[PATCH v3 05/14] libsas: perform sas-transport resets in shost->workq context

Dan Williams
2012-01-06T00:59:26Z

Extend the sas transport class to allow transport users to attach extra
data to a sas_phy (->hostdata). Use this area in libsas to move resets
to workq context in preparation for scheduling ata device resets through
libata-eh.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/scsi/libsas/sas_event.c | 2 +
drivers/scsi/libsas/sas_init.c | 59 +++++++++++++++++++++++++++++++++++-
drivers/scsi/libsas/sas_internal.h | 10 ++++++
drivers/scsi/scsi_transport_sas.c | 18 ++++++++++-
include/scsi/scsi_transport_sas.h | 5 ++-
5 files changed, 90 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/libsas/sas_event.c b/drivers/scsi/libsas/sas_event.c
index 933d757..dbfacee 100644
--- a/drivers/scsi/libsas/sas_event.c
+++ b/drivers/scsi/libsas/sas_event.c
@@ -27,7 +27,7 @@
#include "sas_internal.h"
#include "sas_dump.h"

-static void sas_queue_work(struct sas_ha_struct *ha, struct work_struct *work)
+void sas_queue_work(struct sas_ha_struct *ha, struct work_struct *work)
{
if (!test_bit(SAS_HA_REGISTERED, &ha->state))
return;
diff --git a/drivers/scsi/libsas/sas_init.c b/drivers/scsi/libsas/sas_init.c
index e17fe35..cb65adf 100644
--- a/drivers/scsi/libsas/sas_init.c
+++ b/drivers/scsi/libsas/sas_init.c
@@ -290,9 +290,66 @@ int sas_set_phy_speed(struct sas_phy *phy,
return ret;
}

+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);
+
+ d->reset_result = sas_phy_reset(d->phy, d->hard_reset);
+}
+
+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_WORK(&d->reset_work, phy_reset_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->state_lock);
+ sas_queue_work(ha, &d->reset_work);
+ spin_unlock_irq(&ha->state_lock);
+
+ rc = sas_drain_work(ha);
+ if (rc == 0)
+ rc = d->reset_result;
+ mutex_unlock(&d->event_lock);
+
+ return rc;
+}
+
static struct sas_function_template sft = {
.phy_enable = sas_phy_enable,
- .phy_reset = sas_phy_reset,
+ .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,
diff --git a/drivers/scsi/libsas/sas_internal.h b/drivers/scsi/libsas/sas_internal.h
index 662ffcb..9ba65e0 100644
--- a/drivers/scsi/libsas/sas_internal.h
+++ b/drivers/scsi/libsas/sas_internal.h
@@ -38,6 +38,15 @@
#define TO_SAS_TASK(_scsi_cmd) ((void *)(_scsi_cmd)->host_scribble)
#define ASSIGN_SAS_TASK(_sc, _t) do { (_sc)->host_scribble = (void *) _t; } while (0)

+struct sas_phy_data {
+ /* let reset be performed in sas_queue_work() context */
+ struct sas_phy *phy;
+ struct mutex event_lock;
+ int hard_reset;
+ int reset_result;
+ struct work_struct reset_work;
+};
+
void sas_scsi_recover_host(struct Scsi_Host *shost);

int sas_show_class(enum sas_class class, char *buf);
@@ -66,6 +75,7 @@ void sas_porte_broadcast_rcvd(struct work_struct *work);
void sas_porte_link_reset_err(struct work_struct *work);
void sas_porte_timer_event(struct work_struct *work);
void sas_porte_hard_reset(struct work_struct *work);
+void sas_queue_work(struct sas_ha_struct *ha, struct work_struct *work);

int sas_notify_lldd_dev_found(struct domain_device *);
void sas_notify_lldd_dev_gone(struct domain_device *);
diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c
index 9421bae..ab3bd0b 100644
--- a/drivers/scsi/scsi_transport_sas.c
+++ b/drivers/scsi/scsi_transport_sas.c
@@ -652,9 +652,21 @@ sas_phy_linkerror_attr(running_disparity_error_count);
sas_phy_linkerror_attr(loss_of_dword_sync_count);
sas_phy_linkerror_attr(phy_reset_problem_count);

+static int sas_phy_setup(struct transport_container *tc, struct device *dev,
+ struct device *cdev)
+{
+ struct sas_phy *phy = dev_to_phy(dev);
+ struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
+ struct sas_internal *i = to_sas_internal(shost->transportt);
+
+ if (i->f->phy_setup)
+ i->f->phy_setup(phy);
+
+ return 0;
+}

static DECLARE_TRANSPORT_CLASS(sas_phy_class,
- "sas_phy", NULL, NULL, NULL);
+ "sas_phy", sas_phy_setup, NULL, NULL);

static int sas_phy_match(struct attribute_container *cont, struct device *dev)
{
@@ -678,7 +690,11 @@ static int sas_phy_match(struct attribute_container *cont, struct device *dev)
static void sas_phy_release(struct device *dev)
{
struct sas_phy *phy = dev_to_phy(dev);
+ struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
+ struct sas_internal *i = to_sas_internal(shost->transportt);

+ if (i->f->phy_release)
+ i->f->phy_release(phy);
put_device(dev->parent);
kfree(phy);
}
diff --git a/include/scsi/scsi_transport_sas.h b/include/scsi/scsi_transport_sas.h
index 6d14daa..42817fa 100644
--- a/include/scsi/scsi_transport_sas.h
+++ b/include/scsi/scsi_transport_sas.h
@@ -75,7 +75,8 @@ struct sas_phy {
/* for the list of phys belonging to a port */
struct list_head port_siblings;

- struct work_struct reset_work;
+ /* available to the lldd */
+ void *hostdata;
};

#define dev_to_phy(d) \
@@ -169,6 +170,8 @@ struct sas_function_template {
int (*get_bay_identifier)(struct sas_rphy *);
int (*phy_reset)(struct sas_phy *, int);
int (*phy_enable)(struct sas_phy *, int);
+ int (*phy_setup)(struct sas_phy *);
+ void (*phy_release)(struct sas_phy *);
int (*set_phy_speed)(struct sas_phy *, struct sas_phy_linkrates *);
int (*smp_handler)(struct Scsi_Host *, struct sas_rphy *, struct request *);
};