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authorSumit Semwal <sumit.semwal@linaro.org>2015-01-23 08:23:43 +0100
committerSumit Semwal <sumit.semwal@linaro.org>2015-04-21 11:17:16 +0200
commitd8fbe341beb617ebb22b98fb893e4aa32ae2d864 (patch)
tree2e19c951d2b6ffef2319d87ec8a6c39e4e1ab8ee
parentMerge tag 'remoteproc-4.1-next' of git://git.kernel.org/pub/scm/linux/kernel/... (diff)
downloadlinux-d8fbe341beb617ebb22b98fb893e4aa32ae2d864.tar.xz
linux-d8fbe341beb617ebb22b98fb893e4aa32ae2d864.zip
dma-buf: cleanup dma_buf_export() to make it easily extensible
At present, dma_buf_export() takes a series of parameters, which makes it difficult to add any new parameters for exporters, if required. Make it simpler by moving all these parameters into a struct, and pass the struct * as parameter to dma_buf_export(). While at it, unite dma_buf_export_named() with dma_buf_export(), and change all callers accordingly. Reviewed-by: Maarten Lankhorst <maarten.lankhorst@canonical.com> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com> Acked-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
-rw-r--r--Documentation/dma-buf-sharing.txt23
-rw-r--r--drivers/dma-buf/dma-buf.c47
-rw-r--r--drivers/gpu/drm/armada/armada_gem.c10
-rw-r--r--drivers/gpu/drm/drm_prime.c12
-rw-r--r--drivers/gpu/drm/exynos/exynos_drm_dmabuf.c9
-rw-r--r--drivers/gpu/drm/i915/i915_gem_dmabuf.c10
-rw-r--r--drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c9
-rw-r--r--drivers/gpu/drm/tegra/gem.c10
-rw-r--r--drivers/gpu/drm/ttm/ttm_object.c9
-rw-r--r--drivers/gpu/drm/udl/udl_dmabuf.c9
-rw-r--r--drivers/media/v4l2-core/videobuf2-dma-contig.c8
-rw-r--r--drivers/media/v4l2-core/videobuf2-dma-sg.c8
-rw-r--r--drivers/media/v4l2-core/videobuf2-vmalloc.c8
-rw-r--r--drivers/staging/android/ion/ion.c9
-rw-r--r--include/linux/dma-buf.h34
15 files changed, 152 insertions, 63 deletions
diff --git a/Documentation/dma-buf-sharing.txt b/Documentation/dma-buf-sharing.txt
index bb9753b635a3..480c8de3c2c4 100644
--- a/Documentation/dma-buf-sharing.txt
+++ b/Documentation/dma-buf-sharing.txt
@@ -49,25 +49,26 @@ The dma_buf buffer sharing API usage contains the following steps:
The buffer exporter announces its wish to export a buffer. In this, it
connects its own private buffer data, provides implementation for operations
that can be performed on the exported dma_buf, and flags for the file
- associated with this buffer.
+ associated with this buffer. All these fields are filled in struct
+ dma_buf_export_info, defined via the DEFINE_DMA_BUF_EXPORT_INFO macro.
Interface:
- struct dma_buf *dma_buf_export_named(void *priv, struct dma_buf_ops *ops,
- size_t size, int flags,
- const char *exp_name)
+ DEFINE_DMA_BUF_EXPORT_INFO(exp_info)
+ struct dma_buf *dma_buf_export(struct dma_buf_export_info *exp_info)
- If this succeeds, dma_buf_export_named allocates a dma_buf structure, and
+ If this succeeds, dma_buf_export allocates a dma_buf structure, and
returns a pointer to the same. It also associates an anonymous file with this
buffer, so it can be exported. On failure to allocate the dma_buf object,
it returns NULL.
- 'exp_name' is the name of exporter - to facilitate information while
- debugging.
+ 'exp_name' in struct dma_buf_export_info is the name of exporter - to
+ facilitate information while debugging. It is set to KBUILD_MODNAME by
+ default, so exporters don't have to provide a specific name, if they don't
+ wish to.
+
+ DEFINE_DMA_BUF_EXPORT_INFO macro defines the struct dma_buf_export_info,
+ zeroes it out and pre-populates exp_name in it.
