summaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
blob: 0be5e86833371b16d6a532d83f1a3eb0e37c03f8 (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
/*
 * SPDX-License-Identifier: MIT
 *
 * Copyright © 2008-2012 Intel Corporation
 */

#include <linux/errno.h>
#include <linux/mutex.h>

#include <drm/drm_mm.h>
#include <drm/i915_drm.h>

#include "gem/i915_gem_region.h"
#include "i915_drv.h"
#include "i915_gem_stolen.h"
#include "i915_vgpu.h"

/*
 * The BIOS typically reserves some of the system's memory for the exclusive
 * use of the integrated graphics. This memory is no longer available for
 * use by the OS and so the user finds that his system has less memory
 * available than he put in. We refer to this memory as stolen.
 *
 * The BIOS will allocate its framebuffer from the stolen memory. Our
 * goal is try to reuse that object for our own fbcon which must always
 * be available for panics. Anything else we can reuse the stolen memory
 * for is a boon.
 */

int i915_gem_stolen_insert_node_in_range(struct drm_i915_private *i915,
					 struct drm_mm_node *node, u64 size,
					 unsigned alignment, u64 start, u64 end)
{
	int ret;

	if (!drm_mm_initialized(&i915->mm.stolen))
		return -ENODEV;

	/* WaSkipStolenMemoryFirstPage:bdw+ */
	if (INTEL_GEN(i915) >= 8 && start < 4096)
		start = 4096;

	mutex_lock(&i915->mm.stolen_lock);
	ret = drm_mm_insert_node_in_range(&i915->mm.stolen, node,
					  size, alignment, 0,
					  start, end, DRM_MM_INSERT_BEST);
	mutex_unlock(&i915->mm.stolen_lock);

	return ret;
}

int i915_gem_stolen_insert_node(struct drm_i915_private *i915,
				struct drm_mm_node *node, u64 size,
				unsigned alignment)
{
	return i915_gem_stolen_insert_node_in_range(i915, node, size,
						    alignment, 0, U64_MAX);
}

void i915_gem_stolen_remove_node(struct drm_i915_private *i915,
				 struct drm_mm_node *node)
{
	mutex_lock(&i915->mm.stolen_lock);
	drm_mm_remove_node(node);
	mutex_unlock(&i915->mm.stolen_lock);
}

static int i915_adjust_stolen(struct drm_i915_private *i915,
			      struct resource *dsm)
{
	struct i915_ggtt *ggtt = &i915->ggtt;
	struct intel_uncore *uncore = ggtt->vm.gt->uncore;
	struct resource *r;

	if (dsm->start == 0 || dsm->end <= dsm->start)
		return -EINVAL;

	/*
	 * TODO: We have yet too encounter the case where the GTT wasn't at the
	 * end of stolen. With that assumption we could simplify this.
	 */

	/* Make sure we don't clobber the GTT if it's within stolen memory */
	if (INTEL_GEN(i915) <= 4 &&
	    !IS_G33(i915) && !IS_PINEVIEW(i915) && !IS_G4X(i915)) {
		struct resource stolen[2] = {*dsm, *dsm};
		struct resource ggtt_res;
		resource_size_t ggtt_start;

		ggtt_start = intel_uncore_read(uncore, PGTBL_CTL);
		if (IS_GEN(i915, 4))
			ggtt_start = (ggtt_start & PGTBL_ADDRESS_LO_MASK) |
				     (ggtt_start & PGTBL_ADDRESS_HI_MASK) << 28;
		else
			ggtt_start &= PGTBL_ADDRESS_LO_MASK;

		ggtt_res =
			(struct resource) DEFINE_RES_MEM(ggtt_start,
							 ggtt_total_entries(ggtt) * 4);

		if (ggtt_res.start >= stolen[0].start && ggtt_res.start < stolen[0].end)
			stolen[0].end = ggtt_res.start;
		if (ggtt_res.end > stolen[1].start && ggtt_res.end <= stolen[1].end)
			stolen[1].start = ggtt_res.end;

