xref: /openbmc/linux/drivers/gpu/drm/tegra/gem.c (revision 2a598d0b)
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 #include <linux/vmalloc.h>
17 
18 #include <drm/drm_drv.h>
19 #include <drm/drm_prime.h>
20 #include <drm/tegra_drm.h>
21 
22 #include "drm.h"
23 #include "gem.h"
24 
25 MODULE_IMPORT_NS(DMA_BUF);
26 
27 static unsigned int sg_dma_count_chunks(struct scatterlist *sgl, unsigned int nents)
28 {
29 	dma_addr_t next = ~(dma_addr_t)0;
30 	unsigned int count = 0, i;
31 	struct scatterlist *s;
32 
33 	for_each_sg(sgl, s, nents, i) {
34 		/* sg_dma_address(s) is only valid for entries that have sg_dma_len(s) != 0. */
35 		if (!sg_dma_len(s))
36 			continue;
37 
38 		if (sg_dma_address(s) != next) {
39 			next = sg_dma_address(s) + sg_dma_len(s);
40 			count++;
41 		}
42 	}
43 
44 	return count;
45 }
46 
47 static inline unsigned int sgt_dma_count_chunks(struct sg_table *sgt)
48 {
49 	return sg_dma_count_chunks(sgt->sgl, sgt->nents);
50 }
51 
52 static void tegra_bo_put(struct host1x_bo *bo)
53 {
54 	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
55 
56 	drm_gem_object_put(&obj->gem);
57 }
58 
59 static struct host1x_bo_mapping *tegra_bo_pin(struct device *dev, struct host1x_bo *bo,
60 					      enum dma_data_direction direction)
61 {
62 	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
63 	struct drm_gem_object *gem = &obj->gem;
64 	struct host1x_bo_mapping *map;
65 	int err;
66 
67 	map = kzalloc(sizeof(*map), GFP_KERNEL);
68 	if (!map)
69 		return ERR_PTR(-ENOMEM);
70 
71 	kref_init(&map->ref);
72 	map->bo = host1x_bo_get(bo);
73 	map->direction = direction;
74 	map->dev = dev;
75 
76 	/*
77 	 * Imported buffers need special treatment to satisfy the semantics of DMA-BUF.
78 	 */
79 	if (gem->import_attach) {
80 		struct dma_buf *buf = gem->import_attach->dmabuf;
81 
82 		map->attach = dma_buf_attach(buf, dev);
83 		if (IS_ERR(map->attach)) {
84 			err = PTR_ERR(map->attach);
85 			goto free;
86 		}
87 
88 		map->sgt = dma_buf_map_attachment_unlocked(map->attach, direction);
89 		if (IS_ERR(map->sgt)) {
90 			dma_buf_detach(buf, map->attach);
91 			err = PTR_ERR(map->sgt);
92 			map->sgt = NULL;
93 			goto free;
94 		}
95 
96 		err = sgt_dma_count_chunks(map->sgt);
97 		map->size = gem->size;
98 
99 		goto out;
100 	}
101 
102 	/*
103 	 * If we don't have a mapping for this buffer yet, return an SG table
104 	 * so that host1x can do the mapping for us via the DMA API.
105 	 */
106 	map->sgt = kzalloc(sizeof(*map->sgt), GFP_KERNEL);
107 	if (!map->sgt) {
108 		err = -ENOMEM;
109 		goto free;
110 	}
111 
112 	if (obj->pages) {
113 		/*
114 		 * If the buffer object was allocated from the explicit IOMMU
115 		 * API code paths, construct an SG table from the pages.
116 		 */
117 		err = sg_alloc_table_from_pages(map->sgt, obj->pages, obj->num_pages, 0, gem->size,
118 						GFP_KERNEL);
119 		if (err < 0)
120 			goto free;
121 	} else {
122 		/*
123 		 * If the buffer object had no pages allocated and if it was
124 		 * not imported, it had to be allocated with the DMA API, so
125 		 * the DMA API helper can be used.
