aboutsummaryrefslogtreecommitdiff
path: root/include/drm/ttm/ttm_bo_driver.h
blob: e2ebe6666e2beb7fc28d234341413140f67fcfba (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
/**************************************************************************
 *
 * Copyright (c) 2006-2009 Vmware, Inc., Palo Alto, CA., USA
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 **************************************************************************/
/*
 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
 */
#ifndef _TTM_BO_DRIVER_H_
#define _TTM_BO_DRIVER_H_

#include <ttm/ttm_bo_api.h>
#include <ttm/ttm_memory.h>
#include <ttm/ttm_module.h>
#include <ttm/ttm_placement.h>
#include <drm/drm_mm.h>
#include <drm/drm_global.h>
#include <drm/drm_vma_manager.h>
#include <linux/workqueue.h>
#include <linux/fs.h>
#include <linux/spinlock.h>
#include <linux/reservation.h>

struct ttm_backend_func {
	/**
	 * struct ttm_backend_func member bind
	 *
	 * @ttm: Pointer to a struct ttm_tt.
	 * @bo_mem: Pointer to a struct ttm_mem_reg describing the
	 * memory type and location for binding.
	 *
	 * Bind the backend pages into the aperture in the location
	 * indicated by @bo_mem. This function should be able to handle
	 * differences between aperture and system page sizes.
	 */
	int (*bind) (struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem);

	/**
	 * struct ttm_backend_func member unbind
	 *
	 * @ttm: Pointer to a struct ttm_tt.
	 *
	 * Unbind previously bound backend pages. This function should be
	 * able to handle differences between aperture and system page sizes.
	 */
	int (*unbind) (struct ttm_tt *ttm);

	/**
	 * struct ttm_backend_func member destroy
	 *
	 * @ttm: Pointer to a struct ttm_tt.
	 *
	 * Destroy the backend. This will be call back from ttm_tt_destroy so
	 * don't call ttm_tt_destroy from the callback or infinite loop.
	 */
	void (*destroy) (struct ttm_tt *ttm);
};

#define TTM_PAGE_FLAG_WRITE           (1 << 3)
#define TTM_PAGE_FLAG_SWAPPED         (1 << 4)
#define TTM_PAGE_FLAG_PERSISTENT_SWAP (1 << 5)
#define TTM_PAGE_FLAG_ZERO_ALLOC      (1 << 6)
#define TTM_PAGE_FLAG_DMA32           (1 << 7)
#define TTM_PAGE_FLAG_SG              (1 << 8)

enum ttm_caching_state {
	tt_uncached,
	tt_wc,
	tt_cached
};

/**
 * struct ttm_tt
 *
 * @bdev: Pointer to a struct ttm_bo_device.
 * @func: Pointer to a struct ttm_backend_func that describes
 * the backend methods.
 * @dummy_read_page: Page to map where the ttm_tt page array contains a NULL
 * pointer.
 * @pages: Array of pages backing the data.
 * @num_pages: Number of pages in the page array.
 * @bdev: Pointer to the current struct ttm_bo_device.
 * @be: Pointer to the ttm backend.
 * @swap_storage: Pointer to shmem struct file for swap storage.
 * @caching_state: The current caching state of the pages.
 * @state: The current binding state of the pages.
 *
 * This is a structure holding the pages, caching- and aperture binding
 * status for a buffer object that isn't backed by fixed (VRAM / AGP)
 * memory.
 */

struct ttm_tt {
	struct ttm_bo_device *bdev;
	struct ttm_backend_func *func;
	struct page *dummy_read_page;
	struct page **pages;
	uint32_t page_flags;
	unsigned long num_pages;
	struct sg_table *sg; /* for SG objects via dma-buf */
	struct ttm_bo_global *glob;
	struct file *swap_storage;
	enum ttm_caching_state caching_state;
	enum {
		tt_bound,
		tt_unbound,
		tt_unpopulated,
	} state;
};

/**
 * struct ttm_dma_tt
 *
 * @ttm: Base ttm_tt struct.
 * @cpu_address: The CPU address of the pages
 * @dma_address: The DMA (bus) addresses of the pages
 * @pages_list: used by some page allocation backend
 *
 * This is a structure holding the pages, caching- and aperture binding
 * status for a buffer object that isn't backed by fixed (VRAM / AGP)
 * memory.
 */
struct ttm_dma_tt {
	struct ttm_tt ttm;
	void **cpu_address;
	dma_addr_t *dma_address;
	struct list_head pages_list;
};

