The network device frontend driver allows the kernel to access network devices exported exported by a virtual machine containing a physical network device driver. Signed-off-by: Ian Pratt Signed-off-by: Christian Limpach Signed-off-by: Chris Wright Cc: netdev@vger.kernel.org --- drivers/net/Kconfig | 2 drivers/xen/Kconfig.net | 14 drivers/xen/Makefile | 3 drivers/xen/net_driver_util.c | 58 + drivers/xen/netfront/Makefile | 4 drivers/xen/netfront/netfront.c | 1326 ++++++++++++++++++++++++++++++++++++++++ include/xen/net_driver_util.h | 48 + 7 files changed, 1455 insertions(+) diff -r eadc12b20f35 drivers/net/Kconfig --- a/drivers/net/Kconfig Fri Jun 09 15:02:44 2006 -0400 +++ b/drivers/net/Kconfig Fri Jun 09 15:03:12 2006 -0400 @@ -2325,6 +2325,8 @@ source "drivers/atm/Kconfig" source "drivers/s390/net/Kconfig" +source "drivers/xen/Kconfig.net" + config ISERIES_VETH tristate "iSeries Virtual Ethernet driver support" depends on PPC_ISERIES diff -r eadc12b20f35 drivers/xen/Makefile --- a/drivers/xen/Makefile Fri Jun 09 15:02:44 2006 -0400 +++ b/drivers/xen/Makefile Fri Jun 09 15:03:12 2006 -0400 @@ -5,3 +5,5 @@ obj-y += console/ obj-y += console/ obj-y += xenbus/ +obj-$(CONFIG_XEN_NETDEV_FRONTEND) += netfront/ + diff -r eadc12b20f35 drivers/xen/Kconfig.net --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/drivers/xen/Kconfig.net Fri Jun 09 15:03:12 2006 -0400 @@ -0,0 +1,14 @@ +menu "Xen network device drivers" + depends on NETDEVICES && XEN + +config XEN_NETDEV_FRONTEND + tristate "Network-device frontend driver" + depends on XEN + default y + help + The network-device frontend driver allows the kernel to access + network interfaces within another guest OS. Unless you are building a + dedicated device-driver domain, or your master control domain + (domain 0), then you almost certainly want to say Y here. + +endmenu diff -r eadc12b20f35 drivers/xen/netfront/Makefile --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/drivers/xen/netfront/Makefile Fri Jun 09 15:03:12 2006 -0400 @@ -0,0 +1,4 @@ + +obj-$(CONFIG_XEN_NETDEV_FRONTEND) := xennet.o + +xennet-objs := netfront.o diff -r eadc12b20f35 drivers/xen/netfront/netfront.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/drivers/xen/netfront/netfront.c Fri Jun 09 15:03:12 2006 -0400 @@ -0,0 +1,1584 @@ +/****************************************************************************** + * Virtual network driver for conversing with remote driver backends. + * + * Copyright (c) 2002-2005, K A Fraser + * Copyright (c) 2005, XenSource Ltd + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation; or, when distributed + * separately from the Linux kernel or incorporated into other + * software packages, subject to the following license: + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this source file (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, modify, + * merge, publish, distribute, sublicense, and/or sell copies of the Software, + * and to permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#ifdef CONFIG_XEN_BALLOON +#include +#endif +#include +#include +#include +#include + +#define GRANT_INVALID_REF 0 + +#define NET_TX_RING_SIZE __RING_SIZE((struct netif_tx_sring *)0, PAGE_SIZE) +#define NET_RX_RING_SIZE __RING_SIZE((struct netif_rx_sring *)0, PAGE_SIZE) + +static inline void init_skb_shinfo(struct sk_buff *skb) +{ + atomic_set(&(skb_shinfo(skb)->dataref), 1); + skb_shinfo(skb)->nr_frags = 