[v6,03/11] net/virtio: add packed virtqueue helpers
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Commit Message
Add helper functions to set/clear and check descriptor flags.
Signed-off-by: Jens Freimann <jfreimann@redhat.com>
---
drivers/net/virtio/virtio_ring.h | 26 ++++++++++++++++++++++++++
drivers/net/virtio/virtqueue.h | 11 +++++++++++
2 files changed, 37 insertions(+)
@@ -78,6 +78,8 @@ 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;
@@ -92,6 +94,30 @@ 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;
+
+ used = !!(desc->flags & VRING_DESC_F_USED(1));
+ avail = !!(desc->flags & VRING_DESC_F_AVAIL(1));
+
+ return used == avail && used == vr->used_wrap_counter;
+}
+
/* The standard layout for the ring is a continuous chunk of memory which
* looks like this. We assume num is a power of 2.
*
@@ -245,6 +245,17 @@ struct virtio_tx_region {
__attribute__((__aligned__(16)));
};
+static inline uint16_t
+update_pq_avail_index(struct virtqueue *vq)
+{
+ if (++vq->vq_avail_idx >= vq->vq_nentries) {
+ vq->vq_avail_idx = 0;
+ vq->vq_ring.avail_wrap_counter ^= 1;
+ }
+
+ return vq->vq_avail_idx;
+}
+
static inline void
vring_desc_init_packed(struct vring *vr, int n)
{