- Exporting modules which do not wish to provide any specific name may use the
- helper define 'dma_buf_export()', with the same arguments as above, but
- without the last argument; a KBUILD_MODNAME pre-processor directive will be
- inserted in place of 'exp_name' instead.
2. Userspace gets a handle to pass around to potential buffer-users
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 5be225c2ba98..c5a9138a6a8d 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -265,43 +265,40 @@ static inline int is_dma_buf_file(struct file *file)
}
/**
- * dma_buf_export_named - Creates a new dma_buf, and associates an anon file
+ * dma_buf_export - Creates a new dma_buf, and associates an anon file
* with this buffer, so it can be exported.
* Also connect the allocator specific data and ops to the buffer.
* Additionally, provide a name string for exporter; useful in debugging.
*
- * @priv: [in] Attach private data of allocator to this buffer
- * @ops: [in] Attach allocator-defined dma buf ops to the new buffer.
- * @size: [in] Size of the buffer
- * @flags: [in] mode flags for the file.
- * @exp_name: [in] name of the exporting module - useful for debugging.
- * @resv: [in] reservation-object, NULL to allocate default one.
+ * @exp_info: [in] holds all the export related information provided
+ * by the exporter. see struct dma_buf_export_info
+ * for further details.
*
* Returns, on success, a newly created dma_buf object, which wraps the
* supplied private data and operations for dma_buf_ops. On either missing
* ops, or error in allocating struct dma_buf, will return negative error.
*
*/
-struct dma_buf *dma_buf_export_named(void *priv, const struct dma_buf_ops *ops,
- size_t size, int flags, const char *exp_name,
- struct reservation_object *resv)
+struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
{
struct dma_buf *dmabuf;
+ struct reservation_object *resv = exp_info->resv;
struct file *file;
size_t alloc_size = sizeof(struct dma_buf);
- if (!resv)
+ if (!exp_info->resv)
alloc_size += sizeof(struct reservation_object);
else
/* prevent &dma_buf[1] == dma_buf->resv */
alloc_size += 1;
- if (WARN_ON(!priv || !ops
- || !ops->map_dma_buf
- || !ops->unmap_dma_buf
- || !ops->release
- || !ops->kmap_atomic
- || !ops->kmap
- || !ops->mmap)) {
+ if (WARN_ON(!exp_info->priv
+ || !exp_info->ops
+ || !exp_info->ops->map_dma_buf
+ || !exp_info->ops->unmap_dma_buf
+ || !exp_info->ops->release
+ || !exp_info->ops->kmap_atomic
+ || !exp_info->ops->kmap
+ || !exp_info->ops->mmap)) {
return ERR_PTR(-EINVAL);
}
@@ -309,10 +306,10 @@ struct dma_buf *dma_buf_export_named(void *priv, const struct dma_buf_ops *ops,
if (dmabuf == NULL)
return ERR_PTR(-ENOMEM);
- dmabuf->priv = priv;
- dmabuf->ops = ops;
- dmabuf->size = size;
- dmabuf->exp_name = exp_name;
+ dmabuf->priv = exp_info->priv;
+ dmabuf->ops = exp_info->ops;
+ dmabuf->size = exp_info->size;
+ dmabuf->exp_name = exp_info->exp_name;
init_waitqueue_head(&dmabuf->poll);
dmabuf->cb_excl.poll = dmabuf->cb_shared.poll = &dmabuf->poll;
dmabuf->cb_excl.active = dmabuf->cb_shared.active = 0;
@@ -323,7 +320,8 @@ struct dma_buf *dma_buf_export_named(void *priv, const struct dma_buf_ops *ops,
}
dmabuf->resv = resv;
- file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf, flags);
+ file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf,
+ exp_info->flags);
if (IS_ERR(file)) {
kfree(dmabuf);
return ERR_CAST(file);
@@ -341,8 +339,7 @@ struct dma_buf *dma_buf_export_named(void *priv, const struct dma_buf_ops *ops,
return dmabuf;
}
-EXPORT_SYMBOL_GPL(dma_buf_export_named);
-
+EXPORT_SYMBOL_GPL(dma_buf_export);
/**
