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linux/drivers/scsi/libsas/sas_init.c
Dan Williams 87c8331fcf [SCSI] libsas: prevent domain rediscovery competing with ata error handling 
libata error handling provides for a timeout for link recovery.  libsas
must not rescan for previously known devices in this interval otherwise
it may remove a device that is simply waiting for its link to recover.
Let libata-eh make the determination of when the link is stable and
prevent libsas (host workqueue) from taking action while this
determination is pending.

Using a mutex (ha->disco_mutex) to flush and disable revalidation while
eh is running requires any discovery action that may block on eh be
moved to its own context outside the lock.  Probing ATA devices
explicitly waits on ata-eh and the cache-flush-io issued during device
removal may also pend awaiting eh completion.  Essentially any rphy
add/remove activity needs to run outside the lock.

This adds two new cleanup states for sas_unregister_domain_devices()
'allocated-but-not-probed', and 'flagged-for-destruction'.  In the
'allocated-but-not-probed' state  dev->rphy points to a rphy that is
known to have not been through a sas_rphy_add() event.  At domain
teardown check if this device is still pending probe and cleanup
accordingly.  Similarly if a device has already been queued for removal
then sas_unregister_domain_devices has nothing to do.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-02-19 13:52:34 -06:00

350 lines
9 KiB
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/*
* Serial Attached SCSI (SAS) Transport Layer initialization
*
* 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., 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/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;
init_timer(&task->timer);
init_completion(&task->completion);
}
return task;
}
EXPORT_SYMBOL_GPL(sas_alloc_task);
void sas_free_task(struct sas_task *task)
{
if (task) {
BUG_ON(!list_empty(&task->list));
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 =
container_of(work, struct 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->state_lock);
mutex_init(&sas_ha->drain_mutex);
INIT_LIST_HEAD(&sas_ha->defer_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);
return 0;
Undo_ports:
sas_unregister_ports(sas_ha);
Undo_phys:
return error;
}
int sas_unregister_ha(struct sas_ha_struct *sas_ha)
{
unsigned long flags;
/* Set the state to unregistered to avoid further unchained
* events to be queued
*/
spin_lock_irqsave(&sas_ha->state_lock, flags);
clear_bit(SAS_HA_REGISTERED, &sas_ha->state);
spin_unlock_irqrestore(&sas_ha->state_lock, flags);
sas_drain_work(sas_ha);
sas_unregister_ports(sas_ha);
sas_drain_work(sas_ha);
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_phy_enable(struct sas_phy *phy, int enable)
{
int ret;
enum phy_func command;
if (enable)
command = PHY_FUNC_LINK_RESET;
else
command = 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) {
sas_phy_disconnected(asd_phy);
sas_ha->notify_phy_event(asd_phy, PHYE_LOSS_OF_SIGNAL);
}
ret = i->dft->lldd_control_phy(asd_phy, command, 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, command, NULL);
}
return ret;
}
int sas_phy_reset(struct sas_phy *phy, int hard_reset)
{
int ret;
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);
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;
}
static struct sas_function_template sft = {
.phy_enable = sas_phy_enable,
.phy_reset = sas_phy_reset,
.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 <luben_tuikov@adaptec.com>");
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);
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