 187         mpage = blk->mapped_page;
 188         for (pg = blk->first_page; pg <= blk->last_page; pg++) {
 189                 set_silent_ptb(emu, mpage);
 190                 mpage++;
 191         }
 192         blk->mapped_page = -1;
 193         return end_page - start_page; /* return the new empty size */
 194 }
 195
 196 /*
 197  * search empty pages with the given size, and create a memory block
 198  *
 199  * unlike synth_alloc the memory block is aligned to the page start
 200  */
 201 static struct snd_emu10k1_memblk *
 202 search_empty(struct snd_emu10k1 *emu, int size)
 203 {
 204         struct list_head *p;
 205         struct snd_emu10k1_memblk *blk;
 206         int page, psize;
 207
 208         psize = get_aligned_page(size + PAGE_SIZE -1);
 209         page = 0;
 210         list_for_each(p, &emu->memhdr->block) {
 211                 blk = get_emu10k1_memblk(p, mem.list);
 212                 if (page + psize <= blk->first_page)
 213                         goto __found_pages;
 214                 page = blk->last_page + 1;
 215         }
 216         if (page + psize > emu->max_cache_pages)
 217                 return NULL;
 218
 219 __found_pages:
 220         /* create a new memory block */
 221         blk = (struct snd_emu10k1_memblk *)__snd_util_memblk_new(emu->memhdr, psize << PAGE_SHIFT, p->prev);
 222         if (blk == NULL)
 223                 return NULL;
 224         blk->mem.offset = aligned_page_offset(page); /* set aligned offset */
 225         emu10k1_memblk_init(blk);
 226         return blk;
 227 }
 228
 229
 230 /*
 231  * check if the given pointer is valid for pages
 232  */
 233 static int is_valid_page(struct snd_emu10k1 *emu, dma_addr_t addr)
 234 {
 235         if (addr & ~emu->dma_mask) {
 236                 dev_err_ratelimited(emu->card->dev,
 237                         "max memory size is 0x%lx (addr = 0x%lx)!!\n",
 238                         emu->dma_mask, (unsigned long)addr);
 239                 return 0;
 240         }
 241         if (addr & (EMUPAGESIZE-1)) {
 242                 dev_err_ratelimited(emu->card->dev, "page is not aligned\n");
 243                 return 0;
 244         }
 245         return 1;
 246 }
 247
 248 /*
 249  * map the given memory block on PTB.
 250  * if the block is already mapped, update the link order.
 251  * if no empty pages are found, tries to release unused memory blocks
 252  * and retry the mapping.
 253  */
 254 int snd_emu10k1_memblk_map(struct snd_emu10k1 *emu, struct snd_emu10k1_memblk *blk)
 255 {
 256         int err;
 257         int size;
 258         struct list_head *p, *nextp;
 259         struct snd_emu10k1_memblk *deleted;
 260         unsigned long flags;
 261
 262         spin_lock_irqsave(&emu->memblk_lock, flags);
 263         if (blk->mapped_page >= 0) {
 264                 /* update order link */
 265                 list_move_tail(&blk->mapped_order_link,
 266                                &emu->mapped_order_link_head);
 267                 spin_unlock_irqrestore(&emu->memblk_lock, flags);
 268                 return 0;
 269         }
 270         if ((err = map_memblk(emu, blk)) < 0) {
 271                 /* no enough page - try to unmap some blocks */
 272                 /* starting from the oldest block */
 273                 p = emu->mapped_order_link_head.next;
 274                 for (; p != &emu->mapped_order_link_head; p = nextp) {
 275                         nextp = p->next;
 276                         deleted = get_emu10k1_memblk(p, mapped_order_link);
 277                         if (deleted->map_locked)
 278                                 continue;
 279                         size = unmap_memblk(emu, deleted);
 280                         if (size >= blk->pages) {
 281                                 /* ok the empty region is enough large */
 282                                 err = map_memblk(emu, blk);
 283                                 break;
 284                         }
 285                 }
 286         }
 287         spin_unlock_irqrestore(&emu->memblk_lock, flags);
 288         return err;
 289 }
 290
 291 EXPORT_SYMBOL(snd_emu10k1_memblk_map);
 292
 293 /*
 294  * page allocation for DMA
 295  */
 296 struct snd_util_memblk *
 297 snd_emu10k1_alloc_pages(struct snd_emu10k1 *emu, struct snd_pcm_substream *substream)
 298 {
 299         struct snd_pcm_runtime *runtime = substream->runtime;
 300         struct snd_util_memhdr *hdr;
 301         struct snd_emu10k1_memblk *blk;
 302         int page, err, idx;
 303
 304         if (snd_BUG_ON(!emu))
 305                 return NULL;
 306         if (snd_BUG_ON(runtime->dma_bytes <= 0 ||
 307                        runtime->dma_bytes >= (emu->address_mode ? MAXPAGES1 : MAXPAGES0) * EMUPAGESIZE))
 308                 return NULL;
 309         hdr = emu->memhdr;
 310         if (snd_BUG_ON(!hdr))
 311                 return NULL;
 312
 313         idx = runtime->period_size >= runtime->buffer_size ?
