[PATCH v1 4/9] ata: libata-scsi: improve ata_get_xlat_func

[Damien Le Moal <dlemoal@kernel.org>]

ata_get_xlat_func() is given only the opcode of a SCSI command to
determine the ATA command to translate to. This makes it impossible to
translate SCSI commands such as SERVICE ACTION IN which need a service
action field to fully specify the command.

In preparation for supporting the translation of the SERVICE ACTION IN
command with service actions different from the SAI_READ_CAPACITY_16 (READ
CAPACITY 16), change ata_get_xlat_func() to take a pointer to a SCSI
command CDB so that all fields of the SCSI command to translate can be
easily inspected.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
---
 drivers/ata/libata-scsi.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 5cddb63a6bc6..f5c838ca0ce9 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -4606,7 +4606,7 @@ static unsigned int ata_scsi_var_len_cdb_xlat(struct ata_queued_cmd *qc)
 /**
  *	ata_get_xlat_func - check if SCSI to ATA translation is possible
  *	@dev: ATA device
- *	@cmd: SCSI command opcode to consider
+ *	@cdb: CDB of the SCSI command to consider
  *
  *	Look up the SCSI command given, and determine whether the
  *	SCSI command is to be translated or simulated.
@@ -4615,9 +4615,10 @@ static unsigned int ata_scsi_var_len_cdb_xlat(struct ata_queued_cmd *qc)
  *	Pointer to translation function if possible, %NULL if not.
  */
 
-static inline ata_xlat_func_t ata_get_xlat_func(struct ata_device *dev, u8 cmd)
+static inline ata_xlat_func_t ata_get_xlat_func(struct ata_device *dev,
+						u8 *cdb)
 {
-	switch (cmd) {
+	switch (cdb[0]) {
 	case READ_6:
 	case READ_10:
 	case READ_16:
@@ -4748,7 +4749,8 @@ enum scsi_qc_status __ata_scsi_queuecmd(struct scsi_cmnd *scmd,
 					struct ata_port *ap)
 	__must_hold(ap->lock)
 {
-	u8 scsi_op = scmd->cmnd[0];
+	u8 *cdb = scmd->cmnd;
+	u8 scsi_op = cdb[0];
 	ata_xlat_func_t xlat_func;
 
 	/*
@@ -4768,7 +4770,7 @@ enum scsi_qc_status __ata_scsi_queuecmd(struct scsi_cmnd *scmd,
 		if (unlikely(scmd->cmd_len > dev->cdb_len))
 			goto bad_cdb_len;
 
-		xlat_func = ata_get_xlat_func(dev, scsi_op);
+		xlat_func = ata_get_xlat_func(dev, cdb);
 	} else if (likely((scsi_op != ATA_16) || !atapi_passthru16)) {
 		/* relay SCSI command to ATAPI device */
 		int len = COMMAND_SIZE(scsi_op);
@@ -4784,7 +4786,7 @@ enum scsi_qc_status __ata_scsi_queuecmd(struct scsi_cmnd *scmd,
 		if (unlikely(scmd->cmd_len > 16))
 			goto bad_cdb_len;
 
-		xlat_func = ata_get_xlat_func(dev, scsi_op);
+		xlat_func = ata_get_xlat_func(dev, cdb);
 	}
 
 	if (xlat_func)
-- 
2.54.0