/*
 * Copyright (C) 2015 Cavium, Inc.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License
 * as published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/netdevice.h>
#include <linux/if_vlan.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/log2.h>
#include <linux/prefetch.h>
#include <linux/irq.h>

#include "nic_reg.h"
#include "nic.h"
#include "nicvf_queues.h"
#include "thunder_bgx.h"

#define DRV_NAME        "thunder-nicvf"
#define DRV_VERSION     "1.0"

/* Supported devices */
static const struct pci_device_id nicvf_id_table[] = {
        { PCI_DEVICE_SUB(PCI_VENDOR_ID_CAVIUM,
                         PCI_DEVICE_ID_THUNDER_NIC_VF,
                         PCI_VENDOR_ID_CAVIUM,
                         PCI_SUBSYS_DEVID_88XX_NIC_VF) },
        { PCI_DEVICE_SUB(PCI_VENDOR_ID_CAVIUM,
                         PCI_DEVICE_ID_THUNDER_PASS1_NIC_VF,
                         PCI_VENDOR_ID_CAVIUM,
                         PCI_SUBSYS_DEVID_88XX_PASS1_NIC_VF) },
        { PCI_DEVICE_SUB(PCI_VENDOR_ID_CAVIUM,
                         PCI_DEVICE_ID_THUNDER_NIC_VF,
                         PCI_VENDOR_ID_CAVIUM,
                         PCI_SUBSYS_DEVID_81XX_NIC_VF) },
        { PCI_DEVICE_SUB(PCI_VENDOR_ID_CAVIUM,
                         PCI_DEVICE_ID_THUNDER_NIC_VF,
                         PCI_VENDOR_ID_CAVIUM,
                         PCI_SUBSYS_DEVID_83XX_NIC_VF) },
        { 0, }  /* end of table */
};

MODULE_AUTHOR("Sunil Goutham");
MODULE_DESCRIPTION("Cavium Thunder NIC Virtual Function Driver");
MODULE_LICENSE("GPL v2");
MODULE_VERSION(DRV_VERSION);
MODULE_DEVICE_TABLE(pci, nicvf_id_table);

static int debug = 0x00;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Debug message level bitmap");

static int cpi_alg = CPI_ALG_NONE;
module_param(cpi_alg, int, S_IRUGO);
MODULE_PARM_DESC(cpi_alg,
                 "PFC algorithm (0=none, 1=VLAN, 2=VLAN16, 3=IP Diffserv)");

static inline u8 nicvf_netdev_qidx(struct nicvf *nic, u8 qidx)
{
        if (nic->sqs_mode)
                return qidx + ((nic->sqs_id + 1) * MAX_CMP_QUEUES_PER_QS);
        else
                return qidx;
}

/* The Cavium ThunderX network controller can *only* be found in SoCs
 * containing the ThunderX ARM64 CPU implementation.  All accesses to the device
 * registers on this platform are implicitly strongly ordered with respect
 * to memory accesses. So writeq_relaxed() and readq_relaxed() are safe to use
 * with no memory barriers in this driver.  The readq()/writeq() functions add
 * explicit ordering operation which in this case are redundant, and only
 * add overhead.
 */

/* Register read/write APIs */
void nicvf_reg_write(struct nicvf *nic, u64 offset, u64 val)
{
        writeq_relaxed(val, nic->reg_base + offset);
}

u64 nicvf_reg_read(struct nicvf *nic, u64 offset)
{
        return readq_relaxed(nic->reg_base + offset);
}

void nicvf_queue_reg_write(struct nicvf *nic, u64 offset,
                           u64 qidx, u64 val)
{
        void __iomem *addr = nic->reg_base + offset;

        writeq_relaxed(val, addr + (qidx << NIC_Q_NUM_SHIFT));
}

u64 nicvf_queue_reg_read(struct nicvf *nic, u64 offset, u64 qidx)
{
        void __iomem *addr = nic->reg_base + offset;

        return readq_relaxed(addr + (qidx << NIC_Q_NUM_SHIFT));
}

/* VF -> PF mailbox communication */
static void nicvf_write_to_mbx(struct nicvf *nic, union nic_mbx *mbx)
{
        u64 *msg = (u64 *)mbx;

        nicvf_reg_write(nic, NIC_VF_PF_MAILBOX_0_1 + 0, msg[0]);
        nicvf_reg_write(nic, NIC_VF_PF_MAILBOX_0_1 + 8, msg[1]);
}

int nicvf_send_msg_to_pf(struct nicvf *nic, union nic_mbx *mbx)
{
        int timeout = NIC_MBOX_MSG_TIMEOUT;
        int sleep = 10;

        nic->pf_acked = false;
        nic->pf_nacked = false;

        nicvf_write_to_mbx(nic, mbx);

        /* Wait for previous message to be acked, timeout 2sec */
        while (!nic->pf_acked) {
                if (nic->pf_nacked) {
                        netdev_err(nic->netdev,
                                   "PF NACK to mbox msg 0x%02x from VF%d\n",
                                   (mbx->msg.msg & 0xFF), nic->vf_id);
                        return -EINVAL;
                }
                msleep(sleep);
                if (nic->pf_acked)
                        break;
                timeout -= sleep;
                if (!timeout) {
                        netdev_err(nic->netdev,
                                   "PF didn't ACK to mbox msg 0x%02x from VF%d\n",
                                   (mbx->msg.msg & 0xFF), nic->vf_id);
                        return -EBUSY;
                }
        }
        return 0;
}

/* Checks if VF is able to comminicate with PF
* and also gets the VNIC number this VF is associated to.
*/
static int nicvf_check_pf_ready(struct nicvf *nic)
{
        union nic_mbx mbx = {};

        mbx.msg.msg = NIC_MBOX_MSG_READY;
        if (nicvf_send_msg_to_pf(nic, &mbx)) {
                netdev_err(nic->netdev,
                           "PF didn't respond to READY msg\n");
                return 0;
        }

        return 1;
}

static void nicvf_read_bgx_stats(struct nicvf *nic, struct bgx_stats_msg *bgx)
{
        if (bgx->rx)
                nic->bgx_stats.rx_stats[bgx->idx] = bgx->stats;
        else
                nic->bgx_stats.tx_stats[bgx->idx] = bgx->stats;
}

static void  nicvf_handle_mbx_intr(struct nicvf *nic)
{
        union nic_mbx mbx = {};
        u64 *mbx_data;
        u64 mbx_addr;
        int i;

        mbx_addr = NIC_VF_PF_MAILBOX_0_1;
        mbx_data = (u64 *)&mbx;

        for (i = 0; i < NIC_PF_VF_MAILBOX_SIZE; i++) {
                *mbx_data = nicvf_reg_read(nic, mbx_addr);
                mbx_data++;
                mbx_addr += sizeof(u64);
        }

