Merge branch 'lro'

1 files changed, 527 insertions, 62 deletions

diff --git a/drivers/net/s2io.c b/drivers/net/s2io.c
index da0d8a85acce..0db218c2dbeb 100644
--- a/drivers/net/s2io.c
+++ b/drivers/net/s2io.c
@@ -57,16 +57,20 @@
 #include <linux/ethtool.h>
 #include <linux/workqueue.h>
 #include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <linux/tcp.h>
+#include <net/tcp.h>
 
 #include <asm/system.h>
 #include <asm/uaccess.h>
 #include <asm/io.h>
+#include <asm/div64.h>
 
 /* local include */
 #include "s2io.h"
 #include "s2io-regs.h"
 
-#define DRV_VERSION "Version 2.0.9.4"
+#define DRV_VERSION "2.0.11.2"
 
 /* S2io Driver name & version. */
 static char s2io_driver_name[] = "Neterion";
@@ -168,6 +172,11 @@ static char ethtool_stats_keys[][ETH_GSTRING_LEN] = {
         {"\n DRIVER STATISTICS"},
         {"single_bit_ecc_errs"},
         {"double_bit_ecc_errs"},
+        ("lro_aggregated_pkts"),
+        ("lro_flush_both_count"),
+        ("lro_out_of_sequence_pkts"),
+        ("lro_flush_due_to_max_pkts"),
+        ("lro_avg_aggr_pkts"),
 };
 
 #define S2IO_STAT_LEN sizeof(ethtool_stats_keys)/ ETH_GSTRING_LEN
@@ -317,6 +326,12 @@ static unsigned int indicate_max_pkts;
 static unsigned int rxsync_frequency = 3;
 /* Interrupt type. Values can be 0(INTA), 1(MSI), 2(MSI_X) */
 static unsigned int intr_type = 0;
+/* Large receive offload feature */
+static unsigned int lro = 0;
+/* Max pkts to be aggregated by LRO at one time. If not specified,
+ * aggregation happens until we hit max IP pkt size(64K)
+ */
+static unsigned int lro_max_pkts = 0xFFFF;
 
 /*
  * S2IO device table.
@@ -1476,6 +1491,19 @@ static int init_nic(struct s2io_nic *nic)
         writel((u32) (val64 >> 32), (add + 4));
         val64 = readq(&bar0->mac_cfg);
 
+        /* Enable FCS stripping by adapter */
+        add = &bar0->mac_cfg;
+        val64 = readq(&bar0->mac_cfg);
+        val64 |= MAC_CFG_RMAC_STRIP_FCS;
+        if (nic->device_type == XFRAME_II_DEVICE)
+                writeq(val64, &bar0->mac_cfg);
+        else {
+                writeq(RMAC_CFG_KEY(0x4C0D), &bar0->rmac_cfg_key);
+                writel((u32) (val64), add);
+                writeq(RMAC_CFG_KEY(0x4C0D), &bar0->rmac_cfg_key);
+                writel((u32) (val64 >> 32), (add + 4));
+        }
+
         /*
          * Set the time value to be inserted in the pause frame
          * generated by xena.
@@ -2569,6 +2597,8 @@ static void rx_intr_handler(ring_info_t *ring_data)
 #ifndef CONFIG_S2IO_NAPI
         int pkt_cnt = 0;
 #endif
+        int i;
+
         spin_lock(&nic->rx_lock);
         if (atomic_read(&nic->card_state) == CARD_DOWN) {
                 DBG_PRINT(INTR_DBG, "%s: %s going down for reset\n",
@@ -2661,6 +2691,18 @@ static void rx_intr_handler(ring_info_t *ring_data)
                         break;
 #endif
         }
+        if (nic->lro) {
+                /* Clear all LRO sessions before exiting */
+                for (i=0; i<MAX_LRO_SESSIONS; i++) {
+                        lro_t *lro = &nic->lro0_n[i];
+                        if (lro->in_use) {
+                                update_L3L4_header(nic, lro);
+                                queue_rx_frame(lro->parent);
+                                clear_lro_session(lro);
+                        }
+                }
+        }
+
         spin_unlock(&nic->rx_lock);
 }
 
