diff mbox

[dpdk-dev,11/14] vhost: add helpers for packed virtqueues

Message ID 20180129141143.13437-12-jfreimann@redhat.com (mailing list archive)
State Superseded, archived
Delegated to: Maxime Coquelin
Headers

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Jens Freimann Jan. 29, 2018, 2:11 p.m. UTC 
  Add some helper functions to set/check descriptor flags
and toggle the used wrap counter.

Signed-off-by: Jens Freimann <jfreimann@redhat.com>
---
 lib/librte_vhost/virtio-1.1.h | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

Comments

Maxime Coquelin Feb. 1, 2018, 9:20 a.m. UTC | #1 
On 01/29/2018 03:11 PM, Jens Freimann wrote:
> Add some helper functions to set/check descriptor flags
> and toggle the used wrap counter.
> 
> Signed-off-by: Jens Freimann<jfreimann@redhat.com>
> ---
>   lib/librte_vhost/virtio-1.1.h | 43 +++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 43 insertions(+)
> 
> diff --git a/lib/librte_vhost/virtio-1.1.h b/lib/librte_vhost/virtio-1.1.h
> index 5ca0bc33f..84039797e 100644
> --- a/lib/librte_vhost/virtio-1.1.h
> +++ b/lib/librte_vhost/virtio-1.1.h
> @@ -17,4 +17,47 @@ struct vring_desc_1_1 {
>   	uint16_t flags;
>   };
>   
> +static inline void
> +toggle_wrap_counter(struct vhost_virtqueue *vq)
> +{
> +	vq->used_wrap_counter ^= 1;
> +}
> +
> +static inline int
> +desc_is_avail(struct vhost_virtqueue *vq, struct vring_desc_1_1 *desc)
> +{
> +	if (!vq)
> +		return -1;

Maybe use unlikely() here?

Maxime
diff mbox

Patch

diff --git a/lib/librte_vhost/virtio-1.1.h b/lib/librte_vhost/virtio-1.1.h
index 5ca0bc33f..84039797e 100644
--- a/lib/librte_vhost/virtio-1.1.h
+++ b/lib/librte_vhost/virtio-1.1.h
@@ -17,4 +17,47 @@  struct vring_desc_1_1 {
 	uint16_t flags;
 };
 
+static inline void
+toggle_wrap_counter(struct vhost_virtqueue *vq)
+{
+	vq->used_wrap_counter ^= 1;
+}
+
+static inline int
+desc_is_avail(struct vhost_virtqueue *vq, struct vring_desc_1_1 *desc)
+{
+	if (!vq)
+		return -1;
+
+	if (vq->used_wrap_counter == 1)
+		if ((desc->flags & DESC_AVAIL) && !(desc->flags & DESC_USED))
+			return 1;
+	if (vq->used_wrap_counter == 0)
+		if (!(desc->flags & DESC_AVAIL) && (desc->flags & DESC_USED))
+			return 1;
+	return 0;
+}
+
+static inline void
+_set_desc_used(struct vring_desc_1_1 *desc, int wrap_counter)
+{
+	uint16_t flags = desc->flags;
+
+	if (wrap_counter == 1) {
+		flags |= DESC_USED;
+		flags |= DESC_AVAIL;
+	} else {
+		flags &= ~DESC_USED;
+		flags &= ~DESC_AVAIL;
+	}
+
+	desc->flags = flags;
+}
+
+static inline void
+set_desc_used(struct vhost_virtqueue *vq, struct vring_desc_1_1 *desc)
+{
+	_set_desc_used(desc, vq->used_wrap_counter);
+}
+
 #endif /* __VIRTIO_1_1_H */