[PATCH 1/7] dma-buf: some dma_fence_chain improvements

[Christian König]

The callback and the irq work are never used at the same
time. Putting them into an union saves us 24 bytes and
makes the structure only 120 bytes in size.

Signed-off-by: Christian König <christian.koenig at amd.com>
---
 drivers/dma-buf/dma-fence-chain.c | 2 +-
 include/linux/dma-fence-chain.h   | 8 +++++---
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/dma-buf/dma-fence-chain.c b/drivers/dma-buf/dma-fence-chain.c
index 7d129e68ac70..1b4cb3e5cec9 100644
--- a/drivers/dma-buf/dma-fence-chain.c
+++ b/drivers/dma-buf/dma-fence-chain.c
@@ -137,6 +137,7 @@ static void dma_fence_chain_cb(struct dma_fence *f, struct dma_fence_cb *cb)
 	struct dma_fence_chain *chain;
 
 	chain = container_of(cb, typeof(*chain), cb);
+	init_irq_work(&chain->work, dma_fence_chain_irq_work);
 	irq_work_queue(&chain->work);
 	dma_fence_put(f);
 }
@@ -239,7 +240,6 @@ void dma_fence_chain_init(struct dma_fence_chain *chain,
 	rcu_assign_pointer(chain->prev, prev);
 	chain->fence = fence;
 	chain->prev_seqno = 0;
-	init_irq_work(&chain->work, dma_fence_chain_irq_work);
 
 	/* Try to reuse the context of the previous chain node. */
 	if (prev_chain && __dma_fence_is_later(seqno, prev->seqno, prev->ops)) {
diff --git a/include/linux/dma-fence-chain.h b/include/linux/dma-fence-chain.h
index 10462a029da2..9d6a062be640 100644
--- a/include/linux/dma-fence-chain.h
+++ b/include/linux/dma-fence-chain.h
@@ -25,12 +25,14 @@
  */
 struct dma_fence_chain {
 	struct dma_fence base;
-	spinlock_t lock;
 	struct dma_fence __rcu *prev;
 	u64 prev_seqno;
 	struct dma_fence *fence;
-	struct dma_fence_cb cb;
-	struct irq_work work;
+	union {
+		struct dma_fence_cb cb;
+		struct irq_work work;
+	};
+	spinlock_t lock;
 };
 
 extern const struct dma_fence_ops dma_fence_chain_ops;
-- 
2.25.1