// SPDX-License-Identifier: GPL-2.0-only
// Copyright 2014 Cisco Systems, Inc.  All rights reserved.

#include <linux/errno.h>
#include <linux/pci.h>
#include <linux/slab.h>

#include <linux/interrupt.h>
#include <linux/workqueue.h>
#include <linux/spinlock.h>
#include <linux/mempool.h>
#include <scsi/scsi_tcq.h>
#include <linux/ctype.h>

#include "snic_io.h"
#include "snic.h"
#include "cq_enet_desc.h"
#include "snic_fwint.h"

/*
 * snic_handle_link : Handles link flaps.
 */
void
snic_handle_link(struct work_struct *work)
{
        struct snic *snic = container_of(work, struct snic, link_work);

        if (snic->config.xpt_type == SNIC_DAS)
                return;

        snic->link_status = svnic_dev_link_status(snic->vdev);
        snic->link_down_cnt = svnic_dev_link_down_cnt(snic->vdev);
        SNIC_HOST_INFO(snic->shost, "Link Event: Link %s.\n",
                       ((snic->link_status) ? "Up" : "Down"));

        SNIC_ASSERT_NOT_IMPL(1);
}


/*
 * snic_ver_enc : Encodes version str to int
 * version string is similar to netmask string
 */
static int
snic_ver_enc(const char *s)
{
        int v[4] = {0};
        int  i = 0, x = 0;
        char c;
        const char *p = s;

        /* validate version string */
        if ((strlen(s) > 15) || (strlen(s) < 7))
                goto end;

        while ((c = *p++)) {
                if (c == '.') {
                        i++;
                        continue;
                }

                if (i > 3 || !isdigit(c))
                        goto end;

                v[i] = v[i] * 10 + (c - '0');
        }

        /* validate sub version numbers */
        for (i = 3; i >= 0; i--)
                if (v[i] > 0xff)
                        goto end;

        x |= (v[0] << 24) | v[1] << 16 | v[2] << 8 | v[3];

end:
        if (x == 0) {
                SNIC_ERR("Invalid version string [%s].\n", s);

                return -1;
        }

        return x;
} /* end of snic_ver_enc */

/*
 * snic_qeueue_exch_ver_req :
 *
 * Queues Exchange Version Request, to communicate host information
 * in return, it gets firmware version details
 */
int
snic_queue_exch_ver_req(struct snic *snic)
{
        struct snic_req_info *rqi = NULL;
        struct snic_host_req *req = NULL;
        u32 ver = 0;
        int ret = 0;

        SNIC_HOST_INFO(snic->shost, "Exch Ver Req Preparing...\n");

        rqi = snic_req_init(snic, 0);
        if (!rqi) {
                SNIC_HOST_ERR(snic->shost, "Init Exch Ver Req failed\n");
                ret = -ENOMEM;
                goto error;
        }

        req = rqi_to_req(rqi);

        /* Initialize snic_host_req */
        snic_io_hdr_enc(&req->hdr, SNIC_REQ_EXCH_VER, 0, SCSI_NO_TAG,
                        snic->config.hid, 0, (ulong)rqi);
        ver = snic_ver_enc(SNIC_DRV_VERSION);
        req->u.exch_ver.drvr_ver = cpu_to_le32(ver);
        req->u.exch_ver.os_type = cpu_to_le32(SNIC_OS_LINUX);

        snic_handle_untagged_req(snic, rqi);

        ret = snic_queue_wq_desc(snic, req, sizeof(*req));
        if (ret) {
                snic_release_untagged_req(snic, rqi);
                SNIC_HOST_ERR(snic->shost,
                              "Queuing Exch Ver Req failed, err = %d\n",
                              ret);
                goto error;
        }

        SNIC_HOST_INFO(snic->shost, "Exch Ver Req is issued. ret = %d\n", ret);

error:
        return ret;
} /* end of snic_queue_exch_ver_req */

/*
 * snic_io_exch_ver_cmpl_handler
 */
void
snic_io_exch_ver_cmpl_handler(struct snic *snic, struct snic_fw_req *fwreq)
{
        struct snic_req_info *rqi = NULL;
        struct snic_exch_ver_rsp *exv_cmpl = &fwreq->u.exch_ver_cmpl;
        u8 typ, hdr_stat;
        u32 cmnd_id, hid, max_sgs;
        ulong ctx = 0;
        unsigned long flags;

