1 #include <linux/kernel.h> 2 #include <linux/module.h> 3 #include <linux/list.h> 4 #include <linux/slab.h> 5 #include <linux/random.h> 6 #include <linux/string.h> 7 #include <linux/bitops.h> 8 #include <linux/jiffies.h> 9 #include <linux/mtd/nand_ecc.h> 10 11 #if defined(CONFIG_MTD_NAND) || defined(CONFIG_MTD_NAND_MODULE) 12 13 static void inject_single_bit_error(void *data, size_t size) 14 { 15 unsigned long offset = random32() % (size * BITS_PER_BYTE); 16 17 __change_bit(offset, data); 18 } 19 20 static unsigned char data[512]; 21 static unsigned char error_data[512]; 22 23 static int nand_ecc_test(const size_t size) 24 { 25 unsigned char code[3]; 26 unsigned char error_code[3]; 27 char testname[30]; 28 29 BUG_ON(sizeof(data) < size); 30 31 sprintf(testname, "nand-ecc-%zu", size); 32 33 get_random_bytes(data, size); 34 35 memcpy(error_data, data, size); 36 inject_single_bit_error(error_data, size); 37 38 __nand_calculate_ecc(data, size, code); 39 __nand_calculate_ecc(error_data, size, error_code); 40 __nand_correct_data(error_data, code, error_code, size); 41 42 if (!memcmp(data, error_data, size)) { 43 printk(KERN_INFO "mtd_nandecctest: ok - %s\n", testname); 44 return 0; 45 } 46 47 printk(KERN_ERR "mtd_nandecctest: not ok - %s\n", testname); 48 49 printk(KERN_DEBUG "hexdump of data:\n"); 50 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 16, 4, 51 data, size, false); 52 printk(KERN_DEBUG "hexdump of error data:\n"); 53 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 16, 4, 54 error_data, size, false); 55 56 return -1; 57 } 58 59 #else 60 61 static int nand_ecc_test(const size_t size) 62 { 63 return 0; 64 } 65 66 #endif 67 68 static int __init ecc_test_init(void) 69 { 70 srandom32(jiffies); 71 72 nand_ecc_test(256); 73 nand_ecc_test(512); 74 75 return 0; 76 } 77 78 static void __exit ecc_test_exit(void) 79 { 80 } 81 82 module_init(ecc_test_init); 83 module_exit(ecc_test_exit); 84 85 MODULE_DESCRIPTION("NAND ECC function test module"); 86 MODULE_AUTHOR("Akinobu Mita"); 87 MODULE_LICENSE("GPL"); 88