MTD: tests: add mtd_stresstest

This test just performs random operations on random eraseblocks.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

1 files changed, 330 insertions, 0 deletions

diff --git a/drivers/mtd/tests/mtd_stresstest.c b/drivers/mtd/tests/mtd_stresstest.c
new file mode 100644
index 000000000000..63920476b57a
--- /dev/null
+++ b/drivers/mtd/tests/mtd_stresstest.c
@@ -0,0 +1,330 @@
+/*
+ * 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");