drm/nouveau: use the new iterator in nouveau_fence_sync

Simplifying the code a bit.

The new implementation unifies the handling between drivers and so
results in waiting for all shared fernces in all cases.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20211005113742.1101-26-christian.koenig@amd.com

drivers/gpu/drm/nouveau/nouveau_fence.c

@@ -339,14 +339,15 @@ nouveau_fence_wait(struct nouveau_fence *fence, bool lazy, bool intr)
 }
 
 int
-nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan, bool exclusive, bool intr)
+nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan,
+		   bool exclusive, bool intr)
 {
 	struct nouveau_fence_chan *fctx = chan->fence;
-	struct dma_fence *fence;
 	struct dma_resv *resv = nvbo->bo.base.resv;
-	struct dma_resv_list *fobj;
+	struct dma_resv_iter cursor;
+	struct dma_fence *fence;
 	struct nouveau_fence *f;
-	int ret = 0, i;
+	int ret;
 
 	if (!exclusive) {
 		ret = dma_resv_reserve_shared(resv, 1);
@@ -355,10 +356,7 @@ nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan, bool e
 			return ret;
 	}
 
-	fobj = dma_resv_shared_list(resv);
-	fence = dma_resv_excl_fence(resv);
-
-	if (fence) {
+	dma_resv_for_each_fence(&cursor, resv, exclusive, fence) {
 		struct nouveau_channel *prev = NULL;
 		bool must_wait = true;
 
@@ -366,41 +364,19 @@ nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan, bool e
 		if (f) {
 			rcu_read_lock();
 			prev = rcu_dereference(f->channel);
-			if (prev && (prev == chan || fctx->sync(f, prev, chan) == 0))
+			if (prev && (prev == chan ||
+				     fctx->sync(f, prev, chan) == 0))
 				must_wait = false;
 			rcu_read_unlock();
 		}
 
-		if (must_wait)
+		if (must_wait) {
 			ret = dma_fence_wait(fence, intr);
-
-		return ret;
-	}
-
-	if (!exclusive || !fobj)
-		return ret;
-
-	for (i = 0; i < fobj->shared_count && !ret; ++i) {
-		struct nouveau_channel *prev = NULL;
-		bool must_wait = true;
-
-		fence = rcu_dereference_protected(fobj->shared[i],
-						dma_resv_held(resv));
-
-		f = nouveau_local_fence(fence, chan->drm);
-		if (f) {
-			rcu_read_lock();
-			prev = rcu_dereference(f->channel);
-			if (prev && (prev == chan || fctx->sync(f, prev, chan) == 0))
-				must_wait = false;
-			rcu_read_unlock();
+			if (ret)
+				return ret;
 		}
-
-		if (must_wait)
-			ret = dma_fence_wait(fence, intr);
 	}
-
-	return ret;
+	return 0;
 }
 
 void