RDMA/nes: Remove LLTX

NETIF_F_LLTX is deprecated. Remove private TX locking from the driver
and remove the NETIF_F_LLTX feature flag.  This also fixes a warning
in some configs that comes from doing skb_linearize() call in the
hard_start_xmit method with IRQs disabled (if HIGHMEM is enabled,
skb_linearize() may end up enabling BHs, which is a no-no if hard IRQs
are disabled in that context).  By getting rid of LLTX, we do not
disable IRQs when skb_linearize() is called.

Remove the sq_lock as it is not needed for non-LLTX.  Fix ethtool not
to show the counter for sq_lock.

Reported-by: aluno3@poczta.onet.pl
Signed-off-by: Faisal Latif <faisal.latif@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

3 files changed, 63 insertions, 84 deletions

diff --git a/drivers/infiniband/hw/nes/nes_hw.c b/drivers/infiniband/hw/nes/nes_hw.c
index 1c5e946ce226..9a51f25c6cee 100644
--- a/drivers/infiniband/hw/nes/nes_hw.c
+++ b/drivers/infiniband/hw/nes/nes_hw.c
@@ -1644,7 +1644,6 @@ int nes_init_nic_qp(struct nes_device *nesdev, struct net_device *netdev)
         nesvnic->post_cqp_request = nes_post_cqp_request;
         nesvnic->mcrq_mcast_filter = NULL;
 
-        spin_lock_init(&nesvnic->nic.sq_lock);
         spin_lock_init(&nesvnic->nic.rq_lock);
 
         /* setup the RQ */
@@ -2632,9 +2631,9 @@ void nes_nic_ce_handler(struct nes_device *nesdev, struct nes_hw_nic_cq *cq)
                                                 } else
                                                         break;
                                         }
-                                        if (skb)
-                                                dev_kfree_skb_any(skb);
                                 }
+                                if (skb)
+                                        dev_kfree_skb_any(skb);
                                 nesnic->sq_tail++;
                                 nesnic->sq_tail &= nesnic->sq_size-1;
                                 if (sq_cqes > 128) {
diff --git a/drivers/infiniband/hw/nes/nes_hw.h b/drivers/infiniband/hw/nes/nes_hw.h
index bf7ecfa5f976..f41a8710d2a8 100644
--- a/drivers/infiniband/hw/nes/nes_hw.h
+++ b/drivers/infiniband/hw/nes/nes_hw.h
@@ -876,7 +876,6 @@ struct nes_hw_nic {
         u8 replenishing_rq;
         u8 reserved;
 
-        spinlock_t sq_lock;
         spinlock_t rq_lock;
 };
 
@@ -1148,7 +1147,6 @@ struct nes_ib_device;
 struct nes_vnic {
         struct nes_ib_device *nesibdev;
         u64 sq_full;
-        u64 sq_locked;
         u64 tso_requests;
         u64 segmented_tso_requests;
         u64 linearized_skbs;
diff --git a/drivers/infiniband/hw/nes/nes_nic.c b/drivers/infiniband/hw/nes/nes_nic.c
index 8e1d073913ec..025ed9f7d9c2 100644
--- a/drivers/infiniband/hw/nes/nes_nic.c
+++ b/drivers/infiniband/hw/nes/nes_nic.c
@@ -400,8 +400,7 @@ static int nes_nic_send(struct sk_buff *skb, struct net_device *netdev)
         if (skb_headlen(skb) == skb->len) {
                 if (skb_headlen(skb) <= NES_FIRST_FRAG_SIZE) {
                         nic_sqe->wqe_words[NES_NIC_SQ_WQE_LENGTH_2_1_IDX] = 0;
-                        nesnic->tx_skb[nesnic->sq_head] = NULL;
-                        dev_kfree_skb(skb);
+                        nesnic->tx_skb[nesnic->sq_head] = skb;
                 }
         } else {
                 /* Deal with Fragments */
@@ -453,7 +452,6 @@ static int nes_netdev_start_xmit(struct sk_buff *skb, struct net_device *netdev)
         u32 wqe_count=1;
         u32 send_rc;
         struct iphdr *iph;
-        unsigned long flags;
         __le16 *wqe_fragment_length;
         u32 nr_frags;
         u32 original_first_length;
@@ -480,13 +478,6 @@ static int nes_netdev_start_xmit(struct sk_buff *skb, struct net_device *netdev)
         if (netif_queue_stopped(netdev))
                 return NETDEV_TX_BUSY;
 