		/* Pick the larger of the two chunks */
		if (resource_size(&stolen[0]) > resource_size(&stolen[1]))
			*dsm = stolen[0];
		else
			*dsm = stolen[1];

		if (stolen[0].start != stolen[1].start ||
		    stolen[0].end != stolen[1].end) {
			drm_dbg(&i915->drm,
				"GTT within stolen memory at %pR\n",
				&ggtt_res);
			drm_dbg(&i915->drm, "Stolen memory adjusted to %pR\n",
				dsm);
		}
	}

	/*
	 * Verify that nothing else uses this physical address. Stolen
	 * memory should be reserved by the BIOS and hidden from the
	 * kernel. So if the region is already marked as busy, something
	 * is seriously wrong.
	 */
	r = devm_request_mem_region(i915->drm.dev, dsm->start,
				    resource_size(dsm),
				    "Graphics Stolen Memory");
	if (r == NULL) {
		/*
		 * One more attempt but this time requesting region from
		 * start + 1, as we have seen that this resolves the region
		 * conflict with the PCI Bus.
		 * This is a BIOS w/a: Some BIOS wrap stolen in the root
		 * PCI bus, but have an off-by-one error. Hence retry the
		 * reservation starting from 1 instead of 0.
		 * There's also BIOS with off-by-one on the other end.
		 */
		r = devm_request_mem_region(i915->drm.dev, dsm->start + 1,
					    resource_size(dsm) - 2,
					    "Graphics Stolen Memory");
		/*
		 * GEN3 firmware likes to smash pci bridges into the stolen
		 * range. Apparently this works.
		 */
		if (!r && !IS_GEN(i915, 3)) {
			drm_err(&i915->drm,
				"conflict detected with stolen region: %pR\n",
				dsm);

			return -EBUSY;
		}
	}

	return 0;
}

static void i915_gem_cleanup_stolen(struct drm_i915_private *i915)
{
	if (!drm_mm_initialized(&i915->mm.stolen))
		return;

	drm_mm_takedown(&i915->mm.stolen);
}

static void g4x_get_stolen_reserved(struct drm_i915_private *i915,
				    struct intel_uncore *uncore,
				    resource_size_t *base,
				    resource_size_t *size)
{
	u32 reg_val = intel_uncore_read(uncore,
					IS_GM45(i915) ?
					CTG_STOLEN_RESERVED :
					ELK_STOLEN_RESERVED);
	resource_size_t stolen_top = i915->dsm.end + 1;

	drm_dbg(&i915->drm, "%s_STOLEN_RESERVED = %08x\n",
		IS_GM45(i915) ? "CTG" : "ELK", reg_val);

	if ((reg_val & G4X_STOLEN_RESERVED_ENABLE) == 0)
		return;

	/*
	 * Whether ILK really reuses the ELK register for this is unclear.
	 * Let's see if we catch anyone with this supposedly enabled on ILK.
	 */
	drm_WARN(&i915->drm, IS_GEN(i915, 5),
		 "ILK stolen reserved found? 0x%08x\n",
		 reg_val);

	if (!(reg_val & G4X_STOLEN_RESERVED_ADDR2_MASK))
		return;

	*base = (reg_val & G4X_STOLEN_RESERVED_ADDR2_MASK) << 16;
	drm_WARN_ON(&i915->drm,
		    (reg_val & G4X_STOLEN_RESERVED_ADDR1_MASK) < *base);

	*size = stolen_top - *base;
}

static void gen6_get_stolen_reserved(struct drm_i915_private *i915,
				     struct intel_uncore *uncore,
				     resource_size_t *base,
				     resource_size_t *size)
{
	u32 reg_val = intel_uncore_read(uncore, GEN6_STOLEN_RESERVED);

	drm_dbg(&i915->drm, "GEN6_STOLEN_RESERVED = %08x\n", reg_val);

	if (!(reg_val & GEN6_STOLEN_RESERVED_ENABLE))
		return;

