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

#include <linux/module.h>
#include <linux/types.h>
#include <linux/if_vlan.h>
#include <linux/aer.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/ip.h>
#include <linux/pm_runtime.h>
#include <net/pkt_sched.h>

#include <net/ipv6.h>

#include "igc.h"
#include "igc_hw.h"
#include "igc_tsn.h"

#define DRV_SUMMARY     "Intel(R) 2.5G Ethernet Linux Driver"

#define DEFAULT_MSG_ENABLE (NETIF_MSG_DRV | NETIF_MSG_PROBE | NETIF_MSG_LINK)

static int debug = -1;

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

char igc_driver_name[] = "igc";
static const char igc_driver_string[] = DRV_SUMMARY;
static const char igc_copyright[] =
        "Copyright(c) 2018 Intel Corporation.";

static const struct igc_info *igc_info_tbl[] = {
        [board_base] = &igc_base_info,
};

static const struct pci_device_id igc_pci_tbl[] = {
        { PCI_VDEVICE(INTEL, IGC_DEV_ID_I225_LM), board_base },
        { PCI_VDEVICE(INTEL, IGC_DEV_ID_I225_V), board_base },
        { PCI_VDEVICE(INTEL, IGC_DEV_ID_I225_I), board_base },
        { PCI_VDEVICE(INTEL, IGC_DEV_ID_I220_V), board_base },
        { PCI_VDEVICE(INTEL, IGC_DEV_ID_I225_K), board_base },
        { PCI_VDEVICE(INTEL, IGC_DEV_ID_I225_K2), board_base },
        { PCI_VDEVICE(INTEL, IGC_DEV_ID_I225_LMVP), board_base },
        { PCI_VDEVICE(INTEL, IGC_DEV_ID_I225_IT), board_base },
        { PCI_VDEVICE(INTEL, IGC_DEV_ID_I226_LM), board_base },
        { PCI_VDEVICE(INTEL, IGC_DEV_ID_I226_V), board_base },
        { PCI_VDEVICE(INTEL, IGC_DEV_ID_I226_IT), board_base },
        { PCI_VDEVICE(INTEL, IGC_DEV_ID_I221_V), board_base },
        { PCI_VDEVICE(INTEL, IGC_DEV_ID_I226_BLANK_NVM), board_base },
        { PCI_VDEVICE(INTEL, IGC_DEV_ID_I225_BLANK_NVM), board_base },
        /* required last entry */
        {0, }
};

MODULE_DEVICE_TABLE(pci, igc_pci_tbl);

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

void igc_reset(struct igc_adapter *adapter)
{
        struct net_device *dev = adapter->netdev;
        struct igc_hw *hw = &adapter->hw;
        struct igc_fc_info *fc = &hw->fc;
        u32 pba, hwm;

        /* Repartition PBA for greater than 9k MTU if required */
        pba = IGC_PBA_34K;

        /* flow control settings
         * The high water mark must be low enough to fit one full frame
         * after transmitting the pause frame.  As such we must have enough
         * space to allow for us to complete our current transmit and then
         * receive the frame that is in progress from the link partner.
         * Set it to:
         * - the full Rx FIFO size minus one full Tx plus one full Rx frame
         */
        hwm = (pba << 10) - (adapter->max_frame_size + MAX_JUMBO_FRAME_SIZE);

        fc->high_water = hwm & 0xFFFFFFF0;      /* 16-byte granularity */
        fc->low_water = fc->high_water - 16;
        fc->pause_time = 0xFFFF;
        fc->send_xon = 1;
        fc->current_mode = fc->requested_mode;

        hw->mac.ops.reset_hw(hw);

        if (hw->mac.ops.init_hw(hw))
                netdev_err(dev, "Error on hardware initialization\n");

        /* Re-establish EEE setting */
        igc_set_eee_i225(hw, true, true, true);

        if (!netif_running(adapter->netdev))
                igc_power_down_phy_copper_base(&adapter->hw);

        /* Re-enable PTP, where applicable. */
        igc_ptp_reset(adapter);

        /* Re-enable TSN offloading, where applicable. */
        igc_tsn_offload_apply(adapter);

        igc_get_phy_info(hw);
}

/**
 * igc_power_up_link - Power up the phy link
 * @adapter: address of board private structure
 */
static void igc_power_up_link(struct igc_adapter *adapter)
{
        igc_reset_phy(&adapter->hw);

        igc_power_up_phy_copper(&adapter->hw);

        igc_setup_link(&adapter->hw);
}

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

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

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

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

/**
 * igc_clean_tx_ring - Free Tx Buffers
 * @tx_ring: ring to be cleaned
 */
static void igc_clean_tx_ring(struct igc_ring *tx_ring)
{
        u16 i = tx_ring->next_to_clean;
        struct igc_tx_buffer *tx_buffer = &tx_ring->tx_buffer_info[i];

        while (i != tx_ring->next_to_use) {
                union igc_adv_tx_desc *eop_desc, *tx_desc;

                /* Free all the Tx ring sk_buffs */
                dev_kfree_skb_any(tx_buffer->skb);

                /* unmap skb header data */
                dma_unmap_single(tx_ring->dev,
                                 dma_unmap_addr(tx_buffer, dma),
                                 dma_unmap_len(tx_buffer, len),
                                 DMA_TO_DEVICE);

                /* check for eop_desc to determine the end of the packet */
                eop_desc = tx_buffer->next_to_watch;
                tx_desc = IGC_TX_DESC(tx_ring, i);

                /* unmap remaining buffers */
                while (tx_desc != eop_desc) {
                        tx_buffer++;
                        tx_desc++;
                        i++;
                        if (unlikely(i == tx_ring->count)) {
                                i = 0;
                                tx_buffer = tx_ring->tx_buffer_info;
                                tx_desc = IGC_TX_DESC(tx_ring, 0);
                        }

                        /* unmap any remaining paged data */
                        if (dma_unmap_len(tx_buffer, len))
                                dma_unmap_page(tx_ring->dev,
                                               dma_unmap_addr(tx_buffer, dma),
                                               dma_unmap_len(tx_buffer, len),
                                               DMA_TO_DEVICE);
                }

                /* move us one more past the eop_desc for start of next pkt */
                tx_buffer++;
                i++;
                if (unlikely(i == tx_ring->count)) {
                        i = 0;
                        tx_buffer = tx_ring->tx_buffer_info;
                }
        }

        /* reset BQL for queue */
        netdev_tx_reset_queue(txring_txq(tx_ring));

        /* reset next_to_use and next_to_clean */
        tx_ring->next_to_use = 0;
        tx_ring->next_to_clean = 0;
}

/**
 * igc_free_tx_resources - Free Tx Resources per Queue
 * @tx_ring: Tx descriptor ring for a specific queue
 *
 * Free all transmit software resources
 */
void igc_free_tx_resources(struct igc_ring *tx_ring)
{
        igc_clean_tx_ring(tx_ring);

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

        /* if not set, then don't free */
        if (!tx_ring->desc)
                return;

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

        tx_ring->desc = NULL;
}

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

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

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

        for (i = 0; i < adapter->num_tx_queues; i++)
                if (adapter->tx_ring[i])
                        igc_clean_tx_ring(adapter->tx_ring[i]);
}

/**
 * igc_setup_tx_resources - allocate Tx resources (Descriptors)
 * @tx_ring: tx descriptor ring (for a specific queue) to setup
 *
 * Return 0 on success, negative on failure
 */
int igc_setup_tx_resources(struct igc_ring *tx_ring)
{
        struct net_device *ndev = tx_ring->netdev;
        struct device *dev = tx_ring->dev;
        int size = 0;

        size = sizeof(struct igc_tx_buffer) * tx_ring->count;
        tx_ring->tx_buffer_info = vzalloc(size);
        if (!tx_ring->tx_buffer_info)
                goto err;

        /* round up to nearest 4K */
        tx_ring->size = tx_ring->count * sizeof(union igc_adv_tx_desc);
        tx_ring->size = ALIGN(tx_ring->size, 4096);

        tx_ring->desc = dma_alloc_coherent(dev, tx_ring->size,
                                           &tx_ring->dma, GFP_KERNEL);

        if (!tx_ring->desc)
                goto err;

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

        return 0;

err:
        vfree(tx_ring->tx_buffer_info);
        netdev_err(ndev, "Unable to allocate memory for Tx descriptor ring\n");
        return -ENOMEM;
}

/**
 * igc_setup_all_tx_resources - wrapper to allocate Tx resources for all queues
 * @adapter: board private structure
 *
 * Return 0 on success, negative on failure
 */
static int igc_setup_all_tx_resources(struct igc_adapter *adapter)
{
        struct net_device *dev = adapter->netdev;
        int i, err = 0;

        for (i = 0; i < adapter->num_tx_queues; i++) {
                err = igc_setup_tx_resources(adapter->tx_ring[i]);
                if (err) {
                        netdev_err(dev, "Error on Tx queue %u setup\n", i);
                        for (i--; i >= 0; i--)
                                igc_free_tx_resources(adapter->tx_ring[i]);
                        break;
                }
        }

        return err;
}

/**
 * igc_clean_rx_ring - Free Rx Buffers per Queue
 * @rx_ring: ring to free buffers from
 */
static void igc_clean_rx_ring(struct igc_ring *rx_ring)
{
        u16 i = rx_ring->next_to_clean;

        dev_kfree_skb(rx_ring->skb);
        rx_ring->skb = NULL;

        /* Free all the Rx ring sk_buffs */
        while (i != rx_ring->next_to_alloc) {
                struct igc_rx_buffer *buffer_info = &rx_ring->rx_buffer_info[i];

                /* Invalidate cache lines that may have been written to by
                 * device so that we avoid corrupting memory.
                 */
                dma_sync_single_range_for_cpu(rx_ring->dev,
                                              buffer_info->dma,
                                              buffer_info->page_offset,
                                              igc_rx_bufsz(rx_ring),
                                              DMA_FROM_DEVICE);

                /* free resources associated with mapping */
                dma_unmap_page_attrs(rx_ring->dev,
                                     buffer_info->dma,
                                     igc_rx_pg_size(rx_ring),
                                     DMA_FROM_DEVICE,
                                     IGC_RX_DMA_ATTR);
                __page_frag_cache_drain(buffer_info->page,
                                        buffer_info->pagecnt_bias);

                i++;
                if (i == rx_ring->count)
                        i = 0;
        }

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

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

        for (i = 0; i < adapter->num_rx_queues; i++)
                if (adapter->rx_ring[i])
                        igc_clean_rx_ring(adapter->rx_ring[i]);
}

/**
 * igc_free_rx_resources - Free Rx Resources
 * @rx_ring: ring to clean the resources from
 *
 * Free all receive software resources
 */
void igc_free_rx_resources(struct igc_ring *rx_ring)
{
        igc_clean_rx_ring(rx_ring);

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

        /* if not set, then don't free */
        if (!rx_ring->desc)
                return;

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

        rx_ring->desc = NULL;
}

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

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

/**
 * igc_setup_rx_resources - allocate Rx resources (Descriptors)
 * @rx_ring:    rx descriptor ring (for a specific queue) to setup
 *
 * Returns 0 on success, negative on failure
 */
int igc_setup_rx_resources(struct igc_ring *rx_ring)
{
        struct net_device *ndev = rx_ring->netdev;
        struct device *dev = rx_ring->dev;
        int size, desc_len;

        size = sizeof(struct igc_rx_buffer) * rx_ring->count;
        rx_ring->rx_buffer_info = vzalloc(size);
        if (!rx_ring->rx_buffer_info)
                goto err;

        desc_len = sizeof(union igc_adv_rx_desc);

        /* Round up to nearest 4K */
        rx_ring->size = rx_ring->count * desc_len;
        rx_ring->size = ALIGN(rx_ring->size, 4096);

        rx_ring->desc = dma_alloc_coherent(dev, rx_ring->size,
                                           &rx_ring->dma, GFP_KERNEL);

        if (!rx_ring->desc)
                goto err;

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

        return 0;

err:
        vfree(rx_ring->rx_buffer_info);
        rx_ring->rx_buffer_info = NULL;
        netdev_err(ndev, "Unable to allocate memory for Rx descriptor ring\n");
        return -ENOMEM;
}

/**
 * igc_setup_all_rx_resources - wrapper to allocate Rx resources
 *                                (Descriptors) for all queues
 * @adapter: board private structure
 *
 * Return 0 on success, negative on failure
 */
static int igc_setup_all_rx_resources(struct igc_adapter *adapter)
{
        struct net_device *dev = adapter->netdev;
        int i, err = 0;

        for (i = 0; i < adapter->num_rx_queues; i++) {
                err = igc_setup_rx_resources(adapter->rx_ring[i]);
                if (err) {
                        netdev_err(dev, "Error on Rx queue %u setup\n", i);
                        for (i--; i >= 0; i--)
                                igc_free_rx_resources(adapter->rx_ring[i]);
                        break;
                }
        }

        return err;
}

/**
 * igc_configure_rx_ring - Configure a receive ring after Reset
 * @adapter: board private structure
 * @ring: receive ring to be configured
 *
 * Configure the Rx unit of the MAC after a reset.
 */
static void igc_configure_rx_ring(struct igc_adapter *adapter,
                                  struct igc_ring *ring)
{
        struct igc_hw *hw = &adapter->hw;
        union igc_adv_rx_desc *rx_desc;
        int reg_idx = ring->reg_idx;
        u32 srrctl = 0, rxdctl = 0;
        u64 rdba = ring->dma;

        /* disable the queue */
        wr32(IGC_RXDCTL(reg_idx), 0);

        /* Set DMA base address registers */
        wr32(IGC_RDBAL(reg_idx),
             rdba & 0x00000000ffffffffULL);
        wr32(IGC_RDBAH(reg_idx), rdba >> 32);
        wr32(IGC_RDLEN(reg_idx),
             ring->count * sizeof(union igc_adv_rx_desc));

        /* initialize head and tail */
        ring->tail = adapter->io_addr + IGC_RDT(reg_idx);
        wr32(IGC_RDH(reg_idx), 0);
        writel(0, ring->tail);

        /* reset next-to- use/clean to place SW in sync with hardware */
        ring->next_to_clean = 0;
        ring->next_to_use = 0;

        /* set descriptor configuration */
        srrctl = IGC_RX_HDR_LEN << IGC_SRRCTL_BSIZEHDRSIZE_SHIFT;
        if (ring_uses_large_buffer(ring))
                srrctl |= IGC_RXBUFFER_3072 >> IGC_SRRCTL_BSIZEPKT_SHIFT;
        else
                srrctl |= IGC_RXBUFFER_2048 >> IGC_SRRCTL_BSIZEPKT_SHIFT;
        srrctl |= IGC_SRRCTL_DESCTYPE_ADV_ONEBUF;

        wr32(IGC_SRRCTL(reg_idx), srrctl);

        rxdctl |= IGC_RX_PTHRESH;
        rxdctl |= IGC_RX_HTHRESH << 8;
        rxdctl |= IGC_RX_WTHRESH << 16;

        /* initialize rx_buffer_info */
        memset(ring->rx_buffer_info, 0,
               sizeof(struct igc_rx_buffer) * ring->count);

        /* initialize Rx descriptor 0 */
        rx_desc = IGC_RX_DESC(ring, 0);
        rx_desc->wb.upper.length = 0;

        /* enable receive descriptor fetching */
        rxdctl |= IGC_RXDCTL_QUEUE_ENABLE;

        wr32(IGC_RXDCTL(reg_idx), rxdctl);
}

/**
 * igc_configure_rx - Configure receive Unit after Reset
 * @adapter: board private structure
 *
 * Configure the Rx unit of the MAC after a reset.
 */
static void igc_configure_rx(struct igc_adapter *adapter)
{
        int i;

        /* Setup the HW Rx Head and Tail Descriptor Pointers and
         * the Base and Length of the Rx Descriptor Ring
         */
        for (i = 0; i < adapter->num_rx_queues; i++)
                igc_configure_rx_ring(adapter, adapter->rx_ring[i]);
}

