[NET]: Make NAPI polling independent of struct net_device objects.

Several devices have multiple independant RX queues per net
device, and some have a single interrupt doorbell for several
queues.

In either case, it's easier to support layouts like that if the
structure representing the poll is independant from the net
device itself.

The signature of the ->poll() call back goes from:

	int foo_poll(struct net_device *dev, int *budget)

to

	int foo_poll(struct napi_struct *napi, int budget)

The caller is returned the number of RX packets processed (or
the number of "NAPI credits" consumed if you want to get
abstract).  The callee no longer messes around bumping
dev->quota, *budget, etc. because that is all handled in the
caller upon return.

The napi_struct is to be embedded in the device driver private data
structures.

Furthermore, it is the driver's responsibility to disable all NAPI
instances in it's ->stop() device close handler.  Since the
napi_struct is privatized into the driver's private data structures,
only the driver knows how to get at all of the napi_struct instances
it may have per-device.

With lots of help and suggestions from Rusty Russell, Roland Dreier,
Michael Chan, Jeff Garzik, and Jamal Hadi Salim.

Bug fixes from Thomas Graf, Roland Dreier, Peter Zijlstra,
Joseph Fannin, Scott Wood, Hans J. Koch, and Michael Chan.

[ Ported to current tree and all drivers converted.  Integrated
  Stephen's follow-on kerneldoc additions, and restored poll_list
  handling to the old style to fix mutual exclusion issues.  -DaveM ]

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 27 insertions, 69 deletions

diff --git a/drivers/net/cxgb3/cxgb3_main.c b/drivers/net/cxgb3/cxgb3_main.c
index 5ab319cfe5de..5db7d4e27ec0 100644
--- a/drivers/net/cxgb3/cxgb3_main.c
+++ b/drivers/net/cxgb3/cxgb3_main.c
@@ -339,49 +339,17 @@ static void setup_rss(struct adapter *adap)
                       V_RRCPLCPUSIZE(6), cpus, rspq_map);
 }
 
-/*
- * If we have multiple receive queues per port serviced by NAPI we need one
- * netdevice per queue as NAPI operates on netdevices.  We already have one
- * netdevice, namely the one associated with the interface, so we use dummy
- * ones for any additional queues.  Note that these netdevices exist purely
- * so that NAPI has something to work with, they do not represent network
- * ports and are not registered.
- */
-static int init_dummy_netdevs(struct adapter *adap)
+static void init_napi(struct adapter *adap)
 {
-        int i, j, dummy_idx = 0;
-        struct net_device *nd;
-
-        for_each_port(adap, i) {
-                struct net_device *dev = adap->port[i];
-                const struct port_info *pi = netdev_priv(dev);
-
-                for (j = 0; j < pi->nqsets - 1; j++) {
-                        if (!adap->dummy_netdev[dummy_idx]) {
-                                struct port_info *p;
-
-                                nd = alloc_netdev(sizeof(*p), "", ether_setup);
-                                if (!nd)
-                                        goto free_all;
+        int i;
 
-                                p = netdev_priv(nd);
-                                p->adapter = adap;
-                                nd->weight = 64;
-                                set_bit(__LINK_STATE_START, &nd->state);
-                                adap->dummy_netdev[dummy_idx] = nd;
-                        }
-                        strcpy(adap->dummy_netdev[dummy_idx]->name, dev->name);
-                        dummy_idx++;
-                }
-        }
-        return 0;
+        for (i = 0; i < SGE_QSETS; i++) {
+                struct sge_qset *qs = &adap->sge.qs[i];
 
-free_all:
-        while (--dummy_idx >= 0) {
-                free_netdev(adap->dummy_netdev[dummy_idx]);
-                adap->dummy_netdev[dummy_idx] = NULL;
+                if (qs->adap)
+                        netif_napi_add(qs->netdev, &qs->napi, qs->napi.poll,
+                                       64);
         }
-        return -ENOMEM;
 }
 
 /*
@@ -392,20 +360,18 @@ free_all:
 static void quiesce_rx(struct adapter *adap)
 {
         int i;
-        struct net_device *dev;
 
-        for_each_port(adap, i) {
-                dev = adap->port[i];
-                while (test_bit(__LINK_STATE_RX_SCHED, &dev->state))
-                        msleep(1);
-        }
+        for (i = 0; i < SGE_QSETS; i++)
+                if (adap->sge.qs[i].adap)
+                        napi_disable(&adap->sge.qs[i].napi);
+}
 
