diff options
Diffstat (limited to 'drivers/mtd/tests/mtd_nandecctest.c')
| -rw-r--r-- | drivers/mtd/tests/mtd_nandecctest.c | 294 |
1 files changed, 261 insertions, 33 deletions
diff --git a/drivers/mtd/tests/mtd_nandecctest.c b/drivers/mtd/tests/mtd_nandecctest.c index 70d6d7d0d65..b437fa42507 100644 --- a/drivers/mtd/tests/mtd_nandecctest.c +++ b/drivers/mtd/tests/mtd_nandecctest.c @@ -4,60 +4,287 @@ #include <linux/random.h> #include <linux/string.h> #include <linux/bitops.h> -#include <linux/jiffies.h> +#include <linux/slab.h> #include <linux/mtd/nand_ecc.h> +/* + * 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) -static void inject_single_bit_error(void *data, size_t size) +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 + * sizeof(unsigned long) on big-endian systems + */ +#ifdef __LITTLE_ENDIAN +#define __change_bit_le(nr, addr) __change_bit(nr, addr) +#elif defined(__BIG_ENDIAN) +#define __change_bit_le(nr, addr) \ + __change_bit((nr) ^ ((BITS_PER_LONG - 1) & ~0x7), addr) +#else +#error "Unknown byte order" +#endif + +static void single_bit_error_data(void *error_data, void *correct_data, + size_t size) { - unsigned long offset = random32() % (size * BITS_PER_BYTE); + unsigned int offset = random32() % (size * BITS_PER_BYTE); - __change_bit(offset, data); + memcpy(error_data, correct_data, size); + __change_bit_le(offset, error_data); } -static unsigned char data[512]; -static unsigned char error_data[512]; +static void double_bit_error_data(void *error_data, void *correct_data, + size_t size) +{ + unsigned int offset[2]; + + offset[0] = random32() % (size * BITS_PER_BYTE); + do { + offset[1] = random32() % (size * BITS_PER_BYTE); + } while (offset[0] == offset[1]); -static int nand_ecc_test(const size_t size) + memcpy(error_data, correct_data, size); + + __change_bit_le(offset[0], error_data); + __change_bit_le(offset[1], error_data); +} + +static unsigned int random_ecc_bit(size_t size) { - unsigned char code[3]; - unsigned char error_code[3]; - char testname[30]; + unsigned int offset = random32() % (3 * BITS_PER_BYTE); + + if (size == 256) { + /* + * Don't inject a bit error into the insignificant bits (16th + * and 17th bit) in ECC code for 256 byte data block + */ + while (offset == 16 || offset == 17) + offset = random32() % (3 * BITS_PER_BYTE); + } - BUG_ON(sizeof(data) < size); + return offset; +} - sprintf(testname, "nand-ecc-%zu", size); +static void single_bit_error_ecc(void *error_ecc, void *correct_ecc, + size_t size) +{ + unsigned int offset = random_ecc_bit(size); - get_random_bytes(data, size); + memcpy(error_ecc, correct_ecc, 3); + __change_bit_le(offset, error_ecc); +} - memcpy(error_data, data, size); - inject_single_bit_error(error_data, size); +static void double_bit_error_ecc(void *error_ecc, void *correct_ecc, + size_t size) +{ + unsigned int offset[2]; - __nand_calculate_ecc(data, size, code); - __nand_calculate_ecc(error_data, size, error_code); - __nand_correct_data(error_data, code, error_code, size); + offset[0] = random_ecc_bit(size); + do { + offset[1] = random_ecc_bit(size); + } while (offset[0] == offset[1]); - if (!memcmp(data, error_data, size)) { - printk(KERN_INFO "mtd_nandecctest: ok - %s\n", testname); + memcpy(error_ecc, correct_ecc, 3); + __change_bit_le(offset[0], error_ecc); + __change_bit_le(offset[1], error_ecc); +} + +static void no_bit_error(void *error_data, void *error_ecc, + void *correct_data, void *correct_ecc, const size_t size) +{ + memcpy(error_data, correct_data, size); + memcpy(error_ecc, correct_ecc, 3); +} + +static int no_bit_error_verify(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 == 0 && !memcmp(correct_data, error_data, size)) return 0; - } - printk(KERN_ERR "mtd_nandecctest: not ok - %s\n", testname); + return -EINVAL; +} + +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 