// SPDX-License-Identifier: GPL-2.0-only
/*
 * Xilinx Axi Ethernet device driver
 *
 * Copyright (c) 2008 Nissin Systems Co., Ltd.,  Yoshio Kashiwagi
 * Copyright (c) 2005-2008 DLA Systems,  David H. Lynch Jr. <dhlii@dlasys.net>
 * Copyright (c) 2008-2009 Secret Lab Technologies Ltd.
 * Copyright (c) 2010 - 2011 Michal Simek <monstr@monstr.eu>
 * Copyright (c) 2010 - 2011 PetaLogix
 * Copyright (c) 2019 - 2022 Calian Advanced Technologies
 * Copyright (c) 2010 - 2012 Xilinx, Inc. All rights reserved.
 *
 * This is a driver for the Xilinx Axi Ethernet which is used in the Virtex6
 * and Spartan6.
 *
 * TODO:
 *  - Add Axi Fifo support.
 *  - Factor out Axi DMA code into separate driver.
 *  - Test and fix basic multicast filtering.
 *  - Add support for extended multicast filtering.
 *  - Test basic VLAN support.
 *  - Add support for extended VLAN support.
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/etherdevice.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/of.h>
#include <linux/of_mdio.h>
#include <linux/of_net.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/skbuff.h>
#include <linux/math64.h>
#include <linux/phy.h>
#include <linux/mii.h>
#include <linux/ethtool.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/dma/xilinx_dma.h>
#include <linux/circ_buf.h>
#include <net/netdev_queues.h>

#include "xilinx_axienet.h"

/* Descriptors defines for Tx and Rx DMA */
#define TX_BD_NUM_DEFAULT		128
#define RX_BD_NUM_DEFAULT		1024
#define TX_BD_NUM_MIN			(MAX_SKB_FRAGS + 1)
#define TX_BD_NUM_MAX			4096
#define RX_BD_NUM_MAX			4096
#define DMA_NUM_APP_WORDS		5
#define LEN_APP				4
#define RX_BUF_NUM_DEFAULT		128

/* Must be shorter than length of ethtool_drvinfo.driver field to fit */
#define DRIVER_NAME		"xaxienet"
#define DRIVER_DESCRIPTION	"Xilinx Axi Ethernet driver"
#define DRIVER_VERSION		"1.00a"

#define AXIENET_REGS_N		40

static void axienet_rx_submit_desc(struct net_device *ndev);

/* Match table for of_platform binding */
static const struct of_device_id axienet_of_match[] = {
	{ .compatible = "xlnx,axi-ethernet-1.00.a", },
	{ .compatible = "xlnx,axi-ethernet-1.01.a", },
	{ .compatible = "xlnx,axi-ethernet-2.01.a", },
	{},
};

MODULE_DEVICE_TABLE(of, axienet_of_match);

/* Option table for setting up Axi Ethernet hardware options */
static struct axienet_option axienet_options[] = {
	/* Turn on jumbo packet support for both Rx and Tx */
	{
		.opt = XAE_OPTION_JUMBO,
		.reg = XAE_TC_OFFSET,
		.m_or = XAE_TC_JUM_MASK,
	}, {
		.opt = XAE_OPTION_JUMBO,
		.reg = XAE_RCW1_OFFSET,
		.m_or = XAE_RCW1_JUM_MASK,
	}, { /* Turn on VLAN packet support for both Rx and Tx */
		.opt = XAE_OPTION_VLAN,
		.reg = XAE_TC_OFFSET,
		.m_or = XAE_TC_VLAN_MASK,
	}, {
		.opt = XAE_OPTION_VLAN,
		.reg = XAE_RCW1_OFFSET,
		.m_or = XAE_RCW1_VLAN_MASK,
	}, { /* Turn on FCS stripping on receive packets */
		.opt = XAE_OPTION_FCS_STRIP,
		.reg = XAE_RCW1_OFFSET,
		.m_or = XAE_RCW1_FCS_MASK,
	}, { /* Turn on FCS insertion on transmit packets */
		.opt = XAE_OPTION_FCS_INSERT,
		.reg = XAE_TC_OFFSET,
		.m_or = XAE_TC_FCS_MASK,
	}, { /* Turn off length/type field checking on receive packets */
		.opt = XAE_OPTION_LENTYPE_ERR,
		.reg = XAE_RCW1_OFFSET,
		.m_or = XAE_RCW1_LT_DIS_MASK,
	}, { /* Turn on Rx flow control */
		.opt = XAE_OPTION_FLOW_CONTROL,
		.reg = XAE_FCC_OFFSET,
		.m_or = XAE_FCC_FCRX_MASK,
	}, { /* Turn on Tx flow control */
		.opt = XAE_OPTION_FLOW_CONTROL,
		.reg = XAE_FCC_OFFSET,
		.m_or = XAE_FCC_FCTX_MASK,
	}, { /* Turn on promiscuous frame filtering */
		.opt = XAE_OPTION_PROMISC,
		.reg = XAE_FMI_OFFSET,
		.m_or = XAE_FMI_PM_MASK,
	}, { /* Enable transmitter */
		.opt = XAE_OPTION_TXEN,
		.reg = XAE_TC_OFFSET,
		.m_or = XAE_TC_TX_MASK,
	}, { /* Enable receiver */
		.opt = XAE_OPTION_RXEN,
		.reg = XAE_RCW1_OFFSET,
		.m_or = XAE_RCW1_RX_MASK,
	},
	{}
};

static struct skbuf_dma_descriptor *axienet_get_rx_desc(struct axienet_local *lp, int i)
{
	return lp->rx_skb_ring[i & (RX_BUF_NUM_DEFAULT - 1)];
}

static struct skbuf_dma_descriptor *axienet_get_tx_desc(struct axienet_local *lp, int i)
{
	return lp->tx_skb_ring[i & (TX_BD_NUM_MAX - 1)];
}

/**
 * axienet_dma_in32 - Memory mapped Axi DMA register read
 * @lp:		Pointer to axienet local structure
 * @reg:	Address offset from the base address of the Axi DMA core
 *
 * Return: The contents of the Axi DMA register
 *
 * This function returns the contents of the corresponding Axi DMA register.
 */
static inline u32 axienet_dma_in32(struct axienet_local *lp, off_t reg)
{
	return ioread32(lp->dma_regs + reg);
}

static void desc_set_phys_addr(struct axienet_local *lp, dma_addr_t addr,
			       struct axidma_bd *desc)
{
	desc->phys = lower_32_bits(addr);
	if (lp->features & XAE_FEATURE_DMA_64BIT)
		desc->phys_msb = upper_32_bits(addr);
}

static dma_addr_t desc_get_phys_addr(struct axienet_local *lp,
				     struct axidma_bd *desc)
{
	dma_addr_t ret = desc->phys;

	if (lp->features & XAE_FEATURE_DMA_64BIT)
		ret |= ((dma_addr_t)desc->phys_msb << 16) << 16;

	return ret;
}

/**
 * axienet_dma_bd_release - Release buffer descriptor rings
 * @ndev:	Pointer to the net_device structure
 *
 * This function is used to release the descriptors allocated in
 * axienet_dma_bd_init. axienet_dma_bd_release is called when Axi Ethernet
 * driver stop api is called.
 */
static void axienet_dma_bd_release(struct net_device *ndev)
{
	int i;
	struct axienet_local *lp = netdev_priv(ndev);

	/* If we end up here, tx_bd_v must have been DMA allocated. */
	dma_free_coherent(lp->dev,
			  sizeof(*lp->tx_bd_v) * lp->tx_bd_num,
			  lp->tx_bd_v,
			  lp->tx_bd_p);

	if (!lp->rx_bd_v)
		return;

	for (i = 0; i < lp->rx_bd_num; i++) {
		dma_addr_t phys;

		/* A NULL skb means this descriptor has not been initialised
		 * at all.
		 */
		if (!lp->rx_bd_v[i].skb)
			break;

		dev_kfree_skb(lp->rx_bd_v[i].skb);

		/* For each descriptor, we programmed cntrl with the (non-zero)
		 * descriptor size, after it had been successfully allocated.
		 * So a non-zero value in there means we need to unmap it.
		 */
		if (lp->rx_bd_v[i].cntrl) {
			phys = desc_get_phys_addr(lp, &lp->rx_bd_v[i]);
			dma_unmap_single(lp->dev, phys,
					 lp->max_frm_size, DMA_FROM_DEVICE);
		}
	}

	dma_free_coherent(lp->dev,
			  sizeof(*lp->rx_bd_v) * lp->rx_bd_num,
			  lp->rx_bd_v,
			  lp->rx_bd_p);
}

/**
 * axienet_usec_to_timer - Calculate IRQ delay timer value
 * @lp:		Pointer to the axienet_local structure
 * @coalesce_usec: Microseconds to convert into timer value
 */
static u32 axienet_usec_to_timer(struct axienet_local *lp, u32 coalesce_usec)
{
	u32 result;
	u64 clk_rate = 125000000; /* arbitrary guess if no clock rate set */

	if (lp->axi_clk)
		clk_rate = clk_get_rate(lp->axi_clk);

	/* 1 Timeout Interval = 125 * (clock period of SG clock) */
	result = DIV64_U64_ROUND_CLOSEST((u64)coalesce_usec * clk_rate,
					 (u64)125000000);
	if (result > 255)
		result = 255;

	return result;
}

/**
 * axienet_dma_start - Set up DMA registers and start DMA operation
 * @lp:		Pointer to the axienet_local structure
 */
static void axienet_dma_start(struct axienet_local *lp)
{
	/* Start updating the Rx channel control register */
	lp->rx_dma_cr = (lp->coalesce_count_rx << XAXIDMA_COALESCE_SHIFT) |
			XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_ERROR_MASK;
	/* Only set interrupt delay timer if not generating an interrupt on
	 * the first RX packet. Otherwise leave at 0 to disable delay interrupt.
	 */
	if (lp->coalesce_count_rx > 1)
		lp->rx_dma_cr |= (axienet_usec_to_timer(lp, lp->coalesce_usec_rx)
					<< XAXIDMA_DELAY_SHIFT) |
				 XAXIDMA_IRQ_DELAY_MASK;
	axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, lp->rx_dma_cr);

	/* Start updating the Tx channel control register */
	lp->tx_dma_cr = (lp->coalesce_count_tx << XAXIDMA_COALESCE_SHIFT) |
			XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_ERROR_MASK;
	/* Only set interrupt delay timer if not generating an interrupt on
	 * the first TX packet. Otherwise leave at 0 to disable delay interrupt.
	 */
	if (lp->coalesce_count_tx > 1)
		lp->tx_dma_cr |= (axienet_usec_to_timer(lp, lp->coalesce_usec_tx)
					<< XAXIDMA_DELAY_SHIFT) |
				 XAXIDMA_IRQ_DELAY_MASK;
	axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, lp->tx_dma_cr);

	/* Populate the tail pointer and bring the Rx Axi DMA engine out of
	 * halted state. This will make the Rx side ready for reception.
	 */
	axienet_dma_out_addr(lp, XAXIDMA_RX_CDESC_OFFSET, lp->rx_bd_p);
	lp->rx_dma_cr |= XAXIDMA_CR_RUNSTOP_MASK;
	axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, lp->rx_dma_cr);
	axienet_dma_out_addr(lp, XAXIDMA_RX_TDESC_OFFSET, lp->rx_bd_p +
			     (sizeof(*lp->rx_bd_v) * (lp->rx_bd_num - 1)));

	/* Write to the RS (Run-stop) bit in the Tx channel control register.
	 * Tx channel is now ready to run. But only after we write to the
	 * tail pointer register that the Tx channel will start transmitting.
	 */
	axienet_dma_out_addr(lp, XAXIDMA_TX_CDESC_OFFSET, lp->tx_bd_p);
	lp->tx_dma_cr |= XAXIDMA_CR_RUNSTOP_MASK;
	axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, lp->tx_dma_cr);
}

/**
 * axienet_dma_bd_init - Setup buffer descriptor rings for Axi DMA
 * @ndev:	Pointer to the net_device structure
 *
 * Return: 0, on success -ENOMEM, on failure
 *
 * This function is called to initialize the Rx and Tx DMA descriptor
 * rings. This initializes the descriptors with required default values
 * and is called when Axi Ethernet driver reset is called.
 */
static int axienet_dma_bd_init(struct net_device *ndev)
{
	int i;
	struct sk_buff *skb;
	struct axienet_local *lp = netdev_priv(ndev);

	/* Reset the indexes which are used for accessing the BDs */
	lp->tx_bd_ci = 0;
	lp->tx_bd_tail = 0;
	lp->rx_bd_ci = 0;

	/* Allocate the Tx and Rx buffer descriptors. */
	lp->tx_bd_v = dma_alloc_coherent(lp->dev,
					 sizeof(*lp->tx_bd_v) * lp->tx_bd_num,
					 &lp->tx_bd_p, GFP_KERNEL);
	if (!lp->tx_bd_v)
		return -ENOMEM;

	lp->rx_bd_v = dma_alloc_coherent(lp->dev,
					 sizeof(*lp->rx_bd_v) * lp->rx_bd_num,
					 &lp->rx_bd_p, GFP_KERNEL);
	if (!lp->rx_bd_v)
		goto out;

	for (i = 0; i < lp->tx_bd_num; i++) {
		dma_addr_t addr = lp->tx_bd_p +
				  sizeof(*lp->tx_bd_v) *
				  ((i + 1) % lp->tx_bd_num);

		lp->tx_bd_v[i].next = lower_32_bits(addr);
		if (lp->features & XAE_FEATURE_DMA_64BIT)
			lp->tx_bd_v[i].next_msb = upper_32_bits(addr);
	}

	for (i = 0; i < lp->rx_bd_num; i++) {
		dma_addr_t addr;

		addr = lp->rx_bd_p + sizeof(*lp->rx_bd_v) *
			((i + 1) % lp->rx_bd_num);
		lp->rx_bd_v[i].next = lower_32_bits(addr);
		if (lp->features & XAE_FEATURE_DMA_64BIT)
			lp->rx_bd_v[i].next_msb = upper_32_bits(addr);

		skb = netdev_alloc_skb_ip_align(ndev, lp->max_frm_size);
		if (!skb)
			goto out;

		lp->rx_bd_v[i].skb = skb;
		addr = dma_map_single(lp->dev, skb->data,
				      lp->max_frm_size, DMA_FROM_DEVICE);
		if (dma_mapping_error(lp->dev, addr)) {
			netdev_err(ndev, "DMA mapping error\n");
			goto out;
		}
		desc_set_phys_addr(lp, addr, &lp->rx_bd_v[i]);

		lp->rx_bd_v[i].cntrl = lp->max_frm_size;
	}

	axienet_dma_start(lp);

	return 0;
out:
	axienet_dma_bd_release(ndev);
	return -ENOMEM;
}

/**
 * axienet_set_mac_address - Write the MAC address
 * @ndev:	Pointer to the net_device structure
 * @address:	6 byte Address to be written as MAC address
 *
 * This function is called to initialize the MAC address of the Axi Ethernet
 * core. It writes to the UAW0 and UAW1 registers of the core.
 */
static void axienet_set_mac_address(struct net_device *ndev,
				    const void *address)
{
	struct axienet_local *lp = netdev_priv(ndev);

	if (address)
		eth_hw_addr_set(ndev, address);
	if (!is_valid_ether_addr(ndev->dev_addr))
		eth_hw_addr_random(ndev);

