/**********************************************************************
 * Author: Cavium, Inc.
 *
 * Contact: support@cavium.com
 *          Please include "LiquidIO" in the subject.
 *
 * Copyright (c) 2003-2016 Cavium, Inc.
 *
 * This file is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, Version 2, as
 * published by the Free Software Foundation.
 *
 * This file is distributed in the hope that it will be useful, but
 * AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
 * NONINFRINGEMENT.  See the GNU General Public License for more details.
 ***********************************************************************/
#include <linux/pci.h>
#include <linux/netdevice.h>
#include "liquidio_common.h"
#include "octeon_droq.h"
#include "octeon_iq.h"
#include "response_manager.h"
#include "octeon_device.h"
#include "octeon_main.h"
#include "octeon_mailbox.h"
#include "cn23xx_pf_device.h"

/**
 * octeon_mbox_read:
 * @mbox: Pointer mailbox
 *
 * Reads the 8-bytes of data from the mbox register
 * Writes back the acknowldgement inidcating completion of read
 */
int octeon_mbox_read(struct octeon_mbox *mbox)
{
        union octeon_mbox_message msg;
        int ret = 0;

        spin_lock(&mbox->lock);

        msg.u64 = readq(mbox->mbox_read_reg);

        if ((msg.u64 == OCTEON_PFVFACK) || (msg.u64 == OCTEON_PFVFSIG)) {
                spin_unlock(&mbox->lock);
                return 0;
        }

        if (mbox->state & OCTEON_MBOX_STATE_REQUEST_RECEIVING) {
                mbox->mbox_req.data[mbox->mbox_req.recv_len - 1] = msg.u64;
                mbox->mbox_req.recv_len++;
        } else {
                if (mbox->state & OCTEON_MBOX_STATE_RESPONSE_RECEIVING) {
                        mbox->mbox_resp.data[mbox->mbox_resp.recv_len - 1] =
                                msg.u64;
                        mbox->mbox_resp.recv_len++;
                } else {
                        if ((mbox->state & OCTEON_MBOX_STATE_IDLE) &&
                            (msg.s.type == OCTEON_MBOX_REQUEST)) {
                                mbox->state &= ~OCTEON_MBOX_STATE_IDLE;
                                mbox->state |=
                                    OCTEON_MBOX_STATE_REQUEST_RECEIVING;
                                mbox->mbox_req.msg.u64 = msg.u64;
                                mbox->mbox_req.q_no = mbox->q_no;
                                mbox->mbox_req.recv_len = 1;
                        } else {
                                if ((mbox->state &
                                     OCTEON_MBOX_STATE_RESPONSE_PENDING) &&
                                    (msg.s.type == OCTEON_MBOX_RESPONSE)) {
                                        mbox->state &=
                                            ~OCTEON_MBOX_STATE_RESPONSE_PENDING;
                                        mbox->state |=
                                            OCTEON_MBOX_STATE_RESPONSE_RECEIVING
                                            ;
                                        mbox->mbox_resp.msg.u64 = msg.u64;
                                        mbox->mbox_resp.q_no = mbox->q_no;
                                        mbox->mbox_resp.recv_len = 1;
                                } else {
                                        writeq(OCTEON_PFVFERR,
                                               mbox->mbox_read_reg);
                                        mbox->state |= OCTEON_MBOX_STATE_ERROR;
                                        spin_unlock(&mbox->lock);
                                        return 1;
                                }
                        }
                }
        }