 314                                         (emu->delay_pcm_irq * 2) : 0;
 315         mutex_lock(&hdr->block_mutex);
 316         blk = search_empty(emu, runtime->dma_bytes + idx);
 317         if (blk == NULL) {
 318                 mutex_unlock(&hdr->block_mutex);
 319                 return NULL;
 320         }
 321         /* fill buffer addresses but pointers are not stored so that
 322          * snd_free_pci_page() is not called in in synth_free()
 323          */
 324         idx = 0;
 325         for (page = blk->first_page; page <= blk->last_page; page++, idx++) {
 326                 unsigned long ofs = idx << PAGE_SHIFT;
 327                 dma_addr_t addr;
 328                 if (ofs >= runtime->dma_bytes)
 329                         addr = emu->silent_page.addr;
 330                 else
 331                         addr = snd_pcm_sgbuf_get_addr(substream, ofs);
 332                 if (! is_valid_page(emu, addr)) {
 333                         dev_err_ratelimited(emu->card->dev,
 334                                 "emu: failure page = %d\n", idx);
 335                         mutex_unlock(&hdr->block_mutex);
 336                         return NULL;
 337                 }
 338                 emu->page_addr_table[page] = addr;
 339                 emu->page_ptr_table[page] = NULL;
 340         }
 341
 342         /* set PTB entries */
 343         blk->map_locked = 1; /* do not unmap this block! */
 344         err = snd_emu10k1_memblk_map(emu, blk);
 345         if (err < 0) {
 346                 __snd_util_mem_free(hdr, (struct snd_util_memblk *)blk);
 347                 mutex_unlock(&hdr->block_mutex);
 348                 return NULL;
 349         }
 350         mutex_unlock(&hdr->block_mutex);
 351         return (struct snd_util_memblk *)blk;
 352 }
 353
 354
 355 /*
 356  * release DMA buffer from page table
 357  */
 358 int snd_emu10k1_free_pages(struct snd_emu10k1 *emu, struct snd_util_memblk *blk)
 359 {
 360         if (snd_BUG_ON(!emu || !blk))
 361                 return -EINVAL;
 362         return snd_emu10k1_synth_free(emu, blk);
 363 }
 364
 365 /*
 366  * allocate DMA pages, widening the allocation if necessary
 367  *
 368  * See the comment above snd_emu10k1_detect_iommu() in emu10k1_main.c why
 369  * this might be needed.
 370  *
 371  * If you modify this function check whether __synth_free_pages() also needs
 372  * changes.
 373  */
 374 int snd_emu10k1_alloc_pages_maybe_wider(struct snd_emu10k1 *emu, size_t size,
 375                                         struct snd_dma_buffer *dmab)
 376 {
 377         if (emu->iommu_workaround) {
 378                 size_t npages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
 379                 size_t size_real = npages * PAGE_SIZE;
 380
 381                 /*
 382                  * The device has been observed to accesses up to 256 extra
 383                  * bytes, but use 1k to be safe.
 384                  */
 385                 if (size_real < size + 1024)
 386                         size += PAGE_SIZE;
 387         }
 388
 389         return snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV,
 390                                    &emu->pci->dev, size, dmab);
 391 }
 392
 393 /*
 394  * memory allocation using multiple pages (for synth)
 395  * Unlike the DMA allocation above, non-contiguous pages are assined.