0; + skb_shinfo(skb)->frag_list = NULL; +} + +struct netfront_info { + struct list_head list; + struct net_device *netdev; + + struct net_device_stats stats; + + struct netif_tx_front_ring tx; + struct netif_rx_front_ring rx; + + spinlock_t tx_lock; + spinlock_t rx_lock; + + unsigned int handle; + unsigned int evtchn, irq; + + /* Receive-ring batched refills. */ +#define RX_MIN_TARGET 8 +#define RX_DFL_MIN_TARGET 64 +#define RX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256) + unsigned rx_min_target, rx_max_target, rx_target; + struct sk_buff_head rx_batch; + + struct timer_list rx_refill_timer; + + /* + * {tx,rx}_skbs store outstanding skbuffs. The first entry in each + * array is an index into a chain of free entries. + */ + struct sk_buff *tx_skbs[NET_TX_RING_SIZE+1]; + struct sk_buff *rx_skbs[NET_RX_RING_SIZE+1]; + +#define TX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256) + grant_ref_t gref_tx_head; + grant_ref_t grant_tx_ref[NET_TX_RING_SIZE + 1]; + grant_ref_t gref_rx_head; + grant_ref_t grant_rx_ref[NET_TX_RING_SIZE + 1]; + + struct xenbus_device *xbdev; + int tx_ring_ref; + int rx_ring_ref; + u8 mac[ETH_ALEN]; + + unsigned long rx_pfn_array[NET_RX_RING_SIZE]; + struct multicall_entry rx_mcl[NET_RX_RING_SIZE+1]; + struct mmu_update rx_mmu[NET_RX_RING_SIZE]; +}; + +/* + * Access macros for acquiring freeing slots in {tx,rx}_skbs[]. + */ + +static inline void add_id_to_freelist(struct sk_buff **list, unsigned short id) +{ + list[id] = list[0]; + list[0] = (void *)(unsigned long)id; +} + +static inline unsigned short get_id_from_freelist(struct sk_buff **list) +{ + unsigned int id = (unsigned int)(unsigned long)list[0]; + list[0] = list[id]; + return id; +} + +#define DPRINTK(fmt, args...) pr_debug("netfront (%s:%d) " fmt, \ + __FUNCTION__, __LINE__, ##args) +#define IPRINTK(fmt, args...) \ + printk(KERN_INFO "netfront: " fmt, ##args) +#define WPRINTK(fmt, args...) \ + printk(KERN_WARNING "netfront: " fmt, ##args) + + +static int talk_to_backend(struct xenbus_device *, struct netfront_info *); +static int setup_device(struct xenbus_device *, struct netfront_info *); +static struct net_device *create_netdev(int, struct xenbus_device *); + +static void netfront_closing(struct xenbus_device *); + +static void end_access(int, void *); +static void netif_disconnect_backend(struct netfront_info *); +static void close_netdev(struct netfront_info *); +static void netif_free(struct netfront_info *); + +static void show_device(struct netfront_info *); + +static void network_connect(struct net_device *); +static void network_tx_buf_gc(struct net_device *); +static void network_alloc_rx_buffers(struct net_device *); +static int send_fake_arp(struct net_device *); + +static irqreturn_t netif_int(int irq, void *dev_id, struct pt_regs *ptregs); + +#ifdef CONFIG_SYSFS +static int xennet_sysfs_addif(struct net_device *netdev); +static void xennet_sysfs_delif(struct net_device *netdev); +#else /* !CONFIG_SYSFS */ +#define xennet_sysfs_addif(dev) (0) +#define xennet_sysfs_delif(dev) do { } while(0) +#endif + +static inline int xennet_can_sg(struct net_device *dev) +{ + return dev->features & NETIF_F_SG; +} + +/** + * Entry point to this code when a new device is created. Allocate the basic + * structures and the ring buffers for communication with the backend, and + * inform the backend of the appropriate details for those. Switch to + * Connected state. + */ +static int __devinit