        if (mbox->state & OCTEON_MBOX_STATE_REQUEST_RECEIVING) {
                if (mbox->mbox_req.recv_len < mbox->mbox_req.msg.s.len) {
                        ret = 0;
                } else {
                        mbox->state &= ~OCTEON_MBOX_STATE_REQUEST_RECEIVING;
                        mbox->state |= OCTEON_MBOX_STATE_REQUEST_RECEIVED;
                        ret = 1;
                }
        } else {
                if (mbox->state & OCTEON_MBOX_STATE_RESPONSE_RECEIVING) {
                        if (mbox->mbox_resp.recv_len <
                            mbox->mbox_resp.msg.s.len) {
                                ret = 0;
                        } else {
                                mbox->state &=
                                    ~OCTEON_MBOX_STATE_RESPONSE_RECEIVING;
                                mbox->state |=
                                    OCTEON_MBOX_STATE_RESPONSE_RECEIVED;
                                ret = 1;
                        }
                } else {
                        WARN_ON(1);
                }
        }

        writeq(OCTEON_PFVFACK, mbox->mbox_read_reg);

        spin_unlock(&mbox->lock);

        return ret;
}

/**
 * octeon_mbox_write:
 * @oct: Pointer Octeon Device
 * @mbox_cmd: Cmd to send to mailbox.
 *
 * Populates the queue specific mbox structure
 * with cmd information.
 * Write the cmd to mbox register
 */
int octeon_mbox_write(struct octeon_device *oct,
                      struct octeon_mbox_cmd *mbox_cmd)
{
        struct octeon_mbox *mbox = oct->mbox[mbox_cmd->q_no];
        u32 count, i, ret = OCTEON_MBOX_STATUS_SUCCESS;
        long timeout = LIO_MBOX_WRITE_WAIT_TIME;
        unsigned long flags;

        spin_lock_irqsave(&mbox->lock, flags);

        if ((mbox_cmd->msg.s.type == OCTEON_MBOX_RESPONSE) &&
            !(mbox->state & OCTEON_MBOX_STATE_REQUEST_RECEIVED)) {
                spin_unlock_irqrestore(&mbox->lock, flags);
                return OCTEON_MBOX_STATUS_FAILED;
        }

        if ((mbox_cmd->msg.s.type == OCTEON_MBOX_REQUEST) &&
            !(mbox->state & OCTEON_MBOX_STATE_IDLE)) {
                spin_unlock_irqrestore(&mbox->lock, flags);
                return OCTEON_MBOX_STATUS_BUSY;
        }

        if (mbox_cmd->msg.s.type == OCTEON_MBOX_REQUEST) {
                memcpy(&mbox->mbox_resp, mbox_cmd,
                       sizeof(struct octeon_mbox_cmd));
                mbox->state = OCTEON_MBOX_STATE_RESPONSE_PENDING;
        }

        spin_unlock_irqrestore(&mbox->lock, flags);

        count = 0;

        while (readq(mbox->mbox_write_reg) != OCTEON_PFVFSIG) {
                schedule_timeout_uninterruptible(timeout);
                if (count++ == LIO_MBOX_WRITE_WAIT_CNT) {
                        ret = OCTEON_MBOX_STATUS_FAILED;
                        break;
                }
        }

        if (ret == OCTEON_MBOX_STATUS_SUCCESS) {
                writeq(mbox_cmd->msg.u64, mbox->mbox_write_reg);
                for (i = 0; i < (u32)(mbox_cmd->msg.s.len - 1); i++) {
                        count = 0;
                        while (readq(mbox->mbox_write_reg) !=
                               OCTEON_PFVFACK) {
                                schedule_timeout_uninterruptible(timeout);
                                if (count++ == LIO_MBOX_WRITE_WAIT_CNT) {
                                        ret = OCTEON_MBOX_STATUS_FAILED;
                                        break;
                                }
                        }
                        if (ret == OCTEON_MBOX_STATUS_SUCCESS)
                                writeq(mbox_cmd->data[i], mbox->mbox_write_reg);
                        else
                                break;
                }
        }

