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 * The same as csum_partial, but copies from src while it checksums.
23 *
24 * Here even more important to align src and dst on a 32-bit (or even
25 * better 64-bit) boundary
26 */
27 extern __wsum csum_partial_copy_nocheck(const void *, void *, int, __wsum);
28
29 /*
30 * this is a new version of the above that records errors it finds in *errp,
31 * but continues and zeros the rest of the buffer.
32 */
33 extern __wsum csum_partial_copy_from_user(const void __user *src,
34 void *dst, int len, __wsum sum, int *errp);
35
36 /*
37 * Optimized for IP headers, which always checksum on 4 octet boundaries.
38 *
39 * Written by Randolph Chung <tausq@debian.org>, and then mucked with by
40 * LaMont Jones <lamont@debian.org>
41 */
42 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
43 {
44 unsigned int sum;
45
46 __asm__ __volatile__ (
47 " ldws,ma 4(%1), %0\n"
48 " addib,<= -4, %2, 2f\n"
49 "\n"
50 " ldws 4(%1), %%r20\n"
51 " ldws 8(%1), %%r21\n"
52 " add %0, %%r20, %0\n"
53 " ldws,ma 12(%1), %%r19\n"
54 " addc %0, %%r21, %0\n"
55 " addc %0, %%r19, %0\n"
56 "1: ldws,ma 4(%1), %%r19\n"
57 " addib,< 0, %2, 1b\n"
58 " addc %0, %%r19, %0\n"
59 "\n"
60 " extru %0, 31, 16, %%r20\n"
61 " extru %0, 15, 16, %%r21\n"
62 " addc %%r20, %%r21, %0\n"
63 " extru %0, 15, 16, %%r21\n"
64 " add %0, %%r21, %0\n"
65 " subi -1, %0, %0\n"
66 "2:\n"
67 : "=r" (sum), "=r" (iph), "=r" (ihl)
68 : "1" (iph), "2" (ihl)
69 : "r19", "r20", "r21", "memory");
70
71 return (__force __sum16)sum;
72 }
73
74 /*
75 * Fold a partial checksum
76 */
77 static inline __sum16 csum_fold(__wsum csum)
78 {
79 u32 sum = (__force u32)csum;
80 /* add the swapped two 16-bit halves of sum,
81 a possible carry from adding the two 16-bit halves,
82 will carry from the lower half into the upper half,
83 giving us the correct sum in the upper half. */
84 sum += (sum << 16) + (sum >> 16);
85 return (__force __sum16)(~sum >> 16);
86 }
87
88 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
89 __u32 len, __u8 proto,
90 __wsum sum)
91 {
92 __asm__(
93 " add %1, %0, %0\n"
94 " addc %2, %0, %0\n"
95 " addc %3, %0, %0\n"
96 " addc %%r0, %0, %0\n"
97 : "=r" (sum)
98 : "r" (daddr), "r"(saddr), "r"(proto+len), "0"(sum));
99 return sum;
100 }
101
102 /*
103 * computes the checksum of the TCP/UDP pseudo-header
104 * returns a 16-bit checksum, already complemented
105 */
106 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
107 __u32 len, __u8 proto,
108 __wsum sum)
109 {
110 return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
111 }
112
113 /*
114 * this routine is used for miscellaneous IP-like checksums, mainly
115 * in icmp.c
116 */
117 static inline __sum16 ip_compute_csum(const void *buf, int len)
118 {
119 return csum_fold (csum_partial(buf, len, 0));
120 }
121
122
123 #define _HAVE_ARCH_IPV6_CSUM
124 static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
125 const struct in6_addr *daddr,
126 __u32 len, __u8 proto,
127 __wsum sum)
128 {
129 __asm__ __volatile__ (
130
131 #if BITS_PER_LONG > 32
132
133 /*
134 ** We can execute two loads and two adds per cycle on PA 8000.
135 ** But add insn's get serialized waiting for the carry bit.
136 ** Try to keep 4 registers with "live" values ahead of the ALU.
137 */
138
139 " ldd,ma 8(%1), %%r19\n" /* get 1st saddr word */
140 " ldd,ma 8(%2), %%r20\n" /* get 1st daddr word */
141 " add %8, %3, %3\n"/* add 16-bit proto + len */
142 " add %%r19, %0, %0\n"
143 " ldd,ma 8(%1), %%r21\n" /* 2cd saddr */
144 " ldd,ma 8(%2), %%r22\n" /* 2cd daddr */
145 " add,dc %%r20, %0, %0\n"
146 " add,dc %%r21, %0, %0\n"
147 " add,dc %%r22, %0, %0\n"
148 " add,dc %3, %0, %0\n" /* fold in proto+len | carry bit */
149 " extrd,u %0, 31, 32, %%r19\n" /* copy upper half down */
150 " depdi 0, 31, 32, %0\n" /* clear upper half */
151 " add %%r19, %0, %0\n" /* fold into 32-bits */
152 " addc 0, %0, %0\n" /* add carry */
153
154 #else
155
156 /*
157 ** For PA 1.x, the insn order doesn't matter as much.
158 ** Insn stream is serialized on the carry bit here too.
159 ** result from the previous operation (eg r0 + x)
160 */
161
162 " ldw,ma 4(%1), %%r19\n" /* get 1st saddr word */
163 " ldw,ma 4(%2), %%r20\n" /* get 1st daddr word */
164 " add %8, %3, %3\n" /* add 16-bit proto + len */
165 " add %%r19, %0, %0\n"
166 " ldw,ma 4(%1), %%r21\n" /* 2cd saddr */
167 " addc %%r20, %0, %0\n"
168 " ldw,ma 4(%2), %%r22\n" /* 2cd daddr */
169 " addc %%r21, %0, %0\n"
170 " ldw,ma 4(%1), %%r19\n" /* 3rd saddr */
171 " addc %%r22, %0, %0\n"
172 " ldw,ma 4(%2), %%r20\n" /* 3rd daddr */
173 " addc %%r19, %0, %0\n"
174 " ldw,ma 4(%1), %%r21\n" /* 4th saddr */
175 " addc %%r20, %0, %0\n"
176 " ldw,ma 4(%2), %%r22\n" /* 4th daddr */
177 " addc %%r21, %0, %0\n"
178 " addc %%r22, %0, %0\n"
179 " addc %3, %0, %0\n" /* fold in proto+len, catch carry */
180
181 #endif
182 : "=r" (sum), "=r" (saddr), "=r" (daddr), "=r" (len)
183 : "0" (sum), "1" (saddr), "2" (daddr), "3" (len), "r" (proto)
184 : "r19", "r20", "r21", "r22", "memory");
185 return csum_fold(sum);
186 }
187
188 /*
189 * Copy and checksum to user
190 */
191 #define HAVE_CSUM_COPY_USER
192 static __inline__ __wsum csum_and_copy_to_user(const void *src,
193 void __user *dst,
194 int len, __wsum sum,
195 int *err_ptr)
196 {
197 /* code stolen from include/asm-mips64 */
198 sum = csum_partial(src, len, sum);
199
200 if (copy_to_user(dst, src, len)) {
201 *err_ptr = -EFAULT;
202 return (__force __wsum)-1;
203 }
204
205 return sum;
206 }
207
208 #endif
209