1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
|
/*
* include/asm-xtensa/checksum.h
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2001 - 2005 Tensilica Inc.
*/
#ifndef _XTENSA_CHECKSUM_H
#define _XTENSA_CHECKSUM_H
#include <linux/in6.h>
#include <linux/uaccess.h>
#include <asm/core.h>
/*
* computes the checksum of a memory block at buff, length len,
* and adds in "sum" (32-bit)
*
* returns a 32-bit number suitable for feeding into itself
* or csum_tcpudp_magic
*
* this function must be called with even lengths, except
* for the last fragment, which may be odd
*
* it's best to have buff aligned on a 32-bit boundary
*/
asmlinkage __wsum csum_partial(const void *buff, int len, __wsum sum);
/*
* the same as csum_partial, but copies from src while it
* checksums, and handles user-space pointer exceptions correctly, when needed.
*
* here even more important to align src and dst on a 32-bit (or even
* better 64-bit) boundary
*/
asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst,
int len, __wsum sum,
int *src_err_ptr, int *dst_err_ptr);
/*
* Note: when you get a NULL pointer exception here this means someone
* passed in an incorrect kernel address to one of these functions.
*/
static inline
__wsum csum_partial_copy_nocheck(const void *src, void *dst,
int len, __wsum sum)
{
return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL);
}
#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
static inline
__wsum csum_and_copy_from_user(const void __user *src, void *dst,
int len, __wsum sum, int *err_ptr)
{
if (access_ok(dst, len))
return csum_partial_copy_generic((__force const void *)src, dst,
len, sum, err_ptr, NULL);
if (len)
*err_ptr = -EFAULT;
return sum;
}
/*
* Fold a partial checksum
*/
static __inline__ __sum16 csum_fold(__wsum sum)
{
unsigned int __dummy;
__asm__("extui %1, %0, 16, 16\n\t"
"extui %0 ,%0, 0, 16\n\t"
"add %0, %0, %1\n\t"
"slli %1, %0, 16\n\t"
"add %0, %0, %1\n\t"
"extui %0, %0, 16, 16\n\t"
"neg %0, %0\n\t"
"addi %0, %0, -1\n\t"
"extui %0, %0, 0, 16\n\t"
: "=r" (sum), "=&r" (__dummy)
: "0" (sum));
return (__force __sum16)sum;
}
/*
* This is a version of ip_compute_csum() optimized for IP headers,
* which always checksum on 4 octet boundaries.
*/
static __inline__ __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
{
unsigned int sum, tmp, endaddr;
__asm__ __volatile__(
"sub %0, %0, %0\n\t"
#if XCHAL_HAVE_LOOPS
"loopgtz %2, 2f\n\t"
#else
"beqz %2, 2f\n\t"
"slli %4, %2, 2\n\t"
"add %4, %4, %1\n\t"
"0:\t"
#endif
"l32i %3, %1, 0\n\t"
"add %0, %0, %3\n\t"
"bgeu %0, %3, 1f\n\t"
"addi %0, %0, 1\n\t"
"1:\t"
"addi %1, %1, 4\n\t"
#if !XCHAL_HAVE_LOOPS
"blt %1, %4, 0b\n\t"
#endif
"2:\t"
/* Since the input registers which are loaded with iph and ihl
are modified, we must also specify them as outputs, or gcc
will assume they contain their original values. */
: "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (tmp),
"=&r" (endaddr)
: "1" (iph), "2" (ihl)
: "memory");
return csum_fold(sum);
}
static __inline__ __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
__u32 len, __u8 proto,
__wsum sum)
{
#ifdef __XTENSA_EL__
unsigned long len_proto = (len + proto) << 8;
#elif defined(__XTENSA_EB__)
unsigned long len_proto = len + proto;
#else
# error processor byte order undefined!
#endif
__asm__("add %0, %0, %1\n\t"
"bgeu %0, %1, 1f\n\t"
"addi %0, %0, 1\n\t"
"1:\t"
"add %0, %0, %2\n\t"
"bgeu %0, %2, 1f\n\t"
"addi %0, %0, 1\n\t"
"1:\t"
"add %0, %0, %3\n\t"
"bgeu %0, %3, 1f\n\t"
"addi %0, %0, 1\n\t"
"1:\t"
: "=r" (sum), "=r" (len_proto)
: "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum));
return sum;
}
/*
* computes the checksum of the TCP/UDP pseudo-header
* returns a 16-bit checksum, already complemented
*/
static __inline__ __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
__u32 len, __u8 proto,
__wsum sum)
{
return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
}
/*
* this routine is used for miscellaneous IP-like checksums, mainly
* in icmp.c
*/
static __inline__ __sum16 ip_compute_csum(const void *buff, int len)
{
return csum_fold (csum_partial(buff, len, 0));
}
#define _HAVE_ARCH_IPV6_CSUM
static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
const struct in6_addr *daddr,
__u32 len, __u8 proto,
__wsum sum)
{
unsigned int __dummy;
__asm__("l32i %1, %2, 0\n\t"
"add %0, %0, %1\n\t"
"bgeu %0, %1, 1f\n\t"
"addi %0, %0, 1\n\t"
"1:\t"
"l32i %1, %2, 4\n\t"
"add %0, %0, %1\n\t"
"bgeu %0, %1, 1f\n\t"
"addi %0, %0, 1\n\t"
"1:\t"
"l32i %1, %2, 8\n\t"
"add %0, %0, %1\n\t"
"bgeu %0, %1, 1f\n\t"
"addi %0, %0, 1\n\t"
"1:\t"
"l32i %1, %2, 12\n\t"
"add %0, %0, %1\n\t"
"bgeu %0, %1, 1f\n\t"
"addi %0, %0, 1\n\t"
"1:\t"
"l32i %1, %3, 0\n\t"
"add %0, %0, %1\n\t"
"bgeu %0, %1, 1f\n\t"
"addi %0, %0, 1\n\t"
"1:\t"
"l32i %1, %3, 4\n\t"
"add %0, %0, %1\n\t"
"bgeu %0, %1, 1f\n\t"
"addi %0, %0, 1\n\t"
"1:\t"
"l32i %1, %3, 8\n\t"
"add %0, %0, %1\n\t"
"bgeu %0, %1, 1f\n\t"
"addi %0, %0, 1\n\t"
"1:\t"
"l32i %1, %3, 12\n\t"
"add %0, %0, %1\n\t"
"bgeu %0, %1, 1f\n\t"
"addi %0, %0, 1\n\t"
"1:\t"
"add %0, %0, %4\n\t"
"bgeu %0, %4, 1f\n\t"
"addi %0, %0, 1\n\t"
"1:\t"
"add %0, %0, %5\n\t"
"bgeu %0, %5, 1f\n\t"
"addi %0, %0, 1\n\t"
"1:\t"
: "=r" (sum), "=&r" (__dummy)
: "r" (saddr), "r" (daddr),
"r" (htonl(len)), "r" (htonl(proto)), "0" (sum)
: "memory");
return csum_fold(sum);
}
/*
* Copy and checksum to user
*/
#define HAVE_CSUM_COPY_USER
static __inline__ __wsum csum_and_copy_to_user(const void *src,
void __user *dst, int len,
__wsum sum, int *err_ptr)
{
if (access_ok(dst, len))
return csum_partial_copy_generic(src,dst,len,sum,NULL,err_ptr);
if (len)
*err_ptr = -EFAULT;
return (__force __wsum)-1; /* invalid checksum */
}
#endif
|
