1 files changed, 270 insertions, 132 deletions

diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c
index 4f80100ff5f3..6b14f1e919eb 100644
--- a/drivers/gpu/drm/tegra/gem.c
+++ b/drivers/gpu/drm/tegra/gem.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * NVIDIA Tegra DRM GEM helper functions
  *
@@ -7,88 +8,210 @@
  * Based on the GEM/CMA helpers
  *
  * Copyright (c) 2011 Samsung Electronics Co., Ltd.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
  */
 
 #include <linux/dma-buf.h>
 #include <linux/iommu.h>
-#include <drm/tegra_drm.h>
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+
+#include <drm/drm_drv.h>
+#include <drm/drm_dumb_buffers.h>
+#include <drm/drm_prime.h>
 
 #include "drm.h"
 #include "gem.h"
 
+MODULE_IMPORT_NS("DMA_BUF");
+
+static unsigned int sg_dma_count_chunks(struct scatterlist *sgl, unsigned int nents)
+{
+	dma_addr_t next = ~(dma_addr_t)0;
+	unsigned int count = 0, i;
+	struct scatterlist *s;
+
+	for_each_sg(sgl, s, nents, i) {
+		/* sg_dma_address(s) is only valid for entries that have sg_dma_len(s) != 0. */
+		if (!sg_dma_len(s))
+			continue;
+
+		if (sg_dma_address(s) != next) {
+			next = sg_dma_address(s) + sg_dma_len(s);
+			count++;
+		}
+	}
+
+	return count;
+}
+
+static inline unsigned int sgt_dma_count_chunks(struct sg_table *sgt)
+{
+	return sg_dma_count_chunks(sgt->sgl, sgt->nents);
+}
+
 static void tegra_bo_put(struct host1x_bo *bo)
 {
 	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
 
-	drm_gem_object_put_unlocked(&obj->gem);
+	drm_gem_object_put(&obj->gem);
 }
 
-static dma_addr_t tegra_bo_pin(struct host1x_bo *bo, struct sg_table **sgt)
+static struct host1x_bo_mapping *tegra_bo_pin(struct device *dev, struct host1x_bo *bo,
+					      enum dma_data_direction direction)
 {
 	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
+	struct drm_gem_object *gem = &obj->gem;
+	struct host1x_bo_mapping *map;
+	int err;
+
+	map = kzalloc(sizeof(*map), GFP_KERNEL);
+	if (!map)
+		return ERR_PTR(-ENOMEM);
+
+	kref_init(&map->ref);
+	map->bo = host1x_bo_get(bo);
+	map->direction = direction;
+	map->dev = dev;
+
+	/*
+	 * Imported buffers need special treatment to satisfy the semantics of DMA-BUF.
+	 */
+	if (obj->dma_buf) {
+		struct dma_buf *buf = obj->dma_buf;
+
+		map->attach = dma_buf_attach(buf, dev);
+		if (IS_ERR(map->attach)) {
+			err = PTR_ERR(map->attach);
+			goto free;
+		}
+
+		map->sgt = dma_buf_map_attachment_unlocked(map->attach, direction);
+		if (IS_ERR(map->sgt)) {
+			dma_buf_detach(buf, map->attach);
+			err = PTR_ERR(map->sgt);
+			map->sgt = NULL;
+			goto free;
+		}
+
+		err = sgt_dma_count_chunks(map->sgt);
+		map->size = gem->size;
+
+		goto out;
+	}
 
-	*sgt = obj->sgt;
+	/*
+	 * If we don't have a mapping for this buffer yet, return an SG table
+	 * so that host1x can do the mapping for us via the DMA API.
+	 */
+	map->sgt = kzalloc(sizeof(*map->sgt), GFP_KERNEL);
+	if (!map->sgt) {
+		err = -ENOMEM;
+		goto free;
+	}
 
