/*-
 * Copyright (c) 2013-2019, Mellanox Technologies, Ltd.  All rights reserved.
 * Copyright (c) 2022 NVIDIA corporation & affiliates.
 *
 * 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. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY AUTHOR 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 AUTHOR 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.
 *
 * $FreeBSD$
 */

#include <dev/mlx5/driver.h>
#include <dev/mlx5/fs.h>
#include <linux/rbtree.h>
#include <dev/mlx5/mlx5_core/mlx5_core.h>
#include <dev/mlx5/mlx5_core/fs_core.h>
#include <dev/mlx5/mlx5_core/fs_cmd.h>

#define MLX5_FC_STATS_PERIOD msecs_to_jiffies(1000)
#define MLX5_FC_BULK_QUERY_ALLOC_PERIOD msecs_to_jiffies(180 * 1000)
/* Max number of counters to query in bulk read is 32K */
#define MLX5_SW_MAX_COUNTERS_BULK BIT(15)
#define MLX5_INIT_COUNTERS_BULK 8
#define MLX5_FC_POOL_MAX_THRESHOLD BIT(18)
#define MLX5_FC_POOL_USED_BUFF_RATIO 10

struct mlx5_fc_cache {
        u64 packets;
        u64 bytes;
        u64 lastuse;
};

struct mlx5_fc {
        struct list_head list;
        struct llist_node addlist;
        struct llist_node dellist;

        /* last{packets,bytes} members are used when calculating the delta since
         * last reading
         */
        u64 lastpackets;
        u64 lastbytes;

        struct mlx5_fc_bulk *bulk;
        u32 id;
        bool aging;

        struct mlx5_fc_cache cache ____cacheline_aligned_in_smp;
};

static void mlx5_fc_pool_init(struct mlx5_fc_pool *fc_pool, struct mlx5_core_dev *dev);
static void mlx5_fc_pool_cleanup(struct mlx5_fc_pool *fc_pool);
static struct mlx5_fc *mlx5_fc_pool_acquire_counter(struct mlx5_fc_pool *fc_pool);
static void mlx5_fc_pool_release_counter(struct mlx5_fc_pool *fc_pool, struct mlx5_fc *fc);

/* locking scheme:
 *
 * It is the responsibility of the user to prevent concurrent calls or bad
 * ordering to mlx5_fc_create(), mlx5_fc_destroy() and accessing a reference
 * to struct mlx5_fc.
 * e.g en_tc.c is protected by RTNL lock of its caller, and will never call a
 * dump (access to struct mlx5_fc) after a counter is destroyed.
 *
 * access to counter list:
 * - create (user context)
 *   - mlx5_fc_create() only adds to an addlist to be used by
 *     mlx5_fc_stats_work(). addlist is a lockless single linked list
 *     that doesn't require any additional synchronization when adding single
 *     node.
 *   - spawn thread to do the actual destroy
 *
 * - destroy (user context)
 *   - add a counter to lockless dellist
 *   - spawn thread to do the actual del
 *
 * - dump (user context)
 *   user should not call dump after destroy
 *
 * - query (single thread workqueue context)
 *   destroy/dump - no conflict (see destroy)
 *   query/dump - packets and bytes might be inconsistent (since update is not
 *                atomic)
 *   query/create - no conflict (see create)
 *   since every create/destroy spawn the work, only after necessary time has
 *   elapsed, the thread will actually query the hardware.
 */

static struct list_head *mlx5_fc_counters_lookup_next(struct mlx5_core_dev *dev,
                                                      u32 id)
{
        struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
        struct mlx5_fc *counter;
        int next_id = id + 1;

        rcu_read_lock();
        /* skip counters that are in idr, but not yet in counters list */
        while ((counter = idr_get_next(&fc_stats->counters_idr, &next_id)) != NULL &&
                list_empty(&counter->list))
                next_id++;
        rcu_read_unlock();

        return counter ? &counter->list : &fc_stats->counters;
}

static void mlx5_fc_stats_insert(struct mlx5_core_dev *dev,
                                 struct mlx5_fc *counter)
{
        struct list_head *next = mlx5_fc_counters_lookup_next(dev, counter->id);

        list_add_tail(&counter->list, next);
}

static void mlx5_fc_stats_remove(struct mlx5_core_dev *dev,
                                 struct mlx5_fc *counter)
{
        struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;

        list_del(&counter->list);

