/*
 * Copyright (c) 2013, Cisco Systems, 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
 * 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/netdevice.h>
#include <linux/pci.h>

#include "enic_api.h"
#include "usnic_common_pkt_hdr.h"
#include "usnic_fwd.h"
#include "usnic_log.h"

static int usnic_fwd_devcmd_locked(struct usnic_fwd_dev *ufdev, int vnic_idx,
                                        enum vnic_devcmd_cmd cmd, u64 *a0,
                                        u64 *a1)
{
        int status;
        struct net_device *netdev = ufdev->netdev;

        lockdep_assert_held(&ufdev->lock);

        status = enic_api_devcmd_proxy_by_index(netdev,
                        vnic_idx,
                        cmd,
                        a0, a1,
                        1000);
        if (status) {
                if (status == ERR_EINVAL && cmd == CMD_DEL_FILTER) {
                        usnic_dbg("Dev %s vnic idx %u cmd %u already deleted",
                                        ufdev->name, vnic_idx, cmd);
                } else {
                        usnic_err("Dev %s vnic idx %u cmd %u failed with status %d\n",
                                        ufdev->name, vnic_idx, cmd,
                                        status);
                }
        } else {
                usnic_dbg("Dev %s vnic idx %u cmd %u success",
                                ufdev->name, vnic_idx, cmd);
        }

        return status;
}

static int usnic_fwd_devcmd(struct usnic_fwd_dev *ufdev, int vnic_idx,
                                enum vnic_devcmd_cmd cmd, u64 *a0, u64 *a1)
{
        int status;

        spin_lock(&ufdev->lock);
        status = usnic_fwd_devcmd_locked(ufdev, vnic_idx, cmd, a0, a1);
        spin_unlock(&ufdev->lock);

        return status;
}

struct usnic_fwd_dev *usnic_fwd_dev_alloc(struct pci_dev *pdev)
{
        struct usnic_fwd_dev *ufdev;

        ufdev = kzalloc_obj(*ufdev);
        if (!ufdev)
                return NULL;

        ufdev->pdev = pdev;
        ufdev->netdev = pci_get_drvdata(pdev);
        spin_lock_init(&ufdev->lock);
        BUILD_BUG_ON(sizeof(ufdev->name) != sizeof(ufdev->netdev->name));
        strcpy(ufdev->name, ufdev->netdev->name);

        return ufdev;
}

void usnic_fwd_dev_free(struct usnic_fwd_dev *ufdev)
{
        kfree(ufdev);
}

void usnic_fwd_set_mac(struct usnic_fwd_dev *ufdev, const char mac[ETH_ALEN])
{
        spin_lock(&ufdev->lock);
        memcpy(&ufdev->mac, mac, sizeof(ufdev->mac));
        spin_unlock(&ufdev->lock);
}

void usnic_fwd_add_ipaddr(struct usnic_fwd_dev *ufdev, __be32 inaddr)
{
        spin_lock(&ufdev->lock);
        if (!ufdev->inaddr)
                ufdev->inaddr = inaddr;
        spin_unlock(&ufdev->lock);
}

void usnic_fwd_del_ipaddr(struct usnic_fwd_dev *ufdev)
{
        spin_lock(&ufdev->lock);
        ufdev->inaddr = 0;
        spin_unlock(&ufdev->lock);
}

void usnic_fwd_carrier_up(struct usnic_fwd_dev *ufdev)
{
        spin_lock(&ufdev->lock);
        ufdev->link_up = 1;
        spin_unlock(&ufdev->lock);
}

void usnic_fwd_carrier_down(struct usnic_fwd_dev *ufdev)
{
        spin_lock(&ufdev->lock);
        ufdev->link_up = 0;
        spin_unlock(&ufdev->lock);
}

void usnic_fwd_set_mtu(struct usnic_fwd_dev *ufdev, unsigned int mtu)
{
        spin_lock(&ufdev->lock);
        ufdev->mtu = mtu;
        spin_unlock(&ufdev->lock);
}

static int usnic_fwd_dev_ready_locked(struct usnic_fwd_dev *ufdev)
{
        lockdep_assert_held(&ufdev->lock);

        if (!ufdev->link_up)
                return -EPERM;

        return 0;
}

static int validate_filter_locked(struct usnic_fwd_dev *ufdev,
                                        struct filter *filter)
{

        lockdep_assert_held(&ufdev->lock);

        if (filter->type == FILTER_IPV4_5TUPLE) {
                if (!(filter->u.ipv4.flags & FILTER_FIELD_5TUP_DST_AD))
                        return -EACCES;
                if (!(filter->u.ipv4.flags & FILTER_FIELD_5TUP_DST_PT))
                        return -EBUSY;
                else if (ufdev->inaddr == 0)
                        return -EINVAL;
                else if (filter->u.ipv4.dst_port == 0)
                        return -ERANGE;
                else if (ntohl(ufdev->inaddr) != filter->u.ipv4.dst_addr)
                        return -EFAULT;
                else
                        return 0;
        }

        return 0;
}

static void fill_tlv(struct filter_tlv *tlv, struct filter *filter,
                struct filter_action *action)
{
        tlv->type = CLSF_TLV_FILTER;
        tlv->length = sizeof(struct filter);
        *((struct filter *)&tlv->val) = *filter;

        tlv = (struct filter_tlv *)((char *)tlv + sizeof(struct filter_tlv) +
                        sizeof(struct filter));
        tlv->type = CLSF_TLV_ACTION;
        tlv->length = sizeof(struct filter_action);
        *((struct filter_action *)&tlv->val) = *action;
}

