// SPDX-License-Identifier: GPL-2.0
/* Copyright (c)  2018 Intel Corporation */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/if_vlan.h>
#include <linux/aer.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"

static int debug = -1;

MODULE_AUTHOR("Intel Corporation, <linux.nics@intel.com>");
MODULE_DESCRIPTION(DRV_SUMMARY);
MODULE_LICENSE("GPL v2");
MODULE_VERSION(DRV_VERSION);
module_param(debug, int, 0);
MODULE_PARM_DESC(debug, "Debug level (0=none,...,16=all)");

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);

/* forward declaration */
static int igc_sw_init(struct igc_adapter *);
static void igc_configure(struct igc_adapter *adapter);
static void igc_power_down_link(struct igc_adapter *adapter);
static void igc_set_default_mac_filter(struct igc_adapter *adapter);

static void igc_reset(struct igc_adapter *adapter)
{
	if (!netif_running(adapter->netdev))
		igc_power_down_link(adapter);
}

/**
 * igc_power_up_link - Power up the phy/serdes link
 * @adapter: address of board private structure
 */
static void igc_power_up_link(struct igc_adapter *adapter)
{
}

/**
 * igc_power_down_link - Power down the phy/serdes link
 * @adapter: address of board private structure
 */
static void igc_power_down_link(struct igc_adapter *adapter)
{
}

/**
 * igc_release_hw_control - release control of the h/w to f/w
 * @adapter: address of board private structure
 *
 * igc_release_hw_control resets CTRL_EXT:DRV_LOAD bit.
 * For ASF and Pass Through versions of f/w this means that the
 * driver is no longer loaded.
 */
static void igc_release_hw_control(struct igc_adapter *adapter)
{
	struct igc_hw *hw = &adapter->hw;
	u32 ctrl_ext;

	/* Let firmware take over control of h/w */
	ctrl_ext = rd32(IGC_CTRL_EXT);
	wr32(IGC_CTRL_EXT,
	     ctrl_ext & ~IGC_CTRL_EXT_DRV_LOAD);
}

/**
 * igc_get_hw_control - get control of the h/w from f/w
 * @adapter: address of board private structure
 *
 * igc_get_hw_control sets CTRL_EXT:DRV_LOAD bit.
 * For ASF and Pass Through versions of f/w this means that
 * the driver is loaded.
 */
static void igc_get_hw_control(struct igc_adapter *adapter)
{
	struct igc_hw *hw = &adapter->hw;
	u32 ctrl_ext;

	/* Let firmware know the driver has taken over */
	ctrl_ext = rd32(IGC_CTRL_EXT);
	wr32(IGC_CTRL_EXT,
	     ctrl_ext | IGC_CTRL_EXT_DRV_LOAD);
}

/**
 * igc_set_mac - Change the Ethernet Address of the NIC
 * @netdev: network interface device structure
 * @p: pointer to an address structure
 *
 * Returns 0 on success, negative on failure
 */
static int igc_set_mac(struct net_device *netdev, void *p)
{
	struct igc_adapter *adapter = netdev_priv(netdev);
	struct igc_hw *hw = &adapter->hw;
	struct sockaddr *addr = p;

	if (!is_valid_ether_addr(addr->sa_data))
		return -EADDRNOTAVAIL;

	memcpy(netdev->dev_addr, addr->sa_data, netdev->addr_len);
	memcpy(hw->mac.addr, addr->sa_data, netdev->addr_len);

	/* set the correct pool for the new PF MAC address in entry 0 */
	igc_set_default_mac_filter(adapter);

	return 0;
}

static netdev_tx_t igc_xmit_frame(struct sk_buff *skb,
				  struct net_device *netdev)
{
	dev_kfree_skb_any(skb);
	return NETDEV_TX_OK;
}

/**
 * igc_ioctl - I/O control method
 * @netdev: network interface device structure
 * @ifreq: frequency
 * @cmd: command
 */
static int igc_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
{
	switch (cmd) {
	default:
		return -EOPNOTSUPP;
	}
}

/**
 * igc_up - Open the interface and prepare it to handle traffic
 * @adapter: board private structure
 */
static void igc_up(struct igc_adapter *adapter)
{
	int i = 0;

	/* hardware has been reset, we need to reload some things */
	igc_configure(adapter);

	clear_bit(__IGC_DOWN, &adapter->state);

	for (i = 0; i < adapter->num_q_vectors; i++)
		napi_enable(&adapter->q_vector[i]->napi);
}

/**
 * igc_update_stats - Update the board statistics counters
 * @adapter: board private structure
 */
static void igc_update_stats(struct igc_adapter *adapter)
{
}

