/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
 33static int dev;
 34module_param(dev, int, S_IRUGO);
 35MODULE_PARM_DESC(dev, "MTD device number to use");
 36
 37static int count = 10000;
 38module_param(count, int, S_IRUGO);
 39MODULE_PARM_DESC(count, "Number of operations to do (default is 10000)");
 40
 41static struct mtd_info *mtd;
 42static unsigned char *writebuf;
 43static unsigned char *readbuf;
 44static unsigned char *bbt;
 45static int *offsets;
 46
 47static int pgsize;
 48static int bufsize;
 49static int ebcnt;
 50static int pgcnt;
 51static unsigned long next = 1;
 52
 53static inline unsigned int simple_rand(void)
 54{
 55	next = next * 1103515245 + 12345;
 56	return (unsigned int)((next / 65536) % 32768);
 57}
 58
 59static inline void simple_srand(unsigned long seed)
 60{
 61	next = seed;
 62}
 63
 64static int rand_eb(void)
 65{
 66	int eb;
 67
 68again:
 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
 80static 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
 92static 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
104static 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
130static 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
141static 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
169static 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
212static int do_operation(void)
213{
214	if (simple_rand() & 1)
215		return do_read();
216	else
217		return do_write();
218}
219
220static 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
245static 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	if (ebcnt < 2) {
281		printk(PRINT_PREF "error: need at least 2 eraseblocks\n");
282		err = -ENOSPC;
283		goto out_put_mtd;
284	}
285
286	/* Read or write up 2 eraseblocks at a time */
287	bufsize = mtd->erasesize * 2;
288
289	err = -ENOMEM;
290	readbuf = vmalloc(bufsize);
291	writebuf = vmalloc(bufsize);
292	offsets = kmalloc(ebcnt * sizeof(int), GFP_KERNEL);
293	if (!readbuf || !writebuf || !offsets) {
294		printk(PRINT_PREF "error: cannot allocate memory\n");
295		goto out;
296	}
297	for (i = 0; i < ebcnt; i++)
298		offsets[i] = mtd->erasesize;
299	simple_srand(current->pid);
300	for (i = 0; i < bufsize; i++)
301		writebuf[i] = simple_rand();
302
303	err = scan_for_bad_eraseblocks();
304	if (err)
305		goto out;
306
307	/* Do operations */
308	printk(PRINT_PREF "doing operations\n");
309	for (op = 0; op < count; op++) {
310		if ((op & 1023) == 0)
311			printk(PRINT_PREF "%d operations done\n", op);
312		err = do_operation();
313		if (err)
314			goto out;
315		cond_resched();
316	}
317	printk(PRINT_PREF "finished, %d operations done\n", op);
318
319out:
320	kfree(offsets);
321	kfree(bbt);
322	vfree(writebuf);
323	vfree(readbuf);
324out_put_mtd:
325	put_mtd_device(mtd);
326	if (err)
327		printk(PRINT_PREF "error %d occurred\n", err);
328	printk(KERN_INFO "=================================================\n");
329	return err;
330}
331module_init(mtd_stresstest_init);
332
333static void __exit mtd_stresstest_exit(void)
334{
335	return;
336}
337module_exit(mtd_stresstest_exit);
338
339MODULE_DESCRIPTION("Stress test module");
340MODULE_AUTHOR("Adrian Hunter");
341MODULE_LICENSE("GPL");