        SNIC_HOST_INFO(snic->shost, "Exch Ver Compl Received.\n");
        snic_io_hdr_dec(&fwreq->hdr, &typ, &hdr_stat, &cmnd_id, &hid, &ctx);
        SNIC_BUG_ON(snic->config.hid != hid);
        rqi = (struct snic_req_info *) ctx;

        if (hdr_stat) {
                SNIC_HOST_ERR(snic->shost,
                              "Exch Ver Completed w/ err status %d\n",
                              hdr_stat);

                goto exch_cmpl_end;
        }

        spin_lock_irqsave(&snic->snic_lock, flags);
        snic->fwinfo.fw_ver = le32_to_cpu(exv_cmpl->version);
        snic->fwinfo.hid = le32_to_cpu(exv_cmpl->hid);
        snic->fwinfo.max_concur_ios = le32_to_cpu(exv_cmpl->max_concur_ios);
        snic->fwinfo.max_sgs_per_cmd = le32_to_cpu(exv_cmpl->max_sgs_per_cmd);
        snic->fwinfo.max_io_sz = le32_to_cpu(exv_cmpl->max_io_sz);
        snic->fwinfo.max_tgts = le32_to_cpu(exv_cmpl->max_tgts);
        snic->fwinfo.io_tmo = le16_to_cpu(exv_cmpl->io_timeout);

        SNIC_HOST_INFO(snic->shost,
                       "vers %u hid %u max_concur_ios %u max_sgs_per_cmd %u max_io_sz %u max_tgts %u fw tmo %u\n",
                       snic->fwinfo.fw_ver,
                       snic->fwinfo.hid,
                       snic->fwinfo.max_concur_ios,
                       snic->fwinfo.max_sgs_per_cmd,
                       snic->fwinfo.max_io_sz,
                       snic->fwinfo.max_tgts,
                       snic->fwinfo.io_tmo);

        SNIC_HOST_INFO(snic->shost,
                       "HBA Capabilities = 0x%x\n",
                       le32_to_cpu(exv_cmpl->hba_cap));

        /* Updating SGList size */
        max_sgs = snic->fwinfo.max_sgs_per_cmd;
        if (max_sgs && max_sgs < SNIC_MAX_SG_DESC_CNT) {
                snic->shost->sg_tablesize = max_sgs;
                SNIC_HOST_INFO(snic->shost, "Max SGs set to %d\n",
                               snic->shost->sg_tablesize);
        } else if (max_sgs > snic->shost->sg_tablesize) {
                SNIC_HOST_INFO(snic->shost,
                               "Target type %d Supports Larger Max SGList %d than driver's Max SG List %d.\n",
                               snic->config.xpt_type, max_sgs,
                               snic->shost->sg_tablesize);
        }

        if (snic->shost->can_queue > snic->fwinfo.max_concur_ios)
                snic->shost->can_queue = snic->fwinfo.max_concur_ios;

        snic->shost->max_sectors = snic->fwinfo.max_io_sz >> 9;
        if (snic->fwinfo.wait)
                complete(snic->fwinfo.wait);

        spin_unlock_irqrestore(&snic->snic_lock, flags);

exch_cmpl_end:
        snic_release_untagged_req(snic, rqi);

        SNIC_HOST_INFO(snic->shost, "Exch_cmpl Done, hdr_stat %d.\n", hdr_stat);
} /* end of snic_io_exch_ver_cmpl_handler */

/*
 * snic_get_conf
 *
 * Synchronous call, and Retrieves snic params.
 */
int
snic_get_conf(struct snic *snic)
{
        DECLARE_COMPLETION_ONSTACK(wait);
        unsigned long flags;
        int ret;
        int nr_retries = 3;

        SNIC_HOST_INFO(snic->shost, "Retrieving snic params.\n");
        spin_lock_irqsave(&snic->snic_lock, flags);
        memset(&snic->fwinfo, 0, sizeof(snic->fwinfo));
        snic->fwinfo.wait = &wait;
        spin_unlock_irqrestore(&snic->snic_lock, flags);

        /* Additional delay to handle HW Resource initialization. */
        msleep(50);

        /*
         * Exch ver req can be ignored by FW, if HW Resource initialization
         * is in progress, Hence retry.
         */
        do {
                ret = snic_queue_exch_ver_req(snic);
                if (ret)
                        return ret;

                wait_for_completion_timeout(&wait, msecs_to_jiffies(2000));
                spin_lock_irqsave(&snic->snic_lock, flags);
                ret = (snic->fwinfo.fw_ver != 0) ? 0 : -ETIMEDOUT;
                if (ret)
                        SNIC_HOST_ERR(snic->shost,
                                      "Failed to retrieve snic params,\n");

                /* Unset fwinfo.wait, on success or on last retry */
                if (ret == 0 || nr_retries == 1)
                        snic->fwinfo.wait = NULL;

                spin_unlock_irqrestore(&snic->snic_lock, flags);
        } while (ret && --nr_retries);

        return ret;
} /* end of snic_get_info */