-	return obj->paddr;
+	if (obj->pages) {
+		/*
+		 * If the buffer object was allocated from the explicit IOMMU
+		 * API code paths, construct an SG table from the pages.
+		 */
+		err = sg_alloc_table_from_pages(map->sgt, obj->pages, obj->num_pages, 0, gem->size,
+						GFP_KERNEL);
+		if (err < 0)
+			goto free;
+	} else {
+		/*
+		 * If the buffer object had no pages allocated and if it was
+		 * not imported, it had to be allocated with the DMA API, so
+		 * the DMA API helper can be used.
+		 */
+		err = dma_get_sgtable(dev, map->sgt, obj->vaddr, obj->iova, gem->size);
+		if (err < 0)
+			goto free;
+	}
+
+	err = dma_map_sgtable(dev, map->sgt, direction, 0);
+	if (err)
+		goto free_sgt;
+
+out:
+	/*
+	 * If we've manually mapped the buffer object through the IOMMU, make sure to return the
+	 * existing IOVA address of our mapping.
+	 */
+	if (!obj->mm) {
+		map->phys = sg_dma_address(map->sgt->sgl);
+		map->chunks = err;
+	} else {
+		map->phys = obj->iova;
+		map->chunks = 1;
+	}
+
+	map->size = gem->size;
+
+	return map;
+
+free_sgt:
+	sg_free_table(map->sgt);
+free:
+	kfree(map->sgt);
+	kfree(map);
+	return ERR_PTR(err);
 }
 
-static void tegra_bo_unpin(struct host1x_bo *bo, struct sg_table *sgt)
+static void tegra_bo_unpin(struct host1x_bo_mapping *map)
 {
+	if (map->attach) {
+		dma_buf_unmap_attachment_unlocked(map->attach, map->sgt,
+						  map->direction);
+		dma_buf_detach(map->attach->dmabuf, map->attach);
+	} else {
+		dma_unmap_sgtable(map->dev, map->sgt, map->direction, 0);
+		sg_free_table(map->sgt);
+		kfree(map->sgt);
+	}
+
+	host1x_bo_put(map->bo);
+	kfree(map);
 }
 
 static void *tegra_bo_mmap(struct host1x_bo *bo)
 {
 	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
+	struct iosys_map map = { 0 };
+	void *vaddr;
+	int ret;
 
 	if (obj->vaddr)
 		return obj->vaddr;
-	else if (obj->gem.import_attach)
-		return dma_buf_vmap(obj->gem.import_attach->dmabuf);
-	else
-		return vmap(obj->pages, obj->num_pages, VM_MAP,
-			    pgprot_writecombine(PAGE_KERNEL));
-}
 
-static void tegra_bo_munmap(struct host1x_bo *bo, void *addr)
-{
-	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
+	if (obj->dma_buf) {
+		ret = dma_buf_vmap_unlocked(obj->dma_buf, &map);
+		if (ret < 0)
+			return ERR_PTR(ret);
 
-	if (obj->vaddr)
-		return;
-	else if (obj->gem.import_attach)
-		dma_buf_vunmap(obj->gem.import_attach->dmabuf, addr);
-	else
-		vunmap(addr);
-}
+		return map.vaddr;
+	}
 
-static void *tegra_bo_kmap(struct host1x_bo *bo, unsigned int page)
-{
-	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
+	vaddr = vmap(obj->pages, obj->num_pages, VM_MAP,
+		     pgprot_writecombine(PAGE_KERNEL));
+	if (!vaddr)
+		return ERR_PTR(-ENOMEM);
 
-	if (obj->vaddr)
-		return obj->vaddr + page * PAGE_SIZE;
-	else if (obj->gem.import_attach)
-		return dma_buf_kmap(obj->gem.import_attach->dmabuf, page);
-	else
-		return vmap(obj->pages + page, 1, VM_MAP,
-			    pgprot_writecombine(PAGE_KERNEL));
+	return vaddr;
 }
 
-static void tegra_bo_kunmap(struct host1x_bo *bo, unsigned int page,
-			    void *addr)
+static void tegra_bo_munmap(struct host1x_bo *bo, void *addr)
 {
 	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
+	struct iosys_map map = IOSYS_MAP_INIT_VADDR(addr);
 
 	if (obj->vaddr)
 		return;
-	else if (obj->gem.import_attach)
-		dma_buf_kunmap(obj->gem.import_attach->dmabuf, page, addr);
-	else
-		vunmap(addr);
+
+	if (obj->dma_buf)
+		return dma_buf_vunmap_unlocked(obj->dma_buf, &map);
+
+	vunmap(addr);
 }
 
 static struct host1x_bo *tegra_bo_get(struct host1x_bo *bo)
@@ -107,8 +230,6 @@ static const struct host1x_bo_ops tegra_bo_ops = {
 	.unpin = tegra_bo_unpin,
 	.mmap = tegra_bo_mmap,
 	.munmap = tegra_bo_munmap,
-	.kmap = tegra_bo_kmap,
-	.kunmap = tegra_bo_kunmap,
 };
 
 static int tegra_bo_iommu_map(struct tegra_drm *tegra, struct tegra_bo *bo)
@@ -133,10 +254,9 @@ static int tegra_bo_iommu_map(struct tegra_drm *tegra, struct tegra_bo *bo)
 		goto unlock;
 	}
 