	/* Set up unicast MAC address filter set its mac address */
	axienet_iow(lp, XAE_UAW0_OFFSET,
		    (ndev->dev_addr[0]) |
		    (ndev->dev_addr[1] << 8) |
		    (ndev->dev_addr[2] << 16) |
		    (ndev->dev_addr[3] << 24));
	axienet_iow(lp, XAE_UAW1_OFFSET,
		    (((axienet_ior(lp, XAE_UAW1_OFFSET)) &
		      ~XAE_UAW1_UNICASTADDR_MASK) |
		     (ndev->dev_addr[4] |
		     (ndev->dev_addr[5] << 8))));
}

/**
 * netdev_set_mac_address - Write the MAC address (from outside the driver)
 * @ndev:	Pointer to the net_device structure
 * @p:		6 byte Address to be written as MAC address
 *
 * Return: 0 for all conditions. Presently, there is no failure case.
 *
 * This function is called to initialize the MAC address of the Axi Ethernet
 * core. It calls the core specific axienet_set_mac_address. This is the
 * function that goes into net_device_ops structure entry ndo_set_mac_address.
 */
static int netdev_set_mac_address(struct net_device *ndev, void *p)
{
	struct sockaddr *addr = p;

	axienet_set_mac_address(ndev, addr->sa_data);
	return 0;
}

/**
 * axienet_set_multicast_list - Prepare the multicast table
 * @ndev:	Pointer to the net_device structure
 *
 * This function is called to initialize the multicast table during
 * initialization. The Axi Ethernet basic multicast support has a four-entry
 * multicast table which is initialized here. Additionally this function
 * goes into the net_device_ops structure entry ndo_set_multicast_list. This
 * means whenever the multicast table entries need to be updated this
 * function gets called.
 */
static void axienet_set_multicast_list(struct net_device *ndev)
{
	int i = 0;
	u32 reg, af0reg, af1reg;
	struct axienet_local *lp = netdev_priv(ndev);

	reg = axienet_ior(lp, XAE_FMI_OFFSET);
	reg &= ~XAE_FMI_PM_MASK;
	if (ndev->flags & IFF_PROMISC)
		reg |= XAE_FMI_PM_MASK;
	else
		reg &= ~XAE_FMI_PM_MASK;
	axienet_iow(lp, XAE_FMI_OFFSET, reg);

	if (ndev->flags & IFF_ALLMULTI ||
	    netdev_mc_count(ndev) > XAE_MULTICAST_CAM_TABLE_NUM) {
		reg &= 0xFFFFFF00;
		axienet_iow(lp, XAE_FMI_OFFSET, reg);
		axienet_iow(lp, XAE_AF0_OFFSET, 1); /* Multicast bit */
		axienet_iow(lp, XAE_AF1_OFFSET, 0);
		axienet_iow(lp, XAE_AM0_OFFSET, 1); /* ditto */
		axienet_iow(lp, XAE_AM1_OFFSET, 0);
		axienet_iow(lp, XAE_FFE_OFFSET, 1);
		i = 1;
	} else if (!netdev_mc_empty(ndev)) {
		struct netdev_hw_addr *ha;

		netdev_for_each_mc_addr(ha, ndev) {
			if (i >= XAE_MULTICAST_CAM_TABLE_NUM)
				break;

			af0reg = (ha->addr[0]);
			af0reg |= (ha->addr[1] << 8);
			af0reg |= (ha->addr[2] << 16);
			af0reg |= (ha->addr[3] << 24);

			af1reg = (ha->addr[4]);
			af1reg |= (ha->addr[5] << 8);

			reg &= 0xFFFFFF00;
			reg |= i;

			axienet_iow(lp, XAE_FMI_OFFSET, reg);
			axienet_iow(lp, XAE_AF0_OFFSET, af0reg);
			axienet_iow(lp, XAE_AF1_OFFSET, af1reg);
			axienet_iow(lp, XAE_AM0_OFFSET, 0xffffffff);
			axienet_iow(lp, XAE_AM1_OFFSET, 0x0000ffff);
			axienet_iow(lp, XAE_FFE_OFFSET, 1);
			i++;
		}
	}

	for (; i < XAE_MULTICAST_CAM_TABLE_NUM; i++) {
		reg &= 0xFFFFFF00;
		reg |= i;
		axienet_iow(lp, XAE_FMI_OFFSET, reg);
		axienet_iow(lp, XAE_FFE_OFFSET, 0);
	}
}

/**
 * axienet_setoptions - Set an Axi Ethernet option
 * @ndev:	Pointer to the net_device structure
 * @options:	Option to be enabled/disabled
 *
 * The Axi Ethernet core has multiple features which can be selectively turned
 * on or off. The typical options could be jumbo frame option, basic VLAN
 * option, promiscuous mode option etc. This function is used to set or clear
 * these options in the Axi Ethernet hardware. This is done through
 * axienet_option structure .
 */
static void axienet_setoptions(struct net_device *ndev, u32 options)
{
	int reg;
	struct axienet_local *lp = netdev_priv(ndev);
	struct axienet_option *tp = &axienet_options[0];

	while (tp->opt) {
		reg = ((axienet_ior(lp, tp->reg)) & ~(tp->m_or));
		if (options & tp->opt)
			reg |= tp->m_or;
		axienet_iow(lp, tp->reg, reg);
		tp++;
	}

	lp->options |= options;
}

static u64 axienet_stat(struct axienet_local *lp, enum temac_stat stat)
{
	u32 counter;

	if (lp->reset_in_progress)
		return lp->hw_stat_base[stat];

	counter = axienet_ior(lp, XAE_STATS_OFFSET + stat * 8);
	return lp->hw_stat_base[stat] + (counter - lp->hw_last_counter[stat]);
}

static void axienet_stats_update(struct axienet_local *lp, bool reset)
{
	enum temac_stat stat;

	write_seqcount_begin(&lp->hw_stats_seqcount);
	lp->reset_in_progress = reset;
	for (stat = 0; stat < STAT_COUNT; stat++) {
		u32 counter = axienet_ior(lp, XAE_STATS_OFFSET + stat * 8);

		lp->hw_stat_base[stat] += counter - lp->hw_last_counter[stat];
		lp->hw_last_counter[stat] = counter;
	}
	write_seqcount_end(&lp->hw_stats_seqcount);
}

static void axienet_refresh_stats(struct work_struct *work)
{
	struct axienet_local *lp = container_of(work, struct axienet_local,
						stats_work.work);

	mutex_lock(&lp->stats_lock);
	axienet_stats_update(lp, false);
	mutex_unlock(&lp->stats_lock);

	/* Just less than 2^32 bytes at 2.5 GBit/s */
	schedule_delayed_work(&lp->stats_work, 13 * HZ);
}

static int __axienet_device_reset(struct axienet_local *lp)
{
	u32 value;
	int ret;

	/* Save statistics counters in case they will be reset */
	mutex_lock(&lp->stats_lock);
	if (lp->features & XAE_FEATURE_STATS)
		axienet_stats_update(lp, true);

	/* Reset Axi DMA. This would reset Axi Ethernet core as well. The reset
	 * process of Axi DMA takes a while to complete as all pending
	 * commands/transfers will be flushed or completed during this
	 * reset process.
	 * Note that even though both TX and RX have their own reset register,
	 * they both reset the entire DMA core, so only one needs to be used.
	 */
	axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, XAXIDMA_CR_RESET_MASK);
	ret = read_poll_timeout(axienet_dma_in32, value,
				!(value & XAXIDMA_CR_RESET_MASK),
				DELAY_OF_ONE_MILLISEC, 50000, false, lp,
				XAXIDMA_TX_CR_OFFSET);
	if (ret) {
		dev_err(lp->dev, "%s: DMA reset timeout!\n", __func__);
		goto out;
	}

	/* Wait for PhyRstCmplt bit to be set, indicating the PHY reset has finished */
	ret = read_poll_timeout(axienet_ior, value,
				value & XAE_INT_PHYRSTCMPLT_MASK,
				DELAY_OF_ONE_MILLISEC, 50000, false, lp,
				XAE_IS_OFFSET);
	if (ret) {
		dev_err(lp->dev, "%s: timeout waiting for PhyRstCmplt\n", __func__);
		goto out;
	}

	/* Update statistics counters with new values */
	if (lp->features & XAE_FEATURE_STATS) {
		enum temac_stat stat;

		write_seqcount_begin(&lp->hw_stats_seqcount);
		lp->reset_in_progress = false;
		for (stat = 0; stat < STAT_COUNT; stat++) {
			u32 counter =
				axienet_ior(lp, XAE_STATS_OFFSET + stat * 8);

			lp->hw_stat_base[stat] +=
				lp->hw_last_counter[stat] - counter;
			lp->hw_last_counter[stat] = counter;
		}
		write_seqcount_end(&lp->hw_stats_seqcount);
	}

out:
	mutex_unlock(&lp->stats_lock);
	return ret;
}

/**
 * axienet_dma_stop - Stop DMA operation
 * @lp:		Pointer to the axienet_local structure
 */
static void axienet_dma_stop(struct axienet_local *lp)
{
	int count;
	u32 cr, sr;

	cr = axienet_dma_in32(lp, XAXIDMA_RX_CR_OFFSET);
	cr &= ~(XAXIDMA_CR_RUNSTOP_MASK | XAXIDMA_IRQ_ALL_MASK);
	axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, cr);
	synchronize_irq(lp->rx_irq);

	cr = axienet_dma_in32(lp, XAXIDMA_TX_CR_OFFSET);
	cr &= ~(XAXIDMA_CR_RUNSTOP_MASK | XAXIDMA_IRQ_ALL_MASK);
	axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, cr);
	synchronize_irq(lp->tx_irq);

	/* Give DMAs a chance to halt gracefully */
	sr = axienet_dma_in32(lp, XAXIDMA_RX_SR_OFFSET);
	for (count = 0; !(sr & XAXIDMA_SR_HALT_MASK) && count < 5; ++count) {
		msleep(20);
		sr = axienet_dma_in32(lp, XAXIDMA_RX_SR_OFFSET);
	}

	sr = axienet_dma_in32(lp, XAXIDMA_TX_SR_OFFSET);
	for (count = 0; !(sr & XAXIDMA_SR_HALT_MASK) && count < 5; ++count) {
		msleep(20);
		sr = axienet_dma_in32(lp, XAXIDMA_TX_SR_OFFSET);
	}

	/* Do a reset to ensure DMA is really stopped */
	axienet_lock_mii(lp);
	__axienet_device_reset(lp);
	axienet_unlock_mii(lp);
}

/**
 * axienet_device_reset - Reset and initialize the Axi Ethernet hardware.
 * @ndev:	Pointer to the net_device structure
 *
 * This function is called to reset and initialize the Axi Ethernet core. This
 * is typically called during initialization. It does a reset of the Axi DMA
 * Rx/Tx channels and initializes the Axi DMA BDs. Since Axi DMA reset lines
 * are connected to Axi Ethernet reset lines, this in turn resets the Axi
 * Ethernet core. No separate hardware reset is done for the Axi Ethernet
 * core.
 * Returns 0 on success or a negative error number otherwise.
 */
static int axienet_device_reset(struct net_device *ndev)
{
	u32 axienet_status;
	struct axienet_local *lp = netdev_priv(ndev);
	int ret;

	lp->max_frm_size = XAE_MAX_VLAN_FRAME_SIZE;
	lp->options |= XAE_OPTION_VLAN;
	lp->options &= (~XAE_OPTION_JUMBO);

	if (ndev->mtu > XAE_MTU && ndev->mtu <= XAE_JUMBO_MTU) {
		lp->max_frm_size = ndev->mtu + VLAN_ETH_HLEN +
					XAE_TRL_SIZE;

		if (lp->max_frm_size <= lp->rxmem)
			lp->options |= XAE_OPTION_JUMBO;
	}

	if (!lp->use_dmaengine) {
		ret = __axienet_device_reset(lp);
		if (ret)
			return ret;

		ret = axienet_dma_bd_init(ndev);
		if (ret) {
			netdev_err(ndev, "%s: descriptor allocation failed\n",
				   __func__);
			return ret;
		}
	}

	axienet_status = axienet_ior(lp, XAE_RCW1_OFFSET);
	axienet_status &= ~XAE_RCW1_RX_MASK;
	axienet_iow(lp, XAE_RCW1_OFFSET, axienet_status);

	axienet_status = axienet_ior(lp, XAE_IP_OFFSET);
	if (axienet_status & XAE_INT_RXRJECT_MASK)
		axienet_iow(lp, XAE_IS_OFFSET, XAE_INT_RXRJECT_MASK);
	axienet_iow(lp, XAE_IE_OFFSET, lp->eth_irq > 0 ?
		    XAE_INT_RECV_ERROR_MASK : 0);

	axienet_iow(lp, XAE_FCC_OFFSET, XAE_FCC_FCRX_MASK);

	/* Sync default options with HW but leave receiver and
	 * transmitter disabled.
	 */
	axienet_setoptions(ndev, lp->options &
			   ~(XAE_OPTION_TXEN | XAE_OPTION_RXEN));
	axienet_set_mac_address(ndev, NULL);
	axienet_set_multicast_list(ndev);
	axienet_setoptions(ndev, lp->options);

	netif_trans_update(ndev);

	return 0;
}

/**
 * axienet_free_tx_chain - Clean up a series of linked TX descriptors.
 * @lp:		Pointer to the axienet_local structure
 * @first_bd:	Index of first descriptor to clean up
 * @nr_bds:	Max number of descriptors to clean up
 * @force:	Whether to clean descriptors even if not complete
 * @sizep:	Pointer to a u32 filled with the total sum of all bytes
 *		in all cleaned-up descriptors. Ignored if NULL.
 * @budget:	NAPI budget (use 0 when not called from NAPI poll)
 *
 * Would either be called after a successful transmit operation, or after
 * there was an error when setting up the chain.
 * Returns the number of packets handled.
 */
static int axienet_free_tx_chain(struct axienet_local *lp, u32 first_bd,
				 int nr_bds, bool force, u32 *sizep, int budget)
{
	struct axidma_bd *cur_p;
	unsigned int status;
	int i, packets = 0;
	dma_addr_t phys;

	for (i = 0; i < nr_bds; i++) {
		cur_p = &lp->tx_bd_v[(first_bd + i) % lp->tx_bd_num];
		status = cur_p->status;

