xref: /openbmc/linux/drivers/gpu/drm/tegra/gem.c (revision bacf743e)
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 
24 MODULE_IMPORT_NS(DMA_BUF);
25 
26 static 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 
46 static inline unsigned int sgt_dma_count_chunks(struct sg_table *sgt)
47 {
48 	return sg_dma_count_chunks(sgt->sgl, sgt->nents);
49 }
50 
51 static 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 
58 static 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(map->attach, direction);
88 		if (IS_ERR(map->sgt)) {
89 			dma_buf_detach(buf, map->attach);
90 			err = PTR_ERR(map->sgt);
91 			goto free;
92 		}
93 
94 		err = sgt_dma_count_chunks(map->sgt);
95 		map->size = gem->size;
96 
97 		goto out;
98 	}
99 
100 	/*
101 	 * If we don't have a mapping for this buffer yet, return an SG table
102 	 * so that host1x can do the mapping for us via the DMA API.
103 	 */
104 	map->sgt = kzalloc(sizeof(*map->sgt), GFP_KERNEL);
105 	if (!map->sgt) {
106 		err = -ENOMEM;
107 		goto free;
108 	}
109 
110 	if (obj->pages) {
111 		/*
112 		 * If the buffer object was allocated from the explicit IOMMU
113 		 * API code paths, construct an SG table from the pages.
114 		 */
115 		err = sg_alloc_table_from_pages(map->sgt, obj->pages, obj->num_pages, 0, gem->size,
116 						GFP_KERNEL);
117 		if (err < 0)
118 			goto free;
119 	} else {
120 		/*
121 		 * If the buffer object had no pages allocated and if it was
122 		 * not imported, it had to be allocated with the DMA API, so
123 		 * the DMA API helper can be used.
124 		 */
125 		err = dma_get_sgtable(dev, map->sgt, obj->vaddr, obj->iova, gem->size);
126 		if (err < 0)
127 			goto free;
128 	}
129 
130 	err = dma_map_sgtable(dev, map->sgt, direction, 0);
131 	if (err)
132 		goto free_sgt;
133 
134 out:
135 	/*
136 	 * If we've manually mapped the buffer object through the IOMMU, make sure to return the
137 	 * existing IOVA address of our mapping.
138 	 */
139 	if (!obj->mm) {
140 		map->phys = sg_dma_address(map->sgt->sgl);
141 		map->chunks = err;
142 	} else {
143 		map->phys = obj->iova;
144 		map->chunks = 1;
145 	}
146 
147 	map->size = gem->size;
148 
149 	return map;
150 
151 free_sgt:
152 	sg_free_table(map->sgt);
153 free:
154 	kfree(map->sgt);
155 	kfree(map);
156 	return ERR_PTR(err);
157 }
158 
159 static void tegra_bo_unpin(struct host1x_bo_mapping *map)
160 {
161 	if (map->attach) {
162 		dma_buf_unmap_attachment(map->attach, map->sgt, map->direction);
163 		dma_buf_detach(map->attach->dmabuf, map->attach);
164 	} else {
165 		dma_unmap_sgtable(map->dev, map->sgt, map->direction, 0);
166 		sg_free_table(map->sgt);
167 		kfree(map->sgt);
168 	}
169 
170 	host1x_bo_put(map->bo);
171 	kfree(map);
172 }
173 
174 static void *tegra_bo_mmap(struct host1x_bo *bo)
175 {
176 	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
177 	struct iosys_map map;
178 	int ret;
179 
180 	if (obj->vaddr) {
181 		return obj->vaddr;
182 	} else if (obj->gem.import_attach) {
183 		ret = dma_buf_vmap(obj->gem.import_attach->dmabuf, &map);
184 		return ret ? NULL : map.vaddr;
185 	} else {
186 		return vmap(obj->pages, obj->num_pages, VM_MAP,
187 			    pgprot_writecombine(PAGE_KERNEL));
188 	}
189 }
190 
