mtd: introduce mtd_can_have_bb helper

This patch introduces new 'mtd_can_have_bb()' helper function which checks
whether the flash can have bad eraseblocks. Then it changes all the
direct 'mtd->block_isbad' use cases with 'mtd_can_have_bb()'.

Signed-off-by: Artem Bityutskiy <[e-mail]>
Signed-off-by: David Woodhouse <[e-mail]>

drivers/mtd/mtdchar.c

···
 
 		if (copy_from_user(&offs, argp, sizeof(loff_t)))
 			return -EFAULT;
-		if (!mtd->block_isbad)
-			ret = -EOPNOTSUPP;
-		else
-			return mtd_block_isbad(mtd, offs);
+		return mtd_block_isbad(mtd, offs);
 		break;
 	}
 

drivers/mtd/mtdconcat.c

···
 	struct mtd_concat *concat = CONCAT(mtd);
 	int i, res = 0;
 
-	if (!concat->subdev[0]->block_isbad)
+	if (!mtd_can_have_bb(concat->subdev[0]))
 		return res;
 
 	if (ofs > mtd->size)

drivers/mtd/mtdoops.c

···
 			cxt->nextpage = 0;
 	}
 
-	while (mtd->block_isbad) {
+	while (mtd_can_have_bb(mtd)) {
 		ret = mtd_block_isbad(mtd, cxt->nextpage * record_size);
 		if (!ret)
 			break;
···
 	size_t retlen;
 
 	for (page = 0; page < cxt->oops_pages; page++) {
-		if (mtd->block_isbad &&
+		if (mtd_can_have_bb(mtd) &&
 		    mtd_block_isbad(mtd, page * record_size))
 			continue;
 		/* Assume the page is used */

drivers/mtd/mtdswap.c

···
 	offset = mtdswap_eb_offset(d, eb);
 
 	/* Check first if the block is bad. */
-	if (d->mtd->block_isbad && mtd_block_isbad(d->mtd, offset))
+	if (mtd_can_have_bb(d->mtd) && mtd_block_isbad(d->mtd, offset))
 		return MTDSWAP_SCANNED_BAD;
 
 	ops.ooblen = 2 * d->mtd->ecclayout->oobavail;
···
 
 	badcnt = 0;
 
-	if (mtd->block_isbad)
+	if (mtd_can_have_bb(mtd))
 		for (offset = 0; offset < size; offset += mtd->erasesize)
 			if (mtd_block_isbad(mtd, offset))
 				badcnt++;

drivers/mtd/nftlcore.c

···
 	if (memcmp(mtd->name, "DiskOnChip", 10))
 		return;
 
-	if (!mtd->block_isbad) {
+	if (!mtd_can_have_bb(mtd)) {
 		printk(KERN_ERR
 "NFTL no longer supports the old DiskOnChip drivers loaded via docprobe.\n"
 "Please use the new diskonchip driver under the NAND subsystem.\n");

drivers/mtd/redboot.c

···
 
 	if ( directory < 0 ) {
 		offset = master->size + directory * master->erasesize;
-		while (master->block_isbad && 
+		while (mtd_can_have_bb(master) &&
 		       mtd_block_isbad(master, offset)) {
 			if (!offset) {
 			nogood:
···
 		}
 	} else {
 		offset = directory * master->erasesize;
-		while (master->block_isbad && 
+		while (mtd_can_have_bb(master) &&
 		       mtd_block_isbad(master, offset)) {
 			offset += master->erasesize;
 			if (offset == master->size)

drivers/mtd/tests/mtd_readtest.c

···
 		return -ENOMEM;
 	}
 
-	/* NOR flash does not implement block_isbad */
-	if (mtd->block_isbad == NULL)
+	if (!mtd_can_have_bb(mtd))
 		return 0;
 
 	printk(PRINT_PREF "scanning for bad eraseblocks\n");

drivers/mtd/tests/mtd_speedtest.c

···
 		return -ENOMEM;
 	}
 
-	/* NOR flash does not implement block_isbad */
-	if (mtd->block_isbad == NULL)
+	if (!mtd_can_have_bb(mtd))
 		goto out;
 
 	printk(PRINT_PREF "scanning for bad eraseblocks\n");

drivers/mtd/tests/mtd_stresstest.c

···
 		return -ENOMEM;
 	}
 
-	/* NOR flash does not implement block_isbad */
-	if (mtd->block_isbad == NULL)
+	if (!mtd_can_have_bb(mtd))
 		return 0;
 
 	printk(PRINT_PREF "scanning for bad eraseblocks\n");

drivers/mtd/tests/mtd_torturetest.c

···
 	 * Check if there is a bad eraseblock among those we are going to test.
 	 */
 	memset(&bad_ebs[0], 0, sizeof(int) * ebcnt);
-	if (mtd->block_isbad) {
+	if (mtd_can_have_bb(mtd)) {
 		for (i = eb; i < eb + ebcnt; i++) {
 			err = mtd_block_isbad(mtd, (loff_t)i * mtd->erasesize);
 

drivers/mtd/ubi/build.c

···
 	ubi->peb_count  = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
 	ubi->flash_size = ubi->mtd->size;
 
-	if (ubi->mtd->block_isbad && ubi->mtd->block_markbad)
+	if (mtd_can_have_bb(ubi->mtd))
 		ubi->bad_allowed = 1;
 
 	if (ubi->mtd->type == MTD_NORFLASH) {

include/linux/mtd/mtd.h

···
 
 static inline int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
 {
+	if (!mtd->block_isbad)
+		return -EOPNOTSUPP;
 	return mtd->block_isbad(mtd, ofs);
 }
 
···
 static inline int mtd_has_oob(const struct mtd_info *mtd)
 {
 	return mtd->read_oob && mtd->write_oob;
+}
+
+static inline int mtd_can_have_bb(const struct mtd_info *mtd)
+{
+	return !!mtd->block_isbad;
 }
 
 	/* Kernel-side ioctl definitions */