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- /* SPDX-License-Identifier: GPL-2.0-only */
- /*
- * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
- *
- * Joern Rennecke <[email protected]>: Jan 2012
- * -Insn Scheduling improvements to csum core routines.
- * = csum_fold( ) largely derived from ARM version.
- * = ip_fast_cum( ) to have module scheduling
- * -gcc 4.4.x broke networking. Alias analysis needed to be primed.
- * worked around by adding memory clobber to ip_fast_csum( )
- *
- * vineetg: May 2010
- * -Rewrote ip_fast_cscum( ) and csum_fold( ) with fast inline asm
- */
- #ifndef _ASM_ARC_CHECKSUM_H
- #define _ASM_ARC_CHECKSUM_H
- /*
- * Fold a partial checksum
- *
- * The 2 swords comprising the 32bit sum are added, any carry to 16th bit
- * added back and final sword result inverted.
- */
- static inline __sum16 csum_fold(__wsum s)
- {
- unsigned int r = s << 16 | s >> 16; /* ror */
- s = ~s;
- s -= r;
- return s >> 16;
- }
- /*
- * This is a version of ip_compute_csum() optimized for IP headers,
- * which always checksum on 4 octet boundaries.
- */
- static inline __sum16
- ip_fast_csum(const void *iph, unsigned int ihl)
- {
- const void *ptr = iph;
- unsigned int tmp, tmp2, sum;
- __asm__(
- " ld.ab %0, [%3, 4] \n"
- " ld.ab %2, [%3, 4] \n"
- " sub %1, %4, 2 \n"
- " lsr.f lp_count, %1, 1 \n"
- " bcc 0f \n"
- " add.f %0, %0, %2 \n"
- " ld.ab %2, [%3, 4] \n"
- "0: lp 1f \n"
- " ld.ab %1, [%3, 4] \n"
- " adc.f %0, %0, %2 \n"
- " ld.ab %2, [%3, 4] \n"
- " adc.f %0, %0, %1 \n"
- "1: adc.f %0, %0, %2 \n"
- " add.cs %0,%0,1 \n"
- : "=&r"(sum), "=r"(tmp), "=&r"(tmp2), "+&r" (ptr)
- : "r"(ihl)
- : "cc", "lp_count", "memory");
- return csum_fold(sum);
- }
- /*
- * TCP pseudo Header is 12 bytes:
- * SA [4], DA [4], zeroes [1], Proto[1], TCP Seg(hdr+data) Len [2]
- */
- static inline __wsum
- csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
- __u8 proto, __wsum sum)
- {
- __asm__ __volatile__(
- " add.f %0, %0, %1 \n"
- " adc.f %0, %0, %2 \n"
- " adc.f %0, %0, %3 \n"
- " adc.f %0, %0, %4 \n"
- " adc %0, %0, 0 \n"
- : "+&r"(sum)
- : "r"(saddr), "r"(daddr),
- #ifdef CONFIG_CPU_BIG_ENDIAN
- "r"(len),
- #else
- "r"(len << 8),
- #endif
- "r"(htons(proto))
- : "cc");
- return sum;
- }
- #define csum_fold csum_fold
- #define ip_fast_csum ip_fast_csum
- #define csum_tcpudp_nofold csum_tcpudp_nofold
- #include <asm-generic/checksum.h>
- #endif /* _ASM_ARC_CHECKSUM_H */
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