102 строки
2.5 KiB
C
102 строки
2.5 KiB
C
/*
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* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Joern Rennecke <joern.rennecke@embecosm.com>: Jan 2012
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* -Insn Scheduling improvements to csum core routines.
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* = csum_fold( ) largely derived from ARM version.
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* = ip_fast_cum( ) to have module scheduling
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* -gcc 4.4.x broke networking. Alias analysis needed to be primed.
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* worked around by adding memory clobber to ip_fast_csum( )
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*
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* vineetg: May 2010
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* -Rewrote ip_fast_cscum( ) and csum_fold( ) with fast inline asm
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*/
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#ifndef _ASM_ARC_CHECKSUM_H
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#define _ASM_ARC_CHECKSUM_H
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/*
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* Fold a partial checksum
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*
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* The 2 swords comprising the 32bit sum are added, any carry to 16th bit
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* added back and final sword result inverted.
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*/
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static inline __sum16 csum_fold(__wsum s)
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{
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unsigned r = s << 16 | s >> 16; /* ror */
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s = ~s;
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s -= r;
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return s >> 16;
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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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static inline __sum16
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ip_fast_csum(const void *iph, unsigned int ihl)
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{
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const void *ptr = iph;
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unsigned int tmp, tmp2, sum;
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__asm__(
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" ld.ab %0, [%3, 4] \n"
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" ld.ab %2, [%3, 4] \n"
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" sub %1, %4, 2 \n"
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" lsr.f lp_count, %1, 1 \n"
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" bcc 0f \n"
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" add.f %0, %0, %2 \n"
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" ld.ab %2, [%3, 4] \n"
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"0: lp 1f \n"
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" ld.ab %1, [%3, 4] \n"
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" adc.f %0, %0, %2 \n"
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" ld.ab %2, [%3, 4] \n"
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" adc.f %0, %0, %1 \n"
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"1: adc.f %0, %0, %2 \n"
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" add.cs %0,%0,1 \n"
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: "=&r"(sum), "=r"(tmp), "=&r"(tmp2), "+&r" (ptr)
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: "r"(ihl)
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: "cc", "lp_count", "memory");
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return csum_fold(sum);
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}
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/*
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* TCP pseudo Header is 12 bytes:
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* SA [4], DA [4], zeroes [1], Proto[1], TCP Seg(hdr+data) Len [2]
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*/
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static inline __wsum
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csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
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__u8 proto, __wsum sum)
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{
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__asm__ __volatile__(
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" add.f %0, %0, %1 \n"
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" adc.f %0, %0, %2 \n"
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" adc.f %0, %0, %3 \n"
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" adc.f %0, %0, %4 \n"
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" adc %0, %0, 0 \n"
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: "+&r"(sum)
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: "r"(saddr), "r"(daddr),
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#ifdef CONFIG_CPU_BIG_ENDIAN
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"r"(len),
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#else
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"r"(len << 8),
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#endif
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"r"(htons(proto))
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: "cc");
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return sum;
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}
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#define csum_fold csum_fold
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#define ip_fast_csum ip_fast_csum
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#define csum_tcpudp_nofold csum_tcpudp_nofold
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#include <asm-generic/checksum.h>
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#endif /* _ASM_ARC_CHECKSUM_H */
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