[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, 65 insertions, 64 deletions

diff --git a/drivers/net/ehea/ehea_main.c b/drivers/net/ehea/ehea_main.c
index 717b12984d1..5ebd545ab04 100644
--- a/drivers/net/ehea/ehea_main.c
+++ b/drivers/net/ehea/ehea_main.c
@@ -393,9 +393,9 @@ static int ehea_treat_poll_error(struct ehea_port_res *pr, int rq,
 	return 0;
 }
 
-static struct ehea_cqe *ehea_proc_rwqes(struct net_device *dev,
-					struct ehea_port_res *pr,
-					int *budget)
+static int ehea_proc_rwqes(struct net_device *dev,
+			   struct ehea_port_res *pr,
+			   int budget)
 {
 	struct ehea_port *port = pr->port;
 	struct ehea_qp *qp = pr->qp;
@@ -408,18 +408,16 @@ static struct ehea_cqe *ehea_proc_rwqes(struct net_device *dev,
 	int skb_arr_rq2_len = pr->rq2_skba.len;
 	int skb_arr_rq3_len = pr->rq3_skba.len;
 	int processed, processed_rq1, processed_rq2, processed_rq3;
-	int wqe_index, last_wqe_index, rq, my_quota, port_reset;
+	int wqe_index, last_wqe_index, rq, port_reset;
 
 	processed = processed_rq1 = processed_rq2 = processed_rq3 = 0;
 	last_wqe_index = 0;
-	my_quota = min(*budget, dev->quota);
 
 	cqe = ehea_poll_rq1(qp, &wqe_index);
-	while ((my_quota > 0) && cqe) {
+	while ((processed < budget) && cqe) {
 		ehea_inc_rq1(qp);
 		processed_rq1++;
 		processed++;
-		my_quota--;
 		if (netif_msg_rx_status(port))
 			ehea_dump(cqe, sizeof(*cqe), "CQE");
 
@@ -434,14 +432,14 @@ static struct ehea_cqe *ehea_proc_rwqes(struct net_device *dev,
 					if (netif_msg_rx_err(port))
 						ehea_error("LL rq1: skb=NULL");
 
-					skb = netdev_alloc_skb(port->netdev,
+					skb = netdev_alloc_skb(dev,
 							       EHEA_L_PKT_SIZE);
 					if (!skb)
 						break;
 				}
 				skb_copy_to_linear_data(skb, ((char*)cqe) + 64,
 						 cqe->num_bytes_transfered - 4);
-				ehea_fill_skb(port->netdev, skb, cqe);
+				ehea_fill_skb(dev, skb, cqe);
 			} else if (rq == 2) {  /* RQ2 */
 				skb = get_skb_by_index(skb_arr_rq2,
 						       skb_arr_rq2_len, cqe);
@@ -450,7 +448,7 @@ static struct ehea_cqe *ehea_proc_rwqes(struct net_device *dev,
 						ehea_error("rq2: skb=NULL");
 					break;
 				}
-				ehea_fill_skb(port->netdev, skb, cqe);
+				ehea_fill_skb(dev, skb, cqe);
 				processed_rq2++;
 			} else {  /* RQ3 */
 				skb = get_skb_by_index(skb_arr_rq3,
@@ -460,7 +458,7 @@ static struct ehea_cqe *ehea_proc_rwqes(struct net_device *dev,
 						ehea_error("rq3: skb=NULL");
 					break;
 				}
-				ehea_fill_skb(port->netdev, skb, cqe);
+				ehea_fill_skb(dev, skb, cqe);
 				processed_rq3++;
 			}
 
@@ -471,7 +469,7 @@ static struct ehea_cqe *ehea_proc_rwqes(struct net_device *dev,
 			else
 				netif_receive_skb(skb);
 
-			port->netdev->last_rx = jiffies;
+			dev->last_rx = jiffies;
 		} else {
 			pr->p_stats.poll_receive_errors++;
 			port_reset = ehea_treat_poll_error(pr, rq, cqe,
@@ -484,14 +482,12 @@ static struct ehea_cqe *ehea_proc_rwqes(struct net_device *dev,
 	}
 
 	pr->rx_packets += processed;
-	*budget -= processed;
 
 	ehea_refill_rq1(pr, last_wqe_index, processed_rq1);
 	ehea_refill_rq2(pr, processed_rq2);
 	ehea_refill_rq3(pr, processed_rq3);
 