        netdev_dbg(nic->netdev, "Mbox message: msg: 0x%x\n", mbx.msg.msg);
        switch (mbx.msg.msg) {
        case NIC_MBOX_MSG_READY:
                nic->pf_acked = true;
                nic->vf_id = mbx.nic_cfg.vf_id & 0x7F;
                nic->tns_mode = mbx.nic_cfg.tns_mode & 0x7F;
                nic->node = mbx.nic_cfg.node_id;
                if (!nic->set_mac_pending)
                        ether_addr_copy(nic->netdev->dev_addr,
                                        mbx.nic_cfg.mac_addr);
                nic->sqs_mode = mbx.nic_cfg.sqs_mode;
                nic->loopback_supported = mbx.nic_cfg.loopback_supported;
                nic->link_up = false;
                nic->duplex = 0;
                nic->speed = 0;
                break;
        case NIC_MBOX_MSG_ACK:
                nic->pf_acked = true;
                break;
        case NIC_MBOX_MSG_NACK:
                nic->pf_nacked = true;
                break;
        case NIC_MBOX_MSG_RSS_SIZE:
                nic->rss_info.rss_size = mbx.rss_size.ind_tbl_size;
                nic->pf_acked = true;
                break;
        case NIC_MBOX_MSG_BGX_STATS:
                nicvf_read_bgx_stats(nic, &mbx.bgx_stats);
                nic->pf_acked = true;
                break;
        case NIC_MBOX_MSG_BGX_LINK_CHANGE:
                nic->pf_acked = true;
                nic->link_up = mbx.link_status.link_up;
                nic->duplex = mbx.link_status.duplex;
                nic->speed = mbx.link_status.speed;
                if (nic->link_up) {
                        netdev_info(nic->netdev, "%s: Link is Up %d Mbps %s\n",
                                    nic->netdev->name, nic->speed,
                                    nic->duplex == DUPLEX_FULL ?
                                "Full duplex" : "Half duplex");
                        netif_carrier_on(nic->netdev);
                        netif_tx_start_all_queues(nic->netdev);
                } else {
                        netdev_info(nic->netdev, "%s: Link is Down\n",
                                    nic->netdev->name);
                        netif_carrier_off(nic->netdev);
                        netif_tx_stop_all_queues(nic->netdev);
                }
                break;
        case NIC_MBOX_MSG_ALLOC_SQS:
                nic->sqs_count = mbx.sqs_alloc.qs_count;
                nic->pf_acked = true;
                break;
        case NIC_MBOX_MSG_SNICVF_PTR:
                /* Primary VF: make note of secondary VF's pointer
                 * to be used while packet transmission.
                 */
                nic->snicvf[mbx.nicvf.sqs_id] =
                        (struct nicvf *)mbx.nicvf.nicvf;
                nic->pf_acked = true;
                break;
        case NIC_MBOX_MSG_PNICVF_PTR:
                /* Secondary VF/Qset: make note of primary VF's pointer
                 * to be used while packet reception, to handover packet
                 * to primary VF's netdev.
                 */
                nic->pnicvf = (struct nicvf *)mbx.nicvf.nicvf;
                nic->pf_acked = true;
                break;
        default:
                netdev_err(nic->netdev,
                           "Invalid message from PF, msg 0x%x\n", mbx.msg.msg);
                break;
        }
        nicvf_clear_intr(nic, NICVF_INTR_MBOX, 0);
}

static int nicvf_hw_set_mac_addr(struct nicvf *nic, struct net_device *netdev)
{
        union nic_mbx mbx = {};

        mbx.mac.msg = NIC_MBOX_MSG_SET_MAC;
        mbx.mac.vf_id = nic->vf_id;
        ether_addr_copy(mbx.mac.mac_addr, netdev->dev_addr);

        return nicvf_send_msg_to_pf(nic, &mbx);
}

static void nicvf_config_cpi(struct nicvf *nic)
{
        union nic_mbx mbx = {};

        mbx.cpi_cfg.msg = NIC_MBOX_MSG_CPI_CFG;
        mbx.cpi_cfg.vf_id = nic->vf_id;
        mbx.cpi_cfg.cpi_alg = nic->cpi_alg;
        mbx.cpi_cfg.rq_cnt = nic->qs->rq_cnt;

        nicvf_send_msg_to_pf(nic, &mbx);
}

static void nicvf_get_rss_size(struct nicvf *nic)
{
        union nic_mbx mbx = {};

        mbx.rss_size.msg = NIC_MBOX_MSG_RSS_SIZE;
        mbx.rss_size.vf_id = nic->vf_id;
        nicvf_send_msg_to_pf(nic, &mbx);
}

void nicvf_config_rss(struct nicvf *nic)
{
        union nic_mbx mbx = {};
        struct nicvf_rss_info *rss = &nic->rss_info;
        int ind_tbl_len = rss->rss_size;
        int i, nextq = 0;

        mbx.rss_cfg.vf_id = nic->vf_id;
        mbx.rss_cfg.hash_bits = rss->hash_bits;
        while (ind_tbl_len) {
                mbx.rss_cfg.tbl_offset = nextq;
                mbx.rss_cfg.tbl_len = min(ind_tbl_len,
                                               RSS_IND_TBL_LEN_PER_MBX_MSG);
                mbx.rss_cfg.msg = mbx.rss_cfg.tbl_offset ?
                          NIC_MBOX_MSG_RSS_CFG_CONT : NIC_MBOX_MSG_RSS_CFG;

                for (i = 0; i < mbx.rss_cfg.tbl_len; i++)
                        mbx.rss_cfg.ind_tbl[i] = rss->ind_tbl[nextq++];

                nicvf_send_msg_to_pf(nic, &mbx);

                ind_tbl_len -= mbx.rss_cfg.tbl_len;
        }
}

void nicvf_set_rss_key(struct nicvf *nic)
{
        struct nicvf_rss_info *rss = &nic->rss_info;
        u64 key_addr = NIC_VNIC_RSS_KEY_0_4;
        int idx;

        for (idx = 0; idx < RSS_HASH_KEY_SIZE; idx++) {
                nicvf_reg_write(nic, key_addr, rss->key[idx]);
                key_addr += sizeof(u64);
        }
}

static int nicvf_rss_init(struct nicvf *nic)
{
        struct nicvf_rss_info *rss = &nic->rss_info;
        int idx;

        nicvf_get_rss_size(nic);

        if (cpi_alg != CPI_ALG_NONE) {
                rss->enable = false;
                rss->hash_bits = 0;
                return 0;
        }

        rss->enable = true;

        netdev_rss_key_fill(rss->key, RSS_HASH_KEY_SIZE * sizeof(u64));
        nicvf_set_rss_key(nic);

        rss->cfg = RSS_IP_HASH_ENA | RSS_TCP_HASH_ENA | RSS_UDP_HASH_ENA;
        nicvf_reg_write(nic, NIC_VNIC_RSS_CFG, rss->cfg);

        rss->hash_bits =  ilog2(rounddown_pow_of_two(rss->rss_size));

        for (idx = 0; idx < rss->rss_size; idx++)
                rss->ind_tbl[idx] = ethtool_rxfh_indir_default(idx,
                                                               nic->rx_queues);
        nicvf_config_rss(nic);
        return 1;
}

/* Request PF to allocate additional Qsets */
static void nicvf_request_sqs(struct nicvf *nic)
{
        union nic_mbx mbx = {};
        int sqs;
        int sqs_count = nic->sqs_count;
        int rx_queues = 0, tx_queues = 0;

        /* Only primary VF should request */
        if (nic->sqs_mode ||  !nic->sqs_count)
                return;

        mbx.sqs_alloc.msg = NIC_MBOX_MSG_ALLOC_SQS;
        mbx.sqs_alloc.vf_id = nic->vf_id;
        mbx.sqs_alloc.qs_count = nic->sqs_count;
        if (nicvf_send_msg_to_pf(nic, &mbx)) {
                /* No response from PF */
                nic->sqs_count = 0;
                return;
        }

        /* Return if no Secondary Qsets available */
        if (!nic->sqs_count)
                return;

        if (nic->rx_queues > MAX_RCV_QUEUES_PER_QS)
                rx_queues = nic->rx_queues - MAX_RCV_QUEUES_PER_QS;
        if (nic->tx_queues > MAX_SND_QUEUES_PER_QS)
                tx_queues = nic->tx_queues - MAX_SND_QUEUES_PER_QS;

