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 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 void dump_data_ecc(void *error_data, void *error_ecc, void *correct_data, 20 void *correct_ecc, const size_t size) 21 { 22 pr_info("hexdump of error data:\n"); 23 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 4, 24 error_data, size, false); 25 print_hex_dump(KERN_INFO, "hexdump of error ecc: ", 26 DUMP_PREFIX_NONE, 16, 1, error_ecc, 3, false); 27 28 pr_info("hexdump of correct data:\n"); 29 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 4, 30 correct_data, size, false); 31 print_hex_dump(KERN_INFO, "hexdump of correct ecc: ", 32 DUMP_PREFIX_NONE, 16, 1, correct_ecc, 3, false); 33 } 34 35 static int nand_ecc_test(const size_t size) 36 { 37 int err = 0; 38 void *error_data; 39 void *error_ecc; 40 void *correct_data; 41 void *correct_ecc; 42 char testname[30]; 43 44 error_data = kmalloc(size, GFP_KERNEL); 45 error_ecc = kmalloc(3, GFP_KERNEL); 46 correct_data = kmalloc(size, GFP_KERNEL); 47 correct_ecc = kmalloc(3, GFP_KERNEL); 48 49 if (!error_data || !error_ecc || !correct_data || !correct_ecc) { 50 err = -ENOMEM; 51 goto error; 52 } 53 54 sprintf(testname, "nand-ecc-%zu", size); 55 56 get_random_bytes(correct_data, size); 57 58 memcpy(error_data, correct_data, size); 59 inject_single_bit_error(error_data, size); 60 61 __nand_calculate_ecc(correct_data, size, correct_ecc); 62 __nand_calculate_ecc(error_data, size, error_ecc); 63 __nand_correct_data(error_data, correct_ecc, error_ecc, size); 64 65 if (memcmp(correct_data, error_data, size)) { 66 pr_err("mtd_nandecctest: not ok - %s\n", testname); 67 dump_data_ecc(error_data, error_ecc, correct_data, correct_ecc, 68 size); 69 err = -EINVAL; 70 goto error; 71 } 72 pr_info("mtd_nandecctest: ok - %s\n", testname); 73 error: 74 kfree(error_data); 75 kfree(error_ecc); 76 kfree(correct_data); 77 kfree(correct_ecc); 78 79 return err; 80 } 81 82 #else 83 84 static int nand_ecc_test(const size_t size) 85 { 86 return 0; 87 } 88 89 #endif 90 91 static int __init ecc_test_init(void) 92 { 93 int err; 94 95 err = nand_ecc_test(256); 96 if (err) 97 return err; 98 99 return nand_ecc_test(512); 100 } 101 102 static void __exit ecc_test_exit(void) 103 { 104 } 105 106 module_init(ecc_test_init); 107 module_exit(ecc_test_exit); 108 109 MODULE_DESCRIPTION("NAND ECC function test module"); 110 MODULE_AUTHOR("Akinobu Mita"); 111 MODULE_LICENSE("GPL"); 112