-	bo->paddr = bo->mm->start;
+	bo->iova = bo->mm->start;
 
-	bo->size = iommu_map_sg(tegra->domain, bo->paddr, bo->sgt->sgl,
-				bo->sgt->nents, prot);
+	bo->size = iommu_map_sgtable(tegra->domain, bo->iova, bo->sgt, prot);
 	if (!bo->size) {
 		dev_err(tegra->drm->dev, "failed to map buffer\n");
 		err = -ENOMEM;
@@ -161,7 +281,7 @@ static int tegra_bo_iommu_unmap(struct tegra_drm *tegra, struct tegra_bo *bo)
 		return 0;
 
 	mutex_lock(&tegra->mm_lock);
-	iommu_unmap(tegra->domain, bo->paddr, bo->size);
+	iommu_unmap(tegra->domain, bo->iova, bo->size);
 	drm_mm_remove_node(bo->mm);
 	mutex_unlock(&tegra->mm_lock);
 
@@ -170,6 +290,12 @@ static int tegra_bo_iommu_unmap(struct tegra_drm *tegra, struct tegra_bo *bo)
 	return 0;
 }
 
+static const struct drm_gem_object_funcs tegra_gem_object_funcs = {
+	.free = tegra_bo_free_object,
+	.export = tegra_gem_prime_export,
+	.vm_ops = &tegra_bo_vm_ops,
+};
+
 static struct tegra_bo *tegra_bo_alloc_object(struct drm_device *drm,
 					      size_t size)
 {
@@ -180,6 +306,8 @@ static struct tegra_bo *tegra_bo_alloc_object(struct drm_device *drm,
 	if (!bo)
 		return ERR_PTR(-ENOMEM);
 
+	bo->gem.funcs = &tegra_gem_object_funcs;
+
 	host1x_bo_init(&bo->base, &tegra_bo_ops);
 	size = round_up(size, PAGE_SIZE);
 
@@ -203,13 +331,12 @@ free:
 static void tegra_bo_free(struct drm_device *drm, struct tegra_bo *bo)
 {
 	if (bo->pages) {
-		dma_unmap_sg(drm->dev, bo->sgt->sgl, bo->sgt->nents,
-			     DMA_BIDIRECTIONAL);
+		dma_unmap_sgtable(drm->dev, bo->sgt, DMA_FROM_DEVICE, 0);
 		drm_gem_put_pages(&bo->gem, bo->pages, true, true);
 		sg_free_table(bo->sgt);
 		kfree(bo->sgt);
 	} else if (bo->vaddr) {
-		dma_free_wc(drm->dev, bo->gem.size, bo->vaddr, bo->paddr);
+		dma_free_wc(drm->dev, bo->gem.size, bo->vaddr, bo->iova);
 	}
 }
 
@@ -223,18 +350,15 @@ static int tegra_bo_get_pages(struct drm_device *drm, struct tegra_bo *bo)
 
 	bo->num_pages = bo->gem.size >> PAGE_SHIFT;
 
-	bo->sgt = drm_prime_pages_to_sg(bo->pages, bo->num_pages);
+	bo->sgt = drm_prime_pages_to_sg(bo->gem.dev, bo->pages, bo->num_pages);
 	if (IS_ERR(bo->sgt)) {
 		err = PTR_ERR(bo->sgt);
 		goto put_pages;
 	}
 
-	err = dma_map_sg(drm->dev, bo->sgt->sgl, bo->sgt->nents,
-			 DMA_BIDIRECTIONAL);
-	if (err == 0) {
-		err = -EFAULT;
+	err = dma_map_sgtable(drm->dev, bo->sgt, DMA_FROM_DEVICE, 0);
+	if (err)
 		goto free_sgt;
-	}
 
 	return 0;
 
@@ -264,7 +388,7 @@ static int tegra_bo_alloc(struct drm_device *drm, struct tegra_bo *bo)
 	} else {
 		size_t size = bo->gem.size;
 