#define TTM_MEMTYPE_FLAG_FIXED         (1 << 0)	/* Fixed (on-card) PCI memory */
#define TTM_MEMTYPE_FLAG_MAPPABLE      (1 << 1)	/* Memory mappable */
#define TTM_MEMTYPE_FLAG_CMA           (1 << 3)	/* Can't map aperture */

struct ttm_mem_type_manager;

struct ttm_mem_type_manager_func {
	/**
	 * struct ttm_mem_type_manager member init
	 *
	 * @man: Pointer to a memory type manager.
	 * @p_size: Implementation dependent, but typically the size of the
	 * range to be managed in pages.
	 *
	 * Called to initialize a private range manager. The function is
	 * expected to initialize the man::priv member.
	 * Returns 0 on success, negative error code on failure.
	 */
	int  (*init)(struct ttm_mem_type_manager *man, unsigned long p_size);

	/**
	 * struct ttm_mem_type_manager member takedown
	 *
	 * @man: Pointer to a memory type manager.
	 *
	 * Called to undo the setup done in init. All allocated resources
	 * should be freed.
	 */
	int  (*takedown)(struct ttm_mem_type_manager *man);

	/**
	 * struct ttm_mem_type_manager member get_node
	 *
	 * @man: Pointer to a memory type manager.
	 * @bo: Pointer to the buffer object we're allocating space for.
	 * @placement: Placement details.
	 * @flags: Additional placement flags.
	 * @mem: Pointer to a struct ttm_mem_reg to be filled in.
	 *
	 * This function should allocate space in the memory type managed
	 * by @man. Placement details if
	 * applicable are given by @placement. If successful,
	 * @mem::mm_node should be set to a non-null value, and
	 * @mem::start should be set to a value identifying the beginning
	 * of the range allocated, and the function should return zero.
	 * If the memory region accommodate the buffer object, @mem::mm_node
	 * should be set to NULL, and the function should return 0.
	 * If a system error occurred, preventing the request to be fulfilled,
	 * the function should return a negative error code.
	 *
	 * Note that @mem::mm_node will only be dereferenced by
	 * struct ttm_mem_type_manager functions and optionally by the driver,
	 * which has knowledge of the underlying type.
	 *
	 * This function may not be called from within atomic context, so
	 * an implementation can and must use either a mutex or a spinlock to
	 * protect any data structures managing the space.
	 */
	int  (*get_node)(struct ttm_mem_type_manager *man,
			 struct ttm_buffer_object *bo,
			 const struct ttm_place *place,
			 struct ttm_mem_reg *mem);

	/**
	 * struct ttm_mem_type_manager member put_node
	 *
	 * @man: Pointer to a memory type manager.
	 * @mem: Pointer to a struct ttm_mem_reg to be filled in.
	 *
	 * This function frees memory type resources previously allocated
	 * and that are identified by @mem::mm_node and @mem::start. May not
	 * be called from within atomic context.
	 */
	void (*put_node)(struct ttm_mem_type_manager *man,
			 struct ttm_mem_reg *mem);

	/**
	 * struct ttm_mem_type_manager member debug
	 *
	 * @man: Pointer to a memory type manager.
	 * @prefix: Prefix to be used in printout to identify the caller.
	 *
	 * This function is called to print out the state of the memory
	 * type manager to aid debugging of out-of-memory conditions.
	 * It may not be called from within atomic context.
	 */
	void (*debug)(struct ttm_mem_type_manager *man, const char *prefix);
};

/**
 * struct ttm_mem_type_manager
 *
 * @has_type: The memory type has been initialized.
 * @use_type: The memory type is enabled.
 * @flags: TTM_MEMTYPE_XX flags identifying the traits of the memory
 * managed by this memory type.
 * @gpu_offset: If used, the GPU offset of the first managed page of
 * fixed memory or the first managed location in an aperture.
 * @size: Size of the managed region.
 * @available_caching: A mask of available caching types, TTM_PL_FLAG_XX,
 * as defined in ttm_placement_common.h
 * @default_caching: The default caching policy used for a buffer object
 * placed in this memory type if the user doesn't provide one.
 * @func: structure pointer implementing the range manager. See above
 * @priv: Driver private closure for @func.
 * @io_reserve_mutex: Mutex optionally protecting shared io_reserve structures
 * @use_io_reserve_lru: Use an lru list to try to unreserve io_mem_regions
 * reserved by the TTM vm system.
 * @io_reserve_lru: Optional lru list for unreserving io mem regions.
 * @io_reserve_fastpath: Only use bdev::driver::io_mem_reserve to obtain
 * @move_lock: lock for move fence
 * static information. bdev::driver::io_mem_free is never used.
 * @lru: The lru list for this memory type.
 * @move: The fence of the last pipelined move operation.
 *
 * This structure is used to identify and manage memory types for a device.
 * It's set up by the ttm_bo_driver::init_mem_type method.
 */



struct ttm_mem_type_manager {
	struct ttm_bo_device *bdev;

