[deliverable/linux.git] / drivers / gpu / drm / drm_prime.c

/*
 * Copyright © 2012 Red Hat
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 * Authors:
 *      Dave Airlie <airlied@redhat.com>
 *      Rob Clark <rob.clark@linaro.org>
 *
 */

#include <linux/export.h>
#include <linux/dma-buf.h>
#include <drm/drmP.h>

/*
 * DMA-BUF/GEM Object references and lifetime overview:
 *
 * On the export the dma_buf holds a reference to the exporting GEM
 * object. It takes this reference in handle_to_fd_ioctl, when it
 * first calls .prime_export and stores the exporting GEM object in
 * the dma_buf priv. This reference is released when the dma_buf
 * object goes away in the driver .release function.
 *
 * On the import the importing GEM object holds a reference to the
 * dma_buf (which in turn holds a ref to the exporting GEM object).
 * It takes that reference in the fd_to_handle ioctl.
 * It calls dma_buf_get, creates an attachment to it and stores the
 * attachment in the GEM object. When this attachment is destroyed
 * when the imported object is destroyed, we remove the attachment
 * and drop the reference to the dma_buf.
 *
 * Thus the chain of references always flows in one direction
 * (avoiding loops): importing_gem -> dmabuf -> exporting_gem
 *
 * Self-importing: if userspace is using PRIME as a replacement for flink
 * then it will get a fd->handle request for a GEM object that it created.
 * Drivers should detect this situation and return back the gem object
 * from the dma-buf private.  Prime will do this automatically for drivers that
 * use the drm_gem_prime_{import,export} helpers.
 */

struct drm_prime_member {
	struct list_head entry;
	struct dma_buf *dma_buf;
	uint32_t handle;
};
static int drm_prime_add_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf, uint32_t handle);

static int drm_gem_map_attach(struct dma_buf *dma_buf,
			      struct device *target_dev,
			      struct dma_buf_attachment *attach)
{
	struct drm_gem_object *obj = dma_buf->priv;
	struct drm_device *dev = obj->dev;

	if (!dev->driver->gem_prime_pin)
		return 0;

	return dev->driver->gem_prime_pin(obj);
}

static void drm_gem_map_detach(struct dma_buf *dma_buf,
			       struct dma_buf_attachment *attach)
{
	struct drm_gem_object *obj = dma_buf->priv;
	struct drm_device *dev = obj->dev;

	if (dev->driver->gem_prime_unpin)
		dev->driver->gem_prime_unpin(obj);
}

static struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
		enum dma_data_direction dir)
{
	struct drm_gem_object *obj = attach->dmabuf->priv;
	struct sg_table *sgt;

	mutex_lock(&obj->dev->struct_mutex);

	sgt = obj->dev->driver->gem_prime_get_sg_table(obj);

	if (!IS_ERR_OR_NULL(sgt))
		dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir);

	mutex_unlock(&obj->dev->struct_mutex);
	return sgt;
}

static void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
		struct sg_table *sgt, enum dma_data_direction dir)
{
	dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
	sg_free_table(sgt);
	kfree(sgt);
}

static void drm_gem_dmabuf_release(struct dma_buf *dma_buf)
{
	struct drm_gem_object *obj = dma_buf->priv;

	if (obj->export_dma_buf == dma_buf) {
		/* drop the reference on the export fd holds */
		obj->export_dma_buf = NULL;
		drm_gem_object_unreference_unlocked(obj);
	}
}

static void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
{
	struct drm_gem_object *obj = dma_buf->priv;
	struct drm_device *dev = obj->dev;

	return dev->driver->gem_prime_vmap(obj);
}

static void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
{
	struct drm_gem_object *obj = dma_buf->priv;
	struct drm_device *dev = obj->dev;

	dev->driver->gem_prime_vunmap(obj, vaddr);
}

static void *drm_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
		unsigned long page_num)
{
	return NULL;
}

static void drm_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
		unsigned long page_num, void *addr)
{

}
static void *drm_gem_dmabuf_kmap(struct dma_buf *dma_buf,
		unsigned long page_num)
{
	return NULL;
}

static void drm_gem_dmabuf_kunmap(struct dma_buf *dma_buf,
		unsigned long page_num, void *addr)
{

}

static int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf,
		struct vm_area_struct *vma)
{
	return -EINVAL;
}

static const struct dma_buf_ops drm_gem_prime_dmabuf_ops =  {
	.attach = drm_gem_map_attach,
	.detach = drm_gem_map_detach,
	.map_dma_buf = drm_gem_map_dma_buf,
	.unmap_dma_buf = drm_gem_unmap_dma_buf,
	.release = drm_gem_dmabuf_release,
	.kmap = drm_gem_dmabuf_kmap,
	.kmap_atomic = drm_gem_dmabuf_kmap_atomic,
	.kunmap = drm_gem_dmabuf_kunmap,
	.kunmap_atomic = drm_gem_dmabuf_kunmap_atomic,
	.mmap = drm_gem_dmabuf_mmap,
	.vmap = drm_gem_dmabuf_vmap,
	.vunmap = drm_gem_dmabuf_vunmap,
};

