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 <ericvh@gmail.com>
CC: Ron Minnich <rminnich@sandia.gov>
CC: Latchesar Ionkov <lucho@ionkov.net>
CC: v9fs-developer@lists.sourceforge.net

Signed-off-by: Stefano Stabellini <stefano@aporeto.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
This commit is contained in:
Stefano Stabellini 2017-04-05 12:04:00 -07:00 committed by Juergen Gross
parent f023f18ddf
commit f66c72bea1
1 changed files with 56 additions and 0 deletions

View File

@ -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)