1#ifndef _ASM_POWERPC_CHECKSUM_H
2#define _ASM_POWERPC_CHECKSUM_H
3#ifdef __KERNEL__
4
5/*
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12/*
13 * This is a version of ip_compute_csum() optimized for IP headers,
14 * which always checksum on 4 octet boundaries.  ihl is the number
15 * of 32-bit words and is always >= 5.
16 */
17#ifdef CONFIG_GENERIC_CSUM
18#include <asm-generic/checksum.h>
19#else
20extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
21
22/*
23 * computes the checksum of the TCP/UDP pseudo-header
24 * returns a 16-bit checksum, already complemented
25 */
26extern __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
27					unsigned short len,
28					unsigned short proto,
29					__wsum sum);
30
31/*
32 * computes the checksum of a memory block at buff, length len,
33 * and adds in "sum" (32-bit)
34 *
35 * returns a 32-bit number suitable for feeding into itself
36 * or csum_tcpudp_magic
37 *
38 * this function must be called with even lengths, except
39 * for the last fragment, which may be odd
40 *
41 * it's best to have buff aligned on a 32-bit boundary
42 */
43extern __wsum csum_partial(const void *buff, int len, __wsum sum);
44
45/*
46 * Computes the checksum of a memory block at src, length len,
47 * and adds in "sum" (32-bit), while copying the block to dst.
48 * If an access exception occurs on src or dst, it stores -EFAULT
49 * to *src_err or *dst_err respectively (if that pointer is not
50 * NULL), and, for an error on src, zeroes the rest of dst.
51 *
52 * Like csum_partial, this must be called with even lengths,
53 * except for the last fragment.
54 */
55extern __wsum csum_partial_copy_generic(const void *src, void *dst,
56					      int len, __wsum sum,
57					      int *src_err, int *dst_err);
58
59#ifdef __powerpc64__
60#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
61extern __wsum csum_and_copy_from_user(const void __user *src, void *dst,
62				      int len, __wsum sum, int *err_ptr);
63#define HAVE_CSUM_COPY_USER
64extern __wsum csum_and_copy_to_user(const void *src, void __user *dst,
65				    int len, __wsum sum, int *err_ptr);
66#else
67/*
68 * the same as csum_partial, but copies from src to dst while it
69 * checksums.
70 */
71#define csum_partial_copy_from_user(src, dst, len, sum, errp)   \
72        csum_partial_copy_generic((__force const void *)(src), (dst), (len), (sum), (errp), NULL)
73#endif
74
75#define csum_partial_copy_nocheck(src, dst, len, sum)   \
76        csum_partial_copy_generic((src), (dst), (len), (sum), NULL, NULL)
77
78
79/*
80 * turns a 32-bit partial checksum (e.g. from csum_partial) into a
81 * 1's complement 16-bit checksum.
82 */
83static inline __sum16 csum_fold(__wsum sum)
84{
85	unsigned int tmp;
86
87	/* swap the two 16-bit halves of sum */
88	__asm__("rlwinm %0,%1,16,0,31" : "=r" (tmp) : "r" (sum));
89	/* if there is a carry from adding the two 16-bit halves,
90	   it will carry from the lower half into the upper half,
91	   giving us the correct sum in the upper half. */
92	return (__force __sum16)(~((__force u32)sum + tmp) >> 16);
93}
94
95/*
96 * this routine is used for miscellaneous IP-like checksums, mainly
97 * in icmp.c
98 */
99static inline __sum16 ip_compute_csum(const void *buff, int len)
100{
101	return csum_fold(csum_partial(buff, len, 0));
102}
103
104static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
105                                     unsigned short len,
106                                     unsigned short proto,
107                                     __wsum sum)
108{
109#ifdef __powerpc64__
110	unsigned long s = (__force u32)sum;
111
112	s += (__force u32)saddr;
113	s += (__force u32)daddr;
114	s += proto + len;
115	s += (s >> 32);
116	return (__force __wsum) s;
117#else
118    __asm__("\n\
119	addc %0,%0,%1 \n\
120	adde %0,%0,%2 \n\
121	adde %0,%0,%3 \n\
122	addze %0,%0 \n\
123	"
124	: "=r" (sum)
125	: "r" (daddr), "r"(saddr), "r"(proto + len), "0"(sum));
126	return sum;
127#endif
128}
129
130#endif
131#endif /* __KERNEL__ */
132#endif
133