sync_file_ioctl_fence_info has a race between filling the status
of the underlying fences and the overall status of the sync_file.
If fence transitions in the time frame between its sync_fill_fence_info
and the later dma_fence_is_signaled for the sync_file, the returned
information is inconsistent showing non-signaled underlying fences but
an overall signaled state.

This patch changes sync_file_ioctl_fence_info to track what has been
encoded and using that as the overall sync_file status.
Tested-by: NVamsidhar Reddy Gaddam <vamsidhar.gaddam@arm.com>
Signed-off-by: NJohn Einar Reitan <john.reitan@arm.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171009134936.27219-1-john.reitan@arm.com

Up until recently sync_file were create to export a single dma-fence to
userspace, and so we could canabalise a bit insie dma-fence to mark
whether or not we had enable polling for the sync_file itself. However,
with the advent of syncobj, we do allow userspace to create multiple
sync_files for a single dma-fence. (Similarly, that the sw-sync
validation framework also started returning multiple sync-files wrapping
a single dma-fence for a syncpt also triggering the problem.)

This patch reverts my suggestion in commit e2416553
("dma-buf/sync_file: only enable fence signalling on poll()") to use a
single bit in the shared dma-fence and restores the sync_file->flags for
tracking the bits individually.
Reported-by: NGustavo Padovan <gustavo.padovan@collabora.com>
Fixes: f1e8c671 ("dma-buf/sw-sync: Use an rbtree to sort fences in the timeline")
Fixes: e9083420 ("drm: introduce sync objects (v4)")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: dri-devel@lists.freedesktop.org
Cc: <drm-intel-fixes@lists.freedesktop.org> # v4.13-rc1+
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170728212951.7818-1-chris@chris-wilson.co.uk
(cherry picked from commit db1fc97c)

Up until recently sync_file were create to export a single dma-fence to
userspace, and so we could canabalise a bit insie dma-fence to mark
whether or not we had enable polling for the sync_file itself. However,
with the advent of syncobj, we do allow userspace to create multiple
sync_files for a single dma-fence. (Similarly, that the sw-sync
validation framework also started returning multiple sync-files wrapping
a single dma-fence for a syncpt also triggering the problem.)

This patch reverts my suggestion in commit e2416553
("dma-buf/sync_file: only enable fence signalling on poll()") to use a
single bit in the shared dma-fence and restores the sync_file->flags for
tracking the bits individually.
Reported-by: NGustavo Padovan <gustavo.padovan@collabora.com>
Fixes: f1e8c671 ("dma-buf/sw-sync: Use an rbtree to sort fences in the timeline")
Fixes: e9083420 ("drm: introduce sync objects (v4)")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: dri-devel@lists.freedesktop.org
Cc: <drm-intel-fixes@lists.freedesktop.org> # v4.13-rc1+
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170728212951.7818-1-chris@chris-wilson.co.uk

