summaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/drm_property.c
blob: f8ec8f9c3e7a5fb02bf26d8440bc068b7df835ac (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
/*
 * Copyright (c) 2016 Intel Corporation
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting documentation, and
 * that the name of the copyright holders not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  The copyright holders make no representations
 * about the suitability of this software for any purpose.  It is provided "as
 * is" without express or implied warranty.
 *
 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THIS SOFTWARE.
 */

#include <linux/export.h>
#include <drm/drmP.h>
#include <drm/drm_property.h>

#include "drm_crtc_internal.h"

/**
 * DOC: overview
 *
 * Properties as represented by &drm_property are used to extend the modeset
 * interface exposed to userspace. For the atomic modeset IOCTL properties are
 * even the only way to transport metadata about the desired new modeset
 * configuration from userspace to the kernel. Properties have a well-defined
 * value range, which is enforced by the drm core. See the documentation of the
 * flags member of &struct drm_property for an overview of the different
 * property types and ranges.
 *
 * Properties don't store the current value directly, but need to be
 * instatiated by attaching them to a &drm_mode_object with
 * drm_object_attach_property().
 *
 * Property values are only 64bit. To support bigger piles of data (like gamma
 * tables, color correction matrices or large structures) a property can instead
 * point at a &drm_property_blob with that additional data.
 *
 * Properties are defined by their symbolic name, userspace must keep a
 * per-object mapping from those names to the property ID used in the atomic
 * IOCTL and in the get/set property IOCTL.
 */

static bool drm_property_flags_valid(u32 flags)
{
	u32 legacy_type = flags & DRM_MODE_PROP_LEGACY_TYPE;
	u32 ext_type = flags & DRM_MODE_PROP_EXTENDED_TYPE;

	/* Reject undefined/deprecated flags */
	if (flags & ~(DRM_MODE_PROP_LEGACY_TYPE |
		      DRM_MODE_PROP_EXTENDED_TYPE |
		      DRM_MODE_PROP_IMMUTABLE |
		      DRM_MODE_PROP_ATOMIC))
		return false;

	/* We want either a legacy type or an extended type, but not both */
	if (!legacy_type == !ext_type)
		return false;

	/* Only one legacy type at a time please */
	if (legacy_type && !is_power_of_2(legacy_type))
		return false;

	return true;
}

/**
 * drm_property_create - create a new property type
 * @dev: drm device
 * @flags: flags specifying the property type
 * @name: name of the property
 * @num_values: number of pre-defined values
 *
 * This creates a new generic drm property which can then be attached to a drm
 * object with drm_object_attach_property(). The returned property object must
 * be freed with drm_property_destroy(), which is done automatically when
 * calling drm_mode_config_cleanup().
 *
 * Returns:
 * A pointer to the newly created property on success, NULL on failure.
 */
struct drm_property *drm_property_create(struct drm_device *dev,
					 u32 flags, const char *name,
					 int num_values)
{
	struct drm_property *property = NULL;
	int ret;

	if (WARN_ON(!drm_property_flags_valid(flags)))
		return NULL;

	if (WARN_ON(strlen(name) >= DRM_PROP_NAME_LEN))
		return NULL;

	property = kzalloc(sizeof(struct drm_property), GFP_KERNEL);
	if (!property)
		return NULL;

	property->dev = dev;

	if (num_values) {
		property->values = kcalloc(num_values, sizeof(uint64_t),
					   GFP_KERNEL);
		if (!property->values)
			goto fail;
	}

	ret = drm_mode_object_add(dev, &property->base, DRM_MODE_OBJECT_PROPERTY);
	if (ret)
		goto fail;

	property->flags = flags;
	property->num_values = num_values;
	INIT_LIST_HEAD(&property->enum_list);

	strncpy(property->name, name, DRM_PROP_NAME_LEN);
	property->name[DRM_PROP_NAME_LEN-1] = '\0';

	list_add_tail(&property->head, &dev->mode_config.property_list);

	return property;
fail:
	kfree(property->values);
	kfree(property);
	return NULL;
}
EXPORT_SYMBOL(drm_property_create);

