sas_expander.c

Go to the documentation of this file.

/*
 * Serial Attached SCSI (SAS) Expander discovery and configuration
 *
 * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
 * Copyright (C) 2005 Luben Tuikov <[email protected]>
 *
 * 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 <linux/scatterlist.h>
#include <linux/blkdev.h>
#include <linux/slab.h>

#include "sas_internal.h"

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

static int sas_discover_expander(struct domain_device *dev);
static int sas_configure_routing(struct domain_device *dev, u8 *sas_addr);
static int sas_configure_phy(struct domain_device *dev, int phy_id,
                 u8 *sas_addr, int include);
static int sas_disable_routing(struct domain_device *dev,  u8 *sas_addr);

/* ---------- SMP task management ---------- */

static void smp_task_timedout(unsigned long _task)
{
    struct sas_task *task = (void *) _task;
    unsigned long flags;

    spin_lock_irqsave(&task->task_state_lock, flags);
    if (!(task->task_state_flags & SAS_TASK_STATE_DONE))
        task->task_state_flags |= SAS_TASK_STATE_ABORTED;
    spin_unlock_irqrestore(&task->task_state_lock, flags);

    complete(&task->slow_task->completion);
}

static void smp_task_done(struct sas_task *task)
{
    if (!del_timer(&task->slow_task->timer))
        return;
    complete(&task->slow_task->completion);
}

/* Give it some long enough timeout. In seconds. */
#define SMP_TIMEOUT 10

static int smp_execute_task(struct domain_device *dev, void *req, int req_size,
                void *resp, int resp_size)
{
    int res, retry;
    struct sas_task *task = NULL;
    struct sas_internal *i =
        to_sas_internal(dev->port->ha->core.shost->transportt);

    mutex_lock(&dev->ex_dev.cmd_mutex);
    for (retry = 0; retry < 3; retry++) {
        if (test_bit(SAS_DEV_GONE, &dev->state)) {
            res = -ECOMM;
            break;
        }

        task = sas_alloc_slow_task(GFP_KERNEL);
        if (!task) {
            res = -ENOMEM;
            break;
        }
        task->dev = dev;
        task->task_proto = dev->tproto;
        sg_init_one(&task->smp_task.smp_req, req, req_size);
        sg_init_one(&task->smp_task.smp_resp, resp, resp_size);

        task->task_done = smp_task_done;

        task->slow_task->timer.data = (unsigned long) task;
        task->slow_task->timer.function = smp_task_timedout;
        task->slow_task->timer.expires = jiffies + SMP_TIMEOUT*HZ;
        add_timer(&task->slow_task->timer);

        res = i->dft->lldd_execute_task(task, 1, GFP_KERNEL);

        if (res) {
            del_timer(&task->slow_task->timer);
            SAS_DPRINTK("executing SMP task failed:%d\n", res);
            break;
        }

        wait_for_completion(&task->slow_task->completion);
        res = -ECOMM;
        if ((task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
            SAS_DPRINTK("smp task timed out or aborted\n");
            i->dft->lldd_abort_task(task);
            if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
                SAS_DPRINTK("SMP task aborted and not done\n");
                break;
            }
        }
        if (task->task_status.resp == SAS_TASK_COMPLETE &&
            task->task_status.stat == SAM_STAT_GOOD) {
            res = 0;
            break;
        }
        if (task->task_status.resp == SAS_TASK_COMPLETE &&
            task->task_status.stat == SAS_DATA_UNDERRUN) {
            /* no error, but return the number of bytes of
             * underrun */
            res = task->task_status.residual;
            break;
        }
        if (task->task_status.resp == SAS_TASK_COMPLETE &&
            task->task_status.stat == SAS_DATA_OVERRUN) {
            res = -EMSGSIZE;
            break;
        }
        if (task->task_status.resp == SAS_TASK_UNDELIVERED &&
            task->task_status.stat == SAS_DEVICE_UNKNOWN)
            break;
        else {
            SAS_DPRINTK("%s: task to dev %016llx response: 0x%x "
                    "status 0x%x\n", __func__,
                    SAS_ADDR(dev->sas_addr),
                    task->task_status.resp,
                    task->task_status.stat);
            sas_free_task(task);
            task = NULL;
        }
    }
    mutex_unlock(&dev->ex_dev.cmd_mutex);

    BUG_ON(retry == 3 && task != NULL);
    sas_free_task(task);
    return res;
}

/* ---------- Allocations ---------- */

static inline void *alloc_smp_req(int size)
{
    u8 *p = kzalloc(size, GFP_KERNEL);
    if (p)
        p[0] = SMP_REQUEST;
    return p;
}

static inline void *alloc_smp_resp(int size)
{
    return kzalloc(size, GFP_KERNEL);
}

static char sas_route_char(struct domain_device *dev, struct ex_phy *phy)
{
    switch (phy->routing_attr) {
    case TABLE_ROUTING:
        if (dev->ex_dev.t2t_supp)
            return 'U';
        else
            return 'T';
    case DIRECT_ROUTING:
        return 'D';
    case SUBTRACTIVE_ROUTING:
        return 'S';
    default:
        return '?';
    }
}

static enum sas_dev_type to_dev_type(struct discover_resp *dr)
{
    /* This is detecting a failure to transmit initial dev to host
     * FIS as described in section J.5 of sas-2 r16
     */
    if (dr->attached_dev_type == NO_DEVICE && dr->attached_sata_dev &&
        dr->linkrate >= SAS_LINK_RATE_1_5_GBPS)
        return SATA_PENDING;
    else
        return dr->attached_dev_type;
}

static void sas_set_ex_phy(struct domain_device *dev, int phy_id, void *rsp)
{
    enum sas_dev_type dev_type;
    enum sas_linkrate linkrate;
    u8 sas_addr[SAS_ADDR_SIZE];
    struct smp_resp *resp = rsp;
    struct discover_resp *dr = &resp->disc;
    struct sas_ha_struct *ha = dev->port->ha;
    struct expander_device *ex = &dev->ex_dev;
    struct ex_phy *phy = &ex->ex_phy[phy_id];
    struct sas_rphy *rphy = dev->rphy;
    bool new_phy = !phy->phy;
    char *type;

    if (new_phy) {
        if (WARN_ON_ONCE(test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)))
            return;
        phy->phy = sas_phy_alloc(&rphy->dev, phy_id);

        /* FIXME: error_handling */
        BUG_ON(!phy->phy);
    }

    switch (resp->result) {
    case SMP_RESP_PHY_VACANT:
        phy->phy_state = PHY_VACANT;
        break;
    default:
        phy->phy_state = PHY_NOT_PRESENT;
        break;
    case SMP_RESP_FUNC_ACC:
        phy->phy_state = PHY_EMPTY; /* do not know yet */
        break;
    }

    /* check if anything important changed to squelch debug */
    dev_type = phy->attached_dev_type;
    linkrate  = phy->linkrate;
    memcpy(sas_addr, phy->attached_sas_addr, SAS_ADDR_SIZE);

    phy->attached_dev_type = to_dev_type(dr);
    if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state))
        goto out;
    phy->phy_id = phy_id;
    phy->linkrate = dr->linkrate;
    phy->attached_sata_host = dr->attached_sata_host;
    phy->attached_sata_dev  = dr->attached_sata_dev;
    phy->attached_sata_ps   = dr->attached_sata_ps;
    phy->attached_iproto = dr->iproto << 1;
    phy->attached_tproto = dr->tproto << 1;
    /* help some expanders that fail to zero sas_address in the 'no
     * device' case
     */
    if (phy->attached_dev_type == NO_DEVICE ||
        phy->linkrate < SAS_LINK_RATE_1_5_GBPS)
        memset(phy->attached_sas_addr, 0, SAS_ADDR_SIZE);
    else
        memcpy(phy->attached_sas_addr, dr->attached_sas_addr, SAS_ADDR_SIZE);
    phy->attached_phy_id = dr->attached_phy_id;
    phy->phy_change_count = dr->change_count;
    phy->routing_attr = dr->routing_attr;
    phy->virtual = dr->virtual;
    phy->last_da_index = -1;

    phy->phy->identify.sas_address = SAS_ADDR(phy->attached_sas_addr);
    phy->phy->identify.device_type = dr->attached_dev_type;
    phy->phy->identify.initiator_port_protocols = phy->attached_iproto;
    phy->phy->identify.target_port_protocols = phy->attached_tproto;
    if (!phy->attached_tproto && dr->attached_sata_dev)
        phy->phy->identify.target_port_protocols = SAS_PROTOCOL_SATA;
    phy->phy->identify.phy_identifier = phy_id;
    phy->phy->minimum_linkrate_hw = dr->hmin_linkrate;
    phy->phy->maximum_linkrate_hw = dr->hmax_linkrate;
    phy->phy->minimum_linkrate = dr->pmin_linkrate;
    phy->phy->maximum_linkrate = dr->pmax_linkrate;
    phy->phy->negotiated_linkrate = phy->linkrate;

    if (new_phy)
        if (sas_phy_add(phy->phy)) {
            sas_phy_free(phy->phy);
            return;
        }

 out:
    switch (phy->attached_dev_type) {
    case SATA_PENDING:
        type = "stp pending";
        break;
    case NO_DEVICE:
        type = "no device";
        break;
    case SAS_END_DEV:
        if (phy->attached_iproto) {
            if (phy->attached_tproto)
                type = "host+target";
            else
                type = "host";
        } else {
            if (dr->attached_sata_dev)
                type = "stp";
            else
                type = "ssp";
        }
        break;
    case EDGE_DEV:
    case FANOUT_DEV:
        type = "smp";
        break;
    default:
        type = "unknown";
    }

