/*
 * (MPSAFE)
 *
 * Copyright (c) 2009 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Matthew Dillon <dillon@backplane.com>
 *
 * 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.
 * 3. Neither the name of The DragonFly Project nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific, prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
 * COPYRIGHT HOLDERS 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.
 */
/*
 * Primary device and CAM interface to OpenBSD AHCI driver, for DragonFly
 */

#include "ahci.h"

u_int32_t AhciForceGen = 0;
u_int32_t AhciNoFeatures = 0;

/*
 * Device bus methods
 */

static int      ahci_probe (device_t dev);
static int      ahci_attach (device_t dev);
static int      ahci_detach (device_t dev);
static int      ahci_sysctl_link_pwr_mgmt (SYSCTL_HANDLER_ARGS);
#if 0
static int      ahci_shutdown (device_t dev);
static int      ahci_suspend (device_t dev);
static int      ahci_resume (device_t dev);
#endif

static void     ahci_port_thread(void *arg);

static device_method_t ahci_methods[] = {
        DEVMETHOD(device_probe,         ahci_probe),
        DEVMETHOD(device_attach,        ahci_attach),
        DEVMETHOD(device_detach,        ahci_detach),
#if 0
        DEVMETHOD(device_shutdown,      ahci_shutdown),
        DEVMETHOD(device_suspend,       ahci_suspend),
        DEVMETHOD(device_resume,        ahci_resume),
#endif

        DEVMETHOD(bus_print_child,      bus_generic_print_child),
        DEVMETHOD(bus_driver_added,     bus_generic_driver_added),
        DEVMETHOD_END
};

static devclass_t       ahci_devclass;

static driver_t ahci_driver = {
        "ahci",
        ahci_methods,
        sizeof(struct ahci_softc)
};

MODULE_DEPEND(ahci, cam, 1, 1, 1);
DRIVER_MODULE(ahci, pci, ahci_driver, ahci_devclass, NULL, NULL);
MODULE_VERSION(ahci, 1);

/*
 * Device bus method procedures
 */
static int
ahci_probe (device_t dev)
{
        const struct ahci_device *ad;

        if (kgetenv("hint.ahci.disabled"))
                return(ENXIO);

        ad = ahci_lookup_device(dev);
        if (ad) {
                device_set_desc(dev, ad->name);
                return(-5);     /* higher priority the NATA */
        }
        return(ENXIO);
}

static int
ahci_attach (device_t dev)
{
        struct ahci_softc *sc = device_get_softc(dev);

        sc->sc_ad = ahci_lookup_device(dev);
        if (sc->sc_ad == NULL)
                return(ENXIO);

        /*
         * Some chipsets do not properly implement the AHCI spec and may
         * require the link speed to be specifically requested.
         */
        if (kgetenv("hint.ahci.force150"))
                AhciForceGen = 1;
        if (kgetenv("hint.ahci.force300"))
                AhciForceGen = 2;
        if (kgetenv("hint.ahci.force600"))
                AhciForceGen = 3;

        if (kgetenv("hint.ahci.nofeatures"))
                AhciNoFeatures = -1;

        if (kgetenv("hint.ahci.forcefbss"))
                sc->sc_flags |= AHCI_F_FORCE_FBSS;

        return (sc->sc_ad->ad_attach(dev));
}

static int
ahci_detach (device_t dev)
{
        struct ahci_softc *sc = device_get_softc(dev);
        int error = 0;

        if (sc->sc_ad) {
                error = sc->sc_ad->ad_detach(dev);
                sc->sc_ad = NULL;
        }
        return(error);
}

static int
ahci_sysctl_link_pwr_mgmt (SYSCTL_HANDLER_ARGS)
{
        struct ahci_port *ap = arg1;
        int error, link_pwr_mgmt;

        link_pwr_mgmt = ap->link_pwr_mgmt;
        error = sysctl_handle_int(oidp, &link_pwr_mgmt, 0, req);
        if (error || req->newptr == NULL)
                return error;

