From: LEROY Christophe Date: Mon, 2 Feb 2015 17:06:54 +0000 (+0100) Subject: net: fs_enet: Implement NETIF_F_SG feature X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=4fc9b87bae25;p=linux-beck.git net: fs_enet: Implement NETIF_F_SG feature Freescale ethernet controllers have the capability to re-assemble fragmented data into a single ethernet frame. This patch uses this capability and implements NETIP_F_SG feature into the fs_enet ethernet driver. On a MPC885, I get 53% performance improvement on a ftp transfer of a 15Mb file: * Without the patch : 2,8 Mbps * With the patch : 4,3 Mbps Signed-off-by: Christophe Leroy Signed-off-by: David S. Miller --- diff --git a/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c b/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c index 9e2bcb807923..a17628769a1f 100644 --- a/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c +++ b/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c @@ -278,14 +278,20 @@ static int fs_enet_tx_napi(struct napi_struct *napi, int budget) fep->stats.collisions++; /* unmap */ - dma_unmap_single(fep->dev, CBDR_BUFADDR(bdp), - skb->len, DMA_TO_DEVICE); + if (fep->mapped_as_page[dirtyidx]) + dma_unmap_page(fep->dev, CBDR_BUFADDR(bdp), + CBDR_DATLEN(bdp), DMA_TO_DEVICE); + else + dma_unmap_single(fep->dev, CBDR_BUFADDR(bdp), + CBDR_DATLEN(bdp), DMA_TO_DEVICE); /* * Free the sk buffer associated with this last transmit. */ - dev_kfree_skb(skb); - fep->tx_skbuff[dirtyidx] = NULL; + if (skb) { + dev_kfree_skb(skb); + fep->tx_skbuff[dirtyidx] = NULL; + } /* * Update pointer to next buffer descriptor to be transmitted. @@ -299,7 +305,7 @@ static int fs_enet_tx_napi(struct napi_struct *napi, int budget) * Since we have freed up a buffer, the ring is no longer * full. */ - if (!fep->tx_free++) + if (++fep->tx_free >= MAX_SKB_FRAGS) do_wake = 1; has_tx_work = 1; } @@ -509,6 +515,9 @@ static int fs_enet_start_xmit(struct sk_buff *skb, struct net_device *dev) cbd_t __iomem *bdp; int curidx; u16 sc; + int nr_frags = skb_shinfo(skb)->nr_frags; + skb_frag_t *frag; + int len; #ifdef CONFIG_FS_ENET_MPC5121_FEC if (((unsigned long)skb->data) & 0x3) { @@ -530,7 +539,7 @@ static int fs_enet_start_xmit(struct sk_buff *skb, struct net_device *dev) */ bdp = fep->cur_tx; - if (!fep->tx_free || (CBDR_SC(bdp) & BD_ENET_TX_READY)) { + if (fep->tx_free <= nr_frags || (CBDR_SC(bdp) & BD_ENET_TX_READY)) { netif_stop_queue(dev); spin_unlock(&fep->tx_lock); @@ -543,35 +552,42 @@ static int fs_enet_start_xmit(struct sk_buff *skb, struct net_device *dev) } curidx = bdp - fep->tx_bd_base; - /* - * Clear all of the status flags. - */ - CBDC_SC(bdp, BD_ENET_TX_STATS); - - /* - * Save skb pointer. - */ - fep->tx_skbuff[curidx] = skb; - - fep->stats.tx_bytes += skb->len; + len = skb->len; + fep->stats.tx_bytes += len; + if (nr_frags) + len -= skb->data_len; + fep->tx_free -= nr_frags + 1; /* * Push the data cache so the CPM does not get stale memory data. */ CBDW_BUFADDR(bdp, dma_map_single(fep->dev, - skb->data, skb->len, DMA_TO_DEVICE)); - CBDW_DATLEN(bdp, skb->len); + skb->data, len, DMA_TO_DEVICE)); + CBDW_DATLEN(bdp, len); + + fep->mapped_as_page[curidx] = 