/*
 * Copyright (c) 2013-2016, Mellanox Technologies. 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 <linux/kernel.h>
#include <linux/module.h>
#include <linux/mlx5/driver.h>
#include "mlx5_core.h"

/* Scheduling element fw management */
int mlx5_create_scheduling_element_cmd(struct mlx5_core_dev *dev, u8 hierarchy,
                                       void *ctx, u32 *element_id)
{
        u32 out[MLX5_ST_SZ_DW(create_scheduling_element_in)] = {};
        u32 in[MLX5_ST_SZ_DW(create_scheduling_element_in)] = {};
        void *schedc;
        int err;

        schedc = MLX5_ADDR_OF(create_scheduling_element_in, in,
                              scheduling_context);
        MLX5_SET(create_scheduling_element_in, in, opcode,
                 MLX5_CMD_OP_CREATE_SCHEDULING_ELEMENT);
        MLX5_SET(create_scheduling_element_in, in, scheduling_hierarchy,
                 hierarchy);
        memcpy(schedc, ctx, MLX5_ST_SZ_BYTES(scheduling_context));

        err = mlx5_cmd_exec_inout(dev, create_scheduling_element, in, out);
        if (err)
                return err;

        *element_id = MLX5_GET(create_scheduling_element_out, out,
                               scheduling_element_id);
        return 0;
}

int mlx5_modify_scheduling_element_cmd(struct mlx5_core_dev *dev, u8 hierarchy,
                                       void *ctx, u32 element_id,
                                       u32 modify_bitmask)
{
        u32 in[MLX5_ST_SZ_DW(modify_scheduling_element_in)] = {};
        void *schedc;

        schedc = MLX5_ADDR_OF(modify_scheduling_element_in, in,
                              scheduling_context);
        MLX5_SET(modify_scheduling_element_in, in, opcode,
                 MLX5_CMD_OP_MODIFY_SCHEDULING_ELEMENT);
        MLX5_SET(modify_scheduling_element_in, in, scheduling_element_id,
                 element_id);
        MLX5_SET(modify_scheduling_element_in, in, modify_bitmask,
                 modify_bitmask);
        MLX5_SET(modify_scheduling_element_in, in, scheduling_hierarchy,
                 hierarchy);
        memcpy(schedc, ctx, MLX5_ST_SZ_BYTES(scheduling_context));

        return mlx5_cmd_exec_in(dev, modify_scheduling_element, in);
}

int mlx5_destroy_scheduling_element_cmd(struct mlx5_core_dev *dev, u8 hierarchy,
                                        u32 element_id)
{
        u32 in[MLX5_ST_SZ_DW(destroy_scheduling_element_in)] = {};

        MLX5_SET(destroy_scheduling_element_in, in, opcode,
                 MLX5_CMD_OP_DESTROY_SCHEDULING_ELEMENT);
        MLX5_SET(destroy_scheduling_element_in, in, scheduling_element_id,
                 element_id);
        MLX5_SET(destroy_scheduling_element_in, in, scheduling_hierarchy,
                 hierarchy);

        return mlx5_cmd_exec_in(dev, destroy_scheduling_element, in);
}

static bool mlx5_rl_are_equal_raw(struct mlx5_rl_entry *entry, void *rl_in,
                                  u16 uid)
{
        return (!memcmp(entry->rl_raw, rl_in, sizeof(entry->rl_raw)) &&
                entry->uid == uid);
}

/* Finds an entry where we can register the given rate
 * If the rate already exists, return the entry where it is registered,
 * otherwise return the first available entry.
 * If the table is full, return NULL
 */
static struct mlx5_rl_entry *find_rl_entry(struct mlx5_rl_table *table,
                                           void *rl_in, u16 uid, bool dedicated)
{
        struct mlx5_rl_entry *ret_entry = NULL;
        bool empty_found = false;
        int i;

        lockdep_assert_held(&table->rl_lock);
        WARN_ON(!table->rl_entry);

        for (i = 0; i < table->max_size; i++) {
                if (dedicated) {
                        if (!table->rl_entry[i].refcount)
                                return &table->rl_entry[i];
                        continue;
                }

                if (table->rl_entry[i].refcount) {
                        if (table->rl_entry[i].dedicated)
                                continue;
                        if (mlx5_rl_are_equal_raw(&table->rl_entry[i], rl_in,
                                                  uid))
                                return &table->rl_entry[i];
                } else if (!empty_found) {
                        empty_found = true;
                        ret_entry = &table->rl_entry[i];
                }
        }

        return ret_entry;
}

static int mlx5_set_pp_rate_limit_cmd(struct mlx5_core_dev *dev,
                                      struct mlx5_rl_entry *entry, bool set)
{
        u32 in[MLX5_ST_SZ_DW(set_pp_rate_limit_in)] = {};
        void *pp_context;

