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* Merge branch 'for-linus-3.4' of ↵Linus Torvalds2012-03-281-10/+87
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.linaro.org/people/sumitsemwal/linux-dma-buf Pull dma-buf updates from Sumit Semwal: "This includes the following key items: - kernel cpu access support, - flag-passing to dma_buf_fd, - relevant Documentation updates, and - some minor cleanups and fixes. These changes are needed for the drm prime/dma-buf interface code that Dave Airlie plans to submit in this merge window." * 'for-linus-3.4' of git://git.linaro.org/people/sumitsemwal/linux-dma-buf: dma-buf: correct dummy function declarations. dma-buf: document fd flags and O_CLOEXEC requirement dma_buf: Add documentation for the new cpu access support dma-buf: add support for kernel cpu access dma-buf: don't hold the mutex around map/unmap calls dma-buf: add get_dma_buf() dma-buf: pass flags into dma_buf_fd. dma-buf: add dma_data_direction to unmap dma_buf_op dma-buf: Move code out of mutex-protected section in dma_buf_attach() dma-buf: Return error instead of using a goto statement when possible dma-buf: Remove unneeded sanity checks dma-buf: Constify ops argument to dma_buf_export()
| * dma-buf: correct dummy function declarations.Sumit Semwal2012-03-261-13/+14
| | | | | | | | | | | | | | | | | | | | Dummy functions for the newly added cpu access ops need variable names for arguments. Also, the introduction of flags in dma_buf_fd needs to be added to dummy functions as well. Signed-off-by: Sumit Semwal <sumit.semwal@ti.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
| * dma-buf: add support for kernel cpu accessDaniel Vetter2012-03-261-0/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Big differences to other contenders in the field (like ion) is that this also supports highmem, so we have to split up the cpu access from the kernel side into a prepare and a kmap step. Prepare is allowed to fail and should do everything required so that the kmap calls can succeed (like swapin/backing storage allocation, flushing, ...). More in-depth explanations will follow in the follow-up documentation patch. Changes in v2: - Clear up begin_cpu_access confusion noticed by Sumit Semwal. - Don't automatically fallback from the _atomic variants to the non-atomic variants. The _atomic callbacks are not allowed to sleep, so we want exporters to make this decision explicit. The function signatures are explicit, so simpler exporters can still use the same function for both. - Make the unmap functions optional. Simpler exporters with permanent mappings don't need to do anything at unmap time. Changes in v3: - Adjust the WARN_ON checks for the new ->ops functions as suggested by Rob Clark and Sumit Semwal. - Rebased on top of latest dma-buf-next git. Changes in v4: - Fixup a missing - in a return -EINVAL; statement. Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Rob Clark <rob@ti.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
| * dma-buf: don't hold the mutex around map/unmap callsDaniel Vetter2012-03-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The mutex protects the attachment list and hence needs to be held around the callbakc to the exporters (optional) attach/detach functions. Holding the mutex around the map/unmap calls doesn't protect any dma_buf state. Exporters need to properly protect any of their own state anyway (to protect against calls from their own interfaces). So this only makes the locking messier (and lockdep easier to anger). Therefore let's just drop this. v2: Rebased on top of latest dma-buf-next git. Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Rob Clark <rob.clark@linaro.org> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
| * dma-buf: add get_dma_buf()Rob Clark2012-03-261-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | Works in a similar way to get_file(), and is needed in cases such as when the exporter needs to also keep a reference to the dmabuf (that is later released with a dma_buf_put()), and possibly other similar cases. Signed-off-by: Rob Clark <rob@ti.com> Reviewed-by: Dave Airlie <airlied@redhat.com> Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
| * dma-buf: pass flags into dma_buf_fd.Dave Airlie2012-03-261-1/+1
| | | | | | | | | | | | | | | | | | We need to pass the flags into dma_buf_fd at this point, so the flags end up doing the right thing for O_CLOEXEC. Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Rob Clark <rob@ti.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
| * dma-buf: add dma_data_direction to unmap dma_buf_opSumit Semwal2012-03-261-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | Some exporters may use DMA map/unmap APIs in dma-buf ops, which require enum dma_data_direction for both map and unmap operations. Thus, the unmap dma_buf_op also needs to have enum dma_data_direction as a parameter. Reported-by: Tomasz Stanislawski <t.stanislaws@samsung.com> Signed-off-by: Sumit Semwal <sumit.semwal@ti.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
| * dma-buf: Constify ops argument to dma_buf_export()Laurent Pinchart2012-03-191-4/+4
| | | | | | | | | | | | | | | | This allows drivers to make the dma buf operations structure constant. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
* | device.h: audit and cleanup users in main include dirPaul Gortmaker2012-03-161-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The <linux/device.h> header includes a lot of stuff, and it in turn gets a lot of use just for the basic "struct device" which appears so often. Clean up the users as follows: 1) For those headers only needing "struct device" as a pointer in fcn args, replace the include with exactly that. 2) For headers not really using anything from device.h, simply delete the include altogether. 3) For headers relying on getting device.h implicitly before being included themselves, now explicitly include device.h 4) For files in which doing #1 or #2 uncovers an implicit dependency on some other header, fix by explicitly adding the required header(s). Any C files that were implicitly relying on device.h to be present have already been dealt with in advance. Total removals from #1 and #2: 51. Total additions coming from #3: 9. Total other implicit dependencies from #4: 7. As of 3.3-rc1, there were 110, so a net removal of 42 gives about a 38% reduction in device.h presence in include/* Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* dma-buf: Introduce dma buffer sharing mechanismSumit Semwal2012-01-061-0/+176
This is the first step in defining a dma buffer sharing mechanism. A new buffer object dma_buf is added, with operations and API to allow easy sharing of this buffer object across devices. The framework allows: - creation of a buffer object, its association with a file pointer, and associated allocator-defined operations on that buffer. This operation is called the 'export' operation. - different devices to 'attach' themselves to this exported buffer object, to facilitate backing storage negotiation, using dma_buf_attach() API. - the exported buffer object to be shared with the other entity by asking for its 'file-descriptor (fd)', and sharing the fd across. - a received fd to get the buffer object back, where it can be accessed using the associated exporter-defined operations. - the exporter and user to share the scatterlist associated with this buffer object using map_dma_buf and unmap_dma_buf operations. Atleast one 'attach()' call is required to be made prior to calling the map_dma_buf() operation. Couple of building blocks in map_dma_buf() are added to ease introduction of sync'ing across exporter and users, and late allocation by the exporter. For this first version, this framework will work with certain conditions: - *ONLY* exporter will be allowed to mmap to userspace (outside of this framework - mmap is not a buffer object operation), - currently, *ONLY* users that do not need CPU access to the buffer are allowed. More details are there in the documentation patch. This is based on design suggestions from many people at the mini-summits[1], most notably from Arnd Bergmann <arnd@arndb.de>, Rob Clark <rob@ti.com> and Daniel Vetter <daniel@ffwll.ch>. The implementation is inspired from proof-of-concept patch-set from Tomasz Stanislawski <t.stanislaws@samsung.com>, who demonstrated buffer sharing between two v4l2 devices. [2] [1]: https://wiki.linaro.org/OfficeofCTO/MemoryManagement [2]: http://lwn.net/Articles/454389 Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Signed-off-by: Sumit Semwal <sumit.semwal@ti.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Dave Airlie <airlied@redhat.com> Reviewed-and-Tested-by: Rob Clark <rob.clark@linaro.org> Signed-off-by: Dave Airlie <airlied@redhat.com>
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