[SCSI] scsi_transport_sas: add support for transport layer retries (TLR)

The mpt2sas driver wants to use transport layer retries (TLR) so the
simplest thing to do seems to be to add the enabling flags and checks
to the SAS transport class, since they're a SAS specific protocol
feature.

Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/scsi/scsi_transport_sas.h b/include/scsi/scsi_transport_sas.h
index 61ad3594aad..ffeebc34a4f 100644
--- a/include/scsi/scsi_transport_sas.h
+++ b/include/scsi/scsi_transport_sas.h
@@ -107,6 +107,8 @@ struct sas_end_device {
         struct sas_rphy         rphy;
         /* flags */
         unsigned                ready_led_meaning:1;
+        unsigned                tlr_supported:1;
+        unsigned                tlr_enabled:1;
         /* parameters */
         u16                     I_T_nexus_loss_timeout;
         u16                     initiator_response_timeout;
@@ -181,6 +183,11 @@ extern int sas_phy_add(struct sas_phy *);
 extern void sas_phy_delete(struct sas_phy *);
 extern int scsi_is_sas_phy(const struct device *);
 
+unsigned int sas_tlr_supported(struct scsi_device *);
+unsigned int sas_is_tlr_enabled(struct scsi_device *);
+void sas_disable_tlr(struct scsi_device *);
+void sas_enable_tlr(struct scsi_device *);
+
 extern struct sas_rphy *sas_end_device_alloc(struct sas_port *);
 extern struct sas_rphy *sas_expander_alloc(struct sas_port *, enum sas_device_type);
 void sas_rphy_free(struct sas_rphy *);