[PATCH v3 2/2] mtd/nand: More BB Detection, dynamic scan options
Brian Norris
norris at broadcom.com
Thu Jul 15 15:15:44 EDT 2010
This is a revision to PATCH 2/2 that I sent. Link:
http://lists.infradead.org/pipermail/linux-mtd/2010-July/030911.html
Added new flag for scanning of both bytes 1 and 6 of the OOB for
a BB marker (instead of simply one or the other).
The "check_pattern" and "check_short_pattern" functions were updated
to include support for scanning the two different locations in the OOB.
In order to handle increases in variety of necessary scanning patterns,
I implemented dynamic memory allocation of nand_bbt_descr structs
in new function 'nand_create_default_bbt_descr()'. This replaces
some increasingly-unwieldy, statically-declared descriptors. It can
replace several more (e.g. "flashbased" structs). However, I do not
test the flashbased options personally.
Signed-off-by: Brian Norris <norris at broadcom.com>
---
drivers/mtd/nand/nand_base.c | 14 +++++
drivers/mtd/nand/nand_bbt.c | 127 ++++++++++++++++++++++++------------------
include/linux/mtd/bbm.h | 4 +
3 files changed, 90 insertions(+), 55 deletions(-)
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index bd69790..c2901bd 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2963,6 +2963,15 @@ static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
*maf_id == NAND_MFR_MICRON))
chip->options |= NAND_BBT_SCAN2NDPAGE;
+ /*
+ * Numonyx/ST 2K pages, x8 bus use BOTH byte 1 and 6
+ */
+ if (!(busw & NAND_BUSWIDTH_16) &&
+ *maf_id == NAND_MFR_STMICRO &&
+ mtd->writesize == 2048) {
+ chip->options |= NAND_BBT_SCANBYTE1AND6;
+ chip->badblockpos = 0;
+ }
/* Check for AND chips with 4 page planes */
if (chip->options & NAND_4PAGE_ARRAY)
@@ -3322,6 +3331,11 @@ void nand_release(struct mtd_info *mtd)
kfree(chip->bbt);
if (!(chip->options & NAND_OWN_BUFFERS))
kfree(chip->buffers);
+
+ /* Free bad block descriptor memory */
+ if (chip->badblock_pattern && chip->badblock_pattern->options
+ & NAND_BBT_DYNAMICSTRUCT)
+ kfree(chip->badblock_pattern);
}
EXPORT_SYMBOL_GPL(nand_lock);
diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c
index ec1700e..469de17 100644
--- a/drivers/mtd/nand/nand_bbt.c
+++ b/drivers/mtd/nand/nand_bbt.c
@@ -93,6 +93,28 @@ static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_desc
return -1;
}
+ /* Check both positions 1 and 6 for pattern? */
+ if (td->options & NAND_BBT_SCANBYTE1AND6) {
+ if (td->options & NAND_BBT_SCANEMPTY) {
+ p += td->len;
+ end += NAND_SMALL_BADBLOCK_POS - td->offs;
+ /* Check region between positions 1 and 6 */
+ for (i = 0; i < NAND_SMALL_BADBLOCK_POS - td->offs - td->len;
+ i++) {
+ if (*p++ != 0xff)
+ return -1;
+ }
+ }
+ else {
+ p += NAND_SMALL_BADBLOCK_POS - td->offs;
+ }
+ /* Compare the pattern */
+ for (i = 0; i < td->len; i++) {
+ if (p[i] != td->pattern[i])
+ return -1;
+ }
+ }
+
if (td->options & NAND_BBT_SCANEMPTY) {
p += td->len;
end += td->len;
@@ -124,6 +146,13 @@ static int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td)
if (p[td->offs + i] != td->pattern[i])
return -1;
}
+ /* Need to check location 1 AND 6? */
+ if (td->options & NAND_BBT_SCANBYTE1AND6) {
+ for (i = 0; i < td->len; i++) {
+ if (p[NAND_SMALL_BADBLOCK_POS + i] != td->pattern[i])
+ return -1;
+ }
+ }
return 0;
}
@@ -397,12 +426,10 @@ static int create_bbt(struct mtd_info *mtd, uint8_t *buf,
if (bd->options & NAND_BBT_SCANALLPAGES)
len = 1 << (this->bbt_erase_shift - this->page_shift);
- else {
- if (bd->options & NAND_BBT_SCAN2NDPAGE)
- len = 2;
- else
- len = 1;
- }
+ else if (bd->options & NAND_BBT_SCAN2NDPAGE)
+ len = 2;
+ else
+ len = 1;
if (!(bd->options & NAND_BBT_SCANEMPTY)) {
/* We need only read few bytes from the OOB area */
@@ -1092,41 +1119,6 @@ int nand_update_bbt(struct mtd_info *mtd, loff_t offs)
* while scanning a device for factory marked good / bad blocks. */