	/*
	 * No protection. Constant from start.
	 */

	bool has_type;
	bool use_type;
	uint32_t flags;
	uint64_t gpu_offset; /* GPU address space is independent of CPU word size */
	uint64_t size;
	uint32_t available_caching;
	uint32_t default_caching;
	const struct ttm_mem_type_manager_func *func;
	void *priv;
	struct mutex io_reserve_mutex;
	bool use_io_reserve_lru;
	bool io_reserve_fastpath;
	spinlock_t move_lock;

	/*
	 * Protected by @io_reserve_mutex:
	 */

	struct list_head io_reserve_lru;

	/*
	 * Protected by the global->lru_lock.
	 */

	struct list_head lru;

	/*
	 * Protected by @move_lock.
	 */
	struct fence *move;
};

/**
 * struct ttm_bo_driver
 *
 * @create_ttm_backend_entry: Callback to create a struct ttm_backend.
 * @invalidate_caches: Callback to invalidate read caches when a buffer object
 * has been evicted.
 * @init_mem_type: Callback to initialize a struct ttm_mem_type_manager
 * structure.
 * @evict_flags: Callback to obtain placement flags when a buffer is evicted.
 * @move: Callback for a driver to hook in accelerated functions to
 * move a buffer.
 * If set to NULL, a potentially slow memcpy() move is used.
 */

struct ttm_bo_driver {
	/**
	 * ttm_tt_create
	 *
	 * @bdev: pointer to a struct ttm_bo_device:
	 * @size: Size of the data needed backing.
	 * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags.
	 * @dummy_read_page: See struct ttm_bo_device.
	 *
	 * Create a struct ttm_tt to back data with system memory pages.
	 * No pages are actually allocated.
	 * Returns:
	 * NULL: Out of memory.
	 */
	struct ttm_tt *(*ttm_tt_create)(struct ttm_bo_device *bdev,
					unsigned long size,
					uint32_t page_flags,
					struct page *dummy_read_page);

	/**
	 * ttm_tt_populate
	 *
	 * @ttm: The struct ttm_tt to contain the backing pages.
	 *
	 * Allocate all backing pages
	 * Returns:
	 * -ENOMEM: Out of memory.
	 */
	int (*ttm_tt_populate)(struct ttm_tt *ttm);

	/**
	 * ttm_tt_unpopulate
	 *
	 * @ttm: The struct ttm_tt to contain the backing pages.
	 *
	 * Free all backing page
	 */
	void (*ttm_tt_unpopulate)(struct ttm_tt *ttm);

	/**
	 * struct ttm_bo_driver member invalidate_caches
	 *
	 * @bdev: the buffer object device.
	 * @flags: new placement of the rebound buffer object.
	 *
	 * A previosly evicted buffer has been rebound in a
	 * potentially new location. Tell the driver that it might
	 * consider invalidating read (texture) caches on the next command
	 * submission as a consequence.
	 */

	int (*invalidate_caches) (struct ttm_bo_device *bdev, uint32_t flags);
	int (*init_mem_type) (struct ttm_bo_device *bdev, uint32_t type,
			      struct ttm_mem_type_manager *man);
	/**
	 * struct ttm_bo_driver member evict_flags:
	 *
	 * @bo: the buffer object to be evicted
	 *
	 * Return the bo flags for a buffer which is not mapped to the hardware.
	 * These will be placed in proposed_flags so that when the move is
	 * finished, they'll end up in bo->mem.flags
	 */

	 void(*evict_flags) (struct ttm_buffer_object *bo,
				struct ttm_placement *placement);
	/**
	 * struct ttm_bo_driver member move:
	 *
	 * @bo: the buffer to move
	 * @evict: whether this motion is evicting the buffer from
	 * the graphics address space
	 * @interruptible: Use interruptible sleeps if possible when sleeping.
	 * @no_wait: whether this should give up and return -EBUSY
	 * if this move would require sleeping
	 * @new_mem: the new memory region receiving the buffer
	 *
	 * Move a buffer between two memory regions.
	 */
	int (*move) (struct ttm_buffer_object *bo,
		     bool evict, bool interruptible,
		     bool no_wait_gpu,
		     struct ttm_mem_reg *new_mem);

	/**
	 * struct ttm_bo_driver_member verify_access
	 *
	 * @bo: Pointer to a buffer object.
	 * @filp: Pointer to a struct file trying to access the object.
	 *
	 * Called from the map / write / read methods to verify that the
	 * caller is permitted to access the buffer object.
	 * This member may be set to NULL, which will refuse this kind of
	 * access for all buffer objects.
	 * This function should return 0 if access is granted, -EPERM otherwise.
	 */
	int (*verify_access) (struct ttm_buffer_object *bo,
			      struct file *filp);

