pci/cxgb/cxgb_xgmac.c

/**************************************************************************

Copyright (c) 2007, Chelsio Inc.
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

 1. Redistributions of source code must retain the above copyright notice,
    this list of conditions and the following disclaimer.

 2. Neither the name of the Chelsio Corporation nor the names of its
    contributors may be used to endorse or promote products derived from
    this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.

***************************************************************************/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: cxgb_xgmac.c,v 1.1 2010/03/21 21:11:13 jklos Exp $");

#ifdef CONFIG_DEFINED
#include <cxgb_include.h>
#else
#include "cxgb_include.h"
#endif

#undef msleep
#define msleep t3_os_sleep

/*
 * # of exact address filters.  The first one is used for the station address,
 * the rest are available for multicast addresses.
 */
#define EXACT_ADDR_FILTERS 8

static inline int macidx(const struct cmac *mac)
{
    return mac->offset / (XGMAC0_1_BASE_ADDR - XGMAC0_0_BASE_ADDR);
}

static void xaui_serdes_reset(struct cmac *mac)
{
    static const unsigned int clear[] = {
        F_PWRDN0 | F_PWRDN1,    F_RESETPLL01,    F_RESET0 | F_RESET1,
            F_PWRDN2 | F_PWRDN3,    F_RESETPLL23,    F_RESET2 | F_RESET3
    };

    int i;
    adapter_t *adap = mac->adapter;
    u32 ctrl = A_XGM_SERDES_CTRL0 + mac->offset;

    t3_write_reg(adap, ctrl, adap->params.vpd.xauicfg[macidx(mac)] |
             F_RESET3 | F_RESET2 | F_RESET1 | F_RESET0 |
             F_PWRDN3 | F_PWRDN2 | F_PWRDN1 | F_PWRDN0 |
             F_RESETPLL23 | F_RESETPLL01);
    (void)t3_read_reg(adap, ctrl);
    udelay(15);

    for (i = 0; i < ARRAY_SIZE(clear); i++) {
        t3_set_reg_field(adap, ctrl, clear[i], 0);
        udelay(15);
    }
}

void t3b_pcs_reset(struct cmac *mac)
{
    t3_set_reg_field(mac->adapter, A_XGM_RESET_CTRL + mac->offset,
             F_PCS_RESET_, 0);
    udelay(20);
    t3_set_reg_field(mac->adapter, A_XGM_RESET_CTRL + mac->offset, 0,
             F_PCS_RESET_);
}

int t3_mac_reset(struct cmac *mac)
{
    static struct addr_val_pair mac_reset_avp[] = {
        { A_XGM_TX_CTRL, 0 },
        { A_XGM_RX_CTRL, 0 },
        { A_XGM_RX_CFG, F_DISPAUSEFRAMES | F_EN1536BFRAMES |
                        F_RMFCS | F_ENJUMBO | F_ENHASHMCAST },
        { A_XGM_RX_HASH_LOW, 0 },
        { A_XGM_RX_HASH_HIGH, 0 },
        { A_XGM_RX_EXACT_MATCH_LOW_1, 0 },
        { A_XGM_RX_EXACT_MATCH_LOW_2, 0 },
        { A_XGM_RX_EXACT_MATCH_LOW_3, 0 },
        { A_XGM_RX_EXACT_MATCH_LOW_4, 0 },
        { A_XGM_RX_EXACT_MATCH_LOW_5, 0 },
        { A_XGM_RX_EXACT_MATCH_LOW_6, 0 },
        { A_XGM_RX_EXACT_MATCH_LOW_7, 0 },
        { A_XGM_RX_EXACT_MATCH_LOW_8, 0 },
        { A_XGM_STAT_CTRL, F_CLRSTATS }
    };
    u32 val;
    adapter_t *adap = mac->adapter;
    unsigned int oft = mac->offset;

    t3_write_reg(adap, A_XGM_RESET_CTRL + oft, F_MAC_RESET_);
    (void) t3_read_reg(adap, A_XGM_RESET_CTRL + oft);    /* flush */