/**
 * igc_down - Close the interface
 * @adapter: board private structure
 */
static void igc_down(struct igc_adapter *adapter)
{
	struct net_device *netdev = adapter->netdev;
	int i = 0;

	set_bit(__IGC_DOWN, &adapter->state);

	/* set trans_start so we don't get spurious watchdogs during reset */
	netif_trans_update(netdev);

	netif_carrier_off(netdev);
	netif_tx_stop_all_queues(netdev);

	for (i = 0; i < adapter->num_q_vectors; i++)
		napi_disable(&adapter->q_vector[i]->napi);

	adapter->link_speed = 0;
	adapter->link_duplex = 0;
}

/**
 * igc_change_mtu - Change the Maximum Transfer Unit
 * @netdev: network interface device structure
 * @new_mtu: new value for maximum frame size
 *
 * Returns 0 on success, negative on failure
 */
static int igc_change_mtu(struct net_device *netdev, int new_mtu)
{
	int max_frame = new_mtu + ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN;
	struct igc_adapter *adapter = netdev_priv(netdev);
	struct pci_dev *pdev = adapter->pdev;

	/* adjust max frame to be at least the size of a standard frame */
	if (max_frame < (ETH_FRAME_LEN + ETH_FCS_LEN))
		max_frame = ETH_FRAME_LEN + ETH_FCS_LEN;

	while (test_and_set_bit(__IGC_RESETTING, &adapter->state))
		usleep_range(1000, 2000);

	/* igc_down has a dependency on max_frame_size */
	adapter->max_frame_size = max_frame;

	if (netif_running(netdev))
		igc_down(adapter);

	dev_info(&pdev->dev, "changing MTU from %d to %d\n",
		 netdev->mtu, new_mtu);
	netdev->mtu = new_mtu;

	if (netif_running(netdev))
		igc_up(adapter);
	else
		igc_reset(adapter);

	clear_bit(__IGC_RESETTING, &adapter->state);

	return 0;
}

/**
 * igc_get_stats - Get System Network Statistics
 * @netdev: network interface device structure
 *
 * Returns the address of the device statistics structure.
 * The statistics are updated here and also from the timer callback.
 */
static struct net_device_stats *igc_get_stats(struct net_device *netdev)
{
	struct igc_adapter *adapter = netdev_priv(netdev);

	if (!test_bit(__IGC_RESETTING, &adapter->state))
		igc_update_stats(adapter);

	/* only return the current stats */
	return &netdev->stats;
}

/**
 * igc_configure - configure the hardware for RX and TX
 * @adapter: private board structure
 */
static void igc_configure(struct igc_adapter *adapter)
{
	igc_get_hw_control(adapter);
}

/**
 * igc_rar_set_index - Sync RAL[index] and RAH[index] registers with MAC table
 * @adapter: Pointer to adapter structure
 * @index: Index of the RAR entry which need to be synced with MAC table
 */
static void igc_rar_set_index(struct igc_adapter *adapter, u32 index)
{
	u8 *addr = adapter->mac_table[index].addr;
	struct igc_hw *hw = &adapter->hw;
	u32 rar_low, rar_high;

	/* HW expects these to be in network order when they are plugged
	 * into the registers which are little endian.  In order to guarantee
	 * that ordering we need to do an leXX_to_cpup here in order to be
	 * ready for the byteswap that occurs with writel
	 */
	rar_low = le32_to_cpup((__le32 *)(addr));
	rar_high = le16_to_cpup((__le16 *)(addr + 4));

	/* Indicate to hardware the Address is Valid. */
	if (adapter->mac_table[index].state & IGC_MAC_STATE_IN_USE) {
		if (is_valid_ether_addr(addr))
			rar_high |= IGC_RAH_AV;

		rar_high |= IGC_RAH_POOL_1 <<
			adapter->mac_table[index].queue;
	}

	wr32(IGC_RAL(index), rar_low);
	wrfl();
	wr32(IGC_RAH(index), rar_high);
	wrfl();
}

/* Set default MAC address for the PF in the first RAR entry */
static void igc_set_default_mac_filter(struct igc_adapter *adapter)
{
	struct igc_mac_addr *mac_table = &adapter->mac_table[0];

	ether_addr_copy(mac_table->addr, adapter->hw.mac.addr);
	mac_table->state = IGC_MAC_STATE_DEFAULT | IGC_MAC_STATE_IN_USE;

	igc_rar_set_index(adapter, 0);
}

/**
 * igc_open - Called when a network interface is made active
 * @netdev: network interface device structure
 *
 * Returns 0 on success, negative value on failure
 *
 * The open entry point is called when a network interface is made
 * active by the system (IFF_UP).  At this point all resources needed
 * for transmit and receive operations are allocated, the interrupt
 * handler is registered with the OS, the watchdog timer is started,
 * and the stack is notified that the interface is ready.
 */
static int __igc_open(struct net_device *netdev, bool resuming)
{
	struct igc_adapter *adapter = netdev_priv(netdev);
	struct igc_hw *hw = &adapter->hw;
	int i = 0;

