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mtd: nandsim: Introduce debugfs infrastructure 

It's more user friendly to report debug information and statistics
through debugfs, than to use printing facilites.

This patch introduces a very minimal debugfs infrastructure
and moves eraseblock wear report to an entry located at:

/sys/kernel/debug/nandsim/wear_report

This means we can remove rptwear option and just let
the user get the wear report when we needs to.

Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
This commit is contained in:
Ezequiel Garcia 2012-12-03 10:31:40 -03:00 committed by Artem Bityutskiy
parent e58a66d84b
commit 5346c27c5f
1 changed files with 130 additions and 56 deletions
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186
drivers/mtd/nand/nandsim.c
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@ -42,6 +42,8 @@
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>
/* Default simulator parameters values */
#if !defined(CONFIG_NANDSIM_FIRST_ID_BYTE) || \
@ -105,7 +107,6 @@ static char *weakblocks = NULL;
static char *weakpages = NULL;
static unsigned int bitflips = 0;
static char *gravepages = NULL;
static unsigned int rptwear = 0;
static unsigned int overridesize = 0;
static char *cache_file = NULL;
static unsigned int bbt;
@ -130,7 +131,6 @@ module_param(weakblocks, charp, 0400);
module_param(weakpages, charp, 0400);
module_param(bitflips, uint, 0400);
module_param(gravepages, charp, 0400);
module_param(rptwear, uint, 0400);
module_param(overridesize, uint, 0400);
module_param(cache_file, charp, 0400);
module_param(bbt, uint, 0400);
@ -162,7 +162,6 @@ MODULE_PARM_DESC(bitflips, "Maximum number of random bit flips per page (z
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");
MODULE_PARM_DESC(rptwear, "Number of erases between reporting wear, if not zero");
MODULE_PARM_DESC(overridesize, "Specifies the NAND Flash size overriding the ID bytes. "
"The size is specified in erase blocks and as the exponent of a power of two"
" e.g. 5 means a size of 32 erase blocks");
@ -286,6 +285,11 @@ MODULE_PARM_DESC(bch, "Enable BCH ecc and set how many bits should "
/* Maximum page cache pages needed to read or write a NAND page to the cache_file */
#define NS_MAX_HELD_PAGES 16
struct nandsim_debug_info {
struct dentry *dfs_root;
struct dentry *dfs_wear_report;
};
/*
* A union to represent flash memory contents and flash buffer.
*/
@ -365,6 +369,8 @@ struct nandsim {
void *file_buf;
struct page *held_pages[NS_MAX_HELD_PAGES];
int held_cnt;
struct nandsim_debug_info dbg;
};
/*
@ -442,11 +448,123 @@ static LIST_HEAD(grave_pages);
static unsigned long *erase_block_wear = NULL;
static unsigned int wear_eb_count = 0;
static unsigned long total_wear = 0;
static unsigned int rptwear_cnt = 0;
/* MTD structure for NAND controller */
static struct mtd_info *nsmtd;
static int nandsim_debugfs_show(struct seq_file *m, void *private)
{
unsigned long wmin = -1, wmax = 0, avg;
unsigned long deciles[10], decile_max[10], tot = 0;
unsigned int i;
/* Calc wear stats */
for (i = 0; i < wear_eb_count; ++i) {
unsigned long wear = erase_block_wear[i];
if (wear < wmin)
wmin = wear;
if (wear > wmax)
wmax = wear;
tot += wear;
}
for (i = 0; i < 9; ++i) {
deciles[i] = 0;
decile_max[i] = (wmax * (i + 1) + 5) / 10;
}
deciles[9] = 0;
decile_max[9] = wmax;
for (i = 0; i < wear_eb_count; ++i) {
int d;
unsigned long wear = erase_block_wear[i];
for (d = 0; d < 10; ++d)
if (wear <= decile_max[d]) {
deciles[d] += 1;
break;
}
}
avg = tot / wear_eb_count;
/* Output wear report */
seq_printf(m, "Total numbers of erases: %lu\n", tot);
seq_printf(m, "Number of erase blocks: %u\n", wear_eb_count);
seq_printf(m, "Average number of erases: %lu\n", avg);
seq_printf(m, "Maximum number of erases: %lu\n", wmax);
seq_printf(m, "Minimum number of erases: %lu\n", wmin);
for (i = 0; i < 10; ++i) {
unsigned long from = (i ? decile_max[i - 1] + 1 : 0);
if (from > decile_max[i])
continue;
seq_printf(m, "Number of ebs with erase counts from %lu to %lu : %lu\n",
from,
decile_max[i],
deciles[i]);