/**
 * drm_property_create_enum - create a new enumeration property type
 * @dev: drm device
 * @flags: flags specifying the property type
 * @name: name of the property
 * @props: enumeration lists with property values
 * @num_values: number of pre-defined values
 *
 * This creates a new generic drm property which can then be attached to a drm
 * object with drm_object_attach_property(). The returned property object must
 * be freed with drm_property_destroy(), which is done automatically when
 * calling drm_mode_config_cleanup().
 *
 * Userspace is only allowed to set one of the predefined values for enumeration
 * properties.
 *
 * Returns:
 * A pointer to the newly created property on success, NULL on failure.
 */
struct drm_property *drm_property_create_enum(struct drm_device *dev,
					      u32 flags, const char *name,
					      const struct drm_prop_enum_list *props,
					      int num_values)
{
	struct drm_property *property;
	int i, ret;

	flags |= DRM_MODE_PROP_ENUM;

	property = drm_property_create(dev, flags, name, num_values);
	if (!property)
		return NULL;

	for (i = 0; i < num_values; i++) {
		ret = drm_property_add_enum(property,
					    props[i].type,
					    props[i].name);
		if (ret) {
			drm_property_destroy(dev, property);
			return NULL;
		}
	}

	return property;
}
EXPORT_SYMBOL(drm_property_create_enum);

/**
 * drm_property_create_bitmask - create a new bitmask property type
 * @dev: drm device
 * @flags: flags specifying the property type
 * @name: name of the property
 * @props: enumeration lists with property bitflags
 * @num_props: size of the @props array
 * @supported_bits: bitmask of all supported enumeration values
 *
 * This creates a new bitmask drm property which can then be attached to a drm
 * object with drm_object_attach_property(). The returned property object must
 * be freed with drm_property_destroy(), which is done automatically when
 * calling drm_mode_config_cleanup().
 *
 * Compared to plain enumeration properties userspace is allowed to set any
 * or'ed together combination of the predefined property bitflag values
 *
 * Returns:
 * A pointer to the newly created property on success, NULL on failure.
 */
struct drm_property *drm_property_create_bitmask(struct drm_device *dev,
						 u32 flags, const char *name,
						 const struct drm_prop_enum_list *props,
						 int num_props,
						 uint64_t supported_bits)
{
	struct drm_property *property;
	int i, ret;
	int num_values = hweight64(supported_bits);

	flags |= DRM_MODE_PROP_BITMASK;

	property = drm_property_create(dev, flags, name, num_values);
	if (!property)
		return NULL;
	for (i = 0; i < num_props; i++) {
		if (!(supported_bits & (1ULL << props[i].type)))
			continue;

		ret = drm_property_add_enum(property,
					    props[i].type,
					    props[i].name);
		if (ret) {
			drm_property_destroy(dev, property);
			return NULL;
		}
	}

	return property;
}
EXPORT_SYMBOL(drm_property_create_bitmask);

static struct drm_property *property_create_range(struct drm_device *dev,
						  u32 flags, const char *name,
						  uint64_t min, uint64_t max)
{
	struct drm_property *property;

	property = drm_property_create(dev, flags, name, 2);
	if (!property)
		return NULL;

	property->values[0] = min;
	property->values[1] = max;

	return property;
}

/**
 * drm_property_create_range - create a new unsigned ranged property type
 * @dev: drm device
 * @flags: flags specifying the property type
 * @name: name of the property
 * @min: minimum value of the property
 * @max: maximum value of the property
 *
 * This creates a new generic drm property which can then be attached to a drm
 * object with drm_object_attach_property(). The returned property object must
 * be freed with drm_property_destroy(), which is done automatically when
 * calling drm_mode_config_cleanup().
 *
 * Userspace is allowed to set any unsigned integer value in the (min, max)
 * range inclusive.
 *
 * Returns:
 * A pointer to the newly created property on success, NULL on failure.
 */
struct drm_property *drm_property_create_range(struct drm_device *dev,
					       u32 flags, const char *name,
					       uint64_t min, uint64_t max)
{
	return property_create_range(dev, DRM_MODE_PROP_RANGE | flags,
			name, min, max);
}
EXPORT_SYMBOL(drm_property_create_range);