        /* Set no of Rx/Tx queues in each of the SQsets */
        for (sqs = 0; sqs < nic->sqs_count; sqs++) {
                mbx.nicvf.msg = NIC_MBOX_MSG_SNICVF_PTR;
                mbx.nicvf.vf_id = nic->vf_id;
                mbx.nicvf.sqs_id = sqs;
                nicvf_send_msg_to_pf(nic, &mbx);

                nic->snicvf[sqs]->sqs_id = sqs;
                if (rx_queues > MAX_RCV_QUEUES_PER_QS) {
                        nic->snicvf[sqs]->qs->rq_cnt = MAX_RCV_QUEUES_PER_QS;
                        rx_queues -= MAX_RCV_QUEUES_PER_QS;
                } else {
                        nic->snicvf[sqs]->qs->rq_cnt = rx_queues;
                        rx_queues = 0;
                }

                if (tx_queues > MAX_SND_QUEUES_PER_QS) {
                        nic->snicvf[sqs]->qs->sq_cnt = MAX_SND_QUEUES_PER_QS;
                        tx_queues -= MAX_SND_QUEUES_PER_QS;
                } else {
                        nic->snicvf[sqs]->qs->sq_cnt = tx_queues;
                        tx_queues = 0;
                }

                nic->snicvf[sqs]->qs->cq_cnt =
                max(nic->snicvf[sqs]->qs->rq_cnt, nic->snicvf[sqs]->qs->sq_cnt);

                /* Initialize secondary Qset's queues and its interrupts */
                nicvf_open(nic->snicvf[sqs]->netdev);
        }

        /* Update stack with actual Rx/Tx queue count allocated */
        if (sqs_count != nic->sqs_count)
                nicvf_set_real_num_queues(nic->netdev,
                                          nic->tx_queues, nic->rx_queues);
}

/* Send this Qset's nicvf pointer to PF.
 * PF inturn sends primary VF's nicvf struct to secondary Qsets/VFs
 * so that packets received by these Qsets can use primary VF's netdev
 */
static void nicvf_send_vf_struct(struct nicvf *nic)
{
        union nic_mbx mbx = {};

        mbx.nicvf.msg = NIC_MBOX_MSG_NICVF_PTR;
        mbx.nicvf.sqs_mode = nic->sqs_mode;
        mbx.nicvf.nicvf = (u64)nic;
        nicvf_send_msg_to_pf(nic, &mbx);
}

static void nicvf_get_primary_vf_struct(struct nicvf *nic)
{
        union nic_mbx mbx = {};

        mbx.nicvf.msg = NIC_MBOX_MSG_PNICVF_PTR;
        nicvf_send_msg_to_pf(nic, &mbx);
}

int nicvf_set_real_num_queues(struct net_device *netdev,
                              int tx_queues, int rx_queues)
{
        int err = 0;

        err = netif_set_real_num_tx_queues(netdev, tx_queues);
        if (err) {
                netdev_err(netdev,
                           "Failed to set no of Tx queues: %d\n", tx_queues);
                return err;
        }

        err = netif_set_real_num_rx_queues(netdev, rx_queues);
        if (err)
                netdev_err(netdev,
                           "Failed to set no of Rx queues: %d\n", rx_queues);
        return err;
}

static int nicvf_init_resources(struct nicvf *nic)
{
        int err;

        /* Enable Qset */
        nicvf_qset_config(nic, true);

        /* Initialize queues and HW for data transfer */
        err = nicvf_config_data_transfer(nic, true);
        if (err) {
                netdev_err(nic->netdev,
                           "Failed to alloc/config VF's QSet resources\n");
                return err;
        }

        return 0;
}

static void nicvf_snd_pkt_handler(struct net_device *netdev,
                                  struct cqe_send_t *cqe_tx,
                                  int cqe_type, int budget,
                                  unsigned int *tx_pkts, unsigned int *tx_bytes)
{
        struct sk_buff *skb = NULL;
        struct nicvf *nic = netdev_priv(netdev);
        struct snd_queue *sq;
        struct sq_hdr_subdesc *hdr;
        struct sq_hdr_subdesc *tso_sqe;

        sq = &nic->qs->sq[cqe_tx->sq_idx];

        hdr = (struct sq_hdr_subdesc *)GET_SQ_DESC(sq, cqe_tx->sqe_ptr);
        if (hdr->subdesc_type != SQ_DESC_TYPE_HEADER)
                return;

        netdev_dbg(nic->netdev,
                   "%s Qset #%d SQ #%d SQ ptr #%d subdesc count %d\n",
                   __func__, cqe_tx->sq_qs, cqe_tx->sq_idx,
                   cqe_tx->sqe_ptr, hdr->subdesc_cnt);

        nicvf_check_cqe_tx_errs(nic, cqe_tx);
        skb = (struct sk_buff *)sq->skbuff[cqe_tx->sqe_ptr];
        if (skb) {
                /* Check for dummy descriptor used for HW TSO offload on 88xx */
                if (hdr->dont_send) {
                        /* Get actual TSO descriptors and free them */
                        tso_sqe =
                         (struct sq_hdr_subdesc *)GET_SQ_DESC(sq, hdr->rsvd2);
                        nicvf_put_sq_desc(sq, tso_sqe->subdesc_cnt + 1);
                }
                nicvf_put_sq_desc(sq, hdr->subdesc_cnt + 1);
                prefetch(skb);
                (*tx_pkts)++;
                *tx_bytes += skb->len;
                napi_consume_skb(skb, budget);
                sq->skbuff[cqe_tx->sqe_ptr] = (u64)NULL;
        } else {
                /* In case of SW TSO on 88xx, only last segment will have
                 * a SKB attached, so just free SQEs here.
                 */
                if (!nic->hw_tso)
                        nicvf_put_sq_desc(sq, hdr->subdesc_cnt + 1);
        }
}

static inline void nicvf_set_rxhash(struct net_device *netdev,
                                    struct cqe_rx_t *cqe_rx,
                                    struct sk_buff *skb)
{
        u8 hash_type;
        u32 hash;

        if (!(netdev->features & NETIF_F_RXHASH))
                return;

        switch (cqe_rx->rss_alg) {
        case RSS_ALG_TCP_IP:
        case RSS_ALG_UDP_IP:
                hash_type = PKT_HASH_TYPE_L4;
                hash = cqe_rx->rss_tag;
                break;
        case RSS_ALG_IP:
                hash_type = PKT_HASH_TYPE_L3;
                hash = cqe_rx->rss_tag;
                break;
        default:
                hash_type = PKT_HASH_TYPE_NONE;
                hash = 0;
        }

        skb_set_hash(skb, hash, hash_type);
}

static void nicvf_rcv_pkt_handler(struct net_device *netdev,
                                  struct napi_struct *napi,
                                  struct cqe_rx_t *cqe_rx)
{
        struct sk_buff *skb;
        struct nicvf *nic = netdev_priv(netdev);
        int err = 0;
        int rq_idx;

        rq_idx = nicvf_netdev_qidx(nic, cqe_rx->rq_idx);

        if (nic->sqs_mode) {
                /* Use primary VF's 'nicvf' struct */
                nic = nic->pnicvf;
                netdev = nic->netdev;
        }

        /* Check for errors */
        err = nicvf_check_cqe_rx_errs(nic, cqe_rx);
        if (err && !cqe_rx->rb_cnt)
                return;

        skb = nicvf_get_rcv_skb(nic, cqe_rx);
        if (!skb) {
                netdev_dbg(nic->netdev, "Packet not received\n");
                return;
        }

        if (netif_msg_pktdata(nic)) {
                netdev_info(nic->netdev, "%s: skb 0x%p, len=%d\n", netdev->name,
                            skb, skb->len);
                print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 1,
                               skb->data, skb->len, true);
        }

        /* If error packet, drop it here */
        if (err) {
                dev_kfree_skb_any(skb);
                return;
        }

        nicvf_set_rxhash(netdev, cqe_rx, skb);

        skb_record_rx_queue(skb, rq_idx);
        if (netdev->hw_features & NETIF_F_RXCSUM) {
                /* HW by default verifies TCP/UDP/SCTP checksums */
                skb->ip_summed = CHECKSUM_UNNECESSARY;
        } else {
                skb_checksum_none_assert(skb);
        }

