Commit | Line | Data |
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b6489d97 VN |
1 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
2 | ||
7126bd8b AM |
3 | #include <linux/kernel.h> |
4 | #include <linux/module.h> | |
5 | #include <linux/list.h> | |
7126bd8b AM |
6 | #include <linux/random.h> |
7 | #include <linux/string.h> | |
8 | #include <linux/bitops.h> | |
1749c00f | 9 | #include <linux/slab.h> |
7126bd8b AM |
10 | #include <linux/mtd/nand_ecc.h> |
11 | ||
6060fb42 AM |
12 | /* |
13 | * Test the implementation for software ECC | |
14 | * | |
15 | * No actual MTD device is needed, So we don't need to warry about losing | |
16 | * important data by human error. | |
17 | * | |
18 | * This covers possible patterns of corruption which can be reliably corrected | |
19 | * or detected. | |
20 | */ | |
21 | ||
7126bd8b AM |
22 | #if defined(CONFIG_MTD_NAND) || defined(CONFIG_MTD_NAND_MODULE) |
23 | ||
6060fb42 AM |
24 | struct nand_ecc_test { |
25 | const char *name; | |
26 | void (*prepare)(void *, void *, void *, void *, const size_t); | |
27 | int (*verify)(void *, void *, void *, const size_t); | |
28 | }; | |
29 | ||
c092b439 AM |
30 | /* |
31 | * The reason for this __change_bit_le() instead of __change_bit() is to inject | |
32 | * bit error properly within the region which is not a multiple of | |
33 | * sizeof(unsigned long) on big-endian systems | |
34 | */ | |
35 | #ifdef __LITTLE_ENDIAN | |
36 | #define __change_bit_le(nr, addr) __change_bit(nr, addr) | |
37 | #elif defined(__BIG_ENDIAN) | |
38 | #define __change_bit_le(nr, addr) \ | |
39 | __change_bit((nr) ^ ((BITS_PER_LONG - 1) & ~0x7), addr) | |
40 | #else | |
41 | #error "Unknown byte order" | |
42 | #endif | |
43 | ||
6060fb42 AM |
44 | static void single_bit_error_data(void *error_data, void *correct_data, |
45 | size_t size) | |
7126bd8b | 46 | { |
aca662a3 | 47 | unsigned int offset = prandom_u32() % (size * BITS_PER_BYTE); |
7126bd8b | 48 | |
6060fb42 AM |
49 | memcpy(error_data, correct_data, size); |
50 | __change_bit_le(offset, error_data); | |
51 | } | |
52 | ||
6ed089c0 AM |
53 | static void double_bit_error_data(void *error_data, void *correct_data, |
54 | size_t size) | |
55 | { | |
56 | unsigned int offset[2]; | |
57 | ||
aca662a3 | 58 | offset[0] = prandom_u32() % (size * BITS_PER_BYTE); |
6ed089c0 | 59 | do { |
aca662a3 | 60 | offset[1] = prandom_u32() % (size * BITS_PER_BYTE); |
6ed089c0 AM |
61 | } while (offset[0] == offset[1]); |
62 | ||
63 | memcpy(error_data, correct_data, size); | |
64 | ||
65 | __change_bit_le(offset[0], error_data); | |
66 | __change_bit_le(offset[1], error_data); | |
67 | } | |
68 | ||
200ab845 AM |
69 | static unsigned int random_ecc_bit(size_t size) |
70 | { | |
aca662a3 | 71 | unsigned int offset = prandom_u32() % (3 * BITS_PER_BYTE); |
200ab845 AM |
72 | |
73 | if (size == 256) { | |
74 | /* | |
75 | * Don't inject a bit error into the insignificant bits (16th | |
76 | * and 17th bit) in ECC code for 256 byte data block | |
77 | */ | |
78 | while (offset == 16 || offset == 17) | |
aca662a3 | 79 | offset = prandom_u32() % (3 * BITS_PER_BYTE); |
200ab845 AM |
80 | } |
81 | ||
82 | return offset; | |
83 | } | |
84 | ||
85 | static void single_bit_error_ecc(void *error_ecc, void *correct_ecc, | |
86 | size_t size) | |
87 | { | |
88 | unsigned int offset = random_ecc_bit(size); | |
89 | ||
90 | memcpy(error_ecc, correct_ecc, 3); | |
91 | __change_bit_le(offset, error_ecc); | |
92 | } | |
93 | ||
6ed089c0 AM |
94 | static void double_bit_error_ecc(void *error_ecc, void *correct_ecc, |
95 | size_t size) | |
96 | { | |
97 | unsigned int offset[2]; | |
98 | ||
99 | offset[0] = random_ecc_bit(size); | |
100 | do { | |
101 | offset[1] = random_ecc_bit(size); | |
102 | } while (offset[0] == offset[1]); | |
103 | ||
104 | memcpy(error_ecc, correct_ecc, 3); | |
