2 * Copyright © 2008 Intel Corporation
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
24 * Eric Anholt <eric@anholt.net>
28 #include <linux/types.h>
29 #include <linux/slab.h>
31 #include <linux/uaccess.h>
33 #include <linux/file.h>
34 #include <linux/module.h>
35 #include <linux/mman.h>
36 #include <linux/pagemap.h>
37 #include <linux/shmem_fs.h>
38 #include <linux/dma-buf.h>
40 #include <drm/drm_vma_manager.h>
44 * This file provides some of the base ioctls and library routines for
45 * the graphics memory manager implemented by each device driver.
47 * Because various devices have different requirements in terms of
48 * synchronization and migration strategies, implementing that is left up to
49 * the driver, and all that the general API provides should be generic --
50 * allocating objects, reading/writing data with the cpu, freeing objects.
51 * Even there, platform-dependent optimizations for reading/writing data with
52 * the CPU mean we'll likely hook those out to driver-specific calls. However,
53 * the DRI2 implementation wants to have at least allocate/mmap be generic.
55 * The goal was to have swap-backed object allocation managed through
56 * struct file. However, file descriptors as handles to a struct file have
58 * - Process limits prevent more than 1024 or so being used at a time by
60 * - Inability to allocate high fds will aggravate the X Server's select()
61 * handling, and likely that of many GL client applications as well.
63 * This led to a plan of using our own integer IDs (called handles, following
64 * DRM terminology) to mimic fds, and implement the fd syscalls we need as
65 * ioctls. The objects themselves will still include the struct file so
66 * that we can transition to fds if the required kernel infrastructure shows
67 * up at a later date, and as our interface with shmfs for memory allocation.
71 * We make up offsets for buffer objects so we can recognize them at
75 /* pgoff in mmap is an unsigned long, so we need to make sure that
76 * the faked up offset will fit
79 #if BITS_PER_LONG == 64
80 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1)
81 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 16)
83 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFUL >> PAGE_SHIFT) + 1)
84 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFUL >> PAGE_SHIFT) * 16)
88 * drm_gem_init - Initialize the GEM device fields
89 * @dev: drm_devic structure to initialize
92 drm_gem_init(struct drm_device *dev)
94 struct drm_vma_offset_manager *vma_offset_manager;
96 mutex_init(&dev->object_name_lock);
97 idr_init(&dev->object_name_idr);
99 vma_offset_manager = kzalloc(sizeof(*vma_offset_manager), GFP_KERNEL);
100 if (!vma_offset_manager) {
101 DRM_ERROR("out of memory\n");
105 dev->vma_offset_manager = vma_offset_manager;
106 drm_vma_offset_manager_init(vma_offset_manager,
107 DRM_FILE_PAGE_OFFSET_START,
108 DRM_FILE_PAGE_OFFSET_SIZE);
114 drm_gem_destroy(struct drm_device *dev)
117 drm_vma_offset_manager_destroy(dev->vma_offset_manager);
118 kfree(dev->vma_offset_manager);
119 dev->vma_offset_manager = NULL;
123 * drm_gem_object_init - initialize an allocated shmem-backed GEM object
124 * @dev: drm_device the object should be initialized for
125 * @obj: drm_gem_object to initialize
128 * Initialize an already allocated GEM object of the specified size with
129 * shmfs backing store.
131 int drm_gem_object_init(struct drm_device *dev,
132 struct drm_gem_object *obj, size_t size)
136 drm_gem_private_object_init(dev, obj, size);
138 filp = shmem_file_setup("drm mm object", size, VM_NORESERVE);
140 return PTR_ERR(filp);
146 EXPORT_SYMBOL(drm_gem_object_init);
149 * drm_gem_object_init - initialize an allocated private GEM object
150 * @dev: drm_device the object should be initialized for
151 * @obj: drm_gem_object to initialize
154 * Initialize an already allocated GEM object of the specified size with
155 * no GEM provided backing store. Instead the caller is responsible for
156 * backing the object and handling it.
