diff options
Diffstat (limited to 'Documentation/dma-buf-sharing.txt')
-rw-r--r-- | Documentation/dma-buf-sharing.txt | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/Documentation/dma-buf-sharing.txt b/Documentation/dma-buf-sharing.txt index 4966b1be42ac..0b23261561d2 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: | |||
52 | associated with this buffer. | 52 | associated with this buffer. |
53 | 53 | ||
54 | Interface: | 54 | Interface: |
55 | struct dma_buf *dma_buf_export(void *priv, struct dma_buf_ops *ops, | 55 | struct dma_buf *dma_buf_export_named(void *priv, struct dma_buf_ops *ops, |
56 | size_t size, int flags) | 56 | size_t size, int flags, |
57 | const char *exp_name) | ||
57 | 58 | ||
58 | If this succeeds, dma_buf_export allocates a dma_buf structure, and returns a | 59 | If this succeeds, dma_buf_export allocates a dma_buf structure, and returns a |
59 | pointer to the same. It also associates an anonymous file with this buffer, | 60 | pointer to the same. It also associates an anonymous file with this buffer, |
60 | so it can be exported. On failure to allocate the dma_buf object, it returns | 61 | so it can be exported. On failure to allocate the dma_buf object, it returns |
61 | NULL. | 62 | NULL. |
62 | 63 | ||
64 | 'exp_name' is the name of exporter - to facilitate information while | ||
65 | debugging. | ||
66 | |||
67 | Exporting modules which do not wish to provide any specific name may use the | ||
68 | helper define 'dma_buf_export()', with the same arguments as above, but | ||
69 | without the last argument; a __FILE__ pre-processor directive will be | ||
70 | inserted in place of 'exp_name' instead. | ||
71 | |||
63 | 2. Userspace gets a handle to pass around to potential buffer-users | 72 | 2. Userspace gets a handle to pass around to potential buffer-users |
64 | 73 | ||
65 | Userspace entity requests for a file-descriptor (fd) which is a handle to the | 74 | Userspace entity requests for a file-descriptor (fd) which is a handle to the |