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[07/11] dma-buf: Add dma_fence_array_for_each (v2)

Message ID 20220124130328.2376-8-christian.koenig@amd.com
State Accepted
Commit caaf2ae712b7cc3c7717898fe267dbf882a502ef
Headers show
Series [01/11] drm/radeon: use ttm_resource_manager_debug | expand

Commit Message

Christian König Jan. 24, 2022, 1:03 p.m. UTC 
From: Christian König <ckoenig.leichtzumerken@gmail.com>

Add a helper to iterate over all fences in a dma_fence_array object.

v2 (Jason Ekstrand)
 - Return NULL from dma_fence_array_first if head == NULL.  This matches
   the iterator behavior of dma_fence_chain_for_each in that it iterates
   zero times if head == NULL.
 - Return NULL from dma_fence_array_next if index > array->num_fences.

Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Christian König <christian.koenig@amd.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
---
 drivers/dma-buf/dma-fence-array.c | 27 +++++++++++++++++++++++++++
 include/linux/dma-fence-array.h   | 17 +++++++++++++++++
 2 files changed, 44 insertions(+)
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Patch

diff --git a/drivers/dma-buf/dma-fence-array.c b/drivers/dma-buf/dma-fence-array.c
index cb1bacb5a42b..52b85d292383 100644
--- a/drivers/dma-buf/dma-fence-array.c
+++ b/drivers/dma-buf/dma-fence-array.c
@@ -219,3 +219,30 @@  bool dma_fence_match_context(struct dma_fence *fence, u64 context)
 	return true;
 }
 EXPORT_SYMBOL(dma_fence_match_context);
+
+struct dma_fence *dma_fence_array_first(struct dma_fence *head)
+{
+	struct dma_fence_array *array;
+
+	if (!head)
+		return NULL;
+
+	array = to_dma_fence_array(head);
+	if (!array)
+		return head;
+
+	return array->fences[0];
+}
+EXPORT_SYMBOL(dma_fence_array_first);
+
+struct dma_fence *dma_fence_array_next(struct dma_fence *head,
+				       unsigned int index)
+{
+	struct dma_fence_array *array = to_dma_fence_array(head);
+
+	if (!array || index >= array->num_fences)
+		return NULL;
+
+	return array->fences[index];
+}
+EXPORT_SYMBOL(dma_fence_array_next);
diff --git a/include/linux/dma-fence-array.h b/include/linux/dma-fence-array.h
index fec374f69e12..e34dcb0bb462 100644
--- a/include/linux/dma-fence-array.h
+++ b/include/linux/dma-fence-array.h
@@ -61,6 +61,19 @@  to_dma_fence_array(struct dma_fence *fence)
 	return container_of(fence, struct dma_fence_array, base);
 }
 
+/**
+ * dma_fence_array_for_each - iterate over all fences in array
+ * @fence: current fence
+ * @index: index into the array
+ * @head: potential dma_fence_array object
+ *
+ * Test if @array is a dma_fence_array object and if yes iterate over all fences
+ * in the array. If not just iterate over the fence in @array itself.
+ */
+#define dma_fence_array_for_each(fence, index, head)			\
+	for (index = 0, fence = dma_fence_array_first(head); fence;	\
+	     ++(index), fence = dma_fence_array_next(head, index))
+
 struct dma_fence_array *dma_fence_array_create(int num_fences,
 					       struct dma_fence **fences,
 					       u64 context, unsigned seqno,
@@ -68,4 +81,8 @@  struct dma_fence_array *dma_fence_array_create(int num_fences,
 
 bool dma_fence_match_context(struct dma_fence *fence, u64 context);
 
+struct dma_fence *dma_fence_array_first(struct dma_fence *head);
+struct dma_fence *dma_fence_array_next(struct dma_fence *head,
+				       unsigned int index);
+
 #endif /* __LINUX_DMA_FENCE_ARRAY_H */