xref: /openbmc/linux/drivers/gpu/drm/tegra/gem.c (revision fe7498ef)
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 void tegra_bo_put(struct host1x_bo *bo)
27 {
28 	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
29 
30 	drm_gem_object_put(&obj->gem);
31 }
32 
33 /* XXX move this into lib/scatterlist.c? */
34 static int sg_alloc_table_from_sg(struct sg_table *sgt, struct scatterlist *sg,
35 				  unsigned int nents, gfp_t gfp_mask)
36 {
37 	struct scatterlist *dst;
38 	unsigned int i;
39 	int err;
40 
41 	err = sg_alloc_table(sgt, nents, gfp_mask);
42 	if (err < 0)
43 		return err;
44 
45 	dst = sgt->sgl;
46 
47 	for (i = 0; i < nents; i++) {
48 		sg_set_page(dst, sg_page(sg), sg->length, 0);
49 		dst = sg_next(dst);
50 		sg = sg_next(sg);
51 	}
52 
53 	return 0;
54 }
55 
56 static struct sg_table *tegra_bo_pin(struct device *dev, struct host1x_bo *bo,
57 				     dma_addr_t *phys)
58 {
59 	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
60 	struct sg_table *sgt;
61 	int err;
62 
63 	/*
64 	 * If we've manually mapped the buffer object through the IOMMU, make
65 	 * sure to return the IOVA address of our mapping.
66 	 *
67 	 * Similarly, for buffers that have been allocated by the DMA API the
68 	 * physical address can be used for devices that are not attached to
69 	 * an IOMMU. For these devices, callers must pass a valid pointer via
70 	 * the @phys argument.
71 	 *
72 	 * Imported buffers were also already mapped at import time, so the
73 	 * existing mapping can be reused.
74 	 */
75 	if (phys) {
76 		*phys = obj->iova;
77 		return NULL;
78 	}
79 
80 	/*
81 	 * If we don't have a mapping for this buffer yet, return an SG table
82 	 * so that host1x can do the mapping for us via the DMA API.
83 	 */
84 	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
85 	if (!sgt)
86 		return ERR_PTR(-ENOMEM);
87 
88 	if (obj->pages) {
89 		/*
90 		 * If the buffer object was allocated from the explicit IOMMU
91 		 * API code paths, construct an SG table from the pages.
92 		 */
93 		err = sg_alloc_table_from_pages(sgt, obj->pages, obj->num_pages,
94 						0, obj->gem.size, GFP_KERNEL);
95 		if (err < 0)
96 			goto free;
97 	} else if (obj->sgt) {
98 		/*
99 		 * If the buffer object already has an SG table but no pages
100 		 * were allocated for it, it means the buffer was imported and
101 		 * the SG table needs to be copied to avoid overwriting any
102 		 * other potential users of the original SG table.
103 		 */
104 		err = sg_alloc_table_from_sg(sgt, obj->sgt->sgl,
105 					     obj->sgt->orig_nents, GFP_KERNEL);
106 		if (err < 0)
107 			goto free;
108 	} else {
109 		/*
110 		 * If the buffer object had no pages allocated and if it was
111 		 * not imported, it had to be allocated with the DMA API, so
112 		 * the DMA API helper can be used.
