xref: /openbmc/linux/include/drm/drm_gpuva_mgr.h (revision 3ddc8b84)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 
3 #ifndef __DRM_GPUVA_MGR_H__
4 #define __DRM_GPUVA_MGR_H__
5 
6 /*
7  * Copyright (c) 2022 Red Hat.
8  *
9  * Permission is hereby granted, free of charge, to any person obtaining a
10  * copy of this software and associated documentation files (the "Software"),
11  * to deal in the Software without restriction, including without limitation
12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
13  * and/or sell copies of the Software, and to permit persons to whom the
14  * Software is furnished to do so, subject to the following conditions:
15  *
16  * The above copyright notice and this permission notice shall be included in
17  * all copies or substantial portions of the Software.
18  *
19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
22  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
23  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
24  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
25  * OTHER DEALINGS IN THE SOFTWARE.
26  */
27 
28 #include <linux/list.h>
29 #include <linux/rbtree.h>
30 #include <linux/types.h>
31 
32 #include <drm/drm_gem.h>
33 
34 struct drm_gpuva_manager;
35 struct drm_gpuva_fn_ops;
36 
37 /**
38  * enum drm_gpuva_flags - flags for struct drm_gpuva
39  */
40 enum drm_gpuva_flags {
41 	/**
42 	 * @DRM_GPUVA_INVALIDATED:
43 	 *
44 	 * Flag indicating that the &drm_gpuva's backing GEM is invalidated.
45 	 */
46 	DRM_GPUVA_INVALIDATED = (1 << 0),
47 
48 	/**
49 	 * @DRM_GPUVA_SPARSE:
50 	 *
51 	 * Flag indicating that the &drm_gpuva is a sparse mapping.
52 	 */
53 	DRM_GPUVA_SPARSE = (1 << 1),
54 
55 	/**
56 	 * @DRM_GPUVA_USERBITS: user defined bits
57 	 */
58 	DRM_GPUVA_USERBITS = (1 << 2),
59 };
60 
61 /**
62  * struct drm_gpuva - structure to track a GPU VA mapping
63  *
64  * This structure represents a GPU VA mapping and is associated with a
65  * &drm_gpuva_manager.
66  *
67  * Typically, this structure is embedded in bigger driver structures.
68  */
69 struct drm_gpuva {
70 	/**
71 	 * @mgr: the &drm_gpuva_manager this object is associated with
72 	 */
73 	struct drm_gpuva_manager *mgr;
74 
75 	/**
76 	 * @flags: the &drm_gpuva_flags for this mapping
77 	 */
78 	enum drm_gpuva_flags flags;
79 
80 	/**
81 	 * @va: structure containing the address and range of the &drm_gpuva
82 	 */
83 	struct {
84 		/**
85 		 * @addr: the start address
86 		 */
87 		u64 addr;
88 
89 		/*
90 		 * @range: the range
91 		 */
92 		u64 range;
93 	} va;
94 
95 	/**
96 	 * @gem: structure containing the &drm_gem_object and it's offset
97 	 */
98 	struct {
99 		/**
100 		 * @offset: the offset within the &drm_gem_object
101 		 */
102 		u64 offset;
103 
104 		/**
105 		 * @obj: the mapped &drm_gem_object
106 		 */
107 		struct drm_gem_object *obj;
108 
109 		/**
110 		 * @entry: the &list_head to attach this object to a &drm_gem_object
111 		 */
112 		struct list_head entry;
113 	} gem;
114 
115 	/**
116 	 * @rb: structure containing data to store &drm_gpuvas in a rb-tree
117 	 */
118 	struct {
119 		/**
120 		 * @rb: the rb-tree node
121 		 */
122 		struct rb_node node;
123 
124 		/**
125 		 * @entry: The &list_head to additionally connect &drm_gpuvas
126 		 * in the same order they appear in the interval tree. This is
127 		 * useful to keep iterating &drm_gpuvas from a start node found
128 		 * through the rb-tree while doing modifications on the rb-tree
129 		 * itself.
