drm_vm.c revision 7922e2d279e34f0fbe3decfb4ec8a7f6e05afca8
1/** 2 * \file drm_vm.c 3 * Memory mapping for DRM 4 * 5 * \author Rickard E. (Rik) Faith <faith@valinux.com> 6 * \author Gareth Hughes <gareth@valinux.com> 7 */ 8 9/* 10 * Created: Mon Jan 4 08:58:31 1999 by faith@valinux.com 11 * 12 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas. 13 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California. 14 * All Rights Reserved. 15 * 16 * Permission is hereby granted, free of charge, to any person obtaining a 17 * copy of this software and associated documentation files (the "Software"), 18 * to deal in the Software without restriction, including without limitation 19 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 20 * and/or sell copies of the Software, and to permit persons to whom the 21 * Software is furnished to do so, subject to the following conditions: 22 * 23 * The above copyright notice and this permission notice (including the next 24 * paragraph) shall be included in all copies or substantial portions of the 25 * Software. 26 * 27 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 28 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 29 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 30 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 31 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 32 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 33 * OTHER DEALINGS IN THE SOFTWARE. 34 */ 35 36#include <drm/drmP.h> 37#include <linux/export.h> 38#if defined(__ia64__) 39#include <linux/efi.h> 40#include <linux/slab.h> 41#endif 42 43static void drm_vm_open(struct vm_area_struct *vma); 44static void drm_vm_close(struct vm_area_struct *vma); 45 46static pgprot_t drm_io_prot(uint32_t map_type, struct vm_area_struct *vma) 47{ 48 pgprot_t tmp = vm_get_page_prot(vma->vm_flags); 49 50#if defined(__i386__) || defined(__x86_64__) 51 if (boot_cpu_data.x86 > 3 && map_type != _DRM_AGP) { 52 pgprot_val(tmp) |= _PAGE_PCD; 53 pgprot_val(tmp) &= ~_PAGE_PWT; 54 } 55#elif defined(__powerpc__) 56 pgprot_val(tmp) |= _PAGE_NO_CACHE; 57 if (map_type == _DRM_REGISTERS) 58 pgprot_val(tmp) |= _PAGE_GUARDED; 59#elif defined(__ia64__) 60 if (efi_range_is_wc(vma->vm_start, vma->vm_end - 61 vma->vm_start)) 62 tmp = pgprot_writecombine(tmp); 63 else 64 tmp = pgprot_noncached(tmp); 65#elif defined(__sparc__) || defined(__arm__) || defined(__mips__) 66 tmp = pgprot_noncached(tmp); 67#endif 68 return tmp; 69} 70 71static pgprot_t drm_dma_prot(uint32_t map_type, struct vm_area_struct *vma) 72{ 73 pgprot_t tmp = vm_get_page_prot(vma->vm_flags); 74 75#if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE) 76 tmp |= _PAGE_NO_CACHE; 77#endif 78 return tmp; 79} 80 81/** 82 * \c fault method for AGP virtual memory. 83 * 84 * \param vma virtual memory area. 85 * \param address access address. 86 * \return pointer to the page structure. 