-	cqe = ehea_poll_rq1(qp, &wqe_index);
-	return cqe;
+	return processed;
 }
 
 static struct ehea_cqe *ehea_proc_cqes(struct ehea_port_res *pr, int my_quota)
@@ -554,22 +550,27 @@ static struct ehea_cqe *ehea_proc_cqes(struct ehea_port_res *pr, int my_quota)
 }
 
 #define EHEA_NAPI_POLL_NUM_BEFORE_IRQ 16
+#define EHEA_POLL_MAX_CQES 65535
 
-static int ehea_poll(struct net_device *dev, int *budget)
+static int ehea_poll(struct napi_struct *napi, int budget)
 {
-	struct ehea_port_res *pr = dev->priv;
+	struct ehea_port_res *pr = container_of(napi, struct ehea_port_res, napi);
+	struct net_device *dev = pr->port->netdev;
 	struct ehea_cqe *cqe;
 	struct ehea_cqe *cqe_skb = NULL;
 	int force_irq, wqe_index;
-
-	cqe = ehea_poll_rq1(pr->qp, &wqe_index);
-	cqe_skb = ehea_poll_cq(pr->send_cq);
+	int rx = 0;
 
 	force_irq = (pr->poll_counter > EHEA_NAPI_POLL_NUM_BEFORE_IRQ);
+	cqe_skb = ehea_proc_cqes(pr, EHEA_POLL_MAX_CQES);
+
+	if (!force_irq)
+		rx += ehea_proc_rwqes(dev, pr, budget - rx);
 
-	if ((!cqe && !cqe_skb) || force_irq) {
+	while ((rx != budget) || force_irq) {
 		pr->poll_counter = 0;
-		netif_rx_complete(dev);
+		force_irq = 0;
+		netif_rx_complete(dev, napi);
 		ehea_reset_cq_ep(pr->recv_cq);
 		ehea_reset_cq_ep(pr->send_cq);
 		ehea_reset_cq_n1(pr->recv_cq);
@@ -578,43 +579,35 @@ static int ehea_poll(struct net_device *dev, int *budget)
 		cqe_skb = ehea_poll_cq(pr->send_cq);
 
 		if (!cqe && !cqe_skb)
-			return 0;
+			return rx;
 
-		if (!netif_rx_reschedule(dev, dev->quota))
-			return 0;
-	}
-
-	cqe = ehea_proc_rwqes(dev, pr, budget);
-	cqe_skb = ehea_proc_cqes(pr, 300);
+		if (!netif_rx_reschedule(dev, napi))
+			return rx;
 
-	if (cqe || cqe_skb)
-		pr->poll_counter++;
+		cqe_skb = ehea_proc_cqes(pr, EHEA_POLL_MAX_CQES);
+		rx += ehea_proc_rwqes(dev, pr, budget - rx);
+	}
 
-	return 1;
+	pr->poll_counter++;
+	return rx;
 }
 
 #ifdef CONFIG_NET_POLL_CONTROLLER
 static void ehea_netpoll(struct net_device *dev)
 {
 	struct ehea_port *port = netdev_priv(dev);
+	int i;
 
-	netif_rx_schedule(port->port_res[0].d_netdev);
+	for (i = 0; i < port->num_def_qps; i++)
+		netif_rx_schedule(dev, &port->port_res[i].napi);
 }
 #endif
 
-static int ehea_poll_firstqueue(struct net_device *dev, int *budget)
-{
-	struct ehea_port *port = netdev_priv(dev);
-	struct net_device *d_dev = port->port_res[0].d_netdev;
-
-	return ehea_poll(d_dev, budget);
-}
-
 static irqreturn_t ehea_recv_irq_handler(int irq, void *param)
 {
 	struct ehea_port_res *pr = param;
 
-	netif_rx_schedule(pr->d_netdev);
+	netif_rx_schedule(pr->port->netdev, &pr->napi);
 
 	return IRQ_HANDLED;
 }
@@ -1236,14 +1229,7 @@ static int ehea_init_port_res(struct ehea_port *port, struct ehea_port_res *pr,
 
 	kfree(init_attr);
 
