virtio_rxtx_simple_sse.c revision 6b3e017e
1/*-
2 *   BSD LICENSE
3 *
4 *   Copyright(c) 2010-2015 Intel Corporation. All rights reserved.
5 *   All rights reserved.
6 *
7 *   Redistribution and use in source and binary forms, with or without
8 *   modification, are permitted provided that the following conditions
9 *   are met:
10 *
11 *     * Redistributions of source code must retain the above copyright
12 *       notice, this list of conditions and the following disclaimer.
13 *     * Redistributions in binary form must reproduce the above copyright
14 *       notice, this list of conditions and the following disclaimer in
15 *       the documentation and/or other materials provided with the
16 *       distribution.
17 *     * Neither the name of Intel Corporation nor the names of its
18 *       contributors may be used to endorse or promote products derived
19 *       from this software without specific prior written permission.
20 *
21 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34#include <stdint.h>
35#include <stdio.h>
36#include <stdlib.h>
37#include <string.h>
38#include <errno.h>
39
40#include <tmmintrin.h>
41
42#include <rte_byteorder.h>
43#include <rte_branch_prediction.h>
44#include <rte_cycles.h>
45#include <rte_ether.h>
46#include <rte_ethdev.h>
47#include <rte_errno.h>
48#include <rte_memory.h>
49#include <rte_memzone.h>
50#include <rte_mempool.h>
51#include <rte_malloc.h>
52#include <rte_mbuf.h>
53#include <rte_prefetch.h>
54#include <rte_string_fns.h>
55
56#include "virtio_rxtx_simple.h"
57
58#define RTE_VIRTIO_VPMD_RX_BURST 32
59#define RTE_VIRTIO_DESC_PER_LOOP 8
60#define RTE_VIRTIO_VPMD_RX_REARM_THRESH RTE_VIRTIO_VPMD_RX_BURST
61
62/* virtio vPMD receive routine, only accept(nb_pkts >= RTE_VIRTIO_DESC_PER_LOOP)
63 *
64 * This routine is for non-mergeable RX, one desc for each guest buffer.
65 * This routine is based on the RX ring layout optimization. Each entry in the
66 * avail ring points to the desc with the same index in the desc ring and this
67 * will never be changed in the driver.
68 *
69 * - nb_pkts < RTE_VIRTIO_DESC_PER_LOOP, just return no packet
70 */
71uint16_t
72virtio_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
73	uint16_t nb_pkts)
74{
75	struct virtnet_rx *rxvq = rx_queue;
76	struct virtqueue *vq = rxvq->vq;
77	uint16_t nb_used;
78	uint16_t desc_idx;
79	struct vring_used_elem *rused;
80	struct rte_mbuf **sw_ring;
81	struct rte_mbuf **sw_ring_end;
82	uint16_t nb_pkts_received;
83	__m128i shuf_msk1, shuf_msk2, len_adjust;
84
85	shuf_msk1 = _mm_set_epi8(
86		0xFF, 0xFF, 0xFF, 0xFF,
87		0xFF, 0xFF,		/* vlan tci */
88		5, 4,			/* dat len */
89		0xFF, 0xFF, 5, 4,	/* pkt len */
90		0xFF, 0xFF, 0xFF, 0xFF	/* packet type */
91
92	);
93
94	shuf_msk2 = _mm_set_epi8(
95		0xFF, 0xFF, 0xFF, 0xFF,
96		0xFF, 0xFF,		/* vlan tci */
97		13, 12,			/* dat len */
98		0xFF, 0xFF, 13, 12,	/* pkt len */
99		0xFF, 0xFF, 0xFF, 0xFF	/* packet type */
100	);
101
102	/* Subtract the header length.
103	*  In which case do we need the header length in used->len ?
