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Commit 57aa6b54 authored by Adrian Hunter's avatar Adrian Hunter Committed by David Woodhouse
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[MTD] nandsim: Enhance nandsim optionally to report wear information 



A new module parameter 'rptwear' specifies how many erases between
reporting wear information.  Zero means never.

Signed-off-by: default avatarAdrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: default avatarArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: default avatarDavid Woodhouse <dwmw2@infradead.org>
parent 514087e7

drivers/mtd/nand/nandsim.c

+99 −0
Original line number Diff line number Diff line
@@ -99,6 +99,7 @@ static char *weakblocks = NULL; 
static char *weakpages = NULL;

static unsigned int bitflips = 0;

static char *gravepages = NULL;

static unsigned int rptwear = 0;



module_param(first_id_byte,  uint, 0400);

module_param(second_id_byte, uint, 0400);
@@ -119,6 +120,7 @@ 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_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)");
@@ -146,6 +148,7 @@ 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 inbetween reporting wear, if not zero");



/* The largest possible page size */

#define NS_LARGEST_PAGE_SIZE	2048
@@ -162,6 +165,8 @@ MODULE_PARM_DESC(gravepages, "Pages that lose data [: maximum reads (default 
	do { printk(KERN_WARNING NS_OUTPUT_PREFIX " warning: " args); } while(0)

#define NS_ERR(args...) \

	do { printk(KERN_ERR NS_OUTPUT_PREFIX " error: " args); } while(0)

#define NS_INFO(args...) \

	do { printk(KERN_INFO NS_OUTPUT_PREFIX " " args); } while(0)



/* Busy-wait delay macros (microseconds, milliseconds) */

#define NS_UDELAY(us) \
@@ -394,6 +399,11 @@ struct grave_page { 


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;
@@ -801,6 +811,89 @@ static void free_lists(void) 
		list_del(pos);

		kfree(list_entry(pos, struct grave_page, list));

	}

	kfree(erase_block_wear);

}



static int setup_wear_reporting(struct mtd_info *mtd)

{

	size_t mem;



	if (!rptwear)

		return 0;

	wear_eb_count = mtd->size / mtd->erasesize;

	mem = wear_eb_count * sizeof(unsigned long);

	if (mem / sizeof(unsigned long) != wear_eb_count) {

		NS_ERR("Too many erase blocks for wear reporting\n");

		return -ENOMEM;

	}

	erase_block_wear = kzalloc(mem, GFP_KERNEL);

	if (!erase_block_wear) {

		NS_ERR("Too many erase blocks for wear reporting\n");

		return -ENOMEM;

	}

	return 0;

}



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;

	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");

}



/*
@@ -1268,6 +1361,9 @@ static int do_state_action(struct nandsim *ns, uint32_t action) 


		NS_MDELAY(erase_delay);



		if (erase_block_wear)

			update_wear(erase_block_no);



		if (erase_error(erase_block_no)) {

			NS_WARN("simulating erase failure in erase block %u\n", erase_block_no);

			return -1;
@@ -1903,6 +1999,9 @@ static int __init ns_init_module(void) 
		goto error;

	}



	if ((retval = setup_wear_reporting(nsmtd)) != 0)

		goto err_exit;



	if ((retval = init_nandsim(nsmtd)) != 0)

		goto err_exit;