2 * arch/ubicom32/include/asm/checksum.h
3 * Checksum utilities for Ubicom32 architecture.
5 * (C) Copyright 2009, Ubicom, Inc.
7 * This file is part of the Ubicom32 Linux Kernel Port.
9 * The Ubicom32 Linux Kernel Port is free software: you can redistribute
10 * it and/or modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation, either version 2 of the
12 * License, or (at your option) any later version.
14 * The Ubicom32 Linux Kernel Port is distributed in the hope that it
15 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
16 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
17 * the GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with the Ubicom32 Linux Kernel Port. If not,
21 * see <http://www.gnu.org/licenses/>.
23 * Ubicom32 implementation derived from (with many thanks):
28 #ifndef _ASM_UBICOM32_CHECKSUM_H
29 #define _ASM_UBICOM32_CHECKSUM_H
31 #include <linux/in6.h>
34 * computes the checksum of a memory block at buff, length len,
35 * and adds in "sum" (32-bit)
37 * returns a 32-bit number suitable for feeding into itself
38 * or csum_tcpudp_magic
40 * this function must be called with even lengths, except
41 * for the last fragment, which may be odd
43 * it's best to have buff aligned on a 32-bit boundary
45 __wsum
csum_partial(const void *buff
, int len
, __wsum sum
);
48 * the same as csum_partial, but copies from src while it
51 * here even more important to align src and dst on a 32-bit (or even
52 * better 64-bit) boundary
55 __wsum
csum_partial_copy_nocheck(const void *src
, void *dst
,
60 * the same as csum_partial_copy, but copies from user space.
62 * here even more important to align src and dst on a 32-bit (or even
63 * better 64-bit) boundary
66 extern __wsum
csum_partial_copy_from_user(const void __user
*src
,
67 void *dst
, int len
, __wsum sum
, int *csum_err
);
69 __sum16
ip_fast_csum(const void *iph
, unsigned int ihl
);
72 * Fold a partial checksum
75 static inline __sum16
csum_fold(__wsum sum
)
78 " lsr.4 d15, %0, #16 \n\t"
79 " bfextu %0, %0, #16 \n\t"
80 " add.4 %0, d15, %0 \n\t"
81 " lsr.4 d15, %0, #16 \n\t"
82 " bfextu %0, %0, #16 \n\t"
83 " add.4 %0, d15, %0 \n\t"
88 return (__force __sum16
)~sum
;
93 * computes the checksum of the TCP/UDP pseudo-header
94 * returns a 16-bit checksum, already complemented
98 csum_tcpudp_nofold(__be32 saddr
, __be32 daddr
, unsigned short len
,
99 unsigned short proto
, __wsum sum
)
102 " add.4 %0, %2, %0 \n\t"
103 " addc %0, %3, %0 \n\t"
104 " addc %0, %4, %0 \n\t"
105 " addc %0, %5, %0 \n\t"
106 " addc %0, #0, %0 \n\t"
108 : "0"(sum
), "r" (saddr
), "r" (daddr
), "r" (len
), "r"(proto
)
113 static inline __sum16
114 csum_tcpudp_magic(__be32 saddr
, __be32 daddr
, unsigned short len
,
115 unsigned short proto
, __wsum sum
)
117 return csum_fold(csum_tcpudp_nofold(saddr
,daddr
,len
,proto
,sum
));
121 * this routine is used for miscellaneous IP-like checksums, mainly
124 extern __sum16
ip_compute_csum(const void *buff
, int len
);
126 #define _HAVE_ARCH_IPV6_CSUM
128 static __inline__ __sum16
129 csum_ipv6_magic(const struct in6_addr
*saddr
, const struct in6_addr
*daddr
,
130 __u32 len
, unsigned short proto
, __wsum sum
)
133 " add.4 %0, 0(%2), %0 \n\t"
134 " addc %0, 4(%2), %0 \n\t"
135 " addc %0, 8(%2), %0 \n\t"
136 " addc %0, 12(%2), %0 \n\t"
137 " addc %0, 0(%3), %0 \n\t"
138 " addc %0, 4(%3), %0 \n\t"
139 " addc %0, 8(%3), %0 \n\t"
140 " addc %0, 12(%3), %0 \n\t"
141 " addc %0, %4, %0 \n\t"
142 " addc %0, #0, %0 \n\t"
144 : "0" (sum
), "a" (saddr
), "a" (daddr
), "d" (len
+ proto
)
146 return csum_fold(sum
);
149 #endif /* _ASM_UBICOM32_CHECKSUM_H */