igb: Replace LRO with GRO

This patch makes igb invoke the GRO hooks instead of LRO.  As
GRO has a compatible external interface to LRO this is a very
straightforward replacement.

Three things of note:

1) I've kept the LRO Kconfig option until we decide to enable
GRO across the board at which point it can also be killed.

2) The poll_controller stuff is broken in igb as it tries to do
the same work as the normal poll routine.  Since poll_controller
can be called in the middle of a poll, this can't be good.

I noticed this because poll_controller can invoke the GRO hooks
without flushing held GRO packets.

However, this should be harmless (assuming the poll_controller
bug above doesn't kill you first :) since the next ->poll will
clear the backlog.  The only time when we'll have a problem is
if we're already executing the GRO code on the same ring, but
that's no worse than what happens now.

3) I kept the ip_summed check before calling GRO so that we're
on par with previous behaviour.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 84 deletions

diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c
index 3806bb9d8bfa..dbe03c2b49c9 100644
--- a/drivers/net/igb/igb_main.c
+++ b/drivers/net/igb/igb_main.c
@@ -115,9 +115,6 @@ static bool igb_clean_tx_irq(struct igb_ring *);
 static int igb_poll(struct napi_struct *, int);
 static bool igb_clean_rx_irq_adv(struct igb_ring *, int *, int);
 static void igb_alloc_rx_buffers_adv(struct igb_ring *, int);
-#ifdef CONFIG_IGB_LRO
-static int igb_get_skb_hdr(struct sk_buff *skb, void **, void **, u64 *, void *);
-#endif
 static int igb_ioctl(struct net_device *, struct ifreq *, int cmd);
 static void igb_tx_timeout(struct net_device *);
 static void igb_reset_task(struct work_struct *);
@@ -1189,7 +1186,7 @@ static int __devinit igb_probe(struct pci_dev *pdev,
         netdev->features |= NETIF_F_TSO6;
 
 #ifdef CONFIG_IGB_LRO
-        netdev->features |= NETIF_F_LRO;
+        netdev->features |= NETIF_F_GRO;
 #endif
 
         netdev->vlan_features |= NETIF_F_TSO;
@@ -1739,14 +1736,6 @@ int igb_setup_rx_resources(struct igb_adapter *adapter,
         struct pci_dev *pdev = adapter->pdev;
         int size, desc_len;
 
-#ifdef CONFIG_IGB_LRO
-        size = sizeof(struct net_lro_desc) * MAX_LRO_DESCRIPTORS;
-        rx_ring->lro_mgr.lro_arr = vmalloc(size);
-        if (!rx_ring->lro_mgr.lro_arr)
-                goto err;
-        memset(rx_ring->lro_mgr.lro_arr, 0, size);
-#endif
-
         size = sizeof(struct igb_buffer) * rx_ring->count;
         rx_ring->buffer_info = vmalloc(size);
         if (!rx_ring->buffer_info)
@@ -1773,10 +1762,6 @@ int igb_setup_rx_resources(struct igb_adapter *adapter,
         return 0;
 
 err:
-#ifdef CONFIG_IGB_LRO
-        vfree(rx_ring->lro_mgr.lro_arr);
-        rx_ring->lro_mgr.lro_arr = NULL;
-#endif
         vfree(rx_ring->buffer_info);
         dev_err(&adapter->pdev->dev, "Unable to allocate memory for "
                 "the receive descriptor ring\n");
@@ -1930,16 +1915,6 @@ static void igb_configure_rx(struct igb_adapter *adapter)
                 rxdctl |= IGB_RX_HTHRESH << 8;
                 rxdctl |= IGB_RX_WTHRESH << 16;
                 wr32(E1000_RXDCTL(j), rxdctl);
-#ifdef CONFIG_IGB_LRO
-                /* Intitial LRO Settings */
-                ring->lro_mgr.max_aggr = MAX_LRO_AGGR;
-                ring->lro_mgr.max_desc = MAX_LRO_DESCRIPTORS;
-                ring->lro_mgr.get_skb_header = igb_get_skb_hdr;
-                ring->lro_mgr.features = LRO_F_NAPI | LRO_F_EXTRACT_VLAN_ID;
-                ring->lro_mgr.dev = adapter->netdev;
-                ring->lro_mgr.ip_summed = CHECKSUM_UNNECESSARY;
-                ring->lro_mgr.ip_summed_aggr = CHECKSUM_UNNECESSARY;
-#endif
         }
 
         if (adapter->num_rx_queues > 1) {
@@ -2128,11 +2103,6 @@ void igb_free_rx_resources(struct igb_ring *rx_ring)
         vfree(rx_ring->buffer_info);
         rx_ring->buffer_info = NULL;
 
