1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
3 | |
4 | #include <linux/kernel.h> |
5 | #include <linux/module.h> |
6 | #include <linux/list.h> |
7 | #include <linux/random.h> |
8 | #include <linux/string.h> |
9 | #include <linux/bitops.h> |
10 | #include <linux/slab.h> |
11 | #include <linux/mtd/nand-ecc-sw-hamming.h> |
12 | |
13 | #include "mtd_test.h" |
14 | |
15 | /* |
16 | * Test the implementation for software ECC |
17 | * |
18 | * No actual MTD device is needed, So we don't need to warry about losing |
19 | * important data by human error. |
20 | * |
21 | * This covers possible patterns of corruption which can be reliably corrected |
22 | * or detected. |
23 | */ |
24 | |
25 | #if IS_ENABLED(CONFIG_MTD_RAW_NAND) |
26 | |
27 | struct nand_ecc_test { |
28 | const char *name; |
29 | void (*prepare)(void *, void *, void *, void *, const size_t); |
30 | int (*verify)(void *, void *, void *, const size_t); |
31 | }; |
32 | |
33 | /* |
34 | * The reason for this __change_bit_le() instead of __change_bit() is to inject |
35 | * bit error properly within the region which is not a multiple of |
36 | * sizeof(unsigned long) on big-endian systems |
37 | */ |
38 | #ifdef __LITTLE_ENDIAN |
39 | #define __change_bit_le(nr, addr) __change_bit(nr, addr) |
40 | #elif defined(__BIG_ENDIAN) |
41 | #define __change_bit_le(nr, addr) \ |
42 | __change_bit((nr) ^ ((BITS_PER_LONG - 1) & ~0x7), addr) |
43 | #else |
44 | #error "Unknown byte order" |
45 | #endif |
46 | |
47 | static void single_bit_error_data(void *error_data, void *correct_data, |
48 | size_t size) |
49 | { |
50 | unsigned int offset = get_random_u32_below(ceil: size * BITS_PER_BYTE); |
51 | |
52 | memcpy(error_data, correct_data, size); |
53 | __change_bit_le(offset, error_data); |
54 | } |
55 | |
56 | static void double_bit_error_data(void *error_data, void *correct_data, |
57 | size_t size) |
58 | { |
59 | unsigned int offset[2]; |
60 | |
61 | offset[0] = get_random_u32_below(ceil: size * BITS_PER_BYTE); |
62 | do { |
63 | offset[1] = get_random_u32_below(ceil: size * BITS_PER_BYTE); |
64 | } while (offset[0] == offset[1]); |
65 | |
66 | memcpy(error_data, correct_data, size); |
67 | |
68 | __change_bit_le(offset[0], error_data); |
69 | __change_bit_le(offset[1], error_data); |
70 | } |
71 | |
72 | static unsigned int random_ecc_bit(size_t size) |
73 | { |
74 | unsigned int offset = get_random_u32_below(ceil: 3 * BITS_PER_BYTE); |
75 | |
76 | if (size == 256) { |
77 | /* |
78 | * Don't inject a bit error into the insignificant bits (16th |
79 | * and 17th bit) in ECC code for 256 byte data block |
80 | */ |
81 | while (offset == 16 || offset == 17) |
82 | offset = get_random_u32_below(ceil: 3 * BITS_PER_BYTE); |
83 | } |
84 | |
85 | return offset; |
86 | } |
87 | |
88 | static void single_bit_error_ecc(void *error_ecc, void *correct_ecc, |
89 | size_t size) |
90 | { |
91 | unsigned int offset = random_ecc_bit(size); |
92 | |
93 | memcpy(error_ecc, correct_ecc, 3); |
94 | __change_bit_le(offset, error_ecc); |
95 | } |
96 | |
97 | static void double_bit_error_ecc(void *error_ecc, void *correct_ecc, |
98 | size_t size) |
99 | { |
100 | unsigned int offset[2]; |
101 | |
102 | offset[0] = random_ecc_bit(size); |
103 | do { |
104 | offset[1] = random_ecc_bit(size); |
105 | } while (offset[0] == offset[1]); |
106 | |
107 | memcpy(error_ecc, correct_ecc, 3); |
108 | __change_bit_le(offset[0], error_ecc); |
109 | __change_bit_le(offset[1], error_ecc); |
110 | } |
111 | |
112 | static void no_bit_error(void *error_data, void *error_ecc, |
113 | void *correct_data, void *correct_ecc, const size_t size) |
114 | { |
115 | memcpy(error_data, correct_data, size); |
116 | memcpy(error_ecc, correct_ecc, 3); |
117 | } |
118 | |
