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v6.13.7
  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
 25MODULE_IMPORT_NS("DMA_BUF");
 26
 27static 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
 47static inline unsigned int sgt_dma_count_chunks(struct sg_table *sgt)
 48{
 49	return sg_dma_count_chunks(sgt->sgl, sgt->nents);
 50}
 51
 52static 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
 59static 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 (obj->dma_buf) {
 80		struct dma_buf *buf = obj->dma_buf;
 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
136out:
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
153free_sgt:
154	sg_free_table(map->sgt);
155free:
156	kfree(map->sgt);
157	kfree(map);
158	return ERR_PTR(err);
159}
160
161static 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
177static void *tegra_bo_mmap(struct host1x_bo *bo)
178{
179	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
180	struct iosys_map map = { 0 };
181	void *vaddr;
182	int ret;
183
184	if (obj->vaddr)
185		return obj->vaddr;
186
187	if (obj->dma_buf) {
188		ret = dma_buf_vmap_unlocked(obj->dma_buf, &map);
189		if (ret < 0)
190			return ERR_PTR(ret);
191
192		return map.vaddr;
193	}
194
195	vaddr = vmap(obj->pages, obj->num_pages, VM_MAP,
196		     pgprot_writecombine(PAGE_KERNEL));
197	if (!vaddr)
198		return ERR_PTR(-ENOMEM);
199
200	return vaddr;
201}
202
203static void tegra_bo_munmap(struct host1x_bo *bo, void *addr)
204{
205	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
206	struct iosys_map map = IOSYS_MAP_INIT_VADDR(addr);
207
208	if (obj->vaddr)
209		return;
210
211	if (obj->dma_buf)
212		return dma_buf_vunmap_unlocked(obj->dma_buf, &map);
213
214	vunmap(addr);
215}
216
217static struct host1x_bo *tegra_bo_get(struct host1x_bo *bo)
218{
219	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
220
221	drm_gem_object_get(&obj->gem);
222
223	return bo;
224}
225
226static const struct host1x_bo_ops tegra_bo_ops = {
227	.get = tegra_bo_get,
228	.put = tegra_bo_put,
229	.pin = tegra_bo_pin,
230	.unpin = tegra_bo_unpin,
231	.mmap = tegra_bo_mmap,
232	.munmap = tegra_bo_munmap,
233};
234
235static int tegra_bo_iommu_map(struct tegra_drm *tegra, struct tegra_bo *bo)
236{
237	int prot = IOMMU_READ | IOMMU_WRITE;
238	int err;
239
240	if (bo->mm)
241		return -EBUSY;
242
243	bo->mm = kzalloc(sizeof(*bo->mm), GFP_KERNEL);
244	if (!bo->mm)
245		return -ENOMEM;
246
247	mutex_lock(&tegra->mm_lock);
248
249	err = drm_mm_insert_node_generic(&tegra->mm,
250					 bo->mm, bo->gem.size, PAGE_SIZE, 0, 0);
251	if (err < 0) {
252		dev_err(tegra->drm->dev, "out of I/O virtual memory: %d\n",
253			err);
254		goto unlock;
255	}
256
257	bo->iova = bo->mm->start;
258
259	bo->size = iommu_map_sgtable(tegra->domain, bo->iova, bo->sgt, prot);
 
260	if (!bo->size) {
261		dev_err(tegra->drm->dev, "failed to map buffer\n");
262		err = -ENOMEM;
263		goto remove;
264	}
265
266	mutex_unlock(&tegra->mm_lock);
267
268	return 0;
269
270remove:
271	drm_mm_remove_node(bo->mm);
272unlock:
273	mutex_unlock(&tegra->mm_lock);
274	kfree(bo->mm);
275	return err;
276}
277
278static int tegra_bo_iommu_unmap(struct tegra_drm *tegra, struct tegra_bo *bo)
279{
280	if (!bo->mm)
281		return 0;
282
283	mutex_lock(&tegra->mm_lock);
284	iommu_unmap(tegra->domain, bo->iova, bo->size);
285	drm_mm_remove_node(bo->mm);
286	mutex_unlock(&tegra->mm_lock);
287
288	kfree(bo->mm);
289
290	return 0;
291}
292
293static const struct drm_gem_object_funcs tegra_gem_object_funcs = {
294	.free = tegra_bo_free_object,
295	.export = tegra_gem_prime_export,
296	.vm_ops = &tegra_bo_vm_ops,
297};
298
299static struct tegra_bo *tegra_bo_alloc_object(struct drm_device *drm,
300					      size_t size)
301{
302	struct tegra_bo *bo;
303	int err;
304
305	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
306	if (!bo)
307		return ERR_PTR(-ENOMEM);
308
309	bo->gem.funcs = &tegra_gem_object_funcs;
310
311	host1x_bo_init(&bo->base, &tegra_bo_ops);
312	size = round_up(size, PAGE_SIZE);
313
314	err = drm_gem_object_init(drm, &bo->gem, size);
315	if (err < 0)
316		goto free;
317
318	err = drm_gem_create_mmap_offset(&bo->gem);
319	if (err < 0)
320		goto release;
321
322	return bo;
323
324release:
325	drm_gem_object_release(&bo->gem);
326free:
327	kfree(bo);
328	return ERR_PTR(err);
329}
330
331static void tegra_bo_free(struct drm_device *drm, struct tegra_bo *bo)
332{
333	if (bo->pages) {
334		dma_unmap_sgtable(drm->dev, bo->sgt, DMA_FROM_DEVICE, 0);
 
