/*
 * Copyright (c) 2017, 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/etherdevice.h>
#include <linux/mlx5/driver.h>
#include <linux/mlx5/mlx5_ifc.h>
#include <linux/mlx5/mpfs.h>
#include <linux/mlx5/eswitch.h>
#include "mlx5_core.h"
#include "lib/mpfs.h"

/* HW L2 Table (MPFS) management */
static int set_l2table_entry_cmd(struct mlx5_core_dev *dev, u32 index, u8 *mac)
{
        u32 in[MLX5_ST_SZ_DW(set_l2_table_entry_in)] = {};
        u8 *in_mac_addr;

        MLX5_SET(set_l2_table_entry_in, in, opcode, MLX5_CMD_OP_SET_L2_TABLE_ENTRY);
        MLX5_SET(set_l2_table_entry_in, in, table_index, index);

        in_mac_addr = MLX5_ADDR_OF(set_l2_table_entry_in, in, mac_address);
        ether_addr_copy(&in_mac_addr[2], mac);

        return mlx5_cmd_exec_in(dev, set_l2_table_entry, in);
}

static int del_l2table_entry_cmd(struct mlx5_core_dev *dev, u32 index)
{
        u32 in[MLX5_ST_SZ_DW(delete_l2_table_entry_in)] = {};

        MLX5_SET(delete_l2_table_entry_in, in, opcode, MLX5_CMD_OP_DELETE_L2_TABLE_ENTRY);
        MLX5_SET(delete_l2_table_entry_in, in, table_index, index);
        return mlx5_cmd_exec_in(dev, delete_l2_table_entry, in);
}

/* UC L2 table hash node */
struct l2table_node {
        struct l2addr_node node;
        int                index; /* index in HW l2 table */
        int                ref_count;
};

struct mlx5_mpfs {
        struct hlist_head    hash[MLX5_L2_ADDR_HASH_SIZE];
        struct mutex         lock; /* Synchronize l2 table access */
        bool                 enabled;
        u32                  size;
        unsigned long        *bitmap;
};

static int alloc_l2table_index(struct mlx5_mpfs *l2table, u32 *ix)
{
        int err = 0;

        *ix = find_first_zero_bit(l2table->bitmap, l2table->size);
        if (*ix >= l2table->size)
                err = -ENOSPC;
        else
                __set_bit(*ix, l2table->bitmap);

        return err;
}

static void free_l2table_index(struct mlx5_mpfs *l2table, u32 ix)
{
        __clear_bit(ix, l2table->bitmap);
}

int mlx5_mpfs_init(struct mlx5_core_dev *dev)
{
        int l2table_size = 1 << MLX5_CAP_GEN(dev, log_max_l2_table);
        struct mlx5_mpfs *mpfs;

        if (!MLX5_ESWITCH_MANAGER(dev) || l2table_size == 1)
                return 0;

        mpfs = kzalloc_obj(*mpfs);
        if (!mpfs)
                return -ENOMEM;

        mutex_init(&mpfs->lock);
        mpfs->size   = l2table_size;
        mpfs->bitmap = bitmap_zalloc(l2table_size, GFP_KERNEL);
        if (!mpfs->bitmap) {
                kfree(mpfs);
                return -ENOMEM;
        }

        mpfs->enabled = true;

        dev->priv.mpfs = mpfs;
        return 0;
}

void mlx5_mpfs_cleanup(struct mlx5_core_dev *dev)
{
        struct mlx5_mpfs *mpfs = dev->priv.mpfs;

        if (!mpfs)
                return;

        WARN_ON(!hlist_empty(mpfs->hash));
        bitmap_free(mpfs->bitmap);
        kfree(mpfs);
}

int mlx5_mpfs_add_mac(struct mlx5_core_dev *dev, u8 *mac)
{
        struct mlx5_mpfs *mpfs = dev->priv.mpfs;
        struct l2table_node *l2addr;
        int err = 0;
        int index;

        if (!mpfs)
                return 0;

        mutex_lock(&mpfs->lock);

        l2addr = l2addr_hash_find(mpfs->hash, mac, struct l2table_node);
        if (l2addr) {
                l2addr->ref_count++;
                goto out;
        }

        l2addr = l2addr_hash_add(mpfs->hash, mac, struct l2table_node, GFP_KERNEL);
        if (!l2addr) {
                err = -ENOMEM;
                goto out;
        }

        index = -1;

