IPoIB: add LRO support

Add "ipoib_use_lro" module parameter to enable LRO and an
"ipoib_lro_max_aggr" module parameter to set the max number of packets
to be aggregated.  Make LRO controllable and LRO statistics accessible
through ethtool.

Signed-off-by: Vladimir Sokolovsky <vlad@mellanox.co.il>
Signed-off-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

5 files changed, 127 insertions, 1 deletions

diff --git a/drivers/infiniband/ulp/ipoib/Kconfig b/drivers/infiniband/ulp/ipoib/Kconfig
index 1f76bad020f3..691525cf394a 100644
--- a/drivers/infiniband/ulp/ipoib/Kconfig
+++ b/drivers/infiniband/ulp/ipoib/Kconfig
@@ -1,6 +1,7 @@
 config INFINIBAND_IPOIB
         tristate "IP-over-InfiniBand"
         depends on NETDEVICES && INET && (IPV6 || IPV6=n)
+        select INET_LRO
         ---help---
           Support for the IP-over-InfiniBand protocol (IPoIB). This
           transports IP packets over InfiniBand so you can use your IB
diff --git a/drivers/infiniband/ulp/ipoib/ipoib.h b/drivers/infiniband/ulp/ipoib/ipoib.h
index 8754b364f229..2c522572e3c5 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib.h
+++ b/drivers/infiniband/ulp/ipoib/ipoib.h
@@ -50,6 +50,7 @@
 #include <rdma/ib_verbs.h>
 #include <rdma/ib_pack.h>
 #include <rdma/ib_sa.h>
+#include <linux/inet_lro.h>
 
 /* constants */
 
@@ -94,6 +95,9 @@ enum {
         IPOIB_MCAST_FLAG_BUSY     = 2,  /* joining or already joined */
         IPOIB_MCAST_FLAG_ATTACHED = 3,
 
+        IPOIB_MAX_LRO_DESCRIPTORS = 8,
+        IPOIB_LRO_MAX_AGGR        = 64,
+
         MAX_SEND_CQE              = 16,
         IPOIB_CM_COPYBREAK        = 256,
 };
@@ -248,6 +252,11 @@ struct ipoib_ethtool_st {
         u16     max_coalesced_frames;
 };
 
+struct ipoib_lro {
+        struct net_lro_mgr lro_mgr;
+        struct net_lro_desc lro_desc[IPOIB_MAX_LRO_DESCRIPTORS];
+};
+
 /*
  * Device private locking: tx_lock protects members used in TX fast
  * path (and we use LLTX so upper layers don't do extra locking).
@@ -334,6 +343,8 @@ struct ipoib_dev_priv {
         int     hca_caps;
         struct ipoib_ethtool_st ethtool;
         struct timer_list poll_timer;
+
+        struct ipoib_lro lro;
 };
 
 struct ipoib_ah {
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_ethtool.c b/drivers/infiniband/ulp/ipoib/ipoib_ethtool.c
index 10279b79c44d..66af5c1a76e5 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_ethtool.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_ethtool.c
@@ -86,11 +86,57 @@ static int ipoib_set_coalesce(struct net_device *dev,
         return 0;
 }
 
+static const char ipoib_stats_keys[][ETH_GSTRING_LEN] = {
+        "LRO aggregated", "LRO flushed",
+        "LRO avg aggr", "LRO no desc"
+};
+
+static void ipoib_get_strings(struct net_device *netdev, u32 stringset, u8 *data)
+{
+        switch (stringset) {
+        case ETH_SS_STATS:
+                memcpy(data, *ipoib_stats_keys, sizeof(ipoib_stats_keys));
+                break;
+        }
+}
+
+static int ipoib_get_sset_count(struct net_device *dev, int sset)
+{
+        switch (sset) {
+        case ETH_SS_STATS:
+                return ARRAY_SIZE(ipoib_stats_keys);
+        default:
+                return -EOPNOTSUPP;
+        }
+}
+
+static void ipoib_get_ethtool_stats(struct net_device *dev,
+                                struct ethtool_stats *stats, uint64_t *data)
+{
+        struct ipoib_dev_priv *priv = netdev_priv(dev);
+        int index = 0;
+
+        /* Get LRO statistics */
+        data[index++] = priv->lro.lro_mgr.stats.aggregated;
+        data[index++] = priv->lro.lro_mgr.stats.flushed;
+        if (priv->lro.lro_mgr.stats.flushed)
+                data[index++] = priv->lro.lro_mgr.stats.aggregated /
+                                priv->lro.lro_mgr.stats.flushed;
+        else
+                data[index++] = 0;
+        data[index++] = priv->lro.lro_mgr.stats.no_desc;
+}
+
 static const struct ethtool_ops ipoib_ethtool_ops = {
         .get_drvinfo            = ipoib_get_drvinfo,
         .get_tso                = ethtool_op_get_tso,
         .get_coalesce           = ipoib_get_coalesce,
         .set_coalesce           = ipoib_set_coalesce,
+        .get_flags              = ethtool_op_get_flags,
+        .set_flags              = ethtool_op_set_flags,
+        .get_strings            = ipoib_get_strings,
+        .get_sset_count         = ipoib_get_sset_count,
+        .get_ethtool_stats      = ipoib_get_ethtool_stats,
 };
 
