diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/sh64/lib/c-checksum.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/sh64/lib/c-checksum.c')
-rw-r--r-- | arch/sh64/lib/c-checksum.c | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/arch/sh64/lib/c-checksum.c b/arch/sh64/lib/c-checksum.c new file mode 100644 index 000000000000..a82d8f1a7a64 --- /dev/null +++ b/arch/sh64/lib/c-checksum.c | |||
@@ -0,0 +1,231 @@ | |||
1 | /* | ||
2 | * arch/sh/lib/csum_parial.c | ||
3 | * | ||
4 | * This file contains network checksum routines that are better done | ||
5 | * in an architecture-specific manner due to speed.. | ||
6 | */ | ||
7 | |||
8 | #undef DEBUG | ||
9 | |||
10 | #include <linux/config.h> | ||
11 | #include <linux/string.h> | ||
12 | #include <linux/errno.h> | ||
13 | #include <linux/kernel.h> | ||
14 | #include <asm/byteorder.h> | ||
15 | #include <asm/uaccess.h> | ||
16 | |||
17 | static inline unsigned short from64to16(unsigned long long x) | ||
18 | { | ||
19 | /* add up 32-bit words for 33 bits */ | ||
20 | x = (x & 0xffffffff) + (x >> 32); | ||
21 | /* add up 16-bit and 17-bit words for 17+c bits */ | ||
22 | x = (x & 0xffff) + (x >> 16); | ||
23 | /* add up 16-bit and 2-bit for 16+c bit */ | ||
24 | x = (x & 0xffff) + (x >> 16); | ||
25 | /* add up carry.. */ | ||
26 | x = (x & 0xffff) + (x >> 16); | ||
27 | return x; | ||
28 | } | ||
29 | |||
30 | static inline unsigned short foldto16(unsigned long x) | ||
31 | { | ||
32 | /* add up 16-bit for 17 bits */ | ||
33 | x = (x & 0xffff) + (x >> 16); | ||
34 | /* add up carry.. */ | ||
35 | x = (x & 0xffff) + (x >> 16); | ||
36 | return x; | ||
37 | } | ||
38 | |||
39 | static inline unsigned short myfoldto16(unsigned long long x) | ||
40 | { | ||
41 | /* Fold down to 32-bits so we don't loose in the typedef-less | ||
42 | network stack. */ | ||
43 | /* 64 to 33 */ | ||
44 | x = (x & 0xffffffff) + (x >> 32); | ||
45 | /* 33 to 32 */ | ||
46 | x = (x & 0xffffffff) + (x >> 32); | ||
47 | |||
48 | /* add up 16-bit for 17 bits */ | ||
49 | x = (x & 0xffff) + (x >> 16); | ||
50 | /* add up carry.. */ | ||
51 | x = (x & 0xffff) + (x >> 16); | ||
52 | return x; | ||
53 | } | ||
54 | |||
55 | #define odd(x) ((x)&1) | ||
56 | #define U16(x) ntohs(x) | ||
57 | |||
58 | static unsigned long do_csum(const unsigned char *buff, int len) | ||
59 | { | ||
60 | int odd, count; | ||
61 | unsigned long result = 0; | ||
62 | |||
63 | pr_debug("do_csum buff %p, len %d (0x%x)\n", buff, len, len); | ||
64 | #ifdef DEBUG | ||
65 | for (i = 0; i < len; i++) { | ||
66 | if ((i % 26) == 0) | ||
67 | printk("\n"); | ||
68 | printk("%02X ", buff[i]); | ||
69 | } | ||
70 | #endif | ||
71 | |||
72 | if (len <= 0) | ||
73 | goto out; | ||
74 | |||
75 | odd = 1 & (unsigned long) buff; | ||
76 | if (odd) { | ||
77 | result = *buff << 8; | ||
78 | len--; | ||
79 | buff++; | ||
80 | } | ||
81 | count = len >> 1; /* nr of 16-bit words.. */ | ||
82 | if (count) { | ||
83 | if (2 & (unsigned long) buff) { | ||
84 | result += *(unsigned short *) buff; | ||
85 | count--; | ||
86 | len -= 2; | ||
87 | buff += 2; | ||
88 | } | ||
89 | count >>= 1; /* nr of 32-bit words.. */ | ||
90 | if (count) { | ||
91 | unsigned long carry = 0; | ||
92 | do { | ||
93 | unsigned long w = *(unsigned long *) buff; | ||
94 | buff += 4; | ||
95 | count--; | ||
96 | result += carry; | ||
97 | result += w; | ||
98 | carry = (w > result); | ||
99 | } while (count); | ||
100 | result += carry; | ||
101 | result = (result & 0xffff) + (result >> 16); | ||
102 | } | ||
103 | if (len & 2) { | ||
104 | result += *(unsigned short *) buff; | ||
105 | buff += 2; | ||
106 | } | ||
107 | } | ||
108 | if (len & 1) | ||
109 | result += *buff; | ||
110 | result = foldto16(result); | ||
111 | if (odd) | ||
112 | result = ((result >> 8) & 0xff) | ((result & 0xff) << 8); | ||
113 | |||
114 | pr_debug("\nCHECKSUM is 0x%x\n", result); | ||
115 | |||
116 | out: | ||
117 | return result; | ||
118 | } | ||
119 | |||
120 | /* computes the checksum of a memory block at buff, length len, | ||
