xen/9pfs: receive responses

static void p9_xen_response(struct work_struct *work)

{

	struct xen_9pfs_front_priv *priv;

	struct xen_9pfs_dataring *ring;

	RING_IDX cons, prod, masked_cons, masked_prod;

	struct xen_9pfs_header h;

	struct p9_req_t *req;

	int status;

	ring = container_of(work, struct xen_9pfs_dataring, work);

	priv = ring->priv;

	while (1) {

		cons = ring->intf->in_cons;

		prod = ring->intf->in_prod;

		virt_rmb();

		if (xen_9pfs_queued(prod, cons, XEN_9PFS_RING_SIZE) <

		    sizeof(h)) {

			notify_remote_via_irq(ring->irq);

			return;

		}

		masked_prod = xen_9pfs_mask(prod, XEN_9PFS_RING_SIZE);

		masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE);

		/* First, read just the header */

		xen_9pfs_read_packet(&h, ring->data.in, sizeof(h),

				     masked_prod, &masked_cons,

				     XEN_9PFS_RING_SIZE);

		req = p9_tag_lookup(priv->client, h.tag);

		if (!req || req->status != REQ_STATUS_SENT) {

			dev_warn(&priv->dev->dev, "Wrong req tag=%x\n", h.tag);

			cons += h.size;

			virt_mb();

			ring->intf->in_cons = cons;

			continue;

		}

		memcpy(req->rc, &h, sizeof(h));

		req->rc->offset = 0;

		masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE);

		/* Then, read the whole packet (including the header) */

		xen_9pfs_read_packet(req->rc->sdata, ring->data.in, h.size,

				     masked_prod, &masked_cons,

				     XEN_9PFS_RING_SIZE);

		virt_mb();

		cons += h.size;

		ring->intf->in_cons = cons;

		status = (req->status != REQ_STATUS_ERROR) ?

			REQ_STATUS_RCVD : REQ_STATUS_ERROR;

		p9_client_cb(priv->client, req, status);

	}

}

static irqreturn_t xen_9pfs_front_event_handler(int irq, void *r)