scsi: mac53c94: 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/20220218195117.25689-32-bvanassche@acm.orgReviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
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>

drivers/scsi/mac53c94.c

@@ -193,7 +193,8 @@ static void mac53c94_interrupt(int irq, void *dev_id)
 	struct fsc_state *state = (struct fsc_state *) dev_id;
 	struct mac53c94_regs __iomem *regs = state->regs;
 	struct dbdma_regs __iomem *dma = state->dma;
-	struct scsi_cmnd *cmd = state->current_req;
+	struct scsi_cmnd *const cmd = state->current_req;
+	struct scsi_pointer *const scsi_pointer = mac53c94_scsi_pointer(cmd);
 	int nb, stat, seq, intr;
 	static int mac53c94_errors;
 
@@ -263,10 +264,10 @@ static void mac53c94_interrupt(int irq, void *dev_id)
 		/* set DMA controller going if any data to transfer */
 		if ((stat & (STAT_MSG|STAT_CD)) == 0
 		    && (scsi_sg_count(cmd) > 0 || scsi_bufflen(cmd))) {
-			nb = cmd->SCp.this_residual;
+			nb = scsi_pointer->this_residual;
 			if (nb > 0xfff0)
 				nb = 0xfff0;
-			cmd->SCp.this_residual -= nb;
+			scsi_pointer->this_residual -= nb;
 			writeb(nb, &regs->count_lo);
 			writeb(nb >> 8, &regs->count_mid);
 			writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
@@ -293,13 +294,13 @@ static void mac53c94_interrupt(int irq, void *dev_id)
 			cmd_done(state, DID_ERROR << 16);
 			return;
 		}
-		if (cmd->SCp.this_residual != 0
+		if (scsi_pointer->this_residual != 0
 		    && (stat & (STAT_MSG|STAT_CD)) == 0) {
 			/* Set up the count regs to transfer more */
-			nb = cmd->SCp.this_residual;
+			nb = scsi_pointer->this_residual;
 			if (nb > 0xfff0)
 				nb = 0xfff0;
-			cmd->SCp.this_residual -= nb;
+			scsi_pointer->this_residual -= nb;
 			writeb(nb, &regs->count_lo);
 			writeb(nb >> 8, &regs->count_mid);
 			writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
@@ -321,8 +322,8 @@ static void mac53c94_interrupt(int irq, void *dev_id)
 			cmd_done(state, DID_ERROR << 16);
 			return;
 		}
-		cmd->SCp.Status = readb(&regs->fifo);
-		cmd->SCp.Message = readb(&regs->fifo);
+		scsi_pointer->Status = readb(&regs->fifo);
+		scsi_pointer->Message = readb(&regs->fifo);
 		writeb(CMD_ACCEPT_MSG, &regs->command);
 		state->phase = busfreeing;
 		break;
@@ -330,8 +331,8 @@ static void mac53c94_interrupt(int irq, void *dev_id)
 		if (intr != INTR_DISCONNECT) {
 			printk(KERN_DEBUG "got intr %x when expected disconnect\n", intr);
 		}
-		cmd_done(state, (DID_OK << 16) + (cmd->SCp.Message << 8)
-			 + cmd->SCp.Status);
+		cmd_done(state, (DID_OK << 16) + (scsi_pointer->Message << 8)
+			 + scsi_pointer->Status);
 		break;
 	default:
 		printk(KERN_DEBUG "don't know about phase %d\n", state->phase);
@@ -389,7 +390,7 @@ static void set_dma_cmds(struct fsc_state *state, struct scsi_cmnd *cmd)
 	dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
 	dcmds[-1].command = cpu_to_le16(dma_cmd);
 	dcmds->command = cpu_to_le16(DBDMA_STOP);
-	cmd->SCp.this_residual = total;
+	mac53c94_scsi_pointer(cmd)->this_residual = total;
 }
 
 static struct scsi_host_template mac53c94_template = {
@@ -401,6 +402,7 @@ static struct scsi_host_template mac53c94_template = {
 	.this_id	= 7,
 	.sg_tablesize	= SG_ALL,
 	.max_segment_size = 65535,
+	.cmd_size	= sizeof(struct mac53c94_cmd_priv),
 };
 
 static int mac53c94_probe(struct macio_dev *mdev, const struct of_device_id *match)

drivers/scsi/mac53c94.h

@@ -212,4 +212,15 @@ struct mac53c94_regs {
 #define CF4_TEST	0x02
 #define CF4_BBTE	0x01
 
+struct mac53c94_cmd_priv {
+	struct scsi_pointer scsi_pointer;
+};
+
+static inline struct scsi_pointer *mac53c94_scsi_pointer(struct scsi_cmnd *cmd)
+{
+	struct mac53c94_cmd_priv *mcmd = scsi_cmd_priv(cmd);
+
+	return &mcmd->scsi_pointer;
+}
+
 #endif /* _MAC53C94_H */