126 		 */
127 		err = dma_get_sgtable(dev, map->sgt, obj->vaddr, obj->iova, gem->size);
128 		if (err < 0)
129 			goto free;
130 	}
131 
132 	err = dma_map_sgtable(dev, map->sgt, direction, 0);
133 	if (err)
134 		goto free_sgt;
135 
136 out:
137 	/*
138 	 * If we've manually mapped the buffer object through the IOMMU, make sure to return the
139 	 * existing IOVA address of our mapping.
140 	 */
141 	if (!obj->mm) {
142 		map->phys = sg_dma_address(map->sgt->sgl);
143 		map->chunks = err;
144 	} else {
145 		map->phys = obj->iova;
146 		map->chunks = 1;
147 	}
148 
149 	map->size = gem->size;
150 
151 	return map;
152 
153 free_sgt:
154 	sg_free_table(map->sgt);
155 free:
156 	kfree(map->sgt);
157 	kfree(map);
158 	return ERR_PTR(err);
159 }
160 
161 static void tegra_bo_unpin(struct host1x_bo_mapping *map)
162 {
163 	if (map->attach) {
164 		dma_buf_unmap_attachment_unlocked(map->attach, map->sgt,
165 						  map->direction);
166 		dma_buf_detach(map->attach->dmabuf, map->attach);
167 	} else {
168 		dma_unmap_sgtable(map->dev, map->sgt, map->direction, 0);
169 		sg_free_table(map->sgt);
170 		kfree(map->sgt);
171 	}
172 
173 	host1x_bo_put(map->bo);
174 	kfree(map);
175 }
176 
177 static void *tegra_bo_mmap(struct host1x_bo *bo)
178 {
179 	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
180 	struct iosys_map map;
181 	int ret;
182 
183 	if (obj->vaddr) {
184 		return obj->vaddr;
185 	} else if (obj->gem.import_attach) {
186 		ret = dma_buf_vmap_unlocked(obj->gem.import_attach->dmabuf, &map);
187 		return ret ? NULL : map.vaddr;
188 	} else {
189 		return vmap(obj->pages, obj->num_pages, VM_MAP,
190 			    pgprot_writecombine(PAGE_KERNEL));
191 	}
192 }
193 
194 static void tegra_bo_munmap(struct host1x_bo *bo, void *addr)
195 {
196 	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
197 	struct iosys_map map = IOSYS_MAP_INIT_VADDR(addr);
198 
199 	if (obj->vaddr)
200 		return;
201 	else if (obj->gem.import_attach)
202 		dma_buf_vunmap_unlocked(obj->gem.import_attach->dmabuf, &map);
203 	else
204 		vunmap(addr);
205 }
206 
207 static struct host1x_bo *tegra_bo_get(struct host1x_bo *bo)
208 {
209 	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
210 
211 	drm_gem_object_get(&obj->gem);
212 
213 	return bo;
214 }
215 
216 static const struct host1x_bo_ops tegra_bo_ops = {
217 	.get = tegra_bo_get,
218 	.put = tegra_bo_put,
219 	.pin = tegra_bo_pin,
220 	.unpin = tegra_bo_unpin,
221 	.mmap = tegra_bo_mmap,
222 	.munmap = tegra_bo_munmap,
223 };
224 
225 static int tegra_bo_iommu_map(struct tegra_drm *tegra, struct tegra_bo *bo)
226 {
227 	int prot = IOMMU_READ | IOMMU_WRITE;
228 	int err;
229 
230 	if (bo->mm)
231 		return -EBUSY;
232 
233 	bo->mm = kzalloc(sizeof(*bo->mm), GFP_KERNEL);
234 	if (!bo->mm)
235 		return -ENOMEM;
236 
237 	mutex_lock(&tegra->mm_lock);
238 
239 	err = drm_mm_insert_node_generic(&tegra->mm,
240 					 bo->mm, bo->gem.size, PAGE_SIZE, 0, 0);
241 	if (err < 0) {
242 		dev_err(tegra->drm->dev, "out of I/O virtual memory: %d\n",
243 			err);
244 		goto unlock;
245 	}
246 
247 	bo->iova = bo->mm->start;
248 
249 	bo->size = iommu_map_sgtable(tegra->domain, bo->iova, bo->sgt, prot);
250 	if (!bo->size) {
251 		dev_err(tegra->drm->dev, "failed to map buffer\n");
