/*
 * Copyright (c) 2005-2008 Chelsio, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#include "common.h"
#include "regs.h"

/*
 * # 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;
        struct adapter *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);
        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 const 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;
        struct adapter *adap = mac->adapter;
        unsigned int oft = mac->offset;

        t3_write_reg(adap, A_XGM_RESET_CTRL + oft, F_MAC_RESET_);
        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);
        t3_set_reg_field(adap, A_XGM_TXFIFO_CFG + oft, 0, F_UNDERUNFIX);

        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);
        }

        t3_set_reg_field(adap, A_XGM_RX_MAX_PKT_SIZE + oft,
                         V_RXMAXFRAMERSIZE(M_RXMAXFRAMERSIZE),
                         V_RXMAXFRAMERSIZE(MAX_FRAME_SIZE) | F_RXENFRAMER);
        val = F_MAC_RESET_ | F_XGMAC_STOP_EN;

        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);
        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)
{
        struct adapter *adap = mac->adapter;
        unsigned int oft = mac->offset, store;
        int idx = macidx(mac);
        u32 val;

        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);

        /* Stop NIC traffic to reduce the number of TXTOGGLES */
        t3_set_reg_field(adap, A_MPS_CFG, F_ENFORCEPKT, 0);
        /* Ensure TX drains */
        t3_set_reg_field(adap, A_XGM_TX_CFG + oft, F_TXPAUSEEN, 0);

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

        /* Store A_TP_TX_DROP_CFG_CH0 */
        t3_write_reg(adap, A_TP_PIO_ADDR, A_TP_TX_DROP_CFG_CH0 + idx);
        store = t3_read_reg(adap, A_TP_TX_DROP_CFG_CH0 + idx);

        msleep(10);

        /* Change DROP_CFG to 0xc0000011 */
        t3_write_reg(adap, A_TP_PIO_ADDR, A_TP_TX_DROP_CFG_CH0 + idx);
        t3_write_reg(adap, A_TP_PIO_DATA, 0xc0000011);

        /* Check for xgm Rx fifo empty */
        /* Increased loop count to 1000 from 5 cover 1G and 100Mbps case */
        if (t3_wait_op_done(adap, A_XGM_RX_MAX_PKT_SIZE_ERR_CNT + oft,
                            0x80000000, 1, 1000, 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);
        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);
        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);

        /* Restore the DROP_CFG */
        t3_write_reg(adap, A_TP_PIO_ADDR, A_TP_TX_DROP_CFG_CH0 + idx);
        t3_write_reg(adap, A_TP_PIO_DATA, store);

        if (!idx)
                t3_set_reg_field(adap, A_MPS_CFG, 0, F_PORT0ACTIVE);
        else
                t3_set_reg_field(adap, A_MPS_CFG, 0, F_PORT1ACTIVE);

        /* re-enable nic traffic */
        t3_set_reg_field(adap, A_MPS_CFG, F_ENFORCEPKT, 1);

        /*  Set: re-enable NIC traffic */
        t3_set_reg_field(adap, A_MPS_CFG, F_ENFORCEPKT, 1);

        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 (idx >= mac->nucast)
                return -EINVAL;
        set_addr_filter(mac, idx, addr);
        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, int n)
{
        if (n > EXACT_ADDR_FILTERS)
                return -EINVAL;
        mac->nucast = n;
        return 0;
}

void t3_mac_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 */
}

void t3_mac_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 net_device *dev)
{
        u32 val, hash_lo, hash_hi;
        struct adapter *adap = mac->adapter;
        unsigned int oft = mac->offset;

        val = t3_read_reg(adap, A_XGM_RX_CFG + oft) & ~F_COPYALLFRAMES;
        if (dev->flags & IFF_PROMISC)
                val |= F_COPYALLFRAMES;
        t3_write_reg(adap, A_XGM_RX_CFG + oft, val);

        if (dev->flags & IFF_ALLMULTI)
                hash_lo = hash_hi = 0xffffffff;
        else {
                struct netdev_hw_addr *ha;
                int exact_addr_idx = mac->nucast;

