示例#1
0
 /*
 * Notice:
 * - nb_pkts < RTE_I40E_DESCS_PER_LOOP, just return no packet
 * - nb_pkts > RTE_I40E_VPMD_RX_BURST, only scan RTE_I40E_VPMD_RX_BURST
 *   numbers of DD bits
 */
static inline uint16_t
_recv_raw_pkts_vec(struct i40e_rx_queue *rxq, struct rte_mbuf **rx_pkts,
		   uint16_t nb_pkts, uint8_t *split_packet)
{
	volatile union i40e_rx_desc *rxdp;
	struct i40e_rx_entry *sw_ring;
	uint16_t nb_pkts_recd;
	int pos;
	uint32_t *ptype_tbl = rxq->vsi->adapter->ptype_tbl;

	/* mask to shuffle from desc. to mbuf */
	uint8x16_t shuf_msk = {
		0xFF, 0xFF,   /* pkt_type set as unknown */
		0xFF, 0xFF,   /* pkt_type set as unknown */
		14, 15,       /* octet 15~14, low 16 bits pkt_len */
		0xFF, 0xFF,   /* skip high 16 bits pkt_len, zero out */
		14, 15,       /* octet 15~14, 16 bits data_len */
		2, 3,         /* octet 2~3, low 16 bits vlan_macip */
		4, 5, 6, 7    /* octet 4~7, 32bits rss */
		};

	uint8x16_t eop_check = {
		0x02, 0x00, 0x02, 0x00,
		0x02, 0x00, 0x02, 0x00,
		0x00, 0x00, 0x00, 0x00,
		0x00, 0x00, 0x00, 0x00
		};

	uint16x8_t crc_adjust = {
		0, 0,         /* ignore pkt_type field */
		rxq->crc_len, /* sub crc on pkt_len */
		0,            /* ignore high-16bits of pkt_len */
		rxq->crc_len, /* sub crc on data_len */
		0, 0, 0       /* ignore non-length fields */
		};

	/* nb_pkts shall be less equal than RTE_I40E_MAX_RX_BURST */
	nb_pkts = RTE_MIN(nb_pkts, RTE_I40E_MAX_RX_BURST);

	/* nb_pkts has to be floor-aligned to RTE_I40E_DESCS_PER_LOOP */
	nb_pkts = RTE_ALIGN_FLOOR(nb_pkts, RTE_I40E_DESCS_PER_LOOP);

	/* Just the act of getting into the function from the application is
	 * going to cost about 7 cycles
	 */
	rxdp = rxq->rx_ring + rxq->rx_tail;

	rte_prefetch_non_temporal(rxdp);

	/* See if we need to rearm the RX queue - gives the prefetch a bit
	 * of time to act
	 */
	if (rxq->rxrearm_nb > RTE_I40E_RXQ_REARM_THRESH)
		i40e_rxq_rearm(rxq);

	/* Before we start moving massive data around, check to see if
	 * there is actually a packet available
	 */
	if (!(rxdp->wb.qword1.status_error_len &
			rte_cpu_to_le_32(1 << I40E_RX_DESC_STATUS_DD_SHIFT)))
		return 0;

	/* Cache is empty -> need to scan the buffer rings, but first move
	 * the next 'n' mbufs into the cache
	 */
	sw_ring = &rxq->sw_ring[rxq->rx_tail];

	/* A. load 4 packet in one loop
	 * [A*. mask out 4 unused dirty field in desc]
	 * B. copy 4 mbuf point from swring to rx_pkts
	 * C. calc the number of DD bits among the 4 packets
	 * [C*. extract the end-of-packet bit, if requested]
	 * D. fill info. from desc to mbuf
	 */

	for (pos = 0, nb_pkts_recd = 0; pos < nb_pkts;
			pos += RTE_I40E_DESCS_PER_LOOP,
			rxdp += RTE_I40E_DESCS_PER_LOOP) {
		uint64x2_t descs[RTE_I40E_DESCS_PER_LOOP];
		uint8x16_t pkt_mb1, pkt_mb2, pkt_mb3, pkt_mb4;
		uint16x8x2_t sterr_tmp1, sterr_tmp2;
		uint64x2_t mbp1, mbp2;
		uint16x8_t staterr;
		uint16x8_t tmp;
		uint64_t stat;

		int32x4_t len_shl = {0, 0, 0, PKTLEN_SHIFT};

