// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/* Copyright (c) 2019 Mellanox Technologies. All rights reserved */

#include <linux/ptp_clock_kernel.h>
#include <linux/clocksource.h>
#include <linux/timecounter.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/rhashtable.h>
#include <linux/ptp_classify.h>
#include <linux/if_ether.h>
#include <linux/if_vlan.h>
#include <linux/net_tstamp.h>

#include "spectrum.h"
#include "spectrum_ptp.h"
#include "core.h"

#define MLXSW_SP1_PTP_CLOCK_CYCLES_SHIFT        29
#define MLXSW_SP1_PTP_CLOCK_FREQ_KHZ            156257 /* 6.4nSec */
#define MLXSW_SP1_PTP_CLOCK_MASK                64

#define MLXSW_SP1_PTP_HT_GC_INTERVAL            500 /* ms */

/* How long, approximately, should the unmatched entries stay in the hash table
 * before they are collected. Should be evenly divisible by the GC interval.
 */
#define MLXSW_SP1_PTP_HT_GC_TIMEOUT             1000 /* ms */

struct mlxsw_sp_ptp_state {
        struct mlxsw_sp *mlxsw_sp;
        struct rhltable unmatched_ht;
        spinlock_t unmatched_lock; /* protects the HT */
        struct delayed_work ht_gc_dw;
        u32 gc_cycle;
};

struct mlxsw_sp1_ptp_key {
        u8 local_port;
        u8 message_type;
        u16 sequence_id;
        u8 domain_number;
        bool ingress;
};

struct mlxsw_sp1_ptp_unmatched {
        struct mlxsw_sp1_ptp_key key;
        struct rhlist_head ht_node;
        struct rcu_head rcu;
        struct sk_buff *skb;
        u64 timestamp;
        u32 gc_cycle;
};

static const struct rhashtable_params mlxsw_sp1_ptp_unmatched_ht_params = {
        .key_len = sizeof_field(struct mlxsw_sp1_ptp_unmatched, key),
        .key_offset = offsetof(struct mlxsw_sp1_ptp_unmatched, key),
        .head_offset = offsetof(struct mlxsw_sp1_ptp_unmatched, ht_node),
};

struct mlxsw_sp_ptp_clock {
        struct mlxsw_core *core;
        spinlock_t lock; /* protect this structure */
        struct cyclecounter cycles;
        struct timecounter tc;
        u32 nominal_c_mult;
        struct ptp_clock *ptp;
        struct ptp_clock_info ptp_info;
        unsigned long overflow_period;
        struct delayed_work overflow_work;
};

static u64 __mlxsw_sp1_ptp_read_frc(struct mlxsw_sp_ptp_clock *clock,
                                    struct ptp_system_timestamp *sts)
{
        struct mlxsw_core *mlxsw_core = clock->core;
        u32 frc_h1, frc_h2, frc_l;

        frc_h1 = mlxsw_core_read_frc_h(mlxsw_core);
        ptp_read_system_prets(sts);
        frc_l = mlxsw_core_read_frc_l(mlxsw_core);
        ptp_read_system_postts(sts);
        frc_h2 = mlxsw_core_read_frc_h(mlxsw_core);

        if (frc_h1 != frc_h2) {
                /* wrap around */
                ptp_read_system_prets(sts);
                frc_l = mlxsw_core_read_frc_l(mlxsw_core);
                ptp_read_system_postts(sts);
        }

        return (u64) frc_l | (u64) frc_h2 << 32;
}

static u64 mlxsw_sp1_ptp_read_frc(const struct cyclecounter *cc)
{
        struct mlxsw_sp_ptp_clock *clock =
                container_of(cc, struct mlxsw_sp_ptp_clock, cycles);

        return __mlxsw_sp1_ptp_read_frc(clock, NULL) & cc->mask;
}

static int
mlxsw_sp1_ptp_phc_adjfreq(struct mlxsw_sp_ptp_clock *clock, int freq_adj)
{
        struct mlxsw_core *mlxsw_core = clock->core;
        char mtutc_pl[MLXSW_REG_MTUTC_LEN];

        mlxsw_reg_mtutc_pack(mtutc_pl, MLXSW_REG_MTUTC_OPERATION_ADJUST_FREQ,
                             freq_adj, 0);
        return mlxsw_reg_write(mlxsw_core, MLXSW_REG(mtutc), mtutc_pl);
}

static u64 mlxsw_sp1_ptp_ns2cycles(const struct timecounter *tc, u64 nsec)
{
        u64 cycles = (u64) nsec;

        cycles <<= tc->cc->shift;
        cycles = div_u64(cycles, tc->cc->mult);

        return cycles;
}

static int
mlxsw_sp1_ptp_phc_settime(struct mlxsw_sp_ptp_clock *clock, u64 nsec)
{
        struct mlxsw_core *mlxsw_core = clock->core;
        u64 next_sec, next_sec_in_nsec, cycles;
        char mtutc_pl[MLXSW_REG_MTUTC_LEN];
        char mtpps_pl[MLXSW_REG_MTPPS_LEN];
        int err;

        next_sec = div_u64(nsec, NSEC_PER_SEC) + 1;
        next_sec_in_nsec = next_sec * NSEC_PER_SEC;

        spin_lock_bh(&clock->lock);
        cycles = mlxsw_sp1_ptp_ns2cycles(&clock->tc, next_sec_in_nsec);
        spin_unlock_bh(&clock->lock);

        mlxsw_reg_mtpps_vpin_pack(mtpps_pl, cycles);
        err = mlxsw_reg_write(mlxsw_core, MLXSW_REG(mtpps), mtpps_pl);
        if (err)
                return err;