        spin_lock_irqsave(&mbox->lock, flags);
        if (mbox_cmd->msg.s.type == OCTEON_MBOX_RESPONSE) {
                mbox->state = OCTEON_MBOX_STATE_IDLE;
                writeq(OCTEON_PFVFSIG, mbox->mbox_read_reg);
        } else {
                if ((!mbox_cmd->msg.s.resp_needed) ||
                    (ret == OCTEON_MBOX_STATUS_FAILED)) {
                        mbox->state &= ~OCTEON_MBOX_STATE_RESPONSE_PENDING;
                        if (!(mbox->state &
                              (OCTEON_MBOX_STATE_REQUEST_RECEIVING |
                               OCTEON_MBOX_STATE_REQUEST_RECEIVED)))
                                mbox->state = OCTEON_MBOX_STATE_IDLE;
                }
        }
        spin_unlock_irqrestore(&mbox->lock, flags);

        return ret;
}

static void get_vf_stats(struct octeon_device *oct,
                         struct oct_vf_stats *stats)
{
        int i;

        for (i = 0; i < oct->num_iqs; i++) {
                if (!oct->instr_queue[i])
                        continue;
                stats->tx_packets += oct->instr_queue[i]->stats.tx_done;
                stats->tx_bytes += oct->instr_queue[i]->stats.tx_tot_bytes;
        }

        for (i = 0; i < oct->num_oqs; i++) {
                if (!oct->droq[i])
                        continue;
                stats->rx_packets += oct->droq[i]->stats.rx_pkts_received;
                stats->rx_bytes += oct->droq[i]->stats.rx_bytes_received;
        }
}

/**
 * octeon_mbox_process_cmd:
 * @mbox: Pointer mailbox
 * @mbox_cmd: Pointer to command received
 *
 * Process the cmd received in mbox
 */
static int octeon_mbox_process_cmd(struct octeon_mbox *mbox,
                                   struct octeon_mbox_cmd *mbox_cmd)
{
        struct octeon_device *oct = mbox->oct_dev;

        switch (mbox_cmd->msg.s.cmd) {
        case OCTEON_VF_ACTIVE:
                dev_dbg(&oct->pci_dev->dev, "got vfactive sending data back\n");
                mbox_cmd->msg.s.type = OCTEON_MBOX_RESPONSE;
                mbox_cmd->msg.s.resp_needed = 1;
                mbox_cmd->msg.s.len = 2;
                mbox_cmd->data[0] = 0; /* VF version is in mbox_cmd->data[0] */
                ((struct lio_version *)&mbox_cmd->data[0])->major =
                        LIQUIDIO_BASE_MAJOR_VERSION;
                ((struct lio_version *)&mbox_cmd->data[0])->minor =
                        LIQUIDIO_BASE_MINOR_VERSION;
                ((struct lio_version *)&mbox_cmd->data[0])->micro =
                        LIQUIDIO_BASE_MICRO_VERSION;
                memcpy(mbox_cmd->msg.s.params, (uint8_t *)&oct->pfvf_hsword, 6);
                /* Sending core cofig info to the corresponding active VF.*/
                octeon_mbox_write(oct, mbox_cmd);
                break;

        case OCTEON_VF_FLR_REQUEST:
                dev_info(&oct->pci_dev->dev,
                         "got a request for FLR from VF that owns DPI ring %u\n",
                         mbox->q_no);
                pcie_flr(oct->sriov_info.dpiring_to_vfpcidev_lut[mbox->q_no]);
                break;

        case OCTEON_PF_CHANGED_VF_MACADDR:
                if (OCTEON_CN23XX_VF(oct))
                        octeon_pf_changed_vf_macaddr(oct,
                                                     mbox_cmd->msg.s.params);
                break;

        case OCTEON_GET_VF_STATS:
                dev_dbg(&oct->pci_dev->dev, "Got VF stats request. Sending data back\n");
                mbox_cmd->msg.s.type = OCTEON_MBOX_RESPONSE;
                mbox_cmd->msg.s.resp_needed = 1;
                mbox_cmd->msg.s.len = 1 +
                        sizeof(struct oct_vf_stats) / sizeof(u64);
                get_vf_stats(oct, (struct oct_vf_stats *)mbox_cmd->data);
                octeon_mbox_write(oct, mbox_cmd);
                break;
        default:
                break;
        }
        return 0;
}

