Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 784 insertions, 0 deletions

diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c
new file mode 100644
index 000000000..81991090a
--- /dev/null
+++ b/drivers/gpu/drm/tegra/gem.c
@@ -0,0 +1,784 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * NVIDIA Tegra DRM GEM helper functions
+ *
+ * Copyright (C) 2012 Sascha Hauer, Pengutronix
+ * Copyright (C) 2013-2015 NVIDIA CORPORATION, All rights reserved.
+ *
+ * Based on the GEM/CMA helpers
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd.
+ */
+
+#include <linux/dma-buf.h>
+#include <linux/iommu.h>
+#include <linux/module.h>
+
+#include <drm/drm_drv.h>
+#include <drm/drm_prime.h>
+#include <drm/tegra_drm.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(&obj->gem);
+}
+
+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 (gem->import_attach) {
+		struct dma_buf *buf = gem->import_attach->dmabuf;
+
+		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(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;
+	}
+
+	/*
+	 * 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;
+	}
+
+	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_mapping *map)
+{
+	if (map->attach) {
+		dma_buf_unmap_attachment(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;
+	int ret;
+
+	if (obj->vaddr) {
+		return obj->vaddr;
+	} else if (obj->gem.import_attach) {
+		ret = dma_buf_vmap(obj->gem.import_attach->dmabuf, &map);
+		return ret ? NULL : map.vaddr;
+	} 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);
+	struct iosys_map map = IOSYS_MAP_INIT_VADDR(addr);
+
+	if (obj->vaddr)
+		return;
+	else if (obj->gem.import_attach)
+		dma_buf_vunmap(obj->gem.import_attach->dmabuf, &map);
+	else
+		vunmap(addr);
+}
+
+static struct host1x_bo *tegra_bo_get(struct host1x_bo *bo)
+{
+	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
+
+	drm_gem_object_get(&obj->gem);
+
+	return bo;
+}
+
+static const struct host1x_bo_ops tegra_bo_ops = {
+	.get = tegra_bo_get,
+	.put = tegra_bo_put,
+	.pin = tegra_bo_pin,
+	.unpin = tegra_bo_unpin,
+	.mmap = tegra_bo_mmap,
+	.munmap = tegra_bo_munmap,
+};
+
+static int tegra_bo_iommu_map(struct tegra_drm *tegra, struct tegra_bo *bo)
+{
+	int prot = IOMMU_READ | IOMMU_WRITE;
+	int err;
+
+	if (bo->mm)
+		return -EBUSY;
+
+	bo->mm = kzalloc(sizeof(*bo->mm), GFP_KERNEL);
+	if (!bo->mm)
+		return -ENOMEM;
+
+	mutex_lock(&tegra->mm_lock);
+
+	err = drm_mm_insert_node_generic(&tegra->mm,
+					 bo->mm, bo->gem.size, PAGE_SIZE, 0, 0);
+	if (err < 0) {
+		dev_err(tegra->drm->dev, "out of I/O virtual memory: %d\n",
+			err);
+		goto unlock;
+	}
+
+	bo->iova = bo->mm->start;
+
+	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;
+		goto remove;
+	}
+
+	mutex_unlock(&tegra->mm_lock);
+
+	return 0;
+
+remove:
+	drm_mm_remove_node(bo->mm);
+unlock:
+	mutex_unlock(&tegra->mm_lock);
+	kfree(bo->mm);
+	return err;
+}
+
+static int tegra_bo_iommu_unmap(struct tegra_drm *tegra, struct tegra_bo *bo)
+{
+	if (!bo->mm)
