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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /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.c231
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
17static 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
30static 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
39static 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
58static 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) */
122unsigned 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. */
138unsigned int
139csum_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. */
149unsigned int
150csum_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. */
170unsigned int
171csum_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 */
186unsigned 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
193unsigned 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:
223unsigned int
224csum_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}