[PATCH 4/4] [MTD] nandsim: add option to use a file to cache pages
Adrian Hunter
ext-adrian.hunter at nokia.com
Fri May 30 08:56:35 EDT 2008
Add a new optional 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 at nokia.com>
---
drivers/mtd/nand/nandsim.c | 214 +++++++++++++++++++++++++++++++++++++++-----
1 files changed, 190 insertions(+), 24 deletions(-)
diff --git a/drivers/mtd/nand/nandsim.c b/drivers/mtd/nand/nandsim.c
index 68c150c..c8e2559 100644
--- a/drivers/mtd/nand/nandsim.c
+++ b/drivers/mtd/nand/nandsim.c
@@ -39,6 +39,9 @@
#include <linux/delay.h>
#include <linux/list.h>
#include <linux/random.h>
+#include <linux/fs.h>
+
+#include <asm/uaccess.h>
/* Default simulator parameters values */
#if !defined(CONFIG_NANDSIM_FIRST_ID_BYTE) || \
@@ -101,6 +104,7 @@ 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);
@@ -123,12 +127,13 @@ 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)");
@@ -154,6 +159,7 @@ 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
@@ -333,6 +339,11 @@ 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;
};
/*
@@ -422,11 +433,43 @@ 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, 0640);
+ 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++) {
@@ -434,6 +477,12 @@ static int alloc_device(struct nandsim *ns)
}
return 0;
+
+err_free:
+ vfree(ns->pages_written);
+err_close:
+ filp_close(cfile, NULL);
+ return err;
}
/*
@@ -443,6 +492,13 @@ 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)
@@ -1192,6 +1248,30 @@ static int find_operation(struct nandsim *ns, uint32_t flag)
return -1;
}
+static ssize_t read_file(struct file *file, void *buf, size_t count, loff_t *pos)
+{
+ mm_segment_t old_fs;
+ ssize_t tx;
+
+ old_fs = get_fs();
+ set_fs(get_ds());
+ tx = vfs_read(file, (char __user *)buf, count, pos);
+ set_fs(old_fs);
+ return tx;
+}
+
+static ssize_t write_file(struct file *file, void *buf, size_t count, loff_t *pos)
+{
+ mm_segment_t old_fs;
+ ssize_t tx;
+
+ old_fs = get_fs();
+ set_fs(get_ds());
+ tx = vfs_write(file, (char __user *)buf, count, pos);
+ set_fs(old_fs);
+ return tx;
+}
+
/*
* Returns a pointer to the current page.
*/
@@ -1208,6 +1288,38 @@ 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.
*/
@@ -1215,36 +1327,40 @@ 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->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);
}
}
@@ -1256,6 +1372,15 @@ 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) {
@@ -1276,6 +1401,47 @@ 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->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->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->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);
--
1.5.2.5
More information about the linux-mtd
mailing list