root/drivers/net/ethernet/realtek/rtase/rtase_main.c
// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
/*
 *  rtase is the Linux device driver released for Realtek Automotive Switch
 *  controllers with PCI-Express interface.
 *
 *  Copyright(c) 2024 Realtek Semiconductor Corp.
 *
 *  Below is a simplified block diagram of the chip and its relevant interfaces.
 *
 *               *************************
 *               *                       *
 *               *  CPU network device   *
 *               *                       *
 *               *   +-------------+     *
 *               *   |  PCIE Host  |     *
 *               ***********++************
 *                          ||
 *                         PCIE
 *                          ||
 *      ********************++**********************
 *      *            | PCIE Endpoint |             *
 *      *            +---------------+             *
 *      *                | GMAC |                  *
 *      *                +--++--+  Realtek         *
 *      *                   ||     RTL90xx Series  *
 *      *                   ||                     *
 *      *     +-------------++----------------+    *
 *      *     |           | MAC |             |    *
 *      *     |           +-----+             |    *
 *      *     |                               |    *
 *      *     |     Ethernet Switch Core      |    *
 *      *     |                               |    *
 *      *     |   +-----+           +-----+   |    *
 *      *     |   | MAC |...........| MAC |   |    *
 *      *     +---+-----+-----------+-----+---+    *
 *      *         | PHY |...........| PHY |        *
 *      *         +--++-+           +--++-+        *
 *      *************||****************||***********
 *
 *  The block of the Realtek RTL90xx series is our entire chip architecture,
 *  the GMAC is connected to the switch core, and there is no PHY in between.
 *  In addition, this driver is mainly used to control GMAC, but does not
 *  control the switch core, so it is not the same as DSA. Linux only plays
 *  the role of a normal leaf node in this model.
 */

#include <linux/crc32.h>
#include <linux/dma-mapping.h>
#include <linux/etherdevice.h>
#include <linux/if_vlan.h>
#include <linux/in.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/mdio.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/pci.h>
#include <linux/pm_runtime.h>
#include <linux/prefetch.h>
#include <linux/rtnetlink.h>
#include <linux/tcp.h>
#include <asm/irq.h>
#include <net/ip6_checksum.h>
#include <net/netdev_queues.h>
#include <net/page_pool/helpers.h>
#include <net/pkt_cls.h>

#include "rtase.h"

#define RTK_OPTS1_DEBUG_VALUE 0x0BADBEEF
#define RTK_MAGIC_NUMBER      0x0BADBADBADBADBAD

static const struct pci_device_id rtase_pci_tbl[] = {
        {PCI_VDEVICE(REALTEK, 0x906A)},
        {}
};

MODULE_DEVICE_TABLE(pci, rtase_pci_tbl);

MODULE_AUTHOR("Realtek ARD Software Team");
MODULE_DESCRIPTION("Network Driver for the PCIe interface of Realtek Automotive Ethernet Switch");
MODULE_LICENSE("Dual BSD/GPL");

struct rtase_counters {
        __le64 tx_packets;
        __le64 rx_packets;
        __le64 tx_errors;
        __le32 rx_errors;
        __le16 rx_missed;
        __le16 align_errors;
        __le32 tx_one_collision;
        __le32 tx_multi_collision;
        __le64 rx_unicast;
        __le64 rx_broadcast;
        __le32 rx_multicast;
        __le16 tx_aborted;
        __le16 tx_underrun;
} __packed;

static void rtase_w8(const struct rtase_private *tp, u16 reg, u8 val8)
{
        writeb(val8, tp->mmio_addr + reg);
}

static void rtase_w16(const struct rtase_private *tp, u16 reg, u16 val16)
{
        writew(val16, tp->mmio_addr + reg);
}

static void rtase_w32(const struct rtase_private *tp, u16 reg, u32 val32)
{
        writel(val32, tp->mmio_addr + reg);
}

static u8 rtase_r8(const struct rtase_private *tp, u16 reg)
{
        return readb(tp->mmio_addr + reg);
}

static u16 rtase_r16(const struct rtase_private *tp, u16 reg)
{
        return readw(tp->mmio_addr + reg);
}

static u32 rtase_r32(const struct rtase_private *tp, u16 reg)
{
        return readl(tp->mmio_addr + reg);
}

static void rtase_free_desc(struct rtase_private *tp)
{
        struct pci_dev *pdev = tp->pdev;
        u32 i;

        for (i = 0; i < tp->func_tx_queue_num; i++) {
                if (!tp->tx_ring[i].desc)
                        continue;

                dma_free_coherent(&pdev->dev, RTASE_TX_RING_DESC_SIZE,
                                  tp->tx_ring[i].desc,
                                  tp->tx_ring[i].phy_addr);
                tp->tx_ring[i].desc = NULL;
        }

        for (i = 0; i < tp->func_rx_queue_num; i++) {
                if (!tp->rx_ring[i].desc)
                        continue;

                dma_free_coherent(&pdev->dev, RTASE_RX_RING_DESC_SIZE,
                                  tp->rx_ring[i].desc,
                                  tp->rx_ring[i].phy_addr);
                tp->rx_ring[i].desc = NULL;
        }
}

static int rtase_alloc_desc(struct rtase_private *tp)
{
        struct pci_dev *pdev = tp->pdev;
        u32 i;

        /* rx and tx descriptors needs 256 bytes alignment.
         * dma_alloc_coherent provides more.
         */
        for (i = 0; i < tp->func_tx_queue_num; i++) {
                tp->tx_ring[i].desc =
                                dma_alloc_coherent(&pdev->dev,
                                                   RTASE_TX_RING_DESC_SIZE,
                                                   &tp->tx_ring[i].phy_addr,
                                                   GFP_KERNEL);
                if (!tp->tx_ring[i].desc)
                        goto err_out;
        }

        for (i = 0; i < tp->func_rx_queue_num; i++) {
                tp->rx_ring[i].desc =
                                dma_alloc_coherent(&pdev->dev,
                                                   RTASE_RX_RING_DESC_SIZE,
                                                   &tp->rx_ring[i].phy_addr,
                                                   GFP_KERNEL);
                if (!tp->rx_ring[i].desc)
                        goto err_out;
        }

        return 0;

err_out:
        rtase_free_desc(tp);
        return -ENOMEM;
}

static void rtase_unmap_tx_skb(struct pci_dev *pdev, u32 len,
                               struct rtase_tx_desc *desc)
{
        dma_unmap_single(&pdev->dev, le64_to_cpu(desc->addr), len,
                         DMA_TO_DEVICE);
        desc->opts1 = cpu_to_le32(RTK_OPTS1_DEBUG_VALUE);
        desc->opts2 = 0x00;
        desc->addr = cpu_to_le64(RTK_MAGIC_NUMBER);
}

static void rtase_tx_clear_range(struct rtase_ring *ring, u32 start, u32 n)
{
        struct rtase_tx_desc *desc_base = ring->desc;
        struct rtase_private *tp = ring->ivec->tp;
        u32 i;

        for (i = 0; i < n; i++) {
                u32 entry = (start + i) % RTASE_NUM_DESC;
                struct rtase_tx_desc *desc = desc_base + entry;
                u32 len = ring->mis.len[entry];
                struct sk_buff *skb;

                if (len == 0)
                        continue;

                rtase_unmap_tx_skb(tp->pdev, len, desc);
                ring->mis.len[entry] = 0;
                skb = ring->skbuff[entry];
                if (!skb)
                        continue;

                tp->stats.tx_dropped++;
                dev_kfree_skb_any(skb);
                ring->skbuff[entry] = NULL;
        }
}

static void rtase_tx_clear(struct rtase_private *tp)
{
        struct rtase_ring *ring;
        u16 i;

        for (i = 0; i < tp->func_tx_queue_num; i++) {
                ring = &tp->tx_ring[i];
                rtase_tx_clear_range(ring, ring->dirty_idx, RTASE_NUM_DESC);
                ring->cur_idx = 0;
                ring->dirty_idx = 0;
        }
}

static void rtase_mark_to_asic(union rtase_rx_desc *desc, u32 rx_buf_sz)
{
        u32 eor = le32_to_cpu(desc->desc_cmd.opts1) & RTASE_RING_END;

        desc->desc_status.opts2 = 0;
        /* force memory writes to complete before releasing descriptor */
        dma_wmb();
        WRITE_ONCE(desc->desc_cmd.opts1,
                   cpu_to_le32(RTASE_DESC_OWN | eor | rx_buf_sz));
}

static u32 rtase_tx_avail(struct rtase_ring *ring)
{
        return READ_ONCE(ring->dirty_idx) + RTASE_NUM_DESC -
               READ_ONCE(ring->cur_idx);
}

static int tx_handler(struct rtase_ring *ring, int budget)
{
        const struct rtase_private *tp = ring->ivec->tp;
        struct net_device *dev = tp->dev;
        u32 dirty_tx, tx_left;
        u32 bytes_compl = 0;
        u32 pkts_compl = 0;
        int workdone = 0;

        dirty_tx = ring->dirty_idx;
        tx_left = READ_ONCE(ring->cur_idx) - dirty_tx;

        while (tx_left > 0) {
                u32 entry = dirty_tx % RTASE_NUM_DESC;
                struct rtase_tx_desc *desc = ring->desc +
                                       sizeof(struct rtase_tx_desc) * entry;
                u32 status;

                status = le32_to_cpu(desc->opts1);

                if (status & RTASE_DESC_OWN)
                        break;

                rtase_unmap_tx_skb(tp->pdev, ring->mis.len[entry], desc);
                ring->mis.len[entry] = 0;
                if (ring->skbuff[entry]) {
                        pkts_compl++;
                        bytes_compl += ring->skbuff[entry]->len;
                        napi_consume_skb(ring->skbuff[entry], budget);
                        ring->skbuff[entry] = NULL;
                }

                dirty_tx++;
                tx_left--;
                workdone++;

                if (workdone == RTASE_TX_BUDGET_DEFAULT)
                        break;
        }

        if (ring->dirty_idx != dirty_tx) {
                dev_sw_netstats_tx_add(dev, pkts_compl, bytes_compl);
                WRITE_ONCE(ring->dirty_idx, dirty_tx);

                netif_subqueue_completed_wake(dev, ring->index, pkts_compl,
                                              bytes_compl,
                                              rtase_tx_avail(ring),
                                              RTASE_TX_START_THRS);

                if (ring->cur_idx != dirty_tx)
                        rtase_w8(tp, RTASE_TPPOLL, BIT(ring->index));
        }