        ahci_port_link_pwr_mgmt(ap, link_pwr_mgmt);
        return 0;
}

static int
ahci_sysctl_link_pwr_state (SYSCTL_HANDLER_ARGS)
{
        struct ahci_port *ap = arg1;
        const char *state_names[] =
            {"unknown", "active", "partial", "slumber", "devsleep",
             "no device", "no communication", "phy offline"};
        char buf[24];
        int state;

        state = ahci_port_link_pwr_state(ap);
        if (state < 0 || state >= NELEM(state_names))
                state = 0;

        ksnprintf(buf, sizeof(buf), "%s", state_names[state]);
        return sysctl_handle_string(oidp, buf, sizeof(buf), req);
}

#if 0

static int
ahci_shutdown (device_t dev)
{
        return (0);
}

static int
ahci_suspend (device_t dev)
{
        return (0);
}

static int
ahci_resume (device_t dev)
{
        return (0);
}

#endif

/*
 * Sleep (ms) milliseconds, error on the side of caution.
 */
void
ahci_os_sleep(int ms)
{
        int ticks;

        ticks = hz * ms / 1000 + 1;
        tsleep(&ticks, 0, "ahslp", ticks);
}

/*
 * Sleep for a minimum interval and return the number of milliseconds
 * that was.  The minimum value returned is 1
 */
int
ahci_os_softsleep(void)
{
        if (hz >= 1000) {
                tsleep(&ticks, 0, "ahslp", hz / 1000);
                return(1);
        } else {
                tsleep(&ticks, 0, "ahslp", 1);
                return(1000 / hz);
        }
}

void
ahci_os_hardsleep(int us)
{
        DELAY(us);
}

/*
 * Create the OS-specific port helper thread and per-port lock.
 */
void
ahci_os_start_port(struct ahci_port *ap)
{
        struct sysctl_oid *soid;
        char name[16];

        atomic_set_int(&ap->ap_signal, AP_SIGF_INIT | AP_SIGF_THREAD_SYNC);
        lockinit(&ap->ap_lock, "ahcipo", 0, LK_CANRECURSE);
        lockinit(&ap->ap_sim_lock, "ahcicam", 0, LK_CANRECURSE);
        lockinit(&ap->ap_sig_lock, "ahport", 0, 0);
        sysctl_ctx_init(&ap->sysctl_ctx);
        ksnprintf(name, sizeof(name), "%d", ap->ap_num);
        soid = device_get_sysctl_tree(ap->ap_sc->sc_dev);
        ap->sysctl_tree = SYSCTL_ADD_NODE(&ap->sysctl_ctx,
                                SYSCTL_CHILDREN(soid),
                                OID_AUTO, name, CTLFLAG_RD, 0, "");

        if ((ap->ap_sc->sc_cap & (AHCI_REG_CAP_PSC | AHCI_REG_CAP_SSC))) {
                SYSCTL_ADD_PROC(&ap->sysctl_ctx,
                        SYSCTL_CHILDREN(ap->sysctl_tree), OID_AUTO,
                        "link_pwr_mgmt", CTLTYPE_INT | CTLFLAG_RW, ap, 0,
                        ahci_sysctl_link_pwr_mgmt, "I",
                        "Link power management policy "
                        "(0 = disabled, 1 = medium, 2 = aggressive)");
        }
        SYSCTL_ADD_PROC(&ap->sysctl_ctx,
                SYSCTL_CHILDREN(ap->sysctl_tree), OID_AUTO,
                "link_pwr_state", CTLTYPE_STRING | CTLFLAG_RD, ap, 0,
                ahci_sysctl_link_pwr_state, "A", "Link power management state");

        kthread_create(ahci_port_thread, ap, &ap->ap_thread,
                       "%s", PORTNAME(ap));
}

