aa9c33b496
Avoid conditional branch instructions during carry bit additions. Special thanks to Bernd. Simplify: Use ((len + proto) << 8) like every other __LITTLE_ENDIAN__ machine Cc: Bernd Schmidt <bernds_cb1@t-online.de> Signed-off-by: Michael Hennerich <michael.hennerich@analog.com> Signed-off-by: Bryan Wu <cooloney@kernel.org>
102 lines
2.4 KiB
C
102 lines
2.4 KiB
C
#ifndef _BFIN_CHECKSUM_H
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#define _BFIN_CHECKSUM_H
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/*
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* MODIFIED FOR BFIN April 30, 2001 akbar.hussain@lineo.com
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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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__wsum csum_partial(const void *buff, int len, __wsum 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
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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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__wsum csum_partial_copy(const void *src, void *dst,
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int len, __wsum sum);
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/*
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* the same as csum_partial_copy, but copies from user space.
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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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extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
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int len, __wsum sum, int *csum_err);
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#define csum_partial_copy_nocheck(src, dst, len, sum) \
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csum_partial_copy((src), (dst), (len), (sum))
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__sum16 ip_fast_csum(unsigned char *iph, unsigned int ihl);
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/*
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* Fold a partial checksum
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*/
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static inline __sum16 csum_fold(__wsum sum)
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{
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while (sum >> 16)
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sum = (sum & 0xffff) + (sum >> 16);
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return ((~(sum << 16)) >> 16);
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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 __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 int carry;
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__asm__ ("%0 = %0 + %2;\n\t"
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"CC = AC0;\n\t"
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"%1 = CC;\n\t"
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"%0 = %0 + %1;\n\t"
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"%0 = %0 + %3;\n\t"
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"CC = AC0;\n\t"
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"%1 = CC;\n\t"
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"%0 = %0 + %1;\n\t"
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"%0 = %0 + %4;\n\t"
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"CC = AC0;\n\t"
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"%1 = CC;\n\t"
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"%0 = %0 + %1;\n\t"
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: "=d" (sum), "=&d" (carry)
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: "d" (daddr), "d" (saddr), "d" ((len + proto) << 8), "0"(sum)
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: "CC");
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return (sum);
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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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extern __sum16 ip_compute_csum(const void *buff, int len);
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#endif /* _BFIN_CHECKSUM_H */
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