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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 | ||
14 | #include <linux/config.h> | |
15 | #include <linux/in6.h> | |
16 | #include <xtensa/config/core.h> | |
17 | ||
18 | /* | |
19 | * computes the checksum of a memory block at buff, length len, | |
20 | * and adds in "sum" (32-bit) | |
21 | * | |
22 | * returns a 32-bit number suitable for feeding into itself | |
23 | * or csum_tcpudp_magic | |
24 | * | |
25 | * this function must be called with even lengths, except | |
26 | * for the last fragment, which may be odd | |
27 | * | |
28 | * it's best to have buff aligned on a 32-bit boundary | |
29 | */ | |
30 | asmlinkage unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum); | |
31 | ||
32 | /* | |
33 | * the same as csum_partial, but copies from src while it | |
34 | * checksums, and handles user-space pointer exceptions correctly, when needed. | |
35 | * | |
36 | * here even more important to align src and dst on a 32-bit (or even | |
37 | * better 64-bit) boundary | |
38 | */ | |
39 | ||
40 | asmlinkage unsigned int csum_partial_copy_generic( const char *src, char *dst, int len, int sum, | |
41 | int *src_err_ptr, int *dst_err_ptr); | |
42 | ||
43 | /* | |
44 | * Note: when you get a NULL pointer exception here this means someone | |
45 | * passed in an incorrect kernel address to one of these functions. | |
46 | * | |
47 | * If you use these functions directly please don't forget the | |
48 | * verify_area(). | |
49 | */ | |
d99cf715 | 50 | static inline |
9a8fd558 CZ |
51 | unsigned int csum_partial_copy_nocheck ( const char *src, char *dst, |
52 | int len, int sum) | |
53 | { | |
54 | return csum_partial_copy_generic ( src, dst, len, sum, NULL, NULL); | |
55 | } | |
56 | ||
d99cf715 | 57 | static inline |
9a8fd558 CZ |
58 | unsigned int csum_partial_copy_from_user ( const char *src, char *dst, |
59 | int len, int sum, int *err_ptr) | |
60 | { | |
61 | return csum_partial_copy_generic ( src, dst, len, sum, err_ptr, NULL); | |
62 | } | |
63 | ||
64 | /* | |
65 | * These are the old (and unsafe) way of doing checksums, a warning message will be | |
66 | * printed if they are used and an exeption occurs. | |
67 | * | |
68 | * these functions should go away after some time. | |
69 | */ | |
70 | ||
71 | #define csum_partial_copy_fromuser csum_partial_copy | |
72 | unsigned int csum_partial_copy( const char *src, char *dst, int len, int sum); | |
73 | ||
74 | /* | |
75 | * Fold a partial checksum | |
76 | */ | |
77 | ||
78 | static __inline__ unsigned int csum_fold(unsigned int sum) | |
79 | { | |
80 | unsigned int __dummy; | |
81 | __asm__("extui %1, %0, 16, 16\n\t" | |
82 | "extui %0 ,%0, 0, 16\n\t" | |
83 | "add %0, %0, %1\n\t" | |
84 | "slli %1, %0, 16\n\t" | |
85 | "add %0, %0, %1\n\t" | |
86 | "extui %0, %0, 16, 16\n\t" | |
87 | "neg %0, %0\n\t" | |
88 | "addi %0, %0, -1\n\t" | |
89 | "extui %0, %0, 0, 16\n\t" | |
90 | : "=r" (sum), "=&r" (__dummy) | |
91 | : "0" (sum)); | |
92 | return sum; | |
93 | } | |
94 | ||
95 | /* | |
96 | * This is a version of ip_compute_csum() optimized for IP headers, | |
97 | * which always checksum on 4 octet boundaries. | |
98 | */ | |
99 | static __inline__ unsigned short ip_fast_csum(unsigned char * iph, unsigned int ihl) | |
100 | { | |
101 | unsigned int sum, tmp, endaddr; | |
102 | ||
103 | __asm__ __volatile__( | |
104 | "sub %0, %0, %0\n\t" | |
105 | #if XCHAL_HAVE_LOOPS | |
106 | "loopgtz %2, 2f\n\t" | |
107 | #else | |
108 | "beqz %2, 2f\n\t" | |
109 | "slli %4, %2, 2\n\t" | |
110 | "add %4, %4, %1\n\t" | |
111 | "0:\t" | |
112 | #endif | |
113 | "l32i %3, %1, 0\n\t" | |
114 | "add %0, %0, %3\n\t" | |
115 | "bgeu %0, %3, 1f\n\t" | |
116 | "addi %0, %0, 1\n\t" | |
117 | "1:\t" | |
118 | "addi %1, %1, 4\n\t" | |
119 | #if !XCHAL_HAVE_LOOPS | |
120 | "blt %1, %4, 0b\n\t" | |
121 | #endif | |
122 | "2:\t" | |
123 | /* Since the input registers which are loaded with iph and ihl | |
124 | are modified, we must also specify them as outputs, or gcc | |
125 | will assume they contain their original values. */ | |
126 | : "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (tmp), "=&r" (endaddr) | |
127 | : "1" (iph), "2" (ihl)); | |
