[dpdk-dev] [PATCH 04/14] net/virtio: add packed virtqueue helpers
Jens Freimann
jfreimann at redhat.com
Mon Jan 29 15:11:33 CET 2018
Add helper functions to set/clear and check descriptor flags.
Signed-off-by: Jens Freimann <jfreimann at redhat.com>
---
drivers/net/virtio/virtio_ring.h | 32 ++++++++++++++++++++++++++++++++
drivers/net/virtio/virtqueue.c | 3 +++
2 files changed, 35 insertions(+)
diff --git a/drivers/net/virtio/virtio_ring.h b/drivers/net/virtio/virtio_ring.h
index 839359444..47df96aac 100644
--- a/drivers/net/virtio/virtio_ring.h
+++ b/drivers/net/virtio/virtio_ring.h
@@ -74,12 +74,44 @@ struct vring_desc_1_1 {
struct vring {
unsigned int num;
+ unsigned int avail_wrap_counter;
struct vring_desc *desc;
struct vring_avail *avail;
struct vring_used *used;
struct vring_desc_1_1 *desc_1_1;
};
+static inline void toggle_wrap_counter(struct vring *vr)
+{
+ vr->avail_wrap_counter ^= 1;
+}
+
+static inline void _set_desc_avail(struct vring_desc_1_1 *desc,
+ int wrap_counter)
+{
+ uint16_t flags = desc->flags;
+
+ if (wrap_counter) {
+ flags |= DESC_AVAIL;
+ flags &= ~DESC_USED;
+ } else {
+ flags &= ~DESC_AVAIL;
+ flags |= DESC_USED;
+ }
+
+ desc->flags = flags;
+}
+
+static inline void set_desc_avail(struct vring *vr, struct vring_desc_1_1 *desc)
+{
+ _set_desc_avail(desc, vr->avail_wrap_counter);
+}
+
+static inline int desc_is_used(struct vring_desc_1_1 *desc)
+{
+ return !(desc->flags & DESC_AVAIL) == !(desc->flags & DESC_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.
*
diff --git a/drivers/net/virtio/virtqueue.c b/drivers/net/virtio/virtqueue.c
index 1ada4fe08..052444756 100644
--- a/drivers/net/virtio/virtqueue.c
+++ b/drivers/net/virtio/virtqueue.c
@@ -43,6 +43,9 @@ virtqueue_rxvq_flush(struct virtqueue *vq)
uint16_t used_idx, desc_idx;
uint16_t nb_used, i;
+ if (vtpci_packed_queue(vq->hw))
+ return;
+
nb_used = VIRTQUEUE_NUSED(vq);
for (i = 0; i < nb_used; i++) {
--
2.14.3
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