		/* If force is not specified, clean up only descriptors
		 * that have been completed by the MAC.
		 */
		if (!force && !(status & XAXIDMA_BD_STS_COMPLETE_MASK))
			break;

		/* Ensure we see complete descriptor update */
		dma_rmb();
		phys = desc_get_phys_addr(lp, cur_p);
		dma_unmap_single(lp->dev, phys,
				 (cur_p->cntrl & XAXIDMA_BD_CTRL_LENGTH_MASK),
				 DMA_TO_DEVICE);

		if (cur_p->skb && (status & XAXIDMA_BD_STS_COMPLETE_MASK)) {
			napi_consume_skb(cur_p->skb, budget);
			packets++;
		}

		cur_p->app0 = 0;
		cur_p->app1 = 0;
		cur_p->app2 = 0;
		cur_p->app4 = 0;
		cur_p->skb = NULL;
		/* ensure our transmit path and device don't prematurely see status cleared */
		wmb();
		cur_p->cntrl = 0;
		cur_p->status = 0;

		if (sizep)
			*sizep += status & XAXIDMA_BD_STS_ACTUAL_LEN_MASK;
	}

	if (!force) {
		lp->tx_bd_ci += i;
		if (lp->tx_bd_ci >= lp->tx_bd_num)
			lp->tx_bd_ci %= lp->tx_bd_num;
	}

	return packets;
}

/**
 * axienet_check_tx_bd_space - Checks if a BD/group of BDs are currently busy
 * @lp:		Pointer to the axienet_local structure
 * @num_frag:	The number of BDs to check for
 *
 * Return: 0, on success
 *	    NETDEV_TX_BUSY, if any of the descriptors are not free
 *
 * This function is invoked before BDs are allocated and transmission starts.
 * This function returns 0 if a BD or group of BDs can be allocated for
 * transmission. If the BD or any of the BDs are not free the function
 * returns a busy status.
 */
static inline int axienet_check_tx_bd_space(struct axienet_local *lp,
					    int num_frag)
{
	struct axidma_bd *cur_p;

	/* Ensure we see all descriptor updates from device or TX polling */
	rmb();
	cur_p = &lp->tx_bd_v[(READ_ONCE(lp->tx_bd_tail) + num_frag) %
			     lp->tx_bd_num];
	if (cur_p->cntrl)
		return NETDEV_TX_BUSY;
	return 0;
}

/**
 * axienet_dma_tx_cb - DMA engine callback for TX channel.
 * @data:       Pointer to the axienet_local structure.
 * @result:     error reporting through dmaengine_result.
 * This function is called by dmaengine driver for TX channel to notify
 * that the transmit is done.
 */
static void axienet_dma_tx_cb(void *data, const struct dmaengine_result *result)
{
	struct skbuf_dma_descriptor *skbuf_dma;
	struct axienet_local *lp = data;
	struct netdev_queue *txq;
	int len;

	skbuf_dma = axienet_get_tx_desc(lp, lp->tx_ring_tail++);
	len = skbuf_dma->skb->len;
	txq = skb_get_tx_queue(lp->ndev, skbuf_dma->skb);
	u64_stats_update_begin(&lp->tx_stat_sync);
	u64_stats_add(&lp->tx_bytes, len);
	u64_stats_add(&lp->tx_packets, 1);
	u64_stats_update_end(&lp->tx_stat_sync);
	dma_unmap_sg(lp->dev, skbuf_dma->sgl, skbuf_dma->sg_len, DMA_TO_DEVICE);
	dev_consume_skb_any(skbuf_dma->skb);
	netif_txq_completed_wake(txq, 1, len,
				 CIRC_SPACE(lp->tx_ring_head, lp->tx_ring_tail, TX_BD_NUM_MAX),
				 2 * MAX_SKB_FRAGS);
}

/**
 * axienet_start_xmit_dmaengine - Starts the transmission.
 * @skb:        sk_buff pointer that contains data to be Txed.
 * @ndev:       Pointer to net_device structure.
 *
 * Return: NETDEV_TX_OK on success or any non space errors.
 *         NETDEV_TX_BUSY when free element in TX skb ring buffer
 *         is not available.
 *
 * This function is invoked to initiate transmission. The
 * function sets the skbs, register dma callback API and submit
 * the dma transaction.
 * Additionally if checksum offloading is supported,
 * it populates AXI Stream Control fields with appropriate values.
 */
static netdev_tx_t
axienet_start_xmit_dmaengine(struct sk_buff *skb, struct net_device *ndev)
{
	struct dma_async_tx_descriptor *dma_tx_desc = NULL;
	struct axienet_local *lp = netdev_priv(ndev);
	u32 app_metadata[DMA_NUM_APP_WORDS] = {0};
	struct skbuf_dma_descriptor *skbuf_dma;
	struct dma_device *dma_dev;
	struct netdev_queue *txq;
	u32 csum_start_off;
	u32 csum_index_off;
	int sg_len;
	int ret;

	dma_dev = lp->tx_chan->device;
	sg_len = skb_shinfo(skb)->nr_frags + 1;
	if (CIRC_SPACE(lp->tx_ring_head, lp->tx_ring_tail, TX_BD_NUM_MAX) <= sg_len) {
		netif_stop_queue(ndev);
		if (net_ratelimit())
			netdev_warn(ndev, "TX ring unexpectedly full\n");
		return NETDEV_TX_BUSY;
	}

	skbuf_dma = axienet_get_tx_desc(lp, lp->tx_ring_head);
	if (!skbuf_dma)
		goto xmit_error_drop_skb;

	lp->tx_ring_head++;
	sg_init_table(skbuf_dma->sgl, sg_len);
	ret = skb_to_sgvec(skb, skbuf_dma->sgl, 0, skb->len);
	if (ret < 0)
		goto xmit_error_drop_skb;

	ret = dma_map_sg(lp->dev, skbuf_dma->sgl, sg_len, DMA_TO_DEVICE);
	if (!ret)
		goto xmit_error_drop_skb;

	/* Fill up app fields for checksum */
	if (skb->ip_summed == CHECKSUM_PARTIAL) {
		if (lp->features & XAE_FEATURE_FULL_TX_CSUM) {
			/* Tx Full Checksum Offload Enabled */
			app_metadata[0] |= 2;
		} else if (lp->features & XAE_FEATURE_PARTIAL_TX_CSUM) {
			csum_start_off = skb_transport_offset(skb);
			csum_index_off = csum_start_off + skb->csum_offset;
			/* Tx Partial Checksum Offload Enabled */
			app_metadata[0] |= 1;
			app_metadata[1] = (csum_start_off << 16) | csum_index_off;
		}
	} else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
		app_metadata[0] |= 2; /* Tx Full Checksum Offload Enabled */
	}

	dma_tx_desc = dma_dev->device_prep_slave_sg(lp->tx_chan, skbuf_dma->sgl,
			sg_len, DMA_MEM_TO_DEV,
			DMA_PREP_INTERRUPT, (void *)app_metadata);
	if (!dma_tx_desc)
		goto xmit_error_unmap_sg;

	skbuf_dma->skb = skb;
	skbuf_dma->sg_len = sg_len;
	dma_tx_desc->callback_param = lp;
	dma_tx_desc->callback_result = axienet_dma_tx_cb;
	dmaengine_submit(dma_tx_desc);
	dma_async_issue_pending(lp->tx_chan);
	txq = skb_get_tx_queue(lp->ndev, skb);
	netdev_tx_sent_queue(txq, skb->len);
	netif_txq_maybe_stop(txq, CIRC_SPACE(lp->tx_ring_head, lp->tx_ring_tail, TX_BD_NUM_MAX),
			     MAX_SKB_FRAGS + 1, 2 * MAX_SKB_FRAGS);

	return NETDEV_TX_OK;

xmit_error_unmap_sg:
	dma_unmap_sg(lp->dev, skbuf_dma->sgl, sg_len, DMA_TO_DEVICE);
xmit_error_drop_skb:
	dev_kfree_skb_any(skb);
	return NETDEV_TX_OK;
}

/**
 * axienet_tx_poll - Invoked once a transmit is completed by the
 * Axi DMA Tx channel.
 * @napi:	Pointer to NAPI structure.
 * @budget:	Max number of TX packets to process.
 *
 * Return: Number of TX packets processed.
 *
 * This function is invoked from the NAPI processing to notify the completion
 * of transmit operation. It clears fields in the corresponding Tx BDs and
 * unmaps the corresponding buffer so that CPU can regain ownership of the
 * buffer. It finally invokes "netif_wake_queue" to restart transmission if
 * required.
 */
static int axienet_tx_poll(struct napi_struct *napi, int budget)
{
	struct axienet_local *lp = container_of(napi, struct axienet_local, napi_tx);
	struct net_device *ndev = lp->ndev;
	u32 size = 0;
	int packets;

	packets = axienet_free_tx_chain(lp, lp->tx_bd_ci, lp->tx_bd_num, false,
					&size, budget);

	if (packets) {
		u64_stats_update_begin(&lp->tx_stat_sync);
		u64_stats_add(&lp->tx_packets, packets);
		u64_stats_add(&lp->tx_bytes, size);
		u64_stats_update_end(&lp->tx_stat_sync);

		/* Matches barrier in axienet_start_xmit */
		smp_mb();

		if (!axienet_check_tx_bd_space(lp, MAX_SKB_FRAGS + 1))
			netif_wake_queue(ndev);
	}

	if (packets < budget && napi_complete_done(napi, packets)) {
		/* Re-enable TX completion interrupts. This should
		 * cause an immediate interrupt if any TX packets are
		 * already pending.
		 */
		axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, lp->tx_dma_cr);
	}
	return packets;
}

/**
 * axienet_start_xmit - Starts the transmission.
 * @skb:	sk_buff pointer that contains data to be Txed.
 * @ndev:	Pointer to net_device structure.
 *
 * Return: NETDEV_TX_OK, on success
 *	    NETDEV_TX_BUSY, if any of the descriptors are not free
 *
 * This function is invoked from upper layers to initiate transmission. The
 * function uses the next available free BDs and populates their fields to
 * start the transmission. Additionally if checksum offloading is supported,
 * it populates AXI Stream Control fields with appropriate values.
 */
static netdev_tx_t
axienet_start_xmit(struct sk_buff *skb, struct net_device *ndev)
{
	u32 ii;
	u32 num_frag;
	u32 csum_start_off;
	u32 csum_index_off;
	skb_frag_t *frag;
	dma_addr_t tail_p, phys;
	u32 orig_tail_ptr, new_tail_ptr;
	struct axienet_local *lp = netdev_priv(ndev);
	struct axidma_bd *cur_p;

	orig_tail_ptr = lp->tx_bd_tail;
	new_tail_ptr = orig_tail_ptr;

	num_frag = skb_shinfo(skb)->nr_frags;
	cur_p = &lp->tx_bd_v[orig_tail_ptr];

	if (axienet_check_tx_bd_space(lp, num_frag + 1)) {
		/* Should not happen as last start_xmit call should have
		 * checked for sufficient space and queue should only be
		 * woken when sufficient space is available.
		 */
		netif_stop_queue(ndev);
		if (net_ratelimit())
			netdev_warn(ndev, "TX ring unexpectedly full\n");
		return NETDEV_TX_BUSY;
	}

	if (skb->ip_summed == CHECKSUM_PARTIAL) {
		if (lp->features & XAE_FEATURE_FULL_TX_CSUM) {
			/* Tx Full Checksum Offload Enabled */
			cur_p->app0 |= 2;
		} else if (lp->features & XAE_FEATURE_PARTIAL_TX_CSUM) {
			csum_start_off = skb_transport_offset(skb);
			csum_index_off = csum_start_off + skb->csum_offset;
			/* Tx Partial Checksum Offload Enabled */
			cur_p->app0 |= 1;
			cur_p->app1 = (csum_start_off << 16) | csum_index_off;
		}
	} else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
		cur_p->app0 |= 2; /* Tx Full Checksum Offload Enabled */
	}

	phys = dma_map_single(lp->dev, skb->data,
			      skb_headlen(skb), DMA_TO_DEVICE);
	if (unlikely(dma_mapping_error(lp->dev, phys))) {
		if (net_ratelimit())
			netdev_err(ndev, "TX DMA mapping error\n");
		ndev->stats.tx_dropped++;
		dev_kfree_skb_any(skb);
		return NETDEV_TX_OK;
	}
	desc_set_phys_addr(lp, phys, cur_p);
	cur_p->cntrl = skb_headlen(skb) | XAXIDMA_BD_CTRL_TXSOF_MASK;

	for (ii = 0; ii < num_frag; ii++) {
		if (++new_tail_ptr >= lp->tx_bd_num)
			new_tail_ptr = 0;
		cur_p = &lp->tx_bd_v[new_tail_ptr];
		frag = &skb_shinfo(skb)->frags[ii];
		phys = dma_map_single(lp->dev,
				      skb_frag_address(frag),
				      skb_frag_size(frag),
				      DMA_TO_DEVICE);
		if (unlikely(dma_mapping_error(lp->dev, phys))) {
			if (net_ratelimit())
				netdev_err(ndev, "TX DMA mapping error\n");
			ndev->stats.tx_dropped++;
			axienet_free_tx_chain(lp, orig_tail_ptr, ii + 1,
					      true, NULL, 0);
			dev_kfree_skb_any(skb);
			return NETDEV_TX_OK;
		}
		desc_set_phys_addr(lp, phys, cur_p);
		cur_p->cntrl = skb_frag_size(frag);
	}

	cur_p->cntrl |= XAXIDMA_BD_CTRL_TXEOF_MASK;
	cur_p->skb = skb;

	tail_p = lp->tx_bd_p + sizeof(*lp->tx_bd_v) * new_tail_ptr;
	if (++new_tail_ptr >= lp->tx_bd_num)
		new_tail_ptr = 0;
	WRITE_ONCE(lp->tx_bd_tail, new_tail_ptr);

	/* Start the transfer */
	axienet_dma_out_addr(lp, XAXIDMA_TX_TDESC_OFFSET, tail_p);

	/* Stop queue if next transmit may not have space */
	if (axienet_check_tx_bd_space(lp, MAX_SKB_FRAGS + 1)) {
		netif_stop_queue(ndev);

		/* Matches barrier in axienet_tx_poll */
		smp_mb();