87 * 88 * Find the right map and if it's AGP memory find the real physical page to 89 * map, get the page, increment the use count and return it. 90 */ 91#if __OS_HAS_AGP 92static int drm_do_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 93{ 94 struct drm_file *priv = vma->vm_file->private_data; 95 struct drm_device *dev = priv->minor->dev; 96 struct drm_local_map *map = NULL; 97 struct drm_map_list *r_list; 98 struct drm_hash_item *hash; 99 100 /* 101 * Find the right map 102 */ 103 if (!drm_core_has_AGP(dev)) 104 goto vm_fault_error; 105 106 if (!dev->agp || !dev->agp->cant_use_aperture) 107 goto vm_fault_error; 108 109 if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff, &hash)) 110 goto vm_fault_error; 111 112 r_list = drm_hash_entry(hash, struct drm_map_list, hash); 113 map = r_list->map; 114 115 if (map && map->type == _DRM_AGP) { 116 /* 117 * Using vm_pgoff as a selector forces us to use this unusual 118 * addressing scheme. 119 */ 120 resource_size_t offset = (unsigned long)vmf->virtual_address - 121 vma->vm_start; 122 resource_size_t baddr = map->offset + offset; 123 struct drm_agp_mem *agpmem; 124 struct page *page; 125 126#ifdef __alpha__ 127 /* 128 * Adjust to a bus-relative address 129 */ 130 baddr -= dev->hose->mem_space->start; 131#endif 132 133 /* 134 * It's AGP memory - find the real physical page to map 135 */ 136 list_for_each_entry(agpmem, &dev->agp->memory, head) { 137 if (agpmem->bound <= baddr && 138 agpmem->bound + agpmem->pages * PAGE_SIZE > baddr) 139 break; 140 } 141 142 if (&agpmem->head == &dev->agp->memory) 143 goto vm_fault_error; 144 145 /* 146 * Get the page, inc the use count, and return it 147 */ 148 offset = (baddr - agpmem->bound) >> PAGE_SHIFT; 149 page = agpmem->memory->pages[offset]; 150 get_page(page); 151 vmf->page = page; 152 153 DRM_DEBUG 154 ("baddr = 0x%llx page = 0x%p, offset = 0x%llx, count=%d\n", 155 (unsigned long long)baddr, 156 agpmem->memory->pages[offset], 157 (unsigned long long)offset, 158 page_count(page)); 159 return 0; 160 } 161vm_fault_error: 162 return VM_FAULT_SIGBUS; /* Disallow mremap */ 163} 164#else /* __OS_HAS_AGP */ 165static int drm_do_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 166{ 167 return VM_FAULT_SIGBUS; 168} 169#endif /* __OS_HAS_AGP */ 170 171/** 172 * \c nopage method for shared virtual memory. 173 * 174 * \param vma virtual memory area. 175 * \param address access address. 176 * \return pointer to the page structure. 177 * 178 * Get the mapping, find the real physical page to map, get the page, and 179 * return it. 180 */ 181static int drm_do_vm_shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 182{ 183 struct drm_local_map *map = vma->vm_private_data; 184 unsigned long offset; 185 unsigned long i; 186 struct page *page; 187 188 if (!map) 189 return VM_FAULT_SIGBUS; /* Nothing allocated */ 190 191 offset = (unsigned long)vmf->virtual_address - vma->vm_start; 192 i = (unsigned long)map->handle + offset; 193 page = vmalloc_to_page((void *)i); 194 if (!page) 195 return VM_FAULT_SIGBUS; 196 get_page(page); 197 vmf->page = page; 198 199 DRM_DEBUG("shm_fault 0x%lx\n", offset); 200 return 0; 201} 202 203/** 204 * \c close method for shared virtual memory. 205 * 206 * \param vma virtual memory area. 207 * 208 * Deletes map information if we are the last 209 * person to close a mapping and it's not in the global maplist. 