ftgmac100: Add pause frames configuration and support

Hopefully my understanding of how the hardware works is correct,
as the documentation isn't completely clear. So far I have seen
no obvious issue. Pause seem to also work with NC-SI.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/faraday/ftgmac100.c b/drivers/net/ethernet/faraday/ftgmac100.c
index 4cdd25a5742d7ccd13aac61ed5e0f3a4dbc8cb39..949b48c0eae67d480ced7e7feb63555f16f6af7b 100644 (file)
--- a/drivers/net/ethernet/faraday/ftgmac100.c
+++ b/drivers/net/ethernet/faraday/ftgmac100.c
@@ -99,6 +99,11 @@ struct ftgmac100 {
        int cur_duplex;
        bool use_ncsi;
 
+       /* Flow control settings */
+       bool tx_pause;
+       bool rx_pause;
+       bool aneg_pause;
+
        /* Misc */
        bool need_mac_restart;
        bool is_aspeed;
@@ -219,6 +224,23 @@ static int ftgmac100_set_mac_addr(struct net_device *dev, void *p)
        return 0;
 }
 
+static void ftgmac100_config_pause(struct ftgmac100 *priv)
+{
+       u32 fcr = FTGMAC100_FCR_PAUSE_TIME(16);
+
+       /* Throttle tx queue when receiving pause frames */
+       if (priv->rx_pause)
+               fcr |= FTGMAC100_FCR_FC_EN;
+
+       /* Enables sending pause frames when the RX queue is past a
+        * certain threshold.
+        */
+       if (priv->tx_pause)
+               fcr |= FTGMAC100_FCR_FCTHR_EN;
+
+       iowrite32(fcr, priv->base + FTGMAC100_OFFSET_FCR);
+}
+
 static void ftgmac100_init_hw(struct ftgmac100 *priv)
 {
        u32 reg, rfifo_sz, tfifo_sz;
@@ -912,6 +934,7 @@ static void ftgmac100_adjust_link(struct net_device *netdev)
 {
        struct ftgmac100 *priv = netdev_priv(netdev);
        struct phy_device *phydev = netdev->phydev;
+       bool tx_pause, rx_pause;
        int new_speed;
 
        /* We store "no link" as speed 0 */
@@ -920,8 +943,21 @@ static void ftgmac100_adjust_link(struct net_device *netdev)
        else
                new_speed = phydev->speed;
 
+       /* Grab pause settings from PHY if configured to do so */
+       if (priv->aneg_pause) {
+               rx_pause = tx_pause = phydev->pause;
+               if (phydev->asym_pause)
+                       tx_pause = !rx_pause;
+       } else {
+               rx_pause = priv->rx_pause;
+               tx_pause = priv->tx_pause;
+       }
+
+       /* Link hasn't changed, do nothing */
        if (phydev->speed == priv->cur_speed &&
-           phydev->duplex == priv->cur_duplex)
+           phydev->duplex == priv->cur_duplex &&
+           rx_pause == priv->rx_pause &&
+           tx_pause == priv->tx_pause)
                return;
 
        /* Print status if we have a link or we had one and just lost it,
@@ -932,6 +968,8 @@ static void ftgmac100_adjust_link(struct net_device *netdev)
 
        priv->cur_speed = new_speed;
        priv->cur_duplex = phydev->duplex;
+       priv->rx_pause = rx_pause;
+       priv->tx_pause = tx_pause;
 
        /* Link is down, do nothing else */
        if (!new_speed)
@@ -963,6 +1001,12 @@ static int ftgmac100_mii_probe(struct ftgmac100 *priv)
                return PTR_ERR(phydev);
        }
 
+       /* Indicate that we support PAUSE frames (see comment in
+        * Documentation/networking/phy.txt)
+        */
+       phydev->supported |= SUPPORTED_Pause | SUPPORTED_Asym_Pause;
+       phydev->advertising = phydev->supported;
+
        return 0;
 }
 
@@ -1078,6 +1122,48 @@ static int ftgmac100_set_ringparam(struct net_device *netdev,
        return 0;
 }
 