-		bo->vaddr = dma_alloc_wc(drm->dev, size, &bo->paddr,
+		bo->vaddr = dma_alloc_wc(drm->dev, size, &bo->iova,
 					 GFP_KERNEL | __GFP_NOWARN);
 		if (!bo->vaddr) {
 			dev_err(drm->dev,
@@ -324,7 +448,7 @@ struct tegra_bo *tegra_bo_create_with_handle(struct drm_file *file,
 		return ERR_PTR(err);
 	}
 
-	drm_gem_object_put_unlocked(&bo->gem);
+	drm_gem_object_put(&bo->gem);
 
 	return bo;
 }
@@ -341,40 +465,38 @@ static struct tegra_bo *tegra_bo_import(struct drm_device *drm,
 	if (IS_ERR(bo))
 		return bo;
 
-	attach = dma_buf_attach(buf, drm->dev);
-	if (IS_ERR(attach)) {
-		err = PTR_ERR(attach);
-		goto free;
-	}
-
-	get_dma_buf(buf);
+	/*
+	 * If we need to use IOMMU API to map the dma-buf into the internally managed
+	 * domain, map it first to the DRM device to get an sgt.
+	 */
+	if (tegra->domain) {
+		attach = dma_buf_attach(buf, drm->dev);
+		if (IS_ERR(attach)) {
+			err = PTR_ERR(attach);
+			goto free;
+		}
 
-	bo->sgt = dma_buf_map_attachment(attach, DMA_TO_DEVICE);
-	if (IS_ERR(bo->sgt)) {
-		err = PTR_ERR(bo->sgt);
-		goto detach;
-	}
+		bo->sgt = dma_buf_map_attachment_unlocked(attach, DMA_TO_DEVICE);
+		if (IS_ERR(bo->sgt)) {
+			err = PTR_ERR(bo->sgt);
+			goto detach;
+		}
 
-	if (tegra->domain) {
 		err = tegra_bo_iommu_map(tegra, bo);
 		if (err < 0)
 			goto detach;
-	} else {
-		if (bo->sgt->nents > 1) {
-			err = -EINVAL;
-			goto detach;
-		}
 
-		bo->paddr = sg_dma_address(bo->sgt->sgl);
+		bo->gem.import_attach = attach;
 	}
 
-	bo->gem.import_attach = attach;
+	get_dma_buf(buf);
+	bo->dma_buf = buf;
 
 	return bo;
 
 detach:
 	if (!IS_ERR_OR_NULL(bo->sgt))
-		dma_buf_unmap_attachment(attach, bo->sgt, DMA_TO_DEVICE);
+		dma_buf_unmap_attachment_unlocked(attach, bo->sgt, DMA_TO_DEVICE);
 
 	dma_buf_detach(buf, attach);
 	dma_buf_put(buf);
@@ -387,19 +509,33 @@ free:
 void tegra_bo_free_object(struct drm_gem_object *gem)
 {
 	struct tegra_drm *tegra = gem->dev->dev_private;
+	struct host1x_bo_mapping *mapping, *tmp;
 	struct tegra_bo *bo = to_tegra_bo(gem);
 
-	if (tegra->domain)
+	/* remove all mappings of this buffer object from any caches */
+	list_for_each_entry_safe(mapping, tmp, &bo->base.mappings, list) {
+		if (mapping->cache)
+			host1x_bo_unpin(mapping);
+		else
+			dev_err(gem->dev->dev, "mapping %p stale for device %s\n", mapping,
+				dev_name(mapping->dev));
+	}
+
+	if (tegra->domain) {
 		tegra_bo_iommu_unmap(tegra, bo);
 
-	if (gem->import_attach) {
-		dma_buf_unmap_attachment(gem->import_attach, bo->sgt,
-					 DMA_TO_DEVICE);
-		drm_prime_gem_destroy(gem, NULL);
-	} else {
-		tegra_bo_free(gem->dev, bo);
+		if (drm_gem_is_imported(gem)) {
+			dma_buf_unmap_attachment_unlocked(gem->import_attach, bo->sgt,
+							  DMA_TO_DEVICE);
+			dma_buf_detach(gem->import_attach->dmabuf, gem->import_attach);
+		}
 	}
 
