[net-next,05/10] net: netcp: store network statistics in 64 bits

diff --git a/drivers/net/ethernet/ti/netcp.h b/drivers/net/ethernet/ti/netcp.h
index a92abd6..d243c5d 100644
--- a/drivers/net/ethernet/ti/netcp.h
+++ b/drivers/net/ethernet/ti/netcp.h
@@ -23,6 +23,7 @@ 
 
 #include <linux/netdevice.h>
 #include <linux/soc/ti/knav_dma.h>
+#include <linux/u64_stats_sync.h>
 
 /* Maximum Ethernet frame size supported by Keystone switch */
 #define NETCP_MAX_FRAME_SIZE		9504
@@ -68,6 +69,20 @@  struct netcp_addr {
 	struct list_head	node;
 };
 
+struct netcp_stats {
+	struct u64_stats_sync   syncp_rx ____cacheline_aligned_in_smp;
+	u64                     rx_packets;
+	u64                     rx_bytes;
+	u32                     rx_errors;
+	u32                     rx_dropped;
+
+	struct u64_stats_sync   syncp_tx ____cacheline_aligned_in_smp;
+	u64                     tx_packets;
+	u64                     tx_bytes;
+	u32                     tx_errors;
+	u32                     tx_dropped;
+};
+
 struct netcp_intf {
 	struct device		*dev;
 	struct device		*ndev_dev;
@@ -88,6 +103,9 @@  struct netcp_intf {
 	struct napi_struct	rx_napi;
 	struct napi_struct	tx_napi;
 
+	/* 64-bit netcp stats */
+	struct netcp_stats	stats;
+
 	void			*rx_channel;
 	const char		*dma_chan_name;
 	u32			rx_pool_size;
diff --git a/drivers/net/ethernet/ti/netcp_core.c b/drivers/net/ethernet/ti/netcp_core.c
index 286fd8d..b077ed4 100644
--- a/drivers/net/ethernet/ti/netcp_core.c
+++ b/drivers/net/ethernet/ti/netcp_core.c
@@ -629,6 +629,7 @@  static void netcp_free_rx_desc_chain(struct netcp_intf *netcp,
 
 static void netcp_empty_rx_queue(struct netcp_intf *netcp)
 {
+	struct netcp_stats *rx_stats = &netcp->stats;
 	struct knav_dma_desc *desc;
 	unsigned int dma_sz;
 	dma_addr_t dma;
@@ -642,16 +643,17 @@  static void netcp_empty_rx_queue(struct netcp_intf *netcp)
 		if (unlikely(!desc)) {
 			dev_err(netcp->ndev_dev, "%s: failed to unmap Rx desc\n",
 				__func__);
-			netcp->ndev->stats.rx_errors++;
+			rx_stats->rx_errors++;
 			continue;
 		}
 		netcp_free_rx_desc_chain(netcp, desc);
-		netcp->ndev->stats.rx_dropped++;
+		rx_stats->rx_dropped++;
 	}
 }
 
 static int netcp_process_one_rx_packet(struct netcp_intf *netcp)
 {
+	struct netcp_stats *rx_stats = &netcp->stats;
 	unsigned int dma_sz, buf_len, org_buf_len;
 	struct knav_dma_desc *desc, *ndesc;
 	unsigned int pkt_sz = 0, accum_sz;
@@ -757,8 +759,8 @@  static int netcp_process_one_rx_packet(struct netcp_intf *netcp)
 		if (unlikely(ret)) {
 			dev_err(netcp->ndev_dev, "RX hook %d failed: %d\n",
 				rx_hook->order, ret);
-			netcp->ndev->stats.rx_errors++;
 			/* Free the primary descriptor */
+			rx_stats->rx_dropped++;
 			knav_pool_desc_put(netcp->rx_pool, desc);
 			dev_kfree_skb(skb);
 			return 0;
@@ -767,8 +769,10 @@  static int netcp_process_one_rx_packet(struct netcp_intf *netcp)
 	/* Free the primary descriptor */
 	knav_pool_desc_put(netcp->rx_pool, desc);
 
-	netcp->ndev->stats.rx_packets++;
-	netcp->ndev->stats.rx_bytes += skb->len;
+	u64_stats_update_begin(&rx_stats->syncp_rx);
+	rx_stats->rx_packets++;
+	rx_stats->rx_bytes += skb->len;
+	u64_stats_update_end(&rx_stats->syncp_rx);
 
 	/* push skb up the stack */
 	skb->protocol = eth_type_trans(skb, netcp->ndev);
@@ -777,7 +781,7 @@  static int netcp_process_one_rx_packet(struct netcp_intf *netcp)
 
 free_desc:
 	netcp_free_rx_desc_chain(netcp, desc);
-	netcp->ndev->stats.rx_errors++;
+	rx_stats->rx_errors++;
 	return 0;
 }
 
@@ -1008,6 +1012,7 @@  static void netcp_free_tx_desc_chain(struct netcp_intf *netcp,
 static int netcp_process_tx_compl_packets(struct netcp_intf *netcp,
 					  unsigned int budget)
 {
+	struct netcp_stats *tx_stats = &netcp->stats;
 	struct knav_dma_desc *desc;
 	struct netcp_tx_cb *tx_cb;
 	struct sk_buff *skb;
@@ -1022,7 +1027,7 @@  static int netcp_process_tx_compl_packets(struct netcp_intf *netcp,
 		desc = knav_pool_desc_unmap(netcp->tx_pool, dma, dma_sz);
 		if (unlikely(!desc)) {
 			dev_err(netcp->ndev_dev, "failed to unmap Tx desc\n");
-			netcp->ndev->stats.tx_errors++;
+			tx_stats->tx_errors++;
 			continue;
 		}
 