        mlxsw_reg_mtutc_pack(mtutc_pl,
                             MLXSW_REG_MTUTC_OPERATION_SET_TIME_AT_NEXT_SEC,
                             0, next_sec);
        return mlxsw_reg_write(mlxsw_core, MLXSW_REG(mtutc), mtutc_pl);
}

static int mlxsw_sp1_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
{
        struct mlxsw_sp_ptp_clock *clock =
                container_of(ptp, struct mlxsw_sp_ptp_clock, ptp_info);
        int neg_adj = 0;
        u32 diff;
        u64 adj;
        s32 ppb;

        ppb = scaled_ppm_to_ppb(scaled_ppm);

        if (ppb < 0) {
                neg_adj = 1;
                ppb = -ppb;
        }

        adj = clock->nominal_c_mult;
        adj *= ppb;
        diff = div_u64(adj, NSEC_PER_SEC);

        spin_lock_bh(&clock->lock);
        timecounter_read(&clock->tc);
        clock->cycles.mult = neg_adj ? clock->nominal_c_mult - diff :
                                       clock->nominal_c_mult + diff;
        spin_unlock_bh(&clock->lock);

        return mlxsw_sp1_ptp_phc_adjfreq(clock, neg_adj ? -ppb : ppb);
}

static int mlxsw_sp1_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
{
        struct mlxsw_sp_ptp_clock *clock =
                container_of(ptp, struct mlxsw_sp_ptp_clock, ptp_info);
        u64 nsec;

        spin_lock_bh(&clock->lock);
        timecounter_adjtime(&clock->tc, delta);
        nsec = timecounter_read(&clock->tc);
        spin_unlock_bh(&clock->lock);

        return mlxsw_sp1_ptp_phc_settime(clock, nsec);
}

static int mlxsw_sp1_ptp_gettimex(struct ptp_clock_info *ptp,
                                  struct timespec64 *ts,
                                  struct ptp_system_timestamp *sts)
{
        struct mlxsw_sp_ptp_clock *clock =
                container_of(ptp, struct mlxsw_sp_ptp_clock, ptp_info);
        u64 cycles, nsec;

        spin_lock_bh(&clock->lock);
        cycles = __mlxsw_sp1_ptp_read_frc(clock, sts);
        nsec = timecounter_cyc2time(&clock->tc, cycles);
        spin_unlock_bh(&clock->lock);

        *ts = ns_to_timespec64(nsec);

        return 0;
}

static int mlxsw_sp1_ptp_settime(struct ptp_clock_info *ptp,
                                 const struct timespec64 *ts)
{
        struct mlxsw_sp_ptp_clock *clock =
                container_of(ptp, struct mlxsw_sp_ptp_clock, ptp_info);
        u64 nsec = timespec64_to_ns(ts);

        spin_lock_bh(&clock->lock);
        timecounter_init(&clock->tc, &clock->cycles, nsec);
        nsec = timecounter_read(&clock->tc);
        spin_unlock_bh(&clock->lock);

        return mlxsw_sp1_ptp_phc_settime(clock, nsec);
}

static const struct ptp_clock_info mlxsw_sp1_ptp_clock_info = {
        .owner          = THIS_MODULE,
        .name           = "mlxsw_sp_clock",
        .max_adj        = 100000000,
        .adjfine        = mlxsw_sp1_ptp_adjfine,
        .adjtime        = mlxsw_sp1_ptp_adjtime,
        .gettimex64     = mlxsw_sp1_ptp_gettimex,
        .settime64      = mlxsw_sp1_ptp_settime,
};

static void mlxsw_sp1_ptp_clock_overflow(struct work_struct *work)
{
        struct delayed_work *dwork = to_delayed_work(work);
        struct mlxsw_sp_ptp_clock *clock;

        clock = container_of(dwork, struct mlxsw_sp_ptp_clock, overflow_work);

        spin_lock_bh(&clock->lock);
        timecounter_read(&clock->tc);
        spin_unlock_bh(&clock->lock);
        mlxsw_core_schedule_dw(&clock->overflow_work, clock->overflow_period);
}

struct mlxsw_sp_ptp_clock *
mlxsw_sp1_ptp_clock_init(struct mlxsw_sp *mlxsw_sp, struct device *dev)
{
        u64 overflow_cycles, nsec, frac = 0;
        struct mlxsw_sp_ptp_clock *clock;
        int err;

        clock = kzalloc(sizeof(*clock), GFP_KERNEL);
        if (!clock)
                return ERR_PTR(-ENOMEM);

        spin_lock_init(&clock->lock);
        clock->cycles.read = mlxsw_sp1_ptp_read_frc;
        clock->cycles.shift = MLXSW_SP1_PTP_CLOCK_CYCLES_SHIFT;
        clock->cycles.mult = clocksource_khz2mult(MLXSW_SP1_PTP_CLOCK_FREQ_KHZ,
                                                  clock->cycles.shift);
        clock->nominal_c_mult = clock->cycles.mult;
        clock->cycles.mask = CLOCKSOURCE_MASK(MLXSW_SP1_PTP_CLOCK_MASK);
        clock->core = mlxsw_sp->core;

        timecounter_init(&clock->tc, &clock->cycles,
                         ktime_to_ns(ktime_get_real()));

        /* Calculate period in seconds to call the overflow watchdog - to make
         * sure counter is checked at least twice every wrap around.
         * The period is calculated as the minimum between max HW cycles count
         * (The clock source mask) and max amount of cycles that can be
         * multiplied by clock multiplier where the result doesn't exceed
         * 64bits.
         */
        overflow_cycles = div64_u64(~0ULL >> 1, clock->cycles.mult);
        overflow_cycles = min(overflow_cycles, div_u64(clock->cycles.mask, 3));

        nsec = cyclecounter_cyc2ns(&clock->cycles, overflow_cycles, 0, &frac);
        clock->overflow_period = nsecs_to_jiffies(nsec);

