root/drivers/net/ethernet/hisilicon/hip04_eth.c
// SPDX-License-Identifier: GPL-2.0-or-later

/* Copyright (c) 2014 Linaro Ltd.
 * Copyright (c) 2014 Hisilicon Limited.
 */

#include <linux/module.h>
#include <linux/etherdevice.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/ktime.h>
#include <linux/of_address.h>
#include <linux/phy.h>
#include <linux/of_mdio.h>
#include <linux/of_net.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>

#define SC_PPE_RESET_DREQ               0x026C

#define PPE_CFG_RX_ADDR                 0x100
#define PPE_CFG_POOL_GRP                0x300
#define PPE_CFG_RX_BUF_SIZE             0x400
#define PPE_CFG_RX_FIFO_SIZE            0x500
#define PPE_CURR_BUF_CNT                0xa200

#define GE_DUPLEX_TYPE                  0x08
#define GE_MAX_FRM_SIZE_REG             0x3c
#define GE_PORT_MODE                    0x40
#define GE_PORT_EN                      0x44
#define GE_SHORT_RUNTS_THR_REG          0x50
#define GE_TX_LOCAL_PAGE_REG            0x5c
#define GE_TRANSMIT_CONTROL_REG         0x60
#define GE_CF_CRC_STRIP_REG             0x1b0
#define GE_MODE_CHANGE_REG              0x1b4
#define GE_RECV_CONTROL_REG             0x1e0
#define GE_STATION_MAC_ADDRESS          0x210

#define PPE_CFG_BUS_CTRL_REG            0x424
#define PPE_CFG_RX_CTRL_REG             0x428

#if defined(CONFIG_HI13X1_GMAC)
#define PPE_CFG_CPU_ADD_ADDR            0x6D0
#define PPE_CFG_MAX_FRAME_LEN_REG       0x500
#define PPE_CFG_RX_PKT_MODE_REG         0x504
#define PPE_CFG_QOS_VMID_GEN            0x520
#define PPE_CFG_RX_PKT_INT              0x740
#define PPE_INTEN                       0x700
#define PPE_INTSTS                      0x708
#define PPE_RINT                        0x704
#define PPE_CFG_STS_MODE                0x880
#else
#define PPE_CFG_CPU_ADD_ADDR            0x580
#define PPE_CFG_MAX_FRAME_LEN_REG       0x408
#define PPE_CFG_RX_PKT_MODE_REG         0x438
#define PPE_CFG_QOS_VMID_GEN            0x500
#define PPE_CFG_RX_PKT_INT              0x538
#define PPE_INTEN                       0x600
#define PPE_INTSTS                      0x608
#define PPE_RINT                        0x604
#define PPE_CFG_STS_MODE                0x700
#endif /* CONFIG_HI13X1_GMAC */

#define PPE_HIS_RX_PKT_CNT              0x804

#define RESET_DREQ_ALL                  0xffffffff

/* REG_INTERRUPT */
#define RCV_INT                         BIT(10)
#define RCV_NOBUF                       BIT(8)
#define RCV_DROP                        BIT(7)
#define TX_DROP                         BIT(6)
#define DEF_INT_ERR                     (RCV_NOBUF | RCV_DROP | TX_DROP)
#define DEF_INT_MASK                    (RCV_INT | DEF_INT_ERR)

/* TX descriptor config */
#define TX_FREE_MEM                     BIT(0)
#define TX_READ_ALLOC_L3                BIT(1)
#if defined(CONFIG_HI13X1_GMAC)
#define TX_CLEAR_WB                     BIT(7)
#define TX_RELEASE_TO_PPE               BIT(4)
#define TX_FINISH_CACHE_INV             BIT(6)
#define TX_POOL_SHIFT                   16
#else
#define TX_CLEAR_WB                     BIT(4)
#define TX_FINISH_CACHE_INV             BIT(2)
#endif
#define TX_L3_CHECKSUM                  BIT(5)
#define TX_LOOP_BACK                    BIT(11)

/* RX error */
#define RX_PKT_DROP                     BIT(0)
#define RX_L2_ERR                       BIT(1)
#define RX_PKT_ERR                      (RX_PKT_DROP | RX_L2_ERR)

#define SGMII_SPEED_1000                0x08
#define SGMII_SPEED_100                 0x07
#define SGMII_SPEED_10                  0x06
#define MII_SPEED_100                   0x01
#define MII_SPEED_10                    0x00

#define GE_DUPLEX_FULL                  BIT(0)
#define GE_DUPLEX_HALF                  0x00
#define GE_MODE_CHANGE_EN               BIT(0)

#define GE_TX_AUTO_NEG                  BIT(5)
#define GE_TX_ADD_CRC                   BIT(6)
#define GE_TX_SHORT_PAD_THROUGH         BIT(7)

#define GE_RX_STRIP_CRC                 BIT(0)
#define GE_RX_STRIP_PAD                 BIT(3)
#define GE_RX_PAD_EN                    BIT(4)

#define GE_AUTO_NEG_CTL                 BIT(0)

