[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 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 =  {
	.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)
{
	if (dev->driver->gem_prime_pin) {
		int ret = dev->driver->gem_prime_pin(obj);
		if (ret)
			return ERR_PTR(ret);
	}
	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_PTR(PTR_ERR(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
89177644 AP	67	static struct sg_table drm_gem_map_dma_buf(struct dma_buf_attachment attach,
	68	enum dma_data_direction dir)
	69	{
	70	struct drm_gem_object *obj = attach->dmabuf->priv;
	71	struct sg_table *sgt;
	72
	73	mutex_lock(&obj->dev->struct_mutex);
	74
	75	sgt = obj->dev->driver->gem_prime_get_sg_table(obj);
	76
	77	if (!IS_ERR_OR_NULL(sgt))
	78	dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir);
	79
	80	mutex_unlock(&obj->dev->struct_mutex);
	81	return sgt;
	82	}
	83
	84	static void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
	85	struct sg_table *sgt, enum dma_data_direction dir)
	86	{
	87	dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
	88	sg_free_table(sgt);
	89	kfree(sgt);
	90	}
	91
	92	static void drm_gem_dmabuf_release(struct dma_buf *dma_buf)
	93	{
	94	struct drm_gem_object *obj = dma_buf->priv;
	95
	96	if (obj->export_dma_buf == dma_buf) {
	97	/* drop the reference on the export fd holds */
	98	obj->export_dma_buf = NULL;
	99	drm_gem_object_unreference_unlocked(obj);
	100	}
	101	}
	102
	103	static void drm_gem_dmabuf_vmap(struct dma_buf dma_buf)
	104	{
	105	struct drm_gem_object *obj = dma_buf->priv;
	106	struct drm_device *dev = obj->dev;
	107
	108	return dev->driver->gem_prime_vmap(obj);
	109	}
	110
	111	static void drm_gem_dmabuf_vunmap(struct dma_buf dma_buf, void vaddr)
	112	{
	113	struct drm_gem_object *obj = dma_buf->priv;
	114	struct drm_device *dev = obj->dev;
	115
	116	dev->driver->gem_prime_vunmap(obj, vaddr);
	117	}
	118
	119	static void drm_gem_dmabuf_kmap_atomic(struct dma_buf dma_buf,
	120	unsigned long page_num)
	121	{
	122	return NULL;
	123	}
	124
	125	static void drm_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
	126	unsigned long page_num, void *addr)
	127	{
	128
	129	}
	130	static void drm_gem_dmabuf_kmap(struct dma_buf dma_buf,
131	unsigned long page_num)
132	{
133	return NULL;
134	}
135
136	static void drm_gem_dmabuf_kunmap(struct dma_buf *dma_buf,
137	unsigned long page_num, void *addr)
138	{
139
140	}
141
142	static int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf,
143	struct vm_area_struct *vma)
144	{
145	return -EINVAL;
146	}
147
148	static const struct dma_buf_ops drm_gem_prime_dmabuf_ops = {
149	.map_dma_buf = drm_gem_map_dma_buf,
150	.unmap_dma_buf = drm_gem_unmap_dma_buf,
151	.release = drm_gem_dmabuf_release,
152	.kmap = drm_gem_dmabuf_kmap,
153	.kmap_atomic = drm_gem_dmabuf_kmap_atomic,
154	.kunmap = drm_gem_dmabuf_kunmap,
155	.kunmap_atomic = drm_gem_dmabuf_kunmap_atomic,
156	.mmap = drm_gem_dmabuf_mmap,
157	.vmap = drm_gem_dmabuf_vmap,
158	.vunmap = drm_gem_dmabuf_vunmap,
159	};
160
161	/**
162	* DOC: PRIME Helpers
163	*
164	* Drivers can implement @gem_prime_export and @gem_prime_import in terms of
165	* simpler APIs by using the helper functions @drm_gem_prime_export and
166	* @drm_gem_prime_import. These functions implement dma-buf support in terms of