/**
 * DOC: PRIME Helpers
 *
 * Drivers can implement @gem_prime_export and @gem_prime_import in terms of
 * simpler APIs by using the helper functions @drm_gem_prime_export and
 * @drm_gem_prime_import.  These functions implement dma-buf support in terms of
 * five lower-level driver callbacks:
 *
 * Export callbacks:
 *
 *  - @gem_prime_pin (optional): prepare a GEM object for exporting
 *
 *  - @gem_prime_get_sg_table: provide a scatter/gather table of pinned pages
 *
 *  - @gem_prime_vmap: vmap a buffer exported by your driver
 *
 *  - @gem_prime_vunmap: vunmap a buffer exported by your driver
 *
 * Import callback:
 *
 *  - @gem_prime_import_sg_table (import): produce a GEM object from another
 *    driver's scatter/gather table
 */

struct dma_buf *drm_gem_prime_export(struct drm_device *dev,
				     struct drm_gem_object *obj, int flags)
{
	return dma_buf_export(obj, &drm_gem_prime_dmabuf_ops, obj->size,
			     0600);
}
EXPORT_SYMBOL(drm_gem_prime_export);

int drm_gem_prime_handle_to_fd(struct drm_device *dev,
		struct drm_file *file_priv, uint32_t handle, uint32_t flags,
		int *prime_fd)
{
	struct drm_gem_object *obj;
	void *buf;
	int ret = 0;
	struct dma_buf *dmabuf;

	obj = drm_gem_object_lookup(dev, file_priv, handle);
	if (!obj)
		return -ENOENT;

	mutex_lock(&file_priv->prime.lock);
	/* re-export the original imported object */
	if (obj->import_attach) {
		dmabuf = obj->import_attach->dmabuf;
		goto out_have_obj;
	}

	if (obj->export_dma_buf) {
		dmabuf = obj->export_dma_buf;
		goto out_have_obj;
	}

	buf = dev->driver->gem_prime_export(dev, obj, flags);
	if (IS_ERR(buf)) {
		/* normally the created dma-buf takes ownership of the ref,
		 * but if that fails then drop the ref
		 */
		ret = PTR_ERR(buf);
		goto out;
	}
	obj->export_dma_buf = buf;

	/* if we've exported this buffer the cheat and add it to the import list
	 * so we get the correct handle back
	 */
	ret = drm_prime_add_buf_handle(&file_priv->prime,
				       obj->export_dma_buf, handle);
	if (ret)
		goto out;

	*prime_fd = dma_buf_fd(buf, flags);
	mutex_unlock(&file_priv->prime.lock);
	return 0;

out_have_obj:
	get_dma_buf(dmabuf);
	*prime_fd = dma_buf_fd(dmabuf, flags);
out:
	drm_gem_object_unreference_unlocked(obj);
	mutex_unlock(&file_priv->prime.lock);
	return ret;
}
EXPORT_SYMBOL(drm_gem_prime_handle_to_fd);

struct drm_gem_object *drm_gem_prime_import(struct drm_device *dev,
					    struct dma_buf *dma_buf)
{
	struct dma_buf_attachment *attach;
	struct sg_table *sgt;
	struct drm_gem_object *obj;
	int ret;

	if (!dev->driver->gem_prime_import_sg_table)
		return ERR_PTR(-EINVAL);

	if (dma_buf->ops == &drm_gem_prime_dmabuf_ops) {
		obj = dma_buf->priv;
		if (obj->dev == dev) {
			/*
			 * Importing dmabuf exported from out own gem increases
			 * refcount on gem itself instead of f_count of dmabuf.
			 */
			drm_gem_object_reference(obj);
			return obj;
		}
	}

	attach = dma_buf_attach(dma_buf, dev->dev);
	if (IS_ERR(attach))
		return ERR_CAST(attach);

	get_dma_buf(dma_buf);

	sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
	if (IS_ERR_OR_NULL(sgt)) {
		ret = PTR_ERR(sgt);
		goto fail_detach;
	}

	obj = dev->driver->gem_prime_import_sg_table(dev, dma_buf->size, sgt);
	if (IS_ERR(obj)) {
		ret = PTR_ERR(obj);
		goto fail_unmap;
	}

	obj->import_attach = attach;

	return obj;

fail_unmap:
	dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
fail_detach:
	dma_buf_detach(dma_buf, attach);
	dma_buf_put(dma_buf);

	return ERR_PTR(ret);
}
EXPORT_SYMBOL(drm_gem_prime_import);

int drm_gem_prime_fd_to_handle(struct drm_device *dev,
		struct drm_file *file_priv, int prime_fd, uint32_t *handle)
{
	struct dma_buf *dma_buf;
	struct drm_gem_object *obj;
	int ret;

	dma_buf = dma_buf_get(prime_fd);
	if (IS_ERR(dma_buf))
		return PTR_ERR(dma_buf);

	mutex_lock(&file_priv->prime.lock);

	ret = drm_prime_lookup_buf_handle(&file_priv->prime,
			dma_buf, handle);
	if (!ret) {
		ret = 0;
		goto out_put;
	}

