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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23
24#include <linux/init.h>
25#include <linux/module.h>
26#include <linux/moduleparam.h>
27#include <linux/err.h>
28#include <linux/mtd/mtd.h>
29#include <linux/slab.h>
30#include <linux/sched.h>
31#include <linux/vmalloc.h>
32#include <linux/random.h>
33
34#include "mtd_test.h"
35
36static int dev = -EINVAL;
37module_param(dev, int, S_IRUGO);
38MODULE_PARM_DESC(dev, "MTD device number to use");
39
40static int count = 10000;
41module_param(count, int, S_IRUGO);
42MODULE_PARM_DESC(count, "Number of operations to do (default is 10000)");
43
44static struct mtd_info *mtd;
45static unsigned char *writebuf;
46static unsigned char *readbuf;
47static unsigned char *bbt;
48static int *offsets;
49
50static int pgsize;
51static int bufsize;
52static int ebcnt;
53static int pgcnt;
54
55static int rand_eb(void)
56{
57	unsigned int eb;
58
59again:
60	eb = prandom_u32();
61	/* Read or write up 2 eraseblocks at a time - hence 'ebcnt - 1' */
62	eb %= (ebcnt - 1);
63	if (bbt[eb])
64		goto again;
65	return eb;
66}
67
68static int rand_offs(void)
69{
70	unsigned int offs;
71
72	offs = prandom_u32();
73	offs %= bufsize;
74	return offs;
75}
76
77static int rand_len(int offs)
78{
79	unsigned int len;
80
81	len = prandom_u32();
82	len %= (bufsize - offs);
83	return len;
84}
85
86static int do_read(void)
87{
88	int eb = rand_eb();
89	int offs = rand_offs();
90	int len = rand_len(offs);
91	loff_t addr;
92
93	if (bbt[eb + 1]) {
94		if (offs >= mtd->erasesize)
95			offs -= mtd->erasesize;
96		if (offs + len > mtd->erasesize)
97			len = mtd->erasesize - offs;
98	}
99	addr = (loff_t)eb * mtd->erasesize + offs;
100	return mtdtest_read(mtd, addr, len, readbuf);
101}
102
103static int do_write(void)
104{
105	int eb = rand_eb(), offs, err, len;
106	loff_t addr;
107
108	offs = offsets[eb];
109	if (offs >= mtd->erasesize) {
110		err = mtdtest_erase_eraseblock(mtd, eb);
111		if (err)
112			return err;
113		offs = offsets[eb] = 0;
114	}
115	len = rand_len(offs);
116	len = ((len + pgsize - 1) / pgsize) * pgsize;
117	if (offs + len > mtd->erasesize) {
118		if (bbt[eb + 1])
119			len = mtd->erasesize - offs;
120		else {
121			err = mtdtest_erase_eraseblock(mtd, eb + 1);
122			if (err)
123				return err;
124			offsets[eb + 1] = 0;
125		}
126	}
127	addr = (loff_t)eb * mtd->erasesize + offs;
128	err = mtdtest_write(mtd, addr, len, writebuf);
129	if (unlikely(err))
130		return err;
131	offs += len;
132	while (offs > mtd->erasesize) {
133		offsets[eb++] = mtd->erasesize;
134		offs -= mtd->erasesize;
135	}
136	offsets[eb] = offs;
137	return 0;
138}
139
140static int do_operation(void)
141{
142	if (prandom_u32() & 1)
143		return do_read();
144	else
145		return do_write();
146}
147
148static int __init mtd_stresstest_init(void)
149{
150	int err;
151	int i, op;
152	uint64_t tmp;
153
154	printk(KERN_INFO "\n");
155	printk(KERN_INFO "=================================================\n");
156
157	if (dev < 0) {
158		pr_info("Please specify a valid mtd-device via module parameter\n");
159		pr_crit("CAREFUL: This test wipes all data on the specified MTD device!\n");
160		return -EINVAL;
161	}
162
163	pr_info("MTD device: %d\n", dev);
164
165	mtd = get_mtd_device(NULL, dev);
166	if (IS_ERR(mtd)) {
167		err = PTR_ERR(mtd);
168		pr_err("error: cannot get MTD device\n");
169		return err;
170	}
171
172	if (mtd->writesize == 1) {
173		pr_info("not NAND flash, assume page size is 512 "
174		       "bytes.\n");
175		pgsize = 512;
176	} else
177		pgsize = mtd->writesize;
178
179	tmp = mtd->size;
180	do_div(tmp, mtd->erasesize);
181	ebcnt = tmp;
182	pgcnt = mtd->erasesize / pgsize;
183
184	pr_info("MTD device size %llu, eraseblock size %u, "
185	       "page size %u, count of eraseblocks %u, pages per "
186	       "eraseblock %u, OOB size %u\n",
187	       (unsigned long long)mtd->size, mtd->erasesize,
188	       pgsize, ebcnt, pgcnt, mtd->oobsize);
189
190	if (ebcnt < 2) {
191		pr_err("error: need at least 2 eraseblocks\n");
192		err = -ENOSPC;
193		goto out_put_mtd;
194	}
195
196	/* Read or write up 2 eraseblocks at a time */
197	bufsize = mtd->erasesize * 2;
198
199	err = -ENOMEM;
200	readbuf = vmalloc(bufsize);
201	writebuf = vmalloc(bufsize);
202	offsets = kmalloc(ebcnt * sizeof(int), GFP_KERNEL);
203	if (!readbuf || !writebuf || !offsets)
204		goto out;
205	for (i = 0; i < ebcnt; i++)
206		offsets[i] = mtd->erasesize;
207	prandom_bytes(writebuf, bufsize);
208
209	bbt = kzalloc(ebcnt, GFP_KERNEL);
210	if (!bbt)
211		goto out;
212	err = mtdtest_scan_for_bad_eraseblocks(mtd, bbt, 0, ebcnt);
213	if (err)
214		goto out;
215
216	/* Do operations */
217	pr_info("doing operations\n");
218	for (op = 0; op < count; op++) {
219		if ((op & 1023) == 0)
220			pr_info("%d operations done\n", op);
221		err = do_operation();
222		if (err)
223			goto out;
224
225		err = mtdtest_relax();
226		if (err)
227			goto out;
228	}
229	pr_info("finished, %d operations done\n", op);
230
231out:
232	kfree(offsets);
233	kfree(bbt);
234	vfree(writebuf);
235	vfree(readbuf);
236out_put_mtd:
237	put_mtd_device(mtd);
238	if (err)
239		pr_info("error %d occurred\n", err);
240	printk(KERN_INFO "=================================================\n");
241	return err;
242}
243module_init(mtd_stresstest_init);
244
245static void __exit mtd_stresstest_exit(void)
246{
247	return;
248}
249module_exit(mtd_stresstest_exit);
250
251MODULE_DESCRIPTION("Stress test module");
252MODULE_AUTHOR("Adrian Hunter");
253MODULE_LICENSE("GPL");
254