ata: libata-scsi: add support for the RESTORE ELEMENTS AND REBUILD command

Define the translation for the RESTORE ELEMENTS AND REBUILD command
(SERVICE ACTION IN command with service action
SAI_RESTORE_ELEMENTS_AND_REBUILD) into the ATA command
ATA_CMD_RESTORE_ELEMENTS_AND_REBUILD with the new function
ata_scsi_restore_elements_and_rebuild_xlat()

The array of supported commands ata_supported_cmds is modified to add a
new entry for this command. ata_scsi_cmd_is_supported() is also modify to
correctly handle this new entry depending on the target device flag
ATA_DFLAG_DEPOP_RESTORE being set.

The ATA command completion is handled using the function
ata_scsi_depop_ua_cap_changed_complete() so that on a successful
completion, a UNIT ATTENTION with the additional sense code set to
CAPACITY DATA HAS CHANGED is raised.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@kernel.org>

drivers/ata/libata-scsi.c

@@ -3734,6 +3734,11 @@ static const struct ata_scsi_cmd ata_supported_cmds[] = {
 		.sa_valid = true,
 		.sa = SAI_REMOVE_ELEMENT_AND_TRUNCATE
 	},
+	{
+		.op = SERVICE_ACTION_IN_16,	.cdb_len = 16,
+		.sa_valid = true,
+		.sa = SAI_RESTORE_ELEMENTS_AND_REBUILD
+	},
 	{	.op = REPORT_LUNS,		.cdb_len = 12	},
 	{	.op = ATA_12,			.cdb_len = 12	},
 	{	.op = SECURITY_PROTOCOL_IN,	.cdb_len = 12	},
@@ -3819,6 +3824,8 @@ static bool ata_scsi_cmd_is_supported(struct ata_device *dev, u8 op, u16 sa,
 		case SAI_GET_PHYSICAL_ELEMENT_STATUS:
 		case SAI_REMOVE_ELEMENT_AND_TRUNCATE:
 			return dev->flags & ATA_DFLAG_DEPOP;
+		case SAI_RESTORE_ELEMENTS_AND_REBUILD:
+			return dev->flags & ATA_DFLAG_DEPOP_RESTORE;
 		default:
 			return true;
 		}
@@ -4726,8 +4733,9 @@ static void ata_scsi_depop_ua_cap_changed_complete(struct ata_queued_cmd *qc)
 	 * the additional sense code set to CAPACITY DATA HAS CHANGED to be
 	 * raised. Note that this should be done only if the capacity has
 	 * actually changed, which may not be the case if the element that was
-	 * specified for depopulation was already depopulated. But a capacity
+	 * specified for depopulation was already depopulated, or we did not
-	 * change unit attention is harmless, so always raise the unit attention.
+	 * restore any removed element. But a capacity change unit attention is
+	 * harmless, so always raise the unit attention.
 	 */
 	if (is_success && !is_ata_passthru)
 		ata_scsi_set_sense(qc->dev, scmd, UNIT_ATTENTION,
@@ -4779,6 +4787,29 @@ ata_scsi_remove_element_and_truncate_xlat(struct ata_queued_cmd *qc)
 	return 0;
 }
 
+static unsigned int
+ata_scsi_restore_elements_and_rebuild_xlat(struct ata_queued_cmd *qc)
+{
+	struct scsi_cmnd *scmd = qc->scsicmd;
+	struct ata_device *dev = qc->dev;
+	struct ata_taskfile *tf = &qc->tf;
+
+	if (!(dev->flags & ATA_DFLAG_DEPOP_RESTORE)) {
+		ata_scsi_set_sense(dev, scmd, ILLEGAL_REQUEST, 0x20, 0x0);
+		return 1;
+	}
+
+	tf->protocol = ATA_PROT_NODATA;
+	tf->command = ATA_CMD_RESTORE_ELEMENTS_AND_REBUILD;
+	tf->device = ATA_LBA;
+	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48;
+
+	qc->flags |= ATA_QCFLAG_RESULT_TF;
+	qc->complete_fn = ata_scsi_depop_ua_cap_changed_complete;
+
+	return 0;
+}
+
 /**
  *	ata_scsi_var_len_cdb_xlat - SATL variable length CDB to Handler
  *	@qc: Command to be translated
@@ -4864,6 +4895,8 @@ static inline ata_xlat_func_t ata_get_xlat_func(struct ata_device *dev,
 			return ata_scsi_get_phys_element_status_xlat;
 		if (sa == SAI_REMOVE_ELEMENT_AND_TRUNCATE)
 			return ata_scsi_remove_element_and_truncate_xlat;
+		if (sa == SAI_RESTORE_ELEMENTS_AND_REBUILD)
+			return ata_scsi_restore_elements_and_rebuild_xlat;
 		break;
 
 	case ZBC_IN:

include/linux/ata.h

@@ -291,6 +291,7 @@ enum {
 	ATA_CMD_ZAC_MGMT_OUT	= 0x9F,
 	ATA_CMD_GET_PHYS_ELEMENT_STATUS = 0x12,
 	ATA_CMD_REMOVE_ELEMENT_AND_TRUNCATE = 0x7c,
+	ATA_CMD_RESTORE_ELEMENTS_AND_REBUILD = 0x7d,
 
 	/* marked obsolete in the ATA/ATAPI-7 spec */
 	ATA_CMD_RESTORE		= 0x10,