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/in6.h>
15 #include <asm/uaccess.h>
16 #include <variant/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 __wsum csum_partial(const void *buff, int len, __wsum 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 __wsum csum_partial_copy_generic(const void *src, void *dst,
41 int len, __wsum sum,
42 int *src_err_ptr, int *dst_err_ptr);
43
44 /*
45 * Note: when you get a NULL pointer exception here this means someone
46 * passed in an incorrect kernel address to one of these functions.
47 *
48 * If you use these functions directly please don't forget the access_ok().
49 */
50 static inline
csum_partial_copy_nocheck(const void * src,void * dst,int len,__wsum sum)51 __wsum csum_partial_copy_nocheck(const void *src, void *dst,
52 int len, __wsum sum)
53 {
54 return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL);
55 }
56
57 static inline
csum_partial_copy_from_user(const void __user * src,void * dst,int len,__wsum sum,int * err_ptr)58 __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
59 int len, __wsum sum, int *err_ptr)
60 {
61 return csum_partial_copy_generic((__force const void *)src, dst,
62 len, sum, err_ptr, NULL);
63 }
64
65 /*
66 * Fold a partial checksum
67 */
68
csum_fold(__wsum sum)69 static __inline__ __sum16 csum_fold(__wsum sum)
70 {
71 unsigned int __dummy;
72 __asm__("extui %1, %0, 16, 16\n\t"
73 "extui %0 ,%0, 0, 16\n\t"
74 "add %0, %0, %1\n\t"
75 "slli %1, %0, 16\n\t"
76 "add %0, %0, %1\n\t"
77 "extui %0, %0, 16, 16\n\t"
78 "neg %0, %0\n\t"
79 "addi %0, %0, -1\n\t"
80 "extui %0, %0, 0, 16\n\t"
81 : "=r" (sum), "=&r" (__dummy)
82 : "0" (sum));
83 return (__force __sum16)sum;
84 }
85
86 /*
87 * This is a version of ip_compute_csum() optimized for IP headers,
88 * which always checksum on 4 octet boundaries.
89 */
ip_fast_csum(const void * iph,unsigned int ihl)90 static __inline__ __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
91 {
92 unsigned int sum, tmp, endaddr;
93
94 __asm__ __volatile__(
95 "sub %0, %0, %0\n\t"
96 #if XCHAL_HAVE_LOOPS
97 "loopgtz %2, 2f\n\t"
98 #else
99 "beqz %2, 2f\n\t"
100 "slli %4, %2, 2\n\t"
101 "add %4, %4, %1\n\t"
102 "0:\t"
103 #endif
104 "l32i %3, %1, 0\n\t"
105 "add %0, %0, %3\n\t"
106 "bgeu %0, %3, 1f\n\t"
107 "addi %0, %0, 1\n\t"
108 "1:\t"
109 "addi %1, %1, 4\n\t"
110 #if !XCHAL_HAVE_LOOPS
111 "blt %1, %4, 0b\n\t"
112 #endif
113 "2:\t"
114 /* Since the input registers which are loaded with iph and ihl
115 are modified, we must also specify them as outputs, or gcc
116 will assume they contain their original values. */
117 : "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (tmp),
118 "=&r" (endaddr)
119 : "1" (iph), "2" (ihl)
120 : "memory");
121
122 return csum_fold(sum);
123 }
124
csum_tcpudp_nofold(__be32 saddr,__be32 daddr,unsigned short len,unsigned short proto,__wsum sum)125 static __inline__ __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
126 unsigned short len,
127 unsigned short proto,
128 __wsum sum)
129 {
130
131 #ifdef __XTENSA_EL__
132 unsigned long len_proto = (len + proto) << 8;
133 #elif defined(__XTENSA_EB__)
134 unsigned long len_proto = len + proto;
135 #else
136 # error processor byte order undefined!
137 #endif
138 __asm__("add %0, %0, %1\n\t"
139 "bgeu %0, %1, 1f\n\t"
140 "addi %0, %0, 1\n\t"
141 "1:\t"
142 "add %0, %0, %2\n\t"
143 "bgeu %0, %2, 1f\n\t"
144 "addi %0, %0, 1\n\t"
145 "1:\t"
146 "add %0, %0, %3\n\t"
147 "bgeu %0, %3, 1f\n\t"
148 "addi %0, %0, 1\n\t"
149 "1:\t"
150 : "=r" (sum), "=r" (len_proto)
151 : "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum));
152 return sum;
153 }
154
155 /*
156 * computes the checksum of the TCP/UDP pseudo-header
157 * returns a 16-bit checksum, already complemented
158 */
csum_tcpudp_magic(__be32 saddr,__be32 daddr,unsigned short len,unsigned short proto,__wsum sum)159 static __inline__ __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
160 unsigned short len,
161 unsigned short proto,
162 __wsum sum)
163 {
164 return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
165 }
166
167 /*
168 * this routine is used for miscellaneous IP-like checksums, mainly
169 * in icmp.c
170 */
171
ip_compute_csum(const void * buff,int len)172 static __inline__ __sum16 ip_compute_csum(const void *buff, int len)
173 {
174 return csum_fold (csum_partial(buff, len, 0));
175 }
176
177 #define _HAVE_ARCH_IPV6_CSUM
csum_ipv6_magic(const struct in6_addr * saddr,const struct in6_addr * daddr,__u32 len,unsigned short proto,__wsum sum)178 static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
179 const struct in6_addr *daddr,
180 __u32 len, unsigned short proto,
181 __wsum sum)
182 {
183 unsigned int __dummy;
184 __asm__("l32i %1, %2, 0\n\t"
185 "add %0, %0, %1\n\t"
186 "bgeu %0, %1, 1f\n\t"
187 "addi %0, %0, 1\n\t"
188 "1:\t"
189 "l32i %1, %2, 4\n\t"
190 "add %0, %0, %1\n\t"
191 "bgeu %0, %1, 1f\n\t"
192 "addi %0, %0, 1\n\t"
193 "1:\t"
194 "l32i %1, %2, 8\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, 12\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, %3, 0\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, %3, 4\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, 8\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, 12\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 "add %0, %0, %4\n\t"
225 "bgeu %0, %4, 1f\n\t"
226 "addi %0, %0, 1\n\t"
227 "1:\t"
228 "add %0, %0, %5\n\t"
229 "bgeu %0, %5, 1f\n\t"
230 "addi %0, %0, 1\n\t"
231 "1:\t"
232 : "=r" (sum), "=&r" (__dummy)
233 : "r" (saddr), "r" (daddr),
234 "r" (htonl(len)), "r" (htonl(proto)), "0" (sum)
235 : "memory");
236
237 return csum_fold(sum);
238 }
239
240 /*
241 * Copy and checksum to user
242 */
243 #define HAVE_CSUM_COPY_USER
csum_and_copy_to_user(const void * src,void __user * dst,int len,__wsum sum,int * err_ptr)244 static __inline__ __wsum csum_and_copy_to_user(const void *src,
245 void __user *dst, int len,
246 __wsum sum, int *err_ptr)
247 {
248 if (access_ok(VERIFY_WRITE, dst, len))
249 return csum_partial_copy_generic(src,dst,len,sum,NULL,err_ptr);
250
251 if (len)
252 *err_ptr = -EFAULT;
253
254 return (__force __wsum)-1; /* invalid checksum */
255 }
256 #endif
257