252 		err = -ENOMEM;
253 		goto remove;
254 	}
255 
256 	mutex_unlock(&tegra->mm_lock);
257 
258 	return 0;
259 
260 remove:
261 	drm_mm_remove_node(bo->mm);
262 unlock:
263 	mutex_unlock(&tegra->mm_lock);
264 	kfree(bo->mm);
265 	return err;
266 }
267 
268 static int tegra_bo_iommu_unmap(struct tegra_drm *tegra, struct tegra_bo *bo)
269 {
270 	if (!bo->mm)
271 		return 0;
272 
273 	mutex_lock(&tegra->mm_lock);
274 	iommu_unmap(tegra->domain, bo->iova, bo->size);
275 	drm_mm_remove_node(bo->mm);
276 	mutex_unlock(&tegra->mm_lock);
277 
278 	kfree(bo->mm);
279 
280 	return 0;
281 }
282 
283 static const struct drm_gem_object_funcs tegra_gem_object_funcs = {
284 	.free = tegra_bo_free_object,
285 	.export = tegra_gem_prime_export,
286 	.vm_ops = &tegra_bo_vm_ops,
287 };
288 
289 static struct tegra_bo *tegra_bo_alloc_object(struct drm_device *drm,
290 					      size_t size)
291 {
292 	struct tegra_bo *bo;
293 	int err;
294 
295 	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
296 	if (!bo)
297 		return ERR_PTR(-ENOMEM);
298 
299 	bo->gem.funcs = &tegra_gem_object_funcs;
300 
301 	host1x_bo_init(&bo->base, &tegra_bo_ops);
302 	size = round_up(size, PAGE_SIZE);
303 
304 	err = drm_gem_object_init(drm, &bo->gem, size);
305 	if (err < 0)
306 		goto free;
307 
308 	err = drm_gem_create_mmap_offset(&bo->gem);
309 	if (err < 0)
310 		goto release;
311 
312 	return bo;
313 
314 release:
315 	drm_gem_object_release(&bo->gem);
316 free:
317 	kfree(bo);
318 	return ERR_PTR(err);
319 }
320 
321 static void tegra_bo_free(struct drm_device *drm, struct tegra_bo *bo)
322 {
323 	if (bo->pages) {
324 		dma_unmap_sgtable(drm->dev, bo->sgt, DMA_FROM_DEVICE, 0);
325 		drm_gem_put_pages(&bo->gem, bo->pages, true, true);
326 		sg_free_table(bo->sgt);
327 		kfree(bo->sgt);
328 	} else if (bo->vaddr) {
329 		dma_free_wc(drm->dev, bo->gem.size, bo->vaddr, bo->iova);
330 	}
331 }
332 
333 static int tegra_bo_get_pages(struct drm_device *drm, struct tegra_bo *bo)
334 {
335 	int err;
336 
337 	bo->pages = drm_gem_get_pages(&bo->gem);
338 	if (IS_ERR(bo->pages))
339 		return PTR_ERR(bo->pages);
340 
341 	bo->num_pages = bo->gem.size >> PAGE_SHIFT;
342 
343 	bo->sgt = drm_prime_pages_to_sg(bo->gem.dev, bo->pages, bo->num_pages);
344 	if (IS_ERR(bo->sgt)) {
345 		err = PTR_ERR(bo->sgt);
346 		goto put_pages;
347 	}
348 
349 	err = dma_map_sgtable(drm->dev, bo->sgt, DMA_FROM_DEVICE, 0);
350 	if (err)
351 		goto free_sgt;
352 
353 	return 0;
354 
355 free_sgt:
356 	sg_free_table(bo->sgt);
357 	kfree(bo->sgt);
358 put_pages:
359 	drm_gem_put_pages(&bo->gem, bo->pages, false, false);
360 	return err;
361 }
362 
363 static int tegra_bo_alloc(struct drm_device *drm, struct tegra_bo *bo)
364 {
365 	struct tegra_drm *tegra = drm->dev_private;
366 	int err;
367 
368 	if (tegra->domain) {
369 		err = tegra_bo_get_pages(drm, bo);
370 		if (err < 0)
371 			return err;
372 
373 		err = tegra_bo_iommu_map(tegra, bo);
374 		if (err < 0) {
375 			tegra_bo_free(drm, bo);
376 			return err;
377 		}
378 	} else {
379 		size_t size = bo->gem.size;
380 
381 		bo->vaddr = dma_alloc_wc(drm->dev, size, &bo->iova,
382 					 GFP_KERNEL | __GFP_NOWARN);
383 		if (!bo->vaddr) {
384 			dev_err(drm->dev,
