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9a8fd558 CZ |
1 | /* |
2 | * include/asm-xtensa/checksum.h | |
3 | * | |
4 | * This file is subject to the terms and conditions of the GNU General Public | |
5 | * License. See the file "COPYING" in the main directory of this archive | |
6 | * for more details. | |
7 | * | |
8 | * Copyright (C) 2001 - 2005 Tensilica Inc. | |
9 | */ | |
10 | ||
11 | #ifndef _XTENSA_CHECKSUM_H | |
12 | #define _XTENSA_CHECKSUM_H | |
13 | ||
9a8fd558 CZ |
14 | #include <linux/in6.h> |
15 | #include <xtensa/config/core.h> | |
16 | ||
17 | /* | |
18 | * computes the checksum of a memory block at buff, length len, | |
19 | * and adds in "sum" (32-bit) | |
20 | * | |
21 | * returns a 32-bit number suitable for feeding into itself | |
22 | * or csum_tcpudp_magic | |
23 | * | |
24 | * this function must be called with even lengths, except | |
25 | * for the last fragment, which may be odd | |
26 | * | |
27 | * it's best to have buff aligned on a 32-bit boundary | |
28 | */ | |
29 | asmlinkage unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum); | |
30 | ||
31 | /* | |
32 | * the same as csum_partial, but copies from src while it | |
33 | * checksums, and handles user-space pointer exceptions correctly, when needed. | |
34 | * | |
35 | * here even more important to align src and dst on a 32-bit (or even | |
36 | * better 64-bit) boundary | |
37 | */ | |
38 | ||
39 | asmlinkage unsigned int csum_partial_copy_generic( const char *src, char *dst, int len, int sum, | |
40 | int *src_err_ptr, int *dst_err_ptr); | |
41 | ||
42 | /* | |
43 | * Note: when you get a NULL pointer exception here this means someone | |
44 | * passed in an incorrect kernel address to one of these functions. | |
45 | * | |
b9e122c8 | 46 | * If you use these functions directly please don't forget the access_ok(). |
9a8fd558 | 47 | */ |
d99cf715 | 48 | static inline |
9a8fd558 CZ |
49 | unsigned int csum_partial_copy_nocheck ( const char *src, char *dst, |
50 | int len, int sum) | |
51 | { | |
52 | return csum_partial_copy_generic ( src, dst, len, sum, NULL, NULL); | |
53 | } | |
54 | ||
d99cf715 | 55 | static inline |
9a8fd558 CZ |
56 | unsigned int csum_partial_copy_from_user ( const char *src, char *dst, |
57 | int len, int sum, int *err_ptr) | |
58 | { | |
59 | return csum_partial_copy_generic ( src, dst, len, sum, err_ptr, NULL); | |
60 | } | |
61 | ||
62 | /* | |
63 | * These are the old (and unsafe) way of doing checksums, a warning message will be | |
64 | * printed if they are used and an exeption occurs. | |
65 | * | |
66 | * these functions should go away after some time. | |
67 | */ | |
68 | ||
69 | #define csum_partial_copy_fromuser csum_partial_copy | |
70 | unsigned int csum_partial_copy( const char *src, char *dst, int len, int sum); | |
71 | ||
72 | /* | |
73 | * Fold a partial checksum | |
74 | */ | |
75 | ||
76 | static __inline__ unsigned int csum_fold(unsigned int sum) | |