130 		 */
131 		struct list_head entry;
132 
133 		/**
134 		 * @__subtree_last: needed by the interval tree, holding last-in-subtree
135 		 */
136 		u64 __subtree_last;
137 	} rb;
138 };
139 
140 int drm_gpuva_insert(struct drm_gpuva_manager *mgr, struct drm_gpuva *va);
141 void drm_gpuva_remove(struct drm_gpuva *va);
142 
143 void drm_gpuva_link(struct drm_gpuva *va);
144 void drm_gpuva_unlink(struct drm_gpuva *va);
145 
146 struct drm_gpuva *drm_gpuva_find(struct drm_gpuva_manager *mgr,
147 				 u64 addr, u64 range);
148 struct drm_gpuva *drm_gpuva_find_first(struct drm_gpuva_manager *mgr,
149 				       u64 addr, u64 range);
150 struct drm_gpuva *drm_gpuva_find_prev(struct drm_gpuva_manager *mgr, u64 start);
151 struct drm_gpuva *drm_gpuva_find_next(struct drm_gpuva_manager *mgr, u64 end);
152 
153 bool drm_gpuva_interval_empty(struct drm_gpuva_manager *mgr, u64 addr, u64 range);
154 
155 static inline void drm_gpuva_init(struct drm_gpuva *va, u64 addr, u64 range,
156 				  struct drm_gem_object *obj, u64 offset)
157 {
158 	va->va.addr = addr;
159 	va->va.range = range;
160 	va->gem.obj = obj;
161 	va->gem.offset = offset;
162 }
163 
164 /**
165  * drm_gpuva_invalidate() - sets whether the backing GEM of this &drm_gpuva is
166  * invalidated
167  * @va: the &drm_gpuva to set the invalidate flag for
168  * @invalidate: indicates whether the &drm_gpuva is invalidated
169  */
170 static inline void drm_gpuva_invalidate(struct drm_gpuva *va, bool invalidate)
171 {
172 	if (invalidate)
173 		va->flags |= DRM_GPUVA_INVALIDATED;
174 	else
175 		va->flags &= ~DRM_GPUVA_INVALIDATED;
176 }
177 
178 /**
179  * drm_gpuva_invalidated() - indicates whether the backing BO of this &drm_gpuva
180  * is invalidated
181  * @va: the &drm_gpuva to check
182  */
183 static inline bool drm_gpuva_invalidated(struct drm_gpuva *va)
184 {
185 	return va->flags & DRM_GPUVA_INVALIDATED;
186 }
187 
188 /**
189  * struct drm_gpuva_manager - DRM GPU VA Manager
190  *
191  * The DRM GPU VA Manager keeps track of a GPU's virtual address space by using
192  * &maple_tree structures. Typically, this structure is embedded in bigger
193  * driver structures.
194  *
195  * Drivers can pass addresses and ranges in an arbitrary unit, e.g. bytes or
196  * pages.
197  *
198  * There should be one manager instance per GPU virtual address space.
