[PATCH] [MTD] NAND: Enhance nandsim to simulate flash errors
Adrian Hunter
ext-adrian.hunter at nokia.com
Mon Mar 19 06:47:45 EDT 2007
New module parameters have been added to nandsim to
simulate:
bitflips random bit flips
badblocks blocks that are initially marked bad
weakblocks blocks that fail to erase after a
small number of erase cycles
weakpages pages that fail to write after a
small number of successful writes
gravepages pages that fail to read after a
small number of successful reads
Signed-off-by: Adrian Hunter <ext-adrian.hunter at nokia.com>
---
drivers/mtd/nand/nandsim.c | 301 +++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 300 insertions(+), 1 deletions(-)
diff --git a/drivers/mtd/nand/nandsim.c b/drivers/mtd/nand/nandsim.c
index 638e6c2..05b4207 100644
--- a/drivers/mtd/nand/nandsim.c
+++ b/drivers/mtd/nand/nandsim.c
@@ -38,6 +38,7 @@ #include <linux/mtd/nand.h>
#include <linux/mtd/partitions.h>
#include <linux/delay.h>
#include <linux/list.h>
+#include <linux/random.h>
/* Default simulator parameters values */
#if !defined(CONFIG_NANDSIM_FIRST_ID_BYTE) || \
@@ -93,6 +94,11 @@ static uint log = CONFIG_NAND
static uint dbg = CONFIG_NANDSIM_DBG;
static unsigned long parts[MAX_MTD_DEVICES];
static unsigned int parts_num;
+static char *badblocks = NULL;
+static char *weakblocks = NULL;
+static char *weakpages = NULL;
+static unsigned int bitflips = 0;
+static char *gravepages = NULL;
module_param(first_id_byte, uint, 0400);
module_param(second_id_byte, uint, 0400);
@@ -108,6 +114,11 @@ module_param(do_delays, uint, 0400)
module_param(log, uint, 0400);
module_param(dbg, uint, 0400);
module_param_array(parts, ulong, &parts_num, 0400);
+module_param(badblocks, charp, 0400);
+module_param(weakblocks, charp, 0400);
+module_param(weakpages, charp, 0400);
+module_param(bitflips, uint, 0400);
+module_param(gravepages, charp, 0400);
MODULE_PARM_DESC(first_id_byte, "The fist byte returned by NAND Flash 'read ID' command (manufaturer ID)");
MODULE_PARM_DESC(second_id_byte, "The second byte returned by NAND Flash 'read ID' command (chip ID)");
@@ -123,6 +134,18 @@ MODULE_PARM_DESC(do_delays, "Simula
MODULE_PARM_DESC(log, "Perform logging if not zero");
MODULE_PARM_DESC(dbg, "Output debug information if not zero");
MODULE_PARM_DESC(parts, "Partition sizes (in erase blocks) separated by commas");
+/* Page and erase block positions for the following parameters are independent of any partitions */
+MODULE_PARM_DESC(badblocks, "Erase blocks that are initially marked bad, separated by commas");
+MODULE_PARM_DESC(weakblocks, "Weak erase blocks [: remaining erase cycles (defaults to 3)]"
+ " separated by commas e.g. 113:2 means eb 113"
