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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/sched.h>
28#include <linux/vmalloc.h>
29
30#define PRINT_PREF KERN_INFO "mtd_stresstest: "
31
32static int dev;
33module_param(dev, int, S_IRUGO);
34MODULE_PARM_DESC(dev, "MTD device number to use");
35
36static int count = 10000;
37module_param(count, int, S_IRUGO);
38MODULE_PARM_DESC(count, "Number of operations to do (default is 10000)");
39
40static struct mtd_info *mtd;
41static unsigned char *writebuf;
42static unsigned char *readbuf;
43static unsigned char *bbt;
44static int *offsets;
45
46static int pgsize;
47static int bufsize;
48static int ebcnt;
49static int pgcnt;
50static unsigned long next = 1;
51
52static inline unsigned int simple_rand(void)
53{
54 next = next * 1103515245 + 12345;
55 return (unsigned int)((next / 65536) % 32768);
56}
57
58static inline void simple_srand(unsigned long seed)
59{
60 next = seed;
61}
62
63static int rand_eb(void)
64{
65 int eb;
66
67again:
68 if (ebcnt < 32768)
69 eb = simple_rand();
70 else
71 eb = (simple_rand() << 15) | simple_rand();
72
73 eb %= (ebcnt - 1);
74 if (bbt[eb])
75 goto again;
76 return eb;
77}
78
79static int rand_offs(void)
80{
81 int offs;
82
83 if (bufsize < 32768)
84 offs = simple_rand();
85 else
86 offs = (simple_rand() << 15) | simple_rand();
87 offs %= bufsize;
88 return offs;
89}
90
91static int rand_len(int offs)
92{
93 int len;
94
95 if (bufsize < 32768)
96 len = simple_rand();
97 else
98 len = (simple_rand() << 15) | simple_rand();
99 len %= (bufsize - offs);
100 return len;
101}
102
103static int erase_eraseblock(int ebnum)
104{
105 int err;
106 struct erase_info ei;
107 loff_t addr = ebnum * mtd->erasesize;
108
109 memset(&ei, 0, sizeof(struct erase_info));
110 ei.mtd = mtd;
111 ei.addr = addr;
112 ei.len = mtd->erasesize;
113
114 err = mtd->erase(mtd, &ei);
115 if (unlikely(err)) {
116 printk(PRINT_PREF "error %d while erasing EB %d\n", err, ebnum);
117 return err;
118 }
119
120 if (unlikely(ei.state == MTD_ERASE_FAILED)) {
121 printk(PRINT_PREF "some erase error occurred at EB %d\n",
122 ebnum);
123 return -EIO;
124 }
125
126 return 0;
127}
128
129static int is_block_bad(int ebnum)
130{
131 loff_t addr = ebnum * mtd->erasesize;
132 int ret;
133
134 ret = mtd->block_isbad(mtd, addr);
135 if (ret)
136 printk(PRINT_PREF "block %d is bad\n", ebnum);
137 return ret;
138}
139
140static int do_read(void)
141{
142 size_t read = 0;
143 int eb = rand_eb();
144 int offs = rand_offs();
145 int len = rand_len(offs), err;
146 loff_t addr;
147
148 if (bbt[eb + 1]) {
149 if (offs >= mtd->erasesize)
150 offs -= mtd->erasesize;
151 if (offs + len > mtd->erasesize)
152 len = mtd->erasesize - offs;
153 }
154 addr = eb * mtd->erasesize + offs;
155 err = mtd->read(mtd, addr, len, &read, readbuf);
156 if (err == -EUCLEAN)
157 err = 0;
158 if (unlikely(err || read != len)) {
159 printk(PRINT_PREF "error: read failed at 0x%llx\n",
160 (long long)addr);
161 if (!err)
162 err = -EINVAL;
163 return err;
164 }
165 return 0;
166}
167
168static int do_write(void)
169{
170 int eb = rand_eb(), offs, err, len;
171 size_t written = 0;
172 loff_t addr;
173
174 offs = offsets[eb];
175 if (offs >= mtd->erasesize) {
176 err = erase_eraseblock(eb);
177 if (err)
178 return err;
179 offs = offsets[eb] = 0;
180 }
181 len = rand_len(offs);
182 len = ((len + pgsize - 1) / pgsize) * pgsize;
183 if (offs + len > mtd->erasesize) {
184 if (bbt[eb + 1])
185 len = mtd->erasesize - offs;
186 else {
187 err = erase_eraseblock(eb + 1);
