/*
 * Serial Attached SCSI (SAS) Port class
 *
 * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
 * Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
 *
 * This file is licensed under GPLv2.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#include "sas_internal.h"

#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_sas.h>
#include "../scsi_sas_internal.h"

static bool phy_is_wideport_member(struct asd_sas_port *port, struct asd_sas_phy *phy)
{
        struct sas_ha_struct *sas_ha = phy->ha;

        if (memcmp(port->attached_sas_addr, phy->attached_sas_addr,
                   SAS_ADDR_SIZE) != 0 || (sas_ha->strict_wide_ports &&
             memcmp(port->sas_addr, phy->sas_addr, SAS_ADDR_SIZE) != 0))
                return false;
        return true;
}

static void sas_resume_port(struct asd_sas_phy *phy)
{
        struct domain_device *dev;
        struct asd_sas_port *port = phy->port;
        struct sas_ha_struct *sas_ha = phy->ha;
        struct sas_internal *si = to_sas_internal(sas_ha->core.shost->transportt);

        if (si->dft->lldd_port_formed)
                si->dft->lldd_port_formed(phy);

        if (port->suspended)
                port->suspended = 0;
        else {
                /* we only need to handle "link returned" actions once */
                return;
        }

        /* if the port came back:
         * 1/ presume every device came back
         * 2/ force the next revalidation to check all expander phys
         */
        list_for_each_entry(dev, &port->dev_list, dev_list_node) {
                int i, rc;

                rc = sas_notify_lldd_dev_found(dev);
                if (rc) {
                        sas_unregister_dev(port, dev);
                        continue;
                }

                if (dev->dev_type == SAS_EDGE_EXPANDER_DEVICE || dev->dev_type == SAS_FANOUT_EXPANDER_DEVICE) {
                        dev->ex_dev.ex_change_count = -1;
                        for (i = 0; i < dev->ex_dev.num_phys; i++) {
                                struct ex_phy *phy = &dev->ex_dev.ex_phy[i];

                                phy->phy_change_count = -1;
                        }
                }
        }

        sas_discover_event(port, DISCE_RESUME);
}

/**
 * sas_form_port -- add this phy to a port
 * @phy: the phy of interest
 *
 * This function adds this phy to an existing port, thus creating a wide
 * port, or it creates a port and adds the phy to the port.
 */
static void sas_form_port(struct asd_sas_phy *phy)
{
        int i;
        struct sas_ha_struct *sas_ha = phy->ha;
        struct asd_sas_port *port = phy->port;
        struct sas_internal *si =
                to_sas_internal(sas_ha->core.shost->transportt);
        unsigned long flags;

        if (port) {
                if (!phy_is_wideport_member(port, phy))
                        sas_deform_port(phy, 0);
                else if (phy->suspended) {
                        phy->suspended = 0;
                        sas_resume_port(phy);

                        /* phy came back, try to cancel the timeout */
                        wake_up(&sas_ha->eh_wait_q);
                        return;
                } else {
                        SAS_DPRINTK("%s: phy%d belongs to port%d already(%d)!\n",
                                    __func__, phy->id, phy->port->id,
                                    phy->port->num_phys);
                        return;
                }
        }

        /* see if the phy should be part of a wide port */
        spin_lock_irqsave(&sas_ha->phy_port_lock, flags);
        for (i = 0; i < sas_ha->num_phys; i++) {
                port = sas_ha->sas_port[i];
                spin_lock(&port->phy_list_lock);
                if (*(u64 *) port->sas_addr &&
                    phy_is_wideport_member(port, phy) && port->num_phys > 0) {
                        /* wide port */
                        SAS_DPRINTK("phy%d matched wide port%d\n", phy->id,
                                    port->id);
                        break;
                }
                spin_unlock(&port->phy_list_lock);
        }
        /* The phy does not match any existing port, create a new one */
        if (i == sas_ha->num_phys) {
                for (i = 0; i < sas_ha->num_phys; i++) {
                        port = sas_ha->sas_port[i];
                        spin_lock(&port->phy_list_lock);
                        if (*(u64 *)port->sas_addr == 0
                                && port->num_phys == 0) {
                                memcpy(port->sas_addr, phy->sas_addr,
                                        SAS_ADDR_SIZE);
                                break;
                        }
                        spin_unlock(&port->phy_list_lock);
                }
        }

        if (i >= sas_ha->num_phys) {
                printk(KERN_NOTICE "%s: couldn't find a free port, bug?\n",
                       __func__);
                spin_unlock_irqrestore(&sas_ha->phy_port_lock, flags);
                return;
        }

        /* add the phy to the port */
        list_add_tail(&phy->port_phy_el, &port->phy_list);
        sas_phy_set_target(phy, port->port_dev);
        phy->port = port;
        port->num_phys++;
        port->phy_mask |= (1U << phy->id);

        if (*(u64 *)port->attached_sas_addr == 0) {
                port->class = phy->class;
                memcpy(port->attached_sas_addr, phy->attached_sas_addr,
                       SAS_ADDR_SIZE);
                port->iproto = phy->iproto;
                port->tproto = phy->tproto;
                port->oob_mode = phy->oob_mode;
                port->linkrate = phy->linkrate;
        } else
                port->linkrate = max(port->linkrate, phy->linkrate);
        spin_unlock(&port->phy_list_lock);
        spin_unlock_irqrestore(&sas_ha->phy_port_lock, flags);

        if (!port->port) {
                port->port = sas_port_alloc(phy->phy->dev.parent, port->id);
                BUG_ON(!port->port);
                sas_port_add(port->port);
        }
        sas_port_add_phy(port->port, phy->phy);

