1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __SPARC_CHECKSUM_H
3 #define __SPARC_CHECKSUM_H
4
5 /* checksum.h: IP/UDP/TCP checksum routines on the Sparc.
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 fs:src 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
42 unsigned int __csum_partial_copy_sparc_generic (const unsigned char *, unsigned char *);
43
44 static inline __wsum
45 csum_partial_copy_nocheck(const void *src, void *dst, int len)
46 {
47 register unsigned int ret asm("o0") = (unsigned int)src;
48 register char *d asm("o1") = dst;
49 register int l asm("g1") = len;
50
51 __asm__ __volatile__ (
52 "call __csum_partial_copy_sparc_generic\n\t"
53 " mov -1, %%g7\n"
54 : "=&r" (ret), "=&r" (d), "=&r" (l)
55 : "" (ret), "1" (d), "2" (l)
56 : "o2", "o3", "o4", "o5", "o7",
57 "g2", "g3", "g4", "g5", "g7",
58 "memory", "cc");
59 return (__force __wsum)ret;
60 }
61
62 static inline __wsum
63 csum_and_copy_from_user(const void __user *src, void *dst, int len)
64 {
65 if (unlikely(!access_ok(src, len)))
66 return 0;
67 return csum_partial_copy_nocheck((__force void *)src, dst, len);
68 }
69
70 static inline __wsum
71 csum_and_copy_to_user(const void *src, void __user *dst, int len)
72 {
73 if (!access_ok(dst, len))
74 return 0;
75 return csum_partial_copy_nocheck(src, (__force void *)dst, len);
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 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
82 {
83 __sum16 sum;
84
85 /* Note: We must read %2 before we touch %0 for the first time,
86 * because GCC can legitimately use the same register for
87 * both operands.
88 */
89 __asm__ __volatile__("sub\t%2, 4, %%g4\n\t"
90 "ld\t[%1 + 0x00], %0\n\t"
91 "ld\t[%1 + 0x04], %%g2\n\t"
92 "ld\t[%1 + 0x08], %%g3\n\t"
93 "addcc\t%%g2, %0, %0\n\t"
94 "addxcc\t%%g3, %0, %0\n\t"
95 "ld\t[%1 + 0x0c], %%g2\n\t"
96 "ld\t[%1 + 0x10], %%g3\n\t"
97 "addxcc\t%%g2, %0, %0\n\t"
98 "addx\t%0, %%g0, %0\n"
99 "1:\taddcc\t%%g3, %0, %0\n\t"
100 "add\t%1, 4, %1\n\t"
101 "addxcc\t%0, %%g0, %0\n\t"
102 "subcc\t%%g4, 1, %%g4\n\t"
103 "be,a\t2f\n\t"
104 "sll\t%0, 16, %%g2\n\t"
105 "b\t1b\n\t"
106 "ld\t[%1 + 0x10], %%g3\n"
107 "2:\taddcc\t%0, %%g2, %%g2\n\t"
108 "srl\t%%g2, 16, %0\n\t"
109 "addx\t%0, %%g0, %0\n\t"
110 "xnor\t%%g0, %0, %0"
111 : "=r" (sum), "=&r" (iph)
112 : "r" (ihl), "1" (iph)
113 : "g2", "g3", "g4", "cc", "memory");
114 return sum;
115 }
116
117 /* Fold a partial checksum without adding pseudo headers. */
118 static inline __sum16 csum_fold(__wsum sum)
119 {
120 unsigned int tmp;
121
122 __asm__ __volatile__("addcc\t%0, %1, %1\n\t"
123 "srl\t%1, 16, %1\n\t"
124 "addx\t%1, %%g0, %1\n\t"
125 "xnor\t%%g0, %1, %0"
126 : "=&r" (sum), "=r" (tmp)
127 : "" (sum), "1" ((__force u32)sum<<16)
128 : "cc");
129 return (__force __sum16)sum;
130 }
131
132 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
133 __u32 len, __u8 proto,
134 __wsum sum)
135 {
136 __asm__ __volatile__("addcc\t%1, %0, %0\n\t"
137 "addxcc\t%2, %0, %0\n\t"
138 "addxcc\t%3, %0, %0\n\t"
139 "addx\t%0, %%g0, %0\n\t"
140 : "=r" (sum), "=r" (saddr)
141 : "r" (daddr), "r" (proto + len), "" (sum),
142 "1" (saddr)
143 : "cc");
144 return sum;
145 }
146
147 /*
148 * computes the checksum of the TCP/UDP pseudo-header
149 * returns a 16-bit checksum, already complemented
150 */
151 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
152 __u32 len, __u8 proto,
153 __wsum sum)
154 {
155 return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
156 }
157
158 #define _HAVE_ARCH_IPV6_CSUM
159
160 static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
161 const struct in6_addr *daddr,
162 __u32 len, __u8 proto, __wsum sum)
163 {
164 __asm__ __volatile__ (
165 "addcc %3, %4, %%g4\n\t"
166 "addxcc %5, %%g4, %%g4\n\t"
167 "ld [%2 + 0x0c], %%g2\n\t"
168 "ld [%2 + 0x08], %%g3\n\t"
169 "addxcc %%g2, %%g4, %%g4\n\t"
170 "ld [%2 + 0x04], %%g2\n\t"
171 "addxcc %%g3, %%g4, %%g4\n\t"
172 "ld [%2 + 0x00], %%g3\n\t"
173 "addxcc %%g2, %%g4, %%g4\n\t"
174 "ld [%1 + 0x0c], %%g2\n\t"
175 "addxcc %%g3, %%g4, %%g4\n\t"
176 "ld [%1 + 0x08], %%g3\n\t"
177 "addxcc %%g2, %%g4, %%g4\n\t"
178 "ld [%1 + 0x04], %%g2\n\t"
179 "addxcc %%g3, %%g4, %%g4\n\t"
180 "ld [%1 + 0x00], %%g3\n\t"
181 "addxcc %%g2, %%g4, %%g4\n\t"
182 "addxcc %%g3, %%g4, %0\n\t"
183 "addx 0, %0, %0\n"
184 : "=&r" (sum)
185 : "r" (saddr), "r" (daddr),
186 "r"(htonl(len)), "r"(htonl(proto)), "r"(sum)
187 : "g2", "g3", "g4", "cc");
188
189 return csum_fold(sum);
190 }
191
192 /* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
193 static inline __sum16 ip_compute_csum(const void *buff, int len)
194 {
195 return csum_fold(csum_partial(buff, len, 0));
196 }
197
198 #define HAVE_ARCH_CSUM_ADD
199 static inline __wsum csum_add(__wsum csum, __wsum addend)
200 {
201 __asm__ __volatile__(
202 "addcc %0, %1, %0\n"
203 "addx %0, %%g0, %0"
204 : "=r" (csum)
205 : "r" (addend), "" (csum));
206
207 return csum;
208 }
209
210 #endif /* !(__SPARC_CHECKSUM_H) */
211
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