    /* this routine is polled by libata error recovery so filter
     * unimportant messages
     */
    if (new_phy || phy->attached_dev_type != dev_type ||
        phy->linkrate != linkrate ||
        SAS_ADDR(phy->attached_sas_addr) != SAS_ADDR(sas_addr))
        /* pass */;
    else
        return;

    /* if the attached device type changed and ata_eh is active,
     * make sure we run revalidation when eh completes (see:
     * sas_enable_revalidation)
     */
    if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state))
        set_bit(DISCE_REVALIDATE_DOMAIN, &dev->port->disc.pending);

    SAS_DPRINTK("%sex %016llx phy%02d:%c:%X attached: %016llx (%s)\n",
            test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state) ? "ata: " : "",
            SAS_ADDR(dev->sas_addr), phy->phy_id,
            sas_route_char(dev, phy), phy->linkrate,
            SAS_ADDR(phy->attached_sas_addr), type);
}

/* check if we have an existing attached ata device on this expander phy */
struct domain_device *sas_ex_to_ata(struct domain_device *ex_dev, int phy_id)
{
    struct ex_phy *ex_phy = &ex_dev->ex_dev.ex_phy[phy_id];
    struct domain_device *dev;
    struct sas_rphy *rphy;

    if (!ex_phy->port)
        return NULL;

    rphy = ex_phy->port->rphy;
    if (!rphy)
        return NULL;

    dev = sas_find_dev_by_rphy(rphy);

    if (dev && dev_is_sata(dev))
        return dev;

    return NULL;
}

#define DISCOVER_REQ_SIZE  16
#define DISCOVER_RESP_SIZE 56

static int sas_ex_phy_discover_helper(struct domain_device *dev, u8 *disc_req,
                      u8 *disc_resp, int single)
{
    struct discover_resp *dr;
    int res;

    disc_req[9] = single;

    res = smp_execute_task(dev, disc_req, DISCOVER_REQ_SIZE,
                   disc_resp, DISCOVER_RESP_SIZE);
    if (res)
        return res;
    dr = &((struct smp_resp *)disc_resp)->disc;
    if (memcmp(dev->sas_addr, dr->attached_sas_addr, SAS_ADDR_SIZE) == 0) {
        sas_printk("Found loopback topology, just ignore it!\n");
        return 0;
    }
    sas_set_ex_phy(dev, single, disc_resp);
    return 0;
}

int sas_ex_phy_discover(struct domain_device *dev, int single)
{
    struct expander_device *ex = &dev->ex_dev;
    int  res = 0;
    u8   *disc_req;
    u8   *disc_resp;

    disc_req = alloc_smp_req(DISCOVER_REQ_SIZE);
    if (!disc_req)
        return -ENOMEM;

    disc_resp = alloc_smp_req(DISCOVER_RESP_SIZE);
    if (!disc_resp) {
        kfree(disc_req);
        return -ENOMEM;
    }

    disc_req[1] = SMP_DISCOVER;

    if (0 <= single && single < ex->num_phys) {
        res = sas_ex_phy_discover_helper(dev, disc_req, disc_resp, single);
    } else {
        int i;

        for (i = 0; i < ex->num_phys; i++) {
            res = sas_ex_phy_discover_helper(dev, disc_req,
                             disc_resp, i);
            if (res)
                goto out_err;
        }
    }
out_err:
    kfree(disc_resp);
    kfree(disc_req);
    return res;
}

static int sas_expander_discover(struct domain_device *dev)
{
    struct expander_device *ex = &dev->ex_dev;
    int res = -ENOMEM;

    ex->ex_phy = kzalloc(sizeof(*ex->ex_phy)*ex->num_phys, GFP_KERNEL);
    if (!ex->ex_phy)
        return -ENOMEM;

    res = sas_ex_phy_discover(dev, -1);
    if (res)
        goto out_err;

    return 0;
 out_err:
    kfree(ex->ex_phy);
    ex->ex_phy = NULL;
    return res;
}

#define MAX_EXPANDER_PHYS 128

static void ex_assign_report_general(struct domain_device *dev,
                        struct smp_resp *resp)
{
    struct report_general_resp *rg = &resp->rg;

    dev->ex_dev.ex_change_count = be16_to_cpu(rg->change_count);
    dev->ex_dev.max_route_indexes = be16_to_cpu(rg->route_indexes);
    dev->ex_dev.num_phys = min(rg->num_phys, (u8)MAX_EXPANDER_PHYS);
    dev->ex_dev.t2t_supp = rg->t2t_supp;
    dev->ex_dev.conf_route_table = rg->conf_route_table;
    dev->ex_dev.configuring = rg->configuring;
    memcpy(dev->ex_dev.enclosure_logical_id, rg->enclosure_logical_id, 8);
}

#define RG_REQ_SIZE   8
#define RG_RESP_SIZE 32

static int sas_ex_general(struct domain_device *dev)
{
    u8 *rg_req;
    struct smp_resp *rg_resp;
    int res;
    int i;

    rg_req = alloc_smp_req(RG_REQ_SIZE);
    if (!rg_req)
        return -ENOMEM;

    rg_resp = alloc_smp_resp(RG_RESP_SIZE);
    if (!rg_resp) {
        kfree(rg_req);
        return -ENOMEM;
    }

    rg_req[1] = SMP_REPORT_GENERAL;

    for (i = 0; i < 5; i++) {
        res = smp_execute_task(dev, rg_req, RG_REQ_SIZE, rg_resp,
                       RG_RESP_SIZE);

        if (res) {
            SAS_DPRINTK("RG to ex %016llx failed:0x%x\n",
                    SAS_ADDR(dev->sas_addr), res);
            goto out;
        } else if (rg_resp->result != SMP_RESP_FUNC_ACC) {
            SAS_DPRINTK("RG:ex %016llx returned SMP result:0x%x\n",
                    SAS_ADDR(dev->sas_addr), rg_resp->result);
            res = rg_resp->result;
            goto out;
        }

        ex_assign_report_general(dev, rg_resp);

        if (dev->ex_dev.configuring) {
            SAS_DPRINTK("RG: ex %llx self-configuring...\n",
                    SAS_ADDR(dev->sas_addr));
            schedule_timeout_interruptible(5*HZ);
        } else
            break;
    }
out:
    kfree(rg_req);
    kfree(rg_resp);
    return res;
}

static void ex_assign_manuf_info(struct domain_device *dev, void
                    *_mi_resp)
{
    u8 *mi_resp = _mi_resp;
    struct sas_rphy *rphy = dev->rphy;
    struct sas_expander_device *edev = rphy_to_expander_device(rphy);

    memcpy(edev->vendor_id, mi_resp + 12, SAS_EXPANDER_VENDOR_ID_LEN);
    memcpy(edev->product_id, mi_resp + 20, SAS_EXPANDER_PRODUCT_ID_LEN);
    memcpy(edev->product_rev, mi_resp + 36,
           SAS_EXPANDER_PRODUCT_REV_LEN);

    if (mi_resp[8] & 1) {
        memcpy(edev->component_vendor_id, mi_resp + 40,
               SAS_EXPANDER_COMPONENT_VENDOR_ID_LEN);
        edev->component_id = mi_resp[48] << 8 | mi_resp[49];
        edev->component_revision_id = mi_resp[50];
    }
}

