/*
 * Copyright (c) 2015, Mellanox Technologies inc.  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/module.h>
#include <linux/configfs.h>
#include <rdma/ib_verbs.h>
#include <rdma/rdma_cm.h>

#include "core_priv.h"
#include "cma_priv.h"

struct cma_device;

struct cma_dev_group;

struct cma_dev_port_group {
        u32                     port_num;
        struct cma_dev_group    *cma_dev_group;
        struct config_group     group;
};

struct cma_dev_group {
        char                            name[IB_DEVICE_NAME_MAX];
        struct config_group             device_group;
        struct config_group             ports_group;
        struct cma_dev_port_group       *ports;
};

static struct cma_dev_port_group *to_dev_port_group(struct config_item *item)
{
        struct config_group *group;

        if (!item)
                return NULL;

        group = container_of(item, struct config_group, cg_item);
        return container_of(group, struct cma_dev_port_group, group);
}

static bool filter_by_name(struct ib_device *ib_dev, void *cookie)
{
        return !strcmp(dev_name(&ib_dev->dev), cookie);
}

static int cma_configfs_params_get(struct config_item *item,
                                   struct cma_device **pcma_dev,
                                   struct cma_dev_port_group **pgroup)
{
        struct cma_dev_port_group *group = to_dev_port_group(item);
        struct cma_device *cma_dev;

        if (!group)
                return -ENODEV;

        cma_dev = cma_enum_devices_by_ibdev(filter_by_name,
                                            group->cma_dev_group->name);
        if (!cma_dev)
                return -ENODEV;

        *pcma_dev = cma_dev;
        *pgroup = group;

        return 0;
}

static void cma_configfs_params_put(struct cma_device *cma_dev)
{
        cma_dev_put(cma_dev);
}

static ssize_t default_roce_mode_show(struct config_item *item,
                                      char *buf)
{
        struct cma_device *cma_dev;
        struct cma_dev_port_group *group;
        int gid_type;
        ssize_t ret;

        ret = cma_configfs_params_get(item, &cma_dev, &group);
        if (ret)
                return ret;

        gid_type = cma_get_default_gid_type(cma_dev, group->port_num);
        cma_configfs_params_put(cma_dev);

        if (gid_type < 0)
                return gid_type;

        return sysfs_emit(buf, "%s\n", ib_cache_gid_type_str(gid_type));
}

static ssize_t default_roce_mode_store(struct config_item *item,
                                       const char *buf, size_t count)
{
        struct cma_device *cma_dev;
        struct cma_dev_port_group *group;
        int gid_type;
        ssize_t ret;

        ret = cma_configfs_params_get(item, &cma_dev, &group);
        if (ret)
                return ret;

        gid_type = ib_cache_gid_parse_type_str(buf);
        if (gid_type < 0) {
                cma_configfs_params_put(cma_dev);
                return -EINVAL;
        }

        ret = cma_set_default_gid_type(cma_dev, group->port_num, gid_type);

        cma_configfs_params_put(cma_dev);

        return !ret ? strnlen(buf, count) : ret;
}

CONFIGFS_ATTR(, default_roce_mode);

static ssize_t default_roce_tos_show(struct config_item *item, char *buf)
{
        struct cma_device *cma_dev;
        struct cma_dev_port_group *group;
        ssize_t ret;
        u8 tos;

        ret = cma_configfs_params_get(item, &cma_dev, &group);
        if (ret)
                return ret;

        tos = cma_get_default_roce_tos(cma_dev, group->port_num);
        cma_configfs_params_put(cma_dev);

        return sysfs_emit(buf, "%u\n", tos);
}

static ssize_t default_roce_tos_store(struct config_item *item,
                                      const char *buf, size_t count)
{
        struct cma_device *cma_dev;
        struct cma_dev_port_group *group;
        ssize_t ret;
        u8 tos;

        ret = kstrtou8(buf, 0, &tos);
        if (ret)
                return ret;

        ret = cma_configfs_params_get(item, &cma_dev, &group);
        if (ret)
                return ret;

        ret = cma_set_default_roce_tos(cma_dev, group->port_num, tos);
        cma_configfs_params_put(cma_dev);

        return ret ? ret : strnlen(buf, count);
}

CONFIGFS_ATTR(, default_roce_tos);

static struct configfs_attribute *cma_configfs_attributes[] = {
        &attr_default_roce_mode,
        &attr_default_roce_tos,
        NULL,
};

static const struct config_item_type cma_port_group_type = {
        .ct_attrs       = cma_configfs_attributes,
        .ct_owner       = THIS_MODULE
};

static int make_cma_ports(struct cma_dev_group *cma_dev_group,
                          struct cma_device *cma_dev)
{
        struct cma_dev_port_group *ports;
        struct ib_device *ibdev;
        u32 ports_num;
        u32 i;

