[mirror_ubuntu-artful-kernel.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;
};

struct drm_prime_attachment {
	struct sg_table *sgt;
	enum dma_data_direction dir;
};

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;
}

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

	prime_attach = kzalloc(sizeof(*prime_attach), GFP_KERNEL);
	if (!prime_attach)
		return -ENOMEM;

	prime_attach->dir = DMA_NONE;
	attach->priv = prime_attach;

	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_prime_attachment *prime_attach = attach->priv;
	struct drm_gem_object *obj = dma_buf->priv;
	struct drm_device *dev = obj->dev;
	struct sg_table *sgt;

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

	if (!prime_attach)
		return;

	sgt = prime_attach->sgt;

	if (prime_attach->dir != DMA_NONE)
		dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents,
				prime_attach->dir);

	sg_free_table(sgt);
	kfree(sgt);
	kfree(prime_attach);
	attach->priv = NULL;
}

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

	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);
		}
	}
}

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

	if (WARN_ON(dir == DMA_NONE || !prime_attach))
		return ERR_PTR(-EINVAL);

	/* return the cached mapping when possible */
	if (prime_attach->dir == dir)
		return prime_attach->sgt;

	/*
	 * two mappings with different directions for the same attachment are
	 * not allowed
	 */
	if (WARN_ON(prime_attach->dir != DMA_NONE))
		return ERR_PTR(-EBUSY);

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

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

	if (!IS_ERR(sgt)) {
		if (!dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir)) {
			sg_free_table(sgt);
			kfree(sgt);
			sgt = ERR_PTR(-ENOMEM);
		} else {
			prime_attach->sgt = sgt;
			prime_attach->dir = 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)
{
	/* nothing to be done here */
}

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, flags);
}
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 fail_put_dmabuf;

	ret = dma_buf_fd(buf, flags);
	if (ret < 0)
		goto fail_rm_handle;

	*prime_fd = ret;
	mutex_unlock(&file_priv->prime.lock);
	return 0;

out_have_obj:
	get_dma_buf(dmabuf);
	ret = dma_buf_fd(dmabuf, flags);
	if (ret < 0) {
		dma_buf_put(dmabuf);
	} else {
		*prime_fd = ret;
		ret = 0;
	}

	goto out;

fail_rm_handle:
	drm_prime_remove_buf_handle_locked(&file_priv->prime, buf);
fail_put_dmabuf:
	/* clear NOT to be checked when releasing dma_buf */
	obj->export_dma_buf = NULL;
	dma_buf_put(buf);
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) {
		ret = -ENOMEM;
		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 ERR_PTR(ret);
}
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);

