/*
 * Copyright(c) 2017 Intel Corporation.
 *
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * BSD LICENSE
 *
 * 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.
 *  - Neither the name of Intel Corporation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 THE COPYRIGHT
 * OWNER 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.
 *
 */

/*
 * This file contains OPA Virtual Network Interface Controller (VNIC) driver
 * netdev functionality.
 */

#include <linux/if_vlan.h>
#include <linux/crc32.h>

#include "opa_vnic_internal.h"

#define OPA_TX_TIMEOUT_MS 1000

#define OPA_VNIC_SKB_HEADROOM  \
                        ALIGN((OPA_VNIC_HDR_LEN + OPA_VNIC_SKB_MDATA_LEN), 8)

/* This function is overloaded for opa_vnic specific implementation */
static void opa_vnic_get_stats64(struct net_device *netdev,
                                 struct rtnl_link_stats64 *stats)
{
        struct opa_vnic_adapter *adapter = opa_vnic_priv(netdev);
        struct opa_vnic_stats vstats;

        memset(&vstats, 0, sizeof(vstats));
        spin_lock(&adapter->stats_lock);
        adapter->rn_ops->ndo_get_stats64(netdev, &vstats.netstats);
        spin_unlock(&adapter->stats_lock);
        memcpy(stats, &vstats.netstats, sizeof(*stats));
}

/* opa_netdev_start_xmit - transmit function */
static netdev_tx_t opa_netdev_start_xmit(struct sk_buff *skb,
                                         struct net_device *netdev)
{
        struct opa_vnic_adapter *adapter = opa_vnic_priv(netdev);

        v_dbg("xmit: queue %d skb len %d\n", skb->queue_mapping, skb->len);
        /* pad to ensure mininum ethernet packet length */
        if (unlikely(skb->len < ETH_ZLEN)) {
                if (skb_padto(skb, ETH_ZLEN))
                        return NETDEV_TX_OK;

                skb_put(skb, ETH_ZLEN - skb->len);
        }

        opa_vnic_encap_skb(adapter, skb);
        return adapter->rn_ops->ndo_start_xmit(skb, netdev);
}

static u16 opa_vnic_select_queue(struct net_device *netdev, struct sk_buff *skb,
                                 struct net_device *sb_dev)
{
        struct opa_vnic_adapter *adapter = opa_vnic_priv(netdev);
        struct opa_vnic_skb_mdata *mdata;
        int rc;

        /* pass entropy and vl as metadata in skb */
        mdata = skb_push(skb, sizeof(*mdata));
        mdata->entropy = opa_vnic_calc_entropy(skb);
        mdata->vl = opa_vnic_get_vl(adapter, skb);
        rc = adapter->rn_ops->ndo_select_queue(netdev, skb, sb_dev);
        skb_pull(skb, sizeof(*mdata));
        return rc;
}

static void opa_vnic_update_state(struct opa_vnic_adapter *adapter, bool up)
{
        struct __opa_veswport_info *info = &adapter->info;

        mutex_lock(&adapter->lock);
        /* Operational state can only be DROP_ALL or FORWARDING */
        if ((info->vport.config_state == OPA_VNIC_STATE_FORWARDING) && up) {
                info->vport.oper_state = OPA_VNIC_STATE_FORWARDING;
                info->vport.eth_link_status = OPA_VNIC_ETH_LINK_UP;
        } else {
                info->vport.oper_state = OPA_VNIC_STATE_DROP_ALL;
                info->vport.eth_link_status = OPA_VNIC_ETH_LINK_DOWN;
        }

        if (info->vport.config_state == OPA_VNIC_STATE_FORWARDING)
                netif_dormant_off(adapter->netdev);
        else
                netif_dormant_on(adapter->netdev);
        mutex_unlock(&adapter->lock);
}

/* opa_vnic_process_vema_config - process vema configuration updates */
void opa_vnic_process_vema_config(struct opa_vnic_adapter *adapter)
{
        struct __opa_veswport_info *info = &adapter->info;
        struct rdma_netdev *rn = netdev_priv(adapter->netdev);
        u8 port_num[OPA_VESW_MAX_NUM_DEF_PORT] = { 0 };
        struct net_device *netdev = adapter->netdev;
        u8 i, port_count = 0;
        u16 port_mask;

        /* If the base_mac_addr is changed, update the interface mac address */
        if (memcmp(info->vport.base_mac_addr, adapter->vema_mac_addr,
                   ARRAY_SIZE(info->vport.base_mac_addr))) {
                struct sockaddr saddr;

                memcpy(saddr.sa_data, info->vport.base_mac_addr,
                       ARRAY_SIZE(info->vport.base_mac_addr));
                mutex_lock(&adapter->lock);
                eth_commit_mac_addr_change(netdev, &saddr);
                memcpy(adapter->vema_mac_addr,
                       info->vport.base_mac_addr, ETH_ALEN);
                mutex_unlock(&adapter->lock);
        }

        rn->set_id(netdev, info->vesw.vesw_id);

