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>
41 #include <drm/drm_gem.h>
42 #include "drm_internal.h"
46 * This file provides some of the base ioctls and library routines for
47 * the graphics memory manager implemented by each device driver.
49 * Because various devices have different requirements in terms of
50 * synchronization and migration strategies, implementing that is left up to
51 * the driver, and all that the general API provides should be generic --
52 * allocating objects, reading/writing data with the cpu, freeing objects.
53 * Even there, platform-dependent optimizations for reading/writing data with
54 * the CPU mean we'll likely hook those out to driver-specific calls. However,
55 * the DRI2 implementation wants to have at least allocate/mmap be generic.
57 * The goal was to have swap-backed object allocation managed through
58 * struct file. However, file descriptors as handles to a struct file have
60 * - Process limits prevent more than 1024 or so being used at a time by
62 * - Inability to allocate high fds will aggravate the X Server's select()
63 * handling, and likely that of many GL client applications as well.
65 * This led to a plan of using our own integer IDs (called handles, following
66 * DRM terminology) to mimic fds, and implement the fd syscalls we need as
67 * ioctls. The objects themselves will still include the struct file so
68 * that we can transition to fds if the required kernel infrastructure shows
69 * up at a later date, and as our interface with shmfs for memory allocation.
73 * We make up offsets for buffer objects so we can recognize them at
77 /* pgoff in mmap is an unsigned long, so we need to make sure that
78 * the faked up offset will fit
81 #if BITS_PER_LONG == 64
82 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1)
83 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 16)
85 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFUL >> PAGE_SHIFT) + 1)
86 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFUL >> PAGE_SHIFT) * 16)
90 * drm_gem_init - Initialize the GEM device fields
91 * @dev: drm_devic structure to initialize
94 drm_gem_init(struct drm_device *dev)
96 struct drm_vma_offset_manager *vma_offset_manager;
98 mutex_init(&dev->object_name_lock);
99 idr_init(&dev->object_name_idr);
101 vma_offset_manager = kzalloc(sizeof(*vma_offset_manager), GFP_KERNEL);
102 if (!vma_offset_manager) {
103 DRM_ERROR("out of memory\n");
107 dev->vma_offset_manager = vma_offset_manager;
108 drm_vma_offset_manager_init(vma_offset_manager,
109 DRM_FILE_PAGE_OFFSET_START,
110 DRM_FILE_PAGE_OFFSET_SIZE);
116 drm_gem_destroy(struct drm_device *dev)
119 drm_vma_offset_manager_destroy(dev->vma_offset_manager);
120 kfree(dev->vma_offset_manager);
121 dev->vma_offset_manager = NULL;
125 * drm_gem_object_init - initialize an allocated shmem-backed GEM object
126 * @dev: drm_device the object should be initialized for
127 * @obj: drm_gem_object to initialize
130 * Initialize an already allocated GEM object of the specified size with
131 * shmfs backing store.
133 int drm_gem_object_init(struct drm_device *dev,
134 struct drm_gem_object *obj, size_t size)
138 drm_gem_private_object_init(dev, obj, size);
140 filp = shmem_file_setup("drm mm object", size, VM_NORESERVE);
142 return PTR_ERR(filp);
148 EXPORT_SYMBOL(drm_gem_object_init);
151 * drm_gem_private_object_init - initialize an allocated private GEM object
152 * @dev: drm_device the object should be initialized for
153 * @obj: drm_gem_object to initialize
156 * Initialize an already allocated GEM object of the specified size with
157 * no GEM provided backing store. Instead the caller is responsible for
158 * backing the object and handling it.
160 void drm_gem_private_object_init(struct drm_device *dev,
161 struct drm_gem_object *obj, size_t size)
163 BUG_ON((size & (PAGE_SIZE - 1)) != 0);
168 kref_init(&obj->refcount);
169 obj->handle_count = 0;
171 drm_vma_node_reset(&obj->vma_node);
173 EXPORT_SYMBOL(drm_gem_private_object_init);
176 drm_gem_remove_prime_handles(struct drm_gem_object *obj, struct drm_file *filp)
179 * Note: obj->dma_buf can't disappear as long as we still hold a
180 * handle reference in obj->handle_count.