199  */
200 struct drm_gpuva_manager {
201 	/**
202 	 * @name: the name of the DRM GPU VA space
203 	 */
204 	const char *name;
205 
206 	/**
207 	 * @mm_start: start of the VA space
208 	 */
209 	u64 mm_start;
210 
211 	/**
212 	 * @mm_range: length of the VA space
213 	 */
214 	u64 mm_range;
215 
216 	/**
217 	 * @rb: structures to track &drm_gpuva entries
218 	 */
219 	struct {
220 		/**
221 		 * @tree: the rb-tree to track GPU VA mappings
222 		 */
223 		struct rb_root_cached tree;
224 
225 		/**
226 		 * @list: the &list_head to track GPU VA mappings
227 		 */
228 		struct list_head list;
229 	} rb;
230 
231 	/**
232 	 * @kernel_alloc_node:
233 	 *
234 	 * &drm_gpuva representing the address space cutout reserved for
235 	 * the kernel
236 	 */
237 	struct drm_gpuva kernel_alloc_node;
238 
239 	/**
240 	 * @ops: &drm_gpuva_fn_ops providing the split/merge steps to drivers
241 	 */
242 	const struct drm_gpuva_fn_ops *ops;
243 };
244 
245 void drm_gpuva_manager_init(struct drm_gpuva_manager *mgr,
246 			    const char *name,
247 			    u64 start_offset, u64 range,
248 			    u64 reserve_offset, u64 reserve_range,
249 			    const struct drm_gpuva_fn_ops *ops);
250 void drm_gpuva_manager_destroy(struct drm_gpuva_manager *mgr);
251 
252 static inline struct drm_gpuva *
253 __drm_gpuva_next(struct drm_gpuva *va)
254 {
255 	if (va && !list_is_last(&va->rb.entry, &va->mgr->rb.list))
256 		return list_next_entry(va, rb.entry);
257 
258 	return NULL;
259 }
260 
261 /**
262  * drm_gpuva_for_each_va_range() - iterate over a range of &drm_gpuvas
263  * @va__: &drm_gpuva structure to assign to in each iteration step
264  * @mgr__: &drm_gpuva_manager to walk over
265  * @start__: starting offset, the first gpuva will overlap this
266  * @end__: ending offset, the last gpuva will start before this (but may
267  * overlap)
268  *
269  * This iterator walks over all &drm_gpuvas in the &drm_gpuva_manager that lie
270  * between @start__ and @end__. It is implemented similarly to list_for_each(),
271  * but is using the &drm_gpuva_manager's internal interval tree to accelerate
272  * the search for the starting &drm_gpuva, and hence isn't safe against removal
273  * of elements. It assumes that @end__ is within (or is the upper limit of) the
274  * &drm_gpuva_manager. This iterator does not skip over the &drm_gpuva_manager's
275  * @kernel_alloc_node.
276  */
277 #define drm_gpuva_for_each_va_range(va__, mgr__, start__, end__) \
278 	for (va__ = drm_gpuva_find_first((mgr__), (start__), (end__) - (start__)); \
279 	     va__ && (va__->va.addr < (end__)); \
280 	     va__ = __drm_gpuva_next(va__))
281 
282 /**
283  * drm_gpuva_for_each_va_range_safe() - safely iterate over a range of
284  * &drm_gpuvas
285  * @va__: &drm_gpuva to assign to in each iteration step
286  * @next__: another &drm_gpuva to use as temporary storage
287  * @mgr__: &drm_gpuva_manager to walk over
288  * @start__: starting offset, the first gpuva will overlap this
289  * @end__: ending offset, the last gpuva will start before this (but may
290  * overlap)
291  *
292  * This iterator walks over all &drm_gpuvas in the &drm_gpuva_manager that lie
293  * between @start__ and @end__. It is implemented similarly to
294  * list_for_each_safe(), but is using the &drm_gpuva_manager's internal interval
295  * tree to accelerate the search for the starting &drm_gpuva, and hence is safe
296  * against removal of elements. It assumes that @end__ is within (or is the
297  * upper limit of) the &drm_gpuva_manager. This iterator does not skip over the
298  * &drm_gpuva_manager's @kernel_alloc_node.
299  */
300 #define drm_gpuva_for_each_va_range_safe(va__, next__, mgr__, start__, end__) \
301 	for (va__ = drm_gpuva_find_first((mgr__), (start__), (end__) - (start__)), \
302 	     next__ = __drm_gpuva_next(va__); \
303 	     va__ && (va__->va.addr < (end__)); \
304 	     va__ = next__, next__ = __drm_gpuva_next(va__))
305 
306 /**
307  * drm_gpuva_for_each_va() - iterate over all &drm_gpuvas
308  * @va__: &drm_gpuva to assign to in each iteration step
309  * @mgr__: &drm_gpuva_manager to walk over
310  *
311  * This iterator walks over all &drm_gpuva structures associated with the given
312  * &drm_gpuva_manager.