/**
 * igc_configure_tx_ring - Configure transmit ring after Reset
 * @adapter: board private structure
 * @ring: tx ring to configure
 *
 * Configure a transmit ring after a reset.
 */
static void igc_configure_tx_ring(struct igc_adapter *adapter,
                                  struct igc_ring *ring)
{
        struct igc_hw *hw = &adapter->hw;
        int reg_idx = ring->reg_idx;
        u64 tdba = ring->dma;
        u32 txdctl = 0;

        /* disable the queue */
        wr32(IGC_TXDCTL(reg_idx), 0);
        wrfl();
        mdelay(10);

        wr32(IGC_TDLEN(reg_idx),
             ring->count * sizeof(union igc_adv_tx_desc));
        wr32(IGC_TDBAL(reg_idx),
             tdba & 0x00000000ffffffffULL);
        wr32(IGC_TDBAH(reg_idx), tdba >> 32);

        ring->tail = adapter->io_addr + IGC_TDT(reg_idx);
        wr32(IGC_TDH(reg_idx), 0);
        writel(0, ring->tail);

        txdctl |= IGC_TX_PTHRESH;
        txdctl |= IGC_TX_HTHRESH << 8;
        txdctl |= IGC_TX_WTHRESH << 16;

        txdctl |= IGC_TXDCTL_QUEUE_ENABLE;
        wr32(IGC_TXDCTL(reg_idx), txdctl);
}

/**
 * igc_configure_tx - Configure transmit Unit after Reset
 * @adapter: board private structure
 *
 * Configure the Tx unit of the MAC after a reset.
 */
static void igc_configure_tx(struct igc_adapter *adapter)
{
        int i;

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

/**
 * igc_setup_mrqc - configure the multiple receive queue control registers
 * @adapter: Board private structure
 */
static void igc_setup_mrqc(struct igc_adapter *adapter)
{
        struct igc_hw *hw = &adapter->hw;
        u32 j, num_rx_queues;
        u32 mrqc, rxcsum;
        u32 rss_key[10];

        netdev_rss_key_fill(rss_key, sizeof(rss_key));
        for (j = 0; j < 10; j++)
                wr32(IGC_RSSRK(j), rss_key[j]);

        num_rx_queues = adapter->rss_queues;

        if (adapter->rss_indir_tbl_init != num_rx_queues) {
                for (j = 0; j < IGC_RETA_SIZE; j++)
                        adapter->rss_indir_tbl[j] =
                        (j * num_rx_queues) / IGC_RETA_SIZE;
                adapter->rss_indir_tbl_init = num_rx_queues;
        }
        igc_write_rss_indir_tbl(adapter);

        /* Disable raw packet checksumming so that RSS hash is placed in
         * descriptor on writeback.  No need to enable TCP/UDP/IP checksum
         * offloads as they are enabled by default
         */
        rxcsum = rd32(IGC_RXCSUM);
        rxcsum |= IGC_RXCSUM_PCSD;

        /* Enable Receive Checksum Offload for SCTP */
        rxcsum |= IGC_RXCSUM_CRCOFL;

        /* Don't need to set TUOFL or IPOFL, they default to 1 */
        wr32(IGC_RXCSUM, rxcsum);

        /* Generate RSS hash based on packet types, TCP/UDP
         * port numbers and/or IPv4/v6 src and dst addresses
         */
        mrqc = IGC_MRQC_RSS_FIELD_IPV4 |
               IGC_MRQC_RSS_FIELD_IPV4_TCP |
               IGC_MRQC_RSS_FIELD_IPV6 |
               IGC_MRQC_RSS_FIELD_IPV6_TCP |
               IGC_MRQC_RSS_FIELD_IPV6_TCP_EX;

        if (adapter->flags & IGC_FLAG_RSS_FIELD_IPV4_UDP)
                mrqc |= IGC_MRQC_RSS_FIELD_IPV4_UDP;
        if (adapter->flags & IGC_FLAG_RSS_FIELD_IPV6_UDP)
                mrqc |= IGC_MRQC_RSS_FIELD_IPV6_UDP;

        mrqc |= IGC_MRQC_ENABLE_RSS_MQ;

        wr32(IGC_MRQC, mrqc);
}

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

        rctl = rd32(IGC_RCTL);

        rctl &= ~(3 << IGC_RCTL_MO_SHIFT);
        rctl &= ~(IGC_RCTL_LBM_TCVR | IGC_RCTL_LBM_MAC);

        rctl |= IGC_RCTL_EN | IGC_RCTL_BAM | IGC_RCTL_RDMTS_HALF |
                (hw->mac.mc_filter_type << IGC_RCTL_MO_SHIFT);

        /* enable stripping of CRC. Newer features require
         * that the HW strips the CRC.
         */
        rctl |= IGC_RCTL_SECRC;

        /* disable store bad packets and clear size bits. */
        rctl &= ~(IGC_RCTL_SBP | IGC_RCTL_SZ_256);

        /* enable LPE to allow for reception of jumbo frames */
        rctl |= IGC_RCTL_LPE;

        /* disable queue 0 to prevent tail write w/o re-config */
        wr32(IGC_RXDCTL(0), 0);

        /* 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 set_rx_mode
                 */
                rctl |= (IGC_RCTL_SBP | /* Receive bad packets */
                         IGC_RCTL_BAM | /* RX All Bcast Pkts */
                         IGC_RCTL_PMCF); /* RX All MAC Ctrl Pkts */

                rctl &= ~(IGC_RCTL_DPF | /* Allow filtered pause */
                          IGC_RCTL_CFIEN); /* Disable VLAN CFIEN Filter */
        }

        wr32(IGC_RCTL, rctl);
}

/**
 * igc_setup_tctl - configure the transmit control registers
 * @adapter: Board private structure
 */
static void igc_setup_tctl(struct igc_adapter *adapter)
{
        struct igc_hw *hw = &adapter->hw;
        u32 tctl;

        /* disable queue 0 which icould be enabled by default */
        wr32(IGC_TXDCTL(0), 0);

        /* Program the Transmit Control Register */
        tctl = rd32(IGC_TCTL);
        tctl &= ~IGC_TCTL_CT;
        tctl |= IGC_TCTL_PSP | IGC_TCTL_RTLC |
                (IGC_COLLISION_THRESHOLD << IGC_CT_SHIFT);

        /* Enable transmits */
        tctl |= IGC_TCTL_EN;

        wr32(IGC_TCTL, tctl);
}

/**
 * igc_set_mac_filter_hw() - Set MAC address filter in hardware
 * @adapter: Pointer to adapter where the filter should be set
 * @index: Filter index
 * @type: MAC address filter type (source or destination)
 * @addr: MAC address
 * @queue: If non-negative, queue assignment feature is enabled and frames
 *         matching the filter are enqueued onto 'queue'. Otherwise, queue
 *         assignment is disabled.
 */
static void igc_set_mac_filter_hw(struct igc_adapter *adapter, int index,
                                  enum igc_mac_filter_type type,
                                  const u8 *addr, int queue)
{
        struct net_device *dev = adapter->netdev;
        struct igc_hw *hw = &adapter->hw;
        u32 ral, rah;

        if (WARN_ON(index >= hw->mac.rar_entry_count))
                return;

        ral = le32_to_cpup((__le32 *)(addr));
        rah = le16_to_cpup((__le16 *)(addr + 4));

        if (type == IGC_MAC_FILTER_TYPE_SRC) {
                rah &= ~IGC_RAH_ASEL_MASK;
                rah |= IGC_RAH_ASEL_SRC_ADDR;
        }

        if (queue >= 0) {
                rah &= ~IGC_RAH_QSEL_MASK;
                rah |= (queue << IGC_RAH_QSEL_SHIFT);
                rah |= IGC_RAH_QSEL_ENABLE;
        }

        rah |= IGC_RAH_AV;

        wr32(IGC_RAL(index), ral);
        wr32(IGC_RAH(index), rah);

        netdev_dbg(dev, "MAC address filter set in HW: index %d", index);
}

/**
 * igc_clear_mac_filter_hw() - Clear MAC address filter in hardware
 * @adapter: Pointer to adapter where the filter should be cleared
 * @index: Filter index
 */
static void igc_clear_mac_filter_hw(struct igc_adapter *adapter, int index)
{
        struct net_device *dev = adapter->netdev;
        struct igc_hw *hw = &adapter->hw;

        if (WARN_ON(index >= hw->mac.rar_entry_count))
                return;

        wr32(IGC_RAL(index), 0);
        wr32(IGC_RAH(index), 0);

        netdev_dbg(dev, "MAC address filter cleared in HW: index %d", index);
}

/* Set default MAC address for the PF in the first RAR entry */
static void igc_set_default_mac_filter(struct igc_adapter *adapter)
{
        struct net_device *dev = adapter->netdev;
        u8 *addr = adapter->hw.mac.addr;

        netdev_dbg(dev, "Set default MAC address filter: address %pM", addr);

        igc_set_mac_filter_hw(adapter, 0, IGC_MAC_FILTER_TYPE_DST, addr, -1);
}

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

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

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

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

        return 0;
}

/**
 *  igc_write_mc_addr_list - write multicast addresses to MTA
 *  @netdev: network interface device structure
 *
 *  Writes multicast address list to the MTA hash table.
 *  Returns: -ENOMEM on failure
 *           0 on no addresses written
 *           X on writing X addresses to MTA
 **/
static int igc_write_mc_addr_list(struct net_device *netdev)
{
        struct igc_adapter *adapter = netdev_priv(netdev);
        struct igc_hw *hw = &adapter->hw;
        struct netdev_hw_addr *ha;
        u8  *mta_list;
        int i;

        if (netdev_mc_empty(netdev)) {
                /* nothing to program, so clear mc list */
                igc_update_mc_addr_list(hw, NULL, 0);
                return 0;
        }

        mta_list = kcalloc(netdev_mc_count(netdev), 6, GFP_ATOMIC);
        if (!mta_list)
                return -ENOMEM;

        /* The shared function expects a packed array of only addresses. */
        i = 0;
        netdev_for_each_mc_addr(ha, netdev)
                memcpy(mta_list + (i++ * ETH_ALEN), ha->addr, ETH_ALEN);

        igc_update_mc_addr_list(hw, mta_list, i);
        kfree(mta_list);

        return netdev_mc_count(netdev);
}

static __le32 igc_tx_launchtime(struct igc_adapter *adapter, ktime_t txtime)
{
        ktime_t cycle_time = adapter->cycle_time;
        ktime_t base_time = adapter->base_time;
        u32 launchtime;

        /* FIXME: when using ETF together with taprio, we may have a
         * case where 'delta' is larger than the cycle_time, this may
         * cause problems if we don't read the current value of
         * IGC_BASET, as the value writen into the launchtime
         * descriptor field may be misinterpreted.
         */
        div_s64_rem(ktime_sub_ns(txtime, base_time), cycle_time, &launchtime);

        return cpu_to_le32(launchtime);
}

static void igc_tx_ctxtdesc(struct igc_ring *tx_ring,
                            struct igc_tx_buffer *first,
                            u32 vlan_macip_lens, u32 type_tucmd,
                            u32 mss_l4len_idx)
{
        struct igc_adv_tx_context_desc *context_desc;
        u16 i = tx_ring->next_to_use;

        context_desc = IGC_TX_CTXTDESC(tx_ring, i);

        i++;
        tx_ring->next_to_use = (i < tx_ring->count) ? i : 0;

        /* set bits to identify this as an advanced context descriptor */
        type_tucmd |= IGC_TXD_CMD_DEXT | IGC_ADVTXD_DTYP_CTXT;

        /* For i225, context index must be unique per ring. */
        if (test_bit(IGC_RING_FLAG_TX_CTX_IDX, &tx_ring->flags))
                mss_l4len_idx |= tx_ring->reg_idx << 4;

        context_desc->vlan_macip_lens   = cpu_to_le32(vlan_macip_lens);
        context_desc->type_tucmd_mlhl   = cpu_to_le32(type_tucmd);
        context_desc->mss_l4len_idx     = cpu_to_le32(mss_l4len_idx);

        /* We assume there is always a valid Tx time available. Invalid times
         * should have been handled by the upper layers.
         */
        if (tx_ring->launchtime_enable) {
                struct igc_adapter *adapter = netdev_priv(tx_ring->netdev);
                ktime_t txtime = first->skb->tstamp;

                first->skb->tstamp = ktime_set(0, 0);
                context_desc->launch_time = igc_tx_launchtime(adapter,
                                                              txtime);
        } else {
                context_desc->launch_time = 0;
        }
}

static inline bool igc_ipv6_csum_is_sctp(struct sk_buff *skb)
{
        unsigned int offset = 0;

        ipv6_find_hdr(skb, &offset, IPPROTO_SCTP, NULL, NULL);

        return offset == skb_checksum_start_offset(skb);
}

static void igc_tx_csum(struct igc_ring *tx_ring, struct igc_tx_buffer *first)
{
        struct sk_buff *skb = first->skb;
        u32 vlan_macip_lens = 0;
        u32 type_tucmd = 0;

        if (skb->ip_summed != CHECKSUM_PARTIAL) {
csum_failed:
                if (!(first->tx_flags & IGC_TX_FLAGS_VLAN) &&
                    !tx_ring->launchtime_enable)
                        return;
                goto no_csum;
        }

        switch (skb->csum_offset) {
        case offsetof(struct tcphdr, check):
                type_tucmd = IGC_ADVTXD_TUCMD_L4T_TCP;
                fallthrough;
        case offsetof(struct udphdr, check):
                break;
        case offsetof(struct sctphdr, checksum):
                /* validate that this is actually an SCTP request */
                if ((first->protocol == htons(ETH_P_IP) &&
                     (ip_hdr(skb)->protocol == IPPROTO_SCTP)) ||
                    (first->protocol == htons(ETH_P_IPV6) &&
                     igc_ipv6_csum_is_sctp(skb))) {
                        type_tucmd = IGC_ADVTXD_TUCMD_L4T_SCTP;
                        break;
                }
                fallthrough;
        default:
                skb_checksum_help(skb);
                goto csum_failed;
        }

        /* update TX checksum flag */
        first->tx_flags |= IGC_TX_FLAGS_CSUM;
        vlan_macip_lens = skb_checksum_start_offset(skb) -
                          skb_network_offset(skb);
no_csum:
        vlan_macip_lens |= skb_network_offset(skb) << IGC_ADVTXD_MACLEN_SHIFT;

        vlan_macip_lens |= first->tx_flags & IGC_TX_FLAGS_VLAN_MASK;

        igc_tx_ctxtdesc(tx_ring, first, vlan_macip_lens, type_tucmd, 0);
}

static int __igc_maybe_stop_tx(struct igc_ring *tx_ring, const u16 size)
{
        struct net_device *netdev = tx_ring->netdev;

        netif_stop_subqueue(netdev, tx_ring->queue_index);

        /* memory barriier comment */
        smp_mb();

        /* We need to check again in a case another CPU has just
         * made room available.
         */
        if (igc_desc_unused(tx_ring) < size)
                return -EBUSY;

        /* A reprieve! */
        netif_wake_subqueue(netdev, tx_ring->queue_index);

        u64_stats_update_begin(&tx_ring->tx_syncp2);
        tx_ring->tx_stats.restart_queue2++;
        u64_stats_update_end(&tx_ring->tx_syncp2);

        return 0;
}

static inline int igc_maybe_stop_tx(struct igc_ring *tx_ring, const u16 size)
{
        if (igc_desc_unused(tx_ring) >= size)
                return 0;
        return __igc_maybe_stop_tx(tx_ring, size);
}

#define IGC_SET_FLAG(_input, _flag, _result) \
        (((_flag) <= (_result)) ?                               \
         ((u32)((_input) & (_flag)) * ((_result) / (_flag))) :  \
         ((u32)((_input) & (_flag)) / ((_flag) / (_result))))

static u32 igc_tx_cmd_type(struct sk_buff *skb, u32 tx_flags)
{
        /* set type for advanced descriptor with frame checksum insertion */
        u32 cmd_type = IGC_ADVTXD_DTYP_DATA |
                       IGC_ADVTXD_DCMD_DEXT |
                       IGC_ADVTXD_DCMD_IFCS;