        pp_context = MLX5_ADDR_OF(set_pp_rate_limit_in, in, ctx);
        MLX5_SET(set_pp_rate_limit_in, in, opcode,
                 MLX5_CMD_OP_SET_PP_RATE_LIMIT);
        MLX5_SET(set_pp_rate_limit_in, in, uid, entry->uid);
        MLX5_SET(set_pp_rate_limit_in, in, rate_limit_index, entry->index);
        if (set)
                memcpy(pp_context, entry->rl_raw, sizeof(entry->rl_raw));
        return mlx5_cmd_exec_in(dev, set_pp_rate_limit, in);
}

bool mlx5_rl_is_in_range(struct mlx5_core_dev *dev, u32 rate)
{
        struct mlx5_rl_table *table = &dev->priv.rl_table;

        return (rate <= table->max_rate && rate >= table->min_rate);
}
EXPORT_SYMBOL(mlx5_rl_is_in_range);

bool mlx5_rl_are_equal(struct mlx5_rate_limit *rl_0,
                       struct mlx5_rate_limit *rl_1)
{
        return ((rl_0->rate == rl_1->rate) &&
                (rl_0->max_burst_sz == rl_1->max_burst_sz) &&
                (rl_0->typical_pkt_sz == rl_1->typical_pkt_sz));
}
EXPORT_SYMBOL(mlx5_rl_are_equal);

static int mlx5_rl_table_get(struct mlx5_rl_table *table)
{
        int i;

        lockdep_assert_held(&table->rl_lock);

        if (table->rl_entry) {
                table->refcount++;
                return 0;
        }

        table->rl_entry = kcalloc(table->max_size, sizeof(struct mlx5_rl_entry),
                                  GFP_KERNEL);
        if (!table->rl_entry)
                return -ENOMEM;

        /* The index represents the index in HW rate limit table
         * Index 0 is reserved for unlimited rate
         */
        for (i = 0; i < table->max_size; i++)
                table->rl_entry[i].index = i + 1;

        table->refcount++;
        return 0;
}

static void mlx5_rl_table_put(struct mlx5_rl_table *table)
{
        lockdep_assert_held(&table->rl_lock);
        if (--table->refcount)
                return;

        kfree(table->rl_entry);
        table->rl_entry = NULL;
}

static void mlx5_rl_table_free(struct mlx5_core_dev *dev, struct mlx5_rl_table *table)
{
        int i;

        if (!table->rl_entry)
                return;

        /* Clear all configured rates */
        for (i = 0; i < table->max_size; i++)
                if (table->rl_entry[i].refcount)
                        mlx5_set_pp_rate_limit_cmd(dev, &table->rl_entry[i], false);
        kfree(table->rl_entry);
}

static void mlx5_rl_entry_get(struct mlx5_rl_entry *entry)
{
        entry->refcount++;
}

static void
mlx5_rl_entry_put(struct mlx5_core_dev *dev, struct mlx5_rl_entry *entry)
{
        entry->refcount--;
        if (!entry->refcount)
                mlx5_set_pp_rate_limit_cmd(dev, entry, false);
}

int mlx5_rl_add_rate_raw(struct mlx5_core_dev *dev, void *rl_in, u16 uid,
                         bool dedicated_entry, u16 *index)
{
        struct mlx5_rl_table *table = &dev->priv.rl_table;
        struct mlx5_rl_entry *entry;
        u32 rate;
        int err;

        if (!table->max_size)
                return -EOPNOTSUPP;

        rate = MLX5_GET(set_pp_rate_limit_context, rl_in, rate_limit);
        if (!rate || !mlx5_rl_is_in_range(dev, rate)) {
                mlx5_core_err(dev, "Invalid rate: %u, should be %u to %u\n",
                              rate, table->min_rate, table->max_rate);
                return -EINVAL;
        }

        mutex_lock(&table->rl_lock);
        err = mlx5_rl_table_get(table);
        if (err)
                goto out;

        entry = find_rl_entry(table, rl_in, uid, dedicated_entry);
        if (!entry) {
                mlx5_core_err(dev, "Max number of %u rates reached\n",
                              table->max_size);
                err = -ENOSPC;
                goto rl_err;
        }
        if (!entry->refcount) {
                /* new rate limit */
                memcpy(entry->rl_raw, rl_in, sizeof(entry->rl_raw));
                entry->uid = uid;
                err = mlx5_set_pp_rate_limit_cmd(dev, entry, true);
                if (err) {
                        mlx5_core_err(
                                dev,
                                "Failed configuring rate limit(err %d): rate %u, max_burst_sz %u, typical_pkt_sz %u\n",
                                err, rate,
                                MLX5_GET(set_pp_rate_limit_context, rl_in,
                                         burst_upper_bound),
                                MLX5_GET(set_pp_rate_limit_context, rl_in,
                                         typical_packet_size));
                        goto rl_err;
                }