		/* Space might have just been freed - check again */
		if (!axienet_check_tx_bd_space(lp, MAX_SKB_FRAGS + 1))
			netif_wake_queue(ndev);
	}

	return NETDEV_TX_OK;
}

/**
 * axienet_dma_rx_cb - DMA engine callback for RX channel.
 * @data:       Pointer to the skbuf_dma_descriptor structure.
 * @result:     error reporting through dmaengine_result.
 * This function is called by dmaengine driver for RX channel to notify
 * that the packet is received.
 */
static void axienet_dma_rx_cb(void *data, const struct dmaengine_result *result)
{
	struct skbuf_dma_descriptor *skbuf_dma;
	size_t meta_len, meta_max_len, rx_len;
	struct axienet_local *lp = data;
	struct sk_buff *skb;
	u32 *app_metadata;

	skbuf_dma = axienet_get_rx_desc(lp, lp->rx_ring_tail++);
	skb = skbuf_dma->skb;
	app_metadata = dmaengine_desc_get_metadata_ptr(skbuf_dma->desc, &meta_len,
						       &meta_max_len);
	dma_unmap_single(lp->dev, skbuf_dma->dma_address, lp->max_frm_size,
			 DMA_FROM_DEVICE);
	/* TODO: Derive app word index programmatically */
	rx_len = (app_metadata[LEN_APP] & 0xFFFF);
	skb_put(skb, rx_len);
	skb->protocol = eth_type_trans(skb, lp->ndev);
	skb->ip_summed = CHECKSUM_NONE;

	__netif_rx(skb);
	u64_stats_update_begin(&lp->rx_stat_sync);
	u64_stats_add(&lp->rx_packets, 1);
	u64_stats_add(&lp->rx_bytes, rx_len);
	u64_stats_update_end(&lp->rx_stat_sync);
	axienet_rx_submit_desc(lp->ndev);
	dma_async_issue_pending(lp->rx_chan);
}

/**
 * axienet_rx_poll - Triggered by RX ISR to complete the BD processing.
 * @napi:	Pointer to NAPI structure.
 * @budget:	Max number of RX packets to process.
 *
 * Return: Number of RX packets processed.
 */
static int axienet_rx_poll(struct napi_struct *napi, int budget)
{
	u32 length;
	u32 csumstatus;
	u32 size = 0;
	int packets = 0;
	dma_addr_t tail_p = 0;
	struct axidma_bd *cur_p;
	struct sk_buff *skb, *new_skb;
	struct axienet_local *lp = container_of(napi, struct axienet_local, napi_rx);

	cur_p = &lp->rx_bd_v[lp->rx_bd_ci];

	while (packets < budget && (cur_p->status & XAXIDMA_BD_STS_COMPLETE_MASK)) {
		dma_addr_t phys;

		/* Ensure we see complete descriptor update */
		dma_rmb();

		skb = cur_p->skb;
		cur_p->skb = NULL;

		/* skb could be NULL if a previous pass already received the
		 * packet for this slot in the ring, but failed to refill it
		 * with a newly allocated buffer. In this case, don't try to
		 * receive it again.
		 */
		if (likely(skb)) {
			length = cur_p->app4 & 0x0000FFFF;

			phys = desc_get_phys_addr(lp, cur_p);
			dma_unmap_single(lp->dev, phys, lp->max_frm_size,
					 DMA_FROM_DEVICE);

			skb_put(skb, length);
			skb->protocol = eth_type_trans(skb, lp->ndev);
			/*skb_checksum_none_assert(skb);*/
			skb->ip_summed = CHECKSUM_NONE;

			/* if we're doing Rx csum offload, set it up */
			if (lp->features & XAE_FEATURE_FULL_RX_CSUM) {
				csumstatus = (cur_p->app2 &
					      XAE_FULL_CSUM_STATUS_MASK) >> 3;
				if (csumstatus == XAE_IP_TCP_CSUM_VALIDATED ||
				    csumstatus == XAE_IP_UDP_CSUM_VALIDATED) {
					skb->ip_summed = CHECKSUM_UNNECESSARY;
				}
			} else if (lp->features & XAE_FEATURE_PARTIAL_RX_CSUM) {
				skb->csum = be32_to_cpu(cur_p->app3 & 0xFFFF);
				skb->ip_summed = CHECKSUM_COMPLETE;
			}

			napi_gro_receive(napi, skb);

			size += length;
			packets++;
		}

		new_skb = napi_alloc_skb(napi, lp->max_frm_size);
		if (!new_skb)
			break;

		phys = dma_map_single(lp->dev, new_skb->data,
				      lp->max_frm_size,
				      DMA_FROM_DEVICE);
		if (unlikely(dma_mapping_error(lp->dev, phys))) {
			if (net_ratelimit())
				netdev_err(lp->ndev, "RX DMA mapping error\n");
			dev_kfree_skb(new_skb);
			break;
		}
		desc_set_phys_addr(lp, phys, cur_p);

		cur_p->cntrl = lp->max_frm_size;
		cur_p->status = 0;
		cur_p->skb = new_skb;

		/* Only update tail_p to mark this slot as usable after it has
		 * been successfully refilled.
		 */
		tail_p = lp->rx_bd_p + sizeof(*lp->rx_bd_v) * lp->rx_bd_ci;

		if (++lp->rx_bd_ci >= lp->rx_bd_num)
			lp->rx_bd_ci = 0;
		cur_p = &lp->rx_bd_v[lp->rx_bd_ci];
	}

	u64_stats_update_begin(&lp->rx_stat_sync);
	u64_stats_add(&lp->rx_packets, packets);
	u64_stats_add(&lp->rx_bytes, size);
	u64_stats_update_end(&lp->rx_stat_sync);

	if (tail_p)
		axienet_dma_out_addr(lp, XAXIDMA_RX_TDESC_OFFSET, tail_p);

	if (packets < budget && napi_complete_done(napi, packets)) {
		/* Re-enable RX completion interrupts. This should
		 * cause an immediate interrupt if any RX packets are
		 * already pending.
		 */
		axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, lp->rx_dma_cr);
	}
	return packets;
}

/**
 * axienet_tx_irq - Tx Done Isr.
 * @irq:	irq number
 * @_ndev:	net_device pointer
 *
 * Return: IRQ_HANDLED if device generated a TX interrupt, IRQ_NONE otherwise.
 *
 * This is the Axi DMA Tx done Isr. It invokes NAPI polling to complete the
 * TX BD processing.
 */
static irqreturn_t axienet_tx_irq(int irq, void *_ndev)
{
	unsigned int status;
	struct net_device *ndev = _ndev;
	struct axienet_local *lp = netdev_priv(ndev);

	status = axienet_dma_in32(lp, XAXIDMA_TX_SR_OFFSET);

	if (!(status & XAXIDMA_IRQ_ALL_MASK))
		return IRQ_NONE;

	axienet_dma_out32(lp, XAXIDMA_TX_SR_OFFSET, status);

	if (unlikely(status & XAXIDMA_IRQ_ERROR_MASK)) {
		netdev_err(ndev, "DMA Tx error 0x%x\n", status);
		netdev_err(ndev, "Current BD is at: 0x%x%08x\n",
			   (lp->tx_bd_v[lp->tx_bd_ci]).phys_msb,
			   (lp->tx_bd_v[lp->tx_bd_ci]).phys);
		schedule_work(&lp->dma_err_task);
	} else {
		/* Disable further TX completion interrupts and schedule
		 * NAPI to handle the completions.
		 */
		u32 cr = lp->tx_dma_cr;

		cr &= ~(XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_DELAY_MASK);
		if (napi_schedule_prep(&lp->napi_tx)) {
			axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, cr);
			__napi_schedule(&lp->napi_tx);
		}
	}

	return IRQ_HANDLED;
}

/**
 * axienet_rx_irq - Rx Isr.
 * @irq:	irq number
 * @_ndev:	net_device pointer
 *
 * Return: IRQ_HANDLED if device generated a RX interrupt, IRQ_NONE otherwise.
 *
 * This is the Axi DMA Rx Isr. It invokes NAPI polling to complete the RX BD
 * processing.
 */
static irqreturn_t axienet_rx_irq(int irq, void *_ndev)
{
	unsigned int status;
	struct net_device *ndev = _ndev;
	struct axienet_local *lp = netdev_priv(ndev);

	status = axienet_dma_in32(lp, XAXIDMA_RX_SR_OFFSET);

	if (!(status & XAXIDMA_IRQ_ALL_MASK))
		return IRQ_NONE;

	axienet_dma_out32(lp, XAXIDMA_RX_SR_OFFSET, status);

	if (unlikely(status & XAXIDMA_IRQ_ERROR_MASK)) {
		netdev_err(ndev, "DMA Rx error 0x%x\n", status);
		netdev_err(ndev, "Current BD is at: 0x%x%08x\n",
			   (lp->rx_bd_v[lp->rx_bd_ci]).phys_msb,
			   (lp->rx_bd_v[lp->rx_bd_ci]).phys);
		schedule_work(&lp->dma_err_task);
	} else {
		/* Disable further RX completion interrupts and schedule
		 * NAPI receive.
		 */
		u32 cr = lp->rx_dma_cr;

		cr &= ~(XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_DELAY_MASK);
		if (napi_schedule_prep(&lp->napi_rx)) {
			axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, cr);
			__napi_schedule(&lp->napi_rx);
		}
	}

	return IRQ_HANDLED;
}

/**
 * axienet_eth_irq - Ethernet core Isr.
 * @irq:	irq number
 * @_ndev:	net_device pointer
 *
 * Return: IRQ_HANDLED if device generated a core interrupt, IRQ_NONE otherwise.
 *
 * Handle miscellaneous conditions indicated by Ethernet core IRQ.
 */
static irqreturn_t axienet_eth_irq(int irq, void *_ndev)
{
	struct net_device *ndev = _ndev;
	struct axienet_local *lp = netdev_priv(ndev);
	unsigned int pending;

	pending = axienet_ior(lp, XAE_IP_OFFSET);
	if (!pending)
		return IRQ_NONE;

	if (pending & XAE_INT_RXFIFOOVR_MASK)
		ndev->stats.rx_missed_errors++;

	if (pending & XAE_INT_RXRJECT_MASK)
		ndev->stats.rx_dropped++;

	axienet_iow(lp, XAE_IS_OFFSET, pending);
	return IRQ_HANDLED;
}

static void axienet_dma_err_handler(struct work_struct *work);

/**
 * axienet_rx_submit_desc - Submit the rx descriptors to dmaengine.
 * allocate skbuff, map the scatterlist and obtain a descriptor
 * and then add the callback information and submit descriptor.
 *
 * @ndev:	net_device pointer
 *
 */
static void axienet_rx_submit_desc(struct net_device *ndev)
{
	struct dma_async_tx_descriptor *dma_rx_desc = NULL;
	struct axienet_local *lp = netdev_priv(ndev);
	struct skbuf_dma_descriptor *skbuf_dma;
	struct sk_buff *skb;
	dma_addr_t addr;

	skbuf_dma = axienet_get_rx_desc(lp, lp->rx_ring_head);
	if (!skbuf_dma)
		return;

	lp->rx_ring_head++;
	skb = netdev_alloc_skb(ndev, lp->max_frm_size);
	if (!skb)
		return;

	sg_init_table(skbuf_dma->sgl, 1);
	addr = dma_map_single(lp->dev, skb->data, lp->max_frm_size, DMA_FROM_DEVICE);
	if (unlikely(dma_mapping_error(lp->dev, addr))) {
		if (net_ratelimit())
			netdev_err(ndev, "DMA mapping error\n");
		goto rx_submit_err_free_skb;
	}
	sg_dma_address(skbuf_dma->sgl) = addr;
	sg_dma_len(skbuf_dma->sgl) = lp->max_frm_size;
	dma_rx_desc = dmaengine_prep_slave_sg(lp->rx_chan, skbuf_dma->sgl,
					      1, DMA_DEV_TO_MEM,
					      DMA_PREP_INTERRUPT);
	if (!dma_rx_desc)
		goto rx_submit_err_unmap_skb;

	skbuf_dma->skb = skb;
	skbuf_dma->dma_address = sg_dma_address(skbuf_dma->sgl);
	skbuf_dma->desc = dma_rx_desc;
	dma_rx_desc->callback_param = lp;
	dma_rx_desc->callback_result = axienet_dma_rx_cb;
	dmaengine_submit(dma_rx_desc);

	return;

rx_submit_err_unmap_skb:
	dma_unmap_single(lp->dev, addr, lp->max_frm_size, DMA_FROM_DEVICE);
rx_submit_err_free_skb:
	dev_kfree_skb(skb);
}

/**
 * axienet_init_dmaengine - init the dmaengine code.
 * @ndev:       Pointer to net_device structure
 *
 * Return: 0, on success.
 *          non-zero error value on failure
 *
 * This is the dmaengine initialization code.
 */
static int axienet_init_dmaengine(struct net_device *ndev)
{
	struct axienet_local *lp = netdev_priv(ndev);
	struct skbuf_dma_descriptor *skbuf_dma;
	int i, ret;

	lp->tx_chan = dma_request_chan(lp->dev, "tx_chan0");
	if (IS_ERR(lp->tx_chan)) {
		dev_err(lp->dev, "No Ethernet DMA (TX) channel found\n");
		return PTR_ERR(lp->tx_chan);
	}

	lp->rx_chan = dma_request_chan(lp->dev, "rx_chan0");
	if (IS_ERR(lp->rx_chan)) {
		ret = PTR_ERR(lp->rx_chan);
		dev_err(lp->dev, "No Ethernet DMA (RX) channel found\n");
		goto err_dma_release_tx;
	}

	lp->tx_ring_tail = 0;
	lp->tx_ring_head = 0;
	lp->rx_ring_tail = 0;
	lp->rx_ring_head = 0;
	lp->tx_skb_ring = kcalloc(TX_BD_NUM_MAX, sizeof(*lp->tx_skb_ring),
				  GFP_KERNEL);
	if (!lp->tx_skb_ring) {
		ret = -ENOMEM;
		goto err_dma_release_rx;
	}
	for (i = 0; i < TX_BD_NUM_MAX; i++) {
		skbuf_dma = kzalloc(sizeof(*skbuf_dma), GFP_KERNEL);
		if (!skbuf_dma) {
			ret = -ENOMEM;
			goto err_free_tx_skb_ring;
		}
		lp->tx_skb_ring[i] = skbuf_dma;
	}

	lp->rx_skb_ring = kcalloc(RX_BUF_NUM_DEFAULT, sizeof(*lp->rx_skb_ring),
				  GFP_KERNEL);
	if (!lp->rx_skb_ring) {
		ret = -ENOMEM;
		goto err_free_tx_skb_ring;
	}
	for (i = 0; i < RX_BUF_NUM_DEFAULT; i++) {
		skbuf_dma = kzalloc(sizeof(*skbuf_dma), GFP_KERNEL);
		if (!skbuf_dma) {
			ret = -ENOMEM;
			goto err_free_rx_skb_ring;
		}
		lp->rx_skb_ring[i] = skbuf_dma;
	}
	/* TODO: Instead of BD_NUM_DEFAULT use runtime support */
	for (i = 0; i < RX_BUF_NUM_DEFAULT; i++)
		axienet_rx_submit_desc(ndev);
	dma_async_issue_pending(lp->rx_chan);

	return 0;

err_free_rx_skb_ring:
	for (i = 0; i < RX_BUF_NUM_DEFAULT; i++)
		kfree(lp->rx_skb_ring[i]);
	kfree(lp->rx_skb_ring);
err_free_tx_skb_ring:
	for (i = 0; i < TX_BD_NUM_MAX; i++)
		kfree(lp->tx_skb_ring[i]);
	kfree(lp->tx_skb_ring);
err_dma_release_rx:
	dma_release_channel(lp->rx_chan);
err_dma_release_tx:
	dma_release_channel(lp->tx_chan);
	return ret;
}

