scsi: arm: Move the SCSI pointer to private command data

Set .cmd_size in the SCSI host template instead of using the SCSI pointer
from struct scsi_cmnd. This patch prepares for removal of the SCSI pointer
from struct scsi_cmnd. The ARM SCSI drivers have been identified as follows:
$ git grep -l '#include.*arm_scsi.h'
drivers/scsi/arm/acornscsi.c
drivers/scsi/arm/cumana_2.c
drivers/scsi/arm/eesox.c
drivers/scsi/arm/fas216.c
drivers/scsi/arm/powertec.c

Link: https://lore.kernel.org/r/20220218195117.25689-11-bvanassche@acm.org
Cc: Russell King <linux@armlinux.org.uk>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 12 insertions, 8 deletions

diff --git a/drivers/scsi/arm/acornscsi.c b/drivers/scsi/arm/acornscsi.c
index 38aa9333631b..7602639da9b3 100644
--- a/drivers/scsi/arm/acornscsi.c
+++ b/drivers/scsi/arm/acornscsi.c
@@ -729,7 +729,7 @@ intr_ret_t acornscsi_kick(AS_Host *host)
      */
     host->scsi.phase = PHASE_CONNECTING;
     host->SCpnt = SCpnt;
-    host->scsi.SCp = SCpnt->SCp;
+    host->scsi.SCp = *arm_scsi_pointer(SCpnt);
     host->dma.xfer_setup = 0;
     host->dma.xfer_required = 0;
     host->dma.xfer_done = 0;
@@ -1424,6 +1424,7 @@ unsigned char acornscsi_readmessagebyte(AS_Host *host)
 static
 void acornscsi_message(AS_Host *host)
 {
+    struct scsi_pointer *scsi_pointer;
     unsigned char message[16];
     unsigned int msgidx = 0, msglen = 1;
 
@@ -1493,8 +1494,9 @@ void acornscsi_message(AS_Host *host)
 	 *  the saved data pointer for the current I/O process.
 	 */
 	acornscsi_dma_cleanup(host);
-	host->SCpnt->SCp = host->scsi.SCp;
-	host->SCpnt->SCp.sent_command = 0;
+	scsi_pointer = arm_scsi_pointer(host->SCpnt);
+	*scsi_pointer = host->scsi.SCp;
+	scsi_pointer->sent_command = 0;
 	host->scsi.phase = PHASE_MSGIN;
 	break;
 
@@ -1509,7 +1511,7 @@ void acornscsi_message(AS_Host *host)
 	 *  the present command and status areas.'
 	 */
 	acornscsi_dma_cleanup(host);
-	host->scsi.SCp = host->SCpnt->SCp;
+	host->scsi.SCp = *arm_scsi_pointer(host->SCpnt);
 	host->scsi.phase = PHASE_MSGIN;
 	break;
 
@@ -1809,7 +1811,7 @@ int acornscsi_reconnect_finish(AS_Host *host)
 	/*
 	 * Restore data pointer from SAVED pointers.
 	 */
-	host->scsi.SCp = host->SCpnt->SCp;
+	host->scsi.SCp = *arm_scsi_pointer(host->SCpnt);
 #if (DEBUG & (DEBUG_QUEUES|DEBUG_DISCON))
 	printk(", data pointers: [%p, %X]",
 		host->scsi.SCp.ptr, host->scsi.SCp.this_residual);
@@ -2408,6 +2410,7 @@ acornscsi_intr(int irq, void *dev_id)
  */
 static int acornscsi_queuecmd_lck(struct scsi_cmnd *SCpnt)
 {
+    struct scsi_pointer *scsi_pointer = arm_scsi_pointer(SCpnt);
     void (*done)(struct scsi_cmnd *) = scsi_done;
     AS_Host *host = (AS_Host *)SCpnt->device->host->hostdata;
 
@@ -2423,9 +2426,9 @@ static int acornscsi_queuecmd_lck(struct scsi_cmnd *SCpnt)
 
     SCpnt->host_scribble = NULL;
     SCpnt->result = 0;
-    SCpnt->SCp.phase = (int)acornscsi_datadirection(SCpnt->cmnd[0]);
-    SCpnt->SCp.sent_command = 0;
-    SCpnt->SCp.scsi_xferred = 0;
+    scsi_pointer->phase = (int)acornscsi_datadirection(SCpnt->cmnd[0]);
+    scsi_pointer->sent_command = 0;
+    scsi_pointer->scsi_xferred = 0;
 
     init_SCp(SCpnt);
 
@@ -2791,6 +2794,7 @@ static struct scsi_host_template acornscsi_template = {
 	.cmd_per_lun		= 2,
 	.dma_boundary		= PAGE_SIZE - 1,
 	.proc_name		= "acornscsi",
+	.cmd_size		= sizeof(struct arm_cmd_priv),
 };
 
 static int acornscsi_probe(struct expansion_card *ec, const struct ecard_id *id)