+static void netif_release_tx_bufs(struct netfront_info *np)
+{
+ struct sk_buff *skb;
+ int i;
+
+ for (i = 1; i <= NET_TX_RING_SIZE; i++) {
+ if ((unsigned long)np->tx_skbs[i] < PAGE_OFFSET)
+ continue;
+
+ skb = np->tx_skbs[i];
+ gnttab_end_foreign_access_ref(
+ np->grant_tx_ref[i], GNTMAP_readonly);
+ gnttab_release_grant_reference(
+ &np->gref_tx_head, np->grant_tx_ref[i]);
+ np->grant_tx_ref[i] = GRANT_INVALID_REF;
+ add_id_to_freelist(np->tx_skbs, i);
+ dev_kfree_skb_irq(skb);
+ }
+}
+
+static void netif_release_rx_bufs(struct netfront_info *np)
+{
+ struct mmu_update *mmu = np->rx_mmu;
+ struct multicall_entry *mcl = np->rx_mcl;
+ struct sk_buff_head free_list;
+ struct sk_buff *skb;
+ unsigned long mfn;
+ int xfer = 0, noxfer = 0, unused = 0;
+ int id, ref;
+
+ if (np->copying_receiver) {
+ printk("%s: fix me for copying receiver.\n", __FUNCTION__);
+ return;
+ }
+
+ skb_queue_head_init(&free_list);
+
+ spin_lock(&np->rx_lock);
+
+ for (id = 0; id < NET_RX_RING_SIZE; id++) {
+ if ((ref = np->grant_rx_ref[id]) == GRANT_INVALID_REF) {
+ unused++;
+ continue;
+ }
+
+ skb = np->rx_skbs[id];
+ mfn = gnttab_end_foreign_transfer_ref(ref);
+ gnttab_release_grant_reference(&np->gref_rx_head, ref);
+ np->grant_rx_ref[id] = GRANT_INVALID_REF;
+ add_id_to_freelist(np->rx_skbs, id);
+
+ if (0 == mfn) {
+ struct page *page = skb_shinfo(skb)->frags[0].page;
+ balloon_release_driver_page(page);
+ skb_shinfo(skb)->nr_frags = 0;
+ dev_kfree_skb(skb);
+ noxfer++;
+ continue;
+ }
+
+ if (!xen_feature(XENFEAT_auto_translated_physmap)) {
+ /* Remap the page. */
+ struct page *page = skb_shinfo(skb)->frags[0].page;
+ unsigned long pfn = page_to_pfn(page);
+ void *vaddr = page_address(page);
+
+ MULTI_update_va_mapping(mcl, (unsigned long)vaddr,
+ pfn_pte_ma(mfn, PAGE_KERNEL),
+ 0);
+ mcl++;
+ mmu->ptr = ((maddr_t)mfn << PAGE_SHIFT)
+ | MMU_MACHPHYS_UPDATE;
+ mmu->val = pfn;
+ mmu++;
+
+ set_phys_to_machine(pfn, mfn);
+ }
+ __skb_queue_tail(&free_list, skb);
+ xfer++;
+ }
+
+ printk("%s: %d xfer, %d noxfer, %d unused\n",
+ __FUNCTION__, xfer, noxfer, unused);
+
+ if (xfer) {
+ /* Some pages are no longer absent... */
+ balloon_update_driver_allowance(-xfer);
+
+ if (!xen_feature(XENFEAT_auto_translated_physmap)) {
+ /* Do all the remapping work and M2P updates. */
+ mcl->op = __HYPERVISOR_mmu_update;
+ mcl->args[0] = (unsigned long)np->rx_mmu;
+ mcl->args[1] = mmu - np->rx_mmu;
+ mcl->args[2] = 0;
+ mcl->args[3] = DOMID_SELF;
+ mcl++;
+ HYPERVISOR_multicall(np->rx_mcl, mcl - np->rx_mcl);
+ }
+ }
+
+ while ((skb = __skb_dequeue(&free_list)) != NULL)
+ dev_kfree_skb(skb);
+
+ spin_unlock(&np->rx_lock);
+}