        spin_lock(&fc_stats->counters_idr_lock);
        WARN_ON(!idr_remove(&fc_stats->counters_idr, counter->id));
        spin_unlock(&fc_stats->counters_idr_lock);
}

static int get_init_bulk_query_len(struct mlx5_core_dev *dev)
{
        return min_t(int, MLX5_INIT_COUNTERS_BULK,
                     (1 << MLX5_CAP_GEN(dev, log_max_flow_counter_bulk)));
}

static int get_max_bulk_query_len(struct mlx5_core_dev *dev)
{
        return min_t(int, MLX5_SW_MAX_COUNTERS_BULK,
                     (1 << MLX5_CAP_GEN(dev, log_max_flow_counter_bulk)));
}

static void update_counter_cache(int index, u32 *bulk_raw_data,
                                 struct mlx5_fc_cache *cache)
{
        void *stats = MLX5_ADDR_OF(query_flow_counter_out, bulk_raw_data,
                             flow_statistics[index]);
        u64 packets = MLX5_GET64(traffic_counter, stats, packets);
        u64 bytes = MLX5_GET64(traffic_counter, stats, octets);

        if (cache->packets == packets)
                return;

        cache->packets = packets;
        cache->bytes = bytes;
        cache->lastuse = jiffies;
}

static void mlx5_fc_stats_query_counter_range(struct mlx5_core_dev *dev,
                                              struct mlx5_fc *first,
                                              u32 last_id)
{
        struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
        bool query_more_counters = (first->id <= last_id);
        int cur_bulk_len = fc_stats->bulk_query_len;
        u32 *data = fc_stats->bulk_query_out;
        struct mlx5_fc *counter = first;
        u32 bulk_base_id;
        int bulk_len;
        int err;

        while (query_more_counters) {
                /* first id must be aligned to 4 when using bulk query */
                bulk_base_id = counter->id & ~0x3;

                /* number of counters to query inc. the last counter */
                bulk_len = min_t(int, cur_bulk_len,
                                 ALIGN(last_id - bulk_base_id + 1, 4));

                err = mlx5_cmd_fc_bulk_query(dev, bulk_base_id, bulk_len,
                                             data);
                if (err) {
                        mlx5_core_err(dev, "Error doing bulk query: %d\n", err);
                        return;
                }
                query_more_counters = false;

                list_for_each_entry_from(counter, &fc_stats->counters, list) {
                        int counter_index = counter->id - bulk_base_id;
                        struct mlx5_fc_cache *cache = &counter->cache;

                        if (counter->id >= bulk_base_id + bulk_len) {
                                query_more_counters = true;
                                break;
                        }

                        update_counter_cache(counter_index, data, cache);
                }
        }
}

static void mlx5_fc_free(struct mlx5_core_dev *dev, struct mlx5_fc *counter)
{
        mlx5_cmd_fc_free(dev, counter->id);
        kfree(counter);
}

static void mlx5_fc_release(struct mlx5_core_dev *dev, struct mlx5_fc *counter)
{
        struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;

        if (counter->bulk)
                mlx5_fc_pool_release_counter(&fc_stats->fc_pool, counter);
        else
                mlx5_fc_free(dev, counter);
}

static void mlx5_fc_stats_bulk_query_size_increase(struct mlx5_core_dev *dev)
{
        struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
        int max_bulk_len = get_max_bulk_query_len(dev);
        unsigned long now = jiffies;
        u32 *bulk_query_out_tmp;
        int max_out_len;

        if (fc_stats->bulk_query_alloc_failed &&
            time_before(now, fc_stats->next_bulk_query_alloc))
                return;

        max_out_len = mlx5_cmd_fc_get_bulk_query_out_len(max_bulk_len);
        bulk_query_out_tmp = kzalloc(max_out_len, GFP_KERNEL);
        if (!bulk_query_out_tmp) {
                mlx5_core_warn(dev,
                               "Can't increase flow counters bulk query buffer size, insufficient memory, bulk_size(%d)\n",
                               max_bulk_len);
                fc_stats->bulk_query_alloc_failed = true;
                fc_stats->next_bulk_query_alloc =
                        now + MLX5_FC_BULK_QUERY_ALLOC_PERIOD;
                return;
        }

        kfree(fc_stats->bulk_query_out);
        fc_stats->bulk_query_out = bulk_query_out_tmp;
        fc_stats->bulk_query_len = max_bulk_len;
        if (fc_stats->bulk_query_alloc_failed) {
                mlx5_core_info(dev,
                               "Flow counters bulk query buffer size increased, bulk_size(%d)\n",
                               max_bulk_len);
                fc_stats->bulk_query_alloc_failed = false;
        }
}

