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  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * NVIDIA Tegra DRM GEM helper functions
  4 *
  5 * Copyright (C) 2012 Sascha Hauer, Pengutronix
  6 * Copyright (C) 2013-2015 NVIDIA CORPORATION, All rights reserved.
  7 *
  8 * Based on the GEM/CMA helpers
  9 *
 10 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
 11 */
 12
 13#include <linux/dma-buf.h>
 14#include <linux/iommu.h>
 15#include <linux/module.h>
 16
 17#include <drm/drm_drv.h>
 18#include <drm/drm_prime.h>
 19#include <drm/tegra_drm.h>
 20
 21#include "drm.h"
 22#include "gem.h"
 23
 24MODULE_IMPORT_NS(DMA_BUF);
 25
 26static unsigned int sg_dma_count_chunks(struct scatterlist *sgl, unsigned int nents)
 27{
 28	dma_addr_t next = ~(dma_addr_t)0;
 29	unsigned int count = 0, i;
 30	struct scatterlist *s;
 31
 32	for_each_sg(sgl, s, nents, i) {
 33		/* sg_dma_address(s) is only valid for entries that have sg_dma_len(s) != 0. */
 34		if (!sg_dma_len(s))
 35			continue;
 36
 37		if (sg_dma_address(s) != next) {
 38			next = sg_dma_address(s) + sg_dma_len(s);
 39			count++;
 40		}
 41	}
 42
 43	return count;
 44}
 45
 46static inline unsigned int sgt_dma_count_chunks(struct sg_table *sgt)
 47{
 48	return sg_dma_count_chunks(sgt->sgl, sgt->nents);
 49}
 50
 51static void tegra_bo_put(struct host1x_bo *bo)
 52{
 53	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
 54
 55	drm_gem_object_put(&obj->gem);
 56}
 57
 58static struct host1x_bo_mapping *tegra_bo_pin(struct device *dev, struct host1x_bo *bo,
 59					      enum dma_data_direction direction)
 60{
 61	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
 62	struct drm_gem_object *gem = &obj->gem;
 63	struct host1x_bo_mapping *map;
 64	int err;
 65
 66	map = kzalloc(sizeof(*map), GFP_KERNEL);
 67	if (!map)
 68		return ERR_PTR(-ENOMEM);
 69
 70	kref_init(&map->ref);
 71	map->bo = host1x_bo_get(bo);
 72	map->direction = direction;
 73	map->dev = dev;
 74
 75	/*
 76	 * Imported buffers need special treatment to satisfy the semantics of DMA-BUF.
 77	 */
 78	if (gem->import_attach) {
 79		struct dma_buf *buf = gem->import_attach->dmabuf;
 80
 81		map->attach = dma_buf_attach(buf, dev);
 82		if (IS_ERR(map->attach)) {
 83			err = PTR_ERR(map->attach);
 84			goto free;
 85		}
 86
 87		map->sgt = dma_buf_map_attachment_unlocked(map->attach, direction);
 88		if (IS_ERR(map->sgt)) {
 89			dma_buf_detach(buf, map->attach);
 90			err = PTR_ERR(map->sgt);
 91			map->sgt = NULL;
 92			goto free;
 93		}
 94
 95		err = sgt_dma_count_chunks(map->sgt);
 96		map->size = gem->size;
 97
 98		goto out;
 99	}
100
101	/*
102	 * If we don't have a mapping for this buffer yet, return an SG table
103	 * so that host1x can do the mapping for us via the DMA API.
104	 */
105	map->sgt = kzalloc(sizeof(*map->sgt), GFP_KERNEL);
106	if (!map->sgt) {
107		err = -ENOMEM;
108		goto free;
109	}
110
111	if (obj->pages) {
112		/*
113		 * If the buffer object was allocated from the explicit IOMMU
114		 * API code paths, construct an SG table from the pages.
115		 */
116		err = sg_alloc_table_from_pages(map->sgt, obj->pages, obj->num_pages, 0, gem->size,
117						GFP_KERNEL);
118		if (err < 0)
119			goto free;
120	} else {
121		/*
122		 * If the buffer object had no pages allocated and if it was
123		 * not imported, it had to be allocated with the DMA API, so
124		 * the DMA API helper can be used.
