dma-buf: replace dma_buf_export() with dma_buf_export_named()

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.vetter@ffwll.ch>
  [Thanks for the idea!]
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
This commit is contained in:
Sumit Semwal 2013-03-22 18:22:16 +05:30
parent 5f56886521
commit 78df969550
3 changed files with 27 additions and 8 deletions

View File

@ -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

View File

@ -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);
/**

View File

@ -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,
struct device *dev);
void dma_buf_detach(struct dma_buf *dmabuf,
struct dma_buf_attachment *dmabuf_attach);
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 *);
#define dma_buf_export(priv, ops, size, flags) \
dma_buf_export_named(priv, ops, size, flags, __FILE__)
int dma_buf_fd(struct dma_buf *dmabuf, int flags);
struct dma_buf *dma_buf_get(int fd);
void dma_buf_put(struct dma_buf *dmabuf);