Add a warning that this UAPI wasn't such a good idea and shouldn't be
used by anybody.
That should give us a better chance to remove it at some point and
prevents others from running into the same issues.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: T.J. Mercier <tjmercier@google.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220617085702.4298-1-christian.koenig@amd.com
DMA-BUF sysfs statistics are an option of DMA-BUF. It does not make
much sense to bother the user with a question about DMA-BUF sysfs
statistics if DMA-BUF itself is not enabled. Worse, enabling the
statistics enables the feature.
Fixes: bdb8d06dfe ("dmabuf: Add the capability to expose DMA-BUF stats in sysfs")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210902124913.2698760-4-geert@linux-m68k.org
DMA-BUF debug checks are an option of DMA-BUF. Enabling DMABUF_DEBUG
without DMA_SHARED_BUFFER does not have any impact, as drivers/dma-buf/
is not entered during the build when DMA_SHARED_BUFFER is disabled.
Fixes: 84335675f2 ("dma-buf: Add debug option")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210902124913.2698760-3-geert@linux-m68k.org
Move notify between drivers is an option of DMA-BUF. Enabling
DMABUF_MOVE_NOTIFY without DMA_SHARED_BUFFER does not have any impact,
as drivers/dma-buf/ is not entered during the build when
DMA_SHARED_BUFFER is disabled.
Fixes: bb42df4662 ("dma-buf: add dynamic DMA-buf handling v15")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210902124913.2698760-2-geert@linux-m68k.org
Overview
========
The patch adds DMA-BUF statistics to /sys/kernel/dmabuf/buffers. It
allows statistics to be enabled for each DMA-BUF in sysfs by enabling
the config CONFIG_DMABUF_SYSFS_STATS.
The following stats will be exposed by the interface:
/sys/kernel/dmabuf/buffers/<inode_number>/exporter_name
/sys/kernel/dmabuf/buffers/<inode_number>/size
/sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attach_uid>/device
/sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attach_uid>/map_counter
The inode_number is unique for each DMA-BUF and was added earlier [1]
in order to allow userspace to track DMA-BUF usage across different
processes.
Use Cases
=========
The interface provides a way to gather DMA-BUF per-buffer statistics
from production devices. These statistics will be used to derive DMA-BUF
per-exporter stats and per-device usage stats for Android Bug reports.
The corresponding userspace changes can be found at [2].
Telemetry tools will also capture this information(along with other
memory metrics) periodically as well as on important events like a
foreground app kill (which might have been triggered by Low Memory
Killer). It will also contribute to provide a snapshot of the system
memory usage on other events such as OOM kills and Application Not
Responding events.
Background
==========
Currently, there are two existing interfaces that provide information
about DMA-BUFs.
1) /sys/kernel/debug/dma_buf/bufinfo
debugfs is however unsuitable to be mounted in production systems and
cannot be considered as an alternative to the sysfs interface being
proposed.
2) proc/<pid>/fdinfo/<fd>
The proc/<pid>/fdinfo/<fd> files expose information about DMA-BUF fds.
However, the existing procfs interfaces can only provide information
about the buffers for which processes hold fds or have the buffers
mmapped into their address space. Since the procfs interfaces alone
cannot provide a full picture of all DMA-BUFs in the system, there is
the need for an alternate interface to provide this information on
production systems.
The patch contains the following major improvements over v1:
1) Each attachment is represented by its own directory to allow creating
a symlink to the importing device and to also provide room for future
expansion.
2) The number of distinct mappings of each attachment is exposed in a
separate file.
3) The per-buffer statistics are now in /sys/kernel/dmabuf/buffers
inorder to make the interface expandable in future.
All of the improvements above are based on suggestions/feedback from
Daniel Vetter and Christian König.
A shell script that can be run on a classic Linux environment to read
out the DMA-BUF statistics can be found at [3](suggested by John
Stultz).
[1]: https://lore.kernel.org/patchwork/patch/1088791/
[2]: https://android-review.googlesource.com/q/topic:%22dmabuf-sysfs%22+(status:open%20OR%20status:merged)
[3]: https://android-review.googlesource.com/c/platform/system/memory/libmeminfo/+/1549734
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Hridya Valsaraju <hridya@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210603214758.2955251-1-hridya@google.com
We have too many people abusing the struct page they can get at but
really shouldn't in importers. Aside from that the backing page might
simply not exist (for dynamic p2p mappings) looking at it and using it
e.g. for mmap can also wreak the page handling of the exporter
completely. Importers really must go through the proper interface like
dma_buf_mmap for everything.
