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checksum_64.h
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1 #ifndef __SPARC64_CHECKSUM_H
2 #define __SPARC64_CHECKSUM_H
3 
4 /* checksum.h: IP/UDP/TCP checksum routines on the V9.
5  *
6  * Copyright(C) 1995 Linus Torvalds
7  * Copyright(C) 1995 Miguel de Icaza
8  * Copyright(C) 1996 David S. Miller
9  * Copyright(C) 1996 Eddie C. Dost
10  * Copyright(C) 1997 Jakub Jelinek
11  *
12  * derived from:
13  * Alpha checksum c-code
14  * ix86 inline assembly
15  * RFC1071 Computing the Internet Checksum
16  */
17 
18 #include <linux/in6.h>
19 #include <asm/uaccess.h>
20 
21 /* computes the checksum of a memory block at buff, length len,
22  * and adds in "sum" (32-bit)
23  *
24  * returns a 32-bit number suitable for feeding into itself
25  * or csum_tcpudp_magic
26  *
27  * this function must be called with even lengths, except
28  * for the last fragment, which may be odd
29  *
30  * it's best to have buff aligned on a 32-bit boundary
31  */
32 extern __wsum csum_partial(const void * buff, int len, __wsum sum);
33 
34 /* the same as csum_partial, but copies from user space while it
35  * checksums
36  *
37  * here even more important to align src and dst on a 32-bit (or even
38  * better 64-bit) boundary
39  */
40 extern __wsum csum_partial_copy_nocheck(const void *src, void *dst,
41  int len, __wsum sum);
42 
43 extern long __csum_partial_copy_from_user(const void __user *src,
44  void *dst, int len,
45  __wsum sum);
46 
47 static inline __wsum
48 csum_partial_copy_from_user(const void __user *src,
49  void *dst, int len,
50  __wsum sum, int *err)
51 {
52  long ret = __csum_partial_copy_from_user(src, dst, len, sum);
53  if (ret < 0)
54  *err = -EFAULT;
55  return (__force __wsum) ret;
56 }
57 
58 /*
59  * Copy and checksum to user
60  */
61 #define HAVE_CSUM_COPY_USER
62 extern long __csum_partial_copy_to_user(const void *src,
63  void __user *dst, int len,
64  __wsum sum);
65 
66 static inline __wsum
67 csum_and_copy_to_user(const void *src,
68  void __user *dst, int len,
69  __wsum sum, int *err)
70 {
71  long ret = __csum_partial_copy_to_user(src, dst, len, sum);
72  if (ret < 0)
73  *err = -EFAULT;
74  return (__force __wsum) ret;
75 }
76 
77 /* ihl is always 5 or greater, almost always is 5, and iph is word aligned
78  * the majority of the time.
79  */
80 extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
81 
82 /* Fold a partial checksum without adding pseudo headers. */
83 static inline __sum16 csum_fold(__wsum sum)
84 {
85  unsigned int tmp;
86 
87  __asm__ __volatile__(
88 " addcc %0, %1, %1\n"
89 " srl %1, 16, %1\n"
90 " addc %1, %%g0, %1\n"
91 " xnor %%g0, %1, %0\n"
92  : "=&r" (sum), "=r" (tmp)
93  : "0" (sum), "1" ((__force u32)sum<<16)
94  : "cc");
95  return (__force __sum16)sum;
96 }
97 
99  unsigned int len,
100  unsigned short proto,
101  __wsum sum)
102 {
103  __asm__ __volatile__(
104 " addcc %1, %0, %0\n"
105 " addccc %2, %0, %0\n"
106 " addccc %3, %0, %0\n"
107 " addc %0, %%g0, %0\n"
108  : "=r" (sum), "=r" (saddr)
109  : "r" (daddr), "r" (proto + len), "0" (sum), "1" (saddr)
110  : "cc");
111  return sum;
112 }
113 
114 /*
115  * computes the checksum of the TCP/UDP pseudo-header
116  * returns a 16-bit checksum, already complemented
117  */
118 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
119  unsigned short len,
120  unsigned short proto,
121  __wsum sum)
122 {
123  return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
124 }
125 
126 #define _HAVE_ARCH_IPV6_CSUM
127 
128 static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
129  const struct in6_addr *daddr,
130  __u32 len, unsigned short proto,
131  __wsum sum)
132 {
133  __asm__ __volatile__ (
134 " addcc %3, %4, %%g7\n"
135 " addccc %5, %%g7, %%g7\n"
136 " lduw [%2 + 0x0c], %%g2\n"
137 " lduw [%2 + 0x08], %%g3\n"
138 " addccc %%g2, %%g7, %%g7\n"
139 " lduw [%2 + 0x04], %%g2\n"
140 " addccc %%g3, %%g7, %%g7\n"
141 " lduw [%2 + 0x00], %%g3\n"
142 " addccc %%g2, %%g7, %%g7\n"
143 " lduw [%1 + 0x0c], %%g2\n"
144 " addccc %%g3, %%g7, %%g7\n"
145 " lduw [%1 + 0x08], %%g3\n"
146 " addccc %%g2, %%g7, %%g7\n"
147 " lduw [%1 + 0x04], %%g2\n"
148 " addccc %%g3, %%g7, %%g7\n"
149 " lduw [%1 + 0x00], %%g3\n"
150 " addccc %%g2, %%g7, %%g7\n"
151 " addccc %%g3, %%g7, %0\n"
152 " addc 0, %0, %0\n"
153  : "=&r" (sum)
154  : "r" (saddr), "r" (daddr), "r"(htonl(len)),
155  "r"(htonl(proto)), "r"(sum)
156  : "g2", "g3", "g7", "cc");
157 
158  return csum_fold(sum);
159 }
160 
161 /* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
162 static inline __sum16 ip_compute_csum(const void *buff, int len)
163 {
164  return csum_fold(csum_partial(buff, len, 0));
165 }
166 
167 #endif /* !(__SPARC64_CHECKSUM_H) */