210 */ 211static void drm_vm_shm_close(struct vm_area_struct *vma) 212{ 213 struct drm_file *priv = vma->vm_file->private_data; 214 struct drm_device *dev = priv->minor->dev; 215 struct drm_vma_entry *pt, *temp; 216 struct drm_local_map *map; 217 struct drm_map_list *r_list; 218 int found_maps = 0; 219 220 DRM_DEBUG("0x%08lx,0x%08lx\n", 221 vma->vm_start, vma->vm_end - vma->vm_start); 222 atomic_dec(&dev->vma_count); 223 224 map = vma->vm_private_data; 225 226 mutex_lock(&dev->struct_mutex); 227 list_for_each_entry_safe(pt, temp, &dev->vmalist, head) { 228 if (pt->vma->vm_private_data == map) 229 found_maps++; 230 if (pt->vma == vma) { 231 list_del(&pt->head); 232 kfree(pt); 233 } 234 } 235 236 /* We were the only map that was found */ 237 if (found_maps == 1 && map->flags & _DRM_REMOVABLE) { 238 /* Check to see if we are in the maplist, if we are not, then 239 * we delete this mappings information. 240 */ 241 found_maps = 0; 242 list_for_each_entry(r_list, &dev->maplist, head) { 243 if (r_list->map == map) 244 found_maps++; 245 } 246 247 if (!found_maps) { 248 drm_dma_handle_t dmah; 249 250 switch (map->type) { 251 case _DRM_REGISTERS: 252 case _DRM_FRAME_BUFFER: 253 if (drm_core_has_MTRR(dev) && map->mtrr >= 0) { 254 int retcode; 255 retcode = mtrr_del(map->mtrr, 256 map->offset, 257 map->size); 258 DRM_DEBUG("mtrr_del = %d\n", retcode); 259 } 260 iounmap(map->handle); 261 break; 262 case _DRM_SHM: 263 vfree(map->handle); 264 break; 265 case _DRM_AGP: 266 case _DRM_SCATTER_GATHER: 267 break; 268 case _DRM_CONSISTENT: 269 dmah.vaddr = map->handle; 270 dmah.busaddr = map->offset; 271 dmah.size = map->size; 272 __drm_pci_free(dev, &dmah); 273 break; 274 case _DRM_GEM: 275 DRM_ERROR("tried to rmmap GEM object\n"); 276 break; 277 } 278 kfree(map); 279 } 280 } 281 mutex_unlock(&dev->struct_mutex); 282} 283 284/** 285 * \c fault method for DMA virtual memory. 286 * 287 * \param vma virtual memory area. 288 * \param address access address. 289 * \return pointer to the page structure. 290 * 291 * Determine the page number from the page offset and get it from drm_device_dma::pagelist. 292 */ 293static int drm_do_vm_dma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 294{ 295 struct drm_file *priv = vma->vm_file->private_data; 296 struct drm_device *dev = priv->minor->dev; 297 struct drm_device_dma *dma = dev->dma; 298 unsigned long offset; 299 unsigned long page_nr; 300 struct page *page; 301 302 if (!dma) 303 return VM_FAULT_SIGBUS; /* Error */ 304 if (!dma->pagelist) 305 return VM_FAULT_SIGBUS; /* Nothing allocated */ 306 307 offset = (unsigned long)vmf->virtual_address - vma->vm_start; /* vm_[pg]off[set] should be 0 */ 308 page_nr = offset >> PAGE_SHIFT; /* page_nr could just be vmf->pgoff */ 309 page = virt_to_page((dma->pagelist[page_nr] + (offset & (~PAGE_MASK)))); 310 311 get_page(page); 312 vmf->page = page; 313 314 DRM_DEBUG("dma_fault 0x%lx (page %lu)\n", offset, page_nr); 315 return 0; 316} 317 318/** 319 * \c fault method for scatter-gather virtual memory. 320 * 321 * \param vma virtual memory area. 322 * \param address access address. 323 * \return pointer to the page structure. 324 * 325 * Determine the map offset from the page offset and get it from drm_sg_mem::pagelist. 