128 | ||
129 | return csum_fold(sum); | |
130 | } | |
131 | ||
132 | static __inline__ unsigned long csum_tcpudp_nofold(unsigned long saddr, | |
133 | unsigned long daddr, | |
134 | unsigned short len, | |
135 | unsigned short proto, | |
136 | unsigned int sum) | |
137 | { | |
138 | ||
139 | #ifdef __XTENSA_EL__ | |
140 | unsigned long len_proto = (ntohs(len)<<16)+proto*256; | |
141 | #elif defined(__XTENSA_EB__) | |
142 | unsigned long len_proto = (proto<<16)+len; | |
143 | #else | |
144 | # error processor byte order undefined! | |
145 | #endif | |
146 | __asm__("add %0, %0, %1\n\t" | |
147 | "bgeu %0, %1, 1f\n\t" | |
148 | "addi %0, %0, 1\n\t" | |
149 | "1:\t" | |
150 | "add %0, %0, %2\n\t" | |
151 | "bgeu %0, %2, 1f\n\t" | |
152 | "addi %0, %0, 1\n\t" | |
153 | "1:\t" | |
154 | "add %0, %0, %3\n\t" | |
155 | "bgeu %0, %3, 1f\n\t" | |
156 | "addi %0, %0, 1\n\t" | |
157 | "1:\t" | |
158 | : "=r" (sum), "=r" (len_proto) | |
159 | : "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum)); | |
160 | return sum; | |
161 | } | |
162 | ||
163 | /* | |
164 | * computes the checksum of the TCP/UDP pseudo-header | |
165 | * returns a 16-bit checksum, already complemented | |
166 | */ | |
167 | static __inline__ unsigned short int csum_tcpudp_magic(unsigned long saddr, | |
168 | unsigned long daddr, | |
169 | unsigned short len, | |
170 | unsigned short proto, | |
171 | unsigned int sum) | |
172 | { | |
173 | return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum)); | |
174 | } | |
175 | ||
176 | /* | |
177 | * this routine is used for miscellaneous IP-like checksums, mainly | |
178 | * in icmp.c | |
179 | */ | |
180 | ||
181 | static __inline__ unsigned short ip_compute_csum(unsigned char * buff, int len) | |
182 | { | |
183 | return csum_fold (csum_partial(buff, len, 0)); | |
184 | } | |
185 | ||
186 | #define _HAVE_ARCH_IPV6_CSUM | |
187 | static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr, | |
188 | struct in6_addr *daddr, | |
189 | __u32 len, | |
190 | unsigned short proto, | |
191 | unsigned int sum) | |
192 | { | |
193 | unsigned int __dummy; | |
194 | __asm__("l32i %1, %2, 0\n\t" | |
195 | "add %0, %0, %1\n\t" | |
196 | "bgeu %0, %1, 1f\n\t" | |
197 | "addi %0, %0, 1\n\t" | |
198 | "1:\t" | |
199 | "l32i %1, %2, 4\n\t" | |
200 | "add %0, %0, %1\n\t" | |
201 | "bgeu %0, %1, 1f\n\t" | |
202 | "addi %0, %0, 1\n\t" | |
203 | "1:\t" | |
204 | "l32i %1, %2, 8\n\t" | |
205 | "add %0, %0, %1\n\t" | |
206 | "bgeu %0, %1, 1f\n\t" | |
207 | "addi %0, %0, 1\n\t" | |
208 | "1:\t" | |
209 | "l32i %1, %2, 12\n\t" | |
210 | "add %0, %0, %1\n\t" | |
211 | "bgeu %0, %1, 1f\n\t" | |
212 | "addi %0, %0, 1\n\t" | |
213 | "1:\t" | |
214 | "l32i %1, %3, 0\n\t" | |
215 | "add %0, %0, %1\n\t" | |
216 | "bgeu %0, %1, 1f\n\t" | |
217 | "addi %0, %0, 1\n\t" | |
218 | "1:\t" | |
219 | "l32i %1, %3, 4\n\t" | |
220 | "add %0, %0, %1\n\t" | |
221 | "bgeu %0, %1, 1f\n\t" | |
222 | "addi %0, %0, 1\n\t" | |
223 | "1:\t" | |
224 | "l32i %1, %3, 8\n\t" | |
225 | "add %0, %0, %1\n\t" | |
226 | "bgeu %0, %1, 1f\n\t" | |
227 | "addi %0, %0, 1\n\t" | |
228 | "1:\t" | |
229 | "l32i %1, %3, 12\n\t" | |
230 | "add %0, %0, %1\n\t" | |
231 | "bgeu %0, %1, 1f\n\t" | |
232 | "addi %0, %0, 1\n\t" | |
233 | "1:\t" | |
234 | "add %0, %0, %4\n\t" | |
235 | "bgeu %0, %4, 1f\n\t" | |
236 | "addi %0, %0, 1\n\t" | |
237 | "1:\t" | |
238 | "add %0, %0, %5\n\t" | |
239 | "bgeu %0, %5, 1f\n\t" | |
240 | "addi %0, %0, 1\n\t" | |
241 | "1:\t" | |
242 | : "=r" (sum), "=&r" (__dummy) | |
243 | : "r" (saddr), "r" (daddr), | |
244 | "r" (htonl(len)), "r" (htonl(proto)), "0" (sum)); | |
245 | ||
246 | return csum_fold(sum); | |
247 | } | |
248 | ||
249 | /* | |
250 | * Copy and checksum to user | |
251 | */ | |
252 | #define HAVE_CSUM_COPY_USER | |
253 | static __inline__ unsigned int csum_and_copy_to_user (const char *src, char *dst, | |
254 | int len, int sum, int *err_ptr) | |
255 | { | |
256 | if (access_ok(VERIFY_WRITE, dst, len)) | |
257 | return csum_partial_copy_generic(src, dst, len, sum, NULL, err_ptr); | |
258 | ||
259 | if (len) | |
260 | *err_ptr = -EFAULT; | |
261 | ||
262 | return -1; /* invalid checksum */ | |
263 | } | |
264 | #endif |