ceph/src/dpdk/drivers/net/virtio/virtqueue.c

   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
  41 void
  42 virtqueue_disable_intr(struct virtqueue *vq)
  43 {
  44         /*
  45          * Set VRING_AVAIL_F_NO_INTERRUPT to hint host
  46          * not to interrupt when it consumes packets
  47          * Note: this is only considered a hint to the host
  48          */
  49         vq->vq_ring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
  50 }
  51
  52 /*
  53  * Two types of mbuf to be cleaned:
  54  * 1) mbuf that has been consumed by backend but not used by virtio.
  55  * 2) mbuf that hasn't been consued by backend.
  56  */
  57 struct rte_mbuf *
  58 virtqueue_detatch_unused(struct virtqueue *vq)
  59 {
  60         struct rte_mbuf *cookie;
  61         int idx;
  62
  63         if (vq != NULL)
  64                 for (idx = 0; idx < vq->vq_nentries; idx++) {
  65                         cookie = vq->vq_descx[idx].cookie;
  66                         if (cookie != NULL) {
  67                                 vq->vq_descx[idx].cookie = NULL;
  68                                 return cookie;
  69                         }
  70                 }
  71         return NULL;
  72 }