[v2] app/testpmd: optimized MAC swap by using neon intrinsics

  Improved MAC swap performance for ARM platform.
The improvement was achieved by using neon intrinsics
to save CPU cycles and doing swap for four packets
at a time.
The optimization had 15% - 20% throughput boost
in testpmd MAC swap mode.

Signed-off-by: Ruifeng Wang <ruifeng.wang@arm.com>
Reviewed-by: Gavin Hu <gavin.hu@arm.com>
Reviewed-by: Phil Yang <phil.yang@arm.com>
Acked-by: Jerin Jacob <jerinj@marvell.com>
---
v2:
* Defined idx_map as const.
* Added file header line to indicate derivation from macswap_sse.h.

 app/test-pmd/macswap.c      |  4 +-
 app/test-pmd/macswap_neon.h | 97 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 100 insertions(+), 1 deletion(-)
 create mode 100644 app/test-pmd/macswap_neon.h
  

> Improved MAC swap performance for ARM platform.
> The improvement was achieved by using neon intrinsics to save CPU cycles
> and doing swap for four packets at a time.
> The optimization had 15% - 20% throughput boost in testpmd MAC swap
> mode.
> 
> Signed-off-by: Ruifeng Wang <ruifeng.wang@arm.com>
> Reviewed-by: Gavin Hu <gavin.hu@arm.com>
> Reviewed-by: Phil Yang <phil.yang@arm.com>
> Acked-by: Jerin Jacob <jerinj@marvell.com>
> ---
> v2:
> * Defined idx_map as const.
> * Added file header line to indicate derivation from macswap_sse.h.
> 
>  app/test-pmd/macswap.c      |  4 +-
>  app/test-pmd/macswap_neon.h | 97
> +++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 100 insertions(+), 1 deletion(-)  create mode 100644
> app/test-pmd/macswap_neon.h
> 
> diff --git a/app/test-pmd/macswap.c b/app/test-pmd/macswap.c index
> cbb41b7..71af916 100644
> --- a/app/test-pmd/macswap.c
> +++ b/app/test-pmd/macswap.c
> @@ -66,8 +66,10 @@
>  #include <rte_flow.h>
> 
>  #include "testpmd.h"
> -#ifdef RTE_ARCH_X86
> +#if defined(RTE_ARCH_X86)
>  #include "macswap_sse.h"
> +#elif defined(RTE_MACHINE_CPUFLAG_NEON) #include "macswap_neon.h"
>  #else
>  #include "macswap.h"
>  #endif
> diff --git a/app/test-pmd/macswap_neon.h b/app/test-
> pmd/macswap_neon.h new file mode 100644 index 0000000..bdf416a
> --- /dev/null
> +++ b/app/test-pmd/macswap_neon.h
> @@ -0,0 +1,97 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2019 Arm Limited
> + *
> + * Copyright(c) 2019 Intel Corporation
> + *
> + * Derived do_macswap implementation from app/test-pmd/macswap_sse.h
> +*/
> +
> +#ifndef _MACSWAP_NEON_H_
> +#define _MACSWAP_NEON_H_
> +
> +#include "macswap_common.h"
> +#include "rte_vect.h"
> +
> +static inline void
> +do_macswap(struct rte_mbuf *pkts[], uint16_t nb,
> +		struct rte_port *txp)
> +{
> +	struct ether_hdr *eth_hdr[4];
> +	struct rte_mbuf *mb[4];
> +	uint64_t ol_flags;
> +	int i;
> +	int r;
> +	uint8x16_t v0, v1, v2, v3;
> +	/**
> +	 * Index map be used to shuffle the 16 bytes.
> +	 * byte 0-5 will be swapped with byte 6-11.
> +	 * byte 12-15 will keep unchanged.
> +	 */
> +	const uint8x16_t idx_map = {6, 7, 8, 9, 10, 11, 0, 1, 2, 3, 4, 5,
> +				12, 13, 14, 15};
> +
> +	ol_flags = ol_flags_init(txp->dev_conf.txmode.offloads);
> +	vlan_qinq_set(pkts, nb, ol_flags,
> +			txp->tx_vlan_id, txp->tx_vlan_id_outer);
> +
> +	i = 0;
> +	r = nb;
> +
> +	while (r >= 4) {
> +		if (r >= 8) {
> +			rte_prefetch0(rte_pktmbuf_mtod(pkts[i + 4], void *));
> +			rte_prefetch0(rte_pktmbuf_mtod(pkts[i + 5], void *));
> +			rte_prefetch0(rte_pktmbuf_mtod(pkts[i + 6], void *));
> +			rte_prefetch0(rte_pktmbuf_mtod(pkts[i + 7], void *));
> +		}
> +
> +		mb[0] = pkts[i++];
> +		eth_hdr[0] = rte_pktmbuf_mtod(mb[0], struct ether_hdr *);
> +
> +		mb[1] = pkts[i++];
> +		eth_hdr[1] = rte_pktmbuf_mtod(mb[1], struct ether_hdr *);
> +
> +		mb[2] = pkts[i++];
> +		eth_hdr[2] = rte_pktmbuf_mtod(mb[2], struct ether_hdr *);
> +
> +		mb[3] = pkts[i++];
> +		eth_hdr[3] = rte_pktmbuf_mtod(mb[3], struct ether_hdr *);
> +
> +		v0 = vld1q_u8((uint8_t const *)eth_hdr[0]);
> +		v1 = vld1q_u8((uint8_t const *)eth_hdr[1]);
> +		v2 = vld1q_u8((uint8_t const *)eth_hdr[2]);
> +		v3 = vld1q_u8((uint8_t const *)eth_hdr[3]);
> +
> +		v0 = vqtbl1q_u8(v0, idx_map);
> +		v1 = vqtbl1q_u8(v1, idx_map);
> +		v2 = vqtbl1q_u8(v2, idx_map);
> +		v3 = vqtbl1q_u8(v3, idx_map);
> +
> +		vst1q_u8((uint8_t *)eth_hdr[0], v0);
> +		vst1q_u8((uint8_t *)eth_hdr[1], v1);
> +		vst1q_u8((uint8_t *)eth_hdr[2], v2);
> +		vst1q_u8((uint8_t *)eth_hdr[3], v3);
> +
> +		mbuf_field_set(mb[0], ol_flags);
> +		mbuf_field_set(mb[1], ol_flags);
> +		mbuf_field_set(mb[2], ol_flags);
> +		mbuf_field_set(mb[3], ol_flags);
> +		r -= 4;
> +	}
> +
> +	for ( ; i < nb; i++) {
> +		if (i < nb - 1)
> +			rte_prefetch0(rte_pktmbuf_mtod(pkts[i+1], void *));
> +		mb[0] = pkts[i];
> +		eth_hdr[0] = rte_pktmbuf_mtod(mb[0], struct ether_hdr *);
> +
> +		/* Swap dest and src mac addresses. */
> +		v0 = vld1q_u8((uint8_t const *)eth_hdr[0]);
> +		v0 = vqtbl1q_u8(v0, idx_map);
> +		vst1q_u8((uint8_t *)eth_hdr[0], v0);
> +
> +		mbuf_field_set(mb[0], ol_flags);
> +	}
> +}
> +
> +#endif /* _MACSWAP_NEON_H_ */
> --
> 2.7.4

Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
  

On 3/12/2019 1:05 PM, Honnappa Nagarahalli wrote:
>> Improved MAC swap performance for ARM platform.
>> The improvement was achieved by using neon intrinsics to save CPU cycles
>> and doing swap for four packets at a time.
>> The optimization had 15% - 20% throughput boost in testpmd MAC swap
>> mode.
>>
>> Signed-off-by: Ruifeng Wang <ruifeng.wang@arm.com>
>> Reviewed-by: Gavin Hu <gavin.hu@arm.com>
>> Reviewed-by: Phil Yang <phil.yang@arm.com>
>> Acked-by: Jerin Jacob <jerinj@marvell.com>
> 
> Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>

Applied to dpdk-next-net/master, thanks.

What do you think adding a release notes update for this?
If you can send it I can squash to this patch.
  

Hi Ferruh,

> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit@intel.com>
> Sent: 2019年3月16日 2:38
> To: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>; Ruifeng Wang
> (Arm Technology China) <Ruifeng.Wang@arm.com>; wenzhuo.lu@intel.com;
> jingjing.wu@intel.com; bernard.iremonger@intel.com
> Cc: dev@dpdk.org; jerinj@marvell.com; hemant.agrawal@nxp.com; nd
> <nd@arm.com>
> Subject: Re: [dpdk-dev] [PATCH v2] app/testpmd: optimized MAC swap by
> using neon intrinsics
> 
> On 3/12/2019 1:05 PM, Honnappa Nagarahalli wrote:
> >> Improved MAC swap performance for ARM platform.
> >> The improvement was achieved by using neon intrinsics to save CPU
> >> cycles and doing swap for four packets at a time.
> >> The optimization had 15% - 20% throughput boost in testpmd MAC swap
> >> mode.
> >>
> >> Signed-off-by: Ruifeng Wang <ruifeng.wang@arm.com>
> >> Reviewed-by: Gavin Hu <gavin.hu@arm.com>
> >> Reviewed-by: Phil Yang <phil.yang@arm.com>
> >> Acked-by: Jerin Jacob <jerinj@marvell.com>
> >
> > Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> 
> Applied to dpdk-next-net/master, thanks.
> 
> What do you think adding a release notes update for this?
> If you can send it I can squash to this patch.

Thanks for your suggestion.
Release notes updated in:
http://patches.dpdk.org/patch/51247/

Regards,
/Ruifeng