1/*
2 * Copyright �� 2008-2012 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 *
23 * Authors:
24 *    Eric Anholt <eric@anholt.net>
25 *    Chris Wilson <chris@chris-wilson.co.uk>
26 *
27 */
28
29#include <drm/drmP.h>
30#include <drm/i915_drm.h>
31#include "i915_drv.h"
32
33#define KB(x) ((x) * 1024)
34#define MB(x) (KB(x) * 1024)
35
36/*
37 * The BIOS typically reserves some of the system's memory for the exclusive
38 * use of the integrated graphics. This memory is no longer available for
39 * use by the OS and so the user finds that his system has less memory
40 * available than he put in. We refer to this memory as stolen.
41 *
42 * The BIOS will allocate its framebuffer from the stolen memory. Our
43 * goal is try to reuse that object for our own fbcon which must always
44 * be available for panics. Anything else we can reuse the stolen memory
45 * for is a boon.
46 */
47
48int i915_gem_stolen_insert_node_in_range(struct drm_i915_private *dev_priv,
49					 struct drm_mm_node *node, u64 size,
50					 unsigned alignment, u64 start, u64 end)
51{
52	int ret;
53
54	if (!drm_mm_initialized(&dev_priv->mm.stolen))
55		return -ENODEV;
56
57	/* See the comment at the drm_mm_init() call for more about this check.
58	 * WaSkipStolenMemoryFirstPage:bdw,chv (incomplete) */
59	if (INTEL_INFO(dev_priv)->gen == 8 && start < 4096)
60		start = 4096;
61
62	mutex_lock(&dev_priv->mm.stolen_lock);
63	ret = drm_mm_insert_node_in_range(&dev_priv->mm.stolen, node, size,
64					  alignment, start, end,
65					  DRM_MM_SEARCH_DEFAULT);
66	mutex_unlock(&dev_priv->mm.stolen_lock);
67
68	return ret;
69}
70
71int i915_gem_stolen_insert_node(struct drm_i915_private *dev_priv,
72				struct drm_mm_node *node, u64 size,
73				unsigned alignment)
74{
75	return i915_gem_stolen_insert_node_in_range(dev_priv, node, size,
76					alignment, 0,
77					dev_priv->gtt.stolen_usable_size);
78}
79
80void i915_gem_stolen_remove_node(struct drm_i915_private *dev_priv,
81				 struct drm_mm_node *node)
82{
83	mutex_lock(&dev_priv->mm.stolen_lock);
84	drm_mm_remove_node(node);
85	mutex_unlock(&dev_priv->mm.stolen_lock);
86}
87
88static unsigned long i915_stolen_to_physical(struct drm_device *dev)
89{
90	struct drm_i915_private *dev_priv = dev->dev_private;
91	struct resource *r;
92	u32 base;
93
94	/* Almost universally we can find the Graphics Base of Stolen Memory
95	 * at offset 0x5c in the igfx configuration space. On a few (desktop)
96	 * machines this is also mirrored in the bridge device at different
97	 * locations, or in the MCHBAR.
98	 *
99	 * On 865 we just check the TOUD register.
100	 *
101	 * On 830/845/85x the stolen memory base isn't available in any
102	 * register. We need to calculate it as TOM-TSEG_SIZE-stolen_size.
103	 *
104	 */
105	base = 0;
106	if (INTEL_INFO(dev)->gen >= 3) {
107		/* Read Graphics Base of Stolen Memory directly */
108		pci_read_config_dword(dev->pdev, 0x5c, &base);
109		base &= ~((1<<20) - 1);
110	} else if (IS_I865G(dev)) {
111		u16 toud = 0;
112
113		/*
114		 * FIXME is the graphics stolen memory region
115		 * always at TOUD? Ie. is it always the last
116		 * one to be allocated by the BIOS?
