// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 1999 - 2006 Intel Corporation. */

#include "e1000.h"
#include <net/ip6_checksum.h>
#include <linux/io.h>
#include <linux/prefetch.h>
#include <linux/bitops.h>
#include <linux/if_vlan.h>

char e1000_driver_name[] = "e1000";
static char e1000_driver_string[] = "Intel(R) PRO/1000 Network Driver";
static const char e1000_copyright[] = "Copyright (c) 1999-2006 Intel Corporation.";

/* e1000_pci_tbl - PCI Device ID Table
 *
 * Last entry must be all 0s
 *
 * Macro expands to...
 *   {PCI_DEVICE(PCI_VENDOR_ID_INTEL, device_id)}
 */
static const struct pci_device_id e1000_pci_tbl[] = {
        INTEL_E1000_ETHERNET_DEVICE(0x1000),
        INTEL_E1000_ETHERNET_DEVICE(0x1001),
        INTEL_E1000_ETHERNET_DEVICE(0x1004),
        INTEL_E1000_ETHERNET_DEVICE(0x1008),
        INTEL_E1000_ETHERNET_DEVICE(0x1009),
        INTEL_E1000_ETHERNET_DEVICE(0x100C),
        INTEL_E1000_ETHERNET_DEVICE(0x100D),
        INTEL_E1000_ETHERNET_DEVICE(0x100E),
        INTEL_E1000_ETHERNET_DEVICE(0x100F),
        INTEL_E1000_ETHERNET_DEVICE(0x1010),
        INTEL_E1000_ETHERNET_DEVICE(0x1011),
        INTEL_E1000_ETHERNET_DEVICE(0x1012),
        INTEL_E1000_ETHERNET_DEVICE(0x1013),
        INTEL_E1000_ETHERNET_DEVICE(0x1014),
        INTEL_E1000_ETHERNET_DEVICE(0x1015),
        INTEL_E1000_ETHERNET_DEVICE(0x1016),
        INTEL_E1000_ETHERNET_DEVICE(0x1017),
        INTEL_E1000_ETHERNET_DEVICE(0x1018),
        INTEL_E1000_ETHERNET_DEVICE(0x1019),
        INTEL_E1000_ETHERNET_DEVICE(0x101A),
        INTEL_E1000_ETHERNET_DEVICE(0x101D),
        INTEL_E1000_ETHERNET_DEVICE(0x101E),
        INTEL_E1000_ETHERNET_DEVICE(0x1026),
        INTEL_E1000_ETHERNET_DEVICE(0x1027),
        INTEL_E1000_ETHERNET_DEVICE(0x1028),
        INTEL_E1000_ETHERNET_DEVICE(0x1075),
        INTEL_E1000_ETHERNET_DEVICE(0x1076),
        INTEL_E1000_ETHERNET_DEVICE(0x1077),
        INTEL_E1000_ETHERNET_DEVICE(0x1078),
        INTEL_E1000_ETHERNET_DEVICE(0x1079),
        INTEL_E1000_ETHERNET_DEVICE(0x107A),
        INTEL_E1000_ETHERNET_DEVICE(0x107B),
        INTEL_E1000_ETHERNET_DEVICE(0x107C),
        INTEL_E1000_ETHERNET_DEVICE(0x108A),
        INTEL_E1000_ETHERNET_DEVICE(0x1099),
        INTEL_E1000_ETHERNET_DEVICE(0x10B5),
        INTEL_E1000_ETHERNET_DEVICE(0x2E6E),
        /* required last entry */
        {0,}
};

MODULE_DEVICE_TABLE(pci, e1000_pci_tbl);

int e1000_up(struct e1000_adapter *adapter);
void e1000_down(struct e1000_adapter *adapter);
void e1000_reinit_locked(struct e1000_adapter *adapter);
void e1000_reset(struct e1000_adapter *adapter);
int e1000_setup_all_tx_resources(struct e1000_adapter *adapter);
int e1000_setup_all_rx_resources(struct e1000_adapter *adapter);
void e1000_free_all_tx_resources(struct e1000_adapter *adapter);
void e1000_free_all_rx_resources(struct e1000_adapter *adapter);
static int e1000_setup_tx_resources(struct e1000_adapter *adapter,
                                    struct e1000_tx_ring *txdr);
static int e1000_setup_rx_resources(struct e1000_adapter *adapter,
                                    struct e1000_rx_ring *rxdr);
static void e1000_free_tx_resources(struct e1000_adapter *adapter,
                                    struct e1000_tx_ring *tx_ring);
static void e1000_free_rx_resources(struct e1000_adapter *adapter,
                                    struct e1000_rx_ring *rx_ring);
void e1000_update_stats(struct e1000_adapter *adapter);

static int e1000_init_module(void);
static void e1000_exit_module(void);
static int e1000_probe(struct pci_dev *pdev, const struct pci_device_id *ent);
static void e1000_remove(struct pci_dev *pdev);
static int e1000_alloc_queues(struct e1000_adapter *adapter);
static int e1000_sw_init(struct e1000_adapter *adapter);
int e1000_open(struct net_device *netdev);
int e1000_close(struct net_device *netdev);
static void e1000_configure_tx(struct e1000_adapter *adapter);
static void e1000_configure_rx(struct e1000_adapter *adapter);
static void e1000_setup_rctl(struct e1000_adapter *adapter);
static void e1000_clean_all_tx_rings(struct e1000_adapter *adapter);
static void e1000_clean_all_rx_rings(struct e1000_adapter *adapter);
static void e1000_clean_tx_ring(struct e1000_adapter *adapter,
                                struct e1000_tx_ring *tx_ring);
static void e1000_clean_rx_ring(struct e1000_adapter *adapter,
                                struct e1000_rx_ring *rx_ring);
static void e1000_set_rx_mode(struct net_device *netdev);
static void e1000_update_phy_info_task(struct work_struct *work);
static void e1000_watchdog(struct work_struct *work);
static void e1000_82547_tx_fifo_stall_task(struct work_struct *work);
static netdev_tx_t e1000_xmit_frame(struct sk_buff *skb,
                                    struct net_device *netdev);
static int e1000_change_mtu(struct net_device *netdev, int new_mtu);
static int e1000_set_mac(struct net_device *netdev, void *p);
static irqreturn_t e1000_intr(int irq, void *data);
static bool e1000_clean_tx_irq(struct e1000_adapter *adapter,
                               struct e1000_tx_ring *tx_ring);
static int e1000_clean(struct napi_struct *napi, int budget);
static bool e1000_clean_rx_irq(struct e1000_adapter *adapter,
                               struct e1000_rx_ring *rx_ring,
                               int *work_done, int work_to_do);
static bool e1000_clean_jumbo_rx_irq(struct e1000_adapter *adapter,
                                     struct e1000_rx_ring *rx_ring,
                                     int *work_done, int work_to_do);
static void e1000_alloc_dummy_rx_buffers(struct e1000_adapter *adapter,
                                         struct e1000_rx_ring *rx_ring,
                                         int cleaned_count)
{
}
static void e1000_alloc_rx_buffers(struct e1000_adapter *adapter,
                                   struct e1000_rx_ring *rx_ring,
                                   int cleaned_count);
static void e1000_alloc_jumbo_rx_buffers(struct e1000_adapter *adapter,
                                         struct e1000_rx_ring *rx_ring,
                                         int cleaned_count);
static int e1000_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd);
static int e1000_mii_ioctl(struct net_device *netdev, struct ifreq *ifr,
                           int cmd);
static void e1000_enter_82542_rst(struct e1000_adapter *adapter);
static void e1000_leave_82542_rst(struct e1000_adapter *adapter);
static void e1000_tx_timeout(struct net_device *dev, unsigned int txqueue);
static void e1000_reset_task(struct work_struct *work);
static void e1000_smartspeed(struct e1000_adapter *adapter);
static int e1000_82547_fifo_workaround(struct e1000_adapter *adapter,
                                       struct sk_buff *skb);

static bool e1000_vlan_used(struct e1000_adapter *adapter);
static void e1000_vlan_mode(struct net_device *netdev,
                            netdev_features_t features);
static void e1000_vlan_filter_on_off(struct e1000_adapter *adapter,
                                     bool filter_on);
static int e1000_vlan_rx_add_vid(struct net_device *netdev,
                                 __be16 proto, u16 vid);
static int e1000_vlan_rx_kill_vid(struct net_device *netdev,
                                  __be16 proto, u16 vid);
static void e1000_restore_vlan(struct e1000_adapter *adapter);

static int __maybe_unused e1000_suspend(struct device *dev);
static int __maybe_unused e1000_resume(struct device *dev);
static void e1000_shutdown(struct pci_dev *pdev);

#ifdef CONFIG_NET_POLL_CONTROLLER
/* for netdump / net console */
static void e1000_netpoll (struct net_device *netdev);
#endif

#define COPYBREAK_DEFAULT 256
static unsigned int copybreak __read_mostly = COPYBREAK_DEFAULT;
module_param(copybreak, uint, 0644);
MODULE_PARM_DESC(copybreak,
        "Maximum size of packet that is copied to a new buffer on receive");

static pci_ers_result_t e1000_io_error_detected(struct pci_dev *pdev,
                                                pci_channel_state_t state);
static pci_ers_result_t e1000_io_slot_reset(struct pci_dev *pdev);
static void e1000_io_resume(struct pci_dev *pdev);

static const struct pci_error_handlers e1000_err_handler = {
        .error_detected = e1000_io_error_detected,
        .slot_reset = e1000_io_slot_reset,
        .resume = e1000_io_resume,
};

static SIMPLE_DEV_PM_OPS(e1000_pm_ops, e1000_suspend, e1000_resume);

static struct pci_driver e1000_driver = {
        .name     = e1000_driver_name,
        .id_table = e1000_pci_tbl,
        .probe    = e1000_probe,
        .remove   = e1000_remove,
        .driver = {
                .pm = &e1000_pm_ops,
        },
        .shutdown = e1000_shutdown,
        .err_handler = &e1000_err_handler
};

MODULE_AUTHOR("Intel Corporation, <linux.nics@intel.com>");
MODULE_DESCRIPTION("Intel(R) PRO/1000 Network Driver");
MODULE_LICENSE("GPL v2");

#define DEFAULT_MSG_ENABLE (NETIF_MSG_DRV|NETIF_MSG_PROBE|NETIF_MSG_LINK)
static int debug = -1;
module_param(debug, int, 0);
MODULE_PARM_DESC(debug, "Debug level (0=none,...,16=all)");

/**
 * e1000_get_hw_dev - helper function for getting netdev
 * @hw: pointer to HW struct
 *
 * return device used by hardware layer to print debugging information
 *
 **/
struct net_device *e1000_get_hw_dev(struct e1000_hw *hw)
{
        struct e1000_adapter *adapter = hw->back;
        return adapter->netdev;
}

/**
 * e1000_init_module - Driver Registration Routine
 *
 * e1000_init_module is the first routine called when the driver is
 * loaded. All it does is register with the PCI subsystem.
 **/
static int __init e1000_init_module(void)
{
        int ret;
        pr_info("%s\n", e1000_driver_string);

        pr_info("%s\n", e1000_copyright);

        ret = pci_register_driver(&e1000_driver);
        if (copybreak != COPYBREAK_DEFAULT) {
                if (copybreak == 0)
                        pr_info("copybreak disabled\n");
                else
                        pr_info("copybreak enabled for "
                                   "packets <= %u bytes\n", copybreak);
        }
        return ret;
}

module_init(e1000_init_module);

/**
 * e1000_exit_module - Driver Exit Cleanup Routine
 *
 * e1000_exit_module is called just before the driver is removed
 * from memory.
 **/
static void __exit e1000_exit_module(void)
{
        pci_unregister_driver(&e1000_driver);
}

module_exit(e1000_exit_module);

static int e1000_request_irq(struct e1000_adapter *adapter)
{
        struct net_device *netdev = adapter->netdev;
        irq_handler_t handler = e1000_intr;
        int irq_flags = IRQF_SHARED;
        int err;

        err = request_irq(adapter->pdev->irq, handler, irq_flags, netdev->name,
                          netdev);
        if (err) {
                e_err(probe, "Unable to allocate interrupt Error: %d\n", err);
        }

        return err;
}

static void e1000_free_irq(struct e1000_adapter *adapter)
{
        struct net_device *netdev = adapter->netdev;

        free_irq(adapter->pdev->irq, netdev);
}

/**
 * e1000_irq_disable - Mask off interrupt generation on the NIC
 * @adapter: board private structure
 **/
static void e1000_irq_disable(struct e1000_adapter *adapter)
{
        struct e1000_hw *hw = &adapter->hw;

        ew32(IMC, ~0);
        E1000_WRITE_FLUSH();
        synchronize_irq(adapter->pdev->irq);
}