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

        /* Check for stripped VLAN */
        if (cqe_rx->vlan_found && cqe_rx->vlan_stripped)
                __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
                                       ntohs((__force __be16)cqe_rx->vlan_tci));

        if (napi && (netdev->features & NETIF_F_GRO))
                napi_gro_receive(napi, skb);
        else
                netif_receive_skb(skb);
}

static int nicvf_cq_intr_handler(struct net_device *netdev, u8 cq_idx,
                                 struct napi_struct *napi, int budget)
{
        int processed_cqe, work_done = 0, tx_done = 0;
        int cqe_count, cqe_head;
        struct nicvf *nic = netdev_priv(netdev);
        struct queue_set *qs = nic->qs;
        struct cmp_queue *cq = &qs->cq[cq_idx];
        struct cqe_rx_t *cq_desc;
        struct netdev_queue *txq;
        unsigned int tx_pkts = 0, tx_bytes = 0;

        spin_lock_bh(&cq->lock);
loop:
        processed_cqe = 0;
        /* Get no of valid CQ entries to process */
        cqe_count = nicvf_queue_reg_read(nic, NIC_QSET_CQ_0_7_STATUS, cq_idx);
        cqe_count &= CQ_CQE_COUNT;
        if (!cqe_count)
                goto done;

        /* Get head of the valid CQ entries */
        cqe_head = nicvf_queue_reg_read(nic, NIC_QSET_CQ_0_7_HEAD, cq_idx) >> 9;
        cqe_head &= 0xFFFF;

        netdev_dbg(nic->netdev, "%s CQ%d cqe_count %d cqe_head %d\n",
                   __func__, cq_idx, cqe_count, cqe_head);
        while (processed_cqe < cqe_count) {
                /* Get the CQ descriptor */
                cq_desc = (struct cqe_rx_t *)GET_CQ_DESC(cq, cqe_head);
                cqe_head++;
                cqe_head &= (cq->dmem.q_len - 1);
                /* Initiate prefetch for next descriptor */
                prefetch((struct cqe_rx_t *)GET_CQ_DESC(cq, cqe_head));

                if ((work_done >= budget) && napi &&
                    (cq_desc->cqe_type != CQE_TYPE_SEND)) {
                        break;
                }

                netdev_dbg(nic->netdev, "CQ%d cq_desc->cqe_type %d\n",
                           cq_idx, cq_desc->cqe_type);
                switch (cq_desc->cqe_type) {
                case CQE_TYPE_RX:
                        nicvf_rcv_pkt_handler(netdev, napi, cq_desc);
                        work_done++;
                break;
                case CQE_TYPE_SEND:
                        nicvf_snd_pkt_handler(netdev,
                                              (void *)cq_desc, CQE_TYPE_SEND,
                                              budget, &tx_pkts, &tx_bytes);
                        tx_done++;
                break;
                case CQE_TYPE_INVALID:
                case CQE_TYPE_RX_SPLIT:
                case CQE_TYPE_RX_TCP:
                case CQE_TYPE_SEND_PTP:
                        /* Ignore for now */
                break;
                }
                processed_cqe++;
        }
        netdev_dbg(nic->netdev,
                   "%s CQ%d processed_cqe %d work_done %d budget %d\n",
                   __func__, cq_idx, processed_cqe, work_done, budget);

        /* Ring doorbell to inform H/W to reuse processed CQEs */
        nicvf_queue_reg_write(nic, NIC_QSET_CQ_0_7_DOOR,
                              cq_idx, processed_cqe);

        if ((work_done < budget) && napi)
                goto loop;

done:
        /* Wakeup TXQ if its stopped earlier due to SQ full */
        if (tx_done) {
                netdev = nic->pnicvf->netdev;
                txq = netdev_get_tx_queue(netdev,
                                          nicvf_netdev_qidx(nic, cq_idx));
                if (tx_pkts)
                        netdev_tx_completed_queue(txq, tx_pkts, tx_bytes);

                nic = nic->pnicvf;
                if (netif_tx_queue_stopped(txq) && netif_carrier_ok(netdev)) {
                        netif_tx_start_queue(txq);
                        this_cpu_inc(nic->drv_stats->txq_wake);
                        if (netif_msg_tx_err(nic))
                                netdev_warn(netdev,
                                            "%s: Transmit queue wakeup SQ%d\n",
                                            netdev->name, cq_idx);
                }
        }

        spin_unlock_bh(&cq->lock);
        return work_done;
}

static int nicvf_poll(struct napi_struct *napi, int budget)
{
        u64  cq_head;
        int  work_done = 0;
        struct net_device *netdev = napi->dev;
        struct nicvf *nic = netdev_priv(netdev);
        struct nicvf_cq_poll *cq;

        cq = container_of(napi, struct nicvf_cq_poll, napi);
        work_done = nicvf_cq_intr_handler(netdev, cq->cq_idx, napi, budget);

        if (work_done < budget) {
                /* Slow packet rate, exit polling */
                napi_complete(napi);
                /* Re-enable interrupts */
                cq_head = nicvf_queue_reg_read(nic, NIC_QSET_CQ_0_7_HEAD,
                                               cq->cq_idx);
                nicvf_clear_intr(nic, NICVF_INTR_CQ, cq->cq_idx);
                nicvf_queue_reg_write(nic, NIC_QSET_CQ_0_7_HEAD,
                                      cq->cq_idx, cq_head);
                nicvf_enable_intr(nic, NICVF_INTR_CQ, cq->cq_idx);
        }
        return work_done;
}

/* Qset error interrupt handler
 *
 * As of now only CQ errors are handled
 */
static void nicvf_handle_qs_err(unsigned long data)
{
        struct nicvf *nic = (struct nicvf *)data;
        struct queue_set *qs = nic->qs;
        int qidx;
        u64 status;

        netif_tx_disable(nic->netdev);

        /* Check if it is CQ err */
        for (qidx = 0; qidx < qs->cq_cnt; qidx++) {
                status = nicvf_queue_reg_read(nic, NIC_QSET_CQ_0_7_STATUS,
                                              qidx);
                if (!(status & CQ_ERR_MASK))
                        continue;
                /* Process already queued CQEs and reconfig CQ */
                nicvf_disable_intr(nic, NICVF_INTR_CQ, qidx);
                nicvf_sq_disable(nic, qidx);
                nicvf_cq_intr_handler(nic->netdev, qidx, NULL, 0);
                nicvf_cmp_queue_config(nic, qs, qidx, true);
                nicvf_sq_free_used_descs(nic->netdev, &qs->sq[qidx], qidx);
                nicvf_sq_enable(nic, &qs->sq[qidx], qidx);

                nicvf_enable_intr(nic, NICVF_INTR_CQ, qidx);
        }

        netif_tx_start_all_queues(nic->netdev);
        /* Re-enable Qset error interrupt */
        nicvf_enable_intr(nic, NICVF_INTR_QS_ERR, 0);
}

static void nicvf_dump_intr_status(struct nicvf *nic)
{
        if (netif_msg_intr(nic))
                netdev_info(nic->netdev, "%s: interrupt status 0x%llx\n",
                            nic->netdev->name, nicvf_reg_read(nic, NIC_VF_INT));
}

static irqreturn_t nicvf_misc_intr_handler(int irq, void *nicvf_irq)
{
        struct nicvf *nic = (struct nicvf *)nicvf_irq;
        u64 intr;

        nicvf_dump_intr_status(nic);

        intr = nicvf_reg_read(nic, NIC_VF_INT);
        /* Check for spurious interrupt */
        if (!(intr & NICVF_INTR_MBOX_MASK))
                return IRQ_HANDLED;

        nicvf_handle_mbx_intr(nic);

        return IRQ_HANDLED;
}

static irqreturn_t nicvf_intr_handler(int irq, void *cq_irq)
{
        struct nicvf_cq_poll *cq_poll = (struct nicvf_cq_poll *)cq_irq;
        struct nicvf *nic = cq_poll->nicvf;
        int qidx = cq_poll->cq_idx;

        nicvf_dump_intr_status(nic);

