ixgbe: add LRO support

Support for in-kernel LRO with the ability to enable/disable via ethtool
based on comments from Ben Hutchings.

Signed-off-by: Mallikarjuna R Chilakala <mallikarjuna.chilakala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: PJ Waskiewicz <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

3 files changed, 110 insertions, 21 deletions

diff --git a/drivers/net/ixgbe/ixgbe.h b/drivers/net/ixgbe/ixgbe.h
index d98113472a89..956914a5028d 100644
--- a/drivers/net/ixgbe/ixgbe.h
+++ b/drivers/net/ixgbe/ixgbe.h
@@ -32,6 +32,7 @@
 #include <linux/types.h>
 #include <linux/pci.h>
 #include <linux/netdevice.h>
+#include <linux/inet_lro.h>
 
 #include "ixgbe_type.h"
 #include "ixgbe_common.h"
@@ -100,6 +101,9 @@
 #define IXGBE_TX_FLAGS_VLAN_MASK        0xffff0000
 #define IXGBE_TX_FLAGS_VLAN_SHIFT       16
 
+#define IXGBE_MAX_LRO_DESCRIPTORS       8
+#define IXGBE_MAX_LRO_AGGREGATE         32
+
 /* wrapper around a pointer to a socket buffer,
  * so a DMA handle can be stored along with the buffer */
 struct ixgbe_tx_buffer {
@@ -150,6 +154,8 @@ struct ixgbe_ring {
         /* cpu for tx queue */
         int cpu;
 #endif
+        struct net_lro_mgr lro_mgr;
+        bool lro_used;
         struct ixgbe_queue_stats stats;
         u8 v_idx; /* maps directly to the index for this ring in the hardware
                    * vector array, can also be used for finding the bit in EICR
@@ -287,6 +293,9 @@ struct ixgbe_adapter {
 
         unsigned long state;
         u64 tx_busy;
+        u64 lro_aggregated;
+        u64 lro_flushed;
+        u64 lro_no_desc;
 };
 
 enum ixbge_state_t {
diff --git a/drivers/net/ixgbe/ixgbe_ethtool.c b/drivers/net/ixgbe/ixgbe_ethtool.c
index 4e463778bcfd..12990b1fe7e4 100644
--- a/drivers/net/ixgbe/ixgbe_ethtool.c
+++ b/drivers/net/ixgbe/ixgbe_ethtool.c
@@ -90,6 +90,8 @@ static struct ixgbe_stats ixgbe_gstrings_stats[] = {
         {"rx_header_split", IXGBE_STAT(rx_hdr_split)},
         {"alloc_rx_page_failed", IXGBE_STAT(alloc_rx_page_failed)},
         {"alloc_rx_buff_failed", IXGBE_STAT(alloc_rx_buff_failed)},
+        {"lro_aggregated", IXGBE_STAT(lro_aggregated)},
+        {"lro_flushed", IXGBE_STAT(lro_flushed)},
 };
 
 #define IXGBE_QUEUE_STATS_LEN \
@@ -787,6 +789,7 @@ static void ixgbe_get_ethtool_stats(struct net_device *netdev,
         int stat_count = sizeof(struct ixgbe_queue_stats) / sizeof(u64);
         int j, k;
         int i;
+        u64 aggregated = 0, flushed = 0, no_desc = 0;
 
         ixgbe_update_stats(adapter);
         for (i = 0; i < IXGBE_GLOBAL_STATS_LEN; i++) {
@@ -801,11 +804,17 @@ static void ixgbe_get_ethtool_stats(struct net_device *netdev,
                 i += k;
         }
         for (j = 0; j < adapter->num_rx_queues; j++) {
+                aggregated += adapter->rx_ring[j].lro_mgr.stats.aggregated;
+                flushed += adapter->rx_ring[j].lro_mgr.stats.flushed;
+                no_desc += adapter->rx_ring[j].lro_mgr.stats.no_desc;
                 queue_stat = (u64 *)&adapter->rx_ring[j].stats;
                 for (k = 0; k < stat_count; k++)
                         data[i + k] = queue_stat[k];
                 i += k;
         }
+        adapter->lro_aggregated = aggregated;
+        adapter->lro_flushed = flushed;
+        adapter->lro_no_desc = no_desc;
 }
 
 static void ixgbe_get_strings(struct net_device *netdev, u32 stringset,
@@ -973,6 +982,8 @@ static struct ethtool_ops ixgbe_ethtool_ops = {
         .get_ethtool_stats      = ixgbe_get_ethtool_stats,
         .get_coalesce           = ixgbe_get_coalesce,
         .set_coalesce           = ixgbe_set_coalesce,
+        .get_flags              = ethtool_op_get_flags,
+        .set_flags              = ethtool_op_set_flags,
 };
 