326 */ 327static int drm_do_vm_sg_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 328{ 329 struct drm_local_map *map = vma->vm_private_data; 330 struct drm_file *priv = vma->vm_file->private_data; 331 struct drm_device *dev = priv->minor->dev; 332 struct drm_sg_mem *entry = dev->sg; 333 unsigned long offset; 334 unsigned long map_offset; 335 unsigned long page_offset; 336 struct page *page; 337 338 if (!entry) 339 return VM_FAULT_SIGBUS; /* Error */ 340 if (!entry->pagelist) 341 return VM_FAULT_SIGBUS; /* Nothing allocated */ 342 343 offset = (unsigned long)vmf->virtual_address - vma->vm_start; 344 map_offset = map->offset - (unsigned long)dev->sg->virtual; 345 page_offset = (offset >> PAGE_SHIFT) + (map_offset >> PAGE_SHIFT); 346 page = entry->pagelist[page_offset]; 347 get_page(page); 348 vmf->page = page; 349 350 return 0; 351} 352 353static int drm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 354{ 355 return drm_do_vm_fault(vma, vmf); 356} 357 358static int drm_vm_shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 359{ 360 return drm_do_vm_shm_fault(vma, vmf); 361} 362 363static int drm_vm_dma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 364{ 365 return drm_do_vm_dma_fault(vma, vmf); 366} 367 368static int drm_vm_sg_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 369{ 370 return drm_do_vm_sg_fault(vma, vmf); 371} 372 373/** AGP virtual memory operations */ 374static const struct vm_operations_struct drm_vm_ops = { 375 .fault = drm_vm_fault, 376 .open = drm_vm_open, 377 .close = drm_vm_close, 378}; 379 380/** Shared virtual memory operations */ 381static const struct vm_operations_struct drm_vm_shm_ops = { 382 .fault = drm_vm_shm_fault, 383 .open = drm_vm_open, 384 .close = drm_vm_shm_close, 385}; 386 387/** DMA virtual memory operations */ 388static const struct vm_operations_struct drm_vm_dma_ops = { 389 .fault = drm_vm_dma_fault, 390 .open = drm_vm_open, 391 .close = drm_vm_close, 392}; 393 394/** Scatter-gather virtual memory operations */ 395static const struct vm_operations_struct drm_vm_sg_ops = { 396 .fault = drm_vm_sg_fault, 397 .open = drm_vm_open, 398 .close = drm_vm_close, 399}; 400 401/** 402 * \c open method for shared virtual memory. 403 * 404 * \param vma virtual memory area. 405 * 406 * Create a new drm_vma_entry structure as the \p vma private data entry and 407 * add it to drm_device::vmalist. 408 */ 409void drm_vm_open_locked(struct drm_device *dev, 410 struct vm_area_struct *vma) 411{ 412 struct drm_vma_entry *vma_entry; 413 414 DRM_DEBUG("0x%08lx,0x%08lx\n", 415 vma->vm_start, vma->vm_end - vma->vm_start); 416 atomic_inc(&dev->vma_count); 417 418 vma_entry = kmalloc(sizeof(*vma_entry), GFP_KERNEL); 419 if (vma_entry) { 420 vma_entry->vma = vma; 421 vma_entry->pid = current->pid; 422 list_add(&vma_entry->head, &dev->vmalist); 423 } 424} 425EXPORT_SYMBOL_GPL(drm_vm_open_locked); 426 427static void drm_vm_open(struct vm_area_struct *vma) 428{ 429 struct drm_file *priv = vma->vm_file->private_data; 430 struct drm_device *dev = priv->minor->dev; 431 432 mutex_lock(&dev->struct_mutex); 433 drm_vm_open_locked(dev, vma); 434 mutex_unlock(&dev->struct_mutex); 435} 436 437void drm_vm_close_locked(struct drm_device *dev, 438 struct vm_area_struct *vma) 439{ 440 struct drm_vma_entry *pt, *temp; 441 442 DRM_DEBUG("0x%08lx,0x%08lx\n", 443 vma->vm_start, vma->vm_end - vma->vm_start); 444 atomic_dec(&dev->vma_count); 445 446 list_for_each_entry_safe(pt, temp, &dev->vmalist, head) { 447 if (pt->vma == vma) { 448 list_del(&pt->head); 449 kfree(pt); 450 break; 451 } 452 } 453} 454 455/** 456 * \c close method for all virtual memory types. 