188 if (err)
189 return err;
190 offsets[eb + 1] = 0;
191 }
192 }
193 addr = eb * mtd->erasesize + offs;
194 err = mtd->write(mtd, addr, len, &written, writebuf);
195 if (unlikely(err || written != len)) {
196 printk(PRINT_PREF "error: write failed at 0x%llx\n",
197 (long long)addr);
198 if (!err)
199 err = -EINVAL;
200 return err;
201 }
202 offs += len;
203 while (offs > mtd->erasesize) {
204 offsets[eb++] = mtd->erasesize;
205 offs -= mtd->erasesize;
206 }
207 offsets[eb] = offs;
208 return 0;
209}
210
211static int do_operation(void)
212{
213 if (simple_rand() & 1)
214 return do_read();
215 else
216 return do_write();
217}
218
219static int scan_for_bad_eraseblocks(void)
220{
221 int i, bad = 0;
222
223 bbt = kmalloc(ebcnt, GFP_KERNEL);
224 if (!bbt) {
225 printk(PRINT_PREF "error: cannot allocate memory\n");
226 return -ENOMEM;
227 }
228 memset(bbt, 0 , ebcnt);
229
230 printk(PRINT_PREF "scanning for bad eraseblocks\n");
231 for (i = 0; i < ebcnt; ++i) {
232 bbt[i] = is_block_bad(i) ? 1 : 0;
233 if (bbt[i])
234 bad += 1;
235 cond_resched();
236 }
237 printk(PRINT_PREF "scanned %d eraseblocks, %d are bad\n", i, bad);
238 return 0;
239}
240
241static int __init mtd_stresstest_init(void)
242{
243 int err;
244 int i, op;
245 uint64_t tmp;
246
247 printk(KERN_INFO "\n");
248 printk(KERN_INFO "=================================================\n");
249 printk(PRINT_PREF "MTD device: %d\n", dev);
250
251 mtd = get_mtd_device(NULL, dev);
252 if (IS_ERR(mtd)) {
253 err = PTR_ERR(mtd);
254 printk(PRINT_PREF "error: cannot get MTD device\n");
255 return err;
256 }
257
258 if (mtd->writesize == 1) {
259 printk(PRINT_PREF "not NAND flash, assume page size is 512 "
260 "bytes.\n");
261 pgsize = 512;
262 } else
263 pgsize = mtd->writesize;
264
265 tmp = mtd->size;
266 do_div(tmp, mtd->erasesize);
267 ebcnt = tmp;
268 pgcnt = mtd->erasesize / mtd->writesize;
269
270 printk(PRINT_PREF "MTD device size %llu, eraseblock size %u, "
271 "page size %u, count of eraseblocks %u, pages per "
272 "eraseblock %u, OOB size %u\n",
273 (unsigned long long)mtd->size, mtd->erasesize,
274 pgsize, ebcnt, pgcnt, mtd->oobsize);
275
276
277 bufsize = mtd->erasesize * 2;
278
279 err = -ENOMEM;
280 readbuf = vmalloc(bufsize);
281 writebuf = vmalloc(bufsize);
282 offsets = kmalloc(ebcnt * sizeof(int), GFP_KERNEL);
283 if (!readbuf || !writebuf || !offsets) {
284 printk(PRINT_PREF "error: cannot allocate memory\n");
285 goto out;
286 }
287 for (i = 0; i < ebcnt; i++)
288 offsets[i] = mtd->erasesize;
289 simple_srand(current->pid);
290 for (i = 0; i < bufsize; i++)
291 writebuf[i] = simple_rand();
292
293 err = scan_for_bad_eraseblocks();
294 if (err)
295 goto out;
296
297
298 printk(PRINT_PREF "doing operations\n");
299 for (op = 0; op < count; op++) {
300 if ((op & 1023) == 0)
301 printk(PRINT_PREF "%d operations done\n", op);
302 err = do_operation();
303 if (err)
304 goto out;
305 cond_resched();
306 }
307 printk(PRINT_PREF "finished, %d operations done\n", op);
308
309out:
310 kfree(offsets);
311 kfree(bbt);
312 vfree(writebuf);
313 vfree(readbuf);
314 put_mtd_device(mtd);
315 if (err)
316 printk(PRINT_PREF "error %d occurred\n", err);
317 printk(KERN_INFO "=================================================\n");
318 return err;
319}
320module_init(mtd_stresstest_init);
321
322static void __exit mtd_stresstest_exit(void)
323{
324 return;
325}
326module_exit(mtd_stresstest_exit);
327
328MODULE_DESCRIPTION("Stress test module");
329MODULE_AUTHOR("Adrian Hunter");
330MODULE_LICENSE("GPL");
331
