sfc: add EF100 VF support via a write to sriov_numvfs

This patch extends the EF100 PF driver by adding .sriov_configure()
which would allow users to enable and disable virtual functions
using the sriov sysfs.
Signed-off-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>
Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
Link: https://lore.kernel.org/r/75e74d9e-14ce-0524-9668-5ab735a7cf62@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/sfc/Makefile

@@ -8,7 +8,7 @@ sfc-y			+= efx.o efx_common.o efx_channels.o nic.o \
 			   ef100.o ef100_nic.o ef100_netdev.o \
 			   ef100_ethtool.o ef100_rx.o ef100_tx.o
 sfc-$(CONFIG_SFC_MTD)	+= mtd.o
-sfc-$(CONFIG_SFC_SRIOV)	+= sriov.o siena_sriov.o ef10_sriov.o
+sfc-$(CONFIG_SFC_SRIOV)	+= sriov.o siena_sriov.o ef10_sriov.o ef100_sriov.o
 
 obj-$(CONFIG_SFC)	+= sfc.o
 

drivers/net/ethernet/sfc/ef100.c

@@ -2,7 +2,7 @@
 /****************************************************************************
  * Driver for Solarflare network controllers and boards
  * Copyright 2005-2018 Solarflare Communications Inc.
- * Copyright 2019-2020 Xilinx Inc.
+ * Copyright 2019-2022 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
@@ -17,6 +17,7 @@
 #include "io.h"
 #include "ef100_nic.h"
 #include "ef100_netdev.h"
+#include "ef100_sriov.h"
 #include "ef100_regs.h"
 #include "ef100.h"
 
@@ -436,6 +437,10 @@ static void ef100_pci_remove(struct pci_dev *pci_dev)
 	 * blocks, so we have to do it before PCI removal.
 	 */
 	unregister_netdevice_notifier(&efx->netdev_notifier);
+#if defined(CONFIG_SFC_SRIOV)
+	if (!efx->type->is_vf)
+		efx_ef100_pci_sriov_disable(efx);
+#endif
 	ef100_remove(efx);
 	efx_fini_io(efx);
 	netif_dbg(efx, drv, efx->net_dev, "shutdown successful\n");
@@ -524,6 +529,23 @@ static int ef100_pci_probe(struct pci_dev *pci_dev,
 	return rc;
 }
 
+#ifdef CONFIG_SFC_SRIOV
+static int ef100_pci_sriov_configure(struct pci_dev *dev, int num_vfs)
+{
+	struct efx_nic *efx = pci_get_drvdata(dev);
+	int rc;
+
+	if (efx->type->sriov_configure) {
+		rc = efx->type->sriov_configure(efx, num_vfs);
+		if (rc)
+			return rc;
+		else
+			return num_vfs;
+	}
+	return -ENOENT;
+}
+#endif
+
 /* PCI device ID table */
 static const struct pci_device_id ef100_pci_table[] = {
 	{PCI_DEVICE(PCI_VENDOR_ID_XILINX, 0x0100),  /* Riverhead PF */
@@ -538,6 +560,9 @@ struct pci_driver ef100_pci_driver = {
 	.id_table       = ef100_pci_table,
 	.probe          = ef100_pci_probe,
 	.remove         = ef100_pci_remove,
+#ifdef CONFIG_SFC_SRIOV
+	.sriov_configure = ef100_pci_sriov_configure,
+#endif
 	.err_handler    = &efx_err_handlers,
 };
 

drivers/net/ethernet/sfc/ef100_nic.c

@@ -2,7 +2,7 @@
 /****************************************************************************
  * Driver for Solarflare network controllers and boards
  * Copyright 2018 Solarflare Communications Inc.
- * Copyright 2019-2020 Xilinx Inc.
+ * Copyright 2019-2022 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
@@ -22,6 +22,7 @@
 #include "mcdi_filters.h"
 #include "ef100_rx.h"
 #include "ef100_tx.h"
+#include "ef100_sriov.h"
 #include "ef100_netdev.h"
 #include "rx_common.h"
 
@@ -787,6 +788,9 @@ const struct efx_nic_type ef100_pf_nic_type = {
 	.update_stats = ef100_update_stats,
 	.pull_stats = efx_mcdi_mac_pull_stats,
 	.stop_stats = efx_mcdi_mac_stop_stats,
+#ifdef CONFIG_SFC_SRIOV
+	.sriov_configure = efx_ef100_sriov_configure,
+#endif
 
 	/* Per-type bar/size configuration not used on ef100. Location of
 	 * registers is defined by extended capabilities.

drivers/net/ethernet/sfc/ef100_sriov.c

+// SPDX-License-Identifier: GPL-2.0-only
+/****************************************************************************
+ * Driver for Solarflare network controllers and boards
+ * Copyright 2019 Solarflare Communications Inc.
+ * Copyright 2020-2022 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 "ef100_sriov.h"
+#include "ef100_nic.h"
+
+static int efx_ef100_pci_sriov_enable(struct efx_nic *efx, int num_vfs)
+{
+	struct pci_dev *dev = efx->pci_dev;
+	int rc;
+
+	efx->vf_count = num_vfs;
+	rc = pci_enable_sriov(dev, num_vfs);
+	if (rc)
+		goto fail;
+
+	return 0;
+
+fail:
+	netif_err(efx, probe, efx->net_dev, "Failed to enable SRIOV VFs\n");
+	efx->vf_count = 0;
+	return rc;
+}
+
+int efx_ef100_pci_sriov_disable(struct efx_nic *efx)
+{
+	struct pci_dev *dev = efx->pci_dev;
+	unsigned int vfs_assigned;
+
+	vfs_assigned = pci_vfs_assigned(dev);
+	if (vfs_assigned) {
+		netif_info(efx, drv, efx->net_dev, "VFs are assigned to guests; "
+			   "please detach them before disabling SR-IOV\n");
+		return -EBUSY;
+	}
+
+	pci_disable_sriov(dev);
+
+	return 0;
+}
+
+int efx_ef100_sriov_configure(struct efx_nic *efx, int num_vfs)
+{
+	if (num_vfs == 0)
+		return efx_ef100_pci_sriov_disable(efx);
+	else
+		return efx_ef100_pci_sriov_enable(efx, num_vfs);
+}

drivers/net/ethernet/sfc/ef100_sriov.h

+/* SPDX-License-Identifier: GPL-2.0-only */
+/****************************************************************************
+ * Driver for Solarflare network controllers and boards
+ * Copyright 2019 Solarflare Communications Inc.
+ * Copyright 2020-2022 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"
+
+int efx_ef100_sriov_configure(struct efx_nic *efx, int num_vfs);
+int efx_ef100_pci_sriov_disable(struct efx_nic *efx);