sfc: skeleton EF100 PF driver

No TX or RX path, no MCDI, not even an ifup/down handler.
Besides stubs, the bulk of the patch deals with reading the Xilinx
 extended PCIe capability, which tells us where to find our BAR.

Though in the same module, EF100 has its own struct pci_driver,
 which is named sfc_ef100.

A small number of additional nic_type methods are added; those in the
 TX (tx_enqueue) and RX (rx_packet) paths are called through indirect
 call wrappers to minimise the performance impact.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 129 insertions, 0 deletions

diff --git a/drivers/net/ethernet/sfc/ef100_netdev.c b/drivers/net/ethernet/sfc/ef100_netdev.c
new file mode 100644
index 000000000000..f900b375d9b1
--- /dev/null
+++ b/drivers/net/ethernet/sfc/ef100_netdev.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/****************************************************************************
+ * Driver for Solarflare network controllers and boards
+ * Copyright 2018 Solarflare Communications Inc.
+ * Copyright 2019-2020 Xilinx 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 "mcdi_port_common.h"
+#include "mcdi_functions.h"
+#include "efx_common.h"
+#include "efx_channels.h"
+#include "tx_common.h"
+#include "ef100_netdev.h"
+#include "ef100_ethtool.h"
+#include "efx_common.h"
+#include "nic_common.h"
+#include "ef100_nic.h"
+#include "ef100_tx.h"
+#include "ef100_regs.h"
+#include "mcdi_filters.h"
+#include "rx_common.h"
+
+static void ef100_update_name(struct efx_nic *efx)
+{
+	strcpy(efx->name, efx->net_dev->name);
+}
+
+/* Initiate a packet transmission.  We use one channel per CPU
+ * (sharing when we have more CPUs than channels).
+ *
+ * Context: non-blocking.
+ * Note that returning anything other than NETDEV_TX_OK will cause the
+ * OS to free the skb.
+ */
+static netdev_tx_t ef100_hard_start_xmit(struct sk_buff *skb,
+					 struct net_device *net_dev)
+{
+	struct efx_nic *efx = netdev_priv(net_dev);
+	struct efx_tx_queue *tx_queue;
+	struct efx_channel *channel;
+	int rc;
+
+	channel = efx_get_tx_channel(efx, skb_get_queue_mapping(skb));
+	netif_vdbg(efx, tx_queued, efx->net_dev,
+		   "%s len %d data %d channel %d\n", __func__,
+		   skb->len, skb->data_len, channel->channel);
+	if (!efx->n_channels || !efx->n_tx_channels || !channel) {
+		netif_stop_queue(net_dev);
+		goto err;
+	}
+
+	tx_queue = &channel->tx_queue[0];
+	rc = ef100_enqueue_skb(tx_queue, skb);
+	if (rc == 0)
+		return NETDEV_TX_OK;
+
+err:
+	net_dev->stats.tx_dropped++;
+	return NETDEV_TX_OK;
+}
+
+static const struct net_device_ops ef100_netdev_ops = {
+	.ndo_start_xmit         = ef100_hard_start_xmit,
+};
+
+/*	Netdev registration
+ */
+int ef100_netdev_event(struct notifier_block *this,
+		       unsigned long event, void *ptr)
+{
+	struct efx_nic *efx = container_of(this, struct efx_nic, netdev_notifier);
+	struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
+
+	if (netdev_priv(net_dev) == efx && event == NETDEV_CHANGENAME)
+		ef100_update_name(efx);
+
+	return NOTIFY_DONE;
+}
+
+int ef100_register_netdev(struct efx_nic *efx)
+{
+	struct net_device *net_dev = efx->net_dev;
+	int rc;
+
+	net_dev->watchdog_timeo = 5 * HZ;
+	net_dev->irq = efx->pci_dev->irq;
+	net_dev->netdev_ops = &ef100_netdev_ops;
+	net_dev->min_mtu = EFX_MIN_MTU;
+	net_dev->max_mtu = EFX_MAX_MTU;
+	net_dev->ethtool_ops = &ef100_ethtool_ops;
+
+	rtnl_lock();
+
+	rc = dev_alloc_name(net_dev, net_dev->name);
+	if (rc < 0)
+		goto fail_locked;
+	ef100_update_name(efx);
+
+	rc = register_netdevice(net_dev);
+	if (rc)
+		goto fail_locked;
+
+	/* Always start with carrier off; PHY events will detect the link */
+	netif_carrier_off(net_dev);
+
+	efx->state = STATE_READY;
+	rtnl_unlock();
+	efx_init_mcdi_logging(efx);
+
+	return 0;
+
+fail_locked:
+	rtnl_unlock();
+	netif_err(efx, drv, efx->net_dev, "could not register net dev\n");
+	return rc;
+}
+
+void ef100_unregister_netdev(struct efx_nic *efx)
+{
+	if (efx_dev_registered(efx)) {
+		efx_fini_mcdi_logging(efx);
+		efx->state = STATE_UNINIT;
+		unregister_netdev(efx->net_dev);
+	}
+}