#define GE_RX_INT_THRESHOLD             BIT(6)
#define GE_RX_TIMEOUT                   0x04

#define GE_RX_PORT_EN                   BIT(1)
#define GE_TX_PORT_EN                   BIT(2)

#define PPE_CFG_RX_PKT_ALIGN            BIT(18)

#if defined(CONFIG_HI13X1_GMAC)
#define PPE_CFG_QOS_VMID_GRP_SHIFT      4
#define PPE_CFG_RX_CTRL_ALIGN_SHIFT     7
#define PPE_CFG_STS_RX_PKT_CNT_RC       BIT(0)
#define PPE_CFG_QOS_VMID_MODE           BIT(15)
#define PPE_CFG_BUS_LOCAL_REL           (BIT(9) | BIT(15) | BIT(19) | BIT(23))

/* buf unit size is cache_line_size, which is 64, so the shift is 6 */
#define PPE_BUF_SIZE_SHIFT              6
#define PPE_TX_BUF_HOLD                 BIT(31)
#define SOC_CACHE_LINE_MASK             0x3F
#else
#define PPE_CFG_QOS_VMID_GRP_SHIFT      8
#define PPE_CFG_RX_CTRL_ALIGN_SHIFT     11
#define PPE_CFG_STS_RX_PKT_CNT_RC       BIT(12)
#define PPE_CFG_QOS_VMID_MODE           BIT(14)
#define PPE_CFG_BUS_LOCAL_REL           BIT(14)

/* buf unit size is 1, so the shift is 6 */
#define PPE_BUF_SIZE_SHIFT              0
#define PPE_TX_BUF_HOLD                 0
#endif /* CONFIG_HI13X1_GMAC */

#define PPE_CFG_RX_FIFO_FSFU            BIT(11)
#define PPE_CFG_RX_DEPTH_SHIFT          16
#define PPE_CFG_RX_START_SHIFT          0

#define PPE_CFG_BUS_BIG_ENDIEN          BIT(0)

#define RX_DESC_NUM                     128
#define TX_DESC_NUM                     256
#define TX_NEXT(N)                      (((N) + 1) & (TX_DESC_NUM-1))
#define RX_NEXT(N)                      (((N) + 1) & (RX_DESC_NUM-1))

#define GMAC_PPE_RX_PKT_MAX_LEN         379
#define GMAC_MAX_PKT_LEN                1516
#define GMAC_MIN_PKT_LEN                31
#define RX_BUF_SIZE                     1600
#define RESET_TIMEOUT                   1000
#define TX_TIMEOUT                      (6 * HZ)

#define DRV_NAME                        "hip04-ether"
#define DRV_VERSION                     "v1.0"

#define HIP04_MAX_TX_COALESCE_USECS     200
#define HIP04_MIN_TX_COALESCE_USECS     100
#define HIP04_MAX_TX_COALESCE_FRAMES    200
#define HIP04_MIN_TX_COALESCE_FRAMES    100

struct tx_desc {
#if defined(CONFIG_HI13X1_GMAC)
        u32 reserved1[2];
        u32 send_addr;
        u16 send_size;
        u16 data_offset;
        u32 reserved2[7];
        u32 cfg;
        u32 wb_addr;
        u32 reserved3[3];
#else
        u32 send_addr;
        u32 send_size;
        u32 next_addr;
        u32 cfg;
        u32 wb_addr;
#endif
} __aligned(64);

struct rx_desc {
#if defined(CONFIG_HI13X1_GMAC)
        u32 reserved1[3];
        u16 pkt_len;
        u16 reserved_16;
        u32 reserved2[6];
        u32 pkt_err;
        u32 reserved3[5];
#else
        u16 reserved_16;
        u16 pkt_len;
        u32 reserve1[3];
        u32 pkt_err;
        u32 reserve2[4];
#endif
};

struct hip04_priv {
        void __iomem *base;
#if defined(CONFIG_HI13X1_GMAC)
        void __iomem *sysctrl_base;
#endif
        phy_interface_t phy_mode;
        int chan;
        unsigned int port;
        unsigned int group;
        unsigned int speed;
        unsigned int duplex;
        unsigned int reg_inten;

        struct napi_struct napi;
        struct device *dev;
        struct net_device *ndev;

        struct tx_desc *tx_desc;
        dma_addr_t tx_desc_dma;
        struct sk_buff *tx_skb[TX_DESC_NUM];
        dma_addr_t tx_phys[TX_DESC_NUM];
        unsigned int tx_head;

        int tx_coalesce_frames;
        int tx_coalesce_usecs;
        struct hrtimer tx_coalesce_timer;

        unsigned char *rx_buf[RX_DESC_NUM];
        dma_addr_t rx_phys[RX_DESC_NUM];
        unsigned int rx_head;
        unsigned int rx_buf_size;
        unsigned int rx_cnt_remaining;

        struct device_node *phy_node;
        struct phy_device *phy;
        struct regmap *map;
        struct work_struct tx_timeout_task;