/**
 * drm_property_create_signed_range - create a new signed ranged property type
 * @dev: drm device
 * @flags: flags specifying the property type
 * @name: name of the property
 * @min: minimum value of the property
 * @max: maximum value of the property
 *
 * This creates a new generic drm property which can then be attached to a drm
 * object with drm_object_attach_property(). The returned property object must
 * be freed with drm_property_destroy(), which is done automatically when
 * calling drm_mode_config_cleanup().
 *
 * Userspace is allowed to set any signed integer value in the (min, max)
 * range inclusive.
 *
 * Returns:
 * A pointer to the newly created property on success, NULL on failure.
 */
struct drm_property *drm_property_create_signed_range(struct drm_device *dev,
						      u32 flags, const char *name,
						      int64_t min, int64_t max)
{
	return property_create_range(dev, DRM_MODE_PROP_SIGNED_RANGE | flags,
			name, I642U64(min), I642U64(max));
}
EXPORT_SYMBOL(drm_property_create_signed_range);

/**
 * drm_property_create_object - create a new object property type
 * @dev: drm device
 * @flags: flags specifying the property type
 * @name: name of the property
 * @type: object type from DRM_MODE_OBJECT_* defines
 *
 * This creates a new generic drm property which can then be attached to a drm
 * object with drm_object_attach_property(). The returned property object must
 * be freed with drm_property_destroy(), which is done automatically when
 * calling drm_mode_config_cleanup().
 *
 * Userspace is only allowed to set this to any property value of the given
 * @type. Only useful for atomic properties, which is enforced.
 *
 * Returns:
 * A pointer to the newly created property on success, NULL on failure.
 */
struct drm_property *drm_property_create_object(struct drm_device *dev,
						u32 flags, const char *name,
						uint32_t type)
{
	struct drm_property *property;

	flags |= DRM_MODE_PROP_OBJECT;

	if (WARN_ON(!(flags & DRM_MODE_PROP_ATOMIC)))
		return NULL;

	property = drm_property_create(dev, flags, name, 1);
	if (!property)
		return NULL;

	property->values[0] = type;

	return property;
}
EXPORT_SYMBOL(drm_property_create_object);

/**
 * drm_property_create_bool - create a new boolean property type
 * @dev: drm device
 * @flags: flags specifying the property type
 * @name: name of the property
 *
 * This creates a new generic drm property which can then be attached to a drm
 * object with drm_object_attach_property(). The returned property object must
 * be freed with drm_property_destroy(), which is done automatically when
 * calling drm_mode_config_cleanup().
 *
 * This is implemented as a ranged property with only {0, 1} as valid values.
 *
 * Returns:
 * A pointer to the newly created property on success, NULL on failure.
 */
struct drm_property *drm_property_create_bool(struct drm_device *dev,
					      u32 flags, const char *name)
{
	return drm_property_create_range(dev, flags, name, 0, 1);
}
EXPORT_SYMBOL(drm_property_create_bool);

/**
 * drm_property_add_enum - add a possible value to an enumeration property
 * @property: enumeration property to change
 * @value: value of the new enumeration
 * @name: symbolic name of the new enumeration
 *
 * This functions adds enumerations to a property.
 *
 * It's use is deprecated, drivers should use one of the more specific helpers
 * to directly create the property with all enumerations already attached.
 *
 * Returns:
 * Zero on success, error code on failure.
 */
int drm_property_add_enum(struct drm_property *property,
			  uint64_t value, const char *name)
{
	struct drm_property_enum *prop_enum;
	int index = 0;

	if (WARN_ON(strlen(name) >= DRM_PROP_NAME_LEN))
		return -EINVAL;

	if (WARN_ON(!drm_property_type_is(property, DRM_MODE_PROP_ENUM) &&
		    !drm_property_type_is(property, DRM_MODE_PROP_BITMASK)))
		return -EINVAL;

