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1// SPDX-License-Identifier: GPL-2.0-only2#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt3 4#include <linux/kernel.h>5#include <linux/module.h>6#include <linux/list.h>7#include <linux/random.h>8#include <linux/string.h>9#include <linux/bitops.h>10#include <linux/slab.h>11#include <linux/mtd/nand-ecc-sw-hamming.h>12 13#include "mtd_test.h"14 15/*16 * Test the implementation for software ECC17 *18 * No actual MTD device is needed, So we don't need to warry about losing19 * important data by human error.20 *21 * This covers possible patterns of corruption which can be reliably corrected22 * or detected.23 */24 25#if IS_ENABLED(CONFIG_MTD_RAW_NAND)26 27struct nand_ecc_test {28 const char *name;29 void (*prepare)(void *, void *, void *, void *, const size_t);30 int (*verify)(void *, void *, void *, const size_t);31};32 33/*34 * The reason for this __change_bit_le() instead of __change_bit() is to inject35 * bit error properly within the region which is not a multiple of36 * sizeof(unsigned long) on big-endian systems37 */38#ifdef __LITTLE_ENDIAN39#define __change_bit_le(nr, addr) __change_bit(nr, addr)40#elif defined(__BIG_ENDIAN)41#define __change_bit_le(nr, addr) \42 __change_bit((nr) ^ ((BITS_PER_LONG - 1) & ~0x7), addr)43#else44#error "Unknown byte order"45#endif46 47static void single_bit_error_data(void *error_data, void *correct_data,48 size_t size)49{50 unsigned int offset = get_random_u32_below(size * BITS_PER_BYTE);51 52 memcpy(error_data, correct_data, size);53 __change_bit_le(offset, error_data);54}55 56static void double_bit_error_data(void *error_data, void *correct_data,57 size_t size)58{59 unsigned int offset[2];60 61 offset[0] = get_random_u32_below(size * BITS_PER_BYTE);62 do {63 offset[1] = get_random_u32_below(size * BITS_PER_BYTE);64 } while (offset[0] == offset[1]);65 66 memcpy(error_data, correct_data, size);67 68 __change_bit_le(offset[0], error_data);69 __change_bit_le(offset[1], error_data);70}71 72static unsigned int random_ecc_bit(size_t size)73{74 unsigned int offset = get_random_u32_below(3 * BITS_PER_BYTE);75 76 if (size == 256) {77 /*78 * Don't inject a bit error into the insignificant bits (16th79 * and 17th bit) in ECC code for 256 byte data block80 */81 while (offset == 16 || offset == 17)82 offset = get_random_u32_below(3 * BITS_PER_BYTE);83 }84 85 return offset;86}87 88static void single_bit_error_ecc(void *error_ecc, void *correct_ecc,89 size_t size)90{91 unsigned int offset = random_ecc_bit(size);92 93 memcpy(error_ecc, correct_ecc, 3);94 __change_bit_le(offset, error_ecc);95}96 97static void double_bit_error_ecc(void *error_ecc, void *correct_ecc,98 size_t size)99{100 unsigned int offset[2];101 102 offset[0] = random_ecc_bit(size);103 do {104 offset[1] = random_ecc_bit(size);105 } while (offset[0] == offset[1]);106 107 memcpy(error_ecc, correct_ecc, 3);108 __change_bit_le(offset[0], error_ecc);109 __change_bit_le(offset[1], error_ecc);110}111 112static void no_bit_error(void *error_data, void *error_ecc,113 void *correct_data, void *correct_ecc, const size_t size)114{115 memcpy(error_data, correct_data, size);116 memcpy(error_ecc, correct_ecc, 3);117}118 119static int no_bit_error_verify(void *error_data, void *error_ecc,120 void *correct_data, const size_t size)121{122 bool sm_order = IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC);123 unsigned char calc_ecc[3];124 int ret;125 126 ecc_sw_hamming_calculate(error_data, size, calc_ecc, sm_order);127 ret = ecc_sw_hamming_correct(error_data, error_ecc, calc_ecc, size,128 sm_order);129 if (ret == 0 && !memcmp(correct_data, error_data, size))130 return 0;131 132 return -EINVAL;133}134 135static void single_bit_error_in_data(void *error_data, void *error_ecc,136 void *correct_data, void *correct_ecc, const size_t size)137{138 single_bit_error_data(error_data, correct_data, size);139 memcpy(error_ecc, correct_ecc, 3);140}141 142static void single_bit_error_in_ecc(void *error_data, void *error_ecc,143 void *correct_data, void *correct_ecc, const size_t size)144{145 memcpy(error_data, correct_data, size);146 single_bit_error_ecc(error_ecc, correct_ecc, size);147}148 149static int single_bit_error_correct(void *error_data, void *error_ecc,150 void *correct_data, const size_t size)151{152 bool sm_order = IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC);153 unsigned char calc_ecc[3];154 int ret;155 156 ecc_sw_hamming_calculate(error_data, size, calc_ecc, sm_order);157 ret = ecc_sw_hamming_correct(error_data, error_ecc, calc_ecc, size,158 