                entry->dedicated = dedicated_entry;
        }
        mlx5_rl_entry_get(entry);
        *index = entry->index;
        mutex_unlock(&table->rl_lock);
        return 0;

rl_err:
        mlx5_rl_table_put(table);
out:
        mutex_unlock(&table->rl_lock);
        return err;
}
EXPORT_SYMBOL(mlx5_rl_add_rate_raw);

void mlx5_rl_remove_rate_raw(struct mlx5_core_dev *dev, u16 index)
{
        struct mlx5_rl_table *table = &dev->priv.rl_table;
        struct mlx5_rl_entry *entry;

        mutex_lock(&table->rl_lock);
        entry = &table->rl_entry[index - 1];
        mlx5_rl_entry_put(dev, entry);
        mlx5_rl_table_put(table);
        mutex_unlock(&table->rl_lock);
}
EXPORT_SYMBOL(mlx5_rl_remove_rate_raw);

int mlx5_rl_add_rate(struct mlx5_core_dev *dev, u16 *index,
                     struct mlx5_rate_limit *rl)
{
        u8 rl_raw[MLX5_ST_SZ_BYTES(set_pp_rate_limit_context)] = {};

        MLX5_SET(set_pp_rate_limit_context, rl_raw, rate_limit, rl->rate);
        MLX5_SET(set_pp_rate_limit_context, rl_raw, burst_upper_bound,
                 rl->max_burst_sz);
        MLX5_SET(set_pp_rate_limit_context, rl_raw, typical_packet_size,
                 rl->typical_pkt_sz);

        return mlx5_rl_add_rate_raw(dev, rl_raw,
                                    MLX5_CAP_QOS(dev, packet_pacing_uid) ?
                                        MLX5_SHARED_RESOURCE_UID : 0,
                                    false, index);
}
EXPORT_SYMBOL(mlx5_rl_add_rate);

void mlx5_rl_remove_rate(struct mlx5_core_dev *dev, struct mlx5_rate_limit *rl)
{
        u8 rl_raw[MLX5_ST_SZ_BYTES(set_pp_rate_limit_context)] = {};
        struct mlx5_rl_table *table = &dev->priv.rl_table;
        struct mlx5_rl_entry *entry = NULL;

        /* 0 is a reserved value for unlimited rate */
        if (rl->rate == 0)
                return;

        MLX5_SET(set_pp_rate_limit_context, rl_raw, rate_limit, rl->rate);
        MLX5_SET(set_pp_rate_limit_context, rl_raw, burst_upper_bound,
                 rl->max_burst_sz);
        MLX5_SET(set_pp_rate_limit_context, rl_raw, typical_packet_size,
                 rl->typical_pkt_sz);

        mutex_lock(&table->rl_lock);
        entry = find_rl_entry(table, rl_raw,
                              MLX5_CAP_QOS(dev, packet_pacing_uid) ?
                                MLX5_SHARED_RESOURCE_UID : 0, false);
        if (!entry || !entry->refcount) {
                mlx5_core_warn(dev, "Rate %u, max_burst_sz %u typical_pkt_sz %u are not configured\n",
                               rl->rate, rl->max_burst_sz, rl->typical_pkt_sz);
                goto out;
        }
        mlx5_rl_entry_put(dev, entry);
        mlx5_rl_table_put(table);
out:
        mutex_unlock(&table->rl_lock);
}
EXPORT_SYMBOL(mlx5_rl_remove_rate);

int mlx5_init_rl_table(struct mlx5_core_dev *dev)
{
        struct mlx5_rl_table *table = &dev->priv.rl_table;

        if (!MLX5_CAP_GEN(dev, qos) || !MLX5_CAP_QOS(dev, packet_pacing)) {
                table->max_size = 0;
                return 0;
        }

        mutex_init(&table->rl_lock);

        /* First entry is reserved for unlimited rate */
        table->max_size = MLX5_CAP_QOS(dev, packet_pacing_rate_table_size) - 1;
        table->max_rate = MLX5_CAP_QOS(dev, packet_pacing_max_rate);
        table->min_rate = MLX5_CAP_QOS(dev, packet_pacing_min_rate);

        mlx5_core_info(dev, "Rate limit: %u rates are supported, range: %uMbps to %uMbps\n",
                       table->max_size,
                       table->min_rate >> 10,
                       table->max_rate >> 10);

        return 0;
}

void mlx5_cleanup_rl_table(struct mlx5_core_dev *dev)
{
        struct mlx5_rl_table *table = &dev->priv.rl_table;

        if (!MLX5_CAP_GEN(dev, qos) || !MLX5_CAP_QOS(dev, packet_pacing))
                return;

        mlx5_rl_table_free(dev, table);
        mutex_destroy(&table->rl_lock);
}