scsi: qla1280: 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.

Link: https://lore.kernel.org/r/[e-mail]
Reviewed-by: Johannes Thumshirn <[e-mail]>
Reviewed-by: Hannes Reinecke <[e-mail]>
Reviewed-by: Himanshu Madhani <[e-mail]>
Signed-off-by: Bart Van Assche <[e-mail]>
Signed-off-by: Martin K. Petersen <[e-mail]>

drivers/scsi/qla1280.c

···
 #endif
 
 
-/*
- * We use the scsi_pointer structure that's included with each scsi_command
- * to overlay our struct srb over it. qla1280_init() checks that a srb is not
- * bigger than a scsi_pointer.
- */
-
-#define	CMD_SP(Cmnd)		&Cmnd->SCp
 #define	CMD_CDBLEN(Cmnd)	Cmnd->cmd_len
 #define	CMD_CDBP(Cmnd)		Cmnd->cmnd
 #define	CMD_SNSP(Cmnd)		Cmnd->sense_buffer
···
 {
 	struct Scsi_Host *host = cmd->device->host;
 	struct scsi_qla_host *ha = (struct scsi_qla_host *)host->hostdata;
-	struct srb *sp = (struct srb *)CMD_SP(cmd);
+	struct srb *sp = scsi_cmd_priv(cmd);
 	int status;
 
 	sp->cmd = cmd;
···
 	ENTER("qla1280_error_action");
 
 	ha = (struct scsi_qla_host *)(CMD_HOST(cmd)->hostdata);
-	sp = (struct srb *)CMD_SP(cmd);
+	sp = scsi_cmd_priv(cmd);
 	bus = SCSI_BUS_32(cmd);
 	target = SCSI_TCN_32(cmd);
 	lun = SCSI_LUN_32(cmd);
···
 	int i;
 	ha = (struct scsi_qla_host *)host->hostdata;
 
-	sp = (struct srb *)CMD_SP(cmd);
+	sp = scsi_cmd_priv(cmd);
 	printk("SCSI Command @= 0x%p, Handle=0x%p\n", cmd, CMD_HANDLE(cmd));
 	printk("  chan=%d, target = 0x%02x, lun = 0x%02x, cmd_len = 0x%02x\n",
 	       SCSI_BUS_32(cmd), SCSI_TCN_32(cmd), SCSI_LUN_32(cmd),
···
 	   } */
 	printk("  tag=%d, transfersize=0x%x \n",
 	       scsi_cmd_to_rq(cmd)->tag, cmd->transfersize);
-	printk("  SP=0x%p\n", CMD_SP(cmd));
 	printk(" underflow size = 0x%x, direction=0x%x\n",
 	       cmd->underflow, cmd->sc_data_direction);
 }
···
 	.can_queue		= MAX_OUTSTANDING_COMMANDS,
 	.this_id		= -1,
 	.sg_tablesize		= SG_ALL,
+	.cmd_size		= sizeof(struct srb),
 };
 
 
···
 static int __init
 qla1280_init(void)
 {
-	if (sizeof(struct srb) > sizeof(struct scsi_pointer)) {
-		printk(KERN_WARNING
-		       "qla1280: struct srb too big, aborting\n");
-		return -EINVAL;
-	}
-
 #ifdef MODULE
 	/*
 	 * If we are called as a module, the qla1280 pointer may not be null

drivers/scsi/qla1280.h

···
 #define RESPONSE_ENTRY_CNT		63  /* Number of response entries. */
 
 /*
- * SCSI Request Block structure  (sp)  that is placed
- * on cmd->SCp location of every I/O
+ * SCSI Request Block structure (sp) that occurs after each struct scsi_cmnd.
  */
 struct srb {
 	struct list_head list;		/* (8/16) LU queue */