drivers/mtd/tests/mtd_nandecctest.c

   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
  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
  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
  60 static int nand_ecc_test(const size_t size)
  61 {
  62         return 0;
  63 }
  64
  65 #endif
  66
  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
  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");