1 files changed, 56 insertions, 86 deletions

diff --git a/drivers/net/ethernet/faraday/ftgmac100.c b/drivers/net/ethernet/faraday/ftgmac100.c
index 44be11da9d64..5cd854e740a9 100644
--- a/drivers/net/ethernet/faraday/ftgmac100.c
+++ b/drivers/net/ethernet/faraday/ftgmac100.c
@@ -43,8 +43,8 @@
 #define RX_QUEUE_ENTRIES	256	/* must be power of 2 */
 #define TX_QUEUE_ENTRIES	512	/* must be power of 2 */
 
-#define MAX_PKT_SIZE		1518
-#define RX_BUF_SIZE		PAGE_SIZE	/* must be smaller than 0x3fff */
+#define MAX_PKT_SIZE		1536
+#define RX_BUF_SIZE		MAX_PKT_SIZE	/* must be smaller than 0x3fff */
 
 struct ftgmac100_descs {
 	struct ftgmac100_rxdes rxdes[RX_QUEUE_ENTRIES];
@@ -60,7 +60,7 @@ struct ftgmac100 {
 	dma_addr_t descs_dma_addr;
 
 	/* Rx ring */
-	struct page *rx_pages[RX_QUEUE_ENTRIES];
+	struct sk_buff *rx_skbs[RX_QUEUE_ENTRIES];
 	unsigned int rx_pointer;
 	u32 rxdes0_edorr_mask;
 
@@ -293,13 +293,6 @@ static bool ftgmac100_rxdes_packet_ready(struct ftgmac100_rxdes *rxdes)
 	return rxdes->rxdes0 & cpu_to_le32(FTGMAC100_RXDES0_RXPKT_RDY);
 }
 
-static void ftgmac100_rxdes_set_dma_own(const struct ftgmac100 *priv,
-					struct ftgmac100_rxdes *rxdes)
-{
-	/* clear status bits */
-	rxdes->rxdes0 &= cpu_to_le32(priv->rxdes0_edorr_mask);
-}
-
 #define RXDES0_ANY_ERROR		( \
 	FTGMAC100_RXDES0_RX_ERR		| \
 	FTGMAC100_RXDES0_CRC_ERR	| \
@@ -371,58 +364,45 @@ static inline bool ftgmac100_rxdes_csum_err(struct ftgmac100_rxdes *rxdes)
 					      FTGMAC100_RXDES1_IP_CHKSUM_ERR));
 }
 
-static inline struct page **ftgmac100_rxdes_page_slot(struct ftgmac100 *priv,
-						      struct ftgmac100_rxdes *rxdes)
-{
-	return &priv->rx_pages[rxdes - priv->descs->rxdes];
-}
-
-/*
- * rxdes2 is not used by hardware. We use it to keep track of page.
- * Since hardware does not touch it, we can skip cpu_to_le32()/le32_to_cpu().
- */
-static void ftgmac100_rxdes_set_page(struct ftgmac100 *priv,
-				     struct ftgmac100_rxdes *rxdes,
-				     struct page *page)
-{
-	*ftgmac100_rxdes_page_slot(priv, rxdes) = page;
-}
-
-static struct page *ftgmac100_rxdes_get_page(struct ftgmac100 *priv,
-					     struct ftgmac100_rxdes *rxdes)
-{
-	return *ftgmac100_rxdes_page_slot(priv, rxdes);
-}
-
-static int ftgmac100_alloc_rx_page(struct ftgmac100 *priv,
-				   struct ftgmac100_rxdes *rxdes, gfp_t gfp)
+static int ftgmac100_alloc_rx_buf(struct ftgmac100 *priv, unsigned int entry,
+				  struct ftgmac100_rxdes *rxdes, gfp_t gfp)
 {
 	struct net_device *netdev = priv->netdev;
-	struct page *page;
+	struct sk_buff *skb;
 	dma_addr_t map;
 	int err;
 
-	page = alloc_page(gfp);
-	if (!page) {
+	skb = netdev_alloc_skb_ip_align(netdev, RX_BUF_SIZE);
+	if (unlikely(!skb)) {
 		if (net_ratelimit())
-			netdev_err(netdev, "failed to allocate rx page\n");
+			netdev_warn(netdev, "failed to allocate rx skb\n");
 		err = -ENOMEM;
 		map = priv->rx_scratch_dma;
+	} else {
+		map = dma_map_single(priv->dev, skb->data, RX_BUF_SIZE,
+				     DMA_FROM_DEVICE);
+		if (unlikely(dma_mapping_error(priv->dev, map))) {
+			if (net_ratelimit())
+				netdev_err(netdev, "failed to map rx page\n");
+			dev_kfree_skb_any(skb);
+			map = priv->rx_scratch_dma;
+			skb = NULL;
+			err = -ENOMEM;
+		}
 	}
 
-	map = dma_map_page(priv->dev, page, 0, RX_BUF_SIZE, DMA_FROM_DEVICE);
-	if (unlikely(dma_mapping_error(priv->dev, map))) {
-		if (net_ratelimit())
-			netdev_err(netdev, "failed to map rx page\n");
-		__free_page(page);
-		err = -ENOMEM;
-		map = priv->rx_scratch_dma;
-		page = NULL;
-	}
+	/* Store skb */
+	priv->rx_skbs[entry] = skb;
 
-	ftgmac100_rxdes_set_page(priv, rxdes, page);
+	/* Store DMA address into RX desc */
 	ftgmac100_rxdes_set_dma_addr(rxdes, map);
-	ftgmac100_rxdes_set_dma_own(priv, rxdes);
+
+	/* Ensure the above is ordered vs clearing the OWN bit */
+	dma_wmb();
+
+	/* Clean rxdes0 (which resets own bit) */
+	rxdes->rxdes0 &= cpu_to_le32(priv->rxdes0_edorr_mask);
+
 	return 0;
 }
 
