net: Add the get current NAPI context API
Commit 69235aa80090 ("net: Remove the get current NAPI context API")
removed the definition of get_current_napi_context() as rmnet_data
was no longer using it. However, the rmnet_data change to use its
NAPI in multiple contexts was prone to race in hotplug scenarios.
Add back get_current_napi_context() and current_napi to the
softnet_data struct.
CRs-Fixed: 1078373
Change-Id: I7cf1c5e39a5ccbd7a74a096b11efd179a4d0d034
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
diff --git a/net/core/dev.c b/net/core/dev.c
index 4bc19a1..446da53 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4858,8 +4858,7 @@
rcu_read_unlock();
input_queue_head_incr(sd);
if (++work >= quota)
- return work;
-
+ goto state_changed;
}
local_irq_disable();
@@ -4883,6 +4882,10 @@
local_irq_enable();
}
+state_changed:
+ napi_gro_flush(napi, false);
+ sd->current_napi = NULL;
+
return work;
}
@@ -4917,10 +4920,13 @@
void __napi_complete(struct napi_struct *n)
{
+ struct softnet_data *sd = this_cpu_ptr(&softnet_data);
+
BUG_ON(!test_bit(NAPI_STATE_SCHED, &n->state));
list_del_init(&n->poll_list);
smp_mb__before_atomic();
+ sd->current_napi = NULL;
clear_bit(NAPI_STATE_SCHED, &n->state);
}
EXPORT_SYMBOL(__napi_complete);
@@ -5136,6 +5142,14 @@
}
EXPORT_SYMBOL(netif_napi_del);
+struct napi_struct *get_current_napi_context(void)
+{
+ struct softnet_data *sd = this_cpu_ptr(&softnet_data);
+
+ return sd->current_napi;
+}
+EXPORT_SYMBOL(get_current_napi_context);
+
static int napi_poll(struct napi_struct *n, struct list_head *repoll)
{
void *have;
@@ -5155,6 +5169,9 @@
*/
work = 0;
if (test_bit(NAPI_STATE_SCHED, &n->state)) {
+ struct softnet_data *sd = this_cpu_ptr(&softnet_data);
+
+ sd->current_napi = n;
work = n->poll(n, weight);
trace_napi_poll(n, work, weight);
}