dma-fence: Wrap querying the fence->status

The fence->status is an optional field that is only valid once the fence
has been signaled. (Driver may fill the fence->status with an error code
prior to calling dma_fence_signal().) Given the restriction upon its
validity, wrap querying of the fence->status into a helper
dma_fence_get_status().

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170104141222.6992-2-chris@chris-wilson.co.uk

1 files changed, 25 insertions, 0 deletions

diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
index cb6eef308cd9..5e66dfece03c 100644
--- a/drivers/dma-buf/dma-fence.c
+++ b/drivers/dma-buf/dma-fence.c
@@ -282,6 +282,31 @@ int dma_fence_add_callback(struct dma_fence *fence, struct dma_fence_cb *cb,
 EXPORT_SYMBOL(dma_fence_add_callback);
 
 /**
+ * dma_fence_get_status - returns the status upon completion
+ * @fence: [in] the dma_fence to query
+ *
+ * This wraps dma_fence_get_status_locked() to return the error status
+ * condition on a signaled fence. See dma_fence_get_status_locked() for more
+ * details.
+ *
+ * Returns 0 if the fence has not yet been signaled, 1 if the fence has
+ * been signaled without an error condition, or a negative error code
+ * if the fence has been completed in err.
+ */
+int dma_fence_get_status(struct dma_fence *fence)
+{
+        unsigned long flags;
+        int status;
+
+        spin_lock_irqsave(fence->lock, flags);
+        status = dma_fence_get_status_locked(fence);
+        spin_unlock_irqrestore(fence->lock, flags);
+
+        return status;
+}
+EXPORT_SYMBOL(dma_fence_get_status);
+
+/**
  * dma_fence_remove_callback - remove a callback from the signaling list
  * @fence:      [in]    the fence to wait on
  * @cb:         [in]    the callback to remove