        return 0;
}

static void rtase_tx_desc_init(struct rtase_private *tp, u16 idx)
{
        struct rtase_ring *ring = &tp->tx_ring[idx];
        struct rtase_tx_desc *desc;
        u32 i;

        memset(ring->desc, 0x0, RTASE_TX_RING_DESC_SIZE);
        memset(ring->skbuff, 0x0, sizeof(ring->skbuff));
        ring->cur_idx = 0;
        ring->dirty_idx = 0;
        ring->index = idx;
        ring->type = NETDEV_QUEUE_TYPE_TX;
        ring->alloc_fail = 0;

        for (i = 0; i < RTASE_NUM_DESC; i++) {
                ring->mis.len[i] = 0;
                if ((RTASE_NUM_DESC - 1) == i) {
                        desc = ring->desc + sizeof(struct rtase_tx_desc) * i;
                        desc->opts1 = cpu_to_le32(RTASE_RING_END);
                }
        }

        ring->ring_handler = tx_handler;
        if (idx < 4) {
                ring->ivec = &tp->int_vector[idx];
                list_add_tail(&ring->ring_entry,
                              &tp->int_vector[idx].ring_list);
        } else {
                ring->ivec = &tp->int_vector[0];
                list_add_tail(&ring->ring_entry, &tp->int_vector[0].ring_list);
        }

        netif_queue_set_napi(tp->dev, ring->index,
                             ring->type, &ring->ivec->napi);
}

static void rtase_map_to_asic(union rtase_rx_desc *desc, dma_addr_t mapping,
                              u32 rx_buf_sz)
{
        desc->desc_cmd.addr = cpu_to_le64(mapping);

        rtase_mark_to_asic(desc, rx_buf_sz);
}

static void rtase_make_unusable_by_asic(union rtase_rx_desc *desc)
{
        desc->desc_cmd.addr = cpu_to_le64(RTK_MAGIC_NUMBER);
        desc->desc_cmd.opts1 &= ~cpu_to_le32(RTASE_DESC_OWN | RSVD_MASK);
}

static int rtase_alloc_rx_data_buf(struct rtase_ring *ring,
                                   void **p_data_buf,
                                   union rtase_rx_desc *desc,
                                   dma_addr_t *rx_phy_addr)
{
        struct rtase_int_vector *ivec = ring->ivec;
        const struct rtase_private *tp = ivec->tp;
        dma_addr_t mapping;
        struct page *page;

        page = page_pool_dev_alloc_pages(tp->page_pool);
        if (!page) {
                ring->alloc_fail++;
                goto err_out;
        }

        *p_data_buf = page_address(page);
        mapping = page_pool_get_dma_addr(page);
        *rx_phy_addr = mapping;
        rtase_map_to_asic(desc, mapping, tp->rx_buf_sz);

        return 0;

err_out:
        rtase_make_unusable_by_asic(desc);

        return -ENOMEM;
}

static u32 rtase_rx_ring_fill(struct rtase_ring *ring, u32 ring_start,
                              u32 ring_end)
{
        union rtase_rx_desc *desc_base = ring->desc;
        u32 cur;

        for (cur = ring_start; ring_end - cur > 0; cur++) {
                u32 i = cur % RTASE_NUM_DESC;
                union rtase_rx_desc *desc = desc_base + i;
                int ret;

                if (ring->data_buf[i])
                        continue;

                ret = rtase_alloc_rx_data_buf(ring, &ring->data_buf[i], desc,
                                              &ring->mis.data_phy_addr[i]);
                if (ret)
                        break;
        }

        return cur - ring_start;
}

static void rtase_mark_as_last_descriptor(union rtase_rx_desc *desc)
{
        desc->desc_cmd.opts1 |= cpu_to_le32(RTASE_RING_END);
}

static void rtase_rx_ring_clear(struct page_pool *page_pool,
                                struct rtase_ring *ring)
{
        union rtase_rx_desc *desc;
        struct page *page;
        u32 i;

        for (i = 0; i < RTASE_NUM_DESC; i++) {
                desc = ring->desc + sizeof(union rtase_rx_desc) * i;
                page = virt_to_head_page(ring->data_buf[i]);

                if (ring->data_buf[i])
                        page_pool_put_full_page(page_pool, page, true);

                rtase_make_unusable_by_asic(desc);
        }
}

static int rtase_fragmented_frame(u32 status)
{
        return (status & (RTASE_RX_FIRST_FRAG | RTASE_RX_LAST_FRAG)) !=
               (RTASE_RX_FIRST_FRAG | RTASE_RX_LAST_FRAG);
}

static void rtase_rx_csum(const struct rtase_private *tp, struct sk_buff *skb,
                          const union rtase_rx_desc *desc)
{
        u32 opts2 = le32_to_cpu(desc->desc_status.opts2);

        /* rx csum offload */
        if (((opts2 & RTASE_RX_V4F) && !(opts2 & RTASE_RX_IPF)) ||
            (opts2 & RTASE_RX_V6F)) {
                if (((opts2 & RTASE_RX_TCPT) && !(opts2 & RTASE_RX_TCPF)) ||
                    ((opts2 & RTASE_RX_UDPT) && !(opts2 & RTASE_RX_UDPF)))
                        skb->ip_summed = CHECKSUM_UNNECESSARY;
                else
                        skb->ip_summed = CHECKSUM_NONE;
        } else {
                skb->ip_summed = CHECKSUM_NONE;
        }
}

static void rtase_rx_vlan_skb(union rtase_rx_desc *desc, struct sk_buff *skb)
{
        u32 opts2 = le32_to_cpu(desc->desc_status.opts2);

        if (!(opts2 & RTASE_RX_VLAN_TAG))
                return;

        __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
                               swab16(opts2 & RTASE_VLAN_TAG_MASK));
}

static void rtase_rx_skb(const struct rtase_ring *ring, struct sk_buff *skb)
{
        struct rtase_int_vector *ivec = ring->ivec;

        napi_gro_receive(&ivec->napi, skb);
}

static int rx_handler(struct rtase_ring *ring, int budget)
{
        union rtase_rx_desc *desc_base = ring->desc;
        u32 pkt_size, cur_rx, delta, entry, status;
        struct rtase_private *tp = ring->ivec->tp;
        struct net_device *dev = tp->dev;
        union rtase_rx_desc *desc;
        struct sk_buff *skb;
        int workdone = 0;

        cur_rx = ring->cur_idx;
        entry = cur_rx % RTASE_NUM_DESC;
        desc = &desc_base[entry];

        while (workdone < budget) {
                status = le32_to_cpu(desc->desc_status.opts1);

                if (status & RTASE_DESC_OWN)
                        break;

                /* This barrier is needed to keep us from reading
                 * any other fields out of the rx descriptor until
                 * we know the status of RTASE_DESC_OWN
                 */
                dma_rmb();

                if (unlikely(status & RTASE_RX_RES)) {
                        if (net_ratelimit())
                                netdev_warn(dev, "Rx ERROR. status = %08x\n",
                                            status);

                        tp->stats.rx_errors++;

                        if (status & (RTASE_RX_RWT | RTASE_RX_RUNT))
                                tp->stats.rx_length_errors++;

                        if (status & RTASE_RX_CRC)
                                tp->stats.rx_crc_errors++;

                        if (dev->features & NETIF_F_RXALL)
                                goto process_pkt;

                        rtase_mark_to_asic(desc, tp->rx_buf_sz);
                        goto skip_process_pkt;
                }

process_pkt:
                pkt_size = status & RTASE_RX_PKT_SIZE_MASK;
                if (likely(!(dev->features & NETIF_F_RXFCS)))
                        pkt_size -= ETH_FCS_LEN;

                /* The driver does not support incoming fragmented frames.
                 * They are seen as a symptom of over-mtu sized frames.
                 */
                if (unlikely(rtase_fragmented_frame(status))) {
                        tp->stats.rx_dropped++;
                        tp->stats.rx_length_errors++;
                        rtase_mark_to_asic(desc, tp->rx_buf_sz);
                        goto skip_process_pkt;
                }

                dma_sync_single_for_cpu(&tp->pdev->dev,
                                        ring->mis.data_phy_addr[entry],
                                        tp->rx_buf_sz, DMA_FROM_DEVICE);

                skb = build_skb(ring->data_buf[entry], PAGE_SIZE);
                if (!skb) {
                        tp->stats.rx_dropped++;
                        rtase_mark_to_asic(desc, tp->rx_buf_sz);
                        goto skip_process_pkt;
                }
                ring->data_buf[entry] = NULL;

                if (dev->features & NETIF_F_RXCSUM)
                        rtase_rx_csum(tp, skb, desc);

                skb_put(skb, pkt_size);
                skb_mark_for_recycle(skb);
                skb->protocol = eth_type_trans(skb, dev);

                if (skb->pkt_type == PACKET_MULTICAST)
                        tp->stats.multicast++;

                rtase_rx_vlan_skb(desc, skb);
                rtase_rx_skb(ring, skb);

                dev_sw_netstats_rx_add(dev, pkt_size);

skip_process_pkt:
                workdone++;
                cur_rx++;
                entry = cur_rx % RTASE_NUM_DESC;
                desc = ring->desc + sizeof(union rtase_rx_desc) * entry;
        }

        ring->cur_idx = cur_rx;
        delta = rtase_rx_ring_fill(ring, ring->dirty_idx, ring->cur_idx);
        ring->dirty_idx += delta;

        return workdone;
}

static void rtase_rx_desc_init(struct rtase_private *tp, u16 idx)
{
        struct rtase_ring *ring = &tp->rx_ring[idx];
        u16 i;

        memset(ring->desc, 0x0, RTASE_RX_RING_DESC_SIZE);
        memset(ring->data_buf, 0x0, sizeof(ring->data_buf));
        ring->cur_idx = 0;
        ring->dirty_idx = 0;
        ring->index = idx;
        ring->type = NETDEV_QUEUE_TYPE_RX;
        ring->alloc_fail = 0;

        for (i = 0; i < RTASE_NUM_DESC; i++)
                ring->mis.data_phy_addr[i] = 0;

        ring->ring_handler = rx_handler;
        ring->ivec = &tp->int_vector[idx];
        netif_queue_set_napi(tp->dev, ring->index,
                             ring->type, &ring->ivec->napi);
        list_add_tail(&ring->ring_entry, &tp->int_vector[idx].ring_list);
}

static void rtase_rx_clear(struct rtase_private *tp)
{
        u32 i;

        for (i = 0; i < tp->func_rx_queue_num; i++)
                rtase_rx_ring_clear(tp->page_pool, &tp->rx_ring[i]);