[  236.821534] WARNING: kmemcheck: Caught 64-bit read from uninitialized memory (ffff8802538683d0)
[  236.828642] 420000001e7f0000000000000000000000080000000000000000000000000000
[  236.839543]  i i i i u u u u i i i i i i i i u u u u u u u u u u u u u u u u
[  236.850420]                                  ^
[  236.854123] RIP: 0010:[<ffffffff81396f07>]  [<ffffffff81396f07>] fence_signal+0x17/0xd0
[  236.861313] RSP: 0018:ffff88024acd7ba0  EFLAGS: 00010282
[  236.865027] RAX: ffffffff812f6a90 RBX: ffff8802527ca800 RCX: ffff880252cb30e0
[  236.868801] RDX: ffff88024ac5d918 RSI: ffff880252f780e0 RDI: ffff880253868380
[  236.872579] RBP: ffff88024acd7bc0 R08: ffff88024acd7be0 R09: 0000000000000000
[  236.876407] R10: 0000000000000000 R11: 0000000000000000 R12: ffff880253868380
[  236.880185] R13: ffff8802538684d0 R14: ffff880253868380 R15: ffff88024cd48e00
[  236.883983] FS:  00007f1646d1a740(0000) GS:ffff88025d000000(0000) knlGS:0000000000000000
[  236.890959] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  236.894702] CR2: ffff880251360318 CR3: 000000024ad21000 CR4: 00000000001406f0
[  236.898481]  [<ffffffff8130d1ad>] i915_gem_request_retire+0x1cd/0x230
[  236.902439]  [<ffffffff8130e2b3>] i915_gem_request_alloc+0xa3/0x2f0
[  236.906435]  [<ffffffff812fb1bd>] i915_gem_do_execbuffer.isra.41+0xb6d/0x18b0
[  236.910434]  [<ffffffff812fc265>] i915_gem_execbuffer2+0x95/0x1e0
[  236.914390]  [<ffffffff812ad625>] drm_ioctl+0x1e5/0x460
[  236.918275]  [<ffffffff8110d4cf>] do_vfs_ioctl+0x8f/0x5c0
[  236.922168]  [<ffffffff8110da3c>] SyS_ioctl+0x3c/0x70
[  236.926090]  [<ffffffff814b7a5f>] entry_SYSCALL_64_fastpath+0x17/0x93
[  236.930045]  [<ffffffffffffffff>] 0xffffffffffffffff

We only set the timestamp before we mark the fence as signaled. It is
done before to avoid observers having a window in which they may see the
fence as complete but no timestamp. Having it does incur a potential for
the timestamp to be written twice, and even for it to be corrupted if
the u64 write is not atomic. Instead use a new bit to record the
presence of the timestamp, and teach the readers to wait until it is set
if the fence is complete. There still remains a race where the timestamp
for the signaled fence may be shown before the fence is reported as
signaled, but that's a pre-existing error.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Reported-by: NRafael Antognolli <rafael.antognolli@intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170214124001.1930-1-chris@chris-wilson.co.uk

Constructing the name takes the majority of the time for allocating a
sync_file to wrap a fence, and the name is very rarely used (only via
the sync_file status user interface). To reduce the impact on the common
path (that of creating sync_file to pass around), defer the construction
of the name until it is first used.

v2: Update kerneldoc (kbuild test robot)
v3: sync_debug.c was peeking at the name
v4: Comment upon the potential race between two users of
sync_file_get_name() and claim that such a race is below the level of
notice. However, to prevent any future nuisance, use a global spinlock
to serialize the assignment of the name.
v5: Completely avoid the read/write race by only storing the name passed
in from the user inside sync_file->user_name and passing in a buffer to
dynamically construct the name otherwise.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170516111042.24719-1-chris@chris-wilson.co.uk

sync_file uses the reference count of the file, the internal
kref was never getting moved past 1.

We can reintroduce this if we decide we need it later.

[airlied: fix buildbot warnings]
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDave Airlie <airlied@redhat.com>
Acked-by: NSumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170413014144.637-2-airlied@gmail.com

The fence->status is an optional field that is only valid once the fence
has been signaled. (Driver may fill the fence->status with an error code
prior to calling dma_fence_signal().) Given the restriction upon its
validity, wrap querying of the fence->status into a helper
dma_fence_get_status().
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NSumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170104141222.6992-2-chris@chris-wilson.co.uk

- Put the initial overview for dma-buf into dma-buf.rst.
- Put all the comments about detailed semantics into the right
  kernel-doc comment for functions or ops structure member.
- To allow that detail, switch the reworked kerneldoc to inline style
  for dma_buf_ops.
- Tie everything together into a much more streamlined overview
  comment, relying on the hyperlinks for all the details.
- Also sprinkle some links into the kerneldoc for dma_buf and
  dma_buf_attachment to tie it all together.

Cc: linux-doc@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20161209185309.1682-4-daniel.vetter@ffwll.ch

This was missed when adding a dma_fence_get call. While at it also
remove the kerneldoc for the static inline helper - no point
documenting internals down to every detail.