		/* B.1 load 1 mbuf point */
		mbp1 = vld1q_u64((uint64_t *)&sw_ring[pos]);
		/* Read desc statuses backwards to avoid race condition */
		/* A.1 load 4 pkts desc */
		descs[3] =  vld1q_u64((uint64_t *)(rxdp + 3));
		rte_rmb();

		/* B.2 copy 2 mbuf point into rx_pkts  */
		vst1q_u64((uint64_t *)&rx_pkts[pos], mbp1);

		/* B.1 load 1 mbuf point */
		mbp2 = vld1q_u64((uint64_t *)&sw_ring[pos + 2]);

		descs[2] =  vld1q_u64((uint64_t *)(rxdp + 2));
		/* B.1 load 2 mbuf point */
		descs[1] =  vld1q_u64((uint64_t *)(rxdp + 1));
		descs[0] =  vld1q_u64((uint64_t *)(rxdp));

		/* B.2 copy 2 mbuf point into rx_pkts  */
		vst1q_u64((uint64_t *)&rx_pkts[pos + 2], mbp2);

		if (split_packet) {
			rte_mbuf_prefetch_part2(rx_pkts[pos]);
			rte_mbuf_prefetch_part2(rx_pkts[pos + 1]);
			rte_mbuf_prefetch_part2(rx_pkts[pos + 2]);
			rte_mbuf_prefetch_part2(rx_pkts[pos + 3]);
		}

		/* avoid compiler reorder optimization */
		rte_compiler_barrier();

		/* pkt 3,4 shift the pktlen field to be 16-bit aligned*/
		uint32x4_t len3 = vshlq_u32(vreinterpretq_u32_u64(descs[3]),
					    len_shl);
		descs[3] = vreinterpretq_u64_u32(len3);
		uint32x4_t len2 = vshlq_u32(vreinterpretq_u32_u64(descs[2]),
					    len_shl);
		descs[2] = vreinterpretq_u64_u32(len2);

		/* D.1 pkt 3,4 convert format from desc to pktmbuf */
		pkt_mb4 = vqtbl1q_u8(vreinterpretq_u8_u64(descs[3]), shuf_msk);
		pkt_mb3 = vqtbl1q_u8(vreinterpretq_u8_u64(descs[2]), shuf_msk);

		/* C.1 4=>2 filter staterr info only */
		sterr_tmp2 = vzipq_u16(vreinterpretq_u16_u64(descs[1]),
				       vreinterpretq_u16_u64(descs[3]));
		/* C.1 4=>2 filter staterr info only */
		sterr_tmp1 = vzipq_u16(vreinterpretq_u16_u64(descs[0]),
				       vreinterpretq_u16_u64(descs[2]));

		/* C.2 get 4 pkts staterr value  */
		staterr = vzipq_u16(sterr_tmp1.val[1],
				    sterr_tmp2.val[1]).val[0];

		desc_to_olflags_v(rxq, descs, &rx_pkts[pos]);

		/* D.2 pkt 3,4 set in_port/nb_seg and remove crc */
		tmp = vsubq_u16(vreinterpretq_u16_u8(pkt_mb4), crc_adjust);
		pkt_mb4 = vreinterpretq_u8_u16(tmp);
		tmp = vsubq_u16(vreinterpretq_u16_u8(pkt_mb3), crc_adjust);
		pkt_mb3 = vreinterpretq_u8_u16(tmp);

		/* pkt 1,2 shift the pktlen field to be 16-bit aligned*/
		uint32x4_t len1 = vshlq_u32(vreinterpretq_u32_u64(descs[1]),
					    len_shl);
		descs[1] = vreinterpretq_u64_u32(len1);
		uint32x4_t len0 = vshlq_u32(vreinterpretq_u32_u64(descs[0]),
					    len_shl);
		descs[0] = vreinterpretq_u64_u32(len0);

		/* D.1 pkt 1,2 convert format from desc to pktmbuf */
		pkt_mb2 = vqtbl1q_u8(vreinterpretq_u8_u64(descs[1]), shuf_msk);
		pkt_mb1 = vqtbl1q_u8(vreinterpretq_u8_u64(descs[0]), shuf_msk);