        page_pool_destroy(tp->page_pool);
        tp->page_pool = NULL;
}

static int rtase_init_ring(const struct net_device *dev)
{
        struct rtase_private *tp = netdev_priv(dev);
        struct page_pool_params pp_params = { 0 };
        struct page_pool *page_pool;
        u32 num;
        u16 i;

        pp_params.flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV;
        pp_params.order = 0;
        pp_params.pool_size = RTASE_NUM_DESC * tp->func_rx_queue_num;
        pp_params.nid = dev_to_node(&tp->pdev->dev);
        pp_params.dev = &tp->pdev->dev;
        pp_params.dma_dir = DMA_FROM_DEVICE;
        pp_params.max_len = PAGE_SIZE;
        pp_params.offset = 0;

        page_pool = page_pool_create(&pp_params);
        if (IS_ERR(page_pool)) {
                netdev_err(tp->dev, "failed to create page pool\n");
                return -ENOMEM;
        }

        tp->page_pool = page_pool;

        for (i = 0; i < tp->func_tx_queue_num; i++)
                rtase_tx_desc_init(tp, i);

        for (i = 0; i < tp->func_rx_queue_num; i++) {
                rtase_rx_desc_init(tp, i);

                num = rtase_rx_ring_fill(&tp->rx_ring[i], 0, RTASE_NUM_DESC);
                if (num != RTASE_NUM_DESC)
                        goto err_out;

                rtase_mark_as_last_descriptor(tp->rx_ring[i].desc +
                                              sizeof(union rtase_rx_desc) *
                                              (RTASE_NUM_DESC - 1));
        }

        return 0;

err_out:
        rtase_rx_clear(tp);
        return -ENOMEM;
}

static void rtase_interrupt_mitigation(const struct rtase_private *tp)
{
        u32 i;

        for (i = 0; i < tp->func_tx_queue_num; i++)
                rtase_w16(tp, RTASE_INT_MITI_TX + i * 2, tp->tx_int_mit);

        for (i = 0; i < tp->func_rx_queue_num; i++)
                rtase_w16(tp, RTASE_INT_MITI_RX + i * 2, tp->rx_int_mit);
}

static void rtase_tally_counter_addr_fill(const struct rtase_private *tp)
{
        rtase_w32(tp, RTASE_DTCCR4, upper_32_bits(tp->tally_paddr));
        rtase_w32(tp, RTASE_DTCCR0, lower_32_bits(tp->tally_paddr));
}

static void rtase_tally_counter_clear(const struct rtase_private *tp)
{
        u32 cmd = lower_32_bits(tp->tally_paddr);

        rtase_w32(tp, RTASE_DTCCR4, upper_32_bits(tp->tally_paddr));
        rtase_w32(tp, RTASE_DTCCR0, cmd | RTASE_COUNTER_RESET);
}

static void rtase_desc_addr_fill(const struct rtase_private *tp)
{
        const struct rtase_ring *ring;
        u16 i, cmd, val;
        int err;

        for (i = 0; i < tp->func_tx_queue_num; i++) {
                ring = &tp->tx_ring[i];

                rtase_w32(tp, RTASE_TX_DESC_ADDR0,
                          lower_32_bits(ring->phy_addr));
                rtase_w32(tp, RTASE_TX_DESC_ADDR4,
                          upper_32_bits(ring->phy_addr));

                cmd = i | RTASE_TX_DESC_CMD_WE | RTASE_TX_DESC_CMD_CS;
                rtase_w16(tp, RTASE_TX_DESC_COMMAND, cmd);

                err = read_poll_timeout(rtase_r16, val,
                                        !(val & RTASE_TX_DESC_CMD_CS), 10,
                                        1000, false, tp,
                                        RTASE_TX_DESC_COMMAND);

                if (err == -ETIMEDOUT)
                        netdev_err(tp->dev,
                                   "error occurred in fill tx descriptor\n");
        }

        for (i = 0; i < tp->func_rx_queue_num; i++) {
                ring = &tp->rx_ring[i];

                if (i == 0) {
                        rtase_w32(tp, RTASE_Q0_RX_DESC_ADDR0,
                                  lower_32_bits(ring->phy_addr));
                        rtase_w32(tp, RTASE_Q0_RX_DESC_ADDR4,
                                  upper_32_bits(ring->phy_addr));
                } else {
                        rtase_w32(tp, (RTASE_Q1_RX_DESC_ADDR0 + ((i - 1) * 8)),
                                  lower_32_bits(ring->phy_addr));
                        rtase_w32(tp, (RTASE_Q1_RX_DESC_ADDR4 + ((i - 1) * 8)),
                                  upper_32_bits(ring->phy_addr));
                }
        }
}

static void rtase_hw_set_features(const struct net_device *dev,
                                  netdev_features_t features)
{
        const struct rtase_private *tp = netdev_priv(dev);
        u16 rx_config, val;

        rx_config = rtase_r16(tp, RTASE_RX_CONFIG_0);
        if (features & NETIF_F_RXALL)
                rx_config |= (RTASE_ACCEPT_ERR | RTASE_ACCEPT_RUNT);
        else
                rx_config &= ~(RTASE_ACCEPT_ERR | RTASE_ACCEPT_RUNT);

        rtase_w16(tp, RTASE_RX_CONFIG_0, rx_config);

        val = rtase_r16(tp, RTASE_CPLUS_CMD);
        if (features & NETIF_F_RXCSUM)
                rtase_w16(tp, RTASE_CPLUS_CMD, val | RTASE_RX_CHKSUM);
        else
                rtase_w16(tp, RTASE_CPLUS_CMD, val & ~RTASE_RX_CHKSUM);

        rx_config = rtase_r16(tp, RTASE_RX_CONFIG_1);
        if (dev->features & NETIF_F_HW_VLAN_CTAG_RX)
                rx_config |= (RTASE_INNER_VLAN_DETAG_EN |
                              RTASE_OUTER_VLAN_DETAG_EN);
        else
                rx_config &= ~(RTASE_INNER_VLAN_DETAG_EN |
                               RTASE_OUTER_VLAN_DETAG_EN);

        rtase_w16(tp, RTASE_RX_CONFIG_1, rx_config);
}

static void rtase_hw_set_rx_packet_filter(struct net_device *dev)
{
        u32 mc_filter[2] = { 0xFFFFFFFF, 0xFFFFFFFF };
        struct rtase_private *tp = netdev_priv(dev);
        u16 rx_mode;

        rx_mode = rtase_r16(tp, RTASE_RX_CONFIG_0) & ~RTASE_ACCEPT_MASK;
        rx_mode |= RTASE_ACCEPT_BROADCAST | RTASE_ACCEPT_MYPHYS;

        if (dev->flags & IFF_PROMISC) {
                rx_mode |= RTASE_ACCEPT_MULTICAST | RTASE_ACCEPT_ALLPHYS;
        } else if (dev->flags & IFF_ALLMULTI) {
                rx_mode |= RTASE_ACCEPT_MULTICAST;
        } else {
                struct netdev_hw_addr *hw_addr;

                mc_filter[0] = 0;
                mc_filter[1] = 0;

                netdev_for_each_mc_addr(hw_addr, dev) {
                        u32 bit_nr = eth_hw_addr_crc(hw_addr);
                        u32 idx = u32_get_bits(bit_nr, BIT(31));
                        u32 bit = u32_get_bits(bit_nr,
                                               RTASE_MULTICAST_FILTER_MASK);

                        mc_filter[idx] |= BIT(bit);
                        rx_mode |= RTASE_ACCEPT_MULTICAST;
                }
        }

        if (dev->features & NETIF_F_RXALL)
                rx_mode |= RTASE_ACCEPT_ERR | RTASE_ACCEPT_RUNT;

        rtase_w32(tp, RTASE_MAR0, swab32(mc_filter[1]));
        rtase_w32(tp, RTASE_MAR1, swab32(mc_filter[0]));
        rtase_w16(tp, RTASE_RX_CONFIG_0, rx_mode);
}

static void rtase_irq_dis_and_clear(const struct rtase_private *tp)
{
        const struct rtase_int_vector *ivec = &tp->int_vector[0];
        u32 val1;
        u16 val2;
        u8 i;

        rtase_w32(tp, ivec->imr_addr, 0);
        val1 = rtase_r32(tp, ivec->isr_addr);
        rtase_w32(tp, ivec->isr_addr, val1);

        for (i = 1; i < tp->int_nums; i++) {
                ivec = &tp->int_vector[i];
                rtase_w16(tp, ivec->imr_addr, 0);
                val2 = rtase_r16(tp, ivec->isr_addr);
                rtase_w16(tp, ivec->isr_addr, val2);
        }
}

static void rtase_poll_timeout(const struct rtase_private *tp, u32 cond,
                               u32 sleep_us, u64 timeout_us, u16 reg)
{
        int err;
        u8 val;

        err = read_poll_timeout(rtase_r8, val, val & cond, sleep_us,
                                timeout_us, false, tp, reg);

        if (err == -ETIMEDOUT)
                netdev_err(tp->dev, "poll reg 0x00%x timeout\n", reg);
}

static void rtase_nic_reset(const struct net_device *dev)
{
        const struct rtase_private *tp = netdev_priv(dev);
        u16 rx_config;
        u8 val;

        rx_config = rtase_r16(tp, RTASE_RX_CONFIG_0);
        rtase_w16(tp, RTASE_RX_CONFIG_0, rx_config & ~RTASE_ACCEPT_MASK);

        val = rtase_r8(tp, RTASE_MISC);
        rtase_w8(tp, RTASE_MISC, val | RTASE_RX_DV_GATE_EN);

        val = rtase_r8(tp, RTASE_CHIP_CMD);
        rtase_w8(tp, RTASE_CHIP_CMD, val | RTASE_STOP_REQ);
        mdelay(2);

        rtase_poll_timeout(tp, RTASE_STOP_REQ_DONE, 100, 150000,
                           RTASE_CHIP_CMD);

        rtase_poll_timeout(tp, RTASE_TX_FIFO_EMPTY, 100, 100000,
                           RTASE_FIFOR);

        rtase_poll_timeout(tp, RTASE_RX_FIFO_EMPTY, 100, 100000,
                           RTASE_FIFOR);

        val = rtase_r8(tp, RTASE_CHIP_CMD);
        rtase_w8(tp, RTASE_CHIP_CMD, val & ~(RTASE_TE | RTASE_RE));
        val = rtase_r8(tp, RTASE_CHIP_CMD);
        rtase_w8(tp, RTASE_CHIP_CMD, val & ~RTASE_STOP_REQ);