        INIT_DELAYED_WORK(&clock->overflow_work, mlxsw_sp1_ptp_clock_overflow);
        mlxsw_core_schedule_dw(&clock->overflow_work, 0);

        clock->ptp_info = mlxsw_sp1_ptp_clock_info;
        clock->ptp = ptp_clock_register(&clock->ptp_info, dev);
        if (IS_ERR(clock->ptp)) {
                err = PTR_ERR(clock->ptp);
                dev_err(dev, "ptp_clock_register failed %d\n", err);
                goto err_ptp_clock_register;
        }

        return clock;

err_ptp_clock_register:
        cancel_delayed_work_sync(&clock->overflow_work);
        kfree(clock);
        return ERR_PTR(err);
}

void mlxsw_sp1_ptp_clock_fini(struct mlxsw_sp_ptp_clock *clock)
{
        ptp_clock_unregister(clock->ptp);
        cancel_delayed_work_sync(&clock->overflow_work);
        kfree(clock);
}

static int mlxsw_sp_ptp_parse(struct sk_buff *skb,
                              u8 *p_domain_number,
                              u8 *p_message_type,
                              u16 *p_sequence_id)
{
        unsigned int ptp_class;
        struct ptp_header *hdr;

        ptp_class = ptp_classify_raw(skb);

        switch (ptp_class & PTP_CLASS_VMASK) {
        case PTP_CLASS_V1:
        case PTP_CLASS_V2:
                break;
        default:
                return -ERANGE;
        }

        hdr = ptp_parse_header(skb, ptp_class);
        if (!hdr)
                return -EINVAL;

        *p_message_type  = ptp_get_msgtype(hdr, ptp_class);
        *p_domain_number = hdr->domain_number;
        *p_sequence_id   = be16_to_cpu(hdr->sequence_id);

        return 0;
}

/* Returns NULL on successful insertion, a pointer on conflict, or an ERR_PTR on
 * error.
 */
static int
mlxsw_sp1_ptp_unmatched_save(struct mlxsw_sp *mlxsw_sp,
                             struct mlxsw_sp1_ptp_key key,
                             struct sk_buff *skb,
                             u64 timestamp)
{
        int cycles = MLXSW_SP1_PTP_HT_GC_TIMEOUT / MLXSW_SP1_PTP_HT_GC_INTERVAL;
        struct mlxsw_sp_ptp_state *ptp_state = mlxsw_sp->ptp_state;
        struct mlxsw_sp1_ptp_unmatched *unmatched;
        int err;

        unmatched = kzalloc(sizeof(*unmatched), GFP_ATOMIC);
        if (!unmatched)
                return -ENOMEM;

        unmatched->key = key;
        unmatched->skb = skb;
        unmatched->timestamp = timestamp;
        unmatched->gc_cycle = mlxsw_sp->ptp_state->gc_cycle + cycles;

        err = rhltable_insert(&ptp_state->unmatched_ht, &unmatched->ht_node,
                              mlxsw_sp1_ptp_unmatched_ht_params);
        if (err)
                kfree(unmatched);

        return err;
}

static struct mlxsw_sp1_ptp_unmatched *
mlxsw_sp1_ptp_unmatched_lookup(struct mlxsw_sp *mlxsw_sp,
                               struct mlxsw_sp1_ptp_key key, int *p_length)
{
        struct mlxsw_sp1_ptp_unmatched *unmatched, *last = NULL;
        struct rhlist_head *tmp, *list;
        int length = 0;

        list = rhltable_lookup(&mlxsw_sp->ptp_state->unmatched_ht, &key,
                               mlxsw_sp1_ptp_unmatched_ht_params);
        rhl_for_each_entry_rcu(unmatched, tmp, list, ht_node) {
                last = unmatched;
                length++;
        }

        *p_length = length;
        return last;
}

static int
mlxsw_sp1_ptp_unmatched_remove(struct mlxsw_sp *mlxsw_sp,
                               struct mlxsw_sp1_ptp_unmatched *unmatched)
{
        return rhltable_remove(&mlxsw_sp->ptp_state->unmatched_ht,
                               &unmatched->ht_node,
                               mlxsw_sp1_ptp_unmatched_ht_params);
}

/* This function is called in the following scenarios:
 *
 * 1) When a packet is matched with its timestamp.
 * 2) In several situation when it is necessary to immediately pass on
 *    an SKB without a timestamp.
 * 3) From GC indirectly through mlxsw_sp1_ptp_unmatched_finish().
 *    This case is similar to 2) above.
 */
static void mlxsw_sp1_ptp_packet_finish(struct mlxsw_sp *mlxsw_sp,
                                        struct sk_buff *skb, u8 local_port,
                                        bool ingress,
                                        struct skb_shared_hwtstamps *hwtstamps)
{
        struct mlxsw_sp_port *mlxsw_sp_port;