335		drm_gem_put_pages(&bo->gem, bo->pages, true, true);
336		sg_free_table(bo->sgt);
337		kfree(bo->sgt);
338	} else if (bo->vaddr) {
339		dma_free_wc(drm->dev, bo->gem.size, bo->vaddr, bo->iova);
340	}
341}
342
343static int tegra_bo_get_pages(struct drm_device *drm, struct tegra_bo *bo)
344{
345	int err;
346
347	bo->pages = drm_gem_get_pages(&bo->gem);
348	if (IS_ERR(bo->pages))
349		return PTR_ERR(bo->pages);
350
351	bo->num_pages = bo->gem.size >> PAGE_SHIFT;
352
353	bo->sgt = drm_prime_pages_to_sg(bo->gem.dev, bo->pages, bo->num_pages);
354	if (IS_ERR(bo->sgt)) {
355		err = PTR_ERR(bo->sgt);
356		goto put_pages;
357	}
358
359	err = dma_map_sgtable(drm->dev, bo->sgt, DMA_FROM_DEVICE, 0);
360	if (err)
 
 
361		goto free_sgt;
 
362
363	return 0;
364
365free_sgt:
366	sg_free_table(bo->sgt);
367	kfree(bo->sgt);
368put_pages:
369	drm_gem_put_pages(&bo->gem, bo->pages, false, false);
370	return err;
371}
372
373static int tegra_bo_alloc(struct drm_device *drm, struct tegra_bo *bo)
374{
375	struct tegra_drm *tegra = drm->dev_private;
376	int err;
377
378	if (tegra->domain) {
379		err = tegra_bo_get_pages(drm, bo);
380		if (err < 0)
381			return err;
382
383		err = tegra_bo_iommu_map(tegra, bo);
384		if (err < 0) {
385			tegra_bo_free(drm, bo);
386			return err;
387		}
388	} else {
389		size_t size = bo->gem.size;
390
391		bo->vaddr = dma_alloc_wc(drm->dev, size, &bo->iova,
392					 GFP_KERNEL | __GFP_NOWARN);
393		if (!bo->vaddr) {
394			dev_err(drm->dev,
395				"failed to allocate buffer of size %zu\n",
396				size);
397			return -ENOMEM;
398		}
399	}
400
401	return 0;
402}
403
404struct tegra_bo *tegra_bo_create(struct drm_device *drm, size_t size,
405				 unsigned long flags)
406{
407	struct tegra_bo *bo;
408	int err;
409
410	bo = tegra_bo_alloc_object(drm, size);
411	if (IS_ERR(bo))
412		return bo;
413
414	err = tegra_bo_alloc(drm, bo);
415	if (err < 0)
416		goto release;
417
418	if (flags & DRM_TEGRA_GEM_CREATE_TILED)
419		bo->tiling.mode = TEGRA_BO_TILING_MODE_TILED;
420
421	if (flags & DRM_TEGRA_GEM_CREATE_BOTTOM_UP)
422		bo->flags |= TEGRA_BO_BOTTOM_UP;
423
424	return bo;
425
426release:
427	drm_gem_object_release(&bo->gem);
428	kfree(bo);
429	return ERR_PTR(err);
430}
431
432struct tegra_bo *tegra_bo_create_with_handle(struct drm_file *file,
433					     struct drm_device *drm,
434					     size_t size,
435					     unsigned long flags,
436					     u32 *handle)
437{
438	struct tegra_bo *bo;
439	int err;
440
441	bo = tegra_bo_create(drm, size, flags);
442	if (IS_ERR(bo))
443		return bo;
444
445	err = drm_gem_handle_create(file, &bo->gem, handle);
446	if (err) {
447		tegra_bo_free_object(&bo->gem);
448		return ERR_PTR(err);
449	}
450
451	drm_gem_object_put(&bo->gem);
452
453	return bo;
454}
455
456static struct tegra_bo *tegra_bo_import(struct drm_device *drm,
457					struct dma_buf *buf)
458{
459	struct tegra_drm *tegra = drm->dev_private;
460	struct dma_buf_attachment *attach;
461	struct tegra_bo *bo;
462	int err;
463
464	bo = tegra_bo_alloc_object(drm, buf->size);
465	if (IS_ERR(bo))
466		return bo;
467
468	/*
469	 * If we need to use IOMMU API to map the dma-buf into the internally managed
470	 * domain, map it first to the DRM device to get an sgt.
471	 */
472	if (tegra->domain) {
473		attach = dma_buf_attach(buf, drm->dev);
474		if (IS_ERR(attach)) {
475			err = PTR_ERR(attach);
476			goto free;
477		}
478
479		bo->sgt = dma_buf_map_attachment_unlocked(attach, DMA_TO_DEVICE);
480		if (IS_ERR(bo->sgt)) {
481			err = PTR_ERR(bo->sgt);
482			goto detach;
483		}
484
 
 
 
 
 
 
 
