1 files changed, 37 insertions, 46 deletions

diff --git a/drivers/dma-buf/st-dma-fence-chain.c b/drivers/dma-buf/st-dma-fence-chain.c
index 5d45ba7ba3cd..ed4b323886e4 100644
--- a/drivers/dma-buf/st-dma-fence-chain.c
+++ b/drivers/dma-buf/st-dma-fence-chain.c
@@ -58,28 +58,20 @@ static struct dma_fence *mock_fence(void)
 	return &f->base;
 }
 
-static inline struct mock_chain {
-	struct dma_fence_chain base;
-} *to_mock_chain(struct dma_fence *f) {
-	return container_of(f, struct mock_chain, base.base);
-}
-
 static struct dma_fence *mock_chain(struct dma_fence *prev,
 				    struct dma_fence *fence,
 				    u64 seqno)
 {
-	struct mock_chain *f;
+	struct dma_fence_chain *f;
 
-	f = kmalloc(sizeof(*f), GFP_KERNEL);
+	f = dma_fence_chain_alloc();
 	if (!f)
 		return NULL;
 
-	dma_fence_chain_init(&f->base,
-			     dma_fence_get(prev),
-			     dma_fence_get(fence),
+	dma_fence_chain_init(f, dma_fence_get(prev), dma_fence_get(fence),
 			     seqno);
 
-	return &f->base.base;
+	return &f->base;
 }
 
 static int sanitycheck(void *arg)
@@ -92,7 +84,9 @@ static int sanitycheck(void *arg)
 		return -ENOMEM;
 
 	chain = mock_chain(NULL, f, 1);
-	if (!chain)
+	if (chain)
+		dma_fence_enable_sw_signaling(chain);
+	else
 		err = -ENOMEM;
 
 	dma_fence_signal(f);
@@ -151,6 +145,8 @@ static int fence_chains_init(struct fence_chains *fc, unsigned int count,
 		}
 
 		fc->tail = fc->chains[i];
+
+		dma_fence_enable_sw_signaling(fc->chains[i]);
 	}
 
 	fc->chain_length = i;
@@ -318,15 +314,16 @@ static int find_out_of_order(void *arg)
 		goto err;
 	}
 
-	if (fence && fence != fc.chains[1]) {
+	/*
+	 * We signaled the middle fence (2) of the 1-2-3 chain. The behavior
+	 * of the dma-fence-chain is to make us wait for all the fences up to
+	 * the point we want. Since fence 1 is still not signaled, this what
+	 * we should get as fence to wait upon (fence 2 being garbage
+	 * collected during the traversal of the chain).
+	 */
+	if (fence != fc.chains[0]) {
 		pr_err("Incorrect chain-fence.seqno:%lld reported for completed seqno:2\n",
-		       fence->seqno);
-
-		dma_fence_get(fence);
-		err = dma_fence_chain_find_seqno(&fence, 2);
-		dma_fence_put(fence);
-		if (err)
-			pr_err("Reported %d for finding self!\n", err);
+		       fence ? fence->seqno : 0);
 
 		err = -EINVAL;
 	}
@@ -403,7 +400,7 @@ static int __find_race(void *arg)
 		struct dma_fence *fence = dma_fence_get(data->fc.tail);
 		int seqno;
 
-		seqno = prandom_u32_max(data->fc.chain_length) + 1;
+		seqno = get_random_u32_inclusive(1, data->fc.chain_length);
 
 		err = dma_fence_chain_find_seqno(&fence, seqno);
 		if (err) {
@@ -415,26 +412,24 @@ static int __find_race(void *arg)
 		if (!fence)
 			goto signal;
 
-		err = dma_fence_chain_find_seqno(&fence, seqno);
-		if (err) {
-			pr_err("Reported an invalid fence for find-self:%d\n",
-			       seqno);
-			dma_fence_put(fence);
-			break;
-		}
-
-		if (fence->seqno < seqno) {
-			pr_err("Reported an earlier fence.seqno:%lld for seqno:%d\n",
-			       fence->seqno, seqno);
-			err = -EINVAL;
-			dma_fence_put(fence);
-			break;
+		/*
+		 * We can only find ourselves if we are on fence we were
+		 * looking for.
+		 */
+		if (fence->seqno == seqno) {
+			err = dma_fence_chain_find_seqno(&fence, seqno);
+			if (err) {
+				pr_err("Reported an invalid fence for find-self:%d\n",
+				       seqno);
+				dma_fence_put(fence);
+				break;
+			}
 		}
 
 		dma_fence_put(fence);
 
 signal:
-		seqno = prandom_u32_max(data->fc.chain_length - 1);
+		seqno = get_random_u32_below(data->fc.chain_length - 1);
 		dma_fence_signal(data->fc.fences[seqno]);
 		cond_resched();
 	}
@@ -481,10 +476,9 @@ static int find_race(void *arg)
 	for (i = 0; i < ncpus; i++) {
 		int ret;
 
-		ret = kthread_stop(threads[i]);
+		ret = kthread_stop_put(threads[i]);
 		if (ret && !err)
 			err = ret;
-		put_task_struct(threads[i]);
 	}
 	kfree(threads);
 
@@ -596,8 +590,7 @@ static int wait_forward(void *arg)
 	for (i = 0; i < fc.chain_length; i++)
 		dma_fence_signal(fc.fences[i]);
 
-	err = kthread_stop(tsk);
-	put_task_struct(tsk);
+	err = kthread_stop_put(tsk);
 
 err:
 	fence_chains_fini(&fc);
@@ -626,8 +619,7 @@ static int wait_backward(void *arg)
 	for (i = fc.chain_length; i--; )
 		dma_fence_signal(fc.fences[i]);
 
-	err = kthread_stop(tsk);
-	put_task_struct(tsk);
+	err = kthread_stop_put(tsk);
 
 err:
 	fence_chains_fini(&fc);
@@ -642,7 +634,7 @@ static void randomise_fences(struct fence_chains *fc)
 	while (--count) {
 		unsigned int swp;
 
-		swp = prandom_u32_max(count + 1);
+		swp = get_random_u32_below(count + 1);
 		if (swp == count)
 			continue;
 
@@ -674,8 +666,7 @@ static int wait_random(void *arg)
 	for (i = 0; i < fc.chain_length; i++)
 		dma_fence_signal(fc.fences[i]);
 
-	err = kthread_stop(tsk);
-	put_task_struct(tsk);
+	err = kthread_stop_put(tsk);
 
 err:
 	fence_chains_fini(&fc);