[PATCH net-next v43 8/8] eea: introduce callback for ndo_get_stats64 and register netdev

[Xuan Zhuo <xuanzhuo@linux.alibaba.com>]

This commit adds support for ndo_get_stats64 to provide accurate
interface statistics. With the TX and RX data paths now fully functional,
it is appropriate to register the netdevice and expose the interface to
userspace.

Registered the network device via register_netdev, and updated the
corresponding unregister_netdev and dev_close routines to ensure
synchronization.

Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Reviewed-by: Philo Lu <lulie@linux.alibaba.com>
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
 drivers/net/ethernet/alibaba/eea/eea_net.c | 83 ++++++++++++++++++++--
 drivers/net/ethernet/alibaba/eea/eea_net.h |  5 ++
 2 files changed, 84 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/alibaba/eea/eea_net.c b/drivers/net/ethernet/alibaba/eea/eea_net.c
index f4505eed8bdd..63e68580de94 100644
--- a/drivers/net/ethernet/alibaba/eea/eea_net.c
+++ b/drivers/net/ethernet/alibaba/eea/eea_net.c
@@ -112,6 +112,11 @@ static void eea_bind_q_and_cfg(struct eea_net *enet,
 	struct eea_net_tx *tx;
 	int i;
 
+	/* Since 'ndo_get_stats64' is not called in softirq context, there is no
+	 * need to use 'spin_lock_bh'.
+	 */
+	spin_lock(&enet->stats_lock);
+
 	enet->cfg = ctx->cfg;
 	enet->rx = ctx->rx;
 	enet->tx = ctx->tx;
@@ -131,6 +136,8 @@ static void eea_bind_q_and_cfg(struct eea_net *enet,
 
 		blk->rx = rx;
 	}
+
+	spin_unlock(&enet->stats_lock);
 }
 
 static void eea_unbind_q_and_cfg(struct eea_net *enet,
@@ -140,6 +147,8 @@ static void eea_unbind_q_and_cfg(struct eea_net *enet,
 	struct eea_net_rx *rx;
 	int i;
 
+	spin_lock(&enet->stats_lock);
+
 	ctx->cfg = enet->cfg;
 	ctx->rx = enet->rx;
 	ctx->tx = enet->tx;
@@ -156,6 +165,8 @@ static void eea_unbind_q_and_cfg(struct eea_net *enet,
 
 		blk->rx = NULL;
 	}
+
+	spin_unlock(&enet->stats_lock);
 }
 
 static void eea_free_rxtx_q_mem(struct eea_net_init_ctx *ctx)
@@ -342,6 +353,60 @@ static int eea_netdev_open(struct net_device *netdev)
 	return err;
 }
 
+/* Statistics may be reset to zero upon device reset. This is expected behavior
+ * for now and will be addressed in the future.
+ */
+static void eea_stats(struct net_device *netdev, struct rtnl_link_stats64 *tot)
+{
+	struct eea_net *enet = netdev_priv(netdev);
+	u64 packets, bytes, drop, lerr;
+	u32 start;
+	int i;
+
+	spin_lock(&enet->stats_lock);
+
+	if (enet->rx) {
+		for (i = 0; i < enet->cfg.rx_ring_num; i++) {
+			struct eea_net_rx *rx = enet->rx[i];
+
+			do {
+				start = u64_stats_fetch_begin(&rx->stats.syncp);
+				packets = u64_stats_read(&rx->stats.packets);
+				bytes = u64_stats_read(&rx->stats.bytes);
+				drop = u64_stats_read(&rx->stats.drops);
+				lerr = u64_stats_read(&rx->stats.length_errors);
+			} while (u64_stats_fetch_retry(&rx->stats.syncp,
+						       start));
+
+			tot->rx_packets       += packets;
+			tot->rx_bytes         += bytes;
+			tot->rx_dropped       += drop;
+			tot->rx_length_errors += lerr;
+			tot->rx_errors        += lerr;
+		}
+	}
+
+	if (enet->tx) {
+		for (i = 0; i < enet->cfg.tx_ring_num; i++) {
+			struct eea_net_tx *tx = &enet->tx[i];
+
+			do {
+				start = u64_stats_fetch_begin(&tx->stats.syncp);
+				packets = u64_stats_read(&tx->stats.packets);
+				bytes = u64_stats_read(&tx->stats.bytes);
+				drop = u64_stats_read(&tx->stats.drops);
+			} while (u64_stats_fetch_retry(&tx->stats.syncp,
+						       start));
+
+			tot->tx_packets += packets;
+			tot->tx_bytes   += bytes;
+			tot->tx_dropped += drop;
+		}
+	}
+
+	spin_unlock(&enet->stats_lock);
+}
+
 /* resources: ring, buffers, irq */
 int eea_reset_hw_resources(struct eea_net *enet, struct eea_net_init_ctx *ctx)
 {
@@ -349,7 +414,9 @@ int eea_reset_hw_resources(struct eea_net *enet, struct eea_net_init_ctx *ctx)
 	int err, error;
 