	/* never seen this one, need to import */
	obj = dev->driver->gem_prime_import(dev, dma_buf);
	if (IS_ERR(obj)) {
		ret = PTR_ERR(obj);
		goto out_put;
	}

	ret = drm_gem_handle_create(file_priv, obj, handle);
	drm_gem_object_unreference_unlocked(obj);
	if (ret)
		goto out_put;

	ret = drm_prime_add_buf_handle(&file_priv->prime,
			dma_buf, *handle);
	if (ret)
		goto fail;

	mutex_unlock(&file_priv->prime.lock);

	dma_buf_put(dma_buf);

	return 0;

fail:
	/* hmm, if driver attached, we are relying on the free-object path
	 * to detach.. which seems ok..
	 */
	drm_gem_object_handle_unreference_unlocked(obj);
out_put:
	dma_buf_put(dma_buf);
	mutex_unlock(&file_priv->prime.lock);
	return ret;
}
EXPORT_SYMBOL(drm_gem_prime_fd_to_handle);

int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data,
				 struct drm_file *file_priv)
{
	struct drm_prime_handle *args = data;
	uint32_t flags;

	if (!drm_core_check_feature(dev, DRIVER_PRIME))
		return -EINVAL;

	if (!dev->driver->prime_handle_to_fd)
		return -ENOSYS;

	/* check flags are valid */
	if (args->flags & ~DRM_CLOEXEC)
		return -EINVAL;

	/* we only want to pass DRM_CLOEXEC which is == O_CLOEXEC */
	flags = args->flags & DRM_CLOEXEC;

	return dev->driver->prime_handle_to_fd(dev, file_priv,
			args->handle, flags, &args->fd);
}

int drm_prime_fd_to_handle_ioctl(struct drm_device *dev, void *data,
				 struct drm_file *file_priv)
{
	struct drm_prime_handle *args = data;

	if (!drm_core_check_feature(dev, DRIVER_PRIME))
		return -EINVAL;

	if (!dev->driver->prime_fd_to_handle)
		return -ENOSYS;

	return dev->driver->prime_fd_to_handle(dev, file_priv,
			args->fd, &args->handle);
}

/*
 * drm_prime_pages_to_sg
 *
 * this helper creates an sg table object from a set of pages
 * the driver is responsible for mapping the pages into the
 * importers address space
 */
struct sg_table *drm_prime_pages_to_sg(struct page **pages, int nr_pages)
{
	struct sg_table *sg = NULL;
	int ret;

	sg = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
	if (!sg)
		goto out;

	ret = sg_alloc_table_from_pages(sg, pages, nr_pages, 0,
				nr_pages << PAGE_SHIFT, GFP_KERNEL);
	if (ret)
		goto out;

	return sg;
out:
	kfree(sg);
	return NULL;
}
EXPORT_SYMBOL(drm_prime_pages_to_sg);

/* export an sg table into an array of pages and addresses
   this is currently required by the TTM driver in order to do correct fault
   handling */
int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages,
				     dma_addr_t *addrs, int max_pages)
{
	unsigned count;
	struct scatterlist *sg;
	struct page *page;
	u32 len, offset;
	int pg_index;
	dma_addr_t addr;

	pg_index = 0;
	for_each_sg(sgt->sgl, sg, sgt->nents, count) {
		len = sg->length;
		offset = sg->offset;
		page = sg_page(sg);
		addr = sg_dma_address(sg);

		while (len > 0) {
			if (WARN_ON(pg_index >= max_pages))
				return -1;
			pages[pg_index] = page;
			if (addrs)
				addrs[pg_index] = addr;

			page++;
			addr += PAGE_SIZE;
			len -= PAGE_SIZE;
			pg_index++;
		}
	}
	return 0;
}
EXPORT_SYMBOL(drm_prime_sg_to_page_addr_arrays);
/* helper function to cleanup a GEM/prime object */
void drm_prime_gem_destroy(struct drm_gem_object *obj, struct sg_table *sg)
{
	struct dma_buf_attachment *attach;
	struct dma_buf *dma_buf;
	attach = obj->import_attach;
	if (sg)
		dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
	dma_buf = attach->dmabuf;
	dma_buf_detach(attach->dmabuf, attach);
	/* remove the reference */
	dma_buf_put(dma_buf);
}
EXPORT_SYMBOL(drm_prime_gem_destroy);