#define MI_REQ_SIZE   8
#define MI_RESP_SIZE 64

static int sas_ex_manuf_info(struct domain_device *dev)
{
    u8 *mi_req;
    u8 *mi_resp;
    int res;

    mi_req = alloc_smp_req(MI_REQ_SIZE);
    if (!mi_req)
        return -ENOMEM;

    mi_resp = alloc_smp_resp(MI_RESP_SIZE);
    if (!mi_resp) {
        kfree(mi_req);
        return -ENOMEM;
    }

    mi_req[1] = SMP_REPORT_MANUF_INFO;

    res = smp_execute_task(dev, mi_req, MI_REQ_SIZE, mi_resp,MI_RESP_SIZE);
    if (res) {
        SAS_DPRINTK("MI: ex %016llx failed:0x%x\n",
                SAS_ADDR(dev->sas_addr), res);
        goto out;
    } else if (mi_resp[2] != SMP_RESP_FUNC_ACC) {
        SAS_DPRINTK("MI ex %016llx returned SMP result:0x%x\n",
                SAS_ADDR(dev->sas_addr), mi_resp[2]);
        goto out;
    }

    ex_assign_manuf_info(dev, mi_resp);
out:
    kfree(mi_req);
    kfree(mi_resp);
    return res;
}

#define PC_REQ_SIZE  44
#define PC_RESP_SIZE 8

int sas_smp_phy_control(struct domain_device *dev, int phy_id,
            enum phy_func phy_func,
            struct sas_phy_linkrates *rates)
{
    u8 *pc_req;
    u8 *pc_resp;
    int res;

    pc_req = alloc_smp_req(PC_REQ_SIZE);
    if (!pc_req)
        return -ENOMEM;

    pc_resp = alloc_smp_resp(PC_RESP_SIZE);
    if (!pc_resp) {
        kfree(pc_req);
        return -ENOMEM;
    }

    pc_req[1] = SMP_PHY_CONTROL;
    pc_req[9] = phy_id;
    pc_req[10]= phy_func;
    if (rates) {
        pc_req[32] = rates->minimum_linkrate << 4;
        pc_req[33] = rates->maximum_linkrate << 4;
    }

    res = smp_execute_task(dev, pc_req, PC_REQ_SIZE, pc_resp,PC_RESP_SIZE);

    kfree(pc_resp);
    kfree(pc_req);
    return res;
}

static void sas_ex_disable_phy(struct domain_device *dev, int phy_id)
{
    struct expander_device *ex = &dev->ex_dev;
    struct ex_phy *phy = &ex->ex_phy[phy_id];

    sas_smp_phy_control(dev, phy_id, PHY_FUNC_DISABLE, NULL);
    phy->linkrate = SAS_PHY_DISABLED;
}

static void sas_ex_disable_port(struct domain_device *dev, u8 *sas_addr)
{
    struct expander_device *ex = &dev->ex_dev;
    int i;

    for (i = 0; i < ex->num_phys; i++) {
        struct ex_phy *phy = &ex->ex_phy[i];

        if (phy->phy_state == PHY_VACANT ||
            phy->phy_state == PHY_NOT_PRESENT)
            continue;

        if (SAS_ADDR(phy->attached_sas_addr) == SAS_ADDR(sas_addr))
            sas_ex_disable_phy(dev, i);
    }
}

static int sas_dev_present_in_domain(struct asd_sas_port *port,
                        u8 *sas_addr)
{
    struct domain_device *dev;

    if (SAS_ADDR(port->sas_addr) == SAS_ADDR(sas_addr))
        return 1;
    list_for_each_entry(dev, &port->dev_list, dev_list_node) {
        if (SAS_ADDR(dev->sas_addr) == SAS_ADDR(sas_addr))
            return 1;
    }
    return 0;
}

#define RPEL_REQ_SIZE   16
#define RPEL_RESP_SIZE  32
int sas_smp_get_phy_events(struct sas_phy *phy)
{
    int res;
    u8 *req;
    u8 *resp;
    struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
    struct domain_device *dev = sas_find_dev_by_rphy(rphy);

    req = alloc_smp_req(RPEL_REQ_SIZE);
    if (!req)
        return -ENOMEM;

    resp = alloc_smp_resp(RPEL_RESP_SIZE);
    if (!resp) {
        kfree(req);
        return -ENOMEM;
    }

    req[1] = SMP_REPORT_PHY_ERR_LOG;
    req[9] = phy->number;

    res = smp_execute_task(dev, req, RPEL_REQ_SIZE,
                        resp, RPEL_RESP_SIZE);

    if (!res)
        goto out;

    phy->invalid_dword_count = scsi_to_u32(&resp[12]);
    phy->running_disparity_error_count = scsi_to_u32(&resp[16]);
    phy->loss_of_dword_sync_count = scsi_to_u32(&resp[20]);
    phy->phy_reset_problem_count = scsi_to_u32(&resp[24]);

 out:
    kfree(resp);
    return res;

}

#ifdef CONFIG_SCSI_SAS_ATA

#define RPS_REQ_SIZE  16
#define RPS_RESP_SIZE 60

int sas_get_report_phy_sata(struct domain_device *dev, int phy_id,
                struct smp_resp *rps_resp)
{
    int res;
    u8 *rps_req = alloc_smp_req(RPS_REQ_SIZE);
    u8 *resp = (u8 *)rps_resp;

    if (!rps_req)
        return -ENOMEM;

    rps_req[1] = SMP_REPORT_PHY_SATA;
    rps_req[9] = phy_id;

    res = smp_execute_task(dev, rps_req, RPS_REQ_SIZE,
                        rps_resp, RPS_RESP_SIZE);

    /* 0x34 is the FIS type for the D2H fis.  There's a potential
     * standards cockup here.  sas-2 explicitly specifies the FIS
     * should be encoded so that FIS type is in resp[24].
     * However, some expanders endian reverse this.  Undo the
     * reversal here */
    if (!res && resp[27] == 0x34 && resp[24] != 0x34) {
        int i;

        for (i = 0; i < 5; i++) {
            int j = 24 + (i*4);
            u8 a, b;
            a = resp[j + 0];
            b = resp[j + 1];
            resp[j + 0] = resp[j + 3];
            resp[j + 1] = resp[j + 2];
            resp[j + 2] = b;
            resp[j + 3] = a;
        }
    }

    kfree(rps_req);
    return res;
}
#endif

static void sas_ex_get_linkrate(struct domain_device *parent,
                       struct domain_device *child,
                       struct ex_phy *parent_phy)
{
    struct expander_device *parent_ex = &parent->ex_dev;
    struct sas_port *port;
    int i;

    child->pathways = 0;

    port = parent_phy->port;

    for (i = 0; i < parent_ex->num_phys; i++) {
        struct ex_phy *phy = &parent_ex->ex_phy[i];

        if (phy->phy_state == PHY_VACANT ||
            phy->phy_state == PHY_NOT_PRESENT)
            continue;

        if (SAS_ADDR(phy->attached_sas_addr) ==
            SAS_ADDR(child->sas_addr)) {

            child->min_linkrate = min(parent->min_linkrate,
                          phy->linkrate);
            child->max_linkrate = max(parent->max_linkrate,
                          phy->linkrate);
            child->pathways++;
            sas_port_add_phy(port, phy->phy);
        }
    }
    child->linkrate = min(parent_phy->linkrate, child->max_linkrate);
    child->pathways = min(child->pathways, parent->pathways);
}

static struct domain_device *sas_ex_discover_end_dev(
    struct domain_device *parent, int phy_id)
{
    struct expander_device *parent_ex = &parent->ex_dev;
    struct ex_phy *phy = &parent_ex->ex_phy[phy_id];
    struct domain_device *child = NULL;
    struct sas_rphy *rphy;
    int res;

    if (phy->attached_sata_host || phy->attached_sata_ps)
        return NULL;

    child = sas_alloc_device();
    if (!child)
        return NULL;

    kref_get(&parent->kref);
    child->parent = parent;
    child->port   = parent->port;
    child->iproto = phy->attached_iproto;
    memcpy(child->sas_addr, phy->attached_sas_addr, SAS_ADDR_SIZE);
    sas_hash_addr(child->hashed_sas_addr, child->sas_addr);
    if (!phy->port) {
        phy->port = sas_port_alloc(&parent->rphy->dev, phy_id);
        if (unlikely(!phy->port))
            goto out_err;
        if (unlikely(sas_port_add(phy->port) != 0)) {
            sas_port_free(phy->port);
            goto out_err;
        }
    }
    sas_ex_get_linkrate(parent, child, phy);
    sas_device_set_phy(child, phy->port);