385 				"failed to allocate buffer of size %zu\n",
386 				size);
387 			return -ENOMEM;
388 		}
389 	}
390 
391 	return 0;
392 }
393 
394 struct tegra_bo *tegra_bo_create(struct drm_device *drm, size_t size,
395 				 unsigned long flags)
396 {
397 	struct tegra_bo *bo;
398 	int err;
399 
400 	bo = tegra_bo_alloc_object(drm, size);
401 	if (IS_ERR(bo))
402 		return bo;
403 
404 	err = tegra_bo_alloc(drm, bo);
405 	if (err < 0)
406 		goto release;
407 
408 	if (flags & DRM_TEGRA_GEM_CREATE_TILED)
409 		bo->tiling.mode = TEGRA_BO_TILING_MODE_TILED;
410 
411 	if (flags & DRM_TEGRA_GEM_CREATE_BOTTOM_UP)
412 		bo->flags |= TEGRA_BO_BOTTOM_UP;
413 
414 	return bo;
415 
416 release:
417 	drm_gem_object_release(&bo->gem);
418 	kfree(bo);
419 	return ERR_PTR(err);
420 }
421 
422 struct tegra_bo *tegra_bo_create_with_handle(struct drm_file *file,
423 					     struct drm_device *drm,
424 					     size_t size,
425 					     unsigned long flags,
426 					     u32 *handle)
427 {
428 	struct tegra_bo *bo;
429 	int err;
430 
431 	bo = tegra_bo_create(drm, size, flags);
432 	if (IS_ERR(bo))
433 		return bo;
434 
435 	err = drm_gem_handle_create(file, &bo->gem, handle);
436 	if (err) {
437 		tegra_bo_free_object(&bo->gem);
438 		return ERR_PTR(err);
439 	}
440 
441 	drm_gem_object_put(&bo->gem);
442 
443 	return bo;
444 }
445 
446 static struct tegra_bo *tegra_bo_import(struct drm_device *drm,
447 					struct dma_buf *buf)
448 {
449 	struct tegra_drm *tegra = drm->dev_private;
450 	struct dma_buf_attachment *attach;
451 	struct tegra_bo *bo;
452 	int err;
453 
454 	bo = tegra_bo_alloc_object(drm, buf->size);
455 	if (IS_ERR(bo))
456 		return bo;
457 
458 	attach = dma_buf_attach(buf, drm->dev);
459 	if (IS_ERR(attach)) {
460 		err = PTR_ERR(attach);
461 		goto free;
462 	}
463 
464 	get_dma_buf(buf);
465 
466 	bo->sgt = dma_buf_map_attachment_unlocked(attach, DMA_TO_DEVICE);
467 	if (IS_ERR(bo->sgt)) {
468 		err = PTR_ERR(bo->sgt);
469 		goto detach;
470 	}
471 
472 	if (tegra->domain) {
473 		err = tegra_bo_iommu_map(tegra, bo);
474 		if (err < 0)
475 			goto detach;
476 	}
477 
478 	bo->gem.import_attach = attach;
479 
480 	return bo;
481 
482 detach:
483 	if (!IS_ERR_OR_NULL(bo->sgt))
484 		dma_buf_unmap_attachment_unlocked(attach, bo->sgt, DMA_TO_DEVICE);
485 
486 	dma_buf_detach(buf, attach);
487 	dma_buf_put(buf);
488 free:
489 	drm_gem_object_release(&bo->gem);
490 	kfree(bo);
491 	return ERR_PTR(err);
492 }
493 
494 void tegra_bo_free_object(struct drm_gem_object *gem)
495 {
496 	struct tegra_drm *tegra = gem->dev->dev_private;
497 	struct host1x_bo_mapping *mapping, *tmp;
498 	struct tegra_bo *bo = to_tegra_bo(gem);
499 
500 	/* remove all mappings of this buffer object from any caches */
501 	list_for_each_entry_safe(mapping, tmp, &bo->base.mappings, list) {
502 		if (mapping->cache)
503 			host1x_bo_unpin(mapping);
504 		else
505 			dev_err(gem->dev->dev, "mapping %p stale for device %s\n", mapping,
506 				dev_name(mapping->dev));
507 	}
508 
509 	if (tegra->domain)
510 		tegra_bo_iommu_unmap(tegra, bo);
511 
512 	if (gem->import_attach) {
513 		dma_buf_unmap_attachment_unlocked(gem->import_attach, bo->sgt,
514 						  DMA_TO_DEVICE);
515 		drm_prime_gem_destroy(gem, NULL);
516 	} else {