	/* disallow open during test */

	if (test_bit(__IGC_TESTING, &adapter->state)) {
		WARN_ON(resuming);
		return -EBUSY;
	}

	netif_carrier_off(netdev);

	igc_power_up_link(adapter);

	igc_configure(adapter);

	clear_bit(__IGC_DOWN, &adapter->state);

	for (i = 0; i < adapter->num_q_vectors; i++)
		napi_enable(&adapter->q_vector[i]->napi);

	/* start the watchdog. */
	hw->mac.get_link_status = 1;

	return IGC_SUCCESS;
}

static int igc_open(struct net_device *netdev)
{
	return __igc_open(netdev, false);
}

/**
 * igc_close - Disables a network interface
 * @netdev: network interface device structure
 *
 * Returns 0, this is not allowed to fail
 *
 * The close entry point is called when an interface is de-activated
 * by the OS.  The hardware is still under the driver's control, but
 * needs to be disabled.  A global MAC reset is issued to stop the
 * hardware, and all transmit and receive resources are freed.
 */
static int __igc_close(struct net_device *netdev, bool suspending)
{
	struct igc_adapter *adapter = netdev_priv(netdev);

	WARN_ON(test_bit(__IGC_RESETTING, &adapter->state));

	igc_down(adapter);

	igc_release_hw_control(adapter);

	return 0;
}

static int igc_close(struct net_device *netdev)
{
	if (netif_device_present(netdev) || netdev->dismantle)
		return __igc_close(netdev, false);
	return 0;
}

static const struct net_device_ops igc_netdev_ops = {
	.ndo_open		= igc_open,
	.ndo_stop		= igc_close,
	.ndo_start_xmit		= igc_xmit_frame,
	.ndo_set_mac_address	= igc_set_mac,
	.ndo_change_mtu		= igc_change_mtu,
	.ndo_get_stats		= igc_get_stats,
	.ndo_do_ioctl		= igc_ioctl,
};

/* PCIe configuration access */
void igc_read_pci_cfg(struct igc_hw *hw, u32 reg, u16 *value)
{
	struct igc_adapter *adapter = hw->back;

	pci_read_config_word(adapter->pdev, reg, value);
}

void igc_write_pci_cfg(struct igc_hw *hw, u32 reg, u16 *value)
{
	struct igc_adapter *adapter = hw->back;

	pci_write_config_word(adapter->pdev, reg, *value);
}

s32 igc_read_pcie_cap_reg(struct igc_hw *hw, u32 reg, u16 *value)
{
	struct igc_adapter *adapter = hw->back;
	u16 cap_offset;

	cap_offset = pci_find_capability(adapter->pdev, PCI_CAP_ID_EXP);
	if (!cap_offset)
		return -IGC_ERR_CONFIG;

	pci_read_config_word(adapter->pdev, cap_offset + reg, value);

	return IGC_SUCCESS;
}

s32 igc_write_pcie_cap_reg(struct igc_hw *hw, u32 reg, u16 *value)
{
	struct igc_adapter *adapter = hw->back;
	u16 cap_offset;

	cap_offset = pci_find_capability(adapter->pdev, PCI_CAP_ID_EXP);
	if (!cap_offset)
		return -IGC_ERR_CONFIG;

	pci_write_config_word(adapter->pdev, cap_offset + reg, *value);

	return IGC_SUCCESS;
}

u32 igc_rd32(struct igc_hw *hw, u32 reg)
{
	struct igc_adapter *igc = container_of(hw, struct igc_adapter, hw);
	u8 __iomem *hw_addr = READ_ONCE(hw->hw_addr);
	u32 value = 0;

	if (IGC_REMOVED(hw_addr))
		return ~value;

	value = readl(&hw_addr[reg]);

	/* reads should not return all F's */
	if (!(~value) && (!reg || !(~readl(hw_addr)))) {
		struct net_device *netdev = igc->netdev;

		hw->hw_addr = NULL;
		netif_device_detach(netdev);
		netdev_err(netdev, "PCIe link lost, device now detached\n");
	}

	return value;
}

/**
 * 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)
{
	struct igc_adapter *adapter;
	struct net_device *netdev;
	struct igc_hw *hw;
	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_enable_pcie_error_reporting(pdev);

	pci_set_master(pdev);

	err = -ENOMEM;
	netdev = alloc_etherdev_mq(sizeof(struct igc_adapter),
				   IGC_MAX_TX_QUEUES);

	if (!netdev)
		goto err_alloc_etherdev;