	/*
	 * Bitmask enum properties have the additional constraint of values
	 * from 0 to 63
	 */
	if (WARN_ON(drm_property_type_is(property, DRM_MODE_PROP_BITMASK) &&
		    value > 63))
		return -EINVAL;

	list_for_each_entry(prop_enum, &property->enum_list, head) {
		if (WARN_ON(prop_enum->value == value))
			return -EINVAL;
		index++;
	}

	if (WARN_ON(index >= property->num_values))
		return -EINVAL;

	prop_enum = kzalloc(sizeof(struct drm_property_enum), GFP_KERNEL);
	if (!prop_enum)
		return -ENOMEM;

	strncpy(prop_enum->name, name, DRM_PROP_NAME_LEN);
	prop_enum->name[DRM_PROP_NAME_LEN-1] = '\0';
	prop_enum->value = value;

	property->values[index] = value;
	list_add_tail(&prop_enum->head, &property->enum_list);
	return 0;
}
EXPORT_SYMBOL(drm_property_add_enum);

/**
 * drm_property_destroy - destroy a drm property
 * @dev: drm device
 * @property: property to destry
 *
 * This function frees a property including any attached resources like
 * enumeration values.
 */
void drm_property_destroy(struct drm_device *dev, struct drm_property *property)
{
	struct drm_property_enum *prop_enum, *pt;

	list_for_each_entry_safe(prop_enum, pt, &property->enum_list, head) {
		list_del(&prop_enum->head);
		kfree(prop_enum);
	}

	if (property->num_values)
		kfree(property->values);
	drm_mode_object_unregister(dev, &property->base);
	list_del(&property->head);
	kfree(property);
}
EXPORT_SYMBOL(drm_property_destroy);

int drm_mode_getproperty_ioctl(struct drm_device *dev,
			       void *data, struct drm_file *file_priv)
{
	struct drm_mode_get_property *out_resp = data;
	struct drm_property *property;
	int enum_count = 0;
	int value_count = 0;
	int i, copied;
	struct drm_property_enum *prop_enum;
	struct drm_mode_property_enum __user *enum_ptr;
	uint64_t __user *values_ptr;

	if (!drm_core_check_feature(dev, DRIVER_MODESET))
		return -EOPNOTSUPP;

	property = drm_property_find(dev, file_priv, out_resp->prop_id);
	if (!property)
		return -ENOENT;

	strncpy(out_resp->name, property->name, DRM_PROP_NAME_LEN);
	out_resp->name[DRM_PROP_NAME_LEN-1] = 0;
	out_resp->flags = property->flags;

	value_count = property->num_values;
	values_ptr = u64_to_user_ptr(out_resp->values_ptr);

	for (i = 0; i < value_count; i++) {
		if (i < out_resp->count_values &&
		    put_user(property->values[i], values_ptr + i)) {
			return -EFAULT;
		}
	}
	out_resp->count_values = value_count;

	copied = 0;
	enum_ptr = u64_to_user_ptr(out_resp->enum_blob_ptr);

	if (drm_property_type_is(property, DRM_MODE_PROP_ENUM) ||
	    drm_property_type_is(property, DRM_MODE_PROP_BITMASK)) {
		list_for_each_entry(prop_enum, &property->enum_list, head) {
			enum_count++;
			if (out_resp->count_enum_blobs < enum_count)
				continue;

			if (copy_to_user(&enum_ptr[copied].value,
					 &prop_enum->value, sizeof(uint64_t)))
				return -EFAULT;

			if (copy_to_user(&enum_ptr[copied].name,
					 &prop_enum->name, DRM_PROP_NAME_LEN))
				return -EFAULT;
			copied++;
		}
		out_resp->count_enum_blobs = enum_count;
	}

	/*
	 * NOTE: The idea seems to have been to use this to read all the blob
	 * property values. But nothing ever added them to the corresponding
	 * list, userspace always used the special-purpose get_blob ioctl to
	 * read the value for a blob property. It also doesn't make a lot of
	 * sense to return values here when everything else is just metadata for
	 * the property itself.
	 */
	if (drm_property_type_is(property, DRM_MODE_PROP_BLOB))
		out_resp->count_enum_blobs = 0;

	return 0;
}

static void drm_property_free_blob(struct kref *kref)
{
	struct drm_property_blob *blob =
		container_of(kref, struct drm_property_blob, base.refcount);

	mutex_lock(&blob->dev->mode_config.blob_lock);
	list_del(&blob->head_global);
	mutex_unlock(&blob->dev->mode_config.blob_lock);

	drm_mode_object_unregister(blob->dev, &blob->base);

