[PATCH v3 13/18] ata: libata-scsi: handle CDL bits in ata_scsiop_maint_in()

[Niklas Cassel <niklas.cassel@wdc.com>]

From: Damien Le Moal <damien.lemoal@opensource.wdc.com>

For a scsi MAINTENANCE_IN/MI_REPORT_SUPPORTED_OPERATION_CODES operation,
add the translation of the rwcdlp and cdlp bits for the READ16 and
WRITE16 commands. If the ATA device does not support command duration
limits, these bits are always 0. If the ATA device supports command
duration limits, the rwcdlp bit is set to 1 for READ16 and WRITE16 and
the cdlp bits are set to 0x1 for READ16 and 0x2 for WRITE16. These
correspond to the T2A mode page containing the read descriptors and
to the T2B mode page containing the write descriptors, as defined in
SAT-5.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
---
 drivers/ata/libata-scsi.c | 30 ++++++++++++++++++++++++++----
 1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 716c33af999c..2a0a04c9e658 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -3235,7 +3235,7 @@ static unsigned int ata_scsiop_maint_in(struct ata_scsi_args *args, u8 *rbuf)
 {
 	struct ata_device *dev = args->dev;
 	u8 *cdb = args->cmd->cmnd;
-	u8 supported = 0;
+	u8 supported = 0, cdlp = 0, rwcdlp = 0;
 	unsigned int err = 0;
 
 	if (cdb[2] != 1 && cdb[2] != 3) {
@@ -3262,10 +3262,8 @@ static unsigned int ata_scsiop_maint_in(struct ata_scsi_args *args, u8 *rbuf)
 	case MAINTENANCE_IN:
 	case READ_6:
 	case READ_10:
-	case READ_16:
 	case WRITE_6:
 	case WRITE_10:
-	case WRITE_16:
 	case ATA_12:
 	case ATA_16:
 	case VERIFY:
@@ -3275,6 +3273,28 @@ static unsigned int ata_scsiop_maint_in(struct ata_scsi_args *args, u8 *rbuf)
 	case START_STOP:
 		supported = 3;
 		break;
+	case READ_16:
+		supported = 3;
+		if (dev->flags & ATA_DFLAG_CDL) {
+			/*
+			 * CDL read descriptors map to the T2A page, that is,
+			 * rwcdlp = 0x01 and cdlp = 0x01
+			 */
+			rwcdlp = 0x01;
+			cdlp = 0x01 << 3;
+		}
+		break;
+	case WRITE_16:
+		supported = 3;
+		if (dev->flags & ATA_DFLAG_CDL) {
+			/*
+			 * CDL write descriptors map to the T2B page, that is,
+			 * rwcdlp = 0x01 and cdlp = 0x02
+			 */
+			rwcdlp = 0x01;
+			cdlp = 0x02 << 3;
+		}
+		break;
 	case ZBC_IN:
 	case ZBC_OUT:
 		if (ata_id_zoned_cap(dev->id) ||
@@ -3290,7 +3310,9 @@ static unsigned int ata_scsiop_maint_in(struct ata_scsi_args *args, u8 *rbuf)
 		break;
 	}
 out:
-	rbuf[1] = supported; /* supported */
+	/* One command format */
+	rbuf[0] = rwcdlp;
+	rbuf[1] = cdlp | supported;
 	return err;
 }
 
-- 
2.39.1