[RFC v2 04/13] dma-fence: Move array and chain checks to flags

[Tvrtko Ursulin]

With the goal of reducing the need for drivers to touch fence->ops, we
add explicit flags for struct dma_fence_array and struct dma_fence_chain
and make the respective helpers (dma_fence_is_array() and
dma_fence_is_chain()) use them.

This also allows us to remove the exported symbols for the respective
operation tables.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at igalia.com>
---
 drivers/dma-buf/dma-fence-array.c | 2 +-
 drivers/dma-buf/dma-fence-chain.c | 2 +-
 include/linux/dma-fence.h         | 9 ++++-----
 3 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/dma-buf/dma-fence-array.c b/drivers/dma-buf/dma-fence-array.c
index 6657d4b30af9..daf444f5d228 100644
--- a/drivers/dma-buf/dma-fence-array.c
+++ b/drivers/dma-buf/dma-fence-array.c
@@ -167,7 +167,6 @@ const struct dma_fence_ops dma_fence_array_ops = {
 	.release = dma_fence_array_release,
 	.set_deadline = dma_fence_array_set_deadline,
 };
-EXPORT_SYMBOL(dma_fence_array_ops);
 
 /**
  * dma_fence_array_alloc - Allocate a custom fence array
@@ -207,6 +206,7 @@ void dma_fence_array_init(struct dma_fence_array *array,
 	spin_lock_init(&array->lock);
 	dma_fence_init(&array->base, &dma_fence_array_ops, &array->lock,
 		       context, seqno);
+	__set_bit(DMA_FENCE_FLAG_ARRAY_BIT, &array->base.flags);
 	init_irq_work(&array->work, irq_dma_fence_array_work);
 
 	atomic_set(&array->num_pending, signal_on_any ? 1 : num_fences);
diff --git a/drivers/dma-buf/dma-fence-chain.c b/drivers/dma-buf/dma-fence-chain.c
index a8a90acf4f34..f4abe41fb092 100644
--- a/drivers/dma-buf/dma-fence-chain.c
+++ b/drivers/dma-buf/dma-fence-chain.c
@@ -225,7 +225,6 @@ const struct dma_fence_ops dma_fence_chain_ops = {
 	.release = dma_fence_chain_release,
 	.set_deadline = dma_fence_chain_set_deadline,
 };
-EXPORT_SYMBOL(dma_fence_chain_ops);
 
 /**
  * dma_fence_chain_init - initialize a fence chain
@@ -263,6 +262,7 @@ void dma_fence_chain_init(struct dma_fence_chain *chain,
 
 	dma_fence_init64(&chain->base, &dma_fence_chain_ops, &chain->lock,
 			 context, seqno);
+	__set_bit(DMA_FENCE_FLAG_CHAIN_BIT, &chain->base.flags);
 
 	/*
 	 * Chaining dma_fence_chain container together is only allowed through
diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h
index ac6535716dbe..5bafd0a5f1f1 100644
--- a/include/linux/dma-fence.h
+++ b/include/linux/dma-fence.h
@@ -98,6 +98,8 @@ struct dma_fence {
 
 enum dma_fence_flag_bits {
 	DMA_FENCE_FLAG_SEQNO64_BIT,
+	DMA_FENCE_FLAG_ARRAY_BIT,
+	DMA_FENCE_FLAG_CHAIN_BIT,
 	DMA_FENCE_FLAG_SIGNALED_BIT,
 	DMA_FENCE_FLAG_TIMESTAMP_BIT,
 	DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT,
@@ -632,9 +634,6 @@ struct dma_fence *dma_fence_get_stub(void);
 struct dma_fence *dma_fence_allocate_private_stub(ktime_t timestamp);
 u64 dma_fence_context_alloc(unsigned num);
 
-extern const struct dma_fence_ops dma_fence_array_ops;
-extern const struct dma_fence_ops dma_fence_chain_ops;
-
 /**
  * dma_fence_is_array - check if a fence is from the array subclass
  * @fence: the fence to test
@@ -643,7 +642,7 @@ extern const struct dma_fence_ops dma_fence_chain_ops;
  */
 static inline bool dma_fence_is_array(struct dma_fence *fence)
 {
-	return fence->ops == &dma_fence_array_ops;
+	return test_bit(DMA_FENCE_FLAG_ARRAY_BIT, &fence->flags);
 }
 
 /**
@@ -654,7 +653,7 @@ static inline bool dma_fence_is_array(struct dma_fence *fence)
  */
 static inline bool dma_fence_is_chain(struct dma_fence *fence)
 {
-	return fence->ops == &dma_fence_chain_ops;
+	return test_bit(DMA_FENCE_FLAG_CHAIN_BIT, &fence->flags);
 }
 
 /**
-- 
2.48.0