void single_bit_error_in_ecc(void *error_data, void *error_ecc, + void *correct_data, void *correct_ecc, const size_t size) +{ + memcpy(error_data, correct_data, size); + single_bit_error_ecc(error_ecc, correct_ecc, size); +} + +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; - printk(KERN_DEBUG "hexdump of data:\n"); - print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 16, 4, - data, size, false); - printk(KERN_DEBUG "hexdump of error data:\n"); - print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 16, 4, + __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 void double_bit_error_in_data(void *error_data, void *error_ecc, + void *correct_data, void *correct_ecc, const size_t size) +{ + double_bit_error_data(error_data, correct_data, size); + memcpy(error_ecc, correct_ecc, 3); +} + +static void single_bit_error_in_data_and_ecc(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); + single_bit_error_ecc(error_ecc, correct_ecc, size); +} + +static void double_bit_error_in_ecc(void *error_data, void *error_ecc, + void *correct_data, void *correct_ecc, const size_t size) +{ + memcpy(error_data, correct_data, size); + double_bit_error_ecc(error_ecc, correct_ecc, size); +} + +static int double_bit_error_detect(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); + + return (ret == -1) ? 0 : -EINVAL; +} + +static const struct nand_ecc_test nand_ecc_test[] = { + { + .name = "no-bit-error", + .prepare = no_bit_error, + .verify = no_bit_error_verify, + }, + { + .name = "single-bit-error-in-data-correct", + .prepare = single_bit_error_in_data, + .verify = single_bit_error_correct, + }, + { + .name = "single-bit-error-in-ecc-correct", + .prepare = single_bit_error_in_ecc, + .verify = single_bit_error_correct, + }, + { + .name = "double-bit-error-in-data-detect", + .prepare = double_bit_error_in_data, + .verify = double_bit_error_detect, + }, + { + .name = "single-bit-error-in-data-and-ecc-detect", + .prepare = single_bit_error_in_data_and_ecc, + .verify = double_bit_error_detect, + }, + { + .name = "double-bit-error-in-ecc-detect", + .prepare = double_bit_error_in_ecc, + .verify = double_bit_error_detect, + }, +}; + +static void dump_data_ecc(void *error_data, void *error_ecc, void *correct_data, + void *correct_ecc, const size_t size) +{ + pr_info("hexdump of error data:\n"); + print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 4, error_data, size, false); + print_hex_dump(KERN_INFO, "hexdump of error ecc: ", + DUMP_PREFIX_NONE, 16, 1, error_ecc, 3, false); + + pr_info("hexdump of correct data:\n"); + print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 4, + correct_data, size, false); + print_hex_dump(KERN_INFO, "hexdump of correct ecc: ", + DUMP_PREFIX_NONE, 16, 1, correct_ecc, 3, false); +} + +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; - return -1; + error_data = kmalloc(size, GFP_KERNEL); + error_ecc = kmalloc(3, GFP_KERNEL); + correct_data = kmalloc(size, GFP_KERNEL); + correct_ecc = kmalloc(3, GFP_KERNEL); + + if (!error_data || !error_ecc || !correct_data || !correct_ecc) { + err = -ENOMEM; + goto error; + } + + get_random_bytes(correct_data, size); + __nand_calculate_ecc(correct_data, size, correct_ecc); + + 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); + } +error: + kfree(error_data); + kfree(error_ecc); + kfree(correct_data); + kfree(correct_ecc); + + return err; } #else -static int nand_ecc_test(const size_t size) +static int nand_ecc_test_run(const size_t size) { return 0; } @@ -66,12 +293,13 @@ static int nand_ecc_test(const size_t size) static int __init ecc_test_init(void) { - srandom32(jiffies); + int err; - nand_ecc_test(256); - nand_ecc_test(512); + err = nand_ecc_test_run(256); + if (err) + return err; - return 0; + return nand_ecc_test_run(512); } static void __exit ecc_test_exit(void) |