 396  */
 397
 398 /*
 399  * allocate a synth sample area
 400  */
 401 struct snd_util_memblk *
 402 snd_emu10k1_synth_alloc(struct snd_emu10k1 *hw, unsigned int size)
 403 {
 404         struct snd_emu10k1_memblk *blk;
 405         struct snd_util_memhdr *hdr = hw->memhdr;
 406
 407         mutex_lock(&hdr->block_mutex);
 408         blk = (struct snd_emu10k1_memblk *)__snd_util_mem_alloc(hdr, size);
 409         if (blk == NULL) {
 410                 mutex_unlock(&hdr->block_mutex);
 411                 return NULL;
 412         }
 413         if (synth_alloc_pages(hw, blk)) {
 414                 __snd_util_mem_free(hdr, (struct snd_util_memblk *)blk);
 415                 mutex_unlock(&hdr->block_mutex);
 416                 return NULL;
 417         }
 418         snd_emu10k1_memblk_map(hw, blk);
 419         mutex_unlock(&hdr->block_mutex);
 420         return (struct snd_util_memblk *)blk;
 421 }
 422
 423 EXPORT_SYMBOL(snd_emu10k1_synth_alloc);
 424
 425 /*
 426  * free a synth sample area
 427  */
 428 int
 429 snd_emu10k1_synth_free(struct snd_emu10k1 *emu, struct snd_util_memblk *memblk)
 430 {
 431         struct snd_util_memhdr *hdr = emu->memhdr;
 432         struct snd_emu10k1_memblk *blk = (struct snd_emu10k1_memblk *)memblk;
 433         unsigned long flags;
 434
 435         mutex_lock(&hdr->block_mutex);
 436         spin_lock_irqsave(&emu->memblk_lock, flags);
 437         if (blk->mapped_page >= 0)
 438                 unmap_memblk(emu, blk);
 439         spin_unlock_irqrestore(&emu->memblk_lock, flags);
 440         synth_free_pages(emu, blk);
 441          __snd_util_mem_free(hdr, memblk);
 442         mutex_unlock(&hdr->block_mutex);
 443         return 0;
 444 }
 445
 446 EXPORT_SYMBOL(snd_emu10k1_synth_free);
 447
 448 /* check new allocation range */
 449 static void get_single_page_range(struct snd_util_memhdr *hdr,
 450                                   struct snd_emu10k1_memblk *blk,
 451                                   int *first_page_ret, int *last_page_ret)
 452 {
 453         struct list_head *p;
 454         struct snd_emu10k1_memblk *q;
 455         int first_page, last_page;
 456         first_page = blk->first_page;
 457         if ((p = blk->mem.list.prev) != &hdr->block) {
 458                 q = get_emu10k1_memblk(p, mem.list);
 459                 if (q->last_page == first_page)
 460                         first_page++;  /* first page was already allocated */
 461         }
 462         last_page = blk->last_page;
 463         if ((p = blk->mem.list.next) != &hdr->block) {
 464                 q = get_emu10k1_memblk(p, mem.list);
 465                 if (q->first_page == last_page)
 466                         last_page--; /* last page was already allocated */
 467         }
 468         *first_page_ret = first_page;
 469         *last_page_ret = last_page;
 470 }
 471
 472 /* release allocated pages */
 473 static void __synth_free_pages(struct snd_emu10k1 *emu, int first_page,
 474                                int last_page)
 475 {
 476         struct snd_dma_buffer dmab;
 477         int page;
 478
 479         dmab.dev.type = SNDRV_DMA_TYPE_DEV;
 480         dmab.dev.dev = &emu->pci->dev;
 481
 482         for (page = first_page; page <= last_page; page++) {
 483                 if (emu->page_ptr_table[page] == NULL)
 484                         continue;
 485                 dmab.area = emu->page_ptr_table[page];
 486                 dmab.addr = emu->page_addr_table[page];
 487
 488                 /*
 489                  * please keep me in sync with logic in
 490                  * snd_emu10k1_alloc_pages_maybe_wider()
 491                  */
 492                 dmab.bytes = PAGE_SIZE;
 493                 if (emu->iommu_workaround)
 494                         dmab.bytes *= 2;
 495
 496                 snd_dma_free_pages(&dmab);
 497                 emu->page_addr_table[page] = 0;
 498                 emu->page_ptr_table[page] = NULL;
 499         }
 500 }
 501
 502 /*
 503  * allocate kernel pages
 504  */
 505 static int synth_alloc_pages(struct snd_emu10k1 *emu, struct snd_emu10k1_memblk *blk)
 506 {
 507         int page, first_page, last_page;
 508         struct snd_dma_buffer dmab;
 509