	/* hook to notify driver about a driver move so it
	 * can do tiling things */
	void (*move_notify)(struct ttm_buffer_object *bo,
			    struct ttm_mem_reg *new_mem);
	/* notify the driver we are taking a fault on this BO
	 * and have reserved it */
	int (*fault_reserve_notify)(struct ttm_buffer_object *bo);

	/**
	 * notify the driver that we're about to swap out this bo
	 */
	void (*swap_notify) (struct ttm_buffer_object *bo);

	/**
	 * Driver callback on when mapping io memory (for bo_move_memcpy
	 * for instance). TTM will take care to call io_mem_free whenever
	 * the mapping is not use anymore. io_mem_reserve & io_mem_free
	 * are balanced.
	 */
	int (*io_mem_reserve)(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem);
	void (*io_mem_free)(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem);

	/**
	 * Optional driver callback for when BO is removed from the LRU.
	 * Called with LRU lock held immediately before the removal.
	 */
	void (*lru_removal)(struct ttm_buffer_object *bo);

	/**
	 * Return the list_head after which a BO should be inserted in the LRU.
	 */
	struct list_head *(*lru_tail)(struct ttm_buffer_object *bo);
	struct list_head *(*swap_lru_tail)(struct ttm_buffer_object *bo);
};

/**
 * struct ttm_bo_global_ref - Argument to initialize a struct ttm_bo_global.
 */

struct ttm_bo_global_ref {
	struct drm_global_reference ref;
	struct ttm_mem_global *mem_glob;
};

/**
 * struct ttm_bo_global - Buffer object driver global data.
 *
 * @mem_glob: Pointer to a struct ttm_mem_global object for accounting.
 * @dummy_read_page: Pointer to a dummy page used for mapping requests
 * of unpopulated pages.
 * @shrink: A shrink callback object used for buffer object swap.
 * @device_list_mutex: Mutex protecting the device list.
 * This mutex is held while traversing the device list for pm options.
 * @lru_lock: Spinlock protecting the bo subsystem lru lists.
 * @device_list: List of buffer object devices.
 * @swap_lru: Lru list of buffer objects used for swapping.
 */

struct ttm_bo_global {

	/**
	 * Constant after init.
	 */

	struct kobject kobj;
	struct ttm_mem_global *mem_glob;
	struct page *dummy_read_page;
	struct ttm_mem_shrink shrink;
	struct mutex device_list_mutex;
	spinlock_t lru_lock;

	/**
	 * Protected by device_list_mutex.
	 */
	struct list_head device_list;

	/**
	 * Protected by the lru_lock.
	 */
	struct list_head swap_lru;

	/**
	 * Internal protection.
	 */
	atomic_t bo_count;
};


#define TTM_NUM_MEM_TYPES 8

/**
 * struct ttm_bo_device - Buffer object driver device-specific data.
 *
 * @driver: Pointer to a struct ttm_bo_driver struct setup by the driver.
 * @man: An array of mem_type_managers.
 * @vma_manager: Address space manager
 * lru_lock: Spinlock that protects the buffer+device lru lists and
 * ddestroy lists.
 * @dev_mapping: A pointer to the struct address_space representing the
 * device address space.
 * @wq: Work queue structure for the delayed delete workqueue.
 *
 */

struct ttm_bo_device {

	/*
	 * Constant after bo device init / atomic.
	 */
	struct list_head device_list;
	struct ttm_bo_global *glob;
	struct ttm_bo_driver *driver;
	struct ttm_mem_type_manager man[TTM_NUM_MEM_TYPES];

	/*
	 * Protected by internal locks.
	 */
	struct drm_vma_offset_manager vma_manager;

	/*
	 * Protected by the global:lru lock.
	 */
	struct list_head ddestroy;

	/*
	 * Protected by load / firstopen / lastclose /unload sync.
	 */

	struct address_space *dev_mapping;

	/*
	 * Internal protection.
	 */

	struct delayed_work wq;

	bool need_dma32;
};

/**
 * ttm_flag_masked
 *
 * @old: Pointer to the result and original value.
 * @new: New value of bits.
 * @mask: Mask of bits to change.
 *
 * Convenience function to change a number of bits identified by a mask.
 */

static inline uint32_t
ttm_flag_masked(uint32_t *old, uint32_t new, uint32_t mask)
{
	*old ^= (*old ^ new) & mask;
	return *old;
}

