Add helper functions to set/clear and check descriptor flags.
Signed-off-by: Jens Freimann <jfreim...@redhat.com>
---
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
