1 files changed, 48 insertions, 28 deletions

diff --git a/drivers/dma/sf-pdma/sf-pdma.c b/drivers/dma/sf-pdma/sf-pdma.c
index f12606aeff87..6b524eb6bcf3 100644
--- a/drivers/dma/sf-pdma/sf-pdma.c
+++ b/drivers/dma/sf-pdma/sf-pdma.c
@@ -52,16 +52,6 @@ static inline struct sf_pdma_desc *to_sf_pdma_desc(struct virt_dma_desc *vd)
 static struct sf_pdma_desc *sf_pdma_alloc_desc(struct sf_pdma_chan *chan)
 {
 	struct sf_pdma_desc *desc;
-	unsigned long flags;
-
-	spin_lock_irqsave(&chan->lock, flags);
-
-	if (chan->desc && !chan->desc->in_use) {
-		spin_unlock_irqrestore(&chan->lock, flags);
-		return chan->desc;
-	}
-
-	spin_unlock_irqrestore(&chan->lock, flags);
 
 	desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
 	if (!desc)
@@ -111,7 +101,6 @@ sf_pdma_prep_dma_memcpy(struct dma_chan *dchan,	dma_addr_t dest, dma_addr_t src,
 	desc->async_tx = vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
 
 	spin_lock_irqsave(&chan->vchan.lock, iflags);
-	chan->desc = desc;
 	sf_pdma_fill_desc(desc, dest, src, len);
 	spin_unlock_irqrestore(&chan->vchan.lock, iflags);
 
@@ -170,11 +159,17 @@ static size_t sf_pdma_desc_residue(struct sf_pdma_chan *chan,
 	unsigned long flags;
 	u64 residue = 0;
 	struct sf_pdma_desc *desc;
-	struct dma_async_tx_descriptor *tx;
+	struct dma_async_tx_descriptor *tx = NULL;
 
 	spin_lock_irqsave(&chan->vchan.lock, flags);
 
-	tx = &chan->desc->vdesc.tx;
+	list_for_each_entry(vd, &chan->vchan.desc_submitted, node)
+		if (vd->tx.cookie == cookie)
+			tx = &vd->tx;
+
+	if (!tx)
+		goto out;
+
 	if (cookie == tx->chan->completed_cookie)
 		goto out;
 
@@ -241,6 +236,19 @@ static void sf_pdma_enable_request(struct sf_pdma_chan *chan)
 	writel(v, regs->ctrl);
 }
 
+static struct sf_pdma_desc *sf_pdma_get_first_pending_desc(struct sf_pdma_chan *chan)
+{
+	struct virt_dma_chan *vchan = &chan->vchan;
+	struct virt_dma_desc *vdesc;
+
+	if (list_empty(&vchan->desc_issued))
+		return NULL;
+
+	vdesc = list_first_entry(&vchan->desc_issued, struct virt_dma_desc, node);
+
+	return container_of(vdesc, struct sf_pdma_desc, vdesc);
+}
+
 static void sf_pdma_xfer_desc(struct sf_pdma_chan *chan)
 {
 	struct sf_pdma_desc *desc = chan->desc;
@@ -268,8 +276,11 @@ static void sf_pdma_issue_pending(struct dma_chan *dchan)
 
 	spin_lock_irqsave(&chan->vchan.lock, flags);
 
-	if (vchan_issue_pending(&chan->vchan) && chan->desc)
+	if (!chan->desc && vchan_issue_pending(&chan->vchan)) {
+		/* vchan_issue_pending has made a check that desc in not NULL */
+		chan->desc = sf_pdma_get_first_pending_desc(chan);
 		sf_pdma_xfer_desc(chan);
+	}
 
 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
 }
@@ -298,6 +309,11 @@ static void sf_pdma_donebh_tasklet(struct tasklet_struct *t)
 	spin_lock_irqsave(&chan->vchan.lock, flags);
 	list_del(&chan->desc->vdesc.node);
 	vchan_cookie_complete(&chan->desc->vdesc);
+
+	chan->desc = sf_pdma_get_first_pending_desc(chan);
+	if (chan->desc)
+		sf_pdma_xfer_desc(chan);
+
 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
 }
 
