sas_init.c

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/*
 * Serial Attached SCSI (SAS) Transport Layer initialization
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 *
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/spinlock.h>
#include <scsi/sas_ata.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_sas.h>

#include "sas_internal.h"

#include "../scsi_sas_internal.h"

static struct kmem_cache *sas_task_cache;

struct sas_task *sas_alloc_task(gfp_t flags)
{
    struct sas_task *task = kmem_cache_zalloc(sas_task_cache, flags);

    if (task) {
        INIT_LIST_HEAD(&task->list);
        spin_lock_init(&task->task_state_lock);
        task->task_state_flags = SAS_TASK_STATE_PENDING;
    }

    return task;
}
EXPORT_SYMBOL_GPL(sas_alloc_task);

struct sas_task *sas_alloc_slow_task(gfp_t flags)
{
    struct sas_task *task = sas_alloc_task(flags);
    struct sas_task_slow *slow = kmalloc(sizeof(*slow), flags);

    if (!task || !slow) {
        if (task)
            kmem_cache_free(sas_task_cache, task);
        kfree(slow);
        return NULL;
    }

    task->slow_task = slow;
    init_timer(&slow->timer);
    init_completion(&slow->completion);

    return task;
}
EXPORT_SYMBOL_GPL(sas_alloc_slow_task);

void sas_free_task(struct sas_task *task)
{
    if (task) {
        BUG_ON(!list_empty(&task->list));
        kfree(task->slow_task);
        kmem_cache_free(sas_task_cache, task);
    }
}
EXPORT_SYMBOL_GPL(sas_free_task);

/*------------ SAS addr hash -----------*/
void sas_hash_addr(u8 *hashed, const u8 *sas_addr)
{
        const u32 poly = 0x00DB2777;
        u32     r = 0;
        int     i;

        for (i = 0; i < 8; i++) {
                int b;
                for (b = 7; b >= 0; b--) {
                        r <<= 1;
                        if ((1 << b) & sas_addr[i]) {
                                if (!(r & 0x01000000))
                                        r ^= poly;
                        } else if (r & 0x01000000)
                                r ^= poly;
                }
        }

        hashed[0] = (r >> 16) & 0xFF;
        hashed[1] = (r >> 8) & 0xFF ;
        hashed[2] = r & 0xFF;
}


/* ---------- HA events ---------- */

void sas_hae_reset(struct work_struct *work)
{
    struct sas_ha_event *ev = to_sas_ha_event(work);
    struct sas_ha_struct *ha = ev->ha;

    clear_bit(HAE_RESET, &ha->pending);
}

int sas_register_ha(struct sas_ha_struct *sas_ha)
{
    int error = 0;

    mutex_init(&sas_ha->disco_mutex);
    spin_lock_init(&sas_ha->phy_port_lock);
    sas_hash_addr(sas_ha->hashed_sas_addr, sas_ha->sas_addr);

    if (sas_ha->lldd_queue_size == 0)
        sas_ha->lldd_queue_size = 1;
    else if (sas_ha->lldd_queue_size == -1)
        sas_ha->lldd_queue_size = 128; /* Sanity */

    set_bit(SAS_HA_REGISTERED, &sas_ha->state);
    spin_lock_init(&sas_ha->lock);
    mutex_init(&sas_ha->drain_mutex);
    init_waitqueue_head(&sas_ha->eh_wait_q);
    INIT_LIST_HEAD(&sas_ha->defer_q);
    INIT_LIST_HEAD(&sas_ha->eh_dev_q);

    error = sas_register_phys(sas_ha);
    if (error) {
        printk(KERN_NOTICE "couldn't register sas phys:%d\n", error);
        return error;
    }

    error = sas_register_ports(sas_ha);
    if (error) {
        printk(KERN_NOTICE "couldn't register sas ports:%d\n", error);
        goto Undo_phys;
    }

    error = sas_init_events(sas_ha);
    if (error) {
        printk(KERN_NOTICE "couldn't start event thread:%d\n", error);
        goto Undo_ports;
    }

    if (sas_ha->lldd_max_execute_num > 1) {
        error = sas_init_queue(sas_ha);
        if (error) {
            printk(KERN_NOTICE "couldn't start queue thread:%d, "
                   "running in direct mode\n", error);
            sas_ha->lldd_max_execute_num = 1;
        }
    }

