From: Felix Kuehling <Felix.Kuehling@amd.com>
Date: Tue, 6 Feb 2018 20:32:37 -0500
Subject: drm/amdgpu: add amdgpu_sync_clone
Git-commit: 3c728d3aa1fd5c7c2461835a93ac8fad57813db6
Patch-mainline: v4.20 or v4.20-rc7 (next release)
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Cloning a sync object is useful for waiting for a sync object
without locking the original structure indefinitely, blocking
other threads.

Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Acked-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c |   35 +++++++++++++++++++++++++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_sync.h |    1 
 2 files changed, 36 insertions(+)

--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
@@ -322,6 +322,41 @@ struct dma_fence *amdgpu_sync_get_fence(
 	return NULL;
 }
 
+/**
+ * amdgpu_sync_clone - clone a sync object
+ *
+ * @source: sync object to clone
+ * @clone: pointer to destination sync object
+ *
+ * Adds references to all unsignaled fences in @source to @clone. Also
+ * removes signaled fences from @source while at it.
+ */
+int amdgpu_sync_clone(struct amdgpu_sync *source, struct amdgpu_sync *clone)
+{
+	struct amdgpu_sync_entry *e;
+	struct hlist_node *tmp;
+	struct dma_fence *f;
+	int i, r;
+
+	hash_for_each_safe(source->fences, i, tmp, e, node) {
+		f = e->fence;
+		if (!dma_fence_is_signaled(f)) {
+			r = amdgpu_sync_fence(NULL, clone, f, e->explicit);
+			if (r)
+				return r;
+		} else {
+			hash_del(&e->node);
+			dma_fence_put(f);
+			kmem_cache_free(amdgpu_sync_slab, e);
+		}
+	}
+
+	dma_fence_put(clone->last_vm_update);
+	clone->last_vm_update = dma_fence_get(source->last_vm_update);
+
+	return 0;
+}
+
 int amdgpu_sync_wait(struct amdgpu_sync *sync, bool intr)
 {
 	struct amdgpu_sync_entry *e;
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.h
@@ -50,6 +50,7 @@ int amdgpu_sync_resv(struct amdgpu_devic
 struct dma_fence *amdgpu_sync_peek_fence(struct amdgpu_sync *sync,
 				     struct amdgpu_ring *ring);
 struct dma_fence *amdgpu_sync_get_fence(struct amdgpu_sync *sync, bool *explicit);
+int amdgpu_sync_clone(struct amdgpu_sync *source, struct amdgpu_sync *clone);
 int amdgpu_sync_wait(struct amdgpu_sync *sync, bool intr);
 void amdgpu_sync_free(struct amdgpu_sync *sync);
 int amdgpu_sync_init(void);