I'm semi-tempted to enforce this for dynamic importers since those
really have no excuse at all to break the rules.
Unfortuantely we can't store the right pointers somewhere safe to make
sure we oops on something recognizable, so best is to just wrangle
them a bit by flipping all the bits. At least on x86 kernel addresses
have all their high bits sets and the struct page array is fairly low
in the kernel mapping, so flipping all the bits gives us a very high
pointer in userspace and hence excellent chances for an invalid
dereference.
v2: Add a note to the @map_dma_buf hook that exporters shouldn't do
fancy caching tricks, which would blow up with this address scrambling
trick here (Chris)
Enable by default when CONFIG_DMA_API_DEBUG is enabled.
v3: Only one copy of the mangle/unmangle code (Christian)
v4: #ifdef, not #if (0day)
v5: sg_table can also be an ERR_PTR (Chris, Christian)
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: David Stevens <stevensd@chromium.org>
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Link: https://patchwork.freedesktop.org/patch/msgid/20210115164739.3958206-1-daniel.vetter@ffwll.ch
Since commit 84af7a6194 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.
This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.
There are a variety of indentation styles found.
a) 4 spaces + '---help---'
b) 7 spaces + '---help---'
c) 8 spaces + '---help---'
d) 1 space + 1 tab + '---help---'
e) 1 tab + '---help---' (correct indentation)
f) 1 tab + 1 space + '---help---'
g) 1 tab + 2 spaces + '---help---'
In order to convert all of them to 1 tab + 'help', I ran the
following commend:
$ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Improve the help text for the CONFIG_DMABUF_MOVE_NOTIFY symbol by:
1. Removing duplicated single quotes,
2. Adding a missing subject,
3. Fixing a misspelling of "yet",
4. Wrapping long lines.
Fixes: bb42df4662 ("dma-buf: add dynamic DMA-buf handling v15")
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200324125442.21983-1-geert+renesas@glider.be
On the exporter side we add optional explicit pinning callbacks. Which are
called when the importer doesn't implement dynamic handling, move notification
or need the DMA-buf locked in place for its use case.
On the importer side we add an optional move_notify callback. This callback is
used by the exporter to inform the importers that their mappings should be
destroyed as soon as possible.
This allows the exporter to provide the mappings without the need to pin
the backing store.
v2: don't try to invalidate mappings when the callback is NULL,
lock the reservation obj while using the attachments,
add helper to set the callback
v3: move flag for invalidation support into the DMA-buf,
use new attach_info structure to set the callback
v4: use importer_priv field instead of mangling exporter priv.
v5: drop invalidation_supported flag
v6: squash together with pin/unpin changes
v7: pin/unpin takes an attachment now
v8: nuke dma_buf_attachment_(map|unmap)_locked,
everything is now handled backward compatible
v9: always cache when export/importer don't agree on dynamic handling
v10: minimal style cleanup
v11: drop automatically re-entry avoidance
v12: rename callback to move_notify
v13: add might_lock in appropriate places
v14: rebase on separated locking change
v15: add EXPERIMENTAL flag, some more code comments
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/353993/?series=73646&rev=1
This patch adds system heap to the dma-buf heaps framework.
This allows applications to get a page-allocator backed dma-buf
for non-contiguous memory.
This code is an evolution of the Android ION implementation, so
thanks to its original authors and maintainters:
Rebecca Schultz Zavin, Colin Cross, Laura Abbott, and others!
Cc: Laura Abbott <labbott@redhat.com>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Pratik Patel <pratikp@codeaurora.org>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
Cc: Sudipto Paul <Sudipto.Paul@arm.com>
Cc: Andrew F. Davis <afd@ti.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chenbo Feng <fengc@google.com>
Cc: Alistair Strachan <astrachan@google.com>
Cc: Hridya Valsaraju <hridya@google.com>
Cc: Sandeep Patil <sspatil@google.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Reviewed-by: Brian Starkey <brian.starkey@arm.com>
Acked-by: Sandeep Patil <sspatil@android.com>
Acked-by: Laura Abbott <labbott@redhat.com>
Tested-by: Ayan Kumar Halder <ayan.halder@arm.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191203172641.66642-4-john.stultz@linaro.org
This framework allows a unified userspace interface for dma-buf
exporters, allowing userland to allocate specific types of memory
for use in dma-buf sharing.