 	if (!netif_running(enet->netdev) || !enet->started) {
+		spin_lock(&enet->stats_lock);
 		enet->cfg = ctx->cfg;
+		spin_unlock(&enet->stats_lock);
 		return 0;
 	}
 
@@ -607,6 +674,7 @@ static const struct net_device_ops eea_netdev = {
 	.ndo_stop           = eea_netdev_stop,
 	.ndo_start_xmit     = eea_tx_xmit,
 	.ndo_validate_addr  = eth_validate_addr,
+	.ndo_get_stats64    = eea_stats,
 	.ndo_features_check = passthru_features_check,
 };
 
@@ -640,6 +708,8 @@ static struct eea_net *eea_netdev_alloc(struct eea_device *edev, u32 pairs)
 		return NULL;
 	}
 
+	spin_lock_init(&enet->stats_lock);
+
 	return enet;
 }
 
@@ -725,11 +795,13 @@ int eea_net_probe(struct eea_device *edev)
 
 	eea_update_ts_off(edev, enet);
 
-	netdev_dbg(enet->netdev, "eea probe success.\n");
+	netif_carrier_off(enet->netdev);
 
-	/* Queue TX/RX implementation is still in progress. register_netdev is
-	 * deferred until these are completed in subsequent commits.
-	 */
+	err = register_netdev(enet->netdev);
+	if (err)
+		goto err_reset_dev;
+
+	netdev_dbg(enet->netdev, "eea probe success.\n");
 
 	return 0;
 
@@ -781,6 +853,8 @@ void eea_net_remove(struct eea_device *edev, bool ha)
 		return;
 	}
 
+	unregister_netdev(netdev);
+
 	if (!enet->wait_pci_ready) {
 		eea_device_reset(edev);
 		eea_destroy_adminq(enet);
@@ -801,6 +875,7 @@ void eea_net_shutdown(struct eea_device *edev)
 	rtnl_lock();
 
 	netif_device_detach(netdev);
+	dev_close(netdev);
 
 	if (!enet->wait_pci_ready) {
 		eea_device_reset(edev);
diff --git a/drivers/net/ethernet/alibaba/eea/eea_net.h b/drivers/net/ethernet/alibaba/eea/eea_net.h
index 6a5b2f908c76..848bb90bccf8 100644
--- a/drivers/net/ethernet/alibaba/eea/eea_net.h
+++ b/drivers/net/ethernet/alibaba/eea/eea_net.h
@@ -165,6 +165,11 @@ struct eea_net {
 	u32 speed;
 
 	u64 hw_ts_offset;
+
+	/* Protect the tx and rx of struct eea_net, when eea_stats accesses the
+	 * stats from rx and tx queues.
+	 */
+	spinlock_t stats_lock;
 };
 
 int eea_net_probe(struct eea_device *edev);
-- 
2.32.0.3.g01195cf9f