191 static void tegra_bo_munmap(struct host1x_bo *bo, void *addr)
192 {
193 	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
194 	struct iosys_map map = IOSYS_MAP_INIT_VADDR(addr);
195 
196 	if (obj->vaddr)
197 		return;
198 	else if (obj->gem.import_attach)
199 		dma_buf_vunmap(obj->gem.import_attach->dmabuf, &map);
200 	else
201 		vunmap(addr);
202 }
203 
204 static struct host1x_bo *tegra_bo_get(struct host1x_bo *bo)
205 {
206 	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
207 
208 	drm_gem_object_get(&obj->gem);
209 
210 	return bo;
211 }
212 
213 static const struct host1x_bo_ops tegra_bo_ops = {
214 	.get = tegra_bo_get,
215 	.put = tegra_bo_put,
216 	.pin = tegra_bo_pin,
217 	.unpin = tegra_bo_unpin,
218 	.mmap = tegra_bo_mmap,
219 	.munmap = tegra_bo_munmap,
220 };
221 
222 static int tegra_bo_iommu_map(struct tegra_drm *tegra, struct tegra_bo *bo)
223 {
224 	int prot = IOMMU_READ | IOMMU_WRITE;
225 	int err;
226 
227 	if (bo->mm)
228 		return -EBUSY;
229 
230 	bo->mm = kzalloc(sizeof(*bo->mm), GFP_KERNEL);
231 	if (!bo->mm)
232 		return -ENOMEM;
233 
234 	mutex_lock(&tegra->mm_lock);
235 
236 	err = drm_mm_insert_node_generic(&tegra->mm,
237 					 bo->mm, bo->gem.size, PAGE_SIZE, 0, 0);
238 	if (err < 0) {
239 		dev_err(tegra->drm->dev, "out of I/O virtual memory: %d\n",
240 			err);
241 		goto unlock;
242 	}
243 
244 	bo->iova = bo->mm->start;
245 
246 	bo->size = iommu_map_sgtable(tegra->domain, bo->iova, bo->sgt, prot);
247 	if (!bo->size) {
248 		dev_err(tegra->drm->dev, "failed to map buffer\n");
249 		err = -ENOMEM;
250 		goto remove;
251 	}
252 
253 	mutex_unlock(&tegra->mm_lock);
254 
255 	return 0;
256 
257 remove:
258 	drm_mm_remove_node(bo->mm);
259 unlock:
260 	mutex_unlock(&tegra->mm_lock);
261 	kfree(bo->mm);
262 	return err;
263 }
264 
265 static int tegra_bo_iommu_unmap(struct tegra_drm *tegra, struct tegra_bo *bo)
266 {
267 	if (!bo->mm)
268 		return 0;
269 
270 	mutex_lock(&tegra->mm_lock);
271 	iommu_unmap(tegra->domain, bo->iova, bo->size);
272 	drm_mm_remove_node(bo->mm);
273 	mutex_unlock(&tegra->mm_lock);
274 
275 	kfree(bo->mm);
276 
277 	return 0;
278 }
279 
280 static const struct drm_gem_object_funcs tegra_gem_object_funcs = {
281 	.free = tegra_bo_free_object,
282 	.export = tegra_gem_prime_export,
283 	.vm_ops = &tegra_bo_vm_ops,
284 };
285 
286 static struct tegra_bo *tegra_bo_alloc_object(struct drm_device *drm,
287 					      size_t size)
288 {
289 	struct tegra_bo *bo;
290 	int err;
291 
292 	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
293 	if (!bo)
294 		return ERR_PTR(-ENOMEM);
295 
296 	bo->gem.funcs = &tegra_gem_object_funcs;
297 
298 	host1x_bo_init(&bo->base, &tegra_bo_ops);
299 	size = round_up(size, PAGE_SIZE);
300 
301 	err = drm_gem_object_init(drm, &bo->gem, size);
302 	if (err < 0)
303 		goto free;
304 
305 	err = drm_gem_create_mmap_offset(&bo->gem);
306 	if (err < 0)
307 		goto release;
308 
309 	return bo;
310 
311 release:
312 	drm_gem_object_release(&bo->gem);
313 free:
314 	kfree(bo);
315 	return ERR_PTR(err);
316 }
317 
318 static void tegra_bo_free(struct drm_device *drm, struct tegra_bo *bo)
319 {
320 	if (bo->pages) {
321 		dma_unmap_sgtable(drm->dev, bo->sgt, DMA_FROM_DEVICE, 0);
