/*
* Copyright (C) 2006-2008 Nokia Corporation
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; see the file COPYING. If not, write to the Free Software
* Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Test random reads, writes and erases on MTD device.
*
* Author: Adrian Hunter <ext-adrian.hunter@nokia.com>
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/err.h>
#include <linux/mtd/mtd.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/vmalloc.h>
#define PRINT_PREF KERN_INFO "mtd_stresstest: "
static int dev;
module_param(dev, int, S_IRUGO);
MODULE_PARM_DESC(dev, "MTD device number to use");
static int count = 10000;
module_param(count, int, S_IRUGO);
MODULE_PARM_DESC(count, "Number of operations to do (default is 10000)");
static struct mtd_info *mtd;
static unsigned char *writebuf;
static unsigned char *readbuf;
static unsigned char *bbt;
static int *offsets;
static int pgsize;
static int bufsize;
static int ebcnt;
static int pgcnt;
static unsigned long next = 1;
static inline unsigned int simple_rand(void)
{
next = next * 1103515245 + 12345;
return (unsigned int)((next / 65536) % 32768);
}
static inline void simple_srand(unsigned long seed)
{
next = seed;
}
static int rand_eb(void)
{
int eb;
again:
if (ebcnt < 32768)
eb = simple_rand();
else
eb = (simple_rand() << 15) | simple_rand();
/* Read or write up 2 eraseblocks at a time - hence 'ebcnt - 1' */
eb %= (ebcnt - 1);
if (bbt[eb])
goto again;
return eb;
}
static int rand_offs(void)
{
int offs;
if (bufsize < 32768)
offs = simple_rand();
else
offs = (simple_rand() << 15) | simple_rand();
offs %= bufsize;
return offs;
}
static int rand_len(int offs)
{
int len;
if (bufsize < 32768)
len = simple_rand();
else
len = (simple_rand() << 15) | simple_rand();
len %= (bufsize - offs);
return len;
}
static int erase_eraseblock(int ebnum)
{
int err;
struct erase_info ei;
loff_t addr = ebnum * mtd->erasesize;
memset(&ei, 0, sizeof(struct erase_info));
ei.mtd = mtd;
ei.addr = addr;
ei.len = mtd->erasesize;
err = mtd->erase(mtd, &ei);
if (unlikely(err)) {
printk(PRINT_PREF "error %d while erasing EB %d\n", err, ebnum);
return err;
}
if (unlikely(ei.state == MTD_ERASE_FAILED)) {
printk(PRINT_PREF "some erase error occurred at EB %d\n",
ebnum);
return -EIO;
}
return 0;
}
static int is_block_bad(int ebnum)
{
loff_t addr = ebnum * mtd->erasesize;
int ret;
ret = mtd->block_isbad(mtd, addr);
if (ret)
printk(PRINT_PREF "block %d is bad\n", ebnum);
return ret;
}
static int do_read(void)
{
size_t read = 0;
int eb = rand_eb();
int offs = rand_offs();
int len = rand_len(offs), err;
loff_t addr;
if (bbt[eb + 1]) {
if (offs >= mtd->erasesize)
offs -= mtd->erasesize;
if (offs + len > mtd->erasesize)
len = mtd->erasesize - offs;
}
addr = eb * mtd->erasesize + offs;
err = mtd->read(mtd, addr, len, &read, readbuf);
if (err == -EUCLEAN)
err = 0;
if (unlikely(err || read != len)) {
printk(PRINT_PREF "error: read failed at 0x%llx\n",
(long long)addr);
if (!err)
err = -EINVAL;
return err;
}
return 0;
}
static int do_write(void)
{
int eb = rand_eb(), offs, err, len;
size_t written = 0;
loff_t addr;
offs = offsets[eb];
if (offs >= mtd->erasesize) {
err = erase_eraseblock(eb);
if (err)
return err;
offs = offsets[eb] = 0;
}
len = rand_len(offs);