    t3_write_regs(adap, mac_reset_avp, ARRAY_SIZE(mac_reset_avp), oft);
    t3_set_reg_field(adap, A_XGM_RXFIFO_CFG + oft,
             F_RXSTRFRWRD | F_DISERRFRAMES,
             uses_xaui(adap) ? 0 : F_RXSTRFRWRD);

    if (uses_xaui(adap)) {
        if (adap->params.rev == 0) {
            t3_set_reg_field(adap, A_XGM_SERDES_CTRL + oft, 0,
                     F_RXENABLE | F_TXENABLE);
            if (t3_wait_op_done(adap, A_XGM_SERDES_STATUS1 + oft,
                        F_CMULOCK, 1, 5, 2)) {
                CH_ERR(adap,
                       "MAC %d XAUI SERDES CMU lock failed\n",
                       macidx(mac));
                return -1;
            }
            t3_set_reg_field(adap, A_XGM_SERDES_CTRL + oft, 0,
                     F_SERDESRESET_);
        } else
            xaui_serdes_reset(mac);
    }


    if (mac->multiport) {
        t3_write_reg(adap, A_XGM_RX_MAX_PKT_SIZE + oft,
                 MAX_FRAME_SIZE - 4);
        t3_set_reg_field(adap, A_XGM_TXFIFO_CFG + oft, 0,
                 F_DISPREAMBLE);
        t3_set_reg_field(adap, A_XGM_RX_CFG + oft, 0, F_COPYPREAMBLE |
                 F_ENNON802_3PREAMBLE);
        t3_set_reg_field(adap, A_XGM_TXFIFO_CFG + oft,
                 V_TXFIFOTHRESH(M_TXFIFOTHRESH),
                 V_TXFIFOTHRESH(64));
        t3_write_reg(adap, A_XGM_TX_CTRL + oft, F_TXEN);
        t3_write_reg(adap, A_XGM_RX_CTRL + oft, F_RXEN);
    }

    val = F_MAC_RESET_;
    if (is_10G(adap) || mac->multiport)
        val |= F_PCS_RESET_;
    else if (uses_xaui(adap))
        val |= F_PCS_RESET_ | F_XG2G_RESET_;
    else
        val |= F_RGMII_RESET_ | F_XG2G_RESET_;
    t3_write_reg(adap, A_XGM_RESET_CTRL + oft, val);
    (void) t3_read_reg(adap, A_XGM_RESET_CTRL + oft);  /* flush */
    if ((val & F_PCS_RESET_) && adap->params.rev) {
        msleep(1);
        t3b_pcs_reset(mac);
    }

    memset(&mac->stats, 0, sizeof(mac->stats));
    return 0;
}

static int t3b2_mac_reset(struct cmac *mac)
{
    u32 val;
    adapter_t *adap = mac->adapter;
    unsigned int oft = mac->offset;


    /* Stop egress traffic to xgm*/
    if (!macidx(mac))
        t3_set_reg_field(adap, A_MPS_CFG, F_PORT0ACTIVE, 0);
    else
        t3_set_reg_field(adap, A_MPS_CFG, F_PORT1ACTIVE, 0);

    /* PCS in reset */
    t3_write_reg(adap, A_XGM_RESET_CTRL + oft, F_MAC_RESET_);
    (void) t3_read_reg(adap, A_XGM_RESET_CTRL + oft);    /* flush */

    msleep(10);

