tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/* $Id: checksum.h,v 1.33 2002/02/01 22:01:05 davem Exp $ */
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 <asm/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 */
33extern unsigned int csum_partial(const unsigned char * buff, int len, unsigned int 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
42extern unsigned int __csum_partial_copy_sparc_generic (const unsigned char *, unsigned char *);
43
44static inline unsigned int
45csum_partial_copy_nocheck (const unsigned char *src, unsigned char *dst, int len,
46 unsigned int sum)
47{
48 register unsigned int ret asm("o0") = (unsigned int)src;
49 register char *d asm("o1") = dst;
50 register int l asm("g1") = len;
51
52 __asm__ __volatile__ (
53 "call __csum_partial_copy_sparc_generic\n\t"
54 " mov %6, %%g7\n"
55 : "=&r" (ret), "=&r" (d), "=&r" (l)
56 : "0" (ret), "1" (d), "2" (l), "r" (sum)
57 : "o2", "o3", "o4", "o5", "o7",
58 "g2", "g3", "g4", "g5", "g7",
59 "memory", "cc");
60 return ret;
61}
62
63static inline unsigned int
64csum_partial_copy_from_user(const unsigned char __user *src, unsigned char *dst, int len,
65 unsigned int sum, int *err)
66 {
67 if (!access_ok (VERIFY_READ, src, len)) {
68 *err = -EFAULT;
69 memset (dst, 0, len);
70 return sum;
71 } else {
72 register unsigned long ret asm("o0") = (unsigned long)src;
73 register char *d asm("o1") = dst;
74 register int l asm("g1") = len;
75 register unsigned int s asm("g7") = sum;
76
77 __asm__ __volatile__ (
78 ".section __ex_table,#alloc\n\t"
79 ".align 4\n\t"
80 ".word 1f,2\n\t"
81 ".previous\n"
82 "1:\n\t"
83 "call __csum_partial_copy_sparc_generic\n\t"
84 " st %8, [%%sp + 64]\n"
85 : "=&r" (ret), "=&r" (d), "=&r" (l), "=&r" (s)
86 : "0" (ret), "1" (d), "2" (l), "3" (s), "r" (err)
87 : "o2", "o3", "o4", "o5", "o7", "g2", "g3", "g4", "g5",
88 "cc", "memory");
89 return ret;
90 }
91 }
92
93static inline unsigned int
94csum_partial_copy_to_user(const unsigned char *src, unsigned char __user *dst, int len,
95 unsigned int sum, int *err)
96{
97 if (!access_ok (VERIFY_WRITE, dst, len)) {
98 *err = -EFAULT;
99 return sum;
100 } else {
101 register unsigned long ret asm("o0") = (unsigned long)src;
102 register char __user *d asm("o1") = dst;
103 register int l asm("g1") = len;
104 register unsigned int s asm("g7") = sum;
105
106 __asm__ __volatile__ (
107 ".section __ex_table,#alloc\n\t"
108 ".align 4\n\t"
109 ".word 1f,1\n\t"
110 ".previous\n"
111 "1:\n\t"
112 "call __csum_partial_copy_sparc_generic\n\t"
113 " st %8, [%%sp + 64]\n"
114 : "=&r" (ret), "=&r" (d), "=&r" (l), "=&r" (s)
115 : "0" (ret), "1" (d), "2" (l), "3" (s), "r" (err)
116 : "o2", "o3", "o4", "o5", "o7",
117 "g2", "g3", "g4", "g5",
118 "cc", "memory");
119 return ret;
120 }
121}
122
123#define HAVE_CSUM_COPY_USER
124#define csum_and_copy_to_user csum_partial_copy_to_user
125
126/* ihl is always 5 or greater, almost always is 5, and iph is word aligned
127 * the majority of the time.
128 */
129static inline unsigned short ip_fast_csum(const unsigned char *iph,
130 unsigned int ihl)
131{
132 unsigned short sum;
133
134 /* Note: We must read %2 before we touch %0 for the first time,
135 * because GCC can legitimately use the same register for
136 * both operands.
