// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 2017 - 2021 Pensando Systems, Inc */

#include <linux/netdevice.h>
#include <linux/etherdevice.h>

#include "ionic.h"
#include "ionic_bus.h"
#include "ionic_lif.h"
#include "ionic_ethtool.h"

static int ionic_hwstamp_tx_mode(int config_tx_type)
{
        switch (config_tx_type) {
        case HWTSTAMP_TX_OFF:
                return IONIC_TXSTAMP_OFF;
        case HWTSTAMP_TX_ON:
                return IONIC_TXSTAMP_ON;
        case HWTSTAMP_TX_ONESTEP_SYNC:
                return IONIC_TXSTAMP_ONESTEP_SYNC;
        case HWTSTAMP_TX_ONESTEP_P2P:
                return IONIC_TXSTAMP_ONESTEP_P2P;
        default:
                return -ERANGE;
        }
}

static u64 ionic_hwstamp_rx_filt(int config_rx_filter)
{
        switch (config_rx_filter) {
        case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
                return IONIC_PKT_CLS_PTP1_ALL;
        case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
                return IONIC_PKT_CLS_PTP1_SYNC;
        case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
                return IONIC_PKT_CLS_PTP1_SYNC | IONIC_PKT_CLS_PTP1_DREQ;

        case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
                return IONIC_PKT_CLS_PTP2_L4_ALL;
        case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
                return IONIC_PKT_CLS_PTP2_L4_SYNC;
        case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
                return IONIC_PKT_CLS_PTP2_L4_SYNC | IONIC_PKT_CLS_PTP2_L4_DREQ;

        case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
                return IONIC_PKT_CLS_PTP2_L2_ALL;
        case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
                return IONIC_PKT_CLS_PTP2_L2_SYNC;
        case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
                return IONIC_PKT_CLS_PTP2_L2_SYNC | IONIC_PKT_CLS_PTP2_L2_DREQ;

        case HWTSTAMP_FILTER_PTP_V2_EVENT:
                return IONIC_PKT_CLS_PTP2_ALL;
        case HWTSTAMP_FILTER_PTP_V2_SYNC:
                return IONIC_PKT_CLS_PTP2_SYNC;
        case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
                return IONIC_PKT_CLS_PTP2_SYNC | IONIC_PKT_CLS_PTP2_DREQ;

        case HWTSTAMP_FILTER_NTP_ALL:
                return IONIC_PKT_CLS_NTP_ALL;

        default:
                return 0;
        }
}

static int ionic_lif_hwstamp_set_ts_config(struct ionic_lif *lif,
                                           struct hwtstamp_config *new_ts)
{
        struct ionic *ionic = lif->ionic;
        struct hwtstamp_config *config;
        struct hwtstamp_config ts;
        int tx_mode = 0;
        u64 rx_filt = 0;
        int err, err2;
        bool rx_all;
        __le64 mask;

        if (!lif->phc || !lif->phc->ptp)
                return -EOPNOTSUPP;

        mutex_lock(&lif->phc->config_lock);

        if (new_ts) {
                config = new_ts;
        } else {
                /* If called with new_ts == NULL, replay the previous request
                 * primarily for recovery after a FW_RESET.
                 * We saved the previous configuration request info, so copy
                 * the previous request for reference, clear the current state
                 * to match the device's reset state, and run with it.
                 */
                config = &ts;
                memcpy(config, &lif->phc->ts_config, sizeof(*config));
                memset(&lif->phc->ts_config, 0, sizeof(lif->phc->ts_config));
                lif->phc->ts_config_tx_mode = 0;
                lif->phc->ts_config_rx_filt = 0;
        }

        tx_mode = ionic_hwstamp_tx_mode(config->tx_type);
        if (tx_mode < 0) {
                err = tx_mode;
                goto err_queues;
        }

        mask = cpu_to_le64(BIT_ULL(tx_mode));
        if ((ionic->ident.lif.eth.hwstamp_tx_modes & mask) != mask) {
                err = -ERANGE;
                goto err_queues;
        }