@@ -389,10 +405,8 @@ static int sf_pdma_irq_init(struct platform_device *pdev, struct sf_pdma *pdma)
 		chan = &pdma->chans[i];
 
 		irq = platform_get_irq(pdev, i * 2);
-		if (irq < 0) {
-			dev_err(&pdev->dev, "ch(%d) Can't get done irq.\n", i);
+		if (irq < 0)
 			return -EINVAL;
-		}
 
 		r = devm_request_irq(&pdev->dev, irq, sf_pdma_done_isr, 0,
 				     dev_name(&pdev->dev), (void *)chan);
@@ -404,10 +418,8 @@ static int sf_pdma_irq_init(struct platform_device *pdev, struct sf_pdma *pdma)
 		chan->txirq = irq;
 
 		irq = platform_get_irq(pdev, (i * 2) + 1);
-		if (irq < 0) {
-			dev_err(&pdev->dev, "ch(%d) Can't get err irq.\n", i);
+		if (irq < 0)
 			return -EINVAL;
-		}
 
 		r = devm_request_irq(&pdev->dev, irq, sf_pdma_err_isr, 0,
 				     dev_name(&pdev->dev), (void *)chan);
@@ -482,23 +494,30 @@ static void sf_pdma_setup_chans(struct sf_pdma *pdma)
 static int sf_pdma_probe(struct platform_device *pdev)
 {
 	struct sf_pdma *pdma;
-	struct sf_pdma_chan *chan;
 	struct resource *res;
-	int len, chans;
-	int ret;
+	int ret, n_chans;
 	const enum dma_slave_buswidth widths =
 		DMA_SLAVE_BUSWIDTH_1_BYTE | DMA_SLAVE_BUSWIDTH_2_BYTES |
 		DMA_SLAVE_BUSWIDTH_4_BYTES | DMA_SLAVE_BUSWIDTH_8_BYTES |
 		DMA_SLAVE_BUSWIDTH_16_BYTES | DMA_SLAVE_BUSWIDTH_32_BYTES |
 		DMA_SLAVE_BUSWIDTH_64_BYTES;
 
-	chans = PDMA_NR_CH;
-	len = sizeof(*pdma) + sizeof(*chan) * chans;
-	pdma = devm_kzalloc(&pdev->dev, len, GFP_KERNEL);
+	ret = of_property_read_u32(pdev->dev.of_node, "dma-channels", &n_chans);
+	if (ret) {
+		/* backwards-compatibility for no dma-channels property */
+		dev_dbg(&pdev->dev, "set number of channels to default value: 4\n");
+		n_chans = PDMA_MAX_NR_CH;
+	} else if (n_chans > PDMA_MAX_NR_CH) {
+		dev_err(&pdev->dev, "the number of channels exceeds the maximum\n");
+		return -EINVAL;
+	}
+
+	pdma = devm_kzalloc(&pdev->dev, struct_size(pdma, chans, n_chans),
+			    GFP_KERNEL);
 	if (!pdma)
 		return -ENOMEM;
 
-	pdma->n_chans = chans;
+	pdma->n_chans = n_chans;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	pdma->membase = devm_ioremap_resource(&pdev->dev, res);
@@ -556,7 +575,7 @@ static int sf_pdma_remove(struct platform_device *pdev)
 	struct sf_pdma_chan *ch;
 	int i;
 
-	for (i = 0; i < PDMA_NR_CH; i++) {
+	for (i = 0; i < pdma->n_chans; i++) {
 		ch = &pdma->chans[i];
 
 		devm_free_irq(&pdev->dev, ch->txirq, ch);
@@ -574,6 +593,7 @@ static int sf_pdma_remove(struct platform_device *pdev)
 
 static const struct of_device_id sf_pdma_dt_ids[] = {
 	{ .compatible = "sifive,fu540-c000-pdma" },
+	{ .compatible = "sifive,pdma0" },
 	{},
 };
 MODULE_DEVICE_TABLE(of, sf_pdma_dt_ids);