119 | static int no_bit_error_verify(void *error_data, void *error_ecc, |
120 | void *correct_data, const size_t size) |
121 | { |
122 | bool sm_order = IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC); |
123 | unsigned char calc_ecc[3]; |
124 | int ret; |
125 | |
126 | ecc_sw_hamming_calculate(buf: error_data, step_size: size, code: calc_ecc, sm_order); |
127 | ret = ecc_sw_hamming_correct(buf: error_data, read_ecc: error_ecc, calc_ecc, step_size: size, |
128 | sm_order); |
129 | if (ret == 0 && !memcmp(p: correct_data, q: error_data, size)) |
130 | return 0; |
131 | |
132 | return -EINVAL; |
133 | } |
134 | |
135 | static void single_bit_error_in_data(void *error_data, void *error_ecc, |
136 | void *correct_data, void *correct_ecc, const size_t size) |
137 | { |
138 | single_bit_error_data(error_data, correct_data, size); |
139 | memcpy(error_ecc, correct_ecc, 3); |
140 | } |
141 | |
142 | static void single_bit_error_in_ecc(void *error_data, void *error_ecc, |
143 | void *correct_data, void *correct_ecc, const size_t size) |
144 | { |
145 | memcpy(error_data, correct_data, size); |
146 | single_bit_error_ecc(error_ecc, correct_ecc, size); |
147 | } |
148 | |
149 | static int single_bit_error_correct(void *error_data, void *error_ecc, |
150 | void *correct_data, const size_t size) |
151 | { |
152 | bool sm_order = IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC); |
153 | unsigned char calc_ecc[3]; |
154 | int ret; |
155 | |
156 | ecc_sw_hamming_calculate(buf: error_data, step_size: size, code: calc_ecc, sm_order); |
157 | ret = ecc_sw_hamming_correct(buf: error_data, read_ecc: error_ecc, calc_ecc, step_size: size, |
158 | sm_order); |
159 | if (ret == 1 && !memcmp(p: correct_data, q: error_data, size)) |
160 | return 0; |
161 | |
162 | return -EINVAL; |
163 | } |
164 | |
165 | static void double_bit_error_in_data(void *error_data, void *error_ecc, |
166 | void *correct_data, void *correct_ecc, const size_t size) |
167 | { |
168 | double_bit_error_data(error_data, correct_data, size); |
169 | memcpy(error_ecc, correct_ecc, 3); |
170 | } |
171 | |
172 | static void single_bit_error_in_data_and_ecc(void *error_data, void *error_ecc, |
173 | void *correct_data, void *correct_ecc, const size_t size) |
174 | { |
175 | single_bit_error_data(error_data, correct_data, size); |
176 | single_bit_error_ecc(error_ecc, correct_ecc, size); |
177 | } |
178 | |
179 | static void double_bit_error_in_ecc(void *error_data, void *error_ecc, |
180 | void *correct_data, void *correct_ecc, const size_t size) |
181 | { |
182 | memcpy(error_data, correct_data, size); |
183 | double_bit_error_ecc(error_ecc, correct_ecc, size); |
184 | } |
185 | |
186 | static int double_bit_error_detect(void *error_data, void *error_ecc, |
187 | void *correct_data, const size_t size) |
188 | { |
189 | bool sm_order = IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC); |
190 | unsigned char calc_ecc[3]; |
191 | int ret; |
192 | |
193 | ecc_sw_hamming_calculate(buf: error_data, step_size: size, code: calc_ecc, sm_order); |
194 | ret = ecc_sw_hamming_correct(buf: error_data, read_ecc: error_ecc, calc_ecc, step_size: size, |
195 | sm_order); |
196 | |
197 | return (ret == -EBADMSG) ? 0 : -EINVAL; |
198 | } |
199 | |
200 | static const struct nand_ecc_test nand_ecc_test[] = { |
201 | { |
202 | .name = "no-bit-error" , |
203 | .prepare = no_bit_error, |
204 | .verify = no_bit_error_verify, |
205 | }, |
206 | { |
207 | .name = "single-bit-error-in-data-correct" , |
208 | .prepare = single_bit_error_in_data, |
209 | .verify = single_bit_error_correct, |
210 | }, |
211 | { |
212 | .name = "single-bit-error-in-ecc-correct" , |
213 | .prepare = single_bit_error_in_ecc, |
214 | .verify = single_bit_error_correct, |
215 | }, |