105 | __change_bit_le(offset[0], error_ecc); | |
106 | __change_bit_le(offset[1], error_ecc); | |
107 | } | |
108 | ||
ccaa6795 AM |
109 | static void no_bit_error(void *error_data, void *error_ecc, |
110 | void *correct_data, void *correct_ecc, const size_t size) | |
111 | { | |
112 | memcpy(error_data, correct_data, size); | |
113 | memcpy(error_ecc, correct_ecc, 3); | |
114 | } | |
115 | ||
116 | static int no_bit_error_verify(void *error_data, void *error_ecc, | |
117 | void *correct_data, const size_t size) | |
118 | { | |
119 | unsigned char calc_ecc[3]; | |
120 | int ret; | |
121 | ||
122 | __nand_calculate_ecc(error_data, size, calc_ecc); | |
123 | ret = __nand_correct_data(error_data, error_ecc, calc_ecc, size); | |
124 | if (ret == 0 && !memcmp(correct_data, error_data, size)) | |
125 | return 0; | |
126 | ||
127 | return -EINVAL; | |
128 | } | |
129 | ||
6060fb42 AM |
130 | static void single_bit_error_in_data(void *error_data, void *error_ecc, |
131 | void *correct_data, void *correct_ecc, const size_t size) | |
132 | { | |
133 | single_bit_error_data(error_data, correct_data, size); | |
134 | memcpy(error_ecc, correct_ecc, 3); | |
135 | } | |
136 | ||
200ab845 AM |
137 | static void single_bit_error_in_ecc(void *error_data, void *error_ecc, |
138 | void *correct_data, void *correct_ecc, const size_t size) | |
139 | { | |
140 | memcpy(error_data, correct_data, size); | |
141 | single_bit_error_ecc(error_ecc, correct_ecc, size); | |
142 | } | |
143 | ||
6060fb42 AM |
144 | static int single_bit_error_correct(void *error_data, void *error_ecc, |
145 | void *correct_data, const size_t size) | |
146 | { | |
147 | unsigned char calc_ecc[3]; | |
148 | int ret; | |
149 | ||
150 | __nand_calculate_ecc(error_data, size, calc_ecc); | |
151 | ret = __nand_correct_data(error_data, error_ecc, calc_ecc, size); | |
152 | if (ret == 1 && !memcmp(correct_data, error_data, size)) | |
153 | return 0; | |
154 | ||
155 | return -EINVAL; | |
7126bd8b AM |
156 | } |
157 | ||
6ed089c0 AM |
158 | static void double_bit_error_in_data(void *error_data, void *error_ecc, |
159 | void *correct_data, void *correct_ecc, const size_t size) | |
160 | { | |
161 | double_bit_error_data(error_data, correct_data, size); | |
162 | memcpy(error_ecc, correct_ecc, 3); | |
163 | } | |
164 | ||
165 | static void single_bit_error_in_data_and_ecc(void *error_data, void *error_ecc, | |
166 | void *correct_data, void *correct_ecc, const size_t size) | |
167 | { | |
168 | single_bit_error_data(error_data, correct_data, size); | |
169 | single_bit_error_ecc(error_ecc, correct_ecc, size); | |
170 | } | |
171 | ||
172 | static void double_bit_error_in_ecc(void *error_data, void *error_ecc, | |
173 | void *correct_data, void *correct_ecc, const size_t size) | |
174 | { | |
175 | memcpy(error_data, correct_data, size); | |
176 | double_bit_error_ecc(error_ecc, correct_ecc, size); | |
177 | } | |
178 | ||
179 | static int double_bit_error_detect(void *error_data, void *error_ecc, | |
180 | void *correct_data, const size_t size) | |
181 | { | |
182 | unsigned char calc_ecc[3]; | |
183 | int ret; | |
184 | ||
185 | __nand_calculate_ecc(error_data, size, calc_ecc); | |
186 | ret = __nand_correct_data(error_data, error_ecc, calc_ecc, size); | |
187 | ||
188 | return (ret == -1) ? 0 : -EINVAL; | |
189 | } | |
190 | ||
6060fb42 | 191 | static const struct nand_ecc_test nand_ecc_test[] = { |
ccaa6795 AM |
192 | { |
193 | .name = "no-bit-error", | |
194 | .prepare = no_bit_error, | |
195 | .verify = no_bit_error_verify, | |
196 | }, | |
6060fb42 AM |
197 | { |
198 | .name = "single-bit-error-in-data-correct", | |
199 | .prepare = single_bit_error_in_data, | |
200 | .verify = single_bit_error_correct, | |
201 | }, | |
200ab845 AM |
202 | { |
203 | .name = "single-bit-error-in-ecc-correct", | |