        /* Between capturing the packet and finishing it, there is a window of
         * opportunity for the originating port to go away (e.g. due to a
         * split). Also make sure the SKB device reference is still valid.
         */
        mlxsw_sp_port = mlxsw_sp->ports[local_port];
        if (!(mlxsw_sp_port && (!skb->dev || skb->dev == mlxsw_sp_port->dev))) {
                dev_kfree_skb_any(skb);
                return;
        }

        if (ingress) {
                if (hwtstamps)
                        *skb_hwtstamps(skb) = *hwtstamps;
                mlxsw_sp_rx_listener_no_mark_func(skb, local_port, mlxsw_sp);
        } else {
                /* skb_tstamp_tx() allows hwtstamps to be NULL. */
                skb_tstamp_tx(skb, hwtstamps);
                dev_kfree_skb_any(skb);
        }
}

static void mlxsw_sp1_packet_timestamp(struct mlxsw_sp *mlxsw_sp,
                                       struct mlxsw_sp1_ptp_key key,
                                       struct sk_buff *skb,
                                       u64 timestamp)
{
        struct skb_shared_hwtstamps hwtstamps;
        u64 nsec;

        spin_lock_bh(&mlxsw_sp->clock->lock);
        nsec = timecounter_cyc2time(&mlxsw_sp->clock->tc, timestamp);
        spin_unlock_bh(&mlxsw_sp->clock->lock);

        hwtstamps.hwtstamp = ns_to_ktime(nsec);
        mlxsw_sp1_ptp_packet_finish(mlxsw_sp, skb,
                                    key.local_port, key.ingress, &hwtstamps);
}

static void
mlxsw_sp1_ptp_unmatched_finish(struct mlxsw_sp *mlxsw_sp,
                               struct mlxsw_sp1_ptp_unmatched *unmatched)
{
        if (unmatched->skb && unmatched->timestamp)
                mlxsw_sp1_packet_timestamp(mlxsw_sp, unmatched->key,
                                           unmatched->skb,
                                           unmatched->timestamp);
        else if (unmatched->skb)
                mlxsw_sp1_ptp_packet_finish(mlxsw_sp, unmatched->skb,
                                            unmatched->key.local_port,
                                            unmatched->key.ingress, NULL);
        kfree_rcu(unmatched, rcu);
}

static void mlxsw_sp1_ptp_unmatched_free_fn(void *ptr, void *arg)
{
        struct mlxsw_sp1_ptp_unmatched *unmatched = ptr;

        /* This is invoked at a point where the ports are gone already. Nothing
         * to do with whatever is left in the HT but to free it.
         */
        if (unmatched->skb)
                dev_kfree_skb_any(unmatched->skb);
        kfree_rcu(unmatched, rcu);
}

static void mlxsw_sp1_ptp_got_piece(struct mlxsw_sp *mlxsw_sp,
                                    struct mlxsw_sp1_ptp_key key,
                                    struct sk_buff *skb, u64 timestamp)
{
        struct mlxsw_sp1_ptp_unmatched *unmatched;
        int length;
        int err;

        rcu_read_lock();

        spin_lock(&mlxsw_sp->ptp_state->unmatched_lock);

        unmatched = mlxsw_sp1_ptp_unmatched_lookup(mlxsw_sp, key, &length);
        if (skb && unmatched && unmatched->timestamp) {
                unmatched->skb = skb;
        } else if (timestamp && unmatched && unmatched->skb) {
                unmatched->timestamp = timestamp;
        } else {
                /* Either there is no entry to match, or one that is there is
                 * incompatible.
                 */
                if (length < 100)
                        err = mlxsw_sp1_ptp_unmatched_save(mlxsw_sp, key,
                                                           skb, timestamp);
                else
                        err = -E2BIG;
                if (err && skb)
                        mlxsw_sp1_ptp_packet_finish(mlxsw_sp, skb,
                                                    key.local_port,
                                                    key.ingress, NULL);
                unmatched = NULL;
        }

        if (unmatched) {
                err = mlxsw_sp1_ptp_unmatched_remove(mlxsw_sp, unmatched);
                WARN_ON_ONCE(err);
        }

        spin_unlock(&mlxsw_sp->ptp_state->unmatched_lock);

        if (unmatched)
                mlxsw_sp1_ptp_unmatched_finish(mlxsw_sp, unmatched);

        rcu_read_unlock();
}

static void mlxsw_sp1_ptp_got_packet(struct mlxsw_sp *mlxsw_sp,
                                     struct sk_buff *skb, u8 local_port,
                                     bool ingress)
{
        struct mlxsw_sp_port *mlxsw_sp_port;
        struct mlxsw_sp1_ptp_key key;
        u8 types;
        int err;

        mlxsw_sp_port = mlxsw_sp->ports[local_port];
        if (!mlxsw_sp_port)
                goto immediate;

        types = ingress ? mlxsw_sp_port->ptp.ing_types :
                          mlxsw_sp_port->ptp.egr_types;
        if (!types)
                goto immediate;

        memset(&key, 0, sizeof(key));
        key.local_port = local_port;
        key.ingress = ingress;

        err = mlxsw_sp_ptp_parse(skb, &key.domain_number, &key.message_type,
                                 &key.sequence_id);
        if (err)
                goto immediate;

        /* For packets whose timestamping was not enabled on this port, don't
         * bother trying to match the timestamp.
         */
        if (!((1 << key.message_type) & types))
                goto immediate;

        mlxsw_sp1_ptp_got_piece(mlxsw_sp, key, skb, 0);
        return;

immediate:
        mlxsw_sp1_ptp_packet_finish(mlxsw_sp, skb, local_port, ingress, NULL);
}

void mlxsw_sp1_ptp_got_timestamp(struct mlxsw_sp *mlxsw_sp, bool ingress,
                                 u8 local_port, u8 message_type,
                                 u8 domain_number, u16 sequence_id,
                                 u64 timestamp)
{
        struct mlxsw_sp_port *mlxsw_sp_port;
        struct mlxsw_sp1_ptp_key key;
        u8 types;

        mlxsw_sp_port = mlxsw_sp->ports[local_port];
        if (!mlxsw_sp_port)
                return;

        types = ingress ? mlxsw_sp_port->ptp.ing_types :
                          mlxsw_sp_port->ptp.egr_types;

