net: extract napi poll functionality to __napi_poll()

This commit introduces a new function __napi_poll() which does the main
logic of the existing napi_poll() function, and will be called by other
functions in later commits.
This idea and implementation is done by Felix Fietkau <nbd@nbd.name> and
is proposed as part of the patch to move napi work to work_queue
context.
This commit by itself is a code restructure.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Wei Wang <weiwan@google.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/dev.c b/net/core/dev.c
index 21d74d3..59751a2 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6776,15 +6776,10 @@ void __netif_napi_del(struct napi_struct *napi)
 }
 EXPORT_SYMBOL(__netif_napi_del);
 
-static int napi_poll(struct napi_struct *n, struct list_head *repoll)
+static int __napi_poll(struct napi_struct *n, bool *repoll)
 {
-       void *have;
        int work, weight;
 
-       list_del_init(&n->poll_list);
-
-       have = netpoll_poll_lock(n);
-
        weight = n->weight;
 
        /* This NAPI_STATE_SCHED test is for avoiding a race
@@ -6804,7 +6799,7 @@ static int napi_poll(struct napi_struct *n, struct list_head *repoll)
                            n->poll, work, weight);
 
        if (likely(work < weight))
-               goto out_unlock;
+               return work;
 
        /* Drivers must not modify the NAPI state if they
         * consume the entire weight.  In such cases this code
@@ -6813,7 +6808,7 @@ static int napi_poll(struct napi_struct *n, struct list_head *repoll)
         */
        if (unlikely(napi_disable_pending(n))) {
                napi_complete(n);
-               goto out_unlock;
+               return work;
        }
 
        /* The NAPI context has more processing work, but busy-polling
@@ -6826,7 +6821,7 @@ static int napi_poll(struct napi_struct *n, struct list_head *repoll)
                         */
                        napi_schedule(n);
                }
-               goto out_unlock;
+               return work;
        }
 
        if (n->gro_bitmask) {
@@ -6844,12 +6839,29 @@ static int napi_poll(struct napi_struct *n, struct list_head *repoll)
        if (unlikely(!list_empty(&n->poll_list))) {
                pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
                             n->dev ? n->dev->name : "backlog");
-               goto out_unlock;
+               return work;
        }
 
-       list_add_tail(&n->poll_list, repoll);
+       *repoll = true;
+
+       return work;
+}
+
+static int napi_poll(struct napi_struct *n, struct list_head *repoll)
+{
+       bool do_repoll = false;
+       void *have;
+       int work;
+
+       list_del_init(&n->poll_list);
+
+       have = netpoll_poll_lock(n);
+
+       work = __napi_poll(n, &do_repoll);
+
+       if (do_repoll)
+               list_add_tail(&n->poll_list, repoll);
 
-out_unlock:
        netpoll_poll_unlock(have);
 
        return work;