113 		 */
114 		err = dma_get_sgtable(dev, sgt, obj->vaddr, obj->iova,
115 				      obj->gem.size);
116 		if (err < 0)
117 			goto free;
118 	}
119 
120 	return sgt;
121 
122 free:
123 	kfree(sgt);
124 	return ERR_PTR(err);
125 }
126 
127 static void tegra_bo_unpin(struct device *dev, struct sg_table *sgt)
128 {
129 	if (sgt) {
130 		sg_free_table(sgt);
131 		kfree(sgt);
132 	}
133 }
134 
135 static void *tegra_bo_mmap(struct host1x_bo *bo)
136 {
137 	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
138 	struct dma_buf_map map;
139 	int ret;
140 
141 	if (obj->vaddr) {
142 		return obj->vaddr;
143 	} else if (obj->gem.import_attach) {
144 		ret = dma_buf_vmap(obj->gem.import_attach->dmabuf, &map);
145 		return ret ? NULL : map.vaddr;
146 	} else {
147 		return vmap(obj->pages, obj->num_pages, VM_MAP,
148 			    pgprot_writecombine(PAGE_KERNEL));
149 	}
150 }
151 
152 static void tegra_bo_munmap(struct host1x_bo *bo, void *addr)
153 {
154 	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
155 	struct dma_buf_map map = DMA_BUF_MAP_INIT_VADDR(addr);
156 
157 	if (obj->vaddr)
158 		return;
159 	else if (obj->gem.import_attach)
160 		dma_buf_vunmap(obj->gem.import_attach->dmabuf, &map);
161 	else
162 		vunmap(addr);
163 }
164 
165 static struct host1x_bo *tegra_bo_get(struct host1x_bo *bo)
166 {
167 	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
168 
169 	drm_gem_object_get(&obj->gem);
170 
171 	return bo;
172 }
173 
174 static const struct host1x_bo_ops tegra_bo_ops = {
175 	.get = tegra_bo_get,
176 	.put = tegra_bo_put,
177 	.pin = tegra_bo_pin,
178 	.unpin = tegra_bo_unpin,
179 	.mmap = tegra_bo_mmap,
180 	.munmap = tegra_bo_munmap,
181 };
182 
183 static int tegra_bo_iommu_map(struct tegra_drm *tegra, struct tegra_bo *bo)
184 {
185 	int prot = IOMMU_READ | IOMMU_WRITE;
186 	int err;
187 
188 	if (bo->mm)
189 		return -EBUSY;
190 
191 	bo->mm = kzalloc(sizeof(*bo->mm), GFP_KERNEL);
192 	if (!bo->mm)
193 		return -ENOMEM;
194 
195 	mutex_lock(&tegra->mm_lock);
196 
197 	err = drm_mm_insert_node_generic(&tegra->mm,
198 					 bo->mm, bo->gem.size, PAGE_SIZE, 0, 0);
199 	if (err < 0) {
200 		dev_err(tegra->drm->dev, "out of I/O virtual memory: %d\n",
201 			err);
202 		goto unlock;
203 	}
204 
205 	bo->iova = bo->mm->start;
206 
207 	bo->size = iommu_map_sgtable(tegra->domain, bo->iova, bo->sgt, prot);
208 	if (!bo->size) {
209 		dev_err(tegra->drm->dev, "failed to map buffer\n");
210 		err = -ENOMEM;
211 		goto remove;
212 	}
213 
214 	mutex_unlock(&tegra->mm_lock);
215 
216 	return 0;
217 
218 remove:
219 	drm_mm_remove_node(bo->mm);
220 unlock:
221 	mutex_unlock(&tegra->mm_lock);
222 	kfree(bo->mm);
223 	return err;
224 }
225 
226 static int tegra_bo_iommu_unmap(struct tegra_drm *tegra, struct tegra_bo *bo)
227 {
228 	if (!bo->mm)
229 		return 0;
230 
231 	mutex_lock(&tegra->mm_lock);
232 	iommu_unmap(tegra->domain, bo->iova, bo->size);
233 	drm_mm_remove_node(bo->mm);
234 	mutex_unlock(&tegra->mm_lock);
235 
236 	kfree(bo->mm);
237 
238 	return 0;
239 }
240 
241 static const struct drm_gem_object_funcs tegra_gem_object_funcs = {
242 	.free = tegra_bo_free_object,
243 	.export = tegra_gem_prime_export,
244 	.vm_ops = &tegra_bo_vm_ops,
245 };
246 
247 static struct tegra_bo *tegra_bo_alloc_object(struct drm_device *drm,
248 					      size_t size)
249 {
250 	struct tegra_bo *bo;
251 	int err;
252 