        /* written only by tx cleanup */
        unsigned int tx_tail ____cacheline_aligned_in_smp;
};

static inline unsigned int tx_count(unsigned int head, unsigned int tail)
{
        return (head - tail) % TX_DESC_NUM;
}

static void hip04_config_port(struct net_device *ndev, u32 speed, u32 duplex)
{
        struct hip04_priv *priv = netdev_priv(ndev);
        u32 val;

        priv->speed = speed;
        priv->duplex = duplex;

        switch (priv->phy_mode) {
        case PHY_INTERFACE_MODE_SGMII:
                if (speed == SPEED_1000)
                        val = SGMII_SPEED_1000;
                else if (speed == SPEED_100)
                        val = SGMII_SPEED_100;
                else
                        val = SGMII_SPEED_10;
                break;
        case PHY_INTERFACE_MODE_MII:
                if (speed == SPEED_100)
                        val = MII_SPEED_100;
                else
                        val = MII_SPEED_10;
                break;
        default:
                netdev_warn(ndev, "not supported mode\n");
                val = MII_SPEED_10;
                break;
        }
        writel_relaxed(val, priv->base + GE_PORT_MODE);

        val = duplex ? GE_DUPLEX_FULL : GE_DUPLEX_HALF;
        writel_relaxed(val, priv->base + GE_DUPLEX_TYPE);

        val = GE_MODE_CHANGE_EN;
        writel_relaxed(val, priv->base + GE_MODE_CHANGE_REG);
}

static void hip04_reset_dreq(struct hip04_priv *priv)
{
#if defined(CONFIG_HI13X1_GMAC)
        writel_relaxed(RESET_DREQ_ALL, priv->sysctrl_base + SC_PPE_RESET_DREQ);
#endif
}

static void hip04_reset_ppe(struct hip04_priv *priv)
{
        u32 val, tmp, timeout = 0;

        do {
                regmap_read(priv->map, priv->port * 4 + PPE_CURR_BUF_CNT, &val);
                regmap_read(priv->map, priv->port * 4 + PPE_CFG_RX_ADDR, &tmp);
                if (timeout++ > RESET_TIMEOUT)
                        break;
        } while (val & 0xfff);
}

static void hip04_config_fifo(struct hip04_priv *priv)
{
        u32 val;

        val = readl_relaxed(priv->base + PPE_CFG_STS_MODE);
        val |= PPE_CFG_STS_RX_PKT_CNT_RC;
        writel_relaxed(val, priv->base + PPE_CFG_STS_MODE);

        val = BIT(priv->group);
        regmap_write(priv->map, priv->port * 4 + PPE_CFG_POOL_GRP, val);

        val = priv->group << PPE_CFG_QOS_VMID_GRP_SHIFT;
        val |= PPE_CFG_QOS_VMID_MODE;
        writel_relaxed(val, priv->base + PPE_CFG_QOS_VMID_GEN);

        val = RX_BUF_SIZE >> PPE_BUF_SIZE_SHIFT;
        regmap_write(priv->map, priv->port * 4 + PPE_CFG_RX_BUF_SIZE, val);

        val = RX_DESC_NUM << PPE_CFG_RX_DEPTH_SHIFT;
        val |= PPE_CFG_RX_FIFO_FSFU;
        val |= priv->chan << PPE_CFG_RX_START_SHIFT;
        regmap_write(priv->map, priv->port * 4 + PPE_CFG_RX_FIFO_SIZE, val);

        val = NET_IP_ALIGN << PPE_CFG_RX_CTRL_ALIGN_SHIFT;
        writel_relaxed(val, priv->base + PPE_CFG_RX_CTRL_REG);

        val = PPE_CFG_RX_PKT_ALIGN;
        writel_relaxed(val, priv->base + PPE_CFG_RX_PKT_MODE_REG);

        val = PPE_CFG_BUS_LOCAL_REL | PPE_CFG_BUS_BIG_ENDIEN;
        writel_relaxed(val, priv->base + PPE_CFG_BUS_CTRL_REG);

        val = GMAC_PPE_RX_PKT_MAX_LEN;
        writel_relaxed(val, priv->base + PPE_CFG_MAX_FRAME_LEN_REG);

        val = GMAC_MAX_PKT_LEN;
        writel_relaxed(val, priv->base + GE_MAX_FRM_SIZE_REG);

        val = GMAC_MIN_PKT_LEN;
        writel_relaxed(val, priv->base + GE_SHORT_RUNTS_THR_REG);

        val = readl_relaxed(priv->base + GE_TRANSMIT_CONTROL_REG);
        val |= GE_TX_AUTO_NEG | GE_TX_ADD_CRC | GE_TX_SHORT_PAD_THROUGH;
        writel_relaxed(val, priv->base + GE_TRANSMIT_CONTROL_REG);

        val = GE_RX_STRIP_CRC;
        writel_relaxed(val, priv->base + GE_CF_CRC_STRIP_REG);

        val = readl_relaxed(priv->base + GE_RECV_CONTROL_REG);
        val |= GE_RX_STRIP_PAD | GE_RX_PAD_EN;
        writel_relaxed(val, priv->base + GE_RECV_CONTROL_REG);

