linux-toradex.git/Documentation/dma-buf-sharing.txt, branch v4.1.23

dma-buf: cleanup dma_buf_export() to make it easily extensible

2015-04-21T09:17:16+00:00

At present, dma_buf_export() takes a series of parameters, which
makes it difficult to add any new parameters for exporters, if required.

Make it simpler by moving all these parameters into a struct, and pass
the struct * as parameter to dma_buf_export().

While at it, unite dma_buf_export_named() with dma_buf_export(), and
change all callers accordingly.

Reviewed-by: Maarten Lankhorst 
Reviewed-by: Daniel Thompson 
Acked-by: Mauro Carvalho Chehab 
Acked-by: Dave Airlie 
Signed-off-by: Sumit Semwal

Documentation/dma-buf-sharing.txt: update API descriptions

2014-08-28T06:27:24+00:00

Update some descriptions for API arguments and descriptions.

Signed-off-by: Gioh Kim 
Signed-off-by: Sumit Semwal

doc: spelling error changes

2014-05-05T13:32:05+00:00

Fixed multiple spelling errors.

Acked-by: Randy Dunlap 
Signed-off-by: Carlos E. Garcia 
Signed-off-by: Jiri Kosina

dma-buf: update exp_name when using dma_buf_export()

2014-05-05T13:28:05+00:00

commit c0b00a5 ("dma-buf: update debugfs output") modified the
default exporter name to be the KBUILD_MODNAME pre-processor
macro instead of __FILE__ but the documentation was not updated.

Also the "Supporting existing mmap interfaces in exporters" section
title seems wrong since talks about the interface used by importers.

Signed-off-by: Javier Martinez Canillas 
Reviewed-by: Daniel Vetter 
Signed-off-by: Jiri Kosina

dma-buf: Expose buffer size to userspace (v2)

2013-09-10T06:06:45+00:00

Each dma-buf has an associated size and it's reasonable for userspace
to want to know what it is.

Since userspace already has an fd, expose the size using the
size = lseek(fd, SEEK_END, 0); lseek(fd, SEEK_CUR, 0);
idiom.

v2: Added Daniel's sugeested documentation, with minor fixups

Signed-off-by: Christopher James Halse Rogers 
Reviewed-by: Daniel Vetter 
Tested-by: Daniel Vetter 
Signed-off-by: Sumit Semwal

doc: Fix typo in doucmentations

2013-07-25T10:34:15+00:00

Correct typo (double words) in documentations.

Signed-off-by: Masanari Iida 
Acked-by: Randy Dunlap 
Signed-off-by: Jiri Kosina

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

2013-05-01T11:05:36+00:00

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

dma-buf: implement vmap refcounting in the interface logic

2013-02-27T09:43:36+00:00

All drivers which implement this need to have some sort of refcount to
allow concurrent vmap usage. Hence implement this in the dma-buf core.

To protect against concurrent calls we need a lock, which potentially
causes new funny locking inversions. But this shouldn't be a problem
for exporters with statically allocated backing storage, and more
dynamic drivers have decent issues already anyway.

Inspired by some refactoring patches from Aaron Plattner, who
implemented the same idea, but only for drm/prime drivers.

v2: Check in dma_buf_release that no dangling vmaps are left.
Suggested by Aaron Plattner. We might want to do similar checks for
attachments, but that's for another patch. Also fix up ERR_PTR return
for vmap.

v3: Check whether the passed-in vmap address matches with the cached
one for vunmap. Eventually we might want to remove that parameter -
compared to the kmap functions there's no need for the vaddr for
unmapping.  Suggested by Chris Wilson.

v4: Fix a brown-paper-bag bug spotted by Aaron Plattner.

Cc: Aaron Plattner 
Reviewed-by: Aaron Plattner 
Tested-by: Aaron Plattner 
Reviewed-by: Rob Clark 
Signed-off-by: Daniel Vetter 
Signed-off-by: Sumit Semwal

doc: fix quite a few typos within Documentation

2012-11-19T13:28:24+00:00

Correct spelling typo in Documentations

Signed-off-by: Jiri Kosina

dma-buf: add initial vmap documentation

2012-05-25T07:21:11+00:00

Signed-off-by: Dave Airlie 
Signed-off-by: Sumit Semwal