253 	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
254 	if (!bo)
255 		return ERR_PTR(-ENOMEM);
256 
257 	bo->gem.funcs = &tegra_gem_object_funcs;
258 
259 	host1x_bo_init(&bo->base, &tegra_bo_ops);
260 	size = round_up(size, PAGE_SIZE);
261 
262 	err = drm_gem_object_init(drm, &bo->gem, size);
263 	if (err < 0)
264 		goto free;
265 
266 	err = drm_gem_create_mmap_offset(&bo->gem);
267 	if (err < 0)
268 		goto release;
269 
270 	return bo;
271 
272 release:
273 	drm_gem_object_release(&bo->gem);
274 free:
275 	kfree(bo);
276 	return ERR_PTR(err);
277 }
278 
279 static void tegra_bo_free(struct drm_device *drm, struct tegra_bo *bo)
280 {
281 	if (bo->pages) {
282 		dma_unmap_sgtable(drm->dev, bo->sgt, DMA_FROM_DEVICE, 0);
283 		drm_gem_put_pages(&bo->gem, bo->pages, true, true);
284 		sg_free_table(bo->sgt);
285 		kfree(bo->sgt);
286 	} else if (bo->vaddr) {
287 		dma_free_wc(drm->dev, bo->gem.size, bo->vaddr, bo->iova);
288 	}
289 }
290 
291 static int tegra_bo_get_pages(struct drm_device *drm, struct tegra_bo *bo)
292 {
293 	int err;
294 
295 	bo->pages = drm_gem_get_pages(&bo->gem);
296 	if (IS_ERR(bo->pages))
297 		return PTR_ERR(bo->pages);
298 
299 	bo->num_pages = bo->gem.size >> PAGE_SHIFT;
300 
301 	bo->sgt = drm_prime_pages_to_sg(bo->gem.dev, bo->pages, bo->num_pages);
302 	if (IS_ERR(bo->sgt)) {
303 		err = PTR_ERR(bo->sgt);
304 		goto put_pages;
305 	}
306 
307 	err = dma_map_sgtable(drm->dev, bo->sgt, DMA_FROM_DEVICE, 0);
308 	if (err)
309 		goto free_sgt;
310 
311 	return 0;
312 
313 free_sgt:
314 	sg_free_table(bo->sgt);
315 	kfree(bo->sgt);
316 put_pages:
317 	drm_gem_put_pages(&bo->gem, bo->pages, false, false);
318 	return err;
319 }
320 
321 static int tegra_bo_alloc(struct drm_device *drm, struct tegra_bo *bo)
322 {
323 	struct tegra_drm *tegra = drm->dev_private;
324 	int err;
325 
326 	if (tegra->domain) {
327 		err = tegra_bo_get_pages(drm, bo);
328 		if (err < 0)
329 			return err;
330 
331 		err = tegra_bo_iommu_map(tegra, bo);
332 		if (err < 0) {
333 			tegra_bo_free(drm, bo);
334 			return err;
335 		}
336 	} else {
337 		size_t size = bo->gem.size;
338 
339 		bo->vaddr = dma_alloc_wc(drm->dev, size, &bo->iova,
340 					 GFP_KERNEL | __GFP_NOWARN);
341 		if (!bo->vaddr) {
342 			dev_err(drm->dev,
343 				"failed to allocate buffer of size %zu\n",
344 				size);
345 			return -ENOMEM;
346 		}
347 	}
348 
349 	return 0;
350 }
351 
352 struct tegra_bo *tegra_bo_create(struct drm_device *drm, size_t size,
353 				 unsigned long flags)
354 {
355 	struct tegra_bo *bo;
356 	int err;
357 
358 	bo = tegra_bo_alloc_object(drm, size);
359 	if (IS_ERR(bo))
360 		return bo;
361 
362 	err = tegra_bo_alloc(drm, bo);
363 	if (err < 0)
364 		goto release;
365 
366 	if (flags & DRM_TEGRA_GEM_CREATE_TILED)
367 		bo->tiling.mode = TEGRA_BO_TILING_MODE_TILED;
368 
369 	if (flags & DRM_TEGRA_GEM_CREATE_BOTTOM_UP)
370 		bo->flags |= TEGRA_BO_BOTTOM_UP;
371 
372 	return bo;
373 
374 release:
375 	drm_gem_object_release(&bo->gem);
376 	kfree(bo);
377 	return ERR_PTR(err);
378 }
379 
380 struct tegra_bo *tegra_bo_create_with_handle(struct drm_file *file,
381 					     struct drm_device *drm,
382 					     size_t size,
383 					     unsigned long flags,
384 					     u32 *handle)
385 {
386 	struct tegra_bo *bo;
387 	int err;
388 
389 	bo = tegra_bo_create(drm, size, flags);
390 	if (IS_ERR(bo))
391 		return bo;
392 
393 	err = drm_gem_handle_create(file, &bo->gem, handle);