/**
 * e1000_irq_enable - Enable default interrupt generation settings
 * @adapter: board private structure
 **/
static void e1000_irq_enable(struct e1000_adapter *adapter)
{
        struct e1000_hw *hw = &adapter->hw;

        ew32(IMS, IMS_ENABLE_MASK);
        E1000_WRITE_FLUSH();
}

static void e1000_update_mng_vlan(struct e1000_adapter *adapter)
{
        struct e1000_hw *hw = &adapter->hw;
        struct net_device *netdev = adapter->netdev;
        u16 vid = hw->mng_cookie.vlan_id;
        u16 old_vid = adapter->mng_vlan_id;

        if (!e1000_vlan_used(adapter))
                return;

        if (!test_bit(vid, adapter->active_vlans)) {
                if (hw->mng_cookie.status &
                    E1000_MNG_DHCP_COOKIE_STATUS_VLAN_SUPPORT) {
                        e1000_vlan_rx_add_vid(netdev, htons(ETH_P_8021Q), vid);
                        adapter->mng_vlan_id = vid;
                } else {
                        adapter->mng_vlan_id = E1000_MNG_VLAN_NONE;
                }
                if ((old_vid != (u16)E1000_MNG_VLAN_NONE) &&
                    (vid != old_vid) &&
                    !test_bit(old_vid, adapter->active_vlans))
                        e1000_vlan_rx_kill_vid(netdev, htons(ETH_P_8021Q),
                                               old_vid);
        } else {
                adapter->mng_vlan_id = vid;
        }
}

static void e1000_init_manageability(struct e1000_adapter *adapter)
{
        struct e1000_hw *hw = &adapter->hw;

        if (adapter->en_mng_pt) {
                u32 manc = er32(MANC);

                /* disable hardware interception of ARP */
                manc &= ~(E1000_MANC_ARP_EN);

                ew32(MANC, manc);
        }
}

static void e1000_release_manageability(struct e1000_adapter *adapter)
{
        struct e1000_hw *hw = &adapter->hw;

        if (adapter->en_mng_pt) {
                u32 manc = er32(MANC);

                /* re-enable hardware interception of ARP */
                manc |= E1000_MANC_ARP_EN;

                ew32(MANC, manc);
        }
}

/**
 * e1000_configure - configure the hardware for RX and TX
 * @adapter: private board structure
 **/
static void e1000_configure(struct e1000_adapter *adapter)
{
        struct net_device *netdev = adapter->netdev;
        int i;

        e1000_set_rx_mode(netdev);

        e1000_restore_vlan(adapter);
        e1000_init_manageability(adapter);

        e1000_configure_tx(adapter);
        e1000_setup_rctl(adapter);
        e1000_configure_rx(adapter);
        /* call E1000_DESC_UNUSED which always leaves
         * at least 1 descriptor unused to make sure
         * next_to_use != next_to_clean
         */
        for (i = 0; i < adapter->num_rx_queues; i++) {
                struct e1000_rx_ring *ring = &adapter->rx_ring[i];
                adapter->alloc_rx_buf(adapter, ring,
                                      E1000_DESC_UNUSED(ring));
        }
}

int e1000_up(struct e1000_adapter *adapter)
{
        struct e1000_hw *hw = &adapter->hw;

        /* hardware has been reset, we need to reload some things */
        e1000_configure(adapter);

        clear_bit(__E1000_DOWN, &adapter->flags);

        napi_enable(&adapter->napi);

        e1000_irq_enable(adapter);

        netif_wake_queue(adapter->netdev);

        /* fire a link change interrupt to start the watchdog */
        ew32(ICS, E1000_ICS_LSC);
        return 0;
}

/**
 * e1000_power_up_phy - restore link in case the phy was powered down
 * @adapter: address of board private structure
 *
 * The phy may be powered down to save power and turn off link when the
 * driver is unloaded and wake on lan is not enabled (among others)
 * *** this routine MUST be followed by a call to e1000_reset ***
 **/
void e1000_power_up_phy(struct e1000_adapter *adapter)
{
        struct e1000_hw *hw = &adapter->hw;
        u16 mii_reg = 0;

        /* Just clear the power down bit to wake the phy back up */
        if (hw->media_type == e1000_media_type_copper) {
                /* according to the manual, the phy will retain its
                 * settings across a power-down/up cycle
                 */
                e1000_read_phy_reg(hw, PHY_CTRL, &mii_reg);
                mii_reg &= ~MII_CR_POWER_DOWN;
                e1000_write_phy_reg(hw, PHY_CTRL, mii_reg);
        }
}

static void e1000_power_down_phy(struct e1000_adapter *adapter)
{
        struct e1000_hw *hw = &adapter->hw;

        /* Power down the PHY so no link is implied when interface is down *
         * The PHY cannot be powered down if any of the following is true *
         * (a) WoL is enabled
         * (b) AMT is active
         * (c) SoL/IDER session is active
         */
        if (!adapter->wol && hw->mac_type >= e1000_82540 &&
           hw->media_type == e1000_media_type_copper) {
                u16 mii_reg = 0;

                switch (hw->mac_type) {
                case e1000_82540:
                case e1000_82545:
                case e1000_82545_rev_3:
                case e1000_82546:
                case e1000_ce4100:
                case e1000_82546_rev_3:
                case e1000_82541:
                case e1000_82541_rev_2:
                case e1000_82547:
                case e1000_82547_rev_2:
                        if (er32(MANC) & E1000_MANC_SMBUS_EN)
                                goto out;
                        break;
                default:
                        goto out;
                }
                e1000_read_phy_reg(hw, PHY_CTRL, &mii_reg);
                mii_reg |= MII_CR_POWER_DOWN;
                e1000_write_phy_reg(hw, PHY_CTRL, mii_reg);
                msleep(1);
        }
out:
        return;
}

static void e1000_down_and_stop(struct e1000_adapter *adapter)
{
        set_bit(__E1000_DOWN, &adapter->flags);

        cancel_delayed_work_sync(&adapter->watchdog_task);

        /*
         * Since the watchdog task can reschedule other tasks, we should cancel
         * it first, otherwise we can run into the situation when a work is
         * still running after the adapter has been turned down.
         */

        cancel_delayed_work_sync(&adapter->phy_info_task);
        cancel_delayed_work_sync(&adapter->fifo_stall_task);

        /* Only kill reset task if adapter is not resetting */
        if (!test_bit(__E1000_RESETTING, &adapter->flags))
                cancel_work_sync(&adapter->reset_task);
}

void e1000_down(struct e1000_adapter *adapter)
{
        struct e1000_hw *hw = &adapter->hw;
        struct net_device *netdev = adapter->netdev;
        u32 rctl, tctl;

        /* disable receives in the hardware */
        rctl = er32(RCTL);
        ew32(RCTL, rctl & ~E1000_RCTL_EN);
        /* flush and sleep below */

        netif_tx_disable(netdev);

        /* disable transmits in the hardware */
        tctl = er32(TCTL);
        tctl &= ~E1000_TCTL_EN;
        ew32(TCTL, tctl);
        /* flush both disables and wait for them to finish */
        E1000_WRITE_FLUSH();
        msleep(10);

        /* Set the carrier off after transmits have been disabled in the
         * hardware, to avoid race conditions with e1000_watchdog() (which
         * may be running concurrently to us, checking for the carrier
         * bit to decide whether it should enable transmits again). Such
         * a race condition would result into transmission being disabled
         * in the hardware until the next IFF_DOWN+IFF_UP cycle.
         */
        netif_carrier_off(netdev);

        napi_disable(&adapter->napi);

        e1000_irq_disable(adapter);

        /* Setting DOWN must be after irq_disable to prevent
         * a screaming interrupt.  Setting DOWN also prevents
         * tasks from rescheduling.
         */
        e1000_down_and_stop(adapter);

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

        e1000_reset(adapter);
        e1000_clean_all_tx_rings(adapter);
        e1000_clean_all_rx_rings(adapter);
}

void e1000_reinit_locked(struct e1000_adapter *adapter)
{
        while (test_and_set_bit(__E1000_RESETTING, &adapter->flags))
                msleep(1);

        /* only run the task if not already down */
        if (!test_bit(__E1000_DOWN, &adapter->flags)) {
                e1000_down(adapter);
                e1000_up(adapter);
        }

        clear_bit(__E1000_RESETTING, &adapter->flags);
}

void e1000_reset(struct e1000_adapter *adapter)
{
        struct e1000_hw *hw = &adapter->hw;
        u32 pba = 0, tx_space, min_tx_space, min_rx_space;
        bool legacy_pba_adjust = false;
        u16 hwm;

        /* Repartition Pba for greater than 9k mtu
         * To take effect CTRL.RST is required.
         */

        switch (hw->mac_type) {
        case e1000_82542_rev2_0:
        case e1000_82542_rev2_1:
        case e1000_82543:
        case e1000_82544:
        case e1000_82540:
        case e1000_82541:
        case e1000_82541_rev_2:
                legacy_pba_adjust = true;
                pba = E1000_PBA_48K;
                break;
        case e1000_82545:
        case e1000_82545_rev_3:
        case e1000_82546:
        case e1000_ce4100:
        case e1000_82546_rev_3:
                pba = E1000_PBA_48K;
                break;
        case e1000_82547:
        case e1000_82547_rev_2:
                legacy_pba_adjust = true;
                pba = E1000_PBA_30K;
                break;
        case e1000_undefined:
        case e1000_num_macs:
                break;
        }

        if (legacy_pba_adjust) {
                if (hw->max_frame_size > E1000_RXBUFFER_8192)
                        pba -= 8; /* allocate more FIFO for Tx */

                if (hw->mac_type == e1000_82547) {
                        adapter->tx_fifo_head = 0;
                        adapter->tx_head_addr = pba << E1000_TX_HEAD_ADDR_SHIFT;
                        adapter->tx_fifo_size =
                                (E1000_PBA_40K - pba) << E1000_PBA_BYTES_SHIFT;
                        atomic_set(&adapter->tx_fifo_stall, 0);
                }
        } else if (hw->max_frame_size >  ETH_FRAME_LEN + ETH_FCS_LEN) {
                /* adjust PBA for jumbo frames */
                ew32(PBA, pba);

                /* To maintain wire speed transmits, the Tx FIFO should be
                 * large enough to accommodate two full transmit packets,
                 * rounded up to the next 1KB and expressed in KB.  Likewise,
                 * the Rx FIFO should be large enough to accommodate at least
                 * one full receive packet and is similarly rounded up and
                 * expressed in KB.
                 */
                pba = er32(PBA);
                /* upper 16 bits has Tx packet buffer allocation size in KB */
                tx_space = pba >> 16;
                /* lower 16 bits has Rx packet buffer allocation size in KB */
                pba &= 0xffff;
                /* the Tx fifo also stores 16 bytes of information about the Tx
                 * but don't include ethernet FCS because hardware appends it
                 */
                min_tx_space = (hw->max_frame_size +
                                sizeof(struct e1000_tx_desc) -
                                ETH_FCS_LEN) * 2;
                min_tx_space = ALIGN(min_tx_space, 1024);
                min_tx_space >>= 10;
                /* software strips receive CRC, so leave room for it */
                min_rx_space = hw->max_frame_size;
                min_rx_space = ALIGN(min_rx_space, 1024);
                min_rx_space >>= 10;

                /* If current Tx allocation is less than the min Tx FIFO size,
                 * and the min Tx FIFO size is less than the current Rx FIFO
                 * allocation, take space away from current Rx allocation
                 */
                if (tx_space < min_tx_space &&
                    ((min_tx_space - tx_space) < pba)) {
                        pba = pba - (min_tx_space - tx_space);

                        /* PCI/PCIx hardware has PBA alignment constraints */
                        switch (hw->mac_type) {
                        case e1000_82545 ... e1000_82546_rev_3:
                                pba &= ~(E1000_PBA_8K - 1);
                                break;
                        default:
                                break;
                        }

                        /* if short on Rx space, Rx wins and must trump Tx
                         * adjustment or use Early Receive if available
                         */
                        if (pba < min_rx_space)
                                pba = min_rx_space;
                }
        }

        ew32(PBA, pba);

        /* flow control settings:
         * The high water mark must be low enough to fit one full frame
         * (or the size used for early receive) above it in the Rx FIFO.
         * Set it to the lower of:
         * - 90% of the Rx FIFO size, and
         * - the full Rx FIFO size minus the early receive size (for parts
         *   with ERT support assuming ERT set to E1000_ERT_2048), or
         * - the full Rx FIFO size minus one full frame
         */
        hwm = min(((pba << 10) * 9 / 10),
                  ((pba << 10) - hw->max_frame_size));

        hw->fc_high_water = hwm & 0xFFF8;       /* 8-byte granularity */
        hw->fc_low_water = hw->fc_high_water - 8;
        hw->fc_pause_time = E1000_FC_PAUSE_TIME;
        hw->fc_send_xon = 1;
        hw->fc = hw->original_fc;

        /* Allow time for pending master requests to run */
        e1000_reset_hw(hw);
        if (hw->mac_type >= e1000_82544)
                ew32(WUC, 0);

        if (e1000_init_hw(hw))
                e_dev_err("Hardware Error\n");
        e1000_update_mng_vlan(adapter);

        /* if (adapter->hwflags & HWFLAGS_PHY_PWR_BIT) { */
        if (hw->mac_type >= e1000_82544 &&
            hw->autoneg == 1 &&
            hw->autoneg_advertised == ADVERTISE_1000_FULL) {
                u32 ctrl = er32(CTRL);
                /* clear phy power management bit if we are in gig only mode,
                 * which if enabled will attempt negotiation to 100Mb, which
                 * can cause a loss of link at power off or driver unload
                 */
                ctrl &= ~E1000_CTRL_SWDPIN3;
                ew32(CTRL, ctrl);
        }

