[PATCH v5 4/7] libsas: route local link resets through ata-eh

[Dan Williams <dan.j.williams@intel.com>]

Similar to the conversion of the transport-class reset we want bsg
initiated resets to be managed by libata.

Reported-by: Jacek Danecki <jacek.danecki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/scsi/libsas/sas_host_smp.c |   11 ++++++++-
 drivers/scsi/libsas/sas_init.c     |   45 +++++++++++++++++++++---------------
 drivers/scsi/libsas/sas_internal.h |    1 +
 3 files changed, 37 insertions(+), 20 deletions(-)

diff --git a/drivers/scsi/libsas/sas_host_smp.c b/drivers/scsi/libsas/sas_host_smp.c
index bb8f492..e921e53 100644
--- a/drivers/scsi/libsas/sas_host_smp.c
+++ b/drivers/scsi/libsas/sas_host_smp.c
@@ -187,11 +187,14 @@ static void sas_phy_control(struct sas_ha_struct *sas_ha, u8 phy_id,
 	struct sas_internal *i =
 		to_sas_internal(sas_ha->core.shost->transportt);
 	struct sas_phy_linkrates rates;
+	struct asd_sas_phy *asd_phy;
 
 	if (phy_id >= sas_ha->num_phys) {
 		resp_data[2] = SMP_RESP_NO_PHY;
 		return;
 	}
+
+	asd_phy = sas_ha->sas_phy[phy_id];
 	switch (phy_op) {
 	case PHY_FUNC_NOP:
 	case PHY_FUNC_LINK_RESET:
@@ -210,7 +213,13 @@ static void sas_phy_control(struct sas_ha_struct *sas_ha, u8 phy_id,
 	rates.minimum_linkrate = min;
 	rates.maximum_linkrate = max;
 
-	if (i->dft->lldd_control_phy(sas_ha->sas_phy[phy_id], phy_op, &rates))
+	/* filter reset requests through libata eh */
+	if (phy_op == PHY_FUNC_LINK_RESET && sas_try_ata_reset(asd_phy) == 0) {
+		resp_data[2] = SMP_RESP_FUNC_ACC;
+		return;
+	}
+
+	if (i->dft->lldd_control_phy(asd_phy, phy_op, &rates))
 		resp_data[2] = SMP_RESP_FUNC_FAILED;
 	else
 		resp_data[2] = SMP_RESP_FUNC_ACC;
diff --git a/drivers/scsi/libsas/sas_init.c b/drivers/scsi/libsas/sas_init.c
index cf1b532..dc93e118 100644
--- a/drivers/scsi/libsas/sas_init.c
+++ b/drivers/scsi/libsas/sas_init.c
@@ -196,6 +196,27 @@ static int sas_get_linkerrors(struct sas_phy *phy)
 	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;
+}
+
 /**
  * transport_sas_phy_reset - reset a phy and permit libata to manage the link
  *
@@ -204,7 +225,6 @@ static int sas_get_linkerrors(struct sas_phy *phy)
  */
 static int transport_sas_phy_reset(struct sas_phy *phy, int hard_reset)
 {
-	int ret;
 	enum phy_func reset_type;
 
 	if (hard_reset)
@@ -218,21 +238,10 @@ static int transport_sas_phy_reset(struct sas_phy *phy, int hard_reset)
 		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
 		struct sas_internal *i =
 			to_sas_internal(sas_ha->core.shost->transportt);
-		struct domain_device *dev = NULL;
-
-		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) && !hard_reset) {
-			sas_ata_schedule_reset(dev);
-			sas_ata_wait_eh(dev);
-			ret = 0;
-		} else
-			ret = i->dft->lldd_control_phy(asd_phy, reset_type, NULL);
+		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);
@@ -241,12 +250,10 @@ static int transport_sas_phy_reset(struct sas_phy *phy, int hard_reset)
 		if (ata_dev && !hard_reset) {
 			sas_ata_schedule_reset(ata_dev);
 			sas_ata_wait_eh(ata_dev);
-			ret = 0;
+			return 0;
 		} else
-			ret = sas_smp_phy_control(ddev, phy->number, reset_type, NULL);
+			return sas_smp_phy_control(ddev, phy->number, reset_type, NULL);
 	}
-
-	return ret;
 }
 
 static int sas_phy_enable(struct sas_phy *phy, int enable)
diff --git a/drivers/scsi/libsas/sas_internal.h b/drivers/scsi/libsas/sas_internal.h
index c8febc7..4157f6e 100644
--- a/drivers/scsi/libsas/sas_internal.h
+++ b/drivers/scsi/libsas/sas_internal.h
@@ -92,6 +92,7 @@ struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy);
 struct domain_device *sas_ex_to_ata(struct domain_device *ex_dev, int phy_id);
 int sas_get_phy_attached_sas_addr(struct domain_device *dev, int phy_id,
 				  u8 *attached_sas_addr);
+int sas_try_ata_reset(struct asd_sas_phy *phy);
 void sas_hae_reset(struct work_struct *work);
 
 void sas_free_device(struct kref *kref);