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879178cfbe
* sanitize prototypes, annotate * kill useless shifts Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
118 lines
3.5 KiB
C
118 lines
3.5 KiB
C
#ifndef _ASM_POWERPC_CHECKSUM_H
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#define _ASM_POWERPC_CHECKSUM_H
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#ifdef __KERNEL__
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/*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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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. ihl is the number
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* of 32-bit words and is always >= 5.
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*/
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extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
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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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extern __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
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unsigned short len,
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unsigned short proto,
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__wsum sum);
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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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extern __wsum csum_partial(const void *buff, int len, __wsum sum);
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/*
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* Computes the checksum of a memory block at src, length len,
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* and adds in "sum" (32-bit), while copying the block to dst.
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* If an access exception occurs on src or dst, it stores -EFAULT
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* to *src_err or *dst_err respectively (if that pointer is not
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* NULL), and, for an error on src, zeroes the rest of dst.
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*
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* Like csum_partial, this must be called with even lengths,
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* except for the last fragment.
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*/
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extern __wsum csum_partial_copy_generic(const void *src, void *dst,
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int len, __wsum sum,
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int *src_err, int *dst_err);
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/*
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* the same as csum_partial, but copies from src to dst while it
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* checksums.
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*/
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#define csum_partial_copy_from_user(src, dst, len, sum, errp) \
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csum_partial_copy_generic((__force const void *)(src), (dst), (len), (sum), (errp), NULL)
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#define csum_partial_copy_nocheck(src, dst, len, sum) \
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csum_partial_copy_generic((src), (dst), (len), (sum), NULL, NULL)
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/*
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* turns a 32-bit partial checksum (e.g. from csum_partial) into a
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* 1's complement 16-bit checksum.
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*/
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static inline __sum16 csum_fold(__wsum sum)
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{
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unsigned int tmp;
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/* swap the two 16-bit halves of sum */
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__asm__("rlwinm %0,%1,16,0,31" : "=r" (tmp) : "r" (sum));
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/* if there is a carry from adding the two 16-bit halves,
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it will carry from the lower half into the upper half,
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giving us the correct sum in the upper half. */
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return (__force __sum16)(~((__force u32)sum + tmp) >> 16);
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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 __sum16 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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static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
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unsigned short len,
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unsigned short proto,
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__wsum sum)
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{
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#ifdef __powerpc64__
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unsigned long s = (__force u32)sum;
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s += (__force u32)saddr;
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s += (__force u32)daddr;
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s += proto + len;
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s += (s >> 32);
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return (__force __wsum) s;
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#else
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__asm__("\n\
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addc %0,%0,%1 \n\
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adde %0,%0,%2 \n\
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adde %0,%0,%3 \n\
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addze %0,%0 \n\
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"
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: "=r" (sum)
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: "r" (daddr), "r"(saddr), "r"(proto + len), "0"(sum));
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return sum;
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#endif
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}
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#endif /* __KERNEL__ */
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#endif
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