236 строки
5.5 KiB
C
236 строки
5.5 KiB
C
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#ifndef _ASM_SCORE_CHECKSUM_H
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#define _ASM_SCORE_CHECKSUM_H
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#include <linux/in6.h>
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#include <asm/uaccess.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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unsigned int csum_partial(const void *buff, int len, __wsum sum);
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unsigned int csum_partial_copy_from_user(const char *src, char *dst, int len,
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unsigned int sum, int *csum_err);
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unsigned int csum_partial_copy(const char *src, char *dst,
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int len, unsigned int sum);
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/*
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* this is a new version of the above that records errors it finds in *errp,
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* but continues and zeros the rest of the buffer.
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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
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__wsum csum_and_copy_to_user(const void *src, void __user *dst, int len,
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__wsum sum, int *err_ptr)
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{
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sum = csum_partial(src, len, sum);
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if (copy_to_user(dst, src, len)) {
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*err_ptr = -EFAULT;
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return (__force __wsum) -1; /* invalid checksum */
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}
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return sum;
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}
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#define csum_partial_copy_nocheck csum_partial_copy
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/*
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* Fold a partial checksum without adding pseudo headers
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*/
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static inline __sum16 csum_fold(__wsum sum)
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{
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/* the while loop is unnecessary really, it's always enough with two
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iterations */
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__asm__ __volatile__(
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".set volatile\n\t"
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".set\tr1\n\t"
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"slli\tr1,%0, 16\n\t"
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"add\t%0,%0, r1\n\t"
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"cmp.c\tr1, %0\n\t"
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"srli\t%0, %0, 16\n\t"
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"bleu\t1f\n\t"
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"addi\t%0, 0x1\n\t"
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"1:ldi\tr30, 0xffff\n\t"
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"xor\t%0, %0, r30\n\t"
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"slli\t%0, %0, 16\n\t"
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"srli\t%0, %0, 16\n\t"
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".set\tnor1\n\t"
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".set optimize\n\t"
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: "=r" (sum)
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: "0" (sum));
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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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* By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
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* Arnt Gulbrandsen.
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*/
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static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
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{
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unsigned int sum;
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unsigned long dummy;
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__asm__ __volatile__(
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".set volatile\n\t"
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".set\tnor1\n\t"
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"lw\t%0, [%1]\n\t"
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"subri\t%2, %2, 4\n\t"
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"slli\t%2, %2, 2\n\t"
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"lw\t%3, [%1, 4]\n\t"
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"add\t%2, %2, %1\n\t"
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"add\t%0, %0, %3\n\t"
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"cmp.c\t%3, %0\n\t"
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"lw\t%3, [%1, 8]\n\t"
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"bleu\t1f\n\t"
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"addi\t%0, 0x1\n\t"
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"1:\n\t"
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"add\t%0, %0, %3\n\t"
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"cmp.c\t%3, %0\n\t"
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"lw\t%3, [%1, 12]\n\t"
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"bleu\t1f\n\t"
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"addi\t%0, 0x1\n\t"
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"1:add\t%0, %0, %3\n\t"
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"cmp.c\t%3, %0\n\t"
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"bleu\t1f\n\t"
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"addi\t%0, 0x1\n"
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"1:\tlw\t%3, [%1, 16]\n\t"
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"addi\t%1, 4\n\t"
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"add\t%0, %0, %3\n\t"
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"cmp.c\t%3, %0\n\t"
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"bleu\t2f\n\t"
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"addi\t%0, 0x1\n"
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"2:cmp.c\t%2, %1\n\t"
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"bne\t1b\n\t"
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".set\tr1\n\t"
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".set optimize\n\t"
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: "=&r" (sum), "=&r" (iph), "=&r" (ihl), "=&r" (dummy)
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: "1" (iph), "2" (ihl));
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return csum_fold(sum);
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}
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static inline __wsum
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csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
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unsigned short proto, __wsum sum)
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{
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unsigned long tmp = (ntohs(len) << 16) + proto * 256;
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__asm__ __volatile__(
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".set volatile\n\t"
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"add\t%0, %0, %2\n\t"
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"cmp.c\t%2, %0\n\t"
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"bleu\t1f\n\t"
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"addi\t%0, 0x1\n\t"
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"1:\n\t"
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"add\t%0, %0, %3\n\t"
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"cmp.c\t%3, %0\n\t"
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"bleu\t1f\n\t"
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"addi\t%0, 0x1\n\t"
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"1:\n\t"
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"add\t%0, %0, %4\n\t"
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"cmp.c\t%4, %0\n\t"
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"bleu\t1f\n\t"
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"addi\t%0, 0x1\n\t"
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"1:\n\t"
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".set optimize\n\t"
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: "=r" (sum)
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: "0" (daddr), "r"(saddr),
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"r" (tmp),
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"r" (sum));
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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 __sum16
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csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len,
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unsigned short proto, __wsum 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(const void *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 __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
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const struct in6_addr *daddr,
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__u32 len, unsigned short proto,
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__wsum sum)
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{
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__asm__ __volatile__(
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".set\tnoreorder\t\t\t# csum_ipv6_magic\n\t"
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".set\tnoat\n\t"
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"addu\t%0, %5\t\t\t# proto (long in network byte order)\n\t"
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"sltu\t$1, %0, %5\n\t"
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"addu\t%0, $1\n\t"
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"addu\t%0, %6\t\t\t# csum\n\t"
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"sltu\t$1, %0, %6\n\t"
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"lw\t%1, 0(%2)\t\t\t# four words source address\n\t"
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"addu\t%0, $1\n\t"
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"addu\t%0, %1\n\t"
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"sltu\t$1, %0, %1\n\t"
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"lw\t%1, 4(%2)\n\t"
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"addu\t%0, $1\n\t"
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"addu\t%0, %1\n\t"
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"sltu\t$1, %0, %1\n\t"
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"lw\t%1, 8(%2)\n\t"
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"addu\t%0, $1\n\t"
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"addu\t%0, %1\n\t"
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"sltu\t$1, %0, %1\n\t"
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"lw\t%1, 12(%2)\n\t"
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"addu\t%0, $1\n\t"
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"addu\t%0, %1\n\t"
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"sltu\t$1, %0, %1\n\t"
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"lw\t%1, 0(%3)\n\t"
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"addu\t%0, $1\n\t"
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"addu\t%0, %1\n\t"
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"sltu\t$1, %0, %1\n\t"
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"lw\t%1, 4(%3)\n\t"
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"addu\t%0, $1\n\t"
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"addu\t%0, %1\n\t"
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"sltu\t$1, %0, %1\n\t"
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"lw\t%1, 8(%3)\n\t"
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"addu\t%0, $1\n\t"
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"addu\t%0, %1\n\t"
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"sltu\t$1, %0, %1\n\t"
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"lw\t%1, 12(%3)\n\t"
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"addu\t%0, $1\n\t"
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"addu\t%0, %1\n\t"
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"sltu\t$1, %0, %1\n\t"
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"addu\t%0, $1\t\t\t# Add final carry\n\t"
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".set\tnoat\n\t"
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".set\tnoreorder"
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: "=r" (sum), "=r" (proto)
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: "r" (saddr), "r" (daddr),
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"0" (htonl(len)), "1" (htonl(proto)), "r" (sum));
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return csum_fold(sum);
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}
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#endif /* _ASM_SCORE_CHECKSUM_H */
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