104	*/
105	len_adjust = _mm_set_epi16(
106		0, 0,
107		0,
108		(uint16_t)-vq->hw->vtnet_hdr_size,
109		0, (uint16_t)-vq->hw->vtnet_hdr_size,
110		0, 0);
111
112	if (unlikely(nb_pkts < RTE_VIRTIO_DESC_PER_LOOP))
113		return 0;
114
115	nb_used = VIRTQUEUE_NUSED(vq);
116
117	rte_compiler_barrier();
118
119	if (unlikely(nb_used == 0))
120		return 0;
121
122	nb_pkts = RTE_ALIGN_FLOOR(nb_pkts, RTE_VIRTIO_DESC_PER_LOOP);
123	nb_used = RTE_MIN(nb_used, nb_pkts);
124
125	desc_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1));
126	rused = &vq->vq_ring.used->ring[desc_idx];
127	sw_ring  = &vq->sw_ring[desc_idx];
128	sw_ring_end = &vq->sw_ring[vq->vq_nentries];
129
130	rte_prefetch0(rused);
131
132	if (vq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
133		virtio_rxq_rearm_vec(rxvq);
134		if (unlikely(virtqueue_kick_prepare(vq)))
135			virtqueue_notify(vq);
136	}
137
138	for (nb_pkts_received = 0;
139		nb_pkts_received < nb_used;) {
140		__m128i desc[RTE_VIRTIO_DESC_PER_LOOP / 2];
141		__m128i mbp[RTE_VIRTIO_DESC_PER_LOOP / 2];
142		__m128i pkt_mb[RTE_VIRTIO_DESC_PER_LOOP];
143
144		mbp[0] = _mm_loadu_si128((__m128i *)(sw_ring + 0));
145		desc[0] = _mm_loadu_si128((__m128i *)(rused + 0));
146		_mm_storeu_si128((__m128i *)&rx_pkts[0], mbp[0]);
147
148		mbp[1] = _mm_loadu_si128((__m128i *)(sw_ring + 2));
149		desc[1] = _mm_loadu_si128((__m128i *)(rused + 2));
150		_mm_storeu_si128((__m128i *)&rx_pkts[2], mbp[1]);
151
152		mbp[2] = _mm_loadu_si128((__m128i *)(sw_ring + 4));
153		desc[2] = _mm_loadu_si128((__m128i *)(rused + 4));
154		_mm_storeu_si128((__m128i *)&rx_pkts[4], mbp[2]);
155
156		mbp[3] = _mm_loadu_si128((__m128i *)(sw_ring + 6));
157		desc[3] = _mm_loadu_si128((__m128i *)(rused + 6));
158		_mm_storeu_si128((__m128i *)&rx_pkts[6], mbp[3]);
159
160		pkt_mb[1] = _mm_shuffle_epi8(desc[0], shuf_msk2);
161		pkt_mb[0] = _mm_shuffle_epi8(desc[0], shuf_msk1);
162		pkt_mb[1] = _mm_add_epi16(pkt_mb[1], len_adjust);
163		pkt_mb[0] = _mm_add_epi16(pkt_mb[0], len_adjust);
164		_mm_storeu_si128((void *)&rx_pkts[1]->rx_descriptor_fields1,
165			pkt_mb[1]);
166		_mm_storeu_si128((void *)&rx_pkts[0]->rx_descriptor_fields1,
167			pkt_mb[0]);
168
169		pkt_mb[3] = _mm_shuffle_epi8(desc[1], shuf_msk2);
170		pkt_mb[2] = _mm_shuffle_epi8(desc[1], shuf_msk1);
171		pkt_mb[3] = _mm_add_epi16(pkt_mb[3], len_adjust);
172		pkt_mb[2] = _mm_add_epi16(pkt_mb[2], len_adjust);
173		_mm_storeu_si128((void *)&rx_pkts[3]->rx_descriptor_fields1,
174			pkt_mb[3]);
175		_mm_storeu_si128((void *)&rx_pkts[2]->rx_descriptor_fields1,
176			pkt_mb[2]);
177
178		pkt_mb[5] = _mm_shuffle_epi8(desc[2], shuf_msk2);
179		pkt_mb[4] = _mm_shuffle_epi8(desc[2], shuf_msk1);
180		pkt_mb[5] = _mm_add_epi16(pkt_mb[5], len_adjust);
181		pkt_mb[4] = _mm_add_epi16(pkt_mb[4], len_adjust);
182		_mm_storeu_si128((void *)&rx_pkts[5]->rx_descriptor_fields1,
183			pkt_mb[5]);
184		_mm_storeu_si128((void *)&rx_pkts[4]->rx_descriptor_fields1,
185			pkt_mb[4]);
186
187		pkt_mb[7] = _mm_shuffle_epi8(desc[3], shuf_msk2);
188		pkt_mb[6] = _mm_shuffle_epi8(desc[3], shuf_msk1);
189		pkt_mb[7] = _mm_add_epi16(pkt_mb[7], len_adjust);
190		pkt_mb[6] = _mm_add_epi16(pkt_mb[6], len_adjust);
191		_mm_storeu_si128((void *)&rx_pkts[7]->rx_descriptor_fields1,
192			pkt_mb[7]);
193		_mm_storeu_si128((void *)&rx_pkts[6]->rx_descriptor_fields1,
194			pkt_mb[6]);
195
196		if (unlikely(nb_used <= RTE_VIRTIO_DESC_PER_LOOP)) {
197			if (sw_ring + nb_used <= sw_ring_end)
198				nb_pkts_received += nb_used;
199			else
200				nb_pkts_received += sw_ring_end - sw_ring;
201			break;
202		} else {
203			if (unlikely(sw_ring + RTE_VIRTIO_DESC_PER_LOOP >=
204				sw_ring_end)) {
205				nb_pkts_received += sw_ring_end - sw_ring;
206				break;
207			} else {
208				nb_pkts_received += RTE_VIRTIO_DESC_PER_LOOP;
209
210				rx_pkts += RTE_VIRTIO_DESC_PER_LOOP;
211				sw_ring += RTE_VIRTIO_DESC_PER_LOOP;
212				rused   += RTE_VIRTIO_DESC_PER_LOOP;
213				nb_used -= RTE_VIRTIO_DESC_PER_LOOP;
214			}
215		}
216	}
217
218	vq->vq_used_cons_idx += nb_pkts_received;
219	vq->vq_free_cnt += nb_pkts_received;
220	rxvq->stats.packets += nb_pkts_received;
221	return nb_pkts_received;
222}
223