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/slab.h>
  28 #include <linux/sched.h>
  29 #include <linux/vmalloc.h>
  30
  31 #define PRINT_PREF KERN_INFO "mtd_stresstest: "
  32
  33 static int dev;
  34 module_param(dev, int, S_IRUGO);
  35 MODULE_PARM_DESC(dev, "MTD device number to use");
  36
  37 static int count = 10000;
  38 module_param(count, int, S_IRUGO);
  39 MODULE_PARM_DESC(count, "Number of operations to do (default is 10000)");
  40
  41 static struct mtd_info *mtd;
  42 static unsigned char *writebuf;
  43 static unsigned char *readbuf;
  44 static unsigned char *bbt;
  45 static int *offsets;
  46
  47 static int pgsize;
  48 static int bufsize;
  49 static int ebcnt;
  50 static int pgcnt;
  51 static unsigned long next = 1;
  52
  53 static inline unsigned int simple_rand(void)
  54 {
  55         next = next * 1103515245 + 12345;
  56         return (unsigned int)((next / 65536) % 32768);
  57 }
  58
  59 static inline void simple_srand(unsigned long seed)
  60 {
  61         next = seed;
  62 }
  63
  64 static int rand_eb(void)
  65 {
  66         int eb;
  67
  68 again:
  69         if (ebcnt < 32768)
  70                 eb = simple_rand();
  71         else
  72                 eb = (simple_rand() << 15) | simple_rand();
  73         /* Read or write up 2 eraseblocks at a time - hence 'ebcnt - 1' */
  74         eb %= (ebcnt - 1);
  75         if (bbt[eb])
  76                 goto again;
  77         return eb;
  78 }
  79
  80 static int rand_offs(void)
  81 {
  82         int offs;
  83
  84         if (bufsize < 32768)
  85                 offs = simple_rand();
  86         else
  87                 offs = (simple_rand() << 15) | simple_rand();
  88         offs %= bufsize;
  89         return offs;
  90 }
  91
  92 static int rand_len(int offs)
  93 {
  94         int len;
  95
  96         if (bufsize < 32768)
  97                 len = simple_rand();
  98         else
  99                 len = (simple_rand() << 15) | simple_rand();
 100         len %= (bufsize - offs);
 101         return len;
 102 }
 103
 104 static int erase_eraseblock(int ebnum)
 105 {
 106         int err;
 107         struct erase_info ei;
 108         loff_t addr = ebnum * mtd->erasesize;
 109
 110         memset(&ei, 0, sizeof(struct erase_info));
 111         ei.mtd  = mtd;
 112         ei.addr = addr;
 113         ei.len  = mtd->erasesize;
 114
 115         err = mtd->erase(mtd, &ei);
 116         if (unlikely(err)) {
 117                 printk(PRINT_PREF "error %d while erasing EB %d\n", err, ebnum);
 118                 return err;
 119         }
 120
 121         if (unlikely(ei.state == MTD_ERASE_FAILED)) {
 122                 printk(PRINT_PREF "some erase error occurred at EB %d\n",
 123                        ebnum);
 124                 return -EIO;
 125         }
 126
 127         return 0;
 128 }
 129
 130 static int is_block_bad(int ebnum)
 131 {
 132         loff_t addr = ebnum * mtd->erasesize;
 133         int ret;
 134
 135         ret = mtd->block_isbad(mtd, addr);
 136         if (ret)
 137                 printk(PRINT_PREF "block %d is bad\n", ebnum);
 138         return ret;
 139 }
 140
 141 static int do_read(void)
 142 {
 143         size_t read = 0;
 144         int eb = rand_eb();
 145         int offs = rand_offs();
 146         int len = rand_len(offs), err;
 147         loff_t addr;
 148
 149         if (bbt[eb + 1]) {
 150                 if (offs >= mtd->erasesize)
 151                         offs -= mtd->erasesize;
 152                 if (offs + len > mtd->erasesize)
 153                         len = mtd->erasesize - offs;
 154         }
 155         addr = eb * mtd->erasesize + offs;
 156         err = mtd->read(mtd, addr, len, &read, readbuf);
 157         if (err == -EUCLEAN)
 158                 err = 0;
 159         if (unlikely(err || read != len)) {
 160                 printk(PRINT_PREF "error: read failed at 0x%llx\n",
 161                        (long long)addr);
 162                 if (!err)
 163                         err = -EINVAL;
 164                 return err;
 165         }
 166         return 0;
 167 }
 168
 169 static int do_write(void)
 170 {
 171         int eb = rand_eb(), offs, err, len;
 172         size_t written = 0;
 173         loff_t addr;
 174
 175         offs = offsets[eb];
 176         if (offs >= mtd->erasesize) {
 177                 err = erase_eraseblock(eb);
 178                 if (err)
 179                         return err;
 180                 offs = offsets[eb] = 0;
 181         }
 182         len = rand_len(offs);
 183         len = ((len + pgsize - 1) / pgsize) * pgsize;
 184         if (offs + len > mtd->erasesize) {
 185                 if (bbt[eb + 1])
 186                         len = mtd->erasesize - offs;
 187                 else {
 188                         err = erase_eraseblock(eb + 1);
 189                         if (err)
 190                                 return err;
