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author | Ingo Molnar <mingo@elte.hu> | 2008-11-20 09:03:38 +0100 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-11-20 09:03:38 +0100 |
commit | 90accd6fabf9b2fa2705945a4c601877a75d43bf (patch) | |
tree | d393cb54f0228b1313139e4e14adf4f5cf236b59 /arch/cris/include/asm/checksum.h | |
parent | b43d196c4d3fe46d6dda7c987c47792612b80b1b (diff) | |
parent | ee2f6cc7f9ea2542ad46070ed62ba7aa04d08871 (diff) |
Merge branch 'linus' into x86/memory-corruption-check
Diffstat (limited to 'arch/cris/include/asm/checksum.h')
-rw-r--r-- | arch/cris/include/asm/checksum.h | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/arch/cris/include/asm/checksum.h b/arch/cris/include/asm/checksum.h new file mode 100644 index 00000000000..75dcb77d6cb --- /dev/null +++ b/arch/cris/include/asm/checksum.h @@ -0,0 +1,83 @@ +/* TODO: csum_tcpudp_magic could be speeded up, and csum_fold as well */ + +#ifndef _CRIS_CHECKSUM_H +#define _CRIS_CHECKSUM_H + +#include <arch/checksum.h> + +/* + * computes the checksum of a memory block at buff, length len, + * and adds in "sum" (32-bit) + * + * returns a 32-bit number suitable for feeding into itself + * or csum_tcpudp_magic + * + * this function must be called with even lengths, except + * for the last fragment, which may be odd + * + * it's best to have buff aligned on a 32-bit boundary + */ +__wsum csum_partial(const void *buff, int len, __wsum sum); + +/* + * the same as csum_partial, but copies from src while it + * checksums + * + * here even more important to align src and dst on a 32-bit (or even + * better 64-bit) boundary + */ + +__wsum csum_partial_copy_nocheck(const void *src, void *dst, + int len, __wsum sum); + +/* + * Fold a partial checksum into a word + */ + +static inline __sum16 csum_fold(__wsum csum) +{ + u32 sum = (__force u32)csum; + sum = (sum & 0xffff) + (sum >> 16); /* add in end-around carry */ + sum = (sum & 0xffff) + (sum >> 16); /* add in end-around carry */ + return (__force __sum16)~sum; +} + +extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst, + int len, __wsum sum, + int *errptr); + +/* + * 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) +{ + return csum_fold(csum_partial(iph, ihl * 4, 0)); +} + +/* + * computes the checksum of the TCP/UDP pseudo-header + * returns a 16-bit checksum, already complemented + */ + +static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, + unsigned short len, + unsigned short proto, + __wsum sum) +{ + return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum)); +} + +/* + * this routine is used for miscellaneous IP-like checksums, mainly + * in icmp.c + */ + +static inline __sum16 ip_compute_csum(const void *buff, int len) +{ + return csum_fold (csum_partial(buff, len, 0)); +} + +#endif |