From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Freimann Subject: [PATCH v8 3/8] net/virtio: add packed virtqueue helpers Date: Tue, 16 Oct 2018 11:01:29 +0200 Message-ID: <20181016090134.29448-4-jfreimann@redhat.com> References: <20181016090134.29448-1-jfreimann@redhat.com> Cc: tiwei.bie@intel.com, maxime.coquelin@redhat.com, Gavin.Hu@arm.com To: dev@dpdk.org Return-path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id DF42F4F91 for ; Tue, 16 Oct 2018 11:01:58 +0200 (CEST) In-Reply-To: <20181016090134.29448-1-jfreimann@redhat.com> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Add helper functions to set/clear and check descriptor flags. Signed-off-by: Jens Freimann --- drivers/net/virtio/virtio_ring.h | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/drivers/net/virtio/virtio_ring.h b/drivers/net/virtio/virtio_ring.h index f84ab5e34..44cb6eb04 100644 --- a/drivers/net/virtio/virtio_ring.h +++ b/drivers/net/virtio/virtio_ring.h @@ -77,6 +77,8 @@ struct vring_packed_desc_event { struct vring { unsigned int num; + unsigned int avail_wrap_counter; + unsigned int used_wrap_counter; union { struct vring_desc_packed *desc_packed; struct vring_desc *desc; @@ -91,6 +93,35 @@ struct vring { }; }; +static inline void +_set_desc_avail(struct vring_desc_packed *desc, int wrap_counter) +{ + desc->flags |= VRING_DESC_F_AVAIL(wrap_counter) | + VRING_DESC_F_USED(!wrap_counter); +} + +static inline void +set_desc_avail(struct vring *vr, struct vring_desc_packed *desc) +{ + _set_desc_avail(desc, vr->avail_wrap_counter); +} + +static inline int +desc_is_used(struct vring_desc_packed *desc, struct vring *vr) +{ + uint16_t used, avail, flags; + bool is_used; + + rte_smp_mb(); + flags = desc->flags; + avail = !!(flags & VRING_DESC_F_AVAIL(1)); + used = !!(flags & VRING_DESC_F_USED(1)); + is_used = used == avail && used == vr->used_wrap_counter; + rte_smp_rmb(); + + return is_used; +} + /* The standard layout for the ring is a continuous chunk of memory which * looks like this. We assume num is a power of 2. * -- 2.17.1