FreeBSD/Linux Kernel Cross Reference
sys/dev/ice/ice_rss.h

     /* SPDX-License-Identifier: BSD-3-Clause */
     /*  Copyright (c) 2021, Intel Corporation
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    /*$FreeBSD$*/
    
    /**
     * @file ice_rss.h
     * @brief default RSS values if kernel RSS is not enabled
     *
     * This header includes default definitions for RSS functionality if the
     * kernel RSS interface is not enabled. This allows main driver code to avoid
     * having to check the RSS ifdef throughout, but instead just use the RSS
     * definitions, as they will fall back to these defaults when the kernel
     * interface is disabled.
     */
    #ifndef _ICE_RSS_H_
    #define _ICE_RSS_H_
    
    #ifdef RSS
    // We have the kernel RSS interface available
    #include <net/rss_config.h>
    
    /* Make sure our key size buffer has enough space to store the kernel RSS key */
    CTASSERT(ICE_AQC_GET_SET_RSS_KEY_DATA_RSS_KEY_SIZE >= RSS_KEYSIZE);
    #else
    /* The kernel RSS interface is not enabled. Use suitable defaults for the RSS
     * configuration functions.
     *
     * The RSS hash key will be a pre-generated random key.
     * The number of buckets will just match the number of CPUs.
     * The lookup table will be assigned using round-robin with no indirection.
     * The RSS hash configuration will be set to suitable defaults.
     */
    
    #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_IPV6       (1 << 9)        /* IPv6 UDP 4-tuple */
    #define RSS_HASHTYPE_RSS_UDP_IPV6_EX    (1 << 10)       /* IPv6 UDP 4-tuple + ext hdrs */
    
    #define ICE_DEFAULT_RSS_HASH_CONFIG \
            ((u_int)(RSS_HASHTYPE_RSS_IPV4 | \
                     RSS_HASHTYPE_RSS_TCP_IPV4 | \
                     RSS_HASHTYPE_RSS_UDP_IPV4 | \
                     RSS_HASHTYPE_RSS_IPV6 | \
                     RSS_HASHTYPE_RSS_TCP_IPV6 | \
                     RSS_HASHTYPE_RSS_UDP_IPV6))
    
    #define rss_getkey(key) ice_get_default_rss_key(key)
    #define rss_getnumbuckets() (mp_ncpus)
    #define rss_get_indirection_to_bucket(index) (index)
    #define rss_gethashconfig() (ICE_DEFAULT_RSS_HASH_CONFIG)
    
    /**
     * rss_hash2bucket - Determine the bucket for a given hash value
     * @hash_val: the hash value to use
     * @hash_type: the type of the hash
     * @bucket_id: on success, updated with the bucket
     *
     * This function simply verifies that the hash type is known. If it is, then
     * we forward the hash value directly as the bucket id. If the hash type is
     * unknown, we return -1.
     *
     * This is the simplest mechanism for converting a hash value into a bucket,
     * and does not support any form of indirection table.
     */
    static inline int
    rss_hash2bucket(uint32_t hash_val, uint32_t hash_type, uint32_t *bucket_id)
   {
           switch (hash_type) {
           case M_HASHTYPE_RSS_IPV4:
           case M_HASHTYPE_RSS_TCP_IPV4:
           case M_HASHTYPE_RSS_UDP_IPV4:
           case M_HASHTYPE_RSS_IPV6:
           case M_HASHTYPE_RSS_TCP_IPV6:
           case M_HASHTYPE_RSS_UDP_IPV6:
                   *bucket_id = hash_val;
                   return (0);
           default:
                   return (-1);
           }
   }
   
   #endif /* !RSS */
   
   #endif /* _ICE_COMMON_COMPAT_H_ */

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