        /* Enable h/w to recognize an 802.1Q VLAN Ethernet packet */
        ew32(VET, ETHERNET_IEEE_VLAN_TYPE);

        e1000_reset_adaptive(hw);
        e1000_phy_get_info(hw, &adapter->phy_info);

        e1000_release_manageability(adapter);
}

/* Dump the eeprom for users having checksum issues */
static void e1000_dump_eeprom(struct e1000_adapter *adapter)
{
        struct net_device *netdev = adapter->netdev;
        struct ethtool_eeprom eeprom;
        const struct ethtool_ops *ops = netdev->ethtool_ops;
        u8 *data;
        int i;
        u16 csum_old, csum_new = 0;

        eeprom.len = ops->get_eeprom_len(netdev);
        eeprom.offset = 0;

        data = kmalloc(eeprom.len, GFP_KERNEL);
        if (!data)
                return;

        ops->get_eeprom(netdev, &eeprom, data);

        csum_old = (data[EEPROM_CHECKSUM_REG * 2]) +
                   (data[EEPROM_CHECKSUM_REG * 2 + 1] << 8);
        for (i = 0; i < EEPROM_CHECKSUM_REG * 2; i += 2)
                csum_new += data[i] + (data[i + 1] << 8);
        csum_new = EEPROM_SUM - csum_new;

        pr_err("/*********************/\n");
        pr_err("Current EEPROM Checksum : 0x%04x\n", csum_old);
        pr_err("Calculated              : 0x%04x\n", csum_new);

        pr_err("Offset    Values\n");
        pr_err("========  ======\n");
        print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1, data, 128, 0);

        pr_err("Include this output when contacting your support provider.\n");
        pr_err("This is not a software error! Something bad happened to\n");
        pr_err("your hardware or EEPROM image. Ignoring this problem could\n");
        pr_err("result in further problems, possibly loss of data,\n");
        pr_err("corruption or system hangs!\n");
        pr_err("The MAC Address will be reset to 00:00:00:00:00:00,\n");
        pr_err("which is invalid and requires you to set the proper MAC\n");
        pr_err("address manually before continuing to enable this network\n");
        pr_err("device. Please inspect the EEPROM dump and report the\n");
        pr_err("issue to your hardware vendor or Intel Customer Support.\n");
        pr_err("/*********************/\n");

        kfree(data);
}

/**
 * e1000_is_need_ioport - determine if an adapter needs ioport resources or not
 * @pdev: PCI device information struct
 *
 * Return true if an adapter needs ioport resources
 **/
static int e1000_is_need_ioport(struct pci_dev *pdev)
{
        switch (pdev->device) {
        case E1000_DEV_ID_82540EM:
        case E1000_DEV_ID_82540EM_LOM:
        case E1000_DEV_ID_82540EP:
        case E1000_DEV_ID_82540EP_LOM:
        case E1000_DEV_ID_82540EP_LP:
        case E1000_DEV_ID_82541EI:
        case E1000_DEV_ID_82541EI_MOBILE:
        case E1000_DEV_ID_82541ER:
        case E1000_DEV_ID_82541ER_LOM:
        case E1000_DEV_ID_82541GI:
        case E1000_DEV_ID_82541GI_LF:
        case E1000_DEV_ID_82541GI_MOBILE:
        case E1000_DEV_ID_82544EI_COPPER:
        case E1000_DEV_ID_82544EI_FIBER:
        case E1000_DEV_ID_82544GC_COPPER:
        case E1000_DEV_ID_82544GC_LOM:
        case E1000_DEV_ID_82545EM_COPPER:
        case E1000_DEV_ID_82545EM_FIBER:
        case E1000_DEV_ID_82546EB_COPPER:
        case E1000_DEV_ID_82546EB_FIBER:
        case E1000_DEV_ID_82546EB_QUAD_COPPER:
                return true;
        default:
                return false;
        }
}

static netdev_features_t e1000_fix_features(struct net_device *netdev,
        netdev_features_t features)
{
        /* Since there is no support for separate Rx/Tx vlan accel
         * enable/disable make sure Tx flag is always in same state as Rx.
         */
        if (features & NETIF_F_HW_VLAN_CTAG_RX)
                features |= NETIF_F_HW_VLAN_CTAG_TX;
        else
                features &= ~NETIF_F_HW_VLAN_CTAG_TX;

        return features;
}

static int e1000_set_features(struct net_device *netdev,
        netdev_features_t features)
{
        struct e1000_adapter *adapter = netdev_priv(netdev);
        netdev_features_t changed = features ^ netdev->features;

        if (changed & NETIF_F_HW_VLAN_CTAG_RX)
                e1000_vlan_mode(netdev, features);

        if (!(changed & (NETIF_F_RXCSUM | NETIF_F_RXALL)))
                return 0;

        netdev->features = features;
        adapter->rx_csum = !!(features & NETIF_F_RXCSUM);

        if (netif_running(netdev))
                e1000_reinit_locked(adapter);
        else
                e1000_reset(adapter);

        return 1;
}

static const struct net_device_ops e1000_netdev_ops = {
        .ndo_open               = e1000_open,
        .ndo_stop               = e1000_close,
        .ndo_start_xmit         = e1000_xmit_frame,
        .ndo_set_rx_mode        = e1000_set_rx_mode,
        .ndo_set_mac_address    = e1000_set_mac,
        .ndo_tx_timeout         = e1000_tx_timeout,
        .ndo_change_mtu         = e1000_change_mtu,
        .ndo_eth_ioctl          = e1000_ioctl,
        .ndo_validate_addr      = eth_validate_addr,
        .ndo_vlan_rx_add_vid    = e1000_vlan_rx_add_vid,
        .ndo_vlan_rx_kill_vid   = e1000_vlan_rx_kill_vid,
#ifdef CONFIG_NET_POLL_CONTROLLER
        .ndo_poll_controller    = e1000_netpoll,
#endif
        .ndo_fix_features       = e1000_fix_features,
        .ndo_set_features       = e1000_set_features,
};

/**
 * e1000_init_hw_struct - initialize members of hw struct
 * @adapter: board private struct
 * @hw: structure used by e1000_hw.c
 *
 * Factors out initialization of the e1000_hw struct to its own function
 * that can be called very early at init (just after struct allocation).
 * Fields are initialized based on PCI device information and
 * OS network device settings (MTU size).
 * Returns negative error codes if MAC type setup fails.
 */
static int e1000_init_hw_struct(struct e1000_adapter *adapter,
                                struct e1000_hw *hw)
{
        struct pci_dev *pdev = adapter->pdev;

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

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

        hw->max_frame_size = adapter->netdev->mtu +
                             ENET_HEADER_SIZE + ETHERNET_FCS_SIZE;
        hw->min_frame_size = MINIMUM_ETHERNET_FRAME_SIZE;

        /* identify the MAC */
        if (e1000_set_mac_type(hw)) {
                e_err(probe, "Unknown MAC Type\n");
                return -EIO;
        }

        switch (hw->mac_type) {
        default:
                break;
        case e1000_82541:
        case e1000_82547:
        case e1000_82541_rev_2:
        case e1000_82547_rev_2:
                hw->phy_init_script = 1;
                break;
        }

        e1000_set_media_type(hw);
        e1000_get_bus_info(hw);

        hw->wait_autoneg_complete = false;
        hw->tbi_compatibility_en = true;
        hw->adaptive_ifs = true;

        /* Copper options */

        if (hw->media_type == e1000_media_type_copper) {
                hw->mdix = AUTO_ALL_MODES;
                hw->disable_polarity_correction = false;
                hw->master_slave = E1000_MASTER_SLAVE;
        }

        return 0;
}

/**
 * e1000_probe - Device Initialization Routine
 * @pdev: PCI device information struct
 * @ent: entry in e1000_pci_tbl
 *
 * Returns 0 on success, negative on failure
 *
 * e1000_probe initializes an adapter identified by a pci_dev structure.
 * The OS initialization, configuring of the adapter private structure,
 * and a hardware reset occur.
 **/
static int e1000_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
{
        struct net_device *netdev;
        struct e1000_adapter *adapter = NULL;
        struct e1000_hw *hw;

        static int cards_found;
        static int global_quad_port_a; /* global ksp3 port a indication */
        int i, err, pci_using_dac;
        u16 eeprom_data = 0;
        u16 tmp = 0;
        u16 eeprom_apme_mask = E1000_EEPROM_APME;
        int bars, need_ioport;
        bool disable_dev = false;

        /* do not allocate ioport bars when not needed */
        need_ioport = e1000_is_need_ioport(pdev);
        if (need_ioport) {
                bars = pci_select_bars(pdev, IORESOURCE_MEM | IORESOURCE_IO);
                err = pci_enable_device(pdev);
        } else {
                bars = pci_select_bars(pdev, IORESOURCE_MEM);
                err = pci_enable_device_mem(pdev);
        }
        if (err)
                return err;

        err = pci_request_selected_regions(pdev, bars, e1000_driver_name);
        if (err)
                goto err_pci_reg;

        pci_set_master(pdev);
        err = pci_save_state(pdev);
        if (err)
                goto err_alloc_etherdev;

        err = -ENOMEM;
        netdev = alloc_etherdev(sizeof(struct e1000_adapter));
        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;
        adapter->msg_enable = netif_msg_init(debug, DEFAULT_MSG_ENABLE);
        adapter->bars = bars;
        adapter->need_ioport = need_ioport;

        hw = &adapter->hw;
        hw->back = adapter;

        err = -EIO;
        hw->hw_addr = pci_ioremap_bar(pdev, BAR_0);
        if (!hw->hw_addr)
                goto err_ioremap;

        if (adapter->need_ioport) {
                for (i = BAR_1; i < PCI_STD_NUM_BARS; i++) {
                        if (pci_resource_len(pdev, i) == 0)
                                continue;
                        if (pci_resource_flags(pdev, i) & IORESOURCE_IO) {
                                hw->io_base = pci_resource_start(pdev, i);
                                break;
                        }
                }
        }

        /* make ready for any if (hw->...) below */
        err = e1000_init_hw_struct(adapter, hw);
        if (err)
                goto err_sw_init;

        /* there is a workaround being applied below that limits
         * 64-bit DMA addresses to 64-bit hardware.  There are some
         * 32-bit adapters that Tx hang when given 64-bit DMA addresses
         */
        pci_using_dac = 0;

        if ((hw->bus_type == e1000_bus_type_pcix) &&
            !dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64))) {
                pci_using_dac = 1;
        } else {
                err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
                if (err) {
                        pr_err("No usable DMA config, aborting\n");
                        goto err_dma;
                }
        }

        netdev->netdev_ops = &e1000_netdev_ops;
        e1000_set_ethtool_ops(netdev);
        netdev->watchdog_timeo = 5 * HZ;
        netif_napi_add(netdev, &adapter->napi, e1000_clean, 64);

        strncpy(netdev->name, pci_name(pdev), sizeof(netdev->name) - 1);

        adapter->bd_number = cards_found;

        /* setup the private structure */

        err = e1000_sw_init(adapter);
        if (err)
                goto err_sw_init;

        err = -EIO;
        if (hw->mac_type == e1000_ce4100) {
                hw->ce4100_gbe_mdio_base_virt =
                                        ioremap(pci_resource_start(pdev, BAR_1),
                                                pci_resource_len(pdev, BAR_1));

                if (!hw->ce4100_gbe_mdio_base_virt)
                        goto err_mdio_ioremap;
        }

        if (hw->mac_type >= e1000_82543) {
                netdev->hw_features = NETIF_F_SG |
                                   NETIF_F_HW_CSUM |
                                   NETIF_F_HW_VLAN_CTAG_RX;
                netdev->features = NETIF_F_HW_VLAN_CTAG_TX |
                                   NETIF_F_HW_VLAN_CTAG_FILTER;
        }

        if ((hw->mac_type >= e1000_82544) &&
           (hw->mac_type != e1000_82547))
                netdev->hw_features |= NETIF_F_TSO;

        netdev->priv_flags |= IFF_SUPP_NOFCS;

        netdev->features |= netdev->hw_features;
        netdev->hw_features |= (NETIF_F_RXCSUM |
                                NETIF_F_RXALL |
                                NETIF_F_RXFCS);

        if (pci_using_dac) {
                netdev->features |= NETIF_F_HIGHDMA;
                netdev->vlan_features |= NETIF_F_HIGHDMA;
        }

        netdev->vlan_features |= (NETIF_F_TSO |
                                  NETIF_F_HW_CSUM |
                                  NETIF_F_SG);

        /* Do not set IFF_UNICAST_FLT for VMWare's 82545EM */
        if (hw->device_id != E1000_DEV_ID_82545EM_COPPER ||
            hw->subsystem_vendor_id != PCI_VENDOR_ID_VMWARE)
                netdev->priv_flags |= IFF_UNICAST_FLT;

        /* MTU range: 46 - 16110 */
        netdev->min_mtu = ETH_ZLEN - ETH_HLEN;
        netdev->max_mtu = MAX_JUMBO_FRAME_SIZE - (ETH_HLEN + ETH_FCS_LEN);

        adapter->en_mng_pt = e1000_enable_mng_pass_thru(hw);

        /* initialize eeprom parameters */
        if (e1000_init_eeprom_params(hw)) {
                e_err(probe, "EEPROM initialization failed\n");
                goto err_eeprom;
        }

        /* before reading the EEPROM, reset the controller to
         * put the device in a known good starting state
         */

        e1000_reset_hw(hw);