        /* set segmentation bits for TSO */
        cmd_type |= IGC_SET_FLAG(tx_flags, IGC_TX_FLAGS_TSO,
                                 (IGC_ADVTXD_DCMD_TSE));

        /* set timestamp bit if present */
        cmd_type |= IGC_SET_FLAG(tx_flags, IGC_TX_FLAGS_TSTAMP,
                                 (IGC_ADVTXD_MAC_TSTAMP));

        return cmd_type;
}

static void igc_tx_olinfo_status(struct igc_ring *tx_ring,
                                 union igc_adv_tx_desc *tx_desc,
                                 u32 tx_flags, unsigned int paylen)
{
        u32 olinfo_status = paylen << IGC_ADVTXD_PAYLEN_SHIFT;

        /* insert L4 checksum */
        olinfo_status |= (tx_flags & IGC_TX_FLAGS_CSUM) *
                          ((IGC_TXD_POPTS_TXSM << 8) /
                          IGC_TX_FLAGS_CSUM);

        /* insert IPv4 checksum */
        olinfo_status |= (tx_flags & IGC_TX_FLAGS_IPV4) *
                          (((IGC_TXD_POPTS_IXSM << 8)) /
                          IGC_TX_FLAGS_IPV4);

        tx_desc->read.olinfo_status = cpu_to_le32(olinfo_status);
}

static int igc_tx_map(struct igc_ring *tx_ring,
                      struct igc_tx_buffer *first,
                      const u8 hdr_len)
{
        struct sk_buff *skb = first->skb;
        struct igc_tx_buffer *tx_buffer;
        union igc_adv_tx_desc *tx_desc;
        u32 tx_flags = first->tx_flags;
        skb_frag_t *frag;
        u16 i = tx_ring->next_to_use;
        unsigned int data_len, size;
        dma_addr_t dma;
        u32 cmd_type = igc_tx_cmd_type(skb, tx_flags);

        tx_desc = IGC_TX_DESC(tx_ring, i);

        igc_tx_olinfo_status(tx_ring, tx_desc, tx_flags, skb->len - hdr_len);

        size = skb_headlen(skb);
        data_len = skb->data_len;

        dma = dma_map_single(tx_ring->dev, skb->data, size, DMA_TO_DEVICE);

        tx_buffer = first;

        for (frag = &skb_shinfo(skb)->frags[0];; frag++) {
                if (dma_mapping_error(tx_ring->dev, dma))
                        goto dma_error;

                /* record length, and DMA address */
                dma_unmap_len_set(tx_buffer, len, size);
                dma_unmap_addr_set(tx_buffer, dma, dma);

                tx_desc->read.buffer_addr = cpu_to_le64(dma);

                while (unlikely(size > IGC_MAX_DATA_PER_TXD)) {
                        tx_desc->read.cmd_type_len =
                                cpu_to_le32(cmd_type ^ IGC_MAX_DATA_PER_TXD);

                        i++;
                        tx_desc++;
                        if (i == tx_ring->count) {
                                tx_desc = IGC_TX_DESC(tx_ring, 0);
                                i = 0;
                        }
                        tx_desc->read.olinfo_status = 0;

                        dma += IGC_MAX_DATA_PER_TXD;
                        size -= IGC_MAX_DATA_PER_TXD;

                        tx_desc->read.buffer_addr = cpu_to_le64(dma);
                }

                if (likely(!data_len))
                        break;

                tx_desc->read.cmd_type_len = cpu_to_le32(cmd_type ^ size);

                i++;
                tx_desc++;
                if (i == tx_ring->count) {
                        tx_desc = IGC_TX_DESC(tx_ring, 0);
                        i = 0;
                }
                tx_desc->read.olinfo_status = 0;

                size = skb_frag_size(frag);
                data_len -= size;

                dma = skb_frag_dma_map(tx_ring->dev, frag, 0,
                                       size, DMA_TO_DEVICE);

                tx_buffer = &tx_ring->tx_buffer_info[i];
        }

        /* write last descriptor with RS and EOP bits */
        cmd_type |= size | IGC_TXD_DCMD;
        tx_desc->read.cmd_type_len = cpu_to_le32(cmd_type);

        netdev_tx_sent_queue(txring_txq(tx_ring), first->bytecount);

        /* set the timestamp */
        first->time_stamp = jiffies;

        skb_tx_timestamp(skb);

        /* Force memory writes to complete before letting h/w know there
         * are new descriptors to fetch.  (Only applicable for weak-ordered
         * memory model archs, such as IA-64).
         *
         * We also need this memory barrier to make certain all of the
         * status bits have been updated before next_to_watch is written.
         */
        wmb();

        /* set next_to_watch value indicating a packet is present */
        first->next_to_watch = tx_desc;

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

        tx_ring->next_to_use = i;

        /* Make sure there is space in the ring for the next send. */
        igc_maybe_stop_tx(tx_ring, DESC_NEEDED);

        if (netif_xmit_stopped(txring_txq(tx_ring)) || !netdev_xmit_more()) {
                writel(i, tx_ring->tail);
        }

        return 0;
dma_error:
        netdev_err(tx_ring->netdev, "TX DMA map failed\n");
        tx_buffer = &tx_ring->tx_buffer_info[i];

        /* clear dma mappings for failed tx_buffer_info map */
        while (tx_buffer != first) {
                if (dma_unmap_len(tx_buffer, len))
                        dma_unmap_page(tx_ring->dev,
                                       dma_unmap_addr(tx_buffer, dma),
                                       dma_unmap_len(tx_buffer, len),
                                       DMA_TO_DEVICE);
                dma_unmap_len_set(tx_buffer, len, 0);

                if (i-- == 0)
                        i += tx_ring->count;
                tx_buffer = &tx_ring->tx_buffer_info[i];
        }

        if (dma_unmap_len(tx_buffer, len))
                dma_unmap_single(tx_ring->dev,
                                 dma_unmap_addr(tx_buffer, dma),
                                 dma_unmap_len(tx_buffer, len),
                                 DMA_TO_DEVICE);
        dma_unmap_len_set(tx_buffer, len, 0);

        dev_kfree_skb_any(tx_buffer->skb);
        tx_buffer->skb = NULL;

        tx_ring->next_to_use = i;

        return -1;
}

static int igc_tso(struct igc_ring *tx_ring,
                   struct igc_tx_buffer *first,
                   u8 *hdr_len)
{
        u32 vlan_macip_lens, type_tucmd, mss_l4len_idx;
        struct sk_buff *skb = first->skb;
        union {
                struct iphdr *v4;
                struct ipv6hdr *v6;
                unsigned char *hdr;
        } ip;
        union {
                struct tcphdr *tcp;
                struct udphdr *udp;
                unsigned char *hdr;
        } l4;
        u32 paylen, l4_offset;
        int err;

        if (skb->ip_summed != CHECKSUM_PARTIAL)
                return 0;

        if (!skb_is_gso(skb))
                return 0;

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

        ip.hdr = skb_network_header(skb);
        l4.hdr = skb_checksum_start(skb);

        /* ADV DTYP TUCMD MKRLOC/ISCSIHEDLEN */
        type_tucmd = IGC_ADVTXD_TUCMD_L4T_TCP;

        /* initialize outer IP header fields */
        if (ip.v4->version == 4) {
                unsigned char *csum_start = skb_checksum_start(skb);
                unsigned char *trans_start = ip.hdr + (ip.v4->ihl * 4);

                /* IP header will have to cancel out any data that
                 * is not a part of the outer IP header
                 */
                ip.v4->check = csum_fold(csum_partial(trans_start,
                                                      csum_start - trans_start,
                                                      0));
                type_tucmd |= IGC_ADVTXD_TUCMD_IPV4;

                ip.v4->tot_len = 0;
                first->tx_flags |= IGC_TX_FLAGS_TSO |
                                   IGC_TX_FLAGS_CSUM |
                                   IGC_TX_FLAGS_IPV4;
        } else {
                ip.v6->payload_len = 0;
                first->tx_flags |= IGC_TX_FLAGS_TSO |
                                   IGC_TX_FLAGS_CSUM;
        }

        /* determine offset of inner transport header */
        l4_offset = l4.hdr - skb->data;

        /* remove payload length from inner checksum */
        paylen = skb->len - l4_offset;
        if (type_tucmd & IGC_ADVTXD_TUCMD_L4T_TCP) {
                /* compute length of segmentation header */
                *hdr_len = (l4.tcp->doff * 4) + l4_offset;
                csum_replace_by_diff(&l4.tcp->check,
                                     (__force __wsum)htonl(paylen));
        } else {
                /* compute length of segmentation header */
                *hdr_len = sizeof(*l4.udp) + l4_offset;
                csum_replace_by_diff(&l4.udp->check,
                                     (__force __wsum)htonl(paylen));
        }

        /* update gso size and bytecount with header size */
        first->gso_segs = skb_shinfo(skb)->gso_segs;
        first->bytecount += (first->gso_segs - 1) * *hdr_len;

        /* MSS L4LEN IDX */
        mss_l4len_idx = (*hdr_len - l4_offset) << IGC_ADVTXD_L4LEN_SHIFT;
        mss_l4len_idx |= skb_shinfo(skb)->gso_size << IGC_ADVTXD_MSS_SHIFT;

        /* VLAN MACLEN IPLEN */
        vlan_macip_lens = l4.hdr - ip.hdr;
        vlan_macip_lens |= (ip.hdr - skb->data) << IGC_ADVTXD_MACLEN_SHIFT;
        vlan_macip_lens |= first->tx_flags & IGC_TX_FLAGS_VLAN_MASK;

        igc_tx_ctxtdesc(tx_ring, first, vlan_macip_lens,
                        type_tucmd, mss_l4len_idx);

        return 1;
}

static netdev_tx_t igc_xmit_frame_ring(struct sk_buff *skb,
                                       struct igc_ring *tx_ring)
{
        u16 count = TXD_USE_COUNT(skb_headlen(skb));
        __be16 protocol = vlan_get_protocol(skb);
        struct igc_tx_buffer *first;
        u32 tx_flags = 0;
        unsigned short f;
        u8 hdr_len = 0;
        int tso = 0;

        /* need: 1 descriptor per page * PAGE_SIZE/IGC_MAX_DATA_PER_TXD,
         *      + 1 desc for skb_headlen/IGC_MAX_DATA_PER_TXD,
         *      + 2 desc gap to keep tail from touching head,
         *      + 1 desc for context descriptor,
         * otherwise try next time
         */
        for (f = 0; f < skb_shinfo(skb)->nr_frags; f++)
                count += TXD_USE_COUNT(skb_frag_size(
                                                &skb_shinfo(skb)->frags[f]));

        if (igc_maybe_stop_tx(tx_ring, count + 3)) {
                /* this is a hard error */
                return NETDEV_TX_BUSY;
        }

        /* record the location of the first descriptor for this packet */
        first = &tx_ring->tx_buffer_info[tx_ring->next_to_use];
        first->skb = skb;
        first->bytecount = skb->len;
        first->gso_segs = 1;

        if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)) {
                struct igc_adapter *adapter = netdev_priv(tx_ring->netdev);

                /* FIXME: add support for retrieving timestamps from
                 * the other timer registers before skipping the
                 * timestamping request.
                 */
                if (adapter->tstamp_config.tx_type == HWTSTAMP_TX_ON &&
                    !test_and_set_bit_lock(__IGC_PTP_TX_IN_PROGRESS,
                                           &adapter->state)) {
                        skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
                        tx_flags |= IGC_TX_FLAGS_TSTAMP;

                        adapter->ptp_tx_skb = skb_get(skb);
                        adapter->ptp_tx_start = jiffies;
                } else {
                        adapter->tx_hwtstamp_skipped++;
                }
        }

        /* record initial flags and protocol */
        first->tx_flags = tx_flags;
        first->protocol = protocol;

        tso = igc_tso(tx_ring, first, &hdr_len);
        if (tso < 0)
                goto out_drop;
        else if (!tso)
                igc_tx_csum(tx_ring, first);

        igc_tx_map(tx_ring, first, hdr_len);

        return NETDEV_TX_OK;

out_drop:
        dev_kfree_skb_any(first->skb);
        first->skb = NULL;

        return NETDEV_TX_OK;
}

static inline struct igc_ring *igc_tx_queue_mapping(struct igc_adapter *adapter,
                                                    struct sk_buff *skb)
{
        unsigned int r_idx = skb->queue_mapping;

        if (r_idx >= adapter->num_tx_queues)
                r_idx = r_idx % adapter->num_tx_queues;

        return adapter->tx_ring[r_idx];
}

static netdev_tx_t igc_xmit_frame(struct sk_buff *skb,
                                  struct net_device *netdev)
{
        struct igc_adapter *adapter = netdev_priv(netdev);

        /* The minimum packet size with TCTL.PSP set is 17 so pad the skb
         * in order to meet this minimum size requirement.
         */
        if (skb->len < 17) {
                if (skb_padto(skb, 17))
                        return NETDEV_TX_OK;
                skb->len = 17;
        }

        return igc_xmit_frame_ring(skb, igc_tx_queue_mapping(adapter, skb));
}

static void igc_rx_checksum(struct igc_ring *ring,
                            union igc_adv_rx_desc *rx_desc,
                            struct sk_buff *skb)
{
        skb_checksum_none_assert(skb);

        /* Ignore Checksum bit is set */
        if (igc_test_staterr(rx_desc, IGC_RXD_STAT_IXSM))
                return;

        /* Rx checksum disabled via ethtool */
        if (!(ring->netdev->features & NETIF_F_RXCSUM))
                return;

        /* TCP/UDP checksum error bit is set */
        if (igc_test_staterr(rx_desc,
                             IGC_RXDEXT_STATERR_L4E |
                             IGC_RXDEXT_STATERR_IPE)) {
                /* work around errata with sctp packets where the TCPE aka
                 * L4E bit is set incorrectly on 64 byte (60 byte w/o crc)
                 * packets (aka let the stack check the crc32c)
                 */
                if (!(skb->len == 60 &&
                      test_bit(IGC_RING_FLAG_RX_SCTP_CSUM, &ring->flags))) {
                        u64_stats_update_begin(&ring->rx_syncp);
                        ring->rx_stats.csum_err++;
                        u64_stats_update_end(&ring->rx_syncp);
                }
                /* let the stack verify checksum errors */
                return;
        }
        /* It must be a TCP or UDP packet with a valid checksum */
        if (igc_test_staterr(rx_desc, IGC_RXD_STAT_TCPCS |
                                      IGC_RXD_STAT_UDPCS))
                skb->ip_summed = CHECKSUM_UNNECESSARY;

        netdev_dbg(ring->netdev, "cksum success: bits %08X\n",
                   le32_to_cpu(rx_desc->wb.upper.status_error));
}

static inline void igc_rx_hash(struct igc_ring *ring,
                               union igc_adv_rx_desc *rx_desc,
                               struct sk_buff *skb)
{
        if (ring->netdev->features & NETIF_F_RXHASH)
                skb_set_hash(skb,
                             le32_to_cpu(rx_desc->wb.lower.hi_dword.rss),
                             PKT_HASH_TYPE_L3);
}

/**
 * igc_process_skb_fields - Populate skb header fields from Rx descriptor
 * @rx_ring: rx descriptor ring packet is being transacted on
 * @rx_desc: pointer to the EOP Rx descriptor
 * @skb: pointer to current skb being populated
 *
 * This function checks the ring, descriptor, and packet information in order
 * to populate the hash, checksum, VLAN, protocol, and other fields within the
 * skb.
 */
static void igc_process_skb_fields(struct igc_ring *rx_ring,
                                   union igc_adv_rx_desc *rx_desc,
                                   struct sk_buff *skb)
{
        igc_rx_hash(rx_ring, rx_desc, skb);

        igc_rx_checksum(rx_ring, rx_desc, skb);

        skb_record_rx_queue(skb, rx_ring->queue_index);

        skb->protocol = eth_type_trans(skb, rx_ring->netdev);
}

static struct igc_rx_buffer *igc_get_rx_buffer(struct igc_ring *rx_ring,
                                               const unsigned int size)
{
        struct igc_rx_buffer *rx_buffer;

        rx_buffer = &rx_ring->rx_buffer_info[rx_ring->next_to_clean];
        prefetchw(rx_buffer->page);