netfront_probe(struct xenbus_device *dev, + const struct xenbus_device_id *id) +{ + int err; + struct net_device *netdev; + struct netfront_info *info; + unsigned int handle; + + err = xenbus_scanf(XBT_NIL, dev->nodename, "handle", "%u", &handle); + if (err != 1) { + xenbus_dev_fatal(dev, err, "reading handle"); + return err; + } + + netdev = create_netdev(handle, dev); + if (IS_ERR(netdev)) { + err = PTR_ERR(netdev); + xenbus_dev_fatal(dev, err, "creating netdev"); + return err; + } + + info = netdev_priv(netdev); + dev->dev.driver_data = info; + + err = talk_to_backend(dev, info); + if (err) { + xennet_sysfs_delif(info->netdev); + unregister_netdev(netdev); + free_netdev(netdev); + dev->dev.driver_data = NULL; + return err; + } + + return 0; +} + + +/** + * We are reconnecting to the backend, due to a suspend/resume, or a backend + * driver restart. We tear down our netif structure and recreate it, but + * leave the device-layer structures intact so that this is transparent to the + * rest of the kernel. + */ +static int netfront_resume(struct xenbus_device *dev) +{ + struct netfront_info *info = dev->dev.driver_data; + + DPRINTK("%s\n", dev->nodename); + + netif_disconnect_backend(info); + return talk_to_backend(dev, info); +} + +static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[]) +{ + char *s, *e, *macstr; + int i; + + macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL); + if (IS_ERR(macstr)) + return PTR_ERR(macstr); + + for (i = 0; i < ETH_ALEN; i++) { + mac[i] = simple_strtoul(s, &e, 16); + if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) { + kfree(macstr); + return -ENOENT; + } + s = e+1; + } + + kfree(macstr); + return 0; +} + +/* Common code used when first setting up, and when resuming. */ +static int talk_to_backend(struct xenbus_device *dev, + struct netfront_info *info) +{ + const char *message; + struct xenbus_transaction xbt; + int err; + + err = xen_net_read_mac(dev, info->mac); + if (err) { + xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename); + goto out; + } + + /* Create shared ring, alloc event channel. */ + err = setup_device(dev, info); + if (err) + goto out; + +again: + err = xenbus_transaction_start(&xbt); + if (err) { + xenbus_dev_fatal(dev, err, "starting transaction"); + goto destroy_ring; + } + + err = xenbus_printf(xbt, dev->nodename, "tx-ring-ref","%u", + info->tx_ring_ref); + if (err) { + message = "writing tx ring-ref"; + goto abort_transaction; + } + err = xenbus_printf(xbt, dev->nodename, "rx-ring-ref","%u", + info->rx_ring_ref); + if (err) { + message = "writing rx ring-ref"; + goto abort_transaction; + } + err = xenbus_printf(xbt, dev->nodename, + "event-channel", "%u", info->evtchn); + if (err) { + message = "writing event-channel"; + goto abort_transaction; + } + + err = xenbus_transaction_end(xbt, 0); + if (err) { + if (err == -EAGAIN) + goto again; + xenbus_dev_fatal(dev, err, "completing transaction"); + goto destroy_ring; + } + + return 0; + + abort_transaction: + xenbus_transaction_end(xbt, 1); + xenbus_dev_fatal(dev, err, "%s", message); + destroy_ring: + netif_free(info); + out: + return err; +} + + +static int setup_device(struct xenbus_device *dev, struct netfront_info *info) +{ + struct netif_tx_sring *txs; + struct netif_rx_sring *rxs; + int err; + struct net_device *netdev = info->netdev; + + info->tx_ring_ref = GRANT_INVALID_REF; + info->rx_ring_ref = GRANT_INVALID_REF; + info->rx.sring = NULL; + info->tx.sring = NULL; + info->irq = 0; + + txs = (struct netif_tx_sring *)get_zeroed_page(GFP_KERNEL); + if (!txs) { + err = -ENOMEM; + xenbus_dev_fatal(dev, err, "allocating tx ring page"); + goto fail; + } + SHARED_RING_INIT(txs); + FRONT_RING_INIT(&info->tx, txs, PAGE_SIZE); + + err = xenbus_grant_ring(dev, virt_to_mfn(txs)); + if (err < 0) { + free_page((unsigned long)txs); + goto fail; + } + + info->tx_ring_ref = err; + rxs = (struct netif_rx_sring *)get_zeroed_page(GFP_KERNEL); + if (!rxs) { + err = -ENOMEM; + xenbus_dev_fatal(dev, err, "allocating rx ring page"); + goto fail; + } + SHARED_RING_INIT(rxs); + FRONT_RING_INIT(&info->rx, rxs, PAGE_SIZE); + + err = xenbus_grant_ring(dev, virt_to_mfn(rxs)); + if (err < 0) { + free_page((unsigned long)rxs); + goto fail; + } + info->rx_ring_ref = err; + + err = xenbus_alloc_evtchn(dev, &info->evtchn); + if (err) + goto fail; + + memcpy(netdev->dev_addr, info->mac, ETH_ALEN); + err = bind_evtchn_to_irqhandler(info->evtchn, netif_int, + SA_SAMPLE_RANDOM, netdev->name, netdev); + if (err < 0) + goto fail; + info->irq = err; + return 0; + + fail: + netif_free(info); + return err; +} + + +/** + * Callback received when the backend's state changes. + */ +static void backend_changed(struct xenbus_device *dev, + enum xenbus_state backend_state) +{ + struct netfront_info *np = dev->dev.driver_data; + struct net_device *netdev = np->netdev; + + DPRINTK("\n"); + + switch (backend_state) { + case XenbusStateInitialising: + case XenbusStateInitialised: + case XenbusStateConnected: + case XenbusStateUnknown: + case XenbusStateClosed: + break; + + case XenbusStateInitWait: + network_connect(netdev); + xenbus_switch_state(dev, XenbusStateConnected); + (void)send_fake_arp(netdev); + show_device(np); + break; + + case XenbusStateClosing: + netfront_closing(dev); + break; + } +} + + +/** Send a packet on a net device to encourage switches to learn the + * MAC. We send a fake ARP request. + * + * @param dev device + * @return 0 on success, error code otherwise + */ +static int send_fake_arp(struct net_device *dev) +{ + struct sk_buff *skb; + u32 src_ip, dst_ip; + + dst_ip = INADDR_BROADCAST; + src_ip = inet_select_addr(dev, dst_ip, RT_SCOPE_LINK); + + /* No IP? Then nothing to do. */ + if (src_ip == 0) + return 0; + + skb = arp_create(ARPOP_REPLY, ETH_P_ARP, + dst_ip, dev, src_ip, + /*dst_hw*/ NULL, /*src_hw*/ NULL, + /*target_hw*/ dev->dev_addr); + if (skb == NULL) + return -ENOMEM; + + return dev_queue_xmit(skb); +} + + +static int network_open(struct net_device *dev) +{ + struct netfront_info *np = netdev_priv(dev); + + memset(&np->stats, 0, sizeof(np->stats)); + + network_alloc_rx_buffers(dev); + np->rx.sring->rsp_event = np->rx.rsp_cons + 1; + + netif_start_queue(dev); + + return 0; +} + +static inline int netfront_tx_slot_available(struct netfront_info *np) +{ + return RING_FREE_REQUESTS(&np->tx) >= MAX_SKB_FRAGS + 1; +} + +static inline void network_maybe_wake_tx(struct net_device *dev) +{ + struct netfront_info *np = netdev_priv(dev); + + if (unlikely(netif_queue_stopped(dev)) && + netfront_tx_slot_available(np) && + likely(netif_running(dev))) + netif_wake_queue(dev); +} + +static void network_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; + + if (unlikely(!netif_carrier_ok(dev))) + return; + + do { + prod = np->tx.sring->rsp_prod; + rmb(); /* Ensure we see responses up to 'rp'. */ + + for (cons = np->tx.rsp_cons; cons != prod; cons++) { + id = RING_GET_RESPONSE(&np->tx, cons)->id; + skb = np->tx_skbs[id]; + if (unlikely(gnttab_query_foreign_access( + np->grant_tx_ref[id]) != 0)) { + printk(KERN_ALERT "network_tx_buf_gc: warning " + "-- grant still in use by backend " + "domain.