        /* For message types whose timestamping was not enabled on this port,
         * don't bother with the timestamp.
         */
        if (!((1 << message_type) & types))
                return;

        memset(&key, 0, sizeof(key));
        key.local_port = local_port;
        key.domain_number = domain_number;
        key.message_type = message_type;
        key.sequence_id = sequence_id;
        key.ingress = ingress;

        mlxsw_sp1_ptp_got_piece(mlxsw_sp, key, NULL, timestamp);
}

void mlxsw_sp1_ptp_receive(struct mlxsw_sp *mlxsw_sp, struct sk_buff *skb,
                           u8 local_port)
{
        skb_reset_mac_header(skb);
        mlxsw_sp1_ptp_got_packet(mlxsw_sp, skb, local_port, true);
}

void mlxsw_sp1_ptp_transmitted(struct mlxsw_sp *mlxsw_sp,
                               struct sk_buff *skb, u8 local_port)
{
        mlxsw_sp1_ptp_got_packet(mlxsw_sp, skb, local_port, false);
}

static void
mlxsw_sp1_ptp_ht_gc_collect(struct mlxsw_sp_ptp_state *ptp_state,
                            struct mlxsw_sp1_ptp_unmatched *unmatched)
{
        struct mlxsw_sp_ptp_port_dir_stats *stats;
        struct mlxsw_sp_port *mlxsw_sp_port;
        int err;

        /* If an unmatched entry has an SKB, it has to be handed over to the
         * networking stack. This is usually done from a trap handler, which is
         * invoked in a softirq context. Here we are going to do it in process
         * context. If that were to be interrupted by a softirq, it could cause
         * a deadlock when an attempt is made to take an already-taken lock
         * somewhere along the sending path. Disable softirqs to prevent this.
         */
        local_bh_disable();

        spin_lock(&ptp_state->unmatched_lock);
        err = rhltable_remove(&ptp_state->unmatched_ht, &unmatched->ht_node,
                              mlxsw_sp1_ptp_unmatched_ht_params);
        spin_unlock(&ptp_state->unmatched_lock);

        if (err)
                /* The packet was matched with timestamp during the walk. */
                goto out;

        mlxsw_sp_port = ptp_state->mlxsw_sp->ports[unmatched->key.local_port];
        if (mlxsw_sp_port) {
                stats = unmatched->key.ingress ?
                        &mlxsw_sp_port->ptp.stats.rx_gcd :
                        &mlxsw_sp_port->ptp.stats.tx_gcd;
                if (unmatched->skb)
                        stats->packets++;
                else
                        stats->timestamps++;
        }

        /* mlxsw_sp1_ptp_unmatched_finish() invokes netif_receive_skb(). While
         * the comment at that function states that it can only be called in
         * soft IRQ context, this pattern of local_bh_disable() +
         * netif_receive_skb(), in process context, is seen elsewhere in the
         * kernel, notably in pktgen.
         */
        mlxsw_sp1_ptp_unmatched_finish(ptp_state->mlxsw_sp, unmatched);

out:
        local_bh_enable();
}

static void mlxsw_sp1_ptp_ht_gc(struct work_struct *work)
{
        struct delayed_work *dwork = to_delayed_work(work);
        struct mlxsw_sp1_ptp_unmatched *unmatched;
        struct mlxsw_sp_ptp_state *ptp_state;
        struct rhashtable_iter iter;
        u32 gc_cycle;
        void *obj;

        ptp_state = container_of(dwork, struct mlxsw_sp_ptp_state, ht_gc_dw);
        gc_cycle = ptp_state->gc_cycle++;

        rhltable_walk_enter(&ptp_state->unmatched_ht, &iter);
        rhashtable_walk_start(&iter);
        while ((obj = rhashtable_walk_next(&iter))) {
                if (IS_ERR(obj))
                        continue;

                unmatched = obj;
                if (unmatched->gc_cycle <= gc_cycle)
                        mlxsw_sp1_ptp_ht_gc_collect(ptp_state, unmatched);
        }
        rhashtable_walk_stop(&iter);
        rhashtable_walk_exit(&iter);

        mlxsw_core_schedule_dw(&ptp_state->ht_gc_dw,
                               MLXSW_SP1_PTP_HT_GC_INTERVAL);
}

static int mlxsw_sp_ptp_mtptpt_set(struct mlxsw_sp *mlxsw_sp,
                                   enum mlxsw_reg_mtptpt_trap_id trap_id,
                                   u16 message_type)
{
        char mtptpt_pl[MLXSW_REG_MTPTPT_LEN];

        mlxsw_reg_mtptptp_pack(mtptpt_pl, trap_id, message_type);
        return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(mtptpt), mtptpt_pl);
}

static int mlxsw_sp1_ptp_set_fifo_clr_on_trap(struct mlxsw_sp *mlxsw_sp,
                                              bool clr)
{
        char mogcr_pl[MLXSW_REG_MOGCR_LEN] = {0};
        int err;

        err = mlxsw_reg_query(mlxsw_sp->core, MLXSW_REG(mogcr), mogcr_pl);
        if (err)
                return err;

        mlxsw_reg_mogcr_ptp_iftc_set(mogcr_pl, clr);
        mlxsw_reg_mogcr_ptp_eftc_set(mogcr_pl, clr);
        return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(mogcr), mogcr_pl);
}

static int mlxsw_sp1_ptp_mtpppc_set(struct mlxsw_sp *mlxsw_sp,
                                    u16 ing_types, u16 egr_types)
{
        char mtpppc_pl[MLXSW_REG_MTPPPC_LEN];