        /* we are reusing so sync this buffer for CPU use */
        dma_sync_single_range_for_cpu(rx_ring->dev,
                                      rx_buffer->dma,
                                      rx_buffer->page_offset,
                                      size,
                                      DMA_FROM_DEVICE);

        rx_buffer->pagecnt_bias--;

        return rx_buffer;
}

/**
 * igc_add_rx_frag - Add contents of Rx buffer to sk_buff
 * @rx_ring: rx descriptor ring to transact packets on
 * @rx_buffer: buffer containing page to add
 * @skb: sk_buff to place the data into
 * @size: size of buffer to be added
 *
 * This function will add the data contained in rx_buffer->page to the skb.
 */
static void igc_add_rx_frag(struct igc_ring *rx_ring,
                            struct igc_rx_buffer *rx_buffer,
                            struct sk_buff *skb,
                            unsigned int size)
{
#if (PAGE_SIZE < 8192)
        unsigned int truesize = igc_rx_pg_size(rx_ring) / 2;

        skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_buffer->page,
                        rx_buffer->page_offset, size, truesize);
        rx_buffer->page_offset ^= truesize;
#else
        unsigned int truesize = ring_uses_build_skb(rx_ring) ?
                                SKB_DATA_ALIGN(IGC_SKB_PAD + size) :
                                SKB_DATA_ALIGN(size);
        skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_buffer->page,
                        rx_buffer->page_offset, size, truesize);
        rx_buffer->page_offset += truesize;
#endif
}

static struct sk_buff *igc_build_skb(struct igc_ring *rx_ring,
                                     struct igc_rx_buffer *rx_buffer,
                                     union igc_adv_rx_desc *rx_desc,
                                     unsigned int size)
{
        void *va = page_address(rx_buffer->page) + rx_buffer->page_offset;
#if (PAGE_SIZE < 8192)
        unsigned int truesize = igc_rx_pg_size(rx_ring) / 2;
#else
        unsigned int truesize = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) +
                                SKB_DATA_ALIGN(IGC_SKB_PAD + size);
#endif
        struct sk_buff *skb;

        /* prefetch first cache line of first page */
        net_prefetch(va);

        /* build an skb around the page buffer */
        skb = build_skb(va - IGC_SKB_PAD, truesize);
        if (unlikely(!skb))
                return NULL;

        /* update pointers within the skb to store the data */
        skb_reserve(skb, IGC_SKB_PAD);
        __skb_put(skb, size);

        /* update buffer offset */
#if (PAGE_SIZE < 8192)
        rx_buffer->page_offset ^= truesize;
#else
        rx_buffer->page_offset += truesize;
#endif

        return skb;
}

static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring,
                                         struct igc_rx_buffer *rx_buffer,
                                         union igc_adv_rx_desc *rx_desc,
                                         unsigned int size)
{
        void *va = page_address(rx_buffer->page) + rx_buffer->page_offset;
#if (PAGE_SIZE < 8192)
        unsigned int truesize = igc_rx_pg_size(rx_ring) / 2;
#else
        unsigned int truesize = SKB_DATA_ALIGN(size);
#endif
        unsigned int headlen;
        struct sk_buff *skb;

        /* prefetch first cache line of first page */
        net_prefetch(va);

        /* allocate a skb to store the frags */
        skb = napi_alloc_skb(&rx_ring->q_vector->napi, IGC_RX_HDR_LEN);
        if (unlikely(!skb))
                return NULL;

        if (unlikely(igc_test_staterr(rx_desc, IGC_RXDADV_STAT_TSIP))) {
                igc_ptp_rx_pktstamp(rx_ring->q_vector, va, skb);
                va += IGC_TS_HDR_LEN;
                size -= IGC_TS_HDR_LEN;
        }

        /* Determine available headroom for copy */
        headlen = size;
        if (headlen > IGC_RX_HDR_LEN)
                headlen = eth_get_headlen(skb->dev, va, IGC_RX_HDR_LEN);

        /* align pull length to size of long to optimize memcpy performance */
        memcpy(__skb_put(skb, headlen), va, ALIGN(headlen, sizeof(long)));

        /* update all of the pointers */
        size -= headlen;
        if (size) {
                skb_add_rx_frag(skb, 0, rx_buffer->page,
                                (va + headlen) - page_address(rx_buffer->page),
                                size, truesize);
#if (PAGE_SIZE < 8192)
                rx_buffer->page_offset ^= truesize;
#else
                rx_buffer->page_offset += truesize;
#endif
        } else {
                rx_buffer->pagecnt_bias++;
        }

        return skb;
}

/**
 * igc_reuse_rx_page - page flip buffer and store it back on the ring
 * @rx_ring: rx descriptor ring to store buffers on
 * @old_buff: donor buffer to have page reused
 *
 * Synchronizes page for reuse by the adapter
 */
static void igc_reuse_rx_page(struct igc_ring *rx_ring,
                              struct igc_rx_buffer *old_buff)
{
        u16 nta = rx_ring->next_to_alloc;
        struct igc_rx_buffer *new_buff;

        new_buff = &rx_ring->rx_buffer_info[nta];

        /* update, and store next to alloc */
        nta++;
        rx_ring->next_to_alloc = (nta < rx_ring->count) ? nta : 0;

        /* Transfer page from old buffer to new buffer.
         * Move each member individually to avoid possible store
         * forwarding stalls.
         */
        new_buff->dma           = old_buff->dma;
        new_buff->page          = old_buff->page;
        new_buff->page_offset   = old_buff->page_offset;
        new_buff->pagecnt_bias  = old_buff->pagecnt_bias;
}

static inline bool igc_page_is_reserved(struct page *page)
{
        return (page_to_nid(page) != numa_mem_id()) || page_is_pfmemalloc(page);
}

static bool igc_can_reuse_rx_page(struct igc_rx_buffer *rx_buffer)
{
        unsigned int pagecnt_bias = rx_buffer->pagecnt_bias;
        struct page *page = rx_buffer->page;

        /* avoid re-using remote pages */
        if (unlikely(igc_page_is_reserved(page)))
                return false;

#if (PAGE_SIZE < 8192)
        /* if we are only owner of page we can reuse it */
        if (unlikely((page_ref_count(page) - pagecnt_bias) > 1))
                return false;
#else
#define IGC_LAST_OFFSET \
        (SKB_WITH_OVERHEAD(PAGE_SIZE) - IGC_RXBUFFER_2048)

        if (rx_buffer->page_offset > IGC_LAST_OFFSET)
                return false;
#endif

        /* If we have drained the page fragment pool we need to update
         * the pagecnt_bias and page count so that we fully restock the
         * number of references the driver holds.
         */
        if (unlikely(!pagecnt_bias)) {
                page_ref_add(page, USHRT_MAX);
                rx_buffer->pagecnt_bias = USHRT_MAX;
        }

        return true;
}

/**
 * igc_is_non_eop - process handling of non-EOP buffers
 * @rx_ring: Rx ring being processed
 * @rx_desc: Rx descriptor for current buffer
 *
 * This function updates next to clean.  If the buffer is an EOP buffer
 * this function exits returning false, otherwise it will place the
 * sk_buff in the next buffer to be chained and return true indicating
 * that this is in fact a non-EOP buffer.
 */
static bool igc_is_non_eop(struct igc_ring *rx_ring,
                           union igc_adv_rx_desc *rx_desc)
{
        u32 ntc = rx_ring->next_to_clean + 1;

        /* fetch, update, and store next to clean */
        ntc = (ntc < rx_ring->count) ? ntc : 0;
        rx_ring->next_to_clean = ntc;

        prefetch(IGC_RX_DESC(rx_ring, ntc));

        if (likely(igc_test_staterr(rx_desc, IGC_RXD_STAT_EOP)))
                return false;

        return true;
}

/**
 * igc_cleanup_headers - Correct corrupted or empty headers
 * @rx_ring: rx descriptor ring packet is being transacted on
 * @rx_desc: pointer to the EOP Rx descriptor
 * @skb: pointer to current skb being fixed
 *
 * Address the case where we are pulling data in on pages only
 * and as such no data is present in the skb header.
 *
 * In addition if skb is not at least 60 bytes we need to pad it so that
 * it is large enough to qualify as a valid Ethernet frame.
 *
 * Returns true if an error was encountered and skb was freed.
 */
static bool igc_cleanup_headers(struct igc_ring *rx_ring,
                                union igc_adv_rx_desc *rx_desc,
                                struct sk_buff *skb)
{
        if (unlikely(igc_test_staterr(rx_desc, IGC_RXDEXT_STATERR_RXE))) {
                struct net_device *netdev = rx_ring->netdev;

                if (!(netdev->features & NETIF_F_RXALL)) {
                        dev_kfree_skb_any(skb);
                        return true;
                }
        }

        /* if eth_skb_pad returns an error the skb was freed */
        if (eth_skb_pad(skb))
                return true;

        return false;
}

static void igc_put_rx_buffer(struct igc_ring *rx_ring,
                              struct igc_rx_buffer *rx_buffer)
{
        if (igc_can_reuse_rx_page(rx_buffer)) {
                /* hand second half of page back to the ring */
                igc_reuse_rx_page(rx_ring, rx_buffer);
        } else {
                /* We are not reusing the buffer so unmap it and free
                 * any references we are holding to it
                 */
                dma_unmap_page_attrs(rx_ring->dev, rx_buffer->dma,
                                     igc_rx_pg_size(rx_ring), DMA_FROM_DEVICE,
                                     IGC_RX_DMA_ATTR);
                __page_frag_cache_drain(rx_buffer->page,
                                        rx_buffer->pagecnt_bias);
        }

        /* clear contents of rx_buffer */
        rx_buffer->page = NULL;
}

static inline unsigned int igc_rx_offset(struct igc_ring *rx_ring)
{
        return ring_uses_build_skb(rx_ring) ? IGC_SKB_PAD : 0;
}

static bool igc_alloc_mapped_page(struct igc_ring *rx_ring,
                                  struct igc_rx_buffer *bi)
{
        struct page *page = bi->page;
        dma_addr_t dma;

        /* since we are recycling buffers we should seldom need to alloc */
        if (likely(page))
                return true;

        /* alloc new page for storage */
        page = dev_alloc_pages(igc_rx_pg_order(rx_ring));
        if (unlikely(!page)) {
                rx_ring->rx_stats.alloc_failed++;
                return false;
        }

        /* map page for use */
        dma = dma_map_page_attrs(rx_ring->dev, page, 0,
                                 igc_rx_pg_size(rx_ring),
                                 DMA_FROM_DEVICE,
                                 IGC_RX_DMA_ATTR);

        /* if mapping failed free memory back to system since
         * there isn't much point in holding memory we can't use
         */
        if (dma_mapping_error(rx_ring->dev, dma)) {
                __free_page(page);

                rx_ring->rx_stats.alloc_failed++;
                return false;
        }

        bi->dma = dma;
        bi->page = page;
        bi->page_offset = igc_rx_offset(rx_ring);
        bi->pagecnt_bias = 1;

        return true;
}

/**
 * igc_alloc_rx_buffers - Replace used receive buffers; packet split
 * @rx_ring: rx descriptor ring
 * @cleaned_count: number of buffers to clean
 */
static void igc_alloc_rx_buffers(struct igc_ring *rx_ring, u16 cleaned_count)
{
        union igc_adv_rx_desc *rx_desc;
        u16 i = rx_ring->next_to_use;
        struct igc_rx_buffer *bi;
        u16 bufsz;

        /* nothing to do */
        if (!cleaned_count)
                return;

        rx_desc = IGC_RX_DESC(rx_ring, i);
        bi = &rx_ring->rx_buffer_info[i];
        i -= rx_ring->count;

        bufsz = igc_rx_bufsz(rx_ring);

        do {
                if (!igc_alloc_mapped_page(rx_ring, bi))
                        break;

                /* sync the buffer for use by the device */
                dma_sync_single_range_for_device(rx_ring->dev, bi->dma,
                                                 bi->page_offset, bufsz,
                                                 DMA_FROM_DEVICE);

                /* Refresh the desc even if buffer_addrs didn't change
                 * because each write-back erases this info.
                 */
                rx_desc->read.pkt_addr = cpu_to_le64(bi->dma + bi->page_offset);

                rx_desc++;
                bi++;
                i++;
                if (unlikely(!i)) {
                        rx_desc = IGC_RX_DESC(rx_ring, 0);
                        bi = rx_ring->rx_buffer_info;
                        i -= rx_ring->count;
                }

                /* clear the length for the next_to_use descriptor */
                rx_desc->wb.upper.length = 0;

                cleaned_count--;
        } while (cleaned_count);

        i += rx_ring->count;

        if (rx_ring->next_to_use != i) {
                /* record the next descriptor to use */
                rx_ring->next_to_use = i;

                /* update next to alloc since we have filled the ring */
                rx_ring->next_to_alloc = i;

                /* Force memory writes to complete before letting h/w
                 * know there are new descriptors to fetch.  (Only
                 * applicable for weak-ordered memory model archs,
                 * such as IA-64).
                 */
                wmb();
                writel(i, rx_ring->tail);
        }
}

static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
{
        unsigned int total_bytes = 0, total_packets = 0;
        struct igc_ring *rx_ring = q_vector->rx.ring;
        struct sk_buff *skb = rx_ring->skb;
        u16 cleaned_count = igc_desc_unused(rx_ring);

        while (likely(total_packets < budget)) {
                union igc_adv_rx_desc *rx_desc;
                struct igc_rx_buffer *rx_buffer;
                unsigned int size;

                /* return some buffers to hardware, one at a time is too slow */
                if (cleaned_count >= IGC_RX_BUFFER_WRITE) {
                        igc_alloc_rx_buffers(rx_ring, cleaned_count);
                        cleaned_count = 0;
                }

                rx_desc = IGC_RX_DESC(rx_ring, rx_ring->next_to_clean);
                size = le16_to_cpu(rx_desc->wb.upper.length);
                if (!size)
                        break;

                /* This memory barrier is needed to keep us from reading
                 * any other fields out of the rx_desc until we know the
                 * descriptor has been written back
                 */
                dma_rmb();

                rx_buffer = igc_get_rx_buffer(rx_ring, size);

                /* retrieve a buffer from the ring */
                if (skb)
                        igc_add_rx_frag(rx_ring, rx_buffer, skb, size);
                else if (ring_uses_build_skb(rx_ring))
                        skb = igc_build_skb(rx_ring, rx_buffer, rx_desc, size);
                else
                        skb = igc_construct_skb(rx_ring, rx_buffer,
                                                rx_desc, size);

                /* exit if we failed to retrieve a buffer */
                if (!skb) {
                        rx_ring->rx_stats.alloc_failed++;
                        rx_buffer->pagecnt_bias++;
                        break;
                }

                igc_put_rx_buffer(rx_ring, rx_buffer);
                cleaned_count++;

                /* fetch next buffer in frame if non-eop */
                if (igc_is_non_eop(rx_ring, rx_desc))
                        continue;

                /* verify the packet layout is correct */
                if (igc_cleanup_headers(rx_ring, rx_desc, skb)) {
                        skb = NULL;
                        continue;
                }

                /* probably a little skewed due to removing CRC */
                total_bytes += skb->len;

                /* populate checksum, VLAN, and protocol */
                igc_process_skb_fields(rx_ring, rx_desc, skb);

                napi_gro_receive(&q_vector->napi, skb);

                /* reset skb pointer */
                skb = NULL;

