1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/random.h>
#include <linux/string.h>
#include <linux/bitops.h>
#include <linux/slab.h>
#include <linux/mtd/nand_ecc.h>
/*
* Test the implementation for software ECC
*
* No actual MTD device is needed, So we don't need to warry about losing
* important data by human error.
*
* This covers possible patterns of corruption which can be reliably corrected
* or detected.
*/
#if defined(CONFIG_MTD_NAND) || defined(CONFIG_MTD_NAND_MODULE)
struct nand_ecc_test {
const char *name;
void (*prepare)(void *, void *, void *, void *, const size_t);
int (*verify)(void *, void *, void *, const size_t);
};
/*
* The reason for this __change_bit_le() instead of __change_bit() is to inject
* bit error properly within the region which is not a multiple of
* sizeof(unsigned long) on big-endian systems
*/
#ifdef __LITTLE_ENDIAN
#define __change_bit_le(nr, addr) __change_bit(nr, addr)
#elif defined(__BIG_ENDIAN)
#define __change_bit_le(nr, addr) \
__change_bit((nr) ^ ((BITS_PER_LONG - 1) & ~0x7), addr)
#else
#error "Unknown byte order"
#endif
static void single_bit_error_data(void *error_data, void *correct_data,
size_t size)
{
unsigned int offset = random32() % (size * BITS_PER_BYTE);
memcpy(error_data, correct_data, size);
__change_bit_le(offset, error_data);
}
static void single_bit_error_in_data(void *error_data, void *error_ecc,
void *correct_data, void *correct_ecc, const size_t size)
{
single_bit_error_data(error_data, correct_data, size);
memcpy(error_ecc, correct_ecc, 3);
}
static int single_bit_error_correct(void *error_data, void *error_ecc,
void *correct_data, const size_t size)
{
unsigned char calc_ecc[3];
int ret;
__nand_calculate_ecc(error_data, size, calc_ecc);
ret = __nand_correct_data(error_data, error_ecc, calc_ecc, size);
if (ret == 1 && !memcmp(correct_data, error_data, size))
return 0;
return -EINVAL;
}
static const struct nand_ecc_test nand_ecc_test[] = {
{
.name = "single-bit-error-in-data-correct",
.prepare = single_bit_error_in_data,
.verify = single_bit_error_correct,
},
};
static void dump_data_ecc(void *error_data, void *error_ecc, void *correct_data,
void *correct_ecc, const size_t size)
{
pr_info("hexdump of error data:\n");
print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 4,
error_data, size, false);
print_hex_dump(KERN_INFO, "hexdump of error ecc: ",
DUMP_PREFIX_NONE, 16, 1, error_ecc, 3, false);
pr_info("hexdump of correct data:\n");
print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 4,
correct_data, size, false);
print_hex_dump(KERN_INFO, "hexdump of correct ecc: ",
DUMP_PREFIX_NONE, 16, 1, correct_ecc, 3, false);
}
static int nand_ecc_test_run(const size_t size)
{
int i;
int err = 0;
void *error_data;
void *error_ecc;
void *correct_data;
void *correct_ecc;
error_data = kmalloc(size, GFP_KERNEL);
error_ecc = kmalloc(3, GFP_KERNEL);
correct_data = kmalloc(size, GFP_KERNEL);
correct_ecc = kmalloc(3, GFP_KERNEL);
if (!error_data || !error_ecc || !correct_data || !correct_ecc) {
err = -ENOMEM;
goto error;
}
get_random_bytes(correct_data, size);
__nand_calculate_ecc(correct_data, size, correct_ecc);
for (i = 0; i < ARRAY_SIZE(nand_ecc_test); i++) {
nand_ecc_test[i].prepare(error_data, error_ecc,
correct_data, correct_ecc, size);
err = nand_ecc_test[i].verify(error_data, error_ecc,
correct_data, size);
if (err) {
pr_err("mtd_nandecctest: not ok - %s-%zd\n",
nand_ecc_test[i].name, size);
dump_data_ecc(error_data, error_ecc,
correct_data, correct_ecc, size);
break;
}
pr_info("mtd_nandecctest: ok - %s-%zd\n",
nand_ecc_test[i].name, size);
}
error:
kfree(error_data);
kfree(error_ecc);
kfree(correct_data);
kfree(correct_ecc);
return err;
}
#else
static int nand_ecc_test_run(const size_t size)
{
return 0;
}
#endif
static int __init ecc_test_init(void)
{
int err;
err = nand_ecc_test_run(256);
if (err)
return err;
return nand_ecc_test_run(512);
}
static void __exit ecc_test_exit(void)
{
}
module_init(ecc_test_init);
module_exit(ecc_test_exit);
MODULE_DESCRIPTION("NAND ECC function test module");
MODULE_AUTHOR("Akinobu Mita");
MODULE_LICENSE("GPL");
|
