void gnttab_end_foreign_access(grant_ref_t ref, int readonly,
unsigned long page)
{
if (gnttab_end_foreign_access_ref(ref, readonly)) {
put_free_entry(ref);
if (page != 0)
free_page(page);
} else {
/* XXX This needs to be fixed so that the ref and page are
placed on a list to be freed up later. */
printk(KERN_WARNING
"WARNING: leaking g.e. and page still in use!\n");
}
}
void
gnttab_end_foreign_access(grant_ref_t ref, void *page)
{
if (gnttab_end_foreign_access_ref(ref)) {
put_free_entry(ref);
if (page != NULL) {
free(page, M_DEVBUF);
}
}
else {
/* XXX This needs to be fixed so that the ref and page are
placed on a list to be freed up later. */
printf("WARNING: leaking g.e. and page still in use!\n");
}
}
static void xennet_tx_buf_gc(struct net_device *dev)
{
RING_IDX cons, prod;
unsigned short id;
struct netfront_info *np = netdev_priv(dev);
struct sk_buff *skb;
BUG_ON(!netif_carrier_ok(dev));
do {
prod = np->tx.sring->rsp_prod;
rmb();
for (cons = np->tx.rsp_cons; cons != prod; cons++) {
struct xen_netif_tx_response *txrsp;
txrsp = RING_GET_RESPONSE(&np->tx, cons);
if (txrsp->status == NETIF_RSP_NULL)
continue;
id = txrsp->id;
skb = np->tx_skbs[id].skb;
if (unlikely(gnttab_query_foreign_access(
np->grant_tx_ref[id]) != 0)) {
printk(KERN_ALERT "xennet_tx_buf_gc: warning "
"-- grant still in use by backend "
"domain.\n");
BUG();
}
gnttab_end_foreign_access_ref(
np->grant_tx_ref[id], GNTMAP_readonly);
gnttab_release_grant_reference(
&np->gref_tx_head, np->grant_tx_ref[id]);
np->grant_tx_ref[id] = GRANT_INVALID_REF;
add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, id);
dev_kfree_skb_irq(skb);
}
np->tx.rsp_cons = prod;
np->tx.sring->rsp_event =
prod + ((np->tx.sring->req_prod - prod) >> 1) + 1;
mb();
} while ((cons == prod) && (prod != np->tx.sring->rsp_prod));
xennet_maybe_wake_tx(dev);
}
static int xenkbd_connect_backend(struct xenbus_device *dev,
struct xenkbd_info *info)
{
int ret, evtchn;
struct xenbus_transaction xbt;
ret = gnttab_grant_foreign_access(dev->otherend_id,
virt_to_mfn(info->page), 0);
if (ret < 0)
return ret;
info->gref = ret;
ret = xenbus_alloc_evtchn(dev, &evtchn);
if (ret)
goto error_grant;
ret = bind_evtchn_to_irqhandler(evtchn, input_handler,
0, dev->devicetype, info);
if (ret < 0) {
xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
goto error_evtchan;
}
info->irq = ret;
again:
ret = xenbus_transaction_start(&xbt);
if (ret) {
xenbus_dev_fatal(dev, ret, "starting transaction");
goto error_irqh;
}
ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu",
virt_to_mfn(info->page));
if (ret)
goto error_xenbus;
ret = xenbus_printf(xbt, dev->nodename, "page-gref", "%u", info->gref);
if (ret)
goto error_xenbus;
ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
evtchn);
if (ret)
goto error_xenbus;
ret = xenbus_transaction_end(xbt, 0);
if (ret) {
if (ret == -EAGAIN)
goto again;
xenbus_dev_fatal(dev, ret, "completing transaction");
goto error_irqh;
}
xenbus_switch_state(dev, XenbusStateInitialised);
return 0;
error_xenbus:
xenbus_transaction_end(xbt, 1);
xenbus_dev_fatal(dev, ret, "writing xenstore");
error_irqh:
unbind_from_irqhandler(info->irq, info);
info->irq = -1;
error_evtchan:
xenbus_free_evtchn(dev, evtchn);
error_grant:
gnttab_end_foreign_access_ref(info->gref, 0);
info->gref = -1;
return ret;
}
static int xennet_tx_buf_gc(struct net_device *dev)
{
RING_IDX cons, prod;
RING_IDX cons_begin, cons_end;
unsigned short id;
struct netfront_info *np = netdev_priv(dev);
struct sk_buff *skb;
BUG_ON(!netif_carrier_ok(dev));
cons_begin = np->tx.rsp_cons;
do {
prod = np->tx.sring->rsp_prod;
rmb(); /* Ensure we see responses up to 'rp'. */
for (cons = np->tx.rsp_cons; cons != prod; cons++) {
struct xen_netif_tx_response *txrsp;
txrsp = RING_GET_RESPONSE(&np->tx, cons);
if (txrsp->status == NETIF_RSP_NULL)
continue;
id = txrsp->id;
skb = np->tx_skbs[id].skb;
if (unlikely(gnttab_query_foreign_access(
np->grant_tx_ref[id]) != 0)) {
printk(KERN_ALERT "xennet_tx_buf_gc: warning "
"-- grant still in use by backend "
"domain.\n");
BUG();
}
gnttab_end_foreign_access_ref(
np->grant_tx_ref[id], GNTMAP_readonly);
gnttab_release_grant_reference(
&np->gref_tx_head, np->grant_tx_ref[id]);
np->grant_tx_ref[id] = GRANT_INVALID_REF;
add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, id);
dev_kfree_skb_irq(skb);
}
np->tx.rsp_cons = prod;
/*
* Set a new event, then check for race with update of tx_cons.
* Note that it is essential to schedule a callback, no matter
* how few buffers are pending. Even if there is space in the
* transmit ring, higher layers may be blocked because too much
* data is outstanding: in such cases notification from Xen is
* likely to be the only kick that we'll get.
*/
np->tx.sring->rsp_event =
prod + ((np->tx.sring->req_prod - prod) >> 1) + 1;
mb(); /* update shared area */
} while ((cons == prod) && (prod != np->tx.sring->rsp_prod));
cons_end = np->tx.rsp_cons;
xennet_maybe_wake_tx(dev);
return (cons_begin == cons_end);
}
