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(); /* 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)); xennet_maybe_wake_tx(dev); }
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); }