182 mutex_lock(&filp->prime.lock);
184 drm_prime_remove_buf_handle_locked(&filp->prime,
187 mutex_unlock(&filp->prime.lock);
191 * drm_gem_object_handle_free - release resources bound to userspace handles
192 * @obj: GEM object to clean up.
194 * Called after the last handle to the object has been closed
196 * Removes any name for the object. Note that this must be
197 * called before drm_gem_object_free or we'll be touching
200 static void drm_gem_object_handle_free(struct drm_gem_object *obj)
202 struct drm_device *dev = obj->dev;
204 /* Remove any name for this object */
206 idr_remove(&dev->object_name_idr, obj->name);
211 static void drm_gem_object_exported_dma_buf_free(struct drm_gem_object *obj)
213 /* Unbreak the reference cycle if we have an exported dma_buf. */
215 dma_buf_put(obj->dma_buf);
221 drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj)
223 if (WARN_ON(obj->handle_count == 0))
227 * Must bump handle count first as this may be the last
228 * ref, in which case the object would disappear before we
232 mutex_lock(&obj->dev->object_name_lock);
233 if (--obj->handle_count == 0) {
234 drm_gem_object_handle_free(obj);
235 drm_gem_object_exported_dma_buf_free(obj);
237 mutex_unlock(&obj->dev->object_name_lock);
239 drm_gem_object_unreference_unlocked(obj);
243 * drm_gem_handle_delete - deletes the given file-private handle
244 * @filp: drm file-private structure to use for the handle look up
245 * @handle: userspace handle to delete
247 * Removes the GEM handle from the @filp lookup table and if this is the last
248 * handle also cleans up linked resources like GEM names.
251 drm_gem_handle_delete(struct drm_file *filp, u32 handle)
253 struct drm_device *dev;
254 struct drm_gem_object *obj;
256 /* This is gross. The idr system doesn't let us try a delete and
257 * return an error code. It just spews if you fail at deleting.
258 * So, we have to grab a lock around finding the object and then
259 * doing the delete on it and dropping the refcount, or the user
260 * could race us to double-decrement the refcount and cause a
261 * use-after-free later. Given the frequency of our handle lookups,
262 * we may want to use ida for number allocation and a hash table
263 * for the pointers, anyway.
265 spin_lock(&filp->table_lock);
267 /* Check if we currently have a reference on the object */
268 obj = idr_find(&filp->object_idr, handle);
270 spin_unlock(&filp->table_lock);
275 /* Release reference and decrement refcount. */
276 idr_remove(&filp->object_idr, handle);
277 spin_unlock(&filp->table_lock);
279 if (drm_core_check_feature(dev, DRIVER_PRIME))
280 drm_gem_remove_prime_handles(obj, filp);
281 drm_vma_node_revoke(&obj->vma_node, filp->filp);
283 if (dev->driver->gem_close_object)
284 dev->driver->gem_close_object(obj, filp);
285 drm_gem_object_handle_unreference_unlocked(obj);
289 EXPORT_SYMBOL(drm_gem_handle_delete);
292 * drm_gem_dumb_destroy - dumb fb callback helper for gem based drivers
293 * @file: drm file-private structure to remove the dumb handle from
294 * @dev: corresponding drm_device
295 * @handle: the dumb handle to remove
297 * This implements the ->dumb_destroy kms driver callback for drivers which use
298 * gem to manage their backing storage.
300 int drm_gem_dumb_destroy(struct drm_file *file,
301 struct drm_device *dev,
304 return drm_gem_handle_delete(file, handle);
306 EXPORT_SYMBOL(drm_gem_dumb_destroy);
309 * drm_gem_handle_create_tail - internal functions to create a handle
310 * @file_priv: drm file-private structure to register the handle for
311 * @obj: object to register
312 * @handlep: pointer to return the created handle to the caller
314 * This expects the dev->object_name_lock to be held already and will drop it
315 * before returning. Used to avoid races in establishing new handles when
316 * importing an object from either an flink name or a dma-buf.