void drm_prime_init_file_private(struct drm_prime_file_private *prime_fpriv)
{
	INIT_LIST_HEAD(&prime_fpriv->head);
	mutex_init(&prime_fpriv->lock);
}
EXPORT_SYMBOL(drm_prime_init_file_private);

void drm_prime_destroy_file_private(struct drm_prime_file_private *prime_fpriv)
{
	/* by now drm_gem_release should've made sure the list is empty */
	WARN_ON(!list_empty(&prime_fpriv->head));
}
EXPORT_SYMBOL(drm_prime_destroy_file_private);

static int drm_prime_add_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf, uint32_t handle)
{
	struct drm_prime_member *member;

	member = kmalloc(sizeof(*member), GFP_KERNEL);
	if (!member)
		return -ENOMEM;

	get_dma_buf(dma_buf);
	member->dma_buf = dma_buf;
	member->handle = handle;
	list_add(&member->entry, &prime_fpriv->head);
	return 0;
}

int drm_prime_lookup_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf, uint32_t *handle)
{
	struct drm_prime_member *member;

	list_for_each_entry(member, &prime_fpriv->head, entry) {
		if (member->dma_buf == dma_buf) {
			*handle = member->handle;
			return 0;
		}
	}
	return -ENOENT;
}
EXPORT_SYMBOL(drm_prime_lookup_buf_handle);

void drm_prime_remove_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf)
{
	struct drm_prime_member *member, *safe;