Fixes: 30cd85dd ("dma-buf/sync_file: hold reference to fence when creating sync_file")
Cc: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: linux-doc@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20161209185309.1682-3-daniel.vetter@ffwll.ch

This reverts commit ecebca79.

Do not enable fence callback on poll() when using fence_array causes the
fence_array to not signal.

For now we will revert the change and enable signaling everytime time
poll is called with timeout=0 as well.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1479457603-30758-1-git-send-email-gustavo@padovan.org

I plan to usurp the short name of struct fence for a core kernel struct,
and so I need to rename the specialised fence/timeline for DMA
operations to make room.

A consensus was reached in
https://lists.freedesktop.org/archives/dri-devel/2016-July/113083.html
that making clear this fence applies to DMA operations was a good thing.
Since then the patch has grown a bit as usage increases, so hopefully it
remains a good thing!

(v2...: rebase, rerun spatch)
v3: Compile on msm, spotted a manual fixup that I broke.
v4: Try again for msm, sorry Daniel

coccinelle script:
@@

@@
- struct fence
+ struct dma_fence
@@

@@
- struct fence_ops
+ struct dma_fence_ops
@@

@@
- struct fence_cb
+ struct dma_fence_cb
@@

@@
- struct fence_array
+ struct dma_fence_array
@@

@@
- enum fence_flag_bits
+ enum dma_fence_flag_bits
@@

@@
(
- fence_init
+ dma_fence_init
|
- fence_release
+ dma_fence_release
|
- fence_free
+ dma_fence_free
|
- fence_get
+ dma_fence_get
|
- fence_get_rcu
+ dma_fence_get_rcu
|
- fence_put
+ dma_fence_put
|
- fence_signal
+ dma_fence_signal
|
- fence_signal_locked
+ dma_fence_signal_locked
|
- fence_default_wait
+ dma_fence_default_wait
|
- fence_add_callback
+ dma_fence_add_callback
|
- fence_remove_callback
+ dma_fence_remove_callback
|
- fence_enable_sw_signaling
+ dma_fence_enable_sw_signaling
|
- fence_is_signaled_locked
+ dma_fence_is_signaled_locked
|
- fence_is_signaled
+ dma_fence_is_signaled
|
- fence_is_later
+ dma_fence_is_later
|
- fence_later
+ dma_fence_later
|
- fence_wait_timeout
+ dma_fence_wait_timeout
|
- fence_wait_any_timeout
+ dma_fence_wait_any_timeout
|
- fence_wait
+ dma_fence_wait
|
- fence_context_alloc
+ dma_fence_context_alloc
|
- fence_array_create
+ dma_fence_array_create
|
- to_fence_array
+ to_dma_fence_array
|
- fence_is_array
+ dma_fence_is_array
|
- trace_fence_emit
+ trace_dma_fence_emit
|
- FENCE_TRACE
+ DMA_FENCE_TRACE
|
- FENCE_WARN
+ DMA_FENCE_WARN
|
- FENCE_ERR
+ DMA_FENCE_ERR
)
 (
 ...
 )
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Acked-by: NSumit Semwal <sumit.semwal@linaro.org>
Acked-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161025120045.28839-1-chris@chris-wilson.co.uk

fence referencing was out of balance. It was not taking any ref to the
fence at creating time, but it was putting a reference when freeing the
sync file.

This patch fixes the balancing issue by getting a reference for the fence
when creating the sync_file.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NSean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1476899313-22241-1-git-send-email-gustavo@padovan.org

When merging sync_files there is a case when we can end up with only one
fence in the merged sync_file: when all fences belong to the same
timeline.

So for this case a fence_array is not created instead we just assigned the
fence to sync_file->fence. Then we do not use the fences array anymore nor
does free it.

