nxge_fflp_hash.c revision 6f45ec7b0b964c3be967c4880e8867ac1e7763a5
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/types.h>
#include <nxge_fflp_hash.h>
static void nxge_crc32c_word(uint32_t *crcptr, const uint32_t *buf, int len);
/*
* The crc32c algorithms are taken from sctp_crc32 implementation
* common/inet/sctp_crc32.{c,h}
*
*/
/*
* Fast CRC32C calculation algorithm. The basic idea is to look at it
* four bytes (one word) at a time, using four tables. The
* standard algorithm in RFC 3309 uses one table.
*/
/*
* SCTP uses reflected/reverse polynomial CRC32 with generating
* polynomial 0x1EDC6F41L
*/
#define SCTP_POLY 0x1EDC6F41L
/* CRC-CCITT Polynomial */
#define CRC_CCITT_POLY 0x1021
/* The four CRC32c tables. */
static uint32_t crc32c_tab[4][256];
/* The four CRC-CCITT tables. */
static uint16_t crc_ccitt_tab[4][256];
/* the four tables for H1 Computation */
static uint32_t h1table[4][256];
#define CRC_32C_POLY 0x1EDC6F41L
#define COMPUTE_H1_BYTE(crc, data) \
(crc = (crc<<8)^h1table[0][((crc >> 24) ^data) & 0xff])
static uint32_t
reflect_32(uint32_t b)
{
int i;
uint32_t rw = 0;
for (i = 0; i < 32; i++) {
if (b & 1) {
rw |= 1 << (31 - i);
}
b >>= 1;
}
return (rw);
}
static uint32_t
flip32(uint32_t w)
{
return (((w >> 24) | ((w >> 8) & 0xff00) |
((w << 8) & 0xff0000) | (w << 24)));
}
/*
* reference crc-ccitt implementation
*/
uint16_t
crc_ccitt(uint16_t crcin, uint8_t data)
{
uint16_t mcrc, crc = 0, bits = 0;
mcrc = (((crcin >> 8) ^ data) & 0xff) << 8;
for (bits = 0; bits < 8; bits++) {
crc = ((crc ^ mcrc) & 0x8000) ?
(crc << 1) ^ CRC_CCITT_POLY :
crc << 1;
mcrc <<= 1;
}
return ((crcin << 8) ^ crc);
}
/*
* Initialize the crc32c tables.
*/
void
nxge_crc32c_init(void)
{
uint32_t index, bit, byte, crc;
for (index = 0; index < 256; index++) {
crc = reflect_32(index);
for (byte = 0; byte < 4; byte++) {
for (bit = 0; bit < 8; bit++) {
crc = (crc & 0x80000000) ?
(crc << 1) ^ SCTP_POLY : crc << 1;
}
#ifdef _BIG_ENDIAN
crc32c_tab[3 - byte][index] = flip32(reflect_32(crc));
#else
crc32c_tab[byte][index] = reflect_32(crc);
#endif
}
}
}
/*
* Initialize the crc-ccitt tables.
*/
void
nxge_crc_ccitt_init(void)
{
uint16_t crc;
uint16_t index, bit, byte;
for (index = 0; index < 256; index++) {
crc = index << 8;
for (byte = 0; byte < 4; byte++) {
for (bit = 0; bit < 8; bit++) {
crc = (crc & 0x8000) ?
