dmaengine: virt-dma: convert tasklets to use new tasklet_setup() API

In preparation for unconditionally passing the
struct tasklet_struct pointer to all tasklet
callbacks, switch to using the new tasklet_setup()
and from_tasklet() to pass the tasklet pointer explicitly.

Signed-off-by: Romain Perier <romain.perier@gmail.com>
Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20200831103542.305571-31-allen.lkml@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
diff --git a/drivers/dma/virt-dma.c b/drivers/dma/virt-dma.c
index 23e33a8..a6f4265 100644
--- a/drivers/dma/virt-dma.c
+++ b/drivers/dma/virt-dma.c
@@ -80,9 +80,9 @@ EXPORT_SYMBOL_GPL(vchan_find_desc);
  * This tasklet handles the completion of a DMA descriptor by
  * calling its callback and freeing it.
  */
-static void vchan_complete(unsigned long arg)
+static void vchan_complete(struct tasklet_struct *t)
 {
-	struct virt_dma_chan *vc = (struct virt_dma_chan *)arg;
+	struct virt_dma_chan *vc = from_tasklet(vc, t, task);
 	struct virt_dma_desc *vd, *_vd;
 	struct dmaengine_desc_callback cb;
 	LIST_HEAD(head);
@@ -131,7 +131,7 @@ void vchan_init(struct virt_dma_chan *vc, struct dma_device *dmadev)
 	INIT_LIST_HEAD(&vc->desc_completed);
 	INIT_LIST_HEAD(&vc->desc_terminated);
 
-	tasklet_init(&vc->task, vchan_complete, (unsigned long)vc);
+	tasklet_setup(&vc->task, vchan_complete);
 
 	vc->chan.device = dmadev;
 	list_add_tail(&vc->chan.device_node, &dmadev->channels);