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Diffstat (limited to 'kernel/arch/arc/include/asm/checksum.h')
-rw-r--r-- | kernel/arch/arc/include/asm/checksum.h | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/kernel/arch/arc/include/asm/checksum.h b/kernel/arch/arc/include/asm/checksum.h new file mode 100644 index 000000000..10957298b --- /dev/null +++ b/kernel/arch/arc/include/asm/checksum.h @@ -0,0 +1,101 @@ +/* + * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Joern Rennecke <joern.rennecke@embecosm.com>: 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 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, unsigned short len, + unsigned short 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 */ |