        /* Disable interrupts */
        nicvf_disable_intr(nic, NICVF_INTR_CQ, qidx);

        /* Schedule NAPI */
        napi_schedule_irqoff(&cq_poll->napi);

        /* Clear interrupt */
        nicvf_clear_intr(nic, NICVF_INTR_CQ, qidx);

        return IRQ_HANDLED;
}

static irqreturn_t nicvf_rbdr_intr_handler(int irq, void *nicvf_irq)
{
        struct nicvf *nic = (struct nicvf *)nicvf_irq;
        u8 qidx;


        nicvf_dump_intr_status(nic);

        /* Disable RBDR interrupt and schedule softirq */
        for (qidx = 0; qidx < nic->qs->rbdr_cnt; qidx++) {
                if (!nicvf_is_intr_enabled(nic, NICVF_INTR_RBDR, qidx))
                        continue;
                nicvf_disable_intr(nic, NICVF_INTR_RBDR, qidx);
                tasklet_hi_schedule(&nic->rbdr_task);
                /* Clear interrupt */
                nicvf_clear_intr(nic, NICVF_INTR_RBDR, qidx);
        }

        return IRQ_HANDLED;
}

static irqreturn_t nicvf_qs_err_intr_handler(int irq, void *nicvf_irq)
{
        struct nicvf *nic = (struct nicvf *)nicvf_irq;

        nicvf_dump_intr_status(nic);

        /* Disable Qset err interrupt and schedule softirq */
        nicvf_disable_intr(nic, NICVF_INTR_QS_ERR, 0);
        tasklet_hi_schedule(&nic->qs_err_task);
        nicvf_clear_intr(nic, NICVF_INTR_QS_ERR, 0);

        return IRQ_HANDLED;
}

static int nicvf_enable_msix(struct nicvf *nic)
{
        int ret, vec;

        nic->num_vec = NIC_VF_MSIX_VECTORS;

        for (vec = 0; vec < nic->num_vec; vec++)
                nic->msix_entries[vec].entry = vec;

        ret = pci_enable_msix(nic->pdev, nic->msix_entries, nic->num_vec);
        if (ret) {
                netdev_err(nic->netdev,
                           "Req for #%d msix vectors failed\n", nic->num_vec);
                return 0;
        }
        nic->msix_enabled = 1;
        return 1;
}

static void nicvf_disable_msix(struct nicvf *nic)
{
        if (nic->msix_enabled) {
                pci_disable_msix(nic->pdev);
                nic->msix_enabled = 0;
                nic->num_vec = 0;
        }
}

static void nicvf_set_irq_affinity(struct nicvf *nic)
{
        int vec, cpu;
        int irqnum;

        for (vec = 0; vec < nic->num_vec; vec++) {
                if (!nic->irq_allocated[vec])
                        continue;

                if (!zalloc_cpumask_var(&nic->affinity_mask[vec], GFP_KERNEL))
                        return;
                 /* CQ interrupts */
                if (vec < NICVF_INTR_ID_SQ)
                        /* Leave CPU0 for RBDR and other interrupts */
                        cpu = nicvf_netdev_qidx(nic, vec) + 1;
                else
                        cpu = 0;

                cpumask_set_cpu(cpumask_local_spread(cpu, nic->node),
                                nic->affinity_mask[vec]);
                irqnum = nic->msix_entries[vec].vector;
                irq_set_affinity_hint(irqnum, nic->affinity_mask[vec]);
        }
}

static int nicvf_register_interrupts(struct nicvf *nic)
{
        int irq, ret = 0;
        int vector;

        for_each_cq_irq(irq)
                sprintf(nic->irq_name[irq], "%s-rxtx-%d",
                        nic->pnicvf->netdev->name,
                        nicvf_netdev_qidx(nic, irq));

        for_each_sq_irq(irq)
                sprintf(nic->irq_name[irq], "%s-sq-%d",
                        nic->pnicvf->netdev->name,
                        nicvf_netdev_qidx(nic, irq - NICVF_INTR_ID_SQ));

        for_each_rbdr_irq(irq)
                sprintf(nic->irq_name[irq], "%s-rbdr-%d",
                        nic->pnicvf->netdev->name,
                        nic->sqs_mode ? (nic->sqs_id + 1) : 0);

        /* Register CQ interrupts */
        for (irq = 0; irq < nic->qs->cq_cnt; irq++) {
                vector = nic->msix_entries[irq].vector;
                ret = request_irq(vector, nicvf_intr_handler,
                                  0, nic->irq_name[irq], nic->napi[irq]);
                if (ret)
                        goto err;
                nic->irq_allocated[irq] = true;
        }

        /* Register RBDR interrupt */
        for (irq = NICVF_INTR_ID_RBDR;
             irq < (NICVF_INTR_ID_RBDR + nic->qs->rbdr_cnt); irq++) {
                vector = nic->msix_entries[irq].vector;
                ret = request_irq(vector, nicvf_rbdr_intr_handler,
                                  0, nic->irq_name[irq], nic);
                if (ret)
                        goto err;
                nic->irq_allocated[irq] = true;
        }

        /* Register QS error interrupt */
        sprintf(nic->irq_name[NICVF_INTR_ID_QS_ERR], "%s-qset-err-%d",
                nic->pnicvf->netdev->name,
                nic->sqs_mode ? (nic->sqs_id + 1) : 0);
        irq = NICVF_INTR_ID_QS_ERR;
        ret = request_irq(nic->msix_entries[irq].vector,
                          nicvf_qs_err_intr_handler,
                          0, nic->irq_name[irq], nic);
        if (ret)
                goto err;

        nic->irq_allocated[irq] = true;

        /* Set IRQ affinities */
        nicvf_set_irq_affinity(nic);

err:
        if (ret)
                netdev_err(nic->netdev, "request_irq failed, vector %d\n", irq);

        return ret;
}

static void nicvf_unregister_interrupts(struct nicvf *nic)
{
        int irq;

        /* Free registered interrupts */
        for (irq = 0; irq < nic->num_vec; irq++) {
                if (!nic->irq_allocated[irq])
                        continue;

                irq_set_affinity_hint(nic->msix_entries[irq].vector, NULL);
                free_cpumask_var(nic->affinity_mask[irq]);

                if (irq < NICVF_INTR_ID_SQ)
                        free_irq(nic->msix_entries[irq].vector, nic->napi[irq]);
                else
                        free_irq(nic->msix_entries[irq].vector, nic);

                nic->irq_allocated[irq] = false;

        }

        /* Disable MSI-X */
        nicvf_disable_msix(nic);
}

/* Initialize MSIX vectors and register MISC interrupt.
 * Send READY message to PF to check if its alive
 */
static int nicvf_register_misc_interrupt(struct nicvf *nic)
{
        int ret = 0;
        int irq = NICVF_INTR_ID_MISC;

        /* Return if mailbox interrupt is already registered */
        if (nic->msix_enabled)
                return 0;

        /* Enable MSI-X */
        if (!nicvf_enable_msix(nic))
                return 1;

        sprintf(nic->irq_name[irq], "%s Mbox", "NICVF");
        /* Register Misc interrupt */
        ret = request_irq(nic->msix_entries[irq].vector,
                          nicvf_misc_intr_handler, 0, nic->irq_name[irq], nic);

        if (ret)
                return ret;
        nic->irq_allocated[irq] = true;

        /* Enable mailbox interrupt */
        nicvf_enable_intr(nic, NICVF_INTR_MBOX, 0);

