freebsd-dev/sys/netinet/in_rss.h
Adrian Chadd a6c88ec4fb Add another RSS method to query the indirection table entries.
There's 128 indirection table entries which correspond to the
low 7 bits of the 32 bit RSS hash.  Each value will correspond
to an RSS bucket.  (Then each RSS bucket currently will map
to a CPU.)

This is a more explicit way of figuring out which RSS bucket
is in each RSS indirection slot.  It can be inferred by the other
methods but I'd rather drivers use something more simplified and
explicit.
2014-06-26 02:49:51 +00:00

100 lines
3.5 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
/*
* 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
/*
* 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);
/*
* 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);
#endif /* !_NETINET_IN_RSS_H_ */