        /* make sure the EEPROM is good */
        if (e1000_validate_eeprom_checksum(hw) < 0) {
                e_err(probe, "The EEPROM Checksum Is Not Valid\n");
                e1000_dump_eeprom(adapter);
                /* set MAC address to all zeroes to invalidate and temporary
                 * disable this device for the user. This blocks regular
                 * traffic while still permitting ethtool ioctls from reaching
                 * the hardware as well as allowing the user to run the
                 * interface after manually setting a hw addr using
                 * `ip set address`
                 */
                memset(hw->mac_addr, 0, netdev->addr_len);
        } else {
                /* copy the MAC address out of the EEPROM */
                if (e1000_read_mac_addr(hw))
                        e_err(probe, "EEPROM Read Error\n");
        }
        /* don't block initialization here due to bad MAC address */
        memcpy(netdev->dev_addr, hw->mac_addr, netdev->addr_len);

        if (!is_valid_ether_addr(netdev->dev_addr))
                e_err(probe, "Invalid MAC Address\n");


        INIT_DELAYED_WORK(&adapter->watchdog_task, e1000_watchdog);
        INIT_DELAYED_WORK(&adapter->fifo_stall_task,
                          e1000_82547_tx_fifo_stall_task);
        INIT_DELAYED_WORK(&adapter->phy_info_task, e1000_update_phy_info_task);
        INIT_WORK(&adapter->reset_task, e1000_reset_task);

        e1000_check_options(adapter);

        /* Initial Wake on LAN setting
         * If APM wake is enabled in the EEPROM,
         * enable the ACPI Magic Packet filter
         */

        switch (hw->mac_type) {
        case e1000_82542_rev2_0:
        case e1000_82542_rev2_1:
        case e1000_82543:
                break;
        case e1000_82544:
                e1000_read_eeprom(hw,
                        EEPROM_INIT_CONTROL2_REG, 1, &eeprom_data);
                eeprom_apme_mask = E1000_EEPROM_82544_APM;
                break;
        case e1000_82546:
        case e1000_82546_rev_3:
                if (er32(STATUS) & E1000_STATUS_FUNC_1) {
                        e1000_read_eeprom(hw,
                                EEPROM_INIT_CONTROL3_PORT_B, 1, &eeprom_data);
                        break;
                }
                fallthrough;
        default:
                e1000_read_eeprom(hw,
                        EEPROM_INIT_CONTROL3_PORT_A, 1, &eeprom_data);
                break;
        }
        if (eeprom_data & eeprom_apme_mask)
                adapter->eeprom_wol |= E1000_WUFC_MAG;

        /* now that we have the eeprom settings, apply the special cases
         * where the eeprom may be wrong or the board simply won't support
         * wake on lan on a particular port
         */
        switch (pdev->device) {
        case E1000_DEV_ID_82546GB_PCIE:
                adapter->eeprom_wol = 0;
                break;
        case E1000_DEV_ID_82546EB_FIBER:
        case E1000_DEV_ID_82546GB_FIBER:
                /* Wake events only supported on port A for dual fiber
                 * regardless of eeprom setting
                 */
                if (er32(STATUS) & E1000_STATUS_FUNC_1)
                        adapter->eeprom_wol = 0;
                break;
        case E1000_DEV_ID_82546GB_QUAD_COPPER_KSP3:
                /* if quad port adapter, disable WoL on all but port A */
                if (global_quad_port_a != 0)
                        adapter->eeprom_wol = 0;
                else
                        adapter->quad_port_a = true;
                /* Reset for multiple quad port adapters */
                if (++global_quad_port_a == 4)
                        global_quad_port_a = 0;
                break;
        }

        /* initialize the wol settings based on the eeprom settings */
        adapter->wol = adapter->eeprom_wol;
        device_set_wakeup_enable(&adapter->pdev->dev, adapter->wol);

        /* Auto detect PHY address */
        if (hw->mac_type == e1000_ce4100) {
                for (i = 0; i < 32; i++) {
                        hw->phy_addr = i;
                        e1000_read_phy_reg(hw, PHY_ID2, &tmp);

                        if (tmp != 0 && tmp != 0xFF)
                                break;
                }

                if (i >= 32)
                        goto err_eeprom;
        }

        /* reset the hardware with the new settings */
        e1000_reset(adapter);

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

        e1000_vlan_filter_on_off(adapter, false);

        /* print bus type/speed/width info */
        e_info(probe, "(PCI%s:%dMHz:%d-bit) %pM\n",
               ((hw->bus_type == e1000_bus_type_pcix) ? "-X" : ""),
               ((hw->bus_speed == e1000_bus_speed_133) ? 133 :
                (hw->bus_speed == e1000_bus_speed_120) ? 120 :
                (hw->bus_speed == e1000_bus_speed_100) ? 100 :
                (hw->bus_speed == e1000_bus_speed_66) ? 66 : 33),
               ((hw->bus_width == e1000_bus_width_64) ? 64 : 32),
               netdev->dev_addr);

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

        e_info(probe, "Intel(R) PRO/1000 Network Connection\n");

        cards_found++;
        return 0;

err_register:
err_eeprom:
        e1000_phy_hw_reset(hw);

        if (hw->flash_address)
                iounmap(hw->flash_address);
        kfree(adapter->tx_ring);
        kfree(adapter->rx_ring);
err_dma:
err_sw_init:
err_mdio_ioremap:
        iounmap(hw->ce4100_gbe_mdio_base_virt);
        iounmap(hw->hw_addr);
err_ioremap:
        disable_dev = !test_and_set_bit(__E1000_DISABLED, &adapter->flags);
        free_netdev(netdev);
err_alloc_etherdev:
        pci_release_selected_regions(pdev, bars);
err_pci_reg:
        if (!adapter || disable_dev)
                pci_disable_device(pdev);
        return err;
}

/**
 * e1000_remove - Device Removal Routine
 * @pdev: PCI device information struct
 *
 * e1000_remove is called by the PCI subsystem to alert the driver
 * that it should release a PCI device. That could be caused by a
 * Hot-Plug event, or because the driver is going to be removed from
 * memory.
 **/
static void e1000_remove(struct pci_dev *pdev)
{
        struct net_device *netdev = pci_get_drvdata(pdev);
        struct e1000_adapter *adapter = netdev_priv(netdev);
        struct e1000_hw *hw = &adapter->hw;
        bool disable_dev;

        e1000_down_and_stop(adapter);
        e1000_release_manageability(adapter);

        unregister_netdev(netdev);

        e1000_phy_hw_reset(hw);

        kfree(adapter->tx_ring);
        kfree(adapter->rx_ring);

        if (hw->mac_type == e1000_ce4100)
                iounmap(hw->ce4100_gbe_mdio_base_virt);
        iounmap(hw->hw_addr);
        if (hw->flash_address)
                iounmap(hw->flash_address);
        pci_release_selected_regions(pdev, adapter->bars);

        disable_dev = !test_and_set_bit(__E1000_DISABLED, &adapter->flags);
        free_netdev(netdev);

        if (disable_dev)
                pci_disable_device(pdev);
}

/**
 * e1000_sw_init - Initialize general software structures (struct e1000_adapter)
 * @adapter: board private structure to initialize
 *
 * e1000_sw_init initializes the Adapter private data structure.
 * e1000_init_hw_struct MUST be called before this function
 **/
static int e1000_sw_init(struct e1000_adapter *adapter)
{
        adapter->rx_buffer_len = MAXIMUM_ETHERNET_VLAN_SIZE;

        adapter->num_tx_queues = 1;
        adapter->num_rx_queues = 1;

        if (e1000_alloc_queues(adapter)) {
                e_err(probe, "Unable to allocate memory for queues\n");
                return -ENOMEM;
        }

        /* Explicitly disable IRQ since the NIC can be in any state. */
        e1000_irq_disable(adapter);

        spin_lock_init(&adapter->stats_lock);

        set_bit(__E1000_DOWN, &adapter->flags);

        return 0;
}

/**
 * e1000_alloc_queues - Allocate memory for all rings
 * @adapter: board private structure to initialize
 *
 * We allocate one ring per queue at run-time since we don't know the
 * number of queues at compile-time.
 **/
static int e1000_alloc_queues(struct e1000_adapter *adapter)
{
        adapter->tx_ring = kcalloc(adapter->num_tx_queues,
                                   sizeof(struct e1000_tx_ring), GFP_KERNEL);
        if (!adapter->tx_ring)
                return -ENOMEM;

        adapter->rx_ring = kcalloc(adapter->num_rx_queues,
                                   sizeof(struct e1000_rx_ring), GFP_KERNEL);
        if (!adapter->rx_ring) {
                kfree(adapter->tx_ring);
                return -ENOMEM;
        }

        return E1000_SUCCESS;
}

/**
 * e1000_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 task is started,
 * and the stack is notified that the interface is ready.
 **/
int e1000_open(struct net_device *netdev)
{
        struct e1000_adapter *adapter = netdev_priv(netdev);
        struct e1000_hw *hw = &adapter->hw;
        int err;

        /* disallow open during test */
        if (test_bit(__E1000_TESTING, &adapter->flags))
                return -EBUSY;

        netif_carrier_off(netdev);

        /* allocate transmit descriptors */
        err = e1000_setup_all_tx_resources(adapter);
        if (err)
                goto err_setup_tx;

        /* allocate receive descriptors */
        err = e1000_setup_all_rx_resources(adapter);
        if (err)
                goto err_setup_rx;

        e1000_power_up_phy(adapter);

        adapter->mng_vlan_id = E1000_MNG_VLAN_NONE;
        if ((hw->mng_cookie.status &
                          E1000_MNG_DHCP_COOKIE_STATUS_VLAN_SUPPORT)) {
                e1000_update_mng_vlan(adapter);
        }

        /* before we allocate an interrupt, we must be ready to handle it.
         * Setting DEBUG_SHIRQ in the kernel makes it fire an interrupt
         * as soon as we call pci_request_irq, so we have to setup our
         * clean_rx handler before we do so.
         */
        e1000_configure(adapter);

        err = e1000_request_irq(adapter);
        if (err)
                goto err_req_irq;

        /* From here on the code is the same as e1000_up() */
        clear_bit(__E1000_DOWN, &adapter->flags);

        napi_enable(&adapter->napi);

        e1000_irq_enable(adapter);

        netif_start_queue(netdev);

        /* fire a link status change interrupt to start the watchdog */
        ew32(ICS, E1000_ICS_LSC);

        return E1000_SUCCESS;

err_req_irq:
        e1000_power_down_phy(adapter);
        e1000_free_all_rx_resources(adapter);
err_setup_rx:
        e1000_free_all_tx_resources(adapter);
err_setup_tx:
        e1000_reset(adapter);

        return err;
}

/**
 * e1000_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 drivers control, but
 * needs to be disabled.  A global MAC reset is issued to stop the
 * hardware, and all transmit and receive resources are freed.
 **/
int e1000_close(struct net_device *netdev)
{
        struct e1000_adapter *adapter = netdev_priv(netdev);
        struct e1000_hw *hw = &adapter->hw;
        int count = E1000_CHECK_RESET_COUNT;

        while (test_and_set_bit(__E1000_RESETTING, &adapter->flags) && count--)
                usleep_range(10000, 20000);

        WARN_ON(count < 0);

        /* signal that we're down so that the reset task will no longer run */
        set_bit(__E1000_DOWN, &adapter->flags);
        clear_bit(__E1000_RESETTING, &adapter->flags);

        e1000_down(adapter);
        e1000_power_down_phy(adapter);
        e1000_free_irq(adapter);

        e1000_free_all_tx_resources(adapter);
        e1000_free_all_rx_resources(adapter);

        /* kill manageability vlan ID if supported, but not if a vlan with
         * the same ID is registered on the host OS (let 8021q kill it)
         */
        if ((hw->mng_cookie.status &
             E1000_MNG_DHCP_COOKIE_STATUS_VLAN_SUPPORT) &&
            !test_bit(adapter->mng_vlan_id, adapter->active_vlans)) {
                e1000_vlan_rx_kill_vid(netdev, htons(ETH_P_8021Q),
                                       adapter->mng_vlan_id);
        }

        return 0;
}

/**
 * e1000_check_64k_bound - check that memory doesn't cross 64kB boundary
 * @adapter: address of board private structure
 * @start: address of beginning of memory
 * @len: length of memory
 **/
static bool e1000_check_64k_bound(struct e1000_adapter *adapter, void *start,
                                  unsigned long len)
{
        struct e1000_hw *hw = &adapter->hw;
        unsigned long begin = (unsigned long)start;
        unsigned long end = begin + len;

        /* First rev 82545 and 82546 need to not allow any memory
         * write location to cross 64k boundary due to errata 23
         */
        if (hw->mac_type == e1000_82545 ||
            hw->mac_type == e1000_ce4100 ||
            hw->mac_type == e1000_82546) {
                return ((begin ^ (end - 1)) >> 16) == 0;
        }

        return true;
}

/**
 * e1000_setup_tx_resources - allocate Tx resources (Descriptors)
 * @adapter: board private structure
 * @txdr:    tx descriptor ring (for a specific queue) to setup
 *
 * Return 0 on success, negative on failure
 **/
static int e1000_setup_tx_resources(struct e1000_adapter *adapter,
                                    struct e1000_tx_ring *txdr)
{
        struct pci_dev *pdev = adapter->pdev;
        int size;

        size = sizeof(struct e1000_tx_buffer) * txdr->count;
        txdr->buffer_info = vzalloc(size);
        if (!txdr->buffer_info)
                return -ENOMEM;

