stmmac: fix dma api misuse

Enabling DMA_API_DEBUG, warnings are reported at runtime
because the device driver frees DMA memory with wrong functions
and it does not call dma_mapping_error after mapping dma memory.

The first problem is fixed by of introducing a flag that helps us
keeping track which mapping technique was used, so that we can use
the right API for unmap.
This approach was inspired by the e1000 driver, which uses a similar
technique.

Signed-off-by: Andre Draszik <andre.draszik@st.com>
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Reviewed-by: Denis Kirjanov <kda@linux-powerpc.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 51 insertions, 17 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 03652891fcbf..df15f00b1246 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1073,7 +1073,8 @@ static int init_dma_desc_rings(struct net_device *dev)
 		else
 			p = priv->dma_tx + i;
 		p->des2 = 0;
-		priv->tx_skbuff_dma[i] = 0;
+		priv->tx_skbuff_dma[i].buf = 0;
+		priv->tx_skbuff_dma[i].map_as_page = false;
 		priv->tx_skbuff[i] = NULL;
 	}
 
@@ -1112,17 +1113,24 @@ static void dma_free_tx_skbufs(struct stmmac_priv *priv)
 		else
 			p = priv->dma_tx + i;
 
-		if (priv->tx_skbuff_dma[i]) {
-			dma_unmap_single(priv->device,
-					 priv->tx_skbuff_dma[i],
-					 priv->hw->desc->get_tx_len(p),
-					 DMA_TO_DEVICE);
-			priv->tx_skbuff_dma[i] = 0;
+		if (priv->tx_skbuff_dma[i].buf) {
+			if (priv->tx_skbuff_dma[i].map_as_page)
+				dma_unmap_page(priv->device,
+					       priv->tx_skbuff_dma[i].buf,
+					       priv->hw->desc->get_tx_len(p),
+					       DMA_TO_DEVICE);
+			else
+				dma_unmap_single(priv->device,
+						 priv->tx_skbuff_dma[i].buf,
+						 priv->hw->desc->get_tx_len(p),
+						 DMA_TO_DEVICE);
 		}
 
 		if (priv->tx_skbuff[i] != NULL) {
 			dev_kfree_skb_any(priv->tx_skbuff[i]);
 			priv->tx_skbuff[i] = NULL;
+			priv->tx_skbuff_dma[i].buf = 0;
+			priv->tx_skbuff_dma[i].map_as_page = false;
 		}
 	}
 }
@@ -1143,7 +1151,8 @@ static int alloc_dma_desc_resources(struct stmmac_priv *priv)
 	if (!priv->rx_skbuff)
 		goto err_rx_skbuff;
 
-	priv->tx_skbuff_dma = kmalloc_array(txsize, sizeof(dma_addr_t),
+	priv->tx_skbuff_dma = kmalloc_array(txsize,
+					    sizeof(*priv->tx_skbuff_dma),
 					    GFP_KERNEL);
 	if (!priv->tx_skbuff_dma)
 		goto err_tx_skbuff_dma;
@@ -1305,12 +1314,19 @@ static void stmmac_tx_clean(struct stmmac_priv *priv)
 			pr_debug("%s: curr %d, dirty %d\n", __func__,
 				 priv->cur_tx, priv->dirty_tx);
 
-		if (likely(priv->tx_skbuff_dma[entry])) {
-			dma_unmap_single(priv->device,
-					 priv->tx_skbuff_dma[entry],
-					 priv->hw->desc->get_tx_len(p),
-					 DMA_TO_DEVICE);
-			priv->tx_skbuff_dma[entry] = 0;
+		if (likely(priv->tx_skbuff_dma[entry].buf)) {
+			if (priv->tx_skbuff_dma[entry].map_as_page)
+				dma_unmap_page(priv->device,
+					       priv->tx_skbuff_dma[entry].buf,
+					       priv->hw->desc->get_tx_len(p),
+					       DMA_TO_DEVICE);
+			else
+				dma_unmap_single(priv->device,
+						 priv->tx_skbuff_dma[entry].buf,
+						 priv->hw->desc->get_tx_len(p),
+						 DMA_TO_DEVICE);
+			priv->tx_skbuff_dma[entry].buf = 0;
+			priv->tx_skbuff_dma[entry].map_as_page = false;
 		}
 		priv->hw->mode->clean_desc3(priv, p);
 
@@ -1905,12 +1921,16 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 	if (likely(!is_jumbo)) {
 		desc->des2 = dma_map_single(priv->device, skb->data,
 					    nopaged_len, DMA_TO_DEVICE);
-		priv->tx_skbuff_dma[entry] = desc->des2;
+		if (dma_mapping_error(priv->device, desc->des2))
+			goto dma_map_err;
+		priv->tx_skbuff_dma[entry].buf = desc->des2;
 		priv->hw->desc->prepare_tx_desc(desc, 1, nopaged_len,
 						csum_insertion, priv->mode);
 	} else {
 		desc = first;
 		entry = priv->hw->mode->jumbo_frm(priv, skb, csum_insertion);
+		if (unlikely(entry < 0))
+			goto dma_map_err;
 	}
 
 	for (i = 0; i < nfrags; i++) {
@@ -1926,7 +1946,11 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
 		desc->des2 = skb_frag_dma_map(priv->device, frag, 0, len,
 					      DMA_TO_DEVICE);
-		priv->tx_skbuff_dma[entry] = desc->des2;
+		if (dma_mapping_error(priv->device, desc->des2))
+			goto dma_map_err; /* should reuse desc w/o issues */
+
+		priv->tx_skbuff_dma[entry].buf = desc->des2;
+		priv->tx_skbuff_dma[entry].map_as_page = true;
 		priv->hw->desc->prepare_tx_desc(desc, 0, len, csum_insertion,
 						priv->mode);
 		wmb();
@@ -1993,7 +2017,12 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 	priv->hw->dma->enable_dma_transmission(priv->ioaddr);
 
 	spin_unlock(&priv->tx_lock);
+	return NETDEV_TX_OK;
 
+dma_map_err:
+	dev_err(priv->device, "Tx dma map failed\n");
+	dev_kfree_skb(skb);
+	priv->dev->stats.tx_dropped++;
 	return NETDEV_TX_OK;
 }
 
@@ -2046,7 +2075,12 @@ static inline void stmmac_rx_refill(struct stmmac_priv *priv)
 			priv->rx_skbuff_dma[entry] =
 			    dma_map_single(priv->device, skb->data, bfsize,
 					   DMA_FROM_DEVICE);
-
+			if (dma_mapping_error(priv->device,
+					      priv->rx_skbuff_dma[entry])) {
+				dev_err(priv->device, "Rx dma map failed\n");
+				dev_kfree_skb(skb);
+				break;
+			}
 			p->des2 = priv->rx_skbuff_dma[entry];
 
 			priv->hw->mode->refill_desc3(priv, p);