                hash_lo = hash_hi = 0;
                netdev_for_each_mc_addr(ha, dev)
                        if (exact_addr_idx < EXACT_ADDR_FILTERS)
                                set_addr_filter(mac, exact_addr_idx++,
                                                ha->addr);
                        else {
                                int hash = hash_hw_addr(ha->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, divisor;
        int ipg;
        unsigned int thres, v, reg;
        struct adapter *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 (mtu > 1536)
                mtu += 4;

        if (mtu > MAX_FRAME_SIZE - 4)
                return -EINVAL;
        t3_write_reg(adap, A_XGM_RX_MAX_PKT_SIZE + mac->offset, mtu);

        if (adap->params.rev >= T3_REV_B2 &&
            (t3_read_reg(adap, A_XGM_RX_CTRL + mac->offset) & F_RXEN)) {
                t3_mac_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);

                reg = adap->params.rev == T3_REV_B2 ?
                        A_XGM_RX_MAX_PKT_SIZE_ERR_CNT : A_XGM_RXFIFO_CFG;

                /* drain RX FIFO */
                if (t3_wait_op_done(adap, reg + mac->offset,
                                    F_RXFIFO_EMPTY, 1, 20, 5)) {
                        t3_write_reg(adap, A_XGM_RX_CFG + mac->offset, v);
                        t3_mac_enable_exact_filters(mac);
                        return -EIO;
                }
                t3_set_reg_field(adap, A_XGM_RX_MAX_PKT_SIZE + mac->offset,
                                 V_RXMAXPKTSIZE(M_RXMAXPKTSIZE),
                                 V_RXMAXPKTSIZE(mtu));
                t3_write_reg(adap, A_XGM_RX_CFG + mac->offset, v);
                t3_mac_enable_exact_filters(mac);
        } else
                t3_set_reg_field(adap, A_XGM_RX_MAX_PKT_SIZE + mac->offset,
                                 V_RXMAXPKTSIZE(M_RXMAXPKTSIZE),
                                 V_RXMAXPKTSIZE(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 */
        ipg = (adap->params.rev == T3_REV_C) ? 0 : 1;
        t3_set_reg_field(adap, A_XGM_TXFIFO_CFG + mac->offset,
                         V_TXFIFOTHRESH(M_TXFIFOTHRESH) | V_TXIPG(M_TXIPG),
                         V_TXFIFOTHRESH(thres) | V_TXIPG(ipg));

        if (adap->params.rev > 0) {
                divisor = (adap->params.rev == T3_REV_C) ? 64 : 8;
                t3_write_reg(adap, A_XGM_PAUSE_TIMER + mac->offset,
                             (hwm - lwm) * 4 / divisor);
        }
        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;
        struct adapter *adap = mac->adapter;
        unsigned int oft = mac->offset;

        if (duplex >= 0 && duplex != DUPLEX_FULL)
                return -EINVAL;
        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) {
                u32 rx_max_pkt_size =
                    G_RXMAXPKTSIZE(t3_read_reg(adap,
                                               A_XGM_RX_MAX_PKT_SIZE + oft));
                val |= V_RXFIFOPAUSEHWM(rx_fifo_hwm(rx_max_pkt_size) / 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);
        struct adapter *adap = mac->adapter;
        unsigned int oft = mac->offset;
        struct mac_stats *s = &mac->stats;

        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,
                             adap->params.rev == T3_REV_C ?
                             0xc4ffff01 : 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,
                                 adap->params.rev == T3_REV_C ? 0 : 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)
{
        struct adapter *adap = mac->adapter;

        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)
{
        struct adapter *adap = mac->adapter;
        struct mac_stats *s = &mac->stats;
        unsigned int tx_tcnt, tx_xcnt;
        u64 tx_mcnt = s->tx_frames;
        int status;

        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 */
        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 out;
                }
        } else {
                mac->toggle_cnt = 0;
                goto out;
        }

        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 out;
        }

out:
        mac->tx_tcnt = tx_tcnt;
        mac->tx_xcnt = tx_xcnt;
        mac->tx_mcnt = s->tx_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;

        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;
}