        rx_filt = ionic_hwstamp_rx_filt(config->rx_filter);
        rx_all = config->rx_filter != HWTSTAMP_FILTER_NONE && !rx_filt;

        mask = cpu_to_le64(rx_filt);
        if ((ionic->ident.lif.eth.hwstamp_rx_filters & mask) != mask) {
                rx_filt = 0;
                rx_all = true;
                config->rx_filter = HWTSTAMP_FILTER_ALL;
        }

        dev_dbg(ionic->dev, "%s: config_rx_filter %d rx_filt %#llx rx_all %d\n",
                __func__, config->rx_filter, rx_filt, rx_all);

        if (tx_mode) {
                err = ionic_lif_create_hwstamp_txq(lif);
                if (err)
                        goto err_queues;
        }

        if (rx_filt) {
                err = ionic_lif_create_hwstamp_rxq(lif);
                if (err)
                        goto err_queues;
        }

        if (tx_mode != lif->phc->ts_config_tx_mode) {
                err = ionic_lif_set_hwstamp_txmode(lif, tx_mode);
                if (err)
                        goto err_txmode;
        }

        if (rx_filt != lif->phc->ts_config_rx_filt) {
                err = ionic_lif_set_hwstamp_rxfilt(lif, rx_filt);
                if (err)
                        goto err_rxfilt;
        }

        if (rx_all != (lif->phc->ts_config.rx_filter == HWTSTAMP_FILTER_ALL)) {
                err = ionic_lif_config_hwstamp_rxq_all(lif, rx_all);
                if (err)
                        goto err_rxall;
        }

        memcpy(&lif->phc->ts_config, config, sizeof(*config));
        lif->phc->ts_config_rx_filt = rx_filt;
        lif->phc->ts_config_tx_mode = tx_mode;

        mutex_unlock(&lif->phc->config_lock);

        return 0;

err_rxall:
        if (rx_filt != lif->phc->ts_config_rx_filt) {
                rx_filt = lif->phc->ts_config_rx_filt;
                err2 = ionic_lif_set_hwstamp_rxfilt(lif, rx_filt);
                if (err2)
                        dev_err(ionic->dev,
                                "Failed to revert rx timestamp filter: %d\n", err2);
        }
err_rxfilt:
        if (tx_mode != lif->phc->ts_config_tx_mode) {
                tx_mode = lif->phc->ts_config_tx_mode;
                err2 = ionic_lif_set_hwstamp_txmode(lif, tx_mode);
                if (err2)
                        dev_err(ionic->dev,
                                "Failed to revert tx timestamp mode: %d\n", err2);
        }
err_txmode:
        /* special queues remain allocated, just unused */
err_queues:
        mutex_unlock(&lif->phc->config_lock);
        return err;
}

int ionic_lif_hwstamp_set(struct ionic_lif *lif, struct ifreq *ifr)
{
        struct hwtstamp_config config;
        int err;

        if (!lif->phc || !lif->phc->ptp)
                return -EOPNOTSUPP;

        if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
                return -EFAULT;

        mutex_lock(&lif->queue_lock);
        err = ionic_lif_hwstamp_set_ts_config(lif, &config);
        mutex_unlock(&lif->queue_lock);
        if (err) {
                netdev_info(lif->netdev, "hwstamp set failed: %d\n", err);
                return err;
        }

        if (copy_to_user(ifr->ifr_data, &config, sizeof(config)))
                return -EFAULT;

        return 0;
}

void ionic_lif_hwstamp_replay(struct ionic_lif *lif)
{
        int err;

        if (!lif->phc || !lif->phc->ptp)
                return;

        mutex_lock(&lif->queue_lock);
        err = ionic_lif_hwstamp_set_ts_config(lif, NULL);
        mutex_unlock(&lif->queue_lock);
        if (err)
                netdev_info(lif->netdev, "hwstamp replay failed: %d\n", err);
}

