cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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gen_crc32table.c (3406B)

      1// SPDX-License-Identifier: GPL-2.0
      2#include <stdio.h>
      3#include "../include/linux/crc32poly.h"
      4#include "../include/generated/autoconf.h"
      5#include "crc32defs.h"
      6#include <inttypes.h>
      7
      8#define ENTRIES_PER_LINE 4
      9
     10#if CRC_LE_BITS > 8
     11# define LE_TABLE_ROWS (CRC_LE_BITS/8)
     12# define LE_TABLE_SIZE 256
     13#else
     14# define LE_TABLE_ROWS 1
     15# define LE_TABLE_SIZE (1 << CRC_LE_BITS)
     16#endif
     17
     18#if CRC_BE_BITS > 8
     19# define BE_TABLE_ROWS (CRC_BE_BITS/8)
     20# define BE_TABLE_SIZE 256
     21#else
     22# define BE_TABLE_ROWS 1
     23# define BE_TABLE_SIZE (1 << CRC_BE_BITS)
     24#endif
     25
     26static uint32_t crc32table_le[LE_TABLE_ROWS][256];
     27static uint32_t crc32table_be[BE_TABLE_ROWS][256];
     28static uint32_t crc32ctable_le[LE_TABLE_ROWS][256];
     29
     30/**
     31 * crc32init_le() - allocate and initialize LE table data
     32 *
     33 * crc is the crc of the byte i; other entries are filled in based on the
     34 * fact that crctable[i^j] = crctable[i] ^ crctable[j].
     35 *
     36 */
     37static void crc32init_le_generic(const uint32_t polynomial,
     38				 uint32_t (*tab)[256])
     39{
     40	unsigned i, j;
     41	uint32_t crc = 1;
     42
     43	tab[0][0] = 0;
     44
     45	for (i = LE_TABLE_SIZE >> 1; i; i >>= 1) {
     46		crc = (crc >> 1) ^ ((crc & 1) ? polynomial : 0);
     47		for (j = 0; j < LE_TABLE_SIZE; j += 2 * i)
     48			tab[0][i + j] = crc ^ tab[0][j];
     49	}
     50	for (i = 0; i < LE_TABLE_SIZE; i++) {
     51		crc = tab[0][i];
     52		for (j = 1; j < LE_TABLE_ROWS; j++) {
     53			crc = tab[0][crc & 0xff] ^ (crc >> 8);
     54			tab[j][i] = crc;
     55		}
     56	}
     57}
     58
     59static void crc32init_le(void)
     60{
     61	crc32init_le_generic(CRC32_POLY_LE, crc32table_le);
     62}
     63
     64static void crc32cinit_le(void)
     65{
     66	crc32init_le_generic(CRC32C_POLY_LE, crc32ctable_le);
     67}
     68
     69/**
     70 * crc32init_be() - allocate and initialize BE table data
     71 */
     72static void crc32init_be(void)
     73{
     74	unsigned i, j;
     75	uint32_t crc = 0x80000000;
     76
     77	crc32table_be[0][0] = 0;
     78
     79	for (i = 1; i < BE_TABLE_SIZE; i <<= 1) {
     80		crc = (crc << 1) ^ ((crc & 0x80000000) ? CRC32_POLY_BE : 0);
     81		for (j = 0; j < i; j++)
     82			crc32table_be[0][i + j] = crc ^ crc32table_be[0][j];
     83	}
     84	for (i = 0; i < BE_TABLE_SIZE; i++) {
     85		crc = crc32table_be[0][i];
     86		for (j = 1; j < BE_TABLE_ROWS; j++) {
     87			crc = crc32table_be[0][(crc >> 24) & 0xff] ^ (crc << 8);
     88			crc32table_be[j][i] = crc;
     89		}
     90	}
     91}
     92
     93static void output_table(uint32_t (*table)[256], int rows, int len, char *trans)
     94{
     95	int i, j;
     96
     97	for (j = 0 ; j < rows; j++) {
     98		printf("{");
     99		for (i = 0; i < len - 1; i++) {
    100			if (i % ENTRIES_PER_LINE == 0)
    101				printf("\n");
    102			printf("%s(0x%8.8xL), ", trans, table[j][i]);
    103		}
    104		printf("%s(0x%8.8xL)},\n", trans, table[j][len - 1]);
    105	}
    106}
    107
    108int main(int argc, char** argv)
    109{
    110	printf("/* this file is generated - do not edit */\n\n");
    111
    112	if (CRC_LE_BITS > 1) {
    113		crc32init_le();
    114		printf("static const u32 ____cacheline_aligned "
    115		       "crc32table_le[%d][%d] = {",
    116		       LE_TABLE_ROWS, LE_TABLE_SIZE);
    117		output_table(crc32table_le, LE_TABLE_ROWS,
    118			     LE_TABLE_SIZE, "tole");
    119		printf("};\n");
    120	}
    121
    122	if (CRC_BE_BITS > 1) {
    123		crc32init_be();
    124		printf("static const u32 ____cacheline_aligned "
    125		       "crc32table_be[%d][%d] = {",
    126		       BE_TABLE_ROWS, BE_TABLE_SIZE);
    127		output_table(crc32table_be, LE_TABLE_ROWS,
    128			     BE_TABLE_SIZE, "tobe");
    129		printf("};\n");
    130	}
    131	if (CRC_LE_BITS > 1) {
    132		crc32cinit_le();
    133		printf("static const u32 ____cacheline_aligned "
    134		       "crc32ctable_le[%d][%d] = {",
    135		       LE_TABLE_ROWS, LE_TABLE_SIZE);
    136		output_table(crc32ctable_le, LE_TABLE_ROWS,
    137			     LE_TABLE_SIZE, "tole");
    138		printf("};\n");
    139	}
    140
    141	return 0;
    142}