319 drm_gem_handle_create_tail(struct drm_file *file_priv,
320 struct drm_gem_object *obj,
323 struct drm_device *dev = obj->dev;
326 WARN_ON(!mutex_is_locked(&dev->object_name_lock));
329 * Get the user-visible handle using idr. Preload and perform
330 * allocation under our spinlock.
332 idr_preload(GFP_KERNEL);
333 spin_lock(&file_priv->table_lock);
335 ret = idr_alloc(&file_priv->object_idr, obj, 1, 0, GFP_NOWAIT);
336 drm_gem_object_reference(obj);
338 spin_unlock(&file_priv->table_lock);
340 mutex_unlock(&dev->object_name_lock);
346 ret = drm_vma_node_allow(&obj->vma_node, file_priv->filp);
350 if (dev->driver->gem_open_object) {
351 ret = dev->driver->gem_open_object(obj, file_priv);
359 drm_vma_node_revoke(&obj->vma_node, file_priv->filp);
361 spin_lock(&file_priv->table_lock);
362 idr_remove(&file_priv->object_idr, *handlep);
363 spin_unlock(&file_priv->table_lock);
365 drm_gem_object_handle_unreference_unlocked(obj);
370 * drm_gem_handle_create - create a gem handle for an object
371 * @file_priv: drm file-private structure to register the handle for
372 * @obj: object to register
373 * @handlep: pionter to return the created handle to the caller
375 * Create a handle for this object. This adds a handle reference
376 * to the object, which includes a regular reference count. Callers
377 * will likely want to dereference the object afterwards.
379 int drm_gem_handle_create(struct drm_file *file_priv,
380 struct drm_gem_object *obj,
383 mutex_lock(&obj->dev->object_name_lock);
385 return drm_gem_handle_create_tail(file_priv, obj, handlep);
387 EXPORT_SYMBOL(drm_gem_handle_create);
391 * drm_gem_free_mmap_offset - release a fake mmap offset for an object
392 * @obj: obj in question
394 * This routine frees fake offsets allocated by drm_gem_create_mmap_offset().
397 drm_gem_free_mmap_offset(struct drm_gem_object *obj)
399 struct drm_device *dev = obj->dev;
401 drm_vma_offset_remove(dev->vma_offset_manager, &obj->vma_node);
403 EXPORT_SYMBOL(drm_gem_free_mmap_offset);
406 * drm_gem_create_mmap_offset_size - create a fake mmap offset for an object
407 * @obj: obj in question
408 * @size: the virtual size
410 * GEM memory mapping works by handing back to userspace a fake mmap offset
411 * it can use in a subsequent mmap(2) call. The DRM core code then looks
412 * up the object based on the offset and sets up the various memory mapping
415 * This routine allocates and attaches a fake offset for @obj, in cases where
416 * the virtual size differs from the physical size (ie. obj->size). Otherwise
417 * just use drm_gem_create_mmap_offset().
420 drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size)
422 struct drm_device *dev = obj->dev;
424 return drm_vma_offset_add(dev->vma_offset_manager, &obj->vma_node,
427 EXPORT_SYMBOL(drm_gem_create_mmap_offset_size);
430 * drm_gem_create_mmap_offset - create a fake mmap offset for an object
431 * @obj: obj in question
433 * GEM memory mapping works by handing back to userspace a fake mmap offset
434 * it can use in a subsequent mmap(2) call. The DRM core code then looks
435 * up the object based on the offset and sets up the various memory mapping
438 * This routine allocates and attaches a fake offset for @obj.
440 int drm_gem_create_mmap_offset(struct drm_gem_object *obj)
442 return drm_gem_create_mmap_offset_size(obj, obj->size);
444 EXPORT_SYMBOL(drm_gem_create_mmap_offset);
447 * drm_gem_get_pages - helper to allocate backing pages for a GEM object
449 * @obj: obj in question
451 * This reads the page-array of the shmem-backing storage of the given gem
452 * object. An array of pages is returned. If a page is not allocated or
453 * swapped-out, this will allocate/swap-in the required pages. Note that the
454 * whole object is covered by the page-array and pinned in memory.
456 * Use drm_gem_put_pages() to release the array and unpin all pages.
458 * This uses the GFP-mask set on the shmem-mapping (see mapping_set_gfp_mask()).
459 * If you require other GFP-masks, you have to do those allocations yourself.
