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#include <stdint.h>
34
35#include <rte_mbuf.h>
36
37#include "virtqueue.h"
38#include "virtio_logs.h"
39#include "virtio_pci.h"
40#include "virtio_rxtx_simple.h"
41
42void
43virtqueue_disable_intr(struct virtqueue *vq)
44{
45	/*
46	 * Set VRING_AVAIL_F_NO_INTERRUPT to hint host
47	 * not to interrupt when it consumes packets
48	 * Note: this is only considered a hint to the host
49	 */
50	vq->vq_ring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
51}
52
53/*
54 * Two types of mbuf to be cleaned:
55 * 1) mbuf that has been consumed by backend but not used by virtio.
56 * 2) mbuf that hasn't been consued by backend.
57 */
58struct rte_mbuf *
59virtqueue_detach_unused(struct virtqueue *vq)
60{
61	struct rte_mbuf *cookie;
62	struct virtio_hw *hw;
63	uint16_t start, end;
64	int type, idx;
65
66	if (vq == NULL)
67		return NULL;
68
69	hw = vq->hw;
70	type = virtio_get_queue_type(hw, vq->vq_queue_index);
71	start = vq->vq_avail_idx & (vq->vq_nentries - 1);
72	end = (vq->vq_avail_idx + vq->vq_free_cnt) & (vq->vq_nentries - 1);
73
74	for (idx = 0; idx < vq->vq_nentries; idx++) {
75		if (hw->use_simple_rxtx && type == VTNET_RQ) {
76			if (start <= end && idx >= start && idx < end)
77				continue;
78			if (start > end && (idx >= start || idx < end))
79				continue;
80			cookie = vq->sw_ring[idx];
81			if (cookie != NULL) {
82				vq->sw_ring[idx] = NULL;
83				return cookie;
84			}
85		} else {
86			cookie = vq->vq_descx[idx].cookie;
87			if (cookie != NULL) {
88				vq->vq_descx[idx].cookie = NULL;
89				return cookie;
90			}
91		}
92	}
93
94	return NULL;
95}
96
97/* Flush the elements in the used ring. */
98void
99virtqueue_rxvq_flush(struct virtqueue *vq)
100{
101	struct virtnet_rx *rxq = &vq->rxq;
102	struct virtio_hw *hw = vq->hw;
103	struct vring_used_elem *uep;
104	struct vq_desc_extra *dxp;
105	uint16_t used_idx, desc_idx;
106	uint16_t nb_used, i;
107
108	nb_used = VIRTQUEUE_NUSED(vq);
109
110	for (i = 0; i < nb_used; i++) {
111		used_idx = vq->vq_used_cons_idx & (vq->vq_nentries - 1);
112		uep = &vq->vq_ring.used->ring[used_idx];
113		if (hw->use_simple_rxtx) {
114			desc_idx = used_idx;
115			rte_pktmbuf_free(vq->sw_ring[desc_idx]);
116			vq->vq_free_cnt++;
117		} else {
118			desc_idx = (uint16_t)uep->id;
119			dxp = &vq->vq_descx[desc_idx];
120			if (dxp->cookie != NULL) {
121				rte_pktmbuf_free(dxp->cookie);
122				dxp->cookie = NULL;
123			}
124			vq_ring_free_chain(vq, desc_idx);
125		}
126		vq->vq_used_cons_idx++;
127	}
128
129	if (hw->use_simple_rxtx) {
130		while (vq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
131			virtio_rxq_rearm_vec(rxq);
132			if (virtqueue_kick_prepare(vq))
133				virtqueue_notify(vq);
134		}
135	}
136}
137