204 | .prepare = single_bit_error_in_ecc, | |
205 | .verify = single_bit_error_correct, | |
206 | }, | |
6ed089c0 AM |
207 | { |
208 | .name = "double-bit-error-in-data-detect", | |
209 | .prepare = double_bit_error_in_data, | |
210 | .verify = double_bit_error_detect, | |
211 | }, | |
212 | { | |
213 | .name = "single-bit-error-in-data-and-ecc-detect", | |
214 | .prepare = single_bit_error_in_data_and_ecc, | |
215 | .verify = double_bit_error_detect, | |
216 | }, | |
217 | { | |
218 | .name = "double-bit-error-in-ecc-detect", | |
219 | .prepare = double_bit_error_in_ecc, | |
220 | .verify = double_bit_error_detect, | |
221 | }, | |
6060fb42 AM |
222 | }; |
223 | ||
c5b8384a AM |
224 | static void dump_data_ecc(void *error_data, void *error_ecc, void *correct_data, |
225 | void *correct_ecc, const size_t size) | |
226 | { | |
227 | pr_info("hexdump of error data:\n"); | |
228 | print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 4, | |
229 | error_data, size, false); | |
230 | print_hex_dump(KERN_INFO, "hexdump of error ecc: ", | |
231 | DUMP_PREFIX_NONE, 16, 1, error_ecc, 3, false); | |
232 | ||
233 | pr_info("hexdump of correct data:\n"); | |
234 | print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 4, | |
235 | correct_data, size, false); | |
236 | print_hex_dump(KERN_INFO, "hexdump of correct ecc: ", | |
237 | DUMP_PREFIX_NONE, 16, 1, correct_ecc, 3, false); | |
238 | } | |
239 | ||
6060fb42 | 240 | static int nand_ecc_test_run(const size_t size) |
7126bd8b | 241 | { |
6060fb42 | 242 | int i; |
1749c00f AM |
243 | int err = 0; |
244 | void *error_data; | |
245 | void *error_ecc; | |
246 | void *correct_data; | |
247 | void *correct_ecc; | |
7126bd8b | 248 | |
1749c00f AM |
249 | error_data = kmalloc(size, GFP_KERNEL); |
250 | error_ecc = kmalloc(3, GFP_KERNEL); | |
251 | correct_data = kmalloc(size, GFP_KERNEL); | |
252 | correct_ecc = kmalloc(3, GFP_KERNEL); | |
253 | ||
254 | if (!error_data || !error_ecc || !correct_data || !correct_ecc) { | |
255 | err = -ENOMEM; | |
256 | goto error; | |
257 | } | |
7126bd8b | 258 | |
459a86d8 | 259 | prandom_bytes(correct_data, size); |
c5b8384a | 260 | __nand_calculate_ecc(correct_data, size, correct_ecc); |
6060fb42 AM |
261 | |
262 | for (i = 0; i < ARRAY_SIZE(nand_ecc_test); i++) { | |
263 | nand_ecc_test[i].prepare(error_data, error_ecc, | |
264 | correct_data, correct_ecc, size); | |
265 | err = nand_ecc_test[i].verify(error_data, error_ecc, | |
266 | correct_data, size); | |
267 | ||
268 | if (err) { | |
b6489d97 | 269 | pr_err("not ok - %s-%zd\n", |
6060fb42 AM |
270 | nand_ecc_test[i].name, size); |
271 | dump_data_ecc(error_data, error_ecc, | |
272 | correct_data, correct_ecc, size); | |
273 | break; | |
274 | } | |
b6489d97 | 275 | pr_info("ok - %s-%zd\n", |
6060fb42 | 276 | nand_ecc_test[i].name, size); |
7126bd8b | 277 | } |
1749c00f AM |
278 | error: |
279 | kfree(error_data); | |
280 | kfree(error_ecc); | |
281 | kfree(correct_data); | |
282 | kfree(correct_ecc); | |
283 | ||
284 | return err; | |
7126bd8b AM |
285 | } |
286 | ||
287 | #else | |
288 | ||
6060fb42 | 289 | static int nand_ecc_test_run(const size_t size) |
7126bd8b AM |
290 | { |
291 | return 0; | |
292 | } | |
293 | ||
294 | #endif | |
295 | ||
296 | static int __init ecc_test_init(void) | |
297 | { | |
f45c2990 | 298 | int err; |
7126bd8b | 299 | |
6060fb42 | 300 | err = nand_ecc_test_run(256); |
f45c2990 AM |
301 | if (err) |
302 | return err; | |
303 | ||
6060fb42 | 304 | return nand_ecc_test_run(512); |
7126bd8b AM |
305 | } |
306 | ||
307 | static void __exit ecc_test_exit(void) | |
308 | { | |
309 | } | |
310 | ||
311 | module_init(ecc_test_init); | |
312 | module_exit(ecc_test_exit); | |
313 | ||
314 | MODULE_DESCRIPTION("NAND ECC function test module"); | |
315 | MODULE_AUTHOR("Akinobu Mita"); | |
316 | MODULE_LICENSE("GPL"); |