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Commit e078b79d authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab
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[media] vb2-dma-sg: add dmabuf import support 



Add support for importing dmabuf to videobuf2-dma-sg.

Signed-off-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Acked-by: default avatarPawel Osciak <pawel@osciak.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@osg.samsung.com>
parent d790b7ed

drivers/media/v4l2-core/videobuf2-dma-sg.c

+137 −14
Original line number Diff line number Diff line
@@ -41,11 +41,19 @@ struct vb2_dma_sg_buf { 
	int				offset;

	enum dma_data_direction		dma_dir;

	struct sg_table			sg_table;

	/*

	 * This will point to sg_table when used with the MMAP or USERPTR

	 * memory model, and to the dma_buf sglist when used with the

	 * DMABUF memory model.

	 */

	struct sg_table			*dma_sgt;

	size_t				size;

	unsigned int			num_pages;

	atomic_t			refcount;

	struct vb2_vmarea_handler	handler;

	struct vm_area_struct		*vma;



	struct dma_buf_attachment	*db_attach;

};



static void vb2_dma_sg_put(void *buf_priv);
@@ -112,6 +120,7 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, 
	buf->size = size;

	/* size is already page aligned */

	buf->num_pages = size >> PAGE_SHIFT;

	buf->dma_sgt = &buf->sg_table;



	buf->pages = kzalloc(buf->num_pages * sizeof(struct page *),

			     GFP_KERNEL);
@@ -122,7 +131,7 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, 
	if (ret)

		goto fail_pages_alloc;



	ret = sg_alloc_table_from_pages(&buf->sg_table, buf->pages,

	ret = sg_alloc_table_from_pages(buf->dma_sgt, buf->pages,

			buf->num_pages, 0, size, GFP_KERNEL);

	if (ret)

		goto fail_table_alloc;
@@ -147,7 +156,7 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, 


fail_map:

	put_device(buf->dev);

	sg_free_table(sgt);

	sg_free_table(buf->dma_sgt);

fail_table_alloc:

	num_pages = buf->num_pages;

	while (num_pages--)
@@ -171,7 +180,7 @@ static void vb2_dma_sg_put(void *buf_priv) 
		dma_unmap_sg(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);

		if (buf->vaddr)

			vm_unmap_ram(buf->vaddr, buf->num_pages);

		sg_free_table(&buf->sg_table);

		sg_free_table(buf->dma_sgt);

		while (--i >= 0)

			__free_page(buf->pages[i]);

		kfree(buf->pages);
@@ -183,7 +192,11 @@ static void vb2_dma_sg_put(void *buf_priv) 
static void vb2_dma_sg_prepare(void *buf_priv)

{

	struct vb2_dma_sg_buf *buf = buf_priv;

	struct sg_table *sgt = &buf->sg_table;

	struct sg_table *sgt = buf->dma_sgt;



	/* DMABUF exporter will flush the cache for us */

	if (buf->db_attach)

		return;



	dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);

}
@@ -191,7 +204,11 @@ static void vb2_dma_sg_prepare(void *buf_priv) 
static void vb2_dma_sg_finish(void *buf_priv)

{

	struct vb2_dma_sg_buf *buf = buf_priv;

	struct sg_table *sgt = &buf->sg_table;

	struct sg_table *sgt = buf->dma_sgt;



	/* DMABUF exporter will flush the cache for us */

	if (buf->db_attach)

		return;



	dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);

}
@@ -221,6 +238,7 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr, 
	buf->dma_dir = dma_dir;

	buf->offset = vaddr & ~PAGE_MASK;

	buf->size = size;

	buf->dma_sgt = &buf->sg_table;



	first = (vaddr           & PAGE_MASK) >> PAGE_SHIFT;

	last  = ((vaddr + size - 1) & PAGE_MASK) >> PAGE_SHIFT;
@@ -273,7 +291,7 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr, 
	if (num_pages_from_user != buf->num_pages)

		goto userptr_fail_get_user_pages;



	if (sg_alloc_table_from_pages(&buf->sg_table, buf->pages,

	if (sg_alloc_table_from_pages(buf->dma_sgt, buf->pages,

			buf->num_pages, buf->offset, size, 0))

		goto userptr_fail_alloc_table_from_pages;
@@ -315,7 +333,7 @@ static void vb2_dma_sg_put_userptr(void *buf_priv) 
	dma_unmap_sg(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);

	if (buf->vaddr)

		vm_unmap_ram(buf->vaddr, buf->num_pages);

	sg_free_table(&buf->sg_table);

	sg_free_table(buf->dma_sgt);

	while (--i >= 0) {

		if (buf->dma_dir == DMA_FROM_DEVICE)

			set_page_dirty_lock(buf->pages[i]);
@@ -333,14 +351,16 @@ static void *vb2_dma_sg_vaddr(void *buf_priv) 


