ibmvnic: Enable TSO support

This patch enables TSO support. It includes additional
buffers reserved exclusively for large packets. Throughput
is greatly increased with TSO enabled, from about 1 Gb/s to
9 Gb/s on our test systems.

Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 48 insertions, 8 deletions

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index b508877397e1..aedb81c230a6 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -553,6 +553,10 @@ static int reset_tx_pools(struct ibmvnic_adapter *adapter)
                 if (rc)
                         return rc;
 
+                rc = reset_long_term_buff(adapter, &tx_pool->tso_ltb);
+                if (rc)
+                        return rc;
+
                 memset(tx_pool->tx_buff, 0,
                        adapter->req_tx_entries_per_subcrq *
                        sizeof(struct ibmvnic_tx_buff));
@@ -562,6 +566,7 @@ static int reset_tx_pools(struct ibmvnic_adapter *adapter)
 
                 tx_pool->consumer_index = 0;
                 tx_pool->producer_index = 0;
+                tx_pool->tso_index = 0;
         }
 
         return 0;
@@ -581,6 +586,7 @@ static void release_tx_pools(struct ibmvnic_adapter *adapter)
                 tx_pool = &adapter->tx_pool[i];
                 kfree(tx_pool->tx_buff);
                 free_long_term_buff(adapter, &tx_pool->long_term_buff);
+                free_long_term_buff(adapter, &tx_pool->tso_ltb);
                 kfree(tx_pool->free_map);
         }
 
@@ -625,6 +631,16 @@ static int init_tx_pools(struct net_device *netdev)
                         return -1;
                 }
 
+                /* alloc TSO ltb */
+                if (alloc_long_term_buff(adapter, &tx_pool->tso_ltb,
+                                         IBMVNIC_TSO_BUFS *
+                                         IBMVNIC_TSO_BUF_SZ)) {
+                        release_tx_pools(adapter);
+                        return -1;
+                }
+
+                tx_pool->tso_index = 0;
+
                 tx_pool->free_map = kcalloc(adapter->req_tx_entries_per_subcrq,
                                             sizeof(int), GFP_KERNEL);
                 if (!tx_pool->free_map) {
@@ -1201,10 +1217,21 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
                 be32_to_cpu(adapter->login_rsp_buf->off_txsubm_subcrqs));
 
         index = tx_pool->free_map[tx_pool->consumer_index];
-        offset = index * adapter->req_mtu;
-        dst = tx_pool->long_term_buff.buff + offset;
-        memset(dst, 0, adapter->req_mtu);
-        data_dma_addr = tx_pool->long_term_buff.addr + offset;
+
+        if (skb_is_gso(skb)) {
+                offset = tx_pool->tso_index * IBMVNIC_TSO_BUF_SZ;
+                dst = tx_pool->tso_ltb.buff + offset;
+                memset(dst, 0, IBMVNIC_TSO_BUF_SZ);
+                data_dma_addr = tx_pool->tso_ltb.addr + offset;
+                tx_pool->tso_index++;
+                if (tx_pool->tso_index == IBMVNIC_TSO_BUFS)
+                        tx_pool->tso_index = 0;
+        } else {
+                offset = index * adapter->req_mtu;
+                dst = tx_pool->long_term_buff.buff + offset;
+                memset(dst, 0, adapter->req_mtu);
+                data_dma_addr = tx_pool->long_term_buff.addr + offset;
+        }
 
         if (skb_shinfo(skb)->nr_frags) {
                 int cur, i;
@@ -1245,7 +1272,10 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
         tx_crq.v1.n_sge = 1;
         tx_crq.v1.flags1 = IBMVNIC_TX_COMP_NEEDED;
         tx_crq.v1.correlator = cpu_to_be32(index);
-        tx_crq.v1.dma_reg = cpu_to_be16(tx_pool->long_term_buff.map_id);
+        if (skb_is_gso(skb))
+                tx_crq.v1.dma_reg = cpu_to_be16(tx_pool->tso_ltb.map_id);
+        else
+                tx_crq.v1.dma_reg = cpu_to_be16(tx_pool->long_term_buff.map_id);
         tx_crq.v1.sge_len = cpu_to_be32(skb->len);
         tx_crq.v1.ioba = cpu_to_be64(data_dma_addr);
 
@@ -1270,6 +1300,11 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
                 tx_crq.v1.flags1 |= IBMVNIC_TX_CHKSUM_OFFLOAD;
                 hdrs += 2;
         }
+        if (skb_is_gso(skb)) {
+                tx_crq.v1.flags1 |= IBMVNIC_TX_LSO;
+                tx_crq.v1.mss = cpu_to_be16(skb_shinfo(skb)->gso_size);
+                hdrs += 2;
+        }
         /* determine if l2/3/4 headers are sent to firmware */
         if ((*hdrs >> 7) & 1 &&
             (skb->protocol == htons(ETH_P_IP) ||
@@ -2960,10 +2995,10 @@ static void handle_query_ip_offload_rsp(struct ibmvnic_adapter *adapter)
         adapter->ip_offload_ctrl.udp_ipv4_chksum = buf->udp_ipv4_chksum;
         adapter->ip_offload_ctrl.tcp_ipv6_chksum = buf->tcp_ipv6_chksum;
         adapter->ip_offload_ctrl.udp_ipv6_chksum = buf->udp_ipv6_chksum;
+        adapter->ip_offload_ctrl.large_tx_ipv4 = buf->large_tx_ipv4;
+        adapter->ip_offload_ctrl.large_tx_ipv6 = buf->large_tx_ipv6;
 
-        /* large_tx/rx disabled for now, additional features needed */
-        adapter->ip_offload_ctrl.large_tx_ipv4 = 0;
-        adapter->ip_offload_ctrl.large_tx_ipv6 = 0;
+        /* large_rx disabled for now, additional features needed */
         adapter->ip_offload_ctrl.large_rx_ipv4 = 0;
         adapter->ip_offload_ctrl.large_rx_ipv6 = 0;
 
@@ -2979,6 +3014,11 @@ static void handle_query_ip_offload_rsp(struct ibmvnic_adapter *adapter)
             (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)))
                 adapter->netdev->features |= NETIF_F_RXCSUM;
 
+        if (buf->large_tx_ipv4)
+                adapter->netdev->features |= NETIF_F_TSO;
+        if (buf->large_tx_ipv6)
+                adapter->netdev->features |= NETIF_F_TSO6;
+
         memset(&crq, 0, sizeof(crq));
         crq.control_ip_offload.first = IBMVNIC_CRQ_CMD;
         crq.control_ip_offload.cmd = CONTROL_IP_OFFLOAD;