1 #include <linux/kernel.h>
2 #include <linux/module.h>
3 #include <linux/list.h>
4 #include <linux/random.h>
5 #include <linux/string.h>
6 #include <linux/bitops.h>
7 #include <linux/jiffies.h>
8 #include <linux/mtd/nand_ecc.h>
9
10 #if defined(CONFIG_MTD_NAND) || defined(CONFIG_MTD_NAND_MODULE)
11
inject_single_bit_error(void * data,size_t size)12 static void inject_single_bit_error(void *data, size_t size)
13 {
14 unsigned long offset = random32() % (size * BITS_PER_BYTE);
15
16 __change_bit(offset, data);
17 }
18
19 static unsigned char data[512];
20 static unsigned char error_data[512];
21
nand_ecc_test(const size_t size)22 static int nand_ecc_test(const size_t size)
23 {
24 unsigned char code[3];
25 unsigned char error_code[3];
26 char testname[30];
27
28 BUG_ON(sizeof(data) < size);
29
30 sprintf(testname, "nand-ecc-%zu", size);
31
32 get_random_bytes(data, size);
33
34 memcpy(error_data, data, size);
35 inject_single_bit_error(error_data, size);
36
37 __nand_calculate_ecc(data, size, code);
38 __nand_calculate_ecc(error_data, size, error_code);
39 __nand_correct_data(error_data, code, error_code, size);
40
41 if (!memcmp(data, error_data, size)) {
42 printk(KERN_INFO "mtd_nandecctest: ok - %s\n", testname);
43 return 0;
44 }
45
46 printk(KERN_ERR "mtd_nandecctest: not ok - %s\n", testname);
47
48 printk(KERN_DEBUG "hexdump of data:\n");
49 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 16, 4,
50 data, size, false);
51 printk(KERN_DEBUG "hexdump of error data:\n");
52 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 16, 4,
53 error_data, size, false);
54
55 return -1;
56 }
57
58 #else
59
nand_ecc_test(const size_t size)60 static int nand_ecc_test(const size_t size)
61 {
62 return 0;
63 }
64
65 #endif
66
ecc_test_init(void)67 static int __init ecc_test_init(void)
68 {
69 srandom32(jiffies);
70
71 nand_ecc_test(256);
72 nand_ecc_test(512);
73
74 return 0;
75 }
76
ecc_test_exit(void)77 static void __exit ecc_test_exit(void)
78 {
79 }
80
81 module_init(ecc_test_init);
82 module_exit(ecc_test_exit);
83
84 MODULE_DESCRIPTION("NAND ECC function test module");
85 MODULE_AUTHOR("Akinobu Mita");
86 MODULE_LICENSE("GPL");
87