#ifndef CONFIG_HI13X1_GMAC
        val = GE_AUTO_NEG_CTL;
        writel_relaxed(val, priv->base + GE_TX_LOCAL_PAGE_REG);
#endif
}

static void hip04_mac_enable(struct net_device *ndev)
{
        struct hip04_priv *priv = netdev_priv(ndev);
        u32 val;

        /* enable tx & rx */
        val = readl_relaxed(priv->base + GE_PORT_EN);
        val |= GE_RX_PORT_EN | GE_TX_PORT_EN;
        writel_relaxed(val, priv->base + GE_PORT_EN);

        /* clear rx int */
        val = RCV_INT;
        writel_relaxed(val, priv->base + PPE_RINT);

        /* config recv int */
        val = GE_RX_INT_THRESHOLD | GE_RX_TIMEOUT;
        writel_relaxed(val, priv->base + PPE_CFG_RX_PKT_INT);

        /* enable interrupt */
        priv->reg_inten = DEF_INT_MASK;
        writel_relaxed(priv->reg_inten, priv->base + PPE_INTEN);
}

static void hip04_mac_disable(struct net_device *ndev)
{
        struct hip04_priv *priv = netdev_priv(ndev);
        u32 val;

        /* disable int */
        priv->reg_inten &= ~(DEF_INT_MASK);
        writel_relaxed(priv->reg_inten, priv->base + PPE_INTEN);

        /* disable tx & rx */
        val = readl_relaxed(priv->base + GE_PORT_EN);
        val &= ~(GE_RX_PORT_EN | GE_TX_PORT_EN);
        writel_relaxed(val, priv->base + GE_PORT_EN);
}

static void hip04_set_xmit_desc(struct hip04_priv *priv, dma_addr_t phys)
{
        u32 val;

        val = phys >> PPE_BUF_SIZE_SHIFT | PPE_TX_BUF_HOLD;
        writel(val, priv->base + PPE_CFG_CPU_ADD_ADDR);
}

static void hip04_set_recv_desc(struct hip04_priv *priv, dma_addr_t phys)
{
        u32 val;

        val = phys >> PPE_BUF_SIZE_SHIFT;
        regmap_write(priv->map, priv->port * 4 + PPE_CFG_RX_ADDR, val);
}

static u32 hip04_recv_cnt(struct hip04_priv *priv)
{
        return readl(priv->base + PPE_HIS_RX_PKT_CNT);
}

static void hip04_update_mac_address(struct net_device *ndev)
{
        struct hip04_priv *priv = netdev_priv(ndev);

        writel_relaxed(((ndev->dev_addr[0] << 8) | (ndev->dev_addr[1])),
                       priv->base + GE_STATION_MAC_ADDRESS);
        writel_relaxed(((ndev->dev_addr[2] << 24) | (ndev->dev_addr[3] << 16) |
                        (ndev->dev_addr[4] << 8) | (ndev->dev_addr[5])),
                       priv->base + GE_STATION_MAC_ADDRESS + 4);
}

static int hip04_set_mac_address(struct net_device *ndev, void *addr)
{
        eth_mac_addr(ndev, addr);
        hip04_update_mac_address(ndev);
        return 0;
}

static int hip04_tx_reclaim(struct net_device *ndev, bool force)
{
        struct hip04_priv *priv = netdev_priv(ndev);
        unsigned tx_tail = priv->tx_tail;
        struct tx_desc *desc;
        unsigned int bytes_compl = 0, pkts_compl = 0;
        unsigned int count;

        smp_rmb();
        count = tx_count(READ_ONCE(priv->tx_head), tx_tail);
        if (count == 0)
                goto out;

        while (count) {
                desc = &priv->tx_desc[tx_tail];
                if (desc->send_addr != 0) {
                        if (force)
                                desc->send_addr = 0;
                        else
                                break;
                }

                if (priv->tx_phys[tx_tail]) {
                        dma_unmap_single(priv->dev, priv->tx_phys[tx_tail],
                                         priv->tx_skb[tx_tail]->len,
                                         DMA_TO_DEVICE);
                        priv->tx_phys[tx_tail] = 0;
                }
                pkts_compl++;
                bytes_compl += priv->tx_skb[tx_tail]->len;
                dev_kfree_skb(priv->tx_skb[tx_tail]);
                priv->tx_skb[tx_tail] = NULL;
                tx_tail = TX_NEXT(tx_tail);
                count--;
        }

        priv->tx_tail = tx_tail;
        smp_wmb(); /* Ensure tx_tail visible to xmit */

out:
        if (pkts_compl || bytes_compl)
                netdev_completed_queue(ndev, pkts_compl, bytes_compl);

        if (unlikely(netif_queue_stopped(ndev)) && (count < (TX_DESC_NUM - 1)))
                netif_wake_queue(ndev);

        return count;
}

static void hip04_start_tx_timer(struct hip04_priv *priv)
{
        unsigned long ns = priv->tx_coalesce_usecs * NSEC_PER_USEC / 2;