457 * 458 * \param vma virtual memory area. 459 * 460 * Search the \p vma private data entry in drm_device::vmalist, unlink it, and 461 * free it. 462 */ 463static void drm_vm_close(struct vm_area_struct *vma) 464{ 465 struct drm_file *priv = vma->vm_file->private_data; 466 struct drm_device *dev = priv->minor->dev; 467 468 mutex_lock(&dev->struct_mutex); 469 drm_vm_close_locked(dev, vma); 470 mutex_unlock(&dev->struct_mutex); 471} 472 473/** 474 * mmap DMA memory. 475 * 476 * \param file_priv DRM file private. 477 * \param vma virtual memory area. 478 * \return zero on success or a negative number on failure. 479 * 480 * Sets the virtual memory area operations structure to vm_dma_ops, the file 481 * pointer, and calls vm_open(). 482 */ 483static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma) 484{ 485 struct drm_file *priv = filp->private_data; 486 struct drm_device *dev; 487 struct drm_device_dma *dma; 488 unsigned long length = vma->vm_end - vma->vm_start; 489 490 dev = priv->minor->dev; 491 dma = dev->dma; 492 DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n", 493 vma->vm_start, vma->vm_end, vma->vm_pgoff); 494 495 /* Length must match exact page count */ 496 if (!dma || (length >> PAGE_SHIFT) != dma->page_count) { 497 return -EINVAL; 498 } 499 500 if (!capable(CAP_SYS_ADMIN) && 501 (dma->flags & _DRM_DMA_USE_PCI_RO)) { 502 vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE); 503#if defined(__i386__) || defined(__x86_64__) 504 pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW; 505#else 506 /* Ye gads this is ugly. With more thought 507 we could move this up higher and use 508 `protection_map' instead. */ 509 vma->vm_page_prot = 510 __pgprot(pte_val 511 (pte_wrprotect 512 (__pte(pgprot_val(vma->vm_page_prot))))); 513#endif 514 } 515 516 vma->vm_ops = &drm_vm_dma_ops; 517 518 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; 519 520 drm_vm_open_locked(dev, vma); 521 return 0; 522} 523 524static resource_size_t drm_core_get_reg_ofs(struct drm_device *dev) 525{ 526#ifdef __alpha__ 527 return dev->hose->dense_mem_base; 528#else 529 return 0; 530#endif 531} 532 533/** 534 * mmap DMA memory. 535 * 536 * \param file_priv DRM file private. 537 * \param vma virtual memory area. 538 * \return zero on success or a negative number on failure. 539 * 540 * If the virtual memory area has no offset associated with it then it's a DMA 541 * area, so calls mmap_dma(). Otherwise searches the map in drm_device::maplist, 542 * checks that the restricted flag is not set, sets the virtual memory operations 543 * according to the mapping type and remaps the pages. Finally sets the file 544 * pointer and calls vm_open(). 545 */ 546int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma) 547{ 548 struct drm_file *priv = filp->private_data; 549 struct drm_device *dev = priv->minor->dev; 550 struct drm_local_map *map = NULL; 551 resource_size_t offset = 0; 552 struct drm_hash_item *hash; 553 554 DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n", 555 vma->vm_start, vma->vm_end, vma->vm_pgoff); 556 557 if (!priv->authenticated) 558 return -EACCES; 559 560 /* We check for "dma". On Apple's UniNorth, it's valid to have 561 * the AGP mapped at physical address 0 562 * --BenH. 563 */ 564 if (!vma->vm_pgoff 565#if __OS_HAS_AGP 566 && (!dev->agp 567 || dev->agp->agp_info.device->vendor != PCI_VENDOR_ID_APPLE) 