	mutex_lock(&prime_fpriv->lock);
	list_for_each_entry_safe(member, safe, &prime_fpriv->head, entry) {
		if (member->dma_buf == dma_buf) {
			dma_buf_put(dma_buf);
			list_del(&member->entry);
			kfree(member);
		}
	}
	mutex_unlock(&prime_fpriv->lock);
}
EXPORT_SYMBOL(drm_prime_remove_buf_handle);
Commit	Line	Data
3248877e DA	1	/*
	2	* Copyright © 2012 Red Hat
	3	*
	4	* Permission is hereby granted, free of charge, to any person obtaining a
	5	* copy of this software and associated documentation files (the "Software"),
	6	* to deal in the Software without restriction, including without limitation
	7	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	8	* and/or sell copies of the Software, and to permit persons to whom the
	9	* Software is furnished to do so, subject to the following conditions:
	10	*
	11	* The above copyright notice and this permission notice (including the next
	12	* paragraph) shall be included in all copies or substantial portions of the
	13	* Software.
	14	*
	15	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	16	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	17	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	18	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	19	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
	20	* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
	21	* IN THE SOFTWARE.
	22	*
	23	* Authors:
	24	* Dave Airlie <airlied@redhat.com>
	25	* Rob Clark <rob.clark@linaro.org>
	26	*
	27	*/
	28
	29	#include <linux/export.h>
	30	#include <linux/dma-buf.h>
760285e7	31	#include <drm/drmP.h>
3248877e DA	32
	33	/*
	34	* DMA-BUF/GEM Object references and lifetime overview:
	35	*
	36	* On the export the dma_buf holds a reference to the exporting GEM
	37	* object. It takes this reference in handle_to_fd_ioctl, when it
	38	* first calls .prime_export and stores the exporting GEM object in
	39	* the dma_buf priv. This reference is released when the dma_buf
	40	* object goes away in the driver .release function.
	41	*
	42	* On the import the importing GEM object holds a reference to the
	43	* dma_buf (which in turn holds a ref to the exporting GEM object).
	44	* It takes that reference in the fd_to_handle ioctl.
	45	* It calls dma_buf_get, creates an attachment to it and stores the
	46	* attachment in the GEM object. When this attachment is destroyed
	47	* when the imported object is destroyed, we remove the attachment
	48	* and drop the reference to the dma_buf.
	49	*
	50	* Thus the chain of references always flows in one direction
	51	* (avoiding loops): importing_gem -> dmabuf -> exporting_gem
	52	*
	53	* Self-importing: if userspace is using PRIME as a replacement for flink
	54	* then it will get a fd->handle request for a GEM object that it created.
	55	* Drivers should detect this situation and return back the gem object
89177644 AP	56	* from the dma-buf private. Prime will do this automatically for drivers that
89177644 AP	57	* use the drm_gem_prime_{import,export} helpers.
3248877e DA	58	*/
	59
	60	struct drm_prime_member {
	61	struct list_head entry;
	62	struct dma_buf *dma_buf;
	63	uint32_t handle;
	64	};
219b4733	65	static int drm_prime_add_buf_handle(struct drm_prime_file_private prime_fpriv, struct dma_buf dma_buf, uint32_t handle);
3248877e	66
ca793f75 ML	67	static int drm_gem_map_attach(struct dma_buf *dma_buf,
	68	struct device *target_dev,
	69	struct dma_buf_attachment *attach)
	70	{
	71	struct drm_gem_object *obj = dma_buf->priv;
	72	struct drm_device *dev = obj->dev;
	73
	74	if (!dev->driver->gem_prime_pin)
	75	return 0;
	76
	77	return dev->driver->gem_prime_pin(obj);
	78	}
	79
	80	static void drm_gem_map_detach(struct dma_buf *dma_buf,
	81	struct dma_buf_attachment *attach)
	82	{
	83	struct drm_gem_object *obj = dma_buf->priv;
	84	struct drm_device *dev = obj->dev;
	85
	86	if (dev->driver->gem_prime_unpin)
	87	dev->driver->gem_prime_unpin(obj);
	88	}
	89
89177644 AP	90	static struct sg_table drm_gem_map_dma_buf(struct dma_buf_attachment attach,
	91	enum dma_data_direction dir)
	92	{
	93	struct drm_gem_object *obj = attach->dmabuf->priv;
	94	struct sg_table *sgt;
	95
	96	mutex_lock(&obj->dev->struct_mutex);
	97
	98	sgt = obj->dev->driver->gem_prime_get_sg_table(obj);
	99
	100	if (!IS_ERR_OR_NULL(sgt))
	101	dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir);
	102
	103	mutex_unlock(&obj->dev->struct_mutex);
	104	return sgt;
	105	}
	106
	107	static void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
