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path: root/drivers/dma-buf/reservation.c
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2016-11-09reservation: revert "wait only with non-zero timeout specified (v3)" v2Christian König
Reverts commit fb8b7d2b9d80 ("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
2016-10-25dma-buf: Rename struct fence to dma_fenceChris Wilson
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: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/20161025120045.28839-1-chris@chris-wilson.co.uk
2016-10-12dma-buf: Restart reservation_object_test_signaled_rcu() after writesChris Wilson
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
2016-10-12dma-buf: Restart reservation_object_wait_timeout_rcu() after writesChris Wilson
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
2016-10-12dma-buf: Restart reservation_object_get_fences_rcu() after writesChris Wilson
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
2016-08-22reservation: fix small comment typoRob Clark
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
2016-05-31reservation: add headerdoc commentsRob Clark
Signed-off-by: Rob Clark <robdclark@gmail.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
2015-05-21dma-buf: Minor coding style fixesJagan Teki
- 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>
2015-01-22reservation: Remove shadowing local variable 'ret'Michel Dänzer
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>
2015-01-22reservation: wait only with non-zero timeout specified (v3)Jammy Zhou
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>
2014-07-08reservation: add suppport for read-only access using rcuMaarten Lankhorst
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>
2014-07-08reservation: update api and add some helpersMaarten Lankhorst
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>
2014-07-08dma-buf: move to drivers/dma-bufMaarten Lankhorst
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>