    /* Check for xgm Rx fifo empty */
    if (t3_wait_op_done(adap, A_XGM_RX_MAX_PKT_SIZE_ERR_CNT + oft,
                0x80000000, 1, 5, 2)) {
        CH_ERR(adap, "MAC %d Rx fifo drain failed\n",
               macidx(mac));
        return -1;
    }

    t3_write_reg(adap, A_XGM_RESET_CTRL + oft, 0); /*MAC in reset*/
    (void) t3_read_reg(adap, A_XGM_RESET_CTRL + oft);    /* flush */

    val = F_MAC_RESET_;
    if (is_10G(adap))
        val |= F_PCS_RESET_;
    else if (uses_xaui(adap))
        val |= F_PCS_RESET_ | F_XG2G_RESET_;
    else
        val |= F_RGMII_RESET_ | F_XG2G_RESET_;
    t3_write_reg(adap, A_XGM_RESET_CTRL + oft, val);
    (void) t3_read_reg(adap, A_XGM_RESET_CTRL + oft);  /* flush */
    if ((val & F_PCS_RESET_) && adap->params.rev) {
        msleep(1);
        t3b_pcs_reset(mac);
    }
    t3_write_reg(adap, A_XGM_RX_CFG + oft,
         F_DISPAUSEFRAMES | F_EN1536BFRAMES |
                        F_RMFCS | F_ENJUMBO | F_ENHASHMCAST );

    /*Resume egress traffic to xgm*/
    if (!macidx(mac))
        t3_set_reg_field(adap, A_MPS_CFG, 0, F_PORT0ACTIVE);
    else
        t3_set_reg_field(adap, A_MPS_CFG, 0, F_PORT1ACTIVE);

    return 0;
}

/*
 * Set the exact match register 'idx' to recognize the given Ethernet address.
 */
static void set_addr_filter(struct cmac *mac, int idx, const u8 *addr)
{
    u32 addr_lo, addr_hi;
    unsigned int oft = mac->offset + idx * 8;

    addr_lo = (addr[3] << 24) | (addr[2] << 16) | (addr[1] << 8) | addr[0];
    addr_hi = (addr[5] << 8) | addr[4];

    t3_write_reg(mac->adapter, A_XGM_RX_EXACT_MATCH_LOW_1 + oft, addr_lo);
    t3_write_reg(mac->adapter, A_XGM_RX_EXACT_MATCH_HIGH_1 + oft, addr_hi);
}

/* Set one of the station's unicast MAC addresses. */
int t3_mac_set_address(struct cmac *mac, unsigned int idx, u8 addr[6])
{
    if (mac->multiport)
        idx = mac->ext_port + idx * mac->adapter->params.nports;
    if (idx >= mac->nucast)
        return -EINVAL;
    set_addr_filter(mac, idx, addr);
    if (mac->multiport && idx < mac->adapter->params.nports)
        t3_vsc7323_set_addr(mac->adapter, addr, idx);
    return 0;
}

/*
 * Specify the number of exact address filters that should be reserved for
 * unicast addresses.  Caller should reload the unicast and multicast addresses
 * after calling this.
 */
int t3_mac_set_num_ucast(struct cmac *mac, unsigned char n)
{
    if (n > EXACT_ADDR_FILTERS)
        return -EINVAL;
    mac->nucast = n;
    return 0;
}

static void disable_exact_filters(struct cmac *mac)
{
    unsigned int i, reg = mac->offset + A_XGM_RX_EXACT_MATCH_LOW_1;

    for (i = 0; i < EXACT_ADDR_FILTERS; i++, reg += 8) {
        u32 v = t3_read_reg(mac->adapter, reg);
        t3_write_reg(mac->adapter, reg, v);
    }
    t3_read_reg(mac->adapter, A_XGM_RX_EXACT_MATCH_LOW_1); /* flush */
}

static void enable_exact_filters(struct cmac *mac)
{
    unsigned int i, reg = mac->offset + A_XGM_RX_EXACT_MATCH_HIGH_1;

    for (i = 0; i < EXACT_ADDR_FILTERS; i++, reg += 8) {
        u32 v = t3_read_reg(mac->adapter, reg);
        t3_write_reg(mac->adapter, reg, v);
    }
    t3_read_reg(mac->adapter, A_XGM_RX_EXACT_MATCH_LOW_1); /* flush */
}

