diff --git a/drivers/mtd/tests/mtd_nandecctest.c b/drivers/mtd/tests/mtd_nandecctest.c index d90daf879c46..204f796ed3e7 100644 --- a/drivers/mtd/tests/mtd_nandecctest.c +++ b/drivers/mtd/tests/mtd_nandecctest.c @@ -7,8 +7,24 @@ #include #include +/* + * Test the implementation for software ECC + * + * No actual MTD device is needed, So we don't need to warry about losing + * important data by human error. + * + * This covers possible patterns of corruption which can be reliably corrected + * or detected. + */ + #if defined(CONFIG_MTD_NAND) || defined(CONFIG_MTD_NAND_MODULE) +struct nand_ecc_test { + const char *name; + void (*prepare)(void *, void *, void *, void *, const size_t); + int (*verify)(void *, void *, void *, const size_t); +}; + /* * The reason for this __change_bit_le() instead of __change_bit() is to inject * bit error properly within the region which is not a multiple of @@ -23,13 +39,44 @@ #error "Unknown byte order" #endif -static void inject_single_bit_error(void *data, size_t size) +static void single_bit_error_data(void *error_data, void *correct_data, + size_t size) { unsigned int offset = random32() % (size * BITS_PER_BYTE); - __change_bit_le(offset, data); + memcpy(error_data, correct_data, size); + __change_bit_le(offset, error_data); } +static void single_bit_error_in_data(void *error_data, void *error_ecc, + void *correct_data, void *correct_ecc, const size_t size) +{ + single_bit_error_data(error_data, correct_data, size); + memcpy(error_ecc, correct_ecc, 3); +} + +static int single_bit_error_correct(void *error_data, void *error_ecc, + void *correct_data, const size_t size) +{ + unsigned char calc_ecc[3]; + int ret; + + __nand_calculate_ecc(error_data, size, calc_ecc); + ret = __nand_correct_data(error_data, error_ecc, calc_ecc, size); + if (ret == 1 && !memcmp(correct_data, error_data, size)) + return 0; + + return -EINVAL; +} + +static const struct nand_ecc_test nand_ecc_test[] = { + { + .name = "single-bit-error-in-data-correct", + .prepare = single_bit_error_in_data, + .verify = single_bit_error_correct, + }, +}; + static void dump_data_ecc(void *error_data, void *error_ecc, void *correct_data, void *correct_ecc, const size_t size) { @@ -46,14 +93,14 @@ static void dump_data_ecc(void *error_data, void *error_ecc, void *correct_data, DUMP_PREFIX_NONE, 16, 1, correct_ecc, 3, false); } -static int nand_ecc_test(const size_t size) +static int nand_ecc_test_run(const size_t size) { + int i; int err = 0; void *error_data; void *error_ecc; void *correct_data; void *correct_ecc; - char testname[30]; error_data = kmalloc(size, GFP_KERNEL); error_ecc = kmalloc(3, GFP_KERNEL); @@ -65,25 +112,25 @@ static int nand_ecc_test(const size_t size) goto error; } - sprintf(testname, "nand-ecc-%zu", size); - get_random_bytes(correct_data, size); - - memcpy(error_data, correct_data, size); - inject_single_bit_error(error_data, size); - __nand_calculate_ecc(correct_data, size, correct_ecc); - __nand_calculate_ecc(error_data, size, error_ecc); - __nand_correct_data(error_data, correct_ecc, error_ecc, size); - if (memcmp(correct_data, error_data, size)) { - pr_err("mtd_nandecctest: not ok - %s\n", testname); - dump_data_ecc(error_data, error_ecc, correct_data, correct_ecc, - size); - err = -EINVAL; - goto error; + for (i = 0; i < ARRAY_SIZE(nand_ecc_test); i++) { + nand_ecc_test[i].prepare(error_data, error_ecc, + correct_data, correct_ecc, size); + err = nand_ecc_test[i].verify(error_data, error_ecc, + correct_data, size); + + if (err) { + pr_err("mtd_nandecctest: not ok - %s-%zd\n", + nand_ecc_test[i].name, size); + dump_data_ecc(error_data, error_ecc, + correct_data, correct_ecc, size); + break; + } + pr_info("mtd_nandecctest: ok - %s-%zd\n", + nand_ecc_test[i].name, size); } - pr_info("mtd_nandecctest: ok - %s\n", testname); error: kfree(error_data); kfree(error_ecc); @@ -95,7 +142,7 @@ error: #else -static int nand_ecc_test(const size_t size) +static int nand_ecc_test_run(const size_t size) { return 0; } @@ -106,11 +153,11 @@ static int __init ecc_test_init(void) { int err; - err = nand_ecc_test(256); + err = nand_ecc_test_run(256); if (err) return err; - return nand_ecc_test(512); + return nand_ecc_test_run(512); } static void __exit ecc_test_exit(void)