/**
 * axienet_init_legacy_dma - init the dma legacy code.
 * @ndev:       Pointer to net_device structure
 *
 * Return: 0, on success.
 *          non-zero error value on failure
 *
 * This is the dma  initialization code. It also allocates interrupt
 * service routines, enables the interrupt lines and ISR handling.
 *
 */
static int axienet_init_legacy_dma(struct net_device *ndev)
{
	int ret;
	struct axienet_local *lp = netdev_priv(ndev);

	/* Enable worker thread for Axi DMA error handling */
	lp->stopping = false;
	INIT_WORK(&lp->dma_err_task, axienet_dma_err_handler);

	napi_enable(&lp->napi_rx);
	napi_enable(&lp->napi_tx);

	/* Enable interrupts for Axi DMA Tx */
	ret = request_irq(lp->tx_irq, axienet_tx_irq, IRQF_SHARED,
			  ndev->name, ndev);
	if (ret)
		goto err_tx_irq;
	/* Enable interrupts for Axi DMA Rx */
	ret = request_irq(lp->rx_irq, axienet_rx_irq, IRQF_SHARED,
			  ndev->name, ndev);
	if (ret)
		goto err_rx_irq;
	/* Enable interrupts for Axi Ethernet core (if defined) */
	if (lp->eth_irq > 0) {
		ret = request_irq(lp->eth_irq, axienet_eth_irq, IRQF_SHARED,
				  ndev->name, ndev);
		if (ret)
			goto err_eth_irq;
	}

	return 0;

err_eth_irq:
	free_irq(lp->rx_irq, ndev);
err_rx_irq:
	free_irq(lp->tx_irq, ndev);
err_tx_irq:
	napi_disable(&lp->napi_tx);
	napi_disable(&lp->napi_rx);
	cancel_work_sync(&lp->dma_err_task);
	dev_err(lp->dev, "request_irq() failed\n");
	return ret;
}

/**
 * axienet_open - Driver open routine.
 * @ndev:	Pointer to net_device structure
 *
 * Return: 0, on success.
 *	    non-zero error value on failure
 *
 * This is the driver open routine. It calls phylink_start to start the
 * PHY device.
 * It also allocates interrupt service routines, enables the interrupt lines
 * and ISR handling. Axi Ethernet core is reset through Axi DMA core. Buffer
 * descriptors are initialized.
 */
static int axienet_open(struct net_device *ndev)
{
	int ret;
	struct axienet_local *lp = netdev_priv(ndev);

	/* When we do an Axi Ethernet reset, it resets the complete core
	 * including the MDIO. MDIO must be disabled before resetting.
	 * Hold MDIO bus lock to avoid MDIO accesses during the reset.
	 */
	axienet_lock_mii(lp);
	ret = axienet_device_reset(ndev);
	axienet_unlock_mii(lp);

	ret = phylink_of_phy_connect(lp->phylink, lp->dev->of_node, 0);
	if (ret) {
		dev_err(lp->dev, "phylink_of_phy_connect() failed: %d\n", ret);
		return ret;
	}

	phylink_start(lp->phylink);

	/* Start the statistics refresh work */
	schedule_delayed_work(&lp->stats_work, 0);

	if (lp->use_dmaengine) {
		/* Enable interrupts for Axi Ethernet core (if defined) */
		if (lp->eth_irq > 0) {
			ret = request_irq(lp->eth_irq, axienet_eth_irq, IRQF_SHARED,
					  ndev->name, ndev);
			if (ret)
				goto err_phy;
		}

		ret = axienet_init_dmaengine(ndev);
		if (ret < 0)
			goto err_free_eth_irq;
	} else {
		ret = axienet_init_legacy_dma(ndev);
		if (ret)
			goto err_phy;
	}

	return 0;

err_free_eth_irq:
	if (lp->eth_irq > 0)
		free_irq(lp->eth_irq, ndev);
err_phy:
	cancel_delayed_work_sync(&lp->stats_work);
	phylink_stop(lp->phylink);
	phylink_disconnect_phy(lp->phylink);
	return ret;
}

/**
 * axienet_stop - Driver stop routine.
 * @ndev:	Pointer to net_device structure
 *
 * Return: 0, on success.
 *
 * This is the driver stop routine. It calls phylink_disconnect to stop the PHY
 * device. It also removes the interrupt handlers and disables the interrupts.
 * The Axi DMA Tx/Rx BDs are released.
 */
static int axienet_stop(struct net_device *ndev)
{
	struct axienet_local *lp = netdev_priv(ndev);
	int i;

	if (!lp->use_dmaengine) {
		WRITE_ONCE(lp->stopping, true);
		flush_work(&lp->dma_err_task);

		napi_disable(&lp->napi_tx);
		napi_disable(&lp->napi_rx);
	}

	cancel_delayed_work_sync(&lp->stats_work);

	phylink_stop(lp->phylink);
	phylink_disconnect_phy(lp->phylink);

	axienet_setoptions(ndev, lp->options &
			   ~(XAE_OPTION_TXEN | XAE_OPTION_RXEN));

	if (!lp->use_dmaengine) {
		axienet_dma_stop(lp);
		cancel_work_sync(&lp->dma_err_task);
		free_irq(lp->tx_irq, ndev);
		free_irq(lp->rx_irq, ndev);
		axienet_dma_bd_release(ndev);
	} else {
		dmaengine_terminate_sync(lp->tx_chan);
		dmaengine_synchronize(lp->tx_chan);
		dmaengine_terminate_sync(lp->rx_chan);
		dmaengine_synchronize(lp->rx_chan);

		for (i = 0; i < TX_BD_NUM_MAX; i++)
			kfree(lp->tx_skb_ring[i]);
		kfree(lp->tx_skb_ring);
		for (i = 0; i < RX_BUF_NUM_DEFAULT; i++)
			kfree(lp->rx_skb_ring[i]);
		kfree(lp->rx_skb_ring);

		dma_release_channel(lp->rx_chan);
		dma_release_channel(lp->tx_chan);
	}

	axienet_iow(lp, XAE_IE_OFFSET, 0);

	if (lp->eth_irq > 0)
		free_irq(lp->eth_irq, ndev);
	return 0;
}

/**
 * axienet_change_mtu - Driver change mtu routine.
 * @ndev:	Pointer to net_device structure
 * @new_mtu:	New mtu value to be applied
 *
 * Return: Always returns 0 (success).
 *
 * This is the change mtu driver routine. It checks if the Axi Ethernet
 * hardware supports jumbo frames before changing the mtu. This can be
 * called only when the device is not up.
 */
static int axienet_change_mtu(struct net_device *ndev, int new_mtu)
{
	struct axienet_local *lp = netdev_priv(ndev);

	if (netif_running(ndev))
		return -EBUSY;

	if ((new_mtu + VLAN_ETH_HLEN +
		XAE_TRL_SIZE) > lp->rxmem)
		return -EINVAL;

	WRITE_ONCE(ndev->mtu, new_mtu);

	return 0;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
/**
 * axienet_poll_controller - Axi Ethernet poll mechanism.
 * @ndev:	Pointer to net_device structure
 *
 * This implements Rx/Tx ISR poll mechanisms. The interrupts are disabled prior
 * to polling the ISRs and are enabled back after the polling is done.
 */
static void axienet_poll_controller(struct net_device *ndev)
{
	struct axienet_local *lp = netdev_priv(ndev);

	disable_irq(lp->tx_irq);
	disable_irq(lp->rx_irq);
	axienet_rx_irq(lp->tx_irq, ndev);
	axienet_tx_irq(lp->rx_irq, ndev);
	enable_irq(lp->tx_irq);
	enable_irq(lp->rx_irq);
}
#endif

static int axienet_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
{
	struct axienet_local *lp = netdev_priv(dev);

	if (!netif_running(dev))
		return -EINVAL;

	return phylink_mii_ioctl(lp->phylink, rq, cmd);
}

static void
axienet_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
{
	struct axienet_local *lp = netdev_priv(dev);
	unsigned int start;

	netdev_stats_to_stats64(stats, &dev->stats);

	do {
		start = u64_stats_fetch_begin(&lp->rx_stat_sync);
		stats->rx_packets = u64_stats_read(&lp->rx_packets);
		stats->rx_bytes = u64_stats_read(&lp->rx_bytes);
	} while (u64_stats_fetch_retry(&lp->rx_stat_sync, start));

	do {
		start = u64_stats_fetch_begin(&lp->tx_stat_sync);
		stats->tx_packets = u64_stats_read(&lp->tx_packets);
		stats->tx_bytes = u64_stats_read(&lp->tx_bytes);
	} while (u64_stats_fetch_retry(&lp->tx_stat_sync, start));

	if (!(lp->features & XAE_FEATURE_STATS))
		return;

	do {
		start = read_seqcount_begin(&lp->hw_stats_seqcount);
		stats->rx_length_errors =
			axienet_stat(lp, STAT_RX_LENGTH_ERRORS);
		stats->rx_crc_errors = axienet_stat(lp, STAT_RX_FCS_ERRORS);
		stats->rx_frame_errors =
			axienet_stat(lp, STAT_RX_ALIGNMENT_ERRORS);
		stats->rx_errors = axienet_stat(lp, STAT_UNDERSIZE_FRAMES) +
				   axienet_stat(lp, STAT_FRAGMENT_FRAMES) +
				   stats->rx_length_errors +
				   stats->rx_crc_errors +
				   stats->rx_frame_errors;
		stats->multicast = axienet_stat(lp, STAT_RX_MULTICAST_FRAMES);

		stats->tx_aborted_errors =
			axienet_stat(lp, STAT_TX_EXCESS_COLLISIONS);
		stats->tx_fifo_errors =
			axienet_stat(lp, STAT_TX_UNDERRUN_ERRORS);
		stats->tx_window_errors =
			axienet_stat(lp, STAT_TX_LATE_COLLISIONS);
		stats->tx_errors = axienet_stat(lp, STAT_TX_EXCESS_DEFERRAL) +
				   stats->tx_aborted_errors +
				   stats->tx_fifo_errors +
				   stats->tx_window_errors;
	} while (read_seqcount_retry(&lp->hw_stats_seqcount, start));
}

static const struct net_device_ops axienet_netdev_ops = {
	.ndo_open = axienet_open,
	.ndo_stop = axienet_stop,
	.ndo_start_xmit = axienet_start_xmit,
	.ndo_get_stats64 = axienet_get_stats64,
	.ndo_change_mtu	= axienet_change_mtu,
	.ndo_set_mac_address = netdev_set_mac_address,
	.ndo_validate_addr = eth_validate_addr,
	.ndo_eth_ioctl = axienet_ioctl,
	.ndo_set_rx_mode = axienet_set_multicast_list,
#ifdef CONFIG_NET_POLL_CONTROLLER
	.ndo_poll_controller = axienet_poll_controller,
#endif
};

static const struct net_device_ops axienet_netdev_dmaengine_ops = {
	.ndo_open = axienet_open,
	.ndo_stop = axienet_stop,
	.ndo_start_xmit = axienet_start_xmit_dmaengine,
	.ndo_get_stats64 = axienet_get_stats64,
	.ndo_change_mtu	= axienet_change_mtu,
	.ndo_set_mac_address = netdev_set_mac_address,
	.ndo_validate_addr = eth_validate_addr,
	.ndo_eth_ioctl = axienet_ioctl,
	.ndo_set_rx_mode = axienet_set_multicast_list,
};

/**
 * axienet_ethtools_get_drvinfo - Get various Axi Ethernet driver information.
 * @ndev:	Pointer to net_device structure
 * @ed:		Pointer to ethtool_drvinfo structure
 *
 * This implements ethtool command for getting the driver information.
 * Issue "ethtool -i ethX" under linux prompt to execute this function.
 */
static void axienet_ethtools_get_drvinfo(struct net_device *ndev,
					 struct ethtool_drvinfo *ed)
{
	strscpy(ed->driver, DRIVER_NAME, sizeof(ed->driver));
	strscpy(ed->version, DRIVER_VERSION, sizeof(ed->version));
}

/**
 * axienet_ethtools_get_regs_len - Get the total regs length present in the
 *				   AxiEthernet core.
 * @ndev:	Pointer to net_device structure
 *
 * This implements ethtool command for getting the total register length
 * information.
 *
 * Return: the total regs length
 */
static int axienet_ethtools_get_regs_len(struct net_device *ndev)
{
	return sizeof(u32) * AXIENET_REGS_N;
}

