xref: /dpdk/drivers/net/virtio/virtio_rxtx_simple_sse.c (revision 3998e2a07220844d3f3c17f76a781ced3efe0de0)
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.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_VPMD_RX_BURST 32
29 #define RTE_VIRTIO_DESC_PER_LOOP 8
30 #define RTE_VIRTIO_VPMD_RX_REARM_THRESH RTE_VIRTIO_VPMD_RX_BURST
31 
32 /* virtio vPMD receive routine, only accept(nb_pkts >= RTE_VIRTIO_DESC_PER_LOOP)
33  *
34  * This routine is for non-mergeable RX, one desc for each guest buffer.
35  * This routine is based on the RX ring layout optimization. Each entry in the
36  * avail ring points to the desc with the same index in the desc ring and this
37  * will never be changed in the driver.
38  *
39  * - nb_pkts < RTE_VIRTIO_DESC_PER_LOOP, just return no packet
40  */
41 uint16_t
42 virtio_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
43 	uint16_t nb_pkts)
44 {
45 	struct virtnet_rx *rxvq = rx_queue;
46 	struct virtqueue *vq = rxvq->vq;
47 	struct virtio_hw *hw = vq->hw;
48 	uint16_t nb_used;
49 	uint16_t desc_idx;
50 	struct vring_used_elem *rused;
51 	struct rte_mbuf **sw_ring;
52 	struct rte_mbuf **sw_ring_end;
53 	uint16_t nb_pkts_received = 0;
54 	__m128i shuf_msk1, shuf_msk2, len_adjust;
55 
56 	shuf_msk1 = _mm_set_epi8(
57 		0xFF, 0xFF, 0xFF, 0xFF,
58 		0xFF, 0xFF,		/* vlan tci */
59 		5, 4,			/* dat len */
60 		0xFF, 0xFF, 5, 4,	/* pkt len */
61 		0xFF, 0xFF, 0xFF, 0xFF	/* packet type */
62 
63 	);
64 
65 	shuf_msk2 = _mm_set_epi8(
66 		0xFF, 0xFF, 0xFF, 0xFF,
67 		0xFF, 0xFF,		/* vlan tci */
68 		13, 12,			/* dat len */
69 		0xFF, 0xFF, 13, 12,	/* pkt len */
70 		0xFF, 0xFF, 0xFF, 0xFF	/* packet type */
71 	);
72 
73 	/* Subtract the header length.
74 	*  In which case do we need the header length in used->len ?
75 	*/
76 	len_adjust = _mm_set_epi16(
77 		0, 0,
78 		0,
79 		(uint16_t)-vq->hw->vtnet_hdr_size,
80 		0, (uint16_t)-vq->hw->vtnet_hdr_size,
81 		0, 0);
82 
83 	if (unlikely(hw->started == 0))
84 		return nb_pkts_received;
85 
86 	if (unlikely(nb_pkts < RTE_VIRTIO_DESC_PER_LOOP))
87 		return 0;
88 
89 	nb_used = VIRTQUEUE_NUSED(vq);
90 
91 	rte_compiler_barrier();
92 
93 	if (unlikely(nb_used == 0))
94 		return 0;
95 
96 	nb_pkts = RTE_ALIGN_FLOOR(nb_pkts, RTE_VIRTIO_DESC_PER_LOOP);
97 	nb_used = RTE_MIN(nb_used, nb_pkts);
98 
99 	desc_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1));
100 	rused = &vq->vq_ring.used->ring[desc_idx];
101 	sw_ring  = &vq->sw_ring[desc_idx];
102 	sw_ring_end = &vq->sw_ring[vq->vq_nentries];
103 
104 	rte_prefetch0(rused);
105 
106 	if (vq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
107 		virtio_rxq_rearm_vec(rxvq);
108 		if (unlikely(virtqueue_kick_prepare(vq)))
109 			virtqueue_notify(vq);
110 	}
111 
112 	for (nb_pkts_received = 0;
113 		nb_pkts_received < nb_used;) {
114 		__m128i desc[RTE_VIRTIO_DESC_PER_LOOP / 2];
115 		__m128i mbp[RTE_VIRTIO_DESC_PER_LOOP / 2];
116 		__m128i pkt_mb[RTE_VIRTIO_DESC_PER_LOOP];
117 
118 		mbp[0] = _mm_loadu_si128((__m128i *)(sw_ring + 0));
119 		desc[0] = _mm_loadu_si128((__m128i *)(rused + 0));
