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

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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: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This commit is contained in:
Brian Norris 2013-07-30 17:52:55 -07:00 committed by David Woodhouse
parent e79265ba6b
commit 771c568bcf
1 changed files with 48 additions and 22 deletions
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70
drivers/mtd/nand/nand_bbt.c
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@ -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;