/**
 * ttm_tt_init
 *
 * @ttm: The struct ttm_tt.
 * @bdev: pointer to a struct ttm_bo_device:
 * @size: Size of the data needed backing.
 * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags.
 * @dummy_read_page: See struct ttm_bo_device.
 *
 * Create a struct ttm_tt to back data with system memory pages.
 * No pages are actually allocated.
 * Returns:
 * NULL: Out of memory.
 */
extern int ttm_tt_init(struct ttm_tt *ttm, struct ttm_bo_device *bdev,
			unsigned long size, uint32_t page_flags,
			struct page *dummy_read_page);
extern int ttm_dma_tt_init(struct ttm_dma_tt *ttm_dma, struct ttm_bo_device *bdev,
			   unsigned long size, uint32_t page_flags,
			   struct page *dummy_read_page);

/**
 * ttm_tt_fini
 *
 * @ttm: the ttm_tt structure.
 *
 * Free memory of ttm_tt structure
 */
extern void ttm_tt_fini(struct ttm_tt *ttm);
extern void ttm_dma_tt_fini(struct ttm_dma_tt *ttm_dma);

/**
 * ttm_ttm_bind:
 *
 * @ttm: The struct ttm_tt containing backing pages.
 * @bo_mem: The struct ttm_mem_reg identifying the binding location.
 *
 * Bind the pages of @ttm to an aperture location identified by @bo_mem
 */
extern int ttm_tt_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem);

/**
 * ttm_ttm_destroy:
 *
 * @ttm: The struct ttm_tt.
 *
 * Unbind, unpopulate and destroy common struct ttm_tt.
 */
extern void ttm_tt_destroy(struct ttm_tt *ttm);

/**
 * ttm_tt_swapin:
 *
 * @ttm: The struct ttm_tt.
 *
 * Swap in a previously swap out ttm_tt.
 */
extern int ttm_tt_swapin(struct ttm_tt *ttm);

/**
 * ttm_tt_set_placement_caching:
 *
 * @ttm A struct ttm_tt the backing pages of which will change caching policy.
 * @placement: Flag indicating the desired caching policy.
 *
 * This function will change caching policy of any default kernel mappings of
 * the pages backing @ttm. If changing from cached to uncached or
 * write-combined,
 * all CPU caches will first be flushed to make sure the data of the pages
 * hit RAM. This function may be very costly as it involves global TLB
 * and cache flushes and potential page splitting / combining.
 */
extern int ttm_tt_set_placement_caching(struct ttm_tt *ttm, uint32_t placement);
extern int ttm_tt_swapout(struct ttm_tt *ttm,
			  struct file *persistent_swap_storage);

/**
 * ttm_tt_unpopulate - free pages from a ttm
 *
 * @ttm: Pointer to the ttm_tt structure
 *
 * Calls the driver method to free all pages from a ttm
 */
extern void ttm_tt_unpopulate(struct ttm_tt *ttm);

/*
 * ttm_bo.c
 */

/**
 * ttm_mem_reg_is_pci
 *
 * @bdev: Pointer to a struct ttm_bo_device.
 * @mem: A valid struct ttm_mem_reg.
 *
 * Returns true if the memory described by @mem is PCI memory,
 * false otherwise.
 */
extern bool ttm_mem_reg_is_pci(struct ttm_bo_device *bdev,
				   struct ttm_mem_reg *mem);

/**
 * ttm_bo_mem_space
 *
 * @bo: Pointer to a struct ttm_buffer_object. the data of which
 * we want to allocate space for.
 * @proposed_placement: Proposed new placement for the buffer object.
 * @mem: A struct ttm_mem_reg.
 * @interruptible: Sleep interruptible when sliping.
 * @no_wait_gpu: Return immediately if the GPU is busy.
 *
 * Allocate memory space for the buffer object pointed to by @bo, using
 * the placement flags in @mem, potentially evicting other idle buffer objects.
 * This function may sleep while waiting for space to become available.
 * Returns:
 * -EBUSY: No space available (only if no_wait == 1).
 * -ENOMEM: Could not allocate memory for the buffer object, either due to
 * fragmentation or concurrent allocators.
 * -ERESTARTSYS: An interruptible sleep was interrupted by a signal.
 */
extern int ttm_bo_mem_space(struct ttm_buffer_object *bo,
				struct ttm_placement *placement,
				struct ttm_mem_reg *mem,
				bool interruptible,
				bool no_wait_gpu);

extern void ttm_bo_mem_put(struct ttm_buffer_object *bo,
			   struct ttm_mem_reg *mem);
extern void ttm_bo_mem_put_locked(struct ttm_buffer_object *bo,
				  struct ttm_mem_reg *mem);

extern void ttm_bo_global_release(struct drm_global_reference *ref);
extern int ttm_bo_global_init(struct drm_global_reference *ref);

extern int ttm_bo_device_release(struct ttm_bo_device *bdev);

