If userspace already dropped its own reference by closing the sw_sync
fence fd we might end up in a deadlock where
dma_fence_is_signaled_locked() will trigger the release of the fence and
thus try to hold the lock to remove the fence from the list.
dma_fence_is_signaled_locked() tries to release/free the fence and hold
the lock in the process.
We fix that by changing the order operation and clean up the list and
rb-tree first.
v2: Drop fence get/put dance and manipulate the list first (Chris Wilson)
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20170729152217.8362-2-gustavo@padovan.org
Reduce the list iteration when incrementing the timeline by storing the
fences in increasing order.
v2: Prevent spinlock recursion on free during create
v3: Fixup rebase conflict inside comments that escaped the compiler.
Signed-off-by: Chris 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>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170629211253.22766-1-chris@chris-wilson.co.uk
The sync_pt were not adding themselves atomically to the timeline lists,
corruption imminent. Only a single list is required to track the
unsignaled sync_pt, so reduce it and rename the lock more appropriately
along with using idiomatic names to distinguish a list from links along
it.
v2: Prevent spinlock recursion on free during create (next patch) and
fixup crossref in kerneldoc
Signed-off-by: Chris 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>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170629210532.5617-1-chris@chris-wilson.co.uk
Since sync_pt is only allocated from a single location and is no longer
the base class for fences (that is struct dma_fence) it no longer needs
a generic unsized allocator.
Signed-off-by: Chris 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>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170629125930.821-5-chris@chris-wilson.co.uk
If we know the context under which we are called, then we can use the
simpler form of spin_lock_irq (saving the save/restore).
Signed-off-by: Chris 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>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170629125930.821-4-chris@chris-wilson.co.uk
The timeline is u32, which limits any single advance to INT_MAX so that
we can detect all fences that need signaling.
Signed-off-by: Chris 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>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170629125930.821-3-chris@chris-wilson.co.uk
Use the canonical __dma_fence_is_later() to compare the fence seqno
against the timeline seqno to check if the fence is signaled.
Signed-off-by: Chris 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>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170629125930.821-2-chris@chris-wilson.co.uk
Once sw_sync_ioctl_create_fence() returns we no longer have the
*pt pointer to the fence base object thus we need to put the reference
we have from the fence creation to keep a correct reference accounting.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1477515599-7685-1-git-send-email-gustavo@padovan.org
We get 1 warning when building kernel with W=1:
drivers/dma-buf/sw_sync.c:87:23: warning: no previous prototype for 'sync_timeline_create' [-Wmissing-prototypes]
In fact, this function is only used in the file in which it is
declared and don't need a declaration, but can be made static.
So this patch marks it 'static'.
Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1474202961-10099-1-git-send-email-baoyou.xie@linaro.org
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>