	SET_NETDEV_DEV(netdev, &pdev->dev);

	pci_set_drvdata(pdev, netdev);
	adapter = netdev_priv(netdev);
	adapter->netdev = netdev;
	adapter->pdev = pdev;
	hw = &adapter->hw;
	hw->back = adapter;
	adapter->port_num = hw->bus.func;
	adapter->msg_enable = GENMASK(debug - 1, 0);

	err = pci_save_state(pdev);
	if (err)
		goto err_ioremap;

	err = -EIO;
	adapter->io_addr = ioremap(pci_resource_start(pdev, 0),
				   pci_resource_len(pdev, 0));
	if (!adapter->io_addr)
		goto err_ioremap;

	/* hw->hw_addr can be zeroed, so use adapter->io_addr for unmap */
	hw->hw_addr = adapter->io_addr;

	netdev->netdev_ops = &igc_netdev_ops;

	netdev->watchdog_timeo = 5 * HZ;

	netdev->mem_start = pci_resource_start(pdev, 0);
	netdev->mem_end = pci_resource_end(pdev, 0);

	/* PCI config space info */
	hw->vendor_id = pdev->vendor;
	hw->device_id = pdev->device;
	hw->revision_id = pdev->revision;
	hw->subsystem_vendor_id = pdev->subsystem_vendor;
	hw->subsystem_device_id = pdev->subsystem_device;

	/* setup the private structure */
	err = igc_sw_init(adapter);
	if (err)
		goto err_sw_init;

	/* MTU range: 68 - 9216 */
	netdev->min_mtu = ETH_MIN_MTU;
	netdev->max_mtu = MAX_STD_JUMBO_FRAME_SIZE;

	/* reset the hardware with the new settings */
	igc_reset(adapter);

	/* let the f/w know that the h/w is now under the control of the
	 * driver.
	 */
	igc_get_hw_control(adapter);

	strncpy(netdev->name, "eth%d", IFNAMSIZ);
	err = register_netdev(netdev);
	if (err)
		goto err_register;

	 /* carrier off reporting is important to ethtool even BEFORE open */
	netif_carrier_off(netdev);

	/* print pcie link status and MAC address */
	pcie_print_link_status(pdev);
	netdev_info(netdev, "MAC: %pM\n", netdev->dev_addr);

	return 0;

err_register:
	igc_release_hw_control(adapter);
err_sw_init:
err_ioremap:
	free_netdev(netdev);
err_alloc_etherdev:
	pci_release_selected_regions(pdev,
				     pci_select_bars(pdev, IORESOURCE_MEM));
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)
{
	struct net_device *netdev = pci_get_drvdata(pdev);
	struct igc_adapter *adapter = netdev_priv(netdev);

	set_bit(__IGC_DOWN, &adapter->state);
	flush_scheduled_work();

	/* Release control of h/w to f/w.  If f/w is AMT enabled, this
	 * would have already happened in close and is redundant.
	 */
	igc_release_hw_control(adapter);
	unregister_netdev(netdev);

	pci_release_selected_regions(pdev,
				     pci_select_bars(pdev, IORESOURCE_MEM));

	free_netdev(netdev);
	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_sw_init - Initialize general software structures (struct igc_adapter)
 * @adapter: board private structure to initialize
 *
 * igc_sw_init initializes the Adapter private data structure.
 * Fields are initialized based on PCI device information and
 * OS network device settings (MTU size).
 */
static int igc_sw_init(struct igc_adapter *adapter)
{
	struct net_device *netdev = adapter->netdev;
	struct pci_dev *pdev = adapter->pdev;
	struct igc_hw *hw = &adapter->hw;

	/* PCI config space info */

	hw->vendor_id = pdev->vendor;
	hw->device_id = pdev->device;
	hw->subsystem_vendor_id = pdev->subsystem_vendor;
	hw->subsystem_device_id = pdev->subsystem_device;

	pci_read_config_byte(pdev, PCI_REVISION_ID, &hw->revision_id);

	pci_read_config_word(pdev, PCI_COMMAND, &hw->bus.pci_cmd_word);

	/* adjust max frame to be at least the size of a standard frame */
	adapter->max_frame_size = netdev->mtu + ETH_HLEN + ETH_FCS_LEN +
					VLAN_HLEN;

	set_bit(__IGC_DOWN, &adapter->state);

	return 0;
}

/**
 * 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 */