+		return 0;
+
+	mutex_lock(&tegra->mm_lock);
+	iommu_unmap(tegra->domain, bo->iova, bo->size);
+	drm_mm_remove_node(bo->mm);
+	mutex_unlock(&tegra->mm_lock);
+
+	kfree(bo->mm);
+
+	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)
+{
+	struct tegra_bo *bo;
+	int err;
+
+	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
+	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);
+
+	err = drm_gem_object_init(drm, &bo->gem, size);
+	if (err < 0)
+		goto free;
+
+	err = drm_gem_create_mmap_offset(&bo->gem);
+	if (err < 0)
+		goto release;
+
+	return bo;
+
+release:
+	drm_gem_object_release(&bo->gem);
+free:
+	kfree(bo);
+	return ERR_PTR(err);
+}
+
+static void tegra_bo_free(struct drm_device *drm, struct tegra_bo *bo)
+{
+	if (bo->pages) {
+		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->iova);
+	}
+}
+
+static int tegra_bo_get_pages(struct drm_device *drm, struct tegra_bo *bo)
+{
+	int err;
+
+	bo->pages = drm_gem_get_pages(&bo->gem);
+	if (IS_ERR(bo->pages))
+		return PTR_ERR(bo->pages);
+
+	bo->num_pages = bo->gem.size >> PAGE_SHIFT;
+
+	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_sgtable(drm->dev, bo->sgt, DMA_FROM_DEVICE, 0);
+	if (err)
+		goto free_sgt;
+
+	return 0;
+
+free_sgt:
+	sg_free_table(bo->sgt);
+	kfree(bo->sgt);
+put_pages:
+	drm_gem_put_pages(&bo->gem, bo->pages, false, false);
+	return err;
+}
+
+static int tegra_bo_alloc(struct drm_device *drm, struct tegra_bo *bo)
+{
+	struct tegra_drm *tegra = drm->dev_private;
+	int err;
+
+	if (tegra->domain) {
+		err = tegra_bo_get_pages(drm, bo);
+		if (err < 0)
+			return err;
+
+		err = tegra_bo_iommu_map(tegra, bo);
+		if (err < 0) {
+			tegra_bo_free(drm, bo);
+			return err;
+		}
+	} else {
+		size_t size = bo->gem.size;
+
+		bo->vaddr = dma_alloc_wc(drm->dev, size, &bo->iova,
+					 GFP_KERNEL | __GFP_NOWARN);
+		if (!bo->vaddr) {
+			dev_err(drm->dev,
+				"failed to allocate buffer of size %zu\n",
+				size);
+			return -ENOMEM;
+		}
+	}
+
+	return 0;
+}
+
+struct tegra_bo *tegra_bo_create(struct drm_device *drm, size_t size,
+				 unsigned long flags)
+{
+	struct tegra_bo *bo;
+	int err;
+
+	bo = tegra_bo_alloc_object(drm, size);
+	if (IS_ERR(bo))
+		return bo;
+
+	err = tegra_bo_alloc(drm, bo);
+	if (err < 0)
+		goto release;
+
+	if (flags & DRM_TEGRA_GEM_CREATE_TILED)
+		bo->tiling.mode = TEGRA_BO_TILING_MODE_TILED;
+
+	if (flags & DRM_TEGRA_GEM_CREATE_BOTTOM_UP)
+		bo->flags |= TEGRA_BO_BOTTOM_UP;
+
+	return bo;
+
+release:
+	drm_gem_object_release(&bo->gem);
+	kfree(bo);
+	return ERR_PTR(err);
+}
+
+struct tegra_bo *tegra_bo_create_with_handle(struct drm_file *file,
+					     struct drm_device *drm,
+					     size_t size,
+					     unsigned long flags,
+					     u32 *handle)
+{
+	struct tegra_bo *bo;
+	int err;
+
+	bo = tegra_bo_create(drm, size, flags);
+	if (IS_ERR(bo))
+		return bo;
+
+	err = drm_gem_handle_create(file, &bo->gem, handle);
+	if (err) {
+		tegra_bo_free_object(&bo->gem);
+		return ERR_PTR(err);
+	}
+
+	drm_gem_object_put(&bo->gem);