void ionic_lif_hwstamp_recreate_queues(struct ionic_lif *lif)
{
        int err;

        if (!lif->phc || !lif->phc->ptp)
                return;

        mutex_lock(&lif->phc->config_lock);

        if (lif->phc->ts_config_tx_mode) {
                err = ionic_lif_create_hwstamp_txq(lif);
                if (err)
                        netdev_info(lif->netdev, "hwstamp recreate txq failed: %d\n", err);
        }

        if (lif->phc->ts_config_rx_filt) {
                err = ionic_lif_create_hwstamp_rxq(lif);
                if (err)
                        netdev_info(lif->netdev, "hwstamp recreate rxq failed: %d\n", err);
        }

        mutex_unlock(&lif->phc->config_lock);
}

int ionic_lif_hwstamp_get(struct ionic_lif *lif, struct ifreq *ifr)
{
        struct hwtstamp_config config;

        if (!lif->phc || !lif->phc->ptp)
                return -EOPNOTSUPP;

        mutex_lock(&lif->phc->config_lock);
        memcpy(&config, &lif->phc->ts_config, sizeof(config));
        mutex_unlock(&lif->phc->config_lock);

        if (copy_to_user(ifr->ifr_data, &config, sizeof(config)))
                return -EFAULT;
        return 0;
}

static u64 ionic_hwstamp_read(struct ionic *ionic,
                              struct ptp_system_timestamp *sts)
{
        u32 tick_high_before, tick_high, tick_low;

        /* read and discard low part to defeat hw staging of high part */
        (void)ioread32(&ionic->idev.hwstamp_regs->tick_low);

        tick_high_before = ioread32(&ionic->idev.hwstamp_regs->tick_high);

        ptp_read_system_prets(sts);
        tick_low = ioread32(&ionic->idev.hwstamp_regs->tick_low);
        ptp_read_system_postts(sts);

        tick_high = ioread32(&ionic->idev.hwstamp_regs->tick_high);

        /* If tick_high changed, re-read tick_low once more.  Assume tick_high
         * cannot change again so soon as in the span of re-reading tick_low.
         */
        if (tick_high != tick_high_before) {
                ptp_read_system_prets(sts);
                tick_low = ioread32(&ionic->idev.hwstamp_regs->tick_low);
                ptp_read_system_postts(sts);
        }

        return (u64)tick_low | ((u64)tick_high << 32);
}

static u64 ionic_cc_read(const struct cyclecounter *cc)
{
        struct ionic_phc *phc = container_of(cc, struct ionic_phc, cc);
        struct ionic *ionic = phc->lif->ionic;

        return ionic_hwstamp_read(ionic, NULL);
}

static int ionic_setphc_cmd(struct ionic_phc *phc, struct ionic_admin_ctx *ctx)
{
        ctx->work = COMPLETION_INITIALIZER_ONSTACK(ctx->work);

        ctx->cmd.lif_setphc.opcode = IONIC_CMD_LIF_SETPHC;
        ctx->cmd.lif_setphc.lif_index = cpu_to_le16(phc->lif->index);

        ctx->cmd.lif_setphc.tick = cpu_to_le64(phc->tc.cycle_last);
        ctx->cmd.lif_setphc.nsec = cpu_to_le64(phc->tc.nsec);
        ctx->cmd.lif_setphc.frac = cpu_to_le64(phc->tc.frac);
        ctx->cmd.lif_setphc.mult = cpu_to_le32(phc->cc.mult);
        ctx->cmd.lif_setphc.shift = cpu_to_le32(phc->cc.shift);

        return ionic_adminq_post(phc->lif, ctx);
}

static int ionic_phc_adjfine(struct ptp_clock_info *info, long scaled_ppm)
{
        struct ionic_phc *phc = container_of(info, struct ionic_phc, ptp_info);
        struct ionic_admin_ctx ctx = {};
        unsigned long irqflags;
        s64 adj;
        int err;

