drivers/mtd/tests/mtd_nandecctest.c

   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");