1 files changed, 311 insertions, 0 deletions
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_phylink.c b/drivers/net/ethernet/meta/fbnic/fbnic_phylink.c
new file mode 100644
index 000000000000..09c5225111be
--- /dev/null
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_phylink.c
@@ -0,0 +1,311 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) Meta Platforms, Inc. and affiliates. */
+
+#include <linux/pcs/pcs-xpcs.h>
+#include <linux/phy.h>
+#include <linux/phylink.h>
+
+#include "fbnic.h"
+#include "fbnic_mac.h"
+#include "fbnic_netdev.h"
+
+static phy_interface_t fbnic_phylink_select_interface(u8 aui)
+{
+	switch (aui) {
+	case FBNIC_AUI_100GAUI2:
+		return PHY_INTERFACE_MODE_100GBASEP;
+	case FBNIC_AUI_50GAUI1:
+		return PHY_INTERFACE_MODE_50GBASER;
+	case FBNIC_AUI_LAUI2:
+		return PHY_INTERFACE_MODE_LAUI;
+	case FBNIC_AUI_25GAUI:
+		return PHY_INTERFACE_MODE_25GBASER;
+	}
+
+	return PHY_INTERFACE_MODE_NA;
+}
+
+void fbnic_phylink_get_pauseparam(struct net_device *netdev,
+				  struct ethtool_pauseparam *pause)
+{
+	struct fbnic_net *fbn = netdev_priv(netdev);
+
+	phylink_ethtool_get_pauseparam(fbn->phylink, pause);
+}
+
+int fbnic_phylink_set_pauseparam(struct net_device *netdev,
+				 struct ethtool_pauseparam *pause)
+{
+	struct fbnic_net *fbn = netdev_priv(netdev);
+
+	return phylink_ethtool_set_pauseparam(fbn->phylink, pause);
+}
+
+static void
+fbnic_phylink_get_supported_fec_modes(unsigned long *supported)
+{
+	/* The NIC can support up to 8 possible combinations.
+	 * Either 50G-CR, or 100G-CR2
+	 *   This is with RS FEC mode only
+	 * Either 25G-CR, or 50G-CR2
+	 *   This is with No FEC, RS, or Base-R
+	 */
+	if (phylink_test(supported, 100000baseCR2_Full) ||
+	    phylink_test(supported, 50000baseCR_Full))
+		phylink_set(supported, FEC_RS);
+	if (phylink_test(supported, 50000baseCR2_Full) ||
+	    phylink_test(supported, 25000baseCR_Full)) {
+		phylink_set(supported, FEC_BASER);
+		phylink_set(supported, FEC_NONE);
+		phylink_set(supported, FEC_RS);
+	}
+}
+
+int fbnic_phylink_ethtool_ksettings_get(struct net_device *netdev,
+					struct ethtool_link_ksettings *cmd)
+{
+	struct fbnic_net *fbn = netdev_priv(netdev);
+	int err;
+
+	err = phylink_ethtool_ksettings_get(fbn->phylink, cmd);
+	if (!err) {
+		unsigned long *supp = cmd->link_modes.supported;
+
+		cmd->base.port = PORT_DA;
+		cmd->lanes = (fbn->aui & FBNIC_AUI_MODE_R2) ? 2 : 1;
+
+		fbnic_phylink_get_supported_fec_modes(supp);
+	}
+
+	return err;
+}
+
+int fbnic_phylink_get_fecparam(struct net_device *netdev,
+			       struct ethtool_fecparam *fecparam)
+{
+	struct fbnic_net *fbn = netdev_priv(netdev);
+
+	if (fbn->fec & FBNIC_FEC_RS) {
+		fecparam->active_fec = ETHTOOL_FEC_RS;
+		fecparam->fec = ETHTOOL_FEC_RS;
+	} else if (fbn->fec & FBNIC_FEC_BASER) {
+		fecparam->active_fec = ETHTOOL_FEC_BASER;
