net: hix5hd2_gmac: add tx scatter-gather feature

"hisi-gemac-v2" adds the SG/TXCSUM/TSO/UFO features.
This patch only adds the SG(scatter-gather) driver for transmitting,
the drivers of other features will be submitted later.

Signed-off-by: Dongpo Li <lidongpo@hisilicon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/hisilicon/hix5hd2_gmac.c b/drivers/net/ethernet/hisilicon/hix5hd2_gmac.c
index 27cb2e6..18af55b 100644 (file)
--- a/drivers/net/ethernet/hisilicon/hix5hd2_gmac.c
+++ b/drivers/net/ethernet/hisilicon/hix5hd2_gmac.c
@@ -11,6 +11,7 @@
 #include <linux/interrupt.h>
 #include <linux/etherdevice.h>
 #include <linux/platform_device.h>
+#include <linux/of_device.h>
 #include <linux/of_net.h>
 #include <linux/of_mdio.h>
 #include <linux/clk.h>
@@ -183,6 +184,8 @@
 #define DESC_DATA_LEN_OFF              16
 #define DESC_BUFF_LEN_OFF              0
 #define DESC_DATA_MASK                 0x7ff
+#define DESC_SG                                BIT(30)
+#define DESC_FRAGS_NUM_OFF             11
 
 /* DMA descriptor ring helpers */
 #define dma_ring_incr(n, s)            (((n) + 1) & ((s) - 1))
@@ -192,6 +195,7 @@
 #define HW_CAP_TSO                     BIT(0)
 #define GEMAC_V1                       0
 #define GEMAC_V2                       (GEMAC_V1 | HW_CAP_TSO)
+#define HAS_CAP_TSO(hw_cap)            ((hw_cap) & HW_CAP_TSO)
 
 struct hix5hd2_desc {
        __le32 buff_addr;
@@ -205,6 +209,27 @@ struct hix5hd2_desc_sw {
        unsigned int    size;
 };
 
+struct hix5hd2_sg_desc_ring {
+       struct sg_desc *desc;
+       dma_addr_t phys_addr;
+};
+
+struct frags_info {
+       __le32 addr;
+       __le32 size;
+};
+
+/* hardware supported max skb frags num */
+#define SG_MAX_SKB_FRAGS       17
+struct sg_desc {
+       __le32 total_len;
+       __le32 resvd0;
+       __le32 linear_addr;
+       __le32 linear_len;
+       /* reserve one more frags for memory alignment */
+       struct frags_info frags[SG_MAX_SKB_FRAGS + 1];
+};
+
 #define QUEUE_NUMS     4
 struct hix5hd2_priv {
        struct hix5hd2_desc_sw pool[QUEUE_NUMS];
@@ -212,6 +237,7 @@ struct hix5hd2_priv {
 #define rx_bq          pool[1]
 #define tx_bq          pool[2]
 #define tx_rq          pool[3]
+       struct hix5hd2_sg_desc_ring tx_ring;
 
        void __iomem *base;
        void __iomem *ctrl_base;
@@ -225,6 +251,7 @@ struct hix5hd2_priv {
        struct device_node *phy_node;
        phy_interface_t phy_mode;
 
+       unsigned long hw_cap;
        unsigned int speed;
        unsigned int duplex;
 
@@ -515,6 +542,27 @@ next:
        return num;
 }
 
+static void hix5hd2_clean_sg_desc(struct hix5hd2_priv *priv,
+                                 struct sk_buff *skb, u32 pos)
+{
+       struct sg_desc *desc;
+       dma_addr_t addr;
+       u32 len;
+       int i;
+
+       desc = priv->tx_ring.desc + pos;
+
+       addr = le32_to_cpu(desc->linear_addr);
+       len = le32_to_cpu(desc->linear_len);
+       dma_unmap_single(priv->dev, addr, len, DMA_TO_DEVICE);
+
+       for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+               addr = le32_to_cpu(desc->frags[i].addr);
+               len = le32_to_cpu(desc->frags[i].size);
+               dma_unmap_page(priv->dev, addr, len, DMA_TO_DEVICE);
+       }
+}
+
 static void hix5hd2_xmit_reclaim(struct net_device *dev)
 {
        struct sk_buff *skb;
@@ -542,8 +590,15 @@ static void hix5hd2_xmit_reclaim(struct net_device *dev)
                pkts_compl++;
                bytes_compl += skb->len;
                desc = priv->tx_rq.desc + pos;
-               addr = le32_to_cpu(desc->buff_addr);
-               dma_unmap_single(priv->dev, addr, skb->len, DMA_TO_DEVICE);
+
+               if (skb_shinfo(skb)->nr_frags) {
+                       hix5hd2_clean_sg_desc(priv, skb, pos);
+               } else {
+                       addr = le32_to_cpu(desc->buff_addr);
+                       dma_unmap_single(priv->dev, addr, skb->len,
+                                        DMA_TO_DEVICE);
+               }
+
                priv->tx_skb[pos] = NULL;
                dev_consume_skb_any(skb);
                pos = dma_ring_incr(pos, TX_DESC_NUM);
@@ -604,12 +659,66 @@ static irqreturn_t hix5hd2_interrupt(int irq, void *dev_id)
        return IRQ_HANDLED;
 }
 