+ " can be erased only twice before failing");
+MODULE_PARM_DESC(weakpages, "Weak pages [: maximum writes (defaults to 3)]"
+ " separated by commas e.g. 1401:2 means page 1401"
+ " can be written only twice before failing");
+MODULE_PARM_DESC(bitflips, "Maximum number of random bit flips per page (zero by default)");
+MODULE_PARM_DESC(gravepages, "Pages that lose data [: maximum reads (defaults to 3)]"
+ " separated by commas e.g. 1401:2 means page 1401"
+ " can be read only twice before failing");
/* The largest possible page size */
#define NS_LARGEST_PAGE_SIZE 2048
@@ -344,6 +367,33 @@ static struct nandsim_operations {
STATE_DATAOUT, STATE_READY}}
};
+struct weak_block {
+ struct list_head list;
+ unsigned int erase_block_no;
+ unsigned int max_erases;
+ unsigned int erases_done;
+};
+
+static LIST_HEAD(weak_blocks);
+
+struct weak_page {
+ struct list_head list;
+ unsigned int page_no;
+ unsigned int max_writes;
+ unsigned int writes_done;
+};
+
+static LIST_HEAD(weak_pages);
+
+struct grave_page {
+ struct list_head list;
+ unsigned int page_no;
+ unsigned int max_reads;
+ unsigned int reads_done;
+};
+
+static LIST_HEAD(grave_pages);
+
/* MTD structure for NAND controller */
static struct mtd_info *nsmtd;
@@ -555,6 +605,204 @@ static void free_nandsim(struct nandsim
return;
}
+static int parse_badblocks(struct nandsim *ns, struct mtd_info *mtd)
+{
+ char *w;
+ int zero_ok;
+ unsigned int erase_block_no;
+ loff_t offset;
+
+ if (!badblocks)
+ return 0;
+ w = badblocks;
+ do {
+ zero_ok = (*w == '0' ? 1 : 0);
+ erase_block_no = simple_strtoul(w, &w, 0);
+ if (!zero_ok && !erase_block_no) {
+ NS_ERR("invalid badblocks.\n");
+ return -EINVAL;
+ }
+ offset = erase_block_no * ns->geom.secsz;
+ if (mtd->block_markbad(mtd, offset)) {
+ NS_ERR("invalid badblocks.\n");
+ return -EINVAL;
+ }
+ if (*w == ',')
+ w += 1;
+ } while (*w);
+ return 0;
+}
+
+static int parse_weakblocks(void)
+{
+ char *w;
+ int zero_ok;
+ unsigned int erase_block_no;
+ unsigned int max_erases;
+ struct weak_block *wb;
+
+ if (!weakblocks)
+ return 0;
+ w = weakblocks;
+ do {
+ zero_ok = (*w == '0' ? 1 : 0);
+ erase_block_no = simple_strtoul(w, &w, 0);
+ if (!zero_ok && !erase_block_no) {
+ NS_ERR("invalid weakblocks.\n");
+ return -EINVAL;
+ }
+ max_erases = 3;
+ if (*w == ':') {
+ w += 1;
+ max_erases = simple_strtoul(w, &w, 0);
+ }
+ if (*w == ',')
+ w += 1;
+ wb = kzalloc(sizeof(*wb), GFP_KERNEL);
+ if (!wb) {
+ NS_ERR("unable to allocate memory.\n");
+ return -ENOMEM;
+ }
+ wb->erase_block_no = erase_block_no;
+ wb->max_erases = max_erases;
+ list_add(&wb->list, &weak_blocks);
+ } while (*w);
+ return 0;
+}
+
+static int erase_error(unsigned int erase_block_no)
