xref: /linux/include/drm/drm_gem.h (revision 3fd6c59042dbba50391e30862beac979491145fe)
1 #ifndef __DRM_GEM_H__
2 #define __DRM_GEM_H__
3 
4 /*
5  * GEM Graphics Execution Manager Driver Interfaces
6  *
7  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
8  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
9  * Copyright (c) 2009-2010, Code Aurora Forum.
10  * All rights reserved.
11  * Copyright © 2014 Intel Corporation
12  *   Daniel Vetter <daniel.vetter@ffwll.ch>
13  *
14  * Author: Rickard E. (Rik) Faith <faith@valinux.com>
15  * Author: Gareth Hughes <gareth@valinux.com>
16  *
17  * Permission is hereby granted, free of charge, to any person obtaining a
18  * copy of this software and associated documentation files (the "Software"),
19  * to deal in the Software without restriction, including without limitation
20  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
21  * and/or sell copies of the Software, and to permit persons to whom the
22  * Software is furnished to do so, subject to the following conditions:
23  *
24  * The above copyright notice and this permission notice (including the next
25  * paragraph) shall be included in all copies or substantial portions of the
26  * Software.
27  *
28  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
29  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
30  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
31  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
32  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
33  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
34  * OTHER DEALINGS IN THE SOFTWARE.
35  */
36 
37 #include <linux/kref.h>
38 #include <linux/dma-resv.h>
39 #include <linux/list.h>
40 #include <linux/mutex.h>
41 
42 #include <drm/drm_vma_manager.h>
43 
44 struct iosys_map;
45 struct drm_gem_object;
46 
47 /**
48  * enum drm_gem_object_status - bitmask of object state for fdinfo reporting
49  * @DRM_GEM_OBJECT_RESIDENT: object is resident in memory (ie. not unpinned)
50  * @DRM_GEM_OBJECT_PURGEABLE: object marked as purgeable by userspace
51  *
52  * Bitmask of status used for fdinfo memory stats, see &drm_gem_object_funcs.status
53  * and drm_show_fdinfo().  Note that an object can DRM_GEM_OBJECT_PURGEABLE if
54  * it still active or not resident, in which case drm_show_fdinfo() will not
55  * account for it as purgeable.  So drivers do not need to check if the buffer
56  * is idle and resident to return this bit.  (Ie. userspace can mark a buffer
57  * as purgeable even while it is still busy on the GPU.. it does not _actually_
58  * become puregeable until it becomes idle.  The status gem object func does
59  * not need to consider this.)
60  */
61 enum drm_gem_object_status {
62 	DRM_GEM_OBJECT_RESIDENT  = BIT(0),
63 	DRM_GEM_OBJECT_PURGEABLE = BIT(1),
64 };
65 
66 /**
67  * struct drm_gem_object_funcs - GEM object functions
68  */
69 struct drm_gem_object_funcs {
70 	/**
71 	 * @free:
72 	 *
73 	 * Deconstructor for drm_gem_objects.
74 	 *
75 	 * This callback is mandatory.
76 	 */
77 	void (*free)(struct drm_gem_object *obj);
78 
79 	/**
80 	 * @open:
81 	 *
82 	 * Called upon GEM handle creation.
83 	 *
84 	 * This callback is optional.
85 	 */
86 	int (*open)(struct drm_gem_object *obj, struct drm_file *file);
87 
88 	/**
89 	 * @close:
90 	 *
91 	 * Called upon GEM handle release.
92 	 *
93 	 * This callback is optional.
94 	 */
95 	void (*close)(struct drm_gem_object *obj, struct drm_file *file);
96 
97 	/**
98 	 * @print_info:
99 	 *
100 	 * If driver subclasses struct &drm_gem_object, it can implement this
101 	 * optional hook for printing additional driver specific info.
102 	 *
103 	 * drm_printf_indent() should be used in the callback passing it the
104 	 * indent argument.
105 	 *
106 	 * This callback is called from drm_gem_print_info().
107 	 *
108 	 * This callback is optional.
