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>

1 files changed, 28 insertions, 6 deletions

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);