/**
 * axienet_ethtools_get_regs - Dump the contents of all registers present
 *			       in AxiEthernet core.
 * @ndev:	Pointer to net_device structure
 * @regs:	Pointer to ethtool_regs structure
 * @ret:	Void pointer used to return the contents of the registers.
 *
 * This implements ethtool command for getting the Axi Ethernet register dump.
 * Issue "ethtool -d ethX" to execute this function.
 */
static void axienet_ethtools_get_regs(struct net_device *ndev,
				      struct ethtool_regs *regs, void *ret)
{
	u32 *data = (u32 *)ret;
	size_t len = sizeof(u32) * AXIENET_REGS_N;
	struct axienet_local *lp = netdev_priv(ndev);

	regs->version = 0;
	regs->len = len;

	memset(data, 0, len);
	data[0] = axienet_ior(lp, XAE_RAF_OFFSET);
	data[1] = axienet_ior(lp, XAE_TPF_OFFSET);
	data[2] = axienet_ior(lp, XAE_IFGP_OFFSET);
	data[3] = axienet_ior(lp, XAE_IS_OFFSET);
	data[4] = axienet_ior(lp, XAE_IP_OFFSET);
	data[5] = axienet_ior(lp, XAE_IE_OFFSET);
	data[6] = axienet_ior(lp, XAE_TTAG_OFFSET);
	data[7] = axienet_ior(lp, XAE_RTAG_OFFSET);
	data[8] = axienet_ior(lp, XAE_UAWL_OFFSET);
	data[9] = axienet_ior(lp, XAE_UAWU_OFFSET);
	data[10] = axienet_ior(lp, XAE_TPID0_OFFSET);
	data[11] = axienet_ior(lp, XAE_TPID1_OFFSET);
	data[12] = axienet_ior(lp, XAE_PPST_OFFSET);
	data[13] = axienet_ior(lp, XAE_RCW0_OFFSET);
	data[14] = axienet_ior(lp, XAE_RCW1_OFFSET);
	data[15] = axienet_ior(lp, XAE_TC_OFFSET);
	data[16] = axienet_ior(lp, XAE_FCC_OFFSET);
	data[17] = axienet_ior(lp, XAE_EMMC_OFFSET);
	data[18] = axienet_ior(lp, XAE_PHYC_OFFSET);
	data[19] = axienet_ior(lp, XAE_MDIO_MC_OFFSET);
	data[20] = axienet_ior(lp, XAE_MDIO_MCR_OFFSET);
	data[21] = axienet_ior(lp, XAE_MDIO_MWD_OFFSET);
	data[22] = axienet_ior(lp, XAE_MDIO_MRD_OFFSET);
	data[27] = axienet_ior(lp, XAE_UAW0_OFFSET);
	data[28] = axienet_ior(lp, XAE_UAW1_OFFSET);
	data[29] = axienet_ior(lp, XAE_FMI_OFFSET);
	data[30] = axienet_ior(lp, XAE_AF0_OFFSET);
	data[31] = axienet_ior(lp, XAE_AF1_OFFSET);
	if (!lp->use_dmaengine) {
		data[32] = axienet_dma_in32(lp, XAXIDMA_TX_CR_OFFSET);
		data[33] = axienet_dma_in32(lp, XAXIDMA_TX_SR_OFFSET);
		data[34] = axienet_dma_in32(lp, XAXIDMA_TX_CDESC_OFFSET);
		data[35] = axienet_dma_in32(lp, XAXIDMA_TX_TDESC_OFFSET);
		data[36] = axienet_dma_in32(lp, XAXIDMA_RX_CR_OFFSET);
		data[37] = axienet_dma_in32(lp, XAXIDMA_RX_SR_OFFSET);
		data[38] = axienet_dma_in32(lp, XAXIDMA_RX_CDESC_OFFSET);
		data[39] = axienet_dma_in32(lp, XAXIDMA_RX_TDESC_OFFSET);
	}
}

static void
axienet_ethtools_get_ringparam(struct net_device *ndev,
			       struct ethtool_ringparam *ering,
			       struct kernel_ethtool_ringparam *kernel_ering,
			       struct netlink_ext_ack *extack)
{
	struct axienet_local *lp = netdev_priv(ndev);

	ering->rx_max_pending = RX_BD_NUM_MAX;
	ering->rx_mini_max_pending = 0;
	ering->rx_jumbo_max_pending = 0;
	ering->tx_max_pending = TX_BD_NUM_MAX;
	ering->rx_pending = lp->rx_bd_num;
	ering->rx_mini_pending = 0;
	ering->rx_jumbo_pending = 0;
	ering->tx_pending = lp->tx_bd_num;
}

static int
axienet_ethtools_set_ringparam(struct net_device *ndev,
			       struct ethtool_ringparam *ering,
			       struct kernel_ethtool_ringparam *kernel_ering,
			       struct netlink_ext_ack *extack)
{
	struct axienet_local *lp = netdev_priv(ndev);

	if (ering->rx_pending > RX_BD_NUM_MAX ||
	    ering->rx_mini_pending ||
	    ering->rx_jumbo_pending ||
	    ering->tx_pending < TX_BD_NUM_MIN ||
	    ering->tx_pending > TX_BD_NUM_MAX)
		return -EINVAL;

	if (netif_running(ndev))
		return -EBUSY;

	lp->rx_bd_num = ering->rx_pending;
	lp->tx_bd_num = ering->tx_pending;
	return 0;
}

/**
 * axienet_ethtools_get_pauseparam - Get the pause parameter setting for
 *				     Tx and Rx paths.
 * @ndev:	Pointer to net_device structure
 * @epauseparm:	Pointer to ethtool_pauseparam structure.
 *
 * This implements ethtool command for getting axi ethernet pause frame
 * setting. Issue "ethtool -a ethX" to execute this function.
 */
static void
axienet_ethtools_get_pauseparam(struct net_device *ndev,
				struct ethtool_pauseparam *epauseparm)
{
	struct axienet_local *lp = netdev_priv(ndev);

	phylink_ethtool_get_pauseparam(lp->phylink, epauseparm);
}

/**
 * axienet_ethtools_set_pauseparam - Set device pause parameter(flow control)
 *				     settings.
 * @ndev:	Pointer to net_device structure
 * @epauseparm:Pointer to ethtool_pauseparam structure
 *
 * This implements ethtool command for enabling flow control on Rx and Tx
 * paths. Issue "ethtool -A ethX tx on|off" under linux prompt to execute this
 * function.
 *
 * Return: 0 on success, -EFAULT if device is running
 */
static int
axienet_ethtools_set_pauseparam(struct net_device *ndev,
				struct ethtool_pauseparam *epauseparm)
{
	struct axienet_local *lp = netdev_priv(ndev);

	return phylink_ethtool_set_pauseparam(lp->phylink, epauseparm);
}

/**
 * axienet_ethtools_get_coalesce - Get DMA interrupt coalescing count.
 * @ndev:	Pointer to net_device structure
 * @ecoalesce:	Pointer to ethtool_coalesce structure
 * @kernel_coal: ethtool CQE mode setting structure
 * @extack:	extack for reporting error messages
 *
 * This implements ethtool command for getting the DMA interrupt coalescing
 * count on Tx and Rx paths. Issue "ethtool -c ethX" under linux prompt to
 * execute this function.
 *
 * Return: 0 always
 */
static int
axienet_ethtools_get_coalesce(struct net_device *ndev,
			      struct ethtool_coalesce *ecoalesce,
			      struct kernel_ethtool_coalesce *kernel_coal,
			      struct netlink_ext_ack *extack)
{
	struct axienet_local *lp = netdev_priv(ndev);

	ecoalesce->rx_max_coalesced_frames = lp->coalesce_count_rx;
	ecoalesce->rx_coalesce_usecs = lp->coalesce_usec_rx;
	ecoalesce->tx_max_coalesced_frames = lp->coalesce_count_tx;
	ecoalesce->tx_coalesce_usecs = lp->coalesce_usec_tx;
	return 0;
}

/**
 * axienet_ethtools_set_coalesce - Set DMA interrupt coalescing count.
 * @ndev:	Pointer to net_device structure
 * @ecoalesce:	Pointer to ethtool_coalesce structure
 * @kernel_coal: ethtool CQE mode setting structure
 * @extack:	extack for reporting error messages
 *
 * This implements ethtool command for setting the DMA interrupt coalescing
 * count on Tx and Rx paths. Issue "ethtool -C ethX rx-frames 5" under linux
 * prompt to execute this function.
 *
 * Return: 0, on success, Non-zero error value on failure.
 */
static int
axienet_ethtools_set_coalesce(struct net_device *ndev,
			      struct ethtool_coalesce *ecoalesce,
			      struct kernel_ethtool_coalesce *kernel_coal,
			      struct netlink_ext_ack *extack)
{
	struct axienet_local *lp = netdev_priv(ndev);

	if (netif_running(ndev)) {
		NL_SET_ERR_MSG(extack,
			       "Please stop netif before applying configuration");
		return -EBUSY;
	}

	if (ecoalesce->rx_max_coalesced_frames)
		lp->coalesce_count_rx = ecoalesce->rx_max_coalesced_frames;
	if (ecoalesce->rx_coalesce_usecs)
		lp->coalesce_usec_rx = ecoalesce->rx_coalesce_usecs;
	if (ecoalesce->tx_max_coalesced_frames)
		lp->coalesce_count_tx = ecoalesce->tx_max_coalesced_frames;
	if (ecoalesce->tx_coalesce_usecs)
		lp->coalesce_usec_tx = ecoalesce->tx_coalesce_usecs;

	return 0;
}

static int
axienet_ethtools_get_link_ksettings(struct net_device *ndev,
				    struct ethtool_link_ksettings *cmd)
{
	struct axienet_local *lp = netdev_priv(ndev);

	return phylink_ethtool_ksettings_get(lp->phylink, cmd);
}

static int
axienet_ethtools_set_link_ksettings(struct net_device *ndev,
				    const struct ethtool_link_ksettings *cmd)
{
	struct axienet_local *lp = netdev_priv(ndev);

	return phylink_ethtool_ksettings_set(lp->phylink, cmd);
}

static int axienet_ethtools_nway_reset(struct net_device *dev)
{
	struct axienet_local *lp = netdev_priv(dev);

	return phylink_ethtool_nway_reset(lp->phylink);
}

static void axienet_ethtools_get_ethtool_stats(struct net_device *dev,
					       struct ethtool_stats *stats,
					       u64 *data)
{
	struct axienet_local *lp = netdev_priv(dev);
	unsigned int start;

	do {
		start = read_seqcount_begin(&lp->hw_stats_seqcount);
		data[0] = axienet_stat(lp, STAT_RX_BYTES);
		data[1] = axienet_stat(lp, STAT_TX_BYTES);
		data[2] = axienet_stat(lp, STAT_RX_VLAN_FRAMES);
		data[3] = axienet_stat(lp, STAT_TX_VLAN_FRAMES);
		data[6] = axienet_stat(lp, STAT_TX_PFC_FRAMES);
		data[7] = axienet_stat(lp, STAT_RX_PFC_FRAMES);
		data[8] = axienet_stat(lp, STAT_USER_DEFINED0);
		data[9] = axienet_stat(lp, STAT_USER_DEFINED1);
		data[10] = axienet_stat(lp, STAT_USER_DEFINED2);
	} while (read_seqcount_retry(&lp->hw_stats_seqcount, start));
}

static const char axienet_ethtool_stats_strings[][ETH_GSTRING_LEN] = {
	"Received bytes",
	"Transmitted bytes",
	"RX Good VLAN Tagged Frames",
	"TX Good VLAN Tagged Frames",
	"TX Good PFC Frames",
	"RX Good PFC Frames",
	"User Defined Counter 0",
	"User Defined Counter 1",
	"User Defined Counter 2",
};

static void axienet_ethtools_get_strings(struct net_device *dev, u32 stringset, u8 *data)
{
	switch (stringset) {
	case ETH_SS_STATS:
		memcpy(data, axienet_ethtool_stats_strings,
		       sizeof(axienet_ethtool_stats_strings));
		break;
	}
}

static int axienet_ethtools_get_sset_count(struct net_device *dev, int sset)
{
	struct axienet_local *lp = netdev_priv(dev);

	switch (sset) {
	case ETH_SS_STATS:
		if (lp->features & XAE_FEATURE_STATS)
			return ARRAY_SIZE(axienet_ethtool_stats_strings);
		fallthrough;
	default:
		return -EOPNOTSUPP;
	}
}

static void
axienet_ethtools_get_pause_stats(struct net_device *dev,
				 struct ethtool_pause_stats *pause_stats)
{
	struct axienet_local *lp = netdev_priv(dev);
	unsigned int start;

	if (!(lp->features & XAE_FEATURE_STATS))
		return;

	do {
		start = read_seqcount_begin(&lp->hw_stats_seqcount);
		pause_stats->tx_pause_frames =
			axienet_stat(lp, STAT_TX_PAUSE_FRAMES);
		pause_stats->rx_pause_frames =
			axienet_stat(lp, STAT_RX_PAUSE_FRAMES);
	} while (read_seqcount_retry(&lp->hw_stats_seqcount, start));
}

static void
axienet_ethtool_get_eth_mac_stats(struct net_device *dev,
				  struct ethtool_eth_mac_stats *mac_stats)
{
	struct axienet_local *lp = netdev_priv(dev);
	unsigned int start;

	if (!(lp->features & XAE_FEATURE_STATS))
		return;

	do {
		start = read_seqcount_begin(&lp->hw_stats_seqcount);
		mac_stats->FramesTransmittedOK =
			axienet_stat(lp, STAT_TX_GOOD_FRAMES);
		mac_stats->SingleCollisionFrames =
			axienet_stat(lp, STAT_TX_SINGLE_COLLISION_FRAMES);
		mac_stats->MultipleCollisionFrames =
			axienet_stat(lp, STAT_TX_MULTIPLE_COLLISION_FRAMES);
		mac_stats->FramesReceivedOK =
			axienet_stat(lp, STAT_RX_GOOD_FRAMES);
		mac_stats->FrameCheckSequenceErrors =
			axienet_stat(lp, STAT_RX_FCS_ERRORS);
		mac_stats->AlignmentErrors =
			axienet_stat(lp, STAT_RX_ALIGNMENT_ERRORS);
		mac_stats->FramesWithDeferredXmissions =
			axienet_stat(lp, STAT_TX_DEFERRED_FRAMES);
		mac_stats->LateCollisions =
			axienet_stat(lp, STAT_TX_LATE_COLLISIONS);
		mac_stats->FramesAbortedDueToXSColls =
			axienet_stat(lp, STAT_TX_EXCESS_COLLISIONS);
		mac_stats->MulticastFramesXmittedOK =
			axienet_stat(lp, STAT_TX_MULTICAST_FRAMES);
		mac_stats->BroadcastFramesXmittedOK =
			axienet_stat(lp, STAT_TX_BROADCAST_FRAMES);
		mac_stats->FramesWithExcessiveDeferral =
			axienet_stat(lp, STAT_TX_EXCESS_DEFERRAL);
		mac_stats->MulticastFramesReceivedOK =
			axienet_stat(lp, STAT_RX_MULTICAST_FRAMES);
		mac_stats->BroadcastFramesReceivedOK =
			axienet_stat(lp, STAT_RX_BROADCAST_FRAMES);
		mac_stats->InRangeLengthErrors =
			axienet_stat(lp, STAT_RX_LENGTH_ERRORS);
	} while (read_seqcount_retry(&lp->hw_stats_seqcount, start));
}

static void
axienet_ethtool_get_eth_ctrl_stats(struct net_device *dev,
				   struct ethtool_eth_ctrl_stats *ctrl_stats)
{
	struct axienet_local *lp = netdev_priv(dev);
	unsigned int start;

	if (!(lp->features & XAE_FEATURE_STATS))
		return;

	do {
		start = read_seqcount_begin(&lp->hw_stats_seqcount);
		ctrl_stats->MACControlFramesTransmitted =
			axienet_stat(lp, STAT_TX_CONTROL_FRAMES);
		ctrl_stats->MACControlFramesReceived =
			axienet_stat(lp, STAT_RX_CONTROL_FRAMES);
		ctrl_stats->UnsupportedOpcodesReceived =
			axienet_stat(lp, STAT_RX_CONTROL_OPCODE_ERRORS);
	} while (read_seqcount_retry(&lp->hw_stats_seqcount, start));
}

