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authorLinus Torvalds <torvalds@linux-foundation.org>2015-04-24 10:05:39 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-24 10:05:39 -0700
commitb3f4ef0bf21da37e4dfc1cdfa0288ba39186fb56 (patch)
tree7239d8ee8302e3bb7ff74d9bc6195ab6bb52295c /Documentation
parentd6a4c0e5d3d433ef296f8f417e835329a834a256 (diff)
parent72449cb47b0104c32ff8fb9380ade9113375d8d1 (diff)
Merge tag 'dma-buf-for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/sumits/dma-buf
Pull dma-buf updates from Sumit Semwal: "Minor cleanup only; this could've gone in for the 4.0 merge window, but for a copy-paste stupidity from me. It has been in the for-next since then, and no issues reported. - cleanup of dma_buf_export() - correction of copy-paste stupidity while doing the cleanup" * tag 'dma-buf-for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/sumits/dma-buf: staging: android: ion: fix wrong init of dma_buf_export_info dma-buf: cleanup dma_buf_export() to make it easily extensible
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/dma-buf-sharing.txt23
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