485		err = tegra_bo_iommu_map(tegra, bo);
486		if (err < 0)
487			goto detach;
488
489		bo->gem.import_attach = attach;
490	}
491
492	get_dma_buf(buf);
493	bo->dma_buf = buf;
494
495	return bo;
496
497detach:
498	if (!IS_ERR_OR_NULL(bo->sgt))
499		dma_buf_unmap_attachment_unlocked(attach, bo->sgt, DMA_TO_DEVICE);
500
501	dma_buf_detach(buf, attach);
502	dma_buf_put(buf);
503free:
504	drm_gem_object_release(&bo->gem);
505	kfree(bo);
506	return ERR_PTR(err);
507}
508
509void tegra_bo_free_object(struct drm_gem_object *gem)
510{
511	struct tegra_drm *tegra = gem->dev->dev_private;
512	struct host1x_bo_mapping *mapping, *tmp;
513	struct tegra_bo *bo = to_tegra_bo(gem);
514
515	/* remove all mappings of this buffer object from any caches */
516	list_for_each_entry_safe(mapping, tmp, &bo->base.mappings, list) {
517		if (mapping->cache)
518			host1x_bo_unpin(mapping);
519		else
520			dev_err(gem->dev->dev, "mapping %p stale for device %s\n", mapping,
521				dev_name(mapping->dev));
522	}
523
524	if (tegra->domain) {
525		tegra_bo_iommu_unmap(tegra, bo);
526
527		if (gem->import_attach) {
528			dma_buf_unmap_attachment_unlocked(gem->import_attach, bo->sgt,
529							  DMA_TO_DEVICE);
530			dma_buf_detach(gem->import_attach->dmabuf, gem->import_attach);
531		}
 
532	}
533
534	tegra_bo_free(gem->dev, bo);
535
536	if (bo->dma_buf)
537		dma_buf_put(bo->dma_buf);
538
539	drm_gem_object_release(gem);
540	kfree(bo);
541}
542
543int tegra_bo_dumb_create(struct drm_file *file, struct drm_device *drm,
544			 struct drm_mode_create_dumb *args)
545{
546	unsigned int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
547	struct tegra_drm *tegra = drm->dev_private;
548	struct tegra_bo *bo;
549
550	args->pitch = round_up(min_pitch, tegra->pitch_align);
551	args->size = args->pitch * args->height;
552
553	bo = tegra_bo_create_with_handle(file, drm, args->size, 0,
554					 &args->handle);
555	if (IS_ERR(bo))
556		return PTR_ERR(bo);
557
558	return 0;
559}
560
561static vm_fault_t tegra_bo_fault(struct vm_fault *vmf)
562{
563	struct vm_area_struct *vma = vmf->vma;
564	struct drm_gem_object *gem = vma->vm_private_data;
565	struct tegra_bo *bo = to_tegra_bo(gem);
566	struct page *page;
567	pgoff_t offset;
568
569	if (!bo->pages)
570		return VM_FAULT_SIGBUS;
571
572	offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
573	page = bo->pages[offset];
574
575	return vmf_insert_page(vma, vmf->address, page);
576}
577
578const struct vm_operations_struct tegra_bo_vm_ops = {
579	.fault = tegra_bo_fault,
580	.open = drm_gem_vm_open,
581	.close = drm_gem_vm_close,
582};
583
584int __tegra_gem_mmap(struct drm_gem_object *gem, struct vm_area_struct *vma)
585{
586	struct tegra_bo *bo = to_tegra_bo(gem);
587
588	if (!bo->pages) {
589		unsigned long vm_pgoff = vma->vm_pgoff;
590		int err;
591
592		/*
593		 * Clear the VM_PFNMAP flag that was set by drm_gem_mmap(),
594		 * and set the vm_pgoff (used as a fake buffer offset by DRM)
595		 * to 0 as we want to map the whole buffer.
596		 */
597		vm_flags_clear(vma, VM_PFNMAP);
598		vma->vm_pgoff = 0;
599
600		err = dma_mmap_wc(gem->dev->dev, vma, bo->vaddr, bo->iova,
601				  gem->size);
602		if (err < 0) {
603			drm_gem_vm_close(vma);
604			return err;
605		}
606
607		vma->vm_pgoff = vm_pgoff;
608	} else {
609		pgprot_t prot = vm_get_page_prot(vma->vm_flags);
610
611		vm_flags_mod(vma, VM_MIXEDMAP, VM_PFNMAP);
 
612
613		vma->vm_page_prot = pgprot_writecombine(prot);
614	}
615
616	return 0;
617}
618
619int tegra_drm_mmap(struct file *file, struct vm_area_struct *vma)
620{
621	struct drm_gem_object *gem;
622	int err;
623
624	err = drm_gem_mmap(file, vma);
625	if (err < 0)
626		return err;
627
628	gem = vma->vm_private_data;
629
630	return __tegra_gem_mmap(gem, vma);
631}
632
633static struct sg_table *
634tegra_gem_prime_map_dma_buf(struct dma_buf_attachment *attach,
635			    enum dma_data_direction dir)
636{
637	struct drm_gem_object *gem = attach->dmabuf->priv;
638	struct tegra_bo *bo = to_tegra_bo(gem);
639	struct sg_table *sgt;
640
641	sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
642	if (!sgt)
643		return NULL;
644
645	if (bo->pages) {
646		if (sg_alloc_table_from_pages(sgt, bo->pages, bo->num_pages,
647					      0, gem->size, GFP_KERNEL) < 0)
648			goto free;
649	} else {
650		if (dma_get_sgtable(attach->dev, sgt, bo->vaddr, bo->iova,
651				    gem->size) < 0)
652			goto free;
653	}
654
655	if (dma_map_sgtable(attach->dev, sgt, dir, 0))
656		goto free;
657
658	return sgt;
659
660free:
661	sg_free_table(sgt);
662	kfree(sgt);
663	return NULL;
664}
665
666static void tegra_gem_prime_unmap_dma_buf(struct dma_buf_attachment *attach,
667					  struct sg_table *sgt,
668					  enum dma_data_direction dir)
669{
670	struct drm_gem_object *gem = attach->dmabuf->priv;
671	struct tegra_bo *bo = to_tegra_bo(gem);
672
673	if (bo->pages)
674		dma_unmap_sgtable(attach->dev, sgt, dir, 0);
675
676	sg_free_table(sgt);
677	kfree(sgt);
678}
679
680static void tegra_gem_prime_release(struct dma_buf *buf)
681{
682	drm_gem_dmabuf_release(buf);
683}
684
685static int tegra_gem_prime_begin_cpu_access(struct dma_buf *buf,
686					    enum dma_data_direction direction)
687{
688	struct drm_gem_object *gem = buf->priv;
689	struct tegra_bo *bo = to_tegra_bo(gem);
690	struct drm_device *drm = gem->dev;
691
692	if (bo->pages)
693		dma_sync_sgtable_for_cpu(drm->dev, bo->sgt, DMA_FROM_DEVICE);
 