+{
+ struct weak_block *wb;
+
+ list_for_each_entry(wb, &weak_blocks, list)
+ if (wb->erase_block_no == erase_block_no) {
+ if (wb->erases_done >= wb->max_erases)
+ return 1;
+ wb->erases_done += 1;
+ return 0;
+ }
+ return 0;
+}
+
+static int parse_weakpages(void)
+{
+ char *w;
+ int zero_ok;
+ unsigned int page_no;
+ unsigned int max_writes;
+ struct weak_page *wp;
+
+ if (!weakpages)
+ return 0;
+ w = weakpages;
+ do {
+ zero_ok = (*w == '0' ? 1 : 0);
+ page_no = simple_strtoul(w, &w, 0);
+ if (!zero_ok && !page_no) {
+ NS_ERR("invalid weakpagess.\n");
+ return -EINVAL;
+ }
+ max_writes = 3;
+ if (*w == ':') {
+ w += 1;
+ max_writes = simple_strtoul(w, &w, 0);
+ }
+ if (*w == ',')
+ w += 1;
+ wp = kzalloc(sizeof(*wp), GFP_KERNEL);
+ if (!wp) {
+ NS_ERR("unable to allocate memory.\n");
+ return -ENOMEM;
+ }
+ wp->page_no = page_no;
+ wp->max_writes = max_writes;
+ list_add(&wp->list, &weak_pages);
+ } while (*w);
+ return 0;
+}
+
+static int write_error(unsigned int page_no)
+{
+ struct weak_page *wp;
+
+ list_for_each_entry(wp, &weak_pages, list)
+ if (wp->page_no == page_no) {
+ if (wp->writes_done >= wp->max_writes)
+ return 1;
+ wp->writes_done += 1;
+ return 0;
+ }
+ return 0;
+}
+
+static int parse_gravepages(void)
+{
+ char *g;
+ int zero_ok;
+ unsigned int page_no;
+ unsigned int max_reads;
+ struct grave_page *gp;
+
+ if (!gravepages)
+ return 0;
+ g = gravepages;
+ do {
+ zero_ok = (*g == '0' ? 1 : 0);
+ page_no = simple_strtoul(g, &g, 0);
+ if (!zero_ok && !page_no) {
+ NS_ERR("invalid gravepagess.\n");
+ return -EINVAL;
+ }
+ max_reads = 3;
+ if (*g == ':') {
+ g += 1;
+ max_reads = simple_strtoul(g, &g, 0);
+ }
+ if (*g == ',')
+ g += 1;
+ gp = kzalloc(sizeof(*gp), GFP_KERNEL);
+ if (!gp) {
+ NS_ERR("unable to allocate memory.\n");
+ return -ENOMEM;
+ }
+ gp->page_no = page_no;
+ gp->max_reads = max_reads;
+ list_add(&gp->list, &grave_pages);
+ } while (*g);
+ return 0;
+}
+
+static int read_error(unsigned int page_no)
+{
+ struct grave_page *gp;
+
+ list_for_each_entry(gp, &grave_pages, list)
+ if (gp->page_no == page_no) {
+ if (gp->reads_done >= gp->max_reads)
+ return 1;
+ gp->reads_done += 1;
+ return 0;
+ }
+ return 0;
+}
+
+static void free_lists(void)
+{
+ struct list_head *pos, *n;
+ list_for_each_safe(pos, n, &weak_blocks) {
+ list_del(pos);
+ kfree(list_entry(pos, struct weak_block, list));
+ }
+ list_for_each_safe(pos, n, &weak_pages) {
+ list_del(pos);
+ kfree(list_entry(pos, struct weak_page, list));
+ }
+ list_for_each_safe(pos, n, &grave_pages) {
+ list_del(pos);
+ kfree(list_entry(pos, struct grave_page, list));
+ }
+}
+
/*
* Returns the string representation of 'state' state.
