60e58d5c9d
Misc cleanup of lib/crc32.c and related files. - remove unnecessary header files. - straighten out some convoluted ifdef's - rewrite some references to 2 dimensional arrays as 1 dimensional arrays to make them correct. I.e. replace tab[i] with tab[0][i]. - a few trivial whitespace changes - fix a warning in gen_crc32tables.c caused by a mismatch in the type of the pointer passed to output table. Since the table is only used at kernel compile time, it is simpler to make the table big enough to hold the largest column size used. One cannot make the column size smaller in output_table because it has to be used by both the le and be tables and they can have different column sizes. [djwong@us.ibm.com: Minor changelog tweaks] Signed-off-by: Bob Pearson <rpearson@systemfabricworks.com> Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
100 lines
2.2 KiB
C
100 lines
2.2 KiB
C
#include <stdio.h>
|
|
#include "crc32defs.h"
|
|
#include <inttypes.h>
|
|
|
|
#define ENTRIES_PER_LINE 4
|
|
|
|
#define LE_TABLE_SIZE (1 << CRC_LE_BITS)
|
|
#define BE_TABLE_SIZE (1 << CRC_BE_BITS)
|
|
|
|
static uint32_t crc32table_le[4][256];
|
|
static uint32_t crc32table_be[4][256];
|
|
|
|
/**
|
|
* crc32init_le() - allocate and initialize LE table data
|
|
*
|
|
* crc is the crc of the byte i; other entries are filled in based on the
|
|
* fact that crctable[i^j] = crctable[i] ^ crctable[j].
|
|
*
|
|
*/
|
|
static void crc32init_le(void)
|
|
{
|
|
unsigned i, j;
|
|
uint32_t crc = 1;
|
|
|
|
crc32table_le[0][0] = 0;
|
|
|
|
for (i = 1 << (CRC_LE_BITS - 1); i; i >>= 1) {
|
|
crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0);
|
|
for (j = 0; j < LE_TABLE_SIZE; j += 2 * i)
|
|
crc32table_le[0][i + j] = crc ^ crc32table_le[0][j];
|
|
}
|
|
for (i = 0; i < LE_TABLE_SIZE; i++) {
|
|
crc = crc32table_le[0][i];
|
|
for (j = 1; j < 4; j++) {
|
|
crc = crc32table_le[0][crc & 0xff] ^ (crc >> 8);
|
|
crc32table_le[j][i] = crc;
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* crc32init_be() - allocate and initialize BE table data
|
|
*/
|
|
static void crc32init_be(void)
|
|
{
|
|
unsigned i, j;
|
|
uint32_t crc = 0x80000000;
|
|
|
|
crc32table_be[0][0] = 0;
|
|
|
|
for (i = 1; i < BE_TABLE_SIZE; i <<= 1) {
|
|
crc = (crc << 1) ^ ((crc & 0x80000000) ? CRCPOLY_BE : 0);
|
|
for (j = 0; j < i; j++)
|
|
crc32table_be[0][i + j] = crc ^ crc32table_be[0][j];
|
|
}
|
|
for (i = 0; i < BE_TABLE_SIZE; i++) {
|
|
crc = crc32table_be[0][i];
|
|
for (j = 1; j < 4; j++) {
|
|
crc = crc32table_be[0][(crc >> 24) & 0xff] ^ (crc << 8);
|
|
crc32table_be[j][i] = crc;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void output_table(uint32_t (*table)[256], int len, char *trans)
|
|
{
|
|
int i, j;
|
|
|
|
for (j = 0 ; j < 4; j++) {
|
|
printf("{");
|
|
for (i = 0; i < len - 1; i++) {
|
|
if (i % ENTRIES_PER_LINE == 0)
|
|
printf("\n");
|
|
printf("%s(0x%8.8xL), ", trans, table[j][i]);
|
|
}
|
|
printf("%s(0x%8.8xL)},\n", trans, table[j][len - 1]);
|
|
}
|
|
}
|
|
|
|
int main(int argc, char** argv)
|
|
{
|
|
printf("/* this file is generated - do not edit */\n\n");
|
|
|
|
if (CRC_LE_BITS > 1) {
|
|
crc32init_le();
|
|
printf("static const u32 crc32table_le[4][256] = {");
|
|
output_table(crc32table_le, LE_TABLE_SIZE, "tole");
|
|
printf("};\n");
|
|
}
|
|
|
|
if (CRC_BE_BITS > 1) {
|
|
crc32init_be();
|
|
printf("static const u32 crc32table_be[4][256] = {");
|
|
output_table(crc32table_be, BE_TABLE_SIZE, "tobe");
|
|
printf("};\n");
|
|
}
|
|
|
|
return 0;
|
|
}
|