From: Magnus Karlsson <magnus.karls...@intel.com>
The function napi_if_scheduled_mark_missed is used to check if the
NAPI context is scheduled, if so set NAPIF_STATE_MISSED and return
true. Used by the AF_XDP zero-copy i40e Tx code implementation in
order to make sure that irq affinity is honored by the napi context.
Signed-off-by: Magnus Karlsson <magnus.karls...@intel.com>
---
include/linux/netdevice.h | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index ca5ab98053c8..4271f6b4e419 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -535,6 +535,32 @@ static inline void napi_synchronize(const struct
napi_struct *n)
barrier();
}
+/**
+ * napi_if_scheduled_mark_missed - if napi is running, set the
+ * NAPIF_STATE_MISSED
+ * @n: NAPI context
+ *
+ * If napi is running, set the NAPIF_STATE_MISSED, and return true if
+ * NAPI is scheduled.
+ **/
+static inline bool napi_if_scheduled_mark_missed(struct napi_struct *n)
+{
+ unsigned long val, new;
+
+ do {
+ val = READ_ONCE(n->state);
+ if (val & NAPIF_STATE_DISABLE)
+ return true;
+
+ if (!(val & NAPIF_STATE_SCHED))
+ return false;
+
+ new = val | NAPIF_STATE_MISSED;
+ } while (cmpxchg(&n->state, val, new) != val);
+
+ return true;
+}
+
enum netdev_queue_state_t {
__QUEUE_STATE_DRV_XOFF,
__QUEUE_STATE_STACK_XOFF,
--
2.17.1