	108	struct sg_table *sgt, enum dma_data_direction dir)
	109	{
	110	dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
	111	sg_free_table(sgt);
	112	kfree(sgt);
	113	}
	114
	115	static void drm_gem_dmabuf_release(struct dma_buf *dma_buf)
	116	{
	117	struct drm_gem_object *obj = dma_buf->priv;
	118
	119	if (obj->export_dma_buf == dma_buf) {
	120	/* drop the reference on the export fd holds */
	121	obj->export_dma_buf = NULL;
	122	drm_gem_object_unreference_unlocked(obj);
	123	}
	124	}
	125
	126	static void drm_gem_dmabuf_vmap(struct dma_buf dma_buf)
	127	{
	128	struct drm_gem_object *obj = dma_buf->priv;
	129	struct drm_device *dev = obj->dev;
	130
	131	return dev->driver->gem_prime_vmap(obj);
	132	}
	133
	134	static void drm_gem_dmabuf_vunmap(struct dma_buf dma_buf, void vaddr)
	135	{
	136	struct drm_gem_object *obj = dma_buf->priv;
	137	struct drm_device *dev = obj->dev;
	138
	139	dev->driver->gem_prime_vunmap(obj, vaddr);
	140	}
	141
	142	static void drm_gem_dmabuf_kmap_atomic(struct dma_buf dma_buf,
	143	unsigned long page_num)
	144	{
	145	return NULL;
	146	}
	147
	148	static void drm_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
	149	unsigned long page_num, void *addr)
	150	{
	151
	152	}
	153	static void drm_gem_dmabuf_kmap(struct dma_buf dma_buf,
154	unsigned long page_num)
155	{
156	return NULL;
157	}
158
159	static void drm_gem_dmabuf_kunmap(struct dma_buf *dma_buf,
160	unsigned long page_num, void *addr)
161	{
162
163	}
164
165	static int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf,
166	struct vm_area_struct *vma)
167	{
168	return -EINVAL;
169	}
170
171	static const struct dma_buf_ops drm_gem_prime_dmabuf_ops = {
ca793f75 ML	172	.attach = drm_gem_map_attach,
ca793f75 ML	173	.detach = drm_gem_map_detach,
89177644 AP	174	.map_dma_buf = drm_gem_map_dma_buf,
	175	.unmap_dma_buf = drm_gem_unmap_dma_buf,
	176	.release = drm_gem_dmabuf_release,
	177	.kmap = drm_gem_dmabuf_kmap,
	178	.kmap_atomic = drm_gem_dmabuf_kmap_atomic,
	179	.kunmap = drm_gem_dmabuf_kunmap,
	180	.kunmap_atomic = drm_gem_dmabuf_kunmap_atomic,
	181	.mmap = drm_gem_dmabuf_mmap,
	182	.vmap = drm_gem_dmabuf_vmap,
	183	.vunmap = drm_gem_dmabuf_vunmap,
	184	};
	185
	186	/**
	187	* DOC: PRIME Helpers
	188	*
	189	* Drivers can implement @gem_prime_export and @gem_prime_import in terms of
	190	* simpler APIs by using the helper functions @drm_gem_prime_export and
	191	* @drm_gem_prime_import. These functions implement dma-buf support in terms of
	192	* five lower-level driver callbacks:
	193	*
	194	* Export callbacks:
	195	*
	196	* - @gem_prime_pin (optional): prepare a GEM object for exporting
	197	*
	198	* - @gem_prime_get_sg_table: provide a scatter/gather table of pinned pages
	199	*
	200	* - @gem_prime_vmap: vmap a buffer exported by your driver
	201	*
	202	* - @gem_prime_vunmap: vunmap a buffer exported by your driver
	203	*
	204	* Import callback:
	205	*
	206	* - @gem_prime_import_sg_table (import): produce a GEM object from another
	207	* driver's scatter/gather table
	208	*/
	209
	210	struct dma_buf drm_gem_prime_export(struct drm_device dev,
	211	struct drm_gem_object *obj, int flags)
	212	{
ca793f75	213	return dma_buf_export(obj, &drm_gem_prime_dmabuf_ops, obj->size,
102d6dba	214	0600);
89177644 AP	215	}
	216	EXPORT_SYMBOL(drm_gem_prime_export);
	217
3248877e DA	218	int drm_gem_prime_handle_to_fd(struct drm_device *dev,
	219	struct drm_file *file_priv, uint32_t handle, uint32_t flags,
	220	int *prime_fd)
	221	{
	222	struct drm_gem_object *obj;
	223	void *buf;
219b4733 DA	224	int ret = 0;
219b4733 DA	225	struct dma_buf *dmabuf;
3248877e DA	226
	227	obj = drm_gem_object_lookup(dev, file_priv, handle);
	228	if (!obj)
	229	return -ENOENT;
	230
	231	mutex_lock(&file_priv->prime.lock);
	232	/* re-export the original imported object */
	233	if (obj->import_attach) {
219b4733 DA	234	dmabuf = obj->import_attach->dmabuf;
219b4733 DA	235	goto out_have_obj;
3248877e DA	236	}
	237
	238	if (obj->export_dma_buf) {
219b4733 DA	239	dmabuf = obj->export_dma_buf;
219b4733 DA	240	goto out_have_obj;
3248877e	241	}
219b4733 DA	242
	243	buf = dev->driver->gem_prime_export(dev, obj, flags);
	244	if (IS_ERR(buf)) {
	245	/* normally the created dma-buf takes ownership of the ref,
	246	* but if that fails then drop the ref
	247	*/
	248	ret = PTR_ERR(buf);
	249	goto out;
	250	}
	251	obj->export_dma_buf = buf;
	252
0ff926c7 DA	253	/* if we've exported this buffer the cheat and add it to the import list