This patch frees the array.
Reported-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NSean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1474442419-6040-1-git-send-email-gustavo@padovan.org

When we merge several fences, if all of them are signaled already, we
still keep one of them. So instead of using add_fence(), which will not
increase the refcount of signaled fences, we should explicitly call
fence_get() for the fence we are keeping.

This patch fixes a kernel panic that can be triggered by creating a fence
that is expired (or increasing the timeline until it expires), then
creating a merged fence out of it, and deleting the merged fence. This
will make the original expired fence's refcount go to zero.

Testcase: igt/sw_sync/sync_expired_merge
Signed-off-by: NRafael Antognolli <rafael.antognolli@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1473966865-4508-1-git-send-email-rafael.antognolli@intel.com

If we being polled with a timeout of zero, a nonblocking busy query,
we don't need to install any fence callbacks as we will not be waiting.
As we only install the callback once, the overhead comes from the atomic
bit test that also causes serialisation between threads.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Reviewed-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20160829181613.30722-1-chris@chris-wilson.co.uk

Signalling doesn't need to be enabled at sync_file creation, it is only
required if userspace waiting the fence to signal through poll().

Thus we delay fence_add_callback() until poll is called. It only adds the
callback the first time poll() is called. This avoid re-adding the same
callback multiple times.

v2: rebase and update to work with new fence support for sync_file

v3: use atomic operation to set enabled and protect fence_add_callback()

v4: use user bit from fence flags (comment from Chris Wilson)

v5: use ternary if on poll return (comment from Chris Wilson)
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>
  [sumits: remove unused var status]
Link: http://patchwork.freedesktop.org/patch/msgid/1470404378-27961-1-git-send-email-gustavo@padovan.org

Creates a function that given an sync file descriptor returns a
fence containing all fences in the sync_file.

v2: Comments by Daniel Vetter
	- Adapt to new version of fence_collection_init()
	- Hold a reference for the fence we return

v3:
	- Adapt to use fput() directly
	- rename to sync_file_get_fence() as we always return one fence

v4: Adapt to use fence_array

v5: set fence through fence_get()
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>

Create sync_file->fence to abstract the type of fence we are using for
each sync_file. If only one fence is present we use a normal struct fence
but if there is more fences to be added to the sync_file a fence_array
is created.

This change cleans up sync_file a bit. We don't need to have sync_file_cb
array anymore. Instead, as we always have  one fence, only one fence
callback is registered per sync_file.

v2: Comments from Chris Wilson and Christian König
	- Not using fence_ops anymore
	- fence_is_array() was created to differentiate fence from fence_array
	- fence_array_teardown() is now exported and used under fence_is_array()
	- struct sync_file lost num_fences member

v3: Comments from Chris Wilson and Christian König
	- struct sync_file lost status member in favor of fence_is_signaled()
	- drop use of fence_array_teardown()
	- use sizeof(*fence) to allocate only an array on fence pointers

v4: Comments from Chris Wilson
	- use sizeof(*fence) to reallocate array
	- fix typo in comments
	- protect num_fences sum against overflows
	- use array->base instead of casting the to struct fence

v5: fixes checkpatch warnings

v6: fix case where all fences are signaled.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NChristian König <christian.koenig@amd.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>

Christian König changed fence context to a u64 type, so we need to
update all users accordingly.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Acked-by: NSumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1464968791-4564-1-git-send-email-gustavo@padovan.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: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Move sync_file headers file to include/ dir.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix checks reported by checkpatch.pl.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

num_fences was missing a colon mark and sync_file_create() now have
better description.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Move its functions and structs to their own file. Also moves function's
docs to the .c file.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Simplifies the API to only receive the fence it needs to add to the
sync and create a name for the sync_file based on the fence context and
seqno.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There is no plan in the near future to use this function outside of this
file so keep it as static.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There is no plan in the near future to use this function outside of this
file so keep it as static.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

To keep comments in line with drivers/dma-buf/ move all sync_file comments
to sync.c.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

These two functions are just wrappers for one line functions, they
call fd_install() and fput() respectively, so just get rid of them
and use fd_install() and fput() directly for more simplicity.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Change SYNC_IOC_FILE_INFO (former SYNC_IOC_FENCE_INFO) behaviour to avoid
future API breaks and optimize buffer allocation.