                /* update budget accounting */
                total_packets++;
        }

        /* place incomplete frames back on ring for completion */
        rx_ring->skb = skb;

        u64_stats_update_begin(&rx_ring->rx_syncp);
        rx_ring->rx_stats.packets += total_packets;
        rx_ring->rx_stats.bytes += total_bytes;
        u64_stats_update_end(&rx_ring->rx_syncp);
        q_vector->rx.total_packets += total_packets;
        q_vector->rx.total_bytes += total_bytes;

        if (cleaned_count)
                igc_alloc_rx_buffers(rx_ring, cleaned_count);

        return total_packets;
}

/**
 * igc_clean_tx_irq - Reclaim resources after transmit completes
 * @q_vector: pointer to q_vector containing needed info
 * @napi_budget: Used to determine if we are in netpoll
 *
 * returns true if ring is completely cleaned
 */
static bool igc_clean_tx_irq(struct igc_q_vector *q_vector, int napi_budget)
{
        struct igc_adapter *adapter = q_vector->adapter;
        unsigned int total_bytes = 0, total_packets = 0;
        unsigned int budget = q_vector->tx.work_limit;

        struct igc_ring *tx_ring = q_vector->tx.ring;
        unsigned int i = tx_ring->next_to_clean;
        struct igc_tx_buffer *tx_buffer;
        union igc_adv_tx_desc *tx_desc;

        if (test_bit(__IGC_DOWN, &adapter->state))
                return true;

        tx_buffer = &tx_ring->tx_buffer_info[i];
        tx_desc = IGC_TX_DESC(tx_ring, i);
        i -= tx_ring->count;

        do {
                union igc_adv_tx_desc *eop_desc = tx_buffer->next_to_watch;

                /* if next_to_watch is not set then there is no work pending */
                if (!eop_desc)
                        break;

                /* prevent any other reads prior to eop_desc */
                smp_rmb();

                /* if DD is not set pending work has not been completed */
                if (!(eop_desc->wb.status & cpu_to_le32(IGC_TXD_STAT_DD)))
                        break;

                /* clear next_to_watch to prevent false hangs */
                tx_buffer->next_to_watch = NULL;

                /* update the statistics for this packet */
                total_bytes += tx_buffer->bytecount;
                total_packets += tx_buffer->gso_segs;

                /* free the skb */
                napi_consume_skb(tx_buffer->skb, napi_budget);

                /* unmap skb header data */
                dma_unmap_single(tx_ring->dev,
                                 dma_unmap_addr(tx_buffer, dma),
                                 dma_unmap_len(tx_buffer, len),
                                 DMA_TO_DEVICE);

                /* clear tx_buffer data */
                dma_unmap_len_set(tx_buffer, len, 0);

                /* clear last DMA location and unmap remaining buffers */
                while (tx_desc != eop_desc) {
                        tx_buffer++;
                        tx_desc++;
                        i++;
                        if (unlikely(!i)) {
                                i -= tx_ring->count;
                                tx_buffer = tx_ring->tx_buffer_info;
                                tx_desc = IGC_TX_DESC(tx_ring, 0);
                        }

                        /* unmap any remaining paged data */
                        if (dma_unmap_len(tx_buffer, len)) {
                                dma_unmap_page(tx_ring->dev,
                                               dma_unmap_addr(tx_buffer, dma),
                                               dma_unmap_len(tx_buffer, len),
                                               DMA_TO_DEVICE);
                                dma_unmap_len_set(tx_buffer, len, 0);
                        }
                }

                /* move us one more past the eop_desc for start of next pkt */
                tx_buffer++;
                tx_desc++;
                i++;
                if (unlikely(!i)) {
                        i -= tx_ring->count;
                        tx_buffer = tx_ring->tx_buffer_info;
                        tx_desc = IGC_TX_DESC(tx_ring, 0);
                }

                /* issue prefetch for next Tx descriptor */
                prefetch(tx_desc);

                /* update budget accounting */
                budget--;
        } while (likely(budget));

        netdev_tx_completed_queue(txring_txq(tx_ring),
                                  total_packets, total_bytes);

        i += tx_ring->count;
        tx_ring->next_to_clean = i;
        u64_stats_update_begin(&tx_ring->tx_syncp);
        tx_ring->tx_stats.bytes += total_bytes;
        tx_ring->tx_stats.packets += total_packets;
        u64_stats_update_end(&tx_ring->tx_syncp);
        q_vector->tx.total_bytes += total_bytes;
        q_vector->tx.total_packets += total_packets;

        if (test_bit(IGC_RING_FLAG_TX_DETECT_HANG, &tx_ring->flags)) {
                struct igc_hw *hw = &adapter->hw;

                /* Detect a transmit hang in hardware, this serializes the
                 * check with the clearing of time_stamp and movement of i
                 */
                clear_bit(IGC_RING_FLAG_TX_DETECT_HANG, &tx_ring->flags);
                if (tx_buffer->next_to_watch &&
                    time_after(jiffies, tx_buffer->time_stamp +
                    (adapter->tx_timeout_factor * HZ)) &&
                    !(rd32(IGC_STATUS) & IGC_STATUS_TXOFF)) {
                        /* detected Tx unit hang */
                        netdev_err(tx_ring->netdev,
                                   "Detected Tx Unit Hang\n"
                                   "  Tx Queue             <%d>\n"
                                   "  TDH                  <%x>\n"
                                   "  TDT                  <%x>\n"
                                   "  next_to_use          <%x>\n"
                                   "  next_to_clean        <%x>\n"
                                   "buffer_info[next_to_clean]\n"
                                   "  time_stamp           <%lx>\n"
                                   "  next_to_watch        <%p>\n"
                                   "  jiffies              <%lx>\n"
                                   "  desc.status          <%x>\n",
                                   tx_ring->queue_index,
                                   rd32(IGC_TDH(tx_ring->reg_idx)),
                                   readl(tx_ring->tail),
                                   tx_ring->next_to_use,
                                   tx_ring->next_to_clean,
                                   tx_buffer->time_stamp,
                                   tx_buffer->next_to_watch,
                                   jiffies,
                                   tx_buffer->next_to_watch->wb.status);
                        netif_stop_subqueue(tx_ring->netdev,
                                            tx_ring->queue_index);

                        /* we are about to reset, no point in enabling stuff */
                        return true;
                }
        }

#define TX_WAKE_THRESHOLD (DESC_NEEDED * 2)
        if (unlikely(total_packets &&
                     netif_carrier_ok(tx_ring->netdev) &&
                     igc_desc_unused(tx_ring) >= TX_WAKE_THRESHOLD)) {
                /* Make sure that anybody stopping the queue after this
                 * sees the new next_to_clean.
                 */
                smp_mb();
                if (__netif_subqueue_stopped(tx_ring->netdev,
                                             tx_ring->queue_index) &&
                    !(test_bit(__IGC_DOWN, &adapter->state))) {
                        netif_wake_subqueue(tx_ring->netdev,
                                            tx_ring->queue_index);

                        u64_stats_update_begin(&tx_ring->tx_syncp);
                        tx_ring->tx_stats.restart_queue++;
                        u64_stats_update_end(&tx_ring->tx_syncp);
                }
        }

        return !!budget;
}

static int igc_find_mac_filter(struct igc_adapter *adapter,
                               enum igc_mac_filter_type type, const u8 *addr)
{
        struct igc_hw *hw = &adapter->hw;
        int max_entries = hw->mac.rar_entry_count;
        u32 ral, rah;
        int i;

        for (i = 0; i < max_entries; i++) {
                ral = rd32(IGC_RAL(i));
                rah = rd32(IGC_RAH(i));

                if (!(rah & IGC_RAH_AV))
                        continue;
                if (!!(rah & IGC_RAH_ASEL_SRC_ADDR) != type)
                        continue;
                if ((rah & IGC_RAH_RAH_MASK) !=
                    le16_to_cpup((__le16 *)(addr + 4)))
                        continue;
                if (ral != le32_to_cpup((__le32 *)(addr)))
                        continue;

                return i;
        }

        return -1;
}

static int igc_get_avail_mac_filter_slot(struct igc_adapter *adapter)
{
        struct igc_hw *hw = &adapter->hw;
        int max_entries = hw->mac.rar_entry_count;
        u32 rah;
        int i;

        for (i = 0; i < max_entries; i++) {
                rah = rd32(IGC_RAH(i));

                if (!(rah & IGC_RAH_AV))
                        return i;
        }

        return -1;
}

/**
 * igc_add_mac_filter() - Add MAC address filter
 * @adapter: Pointer to adapter where the filter should be added
 * @type: MAC address filter type (source or destination)
 * @addr: MAC address
 * @queue: If non-negative, queue assignment feature is enabled and frames
 *         matching the filter are enqueued onto 'queue'. Otherwise, queue
 *         assignment is disabled.
 *
 * Return: 0 in case of success, negative errno code otherwise.
 */
static int igc_add_mac_filter(struct igc_adapter *adapter,
                              enum igc_mac_filter_type type, const u8 *addr,
                              int queue)
{
        struct net_device *dev = adapter->netdev;
        int index;

        index = igc_find_mac_filter(adapter, type, addr);
        if (index >= 0)
                goto update_filter;

        index = igc_get_avail_mac_filter_slot(adapter);
        if (index < 0)
                return -ENOSPC;

        netdev_dbg(dev, "Add MAC address filter: index %d type %s address %pM queue %d\n",
                   index, type == IGC_MAC_FILTER_TYPE_DST ? "dst" : "src",
                   addr, queue);

update_filter:
        igc_set_mac_filter_hw(adapter, index, type, addr, queue);
        return 0;
}

/**
 * igc_del_mac_filter() - Delete MAC address filter
 * @adapter: Pointer to adapter where the filter should be deleted from
 * @type: MAC address filter type (source or destination)
 * @addr: MAC address
 */
static void igc_del_mac_filter(struct igc_adapter *adapter,
                               enum igc_mac_filter_type type, const u8 *addr)
{
        struct net_device *dev = adapter->netdev;
        int index;

        index = igc_find_mac_filter(adapter, type, addr);
        if (index < 0)
                return;

        if (index == 0) {
                /* If this is the default filter, we don't actually delete it.
                 * We just reset to its default value i.e. disable queue
                 * assignment.
                 */
                netdev_dbg(dev, "Disable default MAC filter queue assignment");

                igc_set_mac_filter_hw(adapter, 0, type, addr, -1);
        } else {
                netdev_dbg(dev, "Delete MAC address filter: index %d type %s address %pM\n",
                           index,
                           type == IGC_MAC_FILTER_TYPE_DST ? "dst" : "src",
                           addr);

                igc_clear_mac_filter_hw(adapter, index);
        }
}

/**
 * igc_add_vlan_prio_filter() - Add VLAN priority filter
 * @adapter: Pointer to adapter where the filter should be added
 * @prio: VLAN priority value
 * @queue: Queue number which matching frames are assigned to
 *
 * Return: 0 in case of success, negative errno code otherwise.
 */
static int igc_add_vlan_prio_filter(struct igc_adapter *adapter, int prio,
                                    int queue)
{
        struct net_device *dev = adapter->netdev;
        struct igc_hw *hw = &adapter->hw;
        u32 vlanpqf;

        vlanpqf = rd32(IGC_VLANPQF);

        if (vlanpqf & IGC_VLANPQF_VALID(prio)) {
                netdev_dbg(dev, "VLAN priority filter already in use\n");
                return -EEXIST;
        }

        vlanpqf |= IGC_VLANPQF_QSEL(prio, queue);
        vlanpqf |= IGC_VLANPQF_VALID(prio);

        wr32(IGC_VLANPQF, vlanpqf);

        netdev_dbg(dev, "Add VLAN priority filter: prio %d queue %d\n",
                   prio, queue);
        return 0;
}

/**
 * igc_del_vlan_prio_filter() - Delete VLAN priority filter
 * @adapter: Pointer to adapter where the filter should be deleted from
 * @prio: VLAN priority value
 */
static void igc_del_vlan_prio_filter(struct igc_adapter *adapter, int prio)
{
        struct igc_hw *hw = &adapter->hw;
        u32 vlanpqf;

        vlanpqf = rd32(IGC_VLANPQF);

        vlanpqf &= ~IGC_VLANPQF_VALID(prio);
        vlanpqf &= ~IGC_VLANPQF_QSEL(prio, IGC_VLANPQF_QUEUE_MASK);

        wr32(IGC_VLANPQF, vlanpqf);

        netdev_dbg(adapter->netdev, "Delete VLAN priority filter: prio %d\n",
                   prio);
}

static int igc_get_avail_etype_filter_slot(struct igc_adapter *adapter)
{
        struct igc_hw *hw = &adapter->hw;
        int i;

        for (i = 0; i < MAX_ETYPE_FILTER; i++) {
                u32 etqf = rd32(IGC_ETQF(i));

                if (!(etqf & IGC_ETQF_FILTER_ENABLE))
                        return i;
        }

        return -1;
}

/**
 * igc_add_etype_filter() - Add ethertype filter
 * @adapter: Pointer to adapter where the filter should be added
 * @etype: Ethertype value
 * @queue: If non-negative, queue assignment feature is enabled and frames
 *         matching the filter are enqueued onto 'queue'. Otherwise, queue
 *         assignment is disabled.
 *
 * Return: 0 in case of success, negative errno code otherwise.
 */
static int igc_add_etype_filter(struct igc_adapter *adapter, u16 etype,
                                int queue)
{
        struct igc_hw *hw = &adapter->hw;
        int index;
        u32 etqf;

        index = igc_get_avail_etype_filter_slot(adapter);
        if (index < 0)
                return -ENOSPC;

        etqf = rd32(IGC_ETQF(index));

        etqf &= ~IGC_ETQF_ETYPE_MASK;
        etqf |= etype;

        if (queue >= 0) {
                etqf &= ~IGC_ETQF_QUEUE_MASK;
                etqf |= (queue << IGC_ETQF_QUEUE_SHIFT);
                etqf |= IGC_ETQF_QUEUE_ENABLE;
        }

        etqf |= IGC_ETQF_FILTER_ENABLE;

        wr32(IGC_ETQF(index), etqf);

        netdev_dbg(adapter->netdev, "Add ethertype filter: etype %04x queue %d\n",
                   etype, queue);
        return 0;
}

static int igc_find_etype_filter(struct igc_adapter *adapter, u16 etype)
{
        struct igc_hw *hw = &adapter->hw;
        int i;

        for (i = 0; i < MAX_ETYPE_FILTER; i++) {
                u32 etqf = rd32(IGC_ETQF(i));

                if ((etqf & IGC_ETQF_ETYPE_MASK) == etype)
                        return i;
        }

        return -1;
}

/**
 * igc_del_etype_filter() - Delete ethertype filter
 * @adapter: Pointer to adapter where the filter should be deleted from
 * @etype: Ethertype value
 */
static void igc_del_etype_filter(struct igc_adapter *adapter, u16 etype)
{
        struct igc_hw *hw = &adapter->hw;
        int index;

        index = igc_find_etype_filter(adapter, etype);
        if (index < 0)
                return;

        wr32(IGC_ETQF(index), 0);

        netdev_dbg(adapter->netdev, "Delete ethertype filter: etype %04x\n",
                   etype);
}

static int igc_enable_nfc_rule(struct igc_adapter *adapter,
                               const struct igc_nfc_rule *rule)
{
        int err;

        if (rule->filter.match_flags & IGC_FILTER_FLAG_ETHER_TYPE) {
                err = igc_add_etype_filter(adapter, rule->filter.etype,
                                           rule->action);
                if (err)
                        return err;
        }

        if (rule->filter.match_flags & IGC_FILTER_FLAG_SRC_MAC_ADDR) {
                err = igc_add_mac_filter(adapter, IGC_MAC_FILTER_TYPE_SRC,
                                         rule->filter.src_addr, rule->action);
                if (err)
                        return err;
        }

        if (rule->filter.match_flags & IGC_FILTER_FLAG_DST_MAC_ADDR) {
                err = igc_add_mac_filter(adapter, IGC_MAC_FILTER_TYPE_DST,
                                         rule->filter.dst_addr, rule->action);
                if (err)
                        return err;
        }

        if (rule->filter.match_flags & IGC_FILTER_FLAG_VLAN_TCI) {
                int prio = (rule->filter.vlan_tci & VLAN_PRIO_MASK) >>
                           VLAN_PRIO_SHIFT;

                err = igc_add_vlan_prio_filter(adapter, prio, rule->action);
                if (err)
                        return err;
        }

        return 0;
}

static void igc_disable_nfc_rule(struct igc_adapter *adapter,
                                 const struct igc_nfc_rule *rule)
{
        if (rule->filter.match_flags & IGC_FILTER_FLAG_ETHER_TYPE)
                igc_del_etype_filter(adapter, rule->filter.etype);

        if (rule->filter.match_flags & IGC_FILTER_FLAG_VLAN_TCI) {
                int prio = (rule->filter.vlan_tci & VLAN_PRIO_MASK) >>
                           VLAN_PRIO_SHIFT;

                igc_del_vlan_prio_filter(adapter, prio);
        }

        if (rule->filter.match_flags & IGC_FILTER_FLAG_SRC_MAC_ADDR)
                igc_del_mac_filter(adapter, IGC_MAC_FILTER_TYPE_SRC,
                                   rule->filter.src_addr);

        if (rule->filter.match_flags & IGC_FILTER_FLAG_DST_MAC_ADDR)
                igc_del_mac_filter(adapter, IGC_MAC_FILTER_TYPE_DST,
                                   rule->filter.dst_addr);
}