/* Calculate the RX hash filter index of an Ethernet address */
static int hash_hw_addr(const u8 *addr)
{
    int hash = 0, octet, bit, i = 0, c;

    for (octet = 0; octet < 6; ++octet)
        for (c = addr[octet], bit = 0; bit < 8; c >>= 1, ++bit) {
            hash ^= (c & 1) << i;
            if (++i == 6)
                i = 0;
        }
    return hash;
}

int t3_mac_set_rx_mode(struct cmac *mac, struct t3_rx_mode *rm)
{
    u32 hash_lo, hash_hi;
    adapter_t *adap = mac->adapter;
    unsigned int oft = mac->offset;

    if (promisc_rx_mode(rm))
        mac->promisc_map |= 1 << mac->ext_port;
    else
        mac->promisc_map &= ~(1 << mac->ext_port);
    t3_set_reg_field(adap, A_XGM_RX_CFG + oft, F_COPYALLFRAMES,
             mac->promisc_map ? F_COPYALLFRAMES : 0);

    if (allmulti_rx_mode(rm) || mac->multiport)
        hash_lo = hash_hi = 0xffffffff;
    else {
        u8 *addr;
        int exact_addr_idx = mac->nucast;

        hash_lo = hash_hi = 0;
        while ((addr = t3_get_next_mcaddr(rm)))
            if (exact_addr_idx < EXACT_ADDR_FILTERS)
                set_addr_filter(mac, exact_addr_idx++, addr);
            else {
                int hash = hash_hw_addr(addr);

                if (hash < 32)
                    hash_lo |= (1 << hash);
                else
                    hash_hi |= (1 << (hash - 32));
            }
    }

    t3_write_reg(adap, A_XGM_RX_HASH_LOW + oft, hash_lo);
    t3_write_reg(adap, A_XGM_RX_HASH_HIGH + oft, hash_hi);
    return 0;
}

static int rx_fifo_hwm(int mtu)
{
    int hwm;

    hwm = max(MAC_RXFIFO_SIZE - 3 * mtu, (MAC_RXFIFO_SIZE * 38) / 100);
    return min(hwm, MAC_RXFIFO_SIZE - 8192);
}

int t3_mac_set_mtu(struct cmac *mac, unsigned int mtu)
{
    int hwm, lwm;
    unsigned int thres, v;
    adapter_t *adap = mac->adapter;

    /*
     * MAX_FRAME_SIZE inludes header + FCS, mtu doesn't.  The HW max
     * packet size register includes header, but not FCS.
     */
    mtu += 14;
    if (mac->multiport)
        mtu += 8;                             /* for preamble */
    if (mtu > MAX_FRAME_SIZE - 4)
        return -EINVAL;
    if (mac->multiport)
        return t3_vsc7323_set_mtu(adap, mtu - 4, mac->ext_port);

    if (adap->params.rev == T3_REV_B2 &&
        (t3_read_reg(adap, A_XGM_RX_CTRL + mac->offset) & F_RXEN)) {
        disable_exact_filters(mac);
        v = t3_read_reg(adap, A_XGM_RX_CFG + mac->offset);
        t3_set_reg_field(adap, A_XGM_RX_CFG + mac->offset,
                 F_ENHASHMCAST | F_COPYALLFRAMES, F_DISBCAST);

        /* drain rx FIFO */
        if (t3_wait_op_done(adap,
                    A_XGM_RX_MAX_PKT_SIZE_ERR_CNT + mac->offset,
                    1 << 31, 1, 20, 5)) {
            t3_write_reg(adap, A_XGM_RX_CFG + mac->offset, v);
            enable_exact_filters(mac);
            return -EIO;
        }
        t3_write_reg(adap, A_XGM_RX_MAX_PKT_SIZE + mac->offset, mtu);
        t3_write_reg(adap, A_XGM_RX_CFG + mac->offset, v);
        enable_exact_filters(mac);
    } else
        t3_write_reg(adap, A_XGM_RX_MAX_PKT_SIZE + mac->offset, mtu);