static void mlx5_fc_stats_work(struct work_struct *work)
{
        struct mlx5_core_dev *dev = container_of(work, struct mlx5_core_dev,
                                                 priv.fc_stats.work.work);
        struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
        /* Take dellist first to ensure that counters cannot be deleted before
         * they are inserted.
         */
        struct llist_node *dellist = llist_del_all(&fc_stats->dellist);
        struct llist_node *addlist = llist_del_all(&fc_stats->addlist);
        struct mlx5_fc *counter = NULL, *last = NULL, *tmp;
        unsigned long now = jiffies;

        if (addlist || !list_empty(&fc_stats->counters))
                queue_delayed_work(fc_stats->wq, &fc_stats->work,
                                   fc_stats->sampling_interval);

        llist_for_each_entry(counter, addlist, addlist) {
                mlx5_fc_stats_insert(dev, counter);
                fc_stats->num_counters++;
        }

        llist_for_each_entry_safe(counter, tmp, dellist, dellist) {
                mlx5_fc_stats_remove(dev, counter);

                mlx5_fc_release(dev, counter);
                fc_stats->num_counters--;
        }

        if (fc_stats->bulk_query_len < get_max_bulk_query_len(dev) &&
            fc_stats->num_counters > get_init_bulk_query_len(dev))
                mlx5_fc_stats_bulk_query_size_increase(dev);

        if (time_before(now, fc_stats->next_query) ||
            list_empty(&fc_stats->counters))
                return;
        last = list_last_entry(&fc_stats->counters, struct mlx5_fc, list);

        counter = list_first_entry(&fc_stats->counters, struct mlx5_fc,
                                   list);
        if (counter)
                mlx5_fc_stats_query_counter_range(dev, counter, last->id);

        fc_stats->next_query = now + fc_stats->sampling_interval;
}

static struct mlx5_fc *mlx5_fc_single_alloc(struct mlx5_core_dev *dev)
{
        struct mlx5_fc *counter;
        int err;

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

        err = mlx5_cmd_fc_alloc(dev, &counter->id);
        if (err) {
                kfree(counter);
                return ERR_PTR(err);
        }

        return counter;
}

static struct mlx5_fc *mlx5_fc_acquire(struct mlx5_core_dev *dev, bool aging)
{
        struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
        struct mlx5_fc *counter;

        if (aging && MLX5_CAP_GEN(dev, flow_counter_bulk_alloc) != 0) {
                counter = mlx5_fc_pool_acquire_counter(&fc_stats->fc_pool);
                if (!IS_ERR(counter))
                        return counter;
        }

        return mlx5_fc_single_alloc(dev);
}

struct mlx5_fc *mlx5_fc_create_ex(struct mlx5_core_dev *dev, bool aging)
{
        struct mlx5_fc *counter = mlx5_fc_acquire(dev, aging);
        struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
        int err = 0;

        if (IS_ERR(counter))
                return counter;

        INIT_LIST_HEAD(&counter->list);
        counter->aging = aging;

        if (aging) {
                u32 id = counter->id;

                counter->cache.lastuse = jiffies;
                counter->lastbytes = counter->cache.bytes;
                counter->lastpackets = counter->cache.packets;

                idr_preload(GFP_KERNEL);
                spin_lock(&fc_stats->counters_idr_lock);

                err = idr_alloc(&fc_stats->counters_idr, counter, id, id + 1,
                                GFP_NOWAIT);

                spin_unlock(&fc_stats->counters_idr_lock);
                idr_preload_end();
                if (err < 0 || err != id)
                        goto err_out_alloc;

                llist_add(&counter->addlist, &fc_stats->addlist);
        }

        return counter;

err_out_alloc:
        mlx5_fc_release(dev, counter);
        return ERR_PTR(err);
}

struct mlx5_fc *mlx5_fc_create(struct mlx5_core_dev *dev, bool aging)
{
        struct mlx5_fc *counter = mlx5_fc_create_ex(dev, aging);
        struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;

        if (aging)
                mod_delayed_work(fc_stats->wq, &fc_stats->work, 0);
        return counter;
}
EXPORT_SYMBOL(mlx5_fc_create);

u32 mlx5_fc_id(struct mlx5_fc *counter)
{
        return counter->id;
}
EXPORT_SYMBOL(mlx5_fc_id);

