>On 1/5/21 3:27 PM, Maxime Coquelin wrote:
>>
>>
>> On 1/5/21 3:16 PM, Maxime Coquelin wrote:
>>>
>>>
>>> On 11/17/20 11:06 AM, Joyce Kong wrote:
>>>> Optimize packed ring Rx batch path with NEON instructions.
>>>>
>>>> Signed-off-by: Joyce Kong <joyce.k...@arm.com>
>>>> Reviewed-by: Ruifeng Wang <ruifeng.w...@arm.com>
>>>> ---
>>>> drivers/net/virtio/virtio_rxtx_packed.h | 15 ++
>>>> drivers/net/virtio/virtio_rxtx_packed_neon.h | 150
>>>> +++++++++++++++++++
>>>> 2 files changed, 165 insertions(+)
>>>> create mode 100644 drivers/net/virtio/virtio_rxtx_packed_neon.h
>>>>
>>>> diff --git a/drivers/net/virtio/virtio_rxtx_packed.h
>>>> b/drivers/net/virtio/virtio_rxtx_packed.h
>>>> index b0b1d63ec..8f5198ad7 100644
>>>> --- a/drivers/net/virtio/virtio_rxtx_packed.h
>>>> +++ b/drivers/net/virtio/virtio_rxtx_packed.h
>>>> @@ -19,9 +19,16 @@
>>>> #include "virtqueue.h"
>>>>
>>>> #define BYTE_SIZE 8
>>>> +
>>>> +#ifdef CC_AVX512_SUPPORT
>>>> /* flag bits offset in packed ring desc higher 64bits */ #define
>>>> FLAGS_BITS_OFFSET ((offsetof(struct vring_packed_desc, flags) - \
>>>> offsetof(struct vring_packed_desc, len)) * BYTE_SIZE)
>>>> +#elif defined(RTE_ARCH_ARM)
>>>> +/* flag bits offset in packed ring desc from ID */ #define
>>>> +FLAGS_BITS_OFFSET ((offsetof(struct vring_packed_desc, flags) - \
>>>> + offsetof(struct vring_packed_desc, id)) * BYTE_SIZE) #endif
>>>>
>>>> #define PACKED_FLAGS_MASK ((0ULL |
>VRING_PACKED_DESC_F_AVAIL_USED) << \
>>>> FLAGS_BITS_OFFSET)
>>>> @@ -44,8 +51,16 @@
>>>> /* net hdr short size mask */
>>>> #define NET_HDR_MASK 0x3F
>>>>
>>>> +#ifdef RTE_ARCH_ARM
>>>> +/* The cache line size on different Arm platforms are different, so
>>>> + * put a four batch size here to match with the minimum cache line
>>>> + * size and accommodate NEON register size.
>>>> + */
>>>> +#define PACKED_BATCH_SIZE 4
>>>> +#else
>>>> #define PACKED_BATCH_SIZE (RTE_CACHE_LINE_SIZE / \
>>>> sizeof(struct vring_packed_desc))
>>>> +#endif
>>>> #define PACKED_BATCH_MASK (PACKED_BATCH_SIZE - 1)
>>>>
>>>> #ifdef VIRTIO_GCC_UNROLL_PRAGMA
>>>> diff --git a/drivers/net/virtio/virtio_rxtx_packed_neon.h
>>>> b/drivers/net/virtio/virtio_rxtx_packed_neon.h
>>>> new file mode 100644
>>>> index 000000000..fb1e49909
>>>> --- /dev/null
>>>> +++ b/drivers/net/virtio/virtio_rxtx_packed_neon.h
>>>> @@ -0,0 +1,150 @@
>>>> +/* SPDX-License-Identifier: BSD-3-Clause
>>>> + * Copyright(c) 2020 Arm Corporation */
>>>> +
>>>> +#include <stdlib.h>
>>>> +#include <stdint.h>
>>>> +#include <stdio.h>
>>>> +#include <string.h>
>>>> +#include <errno.h>
>>>> +
>>>> +#include <rte_net.h>
>>>> +#include <rte_vect.h>
>>>> +
>>>> +#include "virtio_ethdev.h"
>>>> +#include "virtio_pci.h"
>>>> +#include "virtio_rxtx_packed.h"
>>>> +#include "virtqueue.h"
>>>> +
>>>> +static inline uint16_t
>>>> +virtqueue_dequeue_batch_packed_vec(struct virtnet_rx *rxvq,
>>>> + struct rte_mbuf **rx_pkts)
>>>> +{
>>>> + struct virtqueue *vq = rxvq->vq;
>>>> + struct virtio_hw *hw = vq->hw;
>>>> + uint16_t head_size = hw->vtnet_hdr_size;
>>>> + uint16_t id = vq->vq_used_cons_idx;
>>>> + struct vring_packed_desc *p_desc;
>>>> + uint16_t i;
>>>> +
>>>> + if (id & PACKED_BATCH_MASK)
>>>> + return -1;
>>>> +
>>>> + if (unlikely((id + PACKED_BATCH_SIZE) > vq->vq_nentries))
>>>> + return -1;
>>>
>>> This function returns an unsigned short, I think you should return 0
>>> here since it failed to dequeue packets.