Each heap is given its own device node, which a user can allocate
a dma-buf fd from using the DMA_HEAP_IOC_ALLOC.
This code is an evoluiton of the Android ION implementation,
and a big thanks is due to its authors/maintainers over time
for their effort:
Rebecca Schultz Zavin, Colin Cross, Benjamin Gaignard,
Laura Abbott, and many other contributors!
Cc: Laura Abbott <labbott@redhat.com>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Pratik Patel <pratikp@codeaurora.org>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
Cc: Sudipto Paul <Sudipto.Paul@arm.com>
Cc: Andrew F. Davis <afd@ti.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chenbo Feng <fengc@google.com>
Cc: Alistair Strachan <astrachan@google.com>
Cc: Hridya Valsaraju <hridya@google.com>
Cc: Sandeep Patil <sspatil@google.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Brian Starkey <brian.starkey@arm.com>
Acked-by: Sandeep Patil <sspatil@android.com>
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191203172641.66642-2-john.stultz@linaro.org
This reverts commit a69b0e855d.
This patchset doesn't meet the UAPI requirements set out in [1] for the DRM
subsystem. Once the userspace component is reviewed and ready for merge
we can try again.
[1]- https://01.org/linuxgraphics/gfx-docs/drm/gpu/drm-uapi.html#open-source-userspace-requirements
Fixes: a69b0e855d ("dma-buf: Add dma-buf heaps framework")
Cc: Laura Abbott <labbott@redhat.com>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Pratik Patel <pratikp@codeaurora.org>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
Cc: Sudipto Paul <Sudipto.Paul@arm.com>
Cc: Andrew F. Davis <afd@ti.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chenbo Feng <fengc@google.com>
Cc: Alistair Strachan <astrachan@google.com>
Cc: Hridya Valsaraju <hridya@google.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: dri-devel@lists.freedesktop.org
Cc: Brian Starkey <brian.starkey@arm.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: "Paul E. McKenney" <paulmck@linux.ibm.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: "Andrew F. Davis" <afd@ti.com>
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Acked-by: David Airlie <airlied@linux.ie>
Signed-off-by: Sean Paul <sean@poorly.run>
Link: https://patchwork.freedesktop.org/patch/msgid/20191030203003.101156-6-sean@poorly.run
This reverts commit 47a32f9c12.
This patchset doesn't meet the UAPI requirements set out in [1] for the DRM
subsystem. Once the userspace component is reviewed and ready for merge
we can try again.
[1]- https://01.org/linuxgraphics/gfx-docs/drm/gpu/drm-uapi.html#open-source-userspace-requirements
Fixes: 47a32f9c12 ("dma-buf: heaps: Add system heap to dmabuf heaps")
Cc: Laura Abbott <labbott@redhat.com>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Pratik Patel <pratikp@codeaurora.org>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
Cc: Sudipto Paul <Sudipto.Paul@arm.com>
Cc: Andrew F. Davis <afd@ti.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chenbo Feng <fengc@google.com>
Cc: Alistair Strachan <astrachan@google.com>
Cc: Hridya Valsaraju <hridya@google.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: dri-devel@lists.freedesktop.org
Cc: Brian Starkey <brian.starkey@arm.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: "Andrew F. Davis" <afd@ti.com>
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Acked-by: David Airlie <airlied@linux.ie>
Signed-off-by: Sean Paul <sean@poorly.run>
Link: https://patchwork.freedesktop.org/patch/msgid/20191030203003.101156-4-sean@poorly.run
This patch adds system heap to the dma-buf heaps framework.
This allows applications to get a page-allocator backed dma-buf
for non-contiguous memory.
This code is an evolution of the Android ION implementation, so
thanks to its original authors and maintainters:
Rebecca Schultz Zavin, Colin Cross, Laura Abbott, and others!
