xref: /dpdk/drivers/net/virtio/virtio_rxtx_simple_sse.c (revision 1f41d98c207aee8982ced709864c96c463d4503a)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2010-2015 Intel Corporation
3  */
4 
5 #include <stdint.h>
6 #include <stdio.h>
7 #include <stdlib.h>
8 #include <string.h>
9 #include <errno.h>
10 
11 #include <tmmintrin.h>
12 
13 #include <rte_byteorder.h>
14 #include <rte_branch_prediction.h>
15 #include <rte_cycles.h>
16 #include <rte_ether.h>
17 #include <rte_ethdev_driver.h>
18 #include <rte_errno.h>
19 #include <rte_memory.h>
20 #include <rte_mempool.h>
21 #include <rte_malloc.h>
22 #include <rte_mbuf.h>
23 #include <rte_prefetch.h>
24 #include <rte_string_fns.h>
25 
26 #include "virtio_rxtx_simple.h"
27 
28 #define RTE_VIRTIO_DESC_PER_LOOP 8
29 
30 /* virtio vPMD receive routine, only accept(nb_pkts >= RTE_VIRTIO_DESC_PER_LOOP)
31  *
32  * This routine is for non-mergeable RX, one desc for each guest buffer.
33  * This routine is based on the RX ring layout optimization. Each entry in the
34  * avail ring points to the desc with the same index in the desc ring and this
35  * will never be changed in the driver.
36  *
37  * - nb_pkts < RTE_VIRTIO_DESC_PER_LOOP, just return no packet
38  */
39 uint16_t
40 virtio_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
41 	uint16_t nb_pkts)
42 {
43 	struct virtnet_rx *rxvq = rx_queue;
44 	struct virtqueue *vq = rxvq->vq;
45 	struct virtio_hw *hw = vq->hw;
46 	uint16_t nb_used, nb_total;
47 	uint16_t desc_idx;
48 	struct vring_used_elem *rused;
49 	struct rte_mbuf **sw_ring;
50 	struct rte_mbuf **sw_ring_end;
51 	struct rte_mbuf **ref_rx_pkts;
52 	uint16_t nb_pkts_received = 0;
53 	__m128i shuf_msk1, shuf_msk2, len_adjust;
54 
55 	shuf_msk1 = _mm_set_epi8(
56 		0xFF, 0xFF, 0xFF, 0xFF,
57 		0xFF, 0xFF,		/* vlan tci */
58 		5, 4,			/* dat len */
59 		0xFF, 0xFF, 5, 4,	/* pkt len */
60 		0xFF, 0xFF, 0xFF, 0xFF	/* packet type */
61 
62 	);
63 
64 	shuf_msk2 = _mm_set_epi8(
65 		0xFF, 0xFF, 0xFF, 0xFF,
66 		0xFF, 0xFF,		/* vlan tci */
67 		13, 12,			/* dat len */
68 		0xFF, 0xFF, 13, 12,	/* pkt len */
69 		0xFF, 0xFF, 0xFF, 0xFF	/* packet type */
70 	);
71 
72 	/* Subtract the header length.
73 	*  In which case do we need the header length in used->len ?
74 	*/
75 	len_adjust = _mm_set_epi16(
76 		0, 0,
77 		0,
78 		(uint16_t)-vq->hw->vtnet_hdr_size,
79 		0, (uint16_t)-vq->hw->vtnet_hdr_size,
80 		0, 0);
81 
82 	if (unlikely(hw->started == 0))
83 		return nb_pkts_received;
84 
85 	if (unlikely(nb_pkts < RTE_VIRTIO_DESC_PER_LOOP))
86 		return 0;
87 
88 	nb_used = VIRTQUEUE_NUSED(vq);
89 
90 	rte_compiler_barrier();
91 
92 	if (unlikely(nb_used == 0))
93 		return 0;
94 
95 	nb_pkts = RTE_ALIGN_FLOOR(nb_pkts, RTE_VIRTIO_DESC_PER_LOOP);
96 	nb_used = RTE_MIN(nb_used, nb_pkts);
97 
98 	desc_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1));
99 	rused = &vq->vq_split.ring.used->ring[desc_idx];
100 	sw_ring  = &vq->sw_ring[desc_idx];
101 	sw_ring_end = &vq->sw_ring[vq->vq_nentries];
102 
103 	rte_prefetch0(rused);
104 
105 	if (vq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
106 		virtio_rxq_rearm_vec(rxvq);
107 		if (unlikely(virtqueue_kick_prepare(vq)))
108 			virtqueue_notify(vq);
109 	}
110 
111 	nb_total = nb_used;
112 	ref_rx_pkts = rx_pkts;
113 	for (nb_pkts_received = 0;
114 		nb_pkts_received < nb_total;) {
115 		__m128i desc[RTE_VIRTIO_DESC_PER_LOOP / 2];