        mlxsw_reg_mtpppc_pack(mtpppc_pl, ing_types, egr_types);
        return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(mtpppc), mtpppc_pl);
}

struct mlxsw_sp1_ptp_shaper_params {
        u32 ethtool_speed;
        enum mlxsw_reg_qpsc_port_speed port_speed;
        u8 shaper_time_exp;
        u8 shaper_time_mantissa;
        u8 shaper_inc;
        u8 shaper_bs;
        u8 port_to_shaper_credits;
        int ing_timestamp_inc;
        int egr_timestamp_inc;
};

static const struct mlxsw_sp1_ptp_shaper_params
mlxsw_sp1_ptp_shaper_params[] = {
        {
                .ethtool_speed          = SPEED_100,
                .port_speed             = MLXSW_REG_QPSC_PORT_SPEED_100M,
                .shaper_time_exp        = 4,
                .shaper_time_mantissa   = 12,
                .shaper_inc             = 9,
                .shaper_bs              = 1,
                .port_to_shaper_credits = 1,
                .ing_timestamp_inc      = -313,
                .egr_timestamp_inc      = 313,
        },
        {
                .ethtool_speed          = SPEED_1000,
                .port_speed             = MLXSW_REG_QPSC_PORT_SPEED_1G,
                .shaper_time_exp        = 0,
                .shaper_time_mantissa   = 12,
                .shaper_inc             = 6,
                .shaper_bs              = 0,
                .port_to_shaper_credits = 1,
                .ing_timestamp_inc      = -35,
                .egr_timestamp_inc      = 35,
        },
        {
                .ethtool_speed          = SPEED_10000,
                .port_speed             = MLXSW_REG_QPSC_PORT_SPEED_10G,
                .shaper_time_exp        = 0,
                .shaper_time_mantissa   = 2,
                .shaper_inc             = 14,
                .shaper_bs              = 1,
                .port_to_shaper_credits = 1,
                .ing_timestamp_inc      = -11,
                .egr_timestamp_inc      = 11,
        },
        {
                .ethtool_speed          = SPEED_25000,
                .port_speed             = MLXSW_REG_QPSC_PORT_SPEED_25G,
                .shaper_time_exp        = 0,
                .shaper_time_mantissa   = 0,
                .shaper_inc             = 11,
                .shaper_bs              = 1,
                .port_to_shaper_credits = 1,
                .ing_timestamp_inc      = -14,
                .egr_timestamp_inc      = 14,
        },
};

#define MLXSW_SP1_PTP_SHAPER_PARAMS_LEN ARRAY_SIZE(mlxsw_sp1_ptp_shaper_params)

static int mlxsw_sp1_ptp_shaper_params_set(struct mlxsw_sp *mlxsw_sp)
{
        const struct mlxsw_sp1_ptp_shaper_params *params;
        char qpsc_pl[MLXSW_REG_QPSC_LEN];
        int i, err;

        for (i = 0; i < MLXSW_SP1_PTP_SHAPER_PARAMS_LEN; i++) {
                params = &mlxsw_sp1_ptp_shaper_params[i];
                mlxsw_reg_qpsc_pack(qpsc_pl, params->port_speed,
                                    params->shaper_time_exp,
                                    params->shaper_time_mantissa,
                                    params->shaper_inc, params->shaper_bs,
                                    params->port_to_shaper_credits,
                                    params->ing_timestamp_inc,
                                    params->egr_timestamp_inc);
                err = mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(qpsc), qpsc_pl);
                if (err)
                        return err;
        }

        return 0;
}

struct mlxsw_sp_ptp_state *mlxsw_sp1_ptp_init(struct mlxsw_sp *mlxsw_sp)
{
        struct mlxsw_sp_ptp_state *ptp_state;
        u16 message_type;
        int err;

        err = mlxsw_sp1_ptp_shaper_params_set(mlxsw_sp);
        if (err)
                return ERR_PTR(err);

        ptp_state = kzalloc(sizeof(*ptp_state), GFP_KERNEL);
        if (!ptp_state)
                return ERR_PTR(-ENOMEM);
        ptp_state->mlxsw_sp = mlxsw_sp;

        spin_lock_init(&ptp_state->unmatched_lock);

        err = rhltable_init(&ptp_state->unmatched_ht,
                            &mlxsw_sp1_ptp_unmatched_ht_params);
        if (err)
                goto err_hashtable_init;

        /* Delive these message types as PTP0. */
        message_type = BIT(PTP_MSGTYPE_SYNC) |
                       BIT(PTP_MSGTYPE_DELAY_REQ) |
                       BIT(PTP_MSGTYPE_PDELAY_REQ) |
                       BIT(PTP_MSGTYPE_PDELAY_RESP);
        err = mlxsw_sp_ptp_mtptpt_set(mlxsw_sp, MLXSW_REG_MTPTPT_TRAP_ID_PTP0,
                                      message_type);
        if (err)
                goto err_mtptpt_set;

        /* Everything else is PTP1. */
        message_type = ~message_type;
        err = mlxsw_sp_ptp_mtptpt_set(mlxsw_sp, MLXSW_REG_MTPTPT_TRAP_ID_PTP1,
                                      message_type);
        if (err)
                goto err_mtptpt1_set;

        err = mlxsw_sp1_ptp_set_fifo_clr_on_trap(mlxsw_sp, true);
        if (err)
                goto err_fifo_clr;