+		fecparam->fec = ETHTOOL_FEC_BASER;
+	} else {
+		fecparam->active_fec = ETHTOOL_FEC_OFF;
+		fecparam->fec = ETHTOOL_FEC_OFF;
+	}
+
+	if (fbn->aui & FBNIC_AUI_MODE_PAM4)
+		fecparam->fec |= ETHTOOL_FEC_AUTO;
+
+	return 0;
+}
+
+static struct phylink_pcs *
+fbnic_phylink_mac_select_pcs(struct phylink_config *config,
+			     phy_interface_t interface)
+{
+	struct net_device *netdev = to_net_dev(config->dev);
+	struct fbnic_net *fbn = netdev_priv(netdev);
+
+	return fbn->pcs;
+}
+
+static int
+fbnic_phylink_mac_prepare(struct phylink_config *config, unsigned int mode,
+			  phy_interface_t iface)
+{
+	struct net_device *netdev = to_net_dev(config->dev);
+	struct fbnic_net *fbn = netdev_priv(netdev);
+	struct fbnic_dev *fbd = fbn->fbd;
+
+	fbd->mac->prepare(fbd, fbn->aui, fbn->fec);
+
+	return 0;
+}
+
+static void
+fbnic_phylink_mac_config(struct phylink_config *config, unsigned int mode,
+			 const struct phylink_link_state *state)
+{
+}
+
+static int
+fbnic_phylink_mac_finish(struct phylink_config *config, unsigned int mode,
+			 phy_interface_t iface)
+{
+	struct net_device *netdev = to_net_dev(config->dev);
+	struct fbnic_net *fbn = netdev_priv(netdev);
+	struct fbnic_dev *fbd = fbn->fbd;
+
+	/* Retest the link state and restart interrupts */
+	fbd->mac->get_link(fbd, fbn->aui, fbn->fec);
+
+	return 0;
+}
+
+static void
+fbnic_phylink_mac_link_down(struct phylink_config *config, unsigned int mode,
+			    phy_interface_t interface)
+{
+	struct net_device *netdev = to_net_dev(config->dev);
+	struct fbnic_net *fbn = netdev_priv(netdev);
+	struct fbnic_dev *fbd = fbn->fbd;
+
+	fbd->mac->link_down(fbd);
+
+	fbn->link_down_events++;
+}
+
+static void
+fbnic_phylink_mac_link_up(struct phylink_config *config,
+			  struct phy_device *phy, unsigned int mode,
+			  phy_interface_t interface, int speed, int duplex,
+			  bool tx_pause, bool rx_pause)
+{
+	struct net_device *netdev = to_net_dev(config->dev);
+	struct fbnic_net *fbn = netdev_priv(netdev);
+	struct fbnic_dev *fbd = fbn->fbd;
+
+	fbn->tx_pause = tx_pause;
+	fbnic_config_drop_mode(fbn, tx_pause);
+
+	fbd->mac->link_up(fbd, tx_pause, rx_pause);
+}
+
+static const struct phylink_mac_ops fbnic_phylink_mac_ops = {
+	.mac_select_pcs = fbnic_phylink_mac_select_pcs,
+	.mac_prepare = fbnic_phylink_mac_prepare,
+	.mac_config = fbnic_phylink_mac_config,
+	.mac_finish = fbnic_phylink_mac_finish,
+	.mac_link_down = fbnic_phylink_mac_link_down,
+	.mac_link_up = fbnic_phylink_mac_link_up,
+};
+
+/**
+ * fbnic_phylink_create - Phylink device creation
+ * @netdev: Network Device struct to attach phylink device
+ *
+ * Initialize and attach a phylink instance to the device. The phylink
+ * device will make use of the netdev struct to track carrier and will
+ * eventually be used to expose the current state of the MAC and PCS
+ * setup.