	BUG_ON(!buf);



	if (!buf->vaddr)

	if (!buf->vaddr) {

		if (buf->db_attach)

			buf->vaddr = dma_buf_vmap(buf->db_attach->dmabuf);

		else

			buf->vaddr = vm_map_ram(buf->pages,

					buf->num_pages,

					-1,

					PAGE_KERNEL);

					buf->num_pages, -1, PAGE_KERNEL);

	}



	/* add offset in case userptr is not page-aligned */

	return buf->vaddr + buf->offset;

	return buf->vaddr ? buf->vaddr + buf->offset : NULL;

}



static unsigned int vb2_dma_sg_num_users(void *buf_priv)
@@ -387,11 +407,110 @@ static int vb2_dma_sg_mmap(void *buf_priv, struct vm_area_struct *vma) 
	return 0;

}



/*********************************************/

/*       callbacks for DMABUF buffers        */

/*********************************************/



static int vb2_dma_sg_map_dmabuf(void *mem_priv)

{

	struct vb2_dma_sg_buf *buf = mem_priv;

	struct sg_table *sgt;



	if (WARN_ON(!buf->db_attach)) {

		pr_err("trying to pin a non attached buffer\n");

		return -EINVAL;

	}



	if (WARN_ON(buf->dma_sgt)) {

		pr_err("dmabuf buffer is already pinned\n");

		return 0;

	}



	/* get the associated scatterlist for this buffer */

	sgt = dma_buf_map_attachment(buf->db_attach, buf->dma_dir);

	if (IS_ERR(sgt)) {

		pr_err("Error getting dmabuf scatterlist\n");

		return -EINVAL;

	}



	buf->dma_sgt = sgt;

	buf->vaddr = NULL;



	return 0;

}



static void vb2_dma_sg_unmap_dmabuf(void *mem_priv)

{

	struct vb2_dma_sg_buf *buf = mem_priv;

	struct sg_table *sgt = buf->dma_sgt;



	if (WARN_ON(!buf->db_attach)) {

		pr_err("trying to unpin a not attached buffer\n");

		return;

	}



	if (WARN_ON(!sgt)) {

		pr_err("dmabuf buffer is already unpinned\n");

		return;

	}



	if (buf->vaddr) {

		dma_buf_vunmap(buf->db_attach->dmabuf, buf->vaddr);

		buf->vaddr = NULL;

	}

	dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir);



	buf->dma_sgt = NULL;

}



static void vb2_dma_sg_detach_dmabuf(void *mem_priv)

{

	struct vb2_dma_sg_buf *buf = mem_priv;



	/* if vb2 works correctly you should never detach mapped buffer */

	if (WARN_ON(buf->dma_sgt))

		vb2_dma_sg_unmap_dmabuf(buf);



	/* detach this attachment */

	dma_buf_detach(buf->db_attach->dmabuf, buf->db_attach);

	kfree(buf);

}



static void *vb2_dma_sg_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf,

	unsigned long size, enum dma_data_direction dma_dir)

{

	struct vb2_dma_sg_conf *conf = alloc_ctx;

	struct vb2_dma_sg_buf *buf;

	struct dma_buf_attachment *dba;



	if (dbuf->size < size)

		return ERR_PTR(-EFAULT);



	buf = kzalloc(sizeof(*buf), GFP_KERNEL);

	if (!buf)

		return ERR_PTR(-ENOMEM);



	buf->dev = conf->dev;

	/* create attachment for the dmabuf with the user device */

	dba = dma_buf_attach(dbuf, buf->dev);

	if (IS_ERR(dba)) {

		pr_err("failed to attach dmabuf\n");

		kfree(buf);

		return dba;

	}



	buf->dma_dir = dma_dir;

	buf->size = size;

	buf->db_attach = dba;



	return buf;

}



static void *vb2_dma_sg_cookie(void *buf_priv)

{

	struct vb2_dma_sg_buf *buf = buf_priv;



	return &buf->sg_table;

	return buf->dma_sgt;

}



const struct vb2_mem_ops vb2_dma_sg_memops = {
@@ -404,6 +523,10 @@ const struct vb2_mem_ops vb2_dma_sg_memops = { 
	.vaddr		= vb2_dma_sg_vaddr,

	.mmap		= vb2_dma_sg_mmap,

	.num_users	= vb2_dma_sg_num_users,

	.map_dmabuf	= vb2_dma_sg_map_dmabuf,

	.unmap_dmabuf	= vb2_dma_sg_unmap_dmabuf,

	.attach_dmabuf	= vb2_dma_sg_attach_dmabuf,

	.detach_dmabuf	= vb2_dma_sg_detach_dmabuf,

	.cookie		= vb2_dma_sg_cookie,

};

EXPORT_SYMBOL_GPL(vb2_dma_sg_memops);