#ifdef CONFIG_SCSI_SAS_ATA
    if ((phy->attached_tproto & SAS_PROTOCOL_STP) || phy->attached_sata_dev) {
        res = sas_get_ata_info(child, phy);
        if (res)
            goto out_free;

        sas_init_dev(child);
        res = sas_ata_init(child);
        if (res)
            goto out_free;
        rphy = sas_end_device_alloc(phy->port);
        if (!rphy)
            goto out_free;

        child->rphy = rphy;
        get_device(&rphy->dev);

        list_add_tail(&child->disco_list_node, &parent->port->disco_list);

        res = sas_discover_sata(child);
        if (res) {
            SAS_DPRINTK("sas_discover_sata() for device %16llx at "
                    "%016llx:0x%x returned 0x%x\n",
                    SAS_ADDR(child->sas_addr),
                    SAS_ADDR(parent->sas_addr), phy_id, res);
            goto out_list_del;
        }
    } else
#endif
      if (phy->attached_tproto & SAS_PROTOCOL_SSP) {
        child->dev_type = SAS_END_DEV;
        rphy = sas_end_device_alloc(phy->port);
        /* FIXME: error handling */
        if (unlikely(!rphy))
            goto out_free;
        child->tproto = phy->attached_tproto;
        sas_init_dev(child);

        child->rphy = rphy;
        get_device(&rphy->dev);
        sas_fill_in_rphy(child, rphy);

        list_add_tail(&child->disco_list_node, &parent->port->disco_list);

        res = sas_discover_end_dev(child);
        if (res) {
            SAS_DPRINTK("sas_discover_end_dev() for device %16llx "
                    "at %016llx:0x%x returned 0x%x\n",
                    SAS_ADDR(child->sas_addr),
                    SAS_ADDR(parent->sas_addr), phy_id, res);
            goto out_list_del;
        }
    } else {
        SAS_DPRINTK("target proto 0x%x at %016llx:0x%x not handled\n",
                phy->attached_tproto, SAS_ADDR(parent->sas_addr),
                phy_id);
        goto out_free;
    }

    list_add_tail(&child->siblings, &parent_ex->children);
    return child;

 out_list_del:
    sas_rphy_free(child->rphy);
    list_del(&child->disco_list_node);
    spin_lock_irq(&parent->port->dev_list_lock);
    list_del(&child->dev_list_node);
    spin_unlock_irq(&parent->port->dev_list_lock);
 out_free:
    sas_port_delete(phy->port);
 out_err:
    phy->port = NULL;
    sas_put_device(child);
    return NULL;
}

/* See if this phy is part of a wide port */
static bool sas_ex_join_wide_port(struct domain_device *parent, int phy_id)
{
    struct ex_phy *phy = &parent->ex_dev.ex_phy[phy_id];
    int i;

    for (i = 0; i < parent->ex_dev.num_phys; i++) {
        struct ex_phy *ephy = &parent->ex_dev.ex_phy[i];

        if (ephy == phy)
            continue;

        if (!memcmp(phy->attached_sas_addr, ephy->attached_sas_addr,
                SAS_ADDR_SIZE) && ephy->port) {
            sas_port_add_phy(ephy->port, phy->phy);
            phy->port = ephy->port;
            phy->phy_state = PHY_DEVICE_DISCOVERED;
            return true;
        }
    }

    return false;
}

static struct domain_device *sas_ex_discover_expander(
    struct domain_device *parent, int phy_id)
{
    struct sas_expander_device *parent_ex = rphy_to_expander_device(parent->rphy);
    struct ex_phy *phy = &parent->ex_dev.ex_phy[phy_id];
    struct domain_device *child = NULL;
    struct sas_rphy *rphy;
    struct sas_expander_device *edev;
    struct asd_sas_port *port;
    int res;

    if (phy->routing_attr == DIRECT_ROUTING) {
        SAS_DPRINTK("ex %016llx:0x%x:D <--> ex %016llx:0x%x is not "
                "allowed\n",
                SAS_ADDR(parent->sas_addr), phy_id,
                SAS_ADDR(phy->attached_sas_addr),
                phy->attached_phy_id);
        return NULL;
    }
    child = sas_alloc_device();
    if (!child)
        return NULL;

    phy->port = sas_port_alloc(&parent->rphy->dev, phy_id);
    /* FIXME: better error handling */
    BUG_ON(sas_port_add(phy->port) != 0);


    switch (phy->attached_dev_type) {
    case EDGE_DEV:
        rphy = sas_expander_alloc(phy->port,
                      SAS_EDGE_EXPANDER_DEVICE);
        break;
    case FANOUT_DEV:
        rphy = sas_expander_alloc(phy->port,
                      SAS_FANOUT_EXPANDER_DEVICE);
        break;
    default:
        rphy = NULL;    /* shut gcc up */
        BUG();
    }
    port = parent->port;
    child->rphy = rphy;
    get_device(&rphy->dev);
    edev = rphy_to_expander_device(rphy);
    child->dev_type = phy->attached_dev_type;
    kref_get(&parent->kref);
    child->parent = parent;
    child->port = port;
    child->iproto = phy->attached_iproto;
    child->tproto = phy->attached_tproto;
    memcpy(child->sas_addr, phy->attached_sas_addr, SAS_ADDR_SIZE);
    sas_hash_addr(child->hashed_sas_addr, child->sas_addr);
    sas_ex_get_linkrate(parent, child, phy);
    edev->level = parent_ex->level + 1;
    parent->port->disc.max_level = max(parent->port->disc.max_level,
                       edev->level);
    sas_init_dev(child);
    sas_fill_in_rphy(child, rphy);
    sas_rphy_add(rphy);

    spin_lock_irq(&parent->port->dev_list_lock);
    list_add_tail(&child->dev_list_node, &parent->port->dev_list);
    spin_unlock_irq(&parent->port->dev_list_lock);

    res = sas_discover_expander(child);
    if (res) {
        sas_rphy_delete(rphy);
        spin_lock_irq(&parent->port->dev_list_lock);
        list_del(&child->dev_list_node);
        spin_unlock_irq(&parent->port->dev_list_lock);
        sas_put_device(child);
        return NULL;
    }
    list_add_tail(&child->siblings, &parent->ex_dev.children);
    return child;
}

static int sas_ex_discover_dev(struct domain_device *dev, int phy_id)
{
    struct expander_device *ex = &dev->ex_dev;
    struct ex_phy *ex_phy = &ex->ex_phy[phy_id];
    struct domain_device *child = NULL;
    int res = 0;

    /* Phy state */
    if (ex_phy->linkrate == SAS_SATA_SPINUP_HOLD) {
        if (!sas_smp_phy_control(dev, phy_id, PHY_FUNC_LINK_RESET, NULL))
            res = sas_ex_phy_discover(dev, phy_id);
        if (res)
            return res;
    }

    /* Parent and domain coherency */
    if (!dev->parent && (SAS_ADDR(ex_phy->attached_sas_addr) ==
                 SAS_ADDR(dev->port->sas_addr))) {
        sas_add_parent_port(dev, phy_id);
        return 0;
    }
    if (dev->parent && (SAS_ADDR(ex_phy->attached_sas_addr) ==
                SAS_ADDR(dev->parent->sas_addr))) {
        sas_add_parent_port(dev, phy_id);
        if (ex_phy->routing_attr == TABLE_ROUTING)
            sas_configure_phy(dev, phy_id, dev->port->sas_addr, 1);
        return 0;
    }

    if (sas_dev_present_in_domain(dev->port, ex_phy->attached_sas_addr))
        sas_ex_disable_port(dev, ex_phy->attached_sas_addr);

    if (ex_phy->attached_dev_type == NO_DEVICE) {
        if (ex_phy->routing_attr == DIRECT_ROUTING) {
            memset(ex_phy->attached_sas_addr, 0, SAS_ADDR_SIZE);
            sas_configure_routing(dev, ex_phy->attached_sas_addr);
        }
        return 0;
    } else if (ex_phy->linkrate == SAS_LINK_RATE_UNKNOWN)
        return 0;

    if (ex_phy->attached_dev_type != SAS_END_DEV &&
        ex_phy->attached_dev_type != FANOUT_DEV &&
        ex_phy->attached_dev_type != EDGE_DEV &&
        ex_phy->attached_dev_type != SATA_PENDING) {
        SAS_DPRINTK("unknown device type(0x%x) attached to ex %016llx "
                "phy 0x%x\n", ex_phy->attached_dev_type,
                SAS_ADDR(dev->sas_addr),
                phy_id);
        return 0;
    }

    res = sas_configure_routing(dev, ex_phy->attached_sas_addr);
    if (res) {
        SAS_DPRINTK("configure routing for dev %016llx "
                "reported 0x%x. Forgotten\n",
                SAS_ADDR(ex_phy->attached_sas_addr), res);
        sas_disable_routing(dev, ex_phy->attached_sas_addr);
        return res;
    }