109 	 */
110 	void (*print_info)(struct drm_printer *p, unsigned int indent,
111 			   const struct drm_gem_object *obj);
112 
113 	/**
114 	 * @export:
115 	 *
116 	 * Export backing buffer as a &dma_buf.
117 	 * If this is not set drm_gem_prime_export() is used.
118 	 *
119 	 * This callback is optional.
120 	 */
121 	struct dma_buf *(*export)(struct drm_gem_object *obj, int flags);
122 
123 	/**
124 	 * @pin:
125 	 *
126 	 * Pin backing buffer in memory. Used by the drm_gem_map_attach() helper.
127 	 *
128 	 * This callback is optional.
129 	 */
130 	int (*pin)(struct drm_gem_object *obj);
131 
132 	/**
133 	 * @unpin:
134 	 *
135 	 * Unpin backing buffer. Used by the drm_gem_map_detach() helper.
136 	 *
137 	 * This callback is optional.
138 	 */
139 	void (*unpin)(struct drm_gem_object *obj);
140 
141 	/**
142 	 * @get_sg_table:
143 	 *
144 	 * Returns a Scatter-Gather table representation of the buffer.
145 	 * Used when exporting a buffer by the drm_gem_map_dma_buf() helper.
146 	 * Releasing is done by calling dma_unmap_sg_attrs() and sg_free_table()
147 	 * in drm_gem_unmap_buf(), therefore these helpers and this callback
148 	 * here cannot be used for sg tables pointing at driver private memory
149 	 * ranges.
150 	 *
151 	 * See also drm_prime_pages_to_sg().
152 	 */
153 	struct sg_table *(*get_sg_table)(struct drm_gem_object *obj);
154 
155 	/**
156 	 * @vmap:
157 	 *
158 	 * Returns a virtual address for the buffer. Used by the
159 	 * drm_gem_dmabuf_vmap() helper.
160 	 *
161 	 * This callback is optional.
162 	 */
163 	int (*vmap)(struct drm_gem_object *obj, struct iosys_map *map);
164 
165 	/**
166 	 * @vunmap:
167 	 *
168 	 * Releases the address previously returned by @vmap. Used by the
169 	 * drm_gem_dmabuf_vunmap() helper.
170 	 *
171 	 * This callback is optional.
172 	 */
173 	void (*vunmap)(struct drm_gem_object *obj, struct iosys_map *map);
174 
175 	/**
176 	 * @mmap:
177 	 *
178 	 * Handle mmap() of the gem object, setup vma accordingly.
179 	 *
180 	 * This callback is optional.
181 	 *
182 	 * The callback is used by both drm_gem_mmap_obj() and
183 	 * drm_gem_prime_mmap().  When @mmap is present @vm_ops is not
184 	 * used, the @mmap callback must set vma->vm_ops instead.
185 	 */
186 	int (*mmap)(struct drm_gem_object *obj, struct vm_area_struct *vma);
187 
188 	/**
189 	 * @evict:
190 	 *
191 	 * Evicts gem object out from memory. Used by the drm_gem_object_evict()
192 	 * helper. Returns 0 on success, -errno otherwise.
193 	 *
194 	 * This callback is optional.
195 	 */
196 	int (*evict)(struct drm_gem_object *obj);
197 
198 	/**
199 	 * @status:
200 	 *
201 	 * The optional status callback can return additional object state
202 	 * which determines which stats the object is counted against.  The
203 	 * callback is called under table_lock.  Racing against object status
204 	 * change is "harmless", and the callback can expect to not race
205 	 * against object destruction.
206 	 *
207 	 * Called by drm_show_memory_stats().
208 	 */
209 	enum drm_gem_object_status (*status)(struct drm_gem_object *obj);
210 
211 	/**
212 	 * @rss:
213 	 *
214 	 * Return resident size of the object in physical memory.
215 	 *
216 	 * Called by drm_show_memory_stats().
217 	 */
218 	size_t (*rss)(struct drm_gem_object *obj);
219 
220 	/**
221 	 * @vm_ops:
222 	 *
223 	 * Virtual memory operations used with mmap.
224 	 *
225 	 * This is optional but necessary for mmap support.
