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-rw-r--r--include/asm-xtensa/checksum.h264
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diff --git a/include/asm-xtensa/checksum.h b/include/asm-xtensa/checksum.h
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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 */
30asmlinkage 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
40asmlinkage 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 */
50extern __inline__
51unsigned 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
57extern __inline__
58unsigned 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
72unsigned int csum_partial_copy( const char *src, char *dst, int len, int sum);
73
74/*
75 * Fold a partial checksum
76 */
77
78static __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 */
99static __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
132static __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 */
167static __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
181static __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
187static __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
253static __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
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