116 		__m128i mbp[RTE_VIRTIO_DESC_PER_LOOP / 2];
117 		__m128i pkt_mb[RTE_VIRTIO_DESC_PER_LOOP];
118 
119 		mbp[0] = _mm_loadu_si128((__m128i *)(sw_ring + 0));
120 		desc[0] = _mm_loadu_si128((__m128i *)(rused + 0));
121 		_mm_storeu_si128((__m128i *)&rx_pkts[0], mbp[0]);
122 
123 		mbp[1] = _mm_loadu_si128((__m128i *)(sw_ring + 2));
124 		desc[1] = _mm_loadu_si128((__m128i *)(rused + 2));
125 		_mm_storeu_si128((__m128i *)&rx_pkts[2], mbp[1]);
126 
127 		mbp[2] = _mm_loadu_si128((__m128i *)(sw_ring + 4));
128 		desc[2] = _mm_loadu_si128((__m128i *)(rused + 4));
129 		_mm_storeu_si128((__m128i *)&rx_pkts[4], mbp[2]);
130 
131 		mbp[3] = _mm_loadu_si128((__m128i *)(sw_ring + 6));
132 		desc[3] = _mm_loadu_si128((__m128i *)(rused + 6));
133 		_mm_storeu_si128((__m128i *)&rx_pkts[6], mbp[3]);
134 
135 		pkt_mb[1] = _mm_shuffle_epi8(desc[0], shuf_msk2);
136 		pkt_mb[0] = _mm_shuffle_epi8(desc[0], shuf_msk1);
137 		pkt_mb[1] = _mm_add_epi16(pkt_mb[1], len_adjust);
138 		pkt_mb[0] = _mm_add_epi16(pkt_mb[0], len_adjust);
139 		_mm_storeu_si128((void *)&rx_pkts[1]->rx_descriptor_fields1,
140 			pkt_mb[1]);
141 		_mm_storeu_si128((void *)&rx_pkts[0]->rx_descriptor_fields1,
142 			pkt_mb[0]);
143 
144 		pkt_mb[3] = _mm_shuffle_epi8(desc[1], shuf_msk2);
145 		pkt_mb[2] = _mm_shuffle_epi8(desc[1], shuf_msk1);
146 		pkt_mb[3] = _mm_add_epi16(pkt_mb[3], len_adjust);
147 		pkt_mb[2] = _mm_add_epi16(pkt_mb[2], len_adjust);
148 		_mm_storeu_si128((void *)&rx_pkts[3]->rx_descriptor_fields1,
149 			pkt_mb[3]);
150 		_mm_storeu_si128((void *)&rx_pkts[2]->rx_descriptor_fields1,
151 			pkt_mb[2]);
152 
153 		pkt_mb[5] = _mm_shuffle_epi8(desc[2], shuf_msk2);
154 		pkt_mb[4] = _mm_shuffle_epi8(desc[2], shuf_msk1);
155 		pkt_mb[5] = _mm_add_epi16(pkt_mb[5], len_adjust);
156 		pkt_mb[4] = _mm_add_epi16(pkt_mb[4], len_adjust);
157 		_mm_storeu_si128((void *)&rx_pkts[5]->rx_descriptor_fields1,
158 			pkt_mb[5]);
159 		_mm_storeu_si128((void *)&rx_pkts[4]->rx_descriptor_fields1,
160 			pkt_mb[4]);
161 
162 		pkt_mb[7] = _mm_shuffle_epi8(desc[3], shuf_msk2);
163 		pkt_mb[6] = _mm_shuffle_epi8(desc[3], shuf_msk1);
164 		pkt_mb[7] = _mm_add_epi16(pkt_mb[7], len_adjust);
165 		pkt_mb[6] = _mm_add_epi16(pkt_mb[6], len_adjust);
166 		_mm_storeu_si128((void *)&rx_pkts[7]->rx_descriptor_fields1,
167 			pkt_mb[7]);
168 		_mm_storeu_si128((void *)&rx_pkts[6]->rx_descriptor_fields1,
169 			pkt_mb[6]);
170 
171 		if (unlikely(nb_used <= RTE_VIRTIO_DESC_PER_LOOP)) {
172 			if (sw_ring + nb_used <= sw_ring_end)
173 				nb_pkts_received += nb_used;
174 			else
175 				nb_pkts_received += sw_ring_end - sw_ring;
176 			break;
177 		} else {
178 			if (unlikely(sw_ring + RTE_VIRTIO_DESC_PER_LOOP >=
179 				sw_ring_end)) {
180 				nb_pkts_received += sw_ring_end - sw_ring;
181 				break;
182 			} else {
183 				nb_pkts_received += RTE_VIRTIO_DESC_PER_LOOP;
184 
185 				rx_pkts += RTE_VIRTIO_DESC_PER_LOOP;
186 				sw_ring += RTE_VIRTIO_DESC_PER_LOOP;
187 				rused   += RTE_VIRTIO_DESC_PER_LOOP;
188 				nb_used -= RTE_VIRTIO_DESC_PER_LOOP;
189 			}
190 		}
191 	}
192 
193 	vq->vq_used_cons_idx += nb_pkts_received;
194 	vq->vq_free_cnt += nb_pkts_received;
195 	rxvq->stats.packets += nb_pkts_received;
196 	for (nb_used = 0; nb_used < nb_pkts_received; nb_used++)
197 		virtio_update_packet_stats(&rxvq->stats, ref_rx_pkts[nb_used]);
198 
199 	return nb_pkts_received;
200 }
201