[PATCH v2] net :mana : Add per-cpu stats for MANA device

[Shradha Gupta <shradhagupta@linux.microsoft.com>]

Extend 'ethtool -S' output for mana devices to include per-CPU packet
stats

Signed-off-by: Shradha Gupta <shradhagupta@linux.microsoft.com>
---
 Changes in v2
 * Corrected the patch description to remove redundant built and
   Tested info
 * Used num_possible_cpus() as suggested
 * Added the missing allocation and deallocation sections for
   per-CPU counters.
---
 drivers/net/ethernet/microsoft/mana/mana_en.c | 30 ++++++++++++++
 .../ethernet/microsoft/mana/mana_ethtool.c    | 41 ++++++++++++++++++-
 include/net/mana/mana.h                       | 12 ++++++
 3 files changed, 81 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 59287c6e6cee..0edf1f9e6dfc 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -224,6 +224,7 @@ netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 	int gso_hs = 0; /* zero for non-GSO pkts */
 	u16 txq_idx = skb_get_queue_mapping(skb);
 	struct gdma_dev *gd = apc->ac->gdma_dev;
+	struct mana_pcpu_stats *pcpu_stats;
 	bool ipv4 = false, ipv6 = false;
 	struct mana_tx_package pkg = {};
 	struct netdev_queue *net_txq;
@@ -234,6 +235,8 @@ netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 	struct mana_cq *cq;
 	int err, len;
 
+	pcpu_stats = this_cpu_ptr(apc->pcpu_stats);
+
 	if (unlikely(!apc->port_is_up))
 		goto tx_drop;
 
@@ -412,6 +415,12 @@ netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 	tx_stats->bytes += len;
 	u64_stats_update_end(&tx_stats->syncp);
 
+	/* Also update the per-CPU stats */
+	u64_stats_update_begin(&pcpu_stats->syncp);
+	pcpu_stats->tx_packets++;
+	pcpu_stats->tx_bytes += len;
+	u64_stats_update_end(&pcpu_stats->syncp);
+
 tx_busy:
 	if (netif_tx_queue_stopped(net_txq) && mana_can_tx(gdma_sq)) {
 		netif_tx_wake_queue(net_txq);
@@ -425,6 +434,9 @@ netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 	kfree(pkg.sgl_ptr);
 tx_drop_count:
 	ndev->stats.tx_dropped++;
+	u64_stats_update_begin(&pcpu_stats->syncp);
+	pcpu_stats->tx_dropped++;
+	u64_stats_update_end(&pcpu_stats->syncp);
 tx_drop:
 	dev_kfree_skb_any(skb);
 	return NETDEV_TX_OK;
@@ -1505,6 +1517,8 @@ static void mana_rx_skb(void *buf_va, bool from_pool,
 	struct mana_stats_rx *rx_stats = &rxq->stats;
 	struct net_device *ndev = rxq->ndev;
 	uint pkt_len = cqe->ppi[0].pkt_len;
+	struct mana_pcpu_stats *pcpu_stats;
+	struct mana_port_context *apc;
 	u16 rxq_idx = rxq->rxq_idx;
 	struct napi_struct *napi;
 	struct xdp_buff xdp = {};
@@ -1512,6 +1526,9 @@ static void mana_rx_skb(void *buf_va, bool from_pool,
 	u32 hash_value;
 	u32 act;
 
+	apc = netdev_priv(ndev);
+	pcpu_stats = this_cpu_ptr(apc->pcpu_stats);
+
 	rxq->rx_cq.work_done++;
 	napi = &rxq->rx_cq.napi;
 
@@ -1570,6 +1587,11 @@ static void mana_rx_skb(void *buf_va, bool from_pool,
 		rx_stats->xdp_tx++;
 	u64_stats_update_end(&rx_stats->syncp);
 
+	u64_stats_update_begin(&pcpu_stats->syncp);
+	pcpu_stats->rx_packets++;
+	pcpu_stats->rx_bytes += pkt_len;
+	u64_stats_update_end(&pcpu_stats->syncp);
+
 	if (act == XDP_TX) {
 		skb_set_queue_mapping(skb, rxq_idx);
 		mana_xdp_tx(skb, ndev);
@@ -2660,6 +2682,7 @@ int mana_detach(struct net_device *ndev, bool from_close)
 
 	apc->port_st_save = apc->port_is_up;
 	apc->port_is_up = false;
+	free_percpu(apc->pcpu_stats);
 
