netxen: napi and irq cleanup

o separate and simpler irq handler for msi interrupts, avoids few checks
  than legacy mode.
o avoid redudant tx_has_work() and rx_has_work() checks in interrupt
  and napi, which can uncork irq based on racy (lockless) access to tx
  and rx ring indices. If we get interrupt, there's sufficient reason to
  schedule napi.
o replenish rx ring more often, remove self-imposed threshold rcv_free
  that prevents posting rx desc to card. This improves performance in
  low memory.

Signed-off-by: Dhananjay Phadke <dhananjay@netxen.com>
Tested-by: Vernon Mauery <mauery@us.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 4 insertions, 72 deletions

diff --git a/drivers/net/netxen/netxen_nic_init.c b/drivers/net/netxen/netxen_nic_init.c
index 43eb1f65152d..64fc18d4afb6 100644
--- a/drivers/net/netxen/netxen_nic_init.c
+++ b/drivers/net/netxen/netxen_nic_init.c
@@ -185,7 +185,6 @@ void netxen_initialize_adapter_sw(struct netxen_adapter *adapter)
                 for (ring = 0; ring < NUM_RCV_DESC_RINGS; ring++) {
                         struct netxen_rx_buffer *rx_buf;
                         rcv_desc = &adapter->recv_ctx[ctxid].rcv_desc[ring];
-                        rcv_desc->rcv_free = rcv_desc->max_rx_desc_count;
                         rcv_desc->begin_alloc = 0;
                         rx_buf = rcv_desc->rx_buf_arr;
                         num_rx_bufs = rcv_desc->max_rx_desc_count;
@@ -976,28 +975,6 @@ int netxen_phantom_init(struct netxen_adapter *adapter, int pegtune_val)
         return 0;
 }
 
-int netxen_nic_rx_has_work(struct netxen_adapter *adapter)
-{
-        int ctx;
-
-        for (ctx = 0; ctx < MAX_RCV_CTX; ++ctx) {
-                struct netxen_recv_context *recv_ctx =
-                    &(adapter->recv_ctx[ctx]);
-                u32 consumer;
-                struct status_desc *desc_head;
-                struct status_desc *desc;
-
-                consumer = recv_ctx->status_rx_consumer;
-                desc_head = recv_ctx->rcv_status_desc_head;
-                desc = &desc_head[consumer];
-
-                if (netxen_get_sts_owner(desc) & STATUS_OWNER_HOST)
-                        return 1;
-        }
-
-        return 0;
-}
-
 static int netxen_nic_check_temp(struct netxen_adapter *adapter)
 {
         struct net_device *netdev = adapter->netdev;
@@ -1040,7 +1017,6 @@ static int netxen_nic_check_temp(struct netxen_adapter *adapter)
 
 void netxen_watchdog_task(struct work_struct *work)
 {
-        struct net_device *netdev;
         struct netxen_adapter *adapter =
                 container_of(work, struct netxen_adapter, watchdog_task);
 
@@ -1050,20 +1026,6 @@ void netxen_watchdog_task(struct work_struct *work)
         if (adapter->handle_phy_intr)
                 adapter->handle_phy_intr(adapter);
 
-        netdev = adapter->netdev;
-        if ((netif_running(netdev)) && !netif_carrier_ok(netdev) &&
-                        netxen_nic_link_ok(adapter) ) {
-                printk(KERN_INFO "%s %s (port %d), Link is up\n",
-                               netxen_nic_driver_name, netdev->name, adapter->portnum);
-                netif_carrier_on(netdev);
-                netif_wake_queue(netdev);
-        } else if(!(netif_running(netdev)) && netif_carrier_ok(netdev)) {
-                printk(KERN_ERR "%s %s Link is Down\n",
-                                netxen_nic_driver_name, netdev->name);
-                netif_carrier_off(netdev);
-                netif_stop_queue(netdev);
-        }
-
         mod_timer(&adapter->watchdog_timer, jiffies + 2 * HZ);
 }
 
@@ -1177,7 +1139,6 @@ static void netxen_process_rcv(struct netxen_adapter *adapter, int ctxid,
 
         netdev->last_rx = jiffies;
 
-        rcv_desc->rcv_free++;
         rcv_desc->rcv_pending--;
 