@@ -3668,23 +3710,32 @@ s2io_msi_handle(int irq, void *dev_id, struct pt_regs *regs)
          * else schedule a tasklet to reallocate the buffers.
          */
         for (i = 0; i < config->rx_ring_num; i++) {
-                int rxb_size = atomic_read(&sp->rx_bufs_left[i]);
-                int level = rx_buffer_level(sp, rxb_size, i);
-
-                if ((level == PANIC) && (!TASKLET_IN_USE)) {
-                        DBG_PRINT(INTR_DBG, "%s: Rx BD hit ", dev->name);
-                        DBG_PRINT(INTR_DBG, "PANIC levels\n");
-                        if ((ret = fill_rx_buffers(sp, i)) == -ENOMEM) {
-                                DBG_PRINT(ERR_DBG, "%s:Out of memory",
-                                          dev->name);
-                                DBG_PRINT(ERR_DBG, " in ISR!!\n");
+                if (!sp->lro) {
+                        int rxb_size = atomic_read(&sp->rx_bufs_left[i]);
+                        int level = rx_buffer_level(sp, rxb_size, i);
+
+                        if ((level == PANIC) && (!TASKLET_IN_USE)) {
+                                DBG_PRINT(INTR_DBG, "%s: Rx BD hit ", 
+                                                        dev->name);
+                                DBG_PRINT(INTR_DBG, "PANIC levels\n");
+                                if ((ret = fill_rx_buffers(sp, i)) == -ENOMEM) {
+                                        DBG_PRINT(ERR_DBG, "%s:Out of memory",
+                                                  dev->name);
+                                        DBG_PRINT(ERR_DBG, " in ISR!!\n");
+                                        clear_bit(0, (&sp->tasklet_status));
+                                        atomic_dec(&sp->isr_cnt);
+                                        return IRQ_HANDLED;
+                                }
                                 clear_bit(0, (&sp->tasklet_status));
-                                atomic_dec(&sp->isr_cnt);
-                                return IRQ_HANDLED;
+                        } else if (level == LOW) {
+                                tasklet_schedule(&sp->task);
                         }
-                        clear_bit(0, (&sp->tasklet_status));
-                } else if (level == LOW) {
-                        tasklet_schedule(&sp->task);
+                }
+                else if (fill_rx_buffers(sp, i) == -ENOMEM) {
+                                DBG_PRINT(ERR_DBG, "%s:Out of memory",
+                                                        dev->name);
+                                DBG_PRINT(ERR_DBG, " in Rx Intr!!\n");
+                                break;
                 }
         }
 
@@ -3697,29 +3748,37 @@ s2io_msix_ring_handle(int irq, void *dev_id, struct pt_regs *regs)
 {
         ring_info_t *ring = (ring_info_t *)dev_id;
         nic_t *sp = ring->nic;
+        struct net_device *dev = (struct net_device *) dev_id;
         int rxb_size, level, rng_n;
 
         atomic_inc(&sp->isr_cnt);
         rx_intr_handler(ring);
 