*/
@@ -867,9 +1115,31 @@ static void read_page(struct nandsim *ns
NS_DBG("read_page: page %d not allocated\n", ns->regs.row);
memset(ns->buf.byte, 0xFF, num);
} else {
+ unsigned int page_no = ns->regs.row;
NS_DBG("read_page: page %d allocated, reading from %d\n",
ns->regs.row, ns->regs.column + ns->regs.off);
+ if (read_error(page_no)) {
+ int i;
+ memset(ns->buf.byte, 0xFF, num);
+ for (i = 0; i < num; ++i)
+ ns->buf.byte[i] = random32();
+ NS_WARN("simulating read error in page %u\n", page_no);
+ return;
+ }
memcpy(ns->buf.byte, NS_PAGE_BYTE_OFF(ns), num);
+ if (bitflips && random32() < (1 << 22)) {
+ int flips = 1;
+ if (bitflips > 1)
+ flips = (random32() % (int) bitflips) + 1;
+ while (flips--) {
+ int pos = random32() % (num * 8);
+ ns->buf.byte[pos / 8] ^= (1 << (pos % 8));
+ NS_WARN("read_page: flipping bit %d in page %d "
+ "reading from %d ecc: corrected=%u failed=%u\n",
+ pos, ns->regs.row, ns->regs.column + ns->regs.off,
+ nsmtd->ecc_stats.corrected, nsmtd->ecc_stats.failed);
+ }
+ }
}
}
@@ -928,6 +1198,7 @@ static int do_state_action(struct nandsi
{
int num;
int busdiv = ns->busw == 8 ? 1 : 2;
+ unsigned int erase_block_no, page_no;
action &= ACTION_MASK;
@@ -987,14 +1258,21 @@ static int do_state_action(struct nandsi
8 * (ns->geom.pgaddrbytes - ns->geom.secaddrbytes)) | ns->regs.column;
ns->regs.column = 0;
+ erase_block_no = ns->regs.row >> (ns->geom.secshift - ns->geom.pgshift);
+
NS_DBG("do_state_action: erase sector at address %#x, off = %d\n",
ns->regs.row, NS_RAW_OFFSET(ns));
- NS_LOG("erase sector %d\n", ns->regs.row >> (ns->geom.secshift - ns->geom.pgshift));
+ NS_LOG("erase sector %u\n", erase_block_no);
erase_sector(ns);
NS_MDELAY(erase_delay);
+ if (erase_error(erase_block_no)) {
+ NS_WARN("simulating erase failure in erase block %u\n", erase_block_no);
+ return -1;
+ }
+
break;
case ACTION_PRGPAGE:
@@ -1017,6 +1295,8 @@ static int do_state_action(struct nandsi
if (prog_page(ns, num) == -1)
return -1;
+ page_no = ns->regs.row;
+
NS_DBG("do_state_action: copy %d bytes from int buf to (%#x, %#x), raw off = %d\n",
num, ns->regs.row, ns->regs.column, NS_RAW_OFFSET(ns) + ns->regs.off);
NS_LOG("programm page %d\n", ns->regs.row);
@@ -1024,6 +1304,11 @@ static int do_state_action(struct nandsi
NS_UDELAY(programm_delay);
NS_UDELAY(output_cycle * ns->geom.pgsz / 1000 / busdiv);
+ if (write_error(page_no)) {
+ NS_WARN("simulating write failure in page %u\n", page_no);
+ return -1;
+ }
+
break;
case ACTION_ZEROOFF:
@@ -1602,6 +1887,15 @@ static int __init ns_init_module(void)
nsmtd->owner = THIS_MODULE;
+ if ((retval = parse_weakblocks()) != 0)
+ goto error;
+
+ if ((retval = parse_weakpages()) != 0)
+ goto error;
+
+ if ((retval = parse_gravepages()) != 0)
+ goto error;
+
if ((retval = nand_scan(nsmtd, 1)) != 0) {
NS_ERR("can't register NAND Simulator\n");
if (retval > 0)
@@ -1612,6 +1906,9 @@ static int __init ns_init_module(void)
if ((retval = init_nandsim(nsmtd)) != 0)
goto err_exit;
+ if ((retval = parse_badblocks(nand, nsmtd)) != 0)
+ goto err_exit;
+
if ((retval = nand_default_bbt(nsmtd)) != 0)
goto err_exit;
@@ -1628,6 +1925,7 @@ err_exit:
kfree(nand->partitions[i].name);
error:
kfree(nsmtd);
+ free_lists();
return retval;
}
@@ -1647,6 +1945,7 @@ static void __exit ns_cleanup_module(voi
for (i = 0;i < ARRAY_SIZE(ns->partitions); ++i)
kfree(ns->partitions[i].name);
kfree(nsmtd); /* Free other structures */
+ free_lists();
}
module_exit(ns_cleanup_module);
--
1.4.3
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