/*
 * Copyright (c) 2006 IronPort Systems Inc. <ambrisko@ironport.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */

/* $FreeBSD: src/sys/dev/ipmi/ipmi.c,v 1.16 2011/11/07 15:43:11 ed Exp $ */

/*
 * Copyright 2012, Joyent, Inc.  All rights reserved.
 * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
 */

#include <sys/devops.h>
#include <sys/conf.h>
#include <sys/modctl.h>
#include <sys/types.h>
#include <sys/file.h>
#include <sys/errno.h>
#include <sys/open.h>
#include <sys/cred.h>
#include <sys/uio.h>
#include <sys/stat.h>
#include <sys/cmn_err.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/smbios.h>
#include <sys/smbios_impl.h>
#include <sys/ipmi.h>
#include "ipmivars.h"

/*
 * Request management.
 */

/* Allocate a new request with request and reply buffers. */
struct ipmi_request *
ipmi_alloc_request(struct ipmi_device *dev, long msgid, uint8_t addr,
    uint8_t command, size_t requestlen, size_t replylen)
{
        struct ipmi_request *req;

        req = kmem_zalloc(sizeof (struct ipmi_request) + requestlen + replylen,
            KM_SLEEP);
        req->ir_sz = sizeof (struct ipmi_request) + requestlen + replylen;
        req->ir_owner = dev;
        req->ir_msgid = msgid;
        req->ir_addr = addr;
        req->ir_command = command;
        if (requestlen) {
                req->ir_request = (uchar_t *)&req[1];
                req->ir_requestlen = requestlen;
        }
        if (replylen) {
                req->ir_reply = (uchar_t *)&req[1] + requestlen;
                req->ir_replybuflen = replylen;
        }

        cv_init(&req->ir_cv, NULL, CV_DEFAULT, NULL);
        req->ir_status = IRS_ALLOCATED;

        return (req);
}

/* Free a request no longer in use. */
void
ipmi_free_request(struct ipmi_request *req)
{
        if (req == NULL)
                return;

        cv_destroy(&req->ir_cv);

        kmem_free(req, req->ir_sz);
}

/* Store a processed request on the appropriate completion queue. */
/*ARGSUSED*/
void
ipmi_complete_request(struct ipmi_softc *sc, struct ipmi_request *req)
{
        struct ipmi_device *dev;

        IPMI_LOCK_ASSERT(sc);

        if (req->ir_status == IRS_CANCELED) {
                ASSERT(req->ir_owner == NULL);
                ipmi_free_request(req);
                return;
        }

        req->ir_status = IRS_COMPLETED;

        /*
         * Anonymous requests (from inside the driver) always have a
         * waiter that we awaken.
         */
        if (req->ir_owner == NULL) {
                cv_signal(&req->ir_cv);
        } else {
                dev = req->ir_owner;
                TAILQ_INSERT_TAIL(&dev->ipmi_completed_requests, req, ir_link);
                pollwakeup(&dev->ipmi_pollhead, POLLIN | POLLRDNORM);

                dev->ipmi_status &= ~IPMI_BUSY;
                if (dev->ipmi_status & IPMI_CLOSING)
                        cv_signal(&dev->ipmi_cv);
        }
}

/*
 * Enqueue an internal driver request and wait until it is completed.
 */
static int
ipmi_submit_driver_request(struct ipmi_softc *sc, struct ipmi_request **preq,
    int timo)
{
        int error;
        struct ipmi_request *req = *preq;

        ASSERT(req->ir_owner == NULL);

        IPMI_LOCK(sc);
        error = sc->ipmi_enqueue_request(sc, req);

        if (error != 0) {
                IPMI_UNLOCK(sc);
                return (error);
        }

        while (req->ir_status != IRS_COMPLETED && error >= 0)
                if (timo == 0)
                        cv_wait(&req->ir_cv, &sc->ipmi_lock);
                else
                        error = cv_timedwait(&req->ir_cv, &sc->ipmi_lock,
                            ddi_get_lbolt() + timo);

        switch (req->ir_status) {
                case IRS_QUEUED:
                        TAILQ_REMOVE(&sc->ipmi_pending_requests, req, ir_link);
                        req->ir_status = IRS_CANCELED;
                        error = EWOULDBLOCK;
                        break;
                case IRS_PROCESSED:
                        req->ir_status = IRS_CANCELED;
                        error = EWOULDBLOCK;
                        *preq = NULL;
                        break;
                case IRS_COMPLETED:
                        error = req->ir_error;
                        break;
                default:
                        panic("IPMI: Invalid request status");
                        break;
        }
        IPMI_UNLOCK(sc);

        return (error);
}

/*
 * Helper routine for polled system interfaces that use
 * ipmi_polled_enqueue_request() to queue requests.  This request
 * waits until there is a pending request and then returns the first
 * request.  If the driver is shutting down, it returns NULL.
 */
struct ipmi_request *
ipmi_dequeue_request(struct ipmi_softc *sc)
{
        struct ipmi_request *req;