* dma_buf_fd - returns a file descriptor for the given dma_buf
diff --git a/drivers/gpu/drm/armada/armada_gem.c b/drivers/gpu/drm/armada/armada_gem.c
index ef5feeecec84..580e10acaa3a 100644
--- a/drivers/gpu/drm/armada/armada_gem.c
+++ b/drivers/gpu/drm/armada/armada_gem.c
@@ -538,8 +538,14 @@ struct dma_buf *
armada_gem_prime_export(struct drm_device *dev, struct drm_gem_object *obj,
int flags)
{
- return dma_buf_export(obj, &armada_gem_prime_dmabuf_ops, obj->size,
- O_RDWR, NULL);
+ DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+
+ exp_info.ops = &armada_gem_prime_dmabuf_ops;
+ exp_info.size = obj->size;
+ exp_info.flags = O_RDWR;
+ exp_info.priv = obj;
+
+ return dma_buf_export(&exp_info);
}
struct drm_gem_object *
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 7482b06cd08f..7fec191b45f7 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -339,13 +339,17 @@ static const struct dma_buf_ops drm_gem_prime_dmabuf_ops = {
struct dma_buf *drm_gem_prime_export(struct drm_device *dev,
struct drm_gem_object *obj, int flags)
{
- struct reservation_object *robj = NULL;
+ DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+
+ exp_info.ops = &drm_gem_prime_dmabuf_ops;
+ exp_info.size = obj->size;
+ exp_info.flags = flags;
+ exp_info.priv = obj;
if (dev->driver->gem_prime_res_obj)
- robj = dev->driver->gem_prime_res_obj(obj);
+ exp_info.resv = dev->driver->gem_prime_res_obj(obj);
- return dma_buf_export(obj, &drm_gem_prime_dmabuf_ops, obj->size,
- flags, robj);
+ return dma_buf_export(&exp_info);
}
EXPORT_SYMBOL(drm_gem_prime_export);
diff --git a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
index 3833bf8ca025..cd485c091b30 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
@@ -185,9 +185,14 @@ struct dma_buf *exynos_dmabuf_prime_export(struct drm_device *drm_dev,
struct drm_gem_object *obj, int flags)
{
struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
+ DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
- return dma_buf_export(obj, &exynos_dmabuf_ops,
- exynos_gem_obj->base.size, flags, NULL);
+ exp_info.ops = &exynos_dmabuf_ops;
+ exp_info.size = exynos_gem_obj->base.size;
+ exp_info.flags = flags;
+ exp_info.priv = obj;
+
+ return dma_buf_export(&exp_info);
}
struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev,
diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
index 82a1f4b57778..7998da27c500 100644
--- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
@@ -230,6 +230,13 @@ struct dma_buf *i915_gem_prime_export(struct drm_device *dev,
struct drm_gem_object *gem_obj, int flags)
{
struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
+ DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+
+ exp_info.ops = &i915_dmabuf_ops;
+ exp_info.size = gem_obj->size;
+ exp_info.flags = flags;
+ exp_info.priv = gem_obj;
+
if (obj->ops->dmabuf_export) {
int ret = obj->ops->dmabuf_export(obj);
@@ -237,8 +244,7 @@ struct dma_buf *i915_gem_prime_export(struct drm_device *dev,
return ERR_PTR(ret);
}
- return dma_buf_export(gem_obj, &i915_dmabuf_ops, gem_obj->size, flags,
- NULL);
+ return dma_buf_export(&exp_info);
}
static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
diff --git a/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c b/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c
index b46dabd9faf7..344fd789170d 100644
--- a/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c
+++ b/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c
@@ -171,7 +171,14 @@ static struct dma_buf_ops omap_dmabuf_ops = {
struct dma_buf *omap_gem_prime_export(struct drm_device *dev,
struct drm_gem_object *obj, int flags)