 510         emu10k1_memblk_init(blk);
 511         get_single_page_range(emu->memhdr, blk, &first_page, &last_page);
 512         /* allocate kernel pages */
 513         for (page = first_page; page <= last_page; page++) {
 514                 if (snd_emu10k1_alloc_pages_maybe_wider(emu, PAGE_SIZE,
 515                                                         &dmab) < 0)
 516                         goto __fail;
 517                 if (!is_valid_page(emu, dmab.addr)) {
 518                         snd_dma_free_pages(&dmab);
 519                         goto __fail;
 520                 }
 521                 emu->page_addr_table[page] = dmab.addr;
 522                 emu->page_ptr_table[page] = dmab.area;
 523         }
 524         return 0;
 525
 526 __fail:
 527         /* release allocated pages */
 528         last_page = page - 1;
 529         __synth_free_pages(emu, first_page, last_page);
 530
 531         return -ENOMEM;
 532 }
 533
 534 /*
 535  * free pages
 536  */
 537 static int synth_free_pages(struct snd_emu10k1 *emu, struct snd_emu10k1_memblk *blk)
 538 {
 539         int first_page, last_page;
 540
 541         get_single_page_range(emu->memhdr, blk, &first_page, &last_page);
 542         __synth_free_pages(emu, first_page, last_page);
 543         return 0;
 544 }
 545
 546 /* calculate buffer pointer from offset address */
 547 static inline void *offset_ptr(struct snd_emu10k1 *emu, int page, int offset)
 548 {
 549         char *ptr;
 550         if (snd_BUG_ON(page < 0 || page >= emu->max_cache_pages))
 551                 return NULL;
 552         ptr = emu->page_ptr_table[page];
 553         if (! ptr) {
 554                 dev_err(emu->card->dev,
 555                         "access to NULL ptr: page = %d\n", page);
 556                 return NULL;
 557         }
 558         ptr += offset & (PAGE_SIZE - 1);
 559         return (void*)ptr;
 560 }
 561
 562 /*
 563  * bzero(blk + offset, size)
 564  */
 565 int snd_emu10k1_synth_bzero(struct snd_emu10k1 *emu, struct snd_util_memblk *blk,
 566                             int offset, int size)
 567 {
 568         int page, nextofs, end_offset, temp, temp1;
 569         void *ptr;
 570         struct snd_emu10k1_memblk *p = (struct snd_emu10k1_memblk *)blk;
 571
 572         offset += blk->offset & (PAGE_SIZE - 1);
 573         end_offset = offset + size;
 574         page = get_aligned_page(offset);
 575         do {
 576                 nextofs = aligned_page_offset(page + 1);
 577                 temp = nextofs - offset;
 578                 temp1 = end_offset - offset;
 579                 if (temp1 < temp)
 580                         temp = temp1;
 581                 ptr = offset_ptr(emu, page + p->first_page, offset);
 582                 if (ptr)
 583                         memset(ptr, 0, temp);
 584                 offset = nextofs;
 585                 page++;
 586         } while (offset < end_offset);
 587         return 0;
 588 }
 589
 590 EXPORT_SYMBOL(snd_emu10k1_synth_bzero);
 591
 592 /*
 593  * copy_from_user(blk + offset, data, size)
 594  */
 595 int snd_emu10k1_synth_copy_from_user(struct snd_emu10k1 *emu, struct snd_util_memblk *blk,
 596                                      int offset, const char __user *data, int size)
 597 {
 598         int page, nextofs, end_offset, temp, temp1;
 599         void *ptr;
 600         struct snd_emu10k1_memblk *p = (struct snd_emu10k1_memblk *)blk;
 601
 602         offset += blk->offset & (PAGE_SIZE - 1);
 603         end_offset = offset + size;
 604         page = get_aligned_page(offset);
 605         do {
 606                 nextofs = aligned_page_offset(page + 1);
 607                 temp = nextofs - offset;
 608                 temp1 = end_offset - offset;
 609                 if (temp1 < temp)
 610                         temp = temp1;
 611                 ptr = offset_ptr(emu, page + p->first_page, offset);
 612                 if (ptr && copy_from_user(ptr, data, temp))
 613                         return -EFAULT;
 614                 offset = nextofs;
 615                 data += temp;
 616                 page++;
 617         } while (offset < end_offset);
 618         return 0;
 619 }
 620
 621 EXPORT_SYMBOL(snd_emu10k1_synth_copy_from_user);