\n"); + break; /* bail immediately */ + } + 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_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(); + } while ((cons == prod) && (prod != np->tx.sring->rsp_prod)); + + network_maybe_wake_tx(dev); +} + + +static void rx_refill_timeout(unsigned long data) +{ + struct net_device *dev = (struct net_device *)data; + netif_rx_schedule(dev); +} + + +static void network_alloc_rx_buffers(struct net_device *dev) +{ + unsigned short id; + struct netfront_info *np = netdev_priv(dev); + struct sk_buff *skb; + int i, batch_target; + RING_IDX req_prod = np->rx.req_prod_pvt; + struct xen_memory_reservation reservation; + grant_ref_t ref; + + if (unlikely(!netif_carrier_ok(dev))) + return; + + /* + * Allocate skbuffs greedily, even though we batch updates to the + * receive ring. This creates a less bursty demand on the memory + * allocator, so should reduce the chance of failed allocation requests + * both for ourself and for other kernel subsystems. + */ + batch_target = np->rx_target - (req_prod - np->rx.rsp_cons); + for (i = skb_queue_len(&np->rx_batch); i < batch_target; i++) { + /* + * Subtract dev_alloc_skb headroom (16 bytes) and shared info + * tailroom then round down to SKB_DATA_ALIGN boundary. + */ + skb = __dev_alloc_skb( + ((PAGE_SIZE - sizeof(struct skb_shared_info)) & + (-SKB_DATA_ALIGN(1))) - 16, + GFP_ATOMIC|__GFP_NOWARN); + if (skb == NULL) { + /* Any skbuffs queued for refill? Force them out. */ + if (i != 0) + goto refill; + /* Could not allocate any skbuffs. Try again later. */ + mod_timer(&np->rx_refill_timer, + jiffies + (HZ/10)); + return; + } + __skb_queue_tail(&np->rx_batch, skb); + } + + /* Is the batch large enough to be worthwhile? */ + if (i < (np->rx_target/2)) + return; + + /* Adjust our fill target if we risked running out of buffers. */ + if (((req_prod - np->rx.sring->rsp_prod) < (np->rx_target / 4)) && + ((np->rx_target *= 2) > np->rx_max_target)) + np->rx_target = np->rx_max_target; + + refill: + for (i = 0; ; i++) { + if ((skb = __skb_dequeue(&np->rx_batch)) == NULL) + break; + + skb->dev = dev; + + id = get_id_from_freelist(np->rx_skbs); + + np->rx_skbs[id] = skb; + + RING_GET_REQUEST(&np->rx, req_prod + i)->id = id; + ref = gnttab_claim_grant_reference(&np->gref_rx_head); + BUG_ON((signed short)ref < 0); + np->grant_rx_ref[id] = ref; + gnttab_grant_foreign_transfer_ref(ref, + np->xbdev->otherend_id, + __pa(skb->head) >> PAGE_SHIFT); + RING_GET_REQUEST(&np->rx, req_prod + i)->gref = ref; + np->rx_pfn_array[i] = virt_to_mfn(skb->head); + +#ifndef CONFIG_XEN_SHADOW_MODE + if (!xen_feature(XENFEAT_auto_translated_physmap)) { + /* Remove this page before passing back to Xen. */ + set_phys_to_machine(__pa(skb->head) >> PAGE_SHIFT, + INVALID_P2M_ENTRY); + MULTI_update_va_mapping(np->rx_mcl+i, + (unsigned long)skb->head, + __pte(0), 0); + } +#endif + } + +#ifdef CONFIG_XEN_BALLOON + /* Tell the ballon driver what is going on. */ + balloon_update_driver_allowance(i); +#endif + + reservation.extent_start = np->rx_pfn_array; + reservation.nr_extents = i; + reservation.extent_order = 0; + reservation.address_bits = 0; + reservation.domid = DOMID_SELF; + +#ifndef