Cc: Laura Abbott <labbott@redhat.com>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Pratik Patel <pratikp@codeaurora.org>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
Cc: Sudipto Paul <Sudipto.Paul@arm.com>
Cc: Andrew F. Davis <afd@ti.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chenbo Feng <fengc@google.com>
Cc: Alistair Strachan <astrachan@google.com>
Cc: Hridya Valsaraju <hridya@google.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Reviewed-by: Brian Starkey <brian.starkey@arm.com>
Acked-by: Laura Abbott <labbott@redhat.com>
Tested-by: Ayan Kumar Halder <ayan.halder@arm.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191021190310.85221-4-john.stultz@linaro.org
This framework allows a unified userspace interface for dma-buf
exporters, allowing userland to allocate specific types of memory
for use in dma-buf sharing.
Each heap is given its own device node, which a user can allocate
a dma-buf fd from using the DMA_HEAP_IOC_ALLOC.
This code is an evoluiton of the Android ION implementation,
and a big thanks is due to its authors/maintainers over time
for their effort:
Rebecca Schultz Zavin, Colin Cross, Benjamin Gaignard,
Laura Abbott, and many other contributors!
Cc: Laura Abbott <labbott@redhat.com>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Pratik Patel <pratikp@codeaurora.org>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
Cc: Sudipto Paul <Sudipto.Paul@arm.com>
Cc: Andrew F. Davis <afd@ti.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chenbo Feng <fengc@google.com>
Cc: Alistair Strachan <astrachan@google.com>
Cc: Hridya Valsaraju <hridya@google.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Reviewed-by: Brian Starkey <brian.starkey@arm.com>
Acked-by: Laura Abbott <labbott@redhat.com>
Tested-by: Ayan Kumar Halder <ayan.halder@arm.com>
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191021190310.85221-2-john.stultz@linaro.org
In light of recent review slip ups, the absence of a suite of tests for
dma-buf became apparent. Given the current plethora of testing
frameworks, opt for one already in use by Intel's CI and so allow easy
hook up into igt.
We introduce a new module that when loaded will execute the list of
selftests and their subtest. The names of the selftests are put into the
modinfo as parameters so that igt can identify each, and run them
independently, principally for ease of error reporting.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Tomi Sarvela <tomi.p.sarvela@intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190819095928.32091-1-chris@chris-wilson.co.uk
There are lots of documents under Documentation/*.txt and a few other
orphan documents elsehwere that belong to the driver-API book.
Move them to their right place.
Reviewed-by: Cornelia Huck <cohuck@redhat.com> # vfio-related parts
Acked-by: Logan Gunthorpe <logang@deltatee.com> # switchtec
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Add SPDX license identifiers to all Make/Kconfig files which:
- Have no license information of any form
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make the anon_inodes facility unconditional so that it can be used by core
VFS code and pidfd code.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[christian@brauner.io: adapt commit message to mention pidfds]
Signed-off-by: Christian Brauner <christian@brauner.io>
udmabuf builds without it, but if userspace can not create memfd
handles in the first place it is rather pointless to include it,
except for test builds.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20180911134216.9760-7-kraxel@redhat.com
A driver to let userspace turn memfd regions into dma-bufs.
Use case: Allows qemu create dmabufs for the vga framebuffer or
virtio-gpu ressources. Then they can be passed around to display
those guest things on the host. To spice client for classic full
framebuffer display, and hopefully some day to wayland server for
seamless guest window display.
qemu test branch:
https://git.kraxel.org/cgit/qemu/log/?h=sirius/udmabuf
Cc: David Airlie <airlied@linux.ie>
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20180827093444.23623-1-kraxel@redhat.com
SW_SYNC allows to run tests on the sync_file framework via debugfs on
<debugfs>/sync/sw_sync
Opening and closing the file triggers creation and release of a sync
timeline. To create fences on this timeline the SW_SYNC_IOC_CREATE_FENCE
ioctl should be used. To increment the timeline value use SW_SYNC_IOC_INC.
Also it exports Sync information on
<debugfs>/sync/info
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We've got a complaint saying that the description was quite obtuse and
indeed it was. This patch tries to improve it.
Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
sync_file is useful to connect one or more fences to the file. The file is
used by userspace to track fences between drivers that share DMA bufs.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Christian König