}
return 0;
}
static int nandsim_debugfs_open(struct inode *inode, struct file *file)
{
return single_open(file, nandsim_debugfs_show, inode->i_private);
}
static const struct file_operations dfs_fops = {
.open = nandsim_debugfs_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
/**
* nandsim_debugfs_create - initialize debugfs
* @dev: nandsim device description object
*
* This function creates all debugfs files for UBI device @ubi. Returns zero in
* case of success and a negative error code in case of failure.
*/
static int nandsim_debugfs_create(struct nandsim *dev)
{
struct nandsim_debug_info *dbg = &dev->dbg;
struct dentry *dent;
int err;
if (!IS_ENABLED(CONFIG_DEBUG_FS))
return 0;
dent = debugfs_create_dir("nandsim", NULL);
if (IS_ERR_OR_NULL(dent)) {
int err = dent ? -ENODEV : PTR_ERR(dent);
NS_ERR("cannot create \"nandsim\" debugfs directory, err %d\n",
err);
return err;
}
dbg->dfs_root = dent;
dent = debugfs_create_file("wear_report", S_IRUSR,
dbg->dfs_root, dev, &dfs_fops);
if (IS_ERR_OR_NULL(dent))
goto out_remove;
dbg->dfs_wear_report = dent;
return 0;
out_remove:
debugfs_remove_recursive(dbg->dfs_root);
err = dent ? PTR_ERR(dent) : -ENODEV;
return err;
}
/**
* nandsim_debugfs_remove - destroy all debugfs files
*/
static void nandsim_debugfs_remove(struct nandsim *ns)
{
if (IS_ENABLED(CONFIG_DEBUG_FS))
debugfs_remove_recursive(ns->dbg.dfs_root);
}
/*
* Allocate array of page pointers, create slab allocation for an array
* and initialize the array by NULL pointers.
@ -911,8 +1029,6 @@ static int setup_wear_reporting(struct mtd_info *mtd)
{
size_t mem;
if (!rptwear)
return 0;
wear_eb_count = div_u64(mtd->size, mtd->erasesize);
mem = wear_eb_count * sizeof(unsigned long);
if (mem / sizeof(unsigned long) != wear_eb_count) {
@ -929,64 +1045,18 @@ static int setup_wear_reporting(struct mtd_info *mtd)
static void update_wear(unsigned int erase_block_no)
{
unsigned long wmin = -1, wmax = 0, avg;
unsigned long deciles[10], decile_max[10], tot = 0;
unsigned int i;
if (!erase_block_wear)
return;
total_wear += 1;
/*
* TODO: Notify this through a debugfs entry,
* instead of showing an error message.
*/
if (total_wear == 0)
NS_ERR("Erase counter total overflow\n");
erase_block_wear[erase_block_no] += 1;
if (erase_block_wear[erase_block_no] == 0)
NS_ERR("Erase counter overflow for erase block %u\n", erase_block_no);
rptwear_cnt += 1;
if (rptwear_cnt < rptwear)
return;
rptwear_cnt = 0;
/* Calc wear stats */
for (i = 0; i < wear_eb_count; ++i) {
unsigned long wear = erase_block_wear[i];
if (wear < wmin)
wmin = wear;
if (wear > wmax)
wmax = wear;
tot += wear;
}
for (i = 0; i < 9; ++i) {
deciles[i] = 0;
decile_max[i] = (wmax * (i + 1) + 5) / 10;
}
deciles[9] = 0;
decile_max[9] = wmax;
for (i = 0; i < wear_eb_count; ++i) {
int d;
unsigned long wear = erase_block_wear[i];
for (d = 0; d < 10; ++d)
if (wear <= decile_max[d]) {
deciles[d] += 1;
break;
}
}
avg = tot / wear_eb_count;
/* Output wear report */
NS_INFO("*** Wear Report ***\n");
NS_INFO("Total numbers of erases: %lu\n", tot);
NS_INFO("Number of erase blocks: %u\n", wear_eb_count);
NS_INFO("Average number of erases: %lu\n", avg);
NS_INFO("Maximum number of erases: %lu\n", wmax);
NS_INFO("Minimum number of erases: %lu\n", wmin);
for (i = 0; i < 10; ++i) {
unsigned long from = (i ? decile_max[i - 1] + 1 : 0);
if (from > decile_max[i])
continue;
NS_INFO("Number of ebs with erase counts from %lu to %lu : %lu\n",
from,
decile_max[i],
deciles[i]);
}
NS_INFO("*** End of Wear Report ***\n");
}
/*
@ -2330,6 +2400,9 @@ static int __init ns_init_module(void)
if ((retval = setup_wear_reporting(nsmtd)) != 0)
goto err_exit;
if ((retval = nandsim_debugfs_create(nand)) != 0)
goto err_exit;
if ((retval = init_nandsim(nsmtd)) != 0)
goto err_exit;
@ -2369,6 +2442,7 @@ static void __exit ns_cleanup_module(void)
struct nandsim *ns = ((struct nand_chip *)nsmtd->priv)->priv;
int i;
nandsim_debugfs_remove(ns);
free_nandsim(ns); /* Free nandsim private resources */
nand_release(nsmtd); /* Unregister driver */
for (i = 0;i < ARRAY_SIZE(ns->partitions); ++i)