+	tegra_bo_free(gem->dev, bo);
+
+	if (bo->dma_buf)
+		dma_buf_put(bo->dma_buf);
+
 	drm_gem_object_release(gem);
 	kfree(bo);
 }
@@ -407,12 +543,13 @@ void tegra_bo_free_object(struct drm_gem_object *gem)
 int tegra_bo_dumb_create(struct drm_file *file, struct drm_device *drm,
 			 struct drm_mode_create_dumb *args)
 {
-	unsigned int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
 	struct tegra_drm *tegra = drm->dev_private;
 	struct tegra_bo *bo;
+	int ret;
 
-	args->pitch = round_up(min_pitch, tegra->pitch_align);
-	args->size = args->pitch * args->height;
+	ret = drm_mode_size_dumb(drm, args, tegra->pitch_align, 0);
+	if (ret)
+		return ret;
 
 	bo = tegra_bo_create_with_handle(file, drm, args->size, 0,
 					 &args->handle);
@@ -458,10 +595,10 @@ int __tegra_gem_mmap(struct drm_gem_object *gem, struct vm_area_struct *vma)
 		 * and set the vm_pgoff (used as a fake buffer offset by DRM)
 		 * to 0 as we want to map the whole buffer.
 		 */
-		vma->vm_flags &= ~VM_PFNMAP;
+		vm_flags_clear(vma, VM_PFNMAP);
 		vma->vm_pgoff = 0;
 
-		err = dma_mmap_wc(gem->dev->dev, vma, bo->vaddr, bo->paddr,
+		err = dma_mmap_wc(gem->dev->dev, vma, bo->vaddr, bo->iova,
 				  gem->size);
 		if (err < 0) {
 			drm_gem_vm_close(vma);
@@ -472,8 +609,7 @@ int __tegra_gem_mmap(struct drm_gem_object *gem, struct vm_area_struct *vma)
 	} else {
 		pgprot_t prot = vm_get_page_prot(vma->vm_flags);
 
-		vma->vm_flags |= VM_MIXEDMAP;
-		vma->vm_flags &= ~VM_PFNMAP;
+		vm_flags_mod(vma, VM_MIXEDMAP, VM_PFNMAP);
 
 		vma->vm_page_prot = pgprot_writecombine(prot);
 	}
@@ -508,25 +644,18 @@ tegra_gem_prime_map_dma_buf(struct dma_buf_attachment *attach,
 		return NULL;
 
 	if (bo->pages) {
-		struct scatterlist *sg;
-		unsigned int i;
-
-		if (sg_alloc_table(sgt, bo->num_pages, GFP_KERNEL))
-			goto free;
-
-		for_each_sg(sgt->sgl, sg, bo->num_pages, i)
-			sg_set_page(sg, bo->pages[i], PAGE_SIZE, 0);
-
-		if (dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir) == 0)
+		if (sg_alloc_table_from_pages(sgt, bo->pages, bo->num_pages,
+					      0, gem->size, GFP_KERNEL) < 0)
 			goto free;
 	} else {
-		if (sg_alloc_table(sgt, 1, GFP_KERNEL))
+		if (dma_get_sgtable(attach->dev, sgt, bo->vaddr, bo->iova,
+				    gem->size) < 0)
 			goto free;
-
-		sg_dma_address(sgt->sgl) = bo->paddr;
-		sg_dma_len(sgt->sgl) = gem->size;
 	}
 
+	if (dma_map_sgtable(attach->dev, sgt, dir, 0))
+		goto free;
+
 	return sgt;
 
 free:
@@ -543,7 +672,7 @@ static void tegra_gem_prime_unmap_dma_buf(struct dma_buf_attachment *attach,
 	struct tegra_bo *bo = to_tegra_bo(gem);
 
 	if (bo->pages)
-		dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
+		dma_unmap_sgtable(attach->dev, sgt, dir, 0);
 
 	sg_free_table(sgt);
 	kfree(sgt);
@@ -562,8 +691,7 @@ static int tegra_gem_prime_begin_cpu_access(struct dma_buf *buf,
 	struct drm_device *drm = gem->dev;
 
 	if (bo->pages)
-		dma_sync_sg_for_cpu(drm->dev, bo->sgt->sgl, bo->sgt->nents,
-				    DMA_FROM_DEVICE);
+		dma_sync_sgtable_for_cpu(drm->dev, bo->sgt, DMA_FROM_DEVICE);
 
