/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */


/*
 * SMP - Serial Management Protocol Device Driver
 *
 * The SMP driver provides user programs access to SAS Serial Management
 * Protocol devices by providing ioctl interface.
 */

#include <sys/modctl.h>
#include <sys/file.h>
#include <sys/scsi/scsi.h>
#include <sys/scsi/targets/smp.h>
#include <sys/sdt.h>

/*
 * Standard entrypoints
 */
static int smp_attach(dev_info_t *, ddi_attach_cmd_t);
static int smp_detach(dev_info_t *, ddi_detach_cmd_t);
static int smp_open(dev_t *, int, int, cred_t *);
static int smp_close(dev_t, int, int, cred_t *);
static int smp_ioctl(dev_t, int, intptr_t, int, cred_t *, int *);

/*
 * Configuration routines
 */
static int smp_do_attach(dev_info_t *);
static int smp_do_detach(dev_info_t *);

/*
 * Command handle routing
 */
static int smp_handle_func(dev_t, intptr_t, int, cred_t *, int *);

/*
 * Logging/debugging routines
 */
static void smp_log(smp_state_t  *, int,  const char *, ...);

int smp_retry_times     = SMP_DEFAULT_RETRY_TIMES;
int smp_retry_delay     = 10000;        /* 10msec */
int smp_delay_cmd       = 1;            /* 1usec */
int smp_single_command  = 1;            /* one command at a time */

static int smp_retry_recovered  = 0;    /* retry recovery counter */
static int smp_retry_failed     = 0;    /* retry failed counter */
static int smp_failed           = 0;

static struct cb_ops smp_cb_ops = {
        smp_open,                       /* open */
        smp_close,                      /* close */
        nodev,                          /* strategy */
        nodev,                          /* print */
        nodev,                          /* dump */
        nodev,                          /* read */
        nodev,                          /* write */
        smp_ioctl,                      /* ioctl */
        nodev,                          /* devmap */
        nodev,                          /* mmap */
        nodev,                          /* segmap */
        nochpoll,                       /* poll */
        ddi_prop_op,                    /* cb_prop_op */
        0,                              /* streamtab  */
        D_MP | D_NEW | D_HOTPLUG        /* Driver compatibility flag */
};

static struct dev_ops smp_dev_ops = {
        DEVO_REV,               /* devo_rev, */
        0,                      /* refcnt  */
        ddi_getinfo_1to1,       /* info */
        nulldev,                /* identify */
        NULL,                   /* probe */
        smp_attach,             /* attach */
        smp_detach,             /* detach */
        nodev,                  /* reset */
        &smp_cb_ops,            /* driver operations */
        (struct bus_ops *)0,    /* bus operations */
        NULL,                   /* power */
        ddi_quiesce_not_needed,         /* quiesce */
};

static void *smp_soft_state = NULL;

static struct modldrv modldrv = {
        &mod_driverops, "smp device driver", &smp_dev_ops
};

static struct modlinkage modlinkage = {
        MODREV_1, &modldrv, NULL
};

int
_init(void)
{
        int err;

        if ((err = ddi_soft_state_init(&smp_soft_state,
            sizeof (smp_state_t), SMP_ESTIMATED_NUM_DEVS)) != 0) {
                return (err);
        }

        if ((err = mod_install(&modlinkage)) != 0) {
                ddi_soft_state_fini(&smp_soft_state);
        }

        return (err);
}

int
_fini(void)
{
        int err;

        if ((err = mod_remove(&modlinkage)) == 0) {
                ddi_soft_state_fini(&smp_soft_state);
        }

        return (err);
}

int
_info(struct modinfo *modinfop)
{
        return (mod_info(&modlinkage, modinfop));
}

/*
 * smp_attach()
 *      attach(9e) entrypoint.
 */
static int
smp_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
{
        int err;

        switch (cmd) {
        case DDI_ATTACH:
                err = smp_do_attach(dip);
                break;
        case DDI_RESUME:
                err = DDI_SUCCESS;
                break;
        default:
                err = DDI_FAILURE;
                break;
        }

        if (err != DDI_SUCCESS) {
                smp_log(NULL, CE_NOTE, "!smp_attach(), "
                    "device unit-address @%s failed",
                    ddi_get_name_addr(dip));
        }
        return (err);
}

/*
 * smp_do_attach()
 *      handle the nitty details of attach.
 */
static int
smp_do_attach(dev_info_t *dip)
{
        int                     instance;
        struct smp_device       *smp_sd;
        uchar_t                 *srmir = NULL;
        uint_t                  srmirlen = 0;
        ddi_devid_t             devid = NULL;
        smp_state_t             *smp_state;

        instance = ddi_get_instance(dip);
        smp_sd = ddi_get_driver_private(dip);
        ASSERT(smp_sd != NULL);