    INIT_LIST_HEAD(&sas_ha->eh_done_q);
    INIT_LIST_HEAD(&sas_ha->eh_ata_q);

    return 0;

Undo_ports:
    sas_unregister_ports(sas_ha);
Undo_phys:

    return error;
}

static void sas_disable_events(struct sas_ha_struct *sas_ha)
{
    /* Set the state to unregistered to avoid further unchained
     * events to be queued, and flush any in-progress drainers
     */
    mutex_lock(&sas_ha->drain_mutex);
    spin_lock_irq(&sas_ha->lock);
    clear_bit(SAS_HA_REGISTERED, &sas_ha->state);
    spin_unlock_irq(&sas_ha->lock);
    __sas_drain_work(sas_ha);
    mutex_unlock(&sas_ha->drain_mutex);
}

int sas_unregister_ha(struct sas_ha_struct *sas_ha)
{
    sas_disable_events(sas_ha);
    sas_unregister_ports(sas_ha);

    /* flush unregistration work */
    mutex_lock(&sas_ha->drain_mutex);
    __sas_drain_work(sas_ha);
    mutex_unlock(&sas_ha->drain_mutex);

    if (sas_ha->lldd_max_execute_num > 1) {
        sas_shutdown_queue(sas_ha);
        sas_ha->lldd_max_execute_num = 1;
    }

    return 0;
}

static int sas_get_linkerrors(struct sas_phy *phy)
{
    if (scsi_is_sas_phy_local(phy)) {
        struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
        struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
        struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
        struct sas_internal *i =
            to_sas_internal(sas_ha->core.shost->transportt);

        return i->dft->lldd_control_phy(asd_phy, PHY_FUNC_GET_EVENTS, NULL);
    }

    return sas_smp_get_phy_events(phy);
}

int sas_try_ata_reset(struct asd_sas_phy *asd_phy)
{
    struct domain_device *dev = NULL;

    /* try to route user requested link resets through libata */
    if (asd_phy->port)
        dev = asd_phy->port->port_dev;

    /* validate that dev has been probed */
    if (dev)
        dev = sas_find_dev_by_rphy(dev->rphy);

    if (dev && dev_is_sata(dev)) {
        sas_ata_schedule_reset(dev);
        sas_ata_wait_eh(dev);
        return 0;
    }

    return -ENODEV;
}

static int transport_sas_phy_reset(struct sas_phy *phy, int hard_reset)
{
    enum phy_func reset_type;

    if (hard_reset)
        reset_type = PHY_FUNC_HARD_RESET;
    else
        reset_type = PHY_FUNC_LINK_RESET;

    if (scsi_is_sas_phy_local(phy)) {
        struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
        struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
        struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
        struct sas_internal *i =
            to_sas_internal(sas_ha->core.shost->transportt);

        if (!hard_reset && sas_try_ata_reset(asd_phy) == 0)
            return 0;
        return i->dft->lldd_control_phy(asd_phy, reset_type, NULL);
    } else {
        struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
        struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
        struct domain_device *ata_dev = sas_ex_to_ata(ddev, phy->number);

        if (ata_dev && !hard_reset) {
            sas_ata_schedule_reset(ata_dev);
            sas_ata_wait_eh(ata_dev);
            return 0;
        } else
            return sas_smp_phy_control(ddev, phy->number, reset_type, NULL);
    }
}

static int sas_phy_enable(struct sas_phy *phy, int enable)
{
    int ret;
    enum phy_func cmd;

    if (enable)
        cmd = PHY_FUNC_LINK_RESET;
    else
        cmd = PHY_FUNC_DISABLE;

    if (scsi_is_sas_phy_local(phy)) {
        struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
        struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
        struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
        struct sas_internal *i =
            to_sas_internal(sas_ha->core.shost->transportt);

        if (enable)
            ret = transport_sas_phy_reset(phy, 0);
        else
            ret = i->dft->lldd_control_phy(asd_phy, cmd, NULL);
    } else {
        struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
        struct domain_device *ddev = sas_find_dev_by_rphy(rphy);

        if (enable)
            ret = transport_sas_phy_reset(phy, 0);
        else
            ret = sas_smp_phy_control(ddev, phy->number, cmd, NULL);
    }
    return ret;
}

int sas_phy_reset(struct sas_phy *phy, int hard_reset)
{
    int ret;
    enum phy_func reset_type;

    if (!phy->enabled)
        return -ENODEV;

