1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __SPARC64_CHECKSUM_H
3 #define __SPARC64_CHECKSUM_H
4 
5 /*  checksum.h:  IP/UDP/TCP checksum routines on the V9.
6  *
7  *  Copyright(C) 1995 Linus Torvalds
8  *  Copyright(C) 1995 Miguel de Icaza
9  *  Copyright(C) 1996 David S. Miller
10  *  Copyright(C) 1996 Eddie C. Dost
11  *  Copyright(C) 1997 Jakub Jelinek
12  *
13  * derived from:
14  *	Alpha checksum c-code
15  *      ix86 inline assembly
16  *      RFC1071 Computing the Internet Checksum
17  */
18 
19 #include <linux/in6.h>
20 #include <linux/uaccess.h>
21 
22 /* computes the checksum of a memory block at buff, length len,
23  * and adds in "sum" (32-bit)
24  *
25  * returns a 32-bit number suitable for feeding into itself
26  * or csum_tcpudp_magic
27  *
28  * this function must be called with even lengths, except
29  * for the last fragment, which may be odd
30  *
31  * it's best to have buff aligned on a 32-bit boundary
32  */
33 __wsum csum_partial(const void * buff, int len, __wsum sum);
34 
35 /* the same as csum_partial, but copies from user space while it
36  * checksums
37  *
38  * here even more important to align src and dst on a 32-bit (or even
39  * better 64-bit) boundary
40  */
41 __wsum csum_partial_copy_nocheck(const void *src, void *dst,
42 				 int len, __wsum sum);
43 
44 long __csum_partial_copy_from_user(const void __user *src,
45 				   void *dst, int len,
46 				   __wsum sum);
47 
48 static inline __wsum
49 csum_partial_copy_from_user(const void __user *src,
50 			    void *dst, int len,
51 			    __wsum sum, int *err)
52 {
53 	long ret = __csum_partial_copy_from_user(src, dst, len, sum);
54 	if (ret < 0)
55 		*err = -EFAULT;
56 	return (__force __wsum) ret;
57 }
58 
59 /*
60  *	Copy and checksum to user
61  */
62 #define HAVE_CSUM_COPY_USER
63 long __csum_partial_copy_to_user(const void *src,
64 				 void __user *dst, int len,
65 				 __wsum sum);
66 
67 static inline __wsum
68 csum_and_copy_to_user(const void *src,
69 		      void __user *dst, int len,
70 		      __wsum sum, int *err)
71 {
72 	long ret = __csum_partial_copy_to_user(src, dst, len, sum);
73 	if (ret < 0)
74 		*err = -EFAULT;
75 	return (__force __wsum) ret;
76 }
77 
78 /* ihl is always 5 or greater, almost always is 5, and iph is word aligned
79  * the majority of the time.
80  */
81 __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
82 
83 /* Fold a partial checksum without adding pseudo headers. */
84 static inline __sum16 csum_fold(__wsum sum)
85 {
86 	unsigned int tmp;
87 
88 	__asm__ __volatile__(
89 "	addcc		%0, %1, %1\n"
90 "	srl		%1, 16, %1\n"
91 "	addc		%1, %%g0, %1\n"
92 "	xnor		%%g0, %1, %0\n"
93 	: "=&r" (sum), "=r" (tmp)
94 	: "0" (sum), "1" ((__force u32)sum<<16)
95 	: "cc");
96 	return (__force __sum16)sum;
97 }
98 
99 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
100 					__u32 len, __u8 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 					__u32 len, __u8 proto,
120 					__wsum sum)
121 {
122 	return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
123 }
124 
125 #define _HAVE_ARCH_IPV6_CSUM
126 
127 static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
128 				      const struct in6_addr *daddr,
129 				      __u32 len, __u8 proto, __wsum sum)
130 {
131 	__asm__ __volatile__ (
132 "	addcc		%3, %4, %%g7\n"
133 "	addccc		%5, %%g7, %%g7\n"
134 "	lduw		[%2 + 0x0c], %%g2\n"
135 "	lduw		[%2 + 0x08], %%g3\n"
136 "	addccc		%%g2, %%g7, %%g7\n"
137 "	lduw		[%2 + 0x04], %%g2\n"
138 "	addccc		%%g3, %%g7, %%g7\n"
139 "	lduw		[%2 + 0x00], %%g3\n"
140 "	addccc		%%g2, %%g7, %%g7\n"
141 "	lduw		[%1 + 0x0c], %%g2\n"
142 "	addccc		%%g3, %%g7, %%g7\n"
143 "	lduw		[%1 + 0x08], %%g3\n"
144 "	addccc		%%g2, %%g7, %%g7\n"
145 "	lduw		[%1 + 0x04], %%g2\n"
146 "	addccc		%%g3, %%g7, %%g7\n"
147 "	lduw		[%1 + 0x00], %%g3\n"
148 "	addccc		%%g2, %%g7, %%g7\n"
149 "	addccc		%%g3, %%g7, %0\n"
150 "	addc		0, %0, %0\n"
151 	: "=&r" (sum)
152 	: "r" (saddr), "r" (daddr), "r"(htonl(len)),
153 	  "r"(htonl(proto)), "r"(sum)
154 	: "g2", "g3", "g7", "cc");
155 
156 	return csum_fold(sum);
157 }
158 
159 /* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
160 static inline __sum16 ip_compute_csum(const void *buff, int len)
161 {
162 	return csum_fold(csum_partial(buff, len, 0));
163 }
164 
165 #define HAVE_ARCH_CSUM_ADD
166 static inline __wsum csum_add(__wsum csum, __wsum addend)
167 {
168 	__asm__ __volatile__(
169 		"addcc   %0, %1, %0\n"
170 		"addx    %0, %%g0, %0"
171 		: "=r" (csum)
172 		: "r" (addend), "0" (csum));
173 
174 	return csum;
175 }
176 
177 #endif /* !(__SPARC64_CHECKSUM_H) */
178