static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
-static struct nand_bbt_descr smallpage_memorybased = {
- .options = 0,
- .offs = NAND_SMALL_BADBLOCK_POS,
- .len = 1,
- .pattern = scan_ff_pattern
-};
-
-static struct nand_bbt_descr smallpage_scan2nd_memorybased = {
- .options = NAND_BBT_SCAN2NDPAGE,
- .offs = NAND_SMALL_BADBLOCK_POS,
- .len = 2,
- .pattern = scan_ff_pattern
-};
-
-static struct nand_bbt_descr largepage_memorybased = {
- .options = 0,
- .offs = NAND_LARGE_BADBLOCK_POS,
- .len = 1,
- .pattern = scan_ff_pattern
-};
-
-static struct nand_bbt_descr largepage_scan2nd_memorybased = {
- .options = NAND_BBT_SCAN2NDPAGE,
- .offs = NAND_LARGE_BADBLOCK_POS,
- .len = 2,
- .pattern = scan_ff_pattern
-};
-
-static struct nand_bbt_descr lastpage_memorybased = {
- .options = NAND_BBT_SCANLASTPAGE,
- .offs = 0,
- .len = 1,
- .pattern = scan_ff_pattern
-};
-
static struct nand_bbt_descr smallpage_flashbased = {
.options = NAND_BBT_SCAN2NDPAGE,
.offs = NAND_SMALL_BADBLOCK_POS,
@@ -1175,6 +1167,43 @@ static struct nand_bbt_descr bbt_mirror_descr = {
.pattern = mirror_pattern
};
+#define BBT_SCAN_OPTIONS (NAND_BBT_SCANLASTPAGE | NAND_BBT_SCAN2NDPAGE | \
+ NAND_BBT_SCANBYTE1AND6)
+/**
+ * nand_create_default_bbt_descr - [Internal] Creates a BBT descriptor structure
+ * @this: NAND chip to create descriptor for
+ *
+ * This function allocates and initializes a nand_bbt_descr for BBM detection
+ * based on the properties of "this". The new descriptor is stored in
+ * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
+ * passed to this function.
+ *
+ * TODO: Handle other flags, replace other static structs
+ * (e.g. handle NAND_BBT_FLASH for flash-based BBT,
+ * replace smallpage_flashbased)
+ *
+ */
+static int nand_create_default_bbt_descr(struct nand_chip *this)
+{
+ struct nand_bbt_descr *bd;
+ if (this->badblock_pattern) {
+ printk(KERN_WARNING "BBT descr already allocated; not replacing.\n");
+ return -EINVAL;
+ }
+ bd = kzalloc(sizeof(*bd), GFP_KERNEL);
+ if (!bd) {
+ printk(KERN_ERR "nand_create_default_bbt_descr: Out of memory\n");
+ return -ENOMEM;
+ }
+ bd->options = this->options & BBT_SCAN_OPTIONS;
+ bd->offs = this->badblockpos;
+ bd->len = (this->options & NAND_BUSWIDTH_16) ? 2 : 1;
+ bd->pattern = scan_ff_pattern;
+ bd->options |= NAND_BBT_DYNAMICSTRUCT;
+ this->badblock_pattern = bd;
+ return 0;
+}
+
/**
* nand_default_bbt - [NAND Interface] Select a default bad block table for the device
* @mtd: MTD device structure
@@ -1217,20 +1246,8 @@ int nand_default_bbt(struct mtd_info *mtd)
} else {
this->bbt_td = NULL;
this->bbt_md = NULL;
- if (!this->badblock_pattern) {
- if (this->options & NAND_BBT_SCANLASTPAGE)
- this->badblock_pattern = &lastpage_memorybased;
- else if (this->options & NAND_BBT_SCAN2NDPAGE)
- this->badblock_pattern = this->badblockpos ==
- NAND_SMALL_BADBLOCK_POS ?
- &smallpage_scan2nd_memorybased :
- &largepage_scan2nd_memorybased;
- else
- this->badblock_pattern = this->badblockpos ==
- NAND_SMALL_BADBLOCK_POS ?
- &smallpage_memorybased :
- &largepage_memorybased;
- }
+ if (!this->badblock_pattern)
+ nand_create_default_bbt_descr(this);
}
return nand_scan_bbt(mtd, this->badblock_pattern);
}
diff --git a/include/linux/mtd/bbm.h b/include/linux/mtd/bbm.h
index 8ad0b86..a04b962 100644
--- a/include/linux/mtd/bbm.h
+++ b/include/linux/mtd/bbm.h
@@ -84,6 +84,10 @@ struct nand_bbt_descr {
#define NAND_BBT_SCAN2NDPAGE 0x00004000
/* Search good / bad pattern on the last page of the eraseblock */
#define NAND_BBT_SCANLASTPAGE 0x00008000
+/* Chip stores bad block marker on BOTH 1st and 6th bytes of OOB */
+#define NAND_BBT_SCANBYTE1AND6 0x00100000
+/* The nand_bbt_descr was created dynamicaly and must be freed */
+#define NAND_BBT_DYNAMICSTRUCT 0x00200000
/* The maximum number of blocks to scan for a bbt */
#define NAND_BBT_SCAN_MAXBLOCKS 4
--
1.7.0.4
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