+ *
+ * Return: 0 on success, negative on failure
+ **/
+int fbnic_phylink_create(struct net_device *netdev)
+{
+	struct fbnic_net *fbn = netdev_priv(netdev);
+	struct fbnic_dev *fbd = fbn->fbd;
+	struct phylink_pcs *pcs;
+	struct phylink *phylink;
+	int err;
+
+	pcs = xpcs_create_pcs_mdiodev(fbd->mdio_bus, 0);
+	if (IS_ERR(pcs)) {
+		err = PTR_ERR(pcs);
+		dev_err(fbd->dev, "Failed to create PCS device: %d\n", err);
+		return err;
+	}
+
+	fbn->pcs = pcs;
+
+	fbn->phylink_config.dev = &netdev->dev;
+	fbn->phylink_config.type = PHYLINK_NETDEV;
+	fbn->phylink_config.mac_capabilities = MAC_SYM_PAUSE | MAC_ASYM_PAUSE |
+					       MAC_25000FD | MAC_50000FD |
+					       MAC_100000FD;
+	fbn->phylink_config.default_an_inband = true;
+
+	__set_bit(PHY_INTERFACE_MODE_100GBASEP,
+		  fbn->phylink_config.supported_interfaces);
+	__set_bit(PHY_INTERFACE_MODE_50GBASER,
+		  fbn->phylink_config.supported_interfaces);
+	__set_bit(PHY_INTERFACE_MODE_LAUI,
+		  fbn->phylink_config.supported_interfaces);
+	__set_bit(PHY_INTERFACE_MODE_25GBASER,
+		  fbn->phylink_config.supported_interfaces);
+
+	fbnic_mac_get_fw_settings(fbd, &fbn->aui, &fbn->fec);
+
+	phylink = phylink_create(&fbn->phylink_config, NULL,
+				 fbnic_phylink_select_interface(fbn->aui),
+				 &fbnic_phylink_mac_ops);
+	if (IS_ERR(phylink)) {
+		err = PTR_ERR(phylink);
+		dev_err(netdev->dev.parent,
+			"Failed to create Phylink interface, err: %d\n", err);
+		xpcs_destroy_pcs(pcs);
+		return err;
+	}
+
+	fbn->phylink = phylink;
+
+	return 0;
+}
+
+/**
+ * fbnic_phylink_destroy - Teardown phylink related interfaces
+ * @netdev: Network Device struct containing phylink device
+ *
+ * Detach and free resources related to phylink interface.
+ **/
+void fbnic_phylink_destroy(struct net_device *netdev)
+{
+	struct fbnic_net *fbn = netdev_priv(netdev);
+
+	if (fbn->phylink)
+		phylink_destroy(fbn->phylink);
+	if (fbn->pcs)
+		xpcs_destroy_pcs(fbn->pcs);
+}
+
+/**
+ * fbnic_phylink_pmd_training_complete_notify - PMD training complete notifier
+ * @netdev: Netdev struct phylink device attached to
+ *
+ * When the link first comes up the PMD will have a period of 2 to 3 seconds
+ * where the link will flutter due to link training. To avoid spamming the
+ * kernel log with messages about this we add a delay of 4 seconds from the
+ * time of the last PCS report of link so that we can guarantee we are unlikely
+ * to see any further link loss events due to link training.
+ **/
+void fbnic_phylink_pmd_training_complete_notify(struct net_device *netdev)
+{
+	struct fbnic_net *fbn = netdev_priv(netdev);
+	struct fbnic_dev *fbd = fbn->fbd;
+
+	if (fbd->pmd_state != FBNIC_PMD_TRAINING)
+		return;
+
+	/* Prevent reading end_of_pmd_training until we verified state */
+	smp_rmb();
+
+	if (!time_before(READ_ONCE(fbd->end_of_pmd_training), jiffies))
+		return;
+
+	/* At this point we have verified that the link has been up for
+	 * the full training duration. As a first step we will try
+	 * transitioning to link ready.
+	 */
+	if (cmpxchg(&fbd->pmd_state, FBNIC_PMD_TRAINING,
+		    FBNIC_PMD_LINK_READY) != FBNIC_PMD_TRAINING)
+		return;
+
+	/* Perform a follow-up check to verify that the link didn't flap
+	 * just before our transition by rechecking the training timer.
+	 */
+	if (!time_before(READ_ONCE(fbd->end_of_pmd_training), jiffies))
+		return;
+
+	/* The training timeout has been completed. We are good to swap out
+	 * link_ready for send_data assuming no other events have occurred
+	 * that would have pulled us back into initialization or training.
+	 */
+	if (cmpxchg(&fbd->pmd_state, FBNIC_PMD_LINK_READY,
+		    FBNIC_PMD_SEND_DATA) != FBNIC_PMD_LINK_READY)
+		return;
+
+	phylink_pcs_change(fbn->pcs, false);
+}