-        for (i = 0; i < ARRAY_SIZE(adap->dummy_netdev); i++) {
-                dev = adap->dummy_netdev[i];
-                if (dev)
-                        while (test_bit(__LINK_STATE_RX_SCHED, &dev->state))
-                                msleep(1);
-        }
+static void enable_all_napi(struct adapter *adap)
+{
+        int i;
+        for (i = 0; i < SGE_QSETS; i++)
+                if (adap->sge.qs[i].adap)
+                        napi_enable(&adap->sge.qs[i].napi);
 }
 
 /**
@@ -418,7 +384,7 @@ static void quiesce_rx(struct adapter *adap)
  */
 static int setup_sge_qsets(struct adapter *adap)
 {
-        int i, j, err, irq_idx = 0, qset_idx = 0, dummy_dev_idx = 0;
+        int i, j, err, irq_idx = 0, qset_idx = 0;
         unsigned int ntxq = SGE_TXQ_PER_SET;
 
         if (adap->params.rev > 0 && !(adap->flags & USING_MSI))
@@ -426,15 +392,14 @@ static int setup_sge_qsets(struct adapter *adap)
 
         for_each_port(adap, i) {
                 struct net_device *dev = adap->port[i];
-                const struct port_info *pi = netdev_priv(dev);
+                struct port_info *pi = netdev_priv(dev);
 
+                pi->qs = &adap->sge.qs[pi->first_qset];
                 for (j = 0; j < pi->nqsets; ++j, ++qset_idx) {
                         err = t3_sge_alloc_qset(adap, qset_idx, 1,
                                 (adap->flags & USING_MSIX) ? qset_idx + 1 :
                                                              irq_idx,
-                                &adap->params.sge.qset[qset_idx], ntxq,
-                                j == 0 ? dev :
-                                         adap-> dummy_netdev[dummy_dev_idx++]);
+                                &adap->params.sge.qset[qset_idx], ntxq, dev);
                         if (err) {
                                 t3_free_sge_resources(adap);
                                 return err;
@@ -845,21 +810,18 @@ static int cxgb_up(struct adapter *adap)
                                 goto out;
                 }
 
-                err = init_dummy_netdevs(adap);
-                if (err)
-                        goto out;
-
                 err = t3_init_hw(adap, 0);
                 if (err)
                         goto out;
 
                 t3_write_reg(adap, A_ULPRX_TDDP_PSZ, V_HPZ0(PAGE_SHIFT - 12));
-                
+
                 err = setup_sge_qsets(adap);
                 if (err)
                         goto out;
 
                 setup_rss(adap);
+                init_napi(adap);
                 adap->flags |= FULL_INIT_DONE;
         }
 
@@ -886,6 +848,7 @@ static int cxgb_up(struct adapter *adap)
                                       adap->name, adap)))
                 goto irq_err;
 
+        enable_all_napi(adap);
         t3_sge_start(adap);
         t3_intr_enable(adap);
 
@@ -1012,8 +975,10 @@ static int cxgb_open(struct net_device *dev)
         int other_ports = adapter->open_device_map & PORT_MASK;
         int err;
 
-        if (!adapter->open_device_map && (err = cxgb_up(adapter)) < 0)
+        if (!adapter->open_device_map && (err = cxgb_up(adapter)) < 0) {
+                quiesce_rx(adapter);
                 return err;
+        }
 
         set_bit(pi->port_id, &adapter->open_device_map);
         if (is_offload(adapter) && !ofld_disable) {
@@ -2524,7 +2489,6 @@ static int __devinit init_one(struct pci_dev *pdev,
 #ifdef CONFIG_NET_POLL_CONTROLLER
                 netdev->poll_controller = cxgb_netpoll;
 #endif
-                netdev->weight = 64;
 
                 SET_ETHTOOL_OPS(netdev, &cxgb_ethtool_ops);
         }
@@ -2625,12 +2589,6 @@ static void __devexit remove_one(struct pci_dev *pdev)
                 t3_free_sge_resources(adapter);
                 cxgb_disable_msi(adapter);
 
-                for (i = 0; i < ARRAY_SIZE(adapter->dummy_netdev); i++)
-                        if (adapter->dummy_netdev[i]) {
-                                free_netdev(adapter->dummy_netdev[i]);
-                                adapter->dummy_netdev[i] = NULL;
-                        }
-
                 for_each_port(adapter, i)
                         if (adapter->port[i])
                                 free_netdev(adapter->port[i]);