/**
 * igc_get_nfc_rule() - Get NFC rule
 * @adapter: Pointer to adapter
 * @location: Rule location
 *
 * Context: Expects adapter->nfc_rule_lock to be held by caller.
 *
 * Return: Pointer to NFC rule at @location. If not found, NULL.
 */
struct igc_nfc_rule *igc_get_nfc_rule(struct igc_adapter *adapter,
                                      u32 location)
{
        struct igc_nfc_rule *rule;

        list_for_each_entry(rule, &adapter->nfc_rule_list, list) {
                if (rule->location == location)
                        return rule;
                if (rule->location > location)
                        break;
        }

        return NULL;
}

/**
 * igc_del_nfc_rule() - Delete NFC rule
 * @adapter: Pointer to adapter
 * @rule: Pointer to rule to be deleted
 *
 * Disable NFC rule in hardware and delete it from adapter.
 *
 * Context: Expects adapter->nfc_rule_lock to be held by caller.
 */
void igc_del_nfc_rule(struct igc_adapter *adapter, struct igc_nfc_rule *rule)
{
        igc_disable_nfc_rule(adapter, rule);

        list_del(&rule->list);
        adapter->nfc_rule_count--;

        kfree(rule);
}

static void igc_flush_nfc_rules(struct igc_adapter *adapter)
{
        struct igc_nfc_rule *rule, *tmp;

        mutex_lock(&adapter->nfc_rule_lock);

        list_for_each_entry_safe(rule, tmp, &adapter->nfc_rule_list, list)
                igc_del_nfc_rule(adapter, rule);

        mutex_unlock(&adapter->nfc_rule_lock);
}

/**
 * igc_add_nfc_rule() - Add NFC rule
 * @adapter: Pointer to adapter
 * @rule: Pointer to rule to be added
 *
 * Enable NFC rule in hardware and add it to adapter.
 *
 * Context: Expects adapter->nfc_rule_lock to be held by caller.
 *
 * Return: 0 on success, negative errno on failure.
 */
int igc_add_nfc_rule(struct igc_adapter *adapter, struct igc_nfc_rule *rule)
{
        struct igc_nfc_rule *pred, *cur;
        int err;

        err = igc_enable_nfc_rule(adapter, rule);
        if (err)
                return err;

        pred = NULL;
        list_for_each_entry(cur, &adapter->nfc_rule_list, list) {
                if (cur->location >= rule->location)
                        break;
                pred = cur;
        }

        list_add(&rule->list, pred ? &pred->list : &adapter->nfc_rule_list);
        adapter->nfc_rule_count++;
        return 0;
}

static void igc_restore_nfc_rules(struct igc_adapter *adapter)
{
        struct igc_nfc_rule *rule;

        mutex_lock(&adapter->nfc_rule_lock);

        list_for_each_entry_reverse(rule, &adapter->nfc_rule_list, list)
                igc_enable_nfc_rule(adapter, rule);

        mutex_unlock(&adapter->nfc_rule_lock);
}

static int igc_uc_sync(struct net_device *netdev, const unsigned char *addr)
{
        struct igc_adapter *adapter = netdev_priv(netdev);

        return igc_add_mac_filter(adapter, IGC_MAC_FILTER_TYPE_DST, addr, -1);
}

static int igc_uc_unsync(struct net_device *netdev, const unsigned char *addr)
{
        struct igc_adapter *adapter = netdev_priv(netdev);

        igc_del_mac_filter(adapter, IGC_MAC_FILTER_TYPE_DST, addr);
        return 0;
}

/**
 * igc_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 igc_set_rx_mode(struct net_device *netdev)
{
        struct igc_adapter *adapter = netdev_priv(netdev);
        struct igc_hw *hw = &adapter->hw;
        u32 rctl = 0, rlpml = MAX_JUMBO_FRAME_SIZE;
        int count;

        /* Check for Promiscuous and All Multicast modes */
        if (netdev->flags & IFF_PROMISC) {
                rctl |= IGC_RCTL_UPE | IGC_RCTL_MPE;
        } else {
                if (netdev->flags & IFF_ALLMULTI) {
                        rctl |= IGC_RCTL_MPE;
                } else {
                        /* Write addresses to the MTA, if the attempt fails
                         * then we should just turn on promiscuous mode so
                         * that we can at least receive multicast traffic
                         */
                        count = igc_write_mc_addr_list(netdev);
                        if (count < 0)
                                rctl |= IGC_RCTL_MPE;
                }
        }

        /* Write addresses to available RAR registers, if there is not
         * sufficient space to store all the addresses then enable
         * unicast promiscuous mode
         */
        if (__dev_uc_sync(netdev, igc_uc_sync, igc_uc_unsync))
                rctl |= IGC_RCTL_UPE;

        /* update state of unicast and multicast */
        rctl |= rd32(IGC_RCTL) & ~(IGC_RCTL_UPE | IGC_RCTL_MPE);
        wr32(IGC_RCTL, rctl);

#if (PAGE_SIZE < 8192)
        if (adapter->max_frame_size <= IGC_MAX_FRAME_BUILD_SKB)
                rlpml = IGC_MAX_FRAME_BUILD_SKB;
#endif
        wr32(IGC_RLPML, rlpml);
}

/**
 * igc_configure - configure the hardware for RX and TX
 * @adapter: private board structure
 */
static void igc_configure(struct igc_adapter *adapter)
{
        struct net_device *netdev = adapter->netdev;
        int i = 0;

        igc_get_hw_control(adapter);
        igc_set_rx_mode(netdev);

        igc_setup_tctl(adapter);
        igc_setup_mrqc(adapter);
        igc_setup_rctl(adapter);

        igc_set_default_mac_filter(adapter);
        igc_restore_nfc_rules(adapter);

        igc_configure_tx(adapter);
        igc_configure_rx(adapter);

        igc_rx_fifo_flush_base(&adapter->hw);

        /* call igc_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 igc_ring *ring = adapter->rx_ring[i];

                igc_alloc_rx_buffers(ring, igc_desc_unused(ring));
        }
}

/**
 * igc_write_ivar - configure ivar for given MSI-X vector
 * @hw: pointer to the HW structure
 * @msix_vector: vector number we are allocating to a given ring
 * @index: row index of IVAR register to write within IVAR table
 * @offset: column offset of in IVAR, should be multiple of 8
 *
 * The IVAR table consists of 2 columns,
 * each containing an cause allocation for an Rx and Tx ring, and a
 * variable number of rows depending on the number of queues supported.
 */
static void igc_write_ivar(struct igc_hw *hw, int msix_vector,
                           int index, int offset)
{
        u32 ivar = array_rd32(IGC_IVAR0, index);

        /* clear any bits that are currently set */
        ivar &= ~((u32)0xFF << offset);

        /* write vector and valid bit */
        ivar |= (msix_vector | IGC_IVAR_VALID) << offset;

        array_wr32(IGC_IVAR0, index, ivar);
}

static void igc_assign_vector(struct igc_q_vector *q_vector, int msix_vector)
{
        struct igc_adapter *adapter = q_vector->adapter;
        struct igc_hw *hw = &adapter->hw;
        int rx_queue = IGC_N0_QUEUE;
        int tx_queue = IGC_N0_QUEUE;

        if (q_vector->rx.ring)
                rx_queue = q_vector->rx.ring->reg_idx;
        if (q_vector->tx.ring)
                tx_queue = q_vector->tx.ring->reg_idx;

        switch (hw->mac.type) {
        case igc_i225:
                if (rx_queue > IGC_N0_QUEUE)
                        igc_write_ivar(hw, msix_vector,
                                       rx_queue >> 1,
                                       (rx_queue & 0x1) << 4);
                if (tx_queue > IGC_N0_QUEUE)
                        igc_write_ivar(hw, msix_vector,
                                       tx_queue >> 1,
                                       ((tx_queue & 0x1) << 4) + 8);
                q_vector->eims_value = BIT(msix_vector);
                break;
        default:
                WARN_ONCE(hw->mac.type != igc_i225, "Wrong MAC type\n");
                break;
        }

        /* add q_vector eims value to global eims_enable_mask */
        adapter->eims_enable_mask |= q_vector->eims_value;

        /* configure q_vector to set itr on first interrupt */
        q_vector->set_itr = 1;
}

/**
 * igc_configure_msix - Configure MSI-X hardware
 * @adapter: Pointer to adapter structure
 *
 * igc_configure_msix sets up the hardware to properly
 * generate MSI-X interrupts.
 */
static void igc_configure_msix(struct igc_adapter *adapter)
{
        struct igc_hw *hw = &adapter->hw;
        int i, vector = 0;
        u32 tmp;

        adapter->eims_enable_mask = 0;

        /* set vector for other causes, i.e. link changes */
        switch (hw->mac.type) {
        case igc_i225:
                /* Turn on MSI-X capability first, or our settings
                 * won't stick.  And it will take days to debug.
                 */
                wr32(IGC_GPIE, IGC_GPIE_MSIX_MODE |
                     IGC_GPIE_PBA | IGC_GPIE_EIAME |
                     IGC_GPIE_NSICR);

                /* enable msix_other interrupt */
                adapter->eims_other = BIT(vector);
                tmp = (vector++ | IGC_IVAR_VALID) << 8;

                wr32(IGC_IVAR_MISC, tmp);
                break;
        default:
                /* do nothing, since nothing else supports MSI-X */
                break;
        } /* switch (hw->mac.type) */

        adapter->eims_enable_mask |= adapter->eims_other;

        for (i = 0; i < adapter->num_q_vectors; i++)
                igc_assign_vector(adapter->q_vector[i], vector++);

        wrfl();
}

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

        if (adapter->msix_entries) {
                u32 ims = IGC_IMS_LSC | IGC_IMS_DOUTSYNC | IGC_IMS_DRSTA;
                u32 regval = rd32(IGC_EIAC);

                wr32(IGC_EIAC, regval | adapter->eims_enable_mask);
                regval = rd32(IGC_EIAM);
                wr32(IGC_EIAM, regval | adapter->eims_enable_mask);
                wr32(IGC_EIMS, adapter->eims_enable_mask);
                wr32(IGC_IMS, ims);
        } else {
                wr32(IGC_IMS, IMS_ENABLE_MASK | IGC_IMS_DRSTA);
                wr32(IGC_IAM, IMS_ENABLE_MASK | IGC_IMS_DRSTA);
        }
}

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

        if (adapter->msix_entries) {
                u32 regval = rd32(IGC_EIAM);

                wr32(IGC_EIAM, regval & ~adapter->eims_enable_mask);
                wr32(IGC_EIMC, adapter->eims_enable_mask);
                regval = rd32(IGC_EIAC);
                wr32(IGC_EIAC, regval & ~adapter->eims_enable_mask);
        }

        wr32(IGC_IAM, 0);
        wr32(IGC_IMC, ~0);
        wrfl();

        if (adapter->msix_entries) {
                int vector = 0, i;

                synchronize_irq(adapter->msix_entries[vector++].vector);

                for (i = 0; i < adapter->num_q_vectors; i++)
                        synchronize_irq(adapter->msix_entries[vector++].vector);
        } else {
                synchronize_irq(adapter->pdev->irq);
        }
}

void igc_set_flag_queue_pairs(struct igc_adapter *adapter,
                              const u32 max_rss_queues)
{
        /* Determine if we need to pair queues. */
        /* If rss_queues > half of max_rss_queues, pair the queues in
         * order to conserve interrupts due to limited supply.
         */
        if (adapter->rss_queues > (max_rss_queues / 2))
                adapter->flags |= IGC_FLAG_QUEUE_PAIRS;
        else
                adapter->flags &= ~IGC_FLAG_QUEUE_PAIRS;
}

unsigned int igc_get_max_rss_queues(struct igc_adapter *adapter)
{
        return IGC_MAX_RX_QUEUES;
}

static void igc_init_queue_configuration(struct igc_adapter *adapter)
{
        u32 max_rss_queues;

        max_rss_queues = igc_get_max_rss_queues(adapter);
        adapter->rss_queues = min_t(u32, max_rss_queues, num_online_cpus());

        igc_set_flag_queue_pairs(adapter, max_rss_queues);
}

/**
 * igc_reset_q_vector - Reset config for interrupt vector
 * @adapter: board private structure to initialize
 * @v_idx: Index of vector to be reset
 *
 * If NAPI is enabled it will delete any references to the
 * NAPI struct. This is preparation for igc_free_q_vector.
 */
static void igc_reset_q_vector(struct igc_adapter *adapter, int v_idx)
{
        struct igc_q_vector *q_vector = adapter->q_vector[v_idx];

        /* if we're coming from igc_set_interrupt_capability, the vectors are
         * not yet allocated
         */
        if (!q_vector)
                return;

        if (q_vector->tx.ring)
                adapter->tx_ring[q_vector->tx.ring->queue_index] = NULL;

        if (q_vector->rx.ring)
                adapter->rx_ring[q_vector->rx.ring->queue_index] = NULL;

        netif_napi_del(&q_vector->napi);
}

/**
 * igc_free_q_vector - Free memory allocated for specific interrupt vector
 * @adapter: board private structure to initialize
 * @v_idx: Index of vector to be freed
 *
 * This function frees the memory allocated to the q_vector.
 */
static void igc_free_q_vector(struct igc_adapter *adapter, int v_idx)
{
        struct igc_q_vector *q_vector = adapter->q_vector[v_idx];

        adapter->q_vector[v_idx] = NULL;

        /* igc_get_stats64() might access the rings on this vector,
         * we must wait a grace period before freeing it.
         */
        if (q_vector)
                kfree_rcu(q_vector, rcu);
}

/**
 * igc_free_q_vectors - Free memory allocated for interrupt vectors
 * @adapter: board private structure to initialize
 *
 * This function frees the memory allocated to the q_vectors.  In addition if
 * NAPI is enabled it will delete any references to the NAPI struct prior
 * to freeing the q_vector.
 */
static void igc_free_q_vectors(struct igc_adapter *adapter)
{
        int v_idx = adapter->num_q_vectors;

        adapter->num_tx_queues = 0;
        adapter->num_rx_queues = 0;
        adapter->num_q_vectors = 0;

        while (v_idx--) {
                igc_reset_q_vector(adapter, v_idx);
                igc_free_q_vector(adapter, v_idx);
        }
}

/**
 * igc_update_itr - update the dynamic ITR value based on statistics
 * @q_vector: pointer to q_vector
 * @ring_container: ring info to update the itr for
 *
 * 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.
 * NOTE: These calculations are only valid when operating in a single-
 * queue environment.
 */
static void igc_update_itr(struct igc_q_vector *q_vector,
                           struct igc_ring_container *ring_container)
{
        unsigned int packets = ring_container->total_packets;
        unsigned int bytes = ring_container->total_bytes;
        u8 itrval = ring_container->itr;