         /*
@@ -1202,13 +1163,6 @@ u32 netxen_process_rcv_ring(struct netxen_adapter *adapter, int ctxid, int max)
         u32 producer = 0;
         int count = 0, ring;
 
-        DPRINTK(INFO, "procesing receive\n");
-        /*
-         * we assume in this case that there is only one port and that is
-         * port #1...changes need to be done in firmware to indicate port
-         * number as part of the descriptor. This way we will be able to get
-         * the netdev which is associated with that device.
-         */
         while (count < max) {
                 desc = &desc_head[consumer];
                 if (!(netxen_get_sts_owner(desc) & STATUS_OWNER_HOST)) {
@@ -1221,10 +1175,8 @@ u32 netxen_process_rcv_ring(struct netxen_adapter *adapter, int ctxid, int max)
                 consumer = (consumer + 1) & (adapter->max_rx_desc_count - 1);
                 count++;
         }
-        if (count) {
-                for (ring = 0; ring < NUM_RCV_DESC_RINGS; ring++) {
-                        netxen_post_rx_buffers_nodb(adapter, ctxid, ring);
-                }
+        for (ring = 0; ring < NUM_RCV_DESC_RINGS; ring++) {
+                netxen_post_rx_buffers_nodb(adapter, ctxid, ring);
         }
 
         /* update the consumer index in phantom */
@@ -1235,20 +1187,18 @@ u32 netxen_process_rcv_ring(struct netxen_adapter *adapter, int ctxid, int max)
                 /* Window = 1 */
                 writel(consumer,
                        NETXEN_CRB_NORMALIZE(adapter,
-                                            recv_crb_registers[adapter->portnum].
+                                    recv_crb_registers[adapter->portnum].
                                             crb_rcv_status_consumer));
-                wmb();
         }
 
         return count;
 }
 
 /* Process Command status ring */
-int netxen_process_cmd_ring(unsigned long data)
+int netxen_process_cmd_ring(struct netxen_adapter *adapter)
 {
         u32 last_consumer;
         u32 consumer;
-        struct netxen_adapter *adapter = (struct netxen_adapter *)data;
         int count1 = 0;
         int count2 = 0;
         struct netxen_cmd_buffer *buffer;
@@ -1435,8 +1385,6 @@ void netxen_post_rx_buffers(struct netxen_adapter *adapter, u32 ctx, u32 ringid)
                 rcv_desc->begin_alloc = index;
                 rcv_desc->rcv_pending += count;
                 rcv_desc->producer = producer;
-                if (rcv_desc->rcv_free >= 32) {
-                        rcv_desc->rcv_free = 0;
                         /* Window = 1 */
                         writel((producer - 1) &
                                (rcv_desc->max_rx_desc_count - 1),
@@ -1460,8 +1408,6 @@ void netxen_post_rx_buffers(struct netxen_adapter *adapter, u32 ctx, u32 ringid)
                         writel(msg,
                                DB_NORMALIZE(adapter,
                                             NETXEN_RCV_PRODUCER_OFFSET));
-                        wmb();
-                }
         }
 }
 
@@ -1525,8 +1471,6 @@ static void netxen_post_rx_buffers_nodb(struct netxen_adapter *adapter,
                 rcv_desc->begin_alloc = index;
                 rcv_desc->rcv_pending += count;
                 rcv_desc->producer = producer;
-                if (rcv_desc->rcv_free >= 32) {
-                        rcv_desc->rcv_free = 0;
                         /* Window = 1 */
                         writel((producer - 1) &
                                (rcv_desc->max_rx_desc_count - 1),
@@ -1536,21 +1480,9 @@ static void netxen_post_rx_buffers_nodb(struct netxen_adapter *adapter,
                                                     rcv_desc_crb[ringid].
                                                     crb_rcv_producer_offset));
                         wmb();
-                }
         }
 }
 
-int netxen_nic_tx_has_work(struct netxen_adapter *adapter)
-{
-        if (find_diff_among(adapter->last_cmd_consumer,
-                            adapter->cmd_producer,
-                            adapter->max_tx_desc_count) > 0)
-                return 1;
-
-        return 0;
-}
-
-
 void netxen_nic_clear_stats(struct netxen_adapter *adapter)
 {
         memset(&adapter->stats, 0, sizeof(adapter->stats));