    if (hard_reset)
        reset_type = PHY_FUNC_HARD_RESET;
    else
        reset_type = PHY_FUNC_LINK_RESET;

    if (scsi_is_sas_phy_local(phy)) {
        struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
        struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
        struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
        struct sas_internal *i =
            to_sas_internal(sas_ha->core.shost->transportt);

        ret = i->dft->lldd_control_phy(asd_phy, reset_type, NULL);
    } else {
        struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
        struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
        ret = sas_smp_phy_control(ddev, phy->number, reset_type, NULL);
    }
    return ret;
}

int sas_set_phy_speed(struct sas_phy *phy,
              struct sas_phy_linkrates *rates)
{
    int ret;

    if ((rates->minimum_linkrate &&
         rates->minimum_linkrate > phy->maximum_linkrate) ||
        (rates->maximum_linkrate &&
         rates->maximum_linkrate < phy->minimum_linkrate))
        return -EINVAL;

    if (rates->minimum_linkrate &&
        rates->minimum_linkrate < phy->minimum_linkrate_hw)
        rates->minimum_linkrate = phy->minimum_linkrate_hw;

    if (rates->maximum_linkrate &&
        rates->maximum_linkrate > phy->maximum_linkrate_hw)
        rates->maximum_linkrate = phy->maximum_linkrate_hw;

    if (scsi_is_sas_phy_local(phy)) {
        struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
        struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
        struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
        struct sas_internal *i =
            to_sas_internal(sas_ha->core.shost->transportt);

        ret = i->dft->lldd_control_phy(asd_phy, PHY_FUNC_SET_LINK_RATE,
                           rates);
    } else {
        struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
        struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
        ret = sas_smp_phy_control(ddev, phy->number,
                      PHY_FUNC_LINK_RESET, rates);

    }

    return ret;
}

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

    set_bit(SAS_HA_REGISTERED, &ha->state);

    /* clear out any stale link events/data from the suspension path */
    for (i = 0; i < ha->num_phys; i++) {
        struct asd_sas_phy *phy = ha->sas_phy[i];

        memset(phy->attached_sas_addr, 0, SAS_ADDR_SIZE);
        phy->port_events_pending = 0;
        phy->phy_events_pending = 0;
        phy->frame_rcvd_size = 0;
    }
}
EXPORT_SYMBOL(sas_prep_resume_ha);

static int phys_suspended(struct sas_ha_struct *ha)
{
    int i, rc = 0;

    for (i = 0; i < ha->num_phys; i++) {
        struct asd_sas_phy *phy = ha->sas_phy[i];

        if (phy->suspended)
            rc++;
    }

    return rc;
}

void sas_resume_ha(struct sas_ha_struct *ha)
{
    const unsigned long tmo = msecs_to_jiffies(25000);
    int i;

    /* deform ports on phys that did not resume
     * at this point we may be racing the phy coming back (as posted
     * by the lldd).  So we post the event and once we are in the
     * libsas context check that the phy remains suspended before
     * tearing it down.
     */
    i = phys_suspended(ha);
    if (i)
        dev_info(ha->dev, "waiting up to 25 seconds for %d phy%s to resume\n",
             i, i > 1 ? "s" : "");
    wait_event_timeout(ha->eh_wait_q, phys_suspended(ha) == 0, tmo);
    for (i = 0; i < ha->num_phys; i++) {
        struct asd_sas_phy *phy = ha->sas_phy[i];

        if (phy->suspended) {
            dev_warn(&phy->phy->dev, "resume timeout\n");
            sas_notify_phy_event(phy, PHYE_RESUME_TIMEOUT);
        }
    }

    /* all phys are back up or timed out, turn on i/o so we can
     * flush out disks that did not return
     */
    scsi_unblock_requests(ha->core.shost);
    sas_drain_work(ha);
}
EXPORT_SYMBOL(sas_resume_ha);