77 | { | |
78 | unsigned int __dummy; | |
79 | __asm__("extui %1, %0, 16, 16\n\t" | |
80 | "extui %0 ,%0, 0, 16\n\t" | |
81 | "add %0, %0, %1\n\t" | |
82 | "slli %1, %0, 16\n\t" | |
83 | "add %0, %0, %1\n\t" | |
84 | "extui %0, %0, 16, 16\n\t" | |
85 | "neg %0, %0\n\t" | |
86 | "addi %0, %0, -1\n\t" | |
87 | "extui %0, %0, 0, 16\n\t" | |
88 | : "=r" (sum), "=&r" (__dummy) | |
89 | : "0" (sum)); | |
90 | return sum; | |
91 | } | |
92 | ||
93 | /* | |
94 | * This is a version of ip_compute_csum() optimized for IP headers, | |
95 | * which always checksum on 4 octet boundaries. | |
96 | */ | |
97 | static __inline__ unsigned short ip_fast_csum(unsigned char * iph, unsigned int ihl) | |
98 | { | |
99 | unsigned int sum, tmp, endaddr; | |
100 | ||
101 | __asm__ __volatile__( | |
102 | "sub %0, %0, %0\n\t" | |
103 | #if XCHAL_HAVE_LOOPS | |
104 | "loopgtz %2, 2f\n\t" | |
105 | #else | |
106 | "beqz %2, 2f\n\t" | |
107 | "slli %4, %2, 2\n\t" | |
108 | "add %4, %4, %1\n\t" | |
109 | "0:\t" | |
110 | #endif | |
111 | "l32i %3, %1, 0\n\t" | |
112 | "add %0, %0, %3\n\t" | |
113 | "bgeu %0, %3, 1f\n\t" | |
114 | "addi %0, %0, 1\n\t" | |
115 | "1:\t" | |
116 | "addi %1, %1, 4\n\t" | |
117 | #if !XCHAL_HAVE_LOOPS | |
118 | "blt %1, %4, 0b\n\t" | |
119 | #endif | |
120 | "2:\t" | |
121 | /* Since the input registers which are loaded with iph and ihl | |
122 | are modified, we must also specify them as outputs, or gcc | |
123 | will assume they contain their original values. */ | |
124 | : "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (tmp), "=&r" (endaddr) | |
125 | : "1" (iph), "2" (ihl)); | |
126 | ||
127 | return csum_fold(sum); | |
128 | } | |
129 | ||
130 | static __inline__ unsigned long csum_tcpudp_nofold(unsigned long saddr, | |
131 | unsigned long daddr, | |
132 | unsigned short len, | |
133 | unsigned short proto, | |
134 | unsigned int sum) | |
135 | { | |
136 | ||
137 | #ifdef __XTENSA_EL__ | |
138 | unsigned long len_proto = (ntohs(len)<<16)+proto*256; | |
139 | #elif defined(__XTENSA_EB__) | |
140 | unsigned long len_proto = (proto<<16)+len; | |
141 | #else | |
142 | # error processor byte order undefined! | |
143 | #endif | |
144 | __asm__("add %0, %0, %1\n\t" | |
145 | "bgeu %0, %1, 1f\n\t" | |
146 | "addi %0, %0, 1\n\t" | |
147 | "1:\t" | |
148 | "add %0, %0, %2\n\t" | |
149 | "bgeu %0, %2, 1f\n\t" | |
150 | "addi %0, %0, 1\n\t" | |
151 | "1:\t" | |
152 | "add %0, %0, %3\n\t" | |
153 | "bgeu %0, %3, 1f\n\t" | |
154 | "addi %0, %0, 1\n\t" | |
155 | "1:\t" | |
156 | : "=r" (sum), "=r" (len_proto) | |
157 | : "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum)); | |
158 | return sum; | |
159 | } | |
160 | ||
161 | /* | |
162 | * computes the checksum of the TCP/UDP pseudo-header | |
163 | * returns a 16-bit checksum, already complemented | |
164 | */ | |
165 | static __inline__ unsigned short int csum_tcpudp_magic(unsigned long saddr, | |
