1 /* TODO: csum_tcpudp_magic could be speeded up, and csum_fold as well */
3 #ifndef _CRIS_CHECKSUM_H
4 #define _CRIS_CHECKSUM_H
6 #include <arch/checksum.h>
9 * computes the checksum of a memory block at buff, length len,
10 * and adds in "sum" (32-bit)
12 * returns a 32-bit number suitable for feeding into itself
13 * or csum_tcpudp_magic
15 * this function must be called with even lengths, except
16 * for the last fragment, which may be odd
18 * it's best to have buff aligned on a 32-bit boundary
20 __wsum
csum_partial(const void *buff
, int len
, __wsum sum
);
23 * the same as csum_partial, but copies from src while it
26 * here even more important to align src and dst on a 32-bit (or even
27 * better 64-bit) boundary
30 __wsum
csum_partial_copy_nocheck(const void *src
, void *dst
,
34 * Fold a partial checksum into a word
37 static inline __sum16
csum_fold(__wsum csum
)
39 u32 sum
= (__force u32
)csum
;
40 sum
= (sum
& 0xffff) + (sum
>> 16); /* add in end-around carry */
41 sum
= (sum
& 0xffff) + (sum
>> 16); /* add in end-around carry */
42 return (__force __sum16
)~sum
;
45 extern __wsum
csum_partial_copy_from_user(const void __user
*src
, void *dst
,
50 * This is a version of ip_compute_csum() optimized for IP headers,
51 * which always checksum on 4 octet boundaries.
55 static inline __sum16
ip_fast_csum(const void *iph
, unsigned int ihl
)
57 return csum_fold(csum_partial(iph
, ihl
* 4, 0));
61 * computes the checksum of the TCP/UDP pseudo-header
62 * returns a 16-bit checksum, already complemented
65 static inline __sum16
csum_tcpudp_magic(__be32 saddr
, __be32 daddr
,
66 __u32 len
, __u8 proto
,
69 return csum_fold(csum_tcpudp_nofold(saddr
,daddr
,len
,proto
,sum
));
73 * this routine is used for miscellaneous IP-like checksums, mainly
77 static inline __sum16
ip_compute_csum(const void *buff
, int len
)
79 return csum_fold (csum_partial(buff
, len
, 0));