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checksum_32.h
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1 #ifndef __SPARC_CHECKSUM_H
2 #define __SPARC_CHECKSUM_H
3 
4 /* checksum.h: IP/UDP/TCP checksum routines on the Sparc.
5  *
6  * Copyright(C) 1995 Linus Torvalds
7  * Copyright(C) 1995 Miguel de Icaza
8  * Copyright(C) 1996 David S. Miller
9  * Copyright(C) 1996 Eddie C. Dost
10  * Copyright(C) 1997 Jakub Jelinek
11  *
12  * derived from:
13  * Alpha checksum c-code
14  * ix86 inline assembly
15  * RFC1071 Computing the Internet Checksum
16  */
17 
18 #include <linux/in6.h>
19 #include <asm/uaccess.h>
20 
21 /* computes the checksum of a memory block at buff, length len,
22  * and adds in "sum" (32-bit)
23  *
24  * returns a 32-bit number suitable for feeding into itself
25  * or csum_tcpudp_magic
26  *
27  * this function must be called with even lengths, except
28  * for the last fragment, which may be odd
29  *
30  * it's best to have buff aligned on a 32-bit boundary
31  */
32 extern __wsum csum_partial(const void *buff, int len, __wsum sum);
33 
34 /* the same as csum_partial, but copies from fs:src while it
35  * checksums
36  *
37  * here even more important to align src and dst on a 32-bit (or even
38  * better 64-bit) boundary
39  */
40 
41 extern unsigned int __csum_partial_copy_sparc_generic (const unsigned char *, unsigned char *);
42 
43 static inline __wsum
44 csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
45 {
46  register unsigned int ret asm("o0") = (unsigned int)src;
47  register char *d asm("o1") = dst;
48  register int l asm("g1") = len;
49 
50  __asm__ __volatile__ (
51  "call __csum_partial_copy_sparc_generic\n\t"
52  " mov %6, %%g7\n"
53  : "=&r" (ret), "=&r" (d), "=&r" (l)
54  : "0" (ret), "1" (d), "2" (l), "r" (sum)
55  : "o2", "o3", "o4", "o5", "o7",
56  "g2", "g3", "g4", "g5", "g7",
57  "memory", "cc");
58  return (__force __wsum)ret;
59 }
60 
61 static inline __wsum
62 csum_partial_copy_from_user(const void __user *src, void *dst, int len,
63  __wsum sum, int *err)
64  {
65  register unsigned long ret asm("o0") = (unsigned long)src;
66  register char *d asm("o1") = dst;
67  register int l asm("g1") = len;
68  register __wsum s asm("g7") = sum;
69 
70  __asm__ __volatile__ (
71  ".section __ex_table,#alloc\n\t"
72  ".align 4\n\t"
73  ".word 1f,2\n\t"
74  ".previous\n"
75  "1:\n\t"
76  "call __csum_partial_copy_sparc_generic\n\t"
77  " st %8, [%%sp + 64]\n"
78  : "=&r" (ret), "=&r" (d), "=&r" (l), "=&r" (s)
79  : "0" (ret), "1" (d), "2" (l), "3" (s), "r" (err)
80  : "o2", "o3", "o4", "o5", "o7", "g2", "g3", "g4", "g5",
81  "cc", "memory");
82  return (__force __wsum)ret;
83 }
84 
85 static inline __wsum
86 csum_partial_copy_to_user(const void *src, void __user *dst, int len,
87  __wsum sum, int *err)
88 {
89  if (!access_ok (VERIFY_WRITE, dst, len)) {
90  *err = -EFAULT;
91  return sum;
92  } else {
93  register unsigned long ret asm("o0") = (unsigned long)src;
94  register char __user *d asm("o1") = dst;
95  register int l asm("g1") = len;
96  register __wsum s asm("g7") = sum;
97 
98  __asm__ __volatile__ (
99  ".section __ex_table,#alloc\n\t"
100  ".align 4\n\t"
101  ".word 1f,1\n\t"
102  ".previous\n"
103  "1:\n\t"
104  "call __csum_partial_copy_sparc_generic\n\t"
105  " st %8, [%%sp + 64]\n"
106  : "=&r" (ret), "=&r" (d), "=&r" (l), "=&r" (s)
107  : "0" (ret), "1" (d), "2" (l), "3" (s), "r" (err)
108  : "o2", "o3", "o4", "o5", "o7",
109  "g2", "g3", "g4", "g5",
110  "cc", "memory");
111  return (__force __wsum)ret;
112  }
113 }
114 
115 #define HAVE_CSUM_COPY_USER
116 #define csum_and_copy_to_user csum_partial_copy_to_user
117 
118 /* ihl is always 5 or greater, almost always is 5, and iph is word aligned
119  * the majority of the time.
120  */
121 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
122 {
123  __sum16 sum;
124 
125  /* Note: We must read %2 before we touch %0 for the first time,
126  * because GCC can legitimately use the same register for
127  * both operands.
