Commit graph

12 commits

Author SHA1 Message Date
Christian König
dbbeec418b UPSTREAM: reservation: revert "wait only with non-zero timeout specified (v3)" v2
Reverts commit fb8b7d2b9d
	("reservation: wait only with non-zero timeout specified (v3)")

Otherwise signaling might never be activated on the fences. This can
result in infinite waiting with hardware which has unreliable interrupts.

v2: still return one when the timeout is zero and we don't have any fences.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com> (v1)
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
  [sumits: fix checkpatch warnings]
Link: http://patchwork.freedesktop.org/patch/msgid/1478553376-18575-4-git-send-email-alexander.deucher@amd.com
(cherry picked from commit 06a66b5c77ede71f0601f4710284ca1076e673fa)
Signed-off-by: Marissa Wall <marissaw@google.com>

Change-Id: I5cb90c048f38f4b1f46ed15c486cc718f97cf0d5
2017-05-23 15:47:17 -07:00
Chris Wilson
8507595081 UPSTREAM: dma-buf: Restart reservation_object_test_signaled_rcu() after writes
In order to be completely generic, we have to double check the read
seqlock after acquiring a reference to the fence. If the driver is
allocating fences from a SLAB_DESTROY_BY_RCU, or similar freelist, then
within an RCU grace period a fence may be freed and reallocated. The RCU
read side critical section does not prevent this reallocation, instead
we have to inspect the reservation's seqlock to double check if the
fences have been reassigned as we were acquiring our reference.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20160829070834.22296-9-chris@chris-wilson.co.uk
(cherry picked from commit b68d8379c28ddfe74b78be9414082f281332d86c)
Signed-off-by: Marissa Wall <marissaw@google.com>

Change-Id: Icc81d30c1c2b7f3ea3c47bb5e0c7f48ffa90e585
2017-05-23 15:47:17 -07:00
Chris Wilson
b0f869d1da UPSTREAM: dma-buf: Restart reservation_object_wait_timeout_rcu() after writes
In order to be completely generic, we have to double check the read
seqlock after acquiring a reference to the fence. If the driver is
allocating fences from a SLAB_DESTROY_BY_RCU, or similar freelist, then
within an RCU grace period a fence may be freed and reallocated. The RCU
read side critical section does not prevent this reallocation, instead
we have to inspect the reservation's seqlock to double check if the
fences have been reassigned as we were acquiring our reference.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20160829070834.22296-8-chris@chris-wilson.co.uk
(cherry picked from commit 1cec20f0ea0e3bc617aed47e0936f17386c131f9)
Signed-off-by: Marissa Wall <marissaw@google.com>

Change-Id: Ie397f56a605ec1e63de54cc59eb2715e58f6cc09
2017-05-23 15:47:17 -07:00
Chris Wilson
2264af0978 UPSTREAM: dma-buf: Restart reservation_object_get_fences_rcu() after writes
In order to be completely generic, we have to double check the read
seqlock after acquiring a reference to the fence. If the driver is
allocating fences from a SLAB_DESTROY_BY_RCU, or similar freelist, then
within an RCU grace period a fence may be freed and reallocated. The RCU
read side critical section does not prevent this reallocation, instead
we have to inspect the reservation's seqlock to double check if the
fences have been reassigned as we were acquiring our reference.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20160829070834.22296-7-chris@chris-wilson.co.uk
(cherry picked from commit fedf54132d2410c3949036e3f611ab8dd9dbe89e)
Signed-off-by: Marissa Wall <marissaw@google.com>

Change-Id: I32dacb1b95a73c49984b88e01e7f7424d069ef07
2017-05-23 15:47:17 -07:00
Rob Clark
f5bef0b85e reservation: fix small comment typo
Signed-off-by: Rob Clark <robdclark@gmail.com>
[danvet: Mark up as function for proper cross-linking.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1471640134-30888-1-git-send-email-robdclark@gmail.com
2016-08-22 09:22:09 +02:00
Rob Clark
dad6c3945f reservation: add headerdoc comments
Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
2016-05-31 22:12:43 +05:30
Jagan Teki
5136629dc5 dma-buf: Minor coding style fixes
- WARNING: Missing a blank line after declarations
- WARNING: line over 80 characters
- WARNING: please, no space before tabs

Signed-off-by: Jagan Teki <jteki@openedev.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
2015-05-21 11:29:59 +05:30
Michel Dänzer
4eb2440ed6 reservation: Remove shadowing local variable 'ret'
It was causing the return value of fence_is_signaled to be ignored, making
reservation objects signal too early.

Cc: stable@vger.kernel.org
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
2015-01-22 16:29:31 +05:30
Jammy Zhou
fb8b7d2b9d reservation: wait only with non-zero timeout specified (v3)
When the timeout value passed to reservation_object_wait_timeout_rcu
is zero, no wait should be done if the fences are not signaled.

Return '1' for idle and '0' for busy if the specified timeout is '0'
to keep consistent with the case of non-zero timeout.

v2: call fence_put if not signaled in the case of timeout==0

v3: switch to reservation_object_test_signaled_rcu

Signed-off-by: Jammy Zhou <Jammy.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-By: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
2015-01-22 11:27:57 +05:30
Maarten Lankhorst
3c3b177a93 reservation: add suppport for read-only access using rcu
This adds some extra functions to deal with rcu.

reservation_object_get_fences_rcu() will obtain the list of shared
and exclusive fences without obtaining the ww_mutex.

reservation_object_wait_timeout_rcu() will wait on all fences of the
reservation_object, without obtaining the ww_mutex.

reservation_object_test_signaled_rcu() will test if all fences of the
reservation_object are signaled without using the ww_mutex.

reservation_object_get_excl and reservation_object_get_list require
the reservation object to be held, updating requires
write_seqcount_begin/end. If only the exclusive fence is needed,
rcu_dereference followed by fence_get_rcu can be used, if the shared
fences are needed it's recommended to use the supplied functions.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Reviewed-By: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-08 13:41:08 -07:00
Maarten Lankhorst
04a5faa8cb reservation: update api and add some helpers
Move the list of shared fences to a struct, and return it in
reservation_object_get_list().
Add reservation_object_get_excl to get the exclusive fence.

Add reservation_object_reserve_shared(), which reserves space
in the reservation_object for 1 more shared fence.

reservation_object_add_shared_fence() and
reservation_object_add_excl_fence() are used to assign a new
fence to a reservation_object pointer, to complete a reservation.

Changes since v1:
- Add reservation_object_get_excl, reorder code a bit.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-08 13:37:35 -07:00
Maarten Lankhorst
35fac7e305 dma-buf: move to drivers/dma-buf
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-08 10:51:06 -07:00
Renamed from drivers/base/reservation.c (Browse further)