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)
{
	mutex_lock(&prime_fpriv->lock);
	drm_prime_remove_buf_handle_locked(prime_fpriv, dma_buf);
	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	};
538d6661 JS	65
	66	struct drm_prime_attachment {
	67	struct sg_table *sgt;
	68	enum dma_data_direction dir;
	69	};
	70
ce92e3c9 SWK	71	static int drm_prime_add_buf_handle(struct drm_prime_file_private prime_fpriv, struct dma_buf dma_buf, uint32_t handle)
	72	{
	73	struct drm_prime_member *member;
	74
	75	member = kmalloc(sizeof(*member), GFP_KERNEL);
	76	if (!member)
	77	return -ENOMEM;
	78
	79	get_dma_buf(dma_buf);
	80	member->dma_buf = dma_buf;
	81	member->handle = handle;
	82	list_add(&member->entry, &prime_fpriv->head);
	83	return 0;
	84	}
3248877e	85
ca793f75 ML	86	static int drm_gem_map_attach(struct dma_buf *dma_buf,
	87	struct device *target_dev,
	88	struct dma_buf_attachment *attach)
	89	{
538d6661	90	struct drm_prime_attachment *prime_attach;
ca793f75 ML	91	struct drm_gem_object *obj = dma_buf->priv;
	92	struct drm_device *dev = obj->dev;
	93
538d6661 JS	94	prime_attach = kzalloc(sizeof(*prime_attach), GFP_KERNEL);
	95	if (!prime_attach)
	96	return -ENOMEM;
	97
	98	prime_attach->dir = DMA_NONE;
	99	attach->priv = prime_attach;
	100
ca793f75 ML	101	if (!dev->driver->gem_prime_pin)
	102	return 0;
	103
	104	return dev->driver->gem_prime_pin(obj);
	105	}
	106
	107	static void drm_gem_map_detach(struct dma_buf *dma_buf,
	108	struct dma_buf_attachment *attach)
	109	{
538d6661	110	struct drm_prime_attachment *prime_attach = attach->priv;
ca793f75 ML	111	struct drm_gem_object *obj = dma_buf->priv;
ca793f75 ML	112	struct drm_device *dev = obj->dev;
538d6661	113	struct sg_table *sgt;
ca793f75 ML	114
	115	if (dev->driver->gem_prime_unpin)
	116	dev->driver->gem_prime_unpin(obj);
538d6661 JS	117
	118	if (!prime_attach)
	119	return;
	120
	121	sgt = prime_attach->sgt;
	122
	123	if (prime_attach->dir != DMA_NONE)
	124	dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents,
	125	prime_attach->dir);
	126
	127	sg_free_table(sgt);
	128	kfree(sgt);
	129	kfree(prime_attach);
	130	attach->priv = NULL;
ca793f75 ML	131	}
ca793f75 ML	132
da34242e YC	133	static void drm_prime_remove_buf_handle_locked(
	134	struct drm_prime_file_private *prime_fpriv,
	135	struct dma_buf *dma_buf)
	136	{
	137	struct drm_prime_member member, safe;
	138
	139	list_for_each_entry_safe(member, safe, &prime_fpriv->head, entry) {
	140	if (member->dma_buf == dma_buf) {
	141	dma_buf_put(dma_buf);
	142	list_del(&member->entry);
	143	kfree(member);
	144	}
	145	}
	146	}
	147
89177644 AP	148	static struct sg_table drm_gem_map_dma_buf(struct dma_buf_attachment attach,
	149	enum dma_data_direction dir)
	150	{
538d6661	151	struct drm_prime_attachment *prime_attach = attach->priv;
89177644 AP	152	struct drm_gem_object *obj = attach->dmabuf->priv;
	153	struct sg_table *sgt;
	154
538d6661 JS	155	if (WARN_ON(dir == DMA_NONE \|\| !prime_attach))
	156	return ERR_PTR(-EINVAL);
	157
	158	/* return the cached mapping when possible */
	159	if (prime_attach->dir == dir)
	160	return prime_attach->sgt;
	161
	162	/*
	163	* two mappings with different directions for the same attachment are
	164	* not allowed
	165	*/
	166	if (WARN_ON(prime_attach->dir != DMA_NONE))
	167	return ERR_PTR(-EBUSY);
	168
89177644 AP	169	mutex_lock(&obj->dev->struct_mutex);
	170
	171	sgt = obj->dev->driver->gem_prime_get_sg_table(obj);
	172
