[PATCH v2 18/64] dmaengine: xgene-dma: wire descriptor cleanup to dma_chan BH

[Allen Pais]

Replace the per-channel tasklet with the shared dma_chan BH helper.
The handler continues to run in softirq context while dmaengine owns
the common scheduling and teardown mechanism.

Signed-off-by: Allen Pais <allen.lkml@xxxxxxxxx>
---
 drivers/dma/xgene-dma.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/dma/xgene-dma.c b/drivers/dma/xgene-dma.c
index fa1173e49900..8d0428c2944e 100644
--- a/drivers/dma/xgene-dma.c
+++ b/drivers/dma/xgene-dma.c
@@ -260,7 +260,6 @@ struct xgene_dma_desc_sw {
  *	These descriptors have already had their cleanup actions run. They
  *	are waiting for the ACK bit to be set by the async tx API.
  * @desc_pool: descriptor pool for DMA operations
- * @tasklet: bottom half where all completed descriptors cleans
  * @tx_ring: transmit ring descriptor that we use to prepare actual
  *	descriptors for further executions
  * @rx_ring: receive ring descriptor that we use to get completed DMA
@@ -280,7 +279,6 @@ struct xgene_dma_chan {
 	struct list_head ld_running;
 	struct list_head ld_completed;
 	struct dma_pool *desc_pool;
-	struct tasklet_struct tasklet;
 	struct xgene_dma_ring tx_ring;
 	struct xgene_dma_ring rx_ring;
 };
@@ -975,9 +973,10 @@ static enum dma_status xgene_dma_tx_status(struct dma_chan *dchan,
 	return dma_cookie_status(dchan, cookie, txstate);
 }
 
-static void xgene_dma_tasklet_cb(struct tasklet_struct *t)
+static void xgene_dma_tasklet_cb(struct dma_chan *c)
 {
-	struct xgene_dma_chan *chan = from_tasklet(chan, t, tasklet);
+	struct xgene_dma_chan *chan = container_of(c, struct xgene_dma_chan,
+						   dma_chan);
 
 	/* Run all cleanup for descriptors which have been completed */
 	xgene_dma_cleanup_descriptors(chan);
@@ -999,11 +998,11 @@ static irqreturn_t xgene_dma_chan_ring_isr(int irq, void *id)
 	disable_irq_nosync(chan->rx_irq);
 
 	/*
-	 * Schedule the tasklet to handle all cleanup of the current
+	 * Schedule the bottom half to handle all cleanup of the current
 	 * transaction. It will start a new transaction if there is
 	 * one pending.
 	 */
-	tasklet_schedule(&chan->tasklet);
+	dma_chan_schedule_bh(&chan->dma_chan);
 
 	return IRQ_HANDLED;
 }
@@ -1539,7 +1538,7 @@ static int xgene_dma_async_register(struct xgene_dma *pdma, int id)
 	INIT_LIST_HEAD(&chan->ld_pending);
 	INIT_LIST_HEAD(&chan->ld_running);
 	INIT_LIST_HEAD(&chan->ld_completed);
-	tasklet_setup(&chan->tasklet, xgene_dma_tasklet_cb);
+	dma_chan_init_bh(&chan->dma_chan, xgene_dma_tasklet_cb);
 
 	chan->pending = 0;
 	chan->desc_pool = NULL;
@@ -1556,7 +1555,7 @@ static int xgene_dma_async_register(struct xgene_dma *pdma, int id)
 	ret = dma_async_device_register(dma_dev);
 	if (ret) {
 		chan_err(chan, "Failed to register async device %d", ret);
-		tasklet_kill(&chan->tasklet);
+		dma_chan_kill_bh(&chan->dma_chan);
 
 		return ret;
 	}
@@ -1579,7 +1578,7 @@ static int xgene_dma_init_async(struct xgene_dma *pdma)
 		if (ret) {
 			for (j = 0; j < i; j++) {
 				dma_async_device_unregister(&pdma->dma_dev[j]);
-				tasklet_kill(&pdma->chan[j].tasklet);
+				dma_chan_kill_bh(&pdma->chan[j].dma_chan);
 			}
 
 			return ret;
@@ -1790,7 +1789,7 @@ static void xgene_dma_remove(struct platform_device *pdev)
 
 	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
 		chan = &pdma->chan[i];
-		tasklet_kill(&chan->tasklet);
+		dma_chan_kill_bh(&chan->dma_chan);
 		xgene_dma_delete_chan_rings(chan);
 	}
 
-- 
2.43.0