117		 */
118		pci_bus_read_config_word(dev->pdev->bus, PCI_DEVFN(0, 0),
119					 I865_TOUD, &toud);
120
121		base = toud << 16;
122	} else if (IS_I85X(dev)) {
123		u32 tseg_size = 0;
124		u32 tom;
125		u8 tmp;
126
127		pci_bus_read_config_byte(dev->pdev->bus, PCI_DEVFN(0, 0),
128					 I85X_ESMRAMC, &tmp);
129
130		if (tmp & TSEG_ENABLE)
131			tseg_size = MB(1);
132
133		pci_bus_read_config_byte(dev->pdev->bus, PCI_DEVFN(0, 1),
134					 I85X_DRB3, &tmp);
135		tom = tmp * MB(32);
136
137		base = tom - tseg_size - dev_priv->gtt.stolen_size;
138	} else if (IS_845G(dev)) {
139		u32 tseg_size = 0;
140		u32 tom;
141		u8 tmp;
142
143		pci_bus_read_config_byte(dev->pdev->bus, PCI_DEVFN(0, 0),
144					 I845_ESMRAMC, &tmp);
145
146		if (tmp & TSEG_ENABLE) {
147			switch (tmp & I845_TSEG_SIZE_MASK) {
148			case I845_TSEG_SIZE_512K:
149				tseg_size = KB(512);
150				break;
151			case I845_TSEG_SIZE_1M:
152				tseg_size = MB(1);
153				break;
154			}
155		}
156
157		pci_bus_read_config_byte(dev->pdev->bus, PCI_DEVFN(0, 0),
158					 I830_DRB3, &tmp);
159		tom = tmp * MB(32);
160
161		base = tom - tseg_size - dev_priv->gtt.stolen_size;
162	} else if (IS_I830(dev)) {
163		u32 tseg_size = 0;
164		u32 tom;
165		u8 tmp;
166
167		pci_bus_read_config_byte(dev->pdev->bus, PCI_DEVFN(0, 0),
168					 I830_ESMRAMC, &tmp);
169
170		if (tmp & TSEG_ENABLE) {
171			if (tmp & I830_TSEG_SIZE_1M)
172				tseg_size = MB(1);
173			else
174				tseg_size = KB(512);
175		}
176
177		pci_bus_read_config_byte(dev->pdev->bus, PCI_DEVFN(0, 0),
178					 I830_DRB3, &tmp);
179		tom = tmp * MB(32);
180
181		base = tom - tseg_size - dev_priv->gtt.stolen_size;
182	}
183
184	if (base == 0)
185		return 0;
186
187	/* make sure we don't clobber the GTT if it's within stolen memory */
188	if (INTEL_INFO(dev)->gen <= 4 && !IS_G33(dev) && !IS_G4X(dev)) {
189		struct {
190			u32 start, end;
191		} stolen[2] = {
192			{ .start = base, .end = base + dev_priv->gtt.stolen_size, },
193			{ .start = base, .end = base + dev_priv->gtt.stolen_size, },
194		};
195		u64 gtt_start, gtt_end;
196
197		gtt_start = I915_READ(PGTBL_CTL);
198		if (IS_GEN4(dev))
199			gtt_start = (gtt_start & PGTBL_ADDRESS_LO_MASK) |
200				(gtt_start & PGTBL_ADDRESS_HI_MASK) << 28;
201		else
202			gtt_start &= PGTBL_ADDRESS_LO_MASK;
203		gtt_end = gtt_start + gtt_total_entries(dev_priv->gtt) * 4;
204
205		if (gtt_start >= stolen[0].start && gtt_start < stolen[0].end)
206			stolen[0].end = gtt_start;
207		if (gtt_end > stolen[1].start && gtt_end <= stolen[1].end)
208			stolen[1].start = gtt_end;
209
210		/* pick the larger of the two chunks */
211		if (stolen[0].end - stolen[0].start >
212		    stolen[1].end - stolen[1].start) {
213			base = stolen[0].start;
214			dev_priv->gtt.stolen_size = stolen[0].end - stolen[0].start;
215		} else {
216			base = stolen[1].start;
217			dev_priv->gtt.stolen_size = stolen[1].end - stolen[1].start;
218		}
219
220		if (stolen[0].start != stolen[1].start ||
221		    stolen[0].end != stolen[1].end) {
222			DRM_DEBUG_KMS("GTT within stolen memory at 0x%llx-0x%llx\n",
223				      (unsigned long long) gtt_start,
224				      (unsigned long long) gtt_end - 1);
225			DRM_DEBUG_KMS("Stolen memory adjusted to 0x%x-0x%x\n",
226				      base, base + (u32) dev_priv->gtt.stolen_size - 1);
227		}
228	}
229
230
231	/* Verify that nothing else uses this physical address. Stolen
232	 * memory should be reserved by the BIOS and hidden from the
233	 * kernel. So if the region is already marked as busy, something
234	 * is seriously wrong.