        rtase_w16(tp, RTASE_RX_CONFIG_0, rx_config);
}

static void rtase_hw_reset(const struct net_device *dev)
{
        const struct rtase_private *tp = netdev_priv(dev);

        rtase_irq_dis_and_clear(tp);

        rtase_nic_reset(dev);
}

static void rtase_set_rx_queue(const struct rtase_private *tp)
{
        u16 reg_data;

        reg_data = rtase_r16(tp, RTASE_FCR);
        switch (tp->func_rx_queue_num) {
        case 1:
                u16p_replace_bits(&reg_data, 0x1, RTASE_FCR_RXQ_MASK);
                break;
        case 2:
                u16p_replace_bits(&reg_data, 0x2, RTASE_FCR_RXQ_MASK);
                break;
        case 4:
                u16p_replace_bits(&reg_data, 0x3, RTASE_FCR_RXQ_MASK);
                break;
        }
        rtase_w16(tp, RTASE_FCR, reg_data);
}

static void rtase_set_tx_queue(const struct rtase_private *tp)
{
        u16 reg_data;

        reg_data = rtase_r16(tp, RTASE_TX_CONFIG_1);
        switch (tp->tx_queue_ctrl) {
        case 1:
                u16p_replace_bits(&reg_data, 0x0, RTASE_TC_MODE_MASK);
                break;
        case 2:
                u16p_replace_bits(&reg_data, 0x1, RTASE_TC_MODE_MASK);
                break;
        case 3:
        case 4:
                u16p_replace_bits(&reg_data, 0x2, RTASE_TC_MODE_MASK);
                break;
        default:
                u16p_replace_bits(&reg_data, 0x3, RTASE_TC_MODE_MASK);
                break;
        }
        rtase_w16(tp, RTASE_TX_CONFIG_1, reg_data);
}

static void rtase_hw_config(struct net_device *dev)
{
        const struct rtase_private *tp = netdev_priv(dev);
        u32 reg_data32;
        u16 reg_data16;

        rtase_hw_reset(dev);

        /* set rx dma burst */
        reg_data16 = rtase_r16(tp, RTASE_RX_CONFIG_0);
        reg_data16 &= ~(RTASE_RX_SINGLE_TAG | RTASE_RX_SINGLE_FETCH);
        u16p_replace_bits(&reg_data16, RTASE_RX_DMA_BURST_256,
                          RTASE_RX_MX_DMA_MASK);
        rtase_w16(tp, RTASE_RX_CONFIG_0, reg_data16);

        /* new rx descritpor */
        reg_data16 = rtase_r16(tp, RTASE_RX_CONFIG_1);
        reg_data16 |= RTASE_RX_NEW_DESC_FORMAT_EN | RTASE_PCIE_NEW_FLOW;
        u16p_replace_bits(&reg_data16, 0xF, RTASE_RX_MAX_FETCH_DESC_MASK);
        rtase_w16(tp, RTASE_RX_CONFIG_1, reg_data16);

        rtase_set_rx_queue(tp);

        rtase_interrupt_mitigation(tp);

        /* set tx dma burst size and interframe gap time */
        reg_data32 = rtase_r32(tp, RTASE_TX_CONFIG_0);
        u32p_replace_bits(&reg_data32, RTASE_TX_DMA_BURST_UNLIMITED,
                          RTASE_TX_DMA_MASK);
        u32p_replace_bits(&reg_data32, RTASE_INTERFRAMEGAP,
                          RTASE_TX_INTER_FRAME_GAP_MASK);
        rtase_w32(tp, RTASE_TX_CONFIG_0, reg_data32);

        /* new tx descriptor */
        reg_data16 = rtase_r16(tp, RTASE_TFUN_CTRL);
        rtase_w16(tp, RTASE_TFUN_CTRL, reg_data16 |
                  RTASE_TX_NEW_DESC_FORMAT_EN);

        /* tx fetch desc number */
        rtase_w8(tp, RTASE_TDFNR, 0x10);

        /* tag num select */
        reg_data16 = rtase_r16(tp, RTASE_MTPS);
        u16p_replace_bits(&reg_data16, 0x4, RTASE_TAG_NUM_SEL_MASK);
        rtase_w16(tp, RTASE_MTPS, reg_data16);

        rtase_set_tx_queue(tp);

        rtase_w16(tp, RTASE_TOKSEL, 0x5555);

        rtase_tally_counter_addr_fill(tp);
        rtase_desc_addr_fill(tp);
        rtase_hw_set_features(dev, dev->features);

        /* enable flow control */
        reg_data16 = rtase_r16(tp, RTASE_CPLUS_CMD);
        reg_data16 |= (RTASE_FORCE_TXFLOW_EN | RTASE_FORCE_RXFLOW_EN);
        rtase_w16(tp, RTASE_CPLUS_CMD, reg_data16);
        /* set near fifo threshold - rx missed issue. */
        rtase_w16(tp, RTASE_RFIFONFULL, 0x190);

        rtase_w16(tp, RTASE_RMS, tp->rx_buf_sz);

        rtase_hw_set_rx_packet_filter(dev);
}

static void rtase_nic_enable(const struct net_device *dev)
{
        const struct rtase_private *tp = netdev_priv(dev);
        u16 rcr = rtase_r16(tp, RTASE_RX_CONFIG_1);
        u8 val;

        rtase_w16(tp, RTASE_RX_CONFIG_1, rcr & ~RTASE_PCIE_RELOAD_EN);
        rtase_w16(tp, RTASE_RX_CONFIG_1, rcr | RTASE_PCIE_RELOAD_EN);

        val = rtase_r8(tp, RTASE_CHIP_CMD);
        rtase_w8(tp, RTASE_CHIP_CMD, val | RTASE_TE | RTASE_RE);

        val = rtase_r8(tp, RTASE_MISC);
        rtase_w8(tp, RTASE_MISC, val & ~RTASE_RX_DV_GATE_EN);
}

static void rtase_enable_hw_interrupt(const struct rtase_private *tp)
{
        const struct rtase_int_vector *ivec = &tp->int_vector[0];
        u32 i;

        rtase_w32(tp, ivec->imr_addr, ivec->imr);

        for (i = 1; i < tp->int_nums; i++) {
                ivec = &tp->int_vector[i];
                rtase_w16(tp, ivec->imr_addr, ivec->imr);
        }
}

static void rtase_hw_start(const struct net_device *dev)
{
        const struct rtase_private *tp = netdev_priv(dev);

        rtase_nic_enable(dev);
        rtase_enable_hw_interrupt(tp);
}

/*  the interrupt handler does RXQ0 and TXQ0, TXQ4~7 interrutp status
 */
static irqreturn_t rtase_interrupt(int irq, void *dev_instance)
{
        const struct rtase_private *tp;
        struct rtase_int_vector *ivec;
        u32 status;

        ivec = dev_instance;
        tp = ivec->tp;
        status = rtase_r32(tp, ivec->isr_addr);

        rtase_w32(tp, ivec->imr_addr, 0x0);
        rtase_w32(tp, ivec->isr_addr, status & ~RTASE_FOVW);

        if (napi_schedule_prep(&ivec->napi))
                __napi_schedule(&ivec->napi);

        return IRQ_HANDLED;
}

/*  the interrupt handler does RXQ1&TXQ1 or RXQ2&TXQ2 or RXQ3&TXQ3 interrupt
 *  status according to interrupt vector
 */
static irqreturn_t rtase_q_interrupt(int irq, void *dev_instance)
{
        const struct rtase_private *tp;
        struct rtase_int_vector *ivec;
        u16 status;

        ivec = dev_instance;
        tp = ivec->tp;
        status = rtase_r16(tp, ivec->isr_addr);

        rtase_w16(tp, ivec->imr_addr, 0x0);
        rtase_w16(tp, ivec->isr_addr, status);

        if (napi_schedule_prep(&ivec->napi))
                __napi_schedule(&ivec->napi);

        return IRQ_HANDLED;
}

static int rtase_poll(struct napi_struct *napi, int budget)
{
        const struct rtase_int_vector *ivec;
        const struct rtase_private *tp;
        struct rtase_ring *ring;
        int total_workdone = 0;

        ivec = container_of(napi, struct rtase_int_vector, napi);
        tp = ivec->tp;

        list_for_each_entry(ring, &ivec->ring_list, ring_entry)
                total_workdone += ring->ring_handler(ring, budget);

        if (total_workdone >= budget)
                return budget;

        if (napi_complete_done(napi, total_workdone)) {
                if (!ivec->index)
                        rtase_w32(tp, ivec->imr_addr, ivec->imr);
                else
                        rtase_w16(tp, ivec->imr_addr, ivec->imr);
        }

        return total_workdone;
}

static int rtase_open(struct net_device *dev)
{
        struct rtase_private *tp = netdev_priv(dev);
        const struct pci_dev *pdev = tp->pdev;
        struct rtase_int_vector *ivec;
        u16 i = 0, j;
        int ret;

        ivec = &tp->int_vector[0];
        tp->rx_buf_sz = RTASE_RX_BUF_SIZE;

        ret = rtase_alloc_desc(tp);
        if (ret)
                return ret;

        ret = rtase_init_ring(dev);
        if (ret)
                goto err_free_all_allocated_mem;

        rtase_hw_config(dev);

        if (tp->sw_flag & RTASE_SWF_MSIX_ENABLED) {
                ret = request_irq(ivec->irq, rtase_interrupt, 0,
                                  dev->name, ivec);
                if (ret)
                        goto err_free_all_allocated_irq;

                /* request other interrupts to handle multiqueue */
                for (i = 1; i < tp->int_nums; i++) {
                        ivec = &tp->int_vector[i];
                        snprintf(ivec->name, sizeof(ivec->name), "%s_int%u",
                                 tp->dev->name, i);
                        ret = request_irq(ivec->irq, rtase_q_interrupt, 0,
                                          ivec->name, ivec);
                        if (ret)
                                goto err_free_all_allocated_irq;
                }
        } else {
                ret = request_irq(pdev->irq, rtase_interrupt, 0, dev->name,
                                  ivec);
                if (ret)
                        goto err_free_all_allocated_mem;
        }

        rtase_hw_start(dev);

        for (i = 0; i < tp->int_nums; i++) {
                ivec = &tp->int_vector[i];
                napi_enable(&ivec->napi);
        }

        netif_carrier_on(dev);
        netif_wake_queue(dev);

        return 0;

err_free_all_allocated_irq:
        for (j = 0; j < i; j++)
                free_irq(tp->int_vector[j].irq, &tp->int_vector[j]);

err_free_all_allocated_mem:
        rtase_free_desc(tp);

        return ret;
}

static void rtase_down(struct net_device *dev)
{
        struct rtase_private *tp = netdev_priv(dev);
        struct rtase_int_vector *ivec;
        struct rtase_ring *ring, *tmp;
        u32 i;

        for (i = 0; i < tp->int_nums; i++) {
                ivec = &tp->int_vector[i];
                napi_disable(&ivec->napi);
                list_for_each_entry_safe(ring, tmp, &ivec->ring_list,
                                         ring_entry) {
                        netif_queue_set_napi(tp->dev, ring->index,
                                             ring->type, NULL);

