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>

13 files changed, 112 insertions, 46 deletions

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);