/**
 * ttm_bo_device_init
 *
 * @bdev: A pointer to a struct ttm_bo_device to initialize.
 * @glob: A pointer to an initialized struct ttm_bo_global.
 * @driver: A pointer to a struct ttm_bo_driver set up by the caller.
 * @mapping: The address space to use for this bo.
 * @file_page_offset: Offset into the device address space that is available
 * for buffer data. This ensures compatibility with other users of the
 * address space.
 *
 * Initializes a struct ttm_bo_device:
 * Returns:
 * !0: Failure.
 */
extern int ttm_bo_device_init(struct ttm_bo_device *bdev,
			      struct ttm_bo_global *glob,
			      struct ttm_bo_driver *driver,
			      struct address_space *mapping,
			      uint64_t file_page_offset, bool need_dma32);

/**
 * ttm_bo_unmap_virtual
 *
 * @bo: tear down the virtual mappings for this BO
 */
extern void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo);

/**
 * ttm_bo_unmap_virtual
 *
 * @bo: tear down the virtual mappings for this BO
 *
 * The caller must take ttm_mem_io_lock before calling this function.
 */
extern void ttm_bo_unmap_virtual_locked(struct ttm_buffer_object *bo);

extern int ttm_mem_io_reserve_vm(struct ttm_buffer_object *bo);
extern void ttm_mem_io_free_vm(struct ttm_buffer_object *bo);
extern int ttm_mem_io_lock(struct ttm_mem_type_manager *man,
			   bool interruptible);
extern void ttm_mem_io_unlock(struct ttm_mem_type_manager *man);

extern void ttm_bo_del_sub_from_lru(struct ttm_buffer_object *bo);
extern void ttm_bo_add_to_lru(struct ttm_buffer_object *bo);

struct list_head *ttm_bo_default_lru_tail(struct ttm_buffer_object *bo);
struct list_head *ttm_bo_default_swap_lru_tail(struct ttm_buffer_object *bo);

/**
 * __ttm_bo_reserve:
 *
 * @bo: A pointer to a struct ttm_buffer_object.
 * @interruptible: Sleep interruptible if waiting.
 * @no_wait: Don't sleep while trying to reserve, rather return -EBUSY.
 * @ticket: ticket used to acquire the ww_mutex.
 *
 * Will not remove reserved buffers from the lru lists.
 * Otherwise identical to ttm_bo_reserve.
 *
 * Returns:
 * -EDEADLK: The reservation may cause a deadlock.
 * Release all buffer reservations, wait for @bo to become unreserved and
 * try again. (only if use_sequence == 1).
 * -ERESTARTSYS: A wait for the buffer to become unreserved was interrupted by
 * a signal. Release all buffer reservations and return to user-space.
 * -EBUSY: The function needed to sleep, but @no_wait was true
 * -EALREADY: Bo already reserved using @ticket. This error code will only
 * be returned if @use_ticket is set to true.
 */
static inline int __ttm_bo_reserve(struct ttm_buffer_object *bo,
				   bool interruptible, bool no_wait,
				   struct ww_acquire_ctx *ticket)
{
	int ret = 0;

	if (no_wait) {
		bool success;
		if (WARN_ON(ticket))
			return -EBUSY;

		success = ww_mutex_trylock(&bo->resv->lock);
		return success ? 0 : -EBUSY;
	}

	if (interruptible)
		ret = ww_mutex_lock_interruptible(&bo->resv->lock, ticket);
	else
		ret = ww_mutex_lock(&bo->resv->lock, ticket);
	if (ret == -EINTR)
		return -ERESTARTSYS;
	return ret;
}