+static u32 hix5hd2_get_desc_cmd(struct sk_buff *skb, unsigned long hw_cap)
+{
+       u32 cmd = 0;
+
+       if (HAS_CAP_TSO(hw_cap)) {
+               if (skb_shinfo(skb)->nr_frags)
+                       cmd |= DESC_SG;
+               cmd |= skb_shinfo(skb)->nr_frags << DESC_FRAGS_NUM_OFF;
+       } else {
+               cmd |= DESC_FL_FULL |
+                       ((skb->len & DESC_DATA_MASK) << DESC_BUFF_LEN_OFF);
+       }
+
+       cmd |= (skb->len & DESC_DATA_MASK) << DESC_DATA_LEN_OFF;
+       cmd |= DESC_VLD_BUSY;
+
+       return cmd;
+}
+
+static int hix5hd2_fill_sg_desc(struct hix5hd2_priv *priv,
+                               struct sk_buff *skb, u32 pos)
+{
+       struct sg_desc *desc;
+       dma_addr_t addr;
+       int ret;
+       int i;
+
+       desc = priv->tx_ring.desc + pos;
+
+       desc->total_len = cpu_to_le32(skb->len);
+       addr = dma_map_single(priv->dev, skb->data, skb_headlen(skb),
+                             DMA_TO_DEVICE);
+       if (unlikely(dma_mapping_error(priv->dev, addr)))
+               return -EINVAL;
+       desc->linear_addr = cpu_to_le32(addr);
+       desc->linear_len = cpu_to_le32(skb_headlen(skb));
+
+       for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+               skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+               int len = frag->size;
+
+               addr = skb_frag_dma_map(priv->dev, frag, 0, len, DMA_TO_DEVICE);
+               ret = dma_mapping_error(priv->dev, addr);
+               if (unlikely(ret))
+                       return -EINVAL;
+               desc->frags[i].addr = cpu_to_le32(addr);
+               desc->frags[i].size = cpu_to_le32(len);
+       }
+
+       return 0;
+}
+
 static int hix5hd2_net_xmit(struct sk_buff *skb, struct net_device *dev)
 {
        struct hix5hd2_priv *priv = netdev_priv(dev);
        struct hix5hd2_desc *desc;
        dma_addr_t addr;
        u32 pos;
+       u32 cmd;
+       int ret;
 
        /* software write pointer */
        pos = dma_cnt(readl_relaxed(priv->base + TX_BQ_WR_ADDR));
@@ -620,18 +729,31 @@ static int hix5hd2_net_xmit(struct sk_buff *skb, struct net_device *dev)
                return NETDEV_TX_BUSY;
        }
 
-       addr = dma_map_single(priv->dev, skb->data, skb->len, DMA_TO_DEVICE);
-       if (dma_mapping_error(priv->dev, addr)) {
-               dev_kfree_skb_any(skb);
-               return NETDEV_TX_OK;
-       }
-
        desc = priv->tx_bq.desc + pos;
+
+       cmd = hix5hd2_get_desc_cmd(skb, priv->hw_cap);
+       desc->cmd = cpu_to_le32(cmd);
+
+       if (skb_shinfo(skb)->nr_frags) {
+               ret = hix5hd2_fill_sg_desc(priv, skb, pos);
+               if (unlikely(ret)) {
+                       dev_kfree_skb_any(skb);
+                       dev->stats.tx_dropped++;
+                       return NETDEV_TX_OK;
+               }
+               addr = priv->tx_ring.phys_addr + pos * sizeof(struct sg_desc);
+       } else {
+               addr = dma_map_single(priv->dev, skb->data, skb->len,
+                                     DMA_TO_DEVICE);
+               if (unlikely(dma_mapping_error(priv->dev, addr))) {
+                       dev_kfree_skb_any(skb);
+                       dev->stats.tx_dropped++;
+                       return NETDEV_TX_OK;
+               }
+       }
        desc->buff_addr = cpu_to_le32(addr);
+
        priv->tx_skb[pos] = skb;
-       desc->cmd = cpu_to_le32(DESC_VLD_BUSY | DESC_FL_FULL |
-                               (skb->len & DESC_DATA_MASK) << DESC_DATA_LEN_OFF |
-                               (skb->len & DESC_DATA_MASK) << DESC_BUFF_LEN_OFF);
 
