net: core: Another step of skb receive list processing

netif_receive_skb_list_internal() now processes a list and hands it
 on to the next function.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/dev.c b/net/core/dev.c
index 308acfd..1e87361 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4843,6 +4843,14 @@ static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
        return ret;
 }
 
+static void __netif_receive_skb_list(struct list_head *head)
+{
+       struct sk_buff *skb, *next;
+
+       list_for_each_entry_safe(skb, next, head, list)
+               __netif_receive_skb(skb);
+}
+
 static int netif_receive_skb_internal(struct sk_buff *skb)
 {
        int ret;
@@ -4883,6 +4891,50 @@ static int netif_receive_skb_internal(struct sk_buff *skb)
        return ret;
 }
 
+static void netif_receive_skb_list_internal(struct list_head *head)
+{
+       struct bpf_prog *xdp_prog = NULL;
+       struct sk_buff *skb, *next;
+
+       list_for_each_entry_safe(skb, next, head, list) {
+               net_timestamp_check(netdev_tstamp_prequeue, skb);
+               if (skb_defer_rx_timestamp(skb))
+                       /* Handled, remove from list */
+                       list_del(&skb->list);
+       }
+
+       if (static_branch_unlikely(&generic_xdp_needed_key)) {
+               preempt_disable();
+               rcu_read_lock();
+               list_for_each_entry_safe(skb, next, head, list) {
+                       xdp_prog = rcu_dereference(skb->dev->xdp_prog);
+                       if (do_xdp_generic(xdp_prog, skb) != XDP_PASS)
+                               /* Dropped, remove from list */
+                               list_del(&skb->list);
+               }
+               rcu_read_unlock();
+               preempt_enable();
+       }
+
+       rcu_read_lock();
+#ifdef CONFIG_RPS
+       if (static_key_false(&rps_needed)) {
+               list_for_each_entry_safe(skb, next, head, list) {
+                       struct rps_dev_flow voidflow, *rflow = &voidflow;
+                       int cpu = get_rps_cpu(skb->dev, skb, &rflow);
+
+                       if (cpu >= 0) {
+                               enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
+                               /* Handled, remove from list */
+                               list_del(&skb->list);
+                       }
+               }
+       }
+#endif
+       __netif_receive_skb_list(head);
+       rcu_read_unlock();
+}
+
 /**
  *     netif_receive_skb - process receive buffer from network
  *     @skb: buffer to process
@@ -4910,20 +4962,19 @@ EXPORT_SYMBOL(netif_receive_skb);
  *     netif_receive_skb_list - process many receive buffers from network
  *     @head: list of skbs to process.
  *
- *     For now, just calls netif_receive_skb() in a loop, ignoring the
- *     return value.
+ *     Since return value of netif_receive_skb() is normally ignored, and
+ *     wouldn't be meaningful for a list, this function returns void.
  *
  *     This function may only be called from softirq context and interrupts
  *     should be enabled.
  */
 void netif_receive_skb_list(struct list_head *head)
 {
-       struct sk_buff *skb, *next;
+       struct sk_buff *skb;
 
        list_for_each_entry(skb, head, list)
                trace_netif_receive_skb_list_entry(skb);
-       list_for_each_entry_safe(skb, next, head, list)
-               netif_receive_skb_internal(skb);
+       netif_receive_skb_list_internal(head);
 }
 EXPORT_SYMBOL(netif_receive_skb_list);