/*
* Altera Nios2 CRC checksum computation
*
* Author: Jeffrey O. Hill
*
* Copyright 2012. Los Alamos National Security, LLC.
* This material was produced under U.S. Government contract
* DE-AC52-06NA25396 for Los Alamos National Laboratory (LANL),
* which is operated by Los Alamos National Security, LLC for
* the U.S. Department of Energy. The U.S. Government has rights
* to use, reproduce, and distribute this software. NEITHER THE
* GOVERNMENT NOR LOS ALAMOS NATIONAL SECURITY, LLC MAKES ANY
* WARRANTY, EXPRESS OR IMPLIED, OR ASSUMES ANY LIABILITY FOR
* THE USE OF THIS SOFTWARE.
*
* COPYRIGHT (c) 1989-2012.
* On-Line Applications Research Corporation (OAR).
*
* Copyright (c) 1997 Mark Brinicome
* Copyright (c) 1997 Causality Limited
*
* Copyright (c) 1995 Zubin Dittia.
* Copyright (c) 1995 Matthew R. Green.
* Copyright (c) 1994 Charles M. Hannum.
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* Based on the arm / sparc version, but using instead
* mostly inline functions in place of naaasty macros.
*
* It would be a great idea to somehow detect at runtime
* that the Nios2 has a user defined instruction that
* computes the CRC and invoke it here (we could call a
* function in the BSP).
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <machine/in_cksum.h>
/*
* Checksum routine for Internet Protocol family headers.
*
* This routine is very heavily used in the network
* code and should be modified for each CPU to be as fast as possible.
*/
static inline uint32_t _NIOS2_Add_ones_complement_64
( uint32_t sum, const uint32_t * const pWd )
{
sum = _NIOS2_Add_ones_complement ( sum, pWd[0] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[1] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[2] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[3] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[4] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[5] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[6] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[7] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[8] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[9] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[10] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[11] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[12] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[13] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[14] );
return _NIOS2_Add_ones_complement ( sum, pWd[15] );
}
static inline uint32_t _NIOS2_Add_ones_complement_32
( uint32_t sum, const uint32_t * const pWd )
{
sum = _NIOS2_Add_ones_complement ( sum, pWd[0] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[1] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[2] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[3] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[4] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[5] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[6] );
return _NIOS2_Add_ones_complement ( sum, pWd[7] );
}
static inline uint32_t _NIOS2_Add_ones_complement_16
( uint32_t sum, const uint32_t * const pWd )
{
sum = _NIOS2_Add_ones_complement ( sum, pWd[0] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[1] );
sum = _NIOS2_Add_ones_complement ( sum, pWd[2] );
return _NIOS2_Add_ones_complement ( sum, pWd[3] );
}
static inline uint32_t _NIOS2_Add_ones_complement_8
( uint32_t sum, const uint32_t * const pWd )
{
sum = _NIOS2_Add_ones_complement ( sum, pWd[0] );
return _NIOS2_Add_ones_complement ( sum, pWd[1] );
}
static inline uint32_t _NIOS2_Add_ones_complement_4
( uint32_t sum, const uint32_t * const pWd )
{
return _NIOS2_Add_ones_complement ( sum, pWd[0] );
}
static inline uint32_t _NIOS2_Reduce_checksum ( uint32_t a )
{
uint32_t tmp;
__asm__ __volatile__ (
" srli %1, %0, 16 \n" /* tmp = a >> 16 */
" andi %0, %0, 0xffff \n" /* a = a & 0xffff */
" add %0, %0, %1 \n" /* a = a + tmp */
: "+&r"(a), "=&r"(tmp)
);
return a;
}
#define combineTokens( A, B ) A ## B
#define ADD_AND_ADVANCE( N ) \
if ( mlen >= N ) { \
sum = combineTokens ( _NIOS2_Add_ones_complement_, N ) \
( sum, ( uint32_t * ) w ); \
mlen -= N; \
w += N; \
}
static int
in_cksum_internal(struct mbuf *m, int off, int len, u_int sum)
{
const uint8_t * w;
int mlen = 0;
int byte_swapped = 0;
for (; m && len; m = m->m_next)
{
if (m->m_len == 0)
continue;
w = mtod(m, u_char *) + off;
mlen = m->m_len - off;
off = 0;
if (len < mlen)
mlen = len;
len -= mlen;
/*
* Ensure that we're aligned on a word boundary here so
* that we can do 32 bit operations below.
*/
if ((3 & (uint32_t)w) != 0)
{
sum = _NIOS2_Reduce_checksum ( sum );
if ((1 & (uint32_t)w) != 0 && mlen >= 1)
{
sum <<= 8u;
sum += *w << 8u;
byte_swapped ^= 1;
w += 1;
mlen -= 1;
}
if ((2 & (uint32_t)w) != 0 && mlen >= 2)
{
sum += *(uint16_t *)w;
w += 2;
mlen -= 2;
}
}
/*
* instead of using a loop, process in unrolled chunks
*/
while ( mlen >= 64 )
{
sum = _NIOS2_Add_ones_complement_64
( sum, ( uint32_t * ) w );
mlen -= 64;
w += 64;
}
ADD_AND_ADVANCE ( 32 );
ADD_AND_ADVANCE ( 16 );
ADD_AND_ADVANCE ( 8 );
ADD_AND_ADVANCE ( 4 );
if ( mlen > 0 )
{
sum = _NIOS2_Reduce_checksum ( sum );
if ( mlen >= 2 )
{
sum += *(uint16_t *)w;
w += 2;
mlen -= 2;
}
if ( mlen == 1 )
{
sum <<= 8u;
sum += *w << 8u;
byte_swapped ^= 1;
}
}
}
if ( byte_swapped )
{
sum = _NIOS2_Reduce_checksum ( sum );
sum <<= 8u;
}
sum = _NIOS2_Add_ones_complement_word_halves ( sum );
sum ^= 0xffff;
return sum;
}
int
in_cksum (
struct mbuf *m,
int len )
{
return in_cksum_internal ( m, 0, len, 0 );
}
int
in4_cksum (
struct mbuf *m,
u_int8_t nxt,
int off,
int len )
{
u_int sum = 0;
if ( nxt != 0 )
{
struct ipovly ipov;
/* pseudo header */
if (off < sizeof(struct ipovly))
panic("in4_cksum: offset too short");
if (m->m_len < sizeof(struct ip))
panic("in4_cksum: bad mbuf chain");
bzero(&ipov, sizeof(ipov));
ipov.ih_len = htons(len);
ipov.ih_pr = nxt;
ipov.ih_src = mtod(m, struct ip *)->ip_src;
ipov.ih_dst = mtod(m, struct ip *)->ip_dst;
u_char * w = (u_char *)&ipov;
if ( sizeof(ipov) != 20 )
panic( "in4_cksum: sizeof(ipov) != 20" );
sum = _NIOS2_Add_ones_complement_16 ( sum, (uint32_t *) w );
w += 16;
sum = _NIOS2_Add_ones_complement_4 ( sum, (uint32_t *) w );
}
/* skip unnecessary part */
while (m && off > 0)
{
if (m->m_len > off)
break;
off -= m->m_len;
m = m->m_next;
}
return (in_cksum_internal(m, off, len, sum));
}