/**
 * ttm_bo_reserve:
 *
 * @bo: A pointer to a struct ttm_buffer_object.
 * @interruptible: Sleep interruptible if waiting.
 * @no_wait: Don't sleep while trying to reserve, rather return -EBUSY.
 * @ticket: ticket used to acquire the ww_mutex.
 *
 * Locks a buffer object for validation. (Or prevents other processes from
 * locking it for validation) and removes it from lru lists, while taking
 * a number of measures to prevent deadlocks.
 *
 * Deadlocks may occur when two processes try to reserve multiple buffers in
 * different order, either by will or as a result of a buffer being evicted
 * to make room for a buffer already reserved. (Buffers are reserved before
 * they are evicted). The following algorithm prevents such deadlocks from
 * occurring:
 * Processes attempting to reserve multiple buffers other than for eviction,
 * (typically execbuf), should first obtain a unique 32-bit
 * validation sequence number,
 * and call this function with @use_ticket == 1 and @ticket->stamp == the unique
 * sequence number. If upon call of this function, the buffer object is already
 * reserved, the validation sequence is checked against the validation
 * sequence of the process currently reserving the buffer,
 * and if the current validation sequence is greater than that of the process
 * holding the reservation, the function returns -EDEADLK. Otherwise it sleeps
 * waiting for the buffer to become unreserved, after which it retries
 * reserving.
 * The caller should, when receiving an -EDEADLK error
 * release all its buffer reservations, wait for @bo to become unreserved, and
 * then rerun the validation with the same validation sequence. This procedure
 * will always guarantee that the process with the lowest validation sequence
 * will eventually succeed, preventing both deadlocks and starvation.
 *
 * Returns:
 * -EDEADLK: The reservation may cause a deadlock.
 * Release all buffer reservations, wait for @bo to become unreserved and
 * try again. (only if use_sequence == 1).
 * -ERESTARTSYS: A wait for the buffer to become unreserved was interrupted by
 * a signal. Release all buffer reservations and return to user-space.
 * -EBUSY: The function needed to sleep, but @no_wait was true
 * -EALREADY: Bo already reserved using @ticket. This error code will only
 * be returned if @use_ticket is set to true.
 */
static inline int ttm_bo_reserve(struct ttm_buffer_object *bo,
				 bool interruptible, bool no_wait,
				 struct ww_acquire_ctx *ticket)
{
	int ret;

	WARN_ON(!atomic_read(&bo->kref.refcount));

	ret = __ttm_bo_reserve(bo, interruptible, no_wait, ticket);
	if (likely(ret == 0))
		ttm_bo_del_sub_from_lru(bo);

	return ret;
}

/**
 * ttm_bo_reserve_slowpath:
 * @bo: A pointer to a struct ttm_buffer_object.
 * @interruptible: Sleep interruptible if waiting.
 * @sequence: Set (@bo)->sequence to this value after lock
 *
 * This is called after ttm_bo_reserve returns -EAGAIN and we backed off
 * from all our other reservations. Because there are no other reservations
 * held by us, this function cannot deadlock any more.
 */
static inline int ttm_bo_reserve_slowpath(struct ttm_buffer_object *bo,
					  bool interruptible,
					  struct ww_acquire_ctx *ticket)
{
	int ret = 0;

	WARN_ON(!atomic_read(&bo->kref.refcount));

	if (interruptible)
		ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock,
						       ticket);
	else
		ww_mutex_lock_slow(&bo->resv->lock, ticket);

	if (likely(ret == 0))
		ttm_bo_del_sub_from_lru(bo);
	else if (ret == -EINTR)
		ret = -ERESTARTSYS;

	return ret;
}

/**
 * __ttm_bo_unreserve
 * @bo: A pointer to a struct ttm_buffer_object.
 *
 * Unreserve a previous reservation of @bo where the buffer object is
 * already on lru lists.
 */
static inline void __ttm_bo_unreserve(struct ttm_buffer_object *bo)
{
	ww_mutex_unlock(&bo->resv->lock);
}

/**
 * ttm_bo_unreserve
 *
 * @bo: A pointer to a struct ttm_buffer_object.
 *
 * Unreserve a previous reservation of @bo.
 */
static inline void ttm_bo_unreserve(struct ttm_buffer_object *bo)
{
	if (!(bo->mem.placement & TTM_PL_FLAG_NO_EVICT)) {
		spin_lock(&bo->glob->lru_lock);
		ttm_bo_add_to_lru(bo);
		spin_unlock(&bo->glob->lru_lock);
	}
	__ttm_bo_unreserve(bo);
}

/**
 * ttm_bo_unreserve_ticket
 * @bo: A pointer to a struct ttm_buffer_object.
 * @ticket: ww_acquire_ctx used for reserving
 *
 * Unreserve a previous reservation of @bo made with @ticket.
 */
static inline void ttm_bo_unreserve_ticket(struct ttm_buffer_object *bo,
					   struct ww_acquire_ctx *t)
{
	ttm_bo_unreserve(bo);
}