158 void drm_gem_private_object_init(struct drm_device *dev,
159 struct drm_gem_object *obj, size_t size)
161 BUG_ON((size & (PAGE_SIZE - 1)) != 0);
166 kref_init(&obj->refcount);
167 obj->handle_count = 0;
169 drm_vma_node_reset(&obj->vma_node);
171 EXPORT_SYMBOL(drm_gem_private_object_init);
174 drm_gem_remove_prime_handles(struct drm_gem_object *obj, struct drm_file *filp)
177 * Note: obj->dma_buf can't disappear as long as we still hold a
178 * handle reference in obj->handle_count.
180 mutex_lock(&filp->prime.lock);
182 drm_prime_remove_buf_handle_locked(&filp->prime,
185 mutex_unlock(&filp->prime.lock);
189 * drm_gem_object_free - release resources bound to userspace handles
190 * @obj: GEM object to clean up.
192 * Called after the last handle to the object has been closed
194 * Removes any name for the object. Note that this must be
195 * called before drm_gem_object_free or we'll be touching
198 static void drm_gem_object_handle_free(struct drm_gem_object *obj)
200 struct drm_device *dev = obj->dev;
202 /* Remove any name for this object */
204 idr_remove(&dev->object_name_idr, obj->name);
209 static void drm_gem_object_exported_dma_buf_free(struct drm_gem_object *obj)
211 /* Unbreak the reference cycle if we have an exported dma_buf. */
213 dma_buf_put(obj->dma_buf);
219 drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj)
221 if (WARN_ON(obj->handle_count == 0))
225 * Must bump handle count first as this may be the last
226 * ref, in which case the object would disappear before we
230 mutex_lock(&obj->dev->object_name_lock);
231 if (--obj->handle_count == 0) {
232 drm_gem_object_handle_free(obj);
233 drm_gem_object_exported_dma_buf_free(obj);
235 mutex_unlock(&obj->dev->object_name_lock);
237 drm_gem_object_unreference_unlocked(obj);
241 * drm_gem_handle_delete - deletes the given file-private handle
242 * @filp: drm file-private structure to use for the handle look up
243 * @handle: userspace handle to delete
245 * Removes the GEM handle from the @filp lookup table and if this is the last
246 * handle also cleans up linked resources like GEM names.
249 drm_gem_handle_delete(struct drm_file *filp, u32 handle)
251 struct drm_device *dev;
252 struct drm_gem_object *obj;
254 /* This is gross. The idr system doesn't let us try a delete and
255 * return an error code. It just spews if you fail at deleting.
256 * So, we have to grab a lock around finding the object and then
257 * doing the delete on it and dropping the refcount, or the user
258 * could race us to double-decrement the refcount and cause a
259 * use-after-free later. Given the frequency of our handle lookups,
260 * we may want to use ida for number allocation and a hash table
261 * for the pointers, anyway.
263 spin_lock(&filp->table_lock);
265 /* Check if we currently have a reference on the object */
266 obj = idr_find(&filp->object_idr, handle);
268 spin_unlock(&filp->table_lock);
273 /* Release reference and decrement refcount. */
274 idr_remove(&filp->object_idr, handle);
275 spin_unlock(&filp->table_lock);
277 if (drm_core_check_feature(dev, DRIVER_PRIME))
278 drm_gem_remove_prime_handles(obj, filp);
279 drm_vma_node_revoke(&obj->vma_node, filp->filp);
281 if (dev->driver->gem_close_object)
282 dev->driver->gem_close_object(obj, filp);
283 drm_gem_object_handle_unreference_unlocked(obj);
287 EXPORT_SYMBOL(drm_gem_handle_delete);
290 * drm_gem_dumb_destroy - dumb fb callback helper for gem based drivers
291 * @file: drm file-private structure to remove the dumb handle from
292 * @dev: corresponding drm_device
293 * @handle: the dumb handle to remove
295 * This implements the ->dumb_destroy kms driver callback for drivers which use
296 * gem to manage their backing storage.
298 int drm_gem_dumb_destroy(struct drm_file *file,
299 struct drm_device *dev,
302 return drm_gem_handle_delete(file, handle);
304 EXPORT_SYMBOL(drm_gem_dumb_destroy);
307 * drm_gem_handle_create_tail - internal functions to create a handle
308 * @file_priv: drm file-private structure to register the handle for
309 * @obj: object to register
310 * @handlep: pionter to return the created handle to the caller
312 * This expects the dev->object_name_lock to be held already and will drop it
313 * before returning. Used to avoid races in establishing new handles when
314 * importing an object from either an flink name or a dma-buf.