    if (sas_ex_join_wide_port(dev, phy_id)) {
        SAS_DPRINTK("Attaching ex phy%d to wide port %016llx\n",
                phy_id, SAS_ADDR(ex_phy->attached_sas_addr));
        return res;
    }

    switch (ex_phy->attached_dev_type) {
    case SAS_END_DEV:
    case SATA_PENDING:
        child = sas_ex_discover_end_dev(dev, phy_id);
        break;
    case FANOUT_DEV:
        if (SAS_ADDR(dev->port->disc.fanout_sas_addr)) {
            SAS_DPRINTK("second fanout expander %016llx phy 0x%x "
                    "attached to ex %016llx phy 0x%x\n",
                    SAS_ADDR(ex_phy->attached_sas_addr),
                    ex_phy->attached_phy_id,
                    SAS_ADDR(dev->sas_addr),
                    phy_id);
            sas_ex_disable_phy(dev, phy_id);
            break;
        } else
            memcpy(dev->port->disc.fanout_sas_addr,
                   ex_phy->attached_sas_addr, SAS_ADDR_SIZE);
        /* fallthrough */
    case EDGE_DEV:
        child = sas_ex_discover_expander(dev, phy_id);
        break;
    default:
        break;
    }

    if (child) {
        int i;

        for (i = 0; i < ex->num_phys; i++) {
            if (ex->ex_phy[i].phy_state == PHY_VACANT ||
                ex->ex_phy[i].phy_state == PHY_NOT_PRESENT)
                continue;
            /*
             * Due to races, the phy might not get added to the
             * wide port, so we add the phy to the wide port here.
             */
            if (SAS_ADDR(ex->ex_phy[i].attached_sas_addr) ==
                SAS_ADDR(child->sas_addr)) {
                ex->ex_phy[i].phy_state= PHY_DEVICE_DISCOVERED;
                if (sas_ex_join_wide_port(dev, i))
                    SAS_DPRINTK("Attaching ex phy%d to wide port %016llx\n",
                            i, SAS_ADDR(ex->ex_phy[i].attached_sas_addr));

            }
        }
    }

    return res;
}

static int sas_find_sub_addr(struct domain_device *dev, u8 *sub_addr)
{
    struct expander_device *ex = &dev->ex_dev;
    int i;

    for (i = 0; i < ex->num_phys; i++) {
        struct ex_phy *phy = &ex->ex_phy[i];

        if (phy->phy_state == PHY_VACANT ||
            phy->phy_state == PHY_NOT_PRESENT)
            continue;

        if ((phy->attached_dev_type == EDGE_DEV ||
             phy->attached_dev_type == FANOUT_DEV) &&
            phy->routing_attr == SUBTRACTIVE_ROUTING) {

            memcpy(sub_addr, phy->attached_sas_addr,SAS_ADDR_SIZE);

            return 1;
        }
    }
    return 0;
}

static int sas_check_level_subtractive_boundary(struct domain_device *dev)
{
    struct expander_device *ex = &dev->ex_dev;
    struct domain_device *child;
    u8 sub_addr[8] = {0, };

    list_for_each_entry(child, &ex->children, siblings) {
        if (child->dev_type != EDGE_DEV &&
            child->dev_type != FANOUT_DEV)
            continue;
        if (sub_addr[0] == 0) {
            sas_find_sub_addr(child, sub_addr);
            continue;
        } else {
            u8 s2[8];

            if (sas_find_sub_addr(child, s2) &&
                (SAS_ADDR(sub_addr) != SAS_ADDR(s2))) {

                SAS_DPRINTK("ex %016llx->%016llx-?->%016llx "
                        "diverges from subtractive "
                        "boundary %016llx\n",
                        SAS_ADDR(dev->sas_addr),
                        SAS_ADDR(child->sas_addr),
                        SAS_ADDR(s2),
                        SAS_ADDR(sub_addr));

                sas_ex_disable_port(child, s2);
            }
        }
    }
    return 0;
}
static int sas_ex_discover_devices(struct domain_device *dev, int single)
{
    struct expander_device *ex = &dev->ex_dev;
    int i = 0, end = ex->num_phys;
    int res = 0;

    if (0 <= single && single < end) {
        i = single;
        end = i+1;
    }

    for ( ; i < end; i++) {
        struct ex_phy *ex_phy = &ex->ex_phy[i];

        if (ex_phy->phy_state == PHY_VACANT ||
            ex_phy->phy_state == PHY_NOT_PRESENT ||
            ex_phy->phy_state == PHY_DEVICE_DISCOVERED)
            continue;

        switch (ex_phy->linkrate) {
        case SAS_PHY_DISABLED:
        case SAS_PHY_RESET_PROBLEM:
        case SAS_SATA_PORT_SELECTOR:
            continue;
        default:
            res = sas_ex_discover_dev(dev, i);
            if (res)
                break;
            continue;
        }
    }

    if (!res)
        sas_check_level_subtractive_boundary(dev);

    return res;
}

static int sas_check_ex_subtractive_boundary(struct domain_device *dev)
{
    struct expander_device *ex = &dev->ex_dev;
    int i;
    u8  *sub_sas_addr = NULL;

    if (dev->dev_type != EDGE_DEV)
        return 0;

    for (i = 0; i < ex->num_phys; i++) {
        struct ex_phy *phy = &ex->ex_phy[i];

        if (phy->phy_state == PHY_VACANT ||
            phy->phy_state == PHY_NOT_PRESENT)
            continue;

        if ((phy->attached_dev_type == FANOUT_DEV ||
             phy->attached_dev_type == EDGE_DEV) &&
            phy->routing_attr == SUBTRACTIVE_ROUTING) {

            if (!sub_sas_addr)
                sub_sas_addr = &phy->attached_sas_addr[0];
            else if (SAS_ADDR(sub_sas_addr) !=
                 SAS_ADDR(phy->attached_sas_addr)) {

                SAS_DPRINTK("ex %016llx phy 0x%x "
                        "diverges(%016llx) on subtractive "
                        "boundary(%016llx). Disabled\n",
                        SAS_ADDR(dev->sas_addr), i,
                        SAS_ADDR(phy->attached_sas_addr),
                        SAS_ADDR(sub_sas_addr));
                sas_ex_disable_phy(dev, i);
            }
        }
    }
    return 0;
}

static void sas_print_parent_topology_bug(struct domain_device *child,
                         struct ex_phy *parent_phy,
                         struct ex_phy *child_phy)
{
    static const char *ex_type[] = {
        [EDGE_DEV] = "edge",
        [FANOUT_DEV] = "fanout",
    };
    struct domain_device *parent = child->parent;

    sas_printk("%s ex %016llx phy 0x%x <--> %s ex %016llx "
           "phy 0x%x has %c:%c routing link!\n",

           ex_type[parent->dev_type],
           SAS_ADDR(parent->sas_addr),
           parent_phy->phy_id,

           ex_type[child->dev_type],
           SAS_ADDR(child->sas_addr),
           child_phy->phy_id,

           sas_route_char(parent, parent_phy),
           sas_route_char(child, child_phy));
}

static int sas_check_eeds(struct domain_device *child,
                 struct ex_phy *parent_phy,
                 struct ex_phy *child_phy)
{
    int res = 0;
    struct domain_device *parent = child->parent;

    if (SAS_ADDR(parent->port->disc.fanout_sas_addr) != 0) {
        res = -ENODEV;
        SAS_DPRINTK("edge ex %016llx phy S:0x%x <--> edge ex %016llx "
                "phy S:0x%x, while there is a fanout ex %016llx\n",
                SAS_ADDR(parent->sas_addr),
                parent_phy->phy_id,
                SAS_ADDR(child->sas_addr),
                child_phy->phy_id,
                SAS_ADDR(parent->port->disc.fanout_sas_addr));
    } else if (SAS_ADDR(parent->port->disc.eeds_a) == 0) {
        memcpy(parent->port->disc.eeds_a, parent->sas_addr,
               SAS_ADDR_SIZE);
        memcpy(parent->port->disc.eeds_b, child->sas_addr,
               SAS_ADDR_SIZE);
    } else if (((SAS_ADDR(parent->port->disc.eeds_a) ==
            SAS_ADDR(parent->sas_addr)) ||
           (SAS_ADDR(parent->port->disc.eeds_a) ==
            SAS_ADDR(child->sas_addr)))
           &&
           ((SAS_ADDR(parent->port->disc.eeds_b) ==
             SAS_ADDR(parent->sas_addr)) ||
            (SAS_ADDR(parent->port->disc.eeds_b) ==
             SAS_ADDR(child->sas_addr))))
        ;
    else {
        res = -ENODEV;
        SAS_DPRINTK("edge ex %016llx phy 0x%x <--> edge ex %016llx "
                "phy 0x%x link forms a third EEDS!\n",
                SAS_ADDR(parent->sas_addr),
                parent_phy->phy_id,
                SAS_ADDR(child->sas_addr),
                child_phy->phy_id);
    }