        /* Handle MTU limit change */
        rtnl_lock();
        netdev->max_mtu = max_t(unsigned int, info->vesw.eth_mtu,
                                netdev->min_mtu);
        if (netdev->mtu > netdev->max_mtu)
                dev_set_mtu(netdev, netdev->max_mtu);
        rtnl_unlock();

        /* Update flow to default port redirection table */
        port_mask = info->vesw.def_port_mask;
        for (i = 0; i < OPA_VESW_MAX_NUM_DEF_PORT; i++) {
                if (port_mask & 1)
                        port_num[port_count++] = i;
                port_mask >>= 1;
        }

        /*
         * Build the flow table. Flow table is required when destination LID
         * is not available. Up to OPA_VNIC_FLOW_TBL_SIZE flows supported.
         * Each flow need a default port number to get its dlid from the
         * u_ucast_dlid array.
         */
        for (i = 0; i < OPA_VNIC_FLOW_TBL_SIZE; i++)
                adapter->flow_tbl[i] = port_count ? port_num[i % port_count] :
                                                    OPA_VNIC_INVALID_PORT;

        /* update state */
        opa_vnic_update_state(adapter, !!(netdev->flags & IFF_UP));
}

/*
 * Set the power on default values in adapter's vema interface structure.
 */
static inline void opa_vnic_set_pod_values(struct opa_vnic_adapter *adapter)
{
        adapter->info.vport.max_mac_tbl_ent = OPA_VNIC_MAC_TBL_MAX_ENTRIES;
        adapter->info.vport.max_smac_ent = OPA_VNIC_MAX_SMAC_LIMIT;
        adapter->info.vport.config_state = OPA_VNIC_STATE_DROP_ALL;
        adapter->info.vport.eth_link_status = OPA_VNIC_ETH_LINK_DOWN;
        adapter->info.vesw.eth_mtu = ETH_DATA_LEN;
}

/* opa_vnic_set_mac_addr - change mac address */
static int opa_vnic_set_mac_addr(struct net_device *netdev, void *addr)
{
        struct opa_vnic_adapter *adapter = opa_vnic_priv(netdev);
        struct sockaddr *sa = addr;
        int rc;

        if (!memcmp(netdev->dev_addr, sa->sa_data, ETH_ALEN))
                return 0;

        mutex_lock(&adapter->lock);
        rc = eth_mac_addr(netdev, addr);
        mutex_unlock(&adapter->lock);
        if (rc)
                return rc;

        adapter->info.vport.uc_macs_gen_count++;
        opa_vnic_vema_report_event(adapter,
                                   OPA_VESWPORT_TRAP_IFACE_UCAST_MAC_CHANGE);
        return 0;
}

/*
 * opa_vnic_mac_send_event - post event on possible mac list exchange
 *  Send trap when digest from uc/mc mac list differs from previous run.
 *  Digest is evaluated similar to how cksum does.
 */
static void opa_vnic_mac_send_event(struct net_device *netdev, u8 event)
{
        struct opa_vnic_adapter *adapter = opa_vnic_priv(netdev);
        struct netdev_hw_addr *ha;
        struct netdev_hw_addr_list *hw_list;
        u32 *ref_crc;
        u32 l, crc = 0;

        switch (event) {
        case OPA_VESWPORT_TRAP_IFACE_UCAST_MAC_CHANGE:
                hw_list = &netdev->uc;
                adapter->info.vport.uc_macs_gen_count++;
                ref_crc = &adapter->umac_hash;
                break;
        case OPA_VESWPORT_TRAP_IFACE_MCAST_MAC_CHANGE:
                hw_list = &netdev->mc;
                adapter->info.vport.mc_macs_gen_count++;
                ref_crc = &adapter->mmac_hash;
                break;
        default:
                return;
        }
        netdev_hw_addr_list_for_each(ha, hw_list) {
                crc = crc32_le(crc, ha->addr, ETH_ALEN);
        }
        l = netdev_hw_addr_list_count(hw_list) * ETH_ALEN;
        crc = ~crc32_le(crc, (void *)&l, sizeof(l));

        if (crc != *ref_crc) {
                *ref_crc = crc;
                opa_vnic_vema_report_event(adapter, event);
        }
}