         rng_n = ring->ring_no;
-        rxb_size = atomic_read(&sp->rx_bufs_left[rng_n]);
-        level = rx_buffer_level(sp, rxb_size, rng_n);
-
-        if ((level == PANIC) && (!TASKLET_IN_USE)) {
-                int ret;
-                DBG_PRINT(INTR_DBG, "%s: Rx BD hit ", __FUNCTION__);
-                DBG_PRINT(INTR_DBG, "PANIC levels\n");
-                if ((ret = fill_rx_buffers(sp, rng_n)) == -ENOMEM) {
-                        DBG_PRINT(ERR_DBG, "Out of memory in %s",
-                                  __FUNCTION__);
+        if (!sp->lro) {
+                rxb_size = atomic_read(&sp->rx_bufs_left[rng_n]);
+                level = rx_buffer_level(sp, rxb_size, rng_n);
+
+                if ((level == PANIC) && (!TASKLET_IN_USE)) {
+                        int ret;
+                        DBG_PRINT(INTR_DBG, "%s: Rx BD hit ", __FUNCTION__);
+                        DBG_PRINT(INTR_DBG, "PANIC levels\n");
+                        if ((ret = fill_rx_buffers(sp, rng_n)) == -ENOMEM) {
+                                DBG_PRINT(ERR_DBG, "Out of memory in %s",
+                                          __FUNCTION__);
+                                clear_bit(0, (&sp->tasklet_status));
+                                return IRQ_HANDLED;
+                        }
                         clear_bit(0, (&sp->tasklet_status));
-                        return IRQ_HANDLED;
+                } else if (level == LOW) {
+                        tasklet_schedule(&sp->task);
                 }
-                clear_bit(0, (&sp->tasklet_status));
-        } else if (level == LOW) {
-                tasklet_schedule(&sp->task);
         }
+        else if (fill_rx_buffers(sp, rng_n) == -ENOMEM) {
+                        DBG_PRINT(ERR_DBG, "%s:Out of memory", dev->name);
+                        DBG_PRINT(ERR_DBG, " in Rx Intr!!\n");
+        }
+
         atomic_dec(&sp->isr_cnt);
 
         return IRQ_HANDLED;
@@ -3875,24 +3934,33 @@ static irqreturn_t s2io_isr(int irq, void *dev_id, struct pt_regs *regs)
          */
 #ifndef CONFIG_S2IO_NAPI
         for (i = 0; i < config->rx_ring_num; i++) {
-                int ret;
-                int rxb_size = atomic_read(&sp->rx_bufs_left[i]);
-                int level = rx_buffer_level(sp, rxb_size, i);
-
-                if ((level == PANIC) && (!TASKLET_IN_USE)) {
-                        DBG_PRINT(INTR_DBG, "%s: Rx BD hit ", dev->name);
-                        DBG_PRINT(INTR_DBG, "PANIC levels\n");
-                        if ((ret = fill_rx_buffers(sp, i)) == -ENOMEM) {
-                                DBG_PRINT(ERR_DBG, "%s:Out of memory",
-                                          dev->name);
-                                DBG_PRINT(ERR_DBG, " in ISR!!\n");
+                if (!sp->lro) {
+                        int ret;
+                        int rxb_size = atomic_read(&sp->rx_bufs_left[i]);
+                        int level = rx_buffer_level(sp, rxb_size, i);
+
+                        if ((level == PANIC) && (!TASKLET_IN_USE)) {
+                                DBG_PRINT(INTR_DBG, "%s: Rx BD hit ", 
+                                                        dev->name);
+                                DBG_PRINT(INTR_DBG, "PANIC levels\n");
+                                if ((ret = fill_rx_buffers(sp, i)) == -ENOMEM) {
+                                        DBG_PRINT(ERR_DBG, "%s:Out of memory",
+                                                  dev->name);
+                                        DBG_PRINT(ERR_DBG, " in ISR!!\n");
+                                        clear_bit(0, (&sp->tasklet_status));
+                                        atomic_dec(&sp->isr_cnt);
+                                        return IRQ_HANDLED;
+                                }
                                 clear_bit(0, (&sp->tasklet_status));
-                                atomic_dec(&sp->isr_cnt);
-                                return IRQ_HANDLED;
+                        } else if (level == LOW) {
+                                tasklet_schedule(&sp->task);
                         }
-                        clear_bit(0, (&sp->tasklet_status));
-                } else if (level == LOW) {
-                        tasklet_schedule(&sp->task);
+                }
+                else if (fill_rx_buffers(sp, i) == -ENOMEM) {
+                                DBG_PRINT(ERR_DBG, "%s:Out of memory",
+                                                        dev->name);
+                                DBG_PRINT(ERR_DBG, " in Rx intr!!\n");
+                                break;
                 }
         }
 #endif
@@ -5043,6 +5111,7 @@ static void s2io_get_ethtool_stats(struct net_device *dev,
         int i = 0;
         nic_t *sp = dev->priv;
         StatInfo_t *stat_info = sp->mac_control.stats_info;
+        u64 tmp;
 