322 		drm_gem_put_pages(&bo->gem, bo->pages, true, true);
323 		sg_free_table(bo->sgt);
324 		kfree(bo->sgt);
325 	} else if (bo->vaddr) {
326 		dma_free_wc(drm->dev, bo->gem.size, bo->vaddr, bo->iova);
327 	}
328 }
329 
330 static int tegra_bo_get_pages(struct drm_device *drm, struct tegra_bo *bo)
331 {
332 	int err;
333 
334 	bo->pages = drm_gem_get_pages(&bo->gem);
335 	if (IS_ERR(bo->pages))
336 		return PTR_ERR(bo->pages);
337 
338 	bo->num_pages = bo->gem.size >> PAGE_SHIFT;
339 
340 	bo->sgt = drm_prime_pages_to_sg(bo->gem.dev, bo->pages, bo->num_pages);
341 	if (IS_ERR(bo->sgt)) {
342 		err = PTR_ERR(bo->sgt);
343 		goto put_pages;
344 	}
345 
346 	err = dma_map_sgtable(drm->dev, bo->sgt, DMA_FROM_DEVICE, 0);
347 	if (err)
348 		goto free_sgt;
349 
350 	return 0;
351 
352 free_sgt:
353 	sg_free_table(bo->sgt);
354 	kfree(bo->sgt);
355 put_pages:
356 	drm_gem_put_pages(&bo->gem, bo->pages, false, false);
357 	return err;
358 }
359 
360 static int tegra_bo_alloc(struct drm_device *drm, struct tegra_bo *bo)
361 {
362 	struct tegra_drm *tegra = drm->dev_private;
363 	int err;
364 
365 	if (tegra->domain) {
366 		err = tegra_bo_get_pages(drm, bo);
367 		if (err < 0)
368 			return err;
369 
370 		err = tegra_bo_iommu_map(tegra, bo);
371 		if (err < 0) {
372 			tegra_bo_free(drm, bo);
373 			return err;
374 		}
375 	} else {
376 		size_t size = bo->gem.size;
377 
378 		bo->vaddr = dma_alloc_wc(drm->dev, size, &bo->iova,
379 					 GFP_KERNEL | __GFP_NOWARN);
380 		if (!bo->vaddr) {
381 			dev_err(drm->dev,
382 				"failed to allocate buffer of size %zu\n",
383 				size);
384 			return -ENOMEM;
385 		}
386 	}
387 
388 	return 0;
389 }
390 
391 struct tegra_bo *tegra_bo_create(struct drm_device *drm, size_t size,
392 				 unsigned long flags)
393 {
394 	struct tegra_bo *bo;
395 	int err;
396 
397 	bo = tegra_bo_alloc_object(drm, size);
398 	if (IS_ERR(bo))
399 		return bo;
400 
401 	err = tegra_bo_alloc(drm, bo);
402 	if (err < 0)
403 		goto release;
404 
405 	if (flags & DRM_TEGRA_GEM_CREATE_TILED)
406 		bo->tiling.mode = TEGRA_BO_TILING_MODE_TILED;
407 
408 	if (flags & DRM_TEGRA_GEM_CREATE_BOTTOM_UP)
409 		bo->flags |= TEGRA_BO_BOTTOM_UP;
410 
411 	return bo;
412 
413 release:
414 	drm_gem_object_release(&bo->gem);
415 	kfree(bo);
416 	return ERR_PTR(err);
417 }
418 
419 struct tegra_bo *tegra_bo_create_with_handle(struct drm_file *file,
420 					     struct drm_device *drm,
421 					     size_t size,
422 					     unsigned long flags,
423 					     u32 *handle)
424 {
425 	struct tegra_bo *bo;
426 	int err;
427 
428 	bo = tegra_bo_create(drm, size, flags);
429 	if (IS_ERR(bo))
430 		return bo;
431 
432 	err = drm_gem_handle_create(file, &bo->gem, handle);
433 	if (err) {
434 		tegra_bo_free_object(&bo->gem);
435 		return ERR_PTR(err);
436 	}
437 
438 	drm_gem_object_put(&bo->gem);
439 
440 	return bo;
441 }
442 
443 static struct tegra_bo *tegra_bo_import(struct drm_device *drm,
444 					struct dma_buf *buf)
445 {
446 	struct tegra_drm *tegra = drm->dev_private;
447 	struct dma_buf_attachment *attach;
448 	struct tegra_bo *bo;
449 	int err;
450 
451 	bo = tegra_bo_alloc_object(drm, buf->size);
452 	if (IS_ERR(bo))
453 		return bo;
454 
455 	attach = dma_buf_attach(buf, drm->dev);