void mlx5_fc_destroy(struct mlx5_core_dev *dev, struct mlx5_fc *counter)
{
        struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;

        if (!counter)
                return;

        if (counter->aging) {
                llist_add(&counter->dellist, &fc_stats->dellist);
                mod_delayed_work(fc_stats->wq, &fc_stats->work, 0);
                return;
        }

        mlx5_fc_release(dev, counter);
}
EXPORT_SYMBOL(mlx5_fc_destroy);

int mlx5_init_fc_stats(struct mlx5_core_dev *dev)
{
        struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
        int init_bulk_len;
        int init_out_len;

        spin_lock_init(&fc_stats->counters_idr_lock);
        idr_init(&fc_stats->counters_idr);
        INIT_LIST_HEAD(&fc_stats->counters);
        init_llist_head(&fc_stats->addlist);
        init_llist_head(&fc_stats->dellist);

        init_bulk_len = get_init_bulk_query_len(dev);
        init_out_len = mlx5_cmd_fc_get_bulk_query_out_len(init_bulk_len);
        fc_stats->bulk_query_out = kzalloc(init_out_len, GFP_KERNEL);
        if (!fc_stats->bulk_query_out)
                return -ENOMEM;
        fc_stats->bulk_query_len = init_bulk_len;

        fc_stats->wq = create_singlethread_workqueue("mlx5_fc");
        if (!fc_stats->wq)
                goto err_wq_create;

        fc_stats->sampling_interval = MLX5_FC_STATS_PERIOD;
        INIT_DELAYED_WORK(&fc_stats->work, mlx5_fc_stats_work);

        mlx5_fc_pool_init(&fc_stats->fc_pool, dev);
        return 0;

err_wq_create:
        kfree(fc_stats->bulk_query_out);
        return -ENOMEM;
}

void mlx5_cleanup_fc_stats(struct mlx5_core_dev *dev)
{
        struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
        struct llist_node *tmplist;
        struct mlx5_fc *counter;
        struct mlx5_fc *tmp;

        if (!dev->priv.fc_stats.wq)
                return;

        cancel_delayed_work_sync(&dev->priv.fc_stats.work);
        destroy_workqueue(dev->priv.fc_stats.wq);
        dev->priv.fc_stats.wq = NULL;

        tmplist = llist_del_all(&fc_stats->addlist);
        llist_for_each_entry_safe(counter, tmp, tmplist, addlist)
                mlx5_fc_release(dev, counter);

        list_for_each_entry_safe(counter, tmp, &fc_stats->counters, list)
                mlx5_fc_release(dev, counter);

        mlx5_fc_pool_cleanup(&fc_stats->fc_pool);
        idr_destroy(&fc_stats->counters_idr);
        kfree(fc_stats->bulk_query_out);
}

int mlx5_fc_query(struct mlx5_core_dev *dev, struct mlx5_fc *counter,
                  u64 *packets, u64 *bytes)
{
        return mlx5_cmd_fc_query(dev, counter->id, packets, bytes);
}
EXPORT_SYMBOL(mlx5_fc_query);

u64 mlx5_fc_query_lastuse(struct mlx5_fc *counter)
{
        return counter->cache.lastuse;
}

void mlx5_fc_query_cached(struct mlx5_fc *counter,
                          u64 *bytes, u64 *packets, u64 *lastuse)
{
        struct mlx5_fc_cache c;

        c = counter->cache;

        *bytes = c.bytes - counter->lastbytes;
        *packets = c.packets - counter->lastpackets;
        *lastuse = c.lastuse;

        counter->lastbytes = c.bytes;
        counter->lastpackets = c.packets;
}

void mlx5_fc_queue_stats_work(struct mlx5_core_dev *dev,
                              struct delayed_work *dwork,
                              unsigned long delay)
{
        struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;

        queue_delayed_work(fc_stats->wq, dwork, delay);
}

void mlx5_fc_update_sampling_interval(struct mlx5_core_dev *dev,
                                      unsigned long interval)
{
        struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;

        fc_stats->sampling_interval = min_t(unsigned long, interval,
                                            fc_stats->sampling_interval);
}

