xref: /dpdk/drivers/net/virtio/virtio_rxtx_simple.c (revision 3e0ceb9f17fff027fc6c8f18de35e11719ffa61e)
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 <rte_cycles.h>
41 #include <rte_memory.h>
42 #include <rte_branch_prediction.h>
43 #include <rte_mempool.h>
44 #include <rte_malloc.h>
45 #include <rte_mbuf.h>
46 #include <rte_ether.h>
47 #include <rte_ethdev.h>
48 #include <rte_prefetch.h>
49 #include <rte_string_fns.h>
50 #include <rte_errno.h>
51 #include <rte_byteorder.h>
52 
53 #include "virtio_rxtx_simple.h"
54 
55 #ifndef __INTEL_COMPILER
56 #pragma GCC diagnostic ignored "-Wcast-qual"
57 #endif
58 
59 int __attribute__((cold))
60 virtqueue_enqueue_recv_refill_simple(struct virtqueue *vq,
61 	struct rte_mbuf *cookie)
62 {
63 	struct vq_desc_extra *dxp;
64 	struct vring_desc *start_dp;
65 	uint16_t desc_idx;
66 
67 	cookie->port = vq->rxq.port_id;
68 
69 	desc_idx = vq->vq_avail_idx & (vq->vq_nentries - 1);
70 	dxp = &vq->vq_descx[desc_idx];
71 	dxp->cookie = (void *)cookie;
72 	vq->sw_ring[desc_idx] = cookie;
73 
74 	start_dp = vq->vq_ring.desc;
75 	start_dp[desc_idx].addr =
76 		VIRTIO_MBUF_ADDR(cookie, vq) +
77 		RTE_PKTMBUF_HEADROOM - vq->hw->vtnet_hdr_size;
78 	start_dp[desc_idx].len = cookie->buf_len -
79 		RTE_PKTMBUF_HEADROOM + vq->hw->vtnet_hdr_size;
80 
81 	vq->vq_free_cnt--;
82 	vq->vq_avail_idx++;
83 
84 	return 0;
85 }
86 
87 uint16_t
88 virtio_xmit_pkts_simple(void *tx_queue, struct rte_mbuf **tx_pkts,
89 	uint16_t nb_pkts)
90 {
91 	struct virtnet_tx *txvq = tx_queue;
92 	struct virtqueue *vq = txvq->vq;
93 	struct virtio_hw *hw = vq->hw;
94 	uint16_t nb_used;
95 	uint16_t desc_idx;
96 	struct vring_desc *start_dp;
97 	uint16_t nb_tail, nb_commit;
98 	int i;
99 	uint16_t desc_idx_max = (vq->vq_nentries >> 1) - 1;
100 	uint16_t nb_tx = 0;
101 
102 	if (unlikely(hw->started == 0))
103 		return nb_tx;
104 
105 	nb_used = VIRTQUEUE_NUSED(vq);
106 	rte_compiler_barrier();
107 
108 	if (nb_used >= VIRTIO_TX_FREE_THRESH)
109 		virtio_xmit_cleanup(vq);
110 
111 	nb_commit = nb_pkts = RTE_MIN((vq->vq_free_cnt >> 1), nb_pkts);
112 	desc_idx = (uint16_t)(vq->vq_avail_idx & desc_idx_max);
113 	start_dp = vq->vq_ring.desc;
114 	nb_tail = (uint16_t) (desc_idx_max + 1 - desc_idx);
115 
116 	if (nb_commit >= nb_tail) {
117 		for (i = 0; i < nb_tail; i++)
118 			vq->vq_descx[desc_idx + i].cookie = tx_pkts[i];
119 		for (i = 0; i < nb_tail; i++) {
120 			start_dp[desc_idx].addr =
121 				VIRTIO_MBUF_DATA_DMA_ADDR(*tx_pkts, vq);
122 			start_dp[desc_idx].len = (*tx_pkts)->pkt_len;
123 			tx_pkts++;
124 			desc_idx++;
125 		}
126 		nb_commit -= nb_tail;
127 		desc_idx = 0;
128 	}
129 	for (i = 0; i < nb_commit; i++)
130 		vq->vq_descx[desc_idx + i].cookie = tx_pkts[i];
131 	for (i = 0; i < nb_commit; i++) {
132 		start_dp[desc_idx].addr =
133 			VIRTIO_MBUF_DATA_DMA_ADDR(*tx_pkts, vq);
134 		start_dp[desc_idx].len = (*tx_pkts)->pkt_len;
135 		tx_pkts++;
136 		desc_idx++;
137 	}
138 
139 	rte_compiler_barrier();
140 
141 	vq->vq_free_cnt -= (uint16_t)(nb_pkts << 1);
142 	vq->vq_avail_idx += nb_pkts;
143 	vq->vq_ring.avail->idx = vq->vq_avail_idx;
144 	txvq->stats.packets += nb_pkts;
145 
146 	if (likely(nb_pkts)) {
147 		if (unlikely(virtqueue_kick_prepare(vq)))
148 			virtqueue_notify(vq);
149 	}
150 
151 	return nb_pkts;
152 }
153 
154 int __attribute__((cold))
155 virtio_rxq_vec_setup(struct virtnet_rx *rxq)
156 {
157 	uintptr_t p;
158 	struct rte_mbuf mb_def = { .buf_addr = 0 }; /* zeroed mbuf */
159 
160 	mb_def.nb_segs = 1;
161 	mb_def.data_off = RTE_PKTMBUF_HEADROOM;
162 	mb_def.port = rxq->port_id;
163 	rte_mbuf_refcnt_set(&mb_def, 1);
164 
165 	/* prevent compiler reordering: rearm_data covers previous fields */
166 	rte_compiler_barrier();
167 	p = (uintptr_t)&mb_def.rearm_data;
168 	rxq->mbuf_initializer = *(uint64_t *)p;
169 
170 	return 0;
171 }
172 
173 /* Stub for linkage when arch specific implementation is not available */
174 uint16_t __attribute__((weak))
175 virtio_recv_pkts_vec(void *rx_queue __rte_unused,
176 		     struct rte_mbuf **rx_pkts __rte_unused,
177 		     uint16_t nb_pkts __rte_unused)
178 {
179 	rte_panic("Wrong weak function linked by linker\n");
180 	return 0;
181 }
182