226 	 */
227 	const struct vm_operations_struct *vm_ops;
228 };
229 
230 /**
231  * struct drm_gem_lru - A simple LRU helper
232  *
233  * A helper for tracking GEM objects in a given state, to aid in
234  * driver's shrinker implementation.  Tracks the count of pages
235  * for lockless &shrinker.count_objects, and provides
236  * &drm_gem_lru_scan for driver's &shrinker.scan_objects
237  * implementation.
238  */
239 struct drm_gem_lru {
240 	/**
241 	 * @lock:
242 	 *
243 	 * Lock protecting movement of GEM objects between LRUs.  All
244 	 * LRUs that the object can move between should be protected
245 	 * by the same lock.
246 	 */
247 	struct mutex *lock;
248 
249 	/**
250 	 * @count:
251 	 *
252 	 * The total number of backing pages of the GEM objects in
253 	 * this LRU.
254 	 */
255 	long count;
256 
257 	/**
258 	 * @list:
259 	 *
260 	 * The LRU list.
261 	 */
262 	struct list_head list;
263 };
264 
265 /**
266  * struct drm_gem_object - GEM buffer object
267  *
268  * This structure defines the generic parts for GEM buffer objects, which are
269  * mostly around handling mmap and userspace handles.
270  *
271  * Buffer objects are often abbreviated to BO.
272  */
273 struct drm_gem_object {
274 	/**
275 	 * @refcount:
276 	 *
277 	 * Reference count of this object
278 	 *
279 	 * Please use drm_gem_object_get() to acquire and drm_gem_object_put_locked()
280 	 * or drm_gem_object_put() to release a reference to a GEM
281 	 * buffer object.
282 	 */
283 	struct kref refcount;
284 
285 	/**
286 	 * @handle_count:
287 	 *
288 	 * This is the GEM file_priv handle count of this object.
289 	 *
290 	 * Each handle also holds a reference. Note that when the handle_count
291 	 * drops to 0 any global names (e.g. the id in the flink namespace) will
292 	 * be cleared.
293 	 *
294 	 * Protected by &drm_device.object_name_lock.
295 	 */
296 	unsigned handle_count;
297 
298 	/**
299 	 * @dev: DRM dev this object belongs to.
300 	 */
301 	struct drm_device *dev;
302 
303 	/**
304 	 * @filp:
305 	 *
306 	 * SHMEM file node used as backing storage for swappable buffer objects.
307 	 * GEM also supports driver private objects with driver-specific backing
308 	 * storage (contiguous DMA memory, special reserved blocks). In this
309 	 * case @filp is NULL.
310 	 */
311 	struct file *filp;
312 
313 	/**
314 	 * @vma_node:
315 	 *
316 	 * Mapping info for this object to support mmap. Drivers are supposed to
317 	 * allocate the mmap offset using drm_gem_create_mmap_offset(). The
318 	 * offset itself can be retrieved using drm_vma_node_offset_addr().
319 	 *
320 	 * Memory mapping itself is handled by drm_gem_mmap(), which also checks
321 	 * that userspace is allowed to access the object.
322 	 */
323 	struct drm_vma_offset_node vma_node;
324 
325 	/**
326 	 * @size:
327 	 *
328 	 * Size of the object, in bytes.  Immutable over the object's
329 	 * lifetime.
330 	 */
331 	size_t size;
332 
333 	/**
334 	 * @name:
335 	 *
336 	 * Global name for this object, starts at 1. 0 means unnamed.
337 	 * Access is covered by &drm_device.object_name_lock. This is used by
338 	 * the GEM_FLINK and GEM_OPEN ioctls.
339 	 */
340 	int name;
341 
342 	/**
343 	 * @dma_buf:
344 	 *
345 	 * dma-buf associated with this GEM object.
346 	 *
347 	 * Pointer to the dma-buf associated with this gem object (either
348 	 * through importing or exporting). We break the resulting reference
349 	 * loop when the last gem handle for this object is released.
350 	 *
351 	 * Protected by &drm_device.object_name_lock.
352 	 */
353 	struct dma_buf *dma_buf;
354 
355 	/**
356 	 * @import_attach:
357 	 *
358 	 * dma-buf attachment backing this object.