        IPMI_LOCK_ASSERT(sc);

        while (!sc->ipmi_detaching && TAILQ_EMPTY(&sc->ipmi_pending_requests))
                cv_wait(&sc->ipmi_request_added, &sc->ipmi_lock);
        if (sc->ipmi_detaching)
                return (NULL);

        req = TAILQ_FIRST(&sc->ipmi_pending_requests);
        TAILQ_REMOVE(&sc->ipmi_pending_requests, req, ir_link);
        req->ir_status = IRS_PROCESSED;

        if (req->ir_owner != NULL)
                req->ir_owner->ipmi_status |= IPMI_BUSY;

        return (req);
}

int
ipmi_polled_enqueue_request(struct ipmi_softc *sc, struct ipmi_request *req)
{

        IPMI_LOCK_ASSERT(sc);

        TAILQ_INSERT_TAIL(&sc->ipmi_pending_requests, req, ir_link);
        req->ir_status = IRS_QUEUED;
        cv_signal(&sc->ipmi_request_added);
        return (0);
}

void
ipmi_shutdown(struct ipmi_softc *sc)
{
        taskq_destroy(sc->ipmi_kthread);

        cv_destroy(&sc->ipmi_request_added);
        mutex_destroy(&sc->ipmi_lock);
}

boolean_t
ipmi_startup(struct ipmi_softc *sc)
{
        struct ipmi_request *req;
        int error, i;

        /* Initialize interface-independent state. */
        mutex_init(&sc->ipmi_lock, NULL, MUTEX_DEFAULT, NULL);
        cv_init(&sc->ipmi_request_added, NULL, CV_DEFAULT, NULL);
        TAILQ_INIT(&sc->ipmi_pending_requests);

        /* Initialize interface-dependent state. */
        error = sc->ipmi_startup(sc);
        if (error) {
                cmn_err(CE_WARN, "Failed to initialize interface: %d", error);
                return (B_FALSE);
        }

        /* Send a GET_DEVICE_ID request. */
        req = ipmi_alloc_driver_request(IPMI_ADDR(IPMI_APP_REQUEST, 0),
            IPMI_GET_DEVICE_ID, 0, 15);

        error = ipmi_submit_driver_request(sc, &req, MAX_TIMEOUT);
        if (error == EWOULDBLOCK) {
                cmn_err(CE_WARN, "Timed out waiting for GET_DEVICE_ID");
                ipmi_free_request(req);
                return (B_FALSE);
        } else if (error) {
                cmn_err(CE_WARN, "Failed GET_DEVICE_ID: %d", error);
                ipmi_free_request(req);
                return (B_FALSE);
        } else if (req->ir_compcode != 0) {
                cmn_err(CE_WARN,
                    "Bad completion code for GET_DEVICE_ID: %d",
                    req->ir_compcode);
                ipmi_free_request(req);
                return (B_FALSE);
        } else if (req->ir_replylen < 5) {
                cmn_err(CE_WARN, "Short reply for GET_DEVICE_ID: %d",
                    req->ir_replylen);
                ipmi_free_request(req);
                return (B_FALSE);
        }

        cmn_err(CE_CONT, "!device rev. %d, firmware rev. %d.%d%d, "
            "version %d.%d",
            req->ir_reply[1] & 0x0f, req->ir_reply[2] & 0x7f,
            req->ir_reply[3] >> 4, req->ir_reply[3] & 0x0f,
            req->ir_reply[4] & 0x0f, req->ir_reply[4] >> 4);

        ipmi_free_request(req);

        req = ipmi_alloc_driver_request(IPMI_ADDR(IPMI_APP_REQUEST, 0),
            IPMI_CLEAR_FLAGS, 1, 0);

        if ((error = ipmi_submit_driver_request(sc, &req, 0)) != 0) {
                cmn_err(CE_WARN, "Failed to clear IPMI flags: %d\n", error);
                ipmi_free_request(req);
                return (B_FALSE);
        }

        /* Magic numbers */
        if (req->ir_compcode == 0xc0) {
                cmn_err(CE_NOTE, "!Clear flags is busy");
        }
        if (req->ir_compcode == 0xc1) {
                cmn_err(CE_NOTE, "!Clear flags illegal");
        }
        ipmi_free_request(req);

        for (i = 0; i < 8; i++) {
                req = ipmi_alloc_driver_request(IPMI_ADDR(IPMI_APP_REQUEST, 0),
                    IPMI_GET_CHANNEL_INFO, 1, 0);
                req->ir_request[0] = (uchar_t)i;

                if (ipmi_submit_driver_request(sc, &req, 0) != 0) {
                        ipmi_free_request(req);
                        break;
                }

                if (req->ir_compcode != 0) {
                        ipmi_free_request(req);
                        break;
                }
                ipmi_free_request(req);
        }
        cmn_err(CE_CONT, "!number of channels %d", i);

        /* probe for watchdog */
        req = ipmi_alloc_driver_request(IPMI_ADDR(IPMI_APP_REQUEST, 0),
            IPMI_GET_WDOG, 0, 0);

        if ((error = ipmi_submit_driver_request(sc, &req, 0)) != 0) {
                cmn_err(CE_WARN, "Failed to check IPMI watchdog: %d\n", error);
                ipmi_free_request(req);
                return (B_FALSE);
        }

        if (req->ir_compcode == 0x00) {
                cmn_err(CE_CONT, "!watchdog supported");

                /*
                 * Here is where we could register a watchdog event handler.
                 * See ipmi_wd_event() in the FreeBSD code.
                 */
        }
        ipmi_free_request(req);

        return (B_TRUE);
}