313  */
314 #define drm_gpuva_for_each_va(va__, mgr__) \
315 	list_for_each_entry(va__, &(mgr__)->rb.list, rb.entry)
316 
317 /**
318  * drm_gpuva_for_each_va_safe() - safely iterate over all &drm_gpuvas
319  * @va__: &drm_gpuva to assign to in each iteration step
320  * @next__: another &drm_gpuva to use as temporary storage
321  * @mgr__: &drm_gpuva_manager to walk over
322  *
323  * This iterator walks over all &drm_gpuva structures associated with the given
324  * &drm_gpuva_manager. It is implemented with list_for_each_entry_safe(), and
325  * hence safe against the removal of elements.
326  */
327 #define drm_gpuva_for_each_va_safe(va__, next__, mgr__) \
328 	list_for_each_entry_safe(va__, next__, &(mgr__)->rb.list, rb.entry)
329 
330 /**
331  * enum drm_gpuva_op_type - GPU VA operation type
332  *
333  * Operations to alter the GPU VA mappings tracked by the &drm_gpuva_manager.
334  */
335 enum drm_gpuva_op_type {
336 	/**
337 	 * @DRM_GPUVA_OP_MAP: the map op type
338 	 */
339 	DRM_GPUVA_OP_MAP,
340 
341 	/**
342 	 * @DRM_GPUVA_OP_REMAP: the remap op type
343 	 */
344 	DRM_GPUVA_OP_REMAP,
345 
346 	/**
347 	 * @DRM_GPUVA_OP_UNMAP: the unmap op type
348 	 */
349 	DRM_GPUVA_OP_UNMAP,
350 
351 	/**
352 	 * @DRM_GPUVA_OP_PREFETCH: the prefetch op type
353 	 */
354 	DRM_GPUVA_OP_PREFETCH,
355 };
356 
357 /**
358  * struct drm_gpuva_op_map - GPU VA map operation
359  *
360  * This structure represents a single map operation generated by the
361  * DRM GPU VA manager.
362  */
363 struct drm_gpuva_op_map {
364 	/**
365 	 * @va: structure containing address and range of a map
366 	 * operation
367 	 */
368 	struct {
369 		/**
370 		 * @addr: the base address of the new mapping
371 		 */
372 		u64 addr;
373 
374 		/**
375 		 * @range: the range of the new mapping
376 		 */
377 		u64 range;
378 	} va;
379 
380 	/**
381 	 * @gem: structure containing the &drm_gem_object and it's offset
382 	 */
383 	struct {
384 		/**
385 		 * @offset: the offset within the &drm_gem_object
386 		 */
387 		u64 offset;
388 
389 		/**
390 		 * @obj: the &drm_gem_object to map
391 		 */
392 		struct drm_gem_object *obj;
393 	} gem;
394 };
395 
396 /**
397  * struct drm_gpuva_op_unmap - GPU VA unmap operation
398  *
399  * This structure represents a single unmap operation generated by the
400  * DRM GPU VA manager.
401  */
402 struct drm_gpuva_op_unmap {
403 	/**
404 	 * @va: the &drm_gpuva to unmap
405 	 */
406 	struct drm_gpuva *va;
407 
408 	/**
409 	 * @keep:
410 	 *
411 	 * Indicates whether this &drm_gpuva is physically contiguous with the
412 	 * original mapping request.
413 	 *
414 	 * Optionally, if &keep is set, drivers may keep the actual page table
415 	 * mappings for this &drm_gpuva, adding the missing page table entries
416 	 * only and update the &drm_gpuva_manager accordingly.