461 * Note that you are not allowed to change gfp-zones during runtime. That is,
462 * shmem_read_mapping_page_gfp() must be called with the same gfp_zone(gfp) as
463 * set during initialization. If you have special zone constraints, set them
464 * after drm_gem_init_object() via mapping_set_gfp_mask(). shmem-core takes care
465 * to keep pages in the required zone during swap-in.
467 struct page **drm_gem_get_pages(struct drm_gem_object *obj)
469 struct address_space *mapping;
470 struct page *p, **pages;
473 /* This is the shared memory object that backs the GEM resource */
474 mapping = file_inode(obj->filp)->i_mapping;
476 /* We already BUG_ON() for non-page-aligned sizes in
477 * drm_gem_object_init(), so we should never hit this unless
478 * driver author is doing something really wrong:
480 WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0);
482 npages = obj->size >> PAGE_SHIFT;
484 pages = drm_malloc_ab(npages, sizeof(struct page *));
486 return ERR_PTR(-ENOMEM);
488 for (i = 0; i < npages; i++) {
489 p = shmem_read_mapping_page(mapping, i);
494 /* Make sure shmem keeps __GFP_DMA32 allocated pages in the
495 * correct region during swapin. Note that this requires
496 * __GFP_DMA32 to be set in mapping_gfp_mask(inode->i_mapping)
497 * so shmem can relocate pages during swapin if required.
499 BUG_ON(mapping_gfp_constraint(mapping, __GFP_DMA32) &&
500 (page_to_pfn(p) >= 0x00100000UL));
507 page_cache_release(pages[i]);
509 drm_free_large(pages);
512 EXPORT_SYMBOL(drm_gem_get_pages);
515 * drm_gem_put_pages - helper to free backing pages for a GEM object
516 * @obj: obj in question
517 * @pages: pages to free
518 * @dirty: if true, pages will be marked as dirty
519 * @accessed: if true, the pages will be marked as accessed
521 void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
522 bool dirty, bool accessed)
526 /* We already BUG_ON() for non-page-aligned sizes in
527 * drm_gem_object_init(), so we should never hit this unless
528 * driver author is doing something really wrong:
530 WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0);
532 npages = obj->size >> PAGE_SHIFT;
534 for (i = 0; i < npages; i++) {
536 set_page_dirty(pages[i]);
539 mark_page_accessed(pages[i]);
541 /* Undo the reference we took when populating the table */
542 page_cache_release(pages[i]);
545 drm_free_large(pages);
547 EXPORT_SYMBOL(drm_gem_put_pages);
549 /** Returns a reference to the object named by the handle. */
550 struct drm_gem_object *
551 drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp,
554 struct drm_gem_object *obj;
556 spin_lock(&filp->table_lock);
558 /* Check if we currently have a reference on the object */
559 obj = idr_find(&filp->object_idr, handle);
561 spin_unlock(&filp->table_lock);
565 drm_gem_object_reference(obj);
567 spin_unlock(&filp->table_lock);
571 EXPORT_SYMBOL(drm_gem_object_lookup);
574 * drm_gem_close_ioctl - implementation of the GEM_CLOSE ioctl
577 * @file_priv: drm file-private structure
579 * Releases the handle to an mm object.
582 drm_gem_close_ioctl(struct drm_device *dev, void *data,
583 struct drm_file *file_priv)
585 struct drm_gem_close *args = data;
588 if (!drm_core_check_feature(dev, DRIVER_GEM))
591 ret = drm_gem_handle_delete(file_priv, args->handle);
597 * drm_gem_flink_ioctl - implementation of the GEM_FLINK ioctl
600 * @file_priv: drm file-private structure
602 * Create a global name for an object, returning the name.
604 * Note that the name does not hold a reference; when the object
605 * is freed, the name goes away.
