Re: [dpdk-dev] [PATCH] Add toeplitz hash algorithm

[Vladimir Medvedkin <medvedkinv@gmail.com>]

Hi Gleb,


2015-04-09 9:37 GMT+03:00 Gleb Natapov <gleb@cloudius-systems.com>:

> On Wed, Apr 08, 2015 at 03:06:13PM -0400, Vladimir Medvedkin wrote:
> > Software implementation of the Toeplitz hash function used by RSS.
> > Can be used either for packet distribution on single queue NIC
> > or for simulating of RSS computation on specific NIC (for example
> > after GRE header decapsulating).
> >
> > Signed-off-by: Vladimir Medvedkin <medvedkinv@gmail.com>
> > ---
> >  lib/librte_hash/Makefile    |   1 +
> >  lib/librte_hash/rte_thash.h | 179
> ++++++++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 180 insertions(+)
> >  create mode 100644 lib/librte_hash/rte_thash.h
> >
> > diff --git a/lib/librte_hash/Makefile b/lib/librte_hash/Makefile
> > index 3696cb1..083a9e5 100644
> > --- a/lib/librte_hash/Makefile
> > +++ b/lib/librte_hash/Makefile
> > @@ -50,6 +50,7 @@ SYMLINK-$(CONFIG_RTE_LIBRTE_HASH)-include := rte_hash.h
> >  SYMLINK-$(CONFIG_RTE_LIBRTE_HASH)-include += rte_hash_crc.h
> >  SYMLINK-$(CONFIG_RTE_LIBRTE_HASH)-include += rte_jhash.h
> >  SYMLINK-$(CONFIG_RTE_LIBRTE_HASH)-include += rte_fbk_hash.h
> > +SYMLINK-$(CONFIG_RTE_LIBRTE_HASH)-include += rte_thash.h
> >
> >  # this lib needs eal
> >  DEPDIRS-$(CONFIG_RTE_LIBRTE_HASH) += lib/librte_eal lib/librte_malloc
> > diff --git a/lib/librte_hash/rte_thash.h b/lib/librte_hash/rte_thash.h
> > new file mode 100644
> > index 0000000..1acfa3a
> > --- /dev/null
> > +++ b/lib/librte_hash/rte_thash.h
> > @@ -0,0 +1,179 @@
> > +/*-
> > + *   BSD LICENSE
> > + *
> > + *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
> > + *   All rights reserved.
> > + *
> > + *   Redistribution and use in source and binary forms, with or without
> > + *   modification, are permitted provided that the following conditions
> > + *   are met:
> > + *
> > + *     * Redistributions of source code must retain the above copyright
> > + *       notice, this list of conditions and the following disclaimer.
> > + *     * 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.
> > + *     * Neither the name of Intel Corporation nor the names of its
> > + *       contributors may be used to endorse or promote products derived
> > + *       from this software without specific prior written permission.
> > + *
> > + *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
> COPYRIGHT
> > + *   OWNER 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.
> > + */
> > +
> > +#ifndef _RTE_THASH_H
> > +#define _RTE_THASH_H
> > +
> > +/**
> > + * @file
> > + *
> > + * toeplitz hash functions.
> > + */
> > +
> > +#ifdef __cplusplus
> > +extern "C" {
> > +#endif
> > +
> > +/**
> > + * Software implementation of the Toeplitz hash function used by RSS.
> > + * Can be used either for packet distribution on single queue NIC
> > + * or for simulating of RSS computation on specific NIC (for example
> > + * after GRE header decapsulating)
> > + */
> > +
> > +#include <stdint.h>
> > +#include <rte_byteorder.h>
> > +
> > +enum rte_thash_flag {
> > +     RTE_THASH_L3 = 0,       //calculate hash tacking into account only
> l3 header
> > +     RTE_THASH_L4            //calculate hash tacking into account l4 +
> l4 headers
> > +};
> > +
> > +/**
> > + * Prepare special converted key to use with rte_softrss_be()
> > + * @param orig
> > + *   pointer to original RSS key
> > + * @param targ
> > + *   pointer to target RSS key
> > + */
> > +
> > +static inline void
> > +rte_convert_rss_key(uint32_t *orig, uint32_t *targ)
> > +{
> > +     int i;
> > +     for (i = 0; i < 10; i++) {
> > +             targ[i] = rte_be_to_cpu_32(orig[i]);
> > +     }
> > +}
> > +
> > +/**
> > + * Generic implementation. Can be used with original rss_key
> > + * All ip's and ports have to be CPU byte order.
> > + * @param sip
> > + *   Source ip address.
> > + * @param dip
> > + *   Destination ip address.
> ipv4, what about ipv6? Why not define rss function that works on byte
> buffer and let caller build it according to whatever fields it want to
> hash?
>
Good idea, I will think about it.


