1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2006-2008 Nokia Corporation
4 *
5 * Test random reads, writes and erases on MTD device.
6 *
7 * Author: Adrian Hunter <ext-adrian.hunter@nokia.com>
8 */
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/moduleparam.h>
15#include <linux/err.h>
16#include <linux/mtd/mtd.h>
17#include <linux/slab.h>
18#include <linux/sched.h>
19#include <linux/vmalloc.h>
20#include <linux/random.h>
21
22#include "mtd_test.h"
23
24static int dev = -EINVAL;
25module_param(dev, int, S_IRUGO);
26MODULE_PARM_DESC(dev, "MTD device number to use");
27
28static int count = 10000;
29module_param(count, int, S_IRUGO);
30MODULE_PARM_DESC(count, "Number of operations to do (default is 10000)");
31
32static struct mtd_info *mtd;
33static unsigned char *writebuf;
34static unsigned char *readbuf;
35static unsigned char *bbt;
36static int *offsets;
37
38static int pgsize;
39static int bufsize;
40static int ebcnt;
41static int pgcnt;
42
43static int rand_eb(void)
44{
45	unsigned int eb;
46
47again:
48	/* Read or write up 2 eraseblocks at a time - hence 'ebcnt - 1' */
49	eb = get_random_u32_below(ebcnt - 1);
50	if (bbt[eb])
51		goto again;
52	return eb;
53}
54
55static int rand_offs(void)
56{
57	return get_random_u32_below(bufsize);
58}
59
60static int rand_len(int offs)
61{
62	return get_random_u32_below(bufsize - offs);
63}
64
65static int do_read(void)
66{
67	int eb = rand_eb();
68	int offs = rand_offs();
69	int len = rand_len(offs);
70	loff_t addr;
71
72	if (bbt[eb + 1]) {
73		if (offs >= mtd->erasesize)
74			offs -= mtd->erasesize;
75		if (offs + len > mtd->erasesize)
76			len = mtd->erasesize - offs;
77	}
78	addr = (loff_t)eb * mtd->erasesize + offs;
79	return mtdtest_read(mtd, addr, len, readbuf);
80}
81
82static int do_write(void)
83{
84	int eb = rand_eb(), offs, err, len;
85	loff_t addr;
86
87	offs = offsets[eb];
88	if (offs >= mtd->erasesize) {
89		err = mtdtest_erase_eraseblock(mtd, eb);
90		if (err)
91			return err;
92		offs = offsets[eb] = 0;
93	}
94	len = rand_len(offs);
95	len = ((len + pgsize - 1) / pgsize) * pgsize;
96	if (offs + len > mtd->erasesize) {
97		if (bbt[eb + 1])
98			len = mtd->erasesize - offs;
99		else {
100			err = mtdtest_erase_eraseblock(mtd, eb + 1);
101			if (err)
102				return err;
103			offsets[eb + 1] = 0;
104		}
105	}
106	addr = (loff_t)eb * mtd->erasesize + offs;
107	err = mtdtest_write(mtd, addr, len, writebuf);
108	if (unlikely(err))
109		return err;
110	offs += len;
111	while (offs > mtd->erasesize) {
112		offsets[eb++] = mtd->erasesize;
113		offs -= mtd->erasesize;
114	}
115	offsets[eb] = offs;
116	return 0;
117}
118
119static int do_operation(void)
120{
121	if (get_random_u32_below(2))
122		return do_read();
123	else
124		return do_write();
125}
126
127static int __init mtd_stresstest_init(void)
128{
129	int err;
130	int i, op;
131	uint64_t tmp;
132
133	printk(KERN_INFO "\n");
134	printk(KERN_INFO "=================================================\n");
135
136	if (dev < 0) {
137		pr_info("Please specify a valid mtd-device via module parameter\n");
138		pr_crit("CAREFUL: This test wipes all data on the specified MTD device!\n");
139		return -EINVAL;
140	}
141
142	pr_info("MTD device: %d\n", dev);
143
144	mtd = get_mtd_device(NULL, dev);
145	if (IS_ERR(mtd)) {
146		err = PTR_ERR(mtd);
147		pr_err("error: cannot get MTD device\n");
148		return err;
149	}
150
151	if (mtd->writesize == 1) {
152		pr_info("not NAND flash, assume page size is 512 "
153		       "bytes.\n");
154		pgsize = 512;
155	} else
156		pgsize = mtd->writesize;
157
158	tmp = mtd->size;
159	do_div(tmp, mtd->erasesize);
160	ebcnt = tmp;
161	pgcnt = mtd->erasesize / pgsize;
162
163	pr_info("MTD device size %llu, eraseblock size %u, "
164	       "page size %u, count of eraseblocks %u, pages per "
165	       "eraseblock %u, OOB size %u\n",
166	       (unsigned long long)mtd->size, mtd->erasesize,
167	       pgsize, ebcnt, pgcnt, mtd->oobsize);
168
169	if (ebcnt < 2) {
170		pr_err("error: need at least 2 eraseblocks\n");
171		err = -ENOSPC;
172		goto out_put_mtd;
173	}
174
175	/* Read or write up 2 eraseblocks at a time */
176	bufsize = mtd->erasesize * 2;
177
178	err = -ENOMEM;
179	readbuf = vmalloc(bufsize);
180	writebuf = vmalloc(bufsize);
181	offsets = kmalloc_array(ebcnt, sizeof(int), GFP_KERNEL);
182	if (!readbuf || !writebuf || !offsets)
183		goto out;
184	for (i = 0; i < ebcnt; i++)
185		offsets[i] = mtd->erasesize;
186	get_random_bytes(writebuf, bufsize);
187
188	bbt = kzalloc(ebcnt, GFP_KERNEL);
189	if (!bbt)
190		goto out;
191	err = mtdtest_scan_for_bad_eraseblocks(mtd, bbt, 0, ebcnt);
192	if (err)
193		goto out;
194
195	/* Do operations */
196	pr_info("doing operations\n");
197	for (op = 0; op < count; op++) {
198		if ((op & 1023) == 0)
199			pr_info("%d operations done\n", op);
200		err = do_operation();
201		if (err)
202			goto out;
203
204		err = mtdtest_relax();
205		if (err)
206			goto out;
207	}
208	pr_info("finished, %d operations done\n", op);
209
210out:
211	kfree(offsets);
212	kfree(bbt);
213	vfree(writebuf);
214	vfree(readbuf);
215out_put_mtd:
216	put_mtd_device(mtd);
217	if (err)
218		pr_info("error %d occurred\n", err);
219	printk(KERN_INFO "=================================================\n");
220	return err;
221}
222module_init(mtd_stresstest_init);
223
224static void __exit mtd_stresstest_exit(void)
225{
226	return;
227}
228module_exit(mtd_stresstest_exit);
229
230MODULE_DESCRIPTION("Stress test module");
231MODULE_AUTHOR("Adrian Hunter");
232MODULE_LICENSE("GPL");
233