359 	 *
360 	 * Any foreign dma_buf imported as a gem object has this set to the
361 	 * attachment point for the device. This is invariant over the lifetime
362 	 * of a gem object.
363 	 *
364 	 * The &drm_gem_object_funcs.free callback is responsible for
365 	 * cleaning up the dma_buf attachment and references acquired at import
366 	 * time.
367 	 *
368 	 * Note that the drm gem/prime core does not depend upon drivers setting
369 	 * this field any more. So for drivers where this doesn't make sense
370 	 * (e.g. virtual devices or a displaylink behind an usb bus) they can
371 	 * simply leave it as NULL.
372 	 */
373 	struct dma_buf_attachment *import_attach;
374 
375 	/**
376 	 * @resv:
377 	 *
378 	 * Pointer to reservation object associated with the this GEM object.
379 	 *
380 	 * Normally (@resv == &@_resv) except for imported GEM objects.
381 	 */
382 	struct dma_resv *resv;
383 
384 	/**
385 	 * @_resv:
386 	 *
387 	 * A reservation object for this GEM object.
388 	 *
389 	 * This is unused for imported GEM objects.
390 	 */
391 	struct dma_resv _resv;
392 
393 	/**
394 	 * @gpuva:
395 	 *
396 	 * Provides the list of GPU VAs attached to this GEM object.
397 	 *
398 	 * Drivers should lock list accesses with the GEMs &dma_resv lock
399 	 * (&drm_gem_object.resv) or a custom lock if one is provided.
400 	 */
401 	struct {
402 		struct list_head list;
403 
404 #ifdef CONFIG_LOCKDEP
405 		struct lockdep_map *lock_dep_map;
406 #endif
407 	} gpuva;
408 
409 	/**
410 	 * @funcs:
411 	 *
412 	 * Optional GEM object functions. If this is set, it will be used instead of the
413 	 * corresponding &drm_driver GEM callbacks.
414 	 *
415 	 * New drivers should use this.
416 	 *
417 	 */
418 	const struct drm_gem_object_funcs *funcs;
419 
420 	/**
421 	 * @lru_node:
422 	 *
423 	 * List node in a &drm_gem_lru.
424 	 */
425 	struct list_head lru_node;
426 
427 	/**
428 	 * @lru:
429 	 *
430 	 * The current LRU list that the GEM object is on.
431 	 */
432 	struct drm_gem_lru *lru;
433 };
434 
435 /**
436  * DRM_GEM_FOPS - Default drm GEM file operations
437  *
438  * This macro provides a shorthand for setting the GEM file ops in the
439  * &file_operations structure.  If all you need are the default ops, use
440  * DEFINE_DRM_GEM_FOPS instead.
441  */
442 #define DRM_GEM_FOPS \
443 	.open		= drm_open,\
444 	.release	= drm_release,\
445 	.unlocked_ioctl	= drm_ioctl,\
446 	.compat_ioctl	= drm_compat_ioctl,\
447 	.poll		= drm_poll,\
448 	.read		= drm_read,\
449 	.llseek		= noop_llseek,\
450 	.mmap		= drm_gem_mmap, \
451 	.fop_flags	= FOP_UNSIGNED_OFFSET
452 
453 /**
454  * DEFINE_DRM_GEM_FOPS() - macro to generate file operations for GEM drivers
455  * @name: name for the generated structure
456  *
457  * This macro autogenerates a suitable &struct file_operations for GEM based
458  * drivers, which can be assigned to &drm_driver.fops. Note that this structure
459  * cannot be shared between drivers, because it contains a reference to the
460  * current module using THIS_MODULE.
461  *
462  * Note that the declaration is already marked as static - if you need a
463  * non-static version of this you're probably doing it wrong and will break the
464  * THIS_MODULE reference by accident.