+
+	return bo;
+}
+
+static struct tegra_bo *tegra_bo_import(struct drm_device *drm,
+					struct dma_buf *buf)
+{
+	struct tegra_drm *tegra = drm->dev_private;
+	struct dma_buf_attachment *attach;
+	struct tegra_bo *bo;
+	int err;
+
+	bo = tegra_bo_alloc_object(drm, buf->size);
+	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);
+
+	bo->sgt = dma_buf_map_attachment(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;
+	}
+
+	bo->gem.import_attach = attach;
+
+	return bo;
+
+detach:
+	if (!IS_ERR_OR_NULL(bo->sgt))
+		dma_buf_unmap_attachment(attach, bo->sgt, DMA_TO_DEVICE);
+
+	dma_buf_detach(buf, attach);
+	dma_buf_put(buf);
+free:
+	drm_gem_object_release(&bo->gem);
+	kfree(bo);
+	return ERR_PTR(err);
+}
+
+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);
+
+	/* 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);
+	}
+
+	drm_gem_object_release(gem);
+	kfree(bo);
+}
+
+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;
+
+	args->pitch = round_up(min_pitch, tegra->pitch_align);
+	args->size = args->pitch * args->height;
+
+	bo = tegra_bo_create_with_handle(file, drm, args->size, 0,
+					 &args->handle);
+	if (IS_ERR(bo))
+		return PTR_ERR(bo);
+
+	return 0;
+}
+
+static vm_fault_t tegra_bo_fault(struct vm_fault *vmf)
+{
+	struct vm_area_struct *vma = vmf->vma;
+	struct drm_gem_object *gem = vma->vm_private_data;
+	struct tegra_bo *bo = to_tegra_bo(gem);
+	struct page *page;
+	pgoff_t offset;
+
+	if (!bo->pages)
+		return VM_FAULT_SIGBUS;
+
+	offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
+	page = bo->pages[offset];
+
+	return vmf_insert_page(vma, vmf->address, page);
+}
+
+const struct vm_operations_struct tegra_bo_vm_ops = {
+	.fault = tegra_bo_fault,
+	.open = drm_gem_vm_open,
+	.close = drm_gem_vm_close,
+};
+
+int __tegra_gem_mmap(struct drm_gem_object *gem, struct vm_area_struct *vma)
+{
+	struct tegra_bo *bo = to_tegra_bo(gem);
+
+	if (!bo->pages) {
+		unsigned long vm_pgoff = vma->vm_pgoff;
+		int err;
+
+		/*
+		 * Clear the VM_PFNMAP flag that was set by drm_gem_mmap(),
+		 * 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;
+		vma->vm_pgoff = 0;
+
+		err = dma_mmap_wc(gem->dev->dev, vma, bo->vaddr, bo->iova,
+				  gem->size);
+		if (err < 0) {
+			drm_gem_vm_close(vma);
+			return err;
+		}
+
+		vma->vm_pgoff = vm_pgoff;
+	} else {
+		pgprot_t prot = vm_get_page_prot(vma->vm_flags);
+
+		vma->vm_flags |= VM_MIXEDMAP;
+		vma->vm_flags &= ~VM_PFNMAP;
+
+		vma->vm_page_prot = pgprot_writecombine(prot);
+	}
+
+	return 0;
+}
+
+int tegra_drm_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct drm_gem_object *gem;
+	int err;
+
+	err = drm_gem_mmap(file, vma);
+	if (err < 0)
+		return err;
+
+	gem = vma->vm_private_data;
+
+	return __tegra_gem_mmap(gem, vma);
+}
+
+static struct sg_table *
+tegra_gem_prime_map_dma_buf(struct dma_buf_attachment *attach,
+			    enum dma_data_direction dir)
+{
+	struct drm_gem_object *gem = attach->dmabuf->priv;
+	struct tegra_bo *bo = to_tegra_bo(gem);