608 drm_gem_flink_ioctl(struct drm_device *dev, void *data,
609 struct drm_file *file_priv)
611 struct drm_gem_flink *args = data;
612 struct drm_gem_object *obj;
615 if (!drm_core_check_feature(dev, DRIVER_GEM))
618 obj = drm_gem_object_lookup(dev, file_priv, args->handle);
622 mutex_lock(&dev->object_name_lock);
623 idr_preload(GFP_KERNEL);
624 /* prevent races with concurrent gem_close. */
625 if (obj->handle_count == 0) {
631 ret = idr_alloc(&dev->object_name_idr, obj, 1, 0, GFP_NOWAIT);
638 args->name = (uint64_t) obj->name;
643 mutex_unlock(&dev->object_name_lock);
644 drm_gem_object_unreference_unlocked(obj);
649 * drm_gem_open - implementation of the GEM_OPEN ioctl
652 * @file_priv: drm file-private structure
654 * Open an object using the global name, returning a handle and the size.
656 * This handle (of course) holds a reference to the object, so the object
657 * will not go away until the handle is deleted.
660 drm_gem_open_ioctl(struct drm_device *dev, void *data,
661 struct drm_file *file_priv)
663 struct drm_gem_open *args = data;
664 struct drm_gem_object *obj;
668 if (!drm_core_check_feature(dev, DRIVER_GEM))
671 mutex_lock(&dev->object_name_lock);
672 obj = idr_find(&dev->object_name_idr, (int) args->name);
674 drm_gem_object_reference(obj);
676 mutex_unlock(&dev->object_name_lock);
680 /* drm_gem_handle_create_tail unlocks dev->object_name_lock. */
681 ret = drm_gem_handle_create_tail(file_priv, obj, &handle);
682 drm_gem_object_unreference_unlocked(obj);
686 args->handle = handle;
687 args->size = obj->size;
693 * gem_gem_open - initalizes GEM file-private structures at devnode open time
694 * @dev: drm_device which is being opened by userspace
695 * @file_private: drm file-private structure to set up
697 * Called at device open time, sets up the structure for handling refcounting
701 drm_gem_open(struct drm_device *dev, struct drm_file *file_private)
703 idr_init(&file_private->object_idr);
704 spin_lock_init(&file_private->table_lock);
708 * Called at device close to release the file's
709 * handle references on objects.
712 drm_gem_object_release_handle(int id, void *ptr, void *data)
714 struct drm_file *file_priv = data;
715 struct drm_gem_object *obj = ptr;
716 struct drm_device *dev = obj->dev;
718 if (drm_core_check_feature(dev, DRIVER_PRIME))
719 drm_gem_remove_prime_handles(obj, file_priv);
720 drm_vma_node_revoke(&obj->vma_node, file_priv->filp);
722 if (dev->driver->gem_close_object)
723 dev->driver->gem_close_object(obj, file_priv);
725 drm_gem_object_handle_unreference_unlocked(obj);
731 * drm_gem_release - release file-private GEM resources
732 * @dev: drm_device which is being closed by userspace
733 * @file_private: drm file-private structure to clean up
735 * Called at close time when the filp is going away.
737 * Releases any remaining references on objects by this filp.
740 drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
742 idr_for_each(&file_private->object_idr,
743 &drm_gem_object_release_handle, file_private);
744 idr_destroy(&file_private->object_idr);
748 drm_gem_object_release(struct drm_gem_object *obj)
750 WARN_ON(obj->dma_buf);
755 drm_gem_free_mmap_offset(obj);
757 EXPORT_SYMBOL(drm_gem_object_release);
760 * drm_gem_object_free - free a GEM object
761 * @kref: kref of the object to free
763 * Called after the last reference to the object has been lost.
764 * Must be called holding struct_ mutex
769 drm_gem_object_free(struct kref *kref)
771 struct drm_gem_object *obj =
772 container_of(kref, struct drm_gem_object, refcount);
773 struct drm_device *dev = obj->dev;
775 WARN_ON(!mutex_is_locked(&dev->struct_mutex));
777 if (dev->driver->gem_free_object != NULL)
778 dev->driver->gem_free_object(obj);
780 EXPORT_SYMBOL(drm_gem_object_free);
782 void drm_gem_vm_open(struct vm_area_struct *vma)
784 struct drm_gem_object *obj = vma->vm_private_data;
786 drm_gem_object_reference(obj);
788 EXPORT_SYMBOL(drm_gem_vm_open);
790 void drm_gem_vm_close(struct vm_area_struct *vma)
792 struct drm_gem_object *obj = vma->vm_private_data;
794 drm_gem_object_unreference_unlocked(obj);
796 EXPORT_SYMBOL(drm_gem_vm_close);
799 * drm_gem_mmap_obj - memory map a GEM object
800 * @obj: the GEM object to map
801 * @obj_size: the object size to be mapped, in bytes
802 * @vma: VMA for the area to be mapped
804 * Set up the VMA to prepare mapping of the GEM object using the gem_vm_ops
805 * provided by the driver. Depending on their requirements, drivers can either
806 * provide a fault handler in their gem_vm_ops (in which case any accesses to
807 * the object will be trapped, to perform migration, GTT binding, surface
808 * register allocation, or performance monitoring), or mmap the buffer memory
809 * synchronously after calling drm_gem_mmap_obj.