 191                         offsets[eb + 1] = 0;
 192                 }
 193         }
 194         addr = eb * mtd->erasesize + offs;
 195         err = mtd->write(mtd, addr, len, &written, writebuf);
 196         if (unlikely(err || written != len)) {
 197                 printk(PRINT_PREF "error: write failed at 0x%llx\n",
 198                        (long long)addr);
 199                 if (!err)
 200                         err = -EINVAL;
 201                 return err;
 202         }
 203         offs += len;
 204         while (offs > mtd->erasesize) {
 205                 offsets[eb++] = mtd->erasesize;
 206                 offs -= mtd->erasesize;
 207         }
 208         offsets[eb] = offs;
 209         return 0;
 210 }
 211
 212 static int do_operation(void)
 213 {
 214         if (simple_rand() & 1)
 215                 return do_read();
 216         else
 217                 return do_write();
 218 }
 219
 220 static int scan_for_bad_eraseblocks(void)
 221 {
 222         int i, bad = 0;
 223
 224         bbt = kzalloc(ebcnt, GFP_KERNEL);
 225         if (!bbt) {
 226                 printk(PRINT_PREF "error: cannot allocate memory\n");
 227                 return -ENOMEM;
 228         }
 229
 230         /* NOR flash does not implement block_isbad */
 231         if (mtd->block_isbad == NULL)
 232                 return 0;
 233
 234         printk(PRINT_PREF "scanning for bad eraseblocks\n");
 235         for (i = 0; i < ebcnt; ++i) {
 236                 bbt[i] = is_block_bad(i) ? 1 : 0;
 237                 if (bbt[i])
 238                         bad += 1;
 239                 cond_resched();
 240         }
 241         printk(PRINT_PREF "scanned %d eraseblocks, %d are bad\n", i, bad);
 242         return 0;
 243 }
 244
 245 static int __init mtd_stresstest_init(void)
 246 {
 247         int err;
 248         int i, op;
 249         uint64_t tmp;
 250
 251         printk(KERN_INFO "\n");
 252         printk(KERN_INFO "=================================================\n");
 253         printk(PRINT_PREF "MTD device: %d\n", dev);
 254
 255         mtd = get_mtd_device(NULL, dev);
 256         if (IS_ERR(mtd)) {
 257                 err = PTR_ERR(mtd);
 258                 printk(PRINT_PREF "error: cannot get MTD device\n");
 259                 return err;
 260         }
 261
 262         if (mtd->writesize == 1) {
 263                 printk(PRINT_PREF "not NAND flash, assume page size is 512 "
 264                        "bytes.\n");
 265                 pgsize = 512;
 266         } else
 267                 pgsize = mtd->writesize;
 268
 269         tmp = mtd->size;
 270         do_div(tmp, mtd->erasesize);
 271         ebcnt = tmp;
 272         pgcnt = mtd->erasesize / pgsize;
 273
 274         printk(PRINT_PREF "MTD device size %llu, eraseblock size %u, "
 275                "page size %u, count of eraseblocks %u, pages per "
 276                "eraseblock %u, OOB size %u\n",
 277                (unsigned long long)mtd->size, mtd->erasesize,
 278                pgsize, ebcnt, pgcnt, mtd->oobsize);
 279
 280         /* Read or write up 2 eraseblocks at a time */
 281         bufsize = mtd->erasesize * 2;
 282
 283         err = -ENOMEM;
 284         readbuf = vmalloc(bufsize);
 285         writebuf = vmalloc(bufsize);
 286         offsets = kmalloc(ebcnt * sizeof(int), GFP_KERNEL);
 287         if (!readbuf || !writebuf || !offsets) {
 288                 printk(PRINT_PREF "error: cannot allocate memory\n");
 289                 goto out;
 290         }
 291         for (i = 0; i < ebcnt; i++)
 292                 offsets[i] = mtd->erasesize;
 293         simple_srand(current->pid);
 294         for (i = 0; i < bufsize; i++)
 295                 writebuf[i] = simple_rand();
 296
 297         err = scan_for_bad_eraseblocks();
 298         if (err)
 299                 goto out;
 300
 301         /* Do operations */
 302         printk(PRINT_PREF "doing operations\n");
 303         for (op = 0; op < count; op++) {
 304                 if ((op & 1023) == 0)
 305                         printk(PRINT_PREF "%d operations done\n", op);
 306                 err = do_operation();
 307                 if (err)
 308                         goto out;
 309                 cond_resched();
 310         }
 311         printk(PRINT_PREF "finished, %d operations done\n", op);
 312
 313 out:
 314         kfree(offsets);
 315         kfree(bbt);
 316         vfree(writebuf);
 317         vfree(readbuf);
 318         put_mtd_device(mtd);
 319         if (err)
 320                 printk(PRINT_PREF "error %d occurred\n", err);
 321         printk(KERN_INFO "=================================================\n");
 322         return err;
 323 }
 324 module_init(mtd_stresstest_init);
 325
 326 static void __exit mtd_stresstest_exit(void)
 327 {
 328         return;
 329 }
 330 module_exit(mtd_stresstest_exit);
 331
 332 MODULE_DESCRIPTION("Stress test module");
 333 MODULE_AUTHOR("Adrian Hunter");
 334 MODULE_LICENSE("GPL");