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authorHans Verkuil <hverkuil@xs4all.nl>2018-01-08 23:20:01 +0300
committerMauro Carvalho Chehab <mchehab@s-opensource.com>2018-01-23 16:05:02 +0300
commit7952be9b6ece3d3c4d61f9811d7e5a984580064a (patch)
treec4ff80f1260e865bada91ddd2a0e5e777514dff8 /drivers/media/common/videobuf2/videobuf2-dma-sg.c
parentc81ceb58e10124b79b9a01c70b9c25b2fe540475 (diff)
downloadlinux-7952be9b6ece3d3c4d61f9811d7e5a984580064a.tar.xz
media: drivers/media/common/videobuf2: rename from videobuf
This directory contains the videobuf2 framework, so name the directory accordingly. The name 'videobuf' typically refers to the old and deprecated videobuf version 1 framework so that was confusing. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Diffstat (limited to 'drivers/media/common/videobuf2/videobuf2-dma-sg.c')
-rw-r--r--drivers/media/common/videobuf2/videobuf2-dma-sg.c669
1 files changed, 669 insertions, 0 deletions
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
new file mode 100644
index 000000000000..753ed3138dcc
--- /dev/null
+++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
@@ -0,0 +1,669 @@
+/*
+ * videobuf2-dma-sg.c - dma scatter/gather memory allocator for videobuf2
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/refcount.h>
+#include <linux/scatterlist.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#include <media/videobuf2-v4l2.h>
+#include <media/videobuf2-memops.h>
+#include <media/videobuf2-dma-sg.h>
+
+static int debug;
+module_param(debug, int, 0644);
+
+#define dprintk(level, fmt, arg...) \
+ do { \
+ if (debug >= level) \
+ printk(KERN_DEBUG "vb2-dma-sg: " fmt, ## arg); \
+ } while (0)
+
+struct vb2_dma_sg_buf {
+ struct device *dev;
+ void *vaddr;
+ struct page **pages;
+ struct frame_vector *vec;
+ 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;
+ refcount_t refcount;
+ struct vb2_vmarea_handler handler;
+
+ struct dma_buf_attachment *db_attach;
+};
+
+static void vb2_dma_sg_put(void *buf_priv);
+
+static int vb2_dma_sg_alloc_compacted(struct vb2_dma_sg_buf *buf,
+ gfp_t gfp_flags)
+{
+ unsigned int last_page = 0;
+ int size = buf->size;
+
+ while (size > 0) {
+ struct page *pages;
+ int order;
+ int i;
+
+ order = get_order(size);
+ /* Dont over allocate*/
+ if ((PAGE_SIZE << order) > size)
+ order--;
+
+ pages = NULL;
+ while (!pages) {
+ pages = alloc_pages(GFP_KERNEL | __GFP_ZERO |
+ __GFP_NOWARN | gfp_flags, order);
+ if (pages)
+ break;
+
+ if (order == 0) {
+ while (last_page--)
+ __free_page(buf->pages[last_page]);
+ return -ENOMEM;
+ }
+ order--;
+ }
+
+ split_page(pages, order);
+ for (i = 0; i < (1 << order); i++)
+ buf->pages[last_page++] = &pages[i];
+
+ size -= PAGE_SIZE << order;
+ }
+
+ return 0;
+}
+
+static void *vb2_dma_sg_alloc(struct device *dev, unsigned long dma_attrs,
+ unsigned long size, enum dma_data_direction dma_dir,
+ gfp_t gfp_flags)
+{
+ struct vb2_dma_sg_buf *buf;
+ struct sg_table *sgt;
+ int ret;
+ int num_pages;
+
+ if (WARN_ON(!dev))
+ return ERR_PTR(-EINVAL);
+
+ buf = kzalloc(sizeof *buf, GFP_KERNEL);
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+
+ buf->vaddr = NULL;
+ buf->dma_dir = dma_dir;
+ buf->offset = 0;
+ buf->size = size;
+ /* size is already page aligned */
+ buf->num_pages = size >> PAGE_SHIFT;
+ buf->dma_sgt = &buf->sg_table;
+
+ buf->pages = kvmalloc_array(buf->num_pages, sizeof(struct page *),
+ GFP_KERNEL | __GFP_ZERO);
+ if (!buf->pages)
+ goto fail_pages_array_alloc;
+
+ ret = vb2_dma_sg_alloc_compacted(buf, gfp_flags);
+ if (ret)
+ goto fail_pages_alloc;
+
+ ret = sg_alloc_table_from_pages(buf->dma_sgt, buf->pages,
+ buf->num_pages, 0, size, GFP_KERNEL);
+ if (ret)
+ goto fail_table_alloc;
+
+ /* Prevent the device from being released while the buffer is used */
+ buf->dev = get_device(dev);
+
+ sgt = &buf->sg_table;
+ /*
+ * No need to sync to the device, this will happen later when the
+ * prepare() memop is called.