694
695	return 0;
696}
697
698static int tegra_gem_prime_end_cpu_access(struct dma_buf *buf,
699					  enum dma_data_direction direction)
700{
701	struct drm_gem_object *gem = buf->priv;
702	struct tegra_bo *bo = to_tegra_bo(gem);
703	struct drm_device *drm = gem->dev;
704
705	if (bo->pages)
706		dma_sync_sgtable_for_device(drm->dev, bo->sgt, DMA_TO_DEVICE);
 
707
708	return 0;
709}
710
711static int tegra_gem_prime_mmap(struct dma_buf *buf, struct vm_area_struct *vma)
712{
713	struct drm_gem_object *gem = buf->priv;
714	int err;
715
716	err = drm_gem_mmap_obj(gem, gem->size, vma);
717	if (err < 0)
718		return err;
719
720	return __tegra_gem_mmap(gem, vma);
721}
722
723static int tegra_gem_prime_vmap(struct dma_buf *buf, struct iosys_map *map)
724{
725	struct drm_gem_object *gem = buf->priv;
726	struct tegra_bo *bo = to_tegra_bo(gem);
727	void *vaddr;
728
729	vaddr = tegra_bo_mmap(&bo->base);
730	if (IS_ERR(vaddr))
731		return PTR_ERR(vaddr);
732
733	iosys_map_set_vaddr(map, vaddr);
734
735	return 0;
736}
737
738static void tegra_gem_prime_vunmap(struct dma_buf *buf, struct iosys_map *map)
739{
740	struct drm_gem_object *gem = buf->priv;
741	struct tegra_bo *bo = to_tegra_bo(gem);
742
743	tegra_bo_munmap(&bo->base, map->vaddr);
744}
745
746static const struct dma_buf_ops tegra_gem_prime_dmabuf_ops = {
747	.map_dma_buf = tegra_gem_prime_map_dma_buf,
748	.unmap_dma_buf = tegra_gem_prime_unmap_dma_buf,
749	.release = tegra_gem_prime_release,
750	.begin_cpu_access = tegra_gem_prime_begin_cpu_access,
751	.end_cpu_access = tegra_gem_prime_end_cpu_access,
752	.mmap = tegra_gem_prime_mmap,
753	.vmap = tegra_gem_prime_vmap,
754	.vunmap = tegra_gem_prime_vunmap,
755};
756
757struct dma_buf *tegra_gem_prime_export(struct drm_gem_object *gem,
758				       int flags)
759{
760	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
761
762	exp_info.exp_name = KBUILD_MODNAME;
763	exp_info.owner = gem->dev->driver->fops->owner;
764	exp_info.ops = &tegra_gem_prime_dmabuf_ops;
765	exp_info.size = gem->size;
766	exp_info.flags = flags;
767	exp_info.priv = gem;
768
769	return drm_gem_dmabuf_export(gem->dev, &exp_info);
770}
771
772struct drm_gem_object *tegra_gem_prime_import(struct drm_device *drm,
773					      struct dma_buf *buf)
774{
775	struct tegra_bo *bo;
776
777	if (buf->ops == &tegra_gem_prime_dmabuf_ops) {
778		struct drm_gem_object *gem = buf->priv;
779
780		if (gem->dev == drm) {
781			drm_gem_object_get(gem);
782			return gem;
783		}
784	}
785
786	bo = tegra_bo_import(drm, buf);
787	if (IS_ERR(bo))
788		return ERR_CAST(bo);
789
790	return &bo->gem;
791}
792
793struct host1x_bo *tegra_gem_lookup(struct drm_file *file, u32 handle)
794{
795	struct drm_gem_object *gem;
796	struct tegra_bo *bo;
797
798	gem = drm_gem_object_lookup(file, handle);
799	if (!gem)
800		return NULL;
801
802	bo = to_tegra_bo(gem);
803	return &bo->base;
804}
v5.9
  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
 16#include <drm/drm_drv.h>
 17#include <drm/drm_prime.h>
 18#include <drm/tegra_drm.h>
 19
 20#include "drm.h"
 21#include "gem.h"
 22
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 23static void tegra_bo_put(struct host1x_bo *bo)
 24{
 25	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
 26
 27	drm_gem_object_put(&obj->gem);
 28}
 29
 30/* XXX move this into lib/scatterlist.c? */
 31static int sg_alloc_table_from_sg(struct sg_table *sgt, struct scatterlist *sg,
 32				  unsigned int nents, gfp_t gfp_mask)
 33{
 34	struct scatterlist *dst;
 35	unsigned int i;
 
