scsi: advansys: 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/20220218195117.25689-14-bvanassche@acm.orgReviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/advansys.c

@@ -2277,6 +2277,15 @@ struct asc_board {
 							dvc_var.adv_dvc_var)
 #define adv_dvc_to_pdev(adv_dvc) to_pci_dev(adv_dvc_to_board(adv_dvc)->dev)
 
+struct advansys_cmd {
+	dma_addr_t dma_handle;
+};
+
+static struct advansys_cmd *advansys_cmd(struct scsi_cmnd *cmd)
+{
+	return scsi_cmd_priv(cmd);
+}
+
 #ifdef ADVANSYS_DEBUG
 static int asc_dbglvl = 3;
 
@@ -6681,7 +6690,7 @@ static void asc_isr_callback(ASC_DVC_VAR *asc_dvc_varp, ASC_QDONE_INFO *qdonep)
 
 	ASC_STATS(boardp->shost, callback);
 
-	dma_unmap_single(boardp->dev, scp->SCp.dma_handle,
+	dma_unmap_single(boardp->dev, advansys_cmd(scp)->dma_handle,
 			 SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
 	/*
 	 * 'qdonep' contains the command's ending status.
@@ -7399,15 +7408,15 @@ static int advansys_slave_configure(struct scsi_device *sdev)
 static __le32 asc_get_sense_buffer_dma(struct scsi_cmnd *scp)
 {
 	struct asc_board *board = shost_priv(scp->device->host);
+	struct advansys_cmd *acmd = advansys_cmd(scp);
 
-	scp->SCp.dma_handle = dma_map_single(board->dev, scp->sense_buffer,
-					     SCSI_SENSE_BUFFERSIZE,
-					     DMA_FROM_DEVICE);
-	if (dma_mapping_error(board->dev, scp->SCp.dma_handle)) {
+	acmd->dma_handle = dma_map_single(board->dev, scp->sense_buffer,
+					SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
+	if (dma_mapping_error(board->dev, acmd->dma_handle)) {
 		ASC_DBG(1, "failed to map sense buffer\n");
 		return 0;
 	}
-	return cpu_to_le32(scp->SCp.dma_handle);
+	return cpu_to_le32(acmd->dma_handle);
 }
 
 static int asc_build_req(struct asc_board *boardp, struct scsi_cmnd *scp,
@@ -10604,6 +10613,7 @@ static struct scsi_host_template advansys_template = {
 	.eh_host_reset_handler = advansys_reset,
 	.bios_param = advansys_biosparam,
 	.slave_configure = advansys_slave_configure,
+	.cmd_size = sizeof(struct advansys_cmd),
 };
 
 static int advansys_wide_init_chip(struct Scsi_Host *shost)