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

    sas_disable_events(ha);
    scsi_block_requests(ha->core.shost);
    for (i = 0; i < ha->num_phys; i++) {
        struct asd_sas_port *port = ha->sas_port[i];

        sas_discover_event(port, DISCE_SUSPEND);
    }

    /* flush suspend events while unregistered */
    mutex_lock(&ha->drain_mutex);
    __sas_drain_work(ha);
    mutex_unlock(&ha->drain_mutex);
}
EXPORT_SYMBOL(sas_suspend_ha);

static void sas_phy_release(struct sas_phy *phy)
{
    kfree(phy->hostdata);
    phy->hostdata = NULL;
}

static void phy_reset_work(struct work_struct *work)
{
    struct sas_phy_data *d = container_of(work, typeof(*d), reset_work.work);

    d->reset_result = transport_sas_phy_reset(d->phy, d->hard_reset);
}

static void phy_enable_work(struct work_struct *work)
{
    struct sas_phy_data *d = container_of(work, typeof(*d), enable_work.work);

    d->enable_result = sas_phy_enable(d->phy, d->enable);
}

static int sas_phy_setup(struct sas_phy *phy)
{
    struct sas_phy_data *d = kzalloc(sizeof(*d), GFP_KERNEL);

    if (!d)
        return -ENOMEM;

    mutex_init(&d->event_lock);
    INIT_SAS_WORK(&d->reset_work, phy_reset_work);
    INIT_SAS_WORK(&d->enable_work, phy_enable_work);
    d->phy = phy;
    phy->hostdata = d;

    return 0;
}

static int queue_phy_reset(struct sas_phy *phy, int hard_reset)
{
    struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
    struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
    struct sas_phy_data *d = phy->hostdata;
    int rc;

    if (!d)
        return -ENOMEM;

    /* libsas workqueue coordinates ata-eh reset with discovery */
    mutex_lock(&d->event_lock);
    d->reset_result = 0;
    d->hard_reset = hard_reset;

    spin_lock_irq(&ha->lock);
    sas_queue_work(ha, &d->reset_work);
    spin_unlock_irq(&ha->lock);

    rc = sas_drain_work(ha);
    if (rc == 0)
        rc = d->reset_result;
    mutex_unlock(&d->event_lock);

    return rc;
}

static int queue_phy_enable(struct sas_phy *phy, int enable)
{
    struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
    struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
    struct sas_phy_data *d = phy->hostdata;
    int rc;

    if (!d)
        return -ENOMEM;

    /* libsas workqueue coordinates ata-eh reset with discovery */
    mutex_lock(&d->event_lock);
    d->enable_result = 0;
    d->enable = enable;

    spin_lock_irq(&ha->lock);
    sas_queue_work(ha, &d->enable_work);
    spin_unlock_irq(&ha->lock);

    rc = sas_drain_work(ha);
    if (rc == 0)
        rc = d->enable_result;
    mutex_unlock(&d->event_lock);

    return rc;
}

static struct sas_function_template sft = {
    .phy_enable = queue_phy_enable,
    .phy_reset = queue_phy_reset,
    .phy_setup = sas_phy_setup,
    .phy_release = sas_phy_release,
    .set_phy_speed = sas_set_phy_speed,
    .get_linkerrors = sas_get_linkerrors,
    .smp_handler = sas_smp_handler,
};

struct scsi_transport_template *
sas_domain_attach_transport(struct sas_domain_function_template *dft)
{
    struct scsi_transport_template *stt = sas_attach_transport(&sft);
    struct sas_internal *i;

    if (!stt)
        return stt;

    i = to_sas_internal(stt);
    i->dft = dft;
    stt->create_work_queue = 1;
    stt->eh_timed_out = sas_scsi_timed_out;
    stt->eh_strategy_handler = sas_scsi_recover_host;

    return stt;
}
EXPORT_SYMBOL_GPL(sas_domain_attach_transport);


void sas_domain_release_transport(struct scsi_transport_template *stt)
{
    sas_release_transport(stt);
}
EXPORT_SYMBOL_GPL(sas_domain_release_transport);

/* ---------- SAS Class register/unregister ---------- */

static int __init sas_class_init(void)
{
    sas_task_cache = KMEM_CACHE(sas_task, SLAB_HWCACHE_ALIGN);
    if (!sas_task_cache)
        return -ENOMEM;

    return 0;
}

static void __exit sas_class_exit(void)
{
    kmem_cache_destroy(sas_task_cache);
}

MODULE_AUTHOR("Luben Tuikov <[email protected]>");
MODULE_DESCRIPTION("SAS Transport Layer");
MODULE_LICENSE("GPL v2");

module_init(sas_class_init);
module_exit(sas_class_exit);

EXPORT_SYMBOL_GPL(sas_register_ha);
EXPORT_SYMBOL_GPL(sas_unregister_ha);