465  */
466 #define DEFINE_DRM_GEM_FOPS(name) \
467 	static const struct file_operations name = {\
468 		.owner		= THIS_MODULE,\
469 		DRM_GEM_FOPS,\
470 	}
471 
472 void drm_gem_object_release(struct drm_gem_object *obj);
473 void drm_gem_object_free(struct kref *kref);
474 int drm_gem_object_init(struct drm_device *dev,
475 			struct drm_gem_object *obj, size_t size);
476 int drm_gem_object_init_with_mnt(struct drm_device *dev,
477 				 struct drm_gem_object *obj, size_t size,
478 				 struct vfsmount *gemfs);
479 void drm_gem_private_object_init(struct drm_device *dev,
480 				 struct drm_gem_object *obj, size_t size);
481 void drm_gem_private_object_fini(struct drm_gem_object *obj);
482 void drm_gem_vm_open(struct vm_area_struct *vma);
483 void drm_gem_vm_close(struct vm_area_struct *vma);
484 int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
485 		     struct vm_area_struct *vma);
486 int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma);
487 
488 /**
489  * drm_gem_object_get - acquire a GEM buffer object reference
490  * @obj: GEM buffer object
491  *
492  * This function acquires an additional reference to @obj. It is illegal to
493  * call this without already holding a reference. No locks required.
494  */
drm_gem_object_get(struct drm_gem_object * obj)495 static inline void drm_gem_object_get(struct drm_gem_object *obj)
496 {
497 	kref_get(&obj->refcount);
498 }
499 
500 __attribute__((nonnull))
501 static inline void
__drm_gem_object_put(struct drm_gem_object * obj)502 __drm_gem_object_put(struct drm_gem_object *obj)
503 {
504 	kref_put(&obj->refcount, drm_gem_object_free);
505 }
506 
507 /**
508  * drm_gem_object_put - drop a GEM buffer object reference
509  * @obj: GEM buffer object
510  *
511  * This releases a reference to @obj.
512  */
513 static inline void
drm_gem_object_put(struct drm_gem_object * obj)514 drm_gem_object_put(struct drm_gem_object *obj)
515 {
516 	if (obj)
517 		__drm_gem_object_put(obj);
518 }
519 
520 int drm_gem_handle_create(struct drm_file *file_priv,
521 			  struct drm_gem_object *obj,
522 			  u32 *handlep);
523 int drm_gem_handle_delete(struct drm_file *filp, u32 handle);
524 
525 
526 void drm_gem_free_mmap_offset(struct drm_gem_object *obj);
527 int drm_gem_create_mmap_offset(struct drm_gem_object *obj);
528 int drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size);
529 
530 struct page **drm_gem_get_pages(struct drm_gem_object *obj);
531 void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
532 		bool dirty, bool accessed);
533 
534 void drm_gem_lock(struct drm_gem_object *obj);
535 void drm_gem_unlock(struct drm_gem_object *obj);
536 
537 int drm_gem_vmap_unlocked(struct drm_gem_object *obj, struct iosys_map *map);
538 void drm_gem_vunmap_unlocked(struct drm_gem_object *obj, struct iosys_map *map);
539 
540 int drm_gem_objects_lookup(struct drm_file *filp, void __user *bo_handles,
541 			   int count, struct drm_gem_object ***objs_out);
542 struct drm_gem_object *drm_gem_object_lookup(struct drm_file *filp, u32 handle);
543 long drm_gem_dma_resv_wait(struct drm_file *filep, u32 handle,
544 				    bool wait_all, unsigned long timeout);
545 int drm_gem_lock_reservations(struct drm_gem_object **objs, int count,
546 			      struct ww_acquire_ctx *acquire_ctx);
547 void drm_gem_unlock_reservations(struct drm_gem_object **objs, int count,
548 				 struct ww_acquire_ctx *acquire_ctx);
549 int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
550 			    u32 handle, u64 *offset);
551 
552 void drm_gem_lru_init(struct drm_gem_lru *lru, struct mutex *lock);
553 void drm_gem_lru_remove(struct drm_gem_object *obj);
554 void drm_gem_lru_move_tail_locked(struct drm_gem_lru *lru, struct drm_gem_object *obj);
555 void drm_gem_lru_move_tail(struct drm_gem_lru *lru, struct drm_gem_object *obj);
556 unsigned long drm_gem_lru_scan(struct drm_gem_lru *lru,
557 			       unsigned int nr_to_scan,
558 			       unsigned long *remaining,
559 			       bool (*shrink)(struct drm_gem_object *obj));
560 
561 int drm_gem_evict(struct drm_gem_object *obj);
562 
563 /**
564  * drm_gem_object_is_shared_for_memory_stats - helper for shared memory stats
565  *
566  * This helper should only be used for fdinfo shared memory stats to determine
567  * if a GEM object is shared.