	*base = reg_val & GEN6_STOLEN_RESERVED_ADDR_MASK;

	switch (reg_val & GEN6_STOLEN_RESERVED_SIZE_MASK) {
	case GEN6_STOLEN_RESERVED_1M:
		*size = 1024 * 1024;
		break;
	case GEN6_STOLEN_RESERVED_512K:
		*size = 512 * 1024;
		break;
	case GEN6_STOLEN_RESERVED_256K:
		*size = 256 * 1024;
		break;
	case GEN6_STOLEN_RESERVED_128K:
		*size = 128 * 1024;
		break;
	default:
		*size = 1024 * 1024;
		MISSING_CASE(reg_val & GEN6_STOLEN_RESERVED_SIZE_MASK);
	}
}

static void vlv_get_stolen_reserved(struct drm_i915_private *i915,
				    struct intel_uncore *uncore,
				    resource_size_t *base,
				    resource_size_t *size)
{
	u32 reg_val = intel_uncore_read(uncore, GEN6_STOLEN_RESERVED);
	resource_size_t stolen_top = i915->dsm.end + 1;

	drm_dbg(&i915->drm, "GEN6_STOLEN_RESERVED = %08x\n", reg_val);

	if (!(reg_val & GEN6_STOLEN_RESERVED_ENABLE))
		return;

	switch (reg_val & GEN7_STOLEN_RESERVED_SIZE_MASK) {
	default:
		MISSING_CASE(reg_val & GEN7_STOLEN_RESERVED_SIZE_MASK);
		fallthrough;
	case GEN7_STOLEN_RESERVED_1M:
		*size = 1024 * 1024;
		break;
	}

	/*
	 * On vlv, the ADDR_MASK portion is left as 0 and HW deduces the
	 * reserved location as (top - size).
	 */
	*base = stolen_top - *size;
}

static void gen7_get_stolen_reserved(struct drm_i915_private *i915,
				     struct intel_uncore *uncore,
				     resource_size_t *base,
				     resource_size_t *size)
{
	u32 reg_val = intel_uncore_read(uncore, GEN6_STOLEN_RESERVED);

	drm_dbg(&i915->drm, "GEN6_STOLEN_RESERVED = %08x\n", reg_val);

	if (!(reg_val & GEN6_STOLEN_RESERVED_ENABLE))
		return;

	*base = reg_val & GEN7_STOLEN_RESERVED_ADDR_MASK;

	switch (reg_val & GEN7_STOLEN_RESERVED_SIZE_MASK) {
	case GEN7_STOLEN_RESERVED_1M:
		*size = 1024 * 1024;
		break;
	case GEN7_STOLEN_RESERVED_256K:
		*size = 256 * 1024;
		break;
	default:
		*size = 1024 * 1024;
		MISSING_CASE(reg_val & GEN7_STOLEN_RESERVED_SIZE_MASK);
	}
}

static void chv_get_stolen_reserved(struct drm_i915_private *i915,
				    struct intel_uncore *uncore,
				    resource_size_t *base,
				    resource_size_t *size)
{
	u32 reg_val = intel_uncore_read(uncore, GEN6_STOLEN_RESERVED);

	drm_dbg(&i915->drm, "GEN6_STOLEN_RESERVED = %08x\n", reg_val);

	if (!(reg_val & GEN6_STOLEN_RESERVED_ENABLE))
		return;

	*base = reg_val & GEN6_STOLEN_RESERVED_ADDR_MASK;

	switch (reg_val & GEN8_STOLEN_RESERVED_SIZE_MASK) {
	case GEN8_STOLEN_RESERVED_1M:
		*size = 1024 * 1024;
		break;
	case GEN8_STOLEN_RESERVED_2M:
		*size = 2 * 1024 * 1024;
		break;
	case GEN8_STOLEN_RESERVED_4M:
		*size = 4 * 1024 * 1024;
		break;
	case GEN8_STOLEN_RESERVED_8M:
		*size = 8 * 1024 * 1024;
		break;
	default:
		*size = 8 * 1024 * 1024;
		MISSING_CASE(reg_val & GEN8_STOLEN_RESERVED_SIZE_MASK);
	}
}

static void bdw_get_stolen_reserved(struct drm_i915_private *i915,
				    struct intel_uncore *uncore,
				    resource_size_t *base,
				    resource_size_t *size)
{
	u32 reg_val = intel_uncore_read(uncore, GEN6_STOLEN_RESERVED);
	resource_size_t stolen_top = i915->dsm.end + 1;

	drm_dbg(&i915->drm, "GEN6_STOLEN_RESERVED = %08x\n", reg_val);

	if (!(reg_val & GEN6_STOLEN_RESERVED_ENABLE))
		return;

	if (!(reg_val & GEN6_STOLEN_RESERVED_ADDR_MASK))
		return;

