File: /usr/src/linux/include/asm-sparc/checksum.h
1 /* $Id: checksum.h,v 1.31 2000/01/31 01:26:52 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 <asm/uaccess.h>
20 #include <asm/cprefix.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 extern 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
42 /* FIXME: Remove these two macros ASAP */
43 #define csum_partial_copy(src, dst, len, sum) \
44 csum_partial_copy_nocheck(src,dst,len,sum)
45 #define csum_partial_copy_fromuser(s, d, l, w) \
46 csum_partial_copy((char *) (s), (d), (l), (w))
47
48 extern unsigned int __csum_partial_copy_sparc_generic (const char *, char *);
49
50 extern __inline__ unsigned int
51 csum_partial_copy_nocheck (const char *src, char *dst, int len,
52 unsigned int sum)
53 {
54 register unsigned int ret asm("o0") = (unsigned int)src;
55 register char *d asm("o1") = dst;
56 register int l asm("g1") = len;
57
58 __asm__ __volatile__ ("
59 call " C_LABEL_STR(__csum_partial_copy_sparc_generic) "
60 mov %4, %%g7
61 " : "=r" (ret) : "0" (ret), "r" (d), "r" (l), "r" (sum) :
62 "o1", "o2", "o3", "o4", "o5", "o7", "g1", "g2", "g3", "g4", "g5", "g7");
63 return ret;
64 }
65
66 extern __inline__ unsigned int
67 csum_partial_copy_from_user(const char *src, char *dst, int len,
68 unsigned int sum, int *err)
69 {
70 if (!access_ok (VERIFY_READ, src, len)) {
71 *err = -EFAULT;
72 memset (dst, 0, len);
73 return sum;
74 } else {
75 register unsigned int ret asm("o0") = (unsigned int)src;
76 register char *d asm("o1") = dst;
77 register int l asm("g1") = len;
78 register unsigned int s asm("g7") = sum;
79
80 __asm__ __volatile__ ("
81 .section __ex_table,#alloc
82 .align 4
83 .word 1f,2
84 .previous
85 1:
86 call " C_LABEL_STR(__csum_partial_copy_sparc_generic) "
87 st %5, [%%sp + 64]
88 " : "=r" (ret) : "0" (ret), "r" (d), "r" (l), "r" (s), "r" (err) :
89 "o1", "o2", "o3", "o4", "o5", "o7", "g1", "g2", "g3", "g4", "g5", "g7");
90 return ret;
91 }
92 }
93
94 extern __inline__ unsigned int
95 csum_partial_copy_to_user(const char *src, char *dst, int len,
96 unsigned int sum, int *err)
97 {
98 if (!access_ok (VERIFY_WRITE, dst, len)) {
99 *err = -EFAULT;
100 return sum;
101 } else {
102 register unsigned int ret asm("o0") = (unsigned int)src;
103 register char *d asm("o1") = dst;
104 register int l asm("g1") = len;
105 register unsigned int s asm("g7") = sum;
106
107 __asm__ __volatile__ ("
108 .section __ex_table,#alloc
109 .align 4
110 .word 1f,1
111 .previous
112 1:
113 call " C_LABEL_STR(__csum_partial_copy_sparc_generic) "
114 st %5, [%%sp + 64]
115 " : "=r" (ret) : "0" (ret), "r" (d), "r" (l), "r" (s), "r" (err) :
116 "o1", "o2", "o3", "o4", "o5", "o7", "g1", "g2", "g3", "g4", "g5", "g7");
117 return ret;
118 }
119 }
120
121 #define HAVE_CSUM_COPY_USER
122 #define csum_and_copy_to_user csum_partial_copy_to_user
123
124 /* ihl is always 5 or greater, almost always is 5, and iph is word aligned
125 * the majority of the time.
126 */
127 extern __inline__ unsigned short ip_fast_csum(__const__ unsigned char *iph,
128 unsigned int ihl)
129 {
130 unsigned short sum;
131
132 /* Note: We must read %2 before we touch %0 for the first time,
133 * because GCC can legitimately use the same register for
134 * both operands.