0; + frag = skb_shinfo(skb)->frags; + while (nr_frags) { + CBDC_SC(bdp, + BD_ENET_TX_STATS | BD_ENET_TX_LAST | BD_ENET_TX_TC); + CBDS_SC(bdp, BD_ENET_TX_READY); + + if ((CBDR_SC(bdp) & BD_ENET_TX_WRAP) == 0) + bdp++, curidx++; + else + bdp = fep->tx_bd_base, curidx = 0; - /* - * If this was the last BD in the ring, start at the beginning again. - */ - if ((CBDR_SC(bdp) & BD_ENET_TX_WRAP) == 0) - fep->cur_tx++; - else - fep->cur_tx = fep->tx_bd_base; + len = skb_frag_size(frag); + CBDW_BUFADDR(bdp, skb_frag_dma_map(fep->dev, frag, 0, len, + DMA_TO_DEVICE)); + CBDW_DATLEN(bdp, len); - if (!--fep->tx_free) - netif_stop_queue(dev); + fep->tx_skbuff[curidx] = NULL; + fep->mapped_as_page[curidx] = 1; + + frag++; + nr_frags--; + } /* Trigger transmission start */ sc = BD_ENET_TX_READY | BD_ENET_TX_INTR | @@ -582,8 +598,22 @@ static int fs_enet_start_xmit(struct sk_buff *skb, struct net_device *dev) * yay for hw reuse :) */ if (skb->len <= 60) sc |= BD_ENET_TX_PAD; + CBDC_SC(bdp, BD_ENET_TX_STATS); CBDS_SC(bdp, sc); + /* Save skb pointer. */ + fep->tx_skbuff[curidx] = skb; + + /* If this was the last BD in the ring, start at the beginning again. */ + if ((CBDR_SC(bdp) & BD_ENET_TX_WRAP) == 0) + bdp++; + else + bdp = fep->tx_bd_base; + fep->cur_tx = bdp; + + if (fep->tx_free < MAX_SKB_FRAGS) + netif_stop_queue(dev); + skb_tx_timestamp(skb); (*fep->ops->tx_kickstart)(dev); @@ -917,7 +947,7 @@ static int fs_enet_probe(struct platform_device *ofdev) } fpi->rx_ring = 32; - fpi->tx_ring = 32; + fpi->tx_ring = 64; fpi->rx_copybreak = 240; fpi->napi_weight = 17; fpi->phy_node = of_parse_phandle(ofdev->dev.of_node, "phy-handle", 0); @@ -955,7 +985,8 @@ static int fs_enet_probe(struct platform_device *ofdev) privsize = sizeof(*fep) + sizeof(struct sk_buff **) * - (fpi->rx_ring + fpi->tx_ring); + (fpi->rx_ring + fpi->tx_ring) + + sizeof(char) * fpi->tx_ring; ndev = alloc_etherdev(privsize); if (!ndev) { @@ -978,6 +1009,8 @@ static int fs_enet_probe(struct platform_device *ofdev) fep->rx_skbuff = (struct sk_buff **)&fep[1]; fep->tx_skbuff = fep->rx_skbuff + fpi->rx_ring; + fep->mapped_as_page = (char *)(fep->rx_skbuff + fpi->rx_ring + + fpi->tx_ring); spin_lock_init(&fep->lock); spin_lock_init(&fep->tx_lock); @@ -1007,6 +1040,8 @@ static int fs_enet_probe(struct platform_device *ofdev) netif_carrier_off(ndev); + ndev->features |= NETIF_F_SG; + ret = register_netdev(ndev); if (ret) goto out_free_bd; diff --git a/drivers/net/ethernet/freescale/fs_enet/fs_enet.h b/drivers/net/ethernet/freescale/fs_enet/fs_enet.h index 3a4b49e0e717..f184d8f952e2 100644 --- a/drivers/net/ethernet/freescale/fs_enet/fs_enet.h +++ b/drivers/net/ethernet/freescale/fs_enet/fs_enet.h @@ -134,6 +134,7 @@ struct fs_enet_private { void __iomem *ring_base; struct sk_buff **rx_skbuff; struct sk_buff **tx_skbuff; + char *mapped_as_page; cbd_t __iomem *rx_bd_base; /* Address of Rx and Tx buffers. */ cbd_t __iomem *tx_bd_base; cbd_t __iomem *dirty_tx; /* ring entries to be free()ed. */