/**
 * octeon_mbox_process_message
 * @mbox: mailbox
 *
 * Process the received mbox message.
 */
int octeon_mbox_process_message(struct octeon_mbox *mbox)
{
        struct octeon_mbox_cmd mbox_cmd;
        unsigned long flags;

        spin_lock_irqsave(&mbox->lock, flags);

        if (mbox->state & OCTEON_MBOX_STATE_ERROR) {
                if (mbox->state & (OCTEON_MBOX_STATE_RESPONSE_PENDING |
                                   OCTEON_MBOX_STATE_RESPONSE_RECEIVING)) {
                        memcpy(&mbox_cmd, &mbox->mbox_resp,
                               sizeof(struct octeon_mbox_cmd));
                        mbox->state = OCTEON_MBOX_STATE_IDLE;
                        writeq(OCTEON_PFVFSIG, mbox->mbox_read_reg);
                        spin_unlock_irqrestore(&mbox->lock, flags);
                        mbox_cmd.recv_status = 1;
                        if (mbox_cmd.fn)
                                mbox_cmd.fn(mbox->oct_dev, &mbox_cmd,
                                            mbox_cmd.fn_arg);
                        return 0;
                }

                mbox->state = OCTEON_MBOX_STATE_IDLE;
                writeq(OCTEON_PFVFSIG, mbox->mbox_read_reg);
                spin_unlock_irqrestore(&mbox->lock, flags);
                return 0;
        }

        if (mbox->state & OCTEON_MBOX_STATE_RESPONSE_RECEIVED) {
                memcpy(&mbox_cmd, &mbox->mbox_resp,
                       sizeof(struct octeon_mbox_cmd));
                mbox->state = OCTEON_MBOX_STATE_IDLE;
                writeq(OCTEON_PFVFSIG, mbox->mbox_read_reg);
                spin_unlock_irqrestore(&mbox->lock, flags);
                mbox_cmd.recv_status = 0;
                if (mbox_cmd.fn)
                        mbox_cmd.fn(mbox->oct_dev, &mbox_cmd, mbox_cmd.fn_arg);
                return 0;
        }

        if (mbox->state & OCTEON_MBOX_STATE_REQUEST_RECEIVED) {
                memcpy(&mbox_cmd, &mbox->mbox_req,
                       sizeof(struct octeon_mbox_cmd));
                if (!mbox_cmd.msg.s.resp_needed) {
                        mbox->state &= ~OCTEON_MBOX_STATE_REQUEST_RECEIVED;
                        if (!(mbox->state &
                              OCTEON_MBOX_STATE_RESPONSE_PENDING))
                                mbox->state = OCTEON_MBOX_STATE_IDLE;
                        writeq(OCTEON_PFVFSIG, mbox->mbox_read_reg);
                }

                spin_unlock_irqrestore(&mbox->lock, flags);
                octeon_mbox_process_cmd(mbox, &mbox_cmd);
                return 0;
        }

        spin_unlock_irqrestore(&mbox->lock, flags);
        WARN_ON(1);

        return 0;
}

int octeon_mbox_cancel(struct octeon_device *oct, int q_no)
{
        struct octeon_mbox *mbox = oct->mbox[q_no];
        struct octeon_mbox_cmd *mbox_cmd;
        unsigned long flags = 0;

        spin_lock_irqsave(&mbox->lock, flags);
        mbox_cmd = &mbox->mbox_resp;

        if (!(mbox->state & OCTEON_MBOX_STATE_RESPONSE_PENDING)) {
                spin_unlock_irqrestore(&mbox->lock, flags);
                return 1;
        }

        mbox->state = OCTEON_MBOX_STATE_IDLE;
        memset(mbox_cmd, 0, sizeof(*mbox_cmd));
        writeq(OCTEON_PFVFSIG, mbox->mbox_read_reg);
        spin_unlock_irqrestore(&mbox->lock, flags);

        return 0;
}