         s2io_updt_stats(sp);
         tmp_stats[i++] =
@@ -5134,6 +5203,16 @@ static void s2io_get_ethtool_stats(struct net_device *dev,
         tmp_stats[i++] = 0;
         tmp_stats[i++] = stat_info->sw_stat.single_ecc_errs;
         tmp_stats[i++] = stat_info->sw_stat.double_ecc_errs;
+        tmp_stats[i++] = stat_info->sw_stat.clubbed_frms_cnt;
+        tmp_stats[i++] = stat_info->sw_stat.sending_both;
+        tmp_stats[i++] = stat_info->sw_stat.outof_sequence_pkts;
+        tmp_stats[i++] = stat_info->sw_stat.flush_max_pkts;
+        tmp = 0;
+        if (stat_info->sw_stat.num_aggregations) {
+                tmp = stat_info->sw_stat.sum_avg_pkts_aggregated;
+                do_div(tmp, stat_info->sw_stat.num_aggregations);
+        }
+        tmp_stats[i++] = tmp;
 }
 
 static int s2io_ethtool_get_regs_len(struct net_device *dev)
@@ -5515,6 +5594,14 @@ static int s2io_card_up(nic_t * sp)
         /* Setting its receive mode */
         s2io_set_multicast(dev);
 
+        if (sp->lro) {
+                /* Initialize max aggregatable pkts based on MTU */
+                sp->lro_max_aggr_per_sess = ((1<<16) - 1) / dev->mtu;
+                /* Check if we can use(if specified) user provided value */
+                if (lro_max_pkts < sp->lro_max_aggr_per_sess)
+                        sp->lro_max_aggr_per_sess = lro_max_pkts;
+        }
+
         /* Enable tasklet for the device */
         tasklet_init(&sp->task, s2io_tasklet, (unsigned long) dev);
 
@@ -5607,6 +5694,7 @@ static int rx_osm_handler(ring_info_t *ring_data, RxD_t * rxdp)
                 ((unsigned long) rxdp->Host_Control);
         int ring_no = ring_data->ring_no;
         u16 l3_csum, l4_csum;
+        lro_t *lro;
 
         skb->dev = dev;
         if (rxdp->Control_1 & RXD_T_CODE) {
@@ -5655,7 +5743,8 @@ static int rx_osm_handler(ring_info_t *ring_data, RxD_t * rxdp)
                         skb_put(skb, buf2_len);
         }
 
-        if ((rxdp->Control_1 & TCP_OR_UDP_FRAME) &&
+        if ((rxdp->Control_1 & TCP_OR_UDP_FRAME) && ((!sp->lro) ||
+            (sp->lro && (!(rxdp->Control_1 & RXD_FRAME_IP_FRAG)))) &&
             (sp->rx_csum)) {
                 l3_csum = RXD_GET_L3_CKSUM(rxdp->Control_1);
                 l4_csum = RXD_GET_L4_CKSUM(rxdp->Control_1);
@@ -5666,6 +5755,54 @@ static int rx_osm_handler(ring_info_t *ring_data, RxD_t * rxdp)
                          * a flag in the RxD.
                          */
                         skb->ip_summed = CHECKSUM_UNNECESSARY;
+                        if (sp->lro) {
+                                u32 tcp_len;
+                                u8 *tcp;
+                                int ret = 0;
+
+                                ret = s2io_club_tcp_session(skb->data, &tcp,
+                                                &tcp_len, &lro, rxdp, sp);
+                                switch (ret) {
+                                        case 3: /* Begin anew */
+                                                lro->parent = skb;
+                                                goto aggregate;
+                                        case 1: /* Aggregate */
+                                        {
+                                                lro_append_pkt(sp, lro,
+                                                        skb, tcp_len);
+                                                goto aggregate;
+                                        }
+                                        case 4: /* Flush session */
+                                        {
+                                                lro_append_pkt(sp, lro,
+                                                        skb, tcp_len);
+                                                queue_rx_frame(lro->parent);
+                                                clear_lro_session(lro);
+                                                sp->mac_control.stats_info->
+                                                    sw_stat.flush_max_pkts++;
+                                                goto aggregate;
+                                        }
+                                        case 2: /* Flush both */
+                                                lro->parent->data_len =
+                                                        lro->frags_len;
+                                                sp->mac_control.stats_info->
+                                                     sw_stat.sending_both++;
+                                                queue_rx_frame(lro->parent);
+                                                clear_lro_session(lro);
+                                                goto send_up;
+                                        case 0: /* sessions exceeded */
+                                        case 5: /*
+                                                 * First pkt in session not
+                                                 * L3/L4 aggregatable
+                                                 */
+                                                break;
+                                        default:
+                                                DBG_PRINT(ERR_DBG,
+                                                        "%s: Samadhana!!\n",
+                                                         __FUNCTION__);
+                                                BUG();
+                                }
+                        }
                 } else {
                         /*
                          * Packet with erroneous checksum, let the
@@ -5677,25 +5814,31 @@ static int rx_osm_handler(ring_info_t *ring_data, RxD_t * rxdp)
                 skb->ip_summed = CHECKSUM_NONE;
         }
 