235	 */
236	r = devm_request_mem_region(dev->dev, base, dev_priv->gtt.stolen_size,
237				    "Graphics Stolen Memory");
238	if (r == NULL) {
239		/*
240		 * One more attempt but this time requesting region from
241		 * base + 1, as we have seen that this resolves the region
242		 * conflict with the PCI Bus.
243		 * This is a BIOS w/a: Some BIOS wrap stolen in the root
244		 * PCI bus, but have an off-by-one error. Hence retry the
245		 * reservation starting from 1 instead of 0.
246		 */
247		r = devm_request_mem_region(dev->dev, base + 1,
248					    dev_priv->gtt.stolen_size - 1,
249					    "Graphics Stolen Memory");
250		/*
251		 * GEN3 firmware likes to smash pci bridges into the stolen
252		 * range. Apparently this works.
253		 */
254		if (r == NULL && !IS_GEN3(dev)) {
255			DRM_ERROR("conflict detected with stolen region: [0x%08x - 0x%08x]\n",
256				  base, base + (uint32_t)dev_priv->gtt.stolen_size);
257			base = 0;
258		}
259	}
260
261	return base;
262}
263
264void i915_gem_cleanup_stolen(struct drm_device *dev)
265{
266	struct drm_i915_private *dev_priv = dev->dev_private;
267
268	if (!drm_mm_initialized(&dev_priv->mm.stolen))
269		return;
270
271	drm_mm_takedown(&dev_priv->mm.stolen);
272}
273
274static void g4x_get_stolen_reserved(struct drm_i915_private *dev_priv,
275				    unsigned long *base, unsigned long *size)
276{
277	uint32_t reg_val = I915_READ(IS_GM45(dev_priv) ?
278				     CTG_STOLEN_RESERVED :
279				     ELK_STOLEN_RESERVED);
280	unsigned long stolen_top = dev_priv->mm.stolen_base +
281		dev_priv->gtt.stolen_size;
282
283	*base = (reg_val & G4X_STOLEN_RESERVED_ADDR2_MASK) << 16;
284
285	WARN_ON((reg_val & G4X_STOLEN_RESERVED_ADDR1_MASK) < *base);
286
287	/* On these platforms, the register doesn't have a size field, so the
288	 * size is the distance between the base and the top of the stolen
289	 * memory. We also have the genuine case where base is zero and there's
290	 * nothing reserved. */
291	if (*base == 0)
292		*size = 0;
293	else
294		*size = stolen_top - *base;
295}
296
297static void gen6_get_stolen_reserved(struct drm_i915_private *dev_priv,
298				     unsigned long *base, unsigned long *size)
299{
300	uint32_t reg_val = I915_READ(GEN6_STOLEN_RESERVED);
301
302	*base = reg_val & GEN6_STOLEN_RESERVED_ADDR_MASK;
303
304	switch (reg_val & GEN6_STOLEN_RESERVED_SIZE_MASK) {
305	case GEN6_STOLEN_RESERVED_1M:
306		*size = 1024 * 1024;
307		break;
308	case GEN6_STOLEN_RESERVED_512K:
309		*size = 512 * 1024;
310		break;
311	case GEN6_STOLEN_RESERVED_256K:
312		*size = 256 * 1024;
313		break;
314	case GEN6_STOLEN_RESERVED_128K:
315		*size = 128 * 1024;
316		break;
317	default:
318		*size = 1024 * 1024;
319		MISSING_CASE(reg_val & GEN6_STOLEN_RESERVED_SIZE_MASK);
320	}
321}
322
323static void gen7_get_stolen_reserved(struct drm_i915_private *dev_priv,
324				     unsigned long *base, unsigned long *size)
325{
326	uint32_t reg_val = I915_READ(GEN6_STOLEN_RESERVED);
327
328	*base = reg_val & GEN7_STOLEN_RESERVED_ADDR_MASK;
329
330	switch (reg_val & GEN7_STOLEN_RESERVED_SIZE_MASK) {
331	case GEN7_STOLEN_RESERVED_1M:
332		*size = 1024 * 1024;
333		break;
334	case GEN7_STOLEN_RESERVED_256K:
335		*size = 256 * 1024;
336		break;
337	default:
338		*size = 1024 * 1024;
339		MISSING_CASE(reg_val & GEN7_STOLEN_RESERVED_SIZE_MASK);
340	}
341}
342
343static void gen8_get_stolen_reserved(struct drm_i915_private *dev_priv,
344				     unsigned long *base, unsigned long *size)
345{
346	uint32_t reg_val = I915_READ(GEN6_STOLEN_RESERVED);
347
348	*base = reg_val & GEN6_STOLEN_RESERVED_ADDR_MASK;
349
350	switch (reg_val & GEN8_STOLEN_RESERVED_SIZE_MASK) {
351	case GEN8_STOLEN_RESERVED_1M:
352		*size = 1024 * 1024;
