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#ifndef __ASM_SH_CHECKSUM_H
#define __ASM_SH_CHECKSUM_H
/*
* 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) 1999 by Kaz Kojima & Niibe Yutaka
*/
#include <linux/config.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
*/
asmlinkage unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum);
/*
* the same as csum_partial, but copies from src while it
* checksums, and handles user-space pointer exceptions correctly, when needed.
*
* here even more important to align src and dst on a 32-bit (or even
* better 64-bit) boundary
*/
asmlinkage unsigned int csum_partial_copy_generic( const char *src, char *dst, int len, int sum,
int *src_err_ptr, int *dst_err_ptr);
/*
* Note: when you get a NULL pointer exception here this means someone
* passed in an incorrect kernel address to one of these functions.
*
* If you use these functions directly please don't forget the
* verify_area().
*/
extern __inline__
unsigned int csum_partial_copy_nocheck ( const char *src, char *dst,
int len, int sum)
{
return csum_partial_copy_generic ( src, dst, len, sum, NULL, NULL);
}
extern __inline__
unsigned int csum_partial_copy_from_user ( const char *src, char *dst,
int len, int sum, int *err_ptr)
{
return csum_partial_copy_generic ( src, dst, len, sum, err_ptr, NULL);
}
/*
* These are the old (and unsafe) way of doing checksums, a warning message will be
* printed if they are used and an exeption occurs.
*
* these functions should go away after some time.
*/
#define csum_partial_copy_fromuser csum_partial_copy
unsigned int csum_partial_copy( const char *src, char *dst, int len, int sum);
/*
* Fold a partial checksum
*/
static __inline__ unsigned int csum_fold(unsigned int sum)
{
unsigned int __dummy;
__asm__("swap.w %0, %1\n\t"
"extu.w %0, %0\n\t"
"extu.w %1, %1\n\t"
"add %1, %0\n\t"
"swap.w %0, %1\n\t"
"add %1, %0\n\t"
"not %0, %0\n\t"
: "=r" (sum), "=&r" (__dummy)
: "0" (sum));
return sum;
}
/*
* This is a version of ip_compute_csum() optimized for IP headers,
* which always checksum on 4 octet boundaries.
*
* i386 version by Jorge Cwik <jorge@laser.satlink.net>, adapted
* for linux by * Arnt Gulbrandsen.
*/
static __inline__ unsigned short ip_fast_csum(unsigned char * iph, unsigned int ihl)
{
unsigned int sum, __dummy0, __dummy1;
__asm__ __volatile__(
"mov.l @%1+, %0\n\t"
"mov.l @%1+, %3\n\t"
"add #-2, %2\n\t"
"clrt\n\t"
"1:\t"
"addc %3, %0\n\t"
"movt %4\n\t"
"mov.l @%1+, %3\n\t"
"dt %2\n\t"
"bf/s 1b\n\t"
" cmp/eq #1, %4\n\t"
"addc %3, %0\n\t"
"addc %2, %0" /* Here %2 is 0, add carry-bit */
/* Since the input registers which are loaded with iph and ihl
are modified, we must also specify them as outputs, or gcc
will assume they contain their original values. */
: "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (__dummy0), "=&z" (__dummy1)
: "1" (iph), "2" (ihl));
return csum_fold(sum);
}
static __inline__ unsigned long csum_tcpudp_nofold(unsigned long saddr,
unsigned long daddr,
unsigned short len,
unsigned short proto,
unsigned int sum)
{
#ifdef __LITTLE_ENDIAN__
unsigned long len_proto = (ntohs(len)<<16)+proto*256;
#else
unsigned long len_proto = (proto<<16)+len;
#endif
__asm__("clrt\n\t"
"addc %0, %1\n\t"
"addc %2, %1\n\t"
"addc %3, %1\n\t"
"movt %0\n\t"
"add %1, %0"
: "=r" (sum), "=r" (len_proto)
: "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum));
return sum;
}
/*
* computes the checksum of the TCP/UDP pseudo-header
* returns a 16-bit checksum, already complemented
*/
static __inline__ unsigned short int csum_tcpudp_magic(unsigned long saddr,
unsigned long daddr,
unsigned short len,
unsigned short proto,
unsigned int sum)
{
return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
}
/*
* this routine is used for miscellaneous IP-like checksums, mainly
* in icmp.c
*/
static __inline__ unsigned short ip_compute_csum(unsigned char * buff, int len)
{
return csum_fold (csum_partial(buff, len, 0));
}
#define _HAVE_ARCH_IPV6_CSUM
#ifdef CONFIG_IPV6
static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
struct in6_addr *daddr,
__u32 len,
unsigned short proto,
unsigned int sum)
{
unsigned int __dummy;
__asm__("clrt\n\t"
"mov.l @(0,%2), %1\n\t"
"addc %1, %0\n\t"
"mov.l @(4,%2), %1\n\t"
"addc %1, %0\n\t"
"mov.l @(8,%2), %1\n\t"
"addc %1, %0\n\t"
"mov.l @(12,%2), %1\n\t"
"addc %1, %0\n\t"
"mov.l @(0,%3), %1\n\t"
"addc %1, %0\n\t"
"mov.l @(4,%3), %1\n\t"
"addc %1, %0\n\t"
"mov.l @(8,%3), %1\n\t"
"addc %1, %0\n\t"
"mov.l @(12,%3), %1\n\t"
"addc %1, %0\n\t"
"addc %4, %0\n\t"
"addc %5, %0\n\t"
"movt %1\n\t"
"add %1, %0\n"
: "=r" (sum), "=&r" (__dummy)
: "r" (saddr), "r" (daddr),
"r" (htonl(len)), "r" (htonl(proto)), "0" (sum));
return csum_fold(sum);
}
#endif
/*
* Copy and checksum to user
*/
#define HAVE_CSUM_COPY_USER
static __inline__ unsigned int csum_and_copy_to_user (const char *src, char *dst,
int len, int sum, int *err_ptr)
{
if (access_ok(VERIFY_WRITE, dst, len))
return csum_partial_copy_generic(src, dst, len, sum, NULL, err_ptr);
if (len)
*err_ptr = -EFAULT;
return -1; /* invalid checksum */
}
#endif /* __ASM_SH_CHECKSUM_H */
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