1 files changed, 44 insertions, 0 deletions

diff --git a/drivers/dma/virt-dma.h b/drivers/dma/virt-dma.h
index 3f776a46a29c..b09b75ab0751 100644
--- a/drivers/dma/virt-dma.h
+++ b/drivers/dma/virt-dma.h
@@ -35,6 +35,7 @@ struct virt_dma_chan {
 	struct list_head desc_completed;
 
 	struct virt_dma_desc *cyclic;
+	struct virt_dma_desc *vd_terminated;
 };
 
 static inline struct virt_dma_chan *to_virt_chan(struct dma_chan *chan)
@@ -104,6 +105,20 @@ static inline void vchan_cookie_complete(struct virt_dma_desc *vd)
 }
 
 /**
+ * vchan_vdesc_fini - Free or reuse a descriptor
+ * @vd: virtual descriptor to free/reuse
+ */
+static inline void vchan_vdesc_fini(struct virt_dma_desc *vd)
+{
+	struct virt_dma_chan *vc = to_virt_chan(vd->tx.chan);
+
+	if (dmaengine_desc_test_reuse(&vd->tx))
+		list_add(&vd->node, &vc->desc_allocated);
+	else
+		vc->desc_free(vd);
+}
+
+/**
  * vchan_cyclic_callback - report the completion of a period
  * @vd: virtual descriptor
  */
@@ -116,6 +131,25 @@ static inline void vchan_cyclic_callback(struct virt_dma_desc *vd)
 }
 
 /**
+ * vchan_terminate_vdesc - Disable pending cyclic callback
+ * @vd: virtual descriptor to be terminated
+ *
+ * vc.lock must be held by caller
+ */
+static inline void vchan_terminate_vdesc(struct virt_dma_desc *vd)
+{
+	struct virt_dma_chan *vc = to_virt_chan(vd->tx.chan);
+
+	/* free up stuck descriptor */
+	if (vc->vd_terminated)
+		vchan_vdesc_fini(vc->vd_terminated);
+
+	vc->vd_terminated = vd;
+	if (vc->cyclic == vd)
+		vc->cyclic = NULL;
+}
+
+/**
  * vchan_next_desc - peek at the next descriptor to be processed
  * @vc: virtual channel to obtain descriptor from
  *
@@ -168,10 +202,20 @@ static inline void vchan_free_chan_resources(struct virt_dma_chan *vc)
  * Makes sure that all scheduled or active callbacks have finished running. For
  * proper operation the caller has to ensure that no new callbacks are scheduled
  * after the invocation of this function started.
+ * Free up the terminated cyclic descriptor to prevent memory leakage.
  */
 static inline void vchan_synchronize(struct virt_dma_chan *vc)
 {
+	unsigned long flags;
+
 	tasklet_kill(&vc->task);
+
+	spin_lock_irqsave(&vc->lock, flags);
+	if (vc->vd_terminated) {
+		vchan_vdesc_fini(vc->vd_terminated);
+		vc->vd_terminated = NULL;
+	}
+	spin_unlock_irqrestore(&vc->lock, flags);
 }
 
 #endif