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, 23 insertions, 10 deletions

diff --git a/drivers/scsi/arm/arm_scsi.h b/drivers/scsi/arm/arm_scsi.h
index 3eb5c6aa93c9..ea9fcd92c6de 100644
--- a/drivers/scsi/arm/arm_scsi.h
+++ b/drivers/scsi/arm/arm_scsi.h
@@ -9,6 +9,17 @@
 
 #define BELT_AND_BRACES
 
+struct arm_cmd_priv {
+	struct scsi_pointer scsi_pointer;
+};
+
+static inline struct scsi_pointer *arm_scsi_pointer(struct scsi_cmnd *cmd)
+{
+	struct arm_cmd_priv *acmd = scsi_cmd_priv(cmd);
+
+	return &acmd->scsi_pointer;
+}
+
 /*
  * The scatter-gather list handling.  This contains all
  * the yucky stuff that needs to be fixed properly.
@@ -76,16 +87,18 @@ static inline void put_next_SCp_byte(struct scsi_pointer *SCp, unsigned char c)
 
 static inline void init_SCp(struct scsi_cmnd *SCpnt)
 {
-	memset(&SCpnt->SCp, 0, sizeof(struct scsi_pointer));
+	struct scsi_pointer *scsi_pointer = arm_scsi_pointer(SCpnt);
+
+	memset(scsi_pointer, 0, sizeof(struct scsi_pointer));
 
 	if (scsi_bufflen(SCpnt)) {
 		unsigned long len = 0;
 
-		SCpnt->SCp.buffer = scsi_sglist(SCpnt);
-		SCpnt->SCp.buffers_residual = scsi_sg_count(SCpnt) - 1;
-		SCpnt->SCp.ptr = sg_virt(SCpnt->SCp.buffer);
-		SCpnt->SCp.this_residual = SCpnt->SCp.buffer->length;
-		SCpnt->SCp.phase = scsi_bufflen(SCpnt);
+		scsi_pointer->buffer = scsi_sglist(SCpnt);
+		scsi_pointer->buffers_residual = scsi_sg_count(SCpnt) - 1;
+		scsi_pointer->ptr = sg_virt(scsi_pointer->buffer);
+		scsi_pointer->this_residual = scsi_pointer->buffer->length;
+		scsi_pointer->phase = scsi_bufflen(SCpnt);
 
 #ifdef BELT_AND_BRACES
 		{	/*
@@ -109,15 +122,15 @@ static inline void init_SCp(struct scsi_cmnd *SCpnt)
 				 * FIXME: Totaly naive fixup. We should abort
 				 * with error
 				 */
-				SCpnt->SCp.phase =
+				scsi_pointer->phase =
 					min_t(unsigned long, len,
 					      scsi_bufflen(SCpnt));
 			}
 		}
 #endif
 	} else {
-		SCpnt->SCp.ptr = NULL;
-		SCpnt->SCp.this_residual = 0;
-		SCpnt->SCp.phase = 0;
+		scsi_pointer->ptr = NULL;
+		scsi_pointer->this_residual = 0;
+		scsi_pointer->phase = 0;
 	}
 }