+ */
+ sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
+ buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+ if (!sgt->nents)
+ goto fail_map;
+
+ buf->handler.refcount = &buf->refcount;
+ buf->handler.put = vb2_dma_sg_put;
+ buf->handler.arg = buf;
+
+ refcount_set(&buf->refcount, 1);
+
+ dprintk(1, "%s: Allocated buffer of %d pages\n",
+ __func__, buf->num_pages);
+ return buf;
+
+fail_map:
+ put_device(buf->dev);
+ sg_free_table(buf->dma_sgt);
+fail_table_alloc:
+ num_pages = buf->num_pages;
+ while (num_pages--)
+ __free_page(buf->pages[num_pages]);
+fail_pages_alloc:
+ kvfree(buf->pages);
+fail_pages_array_alloc:
+ kfree(buf);
+ return ERR_PTR(-ENOMEM);
+}
+
+static void vb2_dma_sg_put(void *buf_priv)
+{
+ struct vb2_dma_sg_buf *buf = buf_priv;
+ struct sg_table *sgt = &buf->sg_table;
+ int i = buf->num_pages;
+
+ if (refcount_dec_and_test(&buf->refcount)) {
+ dprintk(1, "%s: Freeing buffer of %d pages\n", __func__,
+ buf->num_pages);
+ dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
+ buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+ if (buf->vaddr)
+ vm_unmap_ram(buf->vaddr, buf->num_pages);
+ sg_free_table(buf->dma_sgt);
+ while (--i >= 0)
+ __free_page(buf->pages[i]);
+ kvfree(buf->pages);
+ put_device(buf->dev);
+ kfree(buf);
+ }
+}
+
+static void vb2_dma_sg_prepare(void *buf_priv)
+{
+ struct vb2_dma_sg_buf *buf = buf_priv;
+ 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->orig_nents,
+ buf->dma_dir);
+}
+
+static void vb2_dma_sg_finish(void *buf_priv)
+{
+ struct vb2_dma_sg_buf *buf = buf_priv;
+ 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->orig_nents, buf->dma_dir);
+}
+
+static void *vb2_dma_sg_get_userptr(struct device *dev, unsigned long vaddr,
+ unsigned long size,
+ enum dma_data_direction dma_dir)
+{
+ struct vb2_dma_sg_buf *buf;
+ struct sg_table *sgt;
+ struct frame_vector *vec;
+
+ if (WARN_ON(!dev))
+ return ERR_PTR(-EINVAL);
+
+ buf = kzalloc(sizeof *buf, GFP_KERNEL);
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+
+ buf->vaddr = NULL;
+ buf->dev = dev;
+ buf->dma_dir = dma_dir;
+ buf->offset = vaddr & ~PAGE_MASK;
+ buf->size = size;
+ buf->dma_sgt = &buf->sg_table;
+ vec = vb2_create_framevec(vaddr, size, dma_dir == DMA_FROM_DEVICE ||
+ dma_dir == DMA_BIDIRECTIONAL);
+ if (IS_ERR(vec))
+ goto userptr_fail_pfnvec;
+ buf->vec = vec;
+
+ buf->pages = frame_vector_pages(vec);
+ if (IS_ERR(buf->pages))
+ goto userptr_fail_sgtable;
+ buf->num_pages = frame_vector_count(vec);
+
+ if (sg_alloc_table_from_pages(buf->dma_sgt, buf->pages,
+ buf->num_pages, buf->offset, size, 0))
+ goto userptr_fail_sgtable;
+
+ sgt = &buf->sg_table;
+ /*
+ * No need to sync to the device, this will happen later when the
+ * prepare() memop is called.
