[PATCH 4.9 088/109] dma-buf/dma-fence: Extract __dma_fence_is_later()

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>

commit 8111477663813caa1a4469cfe6afaae36cd04513 upstream.

Often we have the task of comparing two seqno known to be on the same
context, so provide a common __dma_fence_is_later().

Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
Cc: Sean Paul <seanpaul@xxxxxxxxxxxx>
Cc: Gustavo Padovan <gustavo@xxxxxxxxxxx>
Reviewed-by: Sean Paul <seanpaul@xxxxxxxxxxxx>
Signed-off-by: Gustavo Padovan <gustavo.padovan@xxxxxxxxxxxxx>
Link: http://patchwork.freedesktop.org/patch/msgid/20170629125930.821-1-chris@xxxxxxxxxxxxxxxxxx
[renamed to __fence_is_later() - gregkh]
Cc: Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 include/linux/fence.h |   15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

--- a/include/linux/fence.h
+++ b/include/linux/fence.h
@@ -281,6 +281,19 @@ fence_is_signaled(struct fence *fence)
 }
 
 /**
+ * __fence_is_later - return if f1 is chronologically later than f2
+ * @f1:	[in]	the first fence's seqno
+ * @f2:	[in]	the second fence's seqno from the same context
+ *
+ * Returns true if f1 is chronologically later than f2. Both fences must be
+ * from the same context, since a seqno is not common across contexts.
+ */
+static inline bool __fence_is_later(u32 f1, u32 f2)
+{
+	return (int)(f1 - f2) > 0;
+}
+
+/**
  * fence_is_later - return if f1 is chronologically later than f2
  * @f1:	[in]	the first fence from the same context
  * @f2:	[in]	the second fence from the same context
@@ -293,7 +306,7 @@ static inline bool fence_is_later(struct
 	if (WARN_ON(f1->context != f2->context))
 		return false;
 
-	return (int)(f1->seqno - f2->seqno) > 0;
+	return __fence_is_later(f1->seqno, f2->seqno);
 }
 
 /**