rps: Fixed build with CONFIG_SMP not enabled.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netdevice.h

@@ -1341,7 +1341,9 @@ struct softnet_data {
 	struct sk_buff		*completion_queue;
 
 	/* Elements below can be accessed between CPUs for RPS */
+#ifdef CONFIG_SMP
 	struct call_single_data	csd ____cacheline_aligned_in_smp;
+#endif
 	struct sk_buff_head	input_pkt_queue;
 	struct napi_struct	backlog;
 };

net/core/dev.c

@@ -2174,6 +2174,7 @@ int weight_p __read_mostly = 64;            /* old backlog weight */
 
 DEFINE_PER_CPU(struct netif_rx_stats, netdev_rx_stat) = { 0, };
 
+#ifdef CONFIG_SMP
 /*
  * get_rps_cpu is called from netif_receive_skb and returns the target
  * CPU from the RPS map of the receiving queue for a given skb.
@@ -2293,6 +2294,7 @@ static void trigger_softirq(void *data)
 	__napi_schedule(&queue->backlog);
 	__get_cpu_var(netdev_rx_stat).received_rps++;
 }
+#endif /* CONFIG_SMP */
 
 /*
  * enqueue_to_backlog is called to queue an skb to a per CPU backlog
@@ -2320,6 +2322,7 @@ static int enqueue_to_backlog(struct sk_buff *skb, int cpu)
 
 		/* Schedule NAPI for backlog device */
 		if (napi_schedule_prep(&queue->backlog)) {
+#ifdef CONFIG_SMP
 			if (cpu != smp_processor_id()) {
 				struct rps_remote_softirq_cpus *rcpus =
 				    &__get_cpu_var(rps_remote_softirq_cpus);
@@ -2328,6 +2331,9 @@ static int enqueue_to_backlog(struct sk_buff *skb, int cpu)
 				__raise_softirq_irqoff(NET_RX_SOFTIRQ);
 			} else
 				__napi_schedule(&queue->backlog);
+#else
+			__napi_schedule(&queue->backlog);
+#endif
 		}
 		goto enqueue;
 	}
@@ -2367,9 +2373,13 @@ int netif_rx(struct sk_buff *skb)
 	if (!skb->tstamp.tv64)
 		net_timestamp(skb);
 
+#ifdef CONFIG_SMP
 	cpu = get_rps_cpu(skb->dev, skb);
 	if (cpu < 0)
 		cpu = smp_processor_id();
+#else
+	cpu = smp_processor_id();
+#endif
 
 	return enqueue_to_backlog(skb, cpu);
 }
@@ -2735,6 +2745,7 @@ int __netif_receive_skb(struct sk_buff *skb)
  */
 int netif_receive_skb(struct sk_buff *skb)
 {
+#ifdef CONFIG_SMP
 	int cpu;
 
 	cpu = get_rps_cpu(skb->dev, skb);
@@ -2743,6 +2754,9 @@ int netif_receive_skb(struct sk_buff *skb)
 		return __netif_receive_skb(skb);
 	else
 		return enqueue_to_backlog(skb, cpu);
+#else
+	return __netif_receive_skb(skb);
+#endif
 }
 EXPORT_SYMBOL(netif_receive_skb);
 
@@ -3168,6 +3182,7 @@ void netif_napi_del(struct napi_struct *napi)
 }
 EXPORT_SYMBOL(netif_napi_del);
 
+#ifdef CONFIG_SMP
 /*
  * net_rps_action sends any pending IPI's for rps.  This is only called from
  * softirq and interrupts must be enabled.
@@ -3184,6 +3199,7 @@ static void net_rps_action(cpumask_t *mask)
 	}
 	cpus_clear(*mask);
 }
+#endif
 
 static void net_rx_action(struct softirq_action *h)
 {
@@ -3191,8 +3207,10 @@ static void net_rx_action(struct softirq_action *h)
 	unsigned long time_limit = jiffies + 2;
 	int budget = netdev_budget;
 	void *have;
+#ifdef CONFIG_SMP
 	int select;
 	struct rps_remote_softirq_cpus *rcpus;
+#endif
 
 	local_irq_disable();
 
@@ -3255,6 +3273,7 @@ static void net_rx_action(struct softirq_action *h)
 		netpoll_poll_unlock(have);
 	}
 out:
+#ifdef CONFIG_SMP
 	rcpus = &__get_cpu_var(rps_remote_softirq_cpus);
 	select = rcpus->select;
 	rcpus->select ^= 1;
@@ -3262,6 +3281,9 @@ static void net_rx_action(struct softirq_action *h)
 	local_irq_enable();
 
 	net_rps_action(&rcpus->mask[select]);
+#else
+	local_irq_enable();
+#endif
 
 #ifdef CONFIG_NET_DMA
 	/*
@@ -6204,9 +6226,11 @@ static int __init net_dev_init(void)
 		queue->completion_queue = NULL;
 		INIT_LIST_HEAD(&queue->poll_list);
 
+#ifdef CONFIG_SMP
 		queue->csd.func = trigger_softirq;
 		queue->csd.info = queue;
 		queue->csd.flags = 0;
+#endif
 
 		queue->backlog.poll = process_backlog;
 		queue->backlog.weight = weight_p;