libata: Implement NCQ autosense

Some newer devices support NCQ autosense (cf ACS-4), so we should
be using it to retrieve the sense code and speed up recovery.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 961acc7..8c8355f 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -1600,6 +1600,8 @@
 	tf->hob_lbah = buf[10];
 	tf->nsect = buf[12];
 	tf->hob_nsect = buf[13];
+	if (ata_id_has_ncq_autosense(dev->id))
+		tf->auxiliary = buf[14] << 16 | buf[15] << 8 | buf[16];
 
 	return 0;
 }
@@ -1797,6 +1799,16 @@
 	memcpy(&qc->result_tf, &tf, sizeof(tf));
 	qc->result_tf.flags = ATA_TFLAG_ISADDR | ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
 	qc->err_mask |= AC_ERR_DEV | AC_ERR_NCQ;
+	if (qc->result_tf.auxiliary) {
+		char sense_key, asc, ascq;
+
+		sense_key = (qc->result_tf.auxiliary >> 16) & 0xff;
+		asc = (qc->result_tf.auxiliary >> 8) & 0xff;
+		ascq = qc->result_tf.auxiliary & 0xff;
+		ata_scsi_set_sense(qc->scsicmd, sense_key, asc, ascq);
+		qc->flags |= ATA_QCFLAG_SENSE_VALID;
+	}
+
 	ehc->i.err_mask &= ~AC_ERR_DEV;
 }
 
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 567859c..6dc2fad 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -270,8 +270,11 @@
 	    ata_scsi_park_show, ata_scsi_park_store);
 EXPORT_SYMBOL_GPL(dev_attr_unload_heads);
 
-static void ata_scsi_set_sense(struct scsi_cmnd *cmd, u8 sk, u8 asc, u8 ascq)
+void ata_scsi_set_sense(struct scsi_cmnd *cmd, u8 sk, u8 asc, u8 ascq)
 {
+	if (!cmd)
+		return;
+
 	cmd->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
 
 	scsi_build_sense_buffer(0, cmd->sense_buffer, sk, asc, ascq);
@@ -1784,6 +1787,8 @@
 	if (((cdb[0] == ATA_16) || (cdb[0] == ATA_12)) &&
 	    ((cdb[2] & 0x20) || need_sense))
 		ata_gen_passthru_sense(qc);
+	else if (qc->flags & ATA_QCFLAG_SENSE_VALID)
+		cmd->result = SAM_STAT_CHECK_CONDITION;
 	else if (need_sense)
 		ata_gen_ata_sense(qc);
 	else
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index f840ca1..8cfdd96 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -137,6 +137,7 @@
 			      struct scsi_host_template *sht);
 extern void ata_scsi_scan_host(struct ata_port *ap, int sync);
 extern int ata_scsi_offline_dev(struct ata_device *dev);
+extern void ata_scsi_set_sense(struct scsi_cmnd *cmd, u8 sk, u8 asc, u8 ascq);
 extern void ata_scsi_media_change_notify(struct ata_device *dev);
 extern void ata_scsi_hotplug(struct work_struct *work);
 extern void ata_schedule_scsi_eh(struct Scsi_Host *shost);
diff --git a/include/linux/ata.h b/include/linux/ata.h
index c1a2f34..e797e1b53 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -528,6 +528,8 @@
 #define ata_id_cdb_intr(id)	(((id)[ATA_ID_CONFIG] & 0x60) == 0x20)
 #define ata_id_has_da(id)	((id)[ATA_ID_SATA_CAPABILITY_2] & (1 << 4))
 #define ata_id_has_devslp(id)	((id)[ATA_ID_FEATURE_SUPP] & (1 << 8))
+#define ata_id_has_ncq_autosense(id) \
+				((id)[ATA_ID_FEATURE_SUPP] & (1 << 7))
 
 static inline bool ata_id_has_hipm(const u16 *id)
 {