	254	* so we get the correct handle back
	255	*/
219b4733 DA	256	ret = drm_prime_add_buf_handle(&file_priv->prime,
	257	obj->export_dma_buf, handle);
	258	if (ret)
	259	goto out;
0ff926c7	260
219b4733	261	*prime_fd = dma_buf_fd(buf, flags);
3248877e DA	262	mutex_unlock(&file_priv->prime.lock);
3248877e DA	263	return 0;
219b4733 DA	264
	265	out_have_obj:
	266	get_dma_buf(dmabuf);
	267	*prime_fd = dma_buf_fd(dmabuf, flags);
	268	out:
	269	drm_gem_object_unreference_unlocked(obj);
	270	mutex_unlock(&file_priv->prime.lock);
	271	return ret;
3248877e DA	272	}
	273	EXPORT_SYMBOL(drm_gem_prime_handle_to_fd);
	274
89177644 AP	275	struct drm_gem_object drm_gem_prime_import(struct drm_device dev,
	276	struct dma_buf *dma_buf)
	277	{
	278	struct dma_buf_attachment *attach;
	279	struct sg_table *sgt;
	280	struct drm_gem_object *obj;
	281	int ret;
	282
	283	if (!dev->driver->gem_prime_import_sg_table)
	284	return ERR_PTR(-EINVAL);
	285
	286	if (dma_buf->ops == &drm_gem_prime_dmabuf_ops) {
	287	obj = dma_buf->priv;
	288	if (obj->dev == dev) {
	289	/*
	290	* Importing dmabuf exported from out own gem increases
	291	* refcount on gem itself instead of f_count of dmabuf.
	292	*/
	293	drm_gem_object_reference(obj);
89177644 AP	294	return obj;
	295	}
	296	}
	297
	298	attach = dma_buf_attach(dma_buf, dev->dev);
	299	if (IS_ERR(attach))
f2a5da4f	300	return ERR_CAST(attach);
89177644	301
011c2282 ID	302	get_dma_buf(dma_buf);
011c2282 ID	303
89177644 AP	304	sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
	305	if (IS_ERR_OR_NULL(sgt)) {
	306	ret = PTR_ERR(sgt);
	307	goto fail_detach;
	308	}
	309
	310	obj = dev->driver->gem_prime_import_sg_table(dev, dma_buf->size, sgt);
	311	if (IS_ERR(obj)) {
	312	ret = PTR_ERR(obj);
	313	goto fail_unmap;
	314	}
	315
	316	obj->import_attach = attach;
	317
	318	return obj;
	319
	320	fail_unmap:
	321	dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
	322	fail_detach:
	323	dma_buf_detach(dma_buf, attach);
011c2282 ID	324	dma_buf_put(dma_buf);
011c2282 ID	325
89177644 AP	326	return ERR_PTR(ret);
	327	}
	328	EXPORT_SYMBOL(drm_gem_prime_import);
	329
3248877e DA	330	int drm_gem_prime_fd_to_handle(struct drm_device *dev,
	331	struct drm_file file_priv, int prime_fd, uint32_t handle)
	332	{
	333	struct dma_buf *dma_buf;
	334	struct drm_gem_object *obj;
	335	int ret;
	336
	337	dma_buf = dma_buf_get(prime_fd);
	338	if (IS_ERR(dma_buf))
	339	return PTR_ERR(dma_buf);
	340
	341	mutex_lock(&file_priv->prime.lock);
	342
219b4733	343	ret = drm_prime_lookup_buf_handle(&file_priv->prime,
3248877e DA	344	dma_buf, handle);
	345	if (!ret) {
	346	ret = 0;
	347	goto out_put;
	348	}
	349
	350	/* never seen this one, need to import */
	351	obj = dev->driver->gem_prime_import(dev, dma_buf);
	352	if (IS_ERR(obj)) {
	353	ret = PTR_ERR(obj);
	354	goto out_put;
	355	}
	356
	357	ret = drm_gem_handle_create(file_priv, obj, handle);
	358	drm_gem_object_unreference_unlocked(obj);
	359	if (ret)
	360	goto out_put;
	361
219b4733	362	ret = drm_prime_add_buf_handle(&file_priv->prime,
3248877e DA	363	dma_buf, *handle);
	364	if (ret)
	365	goto fail;
	366
	367	mutex_unlock(&file_priv->prime.lock);
011c2282 ID	368
	369	dma_buf_put(dma_buf);
	370
3248877e DA	371	return 0;
	372
	373	fail:
	374	/* hmm, if driver attached, we are relying on the free-object path
	375	* to detach.. which seems ok..
	376	*/
	377	drm_gem_object_handle_unreference_unlocked(obj);
	378	out_put:
	379	dma_buf_put(dma_buf);
	380	mutex_unlock(&file_priv->prime.lock);
	381	return ret;
	382	}
	383	EXPORT_SYMBOL(drm_gem_prime_fd_to_handle);
	384
	385	int drm_prime_handle_to_fd_ioctl(struct drm_device dev, void data,
	386	struct drm_file *file_priv)
	387	{
	388	struct drm_prime_handle *args = data;
	389	uint32_t flags;
	390
	391	if (!drm_core_check_feature(dev, DRIVER_PRIME))
	392	return -EINVAL;
	393
	394	if (!dev->driver->prime_handle_to_fd)
	395	return -ENOSYS;
	396
	397	/* check flags are valid */
	398	if (args->flags & ~DRM_CLOEXEC)
	399	return -EINVAL;
	400
	401	/* we only want to pass DRM_CLOEXEC which is == O_CLOEXEC */
	402	flags = args->flags & DRM_CLOEXEC;
	403
	404	return dev->driver->prime_handle_to_fd(dev, file_priv,
	405	args->handle, flags, &args->fd);
	406	}
	407
	408	int drm_prime_fd_to_handle_ioctl(struct drm_device dev, void data,
	409	struct drm_file *file_priv)
	410	{
	411	struct drm_prime_handle *args = data;
	412
	413	if (!drm_core_check_feature(dev, DRIVER_PRIME))