417 	 */
418 	bool keep;
419 };
420 
421 /**
422  * struct drm_gpuva_op_remap - GPU VA remap operation
423  *
424  * This represents a single remap operation generated by the DRM GPU VA manager.
425  *
426  * A remap operation is generated when an existing GPU VA mmapping is split up
427  * by inserting a new GPU VA mapping or by partially unmapping existent
428  * mapping(s), hence it consists of a maximum of two map and one unmap
429  * operation.
430  *
431  * The @unmap operation takes care of removing the original existing mapping.
432  * @prev is used to remap the preceding part, @next the subsequent part.
433  *
434  * If either a new mapping's start address is aligned with the start address
435  * of the old mapping or the new mapping's end address is aligned with the
436  * end address of the old mapping, either @prev or @next is NULL.
437  *
438  * Note, the reason for a dedicated remap operation, rather than arbitrary
439  * unmap and map operations, is to give drivers the chance of extracting driver
440  * specific data for creating the new mappings from the unmap operations's
441  * &drm_gpuva structure which typically is embedded in larger driver specific
442  * structures.
443  */
444 struct drm_gpuva_op_remap {
445 	/**
446 	 * @prev: the preceding part of a split mapping
447 	 */
448 	struct drm_gpuva_op_map *prev;
449 
450 	/**
451 	 * @next: the subsequent part of a split mapping
452 	 */
453 	struct drm_gpuva_op_map *next;
454 
455 	/**
456 	 * @unmap: the unmap operation for the original existing mapping
457 	 */
458 	struct drm_gpuva_op_unmap *unmap;
459 };
460 
461 /**
462  * struct drm_gpuva_op_prefetch - GPU VA prefetch operation
463  *
464  * This structure represents a single prefetch operation generated by the
465  * DRM GPU VA manager.
466  */
467 struct drm_gpuva_op_prefetch {
468 	/**
469 	 * @va: the &drm_gpuva to prefetch
470 	 */
471 	struct drm_gpuva *va;
472 };
473 
474 /**
475  * struct drm_gpuva_op - GPU VA operation
476  *
477  * This structure represents a single generic operation.
478  *
479  * The particular type of the operation is defined by @op.
480  */
481 struct drm_gpuva_op {
482 	/**
483 	 * @entry:
484 	 *
485 	 * The &list_head used to distribute instances of this struct within
486 	 * &drm_gpuva_ops.
487 	 */
488 	struct list_head entry;
489 
490 	/**
491 	 * @op: the type of the operation
492 	 */
493 	enum drm_gpuva_op_type op;
494 
495 	union {
496 		/**
497 		 * @map: the map operation
498 		 */
499 		struct drm_gpuva_op_map map;
500 
501 		/**
502 		 * @remap: the remap operation
503 		 */
504 		struct drm_gpuva_op_remap remap;
505 
506 		/**
507 		 * @unmap: the unmap operation
508 		 */
509 		struct drm_gpuva_op_unmap unmap;
510 
511 		/**
512 		 * @prefetch: the prefetch operation
513 		 */
514 		struct drm_gpuva_op_prefetch prefetch;
515 	};
516 };
517 
518 /**
519  * struct drm_gpuva_ops - wraps a list of &drm_gpuva_op
520  */
521 struct drm_gpuva_ops {
522 	/**
523 	 * @list: the &list_head
524 	 */
525 	struct list_head list;
526 };
527 
528 /**
529  * drm_gpuva_for_each_op() - iterator to walk over &drm_gpuva_ops
530  * @op: &drm_gpuva_op to assign in each iteration step
531  * @ops: &drm_gpuva_ops to walk
532  *
533  * This iterator walks over all ops within a given list of operations.