353		break;
354	case GEN8_STOLEN_RESERVED_2M:
355		*size = 2 * 1024 * 1024;
356		break;
357	case GEN8_STOLEN_RESERVED_4M:
358		*size = 4 * 1024 * 1024;
359		break;
360	case GEN8_STOLEN_RESERVED_8M:
361		*size = 8 * 1024 * 1024;
362		break;
363	default:
364		*size = 8 * 1024 * 1024;
365		MISSING_CASE(reg_val & GEN8_STOLEN_RESERVED_SIZE_MASK);
366	}
367}
368
369static void bdw_get_stolen_reserved(struct drm_i915_private *dev_priv,
370				    unsigned long *base, unsigned long *size)
371{
372	uint32_t reg_val = I915_READ(GEN6_STOLEN_RESERVED);
373	unsigned long stolen_top;
374
375	stolen_top = dev_priv->mm.stolen_base + dev_priv->gtt.stolen_size;
376
377	*base = reg_val & GEN6_STOLEN_RESERVED_ADDR_MASK;
378
379	/* On these platforms, the register doesn't have a size field, so the
380	 * size is the distance between the base and the top of the stolen
381	 * memory. We also have the genuine case where base is zero and there's
382	 * nothing reserved. */
383	if (*base == 0)
384		*size = 0;
385	else
386		*size = stolen_top - *base;
387}
388
389int i915_gem_init_stolen(struct drm_device *dev)
390{
391	struct drm_i915_private *dev_priv = dev->dev_private;
392	unsigned long reserved_total, reserved_base = 0, reserved_size;
393	unsigned long stolen_top;
394
395	mutex_init(&dev_priv->mm.stolen_lock);
396
397#ifdef CONFIG_INTEL_IOMMU
398	if (intel_iommu_gfx_mapped && INTEL_INFO(dev)->gen < 8) {
399		DRM_INFO("DMAR active, disabling use of stolen memory\n");
400		return 0;
401	}
402#endif
403
404	if (dev_priv->gtt.stolen_size == 0)
405		return 0;
406
407	dev_priv->mm.stolen_base = i915_stolen_to_physical(dev);
408	if (dev_priv->mm.stolen_base == 0)
409		return 0;
410
411	stolen_top = dev_priv->mm.stolen_base + dev_priv->gtt.stolen_size;
412
413	switch (INTEL_INFO(dev_priv)->gen) {
414	case 2:
415	case 3:
416		break;
417	case 4:
418		if (IS_G4X(dev))
419			g4x_get_stolen_reserved(dev_priv, &reserved_base,
420						&reserved_size);
421		break;
422	case 5:
423		/* Assume the gen6 maximum for the older platforms. */
424		reserved_size = 1024 * 1024;
425		reserved_base = stolen_top - reserved_size;
426		break;
427	case 6:
428		gen6_get_stolen_reserved(dev_priv, &reserved_base,
429					 &reserved_size);
430		break;
431	case 7:
432		gen7_get_stolen_reserved(dev_priv, &reserved_base,
433					 &reserved_size);
434		break;
435	default:
436		if (IS_BROADWELL(dev_priv) || IS_SKYLAKE(dev_priv))
437			bdw_get_stolen_reserved(dev_priv, &reserved_base,
438						&reserved_size);
439		else
440			gen8_get_stolen_reserved(dev_priv, &reserved_base,
441						 &reserved_size);
442		break;
443	}
444
445	/* It is possible for the reserved base to be zero, but the register
446	 * field for size doesn't have a zero option. */
447	if (reserved_base == 0) {
448		reserved_size = 0;
449		reserved_base = stolen_top;
450	}
451
452	if (reserved_base < dev_priv->mm.stolen_base ||
453	    reserved_base + reserved_size > stolen_top) {
454		DRM_DEBUG_KMS("Stolen reserved area [0x%08lx - 0x%08lx] outside stolen memory [0x%08lx - 0x%08lx]\n",
455			      reserved_base, reserved_base + reserved_size,
456			      dev_priv->mm.stolen_base, stolen_top);
457		return 0;
458	}
459
460	/* It is possible for the reserved area to end before the end of stolen
461	 * memory, so just consider the start. */
462	reserved_total = stolen_top - reserved_base;
463
464	DRM_DEBUG_KMS("Memory reserved for graphics device: %zuK, usable: %luK\n",
465		      dev_priv->gtt.stolen_size >> 10,
466		      (dev_priv->gtt.stolen_size - reserved_total) >> 10);
467
468	dev_priv->gtt.stolen_usable_size = dev_priv->gtt.stolen_size -
469					   reserved_total;
470
471	/*
472	 * Basic memrange allocator for stolen space.