+ */
+ sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
+ buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+ if (!sgt->nents)
+ goto userptr_fail_map;
+
+ return buf;
+
+userptr_fail_map:
+ sg_free_table(&buf->sg_table);
+userptr_fail_sgtable:
+ vb2_destroy_framevec(vec);
+userptr_fail_pfnvec:
+ kfree(buf);
+ return ERR_PTR(-ENOMEM);
+}
+
+/*
+ * @put_userptr: inform the allocator that a USERPTR buffer will no longer
+ * be used
+ */
+static void vb2_dma_sg_put_userptr(void *buf_priv)
+{
+ struct vb2_dma_sg_buf *buf = buf_priv;
+ struct sg_table *sgt = &buf->sg_table;
+ int i = buf->num_pages;
+
+ dprintk(1, "%s: Releasing userspace buffer of %d pages\n",
+ __func__, buf->num_pages);
+ dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir,
+ DMA_ATTR_SKIP_CPU_SYNC);
+ if (buf->vaddr)
+ vm_unmap_ram(buf->vaddr, buf->num_pages);
+ sg_free_table(buf->dma_sgt);
+ if (buf->dma_dir == DMA_FROM_DEVICE ||
+ buf->dma_dir == DMA_BIDIRECTIONAL)
+ while (--i >= 0)
+ set_page_dirty_lock(buf->pages[i]);
+ vb2_destroy_framevec(buf->vec);
+ kfree(buf);
+}
+
+static void *vb2_dma_sg_vaddr(void *buf_priv)
+{
+ struct vb2_dma_sg_buf *buf = buf_priv;
+
+ BUG_ON(!buf);
+
+ 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);
+ }
+
+ /* add offset in case userptr is not page-aligned */
+ return buf->vaddr ? buf->vaddr + buf->offset : NULL;
+}
+
+static unsigned int vb2_dma_sg_num_users(void *buf_priv)
+{
+ struct vb2_dma_sg_buf *buf = buf_priv;
+
+ return refcount_read(&buf->refcount);
+}
+
+static int vb2_dma_sg_mmap(void *buf_priv, struct vm_area_struct *vma)
+{
+ struct vb2_dma_sg_buf *buf = buf_priv;
+ unsigned long uaddr = vma->vm_start;
+ unsigned long usize = vma->vm_end - vma->vm_start;
+ int i = 0;
+
+ if (!buf) {
+ printk(KERN_ERR "No memory to map\n");
+ return -EINVAL;
+ }
+
+ do {
+ int ret;
+
+ ret = vm_insert_page(vma, uaddr, buf->pages[i++]);
+ if (ret) {
+ printk(KERN_ERR "Remapping memory, error: %d\n", ret);
+ return ret;
+ }
+
+ uaddr += PAGE_SIZE;
+ usize -= PAGE_SIZE;
+ } while (usize > 0);
+
+
+ /*
+ * Use common vm_area operations to track buffer refcount.