	kvfree(blob);
}

/**
 * drm_property_create_blob - Create new blob property
 * @dev: DRM device to create property for
 * @length: Length to allocate for blob data
 * @data: If specified, copies data into blob
 *
 * Creates a new blob property for a specified DRM device, optionally
 * copying data. Note that blob properties are meant to be invariant, hence the
 * data must be filled out before the blob is used as the value of any property.
 *
 * Returns:
 * New blob property with a single reference on success, or an ERR_PTR
 * value on failure.
 */
struct drm_property_blob *
drm_property_create_blob(struct drm_device *dev, size_t length,
			 const void *data)
{
	struct drm_property_blob *blob;
	int ret;

	if (!length || length > ULONG_MAX - sizeof(struct drm_property_blob))
		return ERR_PTR(-EINVAL);

	blob = kvzalloc(sizeof(struct drm_property_blob)+length, GFP_KERNEL);
	if (!blob)
		return ERR_PTR(-ENOMEM);

	/* This must be explicitly initialised, so we can safely call list_del
	 * on it in the removal handler, even if it isn't in a file list. */
	INIT_LIST_HEAD(&blob->head_file);
	blob->data = (void *)blob + sizeof(*blob);
	blob->length = length;
	blob->dev = dev;

	if (data)
		memcpy(blob->data, data, length);

	ret = __drm_mode_object_add(dev, &blob->base, DRM_MODE_OBJECT_BLOB,
				    true, drm_property_free_blob);
	if (ret) {
		kvfree(blob);
		return ERR_PTR(-EINVAL);
	}

	mutex_lock(&dev->mode_config.blob_lock);
	list_add_tail(&blob->head_global,
	              &dev->mode_config.property_blob_list);
	mutex_unlock(&dev->mode_config.blob_lock);

	return blob;
}
EXPORT_SYMBOL(drm_property_create_blob);

/**
 * drm_property_blob_put - release a blob property reference
 * @blob: DRM blob property
 *
 * Releases a reference to a blob property. May free the object.
 */
void drm_property_blob_put(struct drm_property_blob *blob)
{
	if (!blob)
		return;

	drm_mode_object_put(&blob->base);
}
EXPORT_SYMBOL(drm_property_blob_put);

void drm_property_destroy_user_blobs(struct drm_device *dev,
				     struct drm_file *file_priv)
{
	struct drm_property_blob *blob, *bt;

	/*
	 * When the file gets released that means no one else can access the
	 * blob list any more, so no need to grab dev->blob_lock.
	 */
	list_for_each_entry_safe(blob, bt, &file_priv->blobs, head_file) {
		list_del_init(&blob->head_file);
		drm_property_blob_put(blob);
	}
}

/**
 * drm_property_blob_get - acquire blob property reference
 * @blob: DRM blob property
 *
 * Acquires a reference to an existing blob property. Returns @blob, which
 * allows this to be used as a shorthand in assignments.
 */
struct drm_property_blob *drm_property_blob_get(struct drm_property_blob *blob)
{
	drm_mode_object_get(&blob->base);
	return blob;
}
EXPORT_SYMBOL(drm_property_blob_get);

/**
 * drm_property_lookup_blob - look up a blob property and take a reference
 * @dev: drm device
 * @id: id of the blob property
 *
 * If successful, this takes an additional reference to the blob property.
 * callers need to make sure to eventually unreference the returned property
 * again, using drm_property_blob_put().
 *
 * Return:
 * NULL on failure, pointer to the blob on success.
 */
struct drm_property_blob *drm_property_lookup_blob(struct drm_device *dev,
					           uint32_t id)
{
	struct drm_mode_object *obj;
	struct drm_property_blob *blob = NULL;

	obj = __drm_mode_object_find(dev, NULL, id, DRM_MODE_OBJECT_BLOB);
	if (obj)
		blob = obj_to_blob(obj);
	return blob;
}
EXPORT_SYMBOL(drm_property_lookup_blob);