-        local_irq_save(flags);
-        if (!spin_trylock(&nesnic->sq_lock)) {
-                local_irq_restore(flags);
-                nesvnic->sq_locked++;
-                return NETDEV_TX_LOCKED;
-        }
-
         /* Check if SQ is full */
         if ((((nesnic->sq_tail+(nesnic->sq_size*2))-nesnic->sq_head) & (nesnic->sq_size - 1)) == 1) {
                 if (!netif_queue_stopped(netdev)) {
@@ -498,7 +489,6 @@ static int nes_netdev_start_xmit(struct sk_buff *skb, struct net_device *netdev)
                         }
                 }
                 nesvnic->sq_full++;
-                spin_unlock_irqrestore(&nesnic->sq_lock, flags);
                 return NETDEV_TX_BUSY;
         }
 
@@ -531,7 +521,6 @@ sq_no_longer_full:
                                         }
                                 }
                                 nesvnic->sq_full++;
-                                spin_unlock_irqrestore(&nesnic->sq_lock, flags);
                                 nes_debug(NES_DBG_NIC_TX, "%s: HNIC SQ full- TSO request has too many frags!\n",
                                                 netdev->name);
                                 return NETDEV_TX_BUSY;
@@ -656,17 +645,13 @@ tso_sq_no_longer_full:
                         skb_set_transport_header(skb, hoffset);
                         skb_set_network_header(skb, nhoffset);
                         send_rc = nes_nic_send(skb, netdev);
-                        if (send_rc != NETDEV_TX_OK) {
-                                spin_unlock_irqrestore(&nesnic->sq_lock, flags);
+                        if (send_rc != NETDEV_TX_OK)
                                 return NETDEV_TX_OK;
-                        }
                 }
         } else {
                 send_rc = nes_nic_send(skb, netdev);
-                if (send_rc != NETDEV_TX_OK) {
-                        spin_unlock_irqrestore(&nesnic->sq_lock, flags);
+                if (send_rc != NETDEV_TX_OK)
                         return NETDEV_TX_OK;
-                }
         }
 
         barrier();
@@ -676,7 +661,6 @@ tso_sq_no_longer_full:
                                 (wqe_count << 24) | (1 << 23) | nesvnic->nic.qp_id);
 
         netdev->trans_start = jiffies;
-        spin_unlock_irqrestore(&nesnic->sq_lock, flags);
 
         return NETDEV_TX_OK;
 }
@@ -1012,7 +996,6 @@ static const char nes_ethtool_stringset[][ETH_GSTRING_LEN] = {
         "Pause Frames Received",
         "Internal Routing Errors",
         "SQ SW Dropped SKBs",
-        "SQ Locked",
         "SQ Full",
         "Segmented TSO Requests",
         "Rx Symbol Errors",
@@ -1129,16 +1112,17 @@ static void nes_netdev_get_ethtool_stats(struct net_device *netdev,
         struct nes_device *nesdev = nesvnic->nesdev;
         u32 nic_count;
         u32 u32temp;
+        u32 index = 0;
 
         target_ethtool_stats->n_stats = NES_ETHTOOL_STAT_COUNT;
-        target_stat_values[0] = nesvnic->nesdev->link_status_interrupts;
-        target_stat_values[1] = nesvnic->linearized_skbs;
-        target_stat_values[2] = nesvnic->tso_requests;
+        target_stat_values[index] = nesvnic->nesdev->link_status_interrupts;
+        target_stat_values[++index] = nesvnic->linearized_skbs;
+        target_stat_values[++index] = nesvnic->tso_requests;
 
         u32temp = nes_read_indexed(nesdev,
                         NES_IDX_MAC_TX_PAUSE_FRAMES + (nesvnic->nesdev->mac_index*0x200));
         nesvnic->nesdev->mac_pause_frames_sent += u32temp;
-        target_stat_values[3] = nesvnic->nesdev->mac_pause_frames_sent;
+        target_stat_values[++index] = nesvnic->nesdev->mac_pause_frames_sent;
 
         u32temp = nes_read_indexed(nesdev,
                         NES_IDX_MAC_RX_PAUSE_FRAMES + (nesvnic->nesdev->mac_index*0x200));
@@ -1209,60 +1193,59 @@ static void nes_netdev_get_ethtool_stats(struct net_device *netdev,
                 nesvnic->endnode_ipv4_tcp_retransmits += u32temp;
         }
 