317 drm_gem_handle_create_tail(struct drm_file *file_priv,
318 struct drm_gem_object *obj,
321 struct drm_device *dev = obj->dev;
324 WARN_ON(!mutex_is_locked(&dev->object_name_lock));
327 * Get the user-visible handle using idr. Preload and perform
328 * allocation under our spinlock.
330 idr_preload(GFP_KERNEL);
331 spin_lock(&file_priv->table_lock);
333 ret = idr_alloc(&file_priv->object_idr, obj, 1, 0, GFP_NOWAIT);
334 drm_gem_object_reference(obj);
336 spin_unlock(&file_priv->table_lock);
338 mutex_unlock(&dev->object_name_lock);
340 drm_gem_object_handle_unreference_unlocked(obj);
345 ret = drm_vma_node_allow(&obj->vma_node, file_priv->filp);
347 drm_gem_handle_delete(file_priv, *handlep);
351 if (dev->driver->gem_open_object) {
352 ret = dev->driver->gem_open_object(obj, file_priv);
354 drm_gem_handle_delete(file_priv, *handlep);
363 * gem_handle_create - create a gem handle for an object
364 * @file_priv: drm file-private structure to register the handle for
365 * @obj: object to register
366 * @handlep: pionter to return the created handle to the caller
368 * Create a handle for this object. This adds a handle reference
369 * to the object, which includes a regular reference count. Callers
370 * will likely want to dereference the object afterwards.
373 drm_gem_handle_create(struct drm_file *file_priv,
374 struct drm_gem_object *obj,
377 mutex_lock(&obj->dev->object_name_lock);
379 return drm_gem_handle_create_tail(file_priv, obj, handlep);
381 EXPORT_SYMBOL(drm_gem_handle_create);
385 * drm_gem_free_mmap_offset - release a fake mmap offset for an object
386 * @obj: obj in question
388 * This routine frees fake offsets allocated by drm_gem_create_mmap_offset().
391 drm_gem_free_mmap_offset(struct drm_gem_object *obj)
393 struct drm_device *dev = obj->dev;
395 drm_vma_offset_remove(dev->vma_offset_manager, &obj->vma_node);
397 EXPORT_SYMBOL(drm_gem_free_mmap_offset);
400 * drm_gem_create_mmap_offset_size - create a fake mmap offset for an object
401 * @obj: obj in question
402 * @size: the virtual size
404 * GEM memory mapping works by handing back to userspace a fake mmap offset
405 * it can use in a subsequent mmap(2) call. The DRM core code then looks
406 * up the object based on the offset and sets up the various memory mapping
409 * This routine allocates and attaches a fake offset for @obj, in cases where
410 * the virtual size differs from the physical size (ie. obj->size). Otherwise
411 * just use drm_gem_create_mmap_offset().
414 drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size)
416 struct drm_device *dev = obj->dev;
418 return drm_vma_offset_add(dev->vma_offset_manager, &obj->vma_node,
421 EXPORT_SYMBOL(drm_gem_create_mmap_offset_size);
424 * drm_gem_create_mmap_offset - create a fake mmap offset for an object
425 * @obj: obj in question
427 * GEM memory mapping works by handing back to userspace a fake mmap offset
428 * it can use in a subsequent mmap(2) call. The DRM core code then looks
429 * up the object based on the offset and sets up the various memory mapping
432 * This routine allocates and attaches a fake offset for @obj.
