net: systemport: Support 64bit statistics

When using Broadcom Systemport device in 32bit Platform, ifconfig can
only report up to 4G tx,rx status, which will be wrapped to 0 when the
number of incoming or outgoing packets exceeds 4G, only taking
around 2 hours in busy network environment (such as streaming).
Therefore, it makes hard for network diagnostic tool to get reliable
statistical result, so the patch is used to add 64bit support for
Broadcom Systemport device in 32bit Platform.

This patch provides 64bit statistics capability on both ethtool and ifconfig.

Signed-off-by: Jianming.qiao <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/broadcom/bcmsysport.c

···
  */
 static const struct bcm_sysport_stats bcm_sysport_gstrings_stats[] = {
 	/* general stats */
-	STAT_NETDEV(rx_packets),
-	STAT_NETDEV(tx_packets),
-	STAT_NETDEV(rx_bytes),
-	STAT_NETDEV(tx_bytes),
+	STAT_NETDEV64(rx_packets),
+	STAT_NETDEV64(tx_packets),
+	STAT_NETDEV64(rx_bytes),
+	STAT_NETDEV64(tx_bytes),
 	STAT_NETDEV(rx_errors),
 	STAT_NETDEV(tx_errors),
 	STAT_NETDEV(rx_dropped),
···
 {
 	switch (type) {
 	case BCM_SYSPORT_STAT_NETDEV:
+	case BCM_SYSPORT_STAT_NETDEV64:
 	case BCM_SYSPORT_STAT_RXCHK:
 	case BCM_SYSPORT_STAT_RBUF:
 	case BCM_SYSPORT_STAT_SOFT:
···
 		s = &bcm_sysport_gstrings_stats[i];
 		switch (s->type) {
 		case BCM_SYSPORT_STAT_NETDEV:
+		case BCM_SYSPORT_STAT_NETDEV64:
 		case BCM_SYSPORT_STAT_SOFT:
 			continue;
 		case BCM_SYSPORT_STAT_MIB_RX:
···
 				  struct ethtool_stats *stats, u64 *data)
 {
 	struct bcm_sysport_priv *priv = netdev_priv(dev);
+	struct bcm_sysport_stats64 *stats64 = &priv->stats64;
+	struct u64_stats_sync *syncp = &priv->syncp;
 	struct bcm_sysport_tx_ring *ring;
+	unsigned int start;
 	int i, j;
 
 	if (netif_running(dev))
···
 		s = &bcm_sysport_gstrings_stats[i];
 		if (s->type == BCM_SYSPORT_STAT_NETDEV)
 			p = (char *)&dev->stats;
+		else if (s->type == BCM_SYSPORT_STAT_NETDEV64)
+			p = (char *)stats64;
 		else
 			p = (char *)priv;
+
 		p += s->stat_offset;
-		data[j] = *(unsigned long *)p;
+
+		if (s->stat_sizeof == sizeof(u64))
+			do {
+				start = u64_stats_fetch_begin_irq(syncp);
+				data[i] = *(u64 *)p;
+			} while (u64_stats_fetch_retry_irq(syncp, start));
+		else
+			data[i] = *(u32 *)p;
 		j++;
 	}
 
···
 static unsigned int bcm_sysport_desc_rx(struct bcm_sysport_priv *priv,
 					unsigned int budget)
 {
+	struct bcm_sysport_stats64 *stats64 = &priv->stats64;
 	struct net_device *ndev = priv->netdev;
 	unsigned int processed = 0, to_process;
 	struct bcm_sysport_cb *cb;
···
 		skb->protocol = eth_type_trans(skb, ndev);
 		ndev->stats.rx_packets++;
 		ndev->stats.rx_bytes += len;
+		u64_stats_update_begin(&priv->syncp);
+		stats64->rx_packets++;
+		stats64->rx_bytes += len;
+		u64_stats_update_end(&priv->syncp);
 
 		napi_gro_receive(&priv->napi, skb);
 next:
···
 	struct device *kdev = &priv->pdev->dev;
 
 	if (cb->skb) {
-		ring->bytes += cb->skb->len;
 		*bytes_compl += cb->skb->len;
 		dma_unmap_single(kdev, dma_unmap_addr(cb, dma_addr),
 				 dma_unmap_len(cb, dma_len),
 				 DMA_TO_DEVICE);
-		ring->packets++;
 		(*pkts_compl)++;
 		bcm_sysport_free_cb(cb);
 	/* SKB fragment */
 	} else if (dma_unmap_addr(cb, dma_addr)) {
-		ring->bytes += dma_unmap_len(cb, dma_len);
+		*bytes_compl += dma_unmap_len(cb, dma_len);
 		dma_unmap_page(kdev, dma_unmap_addr(cb, dma_addr),
 			       dma_unmap_len(cb, dma_len), DMA_TO_DEVICE);
 		dma_unmap_addr_set(cb, dma_addr, 0);
···
 static unsigned int __bcm_sysport_tx_reclaim(struct bcm_sysport_priv *priv,
 					     struct bcm_sysport_tx_ring *ring)
 {
-	struct net_device *ndev = priv->netdev;
 	unsigned int c_index, last_c_index, last_tx_cn, num_tx_cbs;
 	unsigned int pkts_compl = 0, bytes_compl = 0;
+	struct net_device *ndev = priv->netdev;
 	struct bcm_sysport_cb *cb;
 	u32 hw_ind;
 