534  */
535 #define drm_gpuva_for_each_op(op, ops) list_for_each_entry(op, &(ops)->list, entry)
536 
537 /**
538  * drm_gpuva_for_each_op_safe() - iterator to safely walk over &drm_gpuva_ops
539  * @op: &drm_gpuva_op to assign in each iteration step
540  * @next: &next &drm_gpuva_op to store the next step
541  * @ops: &drm_gpuva_ops to walk
542  *
543  * This iterator walks over all ops within a given list of operations. It is
544  * implemented with list_for_each_safe(), so save against removal of elements.
545  */
546 #define drm_gpuva_for_each_op_safe(op, next, ops) \
547 	list_for_each_entry_safe(op, next, &(ops)->list, entry)
548 
549 /**
550  * drm_gpuva_for_each_op_from_reverse() - iterate backwards from the given point
551  * @op: &drm_gpuva_op to assign in each iteration step
552  * @ops: &drm_gpuva_ops to walk
553  *
554  * This iterator walks over all ops within a given list of operations beginning
555  * from the given operation in reverse order.
556  */
557 #define drm_gpuva_for_each_op_from_reverse(op, ops) \
558 	list_for_each_entry_from_reverse(op, &(ops)->list, entry)
559 
560 /**
561  * drm_gpuva_first_op() - returns the first &drm_gpuva_op from &drm_gpuva_ops
562  * @ops: the &drm_gpuva_ops to get the fist &drm_gpuva_op from
563  */
564 #define drm_gpuva_first_op(ops) \
565 	list_first_entry(&(ops)->list, struct drm_gpuva_op, entry)
566 
567 /**
568  * drm_gpuva_last_op() - returns the last &drm_gpuva_op from &drm_gpuva_ops
569  * @ops: the &drm_gpuva_ops to get the last &drm_gpuva_op from
570  */
571 #define drm_gpuva_last_op(ops) \
572 	list_last_entry(&(ops)->list, struct drm_gpuva_op, entry)
573 
574 /**
575  * drm_gpuva_prev_op() - previous &drm_gpuva_op in the list
576  * @op: the current &drm_gpuva_op
577  */
578 #define drm_gpuva_prev_op(op) list_prev_entry(op, entry)
579 
580 /**
581  * drm_gpuva_next_op() - next &drm_gpuva_op in the list
582  * @op: the current &drm_gpuva_op
583  */
584 #define drm_gpuva_next_op(op) list_next_entry(op, entry)
585 
586 struct drm_gpuva_ops *
587 drm_gpuva_sm_map_ops_create(struct drm_gpuva_manager *mgr,
588 			    u64 addr, u64 range,
589 			    struct drm_gem_object *obj, u64 offset);
590 struct drm_gpuva_ops *
591 drm_gpuva_sm_unmap_ops_create(struct drm_gpuva_manager *mgr,
592 			      u64 addr, u64 range);
593 
594 struct drm_gpuva_ops *
595 drm_gpuva_prefetch_ops_create(struct drm_gpuva_manager *mgr,
596 				 u64 addr, u64 range);
597 
598 struct drm_gpuva_ops *
599 drm_gpuva_gem_unmap_ops_create(struct drm_gpuva_manager *mgr,
600 			       struct drm_gem_object *obj);
601 
602 void drm_gpuva_ops_free(struct drm_gpuva_manager *mgr,
603 			struct drm_gpuva_ops *ops);
604 
605 static inline void drm_gpuva_init_from_op(struct drm_gpuva *va,
606 					  struct drm_gpuva_op_map *op)
607 {
608 	drm_gpuva_init(va, op->va.addr, op->va.range,
609 		       op->gem.obj, op->gem.offset);
610 }
611 
612 /**
613  * struct drm_gpuva_fn_ops - callbacks for split/merge steps
614  *
615  * This structure defines the callbacks used by &drm_gpuva_sm_map and
616  * &drm_gpuva_sm_unmap to provide the split/merge steps for map and unmap
617  * operations to drivers.