        if (mpfs->enabled) {
                err = alloc_l2table_index(mpfs, &index);
                if (err)
                        goto hash_del;
                err = set_l2table_entry_cmd(dev, index, mac);
                if (err)
                        goto free_l2table_index;
                mlx5_core_dbg(dev, "MPFS entry %pM, set @index (%d)\n",
                              l2addr->node.addr, index);
        }

        l2addr->index = index;
        l2addr->ref_count = 1;

        mlx5_core_dbg(dev, "MPFS mac added %pM, index (%d)\n", mac, index);
        goto out;
free_l2table_index:
        free_l2table_index(mpfs, index);
hash_del:
        l2addr_hash_del(l2addr);
out:
        mutex_unlock(&mpfs->lock);
        return err;
}
EXPORT_SYMBOL(mlx5_mpfs_add_mac);

int mlx5_mpfs_del_mac(struct mlx5_core_dev *dev, u8 *mac)
{
        struct mlx5_mpfs *mpfs = dev->priv.mpfs;
        struct l2table_node *l2addr;
        int err = 0;
        int index;

        if (!mpfs)
                return 0;

        mutex_lock(&mpfs->lock);

        l2addr = l2addr_hash_find(mpfs->hash, mac, struct l2table_node);
        if (!l2addr) {
                err = -ENOENT;
                goto unlock;
        }

        if (--l2addr->ref_count > 0)
                goto unlock;

        index = l2addr->index;
        if (index >= 0) {
                del_l2table_entry_cmd(dev, index);
                free_l2table_index(mpfs, index);
                mlx5_core_dbg(dev, "MPFS entry %pM, deleted @index (%d)\n",
                              mac, index);
        }
        l2addr_hash_del(l2addr);
        mlx5_core_dbg(dev, "MPFS mac deleted %pM, index (%d)\n", mac, index);
unlock:
        mutex_unlock(&mpfs->lock);
        return err;
}
EXPORT_SYMBOL(mlx5_mpfs_del_mac);

int mlx5_mpfs_enable(struct mlx5_core_dev *dev)
{
        struct mlx5_mpfs *mpfs = dev->priv.mpfs;
        struct l2table_node *l2addr;
        struct hlist_node *n;
        int err = 0, i;

        if (!mpfs)
                return -ENODEV;

        mutex_lock(&mpfs->lock);
        if (mpfs->enabled)
                goto out;
        mpfs->enabled = true;
        mlx5_core_dbg(dev, "MPFS enabling mpfs\n");

        mlx5_mpfs_foreach(l2addr, n, mpfs, i) {
                u32 index;

                err = alloc_l2table_index(mpfs, &index);
                if (err) {
                        mlx5_core_err(dev, "Failed to allocated MPFS index for %pM, err(%d)\n",
                                      l2addr->node.addr, err);
                        goto out;
                }

                err = set_l2table_entry_cmd(dev, index, l2addr->node.addr);
                if (err) {
                        mlx5_core_err(dev, "Failed to set MPFS l2table entry for %pM index=%d, err(%d)\n",
                                      l2addr->node.addr, index, err);
                        free_l2table_index(mpfs, index);
                        goto out;
                }

                l2addr->index = index;
                mlx5_core_dbg(dev, "MPFS entry %pM, set @index (%d)\n",
                              l2addr->node.addr, l2addr->index);
        }
out:
        mutex_unlock(&mpfs->lock);
        return err;
}

void mlx5_mpfs_disable(struct mlx5_core_dev *dev)
{
        struct mlx5_mpfs *mpfs = dev->priv.mpfs;
        struct l2table_node *l2addr;
        struct hlist_node *n;
        int i;

        if (!mpfs)
                return;

        mutex_lock(&mpfs->lock);
        if (!mpfs->enabled)
                goto unlock;
        mlx5_mpfs_foreach(l2addr, n, mpfs, i) {
                if (l2addr->index < 0)
                        continue;
                del_l2table_entry_cmd(dev, l2addr->index);
                free_l2table_index(mpfs, l2addr->index);
                mlx5_core_dbg(dev, "MPFS entry %pM, deleted @index (%d)\n",
                              l2addr->node.addr, l2addr->index);
                l2addr->index = -1;
        }
        mpfs->enabled = false;
        mlx5_core_dbg(dev, "MPFS disabled\n");
unlock:
        mutex_unlock(&mpfs->lock);
}