125		 */
126		err = dma_get_sgtable(dev, map->sgt, obj->vaddr, obj->iova, gem->size);
127		if (err < 0)
128			goto free;
129	}
130
131	err = dma_map_sgtable(dev, map->sgt, direction, 0);
132	if (err)
133		goto free_sgt;
134
135out:
136	/*
137	 * If we've manually mapped the buffer object through the IOMMU, make sure to return the
138	 * existing IOVA address of our mapping.
139	 */
140	if (!obj->mm) {
141		map->phys = sg_dma_address(map->sgt->sgl);
142		map->chunks = err;
143	} else {
144		map->phys = obj->iova;
145		map->chunks = 1;
146	}
147
148	map->size = gem->size;
149
150	return map;
151
152free_sgt:
153	sg_free_table(map->sgt);
154free:
155	kfree(map->sgt);
156	kfree(map);
157	return ERR_PTR(err);
158}
159
160static void tegra_bo_unpin(struct host1x_bo_mapping *map)
161{
162	if (map->attach) {
163		dma_buf_unmap_attachment_unlocked(map->attach, map->sgt,
164						  map->direction);
165		dma_buf_detach(map->attach->dmabuf, map->attach);
166	} else {
167		dma_unmap_sgtable(map->dev, map->sgt, map->direction, 0);
168		sg_free_table(map->sgt);
169		kfree(map->sgt);
170	}
171
172	host1x_bo_put(map->bo);
173	kfree(map);
174}
175
176static void *tegra_bo_mmap(struct host1x_bo *bo)
177{
178	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
179	struct iosys_map map;
180	int ret;
181
182	if (obj->vaddr) {
183		return obj->vaddr;
184	} else if (obj->gem.import_attach) {
185		ret = dma_buf_vmap_unlocked(obj->gem.import_attach->dmabuf, &map);
186		return ret ? NULL : map.vaddr;
187	} else {
188		return vmap(obj->pages, obj->num_pages, VM_MAP,
189			    pgprot_writecombine(PAGE_KERNEL));
190	}
191}
192
193static void tegra_bo_munmap(struct host1x_bo *bo, void *addr)
194{
195	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
196	struct iosys_map map = IOSYS_MAP_INIT_VADDR(addr);
197
198	if (obj->vaddr)
199		return;
200	else if (obj->gem.import_attach)
201		dma_buf_vunmap_unlocked(obj->gem.import_attach->dmabuf, &map);
202	else
203		vunmap(addr);
204}
205
206static struct host1x_bo *tegra_bo_get(struct host1x_bo *bo)
207{
208	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
209
210	drm_gem_object_get(&obj->gem);
211
212	return bo;
213}
214
215static const struct host1x_bo_ops tegra_bo_ops = {
216	.get = tegra_bo_get,
217	.put = tegra_bo_put,
218	.pin = tegra_bo_pin,
219	.unpin = tegra_bo_unpin,
220	.mmap = tegra_bo_mmap,
221	.munmap = tegra_bo_munmap,
222};
223
224static int tegra_bo_iommu_map(struct tegra_drm *tegra, struct tegra_bo *bo)
225{
226	int prot = IOMMU_READ | IOMMU_WRITE;
227	int err;
228
229	if (bo->mm)
230		return -EBUSY;
231
232	bo->mm = kzalloc(sizeof(*bo->mm), GFP_KERNEL);
233	if (!bo->mm)
234		return -ENOMEM;
235
236	mutex_lock(&tegra->mm_lock);
237
238	err = drm_mm_insert_node_generic(&tegra->mm,
239					 bo->mm, bo->gem.size, PAGE_SIZE, 0, 0);
240	if (err < 0) {
241		dev_err(tegra->drm->dev, "out of I/O virtual memory: %d\n",
242			err);
243		goto unlock;
244	}
245
246	bo->iova = bo->mm->start;
247
248	bo->size = iommu_map_sgtable(tegra->domain, bo->iova, bo->sgt, prot);
249	if (!bo->size) {
250		dev_err(tegra->drm->dev, "failed to map buffer\n");
251		err = -ENOMEM;
252		goto remove;
253	}
254
255	mutex_unlock(&tegra->mm_lock);
256
257	return 0;
258
259remove:
260	drm_mm_remove_node(bo->mm);
261unlock:
262	mutex_unlock(&tegra->mm_lock);
263	kfree(bo->mm);
264	return err;
265}
266
267static int tegra_bo_iommu_unmap(struct tegra_drm *tegra, struct tegra_bo *bo)
268{
269	if (!bo->mm)
270		return 0;
271
272	mutex_lock(&tegra->mm_lock);
273	iommu_unmap(tegra->domain, bo->iova, bo->size);
274	drm_mm_remove_node(bo->mm);
275	mutex_unlock(&tegra->mm_lock);
276
277	kfree(bo->mm);
278
279	return 0;
280}
281
282static const struct drm_gem_object_funcs tegra_gem_object_funcs = {
283	.free = tegra_bo_free_object,
284	.export = tegra_gem_prime_export,
285	.vm_ops = &tegra_bo_vm_ops,
286};
287
288static struct tegra_bo *tegra_bo_alloc_object(struct drm_device *drm,
289					      size_t size)
290{
291	struct tegra_bo *bo;
292	int err;
293
294	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
295	if (!bo)
296		return ERR_PTR(-ENOMEM);
297
298	bo->gem.funcs = &tegra_gem_object_funcs;
299
300	host1x_bo_init(&bo->base, &tegra_bo_ops);
301	size = round_up(size, PAGE_SIZE);
302
303	err = drm_gem_object_init(drm, &bo->gem, size);
304	if (err < 0)
305		goto free;
306
307	err = drm_gem_create_mmap_offset(&bo->gem);
308	if (err < 0)
309		goto release;
310
311	return bo;
312
313release:
314	drm_gem_object_release(&bo->gem);
315free:
316	kfree(bo);
317	return ERR_PTR(err);
318}
319
320static void tegra_bo_free(struct drm_device *drm, struct tegra_bo *bo)
321{
322	if (bo->pages) {
323		dma_unmap_sgtable(drm->dev, bo->sgt, DMA_FROM_DEVICE, 0);
324		drm_gem_put_pages(&bo->gem, bo->pages, true, true);
325		sg_free_table(bo->sgt);
326		kfree(bo->sgt);
327	} else if (bo->vaddr) {
328		dma_free_wc(drm->dev, bo->gem.size, bo->vaddr, bo->iova);
329	}
330}
331
332static int tegra_bo_get_pages(struct drm_device *drm, struct tegra_bo *bo)
333{
334	int err;
335
336	bo->pages = drm_gem_get_pages(&bo->gem);
337	if (IS_ERR(bo->pages))
338		return PTR_ERR(bo->pages);
339
340	bo->num_pages = bo->gem.size >> PAGE_SHIFT;
341
342	bo->sgt = drm_prime_pages_to_sg(bo->gem.dev, bo->pages, bo->num_pages);
343	if (IS_ERR(bo->sgt)) {
344		err = PTR_ERR(bo->sgt);
345		goto put_pages;
346	}
347
348	err = dma_map_sgtable(drm->dev, bo->sgt, DMA_FROM_DEVICE, 0);
349	if (err)
350		goto free_sgt;
351
352	return 0;
353
354free_sgt:
355	sg_free_table(bo->sgt);
356	kfree(bo->sgt);
357put_pages:
358	drm_gem_put_pages(&bo->gem, bo->pages, false, false);
359	return err;
360}
361
362static int tegra_bo_alloc(struct drm_device *drm, struct tegra_bo *bo)
363{
364	struct tegra_drm *tegra = drm->dev_private;
365	int err;
366
367	if (tegra->domain) {
368		err = tegra_bo_get_pages(drm, bo);
369		if (err < 0)
370			return err;
371
372		err = tegra_bo_iommu_map(tegra, bo);
373		if (err < 0) {
374			tegra_bo_free(drm, bo);
375			return err;
376		}
377	} else {
378		size_t size = bo->gem.size;
379
380		bo->vaddr = dma_alloc_wc(drm->dev, size, &bo->iova,
381					 GFP_KERNEL | __GFP_NOWARN);
382		if (!bo->vaddr) {
383			dev_err(drm->dev,
384				"failed to allocate buffer of size %zu\n",
385				size);
386			return -ENOMEM;
387		}
388	}
389
390	return 0;
391}
392
393struct tegra_bo *tegra_bo_create(struct drm_device *drm, size_t size,
394				 unsigned long flags)
395{
396	struct tegra_bo *bo;
397	int err;
398
399	bo = tegra_bo_alloc_object(drm, size);
