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authorMagnus Karlsson <magnus.karlsson@intel.com>2018-08-28 14:44:28 +0200
committerAlexei Starovoitov <ast@kernel.org>2018-08-29 12:25:53 -0700
commit6c5c9581044dd6e0cd284ab653502fb9264f08b6 (patch)
treee6fa178bc5bebdf6a58110ede60352ec5ba50151
parentxsk: expose xdp_umem_get_{data,dma} to drivers (diff)
downloadlinux-dev-6c5c9581044dd6e0cd284ab653502fb9264f08b6.tar.xz
linux-dev-6c5c9581044dd6e0cd284ab653502fb9264f08b6.zip
net: add napi_if_scheduled_mark_missed
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.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
-rw-r--r--include/linux/netdevice.h26
1 files changed, 26 insertions, 0 deletions
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,