                        list_del(&ring->ring_entry);
                }
        }

        netif_tx_disable(dev);

        netif_carrier_off(dev);

        rtase_hw_reset(dev);

        rtase_tx_clear(tp);

        rtase_rx_clear(tp);
}

static int rtase_close(struct net_device *dev)
{
        struct rtase_private *tp = netdev_priv(dev);
        const struct pci_dev *pdev = tp->pdev;
        u32 i;

        rtase_down(dev);

        if (tp->sw_flag & RTASE_SWF_MSIX_ENABLED) {
                for (i = 0; i < tp->int_nums; i++)
                        free_irq(tp->int_vector[i].irq, &tp->int_vector[i]);

        } else {
                free_irq(pdev->irq, &tp->int_vector[0]);
        }

        rtase_free_desc(tp);

        return 0;
}

static u32 rtase_tx_vlan_tag(const struct rtase_private *tp,
                             const struct sk_buff *skb)
{
        return (skb_vlan_tag_present(skb)) ?
                (RTASE_TX_VLAN_TAG | swab16(skb_vlan_tag_get(skb))) : 0x00;
}

static u32 rtase_tx_csum(struct sk_buff *skb, const struct net_device *dev)
{
        u32 csum_cmd = 0;
        u8 ip_protocol;

        switch (vlan_get_protocol(skb)) {
        case htons(ETH_P_IP):
                csum_cmd = RTASE_TX_IPCS_C;
                ip_protocol = ip_hdr(skb)->protocol;
                break;

        case htons(ETH_P_IPV6):
                csum_cmd = RTASE_TX_IPV6F_C;
                ip_protocol = ipv6_hdr(skb)->nexthdr;
                break;

        default:
                ip_protocol = IPPROTO_RAW;
                break;
        }

        if (ip_protocol == IPPROTO_TCP)
                csum_cmd |= RTASE_TX_TCPCS_C;
        else if (ip_protocol == IPPROTO_UDP)
                csum_cmd |= RTASE_TX_UDPCS_C;

        csum_cmd |= u32_encode_bits(skb_transport_offset(skb),
                                    RTASE_TCPHO_MASK);

        return csum_cmd;
}

static int rtase_xmit_frags(struct rtase_ring *ring, struct sk_buff *skb,
                            u32 opts1, u32 opts2)
{
        const struct skb_shared_info *info = skb_shinfo(skb);
        const struct rtase_private *tp = ring->ivec->tp;
        const u8 nr_frags = info->nr_frags;
        struct rtase_tx_desc *txd = NULL;
        u32 cur_frag, entry;

        entry = ring->cur_idx;
        for (cur_frag = 0; cur_frag < nr_frags; cur_frag++) {
                const skb_frag_t *frag = &info->frags[cur_frag];
                dma_addr_t mapping;
                u32 status, len;
                void *addr;

                entry = (entry + 1) % RTASE_NUM_DESC;

                txd = ring->desc + sizeof(struct rtase_tx_desc) * entry;
                len = skb_frag_size(frag);
                addr = skb_frag_address(frag);
                mapping = dma_map_single(&tp->pdev->dev, addr, len,
                                         DMA_TO_DEVICE);

                if (unlikely(dma_mapping_error(&tp->pdev->dev, mapping))) {
                        if (unlikely(net_ratelimit()))
                                netdev_err(tp->dev,
                                           "Failed to map TX fragments DMA!\n");

                        goto err_out;
                }

                if (((entry + 1) % RTASE_NUM_DESC) == 0)
                        status = (opts1 | len | RTASE_RING_END);
                else
                        status = opts1 | len;

                if (cur_frag == (nr_frags - 1)) {
                        ring->skbuff[entry] = skb;
                        status |= RTASE_TX_LAST_FRAG;
                }

                ring->mis.len[entry] = len;
                txd->addr = cpu_to_le64(mapping);
                txd->opts2 = cpu_to_le32(opts2);

                /* make sure the operating fields have been updated */
                dma_wmb();
                txd->opts1 = cpu_to_le32(status);
        }

        return cur_frag;

err_out:
        rtase_tx_clear_range(ring, ring->cur_idx + 1, cur_frag);
        return -EIO;
}

static netdev_tx_t rtase_start_xmit(struct sk_buff *skb,
                                    struct net_device *dev)
{
        struct skb_shared_info *shinfo = skb_shinfo(skb);
        struct rtase_private *tp = netdev_priv(dev);
        u32 q_idx, entry, len, opts1, opts2;
        struct netdev_queue *tx_queue;
        bool stop_queue, door_bell;
        u32 mss = shinfo->gso_size;
        struct rtase_tx_desc *txd;
        struct rtase_ring *ring;
        dma_addr_t mapping;
        int frags;

        /* multiqueues */
        q_idx = skb_get_queue_mapping(skb);
        ring = &tp->tx_ring[q_idx];
        tx_queue = netdev_get_tx_queue(dev, q_idx);

        if (unlikely(!rtase_tx_avail(ring))) {
                if (net_ratelimit())
                        netdev_err(dev,
                                   "BUG! Tx Ring full when queue awake!\n");

                netif_stop_queue(dev);
                return NETDEV_TX_BUSY;
        }

        entry = ring->cur_idx % RTASE_NUM_DESC;
        txd = ring->desc + sizeof(struct rtase_tx_desc) * entry;

        opts1 = RTASE_DESC_OWN;
        opts2 = rtase_tx_vlan_tag(tp, skb);

        /* tcp segmentation offload (or tcp large send) */
        if (mss) {
                if (shinfo->gso_type & SKB_GSO_TCPV4) {
                        opts1 |= RTASE_GIANT_SEND_V4;
                } else if (shinfo->gso_type & SKB_GSO_TCPV6) {
                        if (skb_cow_head(skb, 0))
                                goto err_dma_0;

                        tcp_v6_gso_csum_prep(skb);
                        opts1 |= RTASE_GIANT_SEND_V6;
                } else {
                        WARN_ON_ONCE(1);
                }

                opts1 |= u32_encode_bits(skb_transport_offset(skb),
                                         RTASE_TCPHO_MASK);
                opts2 |= u32_encode_bits(mss, RTASE_MSS_MASK);
        } else if (skb->ip_summed == CHECKSUM_PARTIAL) {
                opts2 |= rtase_tx_csum(skb, dev);
        }

        frags = rtase_xmit_frags(ring, skb, opts1, opts2);
        if (unlikely(frags < 0))
                goto err_dma_0;

        if (frags) {
                len = skb_headlen(skb);
                opts1 |= RTASE_TX_FIRST_FRAG;
        } else {
                len = skb->len;
                ring->skbuff[entry] = skb;
                opts1 |= RTASE_TX_FIRST_FRAG | RTASE_TX_LAST_FRAG;
        }

        if (((entry + 1) % RTASE_NUM_DESC) == 0)
                opts1 |= (len | RTASE_RING_END);
        else
                opts1 |= len;

        mapping = dma_map_single(&tp->pdev->dev, skb->data, len,
                                 DMA_TO_DEVICE);

        if (unlikely(dma_mapping_error(&tp->pdev->dev, mapping))) {
                if (unlikely(net_ratelimit()))
                        netdev_err(dev, "Failed to map TX DMA!\n");

                goto err_dma_1;
        }

        ring->mis.len[entry] = len;
        txd->addr = cpu_to_le64(mapping);
        txd->opts2 = cpu_to_le32(opts2);
        txd->opts1 = cpu_to_le32(opts1 & ~RTASE_DESC_OWN);

        /* make sure the operating fields have been updated */
        dma_wmb();

        door_bell = __netdev_tx_sent_queue(tx_queue, skb->len,
                                           netdev_xmit_more());

        txd->opts1 = cpu_to_le32(opts1);

        skb_tx_timestamp(skb);

        /* tx needs to see descriptor changes before updated cur_idx */
        smp_wmb();

        WRITE_ONCE(ring->cur_idx, ring->cur_idx + frags + 1);

        stop_queue = !netif_subqueue_maybe_stop(dev, ring->index,
                                                rtase_tx_avail(ring),
                                                RTASE_TX_STOP_THRS,
                                                RTASE_TX_START_THRS);

        if (door_bell || stop_queue)
                rtase_w8(tp, RTASE_TPPOLL, BIT(ring->index));

        return NETDEV_TX_OK;

err_dma_1:
        ring->skbuff[entry] = NULL;
        rtase_tx_clear_range(ring, ring->cur_idx + 1, frags);

err_dma_0:
        tp->stats.tx_dropped++;
        dev_kfree_skb_any(skb);
        return NETDEV_TX_OK;
}

static void rtase_set_rx_mode(struct net_device *dev)
{
        rtase_hw_set_rx_packet_filter(dev);
}

static void rtase_enable_eem_write(const struct rtase_private *tp)
{
        u8 val;

        val = rtase_r8(tp, RTASE_EEM);
        rtase_w8(tp, RTASE_EEM, val | RTASE_EEM_UNLOCK);
}

static void rtase_disable_eem_write(const struct rtase_private *tp)
{
        u8 val;

        val = rtase_r8(tp, RTASE_EEM);
        rtase_w8(tp, RTASE_EEM, val & ~RTASE_EEM_UNLOCK);
}

static void rtase_rar_set(const struct rtase_private *tp, const u8 *addr)
{
        u32 rar_low, rar_high;

        rar_low = (u32)addr[0] | ((u32)addr[1] << 8) |
                  ((u32)addr[2] << 16) | ((u32)addr[3] << 24);

        rar_high = (u32)addr[4] | ((u32)addr[5] << 8);

        rtase_enable_eem_write(tp);
        rtase_w32(tp, RTASE_MAC0, rar_low);
        rtase_w32(tp, RTASE_MAC4, rar_high);
        rtase_disable_eem_write(tp);
        rtase_w16(tp, RTASE_LBK_CTRL, RTASE_LBK_ATLD | RTASE_LBK_CLR);
}

static int rtase_set_mac_address(struct net_device *dev, void *p)
{
        struct rtase_private *tp = netdev_priv(dev);
        int ret;

        ret = eth_mac_addr(dev, p);
        if (ret)
                return ret;

        rtase_rar_set(tp, dev->dev_addr);

        return 0;
}

static int rtase_change_mtu(struct net_device *dev, int new_mtu)
{
        dev->mtu = new_mtu;

        netdev_update_features(dev);

        return 0;
}

static void rtase_wait_for_quiescence(const struct net_device *dev)
{
        struct rtase_private *tp = netdev_priv(dev);
        struct rtase_int_vector *ivec;
        u32 i;

        for (i = 0; i < tp->int_nums; i++) {
                ivec = &tp->int_vector[i];
                synchronize_irq(ivec->irq);
                /* wait for any pending NAPI task to complete */
                napi_disable(&ivec->napi);
        }

        rtase_irq_dis_and_clear(tp);

        for (i = 0; i < tp->int_nums; i++) {
                ivec = &tp->int_vector[i];
                napi_enable(&ivec->napi);
        }
}

static void rtase_sw_reset(struct net_device *dev)
{
        struct rtase_private *tp = netdev_priv(dev);
        struct rtase_ring *ring, *tmp;
        struct rtase_int_vector *ivec;
        int ret;
        u32 i;

        netif_stop_queue(dev);
        netif_carrier_off(dev);
        rtase_hw_reset(dev);

