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+/*
+ * 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/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 = kmalloc(ebcnt, GFP_KERNEL);
+ if (!bbt) {
+ printk(PRINT_PREF "error: cannot allocate memory\n");
+ return -ENOMEM;
+ }
+ memset(bbt, 0 , ebcnt);
+
+ 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 / mtd->writesize;
+
+ 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");