/* opa_vnic_set_rx_mode - handle uc/mc mac list change */
static void opa_vnic_set_rx_mode(struct net_device *netdev)
{
        opa_vnic_mac_send_event(netdev,
                                OPA_VESWPORT_TRAP_IFACE_UCAST_MAC_CHANGE);

        opa_vnic_mac_send_event(netdev,
                                OPA_VESWPORT_TRAP_IFACE_MCAST_MAC_CHANGE);
}

/* opa_netdev_open - activate network interface */
static int opa_netdev_open(struct net_device *netdev)
{
        struct opa_vnic_adapter *adapter = opa_vnic_priv(netdev);
        int rc;

        rc = adapter->rn_ops->ndo_open(adapter->netdev);
        if (rc) {
                v_dbg("open failed %d\n", rc);
                return rc;
        }

        /* Update status and send trap */
        opa_vnic_update_state(adapter, true);
        opa_vnic_vema_report_event(adapter,
                                   OPA_VESWPORT_TRAP_ETH_LINK_STATUS_CHANGE);
        return 0;
}

/* opa_netdev_close - disable network interface */
static int opa_netdev_close(struct net_device *netdev)
{
        struct opa_vnic_adapter *adapter = opa_vnic_priv(netdev);
        int rc;

        rc = adapter->rn_ops->ndo_stop(adapter->netdev);
        if (rc) {
                v_dbg("close failed %d\n", rc);
                return rc;
        }

        /* Update status and send trap */
        opa_vnic_update_state(adapter, false);
        opa_vnic_vema_report_event(adapter,
                                   OPA_VESWPORT_TRAP_ETH_LINK_STATUS_CHANGE);
        return 0;
}

/* netdev ops */
static const struct net_device_ops opa_netdev_ops = {
        .ndo_open = opa_netdev_open,
        .ndo_stop = opa_netdev_close,
        .ndo_start_xmit = opa_netdev_start_xmit,
        .ndo_get_stats64 = opa_vnic_get_stats64,
        .ndo_set_rx_mode = opa_vnic_set_rx_mode,
        .ndo_select_queue = opa_vnic_select_queue,
        .ndo_set_mac_address = opa_vnic_set_mac_addr,
};

/* opa_vnic_add_netdev - create vnic netdev interface */
struct opa_vnic_adapter *opa_vnic_add_netdev(struct ib_device *ibdev,
                                             u8 port_num, u8 vport_num)
{
        struct opa_vnic_adapter *adapter;
        struct net_device *netdev;
        struct rdma_netdev *rn;
        int rc;

        netdev = ibdev->ops.alloc_rdma_netdev(ibdev, port_num,
                                              RDMA_NETDEV_OPA_VNIC,
                                              "veth%d", NET_NAME_UNKNOWN,
                                              ether_setup);
        if (!netdev)
                return ERR_PTR(-ENOMEM);
        else if (IS_ERR(netdev))
                return ERR_CAST(netdev);

        rn = netdev_priv(netdev);
        adapter = kzalloc_obj(*adapter);
        if (!adapter) {
                rc = -ENOMEM;
                goto adapter_err;
        }

        rn->clnt_priv = adapter;
        rn->hca = ibdev;
        rn->port_num = port_num;
        adapter->netdev = netdev;
        adapter->ibdev = ibdev;
        adapter->port_num = port_num;
        adapter->vport_num = vport_num;
        adapter->rn_ops = netdev->netdev_ops;

        netdev->netdev_ops = &opa_netdev_ops;
        netdev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
        netdev->hard_header_len += OPA_VNIC_SKB_HEADROOM;
        mutex_init(&adapter->lock);
        mutex_init(&adapter->mactbl_lock);
        spin_lock_init(&adapter->stats_lock);

        SET_NETDEV_DEV(netdev, ibdev->dev.parent);

        opa_vnic_set_ethtool_ops(netdev);

        opa_vnic_set_pod_values(adapter);

        rc = register_netdev(netdev);
        if (rc)
                goto netdev_err;

        netif_carrier_off(netdev);
        netif_dormant_on(netdev);
        v_info("initialized\n");

        return adapter;
netdev_err:
        mutex_destroy(&adapter->lock);
        mutex_destroy(&adapter->mactbl_lock);
        kfree(adapter);
adapter_err:
        rn->free_rdma_netdev(netdev);

        return ERR_PTR(rc);
}

/* opa_vnic_rem_netdev - remove vnic netdev interface */
void opa_vnic_rem_netdev(struct opa_vnic_adapter *adapter)
{
        struct net_device *netdev = adapter->netdev;
        struct rdma_netdev *rn = netdev_priv(netdev);

        v_info("removing\n");
        unregister_netdev(netdev);
        opa_vnic_release_mac_tbl(adapter);
        mutex_destroy(&adapter->lock);
        mutex_destroy(&adapter->mactbl_lock);
        kfree(adapter);
        rn->free_rdma_netdev(netdev);
}