(crc << 1) ^ CRC_CCITT_POLY : crc << 1;
}
#ifdef _BIG_ENDIAN
crc_ccitt_tab[3 - byte][index] = crc;
#else
crc_ccitt_tab[byte][index] = crc;
#endif
}
}
}
/*
* Lookup the crc32c for a byte stream
*/
static void
nxge_crc32c_byte(uint32_t *crcptr, const uint8_t *buf, int len)
{
uint32_t crc;
int i;
crc = *crcptr;
for (i = 0; i < len; i++) {
#ifdef _BIG_ENDIAN
crc = (crc << 8) ^ crc32c_tab[3][buf[i] ^ (crc >> 24)];
#else
crc = (crc >> 8) ^ crc32c_tab[0][buf[i] ^ (crc & 0xff)];
#endif
}
*crcptr = crc;
}
/*
* Lookup the crc-ccitt for a byte stream
*/
static void
nxge_crc_ccitt_byte(uint16_t *crcptr, const uint8_t *buf, int len)
{
uint16_t crc;
int i;
crc = *crcptr;
for (i = 0; i < len; i++) {
#ifdef _BIG_ENDIAN
crc = (crc << 8) ^ crc_ccitt_tab[3][buf[i] ^ (crc >> 8)];
#else
crc = (crc << 8) ^ crc_ccitt_tab[0][buf[i] ^ (crc >> 8)];
#endif
}
*crcptr = crc;
}
/*
* Lookup the crc32c for a 32 bit word stream
* Lookup is done fro the 4 bytes in parallel
* from the tables computed earlier
*
*/
static void
nxge_crc32c_word(uint32_t *crcptr, const uint32_t *buf, int len)
{
uint32_t w, crc;
int i;
crc = *crcptr;
for (i = 0; i < len; i++) {
w = crc ^ buf[i];
crc = crc32c_tab[0][w >> 24] ^
crc32c_tab[1][(w >> 16) & 0xff] ^
crc32c_tab[2][(w >> 8) & 0xff] ^
crc32c_tab[3][w & 0xff];
}
*crcptr = crc;
}
/*
* Lookup the crc-ccitt for a stream of bytes
*
* Since the parallel lookup version doesn't work yet,
* use the byte stream version (lookup crc for a byte
* at a time
*
*/
uint16_t
nxge_crc_ccitt(uint16_t crc16, const uint8_t *buf, int len)
{
nxge_crc_ccitt_byte(&crc16, buf, len);
return (crc16);
}
/*
* Lookup the crc32c for a stream of bytes
*
* Tries to lookup the CRC on 4 byte words
* If the buffer is not 4 byte aligned, first compute
* with byte lookup until aligned. Then compute crc
* for each 4 bytes. If there are bytes left at the end of
* the buffer, then perform a byte lookup for the remaining bytes
*
*
*/
uint32_t
nxge_crc32c(uint32_t crc32, const uint8_t *buf, int len)
{
int rem;
rem = 4 - ((uintptr_t)buf) & 3;
if (rem != 0) {
if (len < rem) {
rem = len;
}
nxge_crc32c_byte(&crc32, buf, rem);
buf = buf + rem;
len = len - rem;
}
if (len > 3) {
nxge_crc32c_word(&crc32, (const uint32_t *) buf, len / 4);
}
rem = len & 3;
if (rem != 0) {
nxge_crc32c_byte(&crc32, buf + len - rem, rem);
}
return (crc32);
}
void
nxge_init_h1_table()
{
uint32_t crc, bit, byte, index;
for (index = 0; index < 256; index++) {
crc = index << 24;
for (byte = 0; byte < 4; byte++) {
for (bit = 0; bit < 8; bit++) {
crc = ((crc & 0x80000000)) ?
(crc << 1) ^ CRC_32C_POLY : crc << 1;
}
h1table[byte][index] = crc;
}
}
}
/*
* Reference Neptune H1 computation function
*
* It is a slightly modified implementation of
* CRC-32C implementation
*/
uint32_t
nxge_compute_h1_serial(uint32_t init_value, uint32_t *flow, uint32_t len)
{
int bit, byte;
uint32_t crc_h1 = init_value;
uint8_t *buf;
buf = (uint8_t *)flow;
for (byte = 0; byte < len; byte++) {
for (bit = 0; bit < 8; bit++) {
crc_h1 = (((crc_h1 >> 24) & 0x80) ^
((buf[byte] << bit) & 0x80)) ?
(crc_h1 << 1) ^ CRC_32C_POLY : crc_h1 << 1;
}
}
return (crc_h1);
}
/*
* table based implementation
* uses 4 four tables in parallel
* 1 for each byte of a 32 bit word
*
* This is the default h1 computing function
*
*/
uint32_t
nxge_compute_h1_table4(uint32_t crcin, uint32_t *flow, uint32_t length)
{
uint32_t w, fw, i, crch1 = crcin;
uint32_t *buf;
buf = (uint32_t *)flow;
for (i = 0; i < length / 4; i++) {
#ifdef _BIG_ENDIAN
fw = buf[i];
#else
fw = flip32(buf[i]);
fw = buf[i];
#endif
w = crch1 ^ fw;
crch1 = h1table[3][w >> 24] ^ h1table[2][(w >> 16) & 0xff] ^
h1table[1][(w >> 8) & 0xff] ^ h1table[0][w & 0xff];
}
return (crch1);
}
/*
* table based implementation
* uses a single table and computes h1 for a byte
* at a time.
*
*/
uint32_t
nxge_compute_h1_table1(uint32_t crcin, uint32_t *flow, uint32_t length)
{
uint32_t i, crch1, tmp = crcin;
uint8_t *buf;
buf = (uint8_t *)flow;
tmp = crcin;
for (i = 0; i < length; i++) {
crch1 = COMPUTE_H1_BYTE(tmp, buf[i]);
tmp = crch1;
}
return (crch1);
}