473	 *
474	 * TODO: Notice that some platforms require us to not use the first page
475	 * of the stolen memory but their BIOSes may still put the framebuffer
476	 * on the first page. So we don't reserve this page for now because of
477	 * that. Our current solution is to just prevent new nodes from being
478	 * inserted on the first page - see the check we have at
479	 * i915_gem_stolen_insert_node_in_range(). We may want to fix the fbcon
480	 * problem later.
481	 */
482	drm_mm_init(&dev_priv->mm.stolen, 0, dev_priv->gtt.stolen_usable_size);
483
484	return 0;
485}
486
487static struct sg_table *
488i915_pages_create_for_stolen(struct drm_device *dev,
489			     u32 offset, u32 size)
490{
491	struct drm_i915_private *dev_priv = dev->dev_private;
492	struct sg_table *st;
493	struct scatterlist *sg;
494
495	DRM_DEBUG_DRIVER("offset=0x%x, size=%d\n", offset, size);
496	BUG_ON(offset > dev_priv->gtt.stolen_size - size);
497
498	/* We hide that we have no struct page backing our stolen object
499	 * by wrapping the contiguous physical allocation with a fake
500	 * dma mapping in a single scatterlist.
501	 */
502
503	st = kmalloc(sizeof(*st), GFP_KERNEL);
504	if (st == NULL)
505		return NULL;
506
507	if (sg_alloc_table(st, 1, GFP_KERNEL)) {
508		kfree(st);
509		return NULL;
510	}
511
512	sg = st->sgl;
513	sg->offset = 0;
514	sg->length = size;
515
516	sg_dma_address(sg) = (dma_addr_t)dev_priv->mm.stolen_base + offset;
517	sg_dma_len(sg) = size;
518
519	return st;
520}
521
522static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj)
523{
524	BUG();
525	return -EINVAL;
526}
527
528static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj)
529{
530	/* Should only be called during free */
531	sg_free_table(obj->pages);
532	kfree(obj->pages);
533}
534
535
536static void
537i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
538{
539	struct drm_i915_private *dev_priv = obj->base.dev->dev_private;
540
541	if (obj->stolen) {
542		i915_gem_stolen_remove_node(dev_priv, obj->stolen);
543		kfree(obj->stolen);
544		obj->stolen = NULL;
545	}
546}
547static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = {
548	.get_pages = i915_gem_object_get_pages_stolen,
549	.put_pages = i915_gem_object_put_pages_stolen,
550	.release = i915_gem_object_release_stolen,
551};
552
553static struct drm_i915_gem_object *
554_i915_gem_object_create_stolen(struct drm_device *dev,
555			       struct drm_mm_node *stolen)
556{
557	struct drm_i915_gem_object *obj;
558
559	obj = i915_gem_object_alloc(dev);
560	if (obj == NULL)
561		return NULL;
562
563	drm_gem_private_object_init(dev, &obj->base, stolen->size);
564	i915_gem_object_init(obj, &i915_gem_object_stolen_ops);
565
566	obj->pages = i915_pages_create_for_stolen(dev,
567						  stolen->start, stolen->size);
568	if (obj->pages == NULL)
569		goto cleanup;
570
571	i915_gem_object_pin_pages(obj);
572	obj->stolen = stolen;
573
574	obj->base.read_domains = I915_GEM_DOMAIN_CPU | I915_GEM_DOMAIN_GTT;
575	obj->cache_level = HAS_LLC(dev) ? I915_CACHE_LLC : I915_CACHE_NONE;
576
577	return obj;
578
579cleanup:
580	i915_gem_object_free(obj);
581	return NULL;
582}
583
584struct drm_i915_gem_object *
585i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
586{
