drivers/mtd/tests/mtd_stresstest.c

   1 /*
   2  * Copyright (C) 2006-2008 Nokia Corporation
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 as published by
   6  * the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; see the file COPYING. If not, write to the Free Software
  15  * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  16  *
  17  * Test random reads, writes and erases on MTD device.
  18  *
  19  * Author: Adrian Hunter <ext-adrian.hunter@nokia.com>
  20  */
  21
  22 #include <linux/init.h>
  23 #include <linux/module.h>
  24 #include <linux/moduleparam.h>
  25 #include <linux/err.h>
  26 #include <linux/mtd/mtd.h>
  27 #include <linux/sched.h>
  28 #include <linux/vmalloc.h>
  29
  30 #define PRINT_PREF KERN_INFO "mtd_stresstest: "
  31
  32 static int dev;
  33 module_param(dev, int, S_IRUGO);
  34 MODULE_PARM_DESC(dev, "MTD device number to use");
  35
  36 static int count = 10000;
  37 module_param(count, int, S_IRUGO);
  38 MODULE_PARM_DESC(count, "Number of operations to do (default is 10000)");
  39
  40 static struct mtd_info *mtd;
  41 static unsigned char *writebuf;
  42 static unsigned char *readbuf;
  43 static unsigned char *bbt;
  44 static int *offsets;
  45
  46 static int pgsize;
  47 static int bufsize;
  48 static int ebcnt;
  49 static int pgcnt;
  50 static unsigned long next = 1;
  51
  52 static inline unsigned int simple_rand(void)
  53 {
  54         next = next * 1103515245 + 12345;
  55         return (unsigned int)((next / 65536) % 32768);
  56 }
  57
  58 static inline void simple_srand(unsigned long seed)
  59 {
  60         next = seed;
  61 }
  62
  63 static int rand_eb(void)
  64 {
  65         int eb;
  66
  67 again:
  68         if (ebcnt < 32768)
  69                 eb = simple_rand();
  70         else
  71                 eb = (simple_rand() << 15) | simple_rand();
  72         /* Read or write up 2 eraseblocks at a time - hence 'ebcnt - 1' */
  73         eb %= (ebcnt - 1);
  74         if (bbt[eb])
  75                 goto again;
  76         return eb;
  77 }
  78
  79 static int rand_offs(void)
  80 {
  81         int offs;
  82
  83         if (bufsize < 32768)
  84                 offs = simple_rand();
  85         else
  86                 offs = (simple_rand() << 15) | simple_rand();
  87         offs %= bufsize;
  88         return offs;
  89 }
  90
  91 static int rand_len(int offs)
  92 {
  93         int len;
  94
  95         if (bufsize < 32768)
  96                 len = simple_rand();
  97         else
  98                 len = (simple_rand() << 15) | simple_rand();
  99         len %= (bufsize - offs);
 100         return len;
 101 }
 102
 103 static int erase_eraseblock(int ebnum)
 104 {
 105         int err;
 106         struct erase_info ei;
 107         loff_t addr = ebnum * mtd->erasesize;
 108
 109         memset(&ei, 0, sizeof(struct erase_info));
 110         ei.mtd  = mtd;
 111         ei.addr = addr;
 112         ei.len  = mtd->erasesize;
 113
 114         err = mtd->erase(mtd, &ei);
 115         if (unlikely(err)) {
 116                 printk(PRINT_PREF "error %d while erasing EB %d\n", err, ebnum);
 117                 return err;
 118         }
 119
 120         if (unlikely(ei.state == MTD_ERASE_FAILED)) {
 121                 printk(PRINT_PREF "some erase error occurred at EB %d\n",
 122                        ebnum);
 123                 return -EIO;
 124         }
 125
 126         return 0;
 127 }
 128
 129 static int is_block_bad(int ebnum)
 130 {
 131         loff_t addr = ebnum * mtd->erasesize;
 132         int ret;
 133
 134         ret = mtd->block_isbad(mtd, addr);
 135         if (ret)
 136                 printk(PRINT_PREF "block %d is bad\n", ebnum);
 137         return ret;
 138 }
 139
 140 static int do_read(void)
 141 {
 142         size_t read = 0;
 143         int eb = rand_eb();
 144         int offs = rand_offs();
 145         int len = rand_len(offs), err;
 146         loff_t addr;
 147
 148         if (bbt[eb + 1]) {
 149                 if (offs >= mtd->erasesize)
 150                         offs -= mtd->erasesize;
 151                 if (offs + len > mtd->erasesize)
 152                         len = mtd->erasesize - offs;
 153         }
 154         addr = eb * mtd->erasesize + offs;
 155         err = mtd->read(mtd, addr, len, &read, readbuf);
 156         if (err == -EUCLEAN)
 157                 err = 0;
 158         if (unlikely(err || read != len)) {
 159                 printk(PRINT_PREF "error: read failed at 0x%llx\n",
 160                        (long long)addr);
 161                 if (!err)
 162                         err = -EINVAL;
 163                 return err;
 164         }
 165         return 0;
 166 }
 167
 168 static int do_write(void)
 169 {
 170         int eb = rand_eb(), offs, err, len;
 171         size_t written = 0;
 172         loff_t addr;
 173
 174         offs = offsets[eb];
 175         if (offs >= mtd->erasesize) {
 176                 err = erase_eraseblock(eb);
 177                 if (err)
 178                         return err;
 179                 offs = offsets[eb] = 0;
 180         }
 181         len = rand_len(offs);
 182         len = ((len + pgsize - 1) / pgsize) * pgsize;