400	if (IS_ERR(bo))
401		return bo;
402
403	err = tegra_bo_alloc(drm, bo);
404	if (err < 0)
405		goto release;
406
407	if (flags & DRM_TEGRA_GEM_CREATE_TILED)
408		bo->tiling.mode = TEGRA_BO_TILING_MODE_TILED;
409
410	if (flags & DRM_TEGRA_GEM_CREATE_BOTTOM_UP)
411		bo->flags |= TEGRA_BO_BOTTOM_UP;
412
413	return bo;
414
415release:
416	drm_gem_object_release(&bo->gem);
417	kfree(bo);
418	return ERR_PTR(err);
419}
420
421struct tegra_bo *tegra_bo_create_with_handle(struct drm_file *file,
422					     struct drm_device *drm,
423					     size_t size,
424					     unsigned long flags,
425					     u32 *handle)
426{
427	struct tegra_bo *bo;
428	int err;
429
430	bo = tegra_bo_create(drm, size, flags);
431	if (IS_ERR(bo))
432		return bo;
433
434	err = drm_gem_handle_create(file, &bo->gem, handle);
435	if (err) {
436		tegra_bo_free_object(&bo->gem);
437		return ERR_PTR(err);
438	}
439
440	drm_gem_object_put(&bo->gem);
441
442	return bo;
443}
444
445static struct tegra_bo *tegra_bo_import(struct drm_device *drm,
446					struct dma_buf *buf)
447{
448	struct tegra_drm *tegra = drm->dev_private;
449	struct dma_buf_attachment *attach;
450	struct tegra_bo *bo;
451	int err;
452
453	bo = tegra_bo_alloc_object(drm, buf->size);
454	if (IS_ERR(bo))
455		return bo;
456
457	attach = dma_buf_attach(buf, drm->dev);
458	if (IS_ERR(attach)) {
459		err = PTR_ERR(attach);
460		goto free;
461	}
462
463	get_dma_buf(buf);
464
465	bo->sgt = dma_buf_map_attachment_unlocked(attach, DMA_TO_DEVICE);
466	if (IS_ERR(bo->sgt)) {
467		err = PTR_ERR(bo->sgt);
468		goto detach;
469	}
470
471	if (tegra->domain) {
472		err = tegra_bo_iommu_map(tegra, bo);
473		if (err < 0)
474			goto detach;
475	}
476
477	bo->gem.import_attach = attach;
478
479	return bo;
480
481detach:
482	if (!IS_ERR_OR_NULL(bo->sgt))
483		dma_buf_unmap_attachment_unlocked(attach, bo->sgt, DMA_TO_DEVICE);
484
485	dma_buf_detach(buf, attach);
486	dma_buf_put(buf);
487free:
488	drm_gem_object_release(&bo->gem);
489	kfree(bo);
490	return ERR_PTR(err);
491}
492
493void tegra_bo_free_object(struct drm_gem_object *gem)
494{
495	struct tegra_drm *tegra = gem->dev->dev_private;
496	struct host1x_bo_mapping *mapping, *tmp;
497	struct tegra_bo *bo = to_tegra_bo(gem);
498
499	/* remove all mappings of this buffer object from any caches */
500	list_for_each_entry_safe(mapping, tmp, &bo->base.mappings, list) {
501		if (mapping->cache)
502			host1x_bo_unpin(mapping);
503		else
504			dev_err(gem->dev->dev, "mapping %p stale for device %s\n", mapping,
505				dev_name(mapping->dev));
506	}
507
508	if (tegra->domain)
509		tegra_bo_iommu_unmap(tegra, bo);
510
511	if (gem->import_attach) {
512		dma_buf_unmap_attachment_unlocked(gem->import_attach, bo->sgt,
513						  DMA_TO_DEVICE);
514		drm_prime_gem_destroy(gem, NULL);
515	} else {
516		tegra_bo_free(gem->dev, bo);
517	}
518
519	drm_gem_object_release(gem);
520	kfree(bo);
521}
522
523int tegra_bo_dumb_create(struct drm_file *file, struct drm_device *drm,
524			 struct drm_mode_create_dumb *args)
525{
526	unsigned int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
527	struct tegra_drm *tegra = drm->dev_private;
528	struct tegra_bo *bo;
529
530	args->pitch = round_up(min_pitch, tegra->pitch_align);
531	args->size = args->pitch * args->height;
