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/x86_64/lib/csum-wrappers.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/x86_64/lib/csum-wrappers.c')
-rw-r--r-- | arch/x86_64/lib/csum-wrappers.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/arch/x86_64/lib/csum-wrappers.c b/arch/x86_64/lib/csum-wrappers.c new file mode 100644 index 000000000000..94323f20816e --- /dev/null +++ b/arch/x86_64/lib/csum-wrappers.c | |||
@@ -0,0 +1,129 @@ | |||
1 | /* Copyright 2002,2003 Andi Kleen, SuSE Labs. | ||
2 | * Subject to the GNU Public License v.2 | ||
3 | * | ||
4 | * Wrappers of assembly checksum functions for x86-64. | ||
5 | */ | ||
6 | |||
7 | #include <asm/checksum.h> | ||
8 | #include <linux/module.h> | ||
9 | |||
10 | /** | ||
11 | * csum_partial_copy_from_user - Copy and checksum from user space. | ||
12 | * @src: source address (user space) | ||
13 | * @dst: destination address | ||
14 | * @len: number of bytes to be copied. | ||
15 | * @isum: initial sum that is added into the result (32bit unfolded) | ||
16 | * @errp: set to -EFAULT for an bad source address. | ||
17 | * | ||
18 | * Returns an 32bit unfolded checksum of the buffer. | ||
19 | * src and dst are best aligned to 64bits. | ||
20 | */ | ||
21 | unsigned int | ||
22 | csum_partial_copy_from_user(const unsigned char __user *src, unsigned char *dst, | ||
23 | int len, unsigned int isum, int *errp) | ||
24 | { | ||
25 | might_sleep(); | ||
26 | *errp = 0; | ||
27 | if (likely(access_ok(VERIFY_READ,src, len))) { | ||
28 | /* Why 6, not 7? To handle odd addresses aligned we | ||
29 | would need to do considerable complications to fix the | ||
30 | checksum which is defined as an 16bit accumulator. The | ||
31 | fix alignment code is primarily for performance | ||
32 | compatibility with 32bit and that will handle odd | ||
33 | addresses slowly too. */ | ||
34 | if (unlikely((unsigned long)src & 6)) { | ||
35 | while (((unsigned long)src & 6) && len >= 2) { | ||
36 | __u16 val16; | ||
37 | *errp = __get_user(val16, (__u16 __user *)src); | ||
38 | if (*errp) | ||
39 | return isum; | ||
40 | *(__u16 *)dst = val16; | ||
41 | isum = add32_with_carry(isum, val16); | ||
42 | src += 2; | ||
43 | dst += 2; | ||
44 | len -= 2; | ||
45 | } | ||
46 | } | ||
47 | isum = csum_partial_copy_generic((__force void *)src,dst,len,isum,errp,NULL); | ||
48 | if (likely(*errp == 0)) | ||
49 | return isum; | ||
50 | } | ||
51 | *errp = -EFAULT; | ||
52 | memset(dst,0,len); | ||
53 | return isum; | ||
54 | } | ||
55 | |||
56 | EXPORT_SYMBOL(csum_partial_copy_from_user); | ||
57 | |||
58 | /** | ||
59 | * csum_partial_copy_to_user - Copy and checksum to user space. | ||
60 | * @src: source address | ||
61 | * @dst: destination address (user space) | ||
62 | * @len: number of bytes to be copied. | ||
63 | * @isum: initial sum that is added into the result (32bit unfolded) | ||
64 | * @errp: set to -EFAULT for an bad destination address. | ||
65 | * | ||
66 | * Returns an 32bit unfolded checksum of the buffer. | ||
67 | * src and dst are best aligned to 64bits. | ||
68 | */ | ||
69 | unsigned int | ||
70 | csum_partial_copy_to_user(unsigned const char *src, unsigned char __user *dst, | ||
71 | int len, unsigned int isum, int *errp) | ||
72 | { | ||
73 | might_sleep(); | ||
74 | if (unlikely(!access_ok(VERIFY_WRITE, dst, len))) { | ||
75 | *errp = -EFAULT; | ||
76 | return 0; | ||
77 | } | ||
78 | |||
79 | if (unlikely((unsigned long)dst & 6)) { | ||
80 | while (((unsigned long)dst & 6) && len >= 2) { | ||
81 | __u16 val16 = *(__u16 *)src; | ||
82 | isum = add32_with_carry(isum, val16); | ||
83 | *errp = __put_user(val16, (__u16 __user *)dst); | ||
84 | if (*errp) | ||
85 | return isum; | ||
86 | src += 2; | ||
87 | dst += 2; | ||
88 | len -= 2; | ||
89 | } | ||
90 | } | ||
91 | |||
92 | *errp = 0; | ||
93 | return csum_partial_copy_generic(src, (void __force *)dst,len,isum,NULL,errp); | ||
94 | } | ||
95 | |||
96 | EXPORT_SYMBOL(csum_partial_copy_to_user); | ||
97 | |||
98 | /** | ||
99 | * csum_partial_copy_nocheck - Copy and checksum. | ||
100 | * @src: source address | ||
101 | * @dst: destination address | ||
102 | * @len: number of bytes to be copied. | ||
103 | * @isum: initial sum that is added into the result (32bit unfolded) | ||
104 | * | ||
105 | * Returns an 32bit unfolded checksum of the buffer. | ||
106 | */ | ||
107 | unsigned int | ||
108 | csum_partial_copy_nocheck(const unsigned char *src, unsigned char *dst, int len, unsigned int sum) | ||
109 | { | ||
110 | return csum_partial_copy_generic(src,dst,len,sum,NULL,NULL); | ||
111 | } | ||
112 | |||
113 | unsigned short csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr, | ||
114 | __u32 len, unsigned short proto, unsigned int sum) | ||
115 | { | ||
116 | __u64 rest, sum64; | ||
117 | |||
118 | rest = (__u64)htonl(len) + (__u64)htons(proto) + (__u64)sum; | ||
119 | asm(" addq (%[saddr]),%[sum]\n" | ||
120 | " adcq 8(%[saddr]),%[sum]\n" | ||
121 | " adcq (%[daddr]),%[sum]\n" | ||
122 | " adcq 8(%[daddr]),%[sum]\n" | ||
123 | " adcq $0,%[sum]\n" | ||
124 | : [sum] "=r" (sum64) | ||
125 | : "[sum]" (rest),[saddr] "r" (saddr), [daddr] "r" (daddr)); | ||
126 | return csum_fold(add32_with_carry(sum64 & 0xffffffff, sum64>>32)); | ||
127 | } | ||
128 | |||
129 | EXPORT_SYMBOL(csum_ipv6_magic); | ||