1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _PARISC_CHECKSUM_H
3 #define _PARISC_CHECKSUM_H
4
5 #include <linux/in6.h>
6
7 /*
8 * computes the checksum of a memory block at buff, length len,
9 * and adds in "sum" (32-bit)
10 *
11 * returns a 32-bit number suitable for feeding into itself
12 * or csum_tcpudp_magic
13 *
14 * this function must be called with even lengths, except
15 * for the last fragment, which may be odd
16 *
17 * it's best to have buff aligned on a 32-bit boundary
18 */
19 extern __wsum csum_partial(const void *, int, __wsum);
20
21 /*
22 * Optimized for IP headers, which always checksum on 4 octet boundaries.
23 *
24 * Written by Randolph Chung <tausq@debian.org>, and then mucked with by
25 * LaMont Jones <lamont@debian.org>
26 */
27 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
28 {
29 unsigned int sum;
30 unsigned long t0, t1, t2;
31
32 __asm__ __volatile__ (
33 " ldws,ma 4(%1), %0\n"
34 " addib,<= -4, %2, 2f\n"
35 "\n"
36 " ldws 4(%1), %4\n"
37 " ldws 8(%1), %5\n"
38 " add %0, %4, %0\n"
39 " ldws,ma 12(%1), %3\n"
40 " addc %0, %5, %0\n"
41 " addc %0, %3, %0\n"
42 "1: ldws,ma 4(%1), %3\n"
43 " addib,> -1, %2, 1b\n"
44 " addc %0, %3, %0\n"
45 "\n"
46 " extru %0, 31, 16, %4\n"
47 " extru %0, 15, 16, %5\n"
48 " addc %4, %5, %0\n"
49 " extru %0, 15, 16, %5\n"
50 " add %0, %5, %0\n"
51 " subi -1, %0, %0\n"
52 "2:\n"
53 : "=r" (sum), "=r" (iph), "=r" (ihl), "=r" (t0), "=r" (t1), "=r" (t2)
54 : "1" (iph), "2" (ihl)
55 : "memory");
56
57 return (__force __sum16)sum;
58 }
59
60 /*
61 * Fold a partial checksum
62 */
63 static inline __sum16 csum_fold(__wsum csum)
64 {
65 u32 sum = (__force u32)csum;
66 /* add the swapped two 16-bit halves of sum,
67 a possible carry from adding the two 16-bit halves,
68 will carry from the lower half into the upper half,
69 giving us the correct sum in the upper half. */
70 sum += (sum << 16) + (sum >> 16);
71 return (__force __sum16)(~sum >> 16);
72 }
73
74 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
75 __u32 len, __u8 proto,
76 __wsum sum)
77 {
78 __asm__(
79 " add %1, %0, %0\n"
80 " addc %2, %0, %0\n"
81 " addc %3, %0, %0\n"
82 " addc %%r0, %0, %0\n"
83 : "=r" (sum)
84 : "r" (daddr), "r"(saddr), "r"(proto+len), ""(sum));
85 return sum;
86 }
87
88 /*
89 * computes the checksum of the TCP/UDP pseudo-header
90 * returns a 16-bit checksum, already complemented
91 */
92 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
93 __u32 len, __u8 proto,
94 __wsum sum)
95 {
96 return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
97 }
98
99 /*
100 * this routine is used for miscellaneous IP-like checksums, mainly
101 * in icmp.c
102 */
103 static inline __sum16 ip_compute_csum(const void *buf, int len)
104 {
105 return csum_fold (csum_partial(buf, len, 0));
106 }
107
108
109 #define _HAVE_ARCH_IPV6_CSUM
110 static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
111 const struct in6_addr *daddr,
112 __u32 len, __u8 proto,
113 __wsum sum)
114 {
115 unsigned long t0, t1, t2, t3;
116
117 len += proto; /* add 16-bit proto + len */
118
119 __asm__ __volatile__ (
120
121 #if BITS_PER_LONG > 32
122
123 /*
124 ** We can execute two loads and two adds per cycle on PA 8000.
125 ** But add insn's get serialized waiting for the carry bit.
126 ** Try to keep 4 registers with "live" values ahead of the ALU.
127 */
128
129 " depdi 0, 31, 32, %0\n"/* clear upper half of incoming checksum */
130 " ldd,ma 8(%1), %4\n" /* get 1st saddr word */
131 " ldd,ma 8(%2), %5\n" /* get 1st daddr word */
132 " add %4, %0, %0\n"
133 " ldd,ma 8(%1), %6\n" /* 2nd saddr */
134 " ldd,ma 8(%2), %7\n" /* 2nd daddr */
135 " add,dc %5, %0, %0\n"
136 " add,dc %6, %0, %0\n"
137 " add,dc %7, %0, %0\n"
138 " add,dc %3, %0, %0\n" /* fold in proto+len | carry bit */
139 " extrd,u %0, 31, 32, %4\n"/* copy upper half down */
140 " depdi 0, 31, 32, %0\n"/* clear upper half */
141 " add,dc %4, %0, %0\n" /* fold into 32-bits, plus carry */
142 " addc 0, %0, %0\n" /* add final carry */
143
144 #else
145
146 /*
147 ** For PA 1.x, the insn order doesn't matter as much.
148 ** Insn stream is serialized on the carry bit here too.
149 ** result from the previous operation (eg r0 + x)
150 */
151 " ldw,ma 4(%1), %4\n" /* get 1st saddr word */
152 " ldw,ma 4(%2), %5\n" /* get 1st daddr word */
153 " add %4, %0, %0\n"
154 " ldw,ma 4(%1), %6\n" /* 2nd saddr */
155 " addc %5, %0, %0\n"
156 " ldw,ma 4(%2), %7\n" /* 2nd daddr */
157 " addc %6, %0, %0\n"
158 " ldw,ma 4(%1), %4\n" /* 3rd saddr */
159 " addc %7, %0, %0\n"
160 " ldw,ma 4(%2), %5\n" /* 3rd daddr */
161 " addc %4, %0, %0\n"
162 " ldw,ma 4(%1), %6\n" /* 4th saddr */
163 " addc %5, %0, %0\n"
164 " ldw,ma 4(%2), %7\n" /* 4th daddr */
165 " addc %6, %0, %0\n"
166 " addc %7, %0, %0\n"
167 " addc %3, %0, %0\n" /* fold in proto+len */
168 " addc 0, %0, %0\n" /* add carry */
169
170 #endif
171 : "=r" (sum), "=r" (saddr), "=r" (daddr), "=r" (len),
172 "=r" (t0), "=r" (t1), "=r" (t2), "=r" (t3)
173 : "" (sum), "1" (saddr), "2" (daddr), "3" (len)
174 : "memory");
175 return csum_fold(sum);
176 }
177
178 #endif
179
180
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