	*base = reg_val & GEN6_STOLEN_RESERVED_ADDR_MASK;
	*size = stolen_top - *base;
}

static void icl_get_stolen_reserved(struct drm_i915_private *i915,
				    struct intel_uncore *uncore,
				    resource_size_t *base,
				    resource_size_t *size)
{
	u64 reg_val = intel_uncore_read64(uncore, GEN6_STOLEN_RESERVED);

	drm_dbg(&i915->drm, "GEN6_STOLEN_RESERVED = 0x%016llx\n", reg_val);

	*base = reg_val & GEN11_STOLEN_RESERVED_ADDR_MASK;

	switch (reg_val & GEN8_STOLEN_RESERVED_SIZE_MASK) {
	case GEN8_STOLEN_RESERVED_1M:
		*size = 1024 * 1024;
		break;
	case GEN8_STOLEN_RESERVED_2M:
		*size = 2 * 1024 * 1024;
		break;
	case GEN8_STOLEN_RESERVED_4M:
		*size = 4 * 1024 * 1024;
		break;
	case GEN8_STOLEN_RESERVED_8M:
		*size = 8 * 1024 * 1024;
		break;
	default:
		*size = 8 * 1024 * 1024;
		MISSING_CASE(reg_val & GEN8_STOLEN_RESERVED_SIZE_MASK);
	}
}

static int i915_gem_init_stolen(struct drm_i915_private *i915)
{
	struct intel_uncore *uncore = &i915->uncore;
	resource_size_t reserved_base, stolen_top;
	resource_size_t reserved_total, reserved_size;

	mutex_init(&i915->mm.stolen_lock);

	if (intel_vgpu_active(i915)) {
		drm_notice(&i915->drm,
			   "%s, disabling use of stolen memory\n",
			   "iGVT-g active");
		return 0;
	}

	if (intel_vtd_active() && INTEL_GEN(i915) < 8) {
		drm_notice(&i915->drm,
			   "%s, disabling use of stolen memory\n",
			   "DMAR active");
		return 0;
	}

	if (resource_size(&intel_graphics_stolen_res) == 0)
		return 0;

	i915->dsm = intel_graphics_stolen_res;

	if (i915_adjust_stolen(i915, &i915->dsm))
		return 0;

	GEM_BUG_ON(i915->dsm.start == 0);
	GEM_BUG_ON(i915->dsm.end <= i915->dsm.start);

	stolen_top = i915->dsm.end + 1;
	reserved_base = stolen_top;
	reserved_size = 0;

	switch (INTEL_GEN(i915)) {
	case 2:
	case 3:
		break;
	case 4:
		if (!IS_G4X(i915))
			break;
		fallthrough;
	case 5:
		g4x_get_stolen_reserved(i915, uncore,
					&reserved_base, &reserved_size);
		break;
	case 6:
		gen6_get_stolen_reserved(i915, uncore,
					 &reserved_base, &reserved_size);
		break;
	case 7:
		if (IS_VALLEYVIEW(i915))
			vlv_get_stolen_reserved(i915, uncore,
						&reserved_base, &reserved_size);
		else
			gen7_get_stolen_reserved(i915, uncore,
						 &reserved_base, &reserved_size);
		break;
	case 8:
	case 9:
	case 10:
		if (IS_LP(i915))
			chv_get_stolen_reserved(i915, uncore,
						&reserved_base, &reserved_size);
		else
			bdw_get_stolen_reserved(i915, uncore,
						&reserved_base, &reserved_size);
		break;
	default:
		MISSING_CASE(INTEL_GEN(i915));
		fallthrough;
	case 11:
	case 12:
		icl_get_stolen_reserved(i915, uncore,
					&reserved_base,
					&reserved_size);
		break;
	}

	/*
	 * Our expectation is that the reserved space is at the top of the
	 * stolen region and *never* at the bottom. If we see !reserved_base,
	 * it likely means we failed to read the registers correctly.
	 */
	if (!reserved_base) {
		drm_err(&i915->drm,
			"inconsistent reservation %pa + %pa; ignoring\n",
			&reserved_base, &reserved_size);
		reserved_base = stolen_top;
		reserved_size = 0;
	}

	i915->dsm_reserved =
		(struct resource)DEFINE_RES_MEM(reserved_base, reserved_size);

	if (!resource_contains(&i915->dsm, &i915->dsm_reserved)) {
		drm_err(&i915->drm,
			"Stolen reserved area %pR outside stolen memory %pR\n",
			&i915->dsm_reserved, &i915->dsm);
		return 0;
	}