 	/* Ensure port state updated before txq state */
 	smp_wmb();
@@ -2704,6 +2727,11 @@ static int mana_probe_port(struct mana_context *ac, int port_idx,
 	apc->port_handle = INVALID_MANA_HANDLE;
 	apc->pf_filter_handle = INVALID_MANA_HANDLE;
 	apc->port_idx = port_idx;
+	apc->pcpu_stats = netdev_alloc_pcpu_stats(struct mana_pcpu_stats);
+	if (!apc->pcpu_stats) {
+		err = -ENOMEM;
+		goto no_pcpu_stats;
+	}
 
 	mutex_init(&apc->vport_mutex);
 	apc->vport_use_count = 0;
@@ -2750,6 +2778,8 @@ static int mana_probe_port(struct mana_context *ac, int port_idx,
 	kfree(apc->rxqs);
 	apc->rxqs = NULL;
 free_net:
+	free_percpu(apc->pcpu_stats);
+no_pcpu_stats:
 	*ndev_storage = NULL;
 	netdev_err(ndev, "Failed to probe vPort %d: %d\n", port_idx, err);
 	free_netdev(ndev);
diff --git a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
index ab2413d71f6c..755b249aa904 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
@@ -83,8 +83,10 @@ static int mana_get_sset_count(struct net_device *ndev, int stringset)
 	if (stringset != ETH_SS_STATS)
 		return -EINVAL;
 
-	return ARRAY_SIZE(mana_eth_stats) + num_queues *
-				(MANA_STATS_RX_COUNT + MANA_STATS_TX_COUNT);
+	return ARRAY_SIZE(mana_eth_stats) +
+	       (num_queues * (MANA_STATS_RX_COUNT + MANA_STATS_TX_COUNT)) +
+	       (num_possible_cpus() * (MANA_STATS_RX_PCPU +
+				       MANA_STATS_TX_PCPU));
 }
 
 static void mana_get_strings(struct net_device *ndev, u32 stringset, u8 *data)
@@ -139,6 +141,19 @@ static void mana_get_strings(struct net_device *ndev, u32 stringset, u8 *data)
 		sprintf(p, "tx_%d_mana_map_err", i);
 		p += ETH_GSTRING_LEN;
 	}
+
+	for (i = 0; i < num_possible_cpus(); i++) {
+		sprintf(p, "cpu%d_rx_packets", i);
+		p += ETH_GSTRING_LEN;
+		sprintf(p, "cpu%d_rx_bytes", i);
+		p += ETH_GSTRING_LEN;
+		sprintf(p, "cpu%d_tx_packets", i);
+		p += ETH_GSTRING_LEN;
+		sprintf(p, "cpu%d_tx_bytes", i);
+		p += ETH_GSTRING_LEN;
+		sprintf(p, "cpu%d_tx_dropped", i);
+		p += ETH_GSTRING_LEN;
+	}
 }
 
 static void mana_get_ethtool_stats(struct net_device *ndev,
@@ -222,6 +237,28 @@ static void mana_get_ethtool_stats(struct net_device *ndev,
 		data[i++] = csum_partial;
 		data[i++] = mana_map_err;
 	}
+
+	for_each_possible_cpu(q) {
+		const struct mana_pcpu_stats *pcpu_stats =
+				per_cpu_ptr(apc->pcpu_stats, q);
+		u64 rx_packets, rx_bytes, tx_packets, tx_bytes, tx_dropped;
+		unsigned int start;
+
+		do {
+			start = u64_stats_fetch_begin(&pcpu_stats->syncp);
+			rx_packets = pcpu_stats->rx_packets;
+			tx_packets = pcpu_stats->tx_packets;
+			rx_bytes = pcpu_stats->rx_bytes;
+			tx_bytes = pcpu_stats->tx_bytes;
+			tx_dropped = pcpu_stats->tx_dropped;
+		} while (u64_stats_fetch_retry(&pcpu_stats->syncp, start));
+
+		data[i++] = rx_packets;
+		data[i++] = rx_bytes;
+		data[i++] = tx_packets;
+		data[i++] = tx_bytes;
+		data[i++] = tx_dropped;
+	}
 }
 
 static int mana_get_rxnfc(struct net_device *ndev, struct ethtool_rxnfc *cmd,
diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
index 76147feb0d10..9a2414ee7f02 100644
--- a/include/net/mana/mana.h
+++ b/include/net/mana/mana.h
@@ -51,6 +51,8 @@ enum TRI_STATE {
 /* Update this count whenever the respective structures are changed */
 #define MANA_STATS_RX_COUNT 5
 #define MANA_STATS_TX_COUNT 11
+#define MANA_STATS_RX_PCPU 2
+#define MANA_STATS_TX_PCPU 3
 
 struct mana_stats_rx {
 	u64 packets;
@@ -386,6 +388,15 @@ struct mana_ethtool_stats {
 	u64 rx_cqe_unknown_type;
 };
 
+struct mana_pcpu_stats {
+	u64 rx_packets;
+	u64 rx_bytes;
+	u64 tx_packets;
+	u64 tx_bytes;
+	u64 tx_dropped;
+	struct u64_stats_sync syncp;
+};
+
 struct mana_context {
 	struct gdma_dev *gdma_dev;
 
@@ -449,6 +460,7 @@ struct mana_port_context {
 	bool port_st_save; /* Saved port state */
 
 	struct mana_ethtool_stats eth_stats;
+	struct mana_pcpu_stats __percpu *pcpu_stats;
 };
 
 netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev);
-- 
2.34.1