s390/dasd: increase printing of debug data payload

32 byte are to less for important data from prefix or
other commands.
Print up to 128 byte data. This is enough for the largest
CCW data we have.

Since printk can only print up to 1024 byte at once, print the
different parts of the CCW dumps separately.

Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Link: https://lore.kernel.org/r/20221123160719.3002694-3-sth@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/s390/block/dasd_eckd.c

@@ -5500,7 +5500,7 @@ dasd_eckd_ioctl(struct dasd_block *block, unsigned int cmd, void __user *argp)
  * Dump the range of CCWs into 'page' buffer
  * and return number of printed chars.
  */
-static int
+static void
 dasd_eckd_dump_ccw_range(struct ccw1 *from, struct ccw1 *to, char *page)
 {
 	int len, count;
@@ -5518,16 +5518,21 @@ dasd_eckd_dump_ccw_range(struct ccw1 *from, struct ccw1 *to, char *page)
 		else
 			datap = (char *) ((addr_t) from->cda);
 
-		/* dump data (max 32 bytes) */
-		for (count = 0; count < from->count && count < 32; count++) {
-			if (count % 8 == 0) len += sprintf(page + len, " ");
-			if (count % 4 == 0) len += sprintf(page + len, " ");
+		/* dump data (max 128 bytes) */
+		for (count = 0; count < from->count && count < 128; count++) {
+			if (count % 32 == 0)
+				len += sprintf(page + len, "\n");
+			if (count % 8 == 0)
+				len += sprintf(page + len, " ");
+			if (count % 4 == 0)
+				len += sprintf(page + len, " ");
 			len += sprintf(page + len, "%02x", datap[count]);
 		}
 		len += sprintf(page + len, "\n");
 		from++;
 	}
-	return len;
+	if (len > 0)
+		printk(KERN_ERR "%s", page);
 }
 
 static void
@@ -5619,37 +5624,33 @@ static void dasd_eckd_dump_sense_ccw(struct dasd_device *device,
 	if (req) {
 		/* req == NULL for unsolicited interrupts */
 		/* dump the Channel Program (max 140 Bytes per line) */
-		/* Count CCW and print first CCWs (maximum 1024 % 140 = 7) */
+		/* Count CCW and print first CCWs (maximum 7) */
 		first = req->cpaddr;
 		for (last = first; last->flags & (CCW_FLAG_CC | CCW_FLAG_DC); last++);
 		to = min(first + 6, last);
-		len = sprintf(page, PRINTK_HEADER
-			      " Related CP in req: %p\n", req);
-		dasd_eckd_dump_ccw_range(first, to, page + len);
-		printk(KERN_ERR "%s", page);
+		printk(KERN_ERR PRINTK_HEADER " Related CP in req: %p\n", req);
+		dasd_eckd_dump_ccw_range(first, to, page);
 
 		/* print failing CCW area (maximum 4) */
 		/* scsw->cda is either valid or zero  */
-		len = 0;
 		from = ++to;
 		fail = (struct ccw1 *)(addr_t)
 				irb->scsw.cmd.cpa; /* failing CCW */
 		if (from <  fail - 2) {
 			from = fail - 2;     /* there is a gap - print header */
-			len += sprintf(page, PRINTK_HEADER "......\n");
+			printk(KERN_ERR PRINTK_HEADER "......\n");
 		}
 		to = min(fail + 1, last);
-		len += dasd_eckd_dump_ccw_range(from, to, page + len);
+		dasd_eckd_dump_ccw_range(from, to, page + len);
 
 		/* print last CCWs (maximum 2) */
+		len = 0;
 		from = max(from, ++to);
 		if (from < last - 1) {
 			from = last - 1;     /* there is a gap - print header */
-			len += sprintf(page + len, PRINTK_HEADER "......\n");
+			printk(KERN_ERR PRINTK_HEADER "......\n");
 		}
-		len += dasd_eckd_dump_ccw_range(from, last, page + len);
-		if (len > 0)
-			printk(KERN_ERR "%s", page);
+		dasd_eckd_dump_ccw_range(from, last, page + len);
 	}
 	free_page((unsigned long) page);
 }