217 lines
5.5 KiB
C
217 lines
5.5 KiB
C
#ifndef __ASM_SH_CHECKSUM_H
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#define __ASM_SH_CHECKSUM_H
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/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 1999 by Kaz Kojima & Niibe Yutaka
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*/
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#include <linux/config.h>
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#include <linux/in6.h>
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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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asmlinkage unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum);
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/*
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* the same as csum_partial, but copies from src while it
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* checksums, and handles user-space pointer exceptions correctly, when needed.
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*
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* here even more important to align src and dst on a 32-bit (or even
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* better 64-bit) boundary
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*/
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asmlinkage unsigned int csum_partial_copy_generic(const unsigned char *src, unsigned char *dst,
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int len, int sum, int *src_err_ptr, int *dst_err_ptr);
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/*
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* Note: when you get a NULL pointer exception here this means someone
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* passed in an incorrect kernel address to one of these functions.
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*
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* If you use these functions directly please don't forget the
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* access_ok().
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*/
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static __inline__
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unsigned int csum_partial_copy_nocheck (const unsigned char *src, unsigned char *dst,
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int len, int sum)
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{
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return csum_partial_copy_generic ( src, dst, len, sum, NULL, NULL);
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}
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static __inline__
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unsigned int csum_partial_copy_from_user (const unsigned char *src, unsigned char *dst,
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int len, int sum, int *err_ptr)
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{
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return csum_partial_copy_generic ( src, dst, len, sum, err_ptr, NULL);
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}
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/*
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* Fold a partial checksum
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*/
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static __inline__ unsigned int csum_fold(unsigned int sum)
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{
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unsigned int __dummy;
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__asm__("swap.w %0, %1\n\t"
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"extu.w %0, %0\n\t"
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"extu.w %1, %1\n\t"
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"add %1, %0\n\t"
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"swap.w %0, %1\n\t"
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"add %1, %0\n\t"
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"not %0, %0\n\t"
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: "=r" (sum), "=&r" (__dummy)
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: "0" (sum)
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: "t");
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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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* i386 version by Jorge Cwik <jorge@laser.satlink.net>, adapted
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* for linux by * Arnt Gulbrandsen.
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*/
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static __inline__ unsigned short ip_fast_csum(unsigned char * iph, unsigned int ihl)
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{
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unsigned int sum, __dummy0, __dummy1;
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__asm__ __volatile__(
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"mov.l @%1+, %0\n\t"
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"mov.l @%1+, %3\n\t"
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"add #-2, %2\n\t"
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"clrt\n\t"
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"1:\t"
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"addc %3, %0\n\t"
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"movt %4\n\t"
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"mov.l @%1+, %3\n\t"
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"dt %2\n\t"
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"bf/s 1b\n\t"
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" cmp/eq #1, %4\n\t"
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"addc %3, %0\n\t"
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"addc %2, %0" /* Here %2 is 0, add carry-bit */
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/* Since the input registers which are loaded with iph and ihl
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are modified, we must also specify them as outputs, or gcc
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will assume they contain their original values. */
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: "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (__dummy0), "=&z" (__dummy1)
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: "1" (iph), "2" (ihl)
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: "t");
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return csum_fold(sum);
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}
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static __inline__ unsigned long csum_tcpudp_nofold(unsigned long saddr,
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unsigned long daddr,
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unsigned short len,
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unsigned short proto,
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unsigned int sum)
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{
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#ifdef __LITTLE_ENDIAN__
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unsigned long len_proto = (ntohs(len)<<16)+proto*256;
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#else
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unsigned long len_proto = (proto<<16)+len;
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#endif
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__asm__("clrt\n\t"
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"addc %0, %1\n\t"
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"addc %2, %1\n\t"
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"addc %3, %1\n\t"
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"movt %0\n\t"
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"add %1, %0"
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: "=r" (sum), "=r" (len_proto)
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: "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum)
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: "t");
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return sum;
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}
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/*
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* computes the checksum of the TCP/UDP pseudo-header
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* returns a 16-bit checksum, already complemented
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*/
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static __inline__ unsigned short int csum_tcpudp_magic(unsigned long saddr,
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unsigned long daddr,
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unsigned short len,
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unsigned short proto,
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unsigned int sum)
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{
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return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,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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static __inline__ unsigned short ip_compute_csum(unsigned char * buff, int len)
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{
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return csum_fold (csum_partial(buff, len, 0));
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}
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#define _HAVE_ARCH_IPV6_CSUM
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static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
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struct in6_addr *daddr,
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__u32 len,
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unsigned short proto,
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unsigned int sum)
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{
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unsigned int __dummy;
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__asm__("clrt\n\t"
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"mov.l @(0,%2), %1\n\t"
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"addc %1, %0\n\t"
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"mov.l @(4,%2), %1\n\t"
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"addc %1, %0\n\t"
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"mov.l @(8,%2), %1\n\t"
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"addc %1, %0\n\t"
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"mov.l @(12,%2), %1\n\t"
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"addc %1, %0\n\t"
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"mov.l @(0,%3), %1\n\t"
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"addc %1, %0\n\t"
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"mov.l @(4,%3), %1\n\t"
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"addc %1, %0\n\t"
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"mov.l @(8,%3), %1\n\t"
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"addc %1, %0\n\t"
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"mov.l @(12,%3), %1\n\t"
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"addc %1, %0\n\t"
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"addc %4, %0\n\t"
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"addc %5, %0\n\t"
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"movt %1\n\t"
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"add %1, %0\n"
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: "=r" (sum), "=&r" (__dummy)
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: "r" (saddr), "r" (daddr),
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"r" (htonl(len)), "r" (htonl(proto)), "0" (sum)
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: "t");
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return csum_fold(sum);
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}
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/*
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* Copy and checksum to user
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*/
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#define HAVE_CSUM_COPY_USER
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static __inline__ unsigned int csum_and_copy_to_user (const unsigned char *src,
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unsigned char __user *dst,
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int len, int sum,
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int *err_ptr)
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{
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if (access_ok(VERIFY_WRITE, dst, len))
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return csum_partial_copy_generic(src, dst, len, sum, NULL, err_ptr);
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if (len)
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*err_ptr = -EFAULT;
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return -1; /* invalid checksum */
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}
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#endif /* __ASM_SH_CHECKSUM_H */
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