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/slab.h> 8 #include <linux/mtd/nand_ecc.h> 9 10 #if defined(CONFIG_MTD_NAND) || defined(CONFIG_MTD_NAND_MODULE) 11 12 /* 13 * The reason for this __change_bit_le() instead of __change_bit() is to inject 14 * bit error properly within the region which is not a multiple of 15 * sizeof(unsigned long) on big-endian systems 16 */ 17 #ifdef __LITTLE_ENDIAN 18 #define __change_bit_le(nr, addr) __change_bit(nr, addr) 19 #elif defined(__BIG_ENDIAN) 20 #define __change_bit_le(nr, addr) \ 21 __change_bit((nr) ^ ((BITS_PER_LONG - 1) & ~0x7), addr) 22 #else 23 #error "Unknown byte order" 24 #endif 25 26 static void inject_single_bit_error(void *data, size_t size) 27 { 28 unsigned int offset = random32() % (size * BITS_PER_BYTE); 29 30 __change_bit_le(offset, data); 31 } 32 33 static void dump_data_ecc(void *error_data, void *error_ecc, void *correct_data, 34 void *correct_ecc, const size_t size) 35 { 36 pr_info("hexdump of error data:\n"); 37 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 4, 38 error_data, size, false); 39 print_hex_dump(KERN_INFO, "hexdump of error ecc: ", 40 DUMP_PREFIX_NONE, 16, 1, error_ecc, 3, false); 41 42 pr_info("hexdump of correct data:\n"); 43 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 4, 44 correct_data, size, false); 45 print_hex_dump(KERN_INFO, "hexdump of correct ecc: ", 46 DUMP_PREFIX_NONE, 16, 1, correct_ecc, 3, false); 47 } 48 49 static int nand_ecc_test(const size_t size) 50 { 51 int err = 0; 52 void *error_data; 53 void *error_ecc; 54 void *correct_data; 55 void *correct_ecc; 56 char testname[30]; 57 58 error_data = kmalloc(size, GFP_KERNEL); 59 error_ecc = kmalloc(3, GFP_KERNEL); 60 correct_data = kmalloc(size, GFP_KERNEL); 61 correct_ecc = kmalloc(3, GFP_KERNEL); 62 63 if (!error_data || !error_ecc || !correct_data || !correct_ecc) { 64 err = -ENOMEM; 65 goto error; 66 } 67 68 sprintf(testname, "nand-ecc-%zu", size); 69 70 get_random_bytes(correct_data, size); 71 72 memcpy(error_data, correct_data, size); 73 inject_single_bit_error(error_data, size); 74 75 __nand_calculate_ecc(correct_data, size, correct_ecc); 76 __nand_calculate_ecc(error_data, size, error_ecc); 77 __nand_correct_data(error_data, correct_ecc, error_ecc, size); 78 79 if (memcmp(correct_data, error_data, size)) { 80 pr_err("mtd_nandecctest: not ok - %s\n", testname); 81 dump_data_ecc(error_data, error_ecc, correct_data, correct_ecc, 82 size); 83 err = -EINVAL; 84 goto error; 85 } 86 pr_info("mtd_nandecctest: ok - %s\n", testname); 87 error: 88 kfree(error_data); 89 kfree(error_ecc); 90 kfree(correct_data); 91 kfree(correct_ecc); 92 93 return err; 94 } 95 96 #else 97 98 static int nand_ecc_test(const size_t size) 99 { 100 return 0; 101 } 102 103 #endif 104 105 static int __init ecc_test_init(void) 106 { 107 int err; 108 109 err = nand_ecc_test(256); 110 if (err) 111 return err; 112 113 return nand_ecc_test(512); 114 } 115 116 static void __exit ecc_test_exit(void) 117 { 118 } 119 120 module_init(ecc_test_init); 121 module_exit(ecc_test_exit); 122 123 MODULE_DESCRIPTION("NAND ECC function test module"); 124 MODULE_AUTHOR("Akinobu Mita"); 125 MODULE_LICENSE("GPL"); 126