X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Fmtd%2Ftests%2Fmtd_nandecctest.c;fp=kernel%2Fdrivers%2Fmtd%2Ftests%2Fmtd_nandecctest.c;h=79316159eec63cbca36aa06d27bfaab561b62dc0;hb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;hp=0000000000000000000000000000000000000000;hpb=98260f3884f4a202f9ca5eabed40b1354c489b29;p=kvmfornfv.git diff --git a/kernel/drivers/mtd/tests/mtd_nandecctest.c b/kernel/drivers/mtd/tests/mtd_nandecctest.c new file mode 100644 index 000000000..79316159e --- /dev/null +++ b/kernel/drivers/mtd/tests/mtd_nandecctest.c @@ -0,0 +1,322 @@ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "mtd_test.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 IS_ENABLED(CONFIG_MTD_NAND) + +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 int offset = prandom_u32() % (size * BITS_PER_BYTE); + + memcpy(error_data, correct_data, size); + __change_bit_le(offset, error_data); +} + +static void double_bit_error_data(void *error_data, void *correct_data, + size_t size) +{ + unsigned int offset[2]; + + offset[0] = prandom_u32() % (size * BITS_PER_BYTE); + do { + offset[1] = prandom_u32() % (size * BITS_PER_BYTE); + } while (offset[0] == offset[1]); + + 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 int offset = prandom_u32() % (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 = prandom_u32() % (3 * BITS_PER_BYTE); + } + + return offset; +} + +static void single_bit_error_ecc(void *error_ecc, void *correct_ecc, + size_t size) +{ + unsigned int offset = random_ecc_bit(size); + + memcpy(error_ecc, correct_ecc, 3); + __change_bit_le(offset, error_ecc); +} + +static void double_bit_error_ecc(void *error_ecc, void *correct_ecc, + size_t size) +{ + unsigned int offset[2]; + + offset[0] = random_ecc_bit(size); + do { + offset[1] = random_ecc_bit(size); + } while (offset[0] == offset[1]); + + 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; + + 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; + + __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; + + 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; + } + + prandom_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("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("ok - %s-%zd\n", + nand_ecc_test[i].name, size); + + err = mtdtest_relax(); + if (err) + break; + } +error: + kfree(error_data); + kfree(error_ecc); + kfree(correct_data); + kfree(correct_ecc); + + return err; +} + +#else + +static int nand_ecc_test_run(const size_t size) +{ + return 0; +} + +#endif + +static int __init ecc_test_init(void) +{ + int err; + + err = nand_ecc_test_run(256); + if (err) + return err; + + return nand_ecc_test_run(512); +} + +static void __exit ecc_test_exit(void) +{ +} + +module_init(ecc_test_init); +module_exit(ecc_test_exit); + +MODULE_DESCRIPTION("NAND ECC function test module"); +MODULE_AUTHOR("Akinobu Mita"); +MODULE_LICENSE("GPL");