 36	int err;
 37
 38	err = sg_alloc_table(sgt, nents, gfp_mask);
 39	if (err < 0)
 40		return err;
 
 
 
 
 
 41
 42	dst = sgt->sgl;
 
 
 
 
 43
 44	for (i = 0; i < nents; i++) {
 45		sg_set_page(dst, sg_page(sg), sg->length, 0);
 46		dst = sg_next(dst);
 47		sg = sg_next(sg);
 48	}
 49
 50	return 0;
 51}
 
 
 
 
 
 52
 53static struct sg_table *tegra_bo_pin(struct device *dev, struct host1x_bo *bo,
 54				     dma_addr_t *phys)
 55{
 56	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
 57	struct sg_table *sgt;
 58	int err;
 59
 60	/*
 61	 * If we've manually mapped the buffer object through the IOMMU, make
 62	 * sure to return the IOVA address of our mapping.
 63	 *
 64	 * Similarly, for buffers that have been allocated by the DMA API the
 65	 * physical address can be used for devices that are not attached to
 66	 * an IOMMU. For these devices, callers must pass a valid pointer via
 67	 * the @phys argument.
 68	 *
 69	 * Imported buffers were also already mapped at import time, so the
 70	 * existing mapping can be reused.
 71	 */
 72	if (phys) {
 73		*phys = obj->iova;
 74		return NULL;
 75	}
 76
 77	/*
 78	 * If we don't have a mapping for this buffer yet, return an SG table
 79	 * so that host1x can do the mapping for us via the DMA API.
 80	 */
 81	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
 82	if (!sgt)
 83		return ERR_PTR(-ENOMEM);
 
 
 84
 85	if (obj->pages) {
 86		/*
 87		 * If the buffer object was allocated from the explicit IOMMU
 88		 * API code paths, construct an SG table from the pages.
 89		 */
 90		err = sg_alloc_table_from_pages(sgt, obj->pages, obj->num_pages,
 91						0, obj->gem.size, GFP_KERNEL);
 92		if (err < 0)
 93			goto free;
 94	} else if (obj->sgt) {
 95		/*
 96		 * If the buffer object already has an SG table but no pages
 97		 * were allocated for it, it means the buffer was imported and
 98		 * the SG table needs to be copied to avoid overwriting any
 99		 * other potential users of the original SG table.
100		 */
101		err = sg_alloc_table_from_sg(sgt, obj->sgt->sgl, obj->sgt->nents,
102					     GFP_KERNEL);
103		if (err < 0)
104			goto free;
105	} else {
106		/*
107		 * If the buffer object had no pages allocated and if it was
108		 * not imported, it had to be allocated with the DMA API, so
109		 * the DMA API helper can be used.
110		 */
111		err = dma_get_sgtable(dev, sgt, obj->vaddr, obj->iova,
112				      obj->gem.size);
113		if (err < 0)
114			goto free;
115	}
116
117	return sgt;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
118
 
 
119free:
120	kfree(sgt);
 
121	return ERR_PTR(err);
122}
123
124static void tegra_bo_unpin(struct device *dev, struct sg_table *sgt)
125{
126	if (sgt) {
127		sg_free_table(sgt);
128		kfree(sgt);
 
 
 
 
 
129	}
 
 
 
130}
131
132static void *tegra_bo_mmap(struct host1x_bo *bo)
133{
134	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
 
 
 
135
136	if (obj->vaddr)
137		return obj->vaddr;
138	else if (obj->gem.import_attach)
139		return dma_buf_vmap(obj->gem.import_attach->dmabuf);
140	else
141		return vmap(obj->pages, obj->num_pages, VM_MAP,
142			    pgprot_writecombine(PAGE_KERNEL));
 
 
 
 
 
 
 
 
 
 
143}
144
145static void tegra_bo_munmap(struct host1x_bo *bo, void *addr)
146{
147	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
 
148
149	if (obj->vaddr)
150		return;
151	else if (obj->gem.import_attach)
152		dma_buf_vunmap(obj->gem.import_attach->dmabuf, addr);
153	else
154		vunmap(addr);
 
155}
156
157static struct host1x_bo *tegra_bo_get(struct host1x_bo *bo)
158{
159	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
160
161	drm_gem_object_get(&obj->gem);
162
163	return bo;
164}
165
166static const struct host1x_bo_ops tegra_bo_ops = {
167	.get = tegra_bo_get,
168	.put = tegra_bo_put,
169	.pin = tegra_bo_pin,
170	.unpin = tegra_bo_unpin,
171	.mmap = tegra_bo_mmap,
172	.munmap = tegra_bo_munmap,
173};
174
175static int tegra_bo_iommu_map(struct tegra_drm *tegra, struct tegra_bo *bo)
176{
177	int prot = IOMMU_READ | IOMMU_WRITE;
178	int err;
179
180	if (bo->mm)
181		return -EBUSY;
182
183	bo->mm = kzalloc(sizeof(*bo->mm), GFP_KERNEL);
184	if (!bo->mm)
185		return -ENOMEM;
186
187	mutex_lock(&tegra->mm_lock);
188
189	err = drm_mm_insert_node_generic(&tegra->mm,
190					 bo->mm, bo->gem.size, PAGE_SIZE, 0, 0);
191	if (err < 0) {
192		dev_err(tegra->drm->dev, "out of I/O virtual memory: %d\n",
193			err);
194		goto unlock;
195	}
196
197	bo->iova = bo->mm->start;
198
199	bo->size = iommu_map_sg(tegra->domain, bo->iova, bo->sgt->sgl,
200				bo->sgt->nents, prot);
201	if (!bo->size) {
202		dev_err(tegra->drm->dev, "failed to map buffer\n");
203		err = -ENOMEM;
204		goto remove;
205	}
206
207	mutex_unlock(&tegra->mm_lock);
208
209	return 0;
210
211remove:
212	drm_mm_remove_node(bo->mm);
213unlock:
214	mutex_unlock(&tegra->mm_lock);
215	kfree(bo->mm);
216	return err;
217}
218
219static int tegra_bo_iommu_unmap(struct tegra_drm *tegra, struct tegra_bo *bo)
220{
221	if (!bo->mm)
222		return 0;
223
224	mutex_lock(&tegra->mm_lock);
225	iommu_unmap(tegra->domain, bo->iova, bo->size);
226	drm_mm_remove_node(bo->mm);
227	mutex_unlock(&tegra->mm_lock);
228
229	kfree(bo->mm);
230
231	return 0;
232}
233
 