811 * This function is mainly intended to implement the DMABUF mmap operation, when
812 * the GEM object is not looked up based on its fake offset. To implement the
813 * DRM mmap operation, drivers should use the drm_gem_mmap() function.
815 * drm_gem_mmap_obj() assumes the user is granted access to the buffer while
816 * drm_gem_mmap() prevents unprivileged users from mapping random objects. So
817 * callers must verify access restrictions before calling this helper.
819 * Return 0 or success or -EINVAL if the object size is smaller than the VMA
820 * size, or if no gem_vm_ops are provided.
822 int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
823 struct vm_area_struct *vma)
825 struct drm_device *dev = obj->dev;
827 /* Check for valid size. */
828 if (obj_size < vma->vm_end - vma->vm_start)
831 if (!dev->driver->gem_vm_ops)
834 vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
835 vma->vm_ops = dev->driver->gem_vm_ops;
836 vma->vm_private_data = obj;
837 vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
839 /* Take a ref for this mapping of the object, so that the fault
840 * handler can dereference the mmap offset's pointer to the object.
841 * This reference is cleaned up by the corresponding vm_close
842 * (which should happen whether the vma was created by this call, or
843 * by a vm_open due to mremap or partial unmap or whatever).
845 drm_gem_object_reference(obj);
849 EXPORT_SYMBOL(drm_gem_mmap_obj);
852 * drm_gem_mmap - memory map routine for GEM objects
853 * @filp: DRM file pointer
854 * @vma: VMA for the area to be mapped
856 * If a driver supports GEM object mapping, mmap calls on the DRM file
857 * descriptor will end up here.
859 * Look up the GEM object based on the offset passed in (vma->vm_pgoff will
860 * contain the fake offset we created when the GTT map ioctl was called on
861 * the object) and map it with a call to drm_gem_mmap_obj().
863 * If the caller is not granted access to the buffer object, the mmap will fail
864 * with EACCES. Please see the vma manager for more information.
866 int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
868 struct drm_file *priv = filp->private_data;
869 struct drm_device *dev = priv->minor->dev;
870 struct drm_gem_object *obj = NULL;
871 struct drm_vma_offset_node *node;
874 if (drm_device_is_unplugged(dev))
877 drm_vma_offset_lock_lookup(dev->vma_offset_manager);
878 node = drm_vma_offset_exact_lookup_locked(dev->vma_offset_manager,
882 obj = container_of(node, struct drm_gem_object, vma_node);
884 * When the object is being freed, after it hits 0-refcnt it
885 * proceeds to tear down the object. In the process it will
886 * attempt to remove the VMA offset and so acquire this
887 * mgr->vm_lock. Therefore if we find an object with a 0-refcnt
888 * that matches our range, we know it is in the process of being
889 * destroyed and will be freed as soon as we release the lock -
890 * so we have to check for the 0-refcnted object and treat it as
893 if (!kref_get_unless_zero(&obj->refcount))
896 drm_vma_offset_unlock_lookup(dev->vma_offset_manager);
901 if (!drm_vma_node_is_allowed(node, filp)) {
902 drm_gem_object_unreference_unlocked(obj);
906 ret = drm_gem_mmap_obj(obj, drm_vma_node_size(node) << PAGE_SHIFT,
909 drm_gem_object_unreference_unlocked(obj);
913 EXPORT_SYMBOL(drm_gem_mmap);