587	struct drm_i915_private *dev_priv = dev->dev_private;
588	struct drm_i915_gem_object *obj;
589	struct drm_mm_node *stolen;
590	int ret;
591
592	if (!drm_mm_initialized(&dev_priv->mm.stolen))
593		return NULL;
594
595	DRM_DEBUG_KMS("creating stolen object: size=%x\n", size);
596	if (size == 0)
597		return NULL;
598
599	stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
600	if (!stolen)
601		return NULL;
602
603	ret = i915_gem_stolen_insert_node(dev_priv, stolen, size, 4096);
604	if (ret) {
605		kfree(stolen);
606		return NULL;
607	}
608
609	obj = _i915_gem_object_create_stolen(dev, stolen);
610	if (obj)
611		return obj;
612
613	i915_gem_stolen_remove_node(dev_priv, stolen);
614	kfree(stolen);
615	return NULL;
616}
617
618struct drm_i915_gem_object *
619i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
620					       u32 stolen_offset,
621					       u32 gtt_offset,
622					       u32 size)
623{
624	struct drm_i915_private *dev_priv = dev->dev_private;
625	struct i915_address_space *ggtt = &dev_priv->gtt.base;
626	struct drm_i915_gem_object *obj;
627	struct drm_mm_node *stolen;
628	struct i915_vma *vma;
629	int ret;
630
631	if (!drm_mm_initialized(&dev_priv->mm.stolen))
632		return NULL;
633
634	DRM_DEBUG_KMS("creating preallocated stolen object: stolen_offset=%x, gtt_offset=%x, size=%x\n",
635			stolen_offset, gtt_offset, size);
636
637	/* KISS and expect everything to be page-aligned */
638	if (WARN_ON(size == 0) || WARN_ON(size & 4095) ||
639	    WARN_ON(stolen_offset & 4095))
640		return NULL;
641
642	stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
643	if (!stolen)
644		return NULL;
645
646	stolen->start = stolen_offset;
647	stolen->size = size;
648	mutex_lock(&dev_priv->mm.stolen_lock);
649	ret = drm_mm_reserve_node(&dev_priv->mm.stolen, stolen);
650	mutex_unlock(&dev_priv->mm.stolen_lock);
651	if (ret) {
652		DRM_DEBUG_KMS("failed to allocate stolen space\n");
653		kfree(stolen);
654		return NULL;
655	}
656
657	obj = _i915_gem_object_create_stolen(dev, stolen);
658	if (obj == NULL) {
659		DRM_DEBUG_KMS("failed to allocate stolen object\n");
660		i915_gem_stolen_remove_node(dev_priv, stolen);
661		kfree(stolen);
662		return NULL;
663	}
664
665	/* Some objects just need physical mem from stolen space */
666	if (gtt_offset == I915_GTT_OFFSET_NONE)
667		return obj;
668
669	vma = i915_gem_obj_lookup_or_create_vma(obj, ggtt);
670	if (IS_ERR(vma)) {
671		ret = PTR_ERR(vma);
672		goto err;
673	}
674
675	/* To simplify the initialisation sequence between KMS and GTT,
676	 * we allow construction of the stolen object prior to
677	 * setting up the GTT space. The actual reservation will occur
678	 * later.
679	 */
680	vma->node.start = gtt_offset;
681	vma->node.size = size;
682	if (drm_mm_initialized(&ggtt->mm)) {
683		ret = drm_mm_reserve_node(&ggtt->mm, &vma->node);
684		if (ret) {
685			DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
686			goto err;
687		}
688
689		vma->bound |= GLOBAL_BIND;
690		__i915_vma_set_map_and_fenceable(vma);
691		list_add_tail(&vma->mm_list, &ggtt->inactive_list);
692	}
693
694	list_add_tail(&obj->global_list, &dev_priv->mm.bound_list);
695	i915_gem_object_pin_pages(obj);
696
697	return obj;
698
699err:
700	drm_gem_object_unreference(&obj->base);
701	return NULL;
702}
703