 
 
 
 
 
234static struct tegra_bo *tegra_bo_alloc_object(struct drm_device *drm,
235					      size_t size)
236{
237	struct tegra_bo *bo;
238	int err;
239
240	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
241	if (!bo)
242		return ERR_PTR(-ENOMEM);
243
 
 
244	host1x_bo_init(&bo->base, &tegra_bo_ops);
245	size = round_up(size, PAGE_SIZE);
246
247	err = drm_gem_object_init(drm, &bo->gem, size);
248	if (err < 0)
249		goto free;
250
251	err = drm_gem_create_mmap_offset(&bo->gem);
252	if (err < 0)
253		goto release;
254
255	return bo;
256
257release:
258	drm_gem_object_release(&bo->gem);
259free:
260	kfree(bo);
261	return ERR_PTR(err);
262}
263
264static void tegra_bo_free(struct drm_device *drm, struct tegra_bo *bo)
265{
266	if (bo->pages) {
267		dma_unmap_sg(drm->dev, bo->sgt->sgl, bo->sgt->nents,
268			     DMA_FROM_DEVICE);
269		drm_gem_put_pages(&bo->gem, bo->pages, true, true);
270		sg_free_table(bo->sgt);
271		kfree(bo->sgt);
272	} else if (bo->vaddr) {
273		dma_free_wc(drm->dev, bo->gem.size, bo->vaddr, bo->iova);
274	}
275}
276
277static int tegra_bo_get_pages(struct drm_device *drm, struct tegra_bo *bo)
278{
279	int err;
280
281	bo->pages = drm_gem_get_pages(&bo->gem);
282	if (IS_ERR(bo->pages))
283		return PTR_ERR(bo->pages);
284
285	bo->num_pages = bo->gem.size >> PAGE_SHIFT;
286
287	bo->sgt = drm_prime_pages_to_sg(bo->pages, bo->num_pages);
288	if (IS_ERR(bo->sgt)) {
289		err = PTR_ERR(bo->sgt);
290		goto put_pages;
291	}
292
293	err = dma_map_sg(drm->dev, bo->sgt->sgl, bo->sgt->nents,
294			 DMA_FROM_DEVICE);
295	if (err == 0) {
296		err = -EFAULT;
297		goto free_sgt;
298	}
299
300	return 0;
301
302free_sgt:
303	sg_free_table(bo->sgt);
304	kfree(bo->sgt);
305put_pages:
306	drm_gem_put_pages(&bo->gem, bo->pages, false, false);
307	return err;
308}
309
310static int tegra_bo_alloc(struct drm_device *drm, struct tegra_bo *bo)
311{
312	struct tegra_drm *tegra = drm->dev_private;
313	int err;
314
315	if (tegra->domain) {
316		err = tegra_bo_get_pages(drm, bo);
317		if (err < 0)
318			return err;
319
320		err = tegra_bo_iommu_map(tegra, bo);
321		if (err < 0) {
322			tegra_bo_free(drm, bo);
323			return err;
324		}
325	} else {
326		size_t size = bo->gem.size;
327
328		bo->vaddr = dma_alloc_wc(drm->dev, size, &bo->iova,
329					 GFP_KERNEL | __GFP_NOWARN);
330		if (!bo->vaddr) {
331			dev_err(drm->dev,
332				"failed to allocate buffer of size %zu\n",
333				size);
334			return -ENOMEM;
335		}
336	}
337
338	return 0;
339}
340
341struct tegra_bo *tegra_bo_create(struct drm_device *drm, size_t size,
342				 unsigned long flags)
343{
344	struct tegra_bo *bo;
345	int err;
346
347	bo = tegra_bo_alloc_object(drm, size);
348	if (IS_ERR(bo))
349		return bo;
350
351	err = tegra_bo_alloc(drm, bo);
352	if (err < 0)
353		goto release;
354
355	if (flags & DRM_TEGRA_GEM_CREATE_TILED)
356		bo->tiling.mode = TEGRA_BO_TILING_MODE_TILED;
357
358	if (flags & DRM_TEGRA_GEM_CREATE_BOTTOM_UP)
359		bo->flags |= TEGRA_BO_BOTTOM_UP;
360
361	return bo;
362
363release:
364	drm_gem_object_release(&bo->gem);
365	kfree(bo);
366	return ERR_PTR(err);
367}
368
369struct tegra_bo *tegra_bo_create_with_handle(struct drm_file *file,
370					     struct drm_device *drm,
371					     size_t size,
372					     unsigned long flags,
373					     u32 *handle)
374{
375	struct tegra_bo *bo;
376	int err;
377
378	bo = tegra_bo_create(drm, size, flags);
379	if (IS_ERR(bo))
380		return bo;
381
382	err = drm_gem_handle_create(file, &bo->gem, handle);
383	if (err) {
384		tegra_bo_free_object(&bo->gem);
385		return ERR_PTR(err);
386	}
387
388	drm_gem_object_put(&bo->gem);
389
390	return bo;
391}
392
393static struct tegra_bo *tegra_bo_import(struct drm_device *drm,
394					struct dma_buf *buf)
395{
396	struct tegra_drm *tegra = drm->dev_private;
397	struct dma_buf_attachment *attach;
398	struct tegra_bo *bo;
399	int err;
400
401	bo = tegra_bo_alloc_object(drm, buf->size);
402	if (IS_ERR(bo))
403		return bo;
404
405	attach = dma_buf_attach(buf, drm->dev);
406	if (IS_ERR(attach)) {
407		err = PTR_ERR(attach);
408		goto free;
409	}
 