		/* D.3 copy final 3,4 data to rx_pkts */
		vst1q_u8((void *)&rx_pkts[pos + 3]->rx_descriptor_fields1,
				 pkt_mb4);
		vst1q_u8((void *)&rx_pkts[pos + 2]->rx_descriptor_fields1,
				 pkt_mb3);

		/* D.2 pkt 1,2 set in_port/nb_seg and remove crc */
		tmp = vsubq_u16(vreinterpretq_u16_u8(pkt_mb2), crc_adjust);
		pkt_mb2 = vreinterpretq_u8_u16(tmp);
		tmp = vsubq_u16(vreinterpretq_u16_u8(pkt_mb1), crc_adjust);
		pkt_mb1 = vreinterpretq_u8_u16(tmp);

		/* C* extract and record EOP bit */
		if (split_packet) {
			uint8x16_t eop_shuf_mask = {
					0x00, 0x02, 0x04, 0x06,
					0xFF, 0xFF, 0xFF, 0xFF,
					0xFF, 0xFF, 0xFF, 0xFF,
					0xFF, 0xFF, 0xFF, 0xFF};
			uint8x16_t eop_bits;

			/* and with mask to extract bits, flipping 1-0 */
			eop_bits = vmvnq_u8(vreinterpretq_u8_u16(staterr));
			eop_bits = vandq_u8(eop_bits, eop_check);
			/* the staterr values are not in order, as the count
			 * count of dd bits doesn't care. However, for end of
			 * packet tracking, we do care, so shuffle. This also
			 * compresses the 32-bit values to 8-bit
			 */
			eop_bits = vqtbl1q_u8(eop_bits, eop_shuf_mask);

			/* store the resulting 32-bit value */
			vst1q_lane_u32((uint32_t *)split_packet,
				       vreinterpretq_u32_u8(eop_bits), 0);
			split_packet += RTE_I40E_DESCS_PER_LOOP;

			/* zero-out next pointers */
			rx_pkts[pos]->next = NULL;
			rx_pkts[pos + 1]->next = NULL;
			rx_pkts[pos + 2]->next = NULL;
			rx_pkts[pos + 3]->next = NULL;
		}

		staterr = vshlq_n_u16(staterr, I40E_UINT16_BIT - 1);
		staterr = vreinterpretq_u16_s16(
				vshrq_n_s16(vreinterpretq_s16_u16(staterr),
					    I40E_UINT16_BIT - 1));
		stat = ~vgetq_lane_u64(vreinterpretq_u64_u16(staterr), 0);

		rte_prefetch_non_temporal(rxdp + RTE_I40E_DESCS_PER_LOOP);

		/* D.3 copy final 1,2 data to rx_pkts */
		vst1q_u8((void *)&rx_pkts[pos + 1]->rx_descriptor_fields1,
			 pkt_mb2);
		vst1q_u8((void *)&rx_pkts[pos]->rx_descriptor_fields1,
			 pkt_mb1);
		desc_to_ptype_v(descs, &rx_pkts[pos], ptype_tbl);
		/* C.4 calc avaialbe number of desc */
		if (unlikely(stat == 0)) {
			nb_pkts_recd += RTE_I40E_DESCS_PER_LOOP;
		} else {
			nb_pkts_recd += __builtin_ctzl(stat) / I40E_UINT16_BIT;
			break;
		}
	}

	/* Update our internal tail pointer */
	rxq->rx_tail = (uint16_t)(rxq->rx_tail + nb_pkts_recd);
	rxq->rx_tail = (uint16_t)(rxq->rx_tail & (rxq->nb_rx_desc - 1));
	rxq->rxrearm_nb = (uint16_t)(rxq->rxrearm_nb + nb_pkts_recd);

	return nb_pkts_recd;
}
/* virtio vPMD receive routine, only accept(nb_pkts >= RTE_VIRTIO_DESC_PER_LOOP)
 *
 * This routine is for non-mergeable RX, one desc for each guest buffer.
 * This routine is based on the RX ring layout optimization. Each entry in the
 * avail ring points to the desc with the same index in the desc ring and this
 * will never be changed in the driver.
 *
 * - nb_pkts < RTE_VIRTIO_DESC_PER_LOOP, just return no packet
 */
uint16_t
virtio_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
	uint16_t nb_pkts)
{
	struct virtnet_rx *rxvq = rx_queue;
	struct virtqueue *vq = rxvq->vq;
	uint16_t nb_used;
	uint16_t desc_idx;
	struct vring_used_elem *rused;
	struct rte_mbuf **sw_ring;
	struct rte_mbuf **sw_ring_end;
	uint16_t nb_pkts_received;

