From f66c72bea1293786b9916894019f96bcd729505b Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Wed, 5 Apr 2017 12:04:00 -0700 Subject: [PATCH] xen/9pfs: receive responses Upon receiving a notification from the backend, schedule the p9_xen_response work_struct. p9_xen_response checks if any responses are available, if so, it reads them one by one, calling p9_client_cb to send them up to the 9p layer (p9_client_cb completes the request). Handle the ring following the Xen 9pfs specification. CC: groug@kaod.org CC: jgross@suse.com CC: Eric Van Hensbergen CC: Ron Minnich CC: Latchesar Ionkov CC: v9fs-developer@lists.sourceforge.net Signed-off-by: Stefano Stabellini Reviewed-by: Boris Ostrovsky Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross --- net/9p/trans_xen.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c index 28f30f49d5dd..47864245c0d4 100644 --- a/net/9p/trans_xen.c +++ b/net/9p/trans_xen.c @@ -189,6 +189,62 @@ again: 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)