-        skb->protocol = eth_type_trans(skb, dev);
+        if (!sp->lro) {
+                skb->protocol = eth_type_trans(skb, dev);
 #ifdef CONFIG_S2IO_NAPI
-        if (sp->vlgrp && RXD_GET_VLAN_TAG(rxdp->Control_2)) {
-                /* Queueing the vlan frame to the upper layer */
-                vlan_hwaccel_receive_skb(skb, sp->vlgrp,
-                        RXD_GET_VLAN_TAG(rxdp->Control_2));
-        } else {
-                netif_receive_skb(skb);
-        }
+                if (sp->vlgrp && RXD_GET_VLAN_TAG(rxdp->Control_2)) {
+                        /* Queueing the vlan frame to the upper layer */
+                        vlan_hwaccel_receive_skb(skb, sp->vlgrp,
+                                RXD_GET_VLAN_TAG(rxdp->Control_2));
+                } else {
+                        netif_receive_skb(skb);
+                }
 #else
-        if (sp->vlgrp && RXD_GET_VLAN_TAG(rxdp->Control_2)) {
-                /* Queueing the vlan frame to the upper layer */
-                vlan_hwaccel_rx(skb, sp->vlgrp,
-                        RXD_GET_VLAN_TAG(rxdp->Control_2));
-        } else {
-                netif_rx(skb);
-        }
+                if (sp->vlgrp && RXD_GET_VLAN_TAG(rxdp->Control_2)) {
+                        /* Queueing the vlan frame to the upper layer */
+                        vlan_hwaccel_rx(skb, sp->vlgrp,
+                                RXD_GET_VLAN_TAG(rxdp->Control_2));
+                } else {
+                        netif_rx(skb);
+                }
 #endif
+        } else {
+send_up:
+                queue_rx_frame(skb);
+        }               
         dev->last_rx = jiffies;
+aggregate:
         atomic_dec(&sp->rx_bufs_left[ring_no]);
         return SUCCESS;
 }
@@ -5807,6 +5950,8 @@ module_param(indicate_max_pkts, int, 0);
 #endif
 module_param(rxsync_frequency, int, 0);
 module_param(intr_type, int, 0);
+module_param(lro, int, 0);
+module_param(lro_max_pkts, int, 0);
 
 /**
  *  s2io_init_nic - Initialization of the adapter .
@@ -5938,6 +6083,7 @@ Defaulting to INTA\n");
         else
                 sp->device_type = XFRAME_I_DEVICE;
 
+        sp->lro = lro;
                 
         /* Initialize some PCI/PCI-X fields of the NIC. */
         s2io_init_pci(sp);
@@ -6241,6 +6387,10 @@ Defaulting to INTA\n");
                 DBG_PRINT(ERR_DBG, "%s: 3-Buffer mode support has been "
                           "enabled\n",dev->name);
 