{
- return dma_buf_export(obj, &omap_dmabuf_ops, obj->size, flags, NULL);
+ DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+
+ exp_info.ops = &omap_dmabuf_ops;
+ exp_info.size = obj->size;
+ exp_info.flags = flags;
+ exp_info.priv = obj;
+
+ return dma_buf_export(&exp_info);
}
struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev,
diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c
index cfb481943b6b..1217272a51f2 100644
--- a/drivers/gpu/drm/tegra/gem.c
+++ b/drivers/gpu/drm/tegra/gem.c
@@ -627,8 +627,14 @@ struct dma_buf *tegra_gem_prime_export(struct drm_device *drm,
struct drm_gem_object *gem,
int flags)
{
- return dma_buf_export(gem, &tegra_gem_prime_dmabuf_ops, gem->size,
- flags, NULL);
+ DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+
+ exp_info.ops = &tegra_gem_prime_dmabuf_ops;
+ exp_info.size = gem->size;
+ exp_info.flags = flags;
+ exp_info.priv = gem;
+
+ return dma_buf_export(&exp_info);
}
struct drm_gem_object *tegra_gem_prime_import(struct drm_device *drm,
diff --git a/drivers/gpu/drm/ttm/ttm_object.c b/drivers/gpu/drm/ttm/ttm_object.c
index 12c87110db3a..4f5fa8d65fe9 100644
--- a/drivers/gpu/drm/ttm/ttm_object.c
+++ b/drivers/gpu/drm/ttm/ttm_object.c
@@ -683,6 +683,12 @@ int ttm_prime_handle_to_fd(struct ttm_object_file *tfile,
dma_buf = prime->dma_buf;
if (!dma_buf || !get_dma_buf_unless_doomed(dma_buf)) {
+ DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+
+ exp_info.ops = &tdev->ops;
+ exp_info.size = prime->size;
+ exp_info.flags = flags;
+ exp_info.priv = prime;
/*
* Need to create a new dma_buf, with memory accounting.
@@ -694,8 +700,7 @@ int ttm_prime_handle_to_fd(struct ttm_object_file *tfile,
goto out_unref;
}
- dma_buf = dma_buf_export(prime, &tdev->ops,
- prime->size, flags, NULL);
+ dma_buf = dma_buf_export(&exp_info);
if (IS_ERR(dma_buf)) {
ret = PTR_ERR(dma_buf);
ttm_mem_global_free(tdev->mem_glob,
diff --git a/drivers/gpu/drm/udl/udl_dmabuf.c b/drivers/gpu/drm/udl/udl_dmabuf.c
index ac8a66b4dfc2..e2243edd1ce3 100644
--- a/drivers/gpu/drm/udl/udl_dmabuf.c
+++ b/drivers/gpu/drm/udl/udl_dmabuf.c
@@ -202,7 +202,14 @@ static struct dma_buf_ops udl_dmabuf_ops = {
struct dma_buf *udl_gem_prime_export(struct drm_device *dev,
struct drm_gem_object *obj, int flags)
{
- return dma_buf_export(obj, &udl_dmabuf_ops, obj->size, flags, NULL);
+ DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+
+ exp_info.ops = &udl_dmabuf_ops;
+ exp_info.size = obj->size;
+ exp_info.flags = flags;
+ exp_info.priv = obj;
+
+ return dma_buf_export(&exp_info);
}
static int udl_prime_create(struct drm_device *dev,
diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c
index 69e0483adfee..644dec73d220 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c
@@ -402,6 +402,12 @@ static struct dma_buf *vb2_dc_get_dmabuf(void *buf_priv, unsigned long flags)
{
struct vb2_dc_buf *buf = buf_priv;
struct dma_buf *dbuf;
+ DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+
+ exp_info.ops = &vb2_dc_dmabuf_ops;
+ exp_info.size = buf->size;
+ exp_info.flags = flags;
+ exp_info.priv = buf;
if (!buf->sgt_base)
buf->sgt_base = vb2_dc_get_base_sgt(buf);
@@ -409,7 +415,7 @@ static struct dma_buf *vb2_dc_get_dmabuf(void *buf_priv, unsigned long flags)
if (WARN_ON(!buf->sgt_base))
return NULL;
- dbuf = dma_buf_export(buf, &vb2_dc_dmabuf_ops, buf->size, flags, NULL);
+ dbuf = dma_buf_export(&exp_info);
if (IS_ERR(dbuf))
return NULL;
diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c
index b1838abb6d00..45c708e463b9 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-sg.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c