7e3d88f9	173	if (!IS_ERR(sgt)) {
b720d54a YC	174	if (!dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir)) {
	175	sg_free_table(sgt);
	176	kfree(sgt);
	177	sgt = ERR_PTR(-ENOMEM);
538d6661 JS	178	} else {
	179	prime_attach->sgt = sgt;
	180	prime_attach->dir = dir;
b720d54a YC	181	}
b720d54a YC	182	}
89177644 AP	183
	184	mutex_unlock(&obj->dev->struct_mutex);
	185	return sgt;
	186	}
	187
	188	static void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
	189	struct sg_table *sgt, enum dma_data_direction dir)
	190	{
538d6661	191	/* nothing to be done here */
89177644 AP	192	}
	193
	194	static void drm_gem_dmabuf_release(struct dma_buf *dma_buf)
	195	{
	196	struct drm_gem_object *obj = dma_buf->priv;
	197
	198	if (obj->export_dma_buf == dma_buf) {
	199	/* drop the reference on the export fd holds */
	200	obj->export_dma_buf = NULL;
	201	drm_gem_object_unreference_unlocked(obj);
	202	}
	203	}
	204
	205	static void drm_gem_dmabuf_vmap(struct dma_buf dma_buf)
	206	{
	207	struct drm_gem_object *obj = dma_buf->priv;
	208	struct drm_device *dev = obj->dev;
	209
	210	return dev->driver->gem_prime_vmap(obj);
	211	}
	212
	213	static void drm_gem_dmabuf_vunmap(struct dma_buf dma_buf, void vaddr)
	214	{
	215	struct drm_gem_object *obj = dma_buf->priv;
	216	struct drm_device *dev = obj->dev;
	217
	218	dev->driver->gem_prime_vunmap(obj, vaddr);
	219	}
	220
	221	static void drm_gem_dmabuf_kmap_atomic(struct dma_buf dma_buf,
	222	unsigned long page_num)
	223	{
	224	return NULL;
	225	}
	226
	227	static void drm_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
	228	unsigned long page_num, void *addr)
	229	{
	230
	231	}
	232	static void drm_gem_dmabuf_kmap(struct dma_buf dma_buf,
	233	unsigned long page_num)
	234	{
	235	return NULL;
	236	}
	237
	238	static void drm_gem_dmabuf_kunmap(struct dma_buf *dma_buf,
	239	unsigned long page_num, void *addr)
	240	{
	241
	242	}
	243
	244	static int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf,
	245	struct vm_area_struct *vma)
	246	{
	247	return -EINVAL;
	248	}
	249
	250	static const struct dma_buf_ops drm_gem_prime_dmabuf_ops = {
ca793f75 ML	251	.attach = drm_gem_map_attach,
ca793f75 ML	252	.detach = drm_gem_map_detach,
89177644 AP	253	.map_dma_buf = drm_gem_map_dma_buf,
	254	.unmap_dma_buf = drm_gem_unmap_dma_buf,
	255	.release = drm_gem_dmabuf_release,
	256	.kmap = drm_gem_dmabuf_kmap,
	257	.kmap_atomic = drm_gem_dmabuf_kmap_atomic,
	258	.kunmap = drm_gem_dmabuf_kunmap,
	259	.kunmap_atomic = drm_gem_dmabuf_kunmap_atomic,
	260	.mmap = drm_gem_dmabuf_mmap,
	261	.vmap = drm_gem_dmabuf_vmap,
	262	.vunmap = drm_gem_dmabuf_vunmap,
	263	};
	264
	265	/**
	266	* DOC: PRIME Helpers
	267	*
	268	* Drivers can implement @gem_prime_export and @gem_prime_import in terms of
	269	* simpler APIs by using the helper functions @drm_gem_prime_export and
	270	* @drm_gem_prime_import. These functions implement dma-buf support in terms of
	271	* five lower-level driver callbacks:
	272	*
	273	* Export callbacks:
	274	*
	275	* - @gem_prime_pin (optional): prepare a GEM object for exporting
	276	*
	277	* - @gem_prime_get_sg_table: provide a scatter/gather table of pinned pages
	278	*
	279	* - @gem_prime_vmap: vmap a buffer exported by your driver
	280	*
	281	* - @gem_prime_vunmap: vunmap a buffer exported by your driver
	282	*
	283	* Import callback:
	284	*
	285	* - @gem_prime_import_sg_table (import): produce a GEM object from another
	286	* driver's scatter/gather table