-#ifdef CONFIG_IGB_LRO
-        vfree(rx_ring->lro_mgr.lro_arr);
-        rx_ring->lro_mgr.lro_arr = NULL;
-#endif 
-
         pci_free_consistent(pdev, rx_ring->size, rx_ring->desc, rx_ring->dma);
 
         rx_ring->desc = NULL;
@@ -3768,39 +3738,6 @@ static bool igb_clean_tx_irq(struct igb_ring *tx_ring)
         return (count < tx_ring->count);
 }
 
-#ifdef CONFIG_IGB_LRO
- /**
- * igb_get_skb_hdr - helper function for LRO header processing
- * @skb: pointer to sk_buff to be added to LRO packet
- * @iphdr: pointer to ip header structure
- * @tcph: pointer to tcp header structure
- * @hdr_flags: pointer to header flags
- * @priv: pointer to the receive descriptor for the current sk_buff
- **/
-static int igb_get_skb_hdr(struct sk_buff *skb, void **iphdr, void **tcph,
-                           u64 *hdr_flags, void *priv)
-{
-        union e1000_adv_rx_desc *rx_desc = priv;
-        u16 pkt_type = rx_desc->wb.lower.lo_dword.pkt_info &
-                       (E1000_RXDADV_PKTTYPE_IPV4 | E1000_RXDADV_PKTTYPE_TCP);
-
-        /* Verify that this is a valid IPv4 TCP packet */
-        if (pkt_type != (E1000_RXDADV_PKTTYPE_IPV4 |
-                          E1000_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;
-
-}
-#endif /* CONFIG_IGB_LRO */
-
 /**
  * igb_receive_skb - helper function to handle rx indications
  * @ring: pointer to receive ring receving this packet 
@@ -3815,28 +3752,20 @@ static void igb_receive_skb(struct igb_ring *ring, u8 status,
         struct igb_adapter * adapter = ring->adapter;
         bool vlan_extracted = (adapter->vlgrp && (status & E1000_RXD_STAT_VP));
 
-#ifdef CONFIG_IGB_LRO
-        if (adapter->netdev->features & NETIF_F_LRO &&
-            skb->ip_summed == CHECKSUM_UNNECESSARY) {
+        if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
                 if (vlan_extracted)
-                        lro_vlan_hwaccel_receive_skb(&ring->lro_mgr, skb,
-                                           adapter->vlgrp,
-                                           le16_to_cpu(rx_desc->wb.upper.vlan),
-                                           rx_desc);
+                        vlan_gro_receive(&ring->napi, adapter->vlgrp,
+                                         le16_to_cpu(rx_desc->wb.upper.vlan),
+                                         skb);
                 else
-                        lro_receive_skb(&ring->lro_mgr,skb, rx_desc);
-                ring->lro_used = 1;
+                        napi_gro_receive(&ring->napi, skb);
         } else {
-#endif
                 if (vlan_extracted)
                         vlan_hwaccel_receive_skb(skb, adapter->vlgrp,
                                           le16_to_cpu(rx_desc->wb.upper.vlan));
                 else
-
                         netif_receive_skb(skb);
-#ifdef CONFIG_IGB_LRO
         }
-#endif
 }
 
 
@@ -3991,13 +3920,6 @@ next_desc:
         rx_ring->next_to_clean = i;
         cleaned_count = IGB_DESC_UNUSED(rx_ring);
 
-#ifdef CONFIG_IGB_LRO
-        if (rx_ring->lro_used) {
-                lro_flush_all(&rx_ring->lro_mgr);
-                rx_ring->lro_used = 0;
-        }
-#endif
-
         if (cleaned_count)
                 igb_alloc_rx_buffers_adv(rx_ring, cleaned_count);