xref: /freebsd/sys/netinet/in_rss.h (revision 3bdf775801b218aa5a89564839405b122f4b233e)
1 /*-
2  * Copyright (c) 2010-2011 Juniper Networks, Inc.
3  * All rights reserved.
4  *
5  * This software was developed by Robert N. M. Watson under contract
6  * to Juniper Networks, Inc.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 
32 #ifndef _NETINET_IN_RSS_H_
33 #define	_NETINET_IN_RSS_H_
34 
35 #include <netinet/in.h>		/* in_addr_t */
36 
37 /*
38  * Supported RSS hash functions.
39  */
40 #define	RSS_HASH_NAIVE		0x00000001	/* Poor but fast hash. */
41 #define	RSS_HASH_TOEPLITZ	0x00000002	/* Required by RSS. */
42 #define	RSS_HASH_CRC32		0x00000004	/* Future; some NICs do it. */
43 
44 #define	RSS_HASH_MASK		(RSS_HASH_NAIVE | RSS_HASH_TOEPLITZ)
45 
46 /*
47  * Instances of struct inpcbinfo declare an RSS hash type indicating what
48  * header fields are covered.
49  */
50 #define	RSS_HASHFIELDS_NONE		0
51 #define	RSS_HASHFIELDS_4TUPLE		1
52 #define	RSS_HASHFIELDS_2TUPLE		2
53 
54 /*
55  * Compile-time limits on the size of the indirection table.
56  */
57 #define	RSS_MAXBITS	7
58 #define	RSS_TABLE_MAXLEN	(1 << RSS_MAXBITS)
59 
60 /*
61  * Maximum key size used throughout.  It's OK for hardware to use only the
62  * first 16 bytes, which is all that's required for IPv4.
63  */
64 #define	RSS_KEYSIZE	40
65 
66 /*
67  * Device driver interfaces to query RSS properties that must be programmed
68  * into hardware.
69  */
70 u_int	rss_getbits(void);
71 u_int	rss_getbucket(u_int hash);
72 u_int	rss_getcpu(u_int bucket);
73 void	rss_getkey(uint8_t *key);
74 u_int	rss_gethashalgo(void);
75 u_int	rss_getnumbuckets(void);
76 u_int	rss_getnumcpus(void);
77 
78 /*
79  * Network stack interface to generate a hash for a protocol tuple.
80  */
81 uint32_t	rss_hash_ip4_4tuple(struct in_addr src, u_short srcport,
82 		    struct in_addr dst, u_short dstport);
83 uint32_t	rss_hash_ip4_2tuple(struct in_addr src, struct in_addr dst);
84 uint32_t	rss_hash_ip6_4tuple(struct in6_addr src, u_short srcport,
85 		    struct in6_addr dst, u_short dstport);
86 uint32_t	rss_hash_ip6_2tuple(struct in6_addr src,
87 		    struct in6_addr dst);
88 
89 /*
90  * Network stack interface to query desired CPU affinity of a packet.
91  */
92 struct mbuf	*rss_m2cpuid(struct mbuf *m, uintptr_t source, u_int *cpuid);
93 
94 #endif /* !_NETINET_IN_RSS_H_ */
95