        ibdev = cma_get_ib_dev(cma_dev);

        if (!ibdev)
                return -ENODEV;

        ports_num = ibdev->phys_port_cnt;
        ports = kcalloc(ports_num, sizeof(*cma_dev_group->ports),
                        GFP_KERNEL);

        if (!ports)
                return -ENOMEM;

        for (i = 0; i < ports_num; i++) {
                char port_str[10];

                ports[i].port_num = i + 1;
                snprintf(port_str, sizeof(port_str), "%u", i + 1);
                ports[i].cma_dev_group = cma_dev_group;
                config_group_init_type_name(&ports[i].group,
                                            port_str,
                                            &cma_port_group_type);
                configfs_add_default_group(&ports[i].group,
                                &cma_dev_group->ports_group);

        }
        cma_dev_group->ports = ports;
        return 0;
}

static void release_cma_dev(struct config_item  *item)
{
        struct config_group *group = container_of(item, struct config_group,
                                                  cg_item);
        struct cma_dev_group *cma_dev_group = container_of(group,
                                                           struct cma_dev_group,
                                                           device_group);

        kfree(cma_dev_group);
};

static void release_cma_ports_group(struct config_item  *item)
{
        struct config_group *group = container_of(item, struct config_group,
                                                  cg_item);
        struct cma_dev_group *cma_dev_group = container_of(group,
                                                           struct cma_dev_group,
                                                           ports_group);

        kfree(cma_dev_group->ports);
        cma_dev_group->ports = NULL;
};

static struct configfs_item_operations cma_ports_item_ops = {
        .release = release_cma_ports_group
};

static const struct config_item_type cma_ports_group_type = {
        .ct_item_ops    = &cma_ports_item_ops,
        .ct_owner       = THIS_MODULE
};

static struct configfs_item_operations cma_device_item_ops = {
        .release = release_cma_dev
};

static const struct config_item_type cma_device_group_type = {
        .ct_item_ops    = &cma_device_item_ops,
        .ct_owner       = THIS_MODULE
};

static struct config_group *make_cma_dev(struct config_group *group,
                                         const char *name)
{
        int err = -ENODEV;
        struct cma_device *cma_dev = cma_enum_devices_by_ibdev(filter_by_name,
                                                               (void *)name);
        struct cma_dev_group *cma_dev_group = NULL;

        if (!cma_dev)
                goto fail;

        cma_dev_group = kzalloc(sizeof(*cma_dev_group), GFP_KERNEL);

        if (!cma_dev_group) {
                err = -ENOMEM;
                goto fail;
        }

        strlcpy(cma_dev_group->name, name, sizeof(cma_dev_group->name));

        config_group_init_type_name(&cma_dev_group->ports_group, "ports",
                                    &cma_ports_group_type);

        err = make_cma_ports(cma_dev_group, cma_dev);
        if (err)
                goto fail;

        config_group_init_type_name(&cma_dev_group->device_group, name,
                                    &cma_device_group_type);
        configfs_add_default_group(&cma_dev_group->ports_group,
                        &cma_dev_group->device_group);

        cma_dev_put(cma_dev);
        return &cma_dev_group->device_group;

fail:
        if (cma_dev)
                cma_dev_put(cma_dev);
        kfree(cma_dev_group);
        return ERR_PTR(err);
}

static void drop_cma_dev(struct config_group *cgroup, struct config_item *item)
{
        struct config_group *group =
                container_of(item, struct config_group, cg_item);
        struct cma_dev_group *cma_dev_group =
                container_of(group, struct cma_dev_group, device_group);

        configfs_remove_default_groups(&cma_dev_group->ports_group);
        configfs_remove_default_groups(&cma_dev_group->device_group);
        config_item_put(item);
}

static struct configfs_group_operations cma_subsys_group_ops = {
        .make_group     = make_cma_dev,
        .drop_item      = drop_cma_dev,
};

static const struct config_item_type cma_subsys_type = {
        .ct_group_ops   = &cma_subsys_group_ops,
        .ct_owner       = THIS_MODULE,
};

static struct configfs_subsystem cma_subsys = {
        .su_group       = {
                .cg_item        = {
                        .ci_namebuf     = "rdma_cm",
                        .ci_type        = &cma_subsys_type,
                },
        },
};

int __init cma_configfs_init(void)
{
        int ret;

        config_group_init(&cma_subsys.su_group);
        mutex_init(&cma_subsys.su_mutex);
        ret = configfs_register_subsystem(&cma_subsys);
        if (ret)
                mutex_destroy(&cma_subsys.su_mutex);
        return ret;
}

void __exit cma_configfs_exit(void)
{
        configfs_unregister_subsystem(&cma_subsys);
        mutex_destroy(&cma_subsys.su_mutex);
}