Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 771c568b authored by Brian Norris's avatar Brian Norris Committed by David Woodhouse
Browse files

mtd: nand: add accessors, macros for in-memory BBT 



There is an abundance of magic numbers and complicated shifting/masking
logic in the in-memory BBT code which makes the code unnecessary complex
and hard to read.

This patch adds macros to represent the 00b, 01b, 10b, and 11b
memory-BBT magic numbers, as well as two accessor functions for reading
and marking the memory-BBT bitfield for a given block.

Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
Signed-off-by: default avatarArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent e79265ba

drivers/mtd/nand/nand_bbt.c

+48 −22
Original line number Diff line number Diff line
@@ -71,6 +71,28 @@ 
#include <linux/export.h>

#include <linux/string.h>



#define BBT_BLOCK_GOOD		0x00

#define BBT_BLOCK_WORN		0x01

#define BBT_BLOCK_RESERVED	0x02

#define BBT_BLOCK_FACTORY_BAD	0x03



#define BBT_ENTRY_MASK		0x03

#define BBT_ENTRY_SHIFT		2



static inline uint8_t bbt_get_entry(struct nand_chip *chip, int block)

{

	uint8_t entry = chip->bbt[block >> BBT_ENTRY_SHIFT];

	entry >>= (block & BBT_ENTRY_MASK) * 2;

	return entry & BBT_ENTRY_MASK;

}



static inline void bbt_mark_entry(struct nand_chip *chip, int block,

		uint8_t mark)

{

	uint8_t msk = (mark & BBT_ENTRY_MASK) << ((block & BBT_ENTRY_MASK) * 2);

	chip->bbt[block >> BBT_ENTRY_SHIFT] |= msk;

}



static int check_pattern_no_oob(uint8_t *buf, struct nand_bbt_descr *td)

{

	if (memcmp(buf, td->pattern, td->len))
@@ -216,7 +238,9 @@ static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num, 
				if (reserved_block_code && (tmp == reserved_block_code)) {

					pr_info("nand_read_bbt: reserved block at 0x%012llx\n",

						 (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift);

					this->bbt[offs + (act >> 3)] |= 0x2 << (act & 0x06);

					bbt_mark_entry(this, (offs << 2) +

							(act >> 1),

							BBT_BLOCK_RESERVED);

					mtd->ecc_stats.bbtblocks++;

					continue;

				}
@@ -228,9 +252,13 @@ static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num, 
					 (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift);

				/* Factory marked bad or worn out? */

				if (tmp == 0)

					this->bbt[offs + (act >> 3)] |= 0x3 << (act & 0x06);

					bbt_mark_entry(this, (offs << 2) +

							(act >> 1),

							BBT_BLOCK_FACTORY_BAD);

				else

					this->bbt[offs + (act >> 3)] |= 0x1 << (act & 0x06);

					bbt_mark_entry(this, (offs << 2) +

							(act >> 1),

							BBT_BLOCK_WORN);

				mtd->ecc_stats.badblocks++;

			}

		}
@@ -526,7 +554,7 @@ static int create_bbt(struct mtd_info *mtd, uint8_t *buf, 
			return ret;



		if (ret) {

			this->bbt[i >> 3] |= 0x03 << (i & 0x6);

			bbt_mark_entry(this, i >> 1, BBT_BLOCK_FACTORY_BAD);

			pr_warn("Bad eraseblock %d at 0x%012llx\n",

				i >> 1, (unsigned long long)from);

			mtd->ecc_stats.badblocks++;
@@ -713,10 +741,9 @@ static int write_bbt(struct mtd_info *mtd, uint8_t *buf, 
		for (i = 0; i < td->maxblocks; i++) {

			int block = startblock + dir * i;

			/* Check, if the block is bad */

			switch ((this->bbt[block >> 2] >>

				 (2 * (block & 0x03))) & 0x03) {

			case 0x01:

			case 0x03:

			switch (bbt_get_entry(this, block)) {

			case BBT_BLOCK_WORN:

			case BBT_BLOCK_FACTORY_BAD:

				continue;

			}

			page = block <<
@@ -816,7 +843,7 @@ static int write_bbt(struct mtd_info *mtd, uint8_t *buf, 
		/* Walk through the memory table */

		for (i = 0; i < numblocks;) {

			uint8_t dat;

			dat = this->bbt[bbtoffs + (i >> 2)];

			dat = bbt_get_entry(this, (bbtoffs << 2) + i);

			for (j = 0; j < 4; j++, i++) {

				int sftcnt = (i << (3 - sft)) & sftmsk;

				/* Do not store the reserved bbt blocks! */
@@ -1009,7 +1036,7 @@ static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td) 
{

	struct nand_chip *this = mtd->priv;

	int i, j, chips, block, nrblocks, update;

	uint8_t oldval, newval;

	uint8_t oldval;



	/* Do we have a bbt per chip? */

	if (td->options & NAND_BBT_PERCHIP) {
@@ -1027,10 +1054,10 @@ static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td) 
				continue;

			block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift);

			block <<= 1;

			oldval = this->bbt[(block >> 3)];

			newval = oldval | (0x2 << (block & 0x06));

			this->bbt[(block >> 3)] = newval;

			if ((oldval != newval) && td->reserved_block_code)

			oldval = bbt_get_entry(this, block >> 1);

			bbt_mark_entry(this, block >> 1, BBT_BLOCK_RESERVED);

			if ((oldval != BBT_BLOCK_RESERVED) &&

					td->reserved_block_code)

				nand_update_bbt(mtd, (loff_t)block << (this->bbt_erase_shift - 1));

			continue;

		}
@@ -1041,10 +1068,9 @@ static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td) 
			block = i * nrblocks;

		block <<= 1;

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

			oldval = this->bbt[(block >> 3)];

			newval = oldval | (0x2 << (block & 0x06));

			this->bbt[(block >> 3)] = newval;

			if (oldval != newval)

			oldval = bbt_get_entry(this, block >> 1);

			bbt_mark_entry(this, block >> 1, BBT_BLOCK_RESERVED);

			if (oldval != BBT_BLOCK_RESERVED)

				update = 1;

			block += 2;

		}
@@ -1361,18 +1387,18 @@ int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt) 


	/* Get block number * 2 */

	block = (int)(offs >> (this->bbt_erase_shift - 1));

	res = (this->bbt[block >> 3] >> (block & 0x06)) & 0x03;

	res = bbt_get_entry(this, block >> 1);



	pr_debug("nand_isbad_bbt(): bbt info for offs 0x%08x: "

			"(block %d) 0x%02x\n",

			(unsigned int)offs, block >> 1, res);



	switch ((int)res) {

	case 0x00:

	case BBT_BLOCK_GOOD:

		return 0;

	case 0x01:

	case BBT_BLOCK_WORN:

		return 1;

	case 0x02:

	case BBT_BLOCK_RESERVED:

		return allowbbt ? 0 : 1;

	}

	return 1;