+        if (sp->lro)
+                DBG_PRINT(ERR_DBG, "%s: Large receive offload enabled\n",
+                        dev->name);
+
         /* Initialize device name */
         strcpy(sp->name, dev->name);
         if (sp->device_type & XFRAME_II_DEVICE)
@@ -6351,3 +6501,318 @@ static void s2io_closer(void)
 
 module_init(s2io_starter);
 module_exit(s2io_closer);
+
+static int check_L2_lro_capable(u8 *buffer, struct iphdr **ip, 
+                struct tcphdr **tcp, RxD_t *rxdp)
+{
+        int ip_off;
+        u8 l2_type = (u8)((rxdp->Control_1 >> 37) & 0x7), ip_len;
+
+        if (!(rxdp->Control_1 & RXD_FRAME_PROTO_TCP)) {
+                DBG_PRINT(INIT_DBG,"%s: Non-TCP frames not supported for LRO\n",
+                          __FUNCTION__);
+                return -1;
+        }
+
+        /* TODO:
+         * By default the VLAN field in the MAC is stripped by the card, if this
+         * feature is turned off in rx_pa_cfg register, then the ip_off field
+         * has to be shifted by a further 2 bytes
+         */
+        switch (l2_type) {
+                case 0: /* DIX type */
+                case 4: /* DIX type with VLAN */
+                        ip_off = HEADER_ETHERNET_II_802_3_SIZE;
+                        break;
+                /* LLC, SNAP etc are considered non-mergeable */
+                default:
+                        return -1;
+        }
+
+        *ip = (struct iphdr *)((u8 *)buffer + ip_off);
+        ip_len = (u8)((*ip)->ihl);
+        ip_len <<= 2;
+        *tcp = (struct tcphdr *)((unsigned long)*ip + ip_len);
+
+        return 0;
+}
+
+static int check_for_socket_match(lro_t *lro, struct iphdr *ip,
+                                  struct tcphdr *tcp)
+{
+        DBG_PRINT(INFO_DBG,"%s: Been here...\n", __FUNCTION__);
+        if ((lro->iph->saddr != ip->saddr) || (lro->iph->daddr != ip->daddr) ||
+           (lro->tcph->source != tcp->source) || (lro->tcph->dest != tcp->dest))
+                return -1;
+        return 0;
+}
+
+static inline int get_l4_pyld_length(struct iphdr *ip, struct tcphdr *tcp)
+{
+        return(ntohs(ip->tot_len) - (ip->ihl << 2) - (tcp->doff << 2));
+}
+
+static void initiate_new_session(lro_t *lro, u8 *l2h,
+                     struct iphdr *ip, struct tcphdr *tcp, u32 tcp_pyld_len)
+{
+        DBG_PRINT(INFO_DBG,"%s: Been here...\n", __FUNCTION__);
+        lro->l2h = l2h;
+        lro->iph = ip;
+        lro->tcph = tcp;
+        lro->tcp_next_seq = tcp_pyld_len + ntohl(tcp->seq);
+        lro->tcp_ack = ntohl(tcp->ack_seq);
+        lro->sg_num = 1;
+        lro->total_len = ntohs(ip->tot_len);
+        lro->frags_len = 0;
+        /* 
+         * check if we saw TCP timestamp. Other consistency checks have
+         * already been done.
+         */
+        if (tcp->doff == 8) {
+                u32 *ptr;
+                ptr = (u32 *)(tcp+1);
+                lro->saw_ts = 1;
+                lro->cur_tsval = *(ptr+1);
+                lro->cur_tsecr = *(ptr+2);
+        }
+        lro->in_use = 1;
+}
+
+static void update_L3L4_header(nic_t *sp, lro_t *lro)
+{
+        struct iphdr *ip = lro->iph;
+        struct tcphdr *tcp = lro->tcph;
+        u16 nchk;
+        StatInfo_t *statinfo = sp->mac_control.stats_info;
+        DBG_PRINT(INFO_DBG,"%s: Been here...\n", __FUNCTION__);
+
+        /* Update L3 header */
+        ip->tot_len = htons(lro->total_len);
+        ip->check = 0;
+        nchk = ip_fast_csum((u8 *)lro->iph, ip->ihl);
+        ip->check = nchk;
+
+        /* Update L4 header */
+        tcp->ack_seq = lro->tcp_ack;
+        tcp->window = lro->window;
+
+        /* Update tsecr field if this session has timestamps enabled */
+        if (lro->saw_ts) {
+                u32 *ptr = (u32 *)(tcp + 1);