        /* Check if VF is able to communicate with PF */
        if (!nicvf_check_pf_ready(nic)) {
                nicvf_disable_intr(nic, NICVF_INTR_MBOX, 0);
                nicvf_unregister_interrupts(nic);
                return 1;
        }

        return 0;
}

static netdev_tx_t nicvf_xmit(struct sk_buff *skb, struct net_device *netdev)
{
        struct nicvf *nic = netdev_priv(netdev);
        int qid = skb_get_queue_mapping(skb);
        struct netdev_queue *txq = netdev_get_tx_queue(netdev, qid);

        /* Check for minimum packet length */
        if (skb->len <= ETH_HLEN) {
                dev_kfree_skb(skb);
                return NETDEV_TX_OK;
        }

        if (!netif_tx_queue_stopped(txq) && !nicvf_sq_append_skb(nic, skb)) {
                netif_tx_stop_queue(txq);
                this_cpu_inc(nic->drv_stats->txq_stop);
                if (netif_msg_tx_err(nic))
                        netdev_warn(netdev,
                                    "%s: Transmit ring full, stopping SQ%d\n",
                                    netdev->name, qid);
                return NETDEV_TX_BUSY;
        }

        return NETDEV_TX_OK;
}

static inline void nicvf_free_cq_poll(struct nicvf *nic)
{
        struct nicvf_cq_poll *cq_poll;
        int qidx;

        for (qidx = 0; qidx < nic->qs->cq_cnt; qidx++) {
                cq_poll = nic->napi[qidx];
                if (!cq_poll)
                        continue;
                nic->napi[qidx] = NULL;
                kfree(cq_poll);
        }
}

int nicvf_stop(struct net_device *netdev)
{
        int irq, qidx;
        struct nicvf *nic = netdev_priv(netdev);
        struct queue_set *qs = nic->qs;
        struct nicvf_cq_poll *cq_poll = NULL;
        union nic_mbx mbx = {};

        mbx.msg.msg = NIC_MBOX_MSG_SHUTDOWN;
        nicvf_send_msg_to_pf(nic, &mbx);

        netif_carrier_off(netdev);
        netif_tx_stop_all_queues(nic->netdev);
        nic->link_up = false;

        /* Teardown secondary qsets first */
        if (!nic->sqs_mode) {
                for (qidx = 0; qidx < nic->sqs_count; qidx++) {
                        if (!nic->snicvf[qidx])
                                continue;
                        nicvf_stop(nic->snicvf[qidx]->netdev);
                        nic->snicvf[qidx] = NULL;
                }
        }

        /* Disable RBDR & QS error interrupts */
        for (qidx = 0; qidx < qs->rbdr_cnt; qidx++) {
                nicvf_disable_intr(nic, NICVF_INTR_RBDR, qidx);
                nicvf_clear_intr(nic, NICVF_INTR_RBDR, qidx);
        }
        nicvf_disable_intr(nic, NICVF_INTR_QS_ERR, 0);
        nicvf_clear_intr(nic, NICVF_INTR_QS_ERR, 0);

        /* Wait for pending IRQ handlers to finish */
        for (irq = 0; irq < nic->num_vec; irq++)
                synchronize_irq(nic->msix_entries[irq].vector);

        tasklet_kill(&nic->rbdr_task);
        tasklet_kill(&nic->qs_err_task);
        if (nic->rb_work_scheduled)
                cancel_delayed_work_sync(&nic->rbdr_work);

        for (qidx = 0; qidx < nic->qs->cq_cnt; qidx++) {
                cq_poll = nic->napi[qidx];
                if (!cq_poll)
                        continue;
                napi_synchronize(&cq_poll->napi);
                /* CQ intr is enabled while napi_complete,
                 * so disable it now
                 */
                nicvf_disable_intr(nic, NICVF_INTR_CQ, qidx);
                nicvf_clear_intr(nic, NICVF_INTR_CQ, qidx);
                napi_disable(&cq_poll->napi);
                netif_napi_del(&cq_poll->napi);
        }

        netif_tx_disable(netdev);

        for (qidx = 0; qidx < netdev->num_tx_queues; qidx++)
                netdev_tx_reset_queue(netdev_get_tx_queue(netdev, qidx));

        /* Free resources */
        nicvf_config_data_transfer(nic, false);

        /* Disable HW Qset */
        nicvf_qset_config(nic, false);

        /* disable mailbox interrupt */
        nicvf_disable_intr(nic, NICVF_INTR_MBOX, 0);

        nicvf_unregister_interrupts(nic);

        nicvf_free_cq_poll(nic);

        /* Clear multiqset info */
        nic->pnicvf = nic;

        return 0;
}

static int nicvf_update_hw_max_frs(struct nicvf *nic, int mtu)
{
        union nic_mbx mbx = {};

        mbx.frs.msg = NIC_MBOX_MSG_SET_MAX_FRS;
        mbx.frs.max_frs = mtu;
        mbx.frs.vf_id = nic->vf_id;

        return nicvf_send_msg_to_pf(nic, &mbx);
}

int nicvf_open(struct net_device *netdev)
{
        int cpu, err, qidx;
        struct nicvf *nic = netdev_priv(netdev);
        struct queue_set *qs = nic->qs;
        struct nicvf_cq_poll *cq_poll = NULL;
        union nic_mbx mbx = {};

        netif_carrier_off(netdev);

        err = nicvf_register_misc_interrupt(nic);
        if (err)
                return err;

        /* Register NAPI handler for processing CQEs */
        for (qidx = 0; qidx < qs->cq_cnt; qidx++) {
                cq_poll = kzalloc(sizeof(*cq_poll), GFP_KERNEL);
                if (!cq_poll) {
                        err = -ENOMEM;
                        goto napi_del;
                }
                cq_poll->cq_idx = qidx;
                cq_poll->nicvf = nic;
                netif_napi_add(netdev, &cq_poll->napi, nicvf_poll,
                               NAPI_POLL_WEIGHT);
                napi_enable(&cq_poll->napi);
                nic->napi[qidx] = cq_poll;
        }

        /* Check if we got MAC address from PF or else generate a radom MAC */
        if (!nic->sqs_mode && is_zero_ether_addr(netdev->dev_addr)) {
                eth_hw_addr_random(netdev);
                nicvf_hw_set_mac_addr(nic, netdev);
        }

        if (nic->set_mac_pending) {
                nic->set_mac_pending = false;
                nicvf_hw_set_mac_addr(nic, netdev);
        }

        /* Init tasklet for handling Qset err interrupt */
        tasklet_init(&nic->qs_err_task, nicvf_handle_qs_err,
                     (unsigned long)nic);

        /* Init RBDR tasklet which will refill RBDR */
        tasklet_init(&nic->rbdr_task, nicvf_rbdr_task,
                     (unsigned long)nic);
        INIT_DELAYED_WORK(&nic->rbdr_work, nicvf_rbdr_work);

        /* Configure CPI alorithm */
        nic->cpi_alg = cpi_alg;
        if (!nic->sqs_mode)
                nicvf_config_cpi(nic);

        nicvf_request_sqs(nic);
        if (nic->sqs_mode)
                nicvf_get_primary_vf_struct(nic);

        /* Configure receive side scaling and MTU */
        if (!nic->sqs_mode) {
                nicvf_rss_init(nic);
                if (nicvf_update_hw_max_frs(nic, netdev->mtu))
                        goto cleanup;

                /* Clear percpu stats */
                for_each_possible_cpu(cpu)
                        memset(per_cpu_ptr(nic->drv_stats, cpu), 0,
                               sizeof(struct nicvf_drv_stats));
        }

        err = nicvf_register_interrupts(nic);
        if (err)
                goto cleanup;

        /* Initialize the queues */
        err = nicvf_init_resources(nic);
        if (err)
                goto cleanup;

        /* Make sure queue initialization is written */
        wmb();

        nicvf_reg_write(nic, NIC_VF_INT, -1);
        /* Enable Qset err interrupt */
        nicvf_enable_intr(nic, NICVF_INTR_QS_ERR, 0);