        /* round up to nearest 4K */

        txdr->size = txdr->count * sizeof(struct e1000_tx_desc);
        txdr->size = ALIGN(txdr->size, 4096);

        txdr->desc = dma_alloc_coherent(&pdev->dev, txdr->size, &txdr->dma,
                                        GFP_KERNEL);
        if (!txdr->desc) {
setup_tx_desc_die:
                vfree(txdr->buffer_info);
                return -ENOMEM;
        }

        /* Fix for errata 23, can't cross 64kB boundary */
        if (!e1000_check_64k_bound(adapter, txdr->desc, txdr->size)) {
                void *olddesc = txdr->desc;
                dma_addr_t olddma = txdr->dma;
                e_err(tx_err, "txdr align check failed: %u bytes at %p\n",
                      txdr->size, txdr->desc);
                /* Try again, without freeing the previous */
                txdr->desc = dma_alloc_coherent(&pdev->dev, txdr->size,
                                                &txdr->dma, GFP_KERNEL);
                /* Failed allocation, critical failure */
                if (!txdr->desc) {
                        dma_free_coherent(&pdev->dev, txdr->size, olddesc,
                                          olddma);
                        goto setup_tx_desc_die;
                }

                if (!e1000_check_64k_bound(adapter, txdr->desc, txdr->size)) {
                        /* give up */
                        dma_free_coherent(&pdev->dev, txdr->size, txdr->desc,
                                          txdr->dma);
                        dma_free_coherent(&pdev->dev, txdr->size, olddesc,
                                          olddma);
                        e_err(probe, "Unable to allocate aligned memory "
                              "for the transmit descriptor ring\n");
                        vfree(txdr->buffer_info);
                        return -ENOMEM;
                } else {
                        /* Free old allocation, new allocation was successful */
                        dma_free_coherent(&pdev->dev, txdr->size, olddesc,
                                          olddma);
                }
        }
        memset(txdr->desc, 0, txdr->size);

        txdr->next_to_use = 0;
        txdr->next_to_clean = 0;

        return 0;
}

/**
 * e1000_setup_all_tx_resources - wrapper to allocate Tx resources
 *                                (Descriptors) for all queues
 * @adapter: board private structure
 *
 * Return 0 on success, negative on failure
 **/
int e1000_setup_all_tx_resources(struct e1000_adapter *adapter)
{
        int i, err = 0;

        for (i = 0; i < adapter->num_tx_queues; i++) {
                err = e1000_setup_tx_resources(adapter, &adapter->tx_ring[i]);
                if (err) {
                        e_err(probe, "Allocation for Tx Queue %u failed\n", i);
                        for (i-- ; i >= 0; i--)
                                e1000_free_tx_resources(adapter,
                                                        &adapter->tx_ring[i]);
                        break;
                }
        }

        return err;
}

/**
 * e1000_configure_tx - Configure 8254x Transmit Unit after Reset
 * @adapter: board private structure
 *
 * Configure the Tx unit of the MAC after a reset.
 **/
static void e1000_configure_tx(struct e1000_adapter *adapter)
{
        u64 tdba;
        struct e1000_hw *hw = &adapter->hw;
        u32 tdlen, tctl, tipg;
        u32 ipgr1, ipgr2;

        /* Setup the HW Tx Head and Tail descriptor pointers */

        switch (adapter->num_tx_queues) {
        case 1:
        default:
                tdba = adapter->tx_ring[0].dma;
                tdlen = adapter->tx_ring[0].count *
                        sizeof(struct e1000_tx_desc);
                ew32(TDLEN, tdlen);
                ew32(TDBAH, (tdba >> 32));
                ew32(TDBAL, (tdba & 0x00000000ffffffffULL));
                ew32(TDT, 0);
                ew32(TDH, 0);
                adapter->tx_ring[0].tdh = ((hw->mac_type >= e1000_82543) ?
                                           E1000_TDH : E1000_82542_TDH);
                adapter->tx_ring[0].tdt = ((hw->mac_type >= e1000_82543) ?
                                           E1000_TDT : E1000_82542_TDT);
                break;
        }

        /* Set the default values for the Tx Inter Packet Gap timer */
        if ((hw->media_type == e1000_media_type_fiber ||
             hw->media_type == e1000_media_type_internal_serdes))
                tipg = DEFAULT_82543_TIPG_IPGT_FIBER;
        else
                tipg = DEFAULT_82543_TIPG_IPGT_COPPER;

        switch (hw->mac_type) {
        case e1000_82542_rev2_0:
        case e1000_82542_rev2_1:
                tipg = DEFAULT_82542_TIPG_IPGT;
                ipgr1 = DEFAULT_82542_TIPG_IPGR1;
                ipgr2 = DEFAULT_82542_TIPG_IPGR2;
                break;
        default:
                ipgr1 = DEFAULT_82543_TIPG_IPGR1;
                ipgr2 = DEFAULT_82543_TIPG_IPGR2;
                break;
        }
        tipg |= ipgr1 << E1000_TIPG_IPGR1_SHIFT;
        tipg |= ipgr2 << E1000_TIPG_IPGR2_SHIFT;
        ew32(TIPG, tipg);

        /* Set the Tx Interrupt Delay register */

        ew32(TIDV, adapter->tx_int_delay);
        if (hw->mac_type >= e1000_82540)
                ew32(TADV, adapter->tx_abs_int_delay);

        /* Program the Transmit Control Register */

        tctl = er32(TCTL);
        tctl &= ~E1000_TCTL_CT;
        tctl |= E1000_TCTL_PSP | E1000_TCTL_RTLC |
                (E1000_COLLISION_THRESHOLD << E1000_CT_SHIFT);

        e1000_config_collision_dist(hw);

        /* Setup Transmit Descriptor Settings for eop descriptor */
        adapter->txd_cmd = E1000_TXD_CMD_EOP | E1000_TXD_CMD_IFCS;

        /* only set IDE if we are delaying interrupts using the timers */
        if (adapter->tx_int_delay)
                adapter->txd_cmd |= E1000_TXD_CMD_IDE;

        if (hw->mac_type < e1000_82543)
                adapter->txd_cmd |= E1000_TXD_CMD_RPS;
        else
                adapter->txd_cmd |= E1000_TXD_CMD_RS;

        /* Cache if we're 82544 running in PCI-X because we'll
         * need this to apply a workaround later in the send path.
         */
        if (hw->mac_type == e1000_82544 &&
            hw->bus_type == e1000_bus_type_pcix)
                adapter->pcix_82544 = true;

        ew32(TCTL, tctl);

}

/**
 * e1000_setup_rx_resources - allocate Rx resources (Descriptors)
 * @adapter: board private structure
 * @rxdr:    rx descriptor ring (for a specific queue) to setup
 *
 * Returns 0 on success, negative on failure
 **/
static int e1000_setup_rx_resources(struct e1000_adapter *adapter,
                                    struct e1000_rx_ring *rxdr)
{
        struct pci_dev *pdev = adapter->pdev;
        int size, desc_len;

        size = sizeof(struct e1000_rx_buffer) * rxdr->count;
        rxdr->buffer_info = vzalloc(size);
        if (!rxdr->buffer_info)
                return -ENOMEM;

        desc_len = sizeof(struct e1000_rx_desc);

        /* Round up to nearest 4K */

        rxdr->size = rxdr->count * desc_len;
        rxdr->size = ALIGN(rxdr->size, 4096);

        rxdr->desc = dma_alloc_coherent(&pdev->dev, rxdr->size, &rxdr->dma,
                                        GFP_KERNEL);
        if (!rxdr->desc) {
setup_rx_desc_die:
                vfree(rxdr->buffer_info);
                return -ENOMEM;
        }

        /* Fix for errata 23, can't cross 64kB boundary */
        if (!e1000_check_64k_bound(adapter, rxdr->desc, rxdr->size)) {
                void *olddesc = rxdr->desc;
                dma_addr_t olddma = rxdr->dma;
                e_err(rx_err, "rxdr align check failed: %u bytes at %p\n",
                      rxdr->size, rxdr->desc);
                /* Try again, without freeing the previous */
                rxdr->desc = dma_alloc_coherent(&pdev->dev, rxdr->size,
                                                &rxdr->dma, GFP_KERNEL);
                /* Failed allocation, critical failure */
                if (!rxdr->desc) {
                        dma_free_coherent(&pdev->dev, rxdr->size, olddesc,
                                          olddma);
                        goto setup_rx_desc_die;
                }

                if (!e1000_check_64k_bound(adapter, rxdr->desc, rxdr->size)) {
                        /* give up */
                        dma_free_coherent(&pdev->dev, rxdr->size, rxdr->desc,
                                          rxdr->dma);
                        dma_free_coherent(&pdev->dev, rxdr->size, olddesc,
                                          olddma);
                        e_err(probe, "Unable to allocate aligned memory for "
                              "the Rx descriptor ring\n");
                        goto setup_rx_desc_die;
                } else {
                        /* Free old allocation, new allocation was successful */
                        dma_free_coherent(&pdev->dev, rxdr->size, olddesc,
                                          olddma);
                }
        }
        memset(rxdr->desc, 0, rxdr->size);

        rxdr->next_to_clean = 0;
        rxdr->next_to_use = 0;
        rxdr->rx_skb_top = NULL;

        return 0;
}

/**
 * e1000_setup_all_rx_resources - wrapper to allocate Rx resources
 *                                (Descriptors) for all queues
 * @adapter: board private structure
 *
 * Return 0 on success, negative on failure
 **/
int e1000_setup_all_rx_resources(struct e1000_adapter *adapter)
{
        int i, err = 0;

        for (i = 0; i < adapter->num_rx_queues; i++) {
                err = e1000_setup_rx_resources(adapter, &adapter->rx_ring[i]);
                if (err) {
                        e_err(probe, "Allocation for Rx Queue %u failed\n", i);
                        for (i-- ; i >= 0; i--)
                                e1000_free_rx_resources(adapter,
                                                        &adapter->rx_ring[i]);
                        break;
                }
        }

        return err;
}

/**
 * e1000_setup_rctl - configure the receive control registers
 * @adapter: Board private structure
 **/
static void e1000_setup_rctl(struct e1000_adapter *adapter)
{
        struct e1000_hw *hw = &adapter->hw;
        u32 rctl;

        rctl = er32(RCTL);

        rctl &= ~(3 << E1000_RCTL_MO_SHIFT);

        rctl |= E1000_RCTL_BAM | E1000_RCTL_LBM_NO |
                E1000_RCTL_RDMTS_HALF |
                (hw->mc_filter_type << E1000_RCTL_MO_SHIFT);

        if (hw->tbi_compatibility_on == 1)
                rctl |= E1000_RCTL_SBP;
        else
                rctl &= ~E1000_RCTL_SBP;

        if (adapter->netdev->mtu <= ETH_DATA_LEN)
                rctl &= ~E1000_RCTL_LPE;
        else
                rctl |= E1000_RCTL_LPE;

        /* Setup buffer sizes */
        rctl &= ~E1000_RCTL_SZ_4096;
        rctl |= E1000_RCTL_BSEX;
        switch (adapter->rx_buffer_len) {
        case E1000_RXBUFFER_2048:
        default:
                rctl |= E1000_RCTL_SZ_2048;
                rctl &= ~E1000_RCTL_BSEX;
                break;
        case E1000_RXBUFFER_4096:
                rctl |= E1000_RCTL_SZ_4096;
                break;
        case E1000_RXBUFFER_8192:
                rctl |= E1000_RCTL_SZ_8192;
                break;
        case E1000_RXBUFFER_16384:
                rctl |= E1000_RCTL_SZ_16384;
                break;
        }

        /* This is useful for sniffing bad packets. */
        if (adapter->netdev->features & NETIF_F_RXALL) {
                /* UPE and MPE will be handled by normal PROMISC logic
                 * in e1000e_set_rx_mode
                 */
                rctl |= (E1000_RCTL_SBP | /* Receive bad packets */
                         E1000_RCTL_BAM | /* RX All Bcast Pkts */
                         E1000_RCTL_PMCF); /* RX All MAC Ctrl Pkts */

                rctl &= ~(E1000_RCTL_VFE | /* Disable VLAN filter */
                          E1000_RCTL_DPF | /* Allow filtered pause */
                          E1000_RCTL_CFIEN); /* Dis VLAN CFIEN Filter */
                /* Do not mess with E1000_CTRL_VME, it affects transmit as well,
                 * and that breaks VLANs.
                 */
        }

        ew32(RCTL, rctl);
}

/**
 * e1000_configure_rx - Configure 8254x Receive Unit after Reset
 * @adapter: board private structure
 *
 * Configure the Rx unit of the MAC after a reset.
 **/
static void e1000_configure_rx(struct e1000_adapter *adapter)
{
        u64 rdba;
        struct e1000_hw *hw = &adapter->hw;
        u32 rdlen, rctl, rxcsum;

        if (adapter->netdev->mtu > ETH_DATA_LEN) {
                rdlen = adapter->rx_ring[0].count *
                        sizeof(struct e1000_rx_desc);
                adapter->clean_rx = e1000_clean_jumbo_rx_irq;
                adapter->alloc_rx_buf = e1000_alloc_jumbo_rx_buffers;
        } else {
                rdlen = adapter->rx_ring[0].count *
                        sizeof(struct e1000_rx_desc);
                adapter->clean_rx = e1000_clean_rx_irq;
                adapter->alloc_rx_buf = e1000_alloc_rx_buffers;
        }

