// SPDX-License-Identifier: GPL-2.0
/*
 * Serial Attached SCSI (SAS) Event processing
 *
 * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
 * Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
 */

#include <linux/export.h>
#include <scsi/scsi_host.h>
#include "sas_internal.h"

bool sas_queue_work(struct sas_ha_struct *ha, struct sas_work *sw)
{
        if (!test_bit(SAS_HA_REGISTERED, &ha->state))
                return false;

        if (test_bit(SAS_HA_DRAINING, &ha->state)) {
                /* add it to the defer list, if not already pending */
                if (list_empty(&sw->drain_node))
                        list_add_tail(&sw->drain_node, &ha->defer_q);
                return true;
        }

        return queue_work(ha->event_q, &sw->work);
}

static bool sas_queue_event(int event, struct sas_work *work,
                            struct sas_ha_struct *ha)
{
        unsigned long flags;
        bool rc;

        spin_lock_irqsave(&ha->lock, flags);
        rc = sas_queue_work(ha, work);
        spin_unlock_irqrestore(&ha->lock, flags);

        return rc;
}

void sas_queue_deferred_work(struct sas_ha_struct *ha)
{
        struct sas_work *sw, *_sw;

        spin_lock_irq(&ha->lock);
        list_for_each_entry_safe(sw, _sw, &ha->defer_q, drain_node) {
                list_del_init(&sw->drain_node);

                if (!sas_queue_work(ha, sw)) {
                        pm_runtime_put(ha->dev);
                        sas_free_event(to_asd_sas_event(&sw->work));
                }
        }
        spin_unlock_irq(&ha->lock);
}

void __sas_drain_work(struct sas_ha_struct *ha)
{
        set_bit(SAS_HA_DRAINING, &ha->state);
        /* flush submitters */
        spin_lock_irq(&ha->lock);
        spin_unlock_irq(&ha->lock);

        drain_workqueue(ha->event_q);
        drain_workqueue(ha->disco_q);

        clear_bit(SAS_HA_DRAINING, &ha->state);
        sas_queue_deferred_work(ha);
}

int sas_drain_work(struct sas_ha_struct *ha)
{
        int err;

        err = mutex_lock_interruptible(&ha->drain_mutex);
        if (err)
                return err;
        if (test_bit(SAS_HA_REGISTERED, &ha->state))
                __sas_drain_work(ha);
        mutex_unlock(&ha->drain_mutex);

        return 0;
}
EXPORT_SYMBOL_GPL(sas_drain_work);

void sas_disable_revalidation(struct sas_ha_struct *ha)
{
        mutex_lock(&ha->disco_mutex);
        set_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state);
        mutex_unlock(&ha->disco_mutex);
}

void sas_enable_revalidation(struct sas_ha_struct *ha)
{
        int i;

        mutex_lock(&ha->disco_mutex);
        clear_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state);
        for (i = 0; i < ha->num_phys; i++) {
                struct asd_sas_port *port = ha->sas_port[i];
                const int ev = DISCE_REVALIDATE_DOMAIN;
                struct sas_discovery *d = &port->disc;
                struct asd_sas_phy *sas_phy;

                if (!test_and_clear_bit(ev, &d->pending))
                        continue;

                spin_lock(&port->phy_list_lock);
                if (list_empty(&port->phy_list)) {
                        spin_unlock(&port->phy_list_lock);
                        continue;
                }

                sas_phy = container_of(port->phy_list.next, struct asd_sas_phy,
                                port_phy_el);
                spin_unlock(&port->phy_list_lock);
                sas_notify_port_event(sas_phy,
                                PORTE_BROADCAST_RCVD, GFP_KERNEL);
        }
        mutex_unlock(&ha->disco_mutex);
}


static void sas_port_event_worker(struct work_struct *work)
{
        struct asd_sas_event *ev = to_asd_sas_event(work);
        struct asd_sas_phy *phy = ev->phy;
        struct sas_ha_struct *ha = phy->ha;

        sas_port_event_fns[ev->event](work);
        pm_runtime_put(ha->dev);
        sas_free_event(ev);
}

static void sas_phy_event_worker(struct work_struct *work)
{
        struct asd_sas_event *ev = to_asd_sas_event(work);
        struct asd_sas_phy *phy = ev->phy;
        struct sas_ha_struct *ha = phy->ha;

        sas_phy_event_fns[ev->event](work);
        pm_runtime_put(ha->dev);
        sas_free_event(ev);
}

/* defer works of new phys during suspend */
static bool sas_defer_event(struct asd_sas_phy *phy, struct asd_sas_event *ev)
{
        struct sas_ha_struct *ha = phy->ha;
        unsigned long flags;
        bool deferred = false;

        spin_lock_irqsave(&ha->lock, flags);
        if (test_bit(SAS_HA_RESUMING, &ha->state) && !phy->suspended) {
                struct sas_work *sw = &ev->work;

                list_add_tail(&sw->drain_node, &ha->defer_q);
                deferred = true;
        }
        spin_unlock_irqrestore(&ha->lock, flags);
        return deferred;
}

void sas_notify_port_event(struct asd_sas_phy *phy, enum port_event event,
                           gfp_t gfp_flags)
{
        struct sas_ha_struct *ha = phy->ha;
        struct asd_sas_event *ev;

        BUG_ON(event >= PORT_NUM_EVENTS);

        ev = sas_alloc_event(phy, gfp_flags);
        if (!ev)
                return;

        /* Call pm_runtime_put() with pairs in sas_port_event_worker() */
        pm_runtime_get_noresume(ha->dev);

        INIT_SAS_EVENT(ev, sas_port_event_worker, phy, event);

        if (sas_defer_event(phy, ev))
                return;

        if (!sas_queue_event(event, &ev->work, ha)) {
                pm_runtime_put(ha->dev);
                sas_free_event(ev);
        }
}
EXPORT_SYMBOL_GPL(sas_notify_port_event);

void sas_notify_phy_event(struct asd_sas_phy *phy, enum phy_event event,
                          gfp_t gfp_flags)
{
        struct sas_ha_struct *ha = phy->ha;
        struct asd_sas_event *ev;

        BUG_ON(event >= PHY_NUM_EVENTS);

        ev = sas_alloc_event(phy, gfp_flags);
        if (!ev)
                return;

        /* Call pm_runtime_put() with pairs in sas_phy_event_worker() */
        pm_runtime_get_noresume(ha->dev);

        INIT_SAS_EVENT(ev, sas_phy_event_worker, phy, event);

        if (sas_defer_event(phy, ev))
                return;

        if (!sas_queue_event(event, &ev->work, ha)) {
                pm_runtime_put(ha->dev);
                sas_free_event(ev);
        }
}
EXPORT_SYMBOL_GPL(sas_notify_phy_event);