        /* let's wait a bit while any (async) irq lands on */
        rtase_wait_for_quiescence(dev);
        rtase_tx_clear(tp);
        rtase_rx_clear(tp);

        for (i = 0; i < tp->int_nums; i++) {
                ivec = &tp->int_vector[i];
                list_for_each_entry_safe(ring, tmp, &ivec->ring_list,
                                         ring_entry) {
                        netif_queue_set_napi(tp->dev, ring->index,
                                             ring->type, NULL);

                        list_del(&ring->ring_entry);
                }
        }

        ret = rtase_init_ring(dev);
        if (ret) {
                netdev_err(dev, "unable to init ring\n");
                rtase_free_desc(tp);
                return;
        }

        rtase_hw_config(dev);
        /* always link, so start to transmit & receive */
        rtase_hw_start(dev);

        netif_carrier_on(dev);
        netif_wake_queue(dev);
}

static void rtase_dump_tally_counter(const struct rtase_private *tp)
{
        dma_addr_t paddr = tp->tally_paddr;
        u32 cmd = lower_32_bits(paddr);
        u32 val;
        int err;

        rtase_w32(tp, RTASE_DTCCR4, upper_32_bits(paddr));
        rtase_w32(tp, RTASE_DTCCR0, cmd);
        rtase_w32(tp, RTASE_DTCCR0, cmd | RTASE_COUNTER_DUMP);

        err = read_poll_timeout(rtase_r32, val, !(val & RTASE_COUNTER_DUMP),
                                10, 250, false, tp, RTASE_DTCCR0);

        if (err == -ETIMEDOUT)
                netdev_err(tp->dev, "error occurred in dump tally counter\n");
}

static void rtase_dump_state(const struct net_device *dev)
{
        const struct rtase_private *tp = netdev_priv(dev);
        int max_reg_size = RTASE_PCI_REGS_SIZE;
        const struct rtase_counters *counters;
        const struct rtase_ring *ring;
        u32 dword_rd;
        int n = 0;

        ring = &tp->tx_ring[0];
        netdev_err(dev, "Tx descriptor info:\n");
        netdev_err(dev, "Tx curIdx = 0x%x\n", ring->cur_idx);
        netdev_err(dev, "Tx dirtyIdx = 0x%x\n", ring->dirty_idx);
        netdev_err(dev, "Tx phyAddr = %pad\n", &ring->phy_addr);

        ring = &tp->rx_ring[0];
        netdev_err(dev, "Rx descriptor info:\n");
        netdev_err(dev, "Rx curIdx = 0x%x\n", ring->cur_idx);
        netdev_err(dev, "Rx dirtyIdx = 0x%x\n", ring->dirty_idx);
        netdev_err(dev, "Rx phyAddr = %pad\n", &ring->phy_addr);

        netdev_err(dev, "Device Registers:\n");
        netdev_err(dev, "Chip Command = 0x%02x\n",
                   rtase_r8(tp, RTASE_CHIP_CMD));
        netdev_err(dev, "IMR = %08x\n", rtase_r32(tp, RTASE_IMR0));
        netdev_err(dev, "ISR = %08x\n", rtase_r32(tp, RTASE_ISR0));
        netdev_err(dev, "Boot Ctrl Reg(0xE004) = %04x\n",
                   rtase_r16(tp, RTASE_BOOT_CTL));
        netdev_err(dev, "EPHY ISR(0xE014) = %04x\n",
                   rtase_r16(tp, RTASE_EPHY_ISR));
        netdev_err(dev, "EPHY IMR(0xE016) = %04x\n",
                   rtase_r16(tp, RTASE_EPHY_IMR));
        netdev_err(dev, "CLKSW SET REG(0xE018) = %04x\n",
                   rtase_r16(tp, RTASE_CLKSW_SET));

        netdev_err(dev, "Dump PCI Registers:\n");

        while (n < max_reg_size) {
                if ((n % RTASE_DWORD_MOD) == 0)
                        netdev_err(tp->dev, "0x%03x:\n", n);

                pci_read_config_dword(tp->pdev, n, &dword_rd);
                netdev_err(tp->dev, "%08x\n", dword_rd);
                n += 4;
        }

        netdev_err(dev, "Dump tally counter:\n");
        counters = tp->tally_vaddr;
        rtase_dump_tally_counter(tp);

        netdev_err(dev, "tx_packets %lld\n",
                   le64_to_cpu(counters->tx_packets));
        netdev_err(dev, "rx_packets %lld\n",
                   le64_to_cpu(counters->rx_packets));
        netdev_err(dev, "tx_errors %lld\n",
                   le64_to_cpu(counters->tx_errors));
        netdev_err(dev, "rx_errors %d\n",
                   le32_to_cpu(counters->rx_errors));
        netdev_err(dev, "rx_missed %d\n",
                   le16_to_cpu(counters->rx_missed));
        netdev_err(dev, "align_errors %d\n",
                   le16_to_cpu(counters->align_errors));
        netdev_err(dev, "tx_one_collision %d\n",
                   le32_to_cpu(counters->tx_one_collision));
        netdev_err(dev, "tx_multi_collision %d\n",
                   le32_to_cpu(counters->tx_multi_collision));
        netdev_err(dev, "rx_unicast %lld\n",
                   le64_to_cpu(counters->rx_unicast));
        netdev_err(dev, "rx_broadcast %lld\n",
                   le64_to_cpu(counters->rx_broadcast));
        netdev_err(dev, "rx_multicast %d\n",
                   le32_to_cpu(counters->rx_multicast));
        netdev_err(dev, "tx_aborted %d\n",
                   le16_to_cpu(counters->tx_aborted));
        netdev_err(dev, "tx_underrun %d\n",
                   le16_to_cpu(counters->tx_underrun));
}

static void rtase_tx_timeout(struct net_device *dev, unsigned int txqueue)
{
        rtase_dump_state(dev);
        rtase_sw_reset(dev);
}

static void rtase_get_stats64(struct net_device *dev,
                              struct rtnl_link_stats64 *stats)
{
        const struct rtase_private *tp = netdev_priv(dev);
        const struct rtase_counters *counters;

        counters = tp->tally_vaddr;

        dev_fetch_sw_netstats(stats, dev->tstats);

        /* fetch additional counter values missing in stats collected by driver
         * from tally counter
         */
        rtase_dump_tally_counter(tp);
        stats->rx_errors = tp->stats.rx_errors;
        stats->tx_errors = le64_to_cpu(counters->tx_errors);
        stats->rx_dropped = tp->stats.rx_dropped;
        stats->tx_dropped = tp->stats.tx_dropped;
        stats->multicast = tp->stats.multicast;
        stats->rx_length_errors = tp->stats.rx_length_errors;
}

static void rtase_set_hw_cbs(const struct rtase_private *tp, u32 queue)
{
        u32 idle = tp->tx_qos[queue].idleslope * RTASE_1T_CLOCK;
        u32 val, i;

        val = u32_encode_bits(idle / RTASE_1T_POWER, RTASE_IDLESLOPE_INT_MASK);
        idle %= RTASE_1T_POWER;

        for (i = 1; i <= RTASE_IDLESLOPE_INT_SHIFT; i++) {
                idle *= 2;
                if ((idle / RTASE_1T_POWER) == 1)
                        val |= BIT(RTASE_IDLESLOPE_INT_SHIFT - i);

                idle %= RTASE_1T_POWER;
        }

        rtase_w32(tp, RTASE_TXQCRDT_0 + queue * 4, val);
}

static int rtase_setup_tc_cbs(struct rtase_private *tp,
                              const struct tc_cbs_qopt_offload *qopt)
{
        int queue = qopt->queue;

        if (queue < 0 || queue >= tp->func_tx_queue_num)
                return -EINVAL;

        if (!qopt->enable) {
                tp->tx_qos[queue].hicredit = 0;
                tp->tx_qos[queue].locredit = 0;
                tp->tx_qos[queue].idleslope = 0;
                tp->tx_qos[queue].sendslope = 0;

                rtase_w32(tp, RTASE_TXQCRDT_0 + queue * 4, 0);
        } else {
                tp->tx_qos[queue].hicredit = qopt->hicredit;
                tp->tx_qos[queue].locredit = qopt->locredit;
                tp->tx_qos[queue].idleslope = qopt->idleslope;
                tp->tx_qos[queue].sendslope = qopt->sendslope;

                rtase_set_hw_cbs(tp, queue);
        }

        return 0;
}

static int rtase_setup_tc(struct net_device *dev, enum tc_setup_type type,
                          void *type_data)
{
        struct rtase_private *tp = netdev_priv(dev);

        switch (type) {
        case TC_SETUP_QDISC_CBS:
                return rtase_setup_tc_cbs(tp, type_data);
        default:
                return -EOPNOTSUPP;
        }
}

static netdev_features_t rtase_fix_features(struct net_device *dev,
                                            netdev_features_t features)
{
        netdev_features_t features_fix = features;

