forked from Minki/linux
45b3947c2d
FSVOtest in this case, since I don't have the hardware...
However, all changes seen by gcc are actually
- explicit cast to unsigned short in return expression of functions
returning unsigned short
- csum_fold() return type changed from unsigned int to __sum16
(unsigned short), same as for all other architecture and as net/* expects;
expression actually returned is ((~(sum << 16)) >> 16) with sum being
unsigned 32bit, so it's (a) going to fit into the range of unsigned short
and (b) had been unsigned all along, so no sign expansion mess happened.
Tested-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Miller <davem@davemloft.net>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
140 lines
3.5 KiB
C
140 lines
3.5 KiB
C
/*
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* File: arch/blackfin/lib/checksum.c
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* Based on: none - original work
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* Author:
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*
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* Created:
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* Description: An implementation of the TCP/IP protocol suite for the LINUX
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* operating system. INET is implemented using the BSD Socket
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* interface as the means of communication with the user level.
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*
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* Modified:
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* Copyright 2004-2006 Analog Devices Inc.
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*
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* Bugs: Enter bugs at http://blackfin.uclinux.org/
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see the file COPYING, or write
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* to the Free Software Foundation, Inc.,
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* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <net/checksum.h>
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#include <asm/checksum.h>
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#ifdef CONFIG_IP_CHECKSUM_L1
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static unsigned short do_csum(const unsigned char *buff, int len)__attribute__((l1_text));
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#endif
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static unsigned short do_csum(const unsigned char *buff, int len)
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{
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register unsigned long sum = 0;
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int swappem = 0;
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if (1 & (unsigned long)buff) {
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sum = *buff << 8;
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buff++;
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len--;
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++swappem;
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}
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while (len > 1) {
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sum += *(unsigned short *)buff;
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buff += 2;
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len -= 2;
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}
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if (len > 0)
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sum += *buff;
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/* Fold 32-bit sum to 16 bits */
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while (sum >> 16)
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sum = (sum & 0xffff) + (sum >> 16);
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if (swappem)
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sum = ((sum & 0xff00) >> 8) + ((sum & 0x00ff) << 8);
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return sum;
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}
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/*
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* This is a version of ip_compute_csum() optimized for IP headers,
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* which always checksum on 4 octet boundaries.
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*/
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__sum16 ip_fast_csum(unsigned char *iph, unsigned int ihl)
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{
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return (__force __sum16)~do_csum(iph, ihl * 4);
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}
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/*
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* computes the checksum of a memory block at buff, length len,
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* and adds in "sum" (32-bit)
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*
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* returns a 32-bit number suitable for feeding into itself
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* or csum_tcpudp_magic
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*
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* this function must be called with even lengths, except
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* for the last fragment, which may be odd
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*
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* it's best to have buff aligned on a 32-bit boundary
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*/
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__wsum csum_partial(const void *buff, int len, __wsum sum)
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{
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/*
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* Just in case we get nasty checksum data...
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* Like 0xffff6ec3 in the case of our IPv6 multicast header.
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* We fold to begin with, as well as at the end.
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*/
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sum = (sum & 0xffff) + (sum >> 16);
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sum += do_csum(buff, len);
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sum = (sum & 0xffff) + (sum >> 16);
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return sum;
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}
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/*
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* this routine is used for miscellaneous IP-like checksums, mainly
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* in icmp.c
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*/
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__sum16 ip_compute_csum(const void *buff, int len)
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{
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return (__force __sum16)~do_csum(buff, len);
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}
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/*
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* copy from fs while checksumming, otherwise like csum_partial
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*/
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__wsum
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csum_partial_copy_from_user(const void __user *src, void *dst,
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int len, __wsum sum, int *csum_err)
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{
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if (csum_err)
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*csum_err = 0;
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memcpy(dst, (__force void *)src, len);
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return csum_partial(dst, len, sum);
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}
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/*
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* copy from ds while checksumming, otherwise like csum_partial
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*/
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__wsum csum_partial_copy(const void *src, void *dst, int len, __wsum sum)
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{
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memcpy(dst, src, len);
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return csum_partial(dst, len, sum);
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}
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