1 /* MN10300 Optimised checksumming wrappers
2 *
3 * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public Licence
9 * as published by the Free Software Foundation; either version
10 * 2 of the Licence, or (at your option) any later version.
11 */
12 #include <linux/module.h>
13 #include <linux/errno.h>
14 #include <asm/byteorder.h>
15 #include <asm/uaccess.h>
16 #include <asm/checksum.h>
17 #include "internal.h"
18
from32to16(__wsum sum)19 static inline unsigned short from32to16(__wsum sum)
20 {
21 asm(" add %1,%0 \n"
22 " addc 0xffff,%0 \n"
23 : "=r" (sum)
24 : "r" (sum << 16), "0" (sum & 0xffff0000)
25 : "cc"
26 );
27 return sum >> 16;
28 }
29
ip_fast_csum(const void * iph,unsigned int ihl)30 __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
31 {
32 return ~do_csum(iph, ihl * 4);
33 }
34 EXPORT_SYMBOL(ip_fast_csum);
35
csum_partial(const void * buff,int len,__wsum sum)36 __wsum csum_partial(const void *buff, int len, __wsum sum)
37 {
38 __wsum result;
39
40 result = do_csum(buff, len);
41 result += sum;
42 if (sum > result)
43 result++;
44 return result;
45 }
46 EXPORT_SYMBOL(csum_partial);
47
ip_compute_csum(const void * buff,int len)48 __sum16 ip_compute_csum(const void *buff, int len)
49 {
50 return ~from32to16(do_csum(buff, len));
51 }
52 EXPORT_SYMBOL(ip_compute_csum);
53
csum_partial_copy(const void * src,void * dst,int len,__wsum sum)54 __wsum csum_partial_copy(const void *src, void *dst, int len, __wsum sum)
55 {
56 copy_from_user(dst, src, len);
57 return csum_partial(dst, len, sum);
58 }
59 EXPORT_SYMBOL(csum_partial_copy);
60
csum_partial_copy_nocheck(const void * src,void * dst,int len,__wsum sum)61 __wsum csum_partial_copy_nocheck(const void *src, void *dst,
62 int len, __wsum sum)
63 {
64 sum = csum_partial(src, len, sum);
65 memcpy(dst, src, len);
66 return sum;
67 }
68 EXPORT_SYMBOL(csum_partial_copy_nocheck);
69
csum_partial_copy_from_user(const void * src,void * dst,int len,__wsum sum,int * err_ptr)70 __wsum csum_partial_copy_from_user(const void *src, void *dst,
71 int len, __wsum sum,
72 int *err_ptr)
73 {
74 int missing;
75
76 missing = copy_from_user(dst, src, len);
77 if (missing) {
78 memset(dst + len - missing, 0, missing);
79 *err_ptr = -EFAULT;
80 }
81
82 return csum_partial(dst, len, sum);
83 }
84 EXPORT_SYMBOL(csum_partial_copy_from_user);
85
csum_and_copy_to_user(const void * src,void * dst,int len,__wsum sum,int * err_ptr)86 __wsum csum_and_copy_to_user(const void *src, void *dst,
87 int len, __wsum sum,
88 int *err_ptr)
89 {
90 int missing;
91
92 missing = copy_to_user(dst, src, len);
93 if (missing) {
94 memset(dst + len - missing, 0, missing);
95 *err_ptr = -EFAULT;
96 }
97
98 return csum_partial(src, len, sum);
99 }
100 EXPORT_SYMBOL(csum_and_copy_to_user);
101