	/* It is possible for the reserved area to end before the end of stolen
	 * memory, so just consider the start. */
	reserved_total = stolen_top - reserved_base;

	drm_dbg(&i915->drm,
		"Memory reserved for graphics device: %lluK, usable: %lluK\n",
		(u64)resource_size(&i915->dsm) >> 10,
		((u64)resource_size(&i915->dsm) - reserved_total) >> 10);

	i915->stolen_usable_size =
		resource_size(&i915->dsm) - reserved_total;

	/* Basic memrange allocator for stolen space. */
	drm_mm_init(&i915->mm.stolen, 0, i915->stolen_usable_size);

	return 0;
}

static struct sg_table *
i915_pages_create_for_stolen(struct drm_device *dev,
			     resource_size_t offset, resource_size_t size)
{
	struct drm_i915_private *i915 = to_i915(dev);
	struct sg_table *st;
	struct scatterlist *sg;

	GEM_BUG_ON(range_overflows(offset, size, resource_size(&i915->dsm)));

	/* We hide that we have no struct page backing our stolen object
	 * by wrapping the contiguous physical allocation with a fake
	 * dma mapping in a single scatterlist.
	 */

	st = kmalloc(sizeof(*st), GFP_KERNEL);
	if (st == NULL)
		return ERR_PTR(-ENOMEM);

	if (sg_alloc_table(st, 1, GFP_KERNEL)) {
		kfree(st);
		return ERR_PTR(-ENOMEM);
	}

	sg = st->sgl;
	sg->offset = 0;
	sg->length = size;

	sg_dma_address(sg) = (dma_addr_t)i915->dsm.start + offset;
	sg_dma_len(sg) = size;

	return st;
}

static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj)
{
	struct sg_table *pages =
		i915_pages_create_for_stolen(obj->base.dev,
					     obj->stolen->start,
					     obj->stolen->size);
	if (IS_ERR(pages))
		return PTR_ERR(pages);

	__i915_gem_object_set_pages(obj, pages, obj->stolen->size);

	return 0;
}

static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj,
					     struct sg_table *pages)
{
	/* Should only be called from i915_gem_object_release_stolen() */
	sg_free_table(pages);
	kfree(pages);
}

static void
i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
{
	struct drm_i915_private *i915 = to_i915(obj->base.dev);
	struct drm_mm_node *stolen = fetch_and_zero(&obj->stolen);

	GEM_BUG_ON(!stolen);

	i915_gem_object_release_memory_region(obj);

	i915_gem_stolen_remove_node(i915, stolen);
	kfree(stolen);
}

static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = {
	.name = "i915_gem_object_stolen",
	.get_pages = i915_gem_object_get_pages_stolen,
	.put_pages = i915_gem_object_put_pages_stolen,
	.release = i915_gem_object_release_stolen,
};

static struct drm_i915_gem_object *
__i915_gem_object_create_stolen(struct intel_memory_region *mem,
				struct drm_mm_node *stolen)
{
	static struct lock_class_key lock_class;
	struct drm_i915_gem_object *obj;
	unsigned int cache_level;
	int err = -ENOMEM;

	obj = i915_gem_object_alloc();
	if (!obj)
		goto err;

	drm_gem_private_object_init(&mem->i915->drm, &obj->base, stolen->size);
	i915_gem_object_init(obj, &i915_gem_object_stolen_ops, &lock_class);

	obj->stolen = stolen;
	obj->read_domains = I915_GEM_DOMAIN_CPU | I915_GEM_DOMAIN_GTT;
	cache_level = HAS_LLC(mem->i915) ? I915_CACHE_LLC : I915_CACHE_NONE;
	i915_gem_object_set_cache_coherency(obj, cache_level);

	err = i915_gem_object_pin_pages(obj);
	if (err)
		goto cleanup;

	i915_gem_object_init_memory_region(obj, mem, 0);

	return obj;