    return res;
}

/* Here we spill over 80 columns.  It is intentional.
 */
static int sas_check_parent_topology(struct domain_device *child)
{
    struct expander_device *child_ex = &child->ex_dev;
    struct expander_device *parent_ex;
    int i;
    int res = 0;

    if (!child->parent)
        return 0;

    if (child->parent->dev_type != EDGE_DEV &&
        child->parent->dev_type != FANOUT_DEV)
        return 0;

    parent_ex = &child->parent->ex_dev;

    for (i = 0; i < parent_ex->num_phys; i++) {
        struct ex_phy *parent_phy = &parent_ex->ex_phy[i];
        struct ex_phy *child_phy;

        if (parent_phy->phy_state == PHY_VACANT ||
            parent_phy->phy_state == PHY_NOT_PRESENT)
            continue;

        if (SAS_ADDR(parent_phy->attached_sas_addr) != SAS_ADDR(child->sas_addr))
            continue;

        child_phy = &child_ex->ex_phy[parent_phy->attached_phy_id];

        switch (child->parent->dev_type) {
        case EDGE_DEV:
            if (child->dev_type == FANOUT_DEV) {
                if (parent_phy->routing_attr != SUBTRACTIVE_ROUTING ||
                    child_phy->routing_attr != TABLE_ROUTING) {
                    sas_print_parent_topology_bug(child, parent_phy, child_phy);
                    res = -ENODEV;
                }
            } else if (parent_phy->routing_attr == SUBTRACTIVE_ROUTING) {
                if (child_phy->routing_attr == SUBTRACTIVE_ROUTING) {
                    res = sas_check_eeds(child, parent_phy, child_phy);
                } else if (child_phy->routing_attr != TABLE_ROUTING) {
                    sas_print_parent_topology_bug(child, parent_phy, child_phy);
                    res = -ENODEV;
                }
            } else if (parent_phy->routing_attr == TABLE_ROUTING) {
                if (child_phy->routing_attr == SUBTRACTIVE_ROUTING ||
                    (child_phy->routing_attr == TABLE_ROUTING &&
                     child_ex->t2t_supp && parent_ex->t2t_supp)) {
                    /* All good */;
                } else {
                    sas_print_parent_topology_bug(child, parent_phy, child_phy);
                    res = -ENODEV;
                }
            }
            break;
        case FANOUT_DEV:
            if (parent_phy->routing_attr != TABLE_ROUTING ||
                child_phy->routing_attr != SUBTRACTIVE_ROUTING) {
                sas_print_parent_topology_bug(child, parent_phy, child_phy);
                res = -ENODEV;
            }
            break;
        default:
            break;
        }
    }

    return res;
}

#define RRI_REQ_SIZE  16
#define RRI_RESP_SIZE 44

static int sas_configure_present(struct domain_device *dev, int phy_id,
                 u8 *sas_addr, int *index, int *present)
{
    int i, res = 0;
    struct expander_device *ex = &dev->ex_dev;
    struct ex_phy *phy = &ex->ex_phy[phy_id];
    u8 *rri_req;
    u8 *rri_resp;

    *present = 0;
    *index = 0;

    rri_req = alloc_smp_req(RRI_REQ_SIZE);
    if (!rri_req)
        return -ENOMEM;

    rri_resp = alloc_smp_resp(RRI_RESP_SIZE);
    if (!rri_resp) {
        kfree(rri_req);
        return -ENOMEM;
    }

    rri_req[1] = SMP_REPORT_ROUTE_INFO;
    rri_req[9] = phy_id;

    for (i = 0; i < ex->max_route_indexes ; i++) {
        *(__be16 *)(rri_req+6) = cpu_to_be16(i);
        res = smp_execute_task(dev, rri_req, RRI_REQ_SIZE, rri_resp,
                       RRI_RESP_SIZE);
        if (res)
            goto out;
        res = rri_resp[2];
        if (res == SMP_RESP_NO_INDEX) {
            SAS_DPRINTK("overflow of indexes: dev %016llx "
                    "phy 0x%x index 0x%x\n",
                    SAS_ADDR(dev->sas_addr), phy_id, i);
            goto out;
        } else if (res != SMP_RESP_FUNC_ACC) {
            SAS_DPRINTK("%s: dev %016llx phy 0x%x index 0x%x "
                    "result 0x%x\n", __func__,
                    SAS_ADDR(dev->sas_addr), phy_id, i, res);
            goto out;
        }
        if (SAS_ADDR(sas_addr) != 0) {
            if (SAS_ADDR(rri_resp+16) == SAS_ADDR(sas_addr)) {
                *index = i;
                if ((rri_resp[12] & 0x80) == 0x80)
                    *present = 0;
                else
                    *present = 1;
                goto out;
            } else if (SAS_ADDR(rri_resp+16) == 0) {
                *index = i;
                *present = 0;
                goto out;
            }
        } else if (SAS_ADDR(rri_resp+16) == 0 &&
               phy->last_da_index < i) {
            phy->last_da_index = i;
            *index = i;
            *present = 0;
            goto out;
        }
    }
    res = -1;
out:
    kfree(rri_req);
    kfree(rri_resp);
    return res;
}

#define CRI_REQ_SIZE  44
#define CRI_RESP_SIZE  8

static int sas_configure_set(struct domain_device *dev, int phy_id,
                 u8 *sas_addr, int index, int include)
{
    int res;
    u8 *cri_req;
    u8 *cri_resp;

    cri_req = alloc_smp_req(CRI_REQ_SIZE);
    if (!cri_req)
        return -ENOMEM;

    cri_resp = alloc_smp_resp(CRI_RESP_SIZE);
    if (!cri_resp) {
        kfree(cri_req);
        return -ENOMEM;
    }

    cri_req[1] = SMP_CONF_ROUTE_INFO;
    *(__be16 *)(cri_req+6) = cpu_to_be16(index);
    cri_req[9] = phy_id;
    if (SAS_ADDR(sas_addr) == 0 || !include)
        cri_req[12] |= 0x80;
    memcpy(cri_req+16, sas_addr, SAS_ADDR_SIZE);

    res = smp_execute_task(dev, cri_req, CRI_REQ_SIZE, cri_resp,
                   CRI_RESP_SIZE);
    if (res)
        goto out;
    res = cri_resp[2];
    if (res == SMP_RESP_NO_INDEX) {
        SAS_DPRINTK("overflow of indexes: dev %016llx phy 0x%x "
                "index 0x%x\n",
                SAS_ADDR(dev->sas_addr), phy_id, index);
    }
out:
    kfree(cri_req);
    kfree(cri_resp);
    return res;
}

static int sas_configure_phy(struct domain_device *dev, int phy_id,
                    u8 *sas_addr, int include)
{
    int index;
    int present;
    int res;

    res = sas_configure_present(dev, phy_id, sas_addr, &index, &present);
    if (res)
        return res;
    if (include ^ present)
        return sas_configure_set(dev, phy_id, sas_addr, index,include);

    return res;
}

static int sas_configure_parent(struct domain_device *parent,
                struct domain_device *child,
                u8 *sas_addr, int include)
{
    struct expander_device *ex_parent = &parent->ex_dev;
    int res = 0;
    int i;

    if (parent->parent) {
        res = sas_configure_parent(parent->parent, parent, sas_addr,
                       include);
        if (res)
            return res;
    }

    if (ex_parent->conf_route_table == 0) {
        SAS_DPRINTK("ex %016llx has self-configuring routing table\n",
                SAS_ADDR(parent->sas_addr));
        return 0;
    }

    for (i = 0; i < ex_parent->num_phys; i++) {
        struct ex_phy *phy = &ex_parent->ex_phy[i];

        if ((phy->routing_attr == TABLE_ROUTING) &&
            (SAS_ADDR(phy->attached_sas_addr) ==
             SAS_ADDR(child->sas_addr))) {
            res = sas_configure_phy(parent, i, sas_addr, include);
            if (res)
                return res;
        }
    }

    return res;
}

static int sas_configure_routing(struct domain_device *dev, u8 *sas_addr)
{
    if (dev->parent)
        return sas_configure_parent(dev->parent, dev, sas_addr, 1);
    return 0;
}

static int sas_disable_routing(struct domain_device *dev,  u8 *sas_addr)
{
    if (dev->parent)
        return sas_configure_parent(dev->parent, dev, sas_addr, 0);
    return 0;
}

