scsi: libsas: Introduce struct smp_rps_resp

Similarly to sas report general and discovery responses, define the
structure struct smp_rps_resp to handle SATA PHY report responses using a
structure with a size that is exactly equal to the sas defined response
size.

With this change, struct smp_resp becomes unused and is removed.

Link: https://lore.kernel.org/r/20220609022456.409087-4-damien.lemoal@opensource.wdc.com
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/aic94xx/aic94xx_dev.c

@@ -159,7 +159,7 @@ static int asd_init_target_ddb(struct domain_device *dev)
 		flags |= OPEN_REQUIRED;
 		if ((dev->dev_type == SAS_SATA_DEV) ||
 		    (dev->tproto & SAS_PROTOCOL_STP)) {
-			struct smp_resp *rps_resp = &dev->sata_dev.rps_resp;
+			struct smp_rps_resp *rps_resp = &dev->sata_dev.rps_resp;
 			if (rps_resp->frame_type == SMP_RESPONSE &&
 			    rps_resp->function == SMP_REPORT_PHY_SATA &&
 			    rps_resp->result == SMP_RESP_FUNC_ACC) {

drivers/scsi/libsas/sas_expander.c

@@ -676,10 +676,10 @@ int sas_smp_get_phy_events(struct sas_phy *phy)
 #ifdef CONFIG_SCSI_SAS_ATA
 
 #define RPS_REQ_SIZE  16
-#define RPS_RESP_SIZE 60
+#define RPS_RESP_SIZE sizeof(struct smp_rps_resp)
 
 int sas_get_report_phy_sata(struct domain_device *dev, int phy_id,
-			    struct smp_resp *rps_resp)
+			    struct smp_rps_resp *rps_resp)
 {
 	int res;
 	u8 *rps_req = alloc_smp_req(RPS_REQ_SIZE);

drivers/scsi/libsas/sas_internal.h

@@ -83,7 +83,7 @@ struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy);
 struct domain_device *sas_ex_to_ata(struct domain_device *ex_dev, int phy_id);
 int sas_ex_phy_discover(struct domain_device *dev, int single);
 int sas_get_report_phy_sata(struct domain_device *dev, int phy_id,
-			    struct smp_resp *rps_resp);
+			    struct smp_rps_resp *rps_resp);
 int sas_try_ata_reset(struct asd_sas_phy *phy);
 void sas_hae_reset(struct work_struct *work);
 

include/scsi/libsas.h

@@ -145,7 +145,7 @@ struct sata_device {
 
 	struct ata_port *ap;
 	struct ata_host *ata_host;
-	struct smp_resp rps_resp ____cacheline_aligned; /* report_phy_sata_resp */
+	struct smp_rps_resp rps_resp ____cacheline_aligned; /* report_phy_sata_resp */
 	u8     fis[ATA_RESP_FIS_SIZE];
 };
 

include/scsi/sas.h

@@ -712,16 +712,12 @@ struct smp_disc_resp {
 	struct discover_resp disc;
 } __attribute__ ((packed));
 
-struct smp_resp {
+struct smp_rps_resp {
 	u8    frame_type;
 	u8    function;
 	u8    result;
 	u8    reserved;
-	union {
-		struct report_general_resp  rg;
-		struct discover_resp        disc;
 	struct report_phy_sata_resp rps;
-	};
 } __attribute__ ((packed));
 
 #endif /* _SAS_H_ */