456 	if (IS_ERR(attach)) {
457 		err = PTR_ERR(attach);
458 		goto free;
459 	}
460 
461 	get_dma_buf(buf);
462 
463 	bo->sgt = dma_buf_map_attachment(attach, DMA_TO_DEVICE);
464 	if (IS_ERR(bo->sgt)) {
465 		err = PTR_ERR(bo->sgt);
466 		goto detach;
467 	}
468 
469 	if (tegra->domain) {
470 		err = tegra_bo_iommu_map(tegra, bo);
471 		if (err < 0)
472 			goto detach;
473 	}
474 
475 	bo->gem.import_attach = attach;
476 
477 	return bo;
478 
479 detach:
480 	if (!IS_ERR_OR_NULL(bo->sgt))
481 		dma_buf_unmap_attachment(attach, bo->sgt, DMA_TO_DEVICE);
482 
483 	dma_buf_detach(buf, attach);
484 	dma_buf_put(buf);
485 free:
486 	drm_gem_object_release(&bo->gem);
487 	kfree(bo);
488 	return ERR_PTR(err);
489 }
490 
491 void tegra_bo_free_object(struct drm_gem_object *gem)
492 {
493 	struct tegra_drm *tegra = gem->dev->dev_private;
494 	struct host1x_bo_mapping *mapping, *tmp;
495 	struct tegra_bo *bo = to_tegra_bo(gem);
496 
497 	/* remove all mappings of this buffer object from any caches */
498 	list_for_each_entry_safe(mapping, tmp, &bo->base.mappings, list) {
499 		if (mapping->cache)
500 			host1x_bo_unpin(mapping);
501 		else
502 			dev_err(gem->dev->dev, "mapping %p stale for device %s\n", mapping,
503 				dev_name(mapping->dev));
504 	}
505 
506 	if (tegra->domain)
507 		tegra_bo_iommu_unmap(tegra, bo);
508 
509 	if (gem->import_attach) {
510 		dma_buf_unmap_attachment(gem->import_attach, bo->sgt,
511 					 DMA_TO_DEVICE);
512 		drm_prime_gem_destroy(gem, NULL);
513 	} else {
514 		tegra_bo_free(gem->dev, bo);
515 	}
516 
517 	drm_gem_object_release(gem);
518 	kfree(bo);
519 }
520 
521 int tegra_bo_dumb_create(struct drm_file *file, struct drm_device *drm,
522 			 struct drm_mode_create_dumb *args)
523 {
524 	unsigned int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
525 	struct tegra_drm *tegra = drm->dev_private;
526 	struct tegra_bo *bo;
527 
528 	args->pitch = round_up(min_pitch, tegra->pitch_align);
529 	args->size = args->pitch * args->height;
530 
531 	bo = tegra_bo_create_with_handle(file, drm, args->size, 0,
532 					 &args->handle);
533 	if (IS_ERR(bo))
534 		return PTR_ERR(bo);
535 
536 	return 0;
537 }
538 
539 static vm_fault_t tegra_bo_fault(struct vm_fault *vmf)
540 {
541 	struct vm_area_struct *vma = vmf->vma;
542 	struct drm_gem_object *gem = vma->vm_private_data;
543 	struct tegra_bo *bo = to_tegra_bo(gem);
544 	struct page *page;
545 	pgoff_t offset;
546 
547 	if (!bo->pages)
548 		return VM_FAULT_SIGBUS;
549 
550 	offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
551 	page = bo->pages[offset];
552 
553 	return vmf_insert_page(vma, vmf->address, page);
554 }
555 
556 const struct vm_operations_struct tegra_bo_vm_ops = {
557 	.fault = tegra_bo_fault,
558 	.open = drm_gem_vm_open,
559 	.close = drm_gem_vm_close,
560 };
561 
562 int __tegra_gem_mmap(struct drm_gem_object *gem, struct vm_area_struct *vma)
563 {
564 	struct tegra_bo *bo = to_tegra_bo(gem);
565 
566 	if (!bo->pages) {
567 		unsigned long vm_pgoff = vma->vm_pgoff;
568 		int err;
569 
570 		/*
571 		 * Clear the VM_PFNMAP flag that was set by drm_gem_mmap(),
572 		 * and set the vm_pgoff (used as a fake buffer offset by DRM)
573 		 * to 0 as we want to map the whole buffer.