434 int drm_gem_create_mmap_offset(struct drm_gem_object *obj)
436 return drm_gem_create_mmap_offset_size(obj, obj->size);
438 EXPORT_SYMBOL(drm_gem_create_mmap_offset);
441 * drm_gem_get_pages - helper to allocate backing pages for a GEM object
443 * @obj: obj in question
444 * @gfpmask: gfp mask of requested pages
446 struct page **drm_gem_get_pages(struct drm_gem_object *obj, gfp_t gfpmask)
449 struct address_space *mapping;
450 struct page *p, **pages;
453 /* This is the shared memory object that backs the GEM resource */
454 inode = file_inode(obj->filp);
455 mapping = inode->i_mapping;
457 /* We already BUG_ON() for non-page-aligned sizes in
458 * drm_gem_object_init(), so we should never hit this unless
459 * driver author is doing something really wrong:
461 WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0);
463 npages = obj->size >> PAGE_SHIFT;
465 pages = drm_malloc_ab(npages, sizeof(struct page *));
467 return ERR_PTR(-ENOMEM);
469 gfpmask |= mapping_gfp_mask(mapping);
471 for (i = 0; i < npages; i++) {
472 p = shmem_read_mapping_page_gfp(mapping, i, gfpmask);
477 /* There is a hypothetical issue w/ drivers that require
478 * buffer memory in the low 4GB.. if the pages are un-
479 * pinned, and swapped out, they can end up swapped back
480 * in above 4GB. If pages are already in memory, then
481 * shmem_read_mapping_page_gfp will ignore the gfpmask,
482 * even if the already in-memory page disobeys the mask.
484 * It is only a theoretical issue today, because none of
485 * the devices with this limitation can be populated with
486 * enough memory to trigger the issue. But this BUG_ON()
487 * is here as a reminder in case the problem with
488 * shmem_read_mapping_page_gfp() isn't solved by the time
489 * it does become a real issue.
491 * See this thread: http://lkml.org/lkml/2011/7/11/238
493 BUG_ON((gfpmask & __GFP_DMA32) &&
494 (page_to_pfn(p) >= 0x00100000UL));
501 page_cache_release(pages[i]);
503 drm_free_large(pages);
506 EXPORT_SYMBOL(drm_gem_get_pages);
509 * drm_gem_put_pages - helper to free backing pages for a GEM object
510 * @obj: obj in question
511 * @pages: pages to free
512 * @dirty: if true, pages will be marked as dirty
513 * @accessed: if true, the pages will be marked as accessed
515 void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
516 bool dirty, bool accessed)
520 /* We already BUG_ON() for non-page-aligned sizes in
521 * drm_gem_object_init(), so we should never hit this unless
522 * driver author is doing something really wrong:
524 WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0);
526 npages = obj->size >> PAGE_SHIFT;
528 for (i = 0; i < npages; i++) {
530 set_page_dirty(pages[i]);
533 mark_page_accessed(pages[i]);
535 /* Undo the reference we took when populating the table */
536 page_cache_release(pages[i]);
539 drm_free_large(pages);
541 EXPORT_SYMBOL(drm_gem_put_pages);
543 /** Returns a reference to the object named by the handle. */
544 struct drm_gem_object *
545 drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp,
548 struct drm_gem_object *obj;
550 spin_lock(&filp->table_lock);
552 /* Check if we currently have a reference on the object */
553 obj = idr_find(&filp->object_idr, handle);
555 spin_unlock(&filp->table_lock);
559 drm_gem_object_reference(obj);
561 spin_unlock(&filp->table_lock);
565 EXPORT_SYMBOL(drm_gem_object_lookup);
568 * drm_gem_close_ioctl - implementation of the GEM_CLOSE ioctl
571 * @file_priv: drm file-private structure
573 * Releases the handle to an mm object.
576 drm_gem_close_ioctl(struct drm_device *dev, void *data,
577 struct drm_file *file_priv)
579 struct drm_gem_close *args = data;
582 if (!(dev->driver->driver_features & DRIVER_GEM))
585 ret = drm_gem_handle_delete(file_priv, args->handle);
591 * drm_gem_flink_ioctl - implementation of the GEM_FLINK ioctl
594 * @file_priv: drm file-private structure
596 * Create a global name for an object, returning the name.
598 * Note that the name does not hold a reference; when the object
599 * is freed, the name goes away.