568  *
569  * @obj: obj in question
570  */
drm_gem_object_is_shared_for_memory_stats(struct drm_gem_object * obj)571 static inline bool drm_gem_object_is_shared_for_memory_stats(struct drm_gem_object *obj)
572 {
573 	return (obj->handle_count > 1) || obj->dma_buf;
574 }
575 
576 #ifdef CONFIG_LOCKDEP
577 /**
578  * drm_gem_gpuva_set_lock() - Set the lock protecting accesses to the gpuva list.
579  * @obj: the &drm_gem_object
580  * @lock: the lock used to protect the gpuva list. The locking primitive
581  * must contain a dep_map field.
582  *
583  * Call this if you're not proctecting access to the gpuva list with the
584  * dma-resv lock, but with a custom lock.
585  */
586 #define drm_gem_gpuva_set_lock(obj, lock) \
587 	if (!WARN((obj)->gpuva.lock_dep_map, \
588 		  "GEM GPUVA lock should be set only once.")) \
589 		(obj)->gpuva.lock_dep_map = &(lock)->dep_map
590 #define drm_gem_gpuva_assert_lock_held(obj) \
591 	lockdep_assert((obj)->gpuva.lock_dep_map ? \
592 		       lock_is_held((obj)->gpuva.lock_dep_map) : \
593 		       dma_resv_held((obj)->resv))
594 #else
595 #define drm_gem_gpuva_set_lock(obj, lock) do {} while (0)
596 #define drm_gem_gpuva_assert_lock_held(obj) do {} while (0)
597 #endif
598 
599 /**
600  * drm_gem_gpuva_init() - initialize the gpuva list of a GEM object
601  * @obj: the &drm_gem_object
602  *
603  * This initializes the &drm_gem_object's &drm_gpuvm_bo list.
604  *
605  * Calling this function is only necessary for drivers intending to support the
606  * &drm_driver_feature DRIVER_GEM_GPUVA.
607  *
608  * See also drm_gem_gpuva_set_lock().
609  */
drm_gem_gpuva_init(struct drm_gem_object * obj)610 static inline void drm_gem_gpuva_init(struct drm_gem_object *obj)
611 {
612 	INIT_LIST_HEAD(&obj->gpuva.list);
613 }
614 
615 /**
616  * drm_gem_for_each_gpuvm_bo() - iterator to walk over a list of &drm_gpuvm_bo
617  * @entry__: &drm_gpuvm_bo structure to assign to in each iteration step
618  * @obj__: the &drm_gem_object the &drm_gpuvm_bo to walk are associated with
619  *
620  * This iterator walks over all &drm_gpuvm_bo structures associated with the
621  * &drm_gem_object.
622  */
623 #define drm_gem_for_each_gpuvm_bo(entry__, obj__) \
624 	list_for_each_entry(entry__, &(obj__)->gpuva.list, list.entry.gem)
625 
626 /**
627  * drm_gem_for_each_gpuvm_bo_safe() - iterator to safely walk over a list of
628  * &drm_gpuvm_bo
629  * @entry__: &drm_gpuvm_bostructure to assign to in each iteration step
630  * @next__: &next &drm_gpuvm_bo to store the next step
631  * @obj__: the &drm_gem_object the &drm_gpuvm_bo to walk are associated with
632  *
633  * This iterator walks over all &drm_gpuvm_bo structures associated with the
634  * &drm_gem_object. It is implemented with list_for_each_entry_safe(), hence
635  * it is save against removal of elements.
636  */
637 #define drm_gem_for_each_gpuvm_bo_safe(entry__, next__, obj__) \
638 	list_for_each_entry_safe(entry__, next__, &(obj__)->gpuva.list, list.entry.gem)
639 
640 #endif /* __DRM_GEM_H__ */
641