        /* Enable completion queue interrupt */
        for (qidx = 0; qidx < qs->cq_cnt; qidx++)
                nicvf_enable_intr(nic, NICVF_INTR_CQ, qidx);

        /* Enable RBDR threshold interrupt */
        for (qidx = 0; qidx < qs->rbdr_cnt; qidx++)
                nicvf_enable_intr(nic, NICVF_INTR_RBDR, qidx);

        /* Send VF config done msg to PF */
        mbx.msg.msg = NIC_MBOX_MSG_CFG_DONE;
        nicvf_write_to_mbx(nic, &mbx);

        return 0;
cleanup:
        nicvf_disable_intr(nic, NICVF_INTR_MBOX, 0);
        nicvf_unregister_interrupts(nic);
        tasklet_kill(&nic->qs_err_task);
        tasklet_kill(&nic->rbdr_task);
napi_del:
        for (qidx = 0; qidx < qs->cq_cnt; qidx++) {
                cq_poll = nic->napi[qidx];
                if (!cq_poll)
                        continue;
                napi_disable(&cq_poll->napi);
                netif_napi_del(&cq_poll->napi);
        }
        nicvf_free_cq_poll(nic);
        return err;
}

static int nicvf_change_mtu(struct net_device *netdev, int new_mtu)
{
        struct nicvf *nic = netdev_priv(netdev);

        if (new_mtu > NIC_HW_MAX_FRS)
                return -EINVAL;

        if (new_mtu < NIC_HW_MIN_FRS)
                return -EINVAL;

        netdev->mtu = new_mtu;

        if (!netif_running(netdev))
                return 0;

        if (nicvf_update_hw_max_frs(nic, new_mtu))
                return -EINVAL;

        return 0;
}

static int nicvf_set_mac_address(struct net_device *netdev, void *p)
{
        struct sockaddr *addr = p;
        struct nicvf *nic = netdev_priv(netdev);

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

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

        if (nic->msix_enabled) {
                if (nicvf_hw_set_mac_addr(nic, netdev))
                        return -EBUSY;
        } else {
                nic->set_mac_pending = true;
        }

        return 0;
}

void nicvf_update_lmac_stats(struct nicvf *nic)
{
        int stat = 0;
        union nic_mbx mbx = {};

        if (!netif_running(nic->netdev))
                return;

        mbx.bgx_stats.msg = NIC_MBOX_MSG_BGX_STATS;
        mbx.bgx_stats.vf_id = nic->vf_id;
        /* Rx stats */
        mbx.bgx_stats.rx = 1;
        while (stat < BGX_RX_STATS_COUNT) {
                mbx.bgx_stats.idx = stat;
                if (nicvf_send_msg_to_pf(nic, &mbx))
                        return;
                stat++;
        }

        stat = 0;

        /* Tx stats */
        mbx.bgx_stats.rx = 0;
        while (stat < BGX_TX_STATS_COUNT) {
                mbx.bgx_stats.idx = stat;
                if (nicvf_send_msg_to_pf(nic, &mbx))
                        return;
                stat++;
        }
}

void nicvf_update_stats(struct nicvf *nic)
{
        int qidx, cpu;
        u64 tmp_stats = 0;
        struct nicvf_hw_stats *stats = &nic->hw_stats;
        struct nicvf_drv_stats *drv_stats;
        struct queue_set *qs = nic->qs;

#define GET_RX_STATS(reg) \
        nicvf_reg_read(nic, NIC_VNIC_RX_STAT_0_13 | (reg << 3))
#define GET_TX_STATS(reg) \
        nicvf_reg_read(nic, NIC_VNIC_TX_STAT_0_4 | (reg << 3))

        stats->rx_bytes = GET_RX_STATS(RX_OCTS);
        stats->rx_ucast_frames = GET_RX_STATS(RX_UCAST);
        stats->rx_bcast_frames = GET_RX_STATS(RX_BCAST);
        stats->rx_mcast_frames = GET_RX_STATS(RX_MCAST);
        stats->rx_fcs_errors = GET_RX_STATS(RX_FCS);
        stats->rx_l2_errors = GET_RX_STATS(RX_L2ERR);
        stats->rx_drop_red = GET_RX_STATS(RX_RED);
        stats->rx_drop_red_bytes = GET_RX_STATS(RX_RED_OCTS);
        stats->rx_drop_overrun = GET_RX_STATS(RX_ORUN);
        stats->rx_drop_overrun_bytes = GET_RX_STATS(RX_ORUN_OCTS);
        stats->rx_drop_bcast = GET_RX_STATS(RX_DRP_BCAST);
        stats->rx_drop_mcast = GET_RX_STATS(RX_DRP_MCAST);
        stats->rx_drop_l3_bcast = GET_RX_STATS(RX_DRP_L3BCAST);
        stats->rx_drop_l3_mcast = GET_RX_STATS(RX_DRP_L3MCAST);

        stats->tx_bytes = GET_TX_STATS(TX_OCTS);
        stats->tx_ucast_frames = GET_TX_STATS(TX_UCAST);
        stats->tx_bcast_frames = GET_TX_STATS(TX_BCAST);
        stats->tx_mcast_frames = GET_TX_STATS(TX_MCAST);
        stats->tx_drops = GET_TX_STATS(TX_DROP);

        /* On T88 pass 2.0, the dummy SQE added for TSO notification
         * via CQE has 'dont_send' set. Hence HW drops the pkt pointed
         * pointed by dummy SQE and results in tx_drops counter being
         * incremented. Subtracting it from tx_tso counter will give
         * exact tx_drops counter.
         */
        if (nic->t88 && nic->hw_tso) {
                for_each_possible_cpu(cpu) {
                        drv_stats = per_cpu_ptr(nic->drv_stats, cpu);
                        tmp_stats += drv_stats->tx_tso;
                }
                stats->tx_drops = tmp_stats - stats->tx_drops;
        }
        stats->tx_frames = stats->tx_ucast_frames +
                           stats->tx_bcast_frames +
                           stats->tx_mcast_frames;
        stats->rx_frames = stats->rx_ucast_frames +
                           stats->rx_bcast_frames +
                           stats->rx_mcast_frames;
        stats->rx_drops = stats->rx_drop_red +
                          stats->rx_drop_overrun;

        /* Update RQ and SQ stats */
        for (qidx = 0; qidx < qs->rq_cnt; qidx++)
                nicvf_update_rq_stats(nic, qidx);
        for (qidx = 0; qidx < qs->sq_cnt; qidx++)
                nicvf_update_sq_stats(nic, qidx);
}

static struct rtnl_link_stats64 *nicvf_get_stats64(struct net_device *netdev,
                                            struct rtnl_link_stats64 *stats)
{
        struct nicvf *nic = netdev_priv(netdev);
        struct nicvf_hw_stats *hw_stats = &nic->hw_stats;

        nicvf_update_stats(nic);

        stats->rx_bytes = hw_stats->rx_bytes;
        stats->rx_packets = hw_stats->rx_frames;
        stats->rx_dropped = hw_stats->rx_drops;
        stats->multicast = hw_stats->rx_mcast_frames;

        stats->tx_bytes = hw_stats->tx_bytes;
        stats->tx_packets = hw_stats->tx_frames;
        stats->tx_dropped = hw_stats->tx_drops;

        return stats;
}

static void nicvf_tx_timeout(struct net_device *dev)
{
        struct nicvf *nic = netdev_priv(dev);

        if (netif_msg_tx_err(nic))
                netdev_warn(dev, "%s: Transmit timed out, resetting\n",
                            dev->name);

        this_cpu_inc(nic->drv_stats->tx_timeout);
        schedule_work(&nic->reset_task);
}

static void nicvf_reset_task(struct work_struct *work)
{
        struct nicvf *nic;

        nic = container_of(work, struct nicvf, reset_task);

        if (!netif_running(nic->netdev))
                return;

