freebsd-skq/sys/netinet/in_rss.h
Adrian Chadd 72d33245f5 Implement IPv4 RSS software hash functions to use during packet ingress
and egress.

* rss_mbuf_software_hash_v4 - look at the IPv4 mbuf to fetch the IPv4 details
  + direction to calculate a hash.
* rss_proto_software_hash_v4 - hash the given source/destination IPv4 address,
  port and direction.
* rss_soft_m2cpuid - map the given mbuf to an RSS CPU ("bucket" for now)

These functions are intended to be used by the stack to support
the following:

* Not all NICs do RSS hashing, so we should support some way of doing
  a hash in software;
* The NIC / driver may not hash frames the way we want (eg UDP 4-tuple
  hashing when the stack is only doing 2-tuple hashing for UDP); so we
  may need to re-hash frames;
* .. same with IPv4 fragments - they will need to be re-hashed after
  reassembly;
* .. and same with things like IP tunneling and such;
* The transmit path for things like UDP, RAW and ICMP don't currently
  have any RSS information attached to them - so they'll need an
  RSS calculation performed before transmit.

TODO:

* Counters! Everywhere!
* Add a debug mode that software hashes received frames and compares them
  to the hardware hash provided by the hardware to ensure they match.

The IPv6 part of this is missing - I'm going to do some re-juggling of
where various parts of the RSS framework live before I add the IPv6
code (read: the IPv6 code is going to go into netinet6/in6_rss.[ch],
rather than living here.)

Note: This API is still fluid.  Please keep that in mind.

Differential Revision:	https://reviews.freebsd.org/D527
Reviewed by:	grehan
2014-09-09 03:10:21 +00:00

143 lines
5.2 KiB
C

/*-
* Copyright (c) 2010-2011 Juniper Networks, Inc.
* All rights reserved.
*
* This software was developed by Robert N. M. Watson under contract
* to Juniper Networks, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _NETINET_IN_RSS_H_
#define _NETINET_IN_RSS_H_
#include <netinet/in.h> /* in_addr_t */
/*
* Supported RSS hash functions.
*/
#define RSS_HASH_NAIVE 0x00000001 /* Poor but fast hash. */
#define RSS_HASH_TOEPLITZ 0x00000002 /* Required by RSS. */
#define RSS_HASH_CRC32 0x00000004 /* Future; some NICs do it. */
#define RSS_HASH_MASK (RSS_HASH_NAIVE | RSS_HASH_TOEPLITZ)
/*
* Instances of struct inpcbinfo declare an RSS hash type indicating what
* header fields are covered.
*/
#define RSS_HASHFIELDS_NONE 0
#define RSS_HASHFIELDS_4TUPLE 1
#define RSS_HASHFIELDS_2TUPLE 2
/*
* Define RSS representations of the M_HASHTYPE_* values, representing
* which particular bits are supported. The NICs can then use this to
* calculate which hash types to enable and which not to enable.
*
* The fact that these line up with M_HASHTYPE_* is not to be relied
* upon.
*/
#define RSS_HASHTYPE_RSS_IPV4 (1 << 1) /* IPv4 2-tuple */
#define RSS_HASHTYPE_RSS_TCP_IPV4 (1 << 2) /* TCPv4 4-tuple */
#define RSS_HASHTYPE_RSS_IPV6 (1 << 3) /* IPv6 2-tuple */
#define RSS_HASHTYPE_RSS_TCP_IPV6 (1 << 4) /* TCPv6 4-tuple */
#define RSS_HASHTYPE_RSS_IPV6_EX (1 << 5) /* IPv6 2-tuple + ext hdrs */
#define RSS_HASHTYPE_RSS_TCP_IPV6_EX (1 << 6) /* TCPv6 4-tiple + ext hdrs */
#define RSS_HASHTYPE_RSS_UDP_IPV4 (1 << 7) /* IPv4 UDP 4-tuple */
#define RSS_HASHTYPE_RSS_UDP_IPV4_EX (1 << 8) /* IPv4 UDP 4-tuple + ext hdrs */
#define RSS_HASHTYPE_RSS_UDP_IPV6 (1 << 9) /* IPv6 UDP 4-tuple */
#define RSS_HASHTYPE_RSS_UDP_IPV6_EX (1 << 10) /* IPv6 UDP 4-tuple + ext hdrs */
/*
* Compile-time limits on the size of the indirection table.
*/
#define RSS_MAXBITS 7
#define RSS_TABLE_MAXLEN (1 << RSS_MAXBITS)
/*
* Maximum key size used throughout. It's OK for hardware to use only the
* first 16 bytes, which is all that's required for IPv4.
*/
#define RSS_KEYSIZE 40
/*
* For RSS hash methods that do a software hash on an mbuf, the packet
* direction (ingress / egress) is required.
*
* The default direction (INGRESS) is the "receive into the NIC" - ie,
* what the hardware is hashing on.
*/
#define RSS_HASH_PKT_INGRESS 0
#define RSS_HASH_PKT_EGRESS 1
/*
* Device driver interfaces to query RSS properties that must be programmed
* into hardware.
*/
u_int rss_getbits(void);
u_int rss_getbucket(u_int hash);
u_int rss_get_indirection_to_bucket(u_int index);
u_int rss_getcpu(u_int bucket);
void rss_getkey(uint8_t *key);
u_int rss_gethashalgo(void);
u_int rss_getnumbuckets(void);
u_int rss_getnumcpus(void);
u_int rss_gethashconfig(void);
/*
* Network stack interface to generate a hash for a protocol tuple.
*/
uint32_t rss_hash_ip4_4tuple(struct in_addr src, u_short srcport,
struct in_addr dst, u_short dstport);
uint32_t rss_hash_ip4_2tuple(struct in_addr src, struct in_addr dst);
uint32_t rss_hash_ip6_4tuple(struct in6_addr src, u_short srcport,
struct in6_addr dst, u_short dstport);
uint32_t rss_hash_ip6_2tuple(struct in6_addr src,
struct in6_addr dst);
/*
* Network stack interface to query desired CPU affinity of a packet.
*/
struct mbuf *rss_m2cpuid(struct mbuf *m, uintptr_t source, u_int *cpuid);
u_int rss_hash2cpuid(uint32_t hash_val, uint32_t hash_type);
int rss_hash2bucket(uint32_t hash_val, uint32_t hash_type,
uint32_t *bucket_id);
int rss_m2bucket(struct mbuf *m, uint32_t *bucket_id);
/*
* Functions to calculate a software RSS hash for a given mbuf or
* packet detail.
*/
int rss_mbuf_software_hash_v4(const struct mbuf *m, int dir,
uint32_t *hashval, uint32_t *hashtype);
int rss_proto_software_hash_v4(struct in_addr src,
struct in_addr dst, u_short src_port, u_short dst_port,
int proto, uint32_t *hashval,
uint32_t *hashtype);
struct mbuf * rss_soft_m2cpuid(struct mbuf *m, uintptr_t source,
u_int *cpuid);
#endif /* !_NETINET_IN_RSS_H_ */