        /* Reject phc adjustments during device upgrade */
        if (test_bit(IONIC_LIF_F_FW_RESET, phc->lif->state))
                return -EBUSY;

        /* Adjustment value scaled by 2^16 million */
        adj = (s64)scaled_ppm * phc->init_cc_mult;

        /* Adjustment value to scale */
        adj /= (s64)SCALED_PPM;

        /* Final adjusted multiplier */
        adj += phc->init_cc_mult;

        spin_lock_irqsave(&phc->lock, irqflags);

        /* update the point-in-time basis to now, before adjusting the rate */
        timecounter_read(&phc->tc);
        phc->cc.mult = adj;

        /* Setphc commands are posted in-order, sequenced by phc->lock.  We
         * need to drop the lock before waiting for the command to complete.
         */
        err = ionic_setphc_cmd(phc, &ctx);

        spin_unlock_irqrestore(&phc->lock, irqflags);

        return ionic_adminq_wait(phc->lif, &ctx, err, true);
}

static int ionic_phc_adjtime(struct ptp_clock_info *info, s64 delta)
{
        struct ionic_phc *phc = container_of(info, struct ionic_phc, ptp_info);
        struct ionic_admin_ctx ctx = {};
        unsigned long irqflags;
        int err;

        /* Reject phc adjustments during device upgrade */
        if (test_bit(IONIC_LIF_F_FW_RESET, phc->lif->state))
                return -EBUSY;

        spin_lock_irqsave(&phc->lock, irqflags);

        timecounter_adjtime(&phc->tc, delta);

        /* Setphc commands are posted in-order, sequenced by phc->lock.  We
         * need to drop the lock before waiting for the command to complete.
         */
        err = ionic_setphc_cmd(phc, &ctx);

        spin_unlock_irqrestore(&phc->lock, irqflags);

        return ionic_adminq_wait(phc->lif, &ctx, err, true);
}

static int ionic_phc_settime64(struct ptp_clock_info *info,
                               const struct timespec64 *ts)
{
        struct ionic_phc *phc = container_of(info, struct ionic_phc, ptp_info);
        struct ionic_admin_ctx ctx = {};
        unsigned long irqflags;
        int err;
        u64 ns;

        /* Reject phc adjustments during device upgrade */
        if (test_bit(IONIC_LIF_F_FW_RESET, phc->lif->state))
                return -EBUSY;

        ns = timespec64_to_ns(ts);

        spin_lock_irqsave(&phc->lock, irqflags);

        timecounter_init(&phc->tc, &phc->cc, ns);

        /* Setphc commands are posted in-order, sequenced by phc->lock.  We
         * need to drop the lock before waiting for the command to complete.
         */
        err = ionic_setphc_cmd(phc, &ctx);

        spin_unlock_irqrestore(&phc->lock, irqflags);

        return ionic_adminq_wait(phc->lif, &ctx, err, true);
}

static int ionic_phc_gettimex64(struct ptp_clock_info *info,
                                struct timespec64 *ts,
                                struct ptp_system_timestamp *sts)
{
        struct ionic_phc *phc = container_of(info, struct ionic_phc, ptp_info);
        struct ionic *ionic = phc->lif->ionic;
        unsigned long irqflags;
        u64 tick, ns;

        /* Do not attempt to read device time during upgrade */
        if (test_bit(IONIC_LIF_F_FW_RESET, phc->lif->state))
                return -EBUSY;

        spin_lock_irqsave(&phc->lock, irqflags);

        tick = ionic_hwstamp_read(ionic, sts);

        ns = timecounter_cyc2time(&phc->tc, tick);

        spin_unlock_irqrestore(&phc->lock, irqflags);

        *ts = ns_to_timespec64(ns);

        return 0;
}

static long ionic_phc_aux_work(struct ptp_clock_info *info)
{
        struct ionic_phc *phc = container_of(info, struct ionic_phc, ptp_info);
        struct ionic_admin_ctx ctx = {};
        unsigned long irqflags;
        int err;

