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/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1995, 96, 97, 98, 99, 2001 by Ralf Baechle
* Copyright (C) 1999 Silicon Graphics, Inc.
* Copyright (C) 2001 Thiemo Seufer.
* Copyright (C) 2002 Maciej W. Rozycki
* Copyright (C) 2014 Imagination Technologies Ltd.
*/
#ifndef _ASM_CHECKSUM_H
#define _ASM_CHECKSUM_H
#ifdef CONFIG_GENERIC_CSUM
#include <asm-generic/checksum.h>
#else
#include <linux/in6.h>
#include <linux/uaccess.h>
/*
* computes the checksum of a memory block at buff, length len,
* and adds in "sum" (32-bit)
*
* returns a 32-bit number suitable for feeding into itself
* or csum_tcpudp_magic
*
* this function must be called with even lengths, except
* for the last fragment, which may be odd
*
* it's best to have buff aligned on a 32-bit boundary
*/
__wsum csum_partial(const void *buff, int len, __wsum sum);
__wsum __csum_partial_copy_from_user(const void __user *src, void *dst, int len);
__wsum __csum_partial_copy_to_user(const void *src, void __user *dst, int len);
#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
static inline
__wsum csum_and_copy_from_user(const void __user *src, void *dst, int len)
{
might_fault();
if (!access_ok(src, len))
return 0;
return __csum_partial_copy_from_user(src, dst, len);
}
/*
* Copy and checksum to user
*/
#define HAVE_CSUM_COPY_USER
static inline
__wsum csum_and_copy_to_user(const void *src, void __user *dst, int len)
{
might_fault();
if (!access_ok(dst, len))
return 0;
return __csum_partial_copy_to_user(src, dst, len);
}
/*
* the same as csum_partial, but copies from user space (but on MIPS
* we have just one address space, so this is identical to the above)
*/
#define _HAVE_ARCH_CSUM_AND_COPY
__wsum __csum_partial_copy_nocheck(const void *src, void *dst, int len);
static inline __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len)
{
return __csum_partial_copy_nocheck(src, dst, len);
}
/*
* Fold a partial checksum without adding pseudo headers
*/
static inline __sum16 csum_fold(__wsum csum)
{
u32 sum = (__force u32)csum;
sum += (sum << 16);
csum = (__force __wsum)(sum < (__force u32)csum);
sum >>= 16;
sum += (__force u32)csum;
return (__force __sum16)~sum;
}
#define csum_fold csum_fold
/*
* This is a version of ip_compute_csum() optimized for IP headers,
* which always checksum on 4 octet boundaries.
*
* By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
* Arnt Gulbrandsen.
*/
static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
{
const unsigned int *word = iph;
const unsigned int *stop = word + ihl;
unsigned int csum;
int carry;
csum = word[0];
csum += word[1];
carry = (csum < word[1]);
csum += carry;
csum += word[2];
carry = (csum < word[2]);
csum += carry;
csum += word[3];
carry = (csum < word[3]);
csum += carry;
word += 4;
do {
csum += *word;
carry = (csum < *word);
csum += carry;
word++;
} while (word != stop);
return csum_fold(csum);
}
#define ip_fast_csum ip_fast_csum
static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
__u32 len, __u8 proto,
__wsum isum)
{
const unsigned int sh32 = IS_ENABLED(CONFIG_64BIT) ? 32 : 0;
unsigned long sum = (__force unsigned long)daddr;
unsigned long tmp;
__u32 osum;
tmp = (__force unsigned long)saddr;
sum += tmp;
if (IS_ENABLED(CONFIG_32BIT))
sum += sum < tmp;
/*
* We know PROTO + LEN has the sign bit clear, so cast to a signed
* type to avoid an extraneous zero-extension where TMP is 64-bit.
*/
tmp = (__s32)(proto + len);
tmp <<= IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN) ? 8 : 0;
sum += tmp;
if (IS_ENABLED(CONFIG_32BIT))
sum += sum < tmp;
tmp = (__force unsigned long)isum;
sum += tmp;
if (IS_ENABLED(CONFIG_32BIT)) {
sum += sum < tmp;
osum = sum;
} else if (IS_ENABLED(CONFIG_64BIT)) {
tmp = sum << sh32;
sum += tmp;
osum = sum < tmp;
osum += sum >> sh32;
} else {
BUILD_BUG();
}
return (__force __wsum)osum;
}
#define csum_tcpudp_nofold csum_tcpudp_nofold
/*
* this routine is used for miscellaneous IP-like checksums, mainly
* in icmp.c
*/
static inline __sum16 ip_compute_csum(const void *buff, int len)
{
return csum_fold(csum_partial(buff, len, 0));
}
#define _HAVE_ARCH_IPV6_CSUM
static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
const struct in6_addr *daddr,
__u32 len, __u8 proto,
__wsum sum)
{
__wsum tmp;
__asm__(
" .set push # csum_ipv6_magic\n"
" .set noreorder \n"
" .set noat \n"
" addu %0, %5 # proto (long in network byte order)\n"
" sltu $1, %0, %5 \n"
" addu %0, $1 \n"
" addu %0, %6 # csum\n"
" sltu $1, %0, %6 \n"
" lw %1, 0(%2) # four words source address\n"
" addu %0, $1 \n"
" addu %0, %1 \n"
" sltu $1, %0, %1 \n"
" lw %1, 4(%2) \n"
" addu %0, $1 \n"
" addu %0, %1 \n"
" sltu $1, %0, %1 \n"
" lw %1, 8(%2) \n"
" addu %0, $1 \n"
" addu %0, %1 \n"
" sltu $1, %0, %1 \n"
" lw %1, 12(%2) \n"
" addu %0, $1 \n"
" addu %0, %1 \n"
" sltu $1, %0, %1 \n"
" lw %1, 0(%3) \n"
" addu %0, $1 \n"
" addu %0, %1 \n"
" sltu $1, %0, %1 \n"
" lw %1, 4(%3) \n"
" addu %0, $1 \n"
" addu %0, %1 \n"
" sltu $1, %0, %1 \n"
" lw %1, 8(%3) \n"
" addu %0, $1 \n"
" addu %0, %1 \n"
" sltu $1, %0, %1 \n"
" lw %1, 12(%3) \n"
" addu %0, $1 \n"
" addu %0, %1 \n"
" sltu $1, %0, %1 \n"
" addu %0, $1 # Add final carry\n"
" .set pop"
: "=&r" (sum), "=&r" (tmp)
: "r" (saddr), "r" (daddr),
"0" (htonl(len)), "r" (htonl(proto)), "r" (sum)
: "memory");
return csum_fold(sum);
}
#include <asm-generic/checksum.h>
#endif /* CONFIG_GENERIC_CSUM */
#endif /* _ASM_CHECKSUM_H */
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