        /* allow timer to fire after half the time at the earliest */
        hrtimer_start_range_ns(&priv->tx_coalesce_timer, ns_to_ktime(ns),
                               ns, HRTIMER_MODE_REL);
}

static netdev_tx_t
hip04_mac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
{
        struct hip04_priv *priv = netdev_priv(ndev);
        struct net_device_stats *stats = &ndev->stats;
        unsigned int tx_head = priv->tx_head, count;
        struct tx_desc *desc = &priv->tx_desc[tx_head];
        dma_addr_t phys;

        smp_rmb();
        count = tx_count(tx_head, READ_ONCE(priv->tx_tail));
        if (count == (TX_DESC_NUM - 1)) {
                netif_stop_queue(ndev);
                return NETDEV_TX_BUSY;
        }

        phys = dma_map_single(priv->dev, skb->data, skb->len, DMA_TO_DEVICE);
        if (dma_mapping_error(priv->dev, phys)) {
                dev_kfree_skb(skb);
                return NETDEV_TX_OK;
        }

        priv->tx_skb[tx_head] = skb;
        priv->tx_phys[tx_head] = phys;

        desc->send_size = (__force u32)cpu_to_be32(skb->len);
#if defined(CONFIG_HI13X1_GMAC)
        desc->cfg = (__force u32)cpu_to_be32(TX_CLEAR_WB | TX_FINISH_CACHE_INV
                | TX_RELEASE_TO_PPE | priv->port << TX_POOL_SHIFT);
        desc->data_offset = (__force u32)cpu_to_be32(phys & SOC_CACHE_LINE_MASK);
        desc->send_addr =  (__force u32)cpu_to_be32(phys & ~SOC_CACHE_LINE_MASK);
#else
        desc->cfg = (__force u32)cpu_to_be32(TX_CLEAR_WB | TX_FINISH_CACHE_INV);
        desc->send_addr = (__force u32)cpu_to_be32(phys);
#endif
        phys = priv->tx_desc_dma + tx_head * sizeof(struct tx_desc);
        desc->wb_addr = (__force u32)cpu_to_be32(phys +
                offsetof(struct tx_desc, send_addr));
        skb_tx_timestamp(skb);

        hip04_set_xmit_desc(priv, phys);
        count++;
        netdev_sent_queue(ndev, skb->len);
        priv->tx_head = TX_NEXT(tx_head);

        stats->tx_bytes += skb->len;
        stats->tx_packets++;

        /* Ensure tx_head update visible to tx reclaim */
        smp_wmb();

        /* queue is getting full, better start cleaning up now */
        if (count >= priv->tx_coalesce_frames) {
                if (napi_schedule_prep(&priv->napi)) {
                        /* disable rx interrupt and timer */
                        priv->reg_inten &= ~(RCV_INT);
                        writel_relaxed(DEF_INT_MASK & ~RCV_INT,
                                       priv->base + PPE_INTEN);
                        hrtimer_cancel(&priv->tx_coalesce_timer);
                        __napi_schedule(&priv->napi);
                }
        } else if (!hrtimer_is_queued(&priv->tx_coalesce_timer)) {
                /* cleanup not pending yet, start a new timer */
                hip04_start_tx_timer(priv);
        }

        return NETDEV_TX_OK;
}

static int hip04_rx_poll(struct napi_struct *napi, int budget)
{
        struct hip04_priv *priv = container_of(napi, struct hip04_priv, napi);
        struct net_device *ndev = priv->ndev;
        struct net_device_stats *stats = &ndev->stats;
        struct rx_desc *desc;
        struct sk_buff *skb;
        unsigned char *buf;
        bool last = false;
        dma_addr_t phys;
        int rx = 0;
        int tx_remaining;
        u16 len;
        u32 err;

        /* clean up tx descriptors */
        tx_remaining = hip04_tx_reclaim(ndev, false);
        priv->rx_cnt_remaining += hip04_recv_cnt(priv);
        while (priv->rx_cnt_remaining && !last) {
                buf = priv->rx_buf[priv->rx_head];
                skb = build_skb(buf, priv->rx_buf_size);
                if (unlikely(!skb)) {
                        net_dbg_ratelimited("build_skb failed\n");
                        goto refill;
                }

                dma_unmap_single(priv->dev, priv->rx_phys[priv->rx_head],
                                 RX_BUF_SIZE, DMA_FROM_DEVICE);
                priv->rx_phys[priv->rx_head] = 0;

                desc = (struct rx_desc *)skb->data;
                len = be16_to_cpu((__force __be16)desc->pkt_len);
                err = be32_to_cpu((__force __be32)desc->pkt_err);

                if (0 == len) {
                        dev_kfree_skb_any(skb);
                        last = true;
                } else if ((err & RX_PKT_ERR) || (len >= GMAC_MAX_PKT_LEN)) {
                        dev_kfree_skb_any(skb);
                        stats->rx_dropped++;
                        stats->rx_errors++;
                } else {
                        skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
                        skb_put(skb, len);
                        skb->protocol = eth_type_trans(skb, ndev);
                        napi_gro_receive(&priv->napi, skb);
                        stats->rx_packets++;
                        stats->rx_bytes += len;
                        rx++;
                }