532
533	bo = tegra_bo_create_with_handle(file, drm, args->size, 0,
534					 &args->handle);
535	if (IS_ERR(bo))
536		return PTR_ERR(bo);
537
538	return 0;
539}
540
541static vm_fault_t tegra_bo_fault(struct vm_fault *vmf)
542{
543	struct vm_area_struct *vma = vmf->vma;
544	struct drm_gem_object *gem = vma->vm_private_data;
545	struct tegra_bo *bo = to_tegra_bo(gem);
546	struct page *page;
547	pgoff_t offset;
548
549	if (!bo->pages)
550		return VM_FAULT_SIGBUS;
551
552	offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
553	page = bo->pages[offset];
554
555	return vmf_insert_page(vma, vmf->address, page);
556}
557
558const struct vm_operations_struct tegra_bo_vm_ops = {
559	.fault = tegra_bo_fault,
560	.open = drm_gem_vm_open,
561	.close = drm_gem_vm_close,
562};
563
564int __tegra_gem_mmap(struct drm_gem_object *gem, struct vm_area_struct *vma)
565{
566	struct tegra_bo *bo = to_tegra_bo(gem);
567
568	if (!bo->pages) {
569		unsigned long vm_pgoff = vma->vm_pgoff;
570		int err;
571
572		/*
573		 * Clear the VM_PFNMAP flag that was set by drm_gem_mmap(),
574		 * and set the vm_pgoff (used as a fake buffer offset by DRM)
575		 * to 0 as we want to map the whole buffer.
576		 */
577		vma->vm_flags &= ~VM_PFNMAP;
578		vma->vm_pgoff = 0;
579
580		err = dma_mmap_wc(gem->dev->dev, vma, bo->vaddr, bo->iova,
581				  gem->size);
582		if (err < 0) {
583			drm_gem_vm_close(vma);
584			return err;
585		}
586
587		vma->vm_pgoff = vm_pgoff;
588	} else {
589		pgprot_t prot = vm_get_page_prot(vma->vm_flags);
590
591		vma->vm_flags |= VM_MIXEDMAP;
592		vma->vm_flags &= ~VM_PFNMAP;
593
594		vma->vm_page_prot = pgprot_writecombine(prot);
595	}
596
597	return 0;
598}
599
600int tegra_drm_mmap(struct file *file, struct vm_area_struct *vma)
601{
602	struct drm_gem_object *gem;
603	int err;
604
605	err = drm_gem_mmap(file, vma);
606	if (err < 0)
607		return err;
608
609	gem = vma->vm_private_data;
610
611	return __tegra_gem_mmap(gem, vma);
612}
613
614static struct sg_table *
615tegra_gem_prime_map_dma_buf(struct dma_buf_attachment *attach,
616			    enum dma_data_direction dir)
617{
618	struct drm_gem_object *gem = attach->dmabuf->priv;
619	struct tegra_bo *bo = to_tegra_bo(gem);
620	struct sg_table *sgt;
621
622	sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
623	if (!sgt)
624		return NULL;
625
626	if (bo->pages) {
627		if (sg_alloc_table_from_pages(sgt, bo->pages, bo->num_pages,
628					      0, gem->size, GFP_KERNEL) < 0)
629			goto free;
630	} else {
631		if (dma_get_sgtable(attach->dev, sgt, bo->vaddr, bo->iova,
632				    gem->size) < 0)
633			goto free;
634	}
635
636	if (dma_map_sgtable(attach->dev, sgt, dir, 0))
637		goto free;
638
639	return sgt;
640
641free:
642	sg_free_table(sgt);
643	kfree(sgt);
644	return NULL;
645}
646
647static void tegra_gem_prime_unmap_dma_buf(struct dma_buf_attachment *attach,
648					  struct sg_table *sgt,
649					  enum dma_data_direction dir)
650{
651	struct drm_gem_object *gem = attach->dmabuf->priv;
652	struct tegra_bo *bo = to_tegra_bo(gem);
653
654	if (bo->pages)
655		dma_unmap_sgtable(attach->dev, sgt, dir, 0);
656
657	sg_free_table(sgt);
658	kfree(sgt);
659}
660
661static void tegra_gem_prime_release(struct dma_buf *buf)
662{
663	drm_gem_dmabuf_release(buf);