        /* Do not update phc during device upgrade, but keep polling to resume
         * after upgrade.  Since we don't update the point in time basis, there
         * is no expectation that we are maintaining the phc time during the
         * upgrade.  After upgrade, it will need to be readjusted back to the
         * correct time by the ptp daemon.
         */
        if (test_bit(IONIC_LIF_F_FW_RESET, phc->lif->state))
                return phc->aux_work_delay;

        spin_lock_irqsave(&phc->lock, irqflags);

        /* update point-in-time basis to now */
        timecounter_read(&phc->tc);

        /* Setphc commands are posted in-order, sequenced by phc->lock.  We
         * need to drop the lock before waiting for the command to complete.
         */
        err = ionic_setphc_cmd(phc, &ctx);

        spin_unlock_irqrestore(&phc->lock, irqflags);

        ionic_adminq_wait(phc->lif, &ctx, err, true);

        return phc->aux_work_delay;
}

ktime_t ionic_lif_phc_ktime(struct ionic_lif *lif, u64 tick)
{
        unsigned long irqflags;
        u64 ns;

        if (!lif->phc)
                return 0;

        spin_lock_irqsave(&lif->phc->lock, irqflags);
        ns = timecounter_cyc2time(&lif->phc->tc, tick);
        spin_unlock_irqrestore(&lif->phc->lock, irqflags);

        return ns_to_ktime(ns);
}

static const struct ptp_clock_info ionic_ptp_info = {
        .owner          = THIS_MODULE,
        .name           = "ionic_ptp",
        .adjfine        = ionic_phc_adjfine,
        .adjtime        = ionic_phc_adjtime,
        .gettimex64     = ionic_phc_gettimex64,
        .settime64      = ionic_phc_settime64,
        .do_aux_work    = ionic_phc_aux_work,
};

void ionic_lif_register_phc(struct ionic_lif *lif)
{
        if (!lif->phc || !(lif->hw_features & IONIC_ETH_HW_TIMESTAMP))
                return;

        lif->phc->ptp = ptp_clock_register(&lif->phc->ptp_info, lif->ionic->dev);

        if (IS_ERR(lif->phc->ptp)) {
                dev_warn(lif->ionic->dev, "Cannot register phc device: %ld\n",
                         PTR_ERR(lif->phc->ptp));

                lif->phc->ptp = NULL;
        }

        if (lif->phc->ptp)
                ptp_schedule_worker(lif->phc->ptp, lif->phc->aux_work_delay);
}

void ionic_lif_unregister_phc(struct ionic_lif *lif)
{
        if (!lif->phc || !lif->phc->ptp)
                return;

        ptp_clock_unregister(lif->phc->ptp);

        lif->phc->ptp = NULL;
}

void ionic_lif_alloc_phc(struct ionic_lif *lif)
{
        struct ionic *ionic = lif->ionic;
        struct ionic_phc *phc;
        u64 delay, diff, mult;
        u64 frac = 0;
        u64 features;
        u32 shift;

        if (!ionic->idev.hwstamp_regs)
                return;

        features = le64_to_cpu(ionic->ident.lif.eth.config.features);
        if (!(features & IONIC_ETH_HW_TIMESTAMP))
                return;

        phc = devm_kzalloc(ionic->dev, sizeof(*phc), GFP_KERNEL);
        if (!phc)
                return;

        phc->lif = lif;

        phc->cc.read = ionic_cc_read;
        phc->cc.mask = le64_to_cpu(ionic->ident.dev.hwstamp_mask);
        phc->cc.mult = le32_to_cpu(ionic->ident.dev.hwstamp_mult);
        phc->cc.shift = le32_to_cpu(ionic->ident.dev.hwstamp_shift);

        if (!phc->cc.mult) {
                dev_err(lif->ionic->dev,
                        "Invalid device PHC mask multiplier %u, disabling HW timestamp support\n",
                        phc->cc.mult);
                devm_kfree(lif->ionic->dev, phc);
                lif->phc = NULL;
                return;
        }

        dev_dbg(lif->ionic->dev, "Device PHC mask %#llx mult %u shift %u\n",
                phc->cc.mask, phc->cc.mult, phc->cc.shift);

        spin_lock_init(&phc->lock);
        mutex_init(&phc->config_lock);