@@ -1033,7 +1038,7 @@  static int netcp_process_tx_compl_packets(struct netcp_intf *netcp,
 		netcp_free_tx_desc_chain(netcp, desc, dma_sz);
 		if (!skb) {
 			dev_err(netcp->ndev_dev, "No skb in Tx desc\n");
-			netcp->ndev->stats.tx_errors++;
+			tx_stats->tx_errors++;
 			continue;
 		}
 
@@ -1050,8 +1055,10 @@  static int netcp_process_tx_compl_packets(struct netcp_intf *netcp,
 			netif_wake_subqueue(netcp->ndev, subqueue);
 		}
 
-		netcp->ndev->stats.tx_packets++;
-		netcp->ndev->stats.tx_bytes += skb->len;
+		u64_stats_update_begin(&tx_stats->syncp_tx);
+		tx_stats->tx_packets++;
+		tx_stats->tx_bytes += skb->len;
+		u64_stats_update_end(&tx_stats->syncp_tx);
 		dev_kfree_skb(skb);
 		pkts++;
 	}
@@ -1272,6 +1279,7 @@  static int netcp_tx_submit_skb(struct netcp_intf *netcp,
 static int netcp_ndo_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 {
 	struct netcp_intf *netcp = netdev_priv(ndev);
+	struct netcp_stats *tx_stats = &netcp->stats;
 	int subqueue = skb_get_queue_mapping(skb);
 	struct knav_dma_desc *desc;
 	int desc_count, ret = 0;
@@ -1287,7 +1295,7 @@  static int netcp_ndo_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 			/* If we get here, the skb has already been dropped */
 			dev_warn(netcp->ndev_dev, "padding failed (%d), packet dropped\n",
 				 ret);
-			ndev->stats.tx_dropped++;
+			tx_stats->tx_dropped++;
 			return ret;
 		}
 		skb->len = NETCP_MIN_PACKET_SIZE;
@@ -1315,7 +1323,7 @@  static int netcp_ndo_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 	return NETDEV_TX_OK;
 
 drop:
-	ndev->stats.tx_dropped++;
+	tx_stats->tx_dropped++;
 	if (desc)
 		netcp_free_tx_desc_chain(netcp, desc, sizeof(*desc));
 	dev_kfree_skb(skb);
@@ -1897,12 +1905,46 @@  static int netcp_setup_tc(struct net_device *dev, u32 handle, __be16 proto,
 	return 0;
 }
 
+static struct rtnl_link_stats64 *
+netcp_get_stats(struct net_device *ndev, struct rtnl_link_stats64 *stats)
+{
+	struct netcp_intf *netcp = netdev_priv(ndev);
+	struct netcp_stats *p = &netcp->stats;
+	u64 rxpackets, rxbytes, txpackets, txbytes;
+	unsigned int start;
+
+	do {
+		start = u64_stats_fetch_begin_irq(&p->syncp_rx);
+		rxpackets       = p->rx_packets;
+		rxbytes         = p->rx_bytes;
+	} while (u64_stats_fetch_retry_irq(&p->syncp_rx, start));
+
+	do {
+		start = u64_stats_fetch_begin_irq(&p->syncp_tx);
+		txpackets       = p->tx_packets;
+		txbytes         = p->tx_bytes;
+	} while (u64_stats_fetch_retry_irq(&p->syncp_tx, start));
+
+	stats->rx_packets = rxpackets;
+	stats->rx_bytes = rxbytes;
+	stats->tx_packets = txpackets;
+	stats->tx_bytes = txbytes;
+
+	/* The following are stored as 32 bit */
+	stats->rx_errors = p->rx_errors;
+	stats->rx_dropped = p->rx_dropped;
+	stats->tx_dropped = p->tx_dropped;
+
+	return stats;
+}
+
 static const struct net_device_ops netcp_netdev_ops = {
 	.ndo_open		= netcp_ndo_open,
 	.ndo_stop		= netcp_ndo_stop,
 	.ndo_start_xmit		= netcp_ndo_start_xmit,
 	.ndo_set_rx_mode	= netcp_set_rx_mode,
 	.ndo_do_ioctl           = netcp_ndo_ioctl,
+	.ndo_get_stats64        = netcp_get_stats,
 	.ndo_set_mac_address	= eth_mac_addr,
 	.ndo_validate_addr	= eth_validate_addr,
 	.ndo_vlan_rx_add_vid	= netcp_rx_add_vid,
@@ -1949,6 +1991,8 @@  static int netcp_create_interface(struct netcp_device *netcp_device,
 	INIT_LIST_HEAD(&netcp->txhook_list_head);
 	INIT_LIST_HEAD(&netcp->rxhook_list_head);
 	INIT_LIST_HEAD(&netcp->addr_list);
+	u64_stats_init(&netcp->stats.syncp_rx);
+	u64_stats_init(&netcp->stats.syncp_tx);
 	netcp->netcp_device = netcp_device;
 	netcp->dev = netcp_device->device;
 	netcp->ndev = ndev;