    /*
     * Adjust the PAUSE frame watermarks.  We always set the LWM, and the
     * HWM only if flow-control is enabled.
     */
    hwm = rx_fifo_hwm(mtu);
    lwm = min(3 * (int) mtu, MAC_RXFIFO_SIZE /4);
    v = t3_read_reg(adap, A_XGM_RXFIFO_CFG + mac->offset);
    v &= ~V_RXFIFOPAUSELWM(M_RXFIFOPAUSELWM);
    v |= V_RXFIFOPAUSELWM(lwm / 8);
    if (G_RXFIFOPAUSEHWM(v))
        v = (v & ~V_RXFIFOPAUSEHWM(M_RXFIFOPAUSEHWM)) |
            V_RXFIFOPAUSEHWM(hwm / 8);

    t3_write_reg(adap, A_XGM_RXFIFO_CFG + mac->offset, v);

    /* Adjust the TX FIFO threshold based on the MTU */
    thres = (adap->params.vpd.cclk * 1000) / 15625;
    thres = (thres * mtu) / 1000;
    if (is_10G(adap))
        thres /= 10;
    thres = mtu > thres ? (mtu - thres + 7) / 8 : 0;
    thres = max(thres, 8U);                          /* need at least 8 */
    t3_set_reg_field(adap, A_XGM_TXFIFO_CFG + mac->offset,
             V_TXFIFOTHRESH(M_TXFIFOTHRESH) | V_TXIPG(M_TXIPG),
             V_TXFIFOTHRESH(thres) | V_TXIPG(1));

    /* Assuming a minimum drain rate of 2.5Gbps...
     */
    if (adap->params.rev > 0)
        t3_write_reg(adap, A_XGM_PAUSE_TIMER + mac->offset,
                 (hwm - lwm) * 4 / 8);
    t3_write_reg(adap, A_XGM_TX_PAUSE_QUANTA + mac->offset,
             MAC_RXFIFO_SIZE * 4 * 8 / 512);
    return 0;
}

int t3_mac_set_speed_duplex_fc(struct cmac *mac, int speed, int duplex, int fc)
{
    u32 val;
    adapter_t *adap = mac->adapter;
    unsigned int oft = mac->offset;

    if (duplex >= 0 && duplex != DUPLEX_FULL)
        return -EINVAL;
    if (mac->multiport) {
        val = t3_read_reg(adap, A_XGM_RXFIFO_CFG + oft);
        val &= ~V_RXFIFOPAUSEHWM(M_RXFIFOPAUSEHWM);
        val |= V_RXFIFOPAUSEHWM(rx_fifo_hwm(t3_read_reg(adap,
                    A_XGM_RX_MAX_PKT_SIZE + oft)) / 8);
        t3_write_reg(adap, A_XGM_RXFIFO_CFG + oft, val);

        t3_set_reg_field(adap, A_XGM_TX_CFG + oft, F_TXPAUSEEN,
                    F_TXPAUSEEN);
        return t3_vsc7323_set_speed_fc(adap, speed, fc, mac->ext_port);
    }
    if (speed >= 0) {
        if (speed == SPEED_10)
            val = V_PORTSPEED(0);
        else if (speed == SPEED_100)
            val = V_PORTSPEED(1);
        else if (speed == SPEED_1000)
            val = V_PORTSPEED(2);
        else if (speed == SPEED_10000)
            val = V_PORTSPEED(3);
        else
            return -EINVAL;

        t3_set_reg_field(adap, A_XGM_PORT_CFG + oft,
                 V_PORTSPEED(M_PORTSPEED), val);
    }

    val = t3_read_reg(adap, A_XGM_RXFIFO_CFG + oft);
    val &= ~V_RXFIFOPAUSEHWM(M_RXFIFOPAUSEHWM);
    if (fc & PAUSE_TX)
        val |= V_RXFIFOPAUSEHWM(rx_fifo_hwm(t3_read_reg(adap,
                    A_XGM_RX_MAX_PKT_SIZE + oft)) / 8);
    t3_write_reg(adap, A_XGM_RXFIFO_CFG + oft, val);

