[PATCH v3 1/2] dma-buf: replace dma_buf_export() with dma_buf_export_named()

2013-04-04 Thread Sumit Semwal
For debugging purposes, it is useful to have a name-string added
while exporting buffers. Hence, dma_buf_export() is replaced with
dma_buf_export_named(), which additionally takes 'exp_name' as a
parameter.

For backward compatibility, and for lazy exporters who don't wish to
name themselves, a #define dma_buf_export() is also made available,
which adds a __FILE__ instead of 'exp_name'.

Cc: Daniel Vetter 
  [Thanks for the idea!]
Reviewed-by: Daniel Vetter 
Signed-off-by: Sumit Semwal 
---
 Documentation/dma-buf-sharing.txt |   13 +++--
 drivers/base/dma-buf.c|   11 +++
 include/linux/dma-buf.h   |   11 +--
 3 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/Documentation/dma-buf-sharing.txt 
b/Documentation/dma-buf-sharing.txt
index 4966b1b..0b23261 100644
--- a/Documentation/dma-buf-sharing.txt
+++ b/Documentation/dma-buf-sharing.txt
@@ -52,14 +52,23 @@ The dma_buf buffer sharing API usage contains the following 
steps:
associated with this buffer.

Interface:
-  struct dma_buf *dma_buf_export(void *priv, struct dma_buf_ops *ops,
-size_t size, int flags)
+  struct dma_buf *dma_buf_export_named(void *priv, struct dma_buf_ops *ops,
+size_t size, int flags,
+const char *exp_name)

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.
+
+   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 __FILE__ pre-processor directive will be
+   inserted in place of 'exp_name' instead.
+
 2. Userspace gets a handle to pass around to potential buffer-users

Userspace entity requests for a file-descriptor (fd) which is a handle to 
the
diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c
index 2a7cb0d..d89102a 100644
--- a/drivers/base/dma-buf.c
+++ b/drivers/base/dma-buf.c
@@ -77,22 +77,24 @@ static inline int is_dma_buf_file(struct file *file)
 }

 /**
- * dma_buf_export - Creates a new dma_buf, and associates an anon file
+ * dma_buf_export_named - 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.
  *
  * 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(void *priv, const struct dma_buf_ops *ops,
-   size_t size, int flags)
+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 dma_buf *dmabuf;
struct file *file;
@@ -114,6 +116,7 @@ struct dma_buf *dma_buf_export(void *priv, const struct 
dma_buf_ops *ops,
dmabuf->priv = priv;
dmabuf->ops = ops;
dmabuf->size = size;
+   dmabuf->exp_name = exp_name;

file = anon_inode_getfile("dmabuf", _buf_fops, dmabuf, flags);

@@ -124,7 +127,7 @@ struct dma_buf *dma_buf_export(void *priv, const struct 
dma_buf_ops *ops,

return dmabuf;
 }
-EXPORT_SYMBOL_GPL(dma_buf_export);
+EXPORT_SYMBOL_GPL(dma_buf_export_named);


 /**
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index 9978b61..6f55c04 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -112,6 +112,7 @@ struct dma_buf_ops {
  * @file: file pointer used for sharing buffers across, and for refcounting.
  * @attachments: list of dma_buf_attachment that denotes all devices attached.
  * @ops: dma_buf_ops associated with this buffer object.
+ * @exp_name: name of the exporter; useful for debugging.
  * @priv: exporter specific private data for this buffer object.
  */
 struct dma_buf {
@@ -123,6 +124,7 @@ struct dma_buf {
struct mutex lock;
unsigned vmapping_counter;
void *vmap_ptr;
+   const char *exp_name;
void *priv;
 };

@@ -162,8 +164,13 @@ struct dma_buf_attachment *dma_buf_attach(struct dma_buf 
*dmabuf,
 

[PATCH v3 1/2] dma-buf: replace dma_buf_export() with dma_buf_export_named()

2013-04-04 Thread Sumit Semwal
For debugging purposes, it is useful to have a name-string added
while exporting buffers. Hence, dma_buf_export() is replaced with
dma_buf_export_named(), which additionally takes 'exp_name' as a
parameter.

For backward compatibility, and for lazy exporters who don't wish to
name themselves, a #define dma_buf_export() is also made available,
which adds a __FILE__ instead of 'exp_name'.

Cc: Daniel Vetter daniel.vet...@ffwll.ch
  [Thanks for the idea!]
Reviewed-by: Daniel Vetter daniel.vet...@ffwll.ch
Signed-off-by: Sumit Semwal sumit.sem...@linaro.org
---
 Documentation/dma-buf-sharing.txt |   13 +++--
 drivers/base/dma-buf.c|   11 +++
 include/linux/dma-buf.h   |   11 +--
 3 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/Documentation/dma-buf-sharing.txt 
b/Documentation/dma-buf-sharing.txt
index 4966b1b..0b23261 100644
--- a/Documentation/dma-buf-sharing.txt
+++ b/Documentation/dma-buf-sharing.txt
@@ -52,14 +52,23 @@ The dma_buf buffer sharing API usage contains the following 
steps:
associated with this buffer.
 
Interface:
-  struct dma_buf *dma_buf_export(void *priv, struct dma_buf_ops *ops,
-size_t size, int flags)
+  struct dma_buf *dma_buf_export_named(void *priv, struct dma_buf_ops *ops,
+size_t size, int flags,
+const char *exp_name)
 
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.
+
+   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 __FILE__ pre-processor directive will be
+   inserted in place of 'exp_name' instead.
+
 2. Userspace gets a handle to pass around to potential buffer-users
 
Userspace entity requests for a file-descriptor (fd) which is a handle to 
the
diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c
index 2a7cb0d..d89102a 100644
--- a/drivers/base/dma-buf.c
+++ b/drivers/base/dma-buf.c
@@ -77,22 +77,24 @@ static inline int is_dma_buf_file(struct file *file)
 }
 
 /**
- * dma_buf_export - Creates a new dma_buf, and associates an anon file
+ * dma_buf_export_named - 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.
  *
  * 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(void *priv, const struct dma_buf_ops *ops,
-   size_t size, int flags)
+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 dma_buf *dmabuf;
struct file *file;
@@ -114,6 +116,7 @@ struct dma_buf *dma_buf_export(void *priv, const struct 
dma_buf_ops *ops,
dmabuf-priv = priv;
dmabuf-ops = ops;
dmabuf-size = size;
+   dmabuf-exp_name = exp_name;
 
file = anon_inode_getfile(dmabuf, dma_buf_fops, dmabuf, flags);
 
@@ -124,7 +127,7 @@ struct dma_buf *dma_buf_export(void *priv, const struct 
dma_buf_ops *ops,
 
return dmabuf;
 }
-EXPORT_SYMBOL_GPL(dma_buf_export);
+EXPORT_SYMBOL_GPL(dma_buf_export_named);
 
 
 /**
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index 9978b61..6f55c04 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -112,6 +112,7 @@ struct dma_buf_ops {
  * @file: file pointer used for sharing buffers across, and for refcounting.
  * @attachments: list of dma_buf_attachment that denotes all devices attached.
  * @ops: dma_buf_ops associated with this buffer object.
+ * @exp_name: name of the exporter; useful for debugging.
  * @priv: exporter specific private data for this buffer object.
  */
 struct dma_buf {
@@ -123,6 +124,7 @@ struct dma_buf {
struct mutex lock;
unsigned vmapping_counter;
void *vmap_ptr;
+   const char *exp_name;
void *priv;
 };
 
@@ -162,8 +164,13 @@ struct dma_buf_attachment