sfc: move reset workqueue code

Small functions doing work that will be common, related to reset
workqueue management.

Signed-off-by: Alexandru-Mihai Maftei <amaftei@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/sfc/efx_common.c

@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/****************************************************************************
+ * Driver for Solarflare network controllers and boards
+ * Copyright 2018 Solarflare Communications Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation, incorporated herein by reference.
+ */
+
+#include "net_driver.h"
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include "efx_common.h"
+#include "efx_channels.h"
+#include "efx.h"
+#include "mcdi.h"
+#include "selftest.h"
+#include "rx_common.h"
+#include "tx_common.h"
+#include "nic.h"
+#include "io.h"
+#include "mcdi_pcol.h"
+
+/* Reset workqueue. If any NIC has a hardware failure then a reset will be
+ * queued onto this work queue. This is not a per-nic work queue, because
+ * efx_reset_work() acquires the rtnl lock, so resets are naturally serialised.
+ */
+static struct workqueue_struct *reset_workqueue;
+
+int efx_create_reset_workqueue(void)
+{
+	reset_workqueue = create_singlethread_workqueue("sfc_reset");
+	if (!reset_workqueue) {
+		printk(KERN_ERR "Failed to create reset workqueue\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+void efx_queue_reset_work(struct efx_nic *efx)
+{
+	queue_work(reset_workqueue, &efx->reset_work);
+}
+
+void efx_flush_reset_workqueue(struct efx_nic *efx)
+{
+	cancel_work_sync(&efx->reset_work);
+}
+
+void efx_destroy_reset_workqueue(void)
+{
+	if (reset_workqueue) {
+		destroy_workqueue(reset_workqueue);
+		reset_workqueue = NULL;
+	}
+}