struct usnic_fwd_flow*
usnic_fwd_alloc_flow(struct usnic_fwd_dev *ufdev, struct filter *filter,
                                struct usnic_filter_action *uaction)
{
        struct filter_tlv *tlv;
        struct pci_dev *pdev;
        struct usnic_fwd_flow *flow;
        uint64_t a0, a1;
        uint64_t tlv_size;
        dma_addr_t tlv_pa;
        int status;

        pdev = ufdev->pdev;
        tlv_size = (2*sizeof(struct filter_tlv) + sizeof(struct filter) +
                        sizeof(struct filter_action));

        flow = kzalloc_obj(*flow, GFP_ATOMIC);
        if (!flow)
                return ERR_PTR(-ENOMEM);

        tlv = dma_alloc_coherent(&pdev->dev, tlv_size, &tlv_pa, GFP_ATOMIC);
        if (!tlv) {
                usnic_err("Failed to allocate memory\n");
                status = -ENOMEM;
                goto out_free_flow;
        }

        fill_tlv(tlv, filter, &uaction->action);

        spin_lock(&ufdev->lock);
        status = usnic_fwd_dev_ready_locked(ufdev);
        if (status) {
                usnic_err("Forwarding dev %s not ready with status %d\n",
                                ufdev->name, status);
                goto out_free_tlv;
        }

        status = validate_filter_locked(ufdev, filter);
        if (status) {
                usnic_err("Failed to validate filter with status %d\n",
                                status);
                goto out_free_tlv;
        }

        /* Issue Devcmd */
        a0 = tlv_pa;
        a1 = tlv_size;
        status = usnic_fwd_devcmd_locked(ufdev, uaction->vnic_idx,
                                                CMD_ADD_FILTER, &a0, &a1);
        if (status) {
                usnic_err("VF %s Filter add failed with status:%d",
                                ufdev->name, status);
                status = -EFAULT;
                goto out_free_tlv;
        } else {
                usnic_dbg("VF %s FILTER ID:%llu", ufdev->name, a0);
        }

        flow->flow_id = (uint32_t) a0;
        flow->vnic_idx = uaction->vnic_idx;
        flow->ufdev = ufdev;

out_free_tlv:
        spin_unlock(&ufdev->lock);
        dma_free_coherent(&pdev->dev, tlv_size, tlv, tlv_pa);
        if (!status)
                return flow;
out_free_flow:
        kfree(flow);
        return ERR_PTR(status);
}

int usnic_fwd_dealloc_flow(struct usnic_fwd_flow *flow)
{
        int status;
        u64 a0, a1;

        a0 = flow->flow_id;

        status = usnic_fwd_devcmd(flow->ufdev, flow->vnic_idx,
                                        CMD_DEL_FILTER, &a0, &a1);
        if (status) {
                if (status == ERR_EINVAL) {
                        usnic_dbg("Filter %u already deleted for VF Idx %u pf: %s status: %d",
                                        flow->flow_id, flow->vnic_idx,
                                        flow->ufdev->name, status);
                } else {
                        usnic_err("PF %s VF Idx %u Filter: %u FILTER DELETE failed with status %d",
                                        flow->ufdev->name, flow->vnic_idx,
                                        flow->flow_id, status);
                }
                status = 0;
                /*
                 * Log the error and fake success to the caller because if
                 * a flow fails to be deleted in the firmware, it is an
                 * unrecoverable error.
                 */
        } else {
                usnic_dbg("PF %s VF Idx %u Filter: %u FILTER DELETED",
                                flow->ufdev->name, flow->vnic_idx,
                                flow->flow_id);
        }

        kfree(flow);
        return status;
}

int usnic_fwd_enable_qp(struct usnic_fwd_dev *ufdev, int vnic_idx, int qp_idx)
{
        int status;
        struct net_device *pf_netdev;
        u64 a0, a1;

        pf_netdev = ufdev->netdev;
        a0 = qp_idx;
        a1 = CMD_QP_RQWQ;

        status = usnic_fwd_devcmd(ufdev, vnic_idx, CMD_QP_ENABLE,
                                                &a0, &a1);
        if (status) {
                usnic_err("PF %s VNIC Index %u RQ Index: %u ENABLE Failed with status %d",
                                netdev_name(pf_netdev),
                                vnic_idx,
                                qp_idx,
                                status);
        } else {
                usnic_dbg("PF %s VNIC Index %u RQ Index: %u ENABLED",
                                netdev_name(pf_netdev),
                                vnic_idx, qp_idx);
        }

        return status;
}

int usnic_fwd_disable_qp(struct usnic_fwd_dev *ufdev, int vnic_idx, int qp_idx)
{
        int status;
        u64 a0, a1;
        struct net_device *pf_netdev;

        pf_netdev = ufdev->netdev;
        a0 = qp_idx;
        a1 = CMD_QP_RQWQ;

        status = usnic_fwd_devcmd(ufdev, vnic_idx, CMD_QP_DISABLE,
                        &a0, &a1);
        if (status) {
                usnic_err("PF %s VNIC Index %u RQ Index: %u DISABLE Failed with status %d",
                                netdev_name(pf_netdev),
                                vnic_idx,
                                qp_idx,
                                status);
        } else {
                usnic_dbg("PF %s VNIC Index %u RQ Index: %u DISABLED",
                                netdev_name(pf_netdev),
                                vnic_idx,
                                qp_idx);
        }

        return status;
}