        nicvf_stop(nic->netdev);
        nicvf_open(nic->netdev);
        netif_trans_update(nic->netdev);
}

static int nicvf_config_loopback(struct nicvf *nic,
                                 netdev_features_t features)
{
        union nic_mbx mbx = {};

        mbx.lbk.msg = NIC_MBOX_MSG_LOOPBACK;
        mbx.lbk.vf_id = nic->vf_id;
        mbx.lbk.enable = (features & NETIF_F_LOOPBACK) != 0;

        return nicvf_send_msg_to_pf(nic, &mbx);
}

static netdev_features_t nicvf_fix_features(struct net_device *netdev,
                                            netdev_features_t features)
{
        struct nicvf *nic = netdev_priv(netdev);

        if ((features & NETIF_F_LOOPBACK) &&
            netif_running(netdev) && !nic->loopback_supported)
                features &= ~NETIF_F_LOOPBACK;

        return features;
}

static int nicvf_set_features(struct net_device *netdev,
                              netdev_features_t features)
{
        struct nicvf *nic = netdev_priv(netdev);
        netdev_features_t changed = features ^ netdev->features;

        if (changed & NETIF_F_HW_VLAN_CTAG_RX)
                nicvf_config_vlan_stripping(nic, features);

        if ((changed & NETIF_F_LOOPBACK) && netif_running(netdev))
                return nicvf_config_loopback(nic, features);

        return 0;
}

static const struct net_device_ops nicvf_netdev_ops = {
        .ndo_open               = nicvf_open,
        .ndo_stop               = nicvf_stop,
        .ndo_start_xmit         = nicvf_xmit,
        .ndo_change_mtu         = nicvf_change_mtu,
        .ndo_set_mac_address    = nicvf_set_mac_address,
        .ndo_get_stats64        = nicvf_get_stats64,
        .ndo_tx_timeout         = nicvf_tx_timeout,
        .ndo_fix_features       = nicvf_fix_features,
        .ndo_set_features       = nicvf_set_features,
};

static int nicvf_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
{
        struct device *dev = &pdev->dev;
        struct net_device *netdev;
        struct nicvf *nic;
        int    err, qcount;
        u16    sdevid;

        err = pci_enable_device(pdev);
        if (err) {
                dev_err(dev, "Failed to enable PCI device\n");
                return err;
        }

        err = pci_request_regions(pdev, DRV_NAME);
        if (err) {
                dev_err(dev, "PCI request regions failed 0x%x\n", err);
                goto err_disable_device;
        }

        err = pci_set_dma_mask(pdev, DMA_BIT_MASK(48));
        if (err) {
                dev_err(dev, "Unable to get usable DMA configuration\n");
                goto err_release_regions;
        }

        err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(48));
        if (err) {
                dev_err(dev, "unable to get 48-bit DMA for consistent allocations\n");
                goto err_release_regions;
        }

        qcount = netif_get_num_default_rss_queues();

        /* Restrict multiqset support only for host bound VFs */
        if (pdev->is_virtfn) {
                /* Set max number of queues per VF */
                qcount = min_t(int, num_online_cpus(),
                               (MAX_SQS_PER_VF + 1) * MAX_CMP_QUEUES_PER_QS);
        }

        netdev = alloc_etherdev_mqs(sizeof(struct nicvf), qcount, qcount);
        if (!netdev) {
                err = -ENOMEM;
                goto err_release_regions;
        }

        pci_set_drvdata(pdev, netdev);

        SET_NETDEV_DEV(netdev, &pdev->dev);

        nic = netdev_priv(netdev);
        nic->netdev = netdev;
        nic->pdev = pdev;
        nic->pnicvf = nic;
        nic->max_queues = qcount;

        /* MAP VF's configuration registers */
        nic->reg_base = pcim_iomap(pdev, PCI_CFG_REG_BAR_NUM, 0);
        if (!nic->reg_base) {
                dev_err(dev, "Cannot map config register space, aborting\n");
                err = -ENOMEM;
                goto err_free_netdev;
        }

        nic->drv_stats = netdev_alloc_pcpu_stats(struct nicvf_drv_stats);
        if (!nic->drv_stats) {
                err = -ENOMEM;
                goto err_free_netdev;
        }

        err = nicvf_set_qset_resources(nic);
        if (err)
                goto err_free_netdev;

        /* Check if PF is alive and get MAC address for this VF */
        err = nicvf_register_misc_interrupt(nic);
        if (err)
                goto err_free_netdev;

        nicvf_send_vf_struct(nic);

        if (!pass1_silicon(nic->pdev))
                nic->hw_tso = true;

        pci_read_config_word(nic->pdev, PCI_SUBSYSTEM_ID, &sdevid);
        if (sdevid == 0xA134)
                nic->t88 = true;

        /* Check if this VF is in QS only mode */
        if (nic->sqs_mode)
                return 0;

        err = nicvf_set_real_num_queues(netdev, nic->tx_queues, nic->rx_queues);
        if (err)
                goto err_unregister_interrupts;

        netdev->hw_features = (NETIF_F_RXCSUM | NETIF_F_IP_CSUM | NETIF_F_SG |
                               NETIF_F_TSO | NETIF_F_GRO |
                               NETIF_F_HW_VLAN_CTAG_RX);

        netdev->hw_features |= NETIF_F_RXHASH;

        netdev->features |= netdev->hw_features;
        netdev->hw_features |= NETIF_F_LOOPBACK;

        netdev->vlan_features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_TSO;

        netdev->netdev_ops = &nicvf_netdev_ops;
        netdev->watchdog_timeo = NICVF_TX_TIMEOUT;

        INIT_WORK(&nic->reset_task, nicvf_reset_task);

        err = register_netdev(netdev);
        if (err) {
                dev_err(dev, "Failed to register netdevice\n");
                goto err_unregister_interrupts;
        }

        nic->msg_enable = debug;

        nicvf_set_ethtool_ops(netdev);

        return 0;

err_unregister_interrupts:
        nicvf_unregister_interrupts(nic);
err_free_netdev:
        pci_set_drvdata(pdev, NULL);
        if (nic->drv_stats)
                free_percpu(nic->drv_stats);
        free_netdev(netdev);
err_release_regions:
        pci_release_regions(pdev);
err_disable_device:
        pci_disable_device(pdev);
        return err;
}

static void nicvf_remove(struct pci_dev *pdev)
{
        struct net_device *netdev = pci_get_drvdata(pdev);
        struct nicvf *nic;
        struct net_device *pnetdev;

        if (!netdev)
                return;

        nic = netdev_priv(netdev);
        pnetdev = nic->pnicvf->netdev;

        /* Check if this Qset is assigned to different VF.
         * If yes, clean primary and all secondary Qsets.
         */
        if (pnetdev && (pnetdev->reg_state == NETREG_REGISTERED))
                unregister_netdev(pnetdev);
        nicvf_unregister_interrupts(nic);
        pci_set_drvdata(pdev, NULL);
        if (nic->drv_stats)
                free_percpu(nic->drv_stats);
        free_netdev(netdev);
        pci_release_regions(pdev);
        pci_disable_device(pdev);
}

static void nicvf_shutdown(struct pci_dev *pdev)
{
        nicvf_remove(pdev);
}

static struct pci_driver nicvf_driver = {
        .name = DRV_NAME,
        .id_table = nicvf_id_table,
        .probe = nicvf_probe,
        .remove = nicvf_remove,
        .shutdown = nicvf_shutdown,
};

static int __init nicvf_init_module(void)
{
        pr_info("%s, ver %s\n", DRV_NAME, DRV_VERSION);

        return pci_register_driver(&nicvf_driver);
}

static void __exit nicvf_cleanup_module(void)
{
        pci_unregister_driver(&nicvf_driver);
}

module_init(nicvf_init_module);
module_exit(nicvf_cleanup_module);