517 		tegra_bo_free(gem->dev, bo);
518 	}
519 
520 	drm_gem_object_release(gem);
521 	kfree(bo);
522 }
523 
524 int tegra_bo_dumb_create(struct drm_file *file, struct drm_device *drm,
525 			 struct drm_mode_create_dumb *args)
526 {
527 	unsigned int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
528 	struct tegra_drm *tegra = drm->dev_private;
529 	struct tegra_bo *bo;
530 
531 	args->pitch = round_up(min_pitch, tegra->pitch_align);
532 	args->size = args->pitch * args->height;
533 
534 	bo = tegra_bo_create_with_handle(file, drm, args->size, 0,
535 					 &args->handle);
536 	if (IS_ERR(bo))
537 		return PTR_ERR(bo);
538 
539 	return 0;
540 }
541 
542 static vm_fault_t tegra_bo_fault(struct vm_fault *vmf)
543 {
544 	struct vm_area_struct *vma = vmf->vma;
545 	struct drm_gem_object *gem = vma->vm_private_data;
546 	struct tegra_bo *bo = to_tegra_bo(gem);
547 	struct page *page;
548 	pgoff_t offset;
549 
550 	if (!bo->pages)
551 		return VM_FAULT_SIGBUS;
552 
553 	offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
554 	page = bo->pages[offset];
555 
556 	return vmf_insert_page(vma, vmf->address, page);
557 }
558 
559 const struct vm_operations_struct tegra_bo_vm_ops = {
560 	.fault = tegra_bo_fault,
561 	.open = drm_gem_vm_open,
562 	.close = drm_gem_vm_close,
563 };
564 
565 int __tegra_gem_mmap(struct drm_gem_object *gem, struct vm_area_struct *vma)
566 {
567 	struct tegra_bo *bo = to_tegra_bo(gem);
568 
569 	if (!bo->pages) {
570 		unsigned long vm_pgoff = vma->vm_pgoff;
571 		int err;
572 
573 		/*
574 		 * Clear the VM_PFNMAP flag that was set by drm_gem_mmap(),
575 		 * and set the vm_pgoff (used as a fake buffer offset by DRM)
576 		 * to 0 as we want to map the whole buffer.
577 		 */
578 		vm_flags_clear(vma, VM_PFNMAP);
579 		vma->vm_pgoff = 0;
580 
581 		err = dma_mmap_wc(gem->dev->dev, vma, bo->vaddr, bo->iova,
582 				  gem->size);
583 		if (err < 0) {
584 			drm_gem_vm_close(vma);
585 			return err;
586 		}
587 
588 		vma->vm_pgoff = vm_pgoff;
589 	} else {
590 		pgprot_t prot = vm_get_page_prot(vma->vm_flags);
591 
592 		vm_flags_mod(vma, VM_MIXEDMAP, VM_PFNMAP);
593 
594 		vma->vm_page_prot = pgprot_writecombine(prot);
595 	}
596 
597 	return 0;
598 }
599 
600 int 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 
614 static struct sg_table *
615 tegra_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 
641 free:
642 	sg_free_table(sgt);
643 	kfree(sgt);
644 	return NULL;
645 }
646 
647 static 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 
661 static void tegra_gem_prime_release(struct dma_buf *buf)
662 {
663 	drm_gem_dmabuf_release(buf);
664 }
665 
666 static 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 
679 static 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 
692 static 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 
706 static 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 
721 static 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 
729 static 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 
740 struct 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 
755 struct 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 
776 struct 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 }
788