static int sas_discover_expander(struct domain_device *dev)
{
    int res;

    res = sas_notify_lldd_dev_found(dev);
    if (res)
        return res;

    res = sas_ex_general(dev);
    if (res)
        goto out_err;
    res = sas_ex_manuf_info(dev);
    if (res)
        goto out_err;

    res = sas_expander_discover(dev);
    if (res) {
        SAS_DPRINTK("expander %016llx discovery failed(0x%x)\n",
                SAS_ADDR(dev->sas_addr), res);
        goto out_err;
    }

    sas_check_ex_subtractive_boundary(dev);
    res = sas_check_parent_topology(dev);
    if (res)
        goto out_err;
    return 0;
out_err:
    sas_notify_lldd_dev_gone(dev);
    return res;
}

static int sas_ex_level_discovery(struct asd_sas_port *port, const int level)
{
    int res = 0;
    struct domain_device *dev;

    list_for_each_entry(dev, &port->dev_list, dev_list_node) {
        if (dev->dev_type == EDGE_DEV ||
            dev->dev_type == FANOUT_DEV) {
            struct sas_expander_device *ex =
                rphy_to_expander_device(dev->rphy);

            if (level == ex->level)
                res = sas_ex_discover_devices(dev, -1);
            else if (level > 0)
                res = sas_ex_discover_devices(port->port_dev, -1);

        }
    }

    return res;
}

static int sas_ex_bfs_disc(struct asd_sas_port *port)
{
    int res;
    int level;

    do {
        level = port->disc.max_level;
        res = sas_ex_level_discovery(port, level);
        mb();
    } while (level < port->disc.max_level);

    return res;
}

int sas_discover_root_expander(struct domain_device *dev)
{
    int res;
    struct sas_expander_device *ex = rphy_to_expander_device(dev->rphy);

    res = sas_rphy_add(dev->rphy);
    if (res)
        goto out_err;

    ex->level = dev->port->disc.max_level; /* 0 */
    res = sas_discover_expander(dev);
    if (res)
        goto out_err2;

    sas_ex_bfs_disc(dev->port);

    return res;

out_err2:
    sas_rphy_remove(dev->rphy);
out_err:
    return res;
}

/* ---------- Domain revalidation ---------- */

static int sas_get_phy_discover(struct domain_device *dev,
                int phy_id, struct smp_resp *disc_resp)
{
    int res;
    u8 *disc_req;

    disc_req = alloc_smp_req(DISCOVER_REQ_SIZE);
    if (!disc_req)
        return -ENOMEM;

    disc_req[1] = SMP_DISCOVER;
    disc_req[9] = phy_id;

    res = smp_execute_task(dev, disc_req, DISCOVER_REQ_SIZE,
                   disc_resp, DISCOVER_RESP_SIZE);
    if (res)
        goto out;
    else if (disc_resp->result != SMP_RESP_FUNC_ACC) {
        res = disc_resp->result;
        goto out;
    }
out:
    kfree(disc_req);
    return res;
}

static int sas_get_phy_change_count(struct domain_device *dev,
                    int phy_id, int *pcc)
{
    int res;
    struct smp_resp *disc_resp;

    disc_resp = alloc_smp_resp(DISCOVER_RESP_SIZE);
    if (!disc_resp)
        return -ENOMEM;

    res = sas_get_phy_discover(dev, phy_id, disc_resp);
    if (!res)
        *pcc = disc_resp->disc.change_count;

    kfree(disc_resp);
    return res;
}

static int sas_get_phy_attached_dev(struct domain_device *dev, int phy_id,
                    u8 *sas_addr, enum sas_dev_type *type)
{
    int res;
    struct smp_resp *disc_resp;
    struct discover_resp *dr;

    disc_resp = alloc_smp_resp(DISCOVER_RESP_SIZE);
    if (!disc_resp)
        return -ENOMEM;
    dr = &disc_resp->disc;

    res = sas_get_phy_discover(dev, phy_id, disc_resp);
    if (res == 0) {
        memcpy(sas_addr, disc_resp->disc.attached_sas_addr, 8);
        *type = to_dev_type(dr);
        if (*type == 0)
            memset(sas_addr, 0, 8);
    }
    kfree(disc_resp);
    return res;
}

static int sas_find_bcast_phy(struct domain_device *dev, int *phy_id,
                  int from_phy, bool update)
{
    struct expander_device *ex = &dev->ex_dev;
    int res = 0;
    int i;

    for (i = from_phy; i < ex->num_phys; i++) {
        int phy_change_count = 0;

        res = sas_get_phy_change_count(dev, i, &phy_change_count);
        switch (res) {
        case SMP_RESP_PHY_VACANT:
        case SMP_RESP_NO_PHY:
            continue;
        case SMP_RESP_FUNC_ACC:
            break;
        default:
            return res;
        }

        if (phy_change_count != ex->ex_phy[i].phy_change_count) {
            if (update)
                ex->ex_phy[i].phy_change_count =
                    phy_change_count;
            *phy_id = i;
            return 0;
        }
    }
    return 0;
}

static int sas_get_ex_change_count(struct domain_device *dev, int *ecc)
{
    int res;
    u8  *rg_req;
    struct smp_resp  *rg_resp;

    rg_req = alloc_smp_req(RG_REQ_SIZE);
    if (!rg_req)
        return -ENOMEM;

    rg_resp = alloc_smp_resp(RG_RESP_SIZE);
    if (!rg_resp) {
        kfree(rg_req);
        return -ENOMEM;
    }

    rg_req[1] = SMP_REPORT_GENERAL;

    res = smp_execute_task(dev, rg_req, RG_REQ_SIZE, rg_resp,
                   RG_RESP_SIZE);
    if (res)
        goto out;
    if (rg_resp->result != SMP_RESP_FUNC_ACC) {
        res = rg_resp->result;
        goto out;
    }

    *ecc = be16_to_cpu(rg_resp->rg.change_count);
out:
    kfree(rg_resp);
    kfree(rg_req);
    return res;
}
static int sas_find_bcast_dev(struct domain_device *dev,
                  struct domain_device **src_dev)
{
    struct expander_device *ex = &dev->ex_dev;
    int ex_change_count = -1;
    int phy_id = -1;
    int res;
    struct domain_device *ch;

    res = sas_get_ex_change_count(dev, &ex_change_count);
    if (res)
        goto out;
    if (ex_change_count != -1 && ex_change_count != ex->ex_change_count) {
        /* Just detect if this expander phys phy change count changed,
        * in order to determine if this expander originate BROADCAST,
        * and do not update phy change count field in our structure.
        */
        res = sas_find_bcast_phy(dev, &phy_id, 0, false);
        if (phy_id != -1) {
            *src_dev = dev;
            ex->ex_change_count = ex_change_count;
            SAS_DPRINTK("Expander phy change count has changed\n");
            return res;
        } else
            SAS_DPRINTK("Expander phys DID NOT change\n");
    }
    list_for_each_entry(ch, &ex->children, siblings) {
        if (ch->dev_type == EDGE_DEV || ch->dev_type == FANOUT_DEV) {
            res = sas_find_bcast_dev(ch, src_dev);
            if (*src_dev)
                return res;
        }
    }
out:
    return res;
}

static void sas_unregister_ex_tree(struct asd_sas_port *port, struct domain_device *dev)
{
    struct expander_device *ex = &dev->ex_dev;
    struct domain_device *child, *n;

    list_for_each_entry_safe(child, n, &ex->children, siblings) {
        set_bit(SAS_DEV_GONE, &child->state);
        if (child->dev_type == EDGE_DEV ||
            child->dev_type == FANOUT_DEV)
            sas_unregister_ex_tree(port, child);
        else
            sas_unregister_dev(port, child);
    }
    sas_unregister_dev(port, dev);
}

static void sas_unregister_devs_sas_addr(struct domain_device *parent,
                     int phy_id, bool last)
{
    struct expander_device *ex_dev = &parent->ex_dev;
    struct ex_phy *phy = &ex_dev->ex_phy[phy_id];
    struct domain_device *child, *n, *found = NULL;
    if (last) {
        list_for_each_entry_safe(child, n,
            &ex_dev->children, siblings) {
            if (SAS_ADDR(child->sas_addr) ==
                SAS_ADDR(phy->attached_sas_addr)) {
                set_bit(SAS_DEV_GONE, &child->state);
                if (child->dev_type == EDGE_DEV ||
                    child->dev_type == FANOUT_DEV)
                    sas_unregister_ex_tree(parent->port, child);
                else
                    sas_unregister_dev(parent->port, child);
                found = child;
                break;
            }
        }
        sas_disable_routing(parent, phy->attached_sas_addr);
    }
    memset(phy->attached_sas_addr, 0, SAS_ADDR_SIZE);
    if (phy->port) {
        sas_port_delete_phy(phy->port, phy->phy);
        sas_device_set_phy(found, phy->port);
        if (phy->port->num_phys == 0)
            sas_port_delete(phy->port);
        phy->port = NULL;
    }
}