664}
665
666static int tegra_gem_prime_begin_cpu_access(struct dma_buf *buf,
667					    enum dma_data_direction direction)
668{
669	struct drm_gem_object *gem = buf->priv;
670	struct tegra_bo *bo = to_tegra_bo(gem);
671	struct drm_device *drm = gem->dev;
672
673	if (bo->pages)
674		dma_sync_sgtable_for_cpu(drm->dev, bo->sgt, DMA_FROM_DEVICE);
675
676	return 0;
677}
678
679static int tegra_gem_prime_end_cpu_access(struct dma_buf *buf,
680					  enum dma_data_direction direction)
681{
682	struct drm_gem_object *gem = buf->priv;
683	struct tegra_bo *bo = to_tegra_bo(gem);
684	struct drm_device *drm = gem->dev;
685
686	if (bo->pages)
687		dma_sync_sgtable_for_device(drm->dev, bo->sgt, DMA_TO_DEVICE);
688
689	return 0;
690}
691
692static int tegra_gem_prime_mmap(struct dma_buf *buf, struct vm_area_struct *vma)
693{
694	struct drm_gem_object *gem = buf->priv;
695	int err;
696
697	dma_resv_assert_held(buf->resv);
698
699	err = drm_gem_mmap_obj(gem, gem->size, vma);
700	if (err < 0)
701		return err;
702
703	return __tegra_gem_mmap(gem, vma);
704}
705
706static int tegra_gem_prime_vmap(struct dma_buf *buf, struct iosys_map *map)
707{
708	struct drm_gem_object *gem = buf->priv;
709	struct tegra_bo *bo = to_tegra_bo(gem);
710	void *vaddr;
711
712	vaddr = tegra_bo_mmap(&bo->base);
713	if (IS_ERR(vaddr))
714		return PTR_ERR(vaddr);
715
716	iosys_map_set_vaddr(map, vaddr);
717
718	return 0;
719}
720
721static void tegra_gem_prime_vunmap(struct dma_buf *buf, struct iosys_map *map)
722{
723	struct drm_gem_object *gem = buf->priv;
724	struct tegra_bo *bo = to_tegra_bo(gem);
725
726	tegra_bo_munmap(&bo->base, map->vaddr);
727}
728
729static const struct dma_buf_ops tegra_gem_prime_dmabuf_ops = {
730	.map_dma_buf = tegra_gem_prime_map_dma_buf,
731	.unmap_dma_buf = tegra_gem_prime_unmap_dma_buf,
732	.release = tegra_gem_prime_release,
733	.begin_cpu_access = tegra_gem_prime_begin_cpu_access,
734	.end_cpu_access = tegra_gem_prime_end_cpu_access,
735	.mmap = tegra_gem_prime_mmap,
736	.vmap = tegra_gem_prime_vmap,
737	.vunmap = tegra_gem_prime_vunmap,
738};
739
740struct dma_buf *tegra_gem_prime_export(struct drm_gem_object *gem,
741				       int flags)
742{
743	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
744
745	exp_info.exp_name = KBUILD_MODNAME;
746	exp_info.owner = gem->dev->driver->fops->owner;
747	exp_info.ops = &tegra_gem_prime_dmabuf_ops;
748	exp_info.size = gem->size;
749	exp_info.flags = flags;
750	exp_info.priv = gem;
751
752	return drm_gem_dmabuf_export(gem->dev, &exp_info);
753}
754
755struct drm_gem_object *tegra_gem_prime_import(struct drm_device *drm,
756					      struct dma_buf *buf)
757{
758	struct tegra_bo *bo;
759
760	if (buf->ops == &tegra_gem_prime_dmabuf_ops) {
761		struct drm_gem_object *gem = buf->priv;
762
763		if (gem->dev == drm) {
764			drm_gem_object_get(gem);
765			return gem;
766		}
767	}
768
769	bo = tegra_bo_import(drm, buf);
770	if (IS_ERR(bo))
771		return ERR_CAST(bo);
772
773	return &bo->gem;
774}
775
776struct host1x_bo *tegra_gem_lookup(struct drm_file *file, u32 handle)
777{
778	struct drm_gem_object *gem;
779	struct tegra_bo *bo;
780
781	gem = drm_gem_object_lookup(file, handle);
782	if (!gem)
783		return NULL;
784
785	bo = to_tegra_bo(gem);
786	return &bo->base;
787}