 
 
 
 
410
411	get_dma_buf(buf);
 
 
 
 
412
413	bo->sgt = dma_buf_map_attachment(attach, DMA_TO_DEVICE);
414	if (IS_ERR(bo->sgt)) {
415		err = PTR_ERR(bo->sgt);
416		goto detach;
417	}
418
419	if (tegra->domain) {
420		err = tegra_bo_iommu_map(tegra, bo);
421		if (err < 0)
422			goto detach;
 
 
423	}
424
425	bo->gem.import_attach = attach;
 
426
427	return bo;
428
429detach:
430	if (!IS_ERR_OR_NULL(bo->sgt))
431		dma_buf_unmap_attachment(attach, bo->sgt, DMA_TO_DEVICE);
432
433	dma_buf_detach(buf, attach);
434	dma_buf_put(buf);
435free:
436	drm_gem_object_release(&bo->gem);
437	kfree(bo);
438	return ERR_PTR(err);
439}
440
441void tegra_bo_free_object(struct drm_gem_object *gem)
442{
443	struct tegra_drm *tegra = gem->dev->dev_private;
 
444	struct tegra_bo *bo = to_tegra_bo(gem);
445
446	if (tegra->domain)
 
 
 
 
 
 
 
 
 
447		tegra_bo_iommu_unmap(tegra, bo);
448
449	if (gem->import_attach) {
450		dma_buf_unmap_attachment(gem->import_attach, bo->sgt,
451					 DMA_TO_DEVICE);
452		drm_prime_gem_destroy(gem, NULL);
453	} else {
454		tegra_bo_free(gem->dev, bo);
455	}
456
 
 
 
 
 