216 | { |
217 | .name = "double-bit-error-in-data-detect" , |
218 | .prepare = double_bit_error_in_data, |
219 | .verify = double_bit_error_detect, |
220 | }, |
221 | { |
222 | .name = "single-bit-error-in-data-and-ecc-detect" , |
223 | .prepare = single_bit_error_in_data_and_ecc, |
224 | .verify = double_bit_error_detect, |
225 | }, |
226 | { |
227 | .name = "double-bit-error-in-ecc-detect" , |
228 | .prepare = double_bit_error_in_ecc, |
229 | .verify = double_bit_error_detect, |
230 | }, |
231 | }; |
232 | |
233 | static void dump_data_ecc(void *error_data, void *error_ecc, void *correct_data, |
234 | void *correct_ecc, const size_t size) |
235 | { |
236 | pr_info("hexdump of error data:\n" ); |
237 | print_hex_dump(KERN_INFO, prefix_str: "" , prefix_type: DUMP_PREFIX_OFFSET, rowsize: 16, groupsize: 4, |
238 | buf: error_data, len: size, ascii: false); |
239 | print_hex_dump(KERN_INFO, prefix_str: "hexdump of error ecc: " , |
240 | prefix_type: DUMP_PREFIX_NONE, rowsize: 16, groupsize: 1, buf: error_ecc, len: 3, ascii: false); |
241 | |
242 | pr_info("hexdump of correct data:\n" ); |
243 | print_hex_dump(KERN_INFO, prefix_str: "" , prefix_type: DUMP_PREFIX_OFFSET, rowsize: 16, groupsize: 4, |
244 | buf: correct_data, len: size, ascii: false); |
245 | print_hex_dump(KERN_INFO, prefix_str: "hexdump of correct ecc: " , |
246 | prefix_type: DUMP_PREFIX_NONE, rowsize: 16, groupsize: 1, buf: correct_ecc, len: 3, ascii: false); |
247 | } |
248 | |
249 | static int nand_ecc_test_run(const size_t size) |
250 | { |
251 | bool sm_order = IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC); |
252 | int i; |
253 | int err = 0; |
254 | void *error_data; |
255 | void *error_ecc; |
256 | void *correct_data; |
257 | void *correct_ecc; |
258 | |
259 | error_data = kmalloc(size, GFP_KERNEL); |
260 | error_ecc = kmalloc(size: 3, GFP_KERNEL); |
261 | correct_data = kmalloc(size, GFP_KERNEL); |
262 | correct_ecc = kmalloc(size: 3, GFP_KERNEL); |
263 | |
264 | if (!error_data || !error_ecc || !correct_data || !correct_ecc) { |
265 | err = -ENOMEM; |
266 | goto error; |
267 | } |
268 | |
269 | get_random_bytes(buf: correct_data, len: size); |
270 | ecc_sw_hamming_calculate(buf: correct_data, step_size: size, code: correct_ecc, sm_order); |
271 | for (i = 0; i < ARRAY_SIZE(nand_ecc_test); i++) { |
272 | nand_ecc_test[i].prepare(error_data, error_ecc, |
273 | correct_data, correct_ecc, size); |
274 | err = nand_ecc_test[i].verify(error_data, error_ecc, |
275 | correct_data, size); |
276 | |
277 | if (err) { |
278 | pr_err("not ok - %s-%zd\n" , |
279 | nand_ecc_test[i].name, size); |
280 | dump_data_ecc(error_data, error_ecc, |
281 | correct_data, correct_ecc, size); |
282 | break; |
283 | } |
284 | pr_info("ok - %s-%zd\n" , |
285 | nand_ecc_test[i].name, size); |
286 | |
287 | err = mtdtest_relax(); |
288 | if (err) |
289 | break; |
290 | } |
291 | error: |
292 | kfree(objp: error_data); |
293 | kfree(objp: error_ecc); |
294 | kfree(objp: correct_data); |
295 | kfree(objp: correct_ecc); |
296 | |
297 | return err; |
298 | } |
299 | |
300 | #else |
301 | |
302 | static int nand_ecc_test_run(const size_t size) |
303 | { |
304 | return 0; |
305 | } |
306 | |
307 | #endif |
308 | |
309 | static int __init ecc_test_init(void) |
310 | { |
311 | int err; |
312 | |
313 | err = nand_ecc_test_run(size: 256); |
314 | if (err) |
315 | return err; |
316 | |
317 | return nand_ecc_test_run(size: 512); |
318 | } |
319 | |
320 | static void __exit ecc_test_exit(void) |
321 | { |
322 | } |
323 | |
324 | module_init(ecc_test_init); |
325 | module_exit(ecc_test_exit); |
326 | |
327 | MODULE_DESCRIPTION("NAND ECC function test module" ); |
328 | MODULE_AUTHOR("Akinobu Mita" ); |
329 | MODULE_LICENSE("GPL" ); |
330 | |