        /* max ticks is limited by the multiplier, or by the update period. */
        if (phc->cc.shift + 2 + ilog2(IONIC_PHC_UPDATE_NS) >= 64) {
                /* max ticks that do not overflow when multiplied by max
                 * adjusted multiplier (twice the initial multiplier)
                 */
                diff = U64_MAX / phc->cc.mult / 2;
        } else {
                /* approx ticks at four times the update period */
                diff = (u64)IONIC_PHC_UPDATE_NS << (phc->cc.shift + 2);
                diff = DIV_ROUND_UP(diff, phc->cc.mult);
        }

        /* transform to bitmask */
        diff |= diff >> 1;
        diff |= diff >> 2;
        diff |= diff >> 4;
        diff |= diff >> 8;
        diff |= diff >> 16;
        diff |= diff >> 32;

        /* constrain to the hardware bitmask, and use this as the bitmask */
        diff &= phc->cc.mask;
        phc->cc.mask = diff;

        /* the wrap period is now defined by diff (or phc->cc.mask)
         *
         * we will update the time basis at about 1/4 the wrap period, so
         * should not see a difference of more than +/- diff/4.
         *
         * this is sufficient not see a difference of more than +/- diff/2, as
         * required by timecounter_cyc2time, to detect an old time stamp.
         *
         * adjust the initial multiplier, being careful to avoid overflow:
         *  - do not overflow 63 bits: init_cc_mult * SCALED_PPM
         *  - do not overflow 64 bits: max_mult * (diff / 2)
         *
         * we want to increase the initial multiplier as much as possible, to
         * allow for more precise adjustment in ionic_phc_adjfine.
         *
         * only adjust the multiplier if we can double it or more.
         */
        mult = U64_MAX / 2 / max(diff / 2, SCALED_PPM);
        shift = mult / phc->cc.mult;
        if (shift >= 2) {
                /* initial multiplier will be 2^n of hardware cc.mult */
                shift = fls(shift);
                /* increase cc.mult and cc.shift by the same 2^n and n. */
                phc->cc.mult <<= shift;
                phc->cc.shift += shift;
        }

        dev_dbg(lif->ionic->dev, "Initial PHC mask %#llx mult %u shift %u\n",
                phc->cc.mask, phc->cc.mult, phc->cc.shift);

        /* frequency adjustments are relative to the initial multiplier */
        phc->init_cc_mult = phc->cc.mult;

        timecounter_init(&phc->tc, &phc->cc, ktime_get_real_ns());

        /* Update cycle_last at 1/4 the wrap period, or IONIC_PHC_UPDATE_NS */
        delay = min_t(u64, IONIC_PHC_UPDATE_NS,
                      cyclecounter_cyc2ns(&phc->cc, diff / 4, 0, &frac));
        dev_dbg(lif->ionic->dev, "Work delay %llu ms\n", delay / NSEC_PER_MSEC);

        phc->aux_work_delay = nsecs_to_jiffies(delay);

        phc->ptp_info = ionic_ptp_info;

        /* We have allowed to adjust the multiplier up to +/- 1 part per 1.
         * Here expressed as NORMAL_PPB (1 billion parts per billion).
         */
        phc->ptp_info.max_adj = NORMAL_PPB;

        lif->phc = phc;
}

void ionic_lif_free_phc(struct ionic_lif *lif)
{
        if (!lif->phc)
                return;

        mutex_destroy(&lif->phc->config_lock);

        devm_kfree(lif->ionic->dev, lif->phc);
        lif->phc = NULL;
}