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 = -EINVAL;
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
simple_rand(void)53 static inline unsigned int simple_rand(void)
54 {
55 next = next * 1103515245 + 12345;
56 return (unsigned int)((next / 65536) % 32768);
57 }
58
simple_srand(unsigned long seed)59 static inline void simple_srand(unsigned long seed)
60 {
61 next = seed;
62 }
63
rand_eb(void)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
rand_offs(void)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
rand_len(int offs)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
erase_eraseblock(int ebnum)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
is_block_bad(int ebnum)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
do_read(void)141 static int do_read(void)
142 {
143 size_t read;
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 (mtd_is_bitflip(err))
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
do_write(void)169 static int do_write(void)
170 {
171 int eb = rand_eb(), offs, err, len;
172 size_t written;
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
do_operation(void)212 static int do_operation(void)
213 {
214 if (simple_rand() & 1)
215 return do_read();
216 else
217 return do_write();
218 }
219
scan_for_bad_eraseblocks(void)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 if (!mtd_can_have_bb(mtd))
231 return 0;
232
233 printk(PRINT_PREF "scanning for bad eraseblocks\n");
234 for (i = 0; i < ebcnt; ++i) {
235 bbt[i] = is_block_bad(i) ? 1 : 0;
236 if (bbt[i])
237 bad += 1;
238 cond_resched();
239 }
240 printk(PRINT_PREF "scanned %d eraseblocks, %d are bad\n", i, bad);
241 return 0;
242 }
243
mtd_stresstest_init(void)244 static int __init mtd_stresstest_init(void)
245 {
246 int err;
247 int i, op;
248 uint64_t tmp;
249
250 printk(KERN_INFO "\n");
251 printk(KERN_INFO "=================================================\n");
252
253 if (dev < 0) {
254 printk(PRINT_PREF "Please specify a valid mtd-device via module paramter\n");
255 printk(KERN_CRIT "CAREFUL: This test wipes all data on the specified MTD device!\n");
256 return -EINVAL;
257 }
258
259 printk(PRINT_PREF "MTD device: %d\n", dev);
260
261 mtd = get_mtd_device(NULL, dev);
262 if (IS_ERR(mtd)) {
263 err = PTR_ERR(mtd);
264 printk(PRINT_PREF "error: cannot get MTD device\n");
265 return err;
266 }
267
268 if (mtd->writesize == 1) {
269 printk(PRINT_PREF "not NAND flash, assume page size is 512 "
270 "bytes.\n");
271 pgsize = 512;
272 } else
273 pgsize = mtd->writesize;
274
275 tmp = mtd->size;
276 do_div(tmp, mtd->erasesize);
277 ebcnt = tmp;
278 pgcnt = mtd->erasesize / pgsize;
279
280 printk(PRINT_PREF "MTD device size %llu, eraseblock size %u, "
281 "page size %u, count of eraseblocks %u, pages per "
282 "eraseblock %u, OOB size %u\n",
283 (unsigned long long)mtd->size, mtd->erasesize,
284 pgsize, ebcnt, pgcnt, mtd->oobsize);
285
286 if (ebcnt < 2) {
287 printk(PRINT_PREF "error: need at least 2 eraseblocks\n");
288 err = -ENOSPC;
289 goto out_put_mtd;
290 }
291
292 /* Read or write up 2 eraseblocks at a time */
293 bufsize = mtd->erasesize * 2;
294
295 err = -ENOMEM;
296 readbuf = vmalloc(bufsize);
297 writebuf = vmalloc(bufsize);
298 offsets = kmalloc(ebcnt * sizeof(int), GFP_KERNEL);
299 if (!readbuf || !writebuf || !offsets) {
300 printk(PRINT_PREF "error: cannot allocate memory\n");
301 goto out;
302 }
303 for (i = 0; i < ebcnt; i++)
304 offsets[i] = mtd->erasesize;
305 simple_srand(current->pid);
306 for (i = 0; i < bufsize; i++)
307 writebuf[i] = simple_rand();
308
309 err = scan_for_bad_eraseblocks();
310 if (err)
311 goto out;
312
313 /* Do operations */
314 printk(PRINT_PREF "doing operations\n");
315 for (op = 0; op < count; op++) {
316 if ((op & 1023) == 0)
317 printk(PRINT_PREF "%d operations done\n", op);
318 err = do_operation();
319 if (err)
320 goto out;
321 cond_resched();
322 }
323 printk(PRINT_PREF "finished, %d operations done\n", op);
324
325 out:
326 kfree(offsets);
327 kfree(bbt);
328 vfree(writebuf);
329 vfree(readbuf);
330 out_put_mtd:
331 put_mtd_device(mtd);
332 if (err)
333 printk(PRINT_PREF "error %d occurred\n", err);
334 printk(KERN_INFO "=================================================\n");
335 return err;
336 }
337 module_init(mtd_stresstest_init);
338
mtd_stresstest_exit(void)339 static void __exit mtd_stresstest_exit(void)
340 {
341 return;
342 }
343 module_exit(mtd_stresstest_exit);
344
345 MODULE_DESCRIPTION("Stress test module");
346 MODULE_AUTHOR("Adrian Hunter");
347 MODULE_LICENSE("GPL");
348