	287	*/
	288
	289	struct dma_buf drm_gem_prime_export(struct drm_device dev,
	290	struct drm_gem_object *obj, int flags)
	291	{
ebc0bad4	292	return dma_buf_export(obj, &drm_gem_prime_dmabuf_ops, obj->size, flags);
89177644 AP	293	}
	294	EXPORT_SYMBOL(drm_gem_prime_export);
	295
3248877e DA	296	int drm_gem_prime_handle_to_fd(struct drm_device *dev,
	297	struct drm_file *file_priv, uint32_t handle, uint32_t flags,
	298	int *prime_fd)
	299	{
	300	struct drm_gem_object *obj;
	301	void *buf;
219b4733 DA	302	int ret = 0;
219b4733 DA	303	struct dma_buf *dmabuf;
3248877e DA	304
	305	obj = drm_gem_object_lookup(dev, file_priv, handle);
	306	if (!obj)
	307	return -ENOENT;
	308
	309	mutex_lock(&file_priv->prime.lock);
	310	/* re-export the original imported object */
	311	if (obj->import_attach) {
219b4733 DA	312	dmabuf = obj->import_attach->dmabuf;
219b4733 DA	313	goto out_have_obj;
3248877e DA	314	}
	315
	316	if (obj->export_dma_buf) {
219b4733 DA	317	dmabuf = obj->export_dma_buf;
219b4733 DA	318	goto out_have_obj;
3248877e	319	}
219b4733 DA	320
	321	buf = dev->driver->gem_prime_export(dev, obj, flags);
	322	if (IS_ERR(buf)) {
	323	/* normally the created dma-buf takes ownership of the ref,
	324	* but if that fails then drop the ref
	325	*/
	326	ret = PTR_ERR(buf);
	327	goto out;
	328	}
	329	obj->export_dma_buf = buf;
	330
0ff926c7 DA	331	/* if we've exported this buffer the cheat and add it to the import list
	332	* so we get the correct handle back
	333	*/
219b4733 DA	334	ret = drm_prime_add_buf_handle(&file_priv->prime,
	335	obj->export_dma_buf, handle);
	336	if (ret)
7d8f06ac	337	goto fail_put_dmabuf;
0ff926c7	338
da34242e YC	339	ret = dma_buf_fd(buf, flags);
	340	if (ret < 0)
	341	goto fail_rm_handle;
	342
	343	*prime_fd = ret;
3248877e DA	344	mutex_unlock(&file_priv->prime.lock);
3248877e DA	345	return 0;
219b4733 DA	346
	347	out_have_obj:
	348	get_dma_buf(dmabuf);
da34242e	349	ret = dma_buf_fd(dmabuf, flags);
4a88f73f	350	if (ret < 0) {
da34242e	351	dma_buf_put(dmabuf);
4a88f73f	352	} else {
da34242e	353	*prime_fd = ret;
4a88f73f DV	354	ret = 0;
	355	}
	356
7d8f06ac YC	357	goto out;
7d8f06ac YC	358
da34242e YC	359	fail_rm_handle:
da34242e YC	360	drm_prime_remove_buf_handle_locked(&file_priv->prime, buf);
7d8f06ac YC	361	fail_put_dmabuf:
	362	/* clear NOT to be checked when releasing dma_buf */
	363	obj->export_dma_buf = NULL;
	364	dma_buf_put(buf);
219b4733 DA	365	out:
	366	drm_gem_object_unreference_unlocked(obj);
	367	mutex_unlock(&file_priv->prime.lock);
	368	return ret;
3248877e DA	369	}
	370	EXPORT_SYMBOL(drm_gem_prime_handle_to_fd);
	371
89177644 AP	372	struct drm_gem_object drm_gem_prime_import(struct drm_device dev,
	373	struct dma_buf *dma_buf)
	374	{
	375	struct dma_buf_attachment *attach;
	376	struct sg_table *sgt;
	377	struct drm_gem_object *obj;
	378	int ret;
	379
	380	if (!dev->driver->gem_prime_import_sg_table)
	381	return ERR_PTR(-EINVAL);
	382
	383	if (dma_buf->ops == &drm_gem_prime_dmabuf_ops) {
	384	obj = dma_buf->priv;
	385	if (obj->dev == dev) {
	386	/*
	387	* Importing dmabuf exported from out own gem increases
	388	* refcount on gem itself instead of f_count of dmabuf.
	389	*/
	390	drm_gem_object_reference(obj);
89177644 AP	391	return obj;
	392	}
	393	}
	394
	395	attach = dma_buf_attach(dma_buf, dev->dev);
	396	if (IS_ERR(attach))
f2a5da4f	397	return ERR_CAST(attach);
89177644	398
011c2282 ID	399	get_dma_buf(dma_buf);
011c2282 ID	400
