MTD: tests: add mtd_stresstest

This test just performs random operations on random eraseblocks.

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

diff --git a/drivers/mtd/tests/mtd_stresstest.c b/drivers/mtd/tests/mtd_stresstest.c
new file mode 100644 (file)
index 0000000..6392047
--- /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");