/* Flow counter bluks */

struct mlx5_fc_bulk {
        struct list_head pool_list;
        u32 base_id;
        int bulk_len;
        unsigned long *bitmask;
        struct mlx5_fc fcs[];
};

static void mlx5_fc_init(struct mlx5_fc *counter, struct mlx5_fc_bulk *bulk,
                         u32 id)
{
        counter->bulk = bulk;
        counter->id = id;
}

static int mlx5_fc_bulk_get_free_fcs_amount(struct mlx5_fc_bulk *bulk)
{
        return bitmap_weight(bulk->bitmask, bulk->bulk_len);
}

static struct mlx5_fc_bulk *mlx5_fc_bulk_create(struct mlx5_core_dev *dev)
{
        enum mlx5_fc_bulk_alloc_bitmask alloc_bitmask;
        struct mlx5_fc_bulk *bulk;
        int err = -ENOMEM;
        int bulk_len;
        u32 base_id;
        int i;

        alloc_bitmask = MLX5_CAP_GEN(dev, flow_counter_bulk_alloc);
        bulk_len = alloc_bitmask > 0 ? MLX5_FC_BULK_NUM_FCS(alloc_bitmask) : 1;

        bulk = kvzalloc(struct_size(bulk, fcs, bulk_len), GFP_KERNEL);
        if (!bulk)
                goto err_alloc_bulk;

        bulk->bitmask = kvcalloc(BITS_TO_LONGS(bulk_len), sizeof(unsigned long),
                                 GFP_KERNEL);
        if (!bulk->bitmask)
                goto err_alloc_bitmask;

        err = mlx5_cmd_fc_bulk_alloc(dev, alloc_bitmask, &base_id);
        if (err)
                goto err_mlx5_cmd_bulk_alloc;

        bulk->base_id = base_id;
        bulk->bulk_len = bulk_len;
        for (i = 0; i < bulk_len; i++) {
                mlx5_fc_init(&bulk->fcs[i], bulk, base_id + i);
                set_bit(i, bulk->bitmask);
        }

        return bulk;

err_mlx5_cmd_bulk_alloc:
        kvfree(bulk->bitmask);
err_alloc_bitmask:
        kvfree(bulk);
err_alloc_bulk:
        return ERR_PTR(err);
}

static int
mlx5_fc_bulk_destroy(struct mlx5_core_dev *dev, struct mlx5_fc_bulk *bulk)
{
        if (mlx5_fc_bulk_get_free_fcs_amount(bulk) < bulk->bulk_len) {
                mlx5_core_err(dev, "Freeing bulk before all counters were released\n");
                return -EBUSY;
        }

        mlx5_cmd_fc_free(dev, bulk->base_id);
        kvfree(bulk->bitmask);
        kvfree(bulk);

        return 0;
}

static struct mlx5_fc *mlx5_fc_bulk_acquire_fc(struct mlx5_fc_bulk *bulk)
{
        int free_fc_index = find_first_bit(bulk->bitmask, bulk->bulk_len);

        if (free_fc_index >= bulk->bulk_len)
                return ERR_PTR(-ENOSPC);

        clear_bit(free_fc_index, bulk->bitmask);
        return &bulk->fcs[free_fc_index];
}

static int mlx5_fc_bulk_release_fc(struct mlx5_fc_bulk *bulk, struct mlx5_fc *fc)
{
        int fc_index = fc->id - bulk->base_id;

        if (test_bit(fc_index, bulk->bitmask))
                return -EINVAL;

        set_bit(fc_index, bulk->bitmask);
        return 0;
}

/* Flow counters pool API */

static void mlx5_fc_pool_init(struct mlx5_fc_pool *fc_pool, struct mlx5_core_dev *dev)
{
        fc_pool->dev = dev;
        mutex_init(&fc_pool->pool_lock);
        INIT_LIST_HEAD(&fc_pool->fully_used);
        INIT_LIST_HEAD(&fc_pool->partially_used);
        INIT_LIST_HEAD(&fc_pool->unused);
        fc_pool->available_fcs = 0;
        fc_pool->used_fcs = 0;
        fc_pool->threshold = 0;
}

static void mlx5_fc_pool_cleanup(struct mlx5_fc_pool *fc_pool)
{
        struct mlx5_core_dev *dev = fc_pool->dev;
        struct mlx5_fc_bulk *bulk;
        struct mlx5_fc_bulk *tmp;

        list_for_each_entry_safe(bulk, tmp, &fc_pool->fully_used, pool_list)
                mlx5_fc_bulk_destroy(dev, bulk);
        list_for_each_entry_safe(bulk, tmp, &fc_pool->partially_used, pool_list)
                mlx5_fc_bulk_destroy(dev, bulk);
        list_for_each_entry_safe(bulk, tmp, &fc_pool->unused, pool_list)
                mlx5_fc_bulk_destroy(dev, bulk);
}

