[PATCH 1/2] dma-fence: export dma_fence_might_wait

[Matthew Auld <matthew.auld@intel.com>]

It might be useful for drivers to annotate a path where hitting the
actual wait path might be difficult or unlikely through normal testing.

Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
---
 drivers/dma-buf/dma-fence.c | 19 ++++++++++++++++---
 include/linux/dma-fence.h   |  2 ++
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
index ce0f5eff575d..f2cd036b5243 100644
--- a/drivers/dma-buf/dma-fence.c
+++ b/drivers/dma-buf/dma-fence.c
@@ -335,6 +335,21 @@ void __dma_fence_might_wait(void)
 }
 #endif
 
+/**
+ * dma_fence_might_wait - entering a section which might wait on DMA fence
+ * critical section.
+ *
+ * This is also potentially useful for drivers to call directly, when annotating
+ * a path where hitting the actual wait path might be difficult or unlikely
+ * through normal testing.
+ */
+void dma_fence_might_wait(void)
+{
+	might_sleep();
+	__dma_fence_might_wait();
+}
+EXPORT_SYMBOL(dma_fence_might_wait);
+
 
 /**
  * dma_fence_signal_timestamp_locked - signal completion of a fence
@@ -495,9 +510,7 @@ dma_fence_wait_timeout(struct dma_fence *fence, bool intr, signed long timeout)
 	if (WARN_ON(timeout < 0))
 		return -EINVAL;
 
-	might_sleep();
-
-	__dma_fence_might_wait();
+	dma_fence_might_wait();
 
 	trace_dma_fence_wait_start(fence);
 	if (fence->ops->wait)
diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h
index 6ffb4b2c6371..37bf4beed93f 100644
--- a/include/linux/dma-fence.h
+++ b/include/linux/dma-fence.h
@@ -370,6 +370,8 @@ static inline void dma_fence_end_signalling(bool cookie) {}
 static inline void __dma_fence_might_wait(void) {}
 #endif
 
+void dma_fence_might_wait(void);
+
 int dma_fence_signal(struct dma_fence *fence);
 int dma_fence_signal_locked(struct dma_fence *fence);
 int dma_fence_signal_timestamp(struct dma_fence *fence, ktime_t timestamp);
-- 
2.26.3