+ */
+ vma->vm_private_data = &buf->handler;
+ vma->vm_ops = &vb2_common_vm_ops;
+
+ vma->vm_ops->open(vma);
+
+ return 0;
+}
+
+/*********************************************/
+/* DMABUF ops for exporters */
+/*********************************************/
+
+struct vb2_dma_sg_attachment {
+ struct sg_table sgt;
+ enum dma_data_direction dma_dir;
+};
+
+static int vb2_dma_sg_dmabuf_ops_attach(struct dma_buf *dbuf, struct device *dev,
+ struct dma_buf_attachment *dbuf_attach)
+{
+ struct vb2_dma_sg_attachment *attach;
+ unsigned int i;
+ struct scatterlist *rd, *wr;
+ struct sg_table *sgt;
+ struct vb2_dma_sg_buf *buf = dbuf->priv;
+ int ret;
+
+ attach = kzalloc(sizeof(*attach), GFP_KERNEL);
+ if (!attach)
+ return -ENOMEM;
+
+ sgt = &attach->sgt;
+ /* Copy the buf->base_sgt scatter list to the attachment, as we can't
+ * map the same scatter list to multiple attachments at the same time.
+ */
+ ret = sg_alloc_table(sgt, buf->dma_sgt->orig_nents, GFP_KERNEL);
+ if (ret) {
+ kfree(attach);
+ return -ENOMEM;
+ }
+
+ rd = buf->dma_sgt->sgl;
+ wr = sgt->sgl;
+ for (i = 0; i < sgt->orig_nents; ++i) {
+ sg_set_page(wr, sg_page(rd), rd->length, rd->offset);
+ rd = sg_next(rd);
+ wr = sg_next(wr);
+ }
+
+ attach->dma_dir = DMA_NONE;
+ dbuf_attach->priv = attach;
+
+ return 0;
+}
+
+static void vb2_dma_sg_dmabuf_ops_detach(struct dma_buf *dbuf,
+ struct dma_buf_attachment *db_attach)
+{
+ struct vb2_dma_sg_attachment *attach = db_attach->priv;
+ struct sg_table *sgt;
+
+ if (!attach)
+ return;
+
+ sgt = &attach->sgt;
+
+ /* release the scatterlist cache */
+ if (attach->dma_dir != DMA_NONE)
+ dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
+ attach->dma_dir);
+ sg_free_table(sgt);
+ kfree(attach);
+ db_attach->priv = NULL;
+}
+
+static struct sg_table *vb2_dma_sg_dmabuf_ops_map(
+ struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir)
+{
+ struct vb2_dma_sg_attachment *attach = db_attach->priv;
+ /* stealing dmabuf mutex to serialize map/unmap operations */
+ struct mutex *lock = &db_attach->dmabuf->lock;
+ struct sg_table *sgt;
+
+ mutex_lock(lock);
+
+ sgt = &attach->sgt;
+ /* return previously mapped sg table */
+ if (attach->dma_dir == dma_dir) {
+ mutex_unlock(lock);
+ return sgt;
+ }
+
+ /* release any previous cache */
+ if (attach->dma_dir != DMA_NONE) {
+ dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
+ attach->dma_dir);
+ attach->dma_dir = DMA_NONE;
+ }
+
+ /* mapping to the client with new direction */
+ sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
+ dma_dir);
+ if (!sgt->nents) {
+ pr_err("failed to map scatterlist\n");
+ mutex_unlock(lock);
+ return ERR_PTR(-EIO);
+ }
+
+ attach->dma_dir = dma_dir;
+
+ mutex_unlock(lock);
+
+ return sgt;
+}
+
+static void vb2_dma_sg_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach,
+ struct sg_table *sgt, enum dma_data_direction dma_dir)