-        target_stat_values[4] = nesvnic->nesdev->mac_pause_frames_received;
-        target_stat_values[5] = nesdev->nesadapter->nic_rx_eth_route_err;
-        target_stat_values[6] = nesvnic->tx_sw_dropped;
-        target_stat_values[7] = nesvnic->sq_locked;
-        target_stat_values[8] = nesvnic->sq_full;
-        target_stat_values[9] = nesvnic->segmented_tso_requests;
-        target_stat_values[10] = nesvnic->nesdev->mac_rx_symbol_err_frames;
-        target_stat_values[11] = nesvnic->nesdev->mac_rx_jabber_frames;
-        target_stat_values[12] = nesvnic->nesdev->mac_rx_oversized_frames;
-        target_stat_values[13] = nesvnic->nesdev->mac_rx_short_frames;
-        target_stat_values[14] = nesvnic->endnode_nstat_rx_discard;
-        target_stat_values[15] = nesvnic->endnode_nstat_rx_octets;
-        target_stat_values[16] = nesvnic->endnode_nstat_rx_frames;
-        target_stat_values[17] = nesvnic->endnode_nstat_tx_octets;
-        target_stat_values[18] = nesvnic->endnode_nstat_tx_frames;
-        target_stat_values[19] = mh_detected;
-        target_stat_values[20] = mh_pauses_sent;
-        target_stat_values[21] = nesvnic->endnode_ipv4_tcp_retransmits;
-        target_stat_values[22] = atomic_read(&cm_connects);
-        target_stat_values[23] = atomic_read(&cm_accepts);
-        target_stat_values[24] = atomic_read(&cm_disconnects);
-        target_stat_values[25] = atomic_read(&cm_connecteds);
-        target_stat_values[26] = atomic_read(&cm_connect_reqs);
-        target_stat_values[27] = atomic_read(&cm_rejects);
-        target_stat_values[28] = atomic_read(&mod_qp_timouts);
-        target_stat_values[29] = atomic_read(&qps_created);
-        target_stat_values[30] = atomic_read(&sw_qps_destroyed);
-        target_stat_values[31] = atomic_read(&qps_destroyed);
-        target_stat_values[32] = atomic_read(&cm_closes);
-        target_stat_values[33] = cm_packets_sent;
-        target_stat_values[34] = cm_packets_bounced;
-        target_stat_values[35] = cm_packets_created;
-        target_stat_values[36] = cm_packets_received;
-        target_stat_values[37] = cm_packets_dropped;
-        target_stat_values[38] = cm_packets_retrans;
-        target_stat_values[39] = cm_listens_created;
-        target_stat_values[40] = cm_listens_destroyed;
-        target_stat_values[41] = cm_backlog_drops;
-        target_stat_values[42] = atomic_read(&cm_loopbacks);
-        target_stat_values[43] = atomic_read(&cm_nodes_created);
-        target_stat_values[44] = atomic_read(&cm_nodes_destroyed);
-        target_stat_values[45] = atomic_read(&cm_accel_dropped_pkts);
-        target_stat_values[46] = atomic_read(&cm_resets_recvd);
-        target_stat_values[47] = int_mod_timer_init;
-        target_stat_values[48] = int_mod_cq_depth_1;
-        target_stat_values[49] = int_mod_cq_depth_4;
-        target_stat_values[50] = int_mod_cq_depth_16;
-        target_stat_values[51] = int_mod_cq_depth_24;
-        target_stat_values[52] = int_mod_cq_depth_32;
-        target_stat_values[53] = int_mod_cq_depth_128;
-        target_stat_values[54] = int_mod_cq_depth_256;
-        target_stat_values[55] = nesvnic->lro_mgr.stats.aggregated;
-        target_stat_values[56] = nesvnic->lro_mgr.stats.flushed;
-        target_stat_values[57] = nesvnic->lro_mgr.stats.no_desc;
+        target_stat_values[++index] = nesvnic->nesdev->mac_pause_frames_received;
+        target_stat_values[++index] = nesdev->nesadapter->nic_rx_eth_route_err;
+        target_stat_values[++index] = nesvnic->tx_sw_dropped;
+        target_stat_values[++index] = nesvnic->sq_full;