 183         if (offs + len > mtd->erasesize) {
 184                 if (bbt[eb + 1])
 185                         len = mtd->erasesize - offs;
 186                 else {
 187                         err = erase_eraseblock(eb + 1);
 188                         if (err)
 189                                 return err;
 190                         offsets[eb + 1] = 0;
 191                 }
 192         }
 193         addr = eb * mtd->erasesize + offs;
 194         err = mtd->write(mtd, addr, len, &written, writebuf);
 195         if (unlikely(err || written != len)) {
 196                 printk(PRINT_PREF "error: write failed at 0x%llx\n",
 197                        (long long)addr);
 198                 if (!err)
 199                         err = -EINVAL;
 200                 return err;
 201         }
 202         offs += len;
 203         while (offs > mtd->erasesize) {
 204                 offsets[eb++] = mtd->erasesize;
 205                 offs -= mtd->erasesize;
 206         }
 207         offsets[eb] = offs;
 208         return 0;
 209 }
 210
 211 static int do_operation(void)
 212 {
 213         if (simple_rand() & 1)
 214                 return do_read();
 215         else
 216                 return do_write();
 217 }
 218
 219 static int scan_for_bad_eraseblocks(void)
 220 {
 221         int i, bad = 0;
 222
 223         bbt = kmalloc(ebcnt, GFP_KERNEL);
 224         if (!bbt) {
 225                 printk(PRINT_PREF "error: cannot allocate memory\n");
 226                 return -ENOMEM;
 227         }
 228         memset(bbt, 0 , ebcnt);
 229
 230         printk(PRINT_PREF "scanning for bad eraseblocks\n");
 231         for (i = 0; i < ebcnt; ++i) {
 232                 bbt[i] = is_block_bad(i) ? 1 : 0;
 233                 if (bbt[i])
 234                         bad += 1;
 235                 cond_resched();
 236         }
 237         printk(PRINT_PREF "scanned %d eraseblocks, %d are bad\n", i, bad);
 238         return 0;
 239 }
 240
 241 static int __init mtd_stresstest_init(void)
 242 {
 243         int err;
 244         int i, op;
 245         uint64_t tmp;
 246
 247         printk(KERN_INFO "\n");
 248         printk(KERN_INFO "=================================================\n");
 249         printk(PRINT_PREF "MTD device: %d\n", dev);
 250
 251         mtd = get_mtd_device(NULL, dev);
 252         if (IS_ERR(mtd)) {
 253                 err = PTR_ERR(mtd);
 254                 printk(PRINT_PREF "error: cannot get MTD device\n");
 255                 return err;
 256         }
 257
 258         if (mtd->writesize == 1) {
 259                 printk(PRINT_PREF "not NAND flash, assume page size is 512 "
 260                        "bytes.\n");
 261                 pgsize = 512;
 262         } else
 263                 pgsize = mtd->writesize;
 264
 265         tmp = mtd->size;
 266         do_div(tmp, mtd->erasesize);
 267         ebcnt = tmp;
 268         pgcnt = mtd->erasesize / mtd->writesize;
 269
 270         printk(PRINT_PREF "MTD device size %llu, eraseblock size %u, "
 271                "page size %u, count of eraseblocks %u, pages per "
 272                "eraseblock %u, OOB size %u\n",
 273                (unsigned long long)mtd->size, mtd->erasesize,
 274                pgsize, ebcnt, pgcnt, mtd->oobsize);
 275
 276         /* Read or write up 2 eraseblocks at a time */
 277         bufsize = mtd->erasesize * 2;
 278
 279         err = -ENOMEM;
 280         readbuf = vmalloc(bufsize);
 281         writebuf = vmalloc(bufsize);
 282         offsets = kmalloc(ebcnt * sizeof(int), GFP_KERNEL);
 283         if (!readbuf || !writebuf || !offsets) {
 284                 printk(PRINT_PREF "error: cannot allocate memory\n");
 285                 goto out;
 286         }
 287         for (i = 0; i < ebcnt; i++)
 288                 offsets[i] = mtd->erasesize;
 289         simple_srand(current->pid);
 290         for (i = 0; i < bufsize; i++)
 291                 writebuf[i] = simple_rand();
 292
 293         err = scan_for_bad_eraseblocks();
 294         if (err)
 295                 goto out;
 296
 297         /* Do operations */
 298         printk(PRINT_PREF "doing operations\n");
 299         for (op = 0; op < count; op++) {
 300                 if ((op & 1023) == 0)
 301                         printk(PRINT_PREF "%d operations done\n", op);
 302                 err = do_operation();
 303                 if (err)
 304                         goto out;
 305                 cond_resched();
 306         }
 307         printk(PRINT_PREF "finished, %d operations done\n", op);
 308
 309 out:
 310         kfree(offsets);
 311         kfree(bbt);
 312         vfree(writebuf);
 313         vfree(readbuf);
 314         put_mtd_device(mtd);
 315         if (err)
 316                 printk(PRINT_PREF "error %d occurred\n", err);
 317         printk(KERN_INFO "=================================================\n");
 318         return err;
 319 }
 320 module_init(mtd_stresstest_init);
 321
 322 static void __exit mtd_stresstest_exit(void)
 323 {
 324         return;
 325 }
 326 module_exit(mtd_stresstest_exit);
 327
 328 MODULE_DESCRIPTION("Stress test module");
 329 MODULE_AUTHOR("Adrian Hunter");
 330 MODULE_LICENSE("GPL");