        INIT_DELAYED_WORK(&ptp_state->ht_gc_dw, mlxsw_sp1_ptp_ht_gc);
        mlxsw_core_schedule_dw(&ptp_state->ht_gc_dw,
                               MLXSW_SP1_PTP_HT_GC_INTERVAL);
        return ptp_state;

err_fifo_clr:
        mlxsw_sp_ptp_mtptpt_set(mlxsw_sp, MLXSW_REG_MTPTPT_TRAP_ID_PTP1, 0);
err_mtptpt1_set:
        mlxsw_sp_ptp_mtptpt_set(mlxsw_sp, MLXSW_REG_MTPTPT_TRAP_ID_PTP0, 0);
err_mtptpt_set:
        rhltable_destroy(&ptp_state->unmatched_ht);
err_hashtable_init:
        kfree(ptp_state);
        return ERR_PTR(err);
}

void mlxsw_sp1_ptp_fini(struct mlxsw_sp_ptp_state *ptp_state)
{
        struct mlxsw_sp *mlxsw_sp = ptp_state->mlxsw_sp;

        cancel_delayed_work_sync(&ptp_state->ht_gc_dw);
        mlxsw_sp1_ptp_mtpppc_set(mlxsw_sp, 0, 0);
        mlxsw_sp1_ptp_set_fifo_clr_on_trap(mlxsw_sp, false);
        mlxsw_sp_ptp_mtptpt_set(mlxsw_sp, MLXSW_REG_MTPTPT_TRAP_ID_PTP1, 0);
        mlxsw_sp_ptp_mtptpt_set(mlxsw_sp, MLXSW_REG_MTPTPT_TRAP_ID_PTP0, 0);
        rhltable_free_and_destroy(&ptp_state->unmatched_ht,
                                  &mlxsw_sp1_ptp_unmatched_free_fn, NULL);
        kfree(ptp_state);
}

int mlxsw_sp1_ptp_hwtstamp_get(struct mlxsw_sp_port *mlxsw_sp_port,
                               struct hwtstamp_config *config)
{
        *config = mlxsw_sp_port->ptp.hwtstamp_config;
        return 0;
}

static int mlxsw_sp_ptp_get_message_types(const struct hwtstamp_config *config,
                                          u16 *p_ing_types, u16 *p_egr_types,
                                          enum hwtstamp_rx_filters *p_rx_filter)
{
        enum hwtstamp_rx_filters rx_filter = config->rx_filter;
        enum hwtstamp_tx_types tx_type = config->tx_type;
        u16 ing_types = 0x00;
        u16 egr_types = 0x00;

        switch (tx_type) {
        case HWTSTAMP_TX_OFF:
                egr_types = 0x00;
                break;
        case HWTSTAMP_TX_ON:
                egr_types = 0xff;
                break;
        case HWTSTAMP_TX_ONESTEP_SYNC:
        case HWTSTAMP_TX_ONESTEP_P2P:
                return -ERANGE;
        default:
                return -EINVAL;
        }

        switch (rx_filter) {
        case HWTSTAMP_FILTER_NONE:
                ing_types = 0x00;
                break;
        case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
        case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
        case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
        case HWTSTAMP_FILTER_PTP_V2_SYNC:
                ing_types = 0x01;
                break;
        case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
        case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
        case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
        case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
                ing_types = 0x02;
                break;
        case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
        case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
        case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
        case HWTSTAMP_FILTER_PTP_V2_EVENT:
                ing_types = 0x0f;
                break;
        case HWTSTAMP_FILTER_ALL:
                ing_types = 0xff;
                break;
        case HWTSTAMP_FILTER_SOME:
        case HWTSTAMP_FILTER_NTP_ALL:
                return -ERANGE;
        default:
                return -EINVAL;
        }

        *p_ing_types = ing_types;
        *p_egr_types = egr_types;
        *p_rx_filter = rx_filter;
        return 0;
}

static int mlxsw_sp1_ptp_mtpppc_update(struct mlxsw_sp_port *mlxsw_sp_port,
                                       u16 ing_types, u16 egr_types)
{
        struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
        struct mlxsw_sp_port *tmp;
        u16 orig_ing_types = 0;
        u16 orig_egr_types = 0;
        int err;
        int i;

        /* MTPPPC configures timestamping globally, not per port. Find the
         * configuration that contains all configured timestamping requests.
         */
        for (i = 1; i < mlxsw_core_max_ports(mlxsw_sp->core); i++) {
                tmp = mlxsw_sp->ports[i];
                if (tmp) {
                        orig_ing_types |= tmp->ptp.ing_types;
                        orig_egr_types |= tmp->ptp.egr_types;
                }
                if (tmp && tmp != mlxsw_sp_port) {
                        ing_types |= tmp->ptp.ing_types;
                        egr_types |= tmp->ptp.egr_types;
                }
        }

        if ((ing_types || egr_types) && !(orig_ing_types || orig_egr_types)) {
                err = mlxsw_sp_nve_inc_parsing_depth_get(mlxsw_sp);
                if (err) {
                        netdev_err(mlxsw_sp_port->dev, "Failed to increase parsing depth");
                        return err;
                }
        }
        if (!(ing_types || egr_types) && (orig_ing_types || orig_egr_types))
                mlxsw_sp_nve_inc_parsing_depth_put(mlxsw_sp);

        return mlxsw_sp1_ptp_mtpppc_set(mlxsw_sp_port->mlxsw_sp,
                                       ing_types, egr_types);
}

static bool mlxsw_sp1_ptp_hwtstamp_enabled(struct mlxsw_sp_port *mlxsw_sp_port)
{
        return mlxsw_sp_port->ptp.ing_types || mlxsw_sp_port->ptp.egr_types;
}

static int
mlxsw_sp1_ptp_port_shaper_set(struct mlxsw_sp_port *mlxsw_sp_port, bool enable)
{
        struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
        char qeec_pl[MLXSW_REG_QEEC_LEN];

        mlxsw_reg_qeec_ptps_pack(qeec_pl, mlxsw_sp_port->local_port, enable);
        return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(qeec), qeec_pl);