602 drm_gem_flink_ioctl(struct drm_device *dev, void *data,
603 struct drm_file *file_priv)
605 struct drm_gem_flink *args = data;
606 struct drm_gem_object *obj;
609 if (!(dev->driver->driver_features & DRIVER_GEM))
612 obj = drm_gem_object_lookup(dev, file_priv, args->handle);
616 mutex_lock(&dev->object_name_lock);
617 idr_preload(GFP_KERNEL);
618 /* prevent races with concurrent gem_close. */
619 if (obj->handle_count == 0) {
625 ret = idr_alloc(&dev->object_name_idr, obj, 1, 0, GFP_NOWAIT);
632 args->name = (uint64_t) obj->name;
637 mutex_unlock(&dev->object_name_lock);
638 drm_gem_object_unreference_unlocked(obj);
643 * drm_gem_open - implementation of the GEM_OPEN ioctl
646 * @file_priv: drm file-private structure
648 * Open an object using the global name, returning a handle and the size.
650 * This handle (of course) holds a reference to the object, so the object
651 * will not go away until the handle is deleted.
654 drm_gem_open_ioctl(struct drm_device *dev, void *data,
655 struct drm_file *file_priv)
657 struct drm_gem_open *args = data;
658 struct drm_gem_object *obj;
662 if (!(dev->driver->driver_features & DRIVER_GEM))
665 mutex_lock(&dev->object_name_lock);
666 obj = idr_find(&dev->object_name_idr, (int) args->name);
668 drm_gem_object_reference(obj);
670 mutex_unlock(&dev->object_name_lock);
674 /* drm_gem_handle_create_tail unlocks dev->object_name_lock. */
675 ret = drm_gem_handle_create_tail(file_priv, obj, &handle);
676 drm_gem_object_unreference_unlocked(obj);
680 args->handle = handle;
681 args->size = obj->size;
687 * gem_gem_open - initalizes GEM file-private structures at devnode open time
688 * @dev: drm_device which is being opened by userspace
689 * @file_private: drm file-private structure to set up
691 * Called at device open time, sets up the structure for handling refcounting
695 drm_gem_open(struct drm_device *dev, struct drm_file *file_private)
697 idr_init(&file_private->object_idr);
698 spin_lock_init(&file_private->table_lock);
702 * Called at device close to release the file's
703 * handle references on objects.
706 drm_gem_object_release_handle(int id, void *ptr, void *data)
708 struct drm_file *file_priv = data;
709 struct drm_gem_object *obj = ptr;
710 struct drm_device *dev = obj->dev;
712 if (drm_core_check_feature(dev, DRIVER_PRIME))
713 drm_gem_remove_prime_handles(obj, file_priv);
714 drm_vma_node_revoke(&obj->vma_node, file_priv->filp);
716 if (dev->driver->gem_close_object)
717 dev->driver->gem_close_object(obj, file_priv);
719 drm_gem_object_handle_unreference_unlocked(obj);
725 * drm_gem_release - release file-private GEM resources
726 * @dev: drm_device which is being closed by userspace
727 * @file_private: drm file-private structure to clean up
729 * Called at close time when the filp is going away.
731 * Releases any remaining references on objects by this filp.
734 drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
736 idr_for_each(&file_private->object_idr,
737 &drm_gem_object_release_handle, file_private);
738 idr_destroy(&file_private->object_idr);
742 drm_gem_object_release(struct drm_gem_object *obj)
744 WARN_ON(obj->dma_buf);
749 drm_gem_free_mmap_offset(obj);
751 EXPORT_SYMBOL(drm_gem_object_release);
754 * drm_gem_object_free - free a GEM object
755 * @kref: kref of the object to free
757 * Called after the last reference to the object has been lost.