    t3_set_reg_field(adap, A_XGM_TX_CFG + oft, F_TXPAUSEEN,
            (fc & PAUSE_RX) ? F_TXPAUSEEN : 0);
    return 0;
}

int t3_mac_enable(struct cmac *mac, int which)
{
    int idx = macidx(mac);
    adapter_t *adap = mac->adapter;
    unsigned int oft = mac->offset;
    struct mac_stats *s = &mac->stats;

    if (mac->multiport)
        return t3_vsc7323_enable(adap, mac->ext_port, which);

    if (which & MAC_DIRECTION_TX) {
        t3_write_reg(adap, A_TP_PIO_ADDR, A_TP_TX_DROP_CFG_CH0 + idx);
        t3_write_reg(adap, A_TP_PIO_DATA, 0xc0ede401);
        t3_write_reg(adap, A_TP_PIO_ADDR, A_TP_TX_DROP_MODE);
        t3_set_reg_field(adap, A_TP_PIO_DATA, 1 << idx, 1 << idx);

        t3_write_reg(adap, A_XGM_TX_CTRL + oft, F_TXEN);

        t3_write_reg(adap, A_TP_PIO_ADDR, A_TP_TX_DROP_CNT_CH0 + idx);
        mac->tx_mcnt = s->tx_frames;
        mac->tx_tcnt = (G_TXDROPCNTCH0RCVD(t3_read_reg(adap,
                                   A_TP_PIO_DATA)));
        mac->tx_xcnt = (G_TXSPI4SOPCNT(t3_read_reg(adap,
                        A_XGM_TX_SPI4_SOP_EOP_CNT +
                        oft)));
        mac->rx_mcnt = s->rx_frames;
        mac->rx_pause = s->rx_pause;
        mac->rx_xcnt = (G_TXSPI4SOPCNT(t3_read_reg(adap,
                        A_XGM_RX_SPI4_SOP_EOP_CNT +
                        oft)));
        mac->rx_ocnt = s->rx_fifo_ovfl;
        mac->txen = F_TXEN;
        mac->toggle_cnt = 0;
    }
    if (which & MAC_DIRECTION_RX)
        t3_write_reg(adap, A_XGM_RX_CTRL + oft, F_RXEN);
    return 0;
}

int t3_mac_disable(struct cmac *mac, int which)
{
    adapter_t *adap = mac->adapter;

    if (mac->multiport)
        return t3_vsc7323_disable(adap, mac->ext_port, which);

    if (which & MAC_DIRECTION_TX) {
        t3_write_reg(adap, A_XGM_TX_CTRL + mac->offset, 0);
        mac->txen = 0;
    }
    if (which & MAC_DIRECTION_RX) {
        int val = F_MAC_RESET_;

        t3_set_reg_field(mac->adapter, A_XGM_RESET_CTRL + mac->offset,
                 F_PCS_RESET_, 0);
        msleep(100);
        t3_write_reg(adap, A_XGM_RX_CTRL + mac->offset, 0);
        if (is_10G(adap))
            val |= F_PCS_RESET_;
        else if (uses_xaui(adap))
            val |= F_PCS_RESET_ | F_XG2G_RESET_;
        else
            val |= F_RGMII_RESET_ | F_XG2G_RESET_;
        t3_write_reg(mac->adapter, A_XGM_RESET_CTRL + mac->offset, val);
    }
    return 0;
}

int t3b2_mac_watchdog_task(struct cmac *mac)
{
    int status;
    unsigned int tx_tcnt, tx_xcnt;
    adapter_t *adap = mac->adapter;
    struct mac_stats *s = &mac->stats;
    unsigned int tx_mcnt = (unsigned int)s->tx_frames;
    unsigned int rx_mcnt = (unsigned int)s->rx_frames;
    unsigned int rx_xcnt;

