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 __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 __wsum csum_partial_copy_nocheck(const void *src, void *dst,
41 				 int len, __wsum sum);
42 
43 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 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 __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 
98 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
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 #define HAVE_ARCH_CSUM_ADD
168 static inline __wsum csum_add(__wsum csum, __wsum addend)
169 {
170 	__asm__ __volatile__(
171 		"addcc   %0, %1, %0\n"
172 		"addx    %0, %%g0, %0"
173 		: "=r" (csum)
174 		: "r" (addend), "0" (csum));
175 
176 	return csum;
177 }
178 
179 #endif /* !(__SPARC64_CHECKSUM_H) */
180