128  */
129  __asm__ __volatile__("sub\t%2, 4, %%g4\n\t"
130  "ld\t[%1 + 0x00], %0\n\t"
131  "ld\t[%1 + 0x04], %%g2\n\t"
132  "ld\t[%1 + 0x08], %%g3\n\t"
133  "addcc\t%%g2, %0, %0\n\t"
134  "addxcc\t%%g3, %0, %0\n\t"
135  "ld\t[%1 + 0x0c], %%g2\n\t"
136  "ld\t[%1 + 0x10], %%g3\n\t"
137  "addxcc\t%%g2, %0, %0\n\t"
138  "addx\t%0, %%g0, %0\n"
139  "1:\taddcc\t%%g3, %0, %0\n\t"
140  "add\t%1, 4, %1\n\t"
141  "addxcc\t%0, %%g0, %0\n\t"
142  "subcc\t%%g4, 1, %%g4\n\t"
143  "be,a\t2f\n\t"
144  "sll\t%0, 16, %%g2\n\t"
145  "b\t1b\n\t"
146  "ld\t[%1 + 0x10], %%g3\n"
147  "2:\taddcc\t%0, %%g2, %%g2\n\t"
148  "srl\t%%g2, 16, %0\n\t"
149  "addx\t%0, %%g0, %0\n\t"
150  "xnor\t%%g0, %0, %0"
151  : "=r" (sum), "=&r" (iph)
152  : "r" (ihl), "1" (iph)
153  : "g2", "g3", "g4", "cc", "memory");
154  return sum;
155 }
156 
157 /* Fold a partial checksum without adding pseudo headers. */
158 static inline __sum16 csum_fold(__wsum sum)
159 {
160  unsigned int tmp;
161 
162  __asm__ __volatile__("addcc\t%0, %1, %1\n\t"
163  "srl\t%1, 16, %1\n\t"
164  "addx\t%1, %%g0, %1\n\t"
165  "xnor\t%%g0, %1, %0"
166  : "=&r" (sum), "=r" (tmp)
167  : "0" (sum), "1" ((__force u32)sum<<16)
168  : "cc");
169  return (__force __sum16)sum;
170 }
171 
173  unsigned short len,
174  unsigned short proto,
175  __wsum sum)
176 {
177  __asm__ __volatile__("addcc\t%1, %0, %0\n\t"
178  "addxcc\t%2, %0, %0\n\t"
179  "addxcc\t%3, %0, %0\n\t"
180  "addx\t%0, %%g0, %0\n\t"
181  : "=r" (sum), "=r" (saddr)
182  : "r" (daddr), "r" (proto + len), "0" (sum),
183  "1" (saddr)
184  : "cc");
185  return sum;
186 }
187 
188 /*
189  * computes the checksum of the TCP/UDP pseudo-header
190  * returns a 16-bit checksum, already complemented
191  */
192 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
193  unsigned short len,
194  unsigned short proto,
195  __wsum sum)
196 {
197  return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
198 }
199 
200 #define _HAVE_ARCH_IPV6_CSUM
201 
202 static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
203  const struct in6_addr *daddr,
204  __u32 len, unsigned short proto,
205  __wsum sum)
206 {
207  __asm__ __volatile__ (
208  "addcc %3, %4, %%g4\n\t"
209  "addxcc %5, %%g4, %%g4\n\t"
210  "ld [%2 + 0x0c], %%g2\n\t"
211  "ld [%2 + 0x08], %%g3\n\t"
212  "addxcc %%g2, %%g4, %%g4\n\t"
213  "ld [%2 + 0x04], %%g2\n\t"
214  "addxcc %%g3, %%g4, %%g4\n\t"
215  "ld [%2 + 0x00], %%g3\n\t"
216  "addxcc %%g2, %%g4, %%g4\n\t"
217  "ld [%1 + 0x0c], %%g2\n\t"
218  "addxcc %%g3, %%g4, %%g4\n\t"
219  "ld [%1 + 0x08], %%g3\n\t"
220  "addxcc %%g2, %%g4, %%g4\n\t"
221  "ld [%1 + 0x04], %%g2\n\t"
222  "addxcc %%g3, %%g4, %%g4\n\t"
223  "ld [%1 + 0x00], %%g3\n\t"
224  "addxcc %%g2, %%g4, %%g4\n\t"
225  "addxcc %%g3, %%g4, %0\n\t"
226  "addx 0, %0, %0\n"
227  : "=&r" (sum)
228  : "r" (saddr), "r" (daddr),
229  "r"(htonl(len)), "r"(htonl(proto)), "r"(sum)
230  : "g2", "g3", "g4", "cc");
231 
232  return csum_fold(sum);
233 }
234 
235 /* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
236 static inline __sum16 ip_compute_csum(const void *buff, int len)
237 {
238  return csum_fold(csum_partial(buff, len, 0));
239 }
240 
241 #endif /* !(__SPARC_CHECKSUM_H) */