MTD: nandsim: add option to use a file to cache pages

Add a new module parameter 'cache_file' which causes nandsim
to use that file instead of memory to cache nand data.
Using a file allows the simulation of NAND that is bigger
than the available memory.

Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This commit is contained in:
Adrian Hunter 2008-11-12 16:06:07 +02:00 committed by David Woodhouse
parent 9359ea461b
commit a9fc899188

View file

@ -38,6 +38,8 @@
#include <linux/delay.h>
#include <linux/list.h>
#include <linux/random.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
/* Default simulator parameters values */
#if !defined(CONFIG_NANDSIM_FIRST_ID_BYTE) || \
@ -100,6 +102,7 @@ static unsigned int bitflips = 0;
static char *gravepages = NULL;
static unsigned int rptwear = 0;
static unsigned int overridesize = 0;
static char *cache_file = NULL;
module_param(first_id_byte, uint, 0400);
module_param(second_id_byte, uint, 0400);
@ -122,12 +125,13 @@ 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_PARM_DESC(first_id_byte, "The first byte returned by NAND Flash 'read ID' command (manufacturer ID)");
MODULE_PARM_DESC(second_id_byte, "The second byte returned by NAND Flash 'read ID' command (chip ID)");
MODULE_PARM_DESC(third_id_byte, "The third byte returned by NAND Flash 'read ID' command");
MODULE_PARM_DESC(fourth_id_byte, "The fourth byte returned by NAND Flash 'read ID' command");
MODULE_PARM_DESC(access_delay, "Initial page access delay (microiseconds)");
MODULE_PARM_DESC(access_delay, "Initial page access delay (microseconds)");
MODULE_PARM_DESC(programm_delay, "Page programm delay (microseconds");
MODULE_PARM_DESC(erase_delay, "Sector erase delay (milliseconds)");
MODULE_PARM_DESC(output_cycle, "Word output (from flash) time (nanodeconds)");
@ -153,6 +157,7 @@ MODULE_PARM_DESC(rptwear, "Number of erases inbetween reporting wear, if
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");
MODULE_PARM_DESC(cache_file, "File to use to cache nand pages instead of memory");
/* The largest possible page size */
#define NS_LARGEST_PAGE_SIZE 2048
@ -266,6 +271,9 @@ MODULE_PARM_DESC(overridesize, "Specifies the NAND Flash size overriding the I
*/
#define NS_MAX_PREVSTATES 1
/* Maximum page cache pages needed to read or write a NAND page to the cache_file */
#define NS_MAX_HELD_PAGES 16
/*
* A union to represent flash memory contents and flash buffer.
*/
@ -335,6 +343,13 @@ struct nandsim {
int ale; /* address Latch Enable */
int wp; /* write Protect */
} lines;
/* Fields needed when using a cache file */
struct file *cfile; /* Open file */
unsigned char *pages_written; /* Which pages have been written */
void *file_buf;
struct page *held_pages[NS_MAX_HELD_PAGES];
int held_cnt;
};
/*
@ -427,11 +442,43 @@ static u_char ns_verify_buf[NS_LARGEST_PAGE_SIZE];
*/
static int alloc_device(struct nandsim *ns)
{
int i;
struct file *cfile;
int i, err;
if (cache_file) {
cfile = filp_open(cache_file, O_CREAT | O_RDWR | O_LARGEFILE, 0600);
if (IS_ERR(cfile))
return PTR_ERR(cfile);
if (!cfile->f_op || (!cfile->f_op->read && !cfile->f_op->aio_read)) {
NS_ERR("alloc_device: cache file not readable\n");
err = -EINVAL;
goto err_close;
}
if (!cfile->f_op->write && !cfile->f_op->aio_write) {