        /* no packets, exit with status unchanged */
        if (packets == 0)
                return;

        switch (itrval) {
        case lowest_latency:
                /* handle TSO and jumbo frames */
                if (bytes / packets > 8000)
                        itrval = bulk_latency;
                else if ((packets < 5) && (bytes > 512))
                        itrval = low_latency;
                break;
        case low_latency:  /* 50 usec aka 20000 ints/s */
                if (bytes > 10000) {
                        /* this if handles the TSO accounting */
                        if (bytes / packets > 8000)
                                itrval = bulk_latency;
                        else if ((packets < 10) || ((bytes / packets) > 1200))
                                itrval = bulk_latency;
                        else if ((packets > 35))
                                itrval = lowest_latency;
                } else if (bytes / packets > 2000) {
                        itrval = bulk_latency;
                } else if (packets <= 2 && bytes < 512) {
                        itrval = lowest_latency;
                }
                break;
        case bulk_latency: /* 250 usec aka 4000 ints/s */
                if (bytes > 25000) {
                        if (packets > 35)
                                itrval = low_latency;
                } else if (bytes < 1500) {
                        itrval = low_latency;
                }
                break;
        }

        /* clear work counters since we have the values we need */
        ring_container->total_bytes = 0;
        ring_container->total_packets = 0;

        /* write updated itr to ring container */
        ring_container->itr = itrval;

}

static void igc_set_itr(struct igc_q_vector *q_vector)
{
        struct igc_adapter *adapter = q_vector->adapter;
        u32 new_itr = q_vector->itr_val;
        u8 current_itr = 0;

        /* for non-gigabit speeds, just fix the interrupt rate at 4000 */
        switch (adapter->link_speed) {
        case SPEED_10:
        case SPEED_100:
                current_itr = 0;
                new_itr = IGC_4K_ITR;
                goto set_itr_now;
        default:
                break;
        }

        igc_update_itr(q_vector, &q_vector->tx);
        igc_update_itr(q_vector, &q_vector->rx);

        current_itr = max(q_vector->rx.itr, q_vector->tx.itr);

        /* conservative mode (itr 3) eliminates the lowest_latency setting */
        if (current_itr == lowest_latency &&
            ((q_vector->rx.ring && adapter->rx_itr_setting == 3) ||
            (!q_vector->rx.ring && adapter->tx_itr_setting == 3)))
                current_itr = low_latency;

        switch (current_itr) {
        /* counts and packets in update_itr are dependent on these numbers */
        case lowest_latency:
                new_itr = IGC_70K_ITR; /* 70,000 ints/sec */
                break;
        case low_latency:
                new_itr = IGC_20K_ITR; /* 20,000 ints/sec */
                break;
        case bulk_latency:
                new_itr = IGC_4K_ITR;  /* 4,000 ints/sec */
                break;
        default:
                break;
        }

set_itr_now:
        if (new_itr != q_vector->itr_val) {
                /* this attempts to bias the interrupt rate towards Bulk
                 * by adding intermediate steps when interrupt rate is
                 * increasing
                 */
                new_itr = new_itr > q_vector->itr_val ?
                          max((new_itr * q_vector->itr_val) /
                          (new_itr + (q_vector->itr_val >> 2)),
                          new_itr) : new_itr;
                /* Don't write the value here; it resets the adapter's
                 * internal timer, and causes us to delay far longer than
                 * we should between interrupts.  Instead, we write the ITR
                 * value at the beginning of the next interrupt so the timing
                 * ends up being correct.
                 */
                q_vector->itr_val = new_itr;
                q_vector->set_itr = 1;
        }
}

static void igc_reset_interrupt_capability(struct igc_adapter *adapter)
{
        int v_idx = adapter->num_q_vectors;

        if (adapter->msix_entries) {
                pci_disable_msix(adapter->pdev);
                kfree(adapter->msix_entries);
                adapter->msix_entries = NULL;
        } else if (adapter->flags & IGC_FLAG_HAS_MSI) {
                pci_disable_msi(adapter->pdev);
        }

        while (v_idx--)
                igc_reset_q_vector(adapter, v_idx);
}

/**
 * igc_set_interrupt_capability - set MSI or MSI-X if supported
 * @adapter: Pointer to adapter structure
 * @msix: boolean value for MSI-X capability
 *
 * Attempt to configure interrupts using the best available
 * capabilities of the hardware and kernel.
 */
static void igc_set_interrupt_capability(struct igc_adapter *adapter,
                                         bool msix)
{
        int numvecs, i;
        int err;

        if (!msix)
                goto msi_only;
        adapter->flags |= IGC_FLAG_HAS_MSIX;

        /* Number of supported queues. */
        adapter->num_rx_queues = adapter->rss_queues;

        adapter->num_tx_queues = adapter->rss_queues;

        /* start with one vector for every Rx queue */
        numvecs = adapter->num_rx_queues;

        /* if Tx handler is separate add 1 for every Tx queue */
        if (!(adapter->flags & IGC_FLAG_QUEUE_PAIRS))
                numvecs += adapter->num_tx_queues;

        /* store the number of vectors reserved for queues */
        adapter->num_q_vectors = numvecs;

        /* add 1 vector for link status interrupts */
        numvecs++;

        adapter->msix_entries = kcalloc(numvecs, sizeof(struct msix_entry),
                                        GFP_KERNEL);

        if (!adapter->msix_entries)
                return;

        /* populate entry values */
        for (i = 0; i < numvecs; i++)
                adapter->msix_entries[i].entry = i;

        err = pci_enable_msix_range(adapter->pdev,
                                    adapter->msix_entries,
                                    numvecs,
                                    numvecs);
        if (err > 0)
                return;

        kfree(adapter->msix_entries);
        adapter->msix_entries = NULL;

        igc_reset_interrupt_capability(adapter);

msi_only:
        adapter->flags &= ~IGC_FLAG_HAS_MSIX;

        adapter->rss_queues = 1;
        adapter->flags |= IGC_FLAG_QUEUE_PAIRS;
        adapter->num_rx_queues = 1;
        adapter->num_tx_queues = 1;
        adapter->num_q_vectors = 1;
        if (!pci_enable_msi(adapter->pdev))
                adapter->flags |= IGC_FLAG_HAS_MSI;
}

/**
 * igc_update_ring_itr - update the dynamic ITR value based on packet size
 * @q_vector: pointer to q_vector
 *
 * Stores a new ITR value based on strictly on packet size.  This
 * algorithm is less sophisticated than that used in igc_update_itr,
 * due to the difficulty of synchronizing statistics across multiple
 * receive rings.  The divisors and thresholds used by this function
 * were determined based on theoretical maximum wire speed and testing
 * data, in order to minimize response time while increasing bulk
 * throughput.
 * NOTE: This function is called only when operating in a multiqueue
 * receive environment.
 */
static void igc_update_ring_itr(struct igc_q_vector *q_vector)
{
        struct igc_adapter *adapter = q_vector->adapter;
        int new_val = q_vector->itr_val;
        int avg_wire_size = 0;
        unsigned int packets;

        /* For non-gigabit speeds, just fix the interrupt rate at 4000
         * ints/sec - ITR timer value of 120 ticks.
         */
        switch (adapter->link_speed) {
        case SPEED_10:
        case SPEED_100:
                new_val = IGC_4K_ITR;
                goto set_itr_val;
        default:
                break;
        }

        packets = q_vector->rx.total_packets;
        if (packets)
                avg_wire_size = q_vector->rx.total_bytes / packets;

        packets = q_vector->tx.total_packets;
        if (packets)
                avg_wire_size = max_t(u32, avg_wire_size,
                                      q_vector->tx.total_bytes / packets);

        /* if avg_wire_size isn't set no work was done */
        if (!avg_wire_size)
                goto clear_counts;

        /* Add 24 bytes to size to account for CRC, preamble, and gap */
        avg_wire_size += 24;

        /* Don't starve jumbo frames */
        avg_wire_size = min(avg_wire_size, 3000);

        /* Give a little boost to mid-size frames */
        if (avg_wire_size > 300 && avg_wire_size < 1200)
                new_val = avg_wire_size / 3;
        else
                new_val = avg_wire_size / 2;

        /* conservative mode (itr 3) eliminates the lowest_latency setting */
        if (new_val < IGC_20K_ITR &&
            ((q_vector->rx.ring && adapter->rx_itr_setting == 3) ||
            (!q_vector->rx.ring && adapter->tx_itr_setting == 3)))
                new_val = IGC_20K_ITR;

set_itr_val:
        if (new_val != q_vector->itr_val) {
                q_vector->itr_val = new_val;
                q_vector->set_itr = 1;
        }
clear_counts:
        q_vector->rx.total_bytes = 0;
        q_vector->rx.total_packets = 0;
        q_vector->tx.total_bytes = 0;
        q_vector->tx.total_packets = 0;
}

static void igc_ring_irq_enable(struct igc_q_vector *q_vector)
{
        struct igc_adapter *adapter = q_vector->adapter;
        struct igc_hw *hw = &adapter->hw;

        if ((q_vector->rx.ring && (adapter->rx_itr_setting & 3)) ||
            (!q_vector->rx.ring && (adapter->tx_itr_setting & 3))) {
                if (adapter->num_q_vectors == 1)
                        igc_set_itr(q_vector);
                else
                        igc_update_ring_itr(q_vector);
        }

        if (!test_bit(__IGC_DOWN, &adapter->state)) {
                if (adapter->msix_entries)
                        wr32(IGC_EIMS, q_vector->eims_value);
                else
                        igc_irq_enable(adapter);
        }
}

static void igc_add_ring(struct igc_ring *ring,
                         struct igc_ring_container *head)
{
        head->ring = ring;
        head->count++;
}

/**
 * igc_cache_ring_register - Descriptor ring to register mapping
 * @adapter: board private structure to initialize
 *
 * Once we know the feature-set enabled for the device, we'll cache
 * the register offset the descriptor ring is assigned to.
 */
static void igc_cache_ring_register(struct igc_adapter *adapter)
{
        int i = 0, j = 0;

        switch (adapter->hw.mac.type) {
        case igc_i225:
        default:
                for (; i < adapter->num_rx_queues; i++)
                        adapter->rx_ring[i]->reg_idx = i;
                for (; j < adapter->num_tx_queues; j++)
                        adapter->tx_ring[j]->reg_idx = j;
                break;
        }
}

/**
 * igc_poll - NAPI Rx polling callback
 * @napi: napi polling structure
 * @budget: count of how many packets we should handle
 */
static int igc_poll(struct napi_struct *napi, int budget)
{
        struct igc_q_vector *q_vector = container_of(napi,
                                                     struct igc_q_vector,
                                                     napi);
        bool clean_complete = true;
        int work_done = 0;

        if (q_vector->tx.ring)
                clean_complete = igc_clean_tx_irq(q_vector, budget);

        if (q_vector->rx.ring) {
                int cleaned = igc_clean_rx_irq(q_vector, budget);

                work_done += cleaned;
                if (cleaned >= budget)
                        clean_complete = false;
        }

        /* If all work not completed, return budget and keep polling */
        if (!clean_complete)
                return budget;

        /* Exit the polling mode, but don't re-enable interrupts if stack might
         * poll us due to busy-polling
         */
        if (likely(napi_complete_done(napi, work_done)))
                igc_ring_irq_enable(q_vector);

        return min(work_done, budget - 1);
}

/**
 * igc_alloc_q_vector - Allocate memory for a single interrupt vector
 * @adapter: board private structure to initialize
 * @v_count: q_vectors allocated on adapter, used for ring interleaving
 * @v_idx: index of vector in adapter struct
 * @txr_count: total number of Tx rings to allocate
 * @txr_idx: index of first Tx ring to allocate
 * @rxr_count: total number of Rx rings to allocate
 * @rxr_idx: index of first Rx ring to allocate
 *
 * We allocate one q_vector.  If allocation fails we return -ENOMEM.
 */
static int igc_alloc_q_vector(struct igc_adapter *adapter,
                              unsigned int v_count, unsigned int v_idx,
                              unsigned int txr_count, unsigned int txr_idx,
                              unsigned int rxr_count, unsigned int rxr_idx)
{
        struct igc_q_vector *q_vector;
        struct igc_ring *ring;
        int ring_count;

        /* igc only supports 1 Tx and/or 1 Rx queue per vector */
        if (txr_count > 1 || rxr_count > 1)
                return -ENOMEM;

        ring_count = txr_count + rxr_count;

        /* allocate q_vector and rings */
        q_vector = adapter->q_vector[v_idx];
        if (!q_vector)
                q_vector = kzalloc(struct_size(q_vector, ring, ring_count),
                                   GFP_KERNEL);
        else
                memset(q_vector, 0, struct_size(q_vector, ring, ring_count));
        if (!q_vector)
                return -ENOMEM;

        /* initialize NAPI */
        netif_napi_add(adapter->netdev, &q_vector->napi,
                       igc_poll, 64);

        /* tie q_vector and adapter together */
        adapter->q_vector[v_idx] = q_vector;
        q_vector->adapter = adapter;

        /* initialize work limits */
        q_vector->tx.work_limit = adapter->tx_work_limit;

        /* initialize ITR configuration */
        q_vector->itr_register = adapter->io_addr + IGC_EITR(0);
        q_vector->itr_val = IGC_START_ITR;

        /* initialize pointer to rings */
        ring = q_vector->ring;

        /* initialize ITR */
        if (rxr_count) {
                /* rx or rx/tx vector */
                if (!adapter->rx_itr_setting || adapter->rx_itr_setting > 3)
                        q_vector->itr_val = adapter->rx_itr_setting;
        } else {
                /* tx only vector */
                if (!adapter->tx_itr_setting || adapter->tx_itr_setting > 3)
                        q_vector->itr_val = adapter->tx_itr_setting;
        }

        if (txr_count) {
                /* assign generic ring traits */
                ring->dev = &adapter->pdev->dev;
                ring->netdev = adapter->netdev;

                /* configure backlink on ring */
                ring->q_vector = q_vector;

                /* update q_vector Tx values */
                igc_add_ring(ring, &q_vector->tx);

                /* apply Tx specific ring traits */
                ring->count = adapter->tx_ring_count;
                ring->queue_index = txr_idx;

                /* assign ring to adapter */
                adapter->tx_ring[txr_idx] = ring;

                /* push pointer to next ring */
                ring++;
        }

        if (rxr_count) {
                /* assign generic ring traits */
                ring->dev = &adapter->pdev->dev;
                ring->netdev = adapter->netdev;

                /* configure backlink on ring */
                ring->q_vector = q_vector;

                /* update q_vector Rx values */
                igc_add_ring(ring, &q_vector->rx);

                /* apply Rx specific ring traits */
                ring->count = adapter->rx_ring_count;
                ring->queue_index = rxr_idx;

                /* assign ring to adapter */
                adapter->rx_ring[rxr_idx] = ring;
        }

        return 0;
}

/**
 * igc_alloc_q_vectors - Allocate memory for interrupt vectors
 * @adapter: board private structure to initialize
 *
 * We allocate one q_vector per queue interrupt.  If allocation fails we
 * return -ENOMEM.
 */
static int igc_alloc_q_vectors(struct igc_adapter *adapter)
{
        int rxr_remaining = adapter->num_rx_queues;
        int txr_remaining = adapter->num_tx_queues;
        int rxr_idx = 0, txr_idx = 0, v_idx = 0;
        int q_vectors = adapter->num_q_vectors;
        int err;

        if (q_vectors >= (rxr_remaining + txr_remaining)) {
                for (; rxr_remaining; v_idx++) {
                        err = igc_alloc_q_vector(adapter, q_vectors, v_idx,
                                                 0, 0, 1, rxr_idx);

                        if (err)
                                goto err_out;