618  */
619 struct drm_gpuva_fn_ops {
620 	/**
621 	 * @op_alloc: called when the &drm_gpuva_manager allocates
622 	 * a struct drm_gpuva_op
623 	 *
624 	 * Some drivers may want to embed struct drm_gpuva_op into driver
625 	 * specific structures. By implementing this callback drivers can
626 	 * allocate memory accordingly.
627 	 *
628 	 * This callback is optional.
629 	 */
630 	struct drm_gpuva_op *(*op_alloc)(void);
631 
632 	/**
633 	 * @op_free: called when the &drm_gpuva_manager frees a
634 	 * struct drm_gpuva_op
635 	 *
636 	 * Some drivers may want to embed struct drm_gpuva_op into driver
637 	 * specific structures. By implementing this callback drivers can
638 	 * free the previously allocated memory accordingly.
639 	 *
640 	 * This callback is optional.
641 	 */
642 	void (*op_free)(struct drm_gpuva_op *op);
643 
644 	/**
645 	 * @sm_step_map: called from &drm_gpuva_sm_map to finally insert the
646 	 * mapping once all previous steps were completed
647 	 *
648 	 * The &priv pointer matches the one the driver passed to
649 	 * &drm_gpuva_sm_map or &drm_gpuva_sm_unmap, respectively.
650 	 *
651 	 * Can be NULL if &drm_gpuva_sm_map is used.
652 	 */
653 	int (*sm_step_map)(struct drm_gpuva_op *op, void *priv);
654 
655 	/**
656 	 * @sm_step_remap: called from &drm_gpuva_sm_map and
657 	 * &drm_gpuva_sm_unmap to split up an existent mapping
658 	 *
659 	 * This callback is called when existent mapping needs to be split up.
660 	 * This is the case when either a newly requested mapping overlaps or
661 	 * is enclosed by an existent mapping or a partial unmap of an existent
662 	 * mapping is requested.
663 	 *
664 	 * The &priv pointer matches the one the driver passed to
665 	 * &drm_gpuva_sm_map or &drm_gpuva_sm_unmap, respectively.
666 	 *
667 	 * Can be NULL if neither &drm_gpuva_sm_map nor &drm_gpuva_sm_unmap is
668 	 * used.
669 	 */
670 	int (*sm_step_remap)(struct drm_gpuva_op *op, void *priv);
671 
672 	/**
673 	 * @sm_step_unmap: called from &drm_gpuva_sm_map and
674 	 * &drm_gpuva_sm_unmap to unmap an existent mapping
675 	 *
676 	 * This callback is called when existent mapping needs to be unmapped.
677 	 * This is the case when either a newly requested mapping encloses an
678 	 * existent mapping or an unmap of an existent mapping is requested.
679 	 *
680 	 * The &priv pointer matches the one the driver passed to
681 	 * &drm_gpuva_sm_map or &drm_gpuva_sm_unmap, respectively.
682 	 *
683 	 * Can be NULL if neither &drm_gpuva_sm_map nor &drm_gpuva_sm_unmap is
684 	 * used.
685 	 */
686 	int (*sm_step_unmap)(struct drm_gpuva_op *op, void *priv);
687 };
688 
689 int drm_gpuva_sm_map(struct drm_gpuva_manager *mgr, void *priv,
690 		     u64 addr, u64 range,
691 		     struct drm_gem_object *obj, u64 offset);
692 
693 int drm_gpuva_sm_unmap(struct drm_gpuva_manager *mgr, void *priv,
694 		       u64 addr, u64 range);
695 
696 void drm_gpuva_map(struct drm_gpuva_manager *mgr,
697 		   struct drm_gpuva *va,
698 		   struct drm_gpuva_op_map *op);
699 
700 void drm_gpuva_remap(struct drm_gpuva *prev,
701 		     struct drm_gpuva *next,
702 		     struct drm_gpuva_op_remap *op);
703 
704 void drm_gpuva_unmap(struct drm_gpuva_op_unmap *op);
705 
706 #endif /* __DRM_GPUVA_MGR_H__ */
707