cleanup:
	i915_gem_object_free(obj);
err:
	return ERR_PTR(err);
}

static struct drm_i915_gem_object *
_i915_gem_object_create_stolen(struct intel_memory_region *mem,
			       resource_size_t size,
			       unsigned int flags)
{
	struct drm_i915_private *i915 = mem->i915;
	struct drm_i915_gem_object *obj;
	struct drm_mm_node *stolen;
	int ret;

	if (!drm_mm_initialized(&i915->mm.stolen))
		return ERR_PTR(-ENODEV);

	if (size == 0)
		return ERR_PTR(-EINVAL);

	stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
	if (!stolen)
		return ERR_PTR(-ENOMEM);

	ret = i915_gem_stolen_insert_node(i915, stolen, size, 4096);
	if (ret) {
		obj = ERR_PTR(ret);
		goto err_free;
	}

	obj = __i915_gem_object_create_stolen(mem, stolen);
	if (IS_ERR(obj))
		goto err_remove;

	return obj;

err_remove:
	i915_gem_stolen_remove_node(i915, stolen);
err_free:
	kfree(stolen);
	return obj;
}

struct drm_i915_gem_object *
i915_gem_object_create_stolen(struct drm_i915_private *i915,
			      resource_size_t size)
{
	return i915_gem_object_create_region(i915->mm.regions[INTEL_REGION_STOLEN],
					     size, I915_BO_ALLOC_CONTIGUOUS);
}

static int init_stolen(struct intel_memory_region *mem)
{
	intel_memory_region_set_name(mem, "stolen");

	/*
	 * Initialise stolen early so that we may reserve preallocated
	 * objects for the BIOS to KMS transition.
	 */
	return i915_gem_init_stolen(mem->i915);
}

static void release_stolen(struct intel_memory_region *mem)
{
	i915_gem_cleanup_stolen(mem->i915);
}

static const struct intel_memory_region_ops i915_region_stolen_ops = {
	.init = init_stolen,
	.release = release_stolen,
	.create_object = _i915_gem_object_create_stolen,
};

struct intel_memory_region *i915_gem_stolen_setup(struct drm_i915_private *i915)
{
	return intel_memory_region_create(i915,
					  intel_graphics_stolen_res.start,
					  resource_size(&intel_graphics_stolen_res),
					  PAGE_SIZE, 0,
					  &i915_region_stolen_ops);
}

struct drm_i915_gem_object *
i915_gem_object_create_stolen_for_preallocated(struct drm_i915_private *i915,
					       resource_size_t stolen_offset,
					       resource_size_t size)
{
	struct intel_memory_region *mem = i915->mm.regions[INTEL_REGION_STOLEN];
	struct drm_i915_gem_object *obj;
	struct drm_mm_node *stolen;
	int ret;

	if (!drm_mm_initialized(&i915->mm.stolen))
		return ERR_PTR(-ENODEV);

	drm_dbg(&i915->drm,
		"creating preallocated stolen object: stolen_offset=%pa, size=%pa\n",
		&stolen_offset, &size);

	/* KISS and expect everything to be page-aligned */
	if (GEM_WARN_ON(size == 0) ||
	    GEM_WARN_ON(!IS_ALIGNED(size, I915_GTT_PAGE_SIZE)) ||
	    GEM_WARN_ON(!IS_ALIGNED(stolen_offset, I915_GTT_MIN_ALIGNMENT)))
		return ERR_PTR(-EINVAL);

	stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
	if (!stolen)
		return ERR_PTR(-ENOMEM);

	stolen->start = stolen_offset;
	stolen->size = size;
	mutex_lock(&i915->mm.stolen_lock);
	ret = drm_mm_reserve_node(&i915->mm.stolen, stolen);
	mutex_unlock(&i915->mm.stolen_lock);
	if (ret) {
		obj = ERR_PTR(ret);
		goto err_free;
	}

	obj = __i915_gem_object_create_stolen(mem, stolen);
	if (IS_ERR(obj))
		goto err_stolen;

	i915_gem_object_set_cache_coherency(obj, I915_CACHE_NONE);
	return obj;

err_stolen:
	i915_gem_stolen_remove_node(i915, stolen);
err_free:
	kfree(stolen);
	return obj;
}