/*
 * Copyright (C) 2016 Cavium, Inc.
 *
 * 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.
 */

#include "cptvf.h"

static void cptvf_send_msg_to_pf(struct cpt_vf *cptvf, struct cpt_mbox *mbx)
{
        /* Writing mbox(1) causes interrupt */
        cpt_write_csr64(cptvf->reg_base, CPTX_VFX_PF_MBOXX(0, 0, 0),
                        mbx->msg);
        cpt_write_csr64(cptvf->reg_base, CPTX_VFX_PF_MBOXX(0, 0, 1),
                        mbx->data);
}

/* ACKs PF's mailbox message
 */
void cptvf_mbox_send_ack(struct cpt_vf *cptvf, struct cpt_mbox *mbx)
{
        mbx->msg = CPT_MBOX_MSG_TYPE_ACK;
        cptvf_send_msg_to_pf(cptvf, mbx);
}

/* NACKs PF's mailbox message that VF is not able to
 * complete the action
 */
void cptvf_mbox_send_nack(struct cpt_vf *cptvf, struct cpt_mbox *mbx)
{
        mbx->msg = CPT_MBOX_MSG_TYPE_NACK;
        cptvf_send_msg_to_pf(cptvf, mbx);
}

/* Interrupt handler to handle mailbox messages from VFs */
void cptvf_handle_mbox_intr(struct cpt_vf *cptvf)
{
        struct cpt_mbox mbx = {};

        /*
         * MBOX[0] contains msg
         * MBOX[1] contains data
         */
        mbx.msg  = cpt_read_csr64(cptvf->reg_base, CPTX_VFX_PF_MBOXX(0, 0, 0));
        mbx.data = cpt_read_csr64(cptvf->reg_base, CPTX_VFX_PF_MBOXX(0, 0, 1));
        dev_dbg(&cptvf->pdev->dev, "%s: Mailbox msg 0x%llx from PF\n",
                __func__, mbx.msg);
        switch (mbx.msg) {
        case CPT_MSG_READY:
        {
                cptvf->pf_acked = true;
                cptvf->vfid = mbx.data;
                dev_dbg(&cptvf->pdev->dev, "Received VFID %d\n", cptvf->vfid);
                break;
        }
        case CPT_MSG_QBIND_GRP:
                cptvf->pf_acked = true;
                cptvf->vftype = mbx.data;
                dev_dbg(&cptvf->pdev->dev, "VF %d type %s group %d\n",
                        cptvf->vfid, ((mbx.data == SE_TYPES) ? "SE" : "AE"),
                        cptvf->vfgrp);
                break;
        case CPT_MBOX_MSG_TYPE_ACK:
                cptvf->pf_acked = true;
                break;
        case CPT_MBOX_MSG_TYPE_NACK:
                cptvf->pf_nacked = true;
                break;
        default:
                dev_err(&cptvf->pdev->dev, "Invalid msg from PF, msg 0x%llx\n",
                        mbx.msg);
                break;
        }
}

static int cptvf_send_msg_to_pf_timeout(struct cpt_vf *cptvf,
                                        struct cpt_mbox *mbx)
{
        int timeout = CPT_MBOX_MSG_TIMEOUT;
        int sleep = 10;

        cptvf->pf_acked = false;
        cptvf->pf_nacked = false;
        cptvf_send_msg_to_pf(cptvf, mbx);
        /* Wait for previous message to be acked, timeout 2sec */
        while (!cptvf->pf_acked) {
                if (cptvf->pf_nacked)
                        return -EINVAL;
                msleep(sleep);
                if (cptvf->pf_acked)
                        break;
                timeout -= sleep;
                if (!timeout) {
                        dev_err(&cptvf->pdev->dev, "PF didn't ack to mbox msg %llx from VF%u\n",
                                (mbx->msg & 0xFF), cptvf->vfid);
                        return -EBUSY;
                }
        }

        return 0;
}

/*
 * Checks if VF is able to comminicate with PF
 * and also gets the CPT number this VF is associated to.
 */
int cptvf_check_pf_ready(struct cpt_vf *cptvf)
{
        struct pci_dev *pdev = cptvf->pdev;
        struct cpt_mbox mbx = {};

        mbx.msg = CPT_MSG_READY;
        if (cptvf_send_msg_to_pf_timeout(cptvf, &mbx)) {
                dev_err(&pdev->dev, "PF didn't respond to READY msg\n");
                return -EBUSY;
        }

        return 0;
}

/*
 * Communicate VQs size to PF to program CPT(0)_PF_Q(0-15)_CTL of the VF.
 * Must be ACKed.
 */
int cptvf_send_vq_size_msg(struct cpt_vf *cptvf)
{
        struct pci_dev *pdev = cptvf->pdev;
        struct cpt_mbox mbx = {};

        mbx.msg = CPT_MSG_QLEN;
        mbx.data = cptvf->qsize;
        if (cptvf_send_msg_to_pf_timeout(cptvf, &mbx)) {
                dev_err(&pdev->dev, "PF didn't respond to vq_size msg\n");
                return -EBUSY;
        }

        return 0;
}

/*
 * Communicate VF group required to PF and get the VQ binded to that group
 */
int cptvf_send_vf_to_grp_msg(struct cpt_vf *cptvf)
{
        struct pci_dev *pdev = cptvf->pdev;
        struct cpt_mbox mbx = {};

        mbx.msg = CPT_MSG_QBIND_GRP;
        /* Convey group of the VF */
        mbx.data = cptvf->vfgrp;
        if (cptvf_send_msg_to_pf_timeout(cptvf, &mbx)) {
                dev_err(&pdev->dev, "PF didn't respond to vf_type msg\n");
                return -EBUSY;
        }

        return 0;
}

/*
 * Communicate VF group required to PF and get the VQ binded to that group
 */
int cptvf_send_vf_priority_msg(struct cpt_vf *cptvf)
{
        struct pci_dev *pdev = cptvf->pdev;
        struct cpt_mbox mbx = {};

        mbx.msg = CPT_MSG_VQ_PRIORITY;
        /* Convey group of the VF */
        mbx.data = cptvf->priority;
        if (cptvf_send_msg_to_pf_timeout(cptvf, &mbx)) {
                dev_err(&pdev->dev, "PF didn't respond to vf_type msg\n");
                return -EBUSY;
        }
        return 0;
}

/*
 * Communicate to PF that VF is UP and running
 */
int cptvf_send_vf_up(struct cpt_vf *cptvf)
{
        struct pci_dev *pdev = cptvf->pdev;
        struct cpt_mbox mbx = {};

        mbx.msg = CPT_MSG_VF_UP;
        if (cptvf_send_msg_to_pf_timeout(cptvf, &mbx)) {
                dev_err(&pdev->dev, "PF didn't respond to UP msg\n");
                return -EBUSY;
        }

        return 0;
}

/*
 * Communicate to PF that VF is DOWN and running
 */
int cptvf_send_vf_down(struct cpt_vf *cptvf)
{
        struct pci_dev *pdev = cptvf->pdev;
        struct cpt_mbox mbx = {};

        mbx.msg = CPT_MSG_VF_DOWN;
        if (cptvf_send_msg_to_pf_timeout(cptvf, &mbx)) {
                dev_err(&pdev->dev, "PF didn't respond to DOWN msg\n");
                return -EBUSY;
        }

        return 0;
}