static const struct ethtool_rmon_hist_range axienet_rmon_ranges[] = {
	{   64,    64 },
	{   65,   127 },
	{  128,   255 },
	{  256,   511 },
	{  512,  1023 },
	{ 1024,  1518 },
	{ 1519, 16384 },
	{ },
};

static void
axienet_ethtool_get_rmon_stats(struct net_device *dev,
			       struct ethtool_rmon_stats *rmon_stats,
			       const struct ethtool_rmon_hist_range **ranges)
{
	struct axienet_local *lp = netdev_priv(dev);
	unsigned int start;

	if (!(lp->features & XAE_FEATURE_STATS))
		return;

	do {
		start = read_seqcount_begin(&lp->hw_stats_seqcount);
		rmon_stats->undersize_pkts =
			axienet_stat(lp, STAT_UNDERSIZE_FRAMES);
		rmon_stats->oversize_pkts =
			axienet_stat(lp, STAT_RX_OVERSIZE_FRAMES);
		rmon_stats->fragments =
			axienet_stat(lp, STAT_FRAGMENT_FRAMES);

		rmon_stats->hist[0] =
			axienet_stat(lp, STAT_RX_64_BYTE_FRAMES);
		rmon_stats->hist[1] =
			axienet_stat(lp, STAT_RX_65_127_BYTE_FRAMES);
		rmon_stats->hist[2] =
			axienet_stat(lp, STAT_RX_128_255_BYTE_FRAMES);
		rmon_stats->hist[3] =
			axienet_stat(lp, STAT_RX_256_511_BYTE_FRAMES);
		rmon_stats->hist[4] =
			axienet_stat(lp, STAT_RX_512_1023_BYTE_FRAMES);
		rmon_stats->hist[5] =
			axienet_stat(lp, STAT_RX_1024_MAX_BYTE_FRAMES);
		rmon_stats->hist[6] =
			rmon_stats->oversize_pkts;

		rmon_stats->hist_tx[0] =
			axienet_stat(lp, STAT_TX_64_BYTE_FRAMES);
		rmon_stats->hist_tx[1] =
			axienet_stat(lp, STAT_TX_65_127_BYTE_FRAMES);
		rmon_stats->hist_tx[2] =
			axienet_stat(lp, STAT_TX_128_255_BYTE_FRAMES);
		rmon_stats->hist_tx[3] =
			axienet_stat(lp, STAT_TX_256_511_BYTE_FRAMES);
		rmon_stats->hist_tx[4] =
			axienet_stat(lp, STAT_TX_512_1023_BYTE_FRAMES);
		rmon_stats->hist_tx[5] =
			axienet_stat(lp, STAT_TX_1024_MAX_BYTE_FRAMES);
		rmon_stats->hist_tx[6] =
			axienet_stat(lp, STAT_TX_OVERSIZE_FRAMES);
	} while (read_seqcount_retry(&lp->hw_stats_seqcount, start));

	*ranges = axienet_rmon_ranges;
}

static const struct ethtool_ops axienet_ethtool_ops = {
	.supported_coalesce_params = ETHTOOL_COALESCE_MAX_FRAMES |
				     ETHTOOL_COALESCE_USECS,
	.get_drvinfo    = axienet_ethtools_get_drvinfo,
	.get_regs_len   = axienet_ethtools_get_regs_len,
	.get_regs       = axienet_ethtools_get_regs,
	.get_link       = ethtool_op_get_link,
	.get_ringparam	= axienet_ethtools_get_ringparam,
	.set_ringparam	= axienet_ethtools_set_ringparam,
	.get_pauseparam = axienet_ethtools_get_pauseparam,
	.set_pauseparam = axienet_ethtools_set_pauseparam,
	.get_coalesce   = axienet_ethtools_get_coalesce,
	.set_coalesce   = axienet_ethtools_set_coalesce,
	.get_link_ksettings = axienet_ethtools_get_link_ksettings,
	.set_link_ksettings = axienet_ethtools_set_link_ksettings,
	.nway_reset	= axienet_ethtools_nway_reset,
	.get_ethtool_stats = axienet_ethtools_get_ethtool_stats,
	.get_strings    = axienet_ethtools_get_strings,
	.get_sset_count = axienet_ethtools_get_sset_count,
	.get_pause_stats = axienet_ethtools_get_pause_stats,
	.get_eth_mac_stats = axienet_ethtool_get_eth_mac_stats,
	.get_eth_ctrl_stats = axienet_ethtool_get_eth_ctrl_stats,
	.get_rmon_stats = axienet_ethtool_get_rmon_stats,
};

static struct axienet_local *pcs_to_axienet_local(struct phylink_pcs *pcs)
{
	return container_of(pcs, struct axienet_local, pcs);
}

static void axienet_pcs_get_state(struct phylink_pcs *pcs,
				  struct phylink_link_state *state)
{
	struct mdio_device *pcs_phy = pcs_to_axienet_local(pcs)->pcs_phy;

	phylink_mii_c22_pcs_get_state(pcs_phy, state);
}

static void axienet_pcs_an_restart(struct phylink_pcs *pcs)
{
	struct mdio_device *pcs_phy = pcs_to_axienet_local(pcs)->pcs_phy;

	phylink_mii_c22_pcs_an_restart(pcs_phy);
}

static int axienet_pcs_config(struct phylink_pcs *pcs, unsigned int neg_mode,
			      phy_interface_t interface,
			      const unsigned long *advertising,
			      bool permit_pause_to_mac)
{
	struct mdio_device *pcs_phy = pcs_to_axienet_local(pcs)->pcs_phy;
	struct net_device *ndev = pcs_to_axienet_local(pcs)->ndev;
	struct axienet_local *lp = netdev_priv(ndev);
	int ret;

	if (lp->switch_x_sgmii) {
		ret = mdiodev_write(pcs_phy, XLNX_MII_STD_SELECT_REG,
				    interface == PHY_INTERFACE_MODE_SGMII ?
					XLNX_MII_STD_SELECT_SGMII : 0);
		if (ret < 0) {
			netdev_warn(ndev,
				    "Failed to switch PHY interface: %d\n",
				    ret);
			return ret;
		}
	}

	ret = phylink_mii_c22_pcs_config(pcs_phy, interface, advertising,
					 neg_mode);
	if (ret < 0)
		netdev_warn(ndev, "Failed to configure PCS: %d\n", ret);

	return ret;
}

static const struct phylink_pcs_ops axienet_pcs_ops = {
	.pcs_get_state = axienet_pcs_get_state,
	.pcs_config = axienet_pcs_config,
	.pcs_an_restart = axienet_pcs_an_restart,
};

static struct phylink_pcs *axienet_mac_select_pcs(struct phylink_config *config,
						  phy_interface_t interface)
{
	struct net_device *ndev = to_net_dev(config->dev);
	struct axienet_local *lp = netdev_priv(ndev);

	if (interface == PHY_INTERFACE_MODE_1000BASEX ||
	    interface ==  PHY_INTERFACE_MODE_SGMII)
		return &lp->pcs;

	return NULL;
}

static void axienet_mac_config(struct phylink_config *config, unsigned int mode,
			       const struct phylink_link_state *state)
{
	/* nothing meaningful to do */
}

static void axienet_mac_link_down(struct phylink_config *config,
				  unsigned int mode,
				  phy_interface_t interface)
{
	/* nothing meaningful to do */
}

static void axienet_mac_link_up(struct phylink_config *config,
				struct phy_device *phy,
				unsigned int mode, phy_interface_t interface,
				int speed, int duplex,
				bool tx_pause, bool rx_pause)
{
	struct net_device *ndev = to_net_dev(config->dev);
	struct axienet_local *lp = netdev_priv(ndev);
	u32 emmc_reg, fcc_reg;

	emmc_reg = axienet_ior(lp, XAE_EMMC_OFFSET);
	emmc_reg &= ~XAE_EMMC_LINKSPEED_MASK;

	switch (speed) {
	case SPEED_1000:
		emmc_reg |= XAE_EMMC_LINKSPD_1000;
		break;
	case SPEED_100:
		emmc_reg |= XAE_EMMC_LINKSPD_100;
		break;
	case SPEED_10:
		emmc_reg |= XAE_EMMC_LINKSPD_10;
		break;
	default:
		dev_err(&ndev->dev,
			"Speed other than 10, 100 or 1Gbps is not supported\n");
		break;
	}

	axienet_iow(lp, XAE_EMMC_OFFSET, emmc_reg);

	fcc_reg = axienet_ior(lp, XAE_FCC_OFFSET);
	if (tx_pause)
		fcc_reg |= XAE_FCC_FCTX_MASK;
	else
		fcc_reg &= ~XAE_FCC_FCTX_MASK;
	if (rx_pause)
		fcc_reg |= XAE_FCC_FCRX_MASK;
	else
		fcc_reg &= ~XAE_FCC_FCRX_MASK;
	axienet_iow(lp, XAE_FCC_OFFSET, fcc_reg);
}

static const struct phylink_mac_ops axienet_phylink_ops = {
	.mac_select_pcs = axienet_mac_select_pcs,
	.mac_config = axienet_mac_config,
	.mac_link_down = axienet_mac_link_down,
	.mac_link_up = axienet_mac_link_up,
};

/**
 * axienet_dma_err_handler - Work queue task for Axi DMA Error
 * @work:	pointer to work_struct
 *
 * Resets the Axi DMA and Axi Ethernet devices, and reconfigures the
 * Tx/Rx BDs.
 */
static void axienet_dma_err_handler(struct work_struct *work)
{
	u32 i;
	u32 axienet_status;
	struct axidma_bd *cur_p;
	struct axienet_local *lp = container_of(work, struct axienet_local,
						dma_err_task);
	struct net_device *ndev = lp->ndev;

	/* Don't bother if we are going to stop anyway */
	if (READ_ONCE(lp->stopping))
		return;

	napi_disable(&lp->napi_tx);
	napi_disable(&lp->napi_rx);

	axienet_setoptions(ndev, lp->options &
			   ~(XAE_OPTION_TXEN | XAE_OPTION_RXEN));

	axienet_dma_stop(lp);

	for (i = 0; i < lp->tx_bd_num; i++) {
		cur_p = &lp->tx_bd_v[i];
		if (cur_p->cntrl) {
			dma_addr_t addr = desc_get_phys_addr(lp, cur_p);

			dma_unmap_single(lp->dev, addr,
					 (cur_p->cntrl &
					  XAXIDMA_BD_CTRL_LENGTH_MASK),
					 DMA_TO_DEVICE);
		}
		if (cur_p->skb)
			dev_kfree_skb_irq(cur_p->skb);
		cur_p->phys = 0;
		cur_p->phys_msb = 0;
		cur_p->cntrl = 0;
		cur_p->status = 0;
		cur_p->app0 = 0;
		cur_p->app1 = 0;
		cur_p->app2 = 0;
		cur_p->app3 = 0;
		cur_p->app4 = 0;
		cur_p->skb = NULL;
	}

	for (i = 0; i < lp->rx_bd_num; i++) {
		cur_p = &lp->rx_bd_v[i];
		cur_p->status = 0;
		cur_p->app0 = 0;
		cur_p->app1 = 0;
		cur_p->app2 = 0;
		cur_p->app3 = 0;
		cur_p->app4 = 0;
	}

	lp->tx_bd_ci = 0;
	lp->tx_bd_tail = 0;
	lp->rx_bd_ci = 0;

	axienet_dma_start(lp);

	axienet_status = axienet_ior(lp, XAE_RCW1_OFFSET);
	axienet_status &= ~XAE_RCW1_RX_MASK;
	axienet_iow(lp, XAE_RCW1_OFFSET, axienet_status);

	axienet_status = axienet_ior(lp, XAE_IP_OFFSET);
	if (axienet_status & XAE_INT_RXRJECT_MASK)
		axienet_iow(lp, XAE_IS_OFFSET, XAE_INT_RXRJECT_MASK);
	axienet_iow(lp, XAE_IE_OFFSET, lp->eth_irq > 0 ?
		    XAE_INT_RECV_ERROR_MASK : 0);
	axienet_iow(lp, XAE_FCC_OFFSET, XAE_FCC_FCRX_MASK);

	/* Sync default options with HW but leave receiver and
	 * transmitter disabled.
	 */
	axienet_setoptions(ndev, lp->options &
			   ~(XAE_OPTION_TXEN | XAE_OPTION_RXEN));
	axienet_set_mac_address(ndev, NULL);
	axienet_set_multicast_list(ndev);
	napi_enable(&lp->napi_rx);
	napi_enable(&lp->napi_tx);
	axienet_setoptions(ndev, lp->options);
}

/**
 * axienet_probe - Axi Ethernet probe function.
 * @pdev:	Pointer to platform device structure.
 *
 * Return: 0, on success
 *	    Non-zero error value on failure.
 *
 * This is the probe routine for Axi Ethernet driver. This is called before
 * any other driver routines are invoked. It allocates and sets up the Ethernet
 * device. Parses through device tree and populates fields of
 * axienet_local. It registers the Ethernet device.
 */
static int axienet_probe(struct platform_device *pdev)
{
	int ret;
	struct device_node *np;
	struct axienet_local *lp;
	struct net_device *ndev;
	struct resource *ethres;
	u8 mac_addr[ETH_ALEN];
	int addr_width = 32;
	u32 value;

	ndev = alloc_etherdev(sizeof(*lp));
	if (!ndev)
		return -ENOMEM;

	platform_set_drvdata(pdev, ndev);

	SET_NETDEV_DEV(ndev, &pdev->dev);
	ndev->features = NETIF_F_SG;
	ndev->ethtool_ops = &axienet_ethtool_ops;

	/* MTU range: 64 - 9000 */
	ndev->min_mtu = 64;
	ndev->max_mtu = XAE_JUMBO_MTU;

	lp = netdev_priv(ndev);
	lp->ndev = ndev;
	lp->dev = &pdev->dev;
	lp->options = XAE_OPTION_DEFAULTS;
	lp->rx_bd_num = RX_BD_NUM_DEFAULT;
	lp->tx_bd_num = TX_BD_NUM_DEFAULT;

	u64_stats_init(&lp->rx_stat_sync);
	u64_stats_init(&lp->tx_stat_sync);

	mutex_init(&lp->stats_lock);
	seqcount_mutex_init(&lp->hw_stats_seqcount, &lp->stats_lock);
	INIT_DEFERRABLE_WORK(&lp->stats_work, axienet_refresh_stats);

	lp->axi_clk = devm_clk_get_optional(&pdev->dev, "s_axi_lite_clk");
	if (!lp->axi_clk) {
		/* For backward compatibility, if named AXI clock is not present,
		 * treat the first clock specified as the AXI clock.
		 */
		lp->axi_clk = devm_clk_get_optional(&pdev->dev, NULL);
	}
	if (IS_ERR(lp->axi_clk)) {
		ret = PTR_ERR(lp->axi_clk);
		goto free_netdev;
	}
	ret = clk_prepare_enable(lp->axi_clk);
	if (ret) {
		dev_err(&pdev->dev, "Unable to enable AXI clock: %d\n", ret);
		goto free_netdev;
	}

	lp->misc_clks[0].id = "axis_clk";
	lp->misc_clks[1].id = "ref_clk";
	lp->misc_clks[2].id = "mgt_clk";

	ret = devm_clk_bulk_get_optional(&pdev->dev, XAE_NUM_MISC_CLOCKS, lp->misc_clks);
	if (ret)
		goto cleanup_clk;

	ret = clk_bulk_prepare_enable(XAE_NUM_MISC_CLOCKS, lp->misc_clks);
	if (ret)
		goto cleanup_clk;