refill:
                buf = netdev_alloc_frag(priv->rx_buf_size);
                if (!buf)
                        goto done;
                phys = dma_map_single(priv->dev, buf,
                                      RX_BUF_SIZE, DMA_FROM_DEVICE);
                if (dma_mapping_error(priv->dev, phys))
                        goto done;
                priv->rx_buf[priv->rx_head] = buf;
                priv->rx_phys[priv->rx_head] = phys;
                hip04_set_recv_desc(priv, phys);

                priv->rx_head = RX_NEXT(priv->rx_head);
                if (rx >= budget) {
                        --priv->rx_cnt_remaining;
                        goto done;
                }

                if (--priv->rx_cnt_remaining == 0)
                        priv->rx_cnt_remaining += hip04_recv_cnt(priv);
        }

        if (!(priv->reg_inten & RCV_INT)) {
                /* enable rx interrupt */
                priv->reg_inten |= RCV_INT;
                writel_relaxed(priv->reg_inten, priv->base + PPE_INTEN);
        }
        napi_complete_done(napi, rx);
done:
        /* start a new timer if necessary */
        if (rx < budget && tx_remaining)
                hip04_start_tx_timer(priv);

        return rx;
}

static irqreturn_t hip04_mac_interrupt(int irq, void *dev_id)
{
        struct net_device *ndev = (struct net_device *)dev_id;
        struct hip04_priv *priv = netdev_priv(ndev);
        struct net_device_stats *stats = &ndev->stats;
        u32 ists = readl_relaxed(priv->base + PPE_INTSTS);

        if (!ists)
                return IRQ_NONE;

        writel_relaxed(DEF_INT_MASK, priv->base + PPE_RINT);

        if (unlikely(ists & DEF_INT_ERR)) {
                if (ists & (RCV_NOBUF | RCV_DROP)) {
                        stats->rx_errors++;
                        stats->rx_dropped++;
                        netdev_err(ndev, "rx drop\n");
                }
                if (ists & TX_DROP) {
                        stats->tx_dropped++;
                        netdev_err(ndev, "tx drop\n");
                }
        }

        if (ists & RCV_INT && napi_schedule_prep(&priv->napi)) {
                /* disable rx interrupt */
                priv->reg_inten &= ~(RCV_INT);
                writel_relaxed(DEF_INT_MASK & ~RCV_INT, priv->base + PPE_INTEN);
                hrtimer_cancel(&priv->tx_coalesce_timer);
                __napi_schedule(&priv->napi);
        }

        return IRQ_HANDLED;
}

static enum hrtimer_restart tx_done(struct hrtimer *hrtimer)
{
        struct hip04_priv *priv;

        priv = container_of(hrtimer, struct hip04_priv, tx_coalesce_timer);

        if (napi_schedule_prep(&priv->napi)) {
                /* disable rx interrupt */
                priv->reg_inten &= ~(RCV_INT);
                writel_relaxed(DEF_INT_MASK & ~RCV_INT, priv->base + PPE_INTEN);
                __napi_schedule(&priv->napi);
        }

        return HRTIMER_NORESTART;
}

static void hip04_adjust_link(struct net_device *ndev)
{
        struct hip04_priv *priv = netdev_priv(ndev);
        struct phy_device *phy = priv->phy;

        if ((priv->speed != phy->speed) || (priv->duplex != phy->duplex)) {
                hip04_config_port(ndev, phy->speed, phy->duplex);
                phy_print_status(phy);
        }
}

static int hip04_mac_open(struct net_device *ndev)
{
        struct hip04_priv *priv = netdev_priv(ndev);
        int i;

        priv->rx_head = 0;
        priv->rx_cnt_remaining = 0;
        priv->tx_head = 0;
        priv->tx_tail = 0;
        hip04_reset_ppe(priv);

        for (i = 0; i < RX_DESC_NUM; i++) {
                dma_addr_t phys;

                phys = dma_map_single(priv->dev, priv->rx_buf[i],
                                      RX_BUF_SIZE, DMA_FROM_DEVICE);
                if (dma_mapping_error(priv->dev, phys))
                        return -EIO;

                priv->rx_phys[i] = phys;
                hip04_set_recv_desc(priv, phys);
        }

        if (priv->phy)
                phy_start(priv->phy);

        netdev_reset_queue(ndev);
        netif_start_queue(ndev);
        hip04_mac_enable(ndev);
        napi_enable(&priv->napi);

        return 0;
}

static int hip04_mac_stop(struct net_device *ndev)
{
        struct hip04_priv *priv = netdev_priv(ndev);
        int i;

        napi_disable(&priv->napi);
        netif_stop_queue(ndev);
        hip04_mac_disable(ndev);
        hip04_tx_reclaim(ndev, true);
        hip04_reset_ppe(priv);

        if (priv->phy)
                phy_stop(priv->phy);