+{
+ /* nothing to be done here */
+}
+
+static void vb2_dma_sg_dmabuf_ops_release(struct dma_buf *dbuf)
+{
+ /* drop reference obtained in vb2_dma_sg_get_dmabuf */
+ vb2_dma_sg_put(dbuf->priv);
+}
+
+static void *vb2_dma_sg_dmabuf_ops_kmap(struct dma_buf *dbuf, unsigned long pgnum)
+{
+ struct vb2_dma_sg_buf *buf = dbuf->priv;
+
+ return buf->vaddr ? buf->vaddr + pgnum * PAGE_SIZE : NULL;
+}
+
+static void *vb2_dma_sg_dmabuf_ops_vmap(struct dma_buf *dbuf)
+{
+ struct vb2_dma_sg_buf *buf = dbuf->priv;
+
+ return vb2_dma_sg_vaddr(buf);
+}
+
+static int vb2_dma_sg_dmabuf_ops_mmap(struct dma_buf *dbuf,
+ struct vm_area_struct *vma)
+{
+ return vb2_dma_sg_mmap(dbuf->priv, vma);
+}
+
+static const struct dma_buf_ops vb2_dma_sg_dmabuf_ops = {
+ .attach = vb2_dma_sg_dmabuf_ops_attach,
+ .detach = vb2_dma_sg_dmabuf_ops_detach,
+ .map_dma_buf = vb2_dma_sg_dmabuf_ops_map,
+ .unmap_dma_buf = vb2_dma_sg_dmabuf_ops_unmap,
+ .map = vb2_dma_sg_dmabuf_ops_kmap,
+ .map_atomic = vb2_dma_sg_dmabuf_ops_kmap,
+ .vmap = vb2_dma_sg_dmabuf_ops_vmap,
+ .mmap = vb2_dma_sg_dmabuf_ops_mmap,
+ .release = vb2_dma_sg_dmabuf_ops_release,
+};
+
+static struct dma_buf *vb2_dma_sg_get_dmabuf(void *buf_priv, unsigned long flags)
+{
+ struct vb2_dma_sg_buf *buf = buf_priv;
+ struct dma_buf *dbuf;
+ DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+
+ exp_info.ops = &vb2_dma_sg_dmabuf_ops;
+ exp_info.size = buf->size;
+ exp_info.flags = flags;
+ exp_info.priv = buf;
+
+ if (WARN_ON(!buf->dma_sgt))
+ return NULL;
+
+ dbuf = dma_buf_export(&exp_info);
+ if (IS_ERR(dbuf))
+ return NULL;
+
+ /* dmabuf keeps reference to vb2 buffer */
+ refcount_inc(&buf->refcount);
+
+ return dbuf;
+}
+
+/*********************************************/
+/* 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(struct device *dev, struct dma_buf *dbuf,
+ unsigned long size, enum dma_data_direction dma_dir)
+{
+ struct vb2_dma_sg_buf *buf;
+ struct dma_buf_attachment *dba;
+
+ if (WARN_ON(!dev))
+ return ERR_PTR(-EINVAL);
+
+ if (dbuf->size < size)
+ return ERR_PTR(-EFAULT);
+
+ buf = kzalloc(sizeof(*buf), GFP_KERNEL);
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+
+ buf->dev = 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->dma_sgt;
+}
+
+const struct vb2_mem_ops vb2_dma_sg_memops = {
+ .alloc = vb2_dma_sg_alloc,
+ .put = vb2_dma_sg_put,
+ .get_userptr = vb2_dma_sg_get_userptr,
+ .put_userptr = vb2_dma_sg_put_userptr,
+ .prepare = vb2_dma_sg_prepare,
+ .finish = vb2_dma_sg_finish,
+ .vaddr = vb2_dma_sg_vaddr,
+ .mmap = vb2_dma_sg_mmap,
+ .num_users = vb2_dma_sg_num_users,
+ .get_dmabuf = vb2_dma_sg_get_dmabuf,
+ .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);
+
+MODULE_DESCRIPTION("dma scatter/gather memory handling routines for videobuf2");
+MODULE_AUTHOR("Andrzej Pietrasiewicz");
+MODULE_LICENSE("GPL");