121 | and adds in "sum" (32-bit) */ | ||
122 | unsigned int csum_partial(const unsigned char *buff, int len, unsigned int sum) | ||
123 | { | ||
124 | unsigned long long result = do_csum(buff, len); | ||
125 | |||
126 | /* add in old sum, and carry.. */ | ||
127 | result += sum; | ||
128 | /* 32+c bits -> 32 bits */ | ||
129 | result = (result & 0xffffffff) + (result >> 32); | ||
130 | |||
131 | pr_debug("csum_partial, buff %p len %d sum 0x%x result=0x%016Lx\n", | ||
132 | buff, len, sum, result); | ||
133 | |||
134 | return result; | ||
135 | } | ||
136 | |||
137 | /* Copy while checksumming, otherwise like csum_partial. */ | ||
138 | unsigned int | ||
139 | csum_partial_copy(const unsigned char *src, unsigned char *dst, int len, unsigned int sum) | ||
140 | { | ||
141 | sum = csum_partial(src, len, sum); | ||
142 | memcpy(dst, src, len); | ||
143 | |||
144 | return sum; | ||
145 | } | ||
146 | |||
147 | /* Copy from userspace and compute checksum. If we catch an exception | ||
148 | then zero the rest of the buffer. */ | ||
149 | unsigned int | ||
150 | csum_partial_copy_from_user(const unsigned char *src, unsigned char *dst, int len, | ||
151 | unsigned int sum, int *err_ptr) | ||
152 | { | ||
153 | int missing; | ||
154 | |||
155 | pr_debug | ||
156 | ("csum_partial_copy_from_user src %p, dest %p, len %d, sum %08x, err_ptr %p\n", | ||
157 | src, dst, len, sum, err_ptr); | ||
158 | missing = copy_from_user(dst, src, len); | ||
159 | pr_debug(" access_ok %d\n", __access_ok((unsigned long) src, len)); | ||
160 | pr_debug(" missing %d\n", missing); | ||
161 | if (missing) { | ||
162 | memset(dst + len - missing, 0, missing); | ||
163 | *err_ptr = -EFAULT; | ||
164 | } | ||
165 | |||
166 | return csum_partial(dst, len, sum); | ||
167 | } | ||
168 | |||
169 | /* Copy to userspace and compute checksum. */ | ||
170 | unsigned int | ||
171 | csum_partial_copy_to_user(const unsigned char *src, unsigned char *dst, int len, | ||
172 | unsigned int sum, int *err_ptr) | ||
173 | { | ||
174 | sum = csum_partial(src, len, sum); | ||
175 | |||
176 | if (copy_to_user(dst, src, len)) | ||
177 | *err_ptr = -EFAULT; | ||
178 | |||
179 | return sum; | ||
180 | } | ||
181 | |||
182 | /* | ||
183 | * This is a version of ip_compute_csum() optimized for IP headers, | ||
184 | * which always checksum on 4 octet boundaries. | ||
185 | */ | ||
186 | unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl) | ||
187 | { | ||
188 | pr_debug("ip_fast_csum %p,%d\n", iph, ihl); | ||
189 | |||
190 | return ~do_csum(iph, ihl * 4); | ||
191 | } | ||
192 | |||
193 | unsigned int csum_tcpudp_nofold(unsigned long saddr, | ||
194 | unsigned long daddr, | ||
195 | unsigned short len, | ||
196 | unsigned short proto, unsigned int sum) | ||
197 | { | ||
198 | unsigned long long result; | ||
199 | |||
200 | pr_debug("ntohs(0x%x)=0x%x\n", 0xdead, ntohs(0xdead)); | ||
201 | pr_debug("htons(0x%x)=0x%x\n", 0xdead, htons(0xdead)); | ||
202 | |||
203 | result = ((unsigned long long) saddr + | ||
204 | (unsigned long long) daddr + | ||
205 | (unsigned long long) sum + | ||
206 | ((unsigned long long) ntohs(len) << 16) + | ||
207 | ((unsigned long long) proto << 8)); | ||
208 | |||
209 | /* Fold down to 32-bits so we don't loose in the typedef-less | ||
210 | network stack. */ | ||
211 | /* 64 to 33 */ | ||
212 | result = (result & 0xffffffff) + (result >> 32); | ||
213 | /* 33 to 32 */ | ||
214 | result = (result & 0xffffffff) + (result >> 32); | ||
215 | |||
216 | pr_debug("%s saddr %x daddr %x len %x proto %x sum %x result %08Lx\n", | ||
217 | __FUNCTION__, saddr, daddr, len, proto, sum, result); | ||
218 | |||
219 | return result; | ||
220 | } | ||
221 | |||
222 | // Post SIM: | ||
223 | unsigned int | ||
224 | csum_partial_copy_nocheck(const unsigned char *src, unsigned char *dst, int len, unsigned int sum) | ||
225 | { | ||
226 | // unsigned dummy; | ||
227 | pr_debug("csum_partial_copy_nocheck src %p dst %p len %d\n", src, dst, | ||
228 | len); | ||
229 | |||
230 | return csum_partial_copy(src, dst, len, sum); | ||
231 | } | ||