167	* five lower-level driver callbacks:
168	*
169	* Export callbacks:
170	*
171	* - @gem_prime_pin (optional): prepare a GEM object for exporting
172	*
173	* - @gem_prime_get_sg_table: provide a scatter/gather table of pinned pages
174	*
175	* - @gem_prime_vmap: vmap a buffer exported by your driver
176	*
177	* - @gem_prime_vunmap: vunmap a buffer exported by your driver
178	*
179	* Import callback:
180	*
181	* - @gem_prime_import_sg_table (import): produce a GEM object from another
182	* driver's scatter/gather table
183	*/
184
185	struct dma_buf drm_gem_prime_export(struct drm_device dev,
186	struct drm_gem_object *obj, int flags)
187	{
188	if (dev->driver->gem_prime_pin) {
189	int ret = dev->driver->gem_prime_pin(obj);
190	if (ret)
191	return ERR_PTR(ret);
192	}
193	return dma_buf_export(obj, &drm_gem_prime_dmabuf_ops, obj->size,
194	0600);
195	}
196	EXPORT_SYMBOL(drm_gem_prime_export);
197
3248877e DA	198	int drm_gem_prime_handle_to_fd(struct drm_device *dev,
	199	struct drm_file *file_priv, uint32_t handle, uint32_t flags,
	200	int *prime_fd)
	201	{
	202	struct drm_gem_object *obj;
	203	void *buf;
219b4733 DA	204	int ret = 0;
219b4733 DA	205	struct dma_buf *dmabuf;
3248877e DA	206
	207	obj = drm_gem_object_lookup(dev, file_priv, handle);
	208	if (!obj)
	209	return -ENOENT;
	210
	211	mutex_lock(&file_priv->prime.lock);
	212	/* re-export the original imported object */
	213	if (obj->import_attach) {
219b4733 DA	214	dmabuf = obj->import_attach->dmabuf;
219b4733 DA	215	goto out_have_obj;
3248877e DA	216	}
	217
	218	if (obj->export_dma_buf) {
219b4733 DA	219	dmabuf = obj->export_dma_buf;
219b4733 DA	220	goto out_have_obj;
3248877e	221	}
219b4733 DA	222
	223	buf = dev->driver->gem_prime_export(dev, obj, flags);
	224	if (IS_ERR(buf)) {
	225	/* normally the created dma-buf takes ownership of the ref,
	226	* but if that fails then drop the ref
	227	*/
	228	ret = PTR_ERR(buf);
	229	goto out;
	230	}
	231	obj->export_dma_buf = buf;
	232
0ff926c7 DA	233	/* if we've exported this buffer the cheat and add it to the import list
	234	* so we get the correct handle back
	235	*/
219b4733 DA	236	ret = drm_prime_add_buf_handle(&file_priv->prime,
	237	obj->export_dma_buf, handle);
	238	if (ret)
	239	goto out;
0ff926c7	240
219b4733	241	*prime_fd = dma_buf_fd(buf, flags);
3248877e DA	242	mutex_unlock(&file_priv->prime.lock);
3248877e DA	243	return 0;
219b4733 DA	244
	245	out_have_obj:
	246	get_dma_buf(dmabuf);
	247	*prime_fd = dma_buf_fd(dmabuf, flags);
	248	out:
	249	drm_gem_object_unreference_unlocked(obj);
	250	mutex_unlock(&file_priv->prime.lock);
	251	return ret;
3248877e DA	252	}
	253	EXPORT_SYMBOL(drm_gem_prime_handle_to_fd);
	254
89177644 AP	255	struct drm_gem_object drm_gem_prime_import(struct drm_device dev,
	256	struct dma_buf *dma_buf)
	257	{
	258	struct dma_buf_attachment *attach;
	259	struct sg_table *sgt;
	260	struct drm_gem_object *obj;
	261	int ret;
	262
	263	if (!dev->driver->gem_prime_import_sg_table)
	264	return ERR_PTR(-EINVAL);
	265
	266	if (dma_buf->ops == &drm_gem_prime_dmabuf_ops) {
	267	obj = dma_buf->priv;
	268	if (obj->dev == dev) {
	269	/*
	270	* Importing dmabuf exported from out own gem increases
	271	* refcount on gem itself instead of f_count of dmabuf.
