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, int len);
42 __wsum csum_and_copy_from_user(const void __user *src, void *dst, int len);
43 __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len);
44 
45 /* ihl is always 5 or greater, almost always is 5, and iph is word aligned
46  * the majority of the time.
47  */
48 __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
49 
50 /* Fold a partial checksum without adding pseudo headers. */
51 static inline __sum16 csum_fold(__wsum sum)
52 {
53 	unsigned int tmp;
54 
55 	__asm__ __volatile__(
56 "	addcc		%0, %1, %1\n"
57 "	srl		%1, 16, %1\n"
58 "	addc		%1, %%g0, %1\n"
59 "	xnor		%%g0, %1, %0\n"
60 	: "=&r" (sum), "=r" (tmp)
61 	: "0" (sum), "1" ((__force u32)sum<<16)
62 	: "cc");
63 	return (__force __sum16)sum;
64 }
65 
66 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
67 					__u32 len, __u8 proto,
68 					__wsum sum)
69 {
70 	__asm__ __volatile__(
71 "	addcc		%1, %0, %0\n"
72 "	addccc		%2, %0, %0\n"
73 "	addccc		%3, %0, %0\n"
74 "	addc		%0, %%g0, %0\n"
75 	: "=r" (sum), "=r" (saddr)
76 	: "r" (daddr), "r" (proto + len), "0" (sum), "1" (saddr)
77 	: "cc");
78 	return sum;
79 }
80 
81 /*
82  * computes the checksum of the TCP/UDP pseudo-header
83  * returns a 16-bit checksum, already complemented
84  */
85 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
86 					__u32 len, __u8 proto,
87 					__wsum sum)
88 {
89 	return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
90 }
91 
92 #define _HAVE_ARCH_IPV6_CSUM
93 
94 static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
95 				      const struct in6_addr *daddr,
96 				      __u32 len, __u8 proto, __wsum sum)
97 {
98 	__asm__ __volatile__ (
99 "	addcc		%3, %4, %%g7\n"
100 "	addccc		%5, %%g7, %%g7\n"
101 "	lduw		[%2 + 0x0c], %%g2\n"
102 "	lduw		[%2 + 0x08], %%g3\n"
103 "	addccc		%%g2, %%g7, %%g7\n"
104 "	lduw		[%2 + 0x04], %%g2\n"
105 "	addccc		%%g3, %%g7, %%g7\n"
106 "	lduw		[%2 + 0x00], %%g3\n"
107 "	addccc		%%g2, %%g7, %%g7\n"
108 "	lduw		[%1 + 0x0c], %%g2\n"
109 "	addccc		%%g3, %%g7, %%g7\n"
110 "	lduw		[%1 + 0x08], %%g3\n"
111 "	addccc		%%g2, %%g7, %%g7\n"
112 "	lduw		[%1 + 0x04], %%g2\n"
113 "	addccc		%%g3, %%g7, %%g7\n"
114 "	lduw		[%1 + 0x00], %%g3\n"
115 "	addccc		%%g2, %%g7, %%g7\n"
116 "	addccc		%%g3, %%g7, %0\n"
117 "	addc		0, %0, %0\n"
118 	: "=&r" (sum)
119 	: "r" (saddr), "r" (daddr), "r"(htonl(len)),
120 	  "r"(htonl(proto)), "r"(sum)
121 	: "g2", "g3", "g7", "cc");
122 
123 	return csum_fold(sum);
124 }
125 
126 /* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
127 static inline __sum16 ip_compute_csum(const void *buff, int len)
128 {
129 	return csum_fold(csum_partial(buff, len, 0));
130 }
131 
132 #define HAVE_ARCH_CSUM_ADD
133 static inline __wsum csum_add(__wsum csum, __wsum addend)
134 {
135 	__asm__ __volatile__(
136 		"addcc   %0, %1, %0\n"
137 		"addx    %0, %%g0, %0"
138 		: "=r" (csum)
139 		: "r" (addend), "0" (csum));
140 
141 	return csum;
142 }
143 
144 #endif /* !(__SPARC64_CHECKSUM_H) */
145