	414	return -EINVAL;
	415
	416	if (!dev->driver->prime_fd_to_handle)
	417	return -ENOSYS;
	418
	419	return dev->driver->prime_fd_to_handle(dev, file_priv,
	420	args->fd, &args->handle);
	421	}
	422
	423	/*
	424	* drm_prime_pages_to_sg
	425	*
	426	* this helper creates an sg table object from a set of pages
	427	* the driver is responsible for mapping the pages into the
	428	* importers address space
	429	*/
	430	struct sg_table drm_prime_pages_to_sg(struct page *pages, int nr_pages)
	431	{
	432	struct sg_table *sg = NULL;
3248877e DA	433	int ret;
	434
	435	sg = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
	436	if (!sg)
	437	goto out;
	438
dca25cb8 RS	439	ret = sg_alloc_table_from_pages(sg, pages, nr_pages, 0,
dca25cb8 RS	440	nr_pages << PAGE_SHIFT, GFP_KERNEL);
3248877e DA	441	if (ret)
	442	goto out;
	443
3248877e DA	444	return sg;
	445	out:
	446	kfree(sg);
	447	return NULL;
	448	}
	449	EXPORT_SYMBOL(drm_prime_pages_to_sg);
	450
51ab7ba2 DA	451	/* export an sg table into an array of pages and addresses
	452	this is currently required by the TTM driver in order to do correct fault
	453	handling */
	454	int drm_prime_sg_to_page_addr_arrays(struct sg_table sgt, struct page *pages,
	455	dma_addr_t *addrs, int max_pages)
	456	{
	457	unsigned count;
	458	struct scatterlist *sg;
	459	struct page *page;
	460	u32 len, offset;
	461	int pg_index;
	462	dma_addr_t addr;
	463
	464	pg_index = 0;
	465	for_each_sg(sgt->sgl, sg, sgt->nents, count) {
	466	len = sg->length;
	467	offset = sg->offset;
	468	page = sg_page(sg);
	469	addr = sg_dma_address(sg);
	470
	471	while (len > 0) {
	472	if (WARN_ON(pg_index >= max_pages))
	473	return -1;
	474	pages[pg_index] = page;
	475	if (addrs)
	476	addrs[pg_index] = addr;
	477
	478	page++;
	479	addr += PAGE_SIZE;
	480	len -= PAGE_SIZE;
	481	pg_index++;
	482	}
	483	}
	484	return 0;
	485	}
	486	EXPORT_SYMBOL(drm_prime_sg_to_page_addr_arrays);
3248877e DA	487	/* helper function to cleanup a GEM/prime object */
	488	void drm_prime_gem_destroy(struct drm_gem_object obj, struct sg_table sg)
	489	{
	490	struct dma_buf_attachment *attach;
	491	struct dma_buf *dma_buf;
	492	attach = obj->import_attach;
	493	if (sg)
	494	dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
	495	dma_buf = attach->dmabuf;
	496	dma_buf_detach(attach->dmabuf, attach);
	497	/* remove the reference */
	498	dma_buf_put(dma_buf);
	499	}
	500	EXPORT_SYMBOL(drm_prime_gem_destroy);
	501
	502	void drm_prime_init_file_private(struct drm_prime_file_private *prime_fpriv)
	503	{
	504	INIT_LIST_HEAD(&prime_fpriv->head);
	505	mutex_init(&prime_fpriv->lock);
	506	}
	507	EXPORT_SYMBOL(drm_prime_init_file_private);
	508
	509	void drm_prime_destroy_file_private(struct drm_prime_file_private *prime_fpriv)
	510	{
98b76231 ID	511	/* by now drm_gem_release should've made sure the list is empty */
98b76231 ID	512	WARN_ON(!list_empty(&prime_fpriv->head));
3248877e DA	513	}
	514	EXPORT_SYMBOL(drm_prime_destroy_file_private);
	515
219b4733	516	static int drm_prime_add_buf_handle(struct drm_prime_file_private prime_fpriv, struct dma_buf dma_buf, uint32_t handle)
3248877e DA	517	{
	518	struct drm_prime_member *member;
	519
	520	member = kmalloc(sizeof(*member), GFP_KERNEL);
	521	if (!member)
	522	return -ENOMEM;
	523
219b4733	524	get_dma_buf(dma_buf);
3248877e DA	525	member->dma_buf = dma_buf;
	526	member->handle = handle;
	527	list_add(&member->entry, &prime_fpriv->head);
	528	return 0;
	529	}
3248877e	530
219b4733	531	int drm_prime_lookup_buf_handle(struct drm_prime_file_private prime_fpriv, struct dma_buf dma_buf, uint32_t *handle)
3248877e DA	532	{
	533	struct drm_prime_member *member;
	534
	535	list_for_each_entry(member, &prime_fpriv->head, entry) {
	536	if (member->dma_buf == dma_buf) {
	537	*handle = member->handle;
	538	return 0;
	539	}
	540	}
	541	return -ENOENT;
	542	}
219b4733	543	EXPORT_SYMBOL(drm_prime_lookup_buf_handle);
3248877e	544
219b4733	545	void drm_prime_remove_buf_handle(struct drm_prime_file_private prime_fpriv, struct dma_buf dma_buf)
3248877e DA	546	{
	547	struct drm_prime_member member, safe;
	548
	549	mutex_lock(&prime_fpriv->lock);
	550	list_for_each_entry_safe(member, safe, &prime_fpriv->head, entry) {
	551	if (member->dma_buf == dma_buf) {
219b4733	552	dma_buf_put(dma_buf);
3248877e DA	553	list_del(&member->entry);
	554	kfree(member);
	555	}
	556	}
	557	mutex_unlock(&prime_fpriv->lock);
	558	}
219b4733	559	EXPORT_SYMBOL(drm_prime_remove_buf_handle);