+                *(ptr+2) = lro->cur_tsecr;
+        }
+
+        /* Update counters required for calculation of
+         * average no. of packets aggregated.
+         */
+        statinfo->sw_stat.sum_avg_pkts_aggregated += lro->sg_num;
+        statinfo->sw_stat.num_aggregations++;
+}
+
+static void aggregate_new_rx(lro_t *lro, struct iphdr *ip,
+                struct tcphdr *tcp, u32 l4_pyld)
+{
+        DBG_PRINT(INFO_DBG,"%s: Been here...\n", __FUNCTION__);
+        lro->total_len += l4_pyld;
+        lro->frags_len += l4_pyld;
+        lro->tcp_next_seq += l4_pyld;
+        lro->sg_num++;
+
+        /* Update ack seq no. and window ad(from this pkt) in LRO object */
+        lro->tcp_ack = tcp->ack_seq;
+        lro->window = tcp->window;
+        
+        if (lro->saw_ts) {
+                u32 *ptr;
+                /* Update tsecr and tsval from this packet */
+                ptr = (u32 *) (tcp + 1);
+                lro->cur_tsval = *(ptr + 1); 
+                lro->cur_tsecr = *(ptr + 2);
+        }
+}
+
+static int verify_l3_l4_lro_capable(lro_t *l_lro, struct iphdr *ip,
+                                    struct tcphdr *tcp, u32 tcp_pyld_len)
+{
+        u8 *ptr;
+
+        DBG_PRINT(INFO_DBG,"%s: Been here...\n", __FUNCTION__);
+
+        if (!tcp_pyld_len) {
+                /* Runt frame or a pure ack */
+                return -1;
+        }
+
+        if (ip->ihl != 5) /* IP has options */
+                return -1;
+
+        if (tcp->urg || tcp->psh || tcp->rst || tcp->syn || tcp->fin ||
+                                                                !tcp->ack) {
+                /*
+                 * Currently recognize only the ack control word and
+                 * any other control field being set would result in
+                 * flushing the LRO session
+                 */
+                return -1;
+        }
+
+        /* 
+         * Allow only one TCP timestamp option. Don't aggregate if
+         * any other options are detected.
+         */
+        if (tcp->doff != 5 && tcp->doff != 8)
+                return -1;
+
+        if (tcp->doff == 8) {
+                ptr = (u8 *)(tcp + 1);  
+                while (*ptr == TCPOPT_NOP)
+                        ptr++;
+                if (*ptr != TCPOPT_TIMESTAMP || *(ptr+1) != TCPOLEN_TIMESTAMP)
+                        return -1;
+
+                /* Ensure timestamp value increases monotonically */
+                if (l_lro)
+                        if (l_lro->cur_tsval > *((u32 *)(ptr+2)))
+                                return -1;
+
+                /* timestamp echo reply should be non-zero */
+                if (*((u32 *)(ptr+6)) == 0) 
+                        return -1;
+        }
+
+        return 0;
+}
+
+static int
+s2io_club_tcp_session(u8 *buffer, u8 **tcp, u32 *tcp_len, lro_t **lro,
+                      RxD_t *rxdp, nic_t *sp)
+{
+        struct iphdr *ip;
+        struct tcphdr *tcph;
+        int ret = 0, i;
+
+        if (!(ret = check_L2_lro_capable(buffer, &ip, (struct tcphdr **)tcp,
+                                         rxdp))) {
+                DBG_PRINT(INFO_DBG,"IP Saddr: %x Daddr: %x\n",
+                          ip->saddr, ip->daddr);
+        } else {
+                return ret;
+        }
+
+        tcph = (struct tcphdr *)*tcp;
+        *tcp_len = get_l4_pyld_length(ip, tcph);
+        for (i=0; i<MAX_LRO_SESSIONS; i++) {
+                lro_t *l_lro = &sp->lro0_n[i];
+                if (l_lro->in_use) {
+                        if (check_for_socket_match(l_lro, ip, tcph))
+                                continue;
+                        /* Sock pair matched */
+                        *lro = l_lro;
+