 void ixgbe_set_ethtool_ops(struct net_device *netdev)
diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index 0d37c9025be4..f429c9a4754f 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -389,24 +389,39 @@ static int __ixgbe_notify_dca(struct device *dev, void *data)
  * ixgbe_receive_skb - Send a completed packet up the stack
  * @adapter: board private structure
  * @skb: packet to send up
- * @is_vlan: packet has a VLAN tag
- * @tag: VLAN tag from descriptor
+ * @status: hardware indication of status of receive
+ * @rx_ring: rx descriptor ring (for a specific queue) to setup
+ * @rx_desc: rx descriptor
  **/
 static void ixgbe_receive_skb(struct ixgbe_adapter *adapter,
-                              struct sk_buff *skb, bool is_vlan,
-                              u16 tag)
+                              struct sk_buff *skb, u8 status,
+                              struct ixgbe_ring *ring,
+                              union ixgbe_adv_rx_desc *rx_desc)
 {
-        if (!(adapter->flags & IXGBE_FLAG_IN_NETPOLL)) {
-                if (adapter->vlgrp && is_vlan)
-                        vlan_hwaccel_receive_skb(skb, adapter->vlgrp, tag);
-                else
-                        netif_receive_skb(skb);
-        } else {
+        bool is_vlan = (status & IXGBE_RXD_STAT_VP);
+        u16 tag = le16_to_cpu(rx_desc->wb.upper.vlan);
 
+        if (adapter->netdev->features & NETIF_F_LRO &&
+            skb->ip_summed == CHECKSUM_UNNECESSARY) {
                 if (adapter->vlgrp && is_vlan)
-                        vlan_hwaccel_rx(skb, adapter->vlgrp, tag);
+                        lro_vlan_hwaccel_receive_skb(&ring->lro_mgr, skb,
+                                                     adapter->vlgrp, tag,
+                                                     rx_desc);
                 else
-                        netif_rx(skb);
+                        lro_receive_skb(&ring->lro_mgr, skb, rx_desc);
+                ring->lro_used = true;
+        } else {
+                if (!(adapter->flags & IXGBE_FLAG_IN_NETPOLL)) {
+                        if (adapter->vlgrp && is_vlan)
+                                vlan_hwaccel_receive_skb(skb, adapter->vlgrp, tag);
+                        else
+                                netif_receive_skb(skb);
+                } else {
+                        if (adapter->vlgrp && is_vlan)
+                                vlan_hwaccel_rx(skb, adapter->vlgrp, tag);
+                        else
+                                netif_rx(skb);
+                }
         }
 }
 
@@ -546,8 +561,8 @@ static bool ixgbe_clean_rx_irq(struct ixgbe_adapter *adapter,
         struct sk_buff *skb;
         unsigned int i;
         u32 upper_len, len, staterr;
-        u16 hdr_info, vlan_tag;
-        bool is_vlan, cleaned = false;
+        u16 hdr_info;
+        bool cleaned = false;
         int cleaned_count = 0;
         unsigned int total_rx_bytes = 0, total_rx_packets = 0;
 
@@ -556,8 +571,6 @@ static bool ixgbe_clean_rx_irq(struct ixgbe_adapter *adapter,
         rx_desc = IXGBE_RX_DESC_ADV(*rx_ring, i);
         staterr = le32_to_cpu(rx_desc->wb.upper.status_error);
         rx_buffer_info = &rx_ring->rx_buffer_info[i];
-        is_vlan = (staterr & IXGBE_RXD_STAT_VP);
-        vlan_tag = le16_to_cpu(rx_desc->wb.upper.vlan);
 
         while (staterr & IXGBE_RXD_STAT_DD) {
                 if (*work_done >= work_to_do)
@@ -635,7 +648,7 @@ static bool ixgbe_clean_rx_irq(struct ixgbe_adapter *adapter,
                 total_rx_packets++;
 
                 skb->protocol = eth_type_trans(skb, netdev);
-                ixgbe_receive_skb(adapter, skb, is_vlan, vlan_tag);
+                ixgbe_receive_skb(adapter, skb, staterr, rx_ring, rx_desc);
                 netdev->last_rx = jiffies;
 
 next_desc:
@@ -652,8 +665,11 @@ next_desc:
                 rx_buffer_info = next_buffer;
 
                 staterr = le32_to_cpu(rx_desc->wb.upper.status_error);
-                is_vlan = (staterr & IXGBE_RXD_STAT_VP);
-                vlan_tag = le16_to_cpu(rx_desc->wb.upper.vlan);
+        }
+
+        if (rx_ring->lro_used) {
+                lro_flush_all(&rx_ring->lro_mgr);
+                rx_ring->lro_used = false;
         }
 
         rx_ring->next_to_clean = i;
@@ -1382,6 +1398,33 @@ static void ixgbe_configure_tx(struct ixgbe_adapter *adapter)
 