        for (i = 0; i < RX_DESC_NUM; i++) {
                if (priv->rx_phys[i]) {
                        dma_unmap_single(priv->dev, priv->rx_phys[i],
                                         RX_BUF_SIZE, DMA_FROM_DEVICE);
                        priv->rx_phys[i] = 0;
                }
        }

        return 0;
}

static void hip04_timeout(struct net_device *ndev, unsigned int txqueue)
{
        struct hip04_priv *priv = netdev_priv(ndev);

        schedule_work(&priv->tx_timeout_task);
}

static void hip04_tx_timeout_task(struct work_struct *work)
{
        struct hip04_priv *priv;

        priv = container_of(work, struct hip04_priv, tx_timeout_task);
        hip04_mac_stop(priv->ndev);
        hip04_mac_open(priv->ndev);
}

static int hip04_get_coalesce(struct net_device *netdev,
                              struct ethtool_coalesce *ec,
                              struct kernel_ethtool_coalesce *kernel_coal,
                              struct netlink_ext_ack *extack)
{
        struct hip04_priv *priv = netdev_priv(netdev);

        ec->tx_coalesce_usecs = priv->tx_coalesce_usecs;
        ec->tx_max_coalesced_frames = priv->tx_coalesce_frames;

        return 0;
}

static int hip04_set_coalesce(struct net_device *netdev,
                              struct ethtool_coalesce *ec,
                              struct kernel_ethtool_coalesce *kernel_coal,
                              struct netlink_ext_ack *extack)
{
        struct hip04_priv *priv = netdev_priv(netdev);

        if ((ec->tx_coalesce_usecs > HIP04_MAX_TX_COALESCE_USECS ||
             ec->tx_coalesce_usecs < HIP04_MIN_TX_COALESCE_USECS) ||
            (ec->tx_max_coalesced_frames > HIP04_MAX_TX_COALESCE_FRAMES ||
             ec->tx_max_coalesced_frames < HIP04_MIN_TX_COALESCE_FRAMES))
                return -EINVAL;

        priv->tx_coalesce_usecs = ec->tx_coalesce_usecs;
        priv->tx_coalesce_frames = ec->tx_max_coalesced_frames;

        return 0;
}

static void hip04_get_drvinfo(struct net_device *netdev,
                              struct ethtool_drvinfo *drvinfo)
{
        strscpy(drvinfo->driver, DRV_NAME, sizeof(drvinfo->driver));
        strscpy(drvinfo->version, DRV_VERSION, sizeof(drvinfo->version));
}

static const struct ethtool_ops hip04_ethtool_ops = {
        .supported_coalesce_params = ETHTOOL_COALESCE_TX_USECS |
                                     ETHTOOL_COALESCE_TX_MAX_FRAMES,
        .get_coalesce           = hip04_get_coalesce,
        .set_coalesce           = hip04_set_coalesce,
        .get_drvinfo            = hip04_get_drvinfo,
};

static const struct net_device_ops hip04_netdev_ops = {
        .ndo_open               = hip04_mac_open,
        .ndo_stop               = hip04_mac_stop,
        .ndo_start_xmit         = hip04_mac_start_xmit,
        .ndo_set_mac_address    = hip04_set_mac_address,
        .ndo_tx_timeout         = hip04_timeout,
        .ndo_validate_addr      = eth_validate_addr,
};

static int hip04_alloc_ring(struct net_device *ndev, struct device *d)
{
        struct hip04_priv *priv = netdev_priv(ndev);
        int i;

        priv->tx_desc = dma_alloc_coherent(d,
                                           TX_DESC_NUM * sizeof(struct tx_desc),
                                           &priv->tx_desc_dma, GFP_KERNEL);
        if (!priv->tx_desc)
                return -ENOMEM;

        priv->rx_buf_size = RX_BUF_SIZE +
                            SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
        for (i = 0; i < RX_DESC_NUM; i++) {
                priv->rx_buf[i] = netdev_alloc_frag(priv->rx_buf_size);
                if (!priv->rx_buf[i])
                        return -ENOMEM;
        }

        return 0;
}

static void hip04_free_ring(struct net_device *ndev, struct device *d)
{
        struct hip04_priv *priv = netdev_priv(ndev);
        int i;

        for (i = 0; i < RX_DESC_NUM; i++)
                if (priv->rx_buf[i])
                        skb_free_frag(priv->rx_buf[i]);

        for (i = 0; i < TX_DESC_NUM; i++)
                if (priv->tx_skb[i])
                        dev_kfree_skb_any(priv->tx_skb[i]);

        dma_free_coherent(d, TX_DESC_NUM * sizeof(struct tx_desc),
                          priv->tx_desc, priv->tx_desc_dma);
}

static int hip04_mac_probe(struct platform_device *pdev)
{
        struct device *d = &pdev->dev;
        struct device_node *node = d->of_node;
        struct of_phandle_args arg;
        struct net_device *ndev;
        struct hip04_priv *priv;
        int irq;
        int ret;

        ndev = alloc_etherdev(sizeof(struct hip04_priv));
        if (!ndev)
                return -ENOMEM;

        priv = netdev_priv(ndev);
        priv->dev = d;
        priv->ndev = ndev;
        platform_set_drvdata(pdev, ndev);
        SET_NETDEV_DEV(ndev, &pdev->dev);

        priv->base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(priv->base)) {
                ret = PTR_ERR(priv->base);
                goto init_fail;
        }

