fs: use kmem_cache_zalloc instead
[pv_ops_mirror.git] / include / asm-x86 / checksum_64.h
blob419fe88a0342d383962571165f2e2ec04f4d23d3
1 #ifndef _X86_64_CHECKSUM_H
2 #define _X86_64_CHECKSUM_H
4 /*
5 * Checksums for x86-64
6 * Copyright 2002 by Andi Kleen, SuSE Labs
7 * with some code from asm-i386/checksum.h
8 */
10 #include <linux/compiler.h>
11 #include <asm/uaccess.h>
12 #include <asm/byteorder.h>
14 /**
15 * csum_fold - Fold and invert a 32bit checksum.
16 * sum: 32bit unfolded sum
18 * Fold a 32bit running checksum to 16bit and invert it. This is usually
19 * the last step before putting a checksum into a packet.
20 * Make sure not to mix with 64bit checksums.
22 static inline __sum16 csum_fold(__wsum sum)
24 __asm__(
25 " addl %1,%0\n"
26 " adcl $0xffff,%0"
27 : "=r" (sum)
28 : "r" ((__force u32)sum << 16),
29 "0" ((__force u32)sum & 0xffff0000)
31 return (__force __sum16)(~(__force u32)sum >> 16);
35 * This is a version of ip_compute_csum() optimized for IP headers,
36 * which always checksum on 4 octet boundaries.
38 * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
39 * Arnt Gulbrandsen.
42 /**
43 * ip_fast_csum - Compute the IPv4 header checksum efficiently.
44 * iph: ipv4 header
45 * ihl: length of header / 4
46 */
47 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
49 unsigned int sum;
51 asm( " movl (%1), %0\n"
52 " subl $4, %2\n"
53 " jbe 2f\n"
54 " addl 4(%1), %0\n"
55 " adcl 8(%1), %0\n"
56 " adcl 12(%1), %0\n"
57 "1: adcl 16(%1), %0\n"
58 " lea 4(%1), %1\n"
59 " decl %2\n"
60 " jne 1b\n"
61 " adcl $0, %0\n"
62 " movl %0, %2\n"
63 " shrl $16, %0\n"
64 " addw %w2, %w0\n"
65 " adcl $0, %0\n"
66 " notl %0\n"
67 "2:"
68 /* Since the input registers which are loaded with iph and ihl
69 are modified, we must also specify them as outputs, or gcc
70 will assume they contain their original values. */
71 : "=r" (sum), "=r" (iph), "=r" (ihl)
72 : "1" (iph), "2" (ihl)
73 : "memory");
74 return (__force __sum16)sum;
77 /**
78 * csum_tcpup_nofold - Compute an IPv4 pseudo header checksum.
79 * @saddr: source address
80 * @daddr: destination address
81 * @len: length of packet
82 * @proto: ip protocol of packet
83 * @sum: initial sum to be added in (32bit unfolded)
85 * Returns the pseudo header checksum the input data. Result is
86 * 32bit unfolded.
88 static inline __wsum
89 csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
90 unsigned short proto, __wsum sum)
92 asm(" addl %1, %0\n"
93 " adcl %2, %0\n"
94 " adcl %3, %0\n"
95 " adcl $0, %0\n"
96 : "=r" (sum)
97 : "g" (daddr), "g" (saddr),
98 "g" ((len + proto)<<8), "0" (sum));
99 return sum;
103 /**
104 * csum_tcpup_magic - Compute an IPv4 pseudo header checksum.
105 * @saddr: source address
106 * @daddr: destination address
107 * @len: length of packet
108 * @proto: ip protocol of packet
109 * @sum: initial sum to be added in (32bit unfolded)
111 * Returns the 16bit pseudo header checksum the input data already
112 * complemented and ready to be filled in.
114 static inline __sum16
115 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
116 unsigned short len, unsigned short proto, __wsum sum)
118 return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
121 /**
122 * csum_partial - Compute an internet checksum.
123 * @buff: buffer to be checksummed
124 * @len: length of buffer.
125 * @sum: initial sum to be added in (32bit unfolded)
127 * Returns the 32bit unfolded internet checksum of the buffer.
128 * Before filling it in it needs to be csum_fold()'ed.
129 * buff should be aligned to a 64bit boundary if possible.
131 extern __wsum csum_partial(const void *buff, int len, __wsum sum);
133 #define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 1
134 #define HAVE_CSUM_COPY_USER 1
137 /* Do not call this directly. Use the wrappers below */
138 extern __wsum csum_partial_copy_generic(const void *src, const void *dst,
139 int len,
140 __wsum sum,
141 int *src_err_ptr, int *dst_err_ptr);
144 extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
145 int len, __wsum isum, int *errp);
146 extern __wsum csum_partial_copy_to_user(const void *src, void __user *dst,
147 int len, __wsum isum, int *errp);
148 extern __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len,
149 __wsum sum);
151 /* Old names. To be removed. */
152 #define csum_and_copy_to_user csum_partial_copy_to_user
153 #define csum_and_copy_from_user csum_partial_copy_from_user
155 /**
156 * ip_compute_csum - Compute an 16bit IP checksum.
157 * @buff: buffer address.
158 * @len: length of buffer.
160 * Returns the 16bit folded/inverted checksum of the passed buffer.
161 * Ready to fill in.
163 extern __sum16 ip_compute_csum(const void *buff, int len);
166 * csum_ipv6_magic - Compute checksum of an IPv6 pseudo header.
167 * @saddr: source address
168 * @daddr: destination address
169 * @len: length of packet
170 * @proto: protocol of packet
171 * @sum: initial sum (32bit unfolded) to be added in
173 * Computes an IPv6 pseudo header checksum. This sum is added the checksum
174 * into UDP/TCP packets and contains some link layer information.
175 * Returns the unfolded 32bit checksum.
178 struct in6_addr;
180 #define _HAVE_ARCH_IPV6_CSUM 1
181 extern __sum16
182 csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr,
183 __u32 len, unsigned short proto, __wsum sum);
185 static inline unsigned add32_with_carry(unsigned a, unsigned b)
187 asm("addl %2,%0\n\t"
188 "adcl $0,%0"
189 : "=r" (a)
190 : "0" (a), "r" (b));
191 return a;
194 #endif