len = ((len + pgsize - 1) / pgsize) * pgsize;
if (offs + len > mtd->erasesize) {
if (bbt[eb + 1])
len = mtd->erasesize - offs;
else {
err = erase_eraseblock(eb + 1);
if (err)
return err;
offsets[eb + 1] = 0;
}
}
addr = eb * mtd->erasesize + offs;
err = mtd->write(mtd, addr, len, &written, writebuf);
if (unlikely(err || written != len)) {
printk(PRINT_PREF "error: write failed at 0x%llx\n",
(long long)addr);
if (!err)
err = -EINVAL;
return err;
}
offs += len;
while (offs > mtd->erasesize) {
offsets[eb++] = mtd->erasesize;
offs -= mtd->erasesize;
}
offsets[eb] = offs;
return 0;
}
static int do_operation(void)
{
if (simple_rand() & 1)
return do_read();
else
return do_write();
}
static int scan_for_bad_eraseblocks(void)
{
int i, bad = 0;
bbt = kzalloc(ebcnt, GFP_KERNEL);
if (!bbt) {
printk(PRINT_PREF "error: cannot allocate memory\n");
return -ENOMEM;
}
/* NOR flash does not implement block_isbad */
if (mtd->block_isbad == NULL)
return 0;
printk(PRINT_PREF "scanning for bad eraseblocks\n");
for (i = 0; i < ebcnt; ++i) {
bbt[i] = is_block_bad(i) ? 1 : 0;
if (bbt[i])
bad += 1;
cond_resched();
}
printk(PRINT_PREF "scanned %d eraseblocks, %d are bad\n", i, bad);
return 0;
}
static int __init mtd_stresstest_init(void)
{
int err;
int i, op;
uint64_t tmp;
printk(KERN_INFO "\n");
printk(KERN_INFO "=================================================\n");
printk(PRINT_PREF "MTD device: %d\n", dev);
mtd = get_mtd_device(NULL, dev);
if (IS_ERR(mtd)) {
err = PTR_ERR(mtd);
printk(PRINT_PREF "error: cannot get MTD device\n");
return err;
}
if (mtd->writesize == 1) {
printk(PRINT_PREF "not NAND flash, assume page size is 512 "
"bytes.\n");
pgsize = 512;
} else
pgsize = mtd->writesize;
tmp = mtd->size;
do_div(tmp, mtd->erasesize);
ebcnt = tmp;
pgcnt = mtd->erasesize / pgsize;
printk(PRINT_PREF "MTD device size %llu, eraseblock size %u, "
"page size %u, count of eraseblocks %u, pages per "
"eraseblock %u, OOB size %u\n",
(unsigned long long)mtd->size, mtd->erasesize,
pgsize, ebcnt, pgcnt, mtd->oobsize);
/* Read or write up 2 eraseblocks at a time */
bufsize = mtd->erasesize * 2;
err = -ENOMEM;
readbuf = vmalloc(bufsize);
writebuf = vmalloc(bufsize);
offsets = kmalloc(ebcnt * sizeof(int), GFP_KERNEL);
if (!readbuf || !writebuf || !offsets) {
printk(PRINT_PREF "error: cannot allocate memory\n");
goto out;
}
for (i = 0; i < ebcnt; i++)
offsets[i] = mtd->erasesize;
simple_srand(current->pid);
for (i = 0; i < bufsize; i++)
writebuf[i] = simple_rand();
err = scan_for_bad_eraseblocks();
if (err)
goto out;
/* Do operations */
printk(PRINT_PREF "doing operations\n");
for (op = 0; op < count; op++) {
if ((op & 1023) == 0)
printk(PRINT_PREF "%d operations done\n", op);
err = do_operation();
if (err)
goto out;
cond_resched();
}
printk(PRINT_PREF "finished, %d operations done\n", op);
out:
kfree(offsets);
kfree(bbt);
vfree(writebuf);
vfree(readbuf);
put_mtd_device(mtd);
if (err)
printk(PRINT_PREF "error %d occurred\n", err);
printk(KERN_INFO "=================================================\n");
return err;
}
module_init(mtd_stresstest_init);
static void __exit mtd_stresstest_exit(void)
{
return;
}
module_exit(mtd_stresstest_exit);
MODULE_DESCRIPTION("Stress test module");
MODULE_AUTHOR("Adrian Hunter");
MODULE_LICENSE("GPL");