>>>
>>>> + /* Map packed descriptor to mbuf fields. */
>>>> + uint8x16_t shuf_msk1 = {
>>>> + 0xFF, 0xFF, 0xFF, 0xFF, /* pkt_type set as unknown */
>>>> + 0, 1, /* octet 1~0, low 16 bits pkt_len */
>>>> + 0xFF, 0xFF, /* skip high 16 bits of pkt_len, zero
>>>> out
>*/
>>>> + 0, 1, /* octet 1~0, 16 bits data_len */
>>>> + 0xFF, 0xFF, /* vlan tci set as unknown */
>>>> + 0xFF, 0xFF, 0xFF, 0xFF
>>>> + };
>>>> +
>>>> + uint8x16_t shuf_msk2 = {
>>>> + 0xFF, 0xFF, 0xFF, 0xFF, /* pkt_type set as unknown */
>>>> + 8, 9, /* octet 9~8, low 16 bits pkt_len */
>>>> + 0xFF, 0xFF, /* skip high 16 bits of pkt_len, zero
>>>> out
>*/
>>>> + 8, 9, /* octet 9~8, 16 bits data_len */
>>>> + 0xFF, 0xFF, /* vlan tci set as unknown */
>>>> + 0xFF, 0xFF, 0xFF, 0xFF
>>>> + };
>>>> +
>>>> + /* Subtract the header length. */
>>>> + uint16x8_t len_adjust = {
>>>> + 0, 0, /* ignore pkt_type field */
>>>> + head_size, /* sub head_size on pkt_len */
>>>> + 0, /* ignore high 16 bits of pkt_len */
>>>> + head_size, /* sub head_size on data_len */
>>>> + 0, 0, 0 /* ignore non-length fields */
>>>> + };
>>>> +
>>>> + uint64x2_t desc[PACKED_BATCH_SIZE / 2];
>>>> + uint64x2x2_t mbp[PACKED_BATCH_SIZE / 2];
>>>> + uint64x2_t pkt_mb[PACKED_BATCH_SIZE];
>>>> +
>>>> + p_desc = &vq->vq_packed.ring.desc[id];
>>>> + /* Load high 64 bits of packed descriptor 0,1. */
>>>> + desc[0] = vld2q_u64((uint64_t *)(p_desc)).val[1];
>>>> + /* Load high 64 bits of packed descriptor 2,3. */
>>>> + desc[1] = vld2q_u64((uint64_t *)(p_desc + 2)).val[1];
>>>> +
>>>> + /* Only care avail/used bits. */
>>>> + uint32x4_t v_mask = vdupq_n_u32(PACKED_FLAGS_MASK);
>>>> + /* Extract high 32 bits of packed descriptor (id, flags). */
>>>> + uint32x4_t v_desc = vuzp2q_u32(vreinterpretq_u32_u64(desc[0]),
>>>> + vreinterpretq_u32_u64(desc[1]));
>>>> + uint32x4_t v_flag = vandq_u32(v_desc, v_mask);
>>>> +
>>>> + uint32x4_t v_used_flag = vdupq_n_u32(0);
>>>> + if (vq->vq_packed.used_wrap_counter)
>>>> + v_used_flag = vdupq_n_u32(PACKED_FLAGS_MASK);
>>>> +
>>>> + poly128_t desc_stats = vreinterpretq_p128_u32(~vceqq_u32(v_flag,
>>>> +v_used_flag));
>>>> +
>>>> + /* Check all descs are used. */
>>>> + if (desc_stats)
>>>> + return -1;
>>>
>>> Same here. You should return 0 here as the queue is full.
>>
>> Just looked again at the code and at AVX implementation.
>> It should not return 0 here, but any positive value.
>>
>> Maybe the cleanest way would change the function prototype to int.