574 		 */
575 		vma->vm_flags &= ~VM_PFNMAP;
576 		vma->vm_pgoff = 0;
577 
578 		err = dma_mmap_wc(gem->dev->dev, vma, bo->vaddr, bo->iova,
579 				  gem->size);
580 		if (err < 0) {
581 			drm_gem_vm_close(vma);
582 			return err;
583 		}
584 
585 		vma->vm_pgoff = vm_pgoff;
586 	} else {
587 		pgprot_t prot = vm_get_page_prot(vma->vm_flags);
588 
589 		vma->vm_flags |= VM_MIXEDMAP;
590 		vma->vm_flags &= ~VM_PFNMAP;
591 
592 		vma->vm_page_prot = pgprot_writecombine(prot);
593 	}
594 
595 	return 0;
596 }
597 
598 int tegra_drm_mmap(struct file *file, struct vm_area_struct *vma)
599 {
600 	struct drm_gem_object *gem;
601 	int err;
602 
603 	err = drm_gem_mmap(file, vma);
604 	if (err < 0)
605 		return err;
606 
607 	gem = vma->vm_private_data;
608 
609 	return __tegra_gem_mmap(gem, vma);
610 }
611 
612 static struct sg_table *
613 tegra_gem_prime_map_dma_buf(struct dma_buf_attachment *attach,
614 			    enum dma_data_direction dir)
615 {
616 	struct drm_gem_object *gem = attach->dmabuf->priv;
617 	struct tegra_bo *bo = to_tegra_bo(gem);
618 	struct sg_table *sgt;
619 
620 	sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
621 	if (!sgt)
622 		return NULL;
623 
624 	if (bo->pages) {
625 		if (sg_alloc_table_from_pages(sgt, bo->pages, bo->num_pages,
626 					      0, gem->size, GFP_KERNEL) < 0)
627 			goto free;
628 	} else {
629 		if (dma_get_sgtable(attach->dev, sgt, bo->vaddr, bo->iova,
630 				    gem->size) < 0)
631 			goto free;
632 	}
633 
634 	if (dma_map_sgtable(attach->dev, sgt, dir, 0))
635 		goto free;
636 
637 	return sgt;
638 
639 free:
640 	sg_free_table(sgt);
641 	kfree(sgt);
642 	return NULL;
643 }
644 
645 static void tegra_gem_prime_unmap_dma_buf(struct dma_buf_attachment *attach,
646 					  struct sg_table *sgt,
647 					  enum dma_data_direction dir)
648 {
649 	struct drm_gem_object *gem = attach->dmabuf->priv;
650 	struct tegra_bo *bo = to_tegra_bo(gem);
651 
652 	if (bo->pages)
653 		dma_unmap_sgtable(attach->dev, sgt, dir, 0);
654 
655 	sg_free_table(sgt);
656 	kfree(sgt);
657 }
658 
659 static void tegra_gem_prime_release(struct dma_buf *buf)
660 {
661 	drm_gem_dmabuf_release(buf);
662 }
663 
664 static int tegra_gem_prime_begin_cpu_access(struct dma_buf *buf,
665 					    enum dma_data_direction direction)
666 {
667 	struct drm_gem_object *gem = buf->priv;
668 	struct tegra_bo *bo = to_tegra_bo(gem);
669 	struct drm_device *drm = gem->dev;
670 
671 	if (bo->pages)
672 		dma_sync_sgtable_for_cpu(drm->dev, bo->sgt, DMA_FROM_DEVICE);
673 
674 	return 0;
675 }
676 
677 static int tegra_gem_prime_end_cpu_access(struct dma_buf *buf,