+        target_stat_values[++index] = nesvnic->segmented_tso_requests;
+        target_stat_values[++index] = nesvnic->nesdev->mac_rx_symbol_err_frames;
+        target_stat_values[++index] = nesvnic->nesdev->mac_rx_jabber_frames;
+        target_stat_values[++index] = nesvnic->nesdev->mac_rx_oversized_frames;
+        target_stat_values[++index] = nesvnic->nesdev->mac_rx_short_frames;
+        target_stat_values[++index] = nesvnic->endnode_nstat_rx_discard;
+        target_stat_values[++index] = nesvnic->endnode_nstat_rx_octets;
+        target_stat_values[++index] = nesvnic->endnode_nstat_rx_frames;
+        target_stat_values[++index] = nesvnic->endnode_nstat_tx_octets;
+        target_stat_values[++index] = nesvnic->endnode_nstat_tx_frames;
+        target_stat_values[++index] = mh_detected;
+        target_stat_values[++index] = mh_pauses_sent;
+        target_stat_values[++index] = nesvnic->endnode_ipv4_tcp_retransmits;
+        target_stat_values[++index] = atomic_read(&cm_connects);
+        target_stat_values[++index] = atomic_read(&cm_accepts);
+        target_stat_values[++index] = atomic_read(&cm_disconnects);
+        target_stat_values[++index] = atomic_read(&cm_connecteds);
+        target_stat_values[++index] = atomic_read(&cm_connect_reqs);
+        target_stat_values[++index] = atomic_read(&cm_rejects);
+        target_stat_values[++index] = atomic_read(&mod_qp_timouts);
+        target_stat_values[++index] = atomic_read(&qps_created);
+        target_stat_values[++index] = atomic_read(&sw_qps_destroyed);
+        target_stat_values[++index] = atomic_read(&qps_destroyed);
+        target_stat_values[++index] = atomic_read(&cm_closes);
+        target_stat_values[++index] = cm_packets_sent;
+        target_stat_values[++index] = cm_packets_bounced;
+        target_stat_values[++index] = cm_packets_created;
+        target_stat_values[++index] = cm_packets_received;
+        target_stat_values[++index] = cm_packets_dropped;
+        target_stat_values[++index] = cm_packets_retrans;
+        target_stat_values[++index] = cm_listens_created;
+        target_stat_values[++index] = cm_listens_destroyed;
+        target_stat_values[++index] = cm_backlog_drops;
+        target_stat_values[++index] = atomic_read(&cm_loopbacks);
+        target_stat_values[++index] = atomic_read(&cm_nodes_created);
+        target_stat_values[++index] = atomic_read(&cm_nodes_destroyed);
+        target_stat_values[++index] = atomic_read(&cm_accel_dropped_pkts);
+        target_stat_values[++index] = atomic_read(&cm_resets_recvd);
+        target_stat_values[++index] = int_mod_timer_init;
+        target_stat_values[++index] = int_mod_cq_depth_1;
+        target_stat_values[++index] = int_mod_cq_depth_4;
+        target_stat_values[++index] = int_mod_cq_depth_16;
+        target_stat_values[++index] = int_mod_cq_depth_24;
+        target_stat_values[++index] = int_mod_cq_depth_32;
+        target_stat_values[++index] = int_mod_cq_depth_128;
+        target_stat_values[++index] = int_mod_cq_depth_256;
+        target_stat_values[++index] = nesvnic->lro_mgr.stats.aggregated;
+        target_stat_values[++index] = nesvnic->lro_mgr.stats.flushed;
+        target_stat_values[++index] = nesvnic->lro_mgr.stats.no_desc;
 
 }
 
@@ -1616,7 +1599,6 @@ struct net_device *nes_netdev_init(struct nes_device *nesdev,
         nes_debug(NES_DBG_INIT, "Enabling VLAN Insert/Delete.\n");
         netdev->features |= NETIF_F_HW_VLAN_TX | NETIF_F_HW_VLAN_RX;
         netdev->vlan_rx_register = nes_netdev_vlan_rx_register;
-        netdev->features |= NETIF_F_LLTX;
 
         /* Fill in the port structure */
         nesvnic->netdev = netdev;