sync: allow async waits to be canceled

In order to allow drivers to cleanly handled teardown we need to allow them
to cancel pending async waits.  To do this cleanly, we move allocation of
sync_fence_waiter to the driver calling sync_async_wait().

Change-Id: Ifcd95648be6ec07026d67f810070a4310f099989
Signed-off-by: Erik Gilling <konkers@android.com>
(cherry picked from commit a9de6e83f2d989cfff17a9982c12b6ee9c076c57)
sync: export sync API symbols

This is needed to allow modules to link against the sync subsystem

Change-Id: I15c1818de329f24e4113ef1d0923413b22fd0eff
Signed-off-by: Erik Gilling <konkers@android.com>
(cherry picked from commit 602f56f31da5a092c86917c027005444e7199b07)
sw_sync: export sw_sync API

Needed to let modules link against sw_sync.

Change-Id: I71d3e52677ef21b6e1ecdb84f831491be1f4fbe6
Signed-off-by: Erik Gilling <konkers@android.com>
(cherry picked from commit 8786b6f2b985dd3dcfbb3716b67c4453e79d74dc)
sync: reorder sync_fence_release

Previously fence's pts were freed before the were the fence was removed from the
global fence list.  This led to a race with the debugfs support where it would
iterate over sync_pts that had been freed.

Change-Id: Ia3ddbf77de42ca593fc2dc353b5d04e42ddf3946
Signed-off-by: Erik Gilling <konkers@android.com>
(cherry picked from commit 4128cda08565638abecc8011329b008928a0e3c4)
sync: optimize fence merges

If the two fences being merged contain sync_pts from the same timeline,
those two pts will be collapsed into a single pt representing the latter
of the two.

Change-Id: Iced7ebb7e5a17a0c8b1a2969ba3388a4edb9ecaf
Signed-off-by: Erik Gilling <konkers@android.com>
(cherry picked from commit c588a0d05b516a8ee2c69d7d4209680fc948d395)
sync: add internal refcounting to fences

If a fence is released while a timeline that one of it's pts is on is being
signaled, it is possible for that fence to be deleted before it is signaled.
This patch adds a refcount for internal references such as signaled pt
processing.

Change-Id: Ie8605e6fd2ac026c207220a03d84e1c1078ec719
Signed-off-by: Erik Gilling <konkers@android.com>
(cherry picked from commit 0e4f6675f8b443cf5d68d36a67f1c7ef4c04cef2)
sync: add reference counting to timelines

If a timeline is destroyed while fences still hold pts on it, the reworked
fence release handler can cause the timeline to be freed before all it's points
are freed.

Change-Id: I1cd8ddb638eded7db9db446ff6b37f3dd165d6c4
Signed-off-by: Erik Gilling <konkers@android.com>
(cherry picked from commit 7d709710624275322b9411179ab45c5fd255cbd1)
sync: Fix error paths

Check the return value of get_unused_fd to make sure a valid
file descriptor is returned.

Make sure to call put_unused_fd even if an error occurs before
the fd can be used.

Change-Id: I0fe8f78d9e30ecfc4d271c5d875424543dae2d0f
Signed-off-by: Rebecca Schultz Zavin <rebecca@android.com>
(cherry picked from commit 3b5577e15de9521563715e4d26f99dfd19a56141)
sw_sync: Fix error paths

Check the return value of get_unused_fd to make sure a valid
file descriptor is returned.

Make sure to call put_unused_fd even if an error occurs before
the fd can be used.

Change-Id: Ibbf55caebc2f8ee6a03f298eb0ae0189c7d10b5c
Signed-off-by: Rebecca Schultz Zavin <rebecca@android.com>
(cherry picked from commit 5be5b6a568e5cf6dd13049e42a0b3b3a34d8f79d)
sync: change wait timeout to mirror poll semantics

Change-Id: Ib38e6d339d41885a33027752690d65a52b6897f6
Signed-off-by: Erik Gilling <konkers@android.com>
(cherry picked from commit cd2982e667f1799bcb00267b1f004dca821d2c68)
sync: fix erase-o in sync_fence_wait

Change-Id: I189707cf658a9f1f2943515c891b43961994e774
Signed-off-by: Erik Gilling <konkers@android.com>
(cherry picked from commit 7020483263826ed2257a350c01fffa7514c0bf0b)
sync: clean up compiler warnings

Change-Id: I8a2ec5db652c61fd04571402067b37273b91e78f
Signed-off-by: Erik Gilling <konkers@android.com>
(cherry picked from commit 699d59e6719a890112a1fbbed69b16ddd4375712)
sync: dump sync state to console on timeout

Change-Id: I74bca6b4a2afa7ed5b1f5233c5165d2edddf269a
Signed-off-by: Erik Gilling <konkers@android.com>
(cherry picked from commit 6acf0f884ffd90dbe85c8c3001fbf0cfab41ee26)
sync: use correct signed type when handling SYNC_IOC_WAIT

Change-Id: Ic7d5adf9b145765e52b23186b8c3c793ccf29be7
Signed-off-by: Erik Gilling <konkers@android.com>
(cherry picked from commit 8b491bb3a6fcecee0fbb23d66d8951605c1632e1)
sync: improve timeout dumps

Change-Id: I3b378d63c324c7b5862dd214f380b5e91131cc2a
Signed-off-by: Erik Gilling <konkers@android.com>
(cherry picked from commit 2612ac76d03e7145517cac7a86ba39cc8b2a5233)
sync: dump sync state of fence errors

Change-Id: I297a43aadf83504993040ea875c7f22d988628f1
Signed-off-by: Erik Gilling <konkers@android.com>
(cherry picked from commit 8236097fc6705ae984bbe64ee40bd31226a82712)
sync: protect unlocked access to fence status

Fence status is checked outside of locks in both sync_fence_wait and
sync_fence_poll.  This patch adds propper barrier protection in these
cases to avoid seeing stale status.

Change-Id: I9d8b6ce6accb415e797df58068a1ccd54e6be445
Signed-off-by: Erik Gilling <konkers@android.com>
(cherry picked from commit cfb0f006a09832bc5a4f02228b7e679c58ba215b)
sync: update new fence status with sync_fence_signal_pt

If a fence's pt is signaled before sync_fence_create is called, the fence
will never transition into the signaled state.  This also address a tiny
race if a merged fence's pt after sync_fence_get_status checks it's status
and before fence->status is updated.

Change-Id: Ic8e292a323db26c6f04cb4757d920278b3125ff6
Signed-off-by: Erik Gilling <konkers@android.com>
(cherry picked from commit 021e7fdd52a0322c5751dec1fa5529036620433b)
sync: use proper barriers when waiting indefinitely

The previous fix only addressed waiting with a timeout.

Change-Id: I8ad735d2d0dfdd53592904e8a54f5689cb5eaa5e
Signed-off-by: Erik Gilling <konkers@android.com>
(cherry picked from commit 86d3cf4982c5db41ff1ec417988fac7a43cb0c68)
sync: refactor sync debug printing

Move driver callbacks to fill strings instead of using seq_files.  This
will allow those values to be used in a future tracepoint patch.

Change-Id: I9b706343e35b11124141fe520e520514a32003d2
Signed-off-by: Erik Gilling <konkers@android.com>
(cherry picked from commit 6df7334f7831c558b57fe442571bf42452cd8aed)