89177644 AP	401	sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
	402	if (IS_ERR_OR_NULL(sgt)) {
	403	ret = PTR_ERR(sgt);
	404	goto fail_detach;
	405	}
	406
	407	obj = dev->driver->gem_prime_import_sg_table(dev, dma_buf->size, sgt);
	408	if (IS_ERR(obj)) {
	409	ret = PTR_ERR(obj);
	410	goto fail_unmap;
	411	}
	412
	413	obj->import_attach = attach;
	414
	415	return obj;
	416
	417	fail_unmap:
	418	dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
	419	fail_detach:
	420	dma_buf_detach(dma_buf, attach);
011c2282 ID	421	dma_buf_put(dma_buf);
011c2282 ID	422
89177644 AP	423	return ERR_PTR(ret);
	424	}
	425	EXPORT_SYMBOL(drm_gem_prime_import);
	426
3248877e DA	427	int drm_gem_prime_fd_to_handle(struct drm_device *dev,
	428	struct drm_file file_priv, int prime_fd, uint32_t handle)
	429	{
	430	struct dma_buf *dma_buf;
	431	struct drm_gem_object *obj;
	432	int ret;
	433
	434	dma_buf = dma_buf_get(prime_fd);
	435	if (IS_ERR(dma_buf))
	436	return PTR_ERR(dma_buf);
	437
	438	mutex_lock(&file_priv->prime.lock);
	439
219b4733	440	ret = drm_prime_lookup_buf_handle(&file_priv->prime,
3248877e DA	441	dma_buf, handle);
	442	if (!ret) {
	443	ret = 0;
	444	goto out_put;
	445	}
	446
	447	/* never seen this one, need to import */
	448	obj = dev->driver->gem_prime_import(dev, dma_buf);
	449	if (IS_ERR(obj)) {
	450	ret = PTR_ERR(obj);
	451	goto out_put;
	452	}
	453
	454	ret = drm_gem_handle_create(file_priv, obj, handle);
	455	drm_gem_object_unreference_unlocked(obj);
	456	if (ret)
	457	goto out_put;
	458
219b4733	459	ret = drm_prime_add_buf_handle(&file_priv->prime,
3248877e DA	460	dma_buf, *handle);
	461	if (ret)
	462	goto fail;
	463
	464	mutex_unlock(&file_priv->prime.lock);
011c2282 ID	465
	466	dma_buf_put(dma_buf);
	467
3248877e DA	468	return 0;
	469
	470	fail:
	471	/* hmm, if driver attached, we are relying on the free-object path
	472	* to detach.. which seems ok..
	473	*/
	474	drm_gem_object_handle_unreference_unlocked(obj);
	475	out_put:
	476	dma_buf_put(dma_buf);
	477	mutex_unlock(&file_priv->prime.lock);
	478	return ret;
	479	}
	480	EXPORT_SYMBOL(drm_gem_prime_fd_to_handle);
	481
	482	int drm_prime_handle_to_fd_ioctl(struct drm_device dev, void data,
	483	struct drm_file *file_priv)
	484	{
	485	struct drm_prime_handle *args = data;
	486	uint32_t flags;
	487
	488	if (!drm_core_check_feature(dev, DRIVER_PRIME))
	489	return -EINVAL;
	490
	491	if (!dev->driver->prime_handle_to_fd)
	492	return -ENOSYS;
	493
	494	/* check flags are valid */
	495	if (args->flags & ~DRM_CLOEXEC)
	496	return -EINVAL;
	497
	498	/* we only want to pass DRM_CLOEXEC which is == O_CLOEXEC */
	499	flags = args->flags & DRM_CLOEXEC;
	500
	501	return dev->driver->prime_handle_to_fd(dev, file_priv,
	502	args->handle, flags, &args->fd);
	503	}
	504
	505	int drm_prime_fd_to_handle_ioctl(struct drm_device dev, void data,
	506	struct drm_file *file_priv)
	507	{
	508	struct drm_prime_handle *args = data;
	509
	510	if (!drm_core_check_feature(dev, DRIVER_PRIME))
	511	return -EINVAL;
	512
	513	if (!dev->driver->prime_fd_to_handle)
	514	return -ENOSYS;
	515
	516	return dev->driver->prime_fd_to_handle(dev, file_priv,
	517	args->fd, &args->handle);
	518	}
	519
	520	/*
	521	* drm_prime_pages_to_sg
	522	*
	523	* this helper creates an sg table object from a set of pages
	524	* the driver is responsible for mapping the pages into the
	525	* importers address space
	526	*/
	527	struct sg_table drm_prime_pages_to_sg(struct page *pages, int nr_pages)