/*
 * ttm_bo_util.c
 */

int ttm_mem_io_reserve(struct ttm_bo_device *bdev,
		       struct ttm_mem_reg *mem);
void ttm_mem_io_free(struct ttm_bo_device *bdev,
		     struct ttm_mem_reg *mem);
/**
 * ttm_bo_move_ttm
 *
 * @bo: A pointer to a struct ttm_buffer_object.
 * @evict: 1: This is an eviction. Don't try to pipeline.
 * @no_wait_gpu: Return immediately if the GPU is busy.
 * @new_mem: struct ttm_mem_reg indicating where to move.
 *
 * Optimized move function for a buffer object with both old and
 * new placement backed by a TTM. The function will, if successful,
 * free any old aperture space, and set (@new_mem)->mm_node to NULL,
 * and update the (@bo)->mem placement flags. If unsuccessful, the old
 * data remains untouched, and it's up to the caller to free the
 * memory space indicated by @new_mem.
 * Returns:
 * !0: Failure.
 */

extern int ttm_bo_move_ttm(struct ttm_buffer_object *bo,
			   bool evict, bool no_wait_gpu,
			   struct ttm_mem_reg *new_mem);

/**
 * ttm_bo_move_memcpy
 *
 * @bo: A pointer to a struct ttm_buffer_object.
 * @evict: 1: This is an eviction. Don't try to pipeline.
 * @interruptible: Sleep interruptible if waiting.
 * @no_wait_gpu: Return immediately if the GPU is busy.
 * @new_mem: struct ttm_mem_reg indicating where to move.
 *
 * Fallback move function for a mappable buffer object in mappable memory.
 * The function will, if successful,
 * free any old aperture space, and set (@new_mem)->mm_node to NULL,
 * and update the (@bo)->mem placement flags. If unsuccessful, the old
 * data remains untouched, and it's up to the caller to free the
 * memory space indicated by @new_mem.
 * Returns:
 * !0: Failure.
 */

extern int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
			      bool evict, bool interruptible,
			      bool no_wait_gpu,
			      struct ttm_mem_reg *new_mem);

/**
 * ttm_bo_free_old_node
 *
 * @bo: A pointer to a struct ttm_buffer_object.
 *
 * Utility function to free an old placement after a successful move.
 */
extern void ttm_bo_free_old_node(struct ttm_buffer_object *bo);

/**
 * ttm_bo_move_accel_cleanup.
 *
 * @bo: A pointer to a struct ttm_buffer_object.
 * @fence: A fence object that signals when moving is complete.
 * @evict: This is an evict move. Don't return until the buffer is idle.
 * @new_mem: struct ttm_mem_reg indicating where to move.
 *
 * Accelerated move function to be called when an accelerated move
 * has been scheduled. The function will create a new temporary buffer object
 * representing the old placement, and put the sync object on both buffer
 * objects. After that the newly created buffer object is unref'd to be
 * destroyed when the move is complete. This will help pipeline
 * buffer moves.
 */

extern int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
				     struct fence *fence, bool evict,
				     struct ttm_mem_reg *new_mem);

/**
 * ttm_bo_pipeline_move.
 *
 * @bo: A pointer to a struct ttm_buffer_object.
 * @fence: A fence object that signals when moving is complete.
 * @evict: This is an evict move. Don't return until the buffer is idle.
 * @new_mem: struct ttm_mem_reg indicating where to move.
 *
 * Function for pipelining accelerated moves. Either free the memory
 * immediately or hang it on a temporary buffer object.
 */
int ttm_bo_pipeline_move(struct ttm_buffer_object *bo,
			 struct fence *fence, bool evict,
			 struct ttm_mem_reg *new_mem);

/**
 * ttm_io_prot
 *
 * @c_state: Caching state.
 * @tmp: Page protection flag for a normal, cached mapping.
 *
 * Utility function that returns the pgprot_t that should be used for
 * setting up a PTE with the caching model indicated by @c_state.
 */
extern pgprot_t ttm_io_prot(uint32_t caching_flags, pgprot_t tmp);

extern const struct ttm_mem_type_manager_func ttm_bo_manager_func;

#if IS_ENABLED(CONFIG_AGP)
#include <linux/agp_backend.h>

/**
 * ttm_agp_tt_create
 *
 * @bdev: Pointer to a struct ttm_bo_device.
 * @bridge: The agp bridge this device is sitting on.
 * @size: Size of the data needed backing.
 * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags.
 * @dummy_read_page: See struct ttm_bo_device.
 *
 *
 * Create a TTM backend that uses the indicated AGP bridge as an aperture
 * for TT memory. This function uses the linux agpgart interface to
 * bind and unbind memory backing a ttm_tt.
 */
extern struct ttm_tt *ttm_agp_tt_create(struct ttm_bo_device *bdev,
					struct agp_bridge_data *bridge,
					unsigned long size, uint32_t page_flags,
					struct page *dummy_read_page);
int ttm_agp_tt_populate(struct ttm_tt *ttm);
void ttm_agp_tt_unpopulate(struct ttm_tt *ttm);
#endif

#endif