	uint8x16_t shuf_msk1 = {
		0xFF, 0xFF, 0xFF, 0xFF, /* packet type */
		4, 5, 0xFF, 0xFF,       /* pkt len */
		4, 5,                   /* dat len */
		0xFF, 0xFF,             /* vlan tci */
		0xFF, 0xFF, 0xFF, 0xFF
	};

	uint8x16_t shuf_msk2 = {
		0xFF, 0xFF, 0xFF, 0xFF, /* packet type */
		12, 13, 0xFF, 0xFF,     /* pkt len */
		12, 13,                 /* dat len */
		0xFF, 0xFF,             /* vlan tci */
		0xFF, 0xFF, 0xFF, 0xFF
	};

	/* Subtract the header length.
	 *  In which case do we need the header length in used->len ?
	 */
	uint16x8_t len_adjust = {
		0, 0,
		(uint16_t)vq->hw->vtnet_hdr_size, 0,
		(uint16_t)vq->hw->vtnet_hdr_size,
		0,
		0, 0
	};

	if (unlikely(nb_pkts < RTE_VIRTIO_DESC_PER_LOOP))
		return 0;

	nb_used = VIRTQUEUE_NUSED(vq);

	rte_rmb();

	if (unlikely(nb_used == 0))
		return 0;

	nb_pkts = RTE_ALIGN_FLOOR(nb_pkts, RTE_VIRTIO_DESC_PER_LOOP);
	nb_used = RTE_MIN(nb_used, nb_pkts);

	desc_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1));
	rused = &vq->vq_ring.used->ring[desc_idx];
	sw_ring  = &vq->sw_ring[desc_idx];
	sw_ring_end = &vq->sw_ring[vq->vq_nentries];

	rte_prefetch_non_temporal(rused);

	if (vq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
		virtio_rxq_rearm_vec(rxvq);
		if (unlikely(virtqueue_kick_prepare(vq)))
			virtqueue_notify(vq);
	}

	for (nb_pkts_received = 0;
		nb_pkts_received < nb_used;) {
		uint64x2_t desc[RTE_VIRTIO_DESC_PER_LOOP / 2];
		uint64x2_t mbp[RTE_VIRTIO_DESC_PER_LOOP / 2];
		uint64x2_t pkt_mb[RTE_VIRTIO_DESC_PER_LOOP];

		mbp[0] = vld1q_u64((uint64_t *)(sw_ring + 0));
		desc[0] = vld1q_u64((uint64_t *)(rused + 0));
		vst1q_u64((uint64_t *)&rx_pkts[0], mbp[0]);

		mbp[1] = vld1q_u64((uint64_t *)(sw_ring + 2));
		desc[1] = vld1q_u64((uint64_t *)(rused + 2));
		vst1q_u64((uint64_t *)&rx_pkts[2], mbp[1]);

		mbp[2] = vld1q_u64((uint64_t *)(sw_ring + 4));
		desc[2] = vld1q_u64((uint64_t *)(rused + 4));
		vst1q_u64((uint64_t *)&rx_pkts[4], mbp[2]);

		mbp[3] = vld1q_u64((uint64_t *)(sw_ring + 6));
		desc[3] = vld1q_u64((uint64_t *)(rused + 6));
		vst1q_u64((uint64_t *)&rx_pkts[6], mbp[3]);

		pkt_mb[1] = vreinterpretq_u64_u8(vqtbl1q_u8(
				vreinterpretq_u8_u64(desc[0]), shuf_msk2));
		pkt_mb[0] = vreinterpretq_u64_u8(vqtbl1q_u8(
				vreinterpretq_u8_u64(desc[0]), shuf_msk1));
		pkt_mb[1] = vreinterpretq_u64_u16(vsubq_u16(
				vreinterpretq_u16_u64(pkt_mb[1]), len_adjust));
		pkt_mb[0] = vreinterpretq_u64_u16(vsubq_u16(
				vreinterpretq_u16_u64(pkt_mb[0]), len_adjust));
		vst1q_u64((void *)&rx_pkts[1]->rx_descriptor_fields1,
			pkt_mb[1]);
		vst1q_u64((void *)&rx_pkts[0]->rx_descriptor_fields1,
			pkt_mb[0]);