 void ipoib_set_ethtool_ops(struct net_device *dev)
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_ib.c b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
index eca8518d79a0..5d50e5261eed 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_ib.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
@@ -288,7 +288,10 @@ static void ipoib_ib_handle_rx_wc(struct net_device *dev, struct ib_wc *wc)
         if (test_bit(IPOIB_FLAG_CSUM, &priv->flags) && likely(wc->csum_ok))
                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 
-        netif_receive_skb(skb);
+        if (dev->features & NETIF_F_LRO)
+                lro_receive_skb(&priv->lro.lro_mgr, skb, NULL);
+        else
+                netif_receive_skb(skb);
 
 repost:
         if (unlikely(ipoib_ib_post_receive(dev, wr_id)))
@@ -440,6 +443,9 @@ poll_more:
         }
 
         if (done < budget) {
+                if (dev->features & NETIF_F_LRO)
+                        lro_flush_all(&priv->lro.lro_mgr);
+
                 netif_rx_complete(dev, napi);
                 if (unlikely(ib_req_notify_cq(priv->recv_cq,
                                               IB_CQ_NEXT_COMP |
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index bfe1dbf99207..fead88f7fb17 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -60,6 +60,15 @@ MODULE_PARM_DESC(send_queue_size, "Number of descriptors in send queue");
 module_param_named(recv_queue_size, ipoib_recvq_size, int, 0444);
 MODULE_PARM_DESC(recv_queue_size, "Number of descriptors in receive queue");
 
+static int lro;
+module_param(lro, bool, 0444);
+MODULE_PARM_DESC(lro,  "Enable LRO (Large Receive Offload)");
+
+static int lro_max_aggr = IPOIB_LRO_MAX_AGGR;
+module_param(lro_max_aggr, int, 0644);
+MODULE_PARM_DESC(lro_max_aggr, "LRO: Max packets to be aggregated "
+                "(default = 64)");
+
 #ifdef CONFIG_INFINIBAND_IPOIB_DEBUG
 int ipoib_debug_level;
 
@@ -936,6 +945,54 @@ static const struct header_ops ipoib_header_ops = {
         .create = ipoib_hard_header,
 };
 
+static int get_skb_hdr(struct sk_buff *skb, void **iphdr,
+                       void **tcph, u64 *hdr_flags, void *priv)
+{
+        unsigned int ip_len;
+        struct iphdr *iph;
+
+        if (unlikely(skb->protocol != htons(ETH_P_IP)))
+                return -1;
+
+        /*
+         * In the future we may add an else clause that verifies the
+         * checksum and allows devices which do not calculate checksum
+         * to use LRO.
+         */
+        if (unlikely(skb->ip_summed != CHECKSUM_UNNECESSARY))
+                return -1;
+
+        /* Check for non-TCP packet */
+        skb_reset_network_header(skb);
+        iph = ip_hdr(skb);
+        if (iph->protocol != IPPROTO_TCP)
+                return -1;
+
+        ip_len = ip_hdrlen(skb);
+        skb_set_transport_header(skb, ip_len);
+        *tcph = tcp_hdr(skb);
+
+        /* check if IP header and TCP header are complete */
+        if (ntohs(iph->tot_len) < ip_len + tcp_hdrlen(skb))
+                return -1;
+
+        *hdr_flags = LRO_IPV4 | LRO_TCP;
+        *iphdr = iph;
+
+        return 0;
+}
+
+static void ipoib_lro_setup(struct ipoib_dev_priv *priv)
+{
+        priv->lro.lro_mgr.max_aggr       = lro_max_aggr;
+        priv->lro.lro_mgr.max_desc       = IPOIB_MAX_LRO_DESCRIPTORS;
+        priv->lro.lro_mgr.lro_arr        = priv->lro.lro_desc;
+        priv->lro.lro_mgr.get_skb_header = get_skb_hdr;
+        priv->lro.lro_mgr.features       = LRO_F_NAPI;
+        priv->lro.lro_mgr.dev            = priv->dev;
+        priv->lro.lro_mgr.ip_summed_aggr = CHECKSUM_UNNECESSARY;
+}
+
 static void ipoib_setup(struct net_device *dev)
 {
         struct ipoib_dev_priv *priv = netdev_priv(dev);
@@ -975,6 +1032,8 @@ static void ipoib_setup(struct net_device *dev)
 
         priv->dev = dev;
 
+        ipoib_lro_setup(priv);
+
         spin_lock_init(&priv->lock);
         spin_lock_init(&priv->tx_lock);
 
@@ -1152,6 +1211,9 @@ static struct net_device *ipoib_add_port(const char *format,
                 priv->dev->features |= NETIF_F_SG | NETIF_F_IP_CSUM;
         }
 
+        if (lro)
+                priv->dev->features |= NETIF_F_LRO;
+
         /*
          * Set the full membership bit, so that we join the right
          * broadcast group, etc.