        DTRACE_PROBE2(smp__attach__detach, int, instance, char *,
            ddi_get_name_addr(dip));

        /* make sure device is there, and establish srmir identity property */
        if (smp_probe(smp_sd) != DDI_PROBE_SUCCESS) {
                smp_log(NULL, CE_NOTE,
                    "!smp_do_attach: failed smp_probe, "
                    "device unit-address @%s", ddi_get_name_addr(dip));
                return (DDI_FAILURE);
        }

        /* if we have not already registered a devid, then do so now  */
        if (ddi_devid_get(dip, &devid) != DDI_SUCCESS) {
                /* get the srmir identity information for use in devid */
                (void) ddi_prop_lookup_byte_array(DDI_DEV_T_ANY, dip,
                    DDI_PROP_DONTPASS | DDI_PROP_NOTPROM,
                    SMP_PROP_REPORT_MANUFACTURER, &srmir, &srmirlen);

                /* Convert smp unit-address and srmir into devid */
                if (ddi_devid_smp_encode(DEVID_SMP_ENCODE_VERSION_LATEST,
                    (char *)ddi_driver_name(dip), ddi_get_name_addr(dip),
                    srmir, srmirlen, &devid) == DDI_SUCCESS) {
                        /* register the devid */
                        (void) ddi_devid_register(dip, devid);
                }
                ddi_prop_free(srmir);
        }

        /* We don't need the devid for our own operation, so free now. */
        if (devid)
                ddi_devid_free(devid);

        /* we are now done with srmir identity property defined by smp_probe */
        (void) ndi_prop_remove(DDI_DEV_T_NONE,
            dip, SMP_PROP_REPORT_MANUFACTURER);

        if (ddi_soft_state_zalloc(smp_soft_state, instance) != DDI_SUCCESS) {
                smp_log(NULL, CE_NOTE,
                    "!smp_do_attach: failed to allocate softstate, "
                    "device unit-address @%s", ddi_get_name_addr(dip));
                return (DDI_FAILURE);
        }

        smp_state = ddi_get_soft_state(smp_soft_state, instance);
        smp_state->smp_sd = smp_sd;

        /*
         * For simplicity, the minor number == the instance number
         */
        if (ddi_create_minor_node(dip, "smp", S_IFCHR,
            instance, DDI_NT_SMP, 0) == DDI_FAILURE) {
                smp_log(smp_state, CE_NOTE,
                    "!smp_do_attach: minor node creation failed, "
                    "device unit-address @%s", ddi_get_name_addr(dip));
                ddi_soft_state_free(smp_soft_state, instance);
                return (DDI_FAILURE);
        }

        mutex_init(&smp_state->smp_mutex, NULL, MUTEX_DRIVER, NULL);
        smp_state->smp_open_flag = SMP_CLOSED;

        ddi_report_dev(dip);
        return (DDI_SUCCESS);
}

/*
 * smp_detach()
 *      detach(9E) entrypoint
 */
static int
smp_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
{
        int instance;
        smp_state_t *smp_state;

        instance = ddi_get_instance(dip);
        smp_state = ddi_get_soft_state(smp_soft_state, instance);

        if (smp_state == NULL) {
                smp_log(NULL, CE_NOTE,
                    "!smp_detach: failed, no softstate found (%d), "
                    "device unit-address @%s",
                    instance, ddi_get_name_addr(dip));
                return (DDI_FAILURE);
        }

        switch (cmd) {
        case DDI_DETACH:
                return (smp_do_detach(dip));
        case DDI_SUSPEND:
                return (DDI_SUCCESS);
        default:
                return (DDI_FAILURE);
        }
}

/*
 * smp_do_detach()
 *      detach the driver, tearing down resources.
 */
static int
smp_do_detach(dev_info_t *dip)
{
        int instance;
        smp_state_t *smp_state;

        instance = ddi_get_instance(dip);
        smp_state = ddi_get_soft_state(smp_soft_state, instance);

        DTRACE_PROBE2(smp__attach__detach, int, instance, char *,
            ddi_get_name_addr(dip));

        mutex_destroy(&smp_state->smp_mutex);
        ddi_soft_state_free(smp_soft_state, instance);
        ddi_remove_minor_node(dip, NULL);
        return (DDI_SUCCESS);
}

