v4.19.13 snapshot.
diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h
new file mode 100644
index 0000000..3ef82d3
--- /dev/null
+++ b/include/linux/netpoll.h
@@ -0,0 +1,124 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Common code for low-level network console, dump, and debugger code
+ *
+ * Derived from netconsole, kgdb-over-ethernet, and netdump patches
+ */
+
+#ifndef _LINUX_NETPOLL_H
+#define _LINUX_NETPOLL_H
+
+#include <linux/netdevice.h>
+#include <linux/interrupt.h>
+#include <linux/rcupdate.h>
+#include <linux/list.h>
+#include <linux/refcount.h>
+
+union inet_addr {
+ __u32 all[4];
+ __be32 ip;
+ __be32 ip6[4];
+ struct in_addr in;
+ struct in6_addr in6;
+};
+
+struct netpoll {
+ struct net_device *dev;
+ char dev_name[IFNAMSIZ];
+ const char *name;
+
+ union inet_addr local_ip, remote_ip;
+ bool ipv6;
+ u16 local_port, remote_port;
+ u8 remote_mac[ETH_ALEN];
+
+ struct work_struct cleanup_work;
+};
+
+struct netpoll_info {
+ refcount_t refcnt;
+
+ struct semaphore dev_lock;
+
+ struct sk_buff_head txq;
+
+ struct delayed_work tx_work;
+
+ struct netpoll *netpoll;
+ struct rcu_head rcu;
+};
+
+#ifdef CONFIG_NETPOLL
+void netpoll_poll_dev(struct net_device *dev);
+void netpoll_poll_disable(struct net_device *dev);
+void netpoll_poll_enable(struct net_device *dev);
+#else
+static inline void netpoll_poll_disable(struct net_device *dev) { return; }
+static inline void netpoll_poll_enable(struct net_device *dev) { return; }
+#endif
+
+void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
+void netpoll_print_options(struct netpoll *np);
+int netpoll_parse_options(struct netpoll *np, char *opt);
+int __netpoll_setup(struct netpoll *np, struct net_device *ndev);
+int netpoll_setup(struct netpoll *np);
+void __netpoll_cleanup(struct netpoll *np);
+void __netpoll_free_async(struct netpoll *np);
+void netpoll_cleanup(struct netpoll *np);
+void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
+ struct net_device *dev);
+static inline void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
+{
+ unsigned long flags;
+ local_irq_save(flags);
+ netpoll_send_skb_on_dev(np, skb, np->dev);
+ local_irq_restore(flags);
+}
+
+#ifdef CONFIG_NETPOLL
+static inline void *netpoll_poll_lock(struct napi_struct *napi)
+{
+ struct net_device *dev = napi->dev;
+
+ if (dev && dev->npinfo) {
+ int owner = smp_processor_id();
+
+ while (cmpxchg(&napi->poll_owner, -1, owner) != -1)
+ cpu_relax();
+
+ return napi;
+ }
+ return NULL;
+}
+
+static inline void netpoll_poll_unlock(void *have)
+{
+ struct napi_struct *napi = have;
+
+ if (napi)
+ smp_store_release(&napi->poll_owner, -1);
+}
+
+static inline bool netpoll_tx_running(struct net_device *dev)
+{
+ return irqs_disabled();
+}
+
+#else
+static inline void *netpoll_poll_lock(struct napi_struct *napi)
+{
+ return NULL;
+}
+static inline void netpoll_poll_unlock(void *have)
+{
+}
+static inline void netpoll_netdev_init(struct net_device *dev)
+{
+}
+static inline bool netpoll_tx_running(struct net_device *dev)
+{
+ return false;
+}
+#endif
+
+#endif