+static void ftgmac100_get_pauseparam(struct net_device *netdev,
+                                    struct ethtool_pauseparam *pause)
+{
+       struct ftgmac100 *priv = netdev_priv(netdev);
+
+       pause->autoneg = priv->aneg_pause;
+       pause->tx_pause = priv->tx_pause;
+       pause->rx_pause = priv->rx_pause;
+}
+
+static int ftgmac100_set_pauseparam(struct net_device *netdev,
+                                   struct ethtool_pauseparam *pause)
+{
+       struct ftgmac100 *priv = netdev_priv(netdev);
+       struct phy_device *phydev = netdev->phydev;
+
+       priv->aneg_pause = pause->autoneg;
+       priv->tx_pause = pause->tx_pause;
+       priv->rx_pause = pause->rx_pause;
+
+       if (phydev) {
+               phydev->advertising &= ~ADVERTISED_Pause;
+               phydev->advertising &= ~ADVERTISED_Asym_Pause;
+
+               if (pause->rx_pause) {
+                       phydev->advertising |= ADVERTISED_Pause;
+                       phydev->advertising |= ADVERTISED_Asym_Pause;
+               }
+
+               if (pause->tx_pause)
+                       phydev->advertising ^= ADVERTISED_Asym_Pause;
+       }
+       if (netif_running(netdev)) {
+               if (phydev && priv->aneg_pause)
+                       phy_start_aneg(phydev);
+               else
+                       ftgmac100_config_pause(priv);
+       }
+
+       return 0;
+}
+
 static const struct ethtool_ops ftgmac100_ethtool_ops = {
        .get_drvinfo            = ftgmac100_get_drvinfo,
        .get_link               = ethtool_op_get_link,
@@ -1086,6 +1172,8 @@ static const struct ethtool_ops ftgmac100_ethtool_ops = {
        .nway_reset             = phy_ethtool_nway_reset,
        .get_ringparam          = ftgmac100_get_ringparam,
        .set_ringparam          = ftgmac100_set_ringparam,
+       .get_pauseparam         = ftgmac100_get_pauseparam,
+       .set_pauseparam         = ftgmac100_set_pauseparam,
 };
 
 static irqreturn_t ftgmac100_interrupt(int irq, void *dev_id)
@@ -1217,6 +1305,7 @@ static int ftgmac100_init_all(struct ftgmac100 *priv, bool ignore_alloc_err)
 
        /* Reinit and restart HW */
        ftgmac100_init_hw(priv);
+       ftgmac100_config_pause(priv);
        ftgmac100_start_hw(priv);
 
        /* Re-enable the device */
@@ -1546,6 +1635,11 @@ static int ftgmac100_probe(struct platform_device *pdev)
 
        netdev->irq = irq;
 
+       /* Enable pause */
+       priv->tx_pause = true;
+       priv->rx_pause = true;
+       priv->aneg_pause = true;
+
        /* MAC address from chip or random one */
        ftgmac100_initial_mac(priv);
 

diff --git a/drivers/net/ethernet/faraday/ftgmac100.h b/drivers/net/ethernet/faraday/ftgmac100.h
index 97912c456e800ac27aa7836a86fef4e777c66b84..0653d8176e6a536601119ffadefcbe55e28c7949 100644 (file)
--- a/drivers/net/ethernet/faraday/ftgmac100.h
+++ b/drivers/net/ethernet/faraday/ftgmac100.h
@@ -198,6 +198,13 @@
 #define FTGMAC100_PHYDATA_MIIWDATA(x)          ((x) & 0xffff)
 #define FTGMAC100_PHYDATA_MIIRDATA(phydata)    (((phydata) >> 16) & 0xffff)
 
+/*
+ * Flow control register
+ */
+#define FTGMAC100_FCR_FC_EN            (1 << 0)
+#define FTGMAC100_FCR_FCTHR_EN         (1 << 2)
+#define FTGMAC100_FCR_PAUSE_TIME(x)    (((x) & 0xffff) << 16)
+
 /*
  * Transmit descriptor, aligned to 16 bytes
  */