/*ARGSUSED*/
static int
smp_open(dev_t *dev_p, int flag, int otyp, cred_t *cred_p)
{
        smp_state_t *smp_state;
        int instance;
        int rv = 0;

        instance = getminor(*dev_p);
        if ((smp_state = ddi_get_soft_state(smp_soft_state, instance))
            == NULL) {
                return (ENXIO);
        }

        mutex_enter(&smp_state->smp_mutex);
        if (flag & FEXCL) {
                if (smp_state->smp_open_flag != SMP_CLOSED) {
                        rv = EBUSY;
                } else {
                        smp_state->smp_open_flag = SMP_EXOPENED;
                }
        } else {
                if (smp_state->smp_open_flag == SMP_EXOPENED) {
                        rv = EBUSY;
                } else {
                        smp_state->smp_open_flag = SMP_SOPENED;
                }
        }
        mutex_exit(&smp_state->smp_mutex);

        return (rv);
}

/*ARGSUSED*/
static int
smp_close(dev_t dev, int flag, int otyp, cred_t *cred_p)
{
        smp_state_t *smp_state;
        int instance;
        int rv = 0;

        instance = getminor(dev);
        if ((smp_state = ddi_get_soft_state(smp_soft_state, instance))
            == NULL) {
                return (ENXIO);
        }

        mutex_enter(&smp_state->smp_mutex);
        if (smp_state->smp_open_flag == SMP_CLOSED) {
                smp_log(smp_state, CE_NOTE, "!smp device is already in close");
        } else {
                smp_state->smp_open_flag = SMP_CLOSED;
        }
        mutex_exit(&smp_state->smp_mutex);
        return (rv);
}

/*ARGSUSED*/
static int
smp_handle_func(dev_t dev,
    intptr_t arg, int flag, cred_t *cred_p, int *rval_p)
{
        usmp_cmd_t usmp_cmd_data, *usmp_cmd = &usmp_cmd_data;
        smp_pkt_t smp_pkt_data, *smp_pkt = &smp_pkt_data;
        smp_state_t *smp_state;
        int instance, retrycount;
        cred_t *cr;
        uint64_t cmd_flags = 0;
        int rval = 0;

#ifdef  _MULTI_DATAMODEL
        usmp_cmd32_t usmp_cmd32_data, *usmp_cmd32 = &usmp_cmd32_data;
#endif

        /* require PRIV_SYS_DEVICES privilege */
        cr = ddi_get_cred();
        if ((drv_priv(cred_p) != 0) && (drv_priv(cr) != 0)) {
                return (EPERM);
        }

        bzero(smp_pkt, sizeof (smp_pkt_t));

        instance = getminor(dev);
        if ((smp_state = ddi_get_soft_state(smp_soft_state, instance))
            == NULL) {
                return (ENXIO);
        }

#ifdef  _MULTI_DATAMODEL
        switch (ddi_model_convert_from(flag & FMODELS)) {
        case DDI_MODEL_ILP32:
                if (ddi_copyin((void *)arg, usmp_cmd32, sizeof (usmp_cmd32_t),
                    flag)) {
                        return (EFAULT);
                }

                usmp_cmd32tousmp_cmd(usmp_cmd32, usmp_cmd);
                break;
        case DDI_MODEL_NONE:
                if (ddi_copyin((void *)arg, usmp_cmd, sizeof (usmp_cmd_t),
                    flag)) {
                        return (EFAULT);
                }
                break;
        }
#else  /* ! _MULTI_DATAMODEL */
        if (ddi_copyin((void *)arg, usmp_cmd, sizeof (usmp_cmd_t), flag)) {
                return (EFAULT);
        }
#endif  /* _MULTI_DATAMODEL */

        if ((usmp_cmd->usmp_reqsize < SMP_MIN_REQUEST_SIZE) ||
            (usmp_cmd->usmp_reqsize > SMP_MAX_REQUEST_SIZE) ||
            (usmp_cmd->usmp_rspsize < SMP_MIN_RESPONSE_SIZE) ||
            (usmp_cmd->usmp_rspsize > SMP_MAX_RESPONSE_SIZE)) {
                rval = EINVAL;
                goto done;
        }

        smp_pkt->smp_pkt_reqsize = usmp_cmd->usmp_reqsize;
        smp_pkt->smp_pkt_rspsize = usmp_cmd->usmp_rspsize;

        /* allocate memory space for smp request and response frame in kernel */
        smp_pkt->smp_pkt_req = kmem_zalloc((size_t)usmp_cmd->usmp_reqsize,
            KM_SLEEP);
        cmd_flags |= SMP_FLAG_REQBUF;

        smp_pkt->smp_pkt_rsp = kmem_zalloc((size_t)usmp_cmd->usmp_rspsize,
            KM_SLEEP);
        cmd_flags |= SMP_FLAG_RSPBUF;

        /* copy smp request frame to kernel space */
        if (ddi_copyin(usmp_cmd->usmp_req, smp_pkt->smp_pkt_req,
            (size_t)usmp_cmd->usmp_reqsize, flag) != 0) {
                rval = EFAULT;
                goto done;
        }