394 	if (err) {
395 		tegra_bo_free_object(&bo->gem);
396 		return ERR_PTR(err);
397 	}
398 
399 	drm_gem_object_put(&bo->gem);
400 
401 	return bo;
402 }
403 
404 static struct tegra_bo *tegra_bo_import(struct drm_device *drm,
405 					struct dma_buf *buf)
406 {
407 	struct tegra_drm *tegra = drm->dev_private;
408 	struct dma_buf_attachment *attach;
409 	struct tegra_bo *bo;
410 	int err;
411 
412 	bo = tegra_bo_alloc_object(drm, buf->size);
413 	if (IS_ERR(bo))
414 		return bo;
415 
416 	attach = dma_buf_attach(buf, drm->dev);
417 	if (IS_ERR(attach)) {
418 		err = PTR_ERR(attach);
419 		goto free;
420 	}
421 
422 	get_dma_buf(buf);
423 
424 	bo->sgt = dma_buf_map_attachment(attach, DMA_TO_DEVICE);
425 	if (IS_ERR(bo->sgt)) {
426 		err = PTR_ERR(bo->sgt);
427 		goto detach;
428 	}
429 
430 	if (tegra->domain) {
431 		err = tegra_bo_iommu_map(tegra, bo);
432 		if (err < 0)
433 			goto detach;
434 	}
435 
436 	bo->gem.import_attach = attach;
437 
438 	return bo;
439 
440 detach:
441 	if (!IS_ERR_OR_NULL(bo->sgt))
442 		dma_buf_unmap_attachment(attach, bo->sgt, DMA_TO_DEVICE);
443 
444 	dma_buf_detach(buf, attach);
445 	dma_buf_put(buf);
446 free:
447 	drm_gem_object_release(&bo->gem);
448 	kfree(bo);
449 	return ERR_PTR(err);
450 }
451 
452 void tegra_bo_free_object(struct drm_gem_object *gem)
453 {
454 	struct tegra_drm *tegra = gem->dev->dev_private;
455 	struct tegra_bo *bo = to_tegra_bo(gem);
456 
457 	if (tegra->domain)
458 		tegra_bo_iommu_unmap(tegra, bo);
459 
460 	if (gem->import_attach) {
461 		dma_buf_unmap_attachment(gem->import_attach, bo->sgt,
462 					 DMA_TO_DEVICE);
463 		drm_prime_gem_destroy(gem, NULL);
464 	} else {
465 		tegra_bo_free(gem->dev, bo);
466 	}
467 
468 	drm_gem_object_release(gem);
469 	kfree(bo);
470 }
471 
472 int tegra_bo_dumb_create(struct drm_file *file, struct drm_device *drm,
473 			 struct drm_mode_create_dumb *args)
474 {
475 	unsigned int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
476 	struct tegra_drm *tegra = drm->dev_private;
477 	struct tegra_bo *bo;
478 
479 	args->pitch = round_up(min_pitch, tegra->pitch_align);
480 	args->size = args->pitch * args->height;
481 
482 	bo = tegra_bo_create_with_handle(file, drm, args->size, 0,
483 					 &args->handle);
484 	if (IS_ERR(bo))
485 		return PTR_ERR(bo);
486 
487 	return 0;
488 }
489 
490 static vm_fault_t tegra_bo_fault(struct vm_fault *vmf)
491 {
492 	struct vm_area_struct *vma = vmf->vma;
493 	struct drm_gem_object *gem = vma->vm_private_data;
494 	struct tegra_bo *bo = to_tegra_bo(gem);
495 	struct page *page;
496 	pgoff_t offset;
497 
498 	if (!bo->pages)
499 		return VM_FAULT_SIGBUS;
500 
501 	offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
502 	page = bo->pages[offset];
503 
504 	return vmf_insert_page(vma, vmf->address, page);
505 }
506 
507 const struct vm_operations_struct tegra_bo_vm_ops = {
508 	.fault = tegra_bo_fault,
509 	.open = drm_gem_vm_open,
510 	.close = drm_gem_vm_close,
511 };
512 
513 int __tegra_gem_mmap(struct drm_gem_object *gem, struct vm_area_struct *vma)
514 {
515 	struct tegra_bo *bo = to_tegra_bo(gem);
516 
517 	if (!bo->pages) {
518 		unsigned long vm_pgoff = vma->vm_pgoff;
519 		int err;
520 
521 		/*
522 		 * Clear the VM_PFNMAP flag that was set by drm_gem_mmap(),
523 		 * and set the vm_pgoff (used as a fake buffer offset by DRM)
524 		 * to 0 as we want to map the whole buffer.