/**
 * drm_property_replace_global_blob - replace existing blob property
 * @dev: drm device
 * @replace: location of blob property pointer to be replaced
 * @length: length of data for new blob, or 0 for no data
 * @data: content for new blob, or NULL for no data
 * @obj_holds_id: optional object for property holding blob ID
 * @prop_holds_id: optional property holding blob ID
 * @return 0 on success or error on failure
 *
 * This function will replace a global property in the blob list, optionally
 * updating a property which holds the ID of that property.
 *
 * If length is 0 or data is NULL, no new blob will be created, and the holding
 * property, if specified, will be set to 0.
 *
 * Access to the replace pointer is assumed to be protected by the caller, e.g.
 * by holding the relevant modesetting object lock for its parent.
 *
 * For example, a drm_connector has a 'PATH' property, which contains the ID
 * of a blob property with the value of the MST path information. Calling this
 * function with replace pointing to the connector's path_blob_ptr, length and
 * data set for the new path information, obj_holds_id set to the connector's
 * base object, and prop_holds_id set to the path property name, will perform
 * a completely atomic update. The access to path_blob_ptr is protected by the
 * caller holding a lock on the connector.
 */
int drm_property_replace_global_blob(struct drm_device *dev,
				     struct drm_property_blob **replace,
				     size_t length,
				     const void *data,
				     struct drm_mode_object *obj_holds_id,
				     struct drm_property *prop_holds_id)
{
	struct drm_property_blob *new_blob = NULL;
	struct drm_property_blob *old_blob = NULL;
	int ret;

	WARN_ON(replace == NULL);

	old_blob = *replace;

	if (length && data) {
		new_blob = drm_property_create_blob(dev, length, data);
		if (IS_ERR(new_blob))
			return PTR_ERR(new_blob);
	}

	if (obj_holds_id) {
		ret = drm_object_property_set_value(obj_holds_id,
						    prop_holds_id,
						    new_blob ?
						        new_blob->base.id : 0);
		if (ret != 0)
			goto err_created;
	}

	drm_property_blob_put(old_blob);
	*replace = new_blob;

	return 0;

err_created:
	drm_property_blob_put(new_blob);
	return ret;
}
EXPORT_SYMBOL(drm_property_replace_global_blob);

/**
 * drm_property_replace_blob - replace a blob property
 * @blob: a pointer to the member blob to be replaced
 * @new_blob: the new blob to replace with
 *
 * Return: true if the blob was in fact replaced.
 */
bool drm_property_replace_blob(struct drm_property_blob **blob,
			       struct drm_property_blob *new_blob)
{
	struct drm_property_blob *old_blob = *blob;

	if (old_blob == new_blob)
		return false;

	drm_property_blob_put(old_blob);
	if (new_blob)
		drm_property_blob_get(new_blob);
	*blob = new_blob;
	return true;
}
EXPORT_SYMBOL(drm_property_replace_blob);

int drm_mode_getblob_ioctl(struct drm_device *dev,
			   void *data, struct drm_file *file_priv)
{
	struct drm_mode_get_blob *out_resp = data;
	struct drm_property_blob *blob;
	int ret = 0;

	if (!drm_core_check_feature(dev, DRIVER_MODESET))
		return -EOPNOTSUPP;

	blob = drm_property_lookup_blob(dev, out_resp->blob_id);
	if (!blob)
		return -ENOENT;

	if (out_resp->length == blob->length) {
		if (copy_to_user(u64_to_user_ptr(out_resp->data),
				 blob->data,
				 blob->length)) {
			ret = -EFAULT;
			goto unref;
		}
	}
	out_resp->length = blob->length;
unref:
	drm_property_blob_put(blob);

	return ret;
}

int drm_mode_createblob_ioctl(struct drm_device *dev,
			      void *data, struct drm_file *file_priv)
{
	struct drm_mode_create_blob *out_resp = data;
	struct drm_property_blob *blob;
	int ret = 0;

	if (!drm_core_check_feature(dev, DRIVER_MODESET))
		return -EOPNOTSUPP;

	blob = drm_property_create_blob(dev, out_resp->length, NULL);
	if (IS_ERR(blob))
		return PTR_ERR(blob);

	if (copy_from_user(blob->data,
			   u64_to_user_ptr(out_resp->data),
			   out_resp->length)) {
		ret = -EFAULT;
		goto out_blob;
	}

