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Commit c3baf278 authored by Boris Brezillon's avatar Boris Brezillon
Browse files

mtd: nand_bbt: Move BBT block selection logic out of write_bbt() 



This clarifies the write_bbt() function by removing the write label
and simplifying the error/exit path.

Signed-off-by: default avatarBoris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: default avatarKyle Roeschley <kyle.roeschley@ni.com>
parent 57d419a4

drivers/mtd/nand/nand_bbt.c

+74 −36
Original line number Diff line number Diff line
@@ -604,6 +604,69 @@ static void search_read_bbts(struct mtd_info *mtd, uint8_t *buf, 
		search_bbt(mtd, buf, md);

}



/**

 * get_bbt_block - Get the first valid eraseblock suitable to store a BBT

 * @this: the NAND device

 * @td: the BBT description

 * @md: the mirror BBT descriptor

 * @chip: the CHIP selector

 *

 * This functions returns a positive block number pointing a valid eraseblock

 * suitable to store a BBT (i.e. in the range reserved for BBT), or -ENOSPC if

 * all blocks are already used of marked bad. If td->pages[chip] was already

 * pointing to a valid block we re-use it, otherwise we search for the next

 * valid one.

 */

static int get_bbt_block(struct nand_chip *this, struct nand_bbt_descr *td,

			 struct nand_bbt_descr *md, int chip)

{

	int startblock, dir, page, numblocks, i;



	/*

	 * There was already a version of the table, reuse the page. This

	 * applies for absolute placement too, as we have the page number in

	 * td->pages.

	 */

	if (td->pages[chip] != -1)

		return td->pages[chip] >>

				(this->bbt_erase_shift - this->page_shift);



	numblocks = (int)(this->chipsize >> this->bbt_erase_shift);

	if (!(td->options & NAND_BBT_PERCHIP))

		numblocks *= this->numchips;



	/*

	 * Automatic placement of the bad block table. Search direction

	 * top -> down?

	 */

	if (td->options & NAND_BBT_LASTBLOCK) {

		startblock = numblocks * (chip + 1) - 1;

		dir = -1;

	} else {

		startblock = chip * numblocks;

		dir = 1;

	}



	for (i = 0; i < td->maxblocks; i++) {

		int block = startblock + dir * i;



		/* Check, if the block is bad */

		switch (bbt_get_entry(this, block)) {

		case BBT_BLOCK_WORN:

		case BBT_BLOCK_FACTORY_BAD:

			continue;

		}



		page = block << (this->bbt_erase_shift - this->page_shift);



		/* Check, if the block is used by the mirror table */

		if (!md || md->pages[chip] != page)

			return block;

	}



	return -ENOSPC;

}



/**

 * write_bbt - [GENERIC] (Re)write the bad block table

 * @mtd: MTD device structure
@@ -621,7 +684,7 @@ static int write_bbt(struct mtd_info *mtd, uint8_t *buf, 
	struct nand_chip *this = mtd_to_nand(mtd);

	struct erase_info einfo;

	int i, res, chip = 0;

	int bits, startblock, dir, page, offs, numblocks, sft, sftmsk;

	int bits, page, offs, numblocks, sft, sftmsk;

	int nrchips, pageoffs, ooboffs;

	uint8_t msk[4];

	uint8_t rcode = td->reserved_block_code;
@@ -653,45 +716,20 @@ static int write_bbt(struct mtd_info *mtd, uint8_t *buf, 


	/* Loop through the chips */

	for (; chip < nrchips; chip++) {

		/*

		 * There was already a version of the table, reuse the page

		 * This applies for absolute placement too, as we have the

		 * page nr. in td->pages.

		 */

		if (td->pages[chip] != -1) {

			page = td->pages[chip];

			goto write;

		int block;



		block = get_bbt_block(this, td, md, chip);

		if (block < 0) {

			pr_err("No space left to write bad block table\n");

			res = block;

			goto outerr;

		}



		/*

		 * Automatic placement of the bad block table. Search direction

		 * top -> down?

		 * get_bbt_block() returns a block number, shift the value to

		 * get a page number.

		 */

		if (td->options & NAND_BBT_LASTBLOCK) {

			startblock = numblocks * (chip + 1) - 1;

			dir = -1;

		} else {

			startblock = chip * numblocks;

			dir = 1;

		}



		for (i = 0; i < td->maxblocks; i++) {

			int block = startblock + dir * i;

			/* Check, if the block is bad */

			switch (bbt_get_entry(this, block)) {

			case BBT_BLOCK_WORN:

			case BBT_BLOCK_FACTORY_BAD:

				continue;

			}

			page = block <<

				(this->bbt_erase_shift - this->page_shift);

			/* Check, if the block is used by the mirror table */

			if (!md || md->pages[chip] != page)

				goto write;

		}

		pr_err("No space left to write bad block table\n");

		return -ENOSPC;

	write:

		page = block << (this->bbt_erase_shift - this->page_shift);



		/* Set up shift count and masks for the flash table */

		bits = td->options & NAND_BBT_NRBITS_MSK;