/*
 * Stop the OS-specific port helper thread and kill the per-port lock.
 */
void
ahci_os_stop_port(struct ahci_port *ap)
{
        if (ap->sysctl_tree) {
                sysctl_ctx_free(&ap->sysctl_ctx);
                ap->sysctl_tree = NULL;
        }

        if (ap->ap_thread) {
                ahci_os_signal_port_thread(ap, AP_SIGF_STOP);
                ahci_os_sleep(10);
                if (ap->ap_thread) {
                        kprintf("%s: Waiting for thread to terminate\n",
                                PORTNAME(ap));
                        while (ap->ap_thread)
                                ahci_os_sleep(100);
                        kprintf("%s: thread terminated\n",
                                PORTNAME(ap));
                }
        }
        lockuninit(&ap->ap_lock);
}

/*
 * Add (mask) to the set of bits being sent to the per-port thread helper
 * and wake the helper up if necessary.
 */
void
ahci_os_signal_port_thread(struct ahci_port *ap, int mask)
{
        lockmgr(&ap->ap_sig_lock, LK_EXCLUSIVE);
        atomic_set_int(&ap->ap_signal, mask);
        lockmgr(&ap->ap_sig_lock, LK_RELEASE);
        wakeup(&ap->ap_thread);
}

/*
 * Unconditionally lock the port structure for access.
 */
void
ahci_os_lock_port(struct ahci_port *ap)
{
        lockmgr(&ap->ap_lock, LK_EXCLUSIVE);
}

/*
 * Conditionally lock the port structure for access.
 *
 * Returns 0 on success, non-zero on failure.
 */
int
ahci_os_lock_port_nb(struct ahci_port *ap)
{
        return (lockmgr(&ap->ap_lock, LK_EXCLUSIVE | LK_NOWAIT));
}

/*
 * Unlock a previously locked port.
 */
void
ahci_os_unlock_port(struct ahci_port *ap)
{
        lockmgr(&ap->ap_lock, LK_RELEASE);
}

/*
 * Per-port thread helper.  This helper thread is responsible for
 * atomically retrieving and clearing the signal mask and calling
 * the machine-independant driver core.
 *
 * MPSAFE
 */
static
void
ahci_port_thread(void *arg)
{
        struct ahci_port *ap = arg;
        int mask;

        /*
         * Sets us up as an interrupt support thread, meaning we are
         * given a higher priority and we can preempt normal threads.
         */
        lwkt_set_interrupt_support_thread();

        /*
         * The helper thread is responsible for the initial port init,
         * so all the ports can be inited in parallel.
         *
         * We also run the state machine which should do all probes.
         * Since CAM is not attached yet we will not get out-of-order
         * SCSI attachments.
         */
        ahci_os_lock_port(ap);
        ahci_port_init(ap);
        atomic_clear_int(&ap->ap_signal, AP_SIGF_THREAD_SYNC);
        wakeup(&ap->ap_signal);
        ahci_port_state_machine(ap, 1);
        atomic_clear_int(&ap->ap_signal, AP_SIGF_INIT);

        /*
         * If attaching synchronous wakeup the frontend (device attach code),
         * otherwise attach asynchronously.  We haven't probed anything yet
         * so the ahci_cam_attach() won't try to probe.
         */
        if (ahci_synchronous_boot) {
                wakeup(&ap->ap_signal);
        } else {
                if (ahci_cam_attach(ap) == 0)
                        ahci_cam_changed(ap, NULL, -1);
        }
        ahci_os_unlock_port(ap);

        /*
         * Then loop on the helper core.
         */
        mask = ap->ap_signal;
        while ((mask & AP_SIGF_STOP) == 0) {
                ahci_port_thread_core(ap, mask);
                lockmgr(&ap->ap_sig_lock, LK_EXCLUSIVE);
                if (ap->ap_signal == 0) {
                        lksleep(&ap->ap_thread, &ap->ap_sig_lock, 0,
                                "ahport", 10 * hz);
                }
                mask = ap->ap_signal;
                atomic_clear_int(&ap->ap_signal, mask);
                lockmgr(&ap->ap_sig_lock, LK_RELEASE);
        }
        ap->ap_thread = NULL;
}