static void mlx5_fc_pool_update_threshold(struct mlx5_fc_pool *fc_pool)
{
        fc_pool->threshold = min_t(int, MLX5_FC_POOL_MAX_THRESHOLD,
                                   fc_pool->used_fcs / MLX5_FC_POOL_USED_BUFF_RATIO);
}

static struct mlx5_fc_bulk *
mlx5_fc_pool_alloc_new_bulk(struct mlx5_fc_pool *fc_pool)
{
        struct mlx5_core_dev *dev = fc_pool->dev;
        struct mlx5_fc_bulk *new_bulk;

        new_bulk = mlx5_fc_bulk_create(dev);
        if (!IS_ERR(new_bulk))
                fc_pool->available_fcs += new_bulk->bulk_len;
        mlx5_fc_pool_update_threshold(fc_pool);
        return new_bulk;
}

static void
mlx5_fc_pool_free_bulk(struct mlx5_fc_pool *fc_pool, struct mlx5_fc_bulk *bulk)
{
        struct mlx5_core_dev *dev = fc_pool->dev;

        fc_pool->available_fcs -= bulk->bulk_len;
        mlx5_fc_bulk_destroy(dev, bulk);
        mlx5_fc_pool_update_threshold(fc_pool);
}

static struct mlx5_fc *
mlx5_fc_pool_acquire_from_list(struct list_head *src_list,
                               struct list_head *next_list,
                               bool move_non_full_bulk)
{
        struct mlx5_fc_bulk *bulk;
        struct mlx5_fc *fc;

        if (list_empty(src_list))
                return ERR_PTR(-ENODATA);

        bulk = list_first_entry(src_list, struct mlx5_fc_bulk, pool_list);
        fc = mlx5_fc_bulk_acquire_fc(bulk);
        if (move_non_full_bulk || mlx5_fc_bulk_get_free_fcs_amount(bulk) == 0)
                list_move(&bulk->pool_list, next_list);
        return fc;
}

static struct mlx5_fc *
mlx5_fc_pool_acquire_counter(struct mlx5_fc_pool *fc_pool)
{
        struct mlx5_fc_bulk *new_bulk;
        struct mlx5_fc *fc;

        mutex_lock(&fc_pool->pool_lock);

        fc = mlx5_fc_pool_acquire_from_list(&fc_pool->partially_used,
                                            &fc_pool->fully_used, false);
        if (IS_ERR(fc))
                fc = mlx5_fc_pool_acquire_from_list(&fc_pool->unused,
                                                    &fc_pool->partially_used,
                                                    true);
        if (IS_ERR(fc)) {
                new_bulk = mlx5_fc_pool_alloc_new_bulk(fc_pool);
                if (IS_ERR(new_bulk)) {
                        fc = ERR_CAST(new_bulk);
                        goto out;
                }
                fc = mlx5_fc_bulk_acquire_fc(new_bulk);
                list_add(&new_bulk->pool_list, &fc_pool->partially_used);
        }
        fc_pool->available_fcs--;
        fc_pool->used_fcs++;

out:
        mutex_unlock(&fc_pool->pool_lock);
        return fc;
}

static void
mlx5_fc_pool_release_counter(struct mlx5_fc_pool *fc_pool, struct mlx5_fc *fc)
{
        struct mlx5_core_dev *dev = fc_pool->dev;
        struct mlx5_fc_bulk *bulk = fc->bulk;
        int bulk_free_fcs_amount;

        mutex_lock(&fc_pool->pool_lock);

        if (mlx5_fc_bulk_release_fc(bulk, fc)) {
                mlx5_core_warn(dev, "Attempted to release a counter which is not acquired\n");
                goto unlock;
        }

        fc_pool->available_fcs++;
        fc_pool->used_fcs--;

        bulk_free_fcs_amount = mlx5_fc_bulk_get_free_fcs_amount(bulk);
        if (bulk_free_fcs_amount == 1)
                list_move_tail(&bulk->pool_list, &fc_pool->partially_used);
        if (bulk_free_fcs_amount == bulk->bulk_len) {
                list_del(&bulk->pool_list);
                if (fc_pool->available_fcs > fc_pool->threshold)
                        mlx5_fc_pool_free_bulk(fc_pool, bulk);
                else
                        list_add(&bulk->pool_list, &fc_pool->unused);
        }

unlock:
        mutex_unlock(&fc_pool->pool_lock);
}