137 */
138 __asm__ __volatile__("sub\t%2, 4, %%g4\n\t"
139 "ld\t[%1 + 0x00], %0\n\t"
140 "ld\t[%1 + 0x04], %%g2\n\t"
141 "ld\t[%1 + 0x08], %%g3\n\t"
142 "addcc\t%%g2, %0, %0\n\t"
143 "addxcc\t%%g3, %0, %0\n\t"
144 "ld\t[%1 + 0x0c], %%g2\n\t"
145 "ld\t[%1 + 0x10], %%g3\n\t"
146 "addxcc\t%%g2, %0, %0\n\t"
147 "addx\t%0, %%g0, %0\n"
148 "1:\taddcc\t%%g3, %0, %0\n\t"
149 "add\t%1, 4, %1\n\t"
150 "addxcc\t%0, %%g0, %0\n\t"
151 "subcc\t%%g4, 1, %%g4\n\t"
152 "be,a\t2f\n\t"
153 "sll\t%0, 16, %%g2\n\t"
154 "b\t1b\n\t"
155 "ld\t[%1 + 0x10], %%g3\n"
156 "2:\taddcc\t%0, %%g2, %%g2\n\t"
157 "srl\t%%g2, 16, %0\n\t"
158 "addx\t%0, %%g0, %0\n\t"
159 "xnor\t%%g0, %0, %0"
160 : "=r" (sum), "=&r" (iph)
161 : "r" (ihl), "1" (iph)
162 : "g2", "g3", "g4", "cc");
163 return sum;
164}
165
166/* Fold a partial checksum without adding pseudo headers. */
167static inline unsigned int csum_fold(unsigned int sum)
168{
169 unsigned int tmp;
170
171 __asm__ __volatile__("addcc\t%0, %1, %1\n\t"
172 "srl\t%1, 16, %1\n\t"
173 "addx\t%1, %%g0, %1\n\t"
174 "xnor\t%%g0, %1, %0"
175 : "=&r" (sum), "=r" (tmp)
176 : "0" (sum), "1" (sum<<16)
177 : "cc");
178 return sum;
179}
180
181static inline unsigned long csum_tcpudp_nofold(unsigned long saddr,
182 unsigned long daddr,
183 unsigned int len,
184 unsigned short proto,
185 unsigned int sum)
186{
187 __asm__ __volatile__("addcc\t%1, %0, %0\n\t"
188 "addxcc\t%2, %0, %0\n\t"
189 "addxcc\t%3, %0, %0\n\t"
190 "addx\t%0, %%g0, %0\n\t"
191 : "=r" (sum), "=r" (saddr)
192 : "r" (daddr), "r" ((proto<<16)+len), "0" (sum),
193 "1" (saddr)
194 : "cc");
195 return sum;
196}
197
198/*
199 * computes the checksum of the TCP/UDP pseudo-header
200 * returns a 16-bit checksum, already complemented
201 */
202static inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
203 unsigned long daddr,
204 unsigned short len,
205 unsigned short proto,
206 unsigned int sum)
207{
208 return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
209}
210
211#define _HAVE_ARCH_IPV6_CSUM
212
213static inline unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
214 struct in6_addr *daddr,
215 __u32 len,
216 unsigned short proto,
217 unsigned int sum)
218{
219 __asm__ __volatile__ (
220 "addcc %3, %4, %%g4\n\t"
221 "addxcc %5, %%g4, %%g4\n\t"
222 "ld [%2 + 0x0c], %%g2\n\t"
223 "ld [%2 + 0x08], %%g3\n\t"
224 "addxcc %%g2, %%g4, %%g4\n\t"
225 "ld [%2 + 0x04], %%g2\n\t"
226 "addxcc %%g3, %%g4, %%g4\n\t"
227 "ld [%2 + 0x00], %%g3\n\t"
228 "addxcc %%g2, %%g4, %%g4\n\t"
229 "ld [%1 + 0x0c], %%g2\n\t"
230 "addxcc %%g3, %%g4, %%g4\n\t"
231 "ld [%1 + 0x08], %%g3\n\t"
232 "addxcc %%g2, %%g4, %%g4\n\t"
233 "ld [%1 + 0x04], %%g2\n\t"
234 "addxcc %%g3, %%g4, %%g4\n\t"
235 "ld [%1 + 0x00], %%g3\n\t"
236 "addxcc %%g2, %%g4, %%g4\n\t"
237 "addxcc %%g3, %%g4, %0\n\t"
238 "addx 0, %0, %0\n"
239 : "=&r" (sum)
240 : "r" (saddr), "r" (daddr),
241 "r"(htonl(len)), "r"(htonl(proto)), "r"(sum)
242 : "g2", "g3", "g4", "cc");
243
244 return csum_fold(sum);
245}
246
247/* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
248static inline unsigned short ip_compute_csum(unsigned char * buff, int len)
249{
250 return csum_fold(csum_partial(buff, len, 0));
251}
252
253#endif /* !(__SPARC_CHECKSUM_H) */