758 * Must be called holding struct_ mutex
763 drm_gem_object_free(struct kref *kref)
765 struct drm_gem_object *obj = (struct drm_gem_object *) kref;
766 struct drm_device *dev = obj->dev;
768 BUG_ON(!mutex_is_locked(&dev->struct_mutex));
770 if (dev->driver->gem_free_object != NULL)
771 dev->driver->gem_free_object(obj);
773 EXPORT_SYMBOL(drm_gem_object_free);
775 void drm_gem_vm_open(struct vm_area_struct *vma)
777 struct drm_gem_object *obj = vma->vm_private_data;
779 drm_gem_object_reference(obj);
781 mutex_lock(&obj->dev->struct_mutex);
782 drm_vm_open_locked(obj->dev, vma);
783 mutex_unlock(&obj->dev->struct_mutex);
785 EXPORT_SYMBOL(drm_gem_vm_open);
787 void drm_gem_vm_close(struct vm_area_struct *vma)
789 struct drm_gem_object *obj = vma->vm_private_data;
790 struct drm_device *dev = obj->dev;
792 mutex_lock(&dev->struct_mutex);
793 drm_vm_close_locked(obj->dev, vma);
794 drm_gem_object_unreference(obj);
795 mutex_unlock(&dev->struct_mutex);
797 EXPORT_SYMBOL(drm_gem_vm_close);
800 * drm_gem_mmap_obj - memory map a GEM object
801 * @obj: the GEM object to map
802 * @obj_size: the object size to be mapped, in bytes
803 * @vma: VMA for the area to be mapped
805 * Set up the VMA to prepare mapping of the GEM object using the gem_vm_ops
806 * provided by the driver. Depending on their requirements, drivers can either
807 * provide a fault handler in their gem_vm_ops (in which case any accesses to
808 * the object will be trapped, to perform migration, GTT binding, surface
809 * register allocation, or performance monitoring), or mmap the buffer memory
810 * synchronously after calling drm_gem_mmap_obj.
812 * This function is mainly intended to implement the DMABUF mmap operation, when
813 * the GEM object is not looked up based on its fake offset. To implement the
814 * DRM mmap operation, drivers should use the drm_gem_mmap() function.
816 * drm_gem_mmap_obj() assumes the user is granted access to the buffer while
817 * drm_gem_mmap() prevents unprivileged users from mapping random objects. So
818 * callers must verify access restrictions before calling this helper.
820 * NOTE: This function has to be protected with dev->struct_mutex
822 * Return 0 or success or -EINVAL if the object size is smaller than the VMA
823 * size, or if no gem_vm_ops are provided.
825 int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
826 struct vm_area_struct *vma)
828 struct drm_device *dev = obj->dev;
830 lockdep_assert_held(&dev->struct_mutex);
832 /* Check for valid size. */
833 if (obj_size < vma->vm_end - vma->vm_start)
836 if (!dev->driver->gem_vm_ops)
839 vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
840 vma->vm_ops = dev->driver->gem_vm_ops;
841 vma->vm_private_data = obj;
842 vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
844 /* Take a ref for this mapping of the object, so that the fault
845 * handler can dereference the mmap offset's pointer to the object.
846 * This reference is cleaned up by the corresponding vm_close
847 * (which should happen whether the vma was created by this call, or
848 * by a vm_open due to mremap or partial unmap or whatever).
850 drm_gem_object_reference(obj);
852 drm_vm_open_locked(dev, vma);
855 EXPORT_SYMBOL(drm_gem_mmap_obj);
858 * drm_gem_mmap - memory map routine for GEM objects
859 * @filp: DRM file pointer
860 * @vma: VMA for the area to be mapped
862 * If a driver supports GEM object mapping, mmap calls on the DRM file
863 * descriptor will end up here.
865 * Look up the GEM object based on the offset passed in (vma->vm_pgoff will
866 * contain the fake offset we created when the GTT map ioctl was called on
867 * the object) and map it with a call to drm_gem_mmap_obj().
869 * If the caller is not granted access to the buffer object, the mmap will fail
870 * with EACCES. Please see the vma manager for more information.
872 int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
874 struct drm_file *priv = filp->private_data;
875 struct drm_device *dev = priv->minor->dev;
876 struct drm_gem_object *obj;
877 struct drm_vma_offset_node *node;
880 if (drm_device_is_unplugged(dev))
883 mutex_lock(&dev->struct_mutex);
885 node = drm_vma_offset_exact_lookup(dev->vma_offset_manager,
889 mutex_unlock(&dev->struct_mutex);
890 return drm_mmap(filp, vma);
891 } else if (!drm_vma_node_is_allowed(node, filp)) {
892 mutex_unlock(&dev->struct_mutex);
896 obj = container_of(node, struct drm_gem_object, vma_node);
897 ret = drm_gem_mmap_obj(obj, drm_vma_node_size(node) << PAGE_SHIFT, vma);
899 mutex_unlock(&dev->struct_mutex);
903 EXPORT_SYMBOL(drm_gem_mmap);