        /* ensure desc updated */
        wmb();
@@ -866,10 +988,40 @@ error_free_pool:
        return -ENOMEM;
 }
 
+static int hix5hd2_init_sg_desc_queue(struct hix5hd2_priv *priv)
+{
+       struct sg_desc *desc;
+       dma_addr_t phys_addr;
+
+       desc = (struct sg_desc *)dma_alloc_coherent(priv->dev,
+                               TX_DESC_NUM * sizeof(struct sg_desc),
+                               &phys_addr, GFP_KERNEL);
+       if (!desc)
+               return -ENOMEM;
+
+       priv->tx_ring.desc = desc;
+       priv->tx_ring.phys_addr = phys_addr;
+
+       return 0;
+}
+
+static void hix5hd2_destroy_sg_desc_queue(struct hix5hd2_priv *priv)
+{
+       if (priv->tx_ring.desc) {
+               dma_free_coherent(priv->dev,
+                                 TX_DESC_NUM * sizeof(struct sg_desc),
+                                 priv->tx_ring.desc, priv->tx_ring.phys_addr);
+               priv->tx_ring.desc = NULL;
+       }
+}
+
+static const struct of_device_id hix5hd2_of_match[];
+
 static int hix5hd2_dev_probe(struct platform_device *pdev)
 {
        struct device *dev = &pdev->dev;
        struct device_node *node = dev->of_node;
+       const struct of_device_id *of_id = NULL;
        struct net_device *ndev;
        struct hix5hd2_priv *priv;
        struct resource *res;
@@ -887,6 +1039,13 @@ static int hix5hd2_dev_probe(struct platform_device *pdev)
        priv->dev = dev;
        priv->netdev = ndev;
 
+       of_id = of_match_device(hix5hd2_of_match, dev);
+       if (!of_id) {
+               ret = -EINVAL;
+               goto out_free_netdev;
+       }
+       priv->hw_cap = (unsigned long)of_id->data;
+
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        priv->base = devm_ioremap_resource(dev, res);
        if (IS_ERR(priv->base)) {
@@ -976,11 +1135,24 @@ static int hix5hd2_dev_probe(struct platform_device *pdev)
        ndev->ethtool_ops = &hix5hd2_ethtools_ops;
        SET_NETDEV_DEV(ndev, dev);
 
+       if (HAS_CAP_TSO(priv->hw_cap))
+               ndev->hw_features |= NETIF_F_SG;
+
+       ndev->features |= ndev->hw_features | NETIF_F_HIGHDMA;
+       ndev->vlan_features |= ndev->features;
+
        ret = hix5hd2_init_hw_desc_queue(priv);
        if (ret)
                goto out_phy_node;
 
        netif_napi_add(ndev, &priv->napi, hix5hd2_poll, NAPI_POLL_WEIGHT);
+
+       if (HAS_CAP_TSO(priv->hw_cap)) {
+               ret = hix5hd2_init_sg_desc_queue(priv);
+               if (ret)
+                       goto out_destroy_queue;
+       }
+
        ret = register_netdev(priv->netdev);
        if (ret) {
                netdev_err(ndev, "register_netdev failed!");
@@ -992,6 +1164,8 @@ static int hix5hd2_dev_probe(struct platform_device *pdev)
        return ret;
 
 out_destroy_queue:
+       if (HAS_CAP_TSO(priv->hw_cap))
+               hix5hd2_destroy_sg_desc_queue(priv);
        netif_napi_del(&priv->napi);
        hix5hd2_destroy_hw_desc_queue(priv);
 out_phy_node:
@@ -1016,6 +1190,8 @@ static int hix5hd2_dev_remove(struct platform_device *pdev)
        mdiobus_unregister(priv->bus);
        mdiobus_free(priv->bus);
 
+       if (HAS_CAP_TSO(priv->hw_cap))
+               hix5hd2_destroy_sg_desc_queue(priv);
        hix5hd2_destroy_hw_desc_queue(priv);
        of_node_put(priv->phy_node);
        cancel_work_sync(&priv->tx_timeout_task);