Now num_fences can be filled by the caller to inform how many fences it
wants to retrieve from the kernel. If the num_fences passed is greater
than zero info->sync_fence_info should point to a buffer with enough space
to fit all fences.

However if num_fences passed to the kernel is 0, the kernel will reply
with number of fences of the sync_file.

Sending first an ioctl with num_fences = 0 can optimize buffer allocation,
in a first call with num_fences = 0 userspace will receive the actual
number of fences in the num_fences filed.

Then it can allocate a buffer with the correct size on sync_fence_info and
call SYNC_IOC_FILE_INFO again, but now with the actual value of num_fences
in the sync_file.

info->sync_fence_info was converted to __u64 pointer to prevent 32bit
compatibility issues. And a flags member was added.

An example userspace code for the later would be:

	struct sync_file_info *info;
	int err, size, num_fences;

	info = malloc(sizeof(*info));

	info.flags = 0;
	err = ioctl(fd, SYNC_IOC_FILE_INFO, info);
	num_fences = info->num_fences;

	if (num_fences) {
		info.flags = 0;
		size = sizeof(struct sync_fence_info) * num_fences;
		info->num_fences = num_fences;
		info->sync_fence_info = (uint64_t) calloc(num_fences,
							  sizeof(struct sync_fence_info));

		err = ioctl(fd, SYNC_IOC_FILE_INFO, info);
	}

Finally the IOCTLs numbers were changed to avoid any potential old
userspace running the old API to get weird errors. Changing the opcodes
will make them fail right away. This is just a precaution, there no
upstream users of these interfaces yet and the only user is Android, but
we don't expect anyone trying to run android userspace and all it
dependencies on top of upstream kernels.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: NGreg Hackmann <ghackmann@google.com>
Acked-by: NRob Clark <robdclark@gmail.com>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove unnecessary else when there is a return statement in the
corresponding if block.
Coccinelle patch used:

@rule1@
expression e1;
@@

	if (e1) { ... return ...; }
-       else{
	        ...
-            }

@rule2@
expression e2;
statement s1;
@@

	if(e2) { ... return ...; }
-       else
		s1
Signed-off-by: NJanani Ravichandran <janani.rvchndrn@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

After removing driver_data struct sync_fence_info has now a fixed size,
thus it doesn't need any field to tell its size, it is already known.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It is unclear in what situations driver_data should be used thus better do
not upstream it for now. If a need arises in the future a discussion can
be started to re-add it.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

info_data is a bit redundant, let's keep it as only sync_file_info. It is
also smaller.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As struct sync_pt doesn't exist anymore it is a good idea remove any
reference to it in the sync_framework. sync_pts were replaced directly by
fences and here we rename it to sync_fence_info to let the fence namespace
clean.

v2: rename fence_info to sync_fence_info (Maarten)
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This ioctl is replicating the work of poll() syscall so let's take the
opportunity that this is still on staging tree and remove the duplication
and force new users to use the poll() standard interface.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

With the removal of struct sync_pt sync_fence_create_dma() now takes
the same arguments as sync_fence_create() so let's keep only
sync_fence_create().
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

All changes to timeline value come through the user via
sync_timeline_signal() calls. When sync_timeline_destroy() is called no
changes on timeline->value happens hence call sync_timeline_signal() with
no increment is pointless.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

signaled_pts is not used in this function.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

struct sync_pt was just wrapping around struct fence and creating an
extra abstraction layer. The only two members of struct sync_pt, child_list
and active_list, were moved to struct fence in an earlier commit. After
removing those two members struct sync_pt is nothing more than struct
fence, so remove it all and use struct fence directly.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>