	528	{
	529	struct sg_table *sg = NULL;
3248877e DA	530	int ret;
	531
	532	sg = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
7e3d88f9 YC	533	if (!sg) {
7e3d88f9 YC	534	ret = -ENOMEM;
3248877e	535	goto out;
7e3d88f9	536	}
3248877e	537
dca25cb8 RS	538	ret = sg_alloc_table_from_pages(sg, pages, nr_pages, 0,
dca25cb8 RS	539	nr_pages << PAGE_SHIFT, GFP_KERNEL);
3248877e DA	540	if (ret)
	541	goto out;
	542
3248877e DA	543	return sg;
	544	out:
	545	kfree(sg);
7e3d88f9	546	return ERR_PTR(ret);
3248877e DA	547	}
	548	EXPORT_SYMBOL(drm_prime_pages_to_sg);
	549
51ab7ba2 DA	550	/* export an sg table into an array of pages and addresses
	551	this is currently required by the TTM driver in order to do correct fault
	552	handling */
	553	int drm_prime_sg_to_page_addr_arrays(struct sg_table sgt, struct page *pages,
	554	dma_addr_t *addrs, int max_pages)
	555	{
	556	unsigned count;
	557	struct scatterlist *sg;
	558	struct page *page;
	559	u32 len, offset;
	560	int pg_index;
	561	dma_addr_t addr;
	562
	563	pg_index = 0;
	564	for_each_sg(sgt->sgl, sg, sgt->nents, count) {
	565	len = sg->length;
	566	offset = sg->offset;
	567	page = sg_page(sg);
	568	addr = sg_dma_address(sg);
	569
	570	while (len > 0) {
	571	if (WARN_ON(pg_index >= max_pages))
	572	return -1;
	573	pages[pg_index] = page;
	574	if (addrs)
	575	addrs[pg_index] = addr;
	576
	577	page++;
	578	addr += PAGE_SIZE;
	579	len -= PAGE_SIZE;
	580	pg_index++;
	581	}
	582	}
	583	return 0;
	584	}
	585	EXPORT_SYMBOL(drm_prime_sg_to_page_addr_arrays);
3248877e DA	586	/* helper function to cleanup a GEM/prime object */
	587	void drm_prime_gem_destroy(struct drm_gem_object obj, struct sg_table sg)
	588	{
	589	struct dma_buf_attachment *attach;
	590	struct dma_buf *dma_buf;
	591	attach = obj->import_attach;
	592	if (sg)
	593	dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
	594	dma_buf = attach->dmabuf;
	595	dma_buf_detach(attach->dmabuf, attach);
	596	/* remove the reference */
	597	dma_buf_put(dma_buf);
	598	}
	599	EXPORT_SYMBOL(drm_prime_gem_destroy);
	600
	601	void drm_prime_init_file_private(struct drm_prime_file_private *prime_fpriv)
	602	{
	603	INIT_LIST_HEAD(&prime_fpriv->head);
	604	mutex_init(&prime_fpriv->lock);
	605	}
	606	EXPORT_SYMBOL(drm_prime_init_file_private);
	607
	608	void drm_prime_destroy_file_private(struct drm_prime_file_private *prime_fpriv)
	609	{
98b76231 ID	610	/* by now drm_gem_release should've made sure the list is empty */
98b76231 ID	611	WARN_ON(!list_empty(&prime_fpriv->head));
3248877e DA	612	}
	613	EXPORT_SYMBOL(drm_prime_destroy_file_private);
	614
219b4733	615	int drm_prime_lookup_buf_handle(struct drm_prime_file_private prime_fpriv, struct dma_buf dma_buf, uint32_t *handle)
3248877e DA	616	{
	617	struct drm_prime_member *member;
	618
	619	list_for_each_entry(member, &prime_fpriv->head, entry) {
	620	if (member->dma_buf == dma_buf) {
	621	*handle = member->handle;
	622	return 0;
	623	}
	624	}
	625	return -ENOENT;
	626	}
219b4733	627	EXPORT_SYMBOL(drm_prime_lookup_buf_handle);
3248877e	628
219b4733	629	void drm_prime_remove_buf_handle(struct drm_prime_file_private prime_fpriv, struct dma_buf dma_buf)
3248877e	630	{
3248877e	631	mutex_lock(&prime_fpriv->lock);
da34242e	632	drm_prime_remove_buf_handle_locked(prime_fpriv, dma_buf);
3248877e DA	633	mutex_unlock(&prime_fpriv->lock);
3248877e DA	634	}
219b4733	635	EXPORT_SYMBOL(drm_prime_remove_buf_handle);