	/* Map device registers */
	lp->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &ethres);
	if (IS_ERR(lp->regs)) {
		ret = PTR_ERR(lp->regs);
		goto cleanup_clk;
	}
	lp->regs_start = ethres->start;

	/* Setup checksum offload, but default to off if not specified */
	lp->features = 0;

	if (axienet_ior(lp, XAE_ABILITY_OFFSET) & XAE_ABILITY_STATS)
		lp->features |= XAE_FEATURE_STATS;

	ret = of_property_read_u32(pdev->dev.of_node, "xlnx,txcsum", &value);
	if (!ret) {
		switch (value) {
		case 1:
			lp->features |= XAE_FEATURE_PARTIAL_TX_CSUM;
			/* Can checksum any contiguous range */
			ndev->features |= NETIF_F_HW_CSUM;
			break;
		case 2:
			lp->features |= XAE_FEATURE_FULL_TX_CSUM;
			/* Can checksum TCP/UDP over IPv4. */
			ndev->features |= NETIF_F_IP_CSUM;
			break;
		}
	}
	ret = of_property_read_u32(pdev->dev.of_node, "xlnx,rxcsum", &value);
	if (!ret) {
		switch (value) {
		case 1:
			lp->features |= XAE_FEATURE_PARTIAL_RX_CSUM;
			ndev->features |= NETIF_F_RXCSUM;
			break;
		case 2:
			lp->features |= XAE_FEATURE_FULL_RX_CSUM;
			ndev->features |= NETIF_F_RXCSUM;
			break;
		}
	}
	/* For supporting jumbo frames, the Axi Ethernet hardware must have
	 * a larger Rx/Tx Memory. Typically, the size must be large so that
	 * we can enable jumbo option and start supporting jumbo frames.
	 * Here we check for memory allocated for Rx/Tx in the hardware from
	 * the device-tree and accordingly set flags.
	 */
	of_property_read_u32(pdev->dev.of_node, "xlnx,rxmem", &lp->rxmem);

	lp->switch_x_sgmii = of_property_read_bool(pdev->dev.of_node,
						   "xlnx,switch-x-sgmii");

	/* Start with the proprietary, and broken phy_type */
	ret = of_property_read_u32(pdev->dev.of_node, "xlnx,phy-type", &value);
	if (!ret) {
		netdev_warn(ndev, "Please upgrade your device tree binary blob to use phy-mode");
		switch (value) {
		case XAE_PHY_TYPE_MII:
			lp->phy_mode = PHY_INTERFACE_MODE_MII;
			break;
		case XAE_PHY_TYPE_GMII:
			lp->phy_mode = PHY_INTERFACE_MODE_GMII;
			break;
		case XAE_PHY_TYPE_RGMII_2_0:
			lp->phy_mode = PHY_INTERFACE_MODE_RGMII_ID;
			break;
		case XAE_PHY_TYPE_SGMII:
			lp->phy_mode = PHY_INTERFACE_MODE_SGMII;
			break;
		case XAE_PHY_TYPE_1000BASE_X:
			lp->phy_mode = PHY_INTERFACE_MODE_1000BASEX;
			break;
		default:
			ret = -EINVAL;
			goto cleanup_clk;
		}
	} else {
		ret = of_get_phy_mode(pdev->dev.of_node, &lp->phy_mode);
		if (ret)
			goto cleanup_clk;
	}
	if (lp->switch_x_sgmii && lp->phy_mode != PHY_INTERFACE_MODE_SGMII &&
	    lp->phy_mode != PHY_INTERFACE_MODE_1000BASEX) {
		dev_err(&pdev->dev, "xlnx,switch-x-sgmii only supported with SGMII or 1000BaseX\n");
		ret = -EINVAL;
		goto cleanup_clk;
	}

	if (!of_property_present(pdev->dev.of_node, "dmas")) {
		/* Find the DMA node, map the DMA registers, and decode the DMA IRQs */
		np = of_parse_phandle(pdev->dev.of_node, "axistream-connected", 0);

		if (np) {
			struct resource dmares;

			ret = of_address_to_resource(np, 0, &dmares);
			if (ret) {
				dev_err(&pdev->dev,
					"unable to get DMA resource\n");
				of_node_put(np);
				goto cleanup_clk;
			}
			lp->dma_regs = devm_ioremap_resource(&pdev->dev,
							     &dmares);
			lp->rx_irq = irq_of_parse_and_map(np, 1);
			lp->tx_irq = irq_of_parse_and_map(np, 0);
			of_node_put(np);
			lp->eth_irq = platform_get_irq_optional(pdev, 0);
		} else {
			/* Check for these resources directly on the Ethernet node. */
			lp->dma_regs = devm_platform_get_and_ioremap_resource(pdev, 1, NULL);
			lp->rx_irq = platform_get_irq(pdev, 1);
			lp->tx_irq = platform_get_irq(pdev, 0);
			lp->eth_irq = platform_get_irq_optional(pdev, 2);
		}
		if (IS_ERR(lp->dma_regs)) {
			dev_err(&pdev->dev, "could not map DMA regs\n");
			ret = PTR_ERR(lp->dma_regs);
			goto cleanup_clk;
		}
		if (lp->rx_irq <= 0 || lp->tx_irq <= 0) {
			dev_err(&pdev->dev, "could not determine irqs\n");
			ret = -ENOMEM;
			goto cleanup_clk;
		}

		/* Reset core now that clocks are enabled, prior to accessing MDIO */
		ret = __axienet_device_reset(lp);
		if (ret)
			goto cleanup_clk;

		/* Autodetect the need for 64-bit DMA pointers.
		 * When the IP is configured for a bus width bigger than 32 bits,
		 * writing the MSB registers is mandatory, even if they are all 0.
		 * We can detect this case by writing all 1's to one such register
		 * and see if that sticks: when the IP is configured for 32 bits
		 * only, those registers are RES0.
		 * Those MSB registers were introduced in IP v7.1, which we check first.
		 */
		if ((axienet_ior(lp, XAE_ID_OFFSET) >> 24) >= 0x9) {
			void __iomem *desc = lp->dma_regs + XAXIDMA_TX_CDESC_OFFSET + 4;

			iowrite32(0x0, desc);
			if (ioread32(desc) == 0) {	/* sanity check */
				iowrite32(0xffffffff, desc);
				if (ioread32(desc) > 0) {
					lp->features |= XAE_FEATURE_DMA_64BIT;
					addr_width = 64;
					dev_info(&pdev->dev,
						 "autodetected 64-bit DMA range\n");
				}
				iowrite32(0x0, desc);
			}
		}
		if (!IS_ENABLED(CONFIG_64BIT) && lp->features & XAE_FEATURE_DMA_64BIT) {
			dev_err(&pdev->dev, "64-bit addressable DMA is not compatible with 32-bit archecture\n");
			ret = -EINVAL;
			goto cleanup_clk;
		}

		ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(addr_width));
		if (ret) {
			dev_err(&pdev->dev, "No suitable DMA available\n");
			goto cleanup_clk;
		}
		netif_napi_add(ndev, &lp->napi_rx, axienet_rx_poll);
		netif_napi_add(ndev, &lp->napi_tx, axienet_tx_poll);
	} else {
		struct xilinx_vdma_config cfg;
		struct dma_chan *tx_chan;

		lp->eth_irq = platform_get_irq_optional(pdev, 0);
		if (lp->eth_irq < 0 && lp->eth_irq != -ENXIO) {
			ret = lp->eth_irq;
			goto cleanup_clk;
		}
		tx_chan = dma_request_chan(lp->dev, "tx_chan0");
		if (IS_ERR(tx_chan)) {
			ret = PTR_ERR(tx_chan);
			dev_err_probe(lp->dev, ret, "No Ethernet DMA (TX) channel found\n");
			goto cleanup_clk;
		}

		cfg.reset = 1;
		/* As name says VDMA but it has support for DMA channel reset */
		ret = xilinx_vdma_channel_set_config(tx_chan, &cfg);
		if (ret < 0) {
			dev_err(&pdev->dev, "Reset channel failed\n");
			dma_release_channel(tx_chan);
			goto cleanup_clk;
		}

		dma_release_channel(tx_chan);
		lp->use_dmaengine = 1;
	}

	if (lp->use_dmaengine)
		ndev->netdev_ops = &axienet_netdev_dmaengine_ops;
	else
		ndev->netdev_ops = &axienet_netdev_ops;
	/* Check for Ethernet core IRQ (optional) */
	if (lp->eth_irq <= 0)
		dev_info(&pdev->dev, "Ethernet core IRQ not defined\n");

	/* Retrieve the MAC address */
	ret = of_get_mac_address(pdev->dev.of_node, mac_addr);
	if (!ret) {
		axienet_set_mac_address(ndev, mac_addr);
	} else {
		dev_warn(&pdev->dev, "could not find MAC address property: %d\n",
			 ret);
		axienet_set_mac_address(ndev, NULL);
	}

	lp->coalesce_count_rx = XAXIDMA_DFT_RX_THRESHOLD;
	lp->coalesce_count_tx = XAXIDMA_DFT_TX_THRESHOLD;
	lp->coalesce_usec_rx = XAXIDMA_DFT_RX_USEC;
	lp->coalesce_usec_tx = XAXIDMA_DFT_TX_USEC;

	ret = axienet_mdio_setup(lp);
	if (ret)
		dev_warn(&pdev->dev,
			 "error registering MDIO bus: %d\n", ret);

	if (lp->phy_mode == PHY_INTERFACE_MODE_SGMII ||
	    lp->phy_mode == PHY_INTERFACE_MODE_1000BASEX) {
		np = of_parse_phandle(pdev->dev.of_node, "pcs-handle", 0);
		if (!np) {
			/* Deprecated: Always use "pcs-handle" for pcs_phy.
			 * Falling back to "phy-handle" here is only for
			 * backward compatibility with old device trees.
			 */
			np = of_parse_phandle(pdev->dev.of_node, "phy-handle", 0);
		}
		if (!np) {
			dev_err(&pdev->dev, "pcs-handle (preferred) or phy-handle required for 1000BaseX/SGMII\n");
			ret = -EINVAL;
			goto cleanup_mdio;
		}
		lp->pcs_phy = of_mdio_find_device(np);
		if (!lp->pcs_phy) {
			ret = -EPROBE_DEFER;
			of_node_put(np);
			goto cleanup_mdio;
		}
		of_node_put(np);
		lp->pcs.ops = &axienet_pcs_ops;
		lp->pcs.neg_mode = true;
		lp->pcs.poll = true;
	}

	lp->phylink_config.dev = &ndev->dev;
	lp->phylink_config.type = PHYLINK_NETDEV;
	lp->phylink_config.mac_capabilities = MAC_SYM_PAUSE | MAC_ASYM_PAUSE |
		MAC_10FD | MAC_100FD | MAC_1000FD;

	__set_bit(lp->phy_mode, lp->phylink_config.supported_interfaces);
	if (lp->switch_x_sgmii) {
		__set_bit(PHY_INTERFACE_MODE_1000BASEX,
			  lp->phylink_config.supported_interfaces);
		__set_bit(PHY_INTERFACE_MODE_SGMII,
			  lp->phylink_config.supported_interfaces);
	}

	lp->phylink = phylink_create(&lp->phylink_config, pdev->dev.fwnode,
				     lp->phy_mode,
				     &axienet_phylink_ops);
	if (IS_ERR(lp->phylink)) {
		ret = PTR_ERR(lp->phylink);
		dev_err(&pdev->dev, "phylink_create error (%i)\n", ret);
		goto cleanup_mdio;
	}

	ret = register_netdev(lp->ndev);
	if (ret) {
		dev_err(lp->dev, "register_netdev() error (%i)\n", ret);
		goto cleanup_phylink;
	}

	return 0;

cleanup_phylink:
	phylink_destroy(lp->phylink);

cleanup_mdio:
	if (lp->pcs_phy)
		put_device(&lp->pcs_phy->dev);
	if (lp->mii_bus)
		axienet_mdio_teardown(lp);
cleanup_clk:
	clk_bulk_disable_unprepare(XAE_NUM_MISC_CLOCKS, lp->misc_clks);
	clk_disable_unprepare(lp->axi_clk);

free_netdev:
	free_netdev(ndev);

	return ret;
}

static void axienet_remove(struct platform_device *pdev)
{
	struct net_device *ndev = platform_get_drvdata(pdev);
	struct axienet_local *lp = netdev_priv(ndev);

	unregister_netdev(ndev);

	if (lp->phylink)
		phylink_destroy(lp->phylink);

	if (lp->pcs_phy)
		put_device(&lp->pcs_phy->dev);

	axienet_mdio_teardown(lp);

	clk_bulk_disable_unprepare(XAE_NUM_MISC_CLOCKS, lp->misc_clks);
	clk_disable_unprepare(lp->axi_clk);

	free_netdev(ndev);
}

static void axienet_shutdown(struct platform_device *pdev)
{
	struct net_device *ndev = platform_get_drvdata(pdev);

	rtnl_lock();
	netif_device_detach(ndev);

	if (netif_running(ndev))
		dev_close(ndev);

	rtnl_unlock();
}

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

	if (!netif_running(ndev))
		return 0;

	netif_device_detach(ndev);

	rtnl_lock();
	axienet_stop(ndev);
	rtnl_unlock();

	return 0;
}

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

	if (!netif_running(ndev))
		return 0;

	rtnl_lock();
	axienet_open(ndev);
	rtnl_unlock();

	netif_device_attach(ndev);

	return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(axienet_pm_ops,
				axienet_suspend, axienet_resume);

static struct platform_driver axienet_driver = {
	.probe = axienet_probe,
	.remove_new = axienet_remove,
	.shutdown = axienet_shutdown,
	.driver = {
		 .name = "xilinx_axienet",
		 .pm = &axienet_pm_ops,
		 .of_match_table = axienet_of_match,
	},
};

module_platform_driver(axienet_driver);

MODULE_DESCRIPTION("Xilinx Axi Ethernet driver");
MODULE_AUTHOR("Xilinx");
MODULE_LICENSE("GPL");