#if defined(CONFIG_HI13X1_GMAC)
        priv->sysctrl_base = devm_platform_ioremap_resource(pdev, 1);
        if (IS_ERR(priv->sysctrl_base)) {
                ret = PTR_ERR(priv->sysctrl_base);
                goto init_fail;
        }
#endif

        ret = of_parse_phandle_with_fixed_args(node, "port-handle", 3, 0, &arg);
        if (ret < 0) {
                dev_warn(d, "no port-handle\n");
                goto init_fail;
        }

        priv->port = arg.args[0];
        priv->chan = arg.args[1] * RX_DESC_NUM;
        priv->group = arg.args[2];

        /* BQL will try to keep the TX queue as short as possible, but it can't
         * be faster than tx_coalesce_usecs, so we need a fast timeout here,
         * but also long enough to gather up enough frames to ensure we don't
         * get more interrupts than necessary.
         * 200us is enough for 16 frames of 1500 bytes at gigabit ethernet rate
         */
        priv->tx_coalesce_frames = TX_DESC_NUM * 3 / 4;
        priv->tx_coalesce_usecs = 200;
        hrtimer_setup(&priv->tx_coalesce_timer, tx_done, CLOCK_MONOTONIC, HRTIMER_MODE_REL);

        priv->map = syscon_node_to_regmap(arg.np);
        of_node_put(arg.np);
        if (IS_ERR(priv->map)) {
                dev_warn(d, "no syscon hisilicon,hip04-ppe\n");
                ret = PTR_ERR(priv->map);
                goto init_fail;
        }

        ret = of_get_phy_mode(node, &priv->phy_mode);
        if (ret) {
                dev_warn(d, "not find phy-mode\n");
                goto init_fail;
        }

        irq = platform_get_irq(pdev, 0);
        if (irq < 0) {
                ret = irq;
                goto init_fail;
        }

        ret = devm_request_irq(d, irq, hip04_mac_interrupt,
                               0, pdev->name, ndev);
        if (ret) {
                netdev_err(ndev, "devm_request_irq failed\n");
                goto init_fail;
        }

        priv->phy_node = of_parse_phandle(node, "phy-handle", 0);
        if (priv->phy_node) {
                priv->phy = of_phy_connect(ndev, priv->phy_node,
                                           &hip04_adjust_link,
                                           0, priv->phy_mode);
                if (!priv->phy) {
                        ret = -EPROBE_DEFER;
                        goto init_fail;
                }
        }

        INIT_WORK(&priv->tx_timeout_task, hip04_tx_timeout_task);

        ndev->netdev_ops = &hip04_netdev_ops;
        ndev->ethtool_ops = &hip04_ethtool_ops;
        ndev->watchdog_timeo = TX_TIMEOUT;
        ndev->priv_flags |= IFF_UNICAST_FLT;
        ndev->irq = irq;
        netif_napi_add(ndev, &priv->napi, hip04_rx_poll);

        hip04_reset_dreq(priv);
        hip04_reset_ppe(priv);
        if (priv->phy_mode == PHY_INTERFACE_MODE_MII)
                hip04_config_port(ndev, SPEED_100, DUPLEX_FULL);

        hip04_config_fifo(priv);
        eth_hw_addr_random(ndev);
        hip04_update_mac_address(ndev);

        ret = hip04_alloc_ring(ndev, d);
        if (ret) {
                netdev_err(ndev, "alloc ring fail\n");
                goto alloc_fail;
        }

        ret = register_netdev(ndev);
        if (ret)
                goto alloc_fail;

        return 0;

alloc_fail:
        hip04_free_ring(ndev, d);
init_fail:
        of_node_put(priv->phy_node);
        free_netdev(ndev);
        return ret;
}

static void hip04_remove(struct platform_device *pdev)
{
        struct net_device *ndev = platform_get_drvdata(pdev);
        struct hip04_priv *priv = netdev_priv(ndev);
        struct device *d = &pdev->dev;

        if (priv->phy)
                phy_disconnect(priv->phy);

        hip04_free_ring(ndev, d);
        unregister_netdev(ndev);
        of_node_put(priv->phy_node);
        cancel_work_sync(&priv->tx_timeout_task);
        free_netdev(ndev);
}

static const struct of_device_id hip04_mac_match[] = {
        { .compatible = "hisilicon,hip04-mac" },
        { }
};

MODULE_DEVICE_TABLE(of, hip04_mac_match);

static struct platform_driver hip04_mac_driver = {
        .probe  = hip04_mac_probe,
        .remove = hip04_remove,
        .driver = {
                .name           = DRV_NAME,
                .of_match_table = hip04_mac_match,
        },
};
module_platform_driver(hip04_mac_driver);

MODULE_DESCRIPTION("HISILICON P04 Ethernet driver");
MODULE_LICENSE("GPL");