@@ -583,11 +583,17 @@ 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(buf, &vb2_dma_sg_dmabuf_ops, buf->size, flags, NULL);
+ dbuf = dma_buf_export(&exp_info);
if (IS_ERR(dbuf))
return NULL;
diff --git a/drivers/media/v4l2-core/videobuf2-vmalloc.c b/drivers/media/v4l2-core/videobuf2-vmalloc.c
index bcde88572429..657ab302a5cf 100644
--- a/drivers/media/v4l2-core/videobuf2-vmalloc.c
+++ b/drivers/media/v4l2-core/videobuf2-vmalloc.c
@@ -368,11 +368,17 @@ static struct dma_buf *vb2_vmalloc_get_dmabuf(void *buf_priv, unsigned long flag
{
struct vb2_vmalloc_buf *buf = buf_priv;
struct dma_buf *dbuf;
+ DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+
+ exp_info.ops = &vb2_vmalloc_dmabuf_ops;
+ exp_info.size = buf->size;
+ exp_info.flags = flags;
+ exp_info.priv = buf;
if (WARN_ON(!buf->vaddr))
return NULL;
- dbuf = dma_buf_export(buf, &vb2_vmalloc_dmabuf_ops, buf->size, flags, NULL);
+ dbuf = dma_buf_export(&exp_info);
if (IS_ERR(dbuf))
return NULL;
diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c
index 0e3d8c7add24..b94d69feff46 100644
--- a/drivers/staging/android/ion/ion.c
+++ b/drivers/staging/android/ion/ion.c
@@ -1106,6 +1106,12 @@ struct dma_buf *ion_share_dma_buf(struct ion_client *client,
struct ion_buffer *buffer;
struct dma_buf *dmabuf;
bool valid_handle;
+ DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+
+ exp_info.ops = &dma_buf_ops;
+ exp_info.size = buffer->size;
+ exp_info.flags = O_RDWR;
+ exp_info.priv = buffer;
mutex_lock(&client->lock);
valid_handle = ion_handle_validate(client, handle);
@@ -1118,8 +1124,7 @@ struct dma_buf *ion_share_dma_buf(struct ion_client *client,
ion_buffer_get(buffer);
mutex_unlock(&client->lock);
- dmabuf = dma_buf_export(buffer, &dma_buf_ops, buffer->size, O_RDWR,
- NULL);
+ dmabuf = dma_buf_export(&exp_info);
if (IS_ERR(dmabuf)) {
ion_buffer_put(buffer);
return dmabuf;
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index 694e1fe1c4b4..2f0b431b73e0 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -163,6 +163,33 @@ struct dma_buf_attachment {
};
/**
+ * struct dma_buf_export_info - holds information needed to export a dma_buf
+ * @exp_name: name of the exporting module - useful for debugging.
+ * @ops: Attach allocator-defined dma buf ops to the new buffer
+ * @size: Size of the buffer
+ * @flags: mode flags for the file
+ * @resv: reservation-object, NULL to allocate default one
+ * @priv: Attach private data of allocator to this buffer
+ *
+ * This structure holds the information required to export the buffer. Used
+ * with dma_buf_export() only.
+ */
+struct dma_buf_export_info {
+ const char *exp_name;
+ const struct dma_buf_ops *ops;
+ size_t size;
+ int flags;
+ struct reservation_object *resv;
+ void *priv;
+};
+
+/**
+ * helper macro for exporters; zeros and fills in most common values
+ */
+#define DEFINE_DMA_BUF_EXPORT_INFO(a) \
+ struct dma_buf_export_info a = { .exp_name = KBUILD_MODNAME }
+
+/**
* get_dma_buf - convenience wrapper for get_file.
* @dmabuf: [in] pointer to dma_buf
*
@@ -181,12 +208,7 @@ struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf,
void dma_buf_detach(struct dma_buf *dmabuf,
struct dma_buf_attachment *dmabuf_attach);
-struct dma_buf *dma_buf_export_named(void *priv, const struct dma_buf_ops *ops,
- size_t size, int flags, const char *,
- struct reservation_object *);
-
-#define dma_buf_export(priv, ops, size, flags, resv) \
- dma_buf_export_named(priv, ops, size, flags, KBUILD_MODNAME, resv)
+struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info);
int dma_buf_fd(struct dma_buf *dmabuf, int flags);
struct dma_buf *dma_buf_get(int fd);