        /* disable receives while setting up the descriptors */
        rctl = er32(RCTL);
        ew32(RCTL, rctl & ~E1000_RCTL_EN);

        /* set the Receive Delay Timer Register */
        ew32(RDTR, adapter->rx_int_delay);

        if (hw->mac_type >= e1000_82540) {
                ew32(RADV, adapter->rx_abs_int_delay);
                if (adapter->itr_setting != 0)
                        ew32(ITR, 1000000000 / (adapter->itr * 256));
        }

        /* Setup the HW Rx Head and Tail Descriptor Pointers and
         * the Base and Length of the Rx Descriptor Ring
         */
        switch (adapter->num_rx_queues) {
        case 1:
        default:
                rdba = adapter->rx_ring[0].dma;
                ew32(RDLEN, rdlen);
                ew32(RDBAH, (rdba >> 32));
                ew32(RDBAL, (rdba & 0x00000000ffffffffULL));
                ew32(RDT, 0);
                ew32(RDH, 0);
                adapter->rx_ring[0].rdh = ((hw->mac_type >= e1000_82543) ?
                                           E1000_RDH : E1000_82542_RDH);
                adapter->rx_ring[0].rdt = ((hw->mac_type >= e1000_82543) ?
                                           E1000_RDT : E1000_82542_RDT);
                break;
        }

        /* Enable 82543 Receive Checksum Offload for TCP and UDP */
        if (hw->mac_type >= e1000_82543) {
                rxcsum = er32(RXCSUM);
                if (adapter->rx_csum)
                        rxcsum |= E1000_RXCSUM_TUOFL;
                else
                        /* don't need to clear IPPCSE as it defaults to 0 */
                        rxcsum &= ~E1000_RXCSUM_TUOFL;
                ew32(RXCSUM, rxcsum);
        }

        /* Enable Receives */
        ew32(RCTL, rctl | E1000_RCTL_EN);
}

/**
 * e1000_free_tx_resources - Free Tx Resources per Queue
 * @adapter: board private structure
 * @tx_ring: Tx descriptor ring for a specific queue
 *
 * Free all transmit software resources
 **/
static void e1000_free_tx_resources(struct e1000_adapter *adapter,
                                    struct e1000_tx_ring *tx_ring)
{
        struct pci_dev *pdev = adapter->pdev;

        e1000_clean_tx_ring(adapter, tx_ring);

        vfree(tx_ring->buffer_info);
        tx_ring->buffer_info = NULL;

        dma_free_coherent(&pdev->dev, tx_ring->size, tx_ring->desc,
                          tx_ring->dma);

        tx_ring->desc = NULL;
}

/**
 * e1000_free_all_tx_resources - Free Tx Resources for All Queues
 * @adapter: board private structure
 *
 * Free all transmit software resources
 **/
void e1000_free_all_tx_resources(struct e1000_adapter *adapter)
{
        int i;

        for (i = 0; i < adapter->num_tx_queues; i++)
                e1000_free_tx_resources(adapter, &adapter->tx_ring[i]);
}

static void
e1000_unmap_and_free_tx_resource(struct e1000_adapter *adapter,
                                 struct e1000_tx_buffer *buffer_info)
{
        if (buffer_info->dma) {
                if (buffer_info->mapped_as_page)
                        dma_unmap_page(&adapter->pdev->dev, buffer_info->dma,
                                       buffer_info->length, DMA_TO_DEVICE);
                else
                        dma_unmap_single(&adapter->pdev->dev, buffer_info->dma,
                                         buffer_info->length,
                                         DMA_TO_DEVICE);
                buffer_info->dma = 0;
        }
        if (buffer_info->skb) {
                dev_kfree_skb_any(buffer_info->skb);
                buffer_info->skb = NULL;
        }
        buffer_info->time_stamp = 0;
        /* buffer_info must be completely set up in the transmit path */
}

/**
 * e1000_clean_tx_ring - Free Tx Buffers
 * @adapter: board private structure
 * @tx_ring: ring to be cleaned
 **/
static void e1000_clean_tx_ring(struct e1000_adapter *adapter,
                                struct e1000_tx_ring *tx_ring)
{
        struct e1000_hw *hw = &adapter->hw;
        struct e1000_tx_buffer *buffer_info;
        unsigned long size;
        unsigned int i;

        /* Free all the Tx ring sk_buffs */

        for (i = 0; i < tx_ring->count; i++) {
                buffer_info = &tx_ring->buffer_info[i];
                e1000_unmap_and_free_tx_resource(adapter, buffer_info);
        }

        netdev_reset_queue(adapter->netdev);
        size = sizeof(struct e1000_tx_buffer) * tx_ring->count;
        memset(tx_ring->buffer_info, 0, size);

        /* Zero out the descriptor ring */

        memset(tx_ring->desc, 0, tx_ring->size);

        tx_ring->next_to_use = 0;
        tx_ring->next_to_clean = 0;
        tx_ring->last_tx_tso = false;

        writel(0, hw->hw_addr + tx_ring->tdh);
        writel(0, hw->hw_addr + tx_ring->tdt);
}

/**
 * e1000_clean_all_tx_rings - Free Tx Buffers for all queues
 * @adapter: board private structure
 **/
static void e1000_clean_all_tx_rings(struct e1000_adapter *adapter)
{
        int i;

        for (i = 0; i < adapter->num_tx_queues; i++)
                e1000_clean_tx_ring(adapter, &adapter->tx_ring[i]);
}

/**
 * e1000_free_rx_resources - Free Rx Resources
 * @adapter: board private structure
 * @rx_ring: ring to clean the resources from
 *
 * Free all receive software resources
 **/
static void e1000_free_rx_resources(struct e1000_adapter *adapter,
                                    struct e1000_rx_ring *rx_ring)
{
        struct pci_dev *pdev = adapter->pdev;

        e1000_clean_rx_ring(adapter, rx_ring);

        vfree(rx_ring->buffer_info);
        rx_ring->buffer_info = NULL;

        dma_free_coherent(&pdev->dev, rx_ring->size, rx_ring->desc,
                          rx_ring->dma);

        rx_ring->desc = NULL;
}

/**
 * e1000_free_all_rx_resources - Free Rx Resources for All Queues
 * @adapter: board private structure
 *
 * Free all receive software resources
 **/
void e1000_free_all_rx_resources(struct e1000_adapter *adapter)
{
        int i;

        for (i = 0; i < adapter->num_rx_queues; i++)
                e1000_free_rx_resources(adapter, &adapter->rx_ring[i]);
}

#define E1000_HEADROOM (NET_SKB_PAD + NET_IP_ALIGN)
static unsigned int e1000_frag_len(const struct e1000_adapter *a)
{
        return SKB_DATA_ALIGN(a->rx_buffer_len + E1000_HEADROOM) +
                SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
}

static void *e1000_alloc_frag(const struct e1000_adapter *a)
{
        unsigned int len = e1000_frag_len(a);
        u8 *data = netdev_alloc_frag(len);

        if (likely(data))
                data += E1000_HEADROOM;
        return data;
}

/**
 * e1000_clean_rx_ring - Free Rx Buffers per Queue
 * @adapter: board private structure
 * @rx_ring: ring to free buffers from
 **/
static void e1000_clean_rx_ring(struct e1000_adapter *adapter,
                                struct e1000_rx_ring *rx_ring)
{
        struct e1000_hw *hw = &adapter->hw;
        struct e1000_rx_buffer *buffer_info;
        struct pci_dev *pdev = adapter->pdev;
        unsigned long size;
        unsigned int i;

        /* Free all the Rx netfrags */
        for (i = 0; i < rx_ring->count; i++) {
                buffer_info = &rx_ring->buffer_info[i];
                if (adapter->clean_rx == e1000_clean_rx_irq) {
                        if (buffer_info->dma)
                                dma_unmap_single(&pdev->dev, buffer_info->dma,
                                                 adapter->rx_buffer_len,
                                                 DMA_FROM_DEVICE);
                        if (buffer_info->rxbuf.data) {
                                skb_free_frag(buffer_info->rxbuf.data);
                                buffer_info->rxbuf.data = NULL;
                        }
                } else if (adapter->clean_rx == e1000_clean_jumbo_rx_irq) {
                        if (buffer_info->dma)
                                dma_unmap_page(&pdev->dev, buffer_info->dma,
                                               adapter->rx_buffer_len,
                                               DMA_FROM_DEVICE);
                        if (buffer_info->rxbuf.page) {
                                put_page(buffer_info->rxbuf.page);
                                buffer_info->rxbuf.page = NULL;
                        }
                }

                buffer_info->dma = 0;
        }

        /* there also may be some cached data from a chained receive */
        napi_free_frags(&adapter->napi);
        rx_ring->rx_skb_top = NULL;

        size = sizeof(struct e1000_rx_buffer) * rx_ring->count;
        memset(rx_ring->buffer_info, 0, size);

        /* Zero out the descriptor ring */
        memset(rx_ring->desc, 0, rx_ring->size);

        rx_ring->next_to_clean = 0;
        rx_ring->next_to_use = 0;

        writel(0, hw->hw_addr + rx_ring->rdh);
        writel(0, hw->hw_addr + rx_ring->rdt);
}

/**
 * e1000_clean_all_rx_rings - Free Rx Buffers for all queues
 * @adapter: board private structure
 **/
static void e1000_clean_all_rx_rings(struct e1000_adapter *adapter)
{
        int i;

        for (i = 0; i < adapter->num_rx_queues; i++)
                e1000_clean_rx_ring(adapter, &adapter->rx_ring[i]);
}

/* The 82542 2.0 (revision 2) needs to have the receive unit in reset
 * and memory write and invalidate disabled for certain operations
 */
static void e1000_enter_82542_rst(struct e1000_adapter *adapter)
{
        struct e1000_hw *hw = &adapter->hw;
        struct net_device *netdev = adapter->netdev;
        u32 rctl;

        e1000_pci_clear_mwi(hw);

        rctl = er32(RCTL);
        rctl |= E1000_RCTL_RST;
        ew32(RCTL, rctl);
        E1000_WRITE_FLUSH();
        mdelay(5);

        if (netif_running(netdev))
                e1000_clean_all_rx_rings(adapter);
}

static void e1000_leave_82542_rst(struct e1000_adapter *adapter)
{
        struct e1000_hw *hw = &adapter->hw;
        struct net_device *netdev = adapter->netdev;
        u32 rctl;

        rctl = er32(RCTL);
        rctl &= ~E1000_RCTL_RST;
        ew32(RCTL, rctl);
        E1000_WRITE_FLUSH();
        mdelay(5);

        if (hw->pci_cmd_word & PCI_COMMAND_INVALIDATE)
                e1000_pci_set_mwi(hw);

        if (netif_running(netdev)) {
                /* No need to loop, because 82542 supports only 1 queue */
                struct e1000_rx_ring *ring = &adapter->rx_ring[0];
                e1000_configure_rx(adapter);
                adapter->alloc_rx_buf(adapter, ring, E1000_DESC_UNUSED(ring));
        }
}

/**
 * e1000_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 e1000_set_mac(struct net_device *netdev, void *p)
{
        struct e1000_adapter *adapter = netdev_priv(netdev);
        struct e1000_hw *hw = &adapter->hw;
        struct sockaddr *addr = p;

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

        /* 82542 2.0 needs to be in reset to write receive address registers */

        if (hw->mac_type == e1000_82542_rev2_0)
                e1000_enter_82542_rst(adapter);

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

        e1000_rar_set(hw, hw->mac_addr, 0);

        if (hw->mac_type == e1000_82542_rev2_0)
                e1000_leave_82542_rst(adapter);

        return 0;
}

/**
 * e1000_set_rx_mode - Secondary Unicast, Multicast and Promiscuous mode set
 * @netdev: network interface device structure
 *
 * The set_rx_mode entry point is called whenever the unicast or multicast
 * address lists or the network interface flags are updated. This routine is
 * responsible for configuring the hardware for proper unicast, multicast,
 * promiscuous mode, and all-multi behavior.
 **/
static void e1000_set_rx_mode(struct net_device *netdev)
{
        struct e1000_adapter *adapter = netdev_priv(netdev);
        struct e1000_hw *hw = &adapter->hw;
        struct netdev_hw_addr *ha;
        bool use_uc = false;
        u32 rctl;
        u32 hash_value;
        int i, rar_entries = E1000_RAR_ENTRIES;
        int mta_reg_count = E1000_NUM_MTA_REGISTERS;
        u32 *mcarray = kcalloc(mta_reg_count, sizeof(u32), GFP_ATOMIC);

        if (!mcarray)
                return;

        /* Check for Promiscuous and All Multicast modes */

        rctl = er32(RCTL);

        if (netdev->flags & IFF_PROMISC) {
                rctl |= (E1000_RCTL_UPE | E1000_RCTL_MPE);
                rctl &= ~E1000_RCTL_VFE;
        } else {
                if (netdev->flags & IFF_ALLMULTI)
                        rctl |= E1000_RCTL_MPE;
                else
                        rctl &= ~E1000_RCTL_MPE;
                /* Enable VLAN filter if there is a VLAN */
                if (e1000_vlan_used(adapter))
                        rctl |= E1000_RCTL_VFE;
        }

        if (netdev_uc_count(netdev) > rar_entries - 1) {
                rctl |= E1000_RCTL_UPE;
        } else if (!(netdev->flags & IFF_PROMISC)) {
                rctl &= ~E1000_RCTL_UPE;
                use_uc = true;
        }

        ew32(RCTL, rctl);

