[SCSI] isci: export phy events via ->lldd_control_phy()

Allow the sas-transport-class to update events for local phys via a new
PHY_FUNC_GET_EVENTS command to ->lldd_control_phy().  Fixup drivers that
are not prepared for new enum phy_func values, and unify
->lldd_control_phy() error codes.

These are the SAS defined phy events that are reported in a
smp-report-phy-error-log command:
 * /sys/class/sas_phy/<phyX>/invalid_dword_count
 * /sys/class/sas_phy/<phyX>/running_disparity_error_count
 * /sys/class/sas_phy/<phyX>/loss_of_dword_sync_count
 * /sys/class/sas_phy/<phyX>/phy_reset_problem_count

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/libsas/sas_init.c b/drivers/scsi/libsas/sas_init.c
index dd56ea8..d81c3b1 100644
--- a/drivers/scsi/libsas/sas_init.c
+++ b/drivers/scsi/libsas/sas_init.c
@@ -177,10 +177,15 @@
 
 static int sas_get_linkerrors(struct sas_phy *phy)
 {
-	if (scsi_is_sas_phy_local(phy))
-		/* FIXME: we have no local phy stats
-		 * gathering at this time */
-		return -EINVAL;
+	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);
 }