568#endif 569 ) 570 return drm_mmap_dma(filp, vma); 571 572 if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff, &hash)) { 573 DRM_ERROR("Could not find map\n"); 574 return -EINVAL; 575 } 576 577 map = drm_hash_entry(hash, struct drm_map_list, hash)->map; 578 if (!map || ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN))) 579 return -EPERM; 580 581 /* Check for valid size. */ 582 if (map->size < vma->vm_end - vma->vm_start) 583 return -EINVAL; 584 585 if (!capable(CAP_SYS_ADMIN) && (map->flags & _DRM_READ_ONLY)) { 586 vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE); 587#if defined(__i386__) || defined(__x86_64__) 588 pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW; 589#else 590 /* Ye gads this is ugly. With more thought 591 we could move this up higher and use 592 `protection_map' instead. */ 593 vma->vm_page_prot = 594 __pgprot(pte_val 595 (pte_wrprotect 596 (__pte(pgprot_val(vma->vm_page_prot))))); 597#endif 598 } 599 600 switch (map->type) { 601#if !defined(__arm__) 602 case _DRM_AGP: 603 if (drm_core_has_AGP(dev) && dev->agp->cant_use_aperture) { 604 /* 605 * On some platforms we can't talk to bus dma address from the CPU, so for 606 * memory of type DRM_AGP, we'll deal with sorting out the real physical 607 * pages and mappings in fault() 608 */ 609#if defined(__powerpc__) 610 pgprot_val(vma->vm_page_prot) |= _PAGE_NO_CACHE; 611#endif 612 vma->vm_ops = &drm_vm_ops; 613 break; 614 } 615 /* fall through to _DRM_FRAME_BUFFER... */ 616#endif 617 case _DRM_FRAME_BUFFER: 618 case _DRM_REGISTERS: 619 offset = drm_core_get_reg_ofs(dev); 620 vma->vm_page_prot = drm_io_prot(map->type, vma); 621 if (io_remap_pfn_range(vma, vma->vm_start, 622 (map->offset + offset) >> PAGE_SHIFT, 623 vma->vm_end - vma->vm_start, 624 vma->vm_page_prot)) 625 return -EAGAIN; 626 DRM_DEBUG(" Type = %d; start = 0x%lx, end = 0x%lx," 627 " offset = 0x%llx\n", 628 map->type, 629 vma->vm_start, vma->vm_end, (unsigned long long)(map->offset + offset)); 630 631 vma->vm_ops = &drm_vm_ops; 632 break; 633 case _DRM_CONSISTENT: 634 /* Consistent memory is really like shared memory. But 635 * it's allocated in a different way, so avoid fault */ 636 if (remap_pfn_range(vma, vma->vm_start, 637 page_to_pfn(virt_to_page(map->handle)), 638 vma->vm_end - vma->vm_start, vma->vm_page_prot)) 639 return -EAGAIN; 640 vma->vm_page_prot = drm_dma_prot(map->type, vma); 641 /* fall through to _DRM_SHM */ 642 case _DRM_SHM: 643 vma->vm_ops = &drm_vm_shm_ops; 644 vma->vm_private_data = (void *)map; 645 break; 646 case _DRM_SCATTER_GATHER: 647 vma->vm_ops = &drm_vm_sg_ops; 648 vma->vm_private_data = (void *)map; 649 vma->vm_page_prot = drm_dma_prot(map->type, vma); 650 break; 651 default: 652 return -EINVAL; /* This should never happen. */ 653 } 654 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; 655 656 drm_vm_open_locked(dev, vma); 657 return 0; 658} 659 660int drm_mmap(struct file *filp, struct vm_area_struct *vma) 661{ 662 struct drm_file *priv = filp->private_data; 663 struct drm_device *dev = priv->minor->dev; 664 int ret; 665 666 if (drm_device_is_unplugged(dev)) 667 return -ENODEV; 668 669 mutex_lock(&dev->struct_mutex); 670 ret = drm_mmap_locked(filp, vma); 671 mutex_unlock(&dev->struct_mutex); 672 673 return ret; 674} 675EXPORT_SYMBOL(drm_mmap); 676