        /* 82542 2.0 needs to be in reset to write receive address registers */

        if (hw->mac_type == e1000_82542_rev2_0)
                e1000_enter_82542_rst(adapter);

        /* load the first 14 addresses into the exact filters 1-14. Unicast
         * addresses take precedence to avoid disabling unicast filtering
         * when possible.
         *
         * RAR 0 is used for the station MAC address
         * if there are not 14 addresses, go ahead and clear the filters
         */
        i = 1;
        if (use_uc)
                netdev_for_each_uc_addr(ha, netdev) {
                        if (i == rar_entries)
                                break;
                        e1000_rar_set(hw, ha->addr, i++);
                }

        netdev_for_each_mc_addr(ha, netdev) {
                if (i == rar_entries) {
                        /* load any remaining addresses into the hash table */
                        u32 hash_reg, hash_bit, mta;
                        hash_value = e1000_hash_mc_addr(hw, ha->addr);
                        hash_reg = (hash_value >> 5) & 0x7F;
                        hash_bit = hash_value & 0x1F;
                        mta = (1 << hash_bit);
                        mcarray[hash_reg] |= mta;
                } else {
                        e1000_rar_set(hw, ha->addr, i++);
                }
        }

        for (; i < rar_entries; i++) {
                E1000_WRITE_REG_ARRAY(hw, RA, i << 1, 0);
                E1000_WRITE_FLUSH();
                E1000_WRITE_REG_ARRAY(hw, RA, (i << 1) + 1, 0);
                E1000_WRITE_FLUSH();
        }

        /* write the hash table completely, write from bottom to avoid
         * both stupid write combining chipsets, and flushing each write
         */
        for (i = mta_reg_count - 1; i >= 0 ; i--) {
                /* If we are on an 82544 has an errata where writing odd
                 * offsets overwrites the previous even offset, but writing
                 * backwards over the range solves the issue by always
                 * writing the odd offset first
                 */
                E1000_WRITE_REG_ARRAY(hw, MTA, i, mcarray[i]);
        }
        E1000_WRITE_FLUSH();

        if (hw->mac_type == e1000_82542_rev2_0)
                e1000_leave_82542_rst(adapter);

        kfree(mcarray);
}

/**
 * e1000_update_phy_info_task - get phy info
 * @work: work struct contained inside adapter struct
 *
 * Need to wait a few seconds after link up to get diagnostic information from
 * the phy
 */
static void e1000_update_phy_info_task(struct work_struct *work)
{
        struct e1000_adapter *adapter = container_of(work,
                                                     struct e1000_adapter,
                                                     phy_info_task.work);

        e1000_phy_get_info(&adapter->hw, &adapter->phy_info);
}

/**
 * e1000_82547_tx_fifo_stall_task - task to complete work
 * @work: work struct contained inside adapter struct
 **/
static void e1000_82547_tx_fifo_stall_task(struct work_struct *work)
{
        struct e1000_adapter *adapter = container_of(work,
                                                     struct e1000_adapter,
                                                     fifo_stall_task.work);
        struct e1000_hw *hw = &adapter->hw;
        struct net_device *netdev = adapter->netdev;
        u32 tctl;

        if (atomic_read(&adapter->tx_fifo_stall)) {
                if ((er32(TDT) == er32(TDH)) &&
                   (er32(TDFT) == er32(TDFH)) &&
                   (er32(TDFTS) == er32(TDFHS))) {
                        tctl = er32(TCTL);
                        ew32(TCTL, tctl & ~E1000_TCTL_EN);
                        ew32(TDFT, adapter->tx_head_addr);
                        ew32(TDFH, adapter->tx_head_addr);
                        ew32(TDFTS, adapter->tx_head_addr);
                        ew32(TDFHS, adapter->tx_head_addr);
                        ew32(TCTL, tctl);
                        E1000_WRITE_FLUSH();

                        adapter->tx_fifo_head = 0;
                        atomic_set(&adapter->tx_fifo_stall, 0);
                        netif_wake_queue(netdev);
                } else if (!test_bit(__E1000_DOWN, &adapter->flags)) {
                        schedule_delayed_work(&adapter->fifo_stall_task, 1);
                }
        }
}

bool e1000_has_link(struct e1000_adapter *adapter)
{
        struct e1000_hw *hw = &adapter->hw;
        bool link_active = false;

        /* get_link_status is set on LSC (link status) interrupt or rx
         * sequence error interrupt (except on intel ce4100).
         * get_link_status will stay false until the
         * e1000_check_for_link establishes link for copper adapters
         * ONLY
         */
        switch (hw->media_type) {
        case e1000_media_type_copper:
                if (hw->mac_type == e1000_ce4100)
                        hw->get_link_status = 1;
                if (hw->get_link_status) {
                        e1000_check_for_link(hw);
                        link_active = !hw->get_link_status;
                } else {
                        link_active = true;
                }
                break;
        case e1000_media_type_fiber:
                e1000_check_for_link(hw);
                link_active = !!(er32(STATUS) & E1000_STATUS_LU);
                break;
        case e1000_media_type_internal_serdes:
                e1000_check_for_link(hw);
                link_active = hw->serdes_has_link;
                break;
        default:
                break;
        }

        return link_active;
}

/**
 * e1000_watchdog - work function
 * @work: work struct contained inside adapter struct
 **/
static void e1000_watchdog(struct work_struct *work)
{
        struct e1000_adapter *adapter = container_of(work,
                                                     struct e1000_adapter,
                                                     watchdog_task.work);
        struct e1000_hw *hw = &adapter->hw;
        struct net_device *netdev = adapter->netdev;
        struct e1000_tx_ring *txdr = adapter->tx_ring;
        u32 link, tctl;

        link = e1000_has_link(adapter);
        if ((netif_carrier_ok(netdev)) && link)
                goto link_up;

        if (link) {
                if (!netif_carrier_ok(netdev)) {
                        u32 ctrl;
                        /* update snapshot of PHY registers on LSC */
                        e1000_get_speed_and_duplex(hw,
                                                   &adapter->link_speed,
                                                   &adapter->link_duplex);

                        ctrl = er32(CTRL);
                        pr_info("%s NIC Link is Up %d Mbps %s, "
                                "Flow Control: %s\n",
                                netdev->name,
                                adapter->link_speed,
                                adapter->link_duplex == FULL_DUPLEX ?
                                "Full Duplex" : "Half Duplex",
                                ((ctrl & E1000_CTRL_TFCE) && (ctrl &
                                E1000_CTRL_RFCE)) ? "RX/TX" : ((ctrl &
                                E1000_CTRL_RFCE) ? "RX" : ((ctrl &
                                E1000_CTRL_TFCE) ? "TX" : "None")));

                        /* adjust timeout factor according to speed/duplex */
                        adapter->tx_timeout_factor = 1;
                        switch (adapter->link_speed) {
                        case SPEED_10:
                                adapter->tx_timeout_factor = 16;
                                break;
                        case SPEED_100:
                                /* maybe add some timeout factor ? */
                                break;
                        }

                        /* enable transmits in the hardware */
                        tctl = er32(TCTL);
                        tctl |= E1000_TCTL_EN;
                        ew32(TCTL, tctl);

                        netif_carrier_on(netdev);
                        if (!test_bit(__E1000_DOWN, &adapter->flags))
                                schedule_delayed_work(&adapter->phy_info_task,
                                                      2 * HZ);
                        adapter->smartspeed = 0;
                }
        } else {
                if (netif_carrier_ok(netdev)) {
                        adapter->link_speed = 0;
                        adapter->link_duplex = 0;
                        pr_info("%s NIC Link is Down\n",
                                netdev->name);
                        netif_carrier_off(netdev);

                        if (!test_bit(__E1000_DOWN, &adapter->flags))
                                schedule_delayed_work(&adapter->phy_info_task,
                                                      2 * HZ);
                }

                e1000_smartspeed(adapter);
        }

link_up:
        e1000_update_stats(adapter);

        hw->tx_packet_delta = adapter->stats.tpt - adapter->tpt_old;
        adapter->tpt_old = adapter->stats.tpt;
        hw->collision_delta = adapter->stats.colc - adapter->colc_old;
        adapter->colc_old = adapter->stats.colc;

        adapter->gorcl = adapter->stats.gorcl - adapter->gorcl_old;
        adapter->gorcl_old = adapter->stats.gorcl;
        adapter->gotcl = adapter->stats.gotcl - adapter->gotcl_old;
        adapter->gotcl_old = adapter->stats.gotcl;

        e1000_update_adaptive(hw);

        if (!netif_carrier_ok(netdev)) {
                if (E1000_DESC_UNUSED(txdr) + 1 < txdr->count) {
                        /* We've lost link, so the controller stops DMA,
                         * but we've got queued Tx work that's never going
                         * to get done, so reset controller to flush Tx.
                         * (Do the reset outside of interrupt context).
                         */
                        adapter->tx_timeout_count++;
                        schedule_work(&adapter->reset_task);
                        /* exit immediately since reset is imminent */
                        return;
                }
        }

        /* Simple mode for Interrupt Throttle Rate (ITR) */
        if (hw->mac_type >= e1000_82540 && adapter->itr_setting == 4) {
                /* Symmetric Tx/Rx gets a reduced ITR=2000;
                 * Total asymmetrical Tx or Rx gets ITR=8000;
                 * everyone else is between 2000-8000.
                 */
                u32 goc = (adapter->gotcl + adapter->gorcl) / 10000;
                u32 dif = (adapter->gotcl > adapter->gorcl ?
                            adapter->gotcl - adapter->gorcl :
                            adapter->gorcl - adapter->gotcl) / 10000;
                u32 itr = goc > 0 ? (dif * 6000 / goc + 2000) : 8000;

                ew32(ITR, 1000000000 / (itr * 256));
        }

        /* Cause software interrupt to ensure rx ring is cleaned */
        ew32(ICS, E1000_ICS_RXDMT0);

        /* Force detection of hung controller every watchdog period */
        adapter->detect_tx_hung = true;

        /* Reschedule the task */
        if (!test_bit(__E1000_DOWN, &adapter->flags))
                schedule_delayed_work(&adapter->watchdog_task, 2 * HZ);
}

enum latency_range {
        lowest_latency = 0,
        low_latency = 1,
        bulk_latency = 2,
        latency_invalid = 255
};

/**
 * e1000_update_itr - update the dynamic ITR value based on statistics
 * @adapter: pointer to adapter
 * @itr_setting: current adapter->itr
 * @packets: the number of packets during this measurement interval
 * @bytes: the number of bytes during this measurement interval
 *
 *      Stores a new ITR value based on packets and byte
 *      counts during the last interrupt.  The advantage of per interrupt
 *      computation is faster updates and more accurate ITR for the current
 *      traffic pattern.  Constants in this function were computed
 *      based on theoretical maximum wire speed and thresholds were set based
 *      on testing data as well as attempting to minimize response time
 *      while increasing bulk throughput.
 *      this functionality is controlled by the InterruptThrottleRate module
 *      parameter (see e1000_param.c)
 **/
static unsigned int e1000_update_itr(struct e1000_adapter *adapter,
                                     u16 itr_setting, int packets, int bytes)
{
        unsigned int retval = itr_setting;
        struct e1000_hw *hw = &adapter->hw;

        if (unlikely(hw->mac_type < e1000_82540))
                goto update_itr_done;

        if (packets == 0)
                goto update_itr_done;

        switch (itr_setting) {
        case lowest_latency:
                /* jumbo frames get bulk treatment*/
                if (bytes/packets > 8000)
                        retval = bulk_latency;
                else if ((packets < 5) && (bytes > 512))
                        retval = low_latency;
                break;
        case low_latency:  /* 50 usec aka 20000 ints/s */
                if (bytes > 10000) {
                        /* jumbo frames need bulk latency setting */
                        if (bytes/packets > 8000)
                                retval = bulk_latency;
                        else if ((packets < 10) || ((bytes/packets) > 1200))
                                retval = bulk_latency;
                        else if ((packets > 35))
                                retval = lowest_latency;
                } else if (bytes/packets > 2000)
                        retval = bulk_latency;
                else if (packets <= 2 && bytes < 512)
                        retval = lowest_latency;
                break;
        case bulk_latency: /* 250 usec aka 4000 ints/s */
                if (bytes > 25000) {
                        if (packets > 35)
                                retval = low_latency;
                } else if (bytes < 6000) {
                        retval = low_latency;
                }
                break;
        }

update_itr_done:
        return retval;
}

static void e1000_set_itr(struct e1000_adapter *adapter)
{
        struct e1000_hw *hw = &adapter->hw;
        u16 current_itr;
        u32 new_itr = adapter->itr;

        if (unlikely(hw->mac_type < e1000_82540))
                return;