678 					  enum dma_data_direction direction)
679 {
680 	struct drm_gem_object *gem = buf->priv;
681 	struct tegra_bo *bo = to_tegra_bo(gem);
682 	struct drm_device *drm = gem->dev;
683 
684 	if (bo->pages)
685 		dma_sync_sgtable_for_device(drm->dev, bo->sgt, DMA_TO_DEVICE);
686 
687 	return 0;
688 }
689 
690 static int tegra_gem_prime_mmap(struct dma_buf *buf, struct vm_area_struct *vma)
691 {
692 	struct drm_gem_object *gem = buf->priv;
693 	int err;
694 
695 	err = drm_gem_mmap_obj(gem, gem->size, vma);
696 	if (err < 0)
697 		return err;
698 
699 	return __tegra_gem_mmap(gem, vma);
700 }
701 
702 static int tegra_gem_prime_vmap(struct dma_buf *buf, struct iosys_map *map)
703 {
704 	struct drm_gem_object *gem = buf->priv;
705 	struct tegra_bo *bo = to_tegra_bo(gem);
706 
707 	iosys_map_set_vaddr(map, bo->vaddr);
708 
709 	return 0;
710 }
711 
712 static void tegra_gem_prime_vunmap(struct dma_buf *buf, struct iosys_map *map)
713 {
714 }
715 
716 static const struct dma_buf_ops tegra_gem_prime_dmabuf_ops = {
717 	.map_dma_buf = tegra_gem_prime_map_dma_buf,
718 	.unmap_dma_buf = tegra_gem_prime_unmap_dma_buf,
719 	.release = tegra_gem_prime_release,
720 	.begin_cpu_access = tegra_gem_prime_begin_cpu_access,
721 	.end_cpu_access = tegra_gem_prime_end_cpu_access,
722 	.mmap = tegra_gem_prime_mmap,
723 	.vmap = tegra_gem_prime_vmap,
724 	.vunmap = tegra_gem_prime_vunmap,
725 };
726 
727 struct dma_buf *tegra_gem_prime_export(struct drm_gem_object *gem,
728 				       int flags)
729 {
730 	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
731 
732 	exp_info.exp_name = KBUILD_MODNAME;
733 	exp_info.owner = gem->dev->driver->fops->owner;
734 	exp_info.ops = &tegra_gem_prime_dmabuf_ops;
735 	exp_info.size = gem->size;
736 	exp_info.flags = flags;
737 	exp_info.priv = gem;
738 
739 	return drm_gem_dmabuf_export(gem->dev, &exp_info);
740 }
741 
742 struct drm_gem_object *tegra_gem_prime_import(struct drm_device *drm,
743 					      struct dma_buf *buf)
744 {
745 	struct tegra_bo *bo;
746 
747 	if (buf->ops == &tegra_gem_prime_dmabuf_ops) {
748 		struct drm_gem_object *gem = buf->priv;
749 
750 		if (gem->dev == drm) {
751 			drm_gem_object_get(gem);
752 			return gem;
753 		}
754 	}
755 
756 	bo = tegra_bo_import(drm, buf);
757 	if (IS_ERR(bo))
758 		return ERR_CAST(bo);
759 
760 	return &bo->gem;
761 }
762 
763 struct host1x_bo *tegra_gem_lookup(struct drm_file *file, u32 handle)
764 {
765 	struct drm_gem_object *gem;
766 	struct tegra_bo *bo;
767 
768 	gem = drm_gem_object_lookup(file, handle);
769 	if (!gem)
770 		return NULL;
771 
772 	bo = to_tegra_bo(gem);
773 	return &bo->base;
774 }
775