NS_ERR("alloc_device: cache file not writeable\n");
err = -EINVAL;
goto err_close;
}
ns->pages_written = vmalloc(ns->geom.pgnum);
if (!ns->pages_written) {
NS_ERR("alloc_device: unable to allocate pages written array\n");
err = -ENOMEM;
goto err_close;
}
ns->file_buf = kmalloc(ns->geom.pgszoob, GFP_KERNEL);
if (!ns->file_buf) {
NS_ERR("alloc_device: unable to allocate file buf\n");
err = -ENOMEM;
goto err_free;
}
ns->cfile = cfile;
memset(ns->pages_written, 0, ns->geom.pgnum);
return 0;
}
ns->pages = vmalloc(ns->geom.pgnum * sizeof(union ns_mem));
if (!ns->pages) {
NS_ERR("alloc_map: unable to allocate page array\n");
NS_ERR("alloc_device: unable to allocate page array\n");
return -ENOMEM;
}
for (i = 0; i < ns->geom.pgnum; i++) {
@ -439,6 +486,12 @@ static int alloc_device(struct nandsim *ns)
}
return 0;
err_free:
vfree(ns->pages_written);
err_close:
filp_close(cfile, NULL);
return err;
}
/*
@ -448,6 +501,13 @@ static void free_device(struct nandsim *ns)
{
int i;
if (ns->cfile) {
kfree(ns->file_buf);
vfree(ns->pages_written);
filp_close(ns->cfile, NULL);
return;
}
if (ns->pages) {
for (i = 0; i < ns->geom.pgnum; i++) {
if (ns->pages[i].byte)
@ -1211,6 +1271,97 @@ static int find_operation(struct nandsim *ns, uint32_t flag)
return -1;
}
static void put_pages(struct nandsim *ns)
{
int i;
for (i = 0; i < ns->held_cnt; i++)
page_cache_release(ns->held_pages[i]);
}
/* Get page cache pages in advance to provide NOFS memory allocation */
static int get_pages(struct nandsim *ns, struct file *file, size_t count, loff_t pos)
{
pgoff_t index, start_index, end_index;
struct page *page;
struct address_space *mapping = file->f_mapping;
start_index = pos >> PAGE_CACHE_SHIFT;
end_index = (pos + count - 1) >> PAGE_CACHE_SHIFT;
if (end_index - start_index + 1 > NS_MAX_HELD_PAGES)
return -EINVAL;
ns->held_cnt = 0;
for (index = start_index; index <= end_index; index++) {
page = find_get_page(mapping, index);
if (page == NULL) {
page = find_or_create_page(mapping, index, GFP_NOFS);
if (page == NULL) {
write_inode_now(mapping->host, 1);
page = find_or_create_page(mapping, index, GFP_NOFS);
}
if (page == NULL) {
put_pages(ns);
return -ENOMEM;
}
unlock_page(page);
}
ns->held_pages[ns->held_cnt++] = page;
}
return 0;
}
static int set_memalloc(void)
{
if (current->flags & PF_MEMALLOC)
return 0;
current->flags |= PF_MEMALLOC;
return 1;
}
static void clear_memalloc(int memalloc)
{
if (memalloc)
current->flags &= ~PF_MEMALLOC;
}
static ssize_t read_file(struct nandsim *ns, struct file *file, void *buf, size_t count, loff_t *pos)
{
mm_segment_t old_fs;
ssize_t tx;
int err, memalloc;
err = get_pages(ns, file, count, *pos);
if (err)
return err;
old_fs = get_fs();
set_fs(get_ds());
memalloc = set_memalloc();
tx = vfs_read(file, (char __user *)buf, count, pos);
clear_memalloc(memalloc);
set_fs(old_fs);
put_pages(ns);
return tx;
}
static ssize_t write_file(struct nandsim *ns, struct file *file, void *buf, size_t count, loff_t *pos)
{
mm_segment_t old_fs;
ssize_t tx;
int err, memalloc;
err = get_pages(ns, file, count, *pos);
if (err)
return err;
old_fs = get_fs();
set_fs(get_ds());
memalloc = set_memalloc();
tx = vfs_write(file, (char __user *)buf, count, pos);
clear_memalloc(memalloc);
set_fs(old_fs);
put_pages(ns);
return tx;
}
/*
* Returns a pointer to the current page.