120 		_mm_storeu_si128((__m128i *)&rx_pkts[0], mbp[0]);
121 
122 		mbp[1] = _mm_loadu_si128((__m128i *)(sw_ring + 2));
123 		desc[1] = _mm_loadu_si128((__m128i *)(rused + 2));
124 		_mm_storeu_si128((__m128i *)&rx_pkts[2], mbp[1]);
125 
126 		mbp[2] = _mm_loadu_si128((__m128i *)(sw_ring + 4));
127 		desc[2] = _mm_loadu_si128((__m128i *)(rused + 4));
128 		_mm_storeu_si128((__m128i *)&rx_pkts[4], mbp[2]);
129 
130 		mbp[3] = _mm_loadu_si128((__m128i *)(sw_ring + 6));
131 		desc[3] = _mm_loadu_si128((__m128i *)(rused + 6));
132 		_mm_storeu_si128((__m128i *)&rx_pkts[6], mbp[3]);
133 
134 		pkt_mb[1] = _mm_shuffle_epi8(desc[0], shuf_msk2);
135 		pkt_mb[0] = _mm_shuffle_epi8(desc[0], shuf_msk1);
136 		pkt_mb[1] = _mm_add_epi16(pkt_mb[1], len_adjust);
137 		pkt_mb[0] = _mm_add_epi16(pkt_mb[0], len_adjust);
138 		_mm_storeu_si128((void *)&rx_pkts[1]->rx_descriptor_fields1,
139 			pkt_mb[1]);
140 		_mm_storeu_si128((void *)&rx_pkts[0]->rx_descriptor_fields1,
141 			pkt_mb[0]);
142 
143 		pkt_mb[3] = _mm_shuffle_epi8(desc[1], shuf_msk2);
144 		pkt_mb[2] = _mm_shuffle_epi8(desc[1], shuf_msk1);
145 		pkt_mb[3] = _mm_add_epi16(pkt_mb[3], len_adjust);
146 		pkt_mb[2] = _mm_add_epi16(pkt_mb[2], len_adjust);
147 		_mm_storeu_si128((void *)&rx_pkts[3]->rx_descriptor_fields1,
148 			pkt_mb[3]);
149 		_mm_storeu_si128((void *)&rx_pkts[2]->rx_descriptor_fields1,
150 			pkt_mb[2]);
151 
152 		pkt_mb[5] = _mm_shuffle_epi8(desc[2], shuf_msk2);
153 		pkt_mb[4] = _mm_shuffle_epi8(desc[2], shuf_msk1);
154 		pkt_mb[5] = _mm_add_epi16(pkt_mb[5], len_adjust);
155 		pkt_mb[4] = _mm_add_epi16(pkt_mb[4], len_adjust);
156 		_mm_storeu_si128((void *)&rx_pkts[5]->rx_descriptor_fields1,
157 			pkt_mb[5]);
158 		_mm_storeu_si128((void *)&rx_pkts[4]->rx_descriptor_fields1,
159 			pkt_mb[4]);
160 
161 		pkt_mb[7] = _mm_shuffle_epi8(desc[3], shuf_msk2);
162 		pkt_mb[6] = _mm_shuffle_epi8(desc[3], shuf_msk1);
163 		pkt_mb[7] = _mm_add_epi16(pkt_mb[7], len_adjust);
164 		pkt_mb[6] = _mm_add_epi16(pkt_mb[6], len_adjust);
165 		_mm_storeu_si128((void *)&rx_pkts[7]->rx_descriptor_fields1,
166 			pkt_mb[7]);
167 		_mm_storeu_si128((void *)&rx_pkts[6]->rx_descriptor_fields1,
168 			pkt_mb[6]);
169 
170 		if (unlikely(nb_used <= RTE_VIRTIO_DESC_PER_LOOP)) {
171 			if (sw_ring + nb_used <= sw_ring_end)
172 				nb_pkts_received += nb_used;
173 			else
174 				nb_pkts_received += sw_ring_end - sw_ring;
175 			break;
176 		} else {
177 			if (unlikely(sw_ring + RTE_VIRTIO_DESC_PER_LOOP >=
178 				sw_ring_end)) {
179 				nb_pkts_received += sw_ring_end - sw_ring;
180 				break;
181 			} else {
182 				nb_pkts_received += RTE_VIRTIO_DESC_PER_LOOP;
183 
184 				rx_pkts += RTE_VIRTIO_DESC_PER_LOOP;
185 				sw_ring += RTE_VIRTIO_DESC_PER_LOOP;
186 				rused   += RTE_VIRTIO_DESC_PER_LOOP;
187 				nb_used -= RTE_VIRTIO_DESC_PER_LOOP;
188 			}
189 		}
190 	}
191 
192 	vq->vq_used_cons_idx += nb_pkts_received;
193 	vq->vq_free_cnt += nb_pkts_received;
194 	rxvq->stats.packets += nb_pkts_received;
195 	return nb_pkts_received;
196 }
197