>
> > + * @param sp
> > + *   Source TCP|UDP port.
> > + * @param dp
> > + *   Destination TCP|UDP port.
> > + * @param flag
> > + *   RTE_THASH_L3:   calculate hash tacking into account only sip and
> dip
> > + *   RTE_THASH_L4:   calculate hash tacking into account sip, dip, sp
> and dp
> > + * @param *rss_key
> > + *   Pointer to 40-byte RSS hash key.
> i40e has 52 byte RSS hash key.
>

> > + * @return
> > + *   Calculated hash value.
> > + */
> > +
> > +static inline uint32_t
> > +rte_softrss(uint32_t sip, uint32_t dip, uint16_t sp, uint16_t dp, enum
> rte_thash_flag flag, uint32_t *rss_key)
> > +{
> > +     uint32_t ret = 0;
> > +     int i;
> > +     for (i = 0; i < 32; i++) {
> > +             if (sip & (1 << (31 - i))) {
> > +                     ret ^= (rte_cpu_to_be_32(*rss_key) <<
> i)|(uint32_t)((uint64_t)(rte_cpu_to_be_32(*(rss_key + 1))) >> (32 - i));
> > +             }
> > +     }
> > +     rss_key++;
> > +     for (i = 0; i < 32; i++) {
> > +             if (dip & (1 << (31 - i))) {
> > +                     ret ^= (rte_cpu_to_be_32(*rss_key) <<
> i)|(uint32_t)((uint64_t)(rte_cpu_to_be_32(*(rss_key + 1))) >> (32 - i));
> > +             }
> > +     }
> > +        if (flag == RTE_THASH_L4) {
> > +             rss_key++;
> > +             for (i = 0; i < 32; i++) {
> > +                     if (((sp<<16)|dp) & (1 << (31 - i))) {
> > +                             ret ^= (rte_cpu_to_be_32(*rss_key) <<
> i)|(uint32_t)((uint64_t)(rte_cpu_to_be_32(*(rss_key + 1))) >> (32 - i));
> > +                     }
> > +             }
> > +     }
> > +     return ret;
> > +}
> > +
> > +/**
> > + * Optimized implementation.
> > + * If you want the calculated hash value matches NIC RSS value
> > + * you have to use special converted key.
> > + * All ip's and ports have to be CPU byte order.
> > + * @param sip
> > + *   Source ip address.
> > + * @param dip
> > + *   Destination ip address.
> > + * @param sp
> > + *   Source TCP|UDP port.
> > + * @param dp
> > + *   Destination TCP|UDP port.
> > + * @param flag
> > + *   RTE_THASH_L3:   calculate hash tacking into account only sip and
> dip
> > + *   RTE_THASH_L4:   calculate hash tacking into account sip, dip, sp
> and dp
> > + * @param *rss_key
> > + *   Pointer to 40-byte RSS hash key.
> > + * @return
> > + *   Calculated hash value.
> > + */
> > +
> > +static inline uint32_t
> > +rte_softrss_be(uint32_t sip, uint32_t dip, uint16_t sp, uint16_t dp,
> enum rte_thash_flag flag, uint32_t *rss_key)
> > +{
> > +     uint32_t ret = 0;
> > +     int i;
> > +     for (i = 0; i < 32; i++) {
> > +             if (sip & (1 << (31 - i))) {
> > +                     ret ^= (*rss_key <<
> i)|(uint32_t)((uint64_t)*(rss_key + 1) >> (32 - i));
> > +             }
> > +     }
> > +     rss_key++;
> > +     for (i = 0; i < 32; i++) {
> > +             if (dip & (1 << (31 - i))) {
> > +                     ret ^= (*rss_key <<
> i)|(uint32_t)((uint64_t)*(rss_key + 1) >> (32 - i));
> > +             }
> > +     }
> > +        if (flag == RTE_THASH_L4) {
> > +             rss_key++;
> > +             for (i = 0; i < 32; i++) {
> > +                     if (((sp<<16)|dp) & (1 << (31 - i))) {
> > +                             ret ^= (*rss_key <<
> i)|(uint32_t)((uint64_t)*(rss_key + 1) >> (32 - i));
> > +                     }
> > +             }
> > +     }
> > +     return ret;
> > +}
> > +
> > +#ifdef __cplusplus
> > +}
> > +#endif
> > +
> > +#endif /* _RTE_THASH_H */
> > --
> > 1.8.3.2
> >
>
> --
>                         Gleb.
>