+                        if ((*lro)->tcp_next_seq != ntohl(tcph->seq)) {
+                                DBG_PRINT(INFO_DBG, "%s:Out of order. expected "
+                                          "0x%x, actual 0x%x\n", __FUNCTION__,
+                                          (*lro)->tcp_next_seq,
+                                          ntohl(tcph->seq));
+
+                                sp->mac_control.stats_info->
+                                   sw_stat.outof_sequence_pkts++;
+                                ret = 2;
+                                break;
+                        }
+
+                        if (!verify_l3_l4_lro_capable(l_lro, ip, tcph,*tcp_len))
+                                ret = 1; /* Aggregate */
+                        else
+                                ret = 2; /* Flush both */
+                        break;
+                }
+        }
+
+        if (ret == 0) {
+                /* Before searching for available LRO objects,
+                 * check if the pkt is L3/L4 aggregatable. If not
+                 * don't create new LRO session. Just send this
+                 * packet up.
+                 */
+                if (verify_l3_l4_lro_capable(NULL, ip, tcph, *tcp_len)) {
+                        return 5;
+                }
+
+                for (i=0; i<MAX_LRO_SESSIONS; i++) {
+                        lro_t *l_lro = &sp->lro0_n[i];
+                        if (!(l_lro->in_use)) {
+                                *lro = l_lro;
+                                ret = 3; /* Begin anew */
+                                break;
+                        }
+                }
+        }
+
+        if (ret == 0) { /* sessions exceeded */
+                DBG_PRINT(INFO_DBG,"%s:All LRO sessions already in use\n",
+                          __FUNCTION__);
+                *lro = NULL;
+                return ret;
+        }
+
+        switch (ret) {
+                case 3:
+                        initiate_new_session(*lro, buffer, ip, tcph, *tcp_len);
+                        break;
+                case 2:
+                        update_L3L4_header(sp, *lro);
+                        break;
+                case 1:
+                        aggregate_new_rx(*lro, ip, tcph, *tcp_len);
+                        if ((*lro)->sg_num == sp->lro_max_aggr_per_sess) {
+                                update_L3L4_header(sp, *lro);
+                                ret = 4; /* Flush the LRO */
+                        }
+                        break;
+                default:
+                        DBG_PRINT(ERR_DBG,"%s:Dont know, can't say!!\n",
+                                __FUNCTION__);
+                        break;
+        }
+
+        return ret;
+}
+
+static void clear_lro_session(lro_t *lro)
+{
+        static u16 lro_struct_size = sizeof(lro_t);
+
+        memset(lro, 0, lro_struct_size);
+}
+
+static void queue_rx_frame(struct sk_buff *skb)
+{
+        struct net_device *dev = skb->dev;
+
+        skb->protocol = eth_type_trans(skb, dev);
+#ifdef CONFIG_S2IO_NAPI
+        netif_receive_skb(skb);
+#else
+        netif_rx(skb);
+#endif
+}
+
+static void lro_append_pkt(nic_t *sp, lro_t *lro, struct sk_buff *skb,
+                           u32 tcp_len)
+{
+        struct sk_buff *tmp, *first = lro->parent;
+
+        first->len += tcp_len;
+        first->data_len = lro->frags_len;
+        skb_pull(skb, (skb->len - tcp_len));
+        if ((tmp = skb_shinfo(first)->frag_list)) {
+                while (tmp->next)
+                        tmp = tmp->next;
+                tmp->next = skb;
+        }
+        else
+                skb_shinfo(first)->frag_list = skb;
+        sp->mac_control.stats_info->sw_stat.clubbed_frms_cnt++;
+        return;
+}