net: thunderx: Receive hashing HW offload support

Adding support for receive hashing HW offload by using RSS_ALG and RSS_TAG fields of CQE_RX descriptor. Also removed dependency on minimum receive queue count to configure RSS so that hash is always generated. This hash is used by RPS logic to distribute flows across multiple CPUs. Offload can be disabled via ethtool. Signed-off-by: Robert Richter <[email protected]> Signed-off-by: Sunil Goutham <[email protected]> Signed-off-by: Aleksey Makarov <[email protected]> Signed-off-by: David S. Miller <[email protected]>
ambv · Aug 31, 2015 · 38bb5d4 · 38bb5d4
1 parent 6051cba
commit 38bb5d4
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Showing 2 changed files with 39 additions and 10 deletions.
diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_ethtool.c b/drivers/net/ethernet/cavium/thunder/nicvf_ethtool.c
@@ -525,17 +525,15 @@ static int nicvf_set_rxfh(struct net_device *dev, const u32 *indir,
 	struct nicvf_rss_info *rss = &nic->rss_info;
 	int idx;
 
-	if ((nic->qs->rq_cnt <= 1) || (nic->cpi_alg != CPI_ALG_NONE)) {
-		rss->enable = false;
-		rss->hash_bits = 0;
-		return -EIO;
-	}
-
-	/* We do not allow change in unsupported parameters */
 	if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
 		return -EOPNOTSUPP;
 
-	rss->enable = true;
+	if (!rss->enable) {
+		netdev_err(nic->netdev,
+			   "RSS is disabled, cannot change settings\n");
+		return -EIO;
+	}
+
 	if (indir) {
 		for (idx = 0; idx < rss->rss_size; idx++)
 			rss->ind_tbl[idx] = indir[idx];

diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
@@ -313,7 +313,7 @@ static int nicvf_rss_init(struct nicvf *nic)
 
 	nicvf_get_rss_size(nic);
 
-	if ((nic->qs->rq_cnt <= 1) || (cpi_alg != CPI_ALG_NONE)) {
+	if (cpi_alg != CPI_ALG_NONE) {
 		rss->enable = false;
 		rss->hash_bits = 0;
 		return 0;
@@ -416,6 +416,34 @@ static void nicvf_snd_pkt_handler(struct net_device *netdev,
 	}
 }
 
+static inline void nicvf_set_rxhash(struct net_device *netdev,
+				    struct cqe_rx_t *cqe_rx,
+				    struct sk_buff *skb)
+{
+	u8 hash_type;
+	u32 hash;
+
+	if (!(netdev->features & NETIF_F_RXHASH))
+		return;
+
+	switch (cqe_rx->rss_alg) {
+	case RSS_ALG_TCP_IP:
+	case RSS_ALG_UDP_IP:
+		hash_type = PKT_HASH_TYPE_L4;
+		hash = cqe_rx->rss_tag;
+		break;
+	case RSS_ALG_IP:
+		hash_type = PKT_HASH_TYPE_L3;
+		hash = cqe_rx->rss_tag;
+		break;
+	default:
+		hash_type = PKT_HASH_TYPE_NONE;
+		hash = 0;
+	}
+
+	skb_set_hash(skb, hash, hash_type);
+}
+
 static void nicvf_rcv_pkt_handler(struct net_device *netdev,
 				  struct napi_struct *napi,
 				  struct cmp_queue *cq,
@@ -451,6 +479,8 @@ static void nicvf_rcv_pkt_handler(struct net_device *netdev,
 
 	nicvf_set_rx_frame_cnt(nic, skb);
 
+	nicvf_set_rxhash(netdev, cqe_rx, skb);
+
 	skb_record_rx_queue(skb, cqe_rx->rq_idx);
 	if (netdev->hw_features & NETIF_F_RXCSUM) {
 		/* HW by default verifies TCP/UDP/SCTP checksums */
@@ -1272,7 +1302,8 @@ static int nicvf_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		goto err_free_netdev;
 
 	netdev->features |= (NETIF_F_RXCSUM | NETIF_F_IP_CSUM | NETIF_F_SG |
-			     NETIF_F_TSO | NETIF_F_GRO);
+			     NETIF_F_TSO | NETIF_F_GRO | NETIF_F_RXHASH);
+
 	netdev->hw_features = netdev->features;
 
 	netdev->netdev_ops = &nicvf_netdev_ops;