From 10104a1ad670889adc1ae3779df968db621b5dbd Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Sat, 28 Apr 2012 15:41:39 -0400 Subject: arch/tile: break out the "csum a long" function to This makes it available to the tilegx network driver. Signed-off-by: Chris Metcalf --- arch/tile/include/asm/checksum.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'arch/tile/include/asm/checksum.h') diff --git a/arch/tile/include/asm/checksum.h b/arch/tile/include/asm/checksum.h index a120766c7264..b21a2fdec9f7 100644 --- a/arch/tile/include/asm/checksum.h +++ b/arch/tile/include/asm/checksum.h @@ -21,4 +21,22 @@ __wsum do_csum(const unsigned char *buff, int len); #define do_csum do_csum +/* + * Return the sum of all the 16-bit subwords in a long. + * This sums two subwords on a 32-bit machine, and four on 64 bits. + * The implementation does two vector adds to capture any overflow. + */ +static inline unsigned int csum_long(unsigned long x) +{ + unsigned long ret; +#ifdef __tilegx__ + ret = __insn_v2sadu(x, 0); + ret = __insn_v2sadu(ret, 0); +#else + ret = __insn_sadh_u(x, 0); + ret = __insn_sadh_u(ret, 0); +#endif + return ret; +} + #endif /* _ASM_TILE_CHECKSUM_H */ -- cgit v1.2.3-59-g8ed1b