>> 0: success
>> -1: failure
>
>
>Joyce, are you fine if I do the cange while applying?
>I have a big series that will conflicts with your patch set, so I'd like to
>have
>yours merged ASAP so I can start the rebase.
>
>Thanks,
>Maxime
>
Maxime, It's ok if you would do the change while applying.
Thanks,
Joyce
>>>> +
>>>> + /* Load 2 mbuf pointers per time. */
>>>> + mbp[0] = vld2q_u64((uint64_t *)&vq->vq_descx[id]);
>>>> + vst1q_u64((uint64_t *)&rx_pkts[0], mbp[0].val[0]);
>>>> +
>>>> + mbp[1] = vld2q_u64((uint64_t *)&vq->vq_descx[id + 2]);
>>>> + vst1q_u64((uint64_t *)&rx_pkts[2], mbp[1].val[0]);
>>>> +
>>>> + /**
>>>> + * Update data length and packet length for descriptor.
>>>> + * structure of pkt_mb:
>>>> + * --------------------------------------------------------------------
>>>> + * |32 bits pkt_type|32 bits pkt_len|16 bits data_len|16 bits vlan_tci|
>>>> + * --------------------------------------------------------------------
>>>> + */
>>>> + pkt_mb[0] = vreinterpretq_u64_u8(vqtbl1q_u8(
>>>> + vreinterpretq_u8_u64(desc[0]), shuf_msk1));
>>>> + pkt_mb[1] = vreinterpretq_u64_u8(vqtbl1q_u8(
>>>> + vreinterpretq_u8_u64(desc[0]), shuf_msk2));
>>>> + pkt_mb[2] = vreinterpretq_u64_u8(vqtbl1q_u8(
>>>> + vreinterpretq_u8_u64(desc[1]), shuf_msk1))'
>>>> + pkt_mb[3] = vreinterpretq_u64_u8(vqtbl1q_u8(
>>>> + vreinterpretq_u8_u64(desc[1]), shuf_msk2));
>>>> +
>>>> + pkt_mb[0] = vreinterpretq_u64_u16(vsubq_u16(
>>>> + vreinterpretq_u16_u64(pkt_mb[0]), len_adjust));
>>>> + pkt_mb[1] = vreinterpretq_u64_u16(vsubq_u16(
>>>> + vreinterpretq_u16_u64(pkt_mb[1]), len_adjust));
>>>> + pkt_mb[2] = vreinterpretq_u64_u16(vsubq_u16(
>>>> + vreinterpretq_u16_u64(pkt_mb[2]), len_adjust));
>>>> + pkt_mb[3] = vreinterpretq_u64_u16(vsubq_u16(
>>>> + vreinterpretq_u16_u64(pkt_mb[3]), len_adjust));
>>>> +
>>>> + vst1q_u64((void *)&rx_pkts[0]->rx_descriptor_fields1, pkt_mb[0]);
>>>> + vst1q_u64((void *)&rx_pkts[1]->rx_descriptor_fields1, pkt_mb[1]);
>>>> + vst1q_u64((void *)&rx_pkts[2]->rx_descriptor_fields1, pkt_mb[2]);
>>>> + vst1q_u64((void *)&rx_pkts[3]->rx_descriptor_fields1, pkt_mb[3]);
>>>> +
>>>> + if (hw->has_rx_offload) {
>>>> + virtio_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
>>>> + char *addr = (char *)rx_pkts[i]->buf_addr +
>>>> + RTE_PKTMBUF_HEADROOM - head_size;
>>>> + virtio_vec_rx_offload(rx_pkts[i],
>>>> + (struct virtio_net_hdr *)addr);
>>>> + }
>>>> + }
>>>> +
>>>> + virtio_update_batch_stats(&rxvq->stats, rx_pkts[0]->pkt_len,
>>>> + rx_pkts[1]->pkt_len, rx_pkts[2]->pkt_len,
>>>> + rx_pkts[3]->pkt_len);
>>>> +
>>>> + vq->vq_free_cnt += PACKED_BATCH_SIZE;
>>>> +
>>>> + vq->vq_used_cons_idx += PACKED_BATCH_SIZE;
>>>> + if (vq->vq_used_cons_idx >= vq->vq_nentries) {
>>>> + vq->vq_used_cons_idx -= vq->vq_nentries;
>>>> + vq->vq_packed.used_wrap_counter ^= 1;
>>>> + }
>>>> +
>>>> + return 0;
>>>> +}
>>>>
>>>