···
 		last_c_index++;
 		last_c_index &= (num_tx_cbs - 1);
 	}
+
+	u64_stats_update_begin(&priv->syncp);
+	ring->packets += pkts_compl;
+	ring->bytes += bytes_compl;
+	u64_stats_update_end(&priv->syncp);
 
 	ring->c_index = c_index;
 
···
 	return 0;
 }
 
-static struct net_device_stats *bcm_sysport_get_nstats(struct net_device *dev)
+static void bcm_sysport_get_stats64(struct net_device *dev,
+				    struct rtnl_link_stats64 *stats)
 {
 	struct bcm_sysport_priv *priv = netdev_priv(dev);
-	unsigned long tx_bytes = 0, tx_packets = 0;
+	struct bcm_sysport_stats64 *stats64 = &priv->stats64;
 	struct bcm_sysport_tx_ring *ring;
+	u64 tx_packets = 0, tx_bytes = 0;
+	unsigned int start;
 	unsigned int q;
+
+	netdev_stats_to_stats64(stats, &dev->stats);
 
 	for (q = 0; q < dev->num_tx_queues; q++) {
 		ring = &priv->tx_rings[q];
-		tx_bytes += ring->bytes;
-		tx_packets += ring->packets;
+		do {
+			start = u64_stats_fetch_begin_irq(&priv->syncp);
+			tx_bytes = ring->bytes;
+			tx_packets = ring->packets;
+		} while (u64_stats_fetch_retry_irq(&priv->syncp, start));
+
+		stats->tx_bytes += tx_bytes;
+		stats->tx_packets += tx_packets;
 	}
 
-	dev->stats.tx_bytes = tx_bytes;
-	dev->stats.tx_packets = tx_packets;
-	return &dev->stats;
+	/* lockless update tx_bytes and tx_packets */
+	u64_stats_update_begin(&priv->syncp);
+	stats64->tx_bytes = stats->tx_bytes;
+	stats64->tx_packets = stats->tx_packets;
+	u64_stats_update_end(&priv->syncp);
+
+	do {
+		start = u64_stats_fetch_begin_irq(&priv->syncp);
+		stats->rx_packets = stats64->rx_packets;
+		stats->rx_bytes = stats64->rx_bytes;
+	} while (u64_stats_fetch_retry_irq(&priv->syncp, start));
 }
 
 static void bcm_sysport_netif_start(struct net_device *dev)
···
 #ifdef CONFIG_NET_POLL_CONTROLLER
 	.ndo_poll_controller	= bcm_sysport_poll_controller,
 #endif
-	.ndo_get_stats		= bcm_sysport_get_nstats,
+	.ndo_get_stats64	= bcm_sysport_get_stats64,
 };
 
 #define REV_FMT	"v%2x.%02x"
···
 
 	/* libphy will adjust the link state accordingly */
 	netif_carrier_off(dev);
+
+	u64_stats_init(&priv->syncp);
 
 	ret = register_netdev(dev);
 	if (ret) {

drivers/net/ethernet/broadcom/bcmsysport.h

···
 /* HW maintains a large list of counters */
 enum bcm_sysport_stat_type {
 	BCM_SYSPORT_STAT_NETDEV = -1,
+	BCM_SYSPORT_STAT_NETDEV64,
 	BCM_SYSPORT_STAT_MIB_RX,
 	BCM_SYSPORT_STAT_MIB_TX,
 	BCM_SYSPORT_STAT_RUNT,
···
 	.stat_sizeof = sizeof(((struct net_device_stats *)0)->m), \
 	.stat_offset = offsetof(struct net_device_stats, m), \
 	.type = BCM_SYSPORT_STAT_NETDEV, \
+}
+
+#define STAT_NETDEV64(m) { \
+	.stat_string = __stringify(m), \
+	.stat_sizeof = sizeof(((struct bcm_sysport_stats64 *)0)->m), \
+	.stat_offset = offsetof(struct bcm_sysport_stats64, m), \
+	.type = BCM_SYSPORT_STAT_NETDEV64, \
 }
 
 #define STAT_MIB(str, m, _type) { \
···
 	enum bcm_sysport_stat_type type;
 	/* reg offset from UMAC base for misc counters */
 	u16 reg_offset;
+};
+
+struct bcm_sysport_stats64 {
+	/* 64bit stats on 32bit/64bit Machine */
+	u64	rx_packets;
+	u64	rx_bytes;
+	u64	tx_packets;
+	u64	tx_bytes;
 };
 
 /* Software house keeping helper structure */
···
 
 	/* Ethtool */
 	u32			msg_enable;
+
+	struct bcm_sysport_stats64	stats64;
+
+	/* For atomic update generic 64bit value on 32bit Machine */
+	struct u64_stats_sync	syncp;
 };
 #endif /* __BCM_SYSPORT_H */