525 		 */
526 		vma->vm_flags &= ~VM_PFNMAP;
527 		vma->vm_pgoff = 0;
528 
529 		err = dma_mmap_wc(gem->dev->dev, vma, bo->vaddr, bo->iova,
530 				  gem->size);
531 		if (err < 0) {
532 			drm_gem_vm_close(vma);
533 			return err;
534 		}
535 
536 		vma->vm_pgoff = vm_pgoff;
537 	} else {
538 		pgprot_t prot = vm_get_page_prot(vma->vm_flags);
539 
540 		vma->vm_flags |= VM_MIXEDMAP;
541 		vma->vm_flags &= ~VM_PFNMAP;
542 
543 		vma->vm_page_prot = pgprot_writecombine(prot);
544 	}
545 
546 	return 0;
547 }
548 
549 int tegra_drm_mmap(struct file *file, struct vm_area_struct *vma)
550 {
551 	struct drm_gem_object *gem;
552 	int err;
553 
554 	err = drm_gem_mmap(file, vma);
555 	if (err < 0)
556 		return err;
557 
558 	gem = vma->vm_private_data;
559 
560 	return __tegra_gem_mmap(gem, vma);
561 }
562 
563 static struct sg_table *
564 tegra_gem_prime_map_dma_buf(struct dma_buf_attachment *attach,
565 			    enum dma_data_direction dir)
566 {
567 	struct drm_gem_object *gem = attach->dmabuf->priv;
568 	struct tegra_bo *bo = to_tegra_bo(gem);
569 	struct sg_table *sgt;
570 
571 	sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
572 	if (!sgt)
573 		return NULL;
574 
575 	if (bo->pages) {
576 		if (sg_alloc_table_from_pages(sgt, bo->pages, bo->num_pages,
577 					      0, gem->size, GFP_KERNEL) < 0)
578 			goto free;
579 	} else {
580 		if (dma_get_sgtable(attach->dev, sgt, bo->vaddr, bo->iova,
581 				    gem->size) < 0)
582 			goto free;
583 	}
584 
585 	if (dma_map_sgtable(attach->dev, sgt, dir, 0))
586 		goto free;
587 
588 	return sgt;
589 
590 free:
591 	sg_free_table(sgt);
592 	kfree(sgt);
593 	return NULL;
594 }
595 
596 static void tegra_gem_prime_unmap_dma_buf(struct dma_buf_attachment *attach,
597 					  struct sg_table *sgt,
598 					  enum dma_data_direction dir)
599 {
600 	struct drm_gem_object *gem = attach->dmabuf->priv;
601 	struct tegra_bo *bo = to_tegra_bo(gem);
602 
603 	if (bo->pages)
604 		dma_unmap_sgtable(attach->dev, sgt, dir, 0);
605 
606 	sg_free_table(sgt);
607 	kfree(sgt);
608 }
609 
610 static void tegra_gem_prime_release(struct dma_buf *buf)
611 {
612 	drm_gem_dmabuf_release(buf);
613 }
614 
615 static int tegra_gem_prime_begin_cpu_access(struct dma_buf *buf,
616 					    enum dma_data_direction direction)
617 {
618 	struct drm_gem_object *gem = buf->priv;
619 	struct tegra_bo *bo = to_tegra_bo(gem);
620 	struct drm_device *drm = gem->dev;
621 
622 	if (bo->pages)
623 		dma_sync_sgtable_for_cpu(drm->dev, bo->sgt, DMA_FROM_DEVICE);
624 
625 	return 0;
626 }
627 
628 static int tegra_gem_prime_end_cpu_access(struct dma_buf *buf,