457	drm_gem_object_release(gem);
458	kfree(bo);
459}
460
461int tegra_bo_dumb_create(struct drm_file *file, struct drm_device *drm,
462			 struct drm_mode_create_dumb *args)
463{
464	unsigned int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
465	struct tegra_drm *tegra = drm->dev_private;
466	struct tegra_bo *bo;
467
468	args->pitch = round_up(min_pitch, tegra->pitch_align);
469	args->size = args->pitch * args->height;
470
471	bo = tegra_bo_create_with_handle(file, drm, args->size, 0,
472					 &args->handle);
473	if (IS_ERR(bo))
474		return PTR_ERR(bo);
475
476	return 0;
477}
478
479static vm_fault_t tegra_bo_fault(struct vm_fault *vmf)
480{
481	struct vm_area_struct *vma = vmf->vma;
482	struct drm_gem_object *gem = vma->vm_private_data;
483	struct tegra_bo *bo = to_tegra_bo(gem);
484	struct page *page;
485	pgoff_t offset;
486
487	if (!bo->pages)
488		return VM_FAULT_SIGBUS;
489
490	offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
491	page = bo->pages[offset];
492
493	return vmf_insert_page(vma, vmf->address, page);
494}
495
496const struct vm_operations_struct tegra_bo_vm_ops = {
497	.fault = tegra_bo_fault,
498	.open = drm_gem_vm_open,
499	.close = drm_gem_vm_close,
500};
501
502int __tegra_gem_mmap(struct drm_gem_object *gem, struct vm_area_struct *vma)
503{
504	struct tegra_bo *bo = to_tegra_bo(gem);
505
506	if (!bo->pages) {
507		unsigned long vm_pgoff = vma->vm_pgoff;
508		int err;
509
510		/*
511		 * Clear the VM_PFNMAP flag that was set by drm_gem_mmap(),
512		 * and set the vm_pgoff (used as a fake buffer offset by DRM)
513		 * to 0 as we want to map the whole buffer.
514		 */
515		vma->vm_flags &= ~VM_PFNMAP;
516		vma->vm_pgoff = 0;
517
518		err = dma_mmap_wc(gem->dev->dev, vma, bo->vaddr, bo->iova,
519				  gem->size);
520		if (err < 0) {
521			drm_gem_vm_close(vma);
522			return err;
523		}
524
525		vma->vm_pgoff = vm_pgoff;
526	} else {
527		pgprot_t prot = vm_get_page_prot(vma->vm_flags);
528
529		vma->vm_flags |= VM_MIXEDMAP;
530		vma->vm_flags &= ~VM_PFNMAP;
531
532		vma->vm_page_prot = pgprot_writecombine(prot);
533	}
534
535	return 0;
536}
537
538int tegra_drm_mmap(struct file *file, struct vm_area_struct *vma)
539{
540	struct drm_gem_object *gem;
541	int err;
542
543	err = drm_gem_mmap(file, vma);
544	if (err < 0)
545		return err;
546
547	gem = vma->vm_private_data;
548
549	return __tegra_gem_mmap(gem, vma);
550}
551
552static struct sg_table *
553tegra_gem_prime_map_dma_buf(struct dma_buf_attachment *attach,
554			    enum dma_data_direction dir)
555{
556	struct drm_gem_object *gem = attach->dmabuf->priv;
557	struct tegra_bo *bo = to_tegra_bo(gem);
558	struct sg_table *sgt;
559
560	sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
561	if (!sgt)
562		return NULL;
563
564	if (bo->pages) {
565		if (sg_alloc_table_from_pages(sgt, bo->pages, bo->num_pages,
566					      0, gem->size, GFP_KERNEL) < 0)
567			goto free;
568	} else {
569		if (dma_get_sgtable(attach->dev, sgt, bo->vaddr, bo->iova,
570				    gem->size) < 0)
571			goto free;
572	}
573
574	if (dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir) == 0)
575		goto free;
576
577	return sgt;
578
579free:
580	sg_free_table(sgt);
581	kfree(sgt);
582	return NULL;
583}
584
585static void tegra_gem_prime_unmap_dma_buf(struct dma_buf_attachment *attach,
586					  struct sg_table *sgt,
587					  enum dma_data_direction dir)
588{
589	struct drm_gem_object *gem = attach->dmabuf->priv;
590	struct tegra_bo *bo = to_tegra_bo(gem);
591
592	if (bo->pages)
593		dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
594
595	sg_free_table(sgt);
596	kfree(sgt);
597}
598
599static void tegra_gem_prime_release(struct dma_buf *buf)
600{
601	drm_gem_dmabuf_release(buf);
602}
603
604static int tegra_gem_prime_begin_cpu_access(struct dma_buf *buf,
605					    enum dma_data_direction direction)
606{
607	struct drm_gem_object *gem = buf->priv;
608	struct tegra_bo *bo = to_tegra_bo(gem);
609	struct drm_device *drm = gem->dev;
610
611	if (bo->pages)
612		dma_sync_sg_for_cpu(drm->dev, bo->sgt->sgl, bo->sgt->nents,
613				    DMA_FROM_DEVICE);
614
615	return 0;
616}
617
618static int tegra_gem_prime_end_cpu_access(struct dma_buf *buf,
619					  enum dma_data_direction direction)
620{
621	struct drm_gem_object *gem = buf->priv;
622	struct tegra_bo *bo = to_tegra_bo(gem);
623	struct drm_device *drm = gem->dev;
624
625	if (bo->pages)
626		dma_sync_sg_for_device(drm->dev, bo->sgt->sgl, bo->sgt->nents,
627				       DMA_TO_DEVICE);
628
629	return 0;
630}
631
632static int tegra_gem_prime_mmap(struct dma_buf *buf, struct vm_area_struct *vma)
633{
634	struct drm_gem_object *gem = buf->priv;
635	int err;
636
637	err = drm_gem_mmap_obj(gem, gem->size, vma);
638	if (err < 0)
639		return err;
640
641	return __tegra_gem_mmap(gem, vma);
642}
643
644static void *tegra_gem_prime_vmap(struct dma_buf *buf)
645{
646	struct drm_gem_object *gem = buf->priv;
647	struct tegra_bo *bo = to_tegra_bo(gem);
 
 
 
 
 
 
 
648
649	return bo->vaddr;
650}
651
652static void tegra_gem_prime_vunmap(struct dma_buf *buf, void *vaddr)
653{
 
 
 
 
654}
655
656static const struct dma_buf_ops tegra_gem_prime_dmabuf_ops = {
657	.map_dma_buf = tegra_gem_prime_map_dma_buf,
658	.unmap_dma_buf = tegra_gem_prime_unmap_dma_buf,
659	.release = tegra_gem_prime_release,
660	.begin_cpu_access = tegra_gem_prime_begin_cpu_access,
661	.end_cpu_access = tegra_gem_prime_end_cpu_access,
662	.mmap = tegra_gem_prime_mmap,
663	.vmap = tegra_gem_prime_vmap,
664	.vunmap = tegra_gem_prime_vunmap,
665};
666
667struct dma_buf *tegra_gem_prime_export(struct drm_gem_object *gem,
668				       int flags)
669{
670	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
671
672	exp_info.exp_name = KBUILD_MODNAME;
673	exp_info.owner = gem->dev->driver->fops->owner;
674	exp_info.ops = &tegra_gem_prime_dmabuf_ops;
675	exp_info.size = gem->size;
676	exp_info.flags = flags;
677	exp_info.priv = gem;
678
679	return drm_gem_dmabuf_export(gem->dev, &exp_info);
680}
681
682struct drm_gem_object *tegra_gem_prime_import(struct drm_device *drm,
683					      struct dma_buf *buf)
684{
685	struct tegra_bo *bo;
686
687	if (buf->ops == &tegra_gem_prime_dmabuf_ops) {
688		struct drm_gem_object *gem = buf->priv;
689
690		if (gem->dev == drm) {
691			drm_gem_object_get(gem);
692			return gem;
693		}
694	}
695
696	bo = tegra_bo_import(drm, buf);
697	if (IS_ERR(bo))
698		return ERR_CAST(bo);
699
700	return &bo->gem;
 
 
 
 
 
 
 
 
 
 
 
 
 
701}