@@ -453,7 +433,6 @@ static bool ftgmac100_rx_packet(struct ftgmac100 *priv, int *processed)
 	struct net_device *netdev = priv->netdev;
 	struct ftgmac100_rxdes *rxdes;
 	struct sk_buff *skb;
-	struct page *page;
 	unsigned int pointer, size;
 	dma_addr_t map;
 
@@ -476,20 +455,12 @@ static bool ftgmac100_rx_packet(struct ftgmac100 *priv, int *processed)
 		goto drop;
 	}
 
-	/* If the packet had no buffer (failed to allocate earlier)
+	/* If the packet had no skb (failed to allocate earlier)
 	 * then try to allocate one and skip
 	 */
-	page = ftgmac100_rxdes_get_page(priv, rxdes);
-	if (!page) {
-		ftgmac100_alloc_rx_page(priv, rxdes, GFP_ATOMIC);
-		goto drop;
-	}
-
-	/* start processing */
-	skb = netdev_alloc_skb_ip_align(netdev, 128);
-	if (unlikely(!skb)) {
-		if (net_ratelimit())
-			netdev_err(netdev, "rx skb alloc failed\n");
+	skb = priv->rx_skbs[pointer];
+	if (!unlikely(skb)) {
+		ftgmac100_alloc_rx_buf(priv, pointer, rxdes, GFP_ATOMIC);
 		goto drop;
 	}
 
@@ -514,33 +485,31 @@ static bool ftgmac100_rx_packet(struct ftgmac100 *priv, int *processed)
 			skb->ip_summed = CHECKSUM_UNNECESSARY;
 	}
 
-	map = ftgmac100_rxdes_get_dma_addr(rxdes);
-
-	dma_unmap_page(priv->dev, map, RX_BUF_SIZE, DMA_FROM_DEVICE);
-
+	/* Grab received size annd transfer to skb */
 	size = ftgmac100_rxdes_data_length(rxdes);
-	skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags, page, 0, size);
+	skb_put(skb, size);
 
-	skb->len += size;
-	skb->data_len += size;
-	skb->truesize += PAGE_SIZE;
+	/* Tear down DMA mapping, do necessary cache management */
+	map = ftgmac100_rxdes_get_dma_addr(rxdes);
+#if defined(CONFIG_ARM) && !defined(CONFIG_ARM_DMA_USE_IOMMU)
+	/* When we don't have an iommu, we can save cycles by not
+	 * invalidating the cache for the part of the packet that
+	 * wasn't received.
+	 */
+	dma_unmap_single(priv->dev, map, size, DMA_FROM_DEVICE);
+#else
+	dma_unmap_single(priv->dev, map, RX_BUF_SIZE, DMA_FROM_DEVICE);
+#endif
 
-	ftgmac100_alloc_rx_page(priv, rxdes, GFP_ATOMIC);
 
+	/* Resplenish rx ring */
+	ftgmac100_alloc_rx_buf(priv, pointer, rxdes, GFP_ATOMIC);
 	priv->rx_pointer = ftgmac100_next_rx_pointer(pointer);
 
-	/* Small frames are copied into linear part of skb to free one page */
-	if (skb->len <= 128) {
-		skb->truesize -= PAGE_SIZE;
-		__pskb_pull_tail(skb, skb->len);
-	} else {
-		/* We pull the minimum amount into linear part */
-		__pskb_pull_tail(skb, ETH_HLEN);
-	}
 	skb->protocol = eth_type_trans(skb, netdev);
 
 	netdev->stats.rx_packets++;
-	netdev->stats.rx_bytes += skb->len;
+	netdev->stats.rx_bytes += size;
 
 	/* push packet to protocol stack */
 	if (skb->ip_summed == CHECKSUM_NONE)
@@ -774,14 +743,15 @@ static void ftgmac100_free_buffers(struct ftgmac100 *priv)
 	/* Free all RX buffers */
 	for (i = 0; i < RX_QUEUE_ENTRIES; i++) {
 		struct ftgmac100_rxdes *rxdes = &priv->descs->rxdes[i];
-		struct page *page = ftgmac100_rxdes_get_page(priv, rxdes);
+		struct sk_buff *skb = priv->rx_skbs[i];
 		dma_addr_t map = ftgmac100_rxdes_get_dma_addr(rxdes);
 
-		if (!page)
+		if (!skb)
 			continue;
 
-		dma_unmap_page(priv->dev, map, RX_BUF_SIZE, DMA_FROM_DEVICE);
-		__free_page(page);
+		priv->rx_skbs[i] = NULL;
+		dma_unmap_single(priv->dev, map, RX_BUF_SIZE, DMA_FROM_DEVICE);
+		dev_kfree_skb_any(skb);
 	}
 
 	/* Free all TX buffers */
@@ -856,7 +826,7 @@ static int ftgmac100_alloc_rx_buffers(struct ftgmac100 *priv)
 	for (i = 0; i < RX_QUEUE_ENTRIES; i++) {
 		struct ftgmac100_rxdes *rxdes = &priv->descs->rxdes[i];
 
-		if (ftgmac100_alloc_rx_page(priv, rxdes, GFP_KERNEL))
+		if (ftgmac100_alloc_rx_buf(priv, i, rxdes, GFP_KERNEL))
 			return -ENOMEM;
 	}
 	return 0;