629 					  enum dma_data_direction direction)
630 {
631 	struct drm_gem_object *gem = buf->priv;
632 	struct tegra_bo *bo = to_tegra_bo(gem);
633 	struct drm_device *drm = gem->dev;
634 
635 	if (bo->pages)
636 		dma_sync_sgtable_for_device(drm->dev, bo->sgt, DMA_TO_DEVICE);
637 
638 	return 0;
639 }
640 
641 static int tegra_gem_prime_mmap(struct dma_buf *buf, struct vm_area_struct *vma)
642 {
643 	struct drm_gem_object *gem = buf->priv;
644 	int err;
645 
646 	err = drm_gem_mmap_obj(gem, gem->size, vma);
647 	if (err < 0)
648 		return err;
649 
650 	return __tegra_gem_mmap(gem, vma);
651 }
652 
653 static int tegra_gem_prime_vmap(struct dma_buf *buf, struct dma_buf_map *map)
654 {
655 	struct drm_gem_object *gem = buf->priv;
656 	struct tegra_bo *bo = to_tegra_bo(gem);
657 
658 	dma_buf_map_set_vaddr(map, bo->vaddr);
659 
660 	return 0;
661 }
662 
663 static void tegra_gem_prime_vunmap(struct dma_buf *buf, struct dma_buf_map *map)
664 {
665 }
666 
667 static const struct dma_buf_ops tegra_gem_prime_dmabuf_ops = {
668 	.map_dma_buf = tegra_gem_prime_map_dma_buf,
669 	.unmap_dma_buf = tegra_gem_prime_unmap_dma_buf,
670 	.release = tegra_gem_prime_release,
671 	.begin_cpu_access = tegra_gem_prime_begin_cpu_access,
672 	.end_cpu_access = tegra_gem_prime_end_cpu_access,
673 	.mmap = tegra_gem_prime_mmap,
674 	.vmap = tegra_gem_prime_vmap,
675 	.vunmap = tegra_gem_prime_vunmap,
676 };
677 
678 struct dma_buf *tegra_gem_prime_export(struct drm_gem_object *gem,
679 				       int flags)
680 {
681 	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
682 
683 	exp_info.exp_name = KBUILD_MODNAME;
684 	exp_info.owner = gem->dev->driver->fops->owner;
685 	exp_info.ops = &tegra_gem_prime_dmabuf_ops;
686 	exp_info.size = gem->size;
687 	exp_info.flags = flags;
688 	exp_info.priv = gem;
689 
690 	return drm_gem_dmabuf_export(gem->dev, &exp_info);
691 }
692 
693 struct drm_gem_object *tegra_gem_prime_import(struct drm_device *drm,
694 					      struct dma_buf *buf)
695 {
696 	struct tegra_bo *bo;
697 
698 	if (buf->ops == &tegra_gem_prime_dmabuf_ops) {
699 		struct drm_gem_object *gem = buf->priv;
700 
701 		if (gem->dev == drm) {
702 			drm_gem_object_get(gem);
703 			return gem;
704 		}
705 	}
706 
707 	bo = tegra_bo_import(drm, buf);
708 	if (IS_ERR(bo))
709 		return ERR_CAST(bo);
710 
711 	return &bo->gem;
712 }
713 
714 struct host1x_bo *tegra_gem_lookup(struct drm_file *file, u32 handle)
715 {
716 	struct drm_gem_object *gem;
717 	struct tegra_bo *bo;
718 
719 	gem = drm_gem_object_lookup(file, handle);
720 	if (!gem)
721 		return NULL;
722 
723 	bo = to_tegra_bo(gem);
724 	return &bo->base;
725 }
726