        SAS_DPRINTK("%s added to %s, phy_mask:0x%x (%16llx)\n",
                    dev_name(&phy->phy->dev), dev_name(&port->port->dev),
                    port->phy_mask,
                    SAS_ADDR(port->attached_sas_addr));

        if (port->port_dev)
                port->port_dev->pathways = port->num_phys;

        /* Tell the LLDD about this port formation. */
        if (si->dft->lldd_port_formed)
                si->dft->lldd_port_formed(phy);

        sas_discover_event(phy->port, DISCE_DISCOVER_DOMAIN);
}

/**
 * sas_deform_port -- remove this phy from the port it belongs to
 * @phy: the phy of interest
 *
 * This is called when the physical link to the other phy has been
 * lost (on this phy), in Event thread context. We cannot delay here.
 */
void sas_deform_port(struct asd_sas_phy *phy, int gone)
{
        struct sas_ha_struct *sas_ha = phy->ha;
        struct asd_sas_port *port = phy->port;
        struct sas_internal *si =
                to_sas_internal(sas_ha->core.shost->transportt);
        struct domain_device *dev;
        unsigned long flags;

        if (!port)
                return;           /* done by a phy event */

        dev = port->port_dev;
        if (dev)
                dev->pathways--;

        if (port->num_phys == 1) {
                sas_unregister_domain_devices(port, gone);
                sas_port_delete(port->port);
                port->port = NULL;
        } else {
                sas_port_delete_phy(port->port, phy->phy);
                sas_device_set_phy(dev, port->port);
        }

        if (si->dft->lldd_port_deformed)
                si->dft->lldd_port_deformed(phy);

        spin_lock_irqsave(&sas_ha->phy_port_lock, flags);
        spin_lock(&port->phy_list_lock);

        list_del_init(&phy->port_phy_el);
        sas_phy_set_target(phy, NULL);
        phy->port = NULL;
        port->num_phys--;
        port->phy_mask &= ~(1U << phy->id);

        if (port->num_phys == 0) {
                INIT_LIST_HEAD(&port->phy_list);
                memset(port->sas_addr, 0, SAS_ADDR_SIZE);
                memset(port->attached_sas_addr, 0, SAS_ADDR_SIZE);
                port->class = 0;
                port->iproto = 0;
                port->tproto = 0;
                port->oob_mode = 0;
                port->phy_mask = 0;
        }
        spin_unlock(&port->phy_list_lock);
        spin_unlock_irqrestore(&sas_ha->phy_port_lock, flags);

        return;
}

/* ---------- SAS port events ---------- */

void sas_porte_bytes_dmaed(struct work_struct *work)
{
        struct asd_sas_event *ev = to_asd_sas_event(work);
        struct asd_sas_phy *phy = ev->phy;

        clear_bit(PORTE_BYTES_DMAED, &phy->port_events_pending);

        sas_form_port(phy);
}

void sas_porte_broadcast_rcvd(struct work_struct *work)
{
        struct asd_sas_event *ev = to_asd_sas_event(work);
        struct asd_sas_phy *phy = ev->phy;
        unsigned long flags;
        u32 prim;

        clear_bit(PORTE_BROADCAST_RCVD, &phy->port_events_pending);

        spin_lock_irqsave(&phy->sas_prim_lock, flags);
        prim = phy->sas_prim;
        spin_unlock_irqrestore(&phy->sas_prim_lock, flags);

        SAS_DPRINTK("broadcast received: %d\n", prim);
        sas_discover_event(phy->port, DISCE_REVALIDATE_DOMAIN);
}

void sas_porte_link_reset_err(struct work_struct *work)
{
        struct asd_sas_event *ev = to_asd_sas_event(work);
        struct asd_sas_phy *phy = ev->phy;

        clear_bit(PORTE_LINK_RESET_ERR, &phy->port_events_pending);

        sas_deform_port(phy, 1);
}

void sas_porte_timer_event(struct work_struct *work)
{
        struct asd_sas_event *ev = to_asd_sas_event(work);
        struct asd_sas_phy *phy = ev->phy;

        clear_bit(PORTE_TIMER_EVENT, &phy->port_events_pending);

        sas_deform_port(phy, 1);
}

void sas_porte_hard_reset(struct work_struct *work)
{
        struct asd_sas_event *ev = to_asd_sas_event(work);
        struct asd_sas_phy *phy = ev->phy;

        clear_bit(PORTE_HARD_RESET, &phy->port_events_pending);

        sas_deform_port(phy, 1);
}

/* ---------- SAS port registration ---------- */

static void sas_init_port(struct asd_sas_port *port,
                          struct sas_ha_struct *sas_ha, int i)
{
        memset(port, 0, sizeof(*port));
        port->id = i;
        INIT_LIST_HEAD(&port->dev_list);
        INIT_LIST_HEAD(&port->disco_list);
        INIT_LIST_HEAD(&port->destroy_list);
        spin_lock_init(&port->phy_list_lock);
        INIT_LIST_HEAD(&port->phy_list);
        port->ha = sas_ha;

        spin_lock_init(&port->dev_list_lock);
}

int sas_register_ports(struct sas_ha_struct *sas_ha)
{
        int i;

        /* initialize the ports and discovery */
        for (i = 0; i < sas_ha->num_phys; i++) {
                struct asd_sas_port *port = sas_ha->sas_port[i];

                sas_init_port(port, sas_ha, i);
                sas_init_disc(&port->disc, port);
        }
        return 0;
}

void sas_unregister_ports(struct sas_ha_struct *sas_ha)
{
        int i;

        for (i = 0; i < sas_ha->num_phys; i++)
                if (sas_ha->sas_phy[i]->port)
                        sas_deform_port(sas_ha->sas_phy[i], 0);

}