diff options
author | Chris Wilson <chris@chris-wilson.co.uk> | 2016-08-15 18:42:18 +0300 |
---|---|---|
committer | Sumit Semwal <sumit.semwal@linaro.org> | 2016-08-16 10:01:35 +0300 |
commit | ae4e46b14bd7a12fb7908425846be7ceb0853bbc (patch) | |
tree | d34ce6b16f6e83e97b7041874c97f17a5b167428 /drivers/dma-buf/dma-buf.c | |
parent | 90844f00049e9f42573fd31d7c32e8fd31d3fd07 (diff) |
dma-buf: Wait on the reservation object when sync'ing before CPU access
Rendering operations to the dma-buf are tracked implicitly via the
reservation_object (dmabuf->resv). This is used to allow poll() to
wait upon outstanding rendering (or just query the current status of
rendering). The dma-buf sync ioctl allows userspace to prepare the
dma-buf for CPU access, which should include waiting upon rendering.
(Some drivers may need to do more work to ensure that the dma-buf mmap
is coherent as well as complete.)
v2: Always wait upon the reservation object implicitly. We choose to do
it after the native handler in case it can do so more efficiently.
Testcase: igt/prime_vgem
Testcase: igt/gem_concurrent_blit # *vgem*
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Eric Anholt <eric@anholt.net>
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: linux-kernel@vger.kernel.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/1471275738-31994-1-git-send-email-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/dma-buf/dma-buf.c')
-rw-r--r-- | drivers/dma-buf/dma-buf.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index ddaee60ae52a..cf04d249a6a4 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -586,6 +586,22 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, } EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); +static int __dma_buf_begin_cpu_access(struct dma_buf *dmabuf, + enum dma_data_direction direction) +{ + bool write = (direction == DMA_BIDIRECTIONAL || + direction == DMA_TO_DEVICE); + struct reservation_object *resv = dmabuf->resv; + long ret; + + /* Wait on any implicit rendering fences */ + ret = reservation_object_wait_timeout_rcu(resv, write, true, + MAX_SCHEDULE_TIMEOUT); + if (ret < 0) + return ret; + + return 0; +} /** * dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the @@ -608,6 +624,13 @@ int dma_buf_begin_cpu_access(struct dma_buf *dmabuf, if (dmabuf->ops->begin_cpu_access) ret = dmabuf->ops->begin_cpu_access(dmabuf, direction); + /* Ensure that all fences are waited upon - but we first allow + * the native handler the chance to do so more efficiently if it + * chooses. A double invocation here will be reasonably cheap no-op. + */ + if (ret == 0) + ret = __dma_buf_begin_cpu_access(dmabuf, direction); + return ret; } EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access); |