    if (mac->multiport) {
      tx_mcnt = t3_read_reg(adap, A_XGM_STAT_TX_FRAME_LOW);
      rx_mcnt = t3_read_reg(adap, A_XGM_STAT_RX_FRAMES_LOW);
    } else {
      tx_mcnt = (unsigned int)s->tx_frames;
      rx_mcnt = (unsigned int)s->rx_frames;
    }
    status = 0;
    tx_xcnt = 1; /* By default tx_xcnt is making progress*/
    tx_tcnt = mac->tx_tcnt; /* If tx_mcnt is progressing ignore tx_tcnt*/
    rx_xcnt = 1; /* By default rx_xcnt is making progress*/
    if (tx_mcnt == mac->tx_mcnt && mac->rx_pause == s->rx_pause) {
        tx_xcnt = (G_TXSPI4SOPCNT(t3_read_reg(adap,
                        A_XGM_TX_SPI4_SOP_EOP_CNT +
                            mac->offset)));
        if (tx_xcnt == 0) {
            t3_write_reg(adap, A_TP_PIO_ADDR,
                    A_TP_TX_DROP_CNT_CH0 + macidx(mac));
            tx_tcnt = (G_TXDROPCNTCH0RCVD(t3_read_reg(adap,
                    A_TP_PIO_DATA)));
        } else {
            goto rxcheck;
        }
    } else {
        mac->toggle_cnt = 0;
        goto rxcheck;
    }

    if ((tx_tcnt != mac->tx_tcnt) && (mac->tx_xcnt == 0)) {
        if (mac->toggle_cnt > 4) {
            status = 2;
            goto out;
        } else {
            status = 1;
            goto out;
        }
    } else {
        mac->toggle_cnt = 0;
        goto rxcheck;
    }

rxcheck:
    if (rx_mcnt != mac->rx_mcnt) {
        rx_xcnt = (G_TXSPI4SOPCNT(t3_read_reg(adap,
                        A_XGM_RX_SPI4_SOP_EOP_CNT +
                        mac->offset))) +
                        (s->rx_fifo_ovfl - mac->rx_ocnt);
        mac->rx_ocnt = s->rx_fifo_ovfl;
    } else
        goto out;

    if (mac->rx_mcnt != s->rx_frames && rx_xcnt == 0 && mac->rx_xcnt == 0) {
        if (!mac->multiport)
          status = 2;
        goto out;
    }

out:
    mac->tx_tcnt = tx_tcnt;
    mac->tx_xcnt = tx_xcnt;
    mac->tx_mcnt = s->tx_frames;
    mac->rx_xcnt = rx_xcnt;
    mac->rx_mcnt = s->rx_frames;
    mac->rx_pause = s->rx_pause;
    if (status == 1) {
        t3_write_reg(adap, A_XGM_TX_CTRL + mac->offset, 0);
        t3_read_reg(adap, A_XGM_TX_CTRL + mac->offset);  /* flush */
        t3_write_reg(adap, A_XGM_TX_CTRL + mac->offset, mac->txen);
        t3_read_reg(adap, A_XGM_TX_CTRL + mac->offset);  /* flush */
        mac->toggle_cnt++;
    } else if (status == 2) {
        t3b2_mac_reset(mac);
        mac->toggle_cnt = 0;
    }
    return status;
}

/*
 * This function is called periodically to accumulate the current values of the
 * RMON counters into the port statistics.  Since the packet counters are only
 * 32 bits they can overflow in ~286 secs at 10G, so the function should be
 * called more frequently than that.  The byte counters are 45-bit wide, they
 * would overflow in ~7.8 hours.
 */
const struct mac_stats *t3_mac_update_stats(struct cmac *mac)
{
#define RMON_READ(mac, addr) t3_read_reg(mac->adapter, addr + mac->offset)
#define RMON_UPDATE(mac, name, reg) \
    (mac)->stats.name += (u64)RMON_READ(mac, A_XGM_STAT_##reg)
#define RMON_UPDATE64(mac, name, reg_lo, reg_hi) \
    (mac)->stats.name += RMON_READ(mac, A_XGM_STAT_##reg_lo) + \
                 ((u64)RMON_READ(mac, A_XGM_STAT_##reg_hi) << 32)

    u32 v, lo;

    if (mac->multiport)
        return t3_vsc7323_update_stats(mac);