	272	*/
	273	drm_gem_object_reference(obj);
89177644 AP	274	return obj;
	275	}
	276	}
	277
	278	attach = dma_buf_attach(dma_buf, dev->dev);
	279	if (IS_ERR(attach))
	280	return ERR_PTR(PTR_ERR(attach));
	281
011c2282 ID	282	get_dma_buf(dma_buf);
011c2282 ID	283
89177644 AP	284	sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
	285	if (IS_ERR_OR_NULL(sgt)) {
	286	ret = PTR_ERR(sgt);
	287	goto fail_detach;
	288	}
	289
	290	obj = dev->driver->gem_prime_import_sg_table(dev, dma_buf->size, sgt);
	291	if (IS_ERR(obj)) {
	292	ret = PTR_ERR(obj);
	293	goto fail_unmap;
	294	}
	295
	296	obj->import_attach = attach;
	297
	298	return obj;
	299
	300	fail_unmap:
	301	dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
	302	fail_detach:
	303	dma_buf_detach(dma_buf, attach);
011c2282 ID	304	dma_buf_put(dma_buf);
011c2282 ID	305
89177644 AP	306	return ERR_PTR(ret);
	307	}
	308	EXPORT_SYMBOL(drm_gem_prime_import);
	309
3248877e DA	310	int drm_gem_prime_fd_to_handle(struct drm_device *dev,
	311	struct drm_file file_priv, int prime_fd, uint32_t handle)
	312	{
	313	struct dma_buf *dma_buf;
	314	struct drm_gem_object *obj;
	315	int ret;
	316
	317	dma_buf = dma_buf_get(prime_fd);
	318	if (IS_ERR(dma_buf))
	319	return PTR_ERR(dma_buf);
	320
	321	mutex_lock(&file_priv->prime.lock);
	322
219b4733	323	ret = drm_prime_lookup_buf_handle(&file_priv->prime,
3248877e DA	324	dma_buf, handle);
	325	if (!ret) {
	326	ret = 0;
	327	goto out_put;
	328	}
	329
	330	/* never seen this one, need to import */
	331	obj = dev->driver->gem_prime_import(dev, dma_buf);
	332	if (IS_ERR(obj)) {
	333	ret = PTR_ERR(obj);
	334	goto out_put;
	335	}
	336
	337	ret = drm_gem_handle_create(file_priv, obj, handle);
	338	drm_gem_object_unreference_unlocked(obj);
	339	if (ret)
	340	goto out_put;
	341
219b4733	342	ret = drm_prime_add_buf_handle(&file_priv->prime,
3248877e DA	343	dma_buf, *handle);
	344	if (ret)
	345	goto fail;
	346
	347	mutex_unlock(&file_priv->prime.lock);
011c2282 ID	348
	349	dma_buf_put(dma_buf);
	350
3248877e DA	351	return 0;
	352
	353	fail:
	354	/* hmm, if driver attached, we are relying on the free-object path
	355	* to detach.. which seems ok..
	356	*/
	357	drm_gem_object_handle_unreference_unlocked(obj);
	358	out_put:
	359	dma_buf_put(dma_buf);
	360	mutex_unlock(&file_priv->prime.lock);
	361	return ret;
	362	}
	363	EXPORT_SYMBOL(drm_gem_prime_fd_to_handle);
	364
	365	int drm_prime_handle_to_fd_ioctl(struct drm_device dev, void data,
	366	struct drm_file *file_priv)
	367	{
	368	struct drm_prime_handle *args = data;
	369	uint32_t flags;
	370
	371	if (!drm_core_check_feature(dev, DRIVER_PRIME))
	372	return -EINVAL;
	373
	374	if (!dev->driver->prime_handle_to_fd)
	375	return -ENOSYS;
	376
	377	/* check flags are valid */
	378	if (args->flags & ~DRM_CLOEXEC)
	379	return -EINVAL;
	380
	381	/* we only want to pass DRM_CLOEXEC which is == O_CLOEXEC */
	382	flags = args->flags & DRM_CLOEXEC;
	383
	384	return dev->driver->prime_handle_to_fd(dev, file_priv,
	385	args->handle, flags, &args->fd);
	386	}
	387
	388	int drm_prime_fd_to_handle_ioctl(struct drm_device dev, void data,
	389	struct drm_file *file_priv)
	390	{
	391	struct drm_prime_handle *args = data;
	392
	393	if (!drm_core_check_feature(dev, DRIVER_PRIME))
	394	return -EINVAL;
	395
	396	if (!dev->driver->prime_fd_to_handle)
	397	return -ENOSYS;
	398
	399	return dev->driver->prime_fd_to_handle(dev, file_priv,
	400	args->fd, &args->handle);
	401	}
	402
	403	/*
	404	* drm_prime_pages_to_sg
	405	*
	406	* this helper creates an sg table object from a set of pages
	407	* the driver is responsible for mapping the pages into the
	408	* importers address space
	409	*/
	410	struct sg_table drm_prime_pages_to_sg(struct page *pages, int nr_pages)
	411	{
	412	struct sg_table *sg = NULL;
3248877e DA	413	int ret;
	414
	415	sg = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
