[Intel-gfx] [PATCH v2] get-fences-locked

[Chris Wilson]

---
 drivers/dma-buf/reservation.c | 58 +++++++++++++++++++++++++++++++++++++++++++
 include/linux/reservation.h   |  4 +++
 2 files changed, 62 insertions(+)

diff --git a/drivers/dma-buf/reservation.c b/drivers/dma-buf/reservation.c
index 3c9ab53be2b9..0f254d0d9bec 100644
--- a/drivers/dma-buf/reservation.c
+++ b/drivers/dma-buf/reservation.c
@@ -133,6 +133,64 @@ void reservation_object_add_excl_fence(struct reservation_object *obj,
 EXPORT_SYMBOL(reservation_object_add_excl_fence);
 
 /**
+ * reservation_object_get_fences_locked - Get an object's shared and exclusive
+ * fences
+ * @obj: the reservation object
+ * @pfence_excl: the returned exclusive fence (or NULL)
+ * @pshared_count: the number of shared fences returned
+ * @pshared: the array of shared fence ptrs returned (array is krealloc'd to
+ * the required size, and must be freed by caller)
+ *
+ * RETURNS
+ * Zero or -errno
+ */
+int reservation_object_get_fences_locked(struct reservation_object *obj,
+				      struct dma_fence **pfence_excl,
+				      unsigned *pshared_count,
+				      struct dma_fence ***pshared)
+{
+	struct dma_fence **shared = NULL;
+	unsigned int count = 0;
+	struct radix_tree_iter iter;
+	void **slot;
+
+	radix_tree_for_each_slot(slot, &obj->shared, &iter, 0) {
+		struct dma_fence *fence = radix_tree_deref_slot(slot);
+
+		if (dma_fence_is_signaled(fence)) {
+			radix_tree_delete(&obj->shared, iter.index);
+			continue;
+		}
+
+		if ((count & -count) == count) {
+			struct dma_fence **nshared;
+			unsigned int sz;
+
+			sz = count ? 2*count : 1;
+			nshared = krealloc(shared,
+					   sz * sizeof(*shared),
+					   GFP_TEMPORARY);
+			if (!nshared) {
+				while (count--)
+					dma_fence_put(shared[count]);
+				kfree(shared);
+				return -ENOMEM;
+			}
+
+			shared = nshared;
+		}
+
+		shared[count++] = dma_fence_get(fence);
+	}
+
+	*pshared_count = count;
+	*pshared = shared;
+	*pfence_excl = dma_fence_get(rcu_dereference(obj->excl));
+	return 0;
+}
+EXPORT_SYMBOL_GPL(reservation_object_get_fences_locked);
+
+/**
  * reservation_object_get_fences_rcu - Get an object's shared and exclusive
  * fences without update side lock held
  * @obj: the reservation object
diff --git a/include/linux/reservation.h b/include/linux/reservation.h
index 697ec52427ca..4f39942906e2 100644
--- a/include/linux/reservation.h
+++ b/include/linux/reservation.h
@@ -161,6 +161,10 @@ void reservation_object_add_shared_fence(struct reservation_object *obj,
 void reservation_object_add_excl_fence(struct reservation_object *obj,
 				       struct dma_fence *fence);
 
+int reservation_object_get_fences_locked(struct reservation_object *obj,
+				      struct dma_fence **pfence_excl,
+				      unsigned *pshared_count,
+				      struct dma_fence ***pshared);
 int reservation_object_get_fences_rcu(struct reservation_object *obj,
 				      struct dma_fence **pfence_excl,
 				      unsigned *pshared_count,
-- 
2.10.2