        /* not support TSO for jumbo frames */
        if (dev->mtu > ETH_DATA_LEN)
                features_fix &= ~NETIF_F_ALL_TSO;

        return features_fix;
}

static int rtase_set_features(struct net_device *dev,
                              netdev_features_t features)
{
        netdev_features_t features_set = features;

        features_set &= NETIF_F_RXALL | NETIF_F_RXCSUM |
                        NETIF_F_HW_VLAN_CTAG_RX;

        if (features_set ^ dev->features)
                rtase_hw_set_features(dev, features_set);

        return 0;
}

static const struct net_device_ops rtase_netdev_ops = {
        .ndo_open = rtase_open,
        .ndo_stop = rtase_close,
        .ndo_start_xmit = rtase_start_xmit,
        .ndo_set_rx_mode = rtase_set_rx_mode,
        .ndo_set_mac_address = rtase_set_mac_address,
        .ndo_change_mtu = rtase_change_mtu,
        .ndo_tx_timeout = rtase_tx_timeout,
        .ndo_get_stats64 = rtase_get_stats64,
        .ndo_setup_tc = rtase_setup_tc,
        .ndo_fix_features = rtase_fix_features,
        .ndo_set_features = rtase_set_features,
};

static void rtase_get_mac_address(struct net_device *dev)
{
        struct rtase_private *tp = netdev_priv(dev);
        u8 mac_addr[ETH_ALEN] __aligned(2) = {};
        u32 i;

        for (i = 0; i < ETH_ALEN; i++)
                mac_addr[i] = rtase_r8(tp, RTASE_MAC0 + i);

        if (!is_valid_ether_addr(mac_addr)) {
                eth_hw_addr_random(dev);
                netdev_warn(dev, "Random ether addr %pM\n", dev->dev_addr);
        } else {
                eth_hw_addr_set(dev, mac_addr);
                ether_addr_copy(dev->perm_addr, dev->dev_addr);
        }

        rtase_rar_set(tp, dev->dev_addr);
}

static int rtase_get_settings(struct net_device *dev,
                              struct ethtool_link_ksettings *cmd)
{
        u32 supported = SUPPORTED_MII | SUPPORTED_Pause | SUPPORTED_Asym_Pause;
        const struct rtase_private *tp = netdev_priv(dev);

        ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.supported,
                                                supported);

        switch (tp->hw_ver) {
        case RTASE_HW_VER_906X_7XA:
        case RTASE_HW_VER_906X_7XC:
                cmd->base.speed = SPEED_5000;
                break;
        case RTASE_HW_VER_907XD_V1:
        case RTASE_HW_VER_907XD_VA:
                cmd->base.speed = SPEED_10000;
                break;
        }

        cmd->base.duplex = DUPLEX_FULL;
        cmd->base.port = PORT_MII;
        cmd->base.autoneg = AUTONEG_DISABLE;

        return 0;
}

static void rtase_get_pauseparam(struct net_device *dev,
                                 struct ethtool_pauseparam *pause)
{
        const struct rtase_private *tp = netdev_priv(dev);
        u16 value = rtase_r16(tp, RTASE_CPLUS_CMD);

        pause->autoneg = AUTONEG_DISABLE;
        pause->tx_pause = !!(value & RTASE_FORCE_TXFLOW_EN);
        pause->rx_pause = !!(value & RTASE_FORCE_RXFLOW_EN);
}

static int rtase_set_pauseparam(struct net_device *dev,
                                struct ethtool_pauseparam *pause)
{
        const struct rtase_private *tp = netdev_priv(dev);
        u16 value = rtase_r16(tp, RTASE_CPLUS_CMD);

        if (pause->autoneg)
                return -EOPNOTSUPP;

        value &= ~(RTASE_FORCE_TXFLOW_EN | RTASE_FORCE_RXFLOW_EN);

        if (pause->tx_pause)
                value |= RTASE_FORCE_TXFLOW_EN;

        if (pause->rx_pause)
                value |= RTASE_FORCE_RXFLOW_EN;

        rtase_w16(tp, RTASE_CPLUS_CMD, value);
        return 0;
}

static void rtase_get_eth_mac_stats(struct net_device *dev,
                                    struct ethtool_eth_mac_stats *stats)
{
        struct rtase_private *tp = netdev_priv(dev);
        const struct rtase_counters *counters;

        counters = tp->tally_vaddr;

        rtase_dump_tally_counter(tp);

        stats->FramesTransmittedOK = le64_to_cpu(counters->tx_packets);
        stats->FramesReceivedOK = le64_to_cpu(counters->rx_packets);
        stats->FramesLostDueToIntMACXmitError =
                le64_to_cpu(counters->tx_errors);
        stats->BroadcastFramesReceivedOK = le64_to_cpu(counters->rx_broadcast);
}

static const struct ethtool_ops rtase_ethtool_ops = {
        .get_link = ethtool_op_get_link,
        .get_link_ksettings = rtase_get_settings,
        .get_pauseparam = rtase_get_pauseparam,
        .set_pauseparam = rtase_set_pauseparam,
        .get_eth_mac_stats = rtase_get_eth_mac_stats,
        .get_ts_info = ethtool_op_get_ts_info,
};

static void rtase_init_netdev_ops(struct net_device *dev)
{
        dev->netdev_ops = &rtase_netdev_ops;
        dev->ethtool_ops = &rtase_ethtool_ops;
}

static void rtase_init_napi(struct rtase_private *tp)
{
        u16 i;

        for (i = 0; i < tp->int_nums; i++) {
                netif_napi_add_config(tp->dev, &tp->int_vector[i].napi,
                                      tp->int_vector[i].poll, i);
                netif_napi_set_irq(&tp->int_vector[i].napi,
                                   tp->int_vector[i].irq);
        }
}

static void rtase_reset_interrupt(struct pci_dev *pdev,
                                  const struct rtase_private *tp)
{
        if (tp->sw_flag & RTASE_SWF_MSIX_ENABLED)
                pci_disable_msix(pdev);
        else
                pci_disable_msi(pdev);
}

static int rtase_alloc_msix(struct pci_dev *pdev, struct rtase_private *tp)
{
        int ret, irq;
        u16 i;

        memset(tp->msix_entry, 0x0, RTASE_NUM_MSIX *
               sizeof(struct msix_entry));

        for (i = 0; i < RTASE_NUM_MSIX; i++)
                tp->msix_entry[i].entry = i;

        ret = pci_enable_msix_exact(pdev, tp->msix_entry, tp->int_nums);

        if (ret)
                return ret;

        for (i = 0; i < tp->int_nums; i++) {
                irq = pci_irq_vector(pdev, i);
                if (irq < 0) {
                        pci_disable_msix(pdev);
                        return irq;
                }

                tp->int_vector[i].irq = irq;
        }

        return 0;
}

static int rtase_alloc_interrupt(struct pci_dev *pdev,
                                 struct rtase_private *tp)
{
        int ret;

        ret = rtase_alloc_msix(pdev, tp);
        if (ret) {
                ret = pci_enable_msi(pdev);
                if (ret) {
                        dev_err(&pdev->dev,
                                "unable to alloc interrupt.(MSI)\n");
                        return ret;
                }

                tp->sw_flag |= RTASE_SWF_MSI_ENABLED;
        } else {
                tp->sw_flag |= RTASE_SWF_MSIX_ENABLED;
        }

        return 0;
}

static void rtase_init_hardware(const struct rtase_private *tp)
{
        u16 i;

        for (i = 0; i < RTASE_VLAN_FILTER_ENTRY_NUM; i++)
                rtase_w32(tp, RTASE_VLAN_ENTRY_0 + i * 4, 0);
}

static void rtase_init_int_vector(struct rtase_private *tp)
{
        u16 i;

        /* interrupt vector 0 */
        tp->int_vector[0].tp = tp;
        tp->int_vector[0].index = 0;
        tp->int_vector[0].imr_addr = RTASE_IMR0;
        tp->int_vector[0].isr_addr = RTASE_ISR0;
        tp->int_vector[0].imr = RTASE_ROK | RTASE_RDU | RTASE_TOK |
                                RTASE_TOK4 | RTASE_TOK5 | RTASE_TOK6 |
                                RTASE_TOK7;
        tp->int_vector[0].poll = rtase_poll;

        memset(tp->int_vector[0].name, 0x0, sizeof(tp->int_vector[0].name));
        INIT_LIST_HEAD(&tp->int_vector[0].ring_list);

        /* interrupt vector 1 ~ 3 */
        for (i = 1; i < tp->int_nums; i++) {
                tp->int_vector[i].tp = tp;
                tp->int_vector[i].index = i;
                tp->int_vector[i].imr_addr = RTASE_IMR1 + (i - 1) * 4;
                tp->int_vector[i].isr_addr = RTASE_ISR1 + (i - 1) * 4;
                tp->int_vector[i].imr = RTASE_Q_ROK | RTASE_Q_RDU |
                                        RTASE_Q_TOK;
                tp->int_vector[i].poll = rtase_poll;

                memset(tp->int_vector[i].name, 0x0,
                       sizeof(tp->int_vector[0].name));
                INIT_LIST_HEAD(&tp->int_vector[i].ring_list);
        }
}

static u16 rtase_calc_time_mitigation(u32 time_us)
{
        u8 msb, time_count, time_unit;
        u16 int_miti;

        time_us = min(time_us, RTASE_MITI_MAX_TIME);

        if (time_us > RTASE_MITI_TIME_COUNT_MASK) {
                msb = fls(time_us);
                time_unit = msb - RTASE_MITI_COUNT_BIT_NUM;
                time_count = time_us >> (msb - RTASE_MITI_COUNT_BIT_NUM);
        } else {
                time_unit = 0;
                time_count = time_us;
        }

        int_miti = u16_encode_bits(time_count, RTASE_MITI_TIME_COUNT_MASK) |
                   u16_encode_bits(time_unit, RTASE_MITI_TIME_UNIT_MASK);

        return int_miti;
}

static u16 rtase_calc_packet_num_mitigation(u16 pkt_num)
{
        u8 msb, pkt_num_count, pkt_num_unit;
        u16 int_miti;

        pkt_num = min(pkt_num, RTASE_MITI_MAX_PKT_NUM);

        if (pkt_num > 60) {
                pkt_num_unit = RTASE_MITI_MAX_PKT_NUM_IDX;
                pkt_num_count = pkt_num / RTASE_MITI_MAX_PKT_NUM_UNIT;
        } else {
                msb = fls(pkt_num);
                if (msb >= RTASE_MITI_COUNT_BIT_NUM) {
                        pkt_num_unit = msb - RTASE_MITI_COUNT_BIT_NUM;
                        pkt_num_count = pkt_num >> (msb -
                                                    RTASE_MITI_COUNT_BIT_NUM);
                } else {
                        pkt_num_unit = 0;
                        pkt_num_count = pkt_num;
                }
        }

        int_miti = u16_encode_bits(pkt_num_count,
                                   RTASE_MITI_PKT_NUM_COUNT_MASK) |
                   u16_encode_bits(pkt_num_unit,
                                   RTASE_MITI_PKT_NUM_UNIT_MASK);

        return int_miti;
}

static void rtase_init_software_variable(struct pci_dev *pdev,
                                         struct rtase_private *tp)
{
        u16 int_miti;

        tp->tx_queue_ctrl = RTASE_TXQ_CTRL;
        tp->func_tx_queue_num = RTASE_FUNC_TXQ_NUM;
        tp->func_rx_queue_num = RTASE_FUNC_RXQ_NUM;
        tp->int_nums = RTASE_INTERRUPT_NUM;

        int_miti = rtase_calc_time_mitigation(RTASE_MITI_DEFAULT_TIME) |
                   rtase_calc_packet_num_mitigation(RTASE_MITI_DEFAULT_PKT_NUM);
        tp->tx_int_mit = int_miti;
        tp->rx_int_mit = int_miti;

        tp->sw_flag = 0;

        rtase_init_int_vector(tp);