*/
@ -1227,6 +1378,38 @@ static inline u_char *NS_PAGE_BYTE_OFF(struct nandsim *ns)
return NS_GET_PAGE(ns)->byte + ns->regs.column + ns->regs.off;
}
int do_read_error(struct nandsim *ns, int num)
{
unsigned int page_no = ns->regs.row;
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 1;
}
return 0;
}
void do_bit_flips(struct nandsim *ns, int 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);
}
}
}
/*
* Fill the NAND buffer with data read from the specified page.
*/
@ -1234,36 +1417,40 @@ static void read_page(struct nandsim *ns, int num)
{
union ns_mem *mypage;
if (ns->cfile) {
if (!ns->pages_written[ns->regs.row]) {
NS_DBG("read_page: page %d not written\n", ns->regs.row);
memset(ns->buf.byte, 0xFF, num);
} else {
loff_t pos;
ssize_t tx;
NS_DBG("read_page: page %d written, reading from %d\n",
ns->regs.row, ns->regs.column + ns->regs.off);
if (do_read_error(ns, num))
return;
pos = (loff_t)ns->regs.row * ns->geom.pgszoob + ns->regs.column + ns->regs.off;
tx = read_file(ns, ns->cfile, ns->buf.byte, num, &pos);
if (tx != num) {
NS_ERR("read_page: read error for page %d ret %ld\n", ns->regs.row, (long)tx);
return;
}
do_bit_flips(ns, num);
}
return;
}
mypage = NS_GET_PAGE(ns);
if (mypage->byte == NULL) {
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);
if (do_read_error(ns, num))
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);
}
}
do_bit_flips(ns, num);
}
}
@ -1275,6 +1462,15 @@ static void erase_sector(struct nandsim *ns)
union ns_mem *mypage;
int i;
if (ns->cfile) {
for (i = 0; i < ns->geom.pgsec; i++)
if (ns->pages_written[ns->regs.row + i]) {
NS_DBG("erase_sector: freeing page %d\n", ns->regs.row + i);
ns->pages_written[ns->regs.row + i] = 0;
}
return;
}
mypage = NS_GET_PAGE(ns);
for (i = 0; i < ns->geom.pgsec; i++) {
if (mypage->byte != NULL) {
@ -1295,6 +1491,47 @@ static int prog_page(struct nandsim *ns, int num)
union ns_mem *mypage;
u_char *pg_off;
if (ns->cfile) {
loff_t off, pos;
ssize_t tx;
int all;
NS_DBG("prog_page: writing page %d\n", ns->regs.row);
pg_off = ns->file_buf + ns->regs.column + ns->regs.off;
off = (loff_t)ns->regs.row * ns->geom.pgszoob + ns->regs.column + ns->regs.off;
if (!ns->pages_written[ns->regs.row]) {
all = 1;
memset(ns->file_buf, 0xff, ns->geom.pgszoob);
} else {
all = 0;
pos = off;
tx = read_file(ns, ns->cfile, pg_off, num, &pos);
if (tx != num) {
NS_ERR("prog_page: read error for page %d ret %ld\n", ns->regs.row, (long)tx);
return -1;
}
}
for (i = 0; i < num; i++)
pg_off[i] &= ns->buf.byte[i];
if (all) {
pos = (loff_t)ns->regs.row * ns->geom.pgszoob;
tx = write_file(ns, ns->cfile, ns->file_buf, ns->geom.pgszoob, &pos);
if (tx != ns->geom.pgszoob) {
NS_ERR("prog_page: write error for page %d ret %ld\n", ns->regs.row, (long)tx);
return -1;
}
ns->pages_written[ns->regs.row] = 1;
} else {
pos = off;
tx = write_file(ns, ns->cfile, pg_off, num, &pos);
if (tx != num) {
NS_ERR("prog_page: write error for page %d ret %ld\n", ns->regs.row, (long)tx);
return -1;
}
}
return 0;
}
mypage = NS_GET_PAGE(ns);
if (mypage->byte == NULL) {
NS_DBG("prog_page: allocating page %d\n", ns->regs.row);