sm_order);159 if (ret == 1 && !memcmp(correct_data, error_data, size))160 return 0;161 162 return -EINVAL;163}164 165static void double_bit_error_in_data(void *error_data, void *error_ecc,166 void *correct_data, void *correct_ecc, const size_t size)167{168 double_bit_error_data(error_data, correct_data, size);169 memcpy(error_ecc, correct_ecc, 3);170}171 172static void single_bit_error_in_data_and_ecc(void *error_data, void *error_ecc,173 void *correct_data, void *correct_ecc, const size_t size)174{175 single_bit_error_data(error_data, correct_data, size);176 single_bit_error_ecc(error_ecc, correct_ecc, size);177}178 179static void double_bit_error_in_ecc(void *error_data, void *error_ecc,180 void *correct_data, void *correct_ecc, const size_t size)181{182 memcpy(error_data, correct_data, size);183 double_bit_error_ecc(error_ecc, correct_ecc, size);184}185 186static int double_bit_error_detect(void *error_data, void *error_ecc,187 void *correct_data, const size_t size)188{189 bool sm_order = IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC);190 unsigned char calc_ecc[3];191 int ret;192 193 ecc_sw_hamming_calculate(error_data, size, calc_ecc, sm_order);194 ret = ecc_sw_hamming_correct(error_data, error_ecc, calc_ecc, size,195 sm_order);196 197 return (ret == -EBADMSG) ? 0 : -EINVAL;198}199 200static const struct nand_ecc_test nand_ecc_test[] = {201 {202 .name = "no-bit-error",203 .prepare = no_bit_error,204 .verify = no_bit_error_verify,205 },206 {207 .name = "single-bit-error-in-data-correct",208 .prepare = single_bit_error_in_data,209 .verify = single_bit_error_correct,210 },211 {212 .name = "single-bit-error-in-ecc-correct",213 .prepare = single_bit_error_in_ecc,214 .verify = single_bit_error_correct,215 },216 {217 .name = "double-bit-error-in-data-detect",218 .prepare = double_bit_error_in_data,219 .verify = double_bit_error_detect,220 },221 {222 .name = "single-bit-error-in-data-and-ecc-detect",223 .prepare = single_bit_error_in_data_and_ecc,224 .verify = double_bit_error_detect,225 },226 {227 .name = "double-bit-error-in-ecc-detect",228 .prepare = double_bit_error_in_ecc,229 .verify = double_bit_error_detect,230 },231};232 233static void dump_data_ecc(void *error_data, void *error_ecc, void *correct_data,234 void *correct_ecc, const size_t size)235{236 pr_info("hexdump of error data:\n");237 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 4,238 error_data, size, false);239 print_hex_dump(KERN_INFO, "hexdump of error ecc: ",240 DUMP_PREFIX_NONE, 16, 1, error_ecc, 3, false);241 242 pr_info("hexdump of correct data:\n");243 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 4,244 correct_data, size, false);245 print_hex_dump(KERN_INFO, "hexdump of correct ecc: ",246 DUMP_PREFIX_NONE, 16, 1, correct_ecc, 3, false);247}248 249static int nand_ecc_test_run(const size_t size)250{251 bool sm_order = IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING_SMC);252 int i;253 int err = 0;254 void *error_data;255 void *error_ecc;256 void *correct_data;257 void *correct_ecc;258 259 error_data = kmalloc(size, GFP_KERNEL);260 error_ecc = kmalloc(3, GFP_KERNEL);261 correct_data = kmalloc(size, GFP_KERNEL);262 correct_ecc = kmalloc(3, GFP_KERNEL);263 264 if (!error_data || !error_ecc || !correct_data || !correct_ecc) {265 err = -ENOMEM;266 goto error;267 }268 269 get_random_bytes(correct_data, size);270 ecc_sw_hamming_calculate(correct_data, size, correct_ecc, sm_order);271 for (i = 0; i < ARRAY_SIZE(nand_ecc_test); i++) {272 nand_ecc_test[i].prepare(error_data, error_ecc,273 correct_data, correct_ecc, size);274 err = nand_ecc_test[i].verify(error_data, error_ecc,275 correct_data, size);276 277 if (err) {278 pr_err("not ok - %s-%zd\n",279 nand_ecc_test[i].name, size);280 dump_data_ecc(error_data, error_ecc,281 correct_data, correct_ecc, size);282 break;283 }284 pr_info("ok - %s-%zd\n",285 nand_ecc_test[i].name, size);286 287 err = mtdtest_relax();288 if (err)289 break;290 }291error:292 kfree(error_data);293 kfree(error_ecc);294 kfree(correct_data);295 kfree(correct_ecc);296 297 return err;298}299 300#else301 302static int nand_ecc_test_run(const size_t size)303{304 return 0;305}306 307#endif308 309static int __init ecc_test_init(void)310{311 int err;312 313 err = nand_ecc_test_run(256);314 if (err)315 return err;316 317 return nand_ecc_test_run(512);318}319 320static void __exit ecc_test_exit(void)321{322}323 324module_init(ecc_test_init);325module_exit(ecc_test_exit);326 327MODULE_DESCRIPTION("NAND ECC function test module");328MODULE_AUTHOR("Akinobu Mita");329MODULE_LICENSE("GPL");330