-	pr->d_netdev = alloc_netdev(0, "", ether_setup);
-	if (!pr->d_netdev)
-		goto out_free;
-	pr->d_netdev->priv = pr;
-	pr->d_netdev->weight = 64;
-	pr->d_netdev->poll = ehea_poll;
-	set_bit(__LINK_STATE_START, &pr->d_netdev->state);
-	strcpy(pr->d_netdev->name, port->netdev->name);
+	netif_napi_add(pr->port->netdev, &pr->napi, ehea_poll, 64);
 
 	ret = 0;
 	goto out;
@@ -1266,8 +1252,6 @@ static int ehea_clean_portres(struct ehea_port *port, struct ehea_port_res *pr)
 {
 	int ret, i;
 
-	free_netdev(pr->d_netdev);
-
 	ret = ehea_destroy_qp(pr->qp);
 
 	if (!ret) {
@@ -2248,6 +2232,22 @@ out:
 	return ret;
 }
 
+static void port_napi_disable(struct ehea_port *port)
+{
+	int i;
+
+	for (i = 0; i < port->num_def_qps; i++)
+		napi_disable(&port->port_res[i].napi);
+}
+
+static void port_napi_enable(struct ehea_port *port)
+{
+	int i;
+
+	for (i = 0; i < port->num_def_qps; i++)
+		napi_enable(&port->port_res[i].napi);
+}
+
 static int ehea_open(struct net_device *dev)
 {
 	int ret;
@@ -2259,8 +2259,10 @@ static int ehea_open(struct net_device *dev)
 		ehea_info("enabling port %s", dev->name);
 
 	ret = ehea_up(dev);
-	if (!ret)
+	if (!ret) {
+		port_napi_enable(port);
 		netif_start_queue(dev);
+	}
 
 	up(&port->port_lock);
 
@@ -2269,7 +2271,7 @@ static int ehea_open(struct net_device *dev)
 
 static int ehea_down(struct net_device *dev)
 {
-	int ret, i;
+	int ret;
 	struct ehea_port *port = netdev_priv(dev);
 
 	if (port->state == EHEA_PORT_DOWN)
@@ -2278,10 +2280,7 @@ static int ehea_down(struct net_device *dev)
 	ehea_drop_multicast_list(dev);
 	ehea_free_interrupts(dev);
 
-	for (i = 0; i < port->num_def_qps; i++)
-		while (test_bit(__LINK_STATE_RX_SCHED,
-				&port->port_res[i].d_netdev->state))
-			msleep(1);
+	port_napi_disable(port);
 
 	port->state = EHEA_PORT_DOWN;
 
@@ -2319,7 +2318,8 @@ static void ehea_reset_port(struct work_struct *work)
 	port->resets++;
 	down(&port->port_lock);
 	netif_stop_queue(dev);
-	netif_poll_disable(dev);
+
+	port_napi_disable(port);
 
 	ehea_down(dev);
 
@@ -2330,7 +2330,8 @@ static void ehea_reset_port(struct work_struct *work)
 	if (netif_msg_timer(port))
 		ehea_info("Device %s resetted successfully", dev->name);
 
-	netif_poll_enable(dev);
+	port_napi_enable(port);
+
 	netif_wake_queue(dev);
 out:
 	up(&port->port_lock);
@@ -2358,7 +2359,9 @@ static void ehea_rereg_mrs(struct work_struct *work)
 							  dev->name);
 						down(&port->port_lock);
 						netif_stop_queue(dev);
-						netif_poll_disable(dev);
+
+						port_napi_disable(port);
+
 						ehea_down(dev);
 						up(&port->port_lock);
 					}
@@ -2406,7 +2409,7 @@ static void ehea_rereg_mrs(struct work_struct *work)
 
 						ret = ehea_up(dev);
 						if (!ret) {
-							netif_poll_enable(dev);
+							port_napi_enable(port);
 							netif_wake_queue(dev);
 						}
 
@@ -2644,11 +2647,9 @@ struct ehea_port *ehea_setup_single_port(struct ehea_adapter *adapter,
 	memcpy(dev->dev_addr, &port->mac_addr, ETH_ALEN);
 
 	dev->open = ehea_open;
-	dev->poll = ehea_poll_firstqueue;
 #ifdef CONFIG_NET_POLL_CONTROLLER
 	dev->poll_controller = ehea_netpoll;
 #endif
-	dev->weight = 64;
 	dev->stop = ehea_stop;
 	dev->hard_start_xmit = ehea_start_xmit;
 	dev->get_stats = ehea_get_stats;