diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/dma-buf-sharing.txt | 23 |
1 files changed, 12 insertions, 11 deletions
diff --git a/Documentation/dma-buf-sharing.txt b/Documentation/dma-buf-sharing.txt index bb9753b635a3..480c8de3c2c4 100644 --- a/Documentation/dma-buf-sharing.txt +++ b/Documentation/dma-buf-sharing.txt @@ -49,25 +49,26 @@ The dma_buf buffer sharing API usage contains the following steps: The buffer exporter announces its wish to export a buffer. In this, it connects its own private buffer data, provides implementation for operations that can be performed on the exported dma_buf, and flags for the file - associated with this buffer. + associated with this buffer. All these fields are filled in struct + dma_buf_export_info, defined via the DEFINE_DMA_BUF_EXPORT_INFO macro. Interface: - struct dma_buf *dma_buf_export_named(void *priv, struct dma_buf_ops *ops, - size_t size, int flags, - const char *exp_name) + DEFINE_DMA_BUF_EXPORT_INFO(exp_info) + struct dma_buf *dma_buf_export(struct dma_buf_export_info *exp_info) - If this succeeds, dma_buf_export_named allocates a dma_buf structure, and + 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. + 'exp_name' in struct dma_buf_export_info is the name of exporter - to + facilitate information while debugging. It is set to KBUILD_MODNAME by + default, so exporters don't have to provide a specific name, if they don't + wish to. + + DEFINE_DMA_BUF_EXPORT_INFO macro defines the struct dma_buf_export_info, + zeroes it out and pre-populates exp_name in it. - 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 KBUILD_MODNAME pre-processor directive will be - inserted in place of 'exp_name' instead. 2. Userspace gets a handle to pass around to potential buffer-users |