}

static int mlxsw_sp1_ptp_port_shaper_check(struct mlxsw_sp_port *mlxsw_sp_port)
{
        bool ptps = false;
        int err, i;
        u32 speed;

        if (!mlxsw_sp1_ptp_hwtstamp_enabled(mlxsw_sp_port))
                return mlxsw_sp1_ptp_port_shaper_set(mlxsw_sp_port, false);

        err = mlxsw_sp_port_speed_get(mlxsw_sp_port, &speed);
        if (err)
                return err;

        for (i = 0; i < MLXSW_SP1_PTP_SHAPER_PARAMS_LEN; i++) {
                if (mlxsw_sp1_ptp_shaper_params[i].ethtool_speed == speed) {
                        ptps = true;
                        break;
                }
        }

        return mlxsw_sp1_ptp_port_shaper_set(mlxsw_sp_port, ptps);
}

void mlxsw_sp1_ptp_shaper_work(struct work_struct *work)
{
        struct delayed_work *dwork = to_delayed_work(work);
        struct mlxsw_sp_port *mlxsw_sp_port;
        int err;

        mlxsw_sp_port = container_of(dwork, struct mlxsw_sp_port,
                                     ptp.shaper_dw);

        if (!mlxsw_sp1_ptp_hwtstamp_enabled(mlxsw_sp_port))
                return;

        err = mlxsw_sp1_ptp_port_shaper_check(mlxsw_sp_port);
        if (err)
                netdev_err(mlxsw_sp_port->dev, "Failed to set up PTP shaper\n");
}

int mlxsw_sp1_ptp_hwtstamp_set(struct mlxsw_sp_port *mlxsw_sp_port,
                               struct hwtstamp_config *config)
{
        enum hwtstamp_rx_filters rx_filter;
        u16 ing_types;
        u16 egr_types;
        int err;

        err = mlxsw_sp_ptp_get_message_types(config, &ing_types, &egr_types,
                                             &rx_filter);
        if (err)
                return err;

        err = mlxsw_sp1_ptp_mtpppc_update(mlxsw_sp_port, ing_types, egr_types);
        if (err)
                return err;

        mlxsw_sp_port->ptp.hwtstamp_config = *config;
        mlxsw_sp_port->ptp.ing_types = ing_types;
        mlxsw_sp_port->ptp.egr_types = egr_types;

        err = mlxsw_sp1_ptp_port_shaper_check(mlxsw_sp_port);
        if (err)
                return err;

        /* Notify the ioctl caller what we are actually timestamping. */
        config->rx_filter = rx_filter;

        return 0;
}

int mlxsw_sp1_ptp_get_ts_info(struct mlxsw_sp *mlxsw_sp,
                              struct ethtool_ts_info *info)
{
        info->phc_index = ptp_clock_index(mlxsw_sp->clock->ptp);

        info->so_timestamping = SOF_TIMESTAMPING_TX_HARDWARE |
                                SOF_TIMESTAMPING_RX_HARDWARE |
                                SOF_TIMESTAMPING_RAW_HARDWARE;

        info->tx_types = BIT(HWTSTAMP_TX_OFF) |
                         BIT(HWTSTAMP_TX_ON);

        info->rx_filters = BIT(HWTSTAMP_FILTER_NONE) |
                           BIT(HWTSTAMP_FILTER_ALL);

        return 0;
}

struct mlxsw_sp_ptp_port_stat {
        char str[ETH_GSTRING_LEN];
        ptrdiff_t offset;
};

#define MLXSW_SP_PTP_PORT_STAT(NAME, FIELD)                             \
        {                                                               \
                .str = NAME,                                            \
                .offset = offsetof(struct mlxsw_sp_ptp_port_stats,      \
                                    FIELD),                             \
        }

static const struct mlxsw_sp_ptp_port_stat mlxsw_sp_ptp_port_stats[] = {
        MLXSW_SP_PTP_PORT_STAT("ptp_rx_gcd_packets",    rx_gcd.packets),
        MLXSW_SP_PTP_PORT_STAT("ptp_rx_gcd_timestamps", rx_gcd.timestamps),
        MLXSW_SP_PTP_PORT_STAT("ptp_tx_gcd_packets",    tx_gcd.packets),
        MLXSW_SP_PTP_PORT_STAT("ptp_tx_gcd_timestamps", tx_gcd.timestamps),
};

#undef MLXSW_SP_PTP_PORT_STAT

#define MLXSW_SP_PTP_PORT_STATS_LEN \
        ARRAY_SIZE(mlxsw_sp_ptp_port_stats)

int mlxsw_sp1_get_stats_count(void)
{
        return MLXSW_SP_PTP_PORT_STATS_LEN;
}

void mlxsw_sp1_get_stats_strings(u8 **p)
{
        int i;

        for (i = 0; i < MLXSW_SP_PTP_PORT_STATS_LEN; i++) {
                memcpy(*p, mlxsw_sp_ptp_port_stats[i].str,
                       ETH_GSTRING_LEN);
                *p += ETH_GSTRING_LEN;
        }
}

void mlxsw_sp1_get_stats(struct mlxsw_sp_port *mlxsw_sp_port,
                         u64 *data, int data_index)
{
        void *stats = &mlxsw_sp_port->ptp.stats;
        ptrdiff_t offset;
        int i;

        data += data_index;
        for (i = 0; i < MLXSW_SP_PTP_PORT_STATS_LEN; i++) {
                offset = mlxsw_sp_ptp_port_stats[i].offset;
                *data++ = *(u64 *)(stats + offset);
        }
}