	416	if (!sg)
	417	goto out;
	418
dca25cb8 RS	419	ret = sg_alloc_table_from_pages(sg, pages, nr_pages, 0,
dca25cb8 RS	420	nr_pages << PAGE_SHIFT, GFP_KERNEL);
3248877e DA	421	if (ret)
	422	goto out;
	423
3248877e DA	424	return sg;
	425	out:
	426	kfree(sg);
	427	return NULL;
	428	}
	429	EXPORT_SYMBOL(drm_prime_pages_to_sg);
	430
51ab7ba2 DA	431	/* export an sg table into an array of pages and addresses
	432	this is currently required by the TTM driver in order to do correct fault
	433	handling */
	434	int drm_prime_sg_to_page_addr_arrays(struct sg_table sgt, struct page *pages,
	435	dma_addr_t *addrs, int max_pages)
	436	{
	437	unsigned count;
	438	struct scatterlist *sg;
	439	struct page *page;
	440	u32 len, offset;
	441	int pg_index;
	442	dma_addr_t addr;
	443
	444	pg_index = 0;
	445	for_each_sg(sgt->sgl, sg, sgt->nents, count) {
	446	len = sg->length;
	447	offset = sg->offset;
	448	page = sg_page(sg);
	449	addr = sg_dma_address(sg);
	450
	451	while (len > 0) {
	452	if (WARN_ON(pg_index >= max_pages))
	453	return -1;
	454	pages[pg_index] = page;
	455	if (addrs)
	456	addrs[pg_index] = addr;
	457
	458	page++;
	459	addr += PAGE_SIZE;
	460	len -= PAGE_SIZE;
	461	pg_index++;
	462	}
	463	}
	464	return 0;
	465	}
	466	EXPORT_SYMBOL(drm_prime_sg_to_page_addr_arrays);
3248877e DA	467	/* helper function to cleanup a GEM/prime object */
	468	void drm_prime_gem_destroy(struct drm_gem_object obj, struct sg_table sg)
	469	{
	470	struct dma_buf_attachment *attach;
	471	struct dma_buf *dma_buf;
	472	attach = obj->import_attach;
	473	if (sg)
	474	dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
	475	dma_buf = attach->dmabuf;
	476	dma_buf_detach(attach->dmabuf, attach);
	477	/* remove the reference */
	478	dma_buf_put(dma_buf);
	479	}
	480	EXPORT_SYMBOL(drm_prime_gem_destroy);
	481
	482	void drm_prime_init_file_private(struct drm_prime_file_private *prime_fpriv)
	483	{
	484	INIT_LIST_HEAD(&prime_fpriv->head);
	485	mutex_init(&prime_fpriv->lock);
	486	}
	487	EXPORT_SYMBOL(drm_prime_init_file_private);
	488
	489	void drm_prime_destroy_file_private(struct drm_prime_file_private *prime_fpriv)
	490	{
98b76231 ID	491	/* by now drm_gem_release should've made sure the list is empty */
98b76231 ID	492	WARN_ON(!list_empty(&prime_fpriv->head));
3248877e DA	493	}
	494	EXPORT_SYMBOL(drm_prime_destroy_file_private);
	495
219b4733	496	static int drm_prime_add_buf_handle(struct drm_prime_file_private prime_fpriv, struct dma_buf dma_buf, uint32_t handle)
3248877e DA	497	{
	498	struct drm_prime_member *member;
	499
	500	member = kmalloc(sizeof(*member), GFP_KERNEL);
	501	if (!member)
	502	return -ENOMEM;
	503
219b4733	504	get_dma_buf(dma_buf);
3248877e DA	505	member->dma_buf = dma_buf;
	506	member->handle = handle;
	507	list_add(&member->entry, &prime_fpriv->head);
	508	return 0;
	509	}
3248877e	510
219b4733	511	int drm_prime_lookup_buf_handle(struct drm_prime_file_private prime_fpriv, struct dma_buf dma_buf, uint32_t *handle)
3248877e DA	512	{
	513	struct drm_prime_member *member;
	514
	515	list_for_each_entry(member, &prime_fpriv->head, entry) {
	516	if (member->dma_buf == dma_buf) {
	517	*handle = member->handle;
	518	return 0;
	519	}
	520	}
	521	return -ENOENT;
	522	}
219b4733	523	EXPORT_SYMBOL(drm_prime_lookup_buf_handle);
3248877e	524
219b4733	525	void drm_prime_remove_buf_handle(struct drm_prime_file_private prime_fpriv, struct dma_buf dma_buf)
3248877e DA	526	{
	527	struct drm_prime_member member, safe;
	528
	529	mutex_lock(&prime_fpriv->lock);
	530	list_for_each_entry_safe(member, safe, &prime_fpriv->head, entry) {
	531	if (member->dma_buf == dma_buf) {
219b4733	532	dma_buf_put(dma_buf);
3248877e DA	533	list_del(&member->entry);
	534	kfree(member);
	535	}
	536	}
	537	mutex_unlock(&prime_fpriv->lock);
	538	}
219b4733	539	EXPORT_SYMBOL(drm_prime_remove_buf_handle);