From c3baf278d3bf8d628df0b28aa4921c5457d40211 Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Mon, 15 Aug 2016 18:22:01 -0500 Subject: [PATCH] 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: Boris Brezillon Tested-by: Kyle Roeschley --- drivers/mtd/nand/nand_bbt.c | 110 +++++++++++++++++++++++++++++--------------- 1 file changed, 74 insertions(+), 36 deletions(-) diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c index 2fbb523..9fbd664 100644 --- a/drivers/mtd/nand/nand_bbt.c +++ b/drivers/mtd/nand/nand_bbt.c @@ -605,6 +605,69 @@ static void search_read_bbts(struct mtd_info *mtd, uint8_t *buf, } /** + * 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 * @buf: temporary buffer @@ -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; -- 2.7.4