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