        /* MTU range: 60 - hw-specific max */
        tp->dev->min_mtu = ETH_ZLEN;
        tp->dev->max_mtu = RTASE_MAX_JUMBO_SIZE;
}

static int rtase_check_mac_version_valid(struct rtase_private *tp)
{
        int ret = -ENODEV;

        tp->hw_ver = rtase_r32(tp, RTASE_TX_CONFIG_0) & RTASE_HW_VER_MASK;

        switch (tp->hw_ver) {
        case RTASE_HW_VER_906X_7XA:
        case RTASE_HW_VER_906X_7XC:
        case RTASE_HW_VER_907XD_V1:
        case RTASE_HW_VER_907XD_VA:
                ret = 0;
                break;
        }

        return ret;
}

static int rtase_init_board(struct pci_dev *pdev, struct net_device **dev_out,
                            void __iomem **ioaddr_out)
{
        struct net_device *dev;
        void __iomem *ioaddr;
        int ret = -ENOMEM;

        /* dev zeroed in alloc_etherdev */
        dev = alloc_etherdev_mq(sizeof(struct rtase_private),
                                RTASE_FUNC_TXQ_NUM);
        if (!dev)
                goto err_out;

        SET_NETDEV_DEV(dev, &pdev->dev);

        ret = pci_enable_device(pdev);
        if (ret)
                goto err_out_free_dev;

        /* make sure PCI base addr 1 is MMIO */
        if (!(pci_resource_flags(pdev, 2) & IORESOURCE_MEM)) {
                ret = -ENODEV;
                goto err_out_disable;
        }

        /* check for weird/broken PCI region reporting */
        if (pci_resource_len(pdev, 2) < RTASE_REGS_SIZE) {
                ret = -ENODEV;
                goto err_out_disable;
        }

        ret = pci_request_regions(pdev, KBUILD_MODNAME);
        if (ret)
                goto err_out_disable;

        ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
        if (ret) {
                dev_err(&pdev->dev, "no usable dma addressing method\n");
                goto err_out_free_res;
        }

        pci_set_master(pdev);

        /* ioremap MMIO region */
        ioaddr = ioremap(pci_resource_start(pdev, 2),
                         pci_resource_len(pdev, 2));
        if (!ioaddr) {
                ret = -EIO;
                goto err_out_free_res;
        }

        *ioaddr_out = ioaddr;
        *dev_out = dev;

        return ret;

err_out_free_res:
        pci_release_regions(pdev);

err_out_disable:
        pci_disable_device(pdev);

err_out_free_dev:
        free_netdev(dev);

err_out:
        *ioaddr_out = NULL;
        *dev_out = NULL;

        return ret;
}

static void rtase_release_board(struct pci_dev *pdev, struct net_device *dev,
                                void __iomem *ioaddr)
{
        const struct rtase_private *tp = netdev_priv(dev);

        rtase_rar_set(tp, tp->dev->perm_addr);
        iounmap(ioaddr);

        if (tp->sw_flag & RTASE_SWF_MSIX_ENABLED)
                pci_disable_msix(pdev);
        else
                pci_disable_msi(pdev);

        pci_release_regions(pdev);
        pci_disable_device(pdev);
        free_netdev(dev);
}

static int rtase_init_one(struct pci_dev *pdev,
                          const struct pci_device_id *ent)
{
        struct net_device *dev = NULL;
        struct rtase_int_vector *ivec;
        void __iomem *ioaddr = NULL;
        struct rtase_private *tp;
        int ret, i;

        if (!pdev->is_physfn && pdev->is_virtfn) {
                dev_err(&pdev->dev,
                        "This module does not support a virtual function.");
                return -EINVAL;
        }

        dev_dbg(&pdev->dev, "Automotive Switch Ethernet driver loaded\n");

        ret = rtase_init_board(pdev, &dev, &ioaddr);
        if (ret)
                return ret;

        tp = netdev_priv(dev);
        tp->mmio_addr = ioaddr;
        tp->dev = dev;
        tp->pdev = pdev;

        /* identify chip attached to board */
        ret = rtase_check_mac_version_valid(tp);
        if (ret) {
                dev_err(&pdev->dev,
                        "unknown chip version: 0x%08x, contact rtase maintainers (see MAINTAINERS file)\n",
                        tp->hw_ver);
                goto err_out_release_board;
        }

        rtase_init_software_variable(pdev, tp);
        rtase_init_hardware(tp);

        ret = rtase_alloc_interrupt(pdev, tp);
        if (ret) {
                dev_err(&pdev->dev, "unable to alloc MSIX/MSI\n");
                goto err_out_del_napi;
        }

        rtase_init_napi(tp);

        rtase_init_netdev_ops(dev);

        dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;

        dev->features |= NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX |
                         NETIF_F_IP_CSUM | NETIF_F_HIGHDMA |
                         NETIF_F_RXCSUM | NETIF_F_SG |
                         NETIF_F_TSO | NETIF_F_IPV6_CSUM |
                         NETIF_F_TSO6;

        dev->hw_features = NETIF_F_SG | NETIF_F_IP_CSUM |
                           NETIF_F_TSO | NETIF_F_RXCSUM |
                           NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX |
                           NETIF_F_RXALL | NETIF_F_RXFCS |
                           NETIF_F_IPV6_CSUM | NETIF_F_TSO6;

        dev->vlan_features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_TSO |
                             NETIF_F_HIGHDMA;
        dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
        netif_set_tso_max_size(dev, RTASE_LSO_64K);
        netif_set_tso_max_segs(dev, RTASE_NIC_MAX_PHYS_BUF_COUNT_LSO2);

        rtase_get_mac_address(dev);

        tp->tally_vaddr = dma_alloc_coherent(&pdev->dev,
                                             sizeof(*tp->tally_vaddr),
                                             &tp->tally_paddr,
                                             GFP_KERNEL);
        if (!tp->tally_vaddr) {
                ret = -ENOMEM;
                goto err_out_free_dma;
        }

        rtase_tally_counter_clear(tp);

        pci_set_drvdata(pdev, dev);

        netif_carrier_off(dev);

        ret = register_netdev(dev);
        if (ret)
                goto err_out_free_dma;

        netdev_dbg(dev, "%pM, IRQ %d\n", dev->dev_addr, dev->irq);

        return 0;

err_out_free_dma:
        if (tp->tally_vaddr) {
                dma_free_coherent(&pdev->dev,
                                  sizeof(*tp->tally_vaddr),
                                  tp->tally_vaddr,
                                  tp->tally_paddr);

                tp->tally_vaddr = NULL;
        }

err_out_del_napi:
        for (i = 0; i < tp->int_nums; i++) {
                ivec = &tp->int_vector[i];
                netif_napi_del(&ivec->napi);
        }

err_out_release_board:
        rtase_release_board(pdev, dev, ioaddr);

        return ret;
}

static void rtase_remove_one(struct pci_dev *pdev)
{
        struct net_device *dev = pci_get_drvdata(pdev);
        struct rtase_private *tp = netdev_priv(dev);
        struct rtase_int_vector *ivec;
        u32 i;

        unregister_netdev(dev);

        for (i = 0; i < tp->int_nums; i++) {
                ivec = &tp->int_vector[i];
                netif_napi_del(&ivec->napi);
        }

        rtase_reset_interrupt(pdev, tp);
        if (tp->tally_vaddr) {
                dma_free_coherent(&pdev->dev,
                                  sizeof(*tp->tally_vaddr),
                                  tp->tally_vaddr,
                                  tp->tally_paddr);
                tp->tally_vaddr = NULL;
        }

        rtase_release_board(pdev, dev, tp->mmio_addr);
        pci_set_drvdata(pdev, NULL);
}

static void rtase_shutdown(struct pci_dev *pdev)
{
        struct net_device *dev = pci_get_drvdata(pdev);
        const struct rtase_private *tp;

        tp = netdev_priv(dev);

        if (netif_running(dev))
                rtase_close(dev);

        rtase_reset_interrupt(pdev, tp);
}

static int rtase_suspend(struct device *device)
{
        struct net_device *dev = dev_get_drvdata(device);

        if (netif_running(dev)) {
                netif_device_detach(dev);
                rtase_hw_reset(dev);
        }

        return 0;
}

static int rtase_resume(struct device *device)
{
        struct net_device *dev = dev_get_drvdata(device);
        struct rtase_private *tp = netdev_priv(dev);
        int ret;

        /* restore last modified mac address */
        rtase_rar_set(tp, dev->dev_addr);

        if (!netif_running(dev))
                goto out;

        rtase_wait_for_quiescence(dev);

        rtase_tx_clear(tp);
        rtase_rx_clear(tp);

        ret = rtase_init_ring(dev);
        if (ret) {
                netdev_err(dev, "unable to init ring\n");
                rtase_free_desc(tp);
                return -ENOMEM;
        }

        rtase_hw_config(dev);
        /* always link, so start to transmit & receive */
        rtase_hw_start(dev);

        netif_device_attach(dev);
out:

        return 0;
}

static const struct dev_pm_ops rtase_pm_ops = {
        SYSTEM_SLEEP_PM_OPS(rtase_suspend, rtase_resume)
};

static struct pci_driver rtase_pci_driver = {
        .name = KBUILD_MODNAME,
        .id_table = rtase_pci_tbl,
        .probe = rtase_init_one,
        .remove = rtase_remove_one,
        .shutdown = rtase_shutdown,
        .driver.pm = pm_ptr(&rtase_pm_ops),
};

module_pci_driver(rtase_pci_driver);