 #define IXGBE_SRRCTL_BSIZEHDRSIZE_SHIFT                 2
 /**
+ * ixgbe_get_skb_hdr - helper function for LRO header processing
+ * @skb: pointer to sk_buff to be added to LRO packet
+ * @iphdr: pointer to tcp header structure
+ * @tcph: pointer to tcp header structure
+ * @hdr_flags: pointer to header flags
+ * @priv: private data
+ **/
+static int ixgbe_get_skb_hdr(struct sk_buff *skb, void **iphdr, void **tcph,
+                             u64 *hdr_flags, void *priv)
+{
+        union ixgbe_adv_rx_desc *rx_desc = priv;
+
+        /* Verify that this is a valid IPv4 TCP packet */
+        if (!(rx_desc->wb.lower.lo_dword.pkt_info &
+            (IXGBE_RXDADV_PKTTYPE_IPV4 | IXGBE_RXDADV_PKTTYPE_TCP)))
+                return -1;
+
+        /* Set network headers */
+        skb_reset_network_header(skb);
+        skb_set_transport_header(skb, ip_hdrlen(skb));
+        *iphdr = ip_hdr(skb);
+        *tcph = tcp_hdr(skb);
+        *hdr_flags = LRO_IPV4 | LRO_TCP;
+        return 0;
+}
+
+/**
  * ixgbe_configure_rx - Configure 8254x Receive Unit after Reset
  * @adapter: board private structure
  *
@@ -1470,6 +1513,17 @@ static void ixgbe_configure_rx(struct ixgbe_adapter *adapter)
                 adapter->rx_ring[i].tail = IXGBE_RDT(i);
         }
 
+        /* Intitial LRO Settings */
+        adapter->rx_ring[i].lro_mgr.max_aggr = IXGBE_MAX_LRO_AGGREGATE;
+        adapter->rx_ring[i].lro_mgr.max_desc = IXGBE_MAX_LRO_DESCRIPTORS;
+        adapter->rx_ring[i].lro_mgr.get_skb_header = ixgbe_get_skb_hdr;
+        adapter->rx_ring[i].lro_mgr.features = LRO_F_EXTRACT_VLAN_ID;
+        if (!(adapter->flags & IXGBE_FLAG_IN_NETPOLL))
+                adapter->rx_ring[i].lro_mgr.features |= LRO_F_NAPI;
+        adapter->rx_ring[i].lro_mgr.dev = adapter->netdev;
+        adapter->rx_ring[i].lro_mgr.ip_summed = CHECKSUM_UNNECESSARY;
+        adapter->rx_ring[i].lro_mgr.ip_summed_aggr = CHECKSUM_UNNECESSARY;
+
         if (adapter->flags & IXGBE_FLAG_RSS_ENABLED) {
                 /* Fill out redirection table */
                 for (i = 0, j = 0; i < 128; i++, j++) {
@@ -2489,12 +2543,18 @@ int ixgbe_setup_rx_resources(struct ixgbe_adapter *adapter,
         struct pci_dev *pdev = adapter->pdev;
         int size;
 
+        size = sizeof(struct net_lro_desc) * IXGBE_MAX_LRO_DESCRIPTORS;
+        rxdr->lro_mgr.lro_arr = vmalloc(size);
+        if (!rxdr->lro_mgr.lro_arr)
+                return -ENOMEM;
+        memset(rxdr->lro_mgr.lro_arr, 0, size);
+
         size = sizeof(struct ixgbe_rx_buffer) * rxdr->count;
         rxdr->rx_buffer_info = vmalloc(size);
         if (!rxdr->rx_buffer_info) {
                 DPRINTK(PROBE, ERR,
                         "vmalloc allocation failed for the rx desc ring\n");
-                return -ENOMEM;
+                goto alloc_failed;
         }
         memset(rxdr->rx_buffer_info, 0, size);
 
@@ -2508,13 +2568,18 @@ int ixgbe_setup_rx_resources(struct ixgbe_adapter *adapter,
                 DPRINTK(PROBE, ERR,
                         "Memory allocation failed for the rx desc ring\n");
                 vfree(rxdr->rx_buffer_info);
-                return -ENOMEM;
+                goto alloc_failed;
         }
 
         rxdr->next_to_clean = 0;
         rxdr->next_to_use = 0;
 
         return 0;
+
+alloc_failed:
+        vfree(rxdr->lro_mgr.lro_arr);
+        rxdr->lro_mgr.lro_arr = NULL;
+        return -ENOMEM;
 }
 
 /**
@@ -2565,6 +2630,9 @@ static void ixgbe_free_rx_resources(struct ixgbe_adapter *adapter,
 {
         struct pci_dev *pdev = adapter->pdev;
 
+        vfree(rx_ring->lro_mgr.lro_arr);
+        rx_ring->lro_mgr.lro_arr = NULL;
+
         ixgbe_clean_rx_ring(adapter, rx_ring);
 
         vfree(rx_ring->rx_buffer_info);
@@ -3517,6 +3585,7 @@ static int __devinit ixgbe_probe(struct pci_dev *pdev,
                            NETIF_F_HW_VLAN_RX |
                            NETIF_F_HW_VLAN_FILTER;
 
+        netdev->features |= NETIF_F_LRO;
         netdev->features |= NETIF_F_TSO;
         netdev->features |= NETIF_F_TSO6;