	/* Dropping the lock between create_blob and our access here is safe
	 * as only the same file_priv can remove the blob; at this point, it is
	 * not associated with any file_priv. */
	mutex_lock(&dev->mode_config.blob_lock);
	out_resp->blob_id = blob->base.id;
	list_add_tail(&blob->head_file, &file_priv->blobs);
	mutex_unlock(&dev->mode_config.blob_lock);

	return 0;

out_blob:
	drm_property_blob_put(blob);
	return ret;
}

int drm_mode_destroyblob_ioctl(struct drm_device *dev,
			       void *data, struct drm_file *file_priv)
{
	struct drm_mode_destroy_blob *out_resp = data;
	struct drm_property_blob *blob = NULL, *bt;
	bool found = false;
	int ret = 0;

	if (!drm_core_check_feature(dev, DRIVER_MODESET))
		return -EOPNOTSUPP;

	blob = drm_property_lookup_blob(dev, out_resp->blob_id);
	if (!blob)
		return -ENOENT;

	mutex_lock(&dev->mode_config.blob_lock);
	/* Ensure the property was actually created by this user. */
	list_for_each_entry(bt, &file_priv->blobs, head_file) {
		if (bt == blob) {
			found = true;
			break;
		}
	}

	if (!found) {
		ret = -EPERM;
		goto err;
	}

	/* We must drop head_file here, because we may not be the last
	 * reference on the blob. */
	list_del_init(&blob->head_file);
	mutex_unlock(&dev->mode_config.blob_lock);

	/* One reference from lookup, and one from the filp. */
	drm_property_blob_put(blob);
	drm_property_blob_put(blob);

	return 0;

err:
	mutex_unlock(&dev->mode_config.blob_lock);
	drm_property_blob_put(blob);

	return ret;
}

/* Some properties could refer to dynamic refcnt'd objects, or things that
 * need special locking to handle lifetime issues (ie. to ensure the prop
 * value doesn't become invalid part way through the property update due to
 * race).  The value returned by reference via 'obj' should be passed back
 * to drm_property_change_valid_put() after the property is set (and the
 * object to which the property is attached has a chance to take its own
 * reference).
 */
bool drm_property_change_valid_get(struct drm_property *property,
				   uint64_t value, struct drm_mode_object **ref)
{
	int i;

	if (property->flags & DRM_MODE_PROP_IMMUTABLE)
		return false;

	*ref = NULL;

	if (drm_property_type_is(property, DRM_MODE_PROP_RANGE)) {
		if (value < property->values[0] || value > property->values[1])
			return false;
		return true;
	} else if (drm_property_type_is(property, DRM_MODE_PROP_SIGNED_RANGE)) {
		int64_t svalue = U642I64(value);

		if (svalue < U642I64(property->values[0]) ||
				svalue > U642I64(property->values[1]))
			return false;
		return true;
	} else if (drm_property_type_is(property, DRM_MODE_PROP_BITMASK)) {
		uint64_t valid_mask = 0;

		for (i = 0; i < property->num_values; i++)
			valid_mask |= (1ULL << property->values[i]);
		return !(value & ~valid_mask);
	} else if (drm_property_type_is(property, DRM_MODE_PROP_BLOB)) {
		struct drm_property_blob *blob;

		if (value == 0)
			return true;

		blob = drm_property_lookup_blob(property->dev, value);
		if (blob) {
			*ref = &blob->base;
			return true;
		} else {
			return false;
		}
	} else if (drm_property_type_is(property, DRM_MODE_PROP_OBJECT)) {
		/* a zero value for an object property translates to null: */
		if (value == 0)
			return true;

		*ref = __drm_mode_object_find(property->dev, NULL, value,
					      property->values[0]);
		return *ref != NULL;
	}

	for (i = 0; i < property->num_values; i++)
		if (property->values[i] == value)
			return true;
	return false;
}

void drm_property_change_valid_put(struct drm_property *property,
		struct drm_mode_object *ref)
{
	if (!ref)
		return;

	if (drm_property_type_is(property, DRM_MODE_PROP_OBJECT)) {
		drm_mode_object_put(ref);
	} else if (drm_property_type_is(property, DRM_MODE_PROP_BLOB))
		drm_property_blob_put(obj_to_blob(ref));
}