+	struct sg_table *sgt;
+
+	sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
+	if (!sgt)
+		return NULL;
+
+	if (bo->pages) {
+		if (sg_alloc_table_from_pages(sgt, bo->pages, bo->num_pages,
+					      0, gem->size, GFP_KERNEL) < 0)
+			goto free;
+	} else {
+		if (dma_get_sgtable(attach->dev, sgt, bo->vaddr, bo->iova,
+				    gem->size) < 0)
+			goto free;
+	}
+
+	if (dma_map_sgtable(attach->dev, sgt, dir, 0))
+		goto free;
+
+	return sgt;
+
+free:
+	sg_free_table(sgt);
+	kfree(sgt);
+	return NULL;
+}
+
+static void tegra_gem_prime_unmap_dma_buf(struct dma_buf_attachment *attach,
+					  struct sg_table *sgt,
+					  enum dma_data_direction dir)
+{
+	struct drm_gem_object *gem = attach->dmabuf->priv;
+	struct tegra_bo *bo = to_tegra_bo(gem);
+
+	if (bo->pages)
+		dma_unmap_sgtable(attach->dev, sgt, dir, 0);
+
+	sg_free_table(sgt);
+	kfree(sgt);
+}
+
+static void tegra_gem_prime_release(struct dma_buf *buf)
+{
+	drm_gem_dmabuf_release(buf);
+}
+
+static int tegra_gem_prime_begin_cpu_access(struct dma_buf *buf,
+					    enum dma_data_direction direction)
+{
+	struct drm_gem_object *gem = buf->priv;
+	struct tegra_bo *bo = to_tegra_bo(gem);
+	struct drm_device *drm = gem->dev;
+
+	if (bo->pages)
+		dma_sync_sgtable_for_cpu(drm->dev, bo->sgt, DMA_FROM_DEVICE);
+
+	return 0;
+}
+
+static int tegra_gem_prime_end_cpu_access(struct dma_buf *buf,
+					  enum dma_data_direction direction)
+{
+	struct drm_gem_object *gem = buf->priv;
+	struct tegra_bo *bo = to_tegra_bo(gem);
+	struct drm_device *drm = gem->dev;
+
+	if (bo->pages)
+		dma_sync_sgtable_for_device(drm->dev, bo->sgt, DMA_TO_DEVICE);
+
+	return 0;
+}
+
+static int tegra_gem_prime_mmap(struct dma_buf *buf, struct vm_area_struct *vma)
+{
+	struct drm_gem_object *gem = buf->priv;
+	int err;
+
+	err = drm_gem_mmap_obj(gem, gem->size, vma);
+	if (err < 0)
+		return err;
+
+	return __tegra_gem_mmap(gem, vma);
+}
+
+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);
+
+	iosys_map_set_vaddr(map, vaddr);
+
+	return 0;
+}
+
+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 = {
+	.map_dma_buf = tegra_gem_prime_map_dma_buf,
+	.unmap_dma_buf = tegra_gem_prime_unmap_dma_buf,
+	.release = tegra_gem_prime_release,
+	.begin_cpu_access = tegra_gem_prime_begin_cpu_access,
+	.end_cpu_access = tegra_gem_prime_end_cpu_access,
+	.mmap = tegra_gem_prime_mmap,
+	.vmap = tegra_gem_prime_vmap,
+	.vunmap = tegra_gem_prime_vunmap,
+};
+
+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 = 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(gem->dev, &exp_info);
+}
+
+struct drm_gem_object *tegra_gem_prime_import(struct drm_device *drm,
+					      struct dma_buf *buf)
+{
+	struct tegra_bo *bo;
+
+	if (buf->ops == &tegra_gem_prime_dmabuf_ops) {
+		struct drm_gem_object *gem = buf->priv;
+
+		if (gem->dev == drm) {
+			drm_gem_object_get(gem);
+			return gem;
+		}
+	}
+
+	bo = tegra_bo_import(drm, buf);
+	if (IS_ERR(bo))
+		return ERR_CAST(bo);
+
+	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;
+}