 	return 0;
 }
@@ -576,22 +704,11 @@ static int tegra_gem_prime_end_cpu_access(struct dma_buf *buf,
 	struct drm_device *drm = gem->dev;
 
 	if (bo->pages)
-		dma_sync_sg_for_device(drm->dev, bo->sgt->sgl, bo->sgt->nents,
-				       DMA_TO_DEVICE);
+		dma_sync_sgtable_for_device(drm->dev, bo->sgt, DMA_TO_DEVICE);
 
 	return 0;
 }
 
-static void *tegra_gem_prime_kmap(struct dma_buf *buf, unsigned long page)
-{
-	return NULL;
-}
-
-static void tegra_gem_prime_kunmap(struct dma_buf *buf, unsigned long page,
-				   void *addr)
-{
-}
-
 static int tegra_gem_prime_mmap(struct dma_buf *buf, struct vm_area_struct *vma)
 {
 	struct drm_gem_object *gem = buf->priv;
@@ -604,16 +721,27 @@ static int tegra_gem_prime_mmap(struct dma_buf *buf, struct vm_area_struct *vma)
 	return __tegra_gem_mmap(gem, vma);
 }
 
-static void *tegra_gem_prime_vmap(struct dma_buf *buf)
+static int tegra_gem_prime_vmap(struct dma_buf *buf, struct iosys_map *map)
 {
 	struct drm_gem_object *gem = buf->priv;
 	struct tegra_bo *bo = to_tegra_bo(gem);
+	void *vaddr;
+
+	vaddr = tegra_bo_mmap(&bo->base);
+	if (IS_ERR(vaddr))
+		return PTR_ERR(vaddr);
 
-	return bo->vaddr;
+	iosys_map_set_vaddr(map, vaddr);
+
+	return 0;
 }
 
-static void tegra_gem_prime_vunmap(struct dma_buf *buf, void *vaddr)
+static void tegra_gem_prime_vunmap(struct dma_buf *buf, struct iosys_map *map)
 {
+	struct drm_gem_object *gem = buf->priv;
+	struct tegra_bo *bo = to_tegra_bo(gem);
+
+	tegra_bo_munmap(&bo->base, map->vaddr);
 }
 
 static const struct dma_buf_ops tegra_gem_prime_dmabuf_ops = {
@@ -622,27 +750,24 @@ static const struct dma_buf_ops tegra_gem_prime_dmabuf_ops = {
 	.release = tegra_gem_prime_release,
 	.begin_cpu_access = tegra_gem_prime_begin_cpu_access,
 	.end_cpu_access = tegra_gem_prime_end_cpu_access,
-	.map = tegra_gem_prime_kmap,
-	.unmap = tegra_gem_prime_kunmap,
 	.mmap = tegra_gem_prime_mmap,
 	.vmap = tegra_gem_prime_vmap,
 	.vunmap = tegra_gem_prime_vunmap,
 };
 
-struct dma_buf *tegra_gem_prime_export(struct drm_device *drm,
-				       struct drm_gem_object *gem,
+struct dma_buf *tegra_gem_prime_export(struct drm_gem_object *gem,
 				       int flags)
 {
 	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 
 	exp_info.exp_name = KBUILD_MODNAME;
-	exp_info.owner = drm->driver->fops->owner;
+	exp_info.owner = gem->dev->driver->fops->owner;
 	exp_info.ops = &tegra_gem_prime_dmabuf_ops;
 	exp_info.size = gem->size;
 	exp_info.flags = flags;
 	exp_info.priv = gem;
 
-	return drm_gem_dmabuf_export(drm, &exp_info);
+	return drm_gem_dmabuf_export(gem->dev, &exp_info);
 }
 
 struct drm_gem_object *tegra_gem_prime_import(struct drm_device *drm,
@@ -665,3 +790,16 @@ struct drm_gem_object *tegra_gem_prime_import(struct drm_device *drm,
 
 	return &bo->gem;
 }
+
+struct host1x_bo *tegra_gem_lookup(struct drm_file *file, u32 handle)
+{
+	struct drm_gem_object *gem;
+	struct tegra_bo *bo;
+
+	gem = drm_gem_object_lookup(file, handle);
+	if (!gem)
+		return NULL;
+
+	bo = to_tegra_bo(gem);
+	return &bo->base;
+}