static int sas_discover_bfs_by_root_level(struct domain_device *root,
                      const int level)
{
    struct expander_device *ex_root = &root->ex_dev;
    struct domain_device *child;
    int res = 0;

    list_for_each_entry(child, &ex_root->children, siblings) {
        if (child->dev_type == EDGE_DEV ||
            child->dev_type == FANOUT_DEV) {
            struct sas_expander_device *ex =
                rphy_to_expander_device(child->rphy);

            if (level > ex->level)
                res = sas_discover_bfs_by_root_level(child,
                                     level);
            else if (level == ex->level)
                res = sas_ex_discover_devices(child, -1);
        }
    }
    return res;
}

static int sas_discover_bfs_by_root(struct domain_device *dev)
{
    int res;
    struct sas_expander_device *ex = rphy_to_expander_device(dev->rphy);
    int level = ex->level+1;

    res = sas_ex_discover_devices(dev, -1);
    if (res)
        goto out;
    do {
        res = sas_discover_bfs_by_root_level(dev, level);
        mb();
        level += 1;
    } while (level <= dev->port->disc.max_level);
out:
    return res;
}

static int sas_discover_new(struct domain_device *dev, int phy_id)
{
    struct ex_phy *ex_phy = &dev->ex_dev.ex_phy[phy_id];
    struct domain_device *child;
    int res;

    SAS_DPRINTK("ex %016llx phy%d new device attached\n",
            SAS_ADDR(dev->sas_addr), phy_id);
    res = sas_ex_phy_discover(dev, phy_id);
    if (res)
        return res;

    if (sas_ex_join_wide_port(dev, phy_id))
        return 0;

    res = sas_ex_discover_devices(dev, phy_id);
    if (res)
        return res;
    list_for_each_entry(child, &dev->ex_dev.children, siblings) {
        if (SAS_ADDR(child->sas_addr) ==
            SAS_ADDR(ex_phy->attached_sas_addr)) {
            if (child->dev_type == EDGE_DEV ||
                child->dev_type == FANOUT_DEV)
                res = sas_discover_bfs_by_root(child);
            break;
        }
    }
    return res;
}

static bool dev_type_flutter(enum sas_dev_type new, enum sas_dev_type old)
{
    if (old == new)
        return true;

    /* treat device directed resets as flutter, if we went
     * SAS_END_DEV to SATA_PENDING the link needs recovery
     */
    if ((old == SATA_PENDING && new == SAS_END_DEV) ||
        (old == SAS_END_DEV && new == SATA_PENDING))
        return true;

    return false;
}

static int sas_rediscover_dev(struct domain_device *dev, int phy_id, bool last)
{
    struct expander_device *ex = &dev->ex_dev;
    struct ex_phy *phy = &ex->ex_phy[phy_id];
    enum sas_dev_type type = NO_DEVICE;
    u8 sas_addr[8];
    int res;

    memset(sas_addr, 0, 8);
    res = sas_get_phy_attached_dev(dev, phy_id, sas_addr, &type);
    switch (res) {
    case SMP_RESP_NO_PHY:
        phy->phy_state = PHY_NOT_PRESENT;
        sas_unregister_devs_sas_addr(dev, phy_id, last);
        return res;
    case SMP_RESP_PHY_VACANT:
        phy->phy_state = PHY_VACANT;
        sas_unregister_devs_sas_addr(dev, phy_id, last);
        return res;
    case SMP_RESP_FUNC_ACC:
        break;
    case -ECOMM:
        break;
    default:
        return res;
    }

    if ((SAS_ADDR(sas_addr) == 0) || (res == -ECOMM)) {
        phy->phy_state = PHY_EMPTY;
        sas_unregister_devs_sas_addr(dev, phy_id, last);
        return res;
    } else if (SAS_ADDR(sas_addr) == SAS_ADDR(phy->attached_sas_addr) &&
           dev_type_flutter(type, phy->attached_dev_type)) {
        struct domain_device *ata_dev = sas_ex_to_ata(dev, phy_id);
        char *action = "";

        sas_ex_phy_discover(dev, phy_id);

        if (ata_dev && phy->attached_dev_type == SATA_PENDING)
            action = ", needs recovery";
        SAS_DPRINTK("ex %016llx phy 0x%x broadcast flutter%s\n",
                SAS_ADDR(dev->sas_addr), phy_id, action);
        return res;
    }

    /* delete the old link */
    if (SAS_ADDR(phy->attached_sas_addr) &&
        SAS_ADDR(sas_addr) != SAS_ADDR(phy->attached_sas_addr)) {
        SAS_DPRINTK("ex %016llx phy 0x%x replace %016llx\n",
                SAS_ADDR(dev->sas_addr), phy_id,
                SAS_ADDR(phy->attached_sas_addr));
        sas_unregister_devs_sas_addr(dev, phy_id, last);
    }

    return sas_discover_new(dev, phy_id);
}

static int sas_rediscover(struct domain_device *dev, const int phy_id)
{
    struct expander_device *ex = &dev->ex_dev;
    struct ex_phy *changed_phy = &ex->ex_phy[phy_id];
    int res = 0;
    int i;
    bool last = true;   /* is this the last phy of the port */

    SAS_DPRINTK("ex %016llx phy%d originated BROADCAST(CHANGE)\n",
            SAS_ADDR(dev->sas_addr), phy_id);

    if (SAS_ADDR(changed_phy->attached_sas_addr) != 0) {
        for (i = 0; i < ex->num_phys; i++) {
            struct ex_phy *phy = &ex->ex_phy[i];

            if (i == phy_id)
                continue;
            if (SAS_ADDR(phy->attached_sas_addr) ==
                SAS_ADDR(changed_phy->attached_sas_addr)) {
                SAS_DPRINTK("phy%d part of wide port with "
                        "phy%d\n", phy_id, i);
                last = false;
                break;
            }
        }
        res = sas_rediscover_dev(dev, phy_id, last);
    } else
        res = sas_discover_new(dev, phy_id);
    return res;
}

int sas_ex_revalidate_domain(struct domain_device *port_dev)
{
    int res;
    struct domain_device *dev = NULL;

    res = sas_find_bcast_dev(port_dev, &dev);
    while (res == 0 && dev) {
        struct expander_device *ex = &dev->ex_dev;
        int i = 0, phy_id;

        do {
            phy_id = -1;
            res = sas_find_bcast_phy(dev, &phy_id, i, true);
            if (phy_id == -1)
                break;
            res = sas_rediscover(dev, phy_id);
            i = phy_id + 1;
        } while (i < ex->num_phys);

        dev = NULL;
        res = sas_find_bcast_dev(port_dev, &dev);
    }
    return res;
}

int sas_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
            struct request *req)
{
    struct domain_device *dev;
    int ret, type;
    struct request *rsp = req->next_rq;

    if (!rsp) {
        printk("%s: space for a smp response is missing\n",
               __func__);
        return -EINVAL;
    }

    /* no rphy means no smp target support (ie aic94xx host) */
    if (!rphy)
        return sas_smp_host_handler(shost, req, rsp);

    type = rphy->identify.device_type;

    if (type != SAS_EDGE_EXPANDER_DEVICE &&
        type != SAS_FANOUT_EXPANDER_DEVICE) {
        printk("%s: can we send a smp request to a device?\n",
               __func__);
        return -EINVAL;
    }

    dev = sas_find_dev_by_rphy(rphy);
    if (!dev) {
        printk("%s: fail to find a domain_device?\n", __func__);
        return -EINVAL;
    }

    /* do we need to support multiple segments? */
    if (req->bio->bi_vcnt > 1 || rsp->bio->bi_vcnt > 1) {
        printk("%s: multiple segments req %u %u, rsp %u %u\n",
               __func__, req->bio->bi_vcnt, blk_rq_bytes(req),
               rsp->bio->bi_vcnt, blk_rq_bytes(rsp));
        return -EINVAL;
    }

    ret = smp_execute_task(dev, bio_data(req->bio), blk_rq_bytes(req),
                   bio_data(rsp->bio), blk_rq_bytes(rsp));
    if (ret > 0) {
        /* positive number is the untransferred residual */
        rsp->resid_len = ret;
        req->resid_len = 0;
        ret = 0;
    } else if (ret == 0) {
        rsp->resid_len = 0;
        req->resid_len = 0;
    }

    return ret;
}