        /* for non-gigabit speeds, just fix the interrupt rate at 4000 */
        if (unlikely(adapter->link_speed != SPEED_1000)) {
                new_itr = 4000;
                goto set_itr_now;
        }

        adapter->tx_itr = e1000_update_itr(adapter, adapter->tx_itr,
                                           adapter->total_tx_packets,
                                           adapter->total_tx_bytes);
        /* conservative mode (itr 3) eliminates the lowest_latency setting */
        if (adapter->itr_setting == 3 && adapter->tx_itr == lowest_latency)
                adapter->tx_itr = low_latency;

        adapter->rx_itr = e1000_update_itr(adapter, adapter->rx_itr,
                                           adapter->total_rx_packets,
                                           adapter->total_rx_bytes);
        /* conservative mode (itr 3) eliminates the lowest_latency setting */
        if (adapter->itr_setting == 3 && adapter->rx_itr == lowest_latency)
                adapter->rx_itr = low_latency;

        current_itr = max(adapter->rx_itr, adapter->tx_itr);

        switch (current_itr) {
        /* counts and packets in update_itr are dependent on these numbers */
        case lowest_latency:
                new_itr = 70000;
                break;
        case low_latency:
                new_itr = 20000; /* aka hwitr = ~200 */
                break;
        case bulk_latency:
                new_itr = 4000;
                break;
        default:
                break;
        }

set_itr_now:
        if (new_itr != adapter->itr) {
                /* this attempts to bias the interrupt rate towards Bulk
                 * by adding intermediate steps when interrupt rate is
                 * increasing
                 */
                new_itr = new_itr > adapter->itr ?
                          min(adapter->itr + (new_itr >> 2), new_itr) :
                          new_itr;
                adapter->itr = new_itr;
                ew32(ITR, 1000000000 / (new_itr * 256));
        }
}

#define E1000_TX_FLAGS_CSUM             0x00000001
#define E1000_TX_FLAGS_VLAN             0x00000002
#define E1000_TX_FLAGS_TSO              0x00000004
#define E1000_TX_FLAGS_IPV4             0x00000008
#define E1000_TX_FLAGS_NO_FCS           0x00000010
#define E1000_TX_FLAGS_VLAN_MASK        0xffff0000
#define E1000_TX_FLAGS_VLAN_SHIFT       16

static int e1000_tso(struct e1000_adapter *adapter,
                     struct e1000_tx_ring *tx_ring, struct sk_buff *skb,
                     __be16 protocol)
{
        struct e1000_context_desc *context_desc;
        struct e1000_tx_buffer *buffer_info;
        unsigned int i;
        u32 cmd_length = 0;
        u16 ipcse = 0, tucse, mss;
        u8 ipcss, ipcso, tucss, tucso, hdr_len;

        if (skb_is_gso(skb)) {
                int err;

                err = skb_cow_head(skb, 0);
                if (err < 0)
                        return err;

                hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
                mss = skb_shinfo(skb)->gso_size;
                if (protocol == htons(ETH_P_IP)) {
                        struct iphdr *iph = ip_hdr(skb);
                        iph->tot_len = 0;
                        iph->check = 0;
                        tcp_hdr(skb)->check = ~csum_tcpudp_magic(iph->saddr,
                                                                 iph->daddr, 0,
                                                                 IPPROTO_TCP,
                                                                 0);
                        cmd_length = E1000_TXD_CMD_IP;
                        ipcse = skb_transport_offset(skb) - 1;
                } else if (skb_is_gso_v6(skb)) {
                        tcp_v6_gso_csum_prep(skb);
                        ipcse = 0;
                }
                ipcss = skb_network_offset(skb);
                ipcso = (void *)&(ip_hdr(skb)->check) - (void *)skb->data;
                tucss = skb_transport_offset(skb);
                tucso = (void *)&(tcp_hdr(skb)->check) - (void *)skb->data;
                tucse = 0;

                cmd_length |= (E1000_TXD_CMD_DEXT | E1000_TXD_CMD_TSE |
                               E1000_TXD_CMD_TCP | (skb->len - (hdr_len)));

                i = tx_ring->next_to_use;
                context_desc = E1000_CONTEXT_DESC(*tx_ring, i);
                buffer_info = &tx_ring->buffer_info[i];

                context_desc->lower_setup.ip_fields.ipcss  = ipcss;
                context_desc->lower_setup.ip_fields.ipcso  = ipcso;
                context_desc->lower_setup.ip_fields.ipcse  = cpu_to_le16(ipcse);
                context_desc->upper_setup.tcp_fields.tucss = tucss;
                context_desc->upper_setup.tcp_fields.tucso = tucso;
                context_desc->upper_setup.tcp_fields.tucse = cpu_to_le16(tucse);
                context_desc->tcp_seg_setup.fields.mss     = cpu_to_le16(mss);
                context_desc->tcp_seg_setup.fields.hdr_len = hdr_len;
                context_desc->cmd_and_length = cpu_to_le32(cmd_length);

                buffer_info->time_stamp = jiffies;
                buffer_info->next_to_watch = i;

                if (++i == tx_ring->count)
                        i = 0;

                tx_ring->next_to_use = i;

                return true;
        }
        return false;
}

static bool e1000_tx_csum(struct e1000_adapter *adapter,
                          struct e1000_tx_ring *tx_ring, struct sk_buff *skb,
                          __be16 protocol)
{
        struct e1000_context_desc *context_desc;
        struct e1000_tx_buffer *buffer_info;
        unsigned int i;
        u8 css;
        u32 cmd_len = E1000_TXD_CMD_DEXT;

        if (skb->ip_summed != CHECKSUM_PARTIAL)
                return false;

        switch (protocol) {
        case cpu_to_be16(ETH_P_IP):
                if (ip_hdr(skb)->protocol == IPPROTO_TCP)
                        cmd_len |= E1000_TXD_CMD_TCP;
                break;
        case cpu_to_be16(ETH_P_IPV6):
                /* XXX not handling all IPV6 headers */
                if (ipv6_hdr(skb)->nexthdr == IPPROTO_TCP)
                        cmd_len |= E1000_TXD_CMD_TCP;
                break;
        default:
                if (unlikely(net_ratelimit()))
                        e_warn(drv, "checksum_partial proto=%x!\n",
                               skb->protocol);
                break;
        }

        css = skb_checksum_start_offset(skb);

        i = tx_ring->next_to_use;
        buffer_info = &tx_ring->buffer_info[i];
        context_desc = E1000_CONTEXT_DESC(*tx_ring, i);

        context_desc->lower_setup.ip_config = 0;
        context_desc->upper_setup.tcp_fields.tucss = css;
        context_desc->upper_setup.tcp_fields.tucso =
                css + skb->csum_offset;
        context_desc->upper_setup.tcp_fields.tucse = 0;
        context_desc->tcp_seg_setup.data = 0;
        context_desc->cmd_and_length = cpu_to_le32(cmd_len);

        buffer_info->time_stamp = jiffies;
        buffer_info->next_to_watch = i;

        if (unlikely(++i == tx_ring->count))
                i = 0;

        tx_ring->next_to_use = i;

        return true;
}

#define E1000_MAX_TXD_PWR       12
#define E1000_MAX_DATA_PER_TXD  (1<<E1000_MAX_TXD_PWR)

static int e1000_tx_map(struct e1000_adapter *adapter,
                        struct e1000_tx_ring *tx_ring,
                        struct sk_buff *skb, unsigned int first,
                        unsigned int max_per_txd, unsigned int nr_frags,
                        unsigned int mss)
{
        struct e1000_hw *hw = &adapter->hw;
        struct pci_dev *pdev = adapter->pdev;
        struct e1000_tx_buffer *buffer_info;
        unsigned int len = skb_headlen(skb);
        unsigned int offset = 0, size, count = 0, i;
        unsigned int f, bytecount, segs;

        i = tx_ring->next_to_use;

        while (len) {
                buffer_info = &tx_ring->buffer_info[i];
                size = min(len, max_per_txd);
                /* Workaround for Controller erratum --
                 * descriptor for non-tso packet in a linear SKB that follows a
                 * tso gets written back prematurely before the data is fully
                 * DMA'd to the controller
                 */
                if (!skb->data_len && tx_ring->last_tx_tso &&
                    !skb_is_gso(skb)) {
                        tx_ring->last_tx_tso = false;
                        size -= 4;
                }

                /* Workaround for premature desc write-backs
                 * in TSO mode.  Append 4-byte sentinel desc
                 */
                if (unlikely(mss && !nr_frags && size == len && size > 8))
                        size -= 4;
                /* work-around for errata 10 and it applies
                 * to all controllers in PCI-X mode
                 * The fix is to make sure that the first descriptor of a
                 * packet is smaller than 2048 - 16 - 16 (or 2016) bytes
                 */
                if (unlikely((hw->bus_type == e1000_bus_type_pcix) &&
                             (size > 2015) && count == 0))
                        size = 2015;

                /* Workaround for potential 82544 hang in PCI-X.  Avoid
                 * terminating buffers within evenly-aligned dwords.
                 */
                if (unlikely(adapter->pcix_82544 &&
                   !((unsigned long)(skb->data + offset + size - 1) & 4) &&
                   size > 4))
                        size -= 4;

                buffer_info->length = size;
                /* set time_stamp *before* dma to help avoid a possible race */
                buffer_info->time_stamp = jiffies;
                buffer_info->mapped_as_page = false;
                buffer_info->dma = dma_map_single(&pdev->dev,
                                                  skb->data + offset,
                                                  size, DMA_TO_DEVICE);
                if (dma_mapping_error(&pdev->dev, buffer_info->dma))
                        goto dma_error;
                buffer_info->next_to_watch = i;

                len -= size;
                offset += size;
                count++;
                if (len) {
                        i++;
                        if (unlikely(i == tx_ring->count))
                                i = 0;
                }
        }

        for (f = 0; f < nr_frags; f++) {
                const skb_frag_t *frag = &skb_shinfo(skb)->frags[f];

                len = skb_frag_size(frag);
                offset = 0;

                while (len) {
                        unsigned long bufend;
                        i++;
                        if (unlikely(i == tx_ring->count))
                                i = 0;

                        buffer_info = &tx_ring->buffer_info[i];
                        size = min(len, max_per_txd);
                        /* Workaround for premature desc write-backs
                         * in TSO mode.  Append 4-byte sentinel desc
                         */
                        if (unlikely(mss && f == (nr_frags-1) &&
                            size == len && size > 8))
                                size -= 4;
                        /* Workaround for potential 82544 hang in PCI-X.
                         * Avoid terminating buffers within evenly-aligned
                         * dwords.
                         */
                        bufend = (unsigned long)
                                page_to_phys(skb_frag_page(frag));
                        bufend += offset + size - 1;
                        if (unlikely(adapter->pcix_82544 &&
                                     !(bufend & 4) &&
                                     size > 4))
                                size -= 4;

                        buffer_info->length = size;
                        buffer_info->time_stamp = jiffies;
                        buffer_info->mapped_as_page = true;
                        buffer_info->dma = skb_frag_dma_map(&pdev->dev, frag,
                                                offset, size, DMA_TO_DEVICE);
                        if (dma_mapping_error(&pdev->dev, buffer_info->dma))
                                goto dma_error;
                        buffer_info->next_to_watch = i;

                        len -= size;
                        offset += size;
                        count++;
                }
        }

        segs = skb_shinfo(skb)->gso_segs ?: 1;
        /* multiply data chunks by size of headers */
        bytecount = ((segs - 1) * skb_headlen(skb)) + skb->len;

        tx_ring->buffer_info[i].skb = skb;
        tx_ring->buffer_info[i].segs = segs;
        tx_ring->buffer_info[i].bytecount = bytecount;
        tx_ring->buffer_info[first].next_to_watch = i;

        return count;

dma_error:
        dev_err(&pdev->dev, "TX DMA map failed\n");
        buffer_info->dma = 0;
        if (count)
                count--;

        while (count--) {
                if (i == 0)
                        i += tx_ring->count;
                i--;
                buffer_info = &tx_ring->buffer_info[i];
                e1000_unmap_and_free_tx_resource(adapter, buffer_info);
        }

        return 0;
}

static void e1000_tx_queue(struct e1000_adapter *adapter,
                           struct e1000_tx_ring *tx_ring, int tx_flags,
                           int count)
{
        struct e1000_tx_desc *tx_desc = NULL;
        struct e1000_tx_buffer *buffer_info;
        u32 txd_upper = 0, txd_lower = E1000_TXD_CMD_IFCS;
        unsigned int i;

        if (likely(tx_flags & E1000_TX_FLAGS_TSO)) {
                txd_lower |= E1000_TXD_CMD_DEXT | E1000_TXD_DTYP_D |
                             E1000_TXD_CMD_TSE;
                txd_upper |= E1000_TXD_POPTS_TXSM << 8;

                if (likely(tx_flags & E1000_TX_FLAGS_IPV4))
                        txd_upper |= E1000_TXD_POPTS_IXSM << 8;
        }

        if (likely(tx_flags & E1000_TX_FLAGS_CSUM)) {
                txd_lower |= E1000_TXD_CMD_DEXT | E1000_TXD_DTYP_D;
                txd_upper |= E1000_TXD_POPTS_TXSM << 8;
        }

        if (unlikely(tx_flags & E1000_TX_FLAGS_VLAN)) {
                txd_lower |= E1000_TXD_CMD_VLE;
                txd_upper |= (tx_flags & E1000_TX_FLAGS_VLAN_MASK);
        }

        if (unlikely(tx_flags & E1000_TX_FLAGS_NO_FCS))
                txd_lower &= ~(E1000_TXD_CMD_IFCS);

        i = tx_ring->next_to_use;

        while (count--) {