166 | unsigned long daddr, | |
167 | unsigned short len, | |
168 | unsigned short proto, | |
169 | unsigned int sum) | |
170 | { | |
171 | return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum)); | |
172 | } | |
173 | ||
174 | /* | |
175 | * this routine is used for miscellaneous IP-like checksums, mainly | |
176 | * in icmp.c | |
177 | */ | |
178 | ||
179 | static __inline__ unsigned short ip_compute_csum(unsigned char * buff, int len) | |
180 | { | |
181 | return csum_fold (csum_partial(buff, len, 0)); | |
182 | } | |
183 | ||
184 | #define _HAVE_ARCH_IPV6_CSUM | |
185 | static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr, | |
186 | struct in6_addr *daddr, | |
187 | __u32 len, | |
188 | unsigned short proto, | |
189 | unsigned int sum) | |
190 | { | |
191 | unsigned int __dummy; | |
192 | __asm__("l32i %1, %2, 0\n\t" | |
193 | "add %0, %0, %1\n\t" | |
194 | "bgeu %0, %1, 1f\n\t" | |
195 | "addi %0, %0, 1\n\t" | |
196 | "1:\t" | |
197 | "l32i %1, %2, 4\n\t" | |
198 | "add %0, %0, %1\n\t" | |
199 | "bgeu %0, %1, 1f\n\t" | |
200 | "addi %0, %0, 1\n\t" | |
201 | "1:\t" | |
202 | "l32i %1, %2, 8\n\t" | |
203 | "add %0, %0, %1\n\t" | |
204 | "bgeu %0, %1, 1f\n\t" | |
205 | "addi %0, %0, 1\n\t" | |
206 | "1:\t" | |
207 | "l32i %1, %2, 12\n\t" | |
208 | "add %0, %0, %1\n\t" | |
209 | "bgeu %0, %1, 1f\n\t" | |
210 | "addi %0, %0, 1\n\t" | |
211 | "1:\t" | |
212 | "l32i %1, %3, 0\n\t" | |
213 | "add %0, %0, %1\n\t" | |
214 | "bgeu %0, %1, 1f\n\t" | |
215 | "addi %0, %0, 1\n\t" | |
216 | "1:\t" | |
217 | "l32i %1, %3, 4\n\t" | |
218 | "add %0, %0, %1\n\t" | |
219 | "bgeu %0, %1, 1f\n\t" | |
220 | "addi %0, %0, 1\n\t" | |
221 | "1:\t" | |
222 | "l32i %1, %3, 8\n\t" | |
223 | "add %0, %0, %1\n\t" | |
224 | "bgeu %0, %1, 1f\n\t" | |
225 | "addi %0, %0, 1\n\t" | |
226 | "1:\t" | |
227 | "l32i %1, %3, 12\n\t" | |
228 | "add %0, %0, %1\n\t" | |
229 | "bgeu %0, %1, 1f\n\t" | |
230 | "addi %0, %0, 1\n\t" | |
231 | "1:\t" | |
232 | "add %0, %0, %4\n\t" | |
233 | "bgeu %0, %4, 1f\n\t" | |
234 | "addi %0, %0, 1\n\t" | |
235 | "1:\t" | |
236 | "add %0, %0, %5\n\t" | |
237 | "bgeu %0, %5, 1f\n\t" | |
238 | "addi %0, %0, 1\n\t" | |
239 | "1:\t" | |
240 | : "=r" (sum), "=&r" (__dummy) | |
241 | : "r" (saddr), "r" (daddr), | |
242 | "r" (htonl(len)), "r" (htonl(proto)), "0" (sum)); | |
243 | ||
244 | return csum_fold(sum); | |
245 | } | |
246 | ||
247 | /* | |
248 | * Copy and checksum to user | |
249 | */ | |
250 | #define HAVE_CSUM_COPY_USER | |
251 | static __inline__ unsigned int csum_and_copy_to_user (const char *src, char *dst, | |
252 | int len, int sum, int *err_ptr) | |
253 | { | |
254 | if (access_ok(VERIFY_WRITE, dst, len)) | |
255 | return csum_partial_copy_generic(src, dst, len, sum, NULL, err_ptr); | |
256 | ||
257 | if (len) | |
258 | *err_ptr = -EFAULT; | |
259 | ||
260 | return -1; /* invalid checksum */ | |
261 | } | |
262 | #endif |