		pkt_mb[3] = vreinterpretq_u64_u8(vqtbl1q_u8(
				vreinterpretq_u8_u64(desc[1]), shuf_msk2));
		pkt_mb[2] = vreinterpretq_u64_u8(vqtbl1q_u8(
				vreinterpretq_u8_u64(desc[1]), shuf_msk1));
		pkt_mb[3] = vreinterpretq_u64_u16(vsubq_u16(
				vreinterpretq_u16_u64(pkt_mb[3]), len_adjust));
		pkt_mb[2] = vreinterpretq_u64_u16(vsubq_u16(
				vreinterpretq_u16_u64(pkt_mb[2]), len_adjust));
		vst1q_u64((void *)&rx_pkts[3]->rx_descriptor_fields1,
			pkt_mb[3]);
		vst1q_u64((void *)&rx_pkts[2]->rx_descriptor_fields1,
			pkt_mb[2]);

		pkt_mb[5] = vreinterpretq_u64_u8(vqtbl1q_u8(
				vreinterpretq_u8_u64(desc[2]), shuf_msk2));
		pkt_mb[4] = vreinterpretq_u64_u8(vqtbl1q_u8(
				vreinterpretq_u8_u64(desc[2]), shuf_msk1));
		pkt_mb[5] = vreinterpretq_u64_u16(vsubq_u16(
				vreinterpretq_u16_u64(pkt_mb[5]), len_adjust));
		pkt_mb[4] = vreinterpretq_u64_u16(vsubq_u16(
				vreinterpretq_u16_u64(pkt_mb[4]), len_adjust));
		vst1q_u64((void *)&rx_pkts[5]->rx_descriptor_fields1,
			pkt_mb[5]);
		vst1q_u64((void *)&rx_pkts[4]->rx_descriptor_fields1,
			pkt_mb[4]);

		pkt_mb[7] = vreinterpretq_u64_u8(vqtbl1q_u8(
				vreinterpretq_u8_u64(desc[3]), shuf_msk2));
		pkt_mb[6] = vreinterpretq_u64_u8(vqtbl1q_u8(
				vreinterpretq_u8_u64(desc[3]), shuf_msk1));
		pkt_mb[7] = vreinterpretq_u64_u16(vsubq_u16(
				vreinterpretq_u16_u64(pkt_mb[7]), len_adjust));
		pkt_mb[6] = vreinterpretq_u64_u16(vsubq_u16(
				vreinterpretq_u16_u64(pkt_mb[6]), len_adjust));
		vst1q_u64((void *)&rx_pkts[7]->rx_descriptor_fields1,
			pkt_mb[7]);
		vst1q_u64((void *)&rx_pkts[6]->rx_descriptor_fields1,
			pkt_mb[6]);

		if (unlikely(nb_used <= RTE_VIRTIO_DESC_PER_LOOP)) {
			if (sw_ring + nb_used <= sw_ring_end)
				nb_pkts_received += nb_used;
			else
				nb_pkts_received += sw_ring_end - sw_ring;
			break;
		} else {
			if (unlikely(sw_ring + RTE_VIRTIO_DESC_PER_LOOP >=
				sw_ring_end)) {
				nb_pkts_received += sw_ring_end - sw_ring;
				break;
			} else {
				nb_pkts_received += RTE_VIRTIO_DESC_PER_LOOP;

				rx_pkts += RTE_VIRTIO_DESC_PER_LOOP;
				sw_ring += RTE_VIRTIO_DESC_PER_LOOP;
				rused   += RTE_VIRTIO_DESC_PER_LOOP;
				nb_used -= RTE_VIRTIO_DESC_PER_LOOP;
			}
		}
	}

	vq->vq_used_cons_idx += nb_pkts_received;
	vq->vq_free_cnt += nb_pkts_received;
	rxvq->stats.packets += nb_pkts_received;
	return nb_pkts_received;
}