[dpdk-dev] [PATCH v2] efd: support lookup using neon intrinsics

Sekhar, Ashwin Ashwin.Sekhar at cavium.com
Fri Apr 28 12:38:02 CEST 2017


On Friday 28 April 2017 03:36 PM, Jianbo Liu wrote:
> On 27 April 2017 at 20:44, Ashwin Sekhar T K
> <ashwin.sekhar at caviumnetworks.com> wrote:
>> * Added file lib/librte_efd/rte_efd_arm64.h to hold arm64
>>   specific definitions
>> * Verified the changes with efd_autotest unit test case
>>
>> Signed-off-by: Ashwin Sekhar T K <ashwin.sekhar at caviumnetworks.com>
>> ---
>> v2:
>> * Slightly modified the content of the commit message body
>> * Added prefix [dpdk-dev] to the email subject line
>>
>>  MAINTAINERS                    |  1 +
>>  lib/librte_efd/rte_efd.c       | 22 ++++++++++++
>>  lib/librte_efd/rte_efd_arm64.h | 76 ++++++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 99 insertions(+)
>>  create mode 100644 lib/librte_efd/rte_efd_arm64.h
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index b6495d2..7d708ae 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -147,6 +147,7 @@ F: lib/librte_eal/common/include/arch/arm/*_64.h
>>  F: lib/librte_acl/acl_run_neon.*
>>  F: lib/librte_lpm/rte_lpm_neon.h
>>  F: lib/librte_hash/rte*_arm64.h
>> +F: lib/librte_efd/rte*_arm64.h
>>  F: drivers/net/ixgbe/ixgbe_rxtx_vec_neon.c
>>  F: drivers/net/i40e/i40e_rxtx_vec_neon.c
>>  F: drivers/net/virtio/virtio_rxtx_simple_neon.c
>> diff --git a/lib/librte_efd/rte_efd.c b/lib/librte_efd/rte_efd.c
>> index f601d62..4d9a088 100644
>> --- a/lib/librte_efd/rte_efd.c
>> +++ b/lib/librte_efd/rte_efd.c
>> @@ -53,6 +53,8 @@
>>  #include "rte_efd.h"
>>  #if defined(RTE_ARCH_X86)
>>  #include "rte_efd_x86.h"
>> +#elif defined(RTE_ARCH_ARM64)
>> +#include "rte_efd_arm64.h"
>>  #endif
>>
>>  #define EFD_KEY(key_idx, table) (table->keys + ((key_idx) * table->key_len))
>> @@ -103,6 +105,7 @@ allocated memory
>>  enum efd_lookup_internal_function {
>>         EFD_LOOKUP_SCALAR = 0,
>>         EFD_LOOKUP_AVX2,
>> +       EFD_LOOKUP_NEON,
>
> Should it be included in "if defined(RTE_ARCH_ARM64)"?
>
The enum can be wrapped under "if defined(RTE_ARCH_ARM64)" with no 
issues, as all its usages are also under "if defined(RTE_ARCH_ARM64)".
I followed EFD_LOOKUP_AVX2 and defined EFD_LOOKUP_NEON on the same lines.
Please advise on whether this change is to be made. Will follow your advice.
>>         EFD_LOOKUP_NUM
>>  };
>>
>> @@ -674,6 +677,16 @@ rte_efd_create(const char *name, uint32_t max_num_rules, uint32_t key_len,
>>                 table->lookup_fn = EFD_LOOKUP_AVX2;
>>         else
>>  #endif
>> +#if defined(RTE_ARCH_ARM64)
>> +       /*
>> +        * For less than or equal to 16 bits, scalar function performs better
>> +        * than vectorised version
>> +        */
>> +       if (RTE_EFD_VALUE_NUM_BITS > 16 &&
>> +           rte_cpu_get_flag_enabled(RTE_CPUFLAG_NEON))
>> +               table->lookup_fn = EFD_LOOKUP_NEON;
>> +       else
>> +#endif
>>                 table->lookup_fn = EFD_LOOKUP_SCALAR;
>>
>>         /*
>> @@ -1271,6 +1284,15 @@ efd_lookup_internal(const struct efd_online_group_entry * const group,
>>                                         group->lookup_table,
>>                                         hash_val_a,
>>                                         hash_val_b);
>> +               break;
>> +#endif
>> +#if defined(RTE_ARCH_ARM64)
>> +       case EFD_LOOKUP_NEON:
>> +               return efd_lookup_internal_neon(group->hash_idx,
>> +                                       group->lookup_table,
>> +                                       hash_val_a,
>> +                                       hash_val_b);
>> +               break;
>>  #endif
>>         case EFD_LOOKUP_SCALAR:
>>         /* Fall-through */
>> diff --git a/lib/librte_efd/rte_efd_arm64.h b/lib/librte_efd/rte_efd_arm64.h
>> new file mode 100644
>> index 0000000..cc93411
>> --- /dev/null
>> +++ b/lib/librte_efd/rte_efd_arm64.h
>> @@ -0,0 +1,76 @@
>> +/*
>> + *   BSD LICENSE
>> + *
>> + *   Copyright (C) Cavium networks Ltd. 2017.
>> + *
>> + *   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 Cavium networks 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.
>> + */
>> +
>> +/*
>> + * rte_efd_arm64.h
>> + * This file holds all arm64 specific EFD functions
>> + */
>> +
>> +#ifndef __RTE_EFD_ARM64_H__
>> +#define __RTE_EFD_ARM64_H__
>> +
>> +#include <rte_vect.h>
>> +
>> +static inline efd_value_t
>> +efd_lookup_internal_neon(const efd_hashfunc_t *group_hash_idx,
>> +               const efd_lookuptbl_t *group_lookup_table,
>> +               const uint32_t hash_val_a, const uint32_t hash_val_b)
>> +{
>> +       efd_value_t value = 0;
>> +       uint32_t i = 0;
>> +       uint32x4_t vhash_val_a = vmovq_n_u32(hash_val_a);
>> +       uint32x4_t vhash_val_b = vmovq_n_u32(hash_val_b);
>> +       int32x4_t vshift = {0, 1, 2, 3};
>> +       uint32x4_t vmask = vdupq_n_u32(0x1);
>> +       int32x4_t vincr = vdupq_n_s32(4);
>> +
>> +       for (; i < RTE_EFD_VALUE_NUM_BITS; i += 4) {
>> +               uint32x4_t vhash_idx = vshll_n_u16(
>> +                       vld1_u16((uint16_t const *)&group_hash_idx[i]), 0);
>> +               uint32x4_t vlookup_table = vshll_n_u16(
>> +                       vld1_u16((uint16_t const *)&group_lookup_table[i]), 0);
>> +               uint32x4_t vhash = vaddq_u32(vhash_val_a,
>> +                                       vmulq_u32(vhash_idx, vhash_val_b));
>> +               int32x4_t vbucket_idx = vnegq_s32(vreinterpretq_s32_u32(
>> +                               vshrq_n_u32(vhash, EFD_LOOKUPTBL_SHIFT)));
>> +               uint32x4_t vresult = vshlq_u32(vlookup_table, vbucket_idx);
>> +
>> +               vresult = vandq_u32(vresult, vmask);
>> +               vresult = vshlq_u32(vresult, vshift);
>> +               value |= vaddvq_u32(vresult);
>> +               vshift = vaddq_s32(vshift, vincr);
>> +       }
>> +
>> +       return value;
>> +}
>> +
>> +#endif /* __RTE_EFD_ARM64_H__ */
>> --
>> 2.7.4
>>
>



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