On Mon, Apr 23, 2018 at 9:56 AM, Björn Töpel <[email protected]> wrote:
> From: Björn Töpel <[email protected]>
>
> Here the actual receive functions of AF_XDP are implemented, that in a
> later commit, will be called from the XDP layers.
>
> There's one set of functions for the XDP_DRV side and another for
> XDP_SKB (generic).
>
> Support for the poll syscall is also implemented.
>
> Signed-off-by: Björn Töpel <[email protected]>
> ---
> +/* Common functions operating for both RXTX and umem queues */
> +
> +static inline u32 xskq_nb_avail(struct xsk_queue *q, u32 dcnt)
> +{
> + u32 entries = q->prod_tail - q->cons_tail;
> +
> + if (entries == 0) {
> + /* Refresh the local pointer */
> + q->prod_tail = READ_ONCE(q->ring->producer);
> + }
> +
> + entries = q->prod_tail - q->cons_tail;
Probably meant to be inside the branch? Though I see the same
pattern in the userspace example program.
> +static inline u32 *xskq_validate_id(struct xsk_queue *q)
> +{
> + while (q->cons_tail != q->cons_head) {
> + struct xdp_umem_ring *ring = (struct xdp_umem_ring *)q->ring;
> + unsigned int idx = q->cons_tail & q->ring_mask;
> +
> + if (xskq_is_valid_id(q, ring->desc[idx]))
> + return &ring->desc[idx];
Missing a q->cons_tail increment in this loop?