135 */
136 __asm__ __volatile__("sub\t%2, 4, %%g4\n\t"
137 "ld\t[%1 + 0x00], %0\n\t"
138 "ld\t[%1 + 0x04], %%g2\n\t"
139 "ld\t[%1 + 0x08], %%g3\n\t"
140 "addcc\t%%g2, %0, %0\n\t"
141 "addxcc\t%%g3, %0, %0\n\t"
142 "ld\t[%1 + 0x0c], %%g2\n\t"
143 "ld\t[%1 + 0x10], %%g3\n\t"
144 "addxcc\t%%g2, %0, %0\n\t"
145 "addx\t%0, %%g0, %0\n"
146 "1:\taddcc\t%%g3, %0, %0\n\t"
147 "add\t%1, 4, %1\n\t"
148 "addxcc\t%0, %%g0, %0\n\t"
149 "subcc\t%%g4, 1, %%g4\n\t"
150 "be,a\t2f\n\t"
151 "sll\t%0, 16, %%g2\n\t"
152 "b\t1b\n\t"
153 "ld\t[%1 + 0x10], %%g3\n"
154 "2:\taddcc\t%0, %%g2, %%g2\n\t"
155 "srl\t%%g2, 16, %0\n\t"
156 "addx\t%0, %%g0, %0\n\t"
157 "xnor\t%%g0, %0, %0"
158 : "=r" (sum), "=&r" (iph)
159 : "r" (ihl), "1" (iph)
160 : "g2", "g3", "g4", "cc");
161 return sum;
162 }
163
164 /* Fold a partial checksum without adding pseudo headers. */
165 extern __inline__ unsigned int csum_fold(unsigned int sum)
166 {
167 unsigned int tmp;
168
169 __asm__ __volatile__("addcc\t%0, %1, %1\n\t"
170 "srl\t%1, 16, %1\n\t"
171 "addx\t%1, %%g0, %1\n\t"
172 "xnor\t%%g0, %1, %0"
173 : "=&r" (sum), "=r" (tmp)
174 : "0" (sum), "1" (sum<<16)
175 : "cc");
176 return sum;
177 }
178
179 extern __inline__ unsigned long csum_tcpudp_nofold(unsigned long saddr,
180 unsigned long daddr,
181 unsigned int len,
182 unsigned short proto,
183 unsigned int sum)
184 {
185 __asm__ __volatile__("addcc\t%1, %0, %0\n\t"
186 "addxcc\t%2, %0, %0\n\t"
187 "addxcc\t%3, %0, %0\n\t"
188 "addx\t%0, %%g0, %0\n\t"
189 : "=r" (sum), "=r" (saddr)
190 : "r" (daddr), "r" ((proto<<16)+len), "0" (sum),
191 "1" (saddr)
192 : "cc");
193 return sum;
194 }
195
196 /*
197 * computes the checksum of the TCP/UDP pseudo-header
198 * returns a 16-bit checksum, already complemented
199 */
200 static inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
201 unsigned long daddr,
202 unsigned short len,
203 unsigned short proto,
204 unsigned int sum)
205 {
206 return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
207 }
208
209 #define _HAVE_ARCH_IPV6_CSUM
210
211 static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
212 struct in6_addr *daddr,
213 __u32 len,
214 unsigned short proto,
215 unsigned int sum)
216 {
217 __asm__ __volatile__ ("
218 addcc %3, %4, %%g4
219 addxcc %5, %%g4, %%g4
220 ld [%2 + 0x0c], %%g2
221 ld [%2 + 0x08], %%g3
222 addxcc %%g2, %%g4, %%g4
223 ld [%2 + 0x04], %%g2
224 addxcc %%g3, %%g4, %%g4
225 ld [%2 + 0x00], %%g3
226 addxcc %%g2, %%g4, %%g4
227 ld [%1 + 0x0c], %%g2
228 addxcc %%g3, %%g4, %%g4
229 ld [%1 + 0x08], %%g3
230 addxcc %%g2, %%g4, %%g4
231 ld [%1 + 0x04], %%g2
232 addxcc %%g3, %%g4, %%g4
233 ld [%1 + 0x00], %%g3
234 addxcc %%g2, %%g4, %%g4
235 addxcc %%g3, %%g4, %0
236 addx 0, %0, %0
237 "
238 : "=&r" (sum)
239 : "r" (saddr), "r" (daddr),
240 "r"(htonl(len)), "r"(htonl(proto)), "r"(sum)
241 : "g2", "g3", "g4", "cc");
242
243 return csum_fold(sum);
244 }
245
246 /* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
247 extern __inline__ unsigned short ip_compute_csum(unsigned char * buff, int len)
248 {
249 return csum_fold(csum_partial(buff, len, 0));
250 }
251
252 #endif /* !(__SPARC_CHECKSUM_H) */
253