        DTRACE_PROBE1(smp__transport__start, caddr_t, smp_pkt->smp_pkt_req);

        smp_pkt->smp_pkt_address = &smp_state->smp_sd->smp_sd_address;
        if (usmp_cmd->usmp_timeout <= 0) {
                smp_pkt->smp_pkt_timeout = SMP_DEFAULT_TIMEOUT;
        } else {
                smp_pkt->smp_pkt_timeout = usmp_cmd->usmp_timeout;
        }

        /* call smp_transport entry and send smp_pkt to HBA driver */
        cmd_flags |= SMP_FLAG_XFER;
        for (retrycount = 0; retrycount <= smp_retry_times; retrycount++) {

                /*
                 * To improve transport reliability, only allow one command
                 * outstanding at a time in smp_transport().
                 *
                 * NOTE: Some expanders have issues with heavy smp load.
                 */
                if (smp_single_command) {
                        mutex_enter(&smp_state->smp_mutex);
                        while (smp_state->smp_busy)
                                cv_wait(&smp_state->smp_cv,
                                    &smp_state->smp_mutex);
                        smp_state->smp_busy = 1;
                        mutex_exit(&smp_state->smp_mutex);
                }

                /* Let the transport know if more retries are possible. */
                smp_pkt->smp_pkt_will_retry =
                    (retrycount < smp_retry_times) ? 1 : 0;

                smp_pkt->smp_pkt_reason = 0;
                rval = smp_transport(smp_pkt);  /* put on the wire */

                if (smp_delay_cmd)
                        delay(drv_usectohz(smp_delay_cmd));

                if (smp_single_command) {
                        mutex_enter(&smp_state->smp_mutex);
                        smp_state->smp_busy = 0;
                        cv_signal(&smp_state->smp_cv);
                        mutex_exit(&smp_state->smp_mutex);
                }

                if (rval == DDI_SUCCESS) {
                        if (retrycount)
                                smp_retry_recovered++;
                        rval = 0;
                        break;
                }

                switch (smp_pkt->smp_pkt_reason) {
                case EAGAIN:
                        if (retrycount < smp_retry_times) {
                                bzero(smp_pkt->smp_pkt_rsp,
                                    (size_t)usmp_cmd->usmp_rspsize);
                                if (smp_retry_delay)
                                        delay(drv_usectohz(smp_retry_delay));
                                continue;
                        } else {
                                smp_retry_failed++;
                                smp_log(smp_state, CE_NOTE,
                                    "!smp_transport failed, smp_pkt_reason %d",
                                    smp_pkt->smp_pkt_reason);
                                rval = smp_pkt->smp_pkt_reason;
                                goto copyout;
                        }
                default:
                        smp_log(smp_state, CE_NOTE,
                            "!smp_transport failed, smp_pkt_reason %d",
                            smp_pkt->smp_pkt_reason);
                        rval = smp_pkt->smp_pkt_reason;
                        goto copyout;
                }
        }

copyout:
        /* copy out smp response to user process */
        if (ddi_copyout(smp_pkt->smp_pkt_rsp, usmp_cmd->usmp_rsp,
            (size_t)usmp_cmd->usmp_rspsize, flag) != 0) {
                rval = EFAULT;
        }

done:
        if ((cmd_flags & SMP_FLAG_XFER) != 0) {
                DTRACE_PROBE2(smp__transport__done, caddr_t,
                    smp_pkt->smp_pkt_rsp, uchar_t, smp_pkt->smp_pkt_reason);
        }
        if ((cmd_flags & SMP_FLAG_REQBUF) != 0) {
                kmem_free(smp_pkt->smp_pkt_req, smp_pkt->smp_pkt_reqsize);
        }
        if ((cmd_flags & SMP_FLAG_RSPBUF) != 0) {
                kmem_free(smp_pkt->smp_pkt_rsp, smp_pkt->smp_pkt_rspsize);
        }

        if (rval)
                smp_failed++;
        return (rval);
}

/*ARGSUSED*/
static int
smp_ioctl(dev_t dev,
    int cmd, intptr_t arg, int flag, cred_t *cred_p, int *rval_p)
{
        int rval = 0;

        switch (cmd) {
        case USMPFUNC:
                /*
                 * The response payload is valid only if return value is 0
                 * or EOVERFLOW.
                 */
                rval = smp_handle_func(dev, arg, flag, cred_p, rval_p);
                break;
        default:
                rval = EINVAL;
        }
        return (rval);
}

static void
smp_log(smp_state_t *smp_state, int level, const char *fmt, ...)
{
        va_list ap;
        char buf[256];
        dev_info_t *dip;

        if (smp_state == (smp_state_t *)NULL) {
                dip = NULL;
        } else {
                dip = smp_state->smp_sd->smp_sd_dev;
        }

        va_start(ap, fmt);
        (void) vsnprintf(buf, sizeof (buf), fmt, ap);
        va_end(ap);

        scsi_log(dip, "smp", level, "%s", buf);
}