                        /* update counts and index */
                        rxr_remaining--;
                        rxr_idx++;
                }
        }

        for (; v_idx < q_vectors; v_idx++) {
                int rqpv = DIV_ROUND_UP(rxr_remaining, q_vectors - v_idx);
                int tqpv = DIV_ROUND_UP(txr_remaining, q_vectors - v_idx);

                err = igc_alloc_q_vector(adapter, q_vectors, v_idx,
                                         tqpv, txr_idx, rqpv, rxr_idx);

                if (err)
                        goto err_out;

                /* update counts and index */
                rxr_remaining -= rqpv;
                txr_remaining -= tqpv;
                rxr_idx++;
                txr_idx++;
        }

        return 0;

err_out:
        adapter->num_tx_queues = 0;
        adapter->num_rx_queues = 0;
        adapter->num_q_vectors = 0;

        while (v_idx--)
                igc_free_q_vector(adapter, v_idx);

        return -ENOMEM;
}

/**
 * igc_init_interrupt_scheme - initialize interrupts, allocate queues/vectors
 * @adapter: Pointer to adapter structure
 * @msix: boolean for MSI-X capability
 *
 * This function initializes the interrupts and allocates all of the queues.
 */
static int igc_init_interrupt_scheme(struct igc_adapter *adapter, bool msix)
{
        struct net_device *dev = adapter->netdev;
        int err = 0;

        igc_set_interrupt_capability(adapter, msix);

        err = igc_alloc_q_vectors(adapter);
        if (err) {
                netdev_err(dev, "Unable to allocate memory for vectors\n");
                goto err_alloc_q_vectors;
        }

        igc_cache_ring_register(adapter);

        return 0;

err_alloc_q_vectors:
        igc_reset_interrupt_capability(adapter);
        return err;
}

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

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

        /* set default ring sizes */
        adapter->tx_ring_count = IGC_DEFAULT_TXD;
        adapter->rx_ring_count = IGC_DEFAULT_RXD;

        /* set default ITR values */
        adapter->rx_itr_setting = IGC_DEFAULT_ITR;
        adapter->tx_itr_setting = IGC_DEFAULT_ITR;

        /* set default work limits */
        adapter->tx_work_limit = IGC_DEFAULT_TX_WORK;

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

        mutex_init(&adapter->nfc_rule_lock);
        INIT_LIST_HEAD(&adapter->nfc_rule_list);
        adapter->nfc_rule_count = 0;

        spin_lock_init(&adapter->stats64_lock);
        /* Assume MSI-X interrupts, will be checked during IRQ allocation */
        adapter->flags |= IGC_FLAG_HAS_MSIX;

        igc_init_queue_configuration(adapter);

        /* This call may decrease the number of queues */
        if (igc_init_interrupt_scheme(adapter, true)) {
                netdev_err(netdev, "Unable to allocate memory for queues\n");
                return -ENOMEM;
        }

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

        set_bit(__IGC_DOWN, &adapter->state);

        return 0;
}

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

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

        clear_bit(__IGC_DOWN, &adapter->state);

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

        if (adapter->msix_entries)
                igc_configure_msix(adapter);
        else
                igc_assign_vector(adapter->q_vector[0], 0);

        /* Clear any pending interrupts. */
        rd32(IGC_ICR);
        igc_irq_enable(adapter);

        netif_tx_start_all_queues(adapter->netdev);

        /* start the watchdog. */
        hw->mac.get_link_status = 1;
        schedule_work(&adapter->watchdog_task);
}

/**
 * igc_update_stats - Update the board statistics counters
 * @adapter: board private structure
 */
void igc_update_stats(struct igc_adapter *adapter)
{
        struct rtnl_link_stats64 *net_stats = &adapter->stats64;
        struct pci_dev *pdev = adapter->pdev;
        struct igc_hw *hw = &adapter->hw;
        u64 _bytes, _packets;
        u64 bytes, packets;
        unsigned int start;
        u32 mpc;
        int i;

        /* Prevent stats update while adapter is being reset, or if the pci
         * connection is down.
         */
        if (adapter->link_speed == 0)
                return;
        if (pci_channel_offline(pdev))
                return;

        packets = 0;
        bytes = 0;

        rcu_read_lock();
        for (i = 0; i < adapter->num_rx_queues; i++) {
                struct igc_ring *ring = adapter->rx_ring[i];
                u32 rqdpc = rd32(IGC_RQDPC(i));

                if (hw->mac.type >= igc_i225)
                        wr32(IGC_RQDPC(i), 0);

                if (rqdpc) {
                        ring->rx_stats.drops += rqdpc;
                        net_stats->rx_fifo_errors += rqdpc;
                }

                do {
                        start = u64_stats_fetch_begin_irq(&ring->rx_syncp);
                        _bytes = ring->rx_stats.bytes;
                        _packets = ring->rx_stats.packets;
                } while (u64_stats_fetch_retry_irq(&ring->rx_syncp, start));
                bytes += _bytes;
                packets += _packets;
        }

        net_stats->rx_bytes = bytes;
        net_stats->rx_packets = packets;

        packets = 0;
        bytes = 0;
        for (i = 0; i < adapter->num_tx_queues; i++) {
                struct igc_ring *ring = adapter->tx_ring[i];

                do {
                        start = u64_stats_fetch_begin_irq(&ring->tx_syncp);
                        _bytes = ring->tx_stats.bytes;
                        _packets = ring->tx_stats.packets;
                } while (u64_stats_fetch_retry_irq(&ring->tx_syncp, start));
                bytes += _bytes;
                packets += _packets;
        }
        net_stats->tx_bytes = bytes;
        net_stats->tx_packets = packets;
        rcu_read_unlock();

        /* read stats registers */
        adapter->stats.crcerrs += rd32(IGC_CRCERRS);
        adapter->stats.gprc += rd32(IGC_GPRC);
        adapter->stats.gorc += rd32(IGC_GORCL);
        rd32(IGC_GORCH); /* clear GORCL */
        adapter->stats.bprc += rd32(IGC_BPRC);
        adapter->stats.mprc += rd32(IGC_MPRC);
        adapter->stats.roc += rd32(IGC_ROC);

        adapter->stats.prc64 += rd32(IGC_PRC64);
        adapter->stats.prc127 += rd32(IGC_PRC127);
        adapter->stats.prc255 += rd32(IGC_PRC255);
        adapter->stats.prc511 += rd32(IGC_PRC511);
        adapter->stats.prc1023 += rd32(IGC_PRC1023);
        adapter->stats.prc1522 += rd32(IGC_PRC1522);
        adapter->stats.tlpic += rd32(IGC_TLPIC);
        adapter->stats.rlpic += rd32(IGC_RLPIC);

        mpc = rd32(IGC_MPC);
        adapter->stats.mpc += mpc;
        net_stats->rx_fifo_errors += mpc;
        adapter->stats.scc += rd32(IGC_SCC);
        adapter->stats.ecol += rd32(IGC_ECOL);
        adapter->stats.mcc += rd32(IGC_MCC);
        adapter->stats.latecol += rd32(IGC_LATECOL);
        adapter->stats.dc += rd32(IGC_DC);
        adapter->stats.rlec += rd32(IGC_RLEC);
        adapter->stats.xonrxc += rd32(IGC_XONRXC);
        adapter->stats.xontxc += rd32(IGC_XONTXC);
        adapter->stats.xoffrxc += rd32(IGC_XOFFRXC);
        adapter->stats.xofftxc += rd32(IGC_XOFFTXC);
        adapter->stats.fcruc += rd32(IGC_FCRUC);
        adapter->stats.gptc += rd32(IGC_GPTC);
        adapter->stats.gotc += rd32(IGC_GOTCL);
        rd32(IGC_GOTCH); /* clear GOTCL */
        adapter->stats.rnbc += rd32(IGC_RNBC);
        adapter->stats.ruc += rd32(IGC_RUC);
        adapter->stats.rfc += rd32(IGC_RFC);
        adapter->stats.rjc += rd32(IGC_RJC);
        adapter->stats.tor += rd32(IGC_TORH);
        adapter->stats.tot += rd32(IGC_TOTH);
        adapter->stats.tpr += rd32(IGC_TPR);

        adapter->stats.ptc64 += rd32(IGC_PTC64);
        adapter->stats.ptc127 += rd32(IGC_PTC127);
        adapter->stats.ptc255 += rd32(IGC_PTC255);
        adapter->stats.ptc511 += rd32(IGC_PTC511);
        adapter->stats.ptc1023 += rd32(IGC_PTC1023);
        adapter->stats.ptc1522 += rd32(IGC_PTC1522);

        adapter->stats.mptc += rd32(IGC_MPTC);
        adapter->stats.bptc += rd32(IGC_BPTC);

        adapter->stats.tpt += rd32(IGC_TPT);
        adapter->stats.colc += rd32(IGC_COLC);
        adapter->stats.colc += rd32(IGC_RERC);

        adapter->stats.algnerrc += rd32(IGC_ALGNERRC);

        adapter->stats.tsctc += rd32(IGC_TSCTC);

        adapter->stats.iac += rd32(IGC_IAC);

        /* Fill out the OS statistics structure */
        net_stats->multicast = adapter->stats.mprc;
        net_stats->collisions = adapter->stats.colc;

        /* Rx Errors */

        /* RLEC on some newer hardware can be incorrect so build
         * our own version based on RUC and ROC
         */
        net_stats->rx_errors = adapter->stats.rxerrc +
                adapter->stats.crcerrs + adapter->stats.algnerrc +
                adapter->stats.ruc + adapter->stats.roc +
                adapter->stats.cexterr;
        net_stats->rx_length_errors = adapter->stats.ruc +
                                      adapter->stats.roc;
        net_stats->rx_crc_errors = adapter->stats.crcerrs;
        net_stats->rx_frame_errors = adapter->stats.algnerrc;
        net_stats->rx_missed_errors = adapter->stats.mpc;

        /* Tx Errors */
        net_stats->tx_errors = adapter->stats.ecol +
                               adapter->stats.latecol;
        net_stats->tx_aborted_errors = adapter->stats.ecol;
        net_stats->tx_window_errors = adapter->stats.latecol;
        net_stats->tx_carrier_errors = adapter->stats.tncrs;

        /* Tx Dropped needs to be maintained elsewhere */

        /* Management Stats */
        adapter->stats.mgptc += rd32(IGC_MGTPTC);
        adapter->stats.mgprc += rd32(IGC_MGTPRC);
        adapter->stats.mgpdc += rd32(IGC_MGTPDC);
}

/**
 * igc_down - Close the interface
 * @adapter: board private structure
 */
void igc_down(struct igc_adapter *adapter)
{
        struct net_device *netdev = adapter->netdev;
        struct igc_hw *hw = &adapter->hw;
        u32 tctl, rctl;
        int i = 0;

        set_bit(__IGC_DOWN, &adapter->state);

        igc_ptp_suspend(adapter);

        /* disable receives in the hardware */
        rctl = rd32(IGC_RCTL);
        wr32(IGC_RCTL, rctl & ~IGC_RCTL_EN);
        /* flush and sleep below */

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

        netif_carrier_off(netdev);
        netif_tx_stop_all_queues(netdev);

        /* disable transmits in the hardware */
        tctl = rd32(IGC_TCTL);
        tctl &= ~IGC_TCTL_EN;
        wr32(IGC_TCTL, tctl);
        /* flush both disables and wait for them to finish */
        wrfl();
        usleep_range(10000, 20000);

        igc_irq_disable(adapter);

        adapter->flags &= ~IGC_FLAG_NEED_LINK_UPDATE;

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

        del_timer_sync(&adapter->watchdog_timer);
        del_timer_sync(&adapter->phy_info_timer);

        /* record the stats before reset*/
        spin_lock(&adapter->stats64_lock);
        igc_update_stats(adapter);
        spin_unlock(&adapter->stats64_lock);

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

        if (!pci_channel_offline(adapter->pdev))
                igc_reset(adapter);

        /* clear VLAN promisc flag so VFTA will be updated if necessary */
        adapter->flags &= ~IGC_FLAG_VLAN_PROMISC;

        igc_clean_all_tx_rings(adapter);
        igc_clean_all_rx_rings(adapter);
}

void igc_reinit_locked(struct igc_adapter *adapter)
{
        while (test_and_set_bit(__IGC_RESETTING, &adapter->state))
                usleep_range(1000, 2000);
        igc_down(adapter);
        igc_up(adapter);
        clear_bit(__IGC_RESETTING, &adapter->state);
}

static void igc_reset_task(struct work_struct *work)
{
        struct igc_adapter *adapter;

        adapter = container_of(work, struct igc_adapter, reset_task);

        igc_rings_dump(adapter);
        igc_regs_dump(adapter);
        netdev_err(adapter->netdev, "Reset adapter\n");
        igc_reinit_locked(adapter);
}

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

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

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

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

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

        netdev_dbg(netdev, "changing MTU from %d to %d\n", netdev->mtu, new_mtu);
        netdev->mtu = new_mtu;

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

        clear_bit(__IGC_RESETTING, &adapter->state);

        return 0;
}

/**
 * igc_get_stats64 - Get System Network Statistics
 * @netdev: network interface device structure
 * @stats: rtnl_link_stats64 pointer
 *
 * Returns the address of the device statistics structure.
 * The statistics are updated here and also from the timer callback.
 */
static void igc_get_stats64(struct net_device *netdev,
                            struct rtnl_link_stats64 *stats)
{
        struct igc_adapter *adapter = netdev_priv(netdev);

        spin_lock(&adapter->stats64_lock);
        if (!test_bit(__IGC_RESETTING, &adapter->state))
                igc_update_stats(adapter);
        memcpy(stats, &adapter->stats64, sizeof(*stats));
        spin_unlock(&adapter->stats64_lock);
}

static netdev_features_t igc_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 igc_set_features(struct net_device *netdev,
                            netdev_features_t features)
{
        netdev_features_t changed = netdev->features ^ features;
        struct igc_adapter *adapter = netdev_priv(netdev);

        /* Add VLAN support */
        if (!(changed & (NETIF_F_RXALL | NETIF_F_NTUPLE)))
                return 0;

        if (!(features & NETIF_F_NTUPLE))
                igc_flush_nfc_rules(adapter);

        netdev->features = features;

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

        return 1;
}

static netdev_features_t
igc_features_check(struct sk_buff *skb, struct net_device *dev,
                   netdev_features_t features)
{
        unsigned int network_hdr_len, mac_hdr_len;

        /* Make certain the headers can be described by a context descriptor */
        mac_hdr_len = skb_network_header(skb) - skb->data;
        if (unlikely(mac_hdr_len > IGC_MAX_MAC_HDR_LEN))
                return features & ~(NETIF_F_HW_CSUM |
                                    NETIF_F_SCTP_CRC |
                                    NETIF_F_HW_VLAN_CTAG_TX |
                                    NETIF_F_TSO |
                                    NETIF_F_TSO6);

        network_hdr_len = skb_checksum_start(skb) - skb_network_header(skb);
        if (unlikely(network_hdr_len >  IGC_MAX_NETWORK_HDR_LEN))
                return features & ~(NETIF_F_HW_CSUM |
                                    NETIF_F_SCTP_CRC |
                                    NETIF_F_TSO |
                                    NETIF_F_TSO6);

        /* We can only support IPv4 TSO in tunnels if we can mangle the
         * inner IP ID field, so strip TSO if MANGLEID is not supported.
         */
        if (skb->encapsulation && !(features & NETIF_F_TSO_MANGLEID))
                features &= ~NETIF_F_TSO;

        return features;
}

static void igc_tsync_interrupt(struct igc_adapter *adapter)
{
        struct igc_hw *hw = &adapter->hw;
        u32 tsicr = rd32(IGC_TSICR);
        u32 ack = 0;

        if (tsicr & IGC_TSICR_TXTS) {
                /* retrieve hardware timestamp */
                schedule_work(&adapter->ptp_tx_work);
                ack |= IGC_TSICR_TXTS;
        }

        /* acknowledge the interrupts */
        wr32(IGC_TSICR, ack);
}

/**
 * igc_msix_other - msix other interrupt handler
 * @irq: interrupt number
 * @data: pointer to a q_vector