igc: Add skeletal frame for Intel(R) 2.5G Ethernet Controller support

This patch adds the beginning framework onto which I am going to add
the igc driver which supports the Intel(R) I225-LM/I225-V 2.5G
Ethernet Controller.

Signed-off-by: Sasha Neftin <[e-mail]>
Tested-by: Aaron Brown <[e-mail]>
Signed-off-by: Jeff Kirsher <[e-mail]>

drivers/net/ethernet/intel/Kconfig

···
 	  To compile this driver as a module, choose M here. The module
 	  will be called fm10k.  MSI-X interrupt support is required
 
+config IGC
+	tristate "Intel(R) Ethernet Controller I225-LM/I225-V support"
+	default n
+	depends on PCI
+	---help---
+	  This driver supports Intel(R) Ethernet Controller I225-LM/I225-V
+	  family of adapters.
+
+	  For more information on how to identify your adapter, go
+	  to the Adapter & Driver ID Guide that can be located at:
+
+	  <http://support.intel.com>
+
+	  To compile this driver as a module, choose M here. The module
+	  will be called igc.
+
 endif # NET_VENDOR_INTEL

drivers/net/ethernet/intel/Makefile

···
 obj-$(CONFIG_E1000) += e1000/
 obj-$(CONFIG_E1000E) += e1000e/
 obj-$(CONFIG_IGB) += igb/
+obj-$(CONFIG_IGC) += igc/
 obj-$(CONFIG_IGBVF) += igbvf/
 obj-$(CONFIG_IXGBE) += ixgbe/
 obj-$(CONFIG_IXGBEVF) += ixgbevf/

drivers/net/ethernet/intel/igc/Makefile

···
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c)  2018 Intel Corporation
+
+#
+# Intel(R) I225-LM/I225-V 2.5G Ethernet Controller
+#
+
+obj-$(CONFIG_IGC) += igc.o
+
+igc-objs := igc_main.o

drivers/net/ethernet/intel/igc/igc.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c)  2018 Intel Corporation */
+
+#ifndef _IGC_H_
+#define _IGC_H_
+
+#include <linux/kobject.h>
+
+#include <linux/pci.h>
+#include <linux/netdevice.h>
+#include <linux/vmalloc.h>
+
+#include <linux/ethtool.h>
+
+#include <linux/sctp.h>
+
+#define IGC_ERR(args...) pr_err("igc: " args)
+
+#define PFX "igc: "
+
+#include <linux/timecounter.h>
+#include <linux/net_tstamp.h>
+#include <linux/ptp_clock_kernel.h>
+
+/* main */
+extern char igc_driver_name[];
+extern char igc_driver_version[];
+
+#endif /* _IGC_H_ */

drivers/net/ethernet/intel/igc/igc_hw.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c)  2018 Intel Corporation */
+
+#ifndef _IGC_HW_H_
+#define _IGC_HW_H_
+
+#define IGC_DEV_ID_I225_LM			0x15F2
+#define IGC_DEV_ID_I225_V			0x15F3
+
+#endif /* _IGC_HW_H_ */

drivers/net/ethernet/intel/igc/igc_main.c

···
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c)  2018 Intel Corporation */
+
+#include <linux/module.h>
+#include <linux/types.h>
+
+#include "igc.h"
+#include "igc_hw.h"
+
+#define DRV_VERSION	"0.0.1-k"
+#define DRV_SUMMARY	"Intel(R) 2.5G Ethernet Linux Driver"
+
+MODULE_AUTHOR("Intel Corporation, <[e-mail]>");
+MODULE_DESCRIPTION(DRV_SUMMARY);
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION(DRV_VERSION);
+
+char igc_driver_name[] = "igc";
+char igc_driver_version[] = DRV_VERSION;
+static const char igc_driver_string[] = DRV_SUMMARY;
+static const char igc_copyright[] =
+	"Copyright(c) 2018 Intel Corporation.";
+
+static const struct pci_device_id igc_pci_tbl[] = {
+	{ PCI_VDEVICE(INTEL, IGC_DEV_ID_I225_LM) },
+	{ PCI_VDEVICE(INTEL, IGC_DEV_ID_I225_V) },
+	/* required last entry */
+	{0, }
+};
+
+MODULE_DEVICE_TABLE(pci, igc_pci_tbl);
+
+/**
+ * igc_probe - Device Initialization Routine
+ * @pdev: PCI device information struct
+ * @ent: entry in igc_pci_tbl
+ *
+ * Returns 0 on success, negative on failure
+ *
+ * igc_probe initializes an adapter identified by a pci_dev structure.
+ * The OS initialization, configuring the adapter private structure,
+ * and a hardware reset occur.
+ */
+static int igc_probe(struct pci_dev *pdev,
+		     const struct pci_device_id *ent)
+{
+	int err, pci_using_dac;
+
+	err = pci_enable_device_mem(pdev);
+	if (err)
+		return err;
+
+	pci_using_dac = 0;
+	err = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
+	if (!err) {
+		err = dma_set_coherent_mask(&pdev->dev,
+					    DMA_BIT_MASK(64));
+		if (!err)
+			pci_using_dac = 1;
+	} else {
+		err = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
+		if (err) {
+			err = dma_set_coherent_mask(&pdev->dev,
+						    DMA_BIT_MASK(32));
+			if (err) {
+				IGC_ERR("Wrong DMA configuration, aborting\n");
+				goto err_dma;
+			}
+		}
+	}
+
+	err = pci_request_selected_regions(pdev,
+					   pci_select_bars(pdev,
+							   IORESOURCE_MEM),
+					   igc_driver_name);
+	if (err)
+		goto err_pci_reg;
+
+	pci_set_master(pdev);
+	err = pci_save_state(pdev);
+	return 0;
+
+err_pci_reg:
+err_dma:
+	pci_disable_device(pdev);
+	return err;
+}
+
+/**
+ * igc_remove - Device Removal Routine
+ * @pdev: PCI device information struct
+ *
+ * igc_remove is called by the PCI subsystem to alert the driver
+ * that it should release a PCI device.  This could be caused by a
+ * Hot-Plug event, or because the driver is going to be removed from
+ * memory.
+ */
+static void igc_remove(struct pci_dev *pdev)
+{
+	pci_release_selected_regions(pdev,
+				     pci_select_bars(pdev, IORESOURCE_MEM));
+
+	pci_disable_device(pdev);
+}
+
+static struct pci_driver igc_driver = {
+	.name     = igc_driver_name,
+	.id_table = igc_pci_tbl,
+	.probe    = igc_probe,
+	.remove   = igc_remove,
+};
+
+/**
+ * igc_init_module - Driver Registration Routine
+ *
+ * igc_init_module is the first routine called when the driver is
+ * loaded. All it does is register with the PCI subsystem.
+ */
+static int __init igc_init_module(void)
+{
+	int ret;
+
+	pr_info("%s - version %s\n",
+		igc_driver_string, igc_driver_version);
+
+	pr_info("%s\n", igc_copyright);
+
+	ret = pci_register_driver(&igc_driver);
+	return ret;
+}
+
+module_init(igc_init_module);
+
+/**
+ * igc_exit_module - Driver Exit Cleanup Routine
+ *
+ * igc_exit_module is called just before the driver is removed
+ * from memory.
+ */
+static void __exit igc_exit_module(void)
+{
+	pci_unregister_driver(&igc_driver);
+}
+
+module_exit(igc_exit_module);
+/* igc_main.c */