linux_dsm_epyc7002/drivers/scsi/libsas/sas_event.c
Johannes Thumshirn 6d311fa7d2 scsi: sas: scsi_queue_work can fail, so make callers aware
libsas uses scsi_queue_work() to queue its internal event notifications.
scsi_queue_work() can return -EINVAL if the work queue doesn't exist and
it does call queue_work() which can return false if the work is already
queued.

Make the SAS event code capable of returning errors up to the caller,
which is handy when changing to dynamically allocated work in libsas
as well, as discussed here: https://lkml.org/lkml/2017/6/14/121.

[mkp: fixed typo]

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-06-27 21:28:04 -04:00

174 lines
4.3 KiB
C

/*
* Serial Attached SCSI (SAS) Event processing
*
* 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 <linux/export.h>
#include <scsi/scsi_host.h>
#include "sas_internal.h"
#include "sas_dump.h"
int sas_queue_work(struct sas_ha_struct *ha, struct sas_work *sw)
{
int rc = 0;
if (!test_bit(SAS_HA_REGISTERED, &ha->state))
return 0;
if (test_bit(SAS_HA_DRAINING, &ha->state)) {
/* add it to the defer list, if not already pending */
if (list_empty(&sw->drain_node))
list_add(&sw->drain_node, &ha->defer_q);
} else
rc = scsi_queue_work(ha->core.shost, &sw->work);
return rc;
}
static int sas_queue_event(int event, unsigned long *pending,
struct sas_work *work,
struct sas_ha_struct *ha)
{
int rc = 0;
if (!test_and_set_bit(event, pending)) {
unsigned long flags;
spin_lock_irqsave(&ha->lock, flags);
rc = sas_queue_work(ha, work);
spin_unlock_irqrestore(&ha->lock, flags);
}
return rc;
}
void __sas_drain_work(struct sas_ha_struct *ha)
{
struct workqueue_struct *wq = ha->core.shost->work_q;
struct sas_work *sw, *_sw;
set_bit(SAS_HA_DRAINING, &ha->state);
/* flush submitters */
spin_lock_irq(&ha->lock);
spin_unlock_irq(&ha->lock);
drain_workqueue(wq);
spin_lock_irq(&ha->lock);
clear_bit(SAS_HA_DRAINING, &ha->state);
list_for_each_entry_safe(sw, _sw, &ha->defer_q, drain_node) {
list_del_init(&sw->drain_node);
sas_queue_work(ha, sw);
}
spin_unlock_irq(&ha->lock);
}
int sas_drain_work(struct sas_ha_struct *ha)
{
int err;
err = mutex_lock_interruptible(&ha->drain_mutex);
if (err)
return err;
if (test_bit(SAS_HA_REGISTERED, &ha->state))
__sas_drain_work(ha);
mutex_unlock(&ha->drain_mutex);
return 0;
}
EXPORT_SYMBOL_GPL(sas_drain_work);
void sas_disable_revalidation(struct sas_ha_struct *ha)
{
mutex_lock(&ha->disco_mutex);
set_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state);
mutex_unlock(&ha->disco_mutex);
}
void sas_enable_revalidation(struct sas_ha_struct *ha)
{
int i;
mutex_lock(&ha->disco_mutex);
clear_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state);
for (i = 0; i < ha->num_phys; i++) {
struct asd_sas_port *port = ha->sas_port[i];
const int ev = DISCE_REVALIDATE_DOMAIN;
struct sas_discovery *d = &port->disc;
if (!test_and_clear_bit(ev, &d->pending))
continue;
sas_queue_event(ev, &d->pending, &d->disc_work[ev].work, ha);
}
mutex_unlock(&ha->disco_mutex);
}
static int notify_ha_event(struct sas_ha_struct *sas_ha, enum ha_event event)
{
BUG_ON(event >= HA_NUM_EVENTS);
return sas_queue_event(event, &sas_ha->pending,
&sas_ha->ha_events[event].work, sas_ha);
}
static int notify_port_event(struct asd_sas_phy *phy, enum port_event event)
{
struct sas_ha_struct *ha = phy->ha;
BUG_ON(event >= PORT_NUM_EVENTS);
return sas_queue_event(event, &phy->port_events_pending,
&phy->port_events[event].work, ha);
}
int sas_notify_phy_event(struct asd_sas_phy *phy, enum phy_event event)
{
struct sas_ha_struct *ha = phy->ha;
BUG_ON(event >= PHY_NUM_EVENTS);
return sas_queue_event(event, &phy->phy_events_pending,
&phy->phy_events[event].work, ha);
}
int sas_init_events(struct sas_ha_struct *sas_ha)
{
static const work_func_t sas_ha_event_fns[HA_NUM_EVENTS] = {
[HAE_RESET] = sas_hae_reset,
};
int i;
for (i = 0; i < HA_NUM_EVENTS; i++) {
INIT_SAS_WORK(&sas_ha->ha_events[i].work, sas_ha_event_fns[i]);
sas_ha->ha_events[i].ha = sas_ha;
}
sas_ha->notify_ha_event = notify_ha_event;
sas_ha->notify_port_event = notify_port_event;
sas_ha->notify_phy_event = sas_notify_phy_event;
return 0;
}