    RMON_UPDATE64(mac, rx_octets, RX_BYTES_LOW, RX_BYTES_HIGH);
    RMON_UPDATE64(mac, rx_frames, RX_FRAMES_LOW, RX_FRAMES_HIGH);
    RMON_UPDATE(mac, rx_mcast_frames, RX_MCAST_FRAMES);
    RMON_UPDATE(mac, rx_bcast_frames, RX_BCAST_FRAMES);
    RMON_UPDATE(mac, rx_fcs_errs, RX_CRC_ERR_FRAMES);
    RMON_UPDATE(mac, rx_pause, RX_PAUSE_FRAMES);
    RMON_UPDATE(mac, rx_jabber, RX_JABBER_FRAMES);
    RMON_UPDATE(mac, rx_short, RX_SHORT_FRAMES);
    RMON_UPDATE(mac, rx_symbol_errs, RX_SYM_CODE_ERR_FRAMES);

    RMON_UPDATE(mac, rx_too_long, RX_OVERSIZE_FRAMES);

    v = RMON_READ(mac, A_XGM_RX_MAX_PKT_SIZE_ERR_CNT);
    if (mac->adapter->params.rev == T3_REV_B2)
        v &= 0x7fffffff;
    mac->stats.rx_too_long += v;

    RMON_UPDATE(mac, rx_frames_64,        RX_64B_FRAMES);
    RMON_UPDATE(mac, rx_frames_65_127,    RX_65_127B_FRAMES);
    RMON_UPDATE(mac, rx_frames_128_255,   RX_128_255B_FRAMES);
    RMON_UPDATE(mac, rx_frames_256_511,   RX_256_511B_FRAMES);
    RMON_UPDATE(mac, rx_frames_512_1023,  RX_512_1023B_FRAMES);
    RMON_UPDATE(mac, rx_frames_1024_1518, RX_1024_1518B_FRAMES);
    RMON_UPDATE(mac, rx_frames_1519_max,  RX_1519_MAXB_FRAMES);

    RMON_UPDATE64(mac, tx_octets, TX_BYTE_LOW, TX_BYTE_HIGH);
    RMON_UPDATE64(mac, tx_frames, TX_FRAME_LOW, TX_FRAME_HIGH);
    RMON_UPDATE(mac, tx_mcast_frames, TX_MCAST);
    RMON_UPDATE(mac, tx_bcast_frames, TX_BCAST);
    RMON_UPDATE(mac, tx_pause, TX_PAUSE);
    /* This counts error frames in general (bad FCS, underrun, etc). */
    RMON_UPDATE(mac, tx_underrun, TX_ERR_FRAMES);

    RMON_UPDATE(mac, tx_frames_64,        TX_64B_FRAMES);
    RMON_UPDATE(mac, tx_frames_65_127,    TX_65_127B_FRAMES);
    RMON_UPDATE(mac, tx_frames_128_255,   TX_128_255B_FRAMES);
    RMON_UPDATE(mac, tx_frames_256_511,   TX_256_511B_FRAMES);
    RMON_UPDATE(mac, tx_frames_512_1023,  TX_512_1023B_FRAMES);
    RMON_UPDATE(mac, tx_frames_1024_1518, TX_1024_1518B_FRAMES);
    RMON_UPDATE(mac, tx_frames_1519_max,  TX_1519_MAXB_FRAMES);

    /* The next stat isn't clear-on-read. */
    t3_write_reg(mac->adapter, A_TP_MIB_INDEX, mac->offset ? 51 : 50);
    v = t3_read_reg(mac->adapter, A_TP_MIB_RDATA);
    lo = (u32)mac->stats.rx_cong_drops;
    mac->stats.rx_cong_drops += (u64)(v - lo);

    return &mac->stats;
}