CONFIG_XEN_SHADOW_MODE + if (!xen_feature(XENFEAT_auto_translated_physmap)) { + /* After all PTEs have been zapped, flush the TLB. */ + np->rx_mcl[i-1].args[MULTI_UVMFLAGS_INDEX] = + UVMF_TLB_FLUSH|UVMF_ALL; + + /* Give away a batch of pages. */ + np->rx_mcl[i].op = __HYPERVISOR_memory_op; + np->rx_mcl[i].args[0] = XENMEM_decrease_reservation; + np->rx_mcl[i].args[1] = (unsigned long)&reservation; + + /* Zap PTEs and give away pages in one big multicall. */ + (void)HYPERVISOR_multicall(np->rx_mcl, i+1); + + /* Check return status of HYPERVISOR_memory_op(). */ + if (unlikely(np->rx_mcl[i].result != i)) + panic("Unable to reduce memory reservation\n"); + } else +#endif + if (HYPERVISOR_memory_op(XENMEM_decrease_reservation, + &reservation) != i) + panic("Unable to reduce memory reservation\n"); + + /* Above is a suitable barrier to ensure backend will see requests. */ + np->rx.req_prod_pvt = req_prod + i; + RING_PUSH_REQUESTS(&np->rx); +} + + +static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev, + struct netif_tx_request *tx) +{ + struct netfront_info *np = netdev_priv(dev); + char *data = skb->data; + unsigned long mfn; + RING_IDX prod = np->tx.req_prod_pvt; + int frags = skb_shinfo(skb)->nr_frags; + unsigned int offset = offset_in_page(data); + unsigned int len = skb_headlen(skb); + unsigned int id; + grant_ref_t ref; + int i; + + while (len > PAGE_SIZE - offset) { + tx->size = PAGE_SIZE - offset; + tx->flags |= NETTXF_more_data; + len -= tx->size; + data += tx->size; + offset = 0; + + id = get_id_from_freelist(np->tx_skbs); + np->tx_skbs[id] = skb_get(skb); + tx = RING_GET_REQUEST(&np->tx, prod++); + tx->id = id; + ref = gnttab_claim_grant_reference(&np->gref_tx_head); + BUG_ON((signed short)ref < 0); + + mfn = virt_to_mfn(data); + gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id, + mfn, GNTMAP_readonly); + + tx->gref = np->grant_tx_ref[id] = ref; + tx->offset = offset; + tx->size = len; + tx->flags = 0; + } + + for (i = 0; i < frags; i++) { + skb_frag_t *frag = skb_shinfo(skb)->frags + i; + + tx->flags |= NETTXF_more_data; + + id = get_id_from_freelist(np->tx_skbs); + np->tx_skbs[id] = skb_get(skb); + tx = RING_GET_REQUEST(&np->tx, prod++); + tx->id = id; + ref = gnttab_claim_grant_reference(&np->gref_tx_head); + BUG_ON((signed short)ref < 0); + + mfn = pfn_to_mfn(page_to_pfn(frag->page)); + gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id, + mfn, GNTMAP_readonly); + + tx->gref = np->grant_tx_ref[id] = ref; + tx->offset = frag->page_offset; + tx->size = frag->size; + tx->flags = 0; + } + + np->tx.req_prod_pvt = prod; +} + +static int network_start_xmit(struct sk_buff *skb, struct net_device *dev) +{ + unsigned short id; + struct netfront_info *np = netdev_priv(dev); + struct netif_tx_request *tx; + char *data = skb->data; + RING_IDX i; + grant_ref_t ref; + unsigned long mfn; + int notify; + int frags = skb_shinfo(skb)->nr_frags; + unsigned int offset = offset_in_page(data); + unsigned int len = skb_headlen(skb); + + frags += (offset + len + PAGE_SIZE - 1) / PAGE_SIZE; + if (unlikely(frags > MAX_SKB_FRAGS + 1)) { + printk(KERN_ALERT "xennet: skb rides the rocket: %d frags\n", + frags); + dump_stack(); + goto drop; + } + + spin_lock_irq(&np->tx_lock); + + if (unlikely(!netif_carrier_ok(dev) || + (frags > 1 && !xennet_can_sg(dev)))) { + spin_unlock_irq(&np->tx_lock); + goto drop; + } + + i = np->tx.req_prod_pvt; + + id = get_id_from_freelist(np->tx_skbs); + np->tx_skbs[id] = skb; + + tx = RING_GET_REQUEST(&np->tx, i); + + tx->id = id; + ref = gnttab_claim_grant_reference(&np->gref_tx_head); + BUG_ON((signed short)ref < 0); + mfn = virt_to_mfn(data); + gnttab_grant_foreign_access_ref( + ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly); + tx->gref = np->grant_tx_ref[id] = ref; + tx->offset = offset; + tx->size = len; + tx->flags = (skb->ip_summed == CHECKSUM_HW) ? NETTXF_csum_blank : 0; + + np->tx.req_prod_pvt = i + 1; + + xennet_make_frags(skb, dev, tx); + tx->size = skb->len; + + RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->tx, notify); + if (notify) + notify_remote_via_irq(np->irq); + + network_tx_buf_gc(dev); + + if (!netfront_tx_slot_available(np)) + netif_stop_queue(dev); + + spin_unlock_irq(&np->tx_lock); + + np->stats.tx_bytes += skb->len; + np->stats.tx_packets++; + + return 0; + + drop: + np->stats.tx_dropped++; + dev_kfree_skb(skb); + return 0; +} + +static irqreturn_t netif_int(int irq, void *dev_id, struct pt_regs *ptregs) +{ + struct net_device *dev = dev_id; + struct netfront_info *np = netdev_priv(dev); + unsigned long flags; + + spin_lock_irqsave(&np->tx_lock, flags); + network_tx_buf_gc(dev); + spin_unlock_irqrestore(&np->tx_lock, flags); + + if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx) && + likely(netif_running(dev))) + netif_rx_schedule(dev); + + return IRQ_HANDLED; +} + + +static int netif_poll(struct net_device *dev, int *pbudget) +{ + struct netfront_info *np = netdev_priv(dev); + struct sk_buff *skb, *nskb; + struct netif_rx_response *rx; + RING_IDX i, rp; + struct mmu_update *mmu = np->rx_mmu; + struct multicall_entry *mcl = np->rx_mcl; + int work_done, budget, more_to_do = 1; + struct sk_buff_head rxq; + unsigned long flags; + unsigned long mfn; + grant_ref_t ref; + + spin_lock(&np->rx_lock); + + if (unlikely(!netif_carrier_ok(dev))) { + spin_unlock(&np->rx_lock); + return 0; + } + + skb_queue_head_init(&rxq); + + if ((budget = *pbudget) > dev->quota) + budget = dev->quota; + rp = np->rx.sring->rsp_prod; + rmb(); /* Ensure we see queued responses up to 'rp'. */ + + for (i = np->rx.rsp_cons, work_done = 0; + (i != rp) && (work_done < budget); + i++, work_done++) { + rx = RING_GET_RESPONSE(&np->rx, i); + + /* + * This definitely indicates a bug, either in this driver or + * in the backend driver. In future this should flag the bad + * situation to the system controller to reboot the backed. + */ + if ((ref = np->grant_rx_ref[rx->id]) == GRANT_INVALID_REF) { + WPRINTK("Bad rx response id %d.\n", rx->id); + work_done--; + continue; + } + + /* Memory pressure, insufficient buffer headroom, ... */ + if ((mfn = gnttab_end_foreign_transfer_ref(ref)) == 0) { + if (net_ratelimit()) + WPRINTK("Unfulfilled rx req (id=%d, st=%d).\n", + rx->id, rx->status); + RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->id = + rx->id; + RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->gref = + ref; + np->rx.req_prod_pvt++; + RING_PUSH_REQUESTS(&np->rx); + work_done--; + continue; + } + + gnttab_release_grant_reference(&np->gref_rx_head, ref); + np->grant_rx_ref[rx->id] = GRANT_INVALID_REF; + + skb = np->rx_skbs[rx->id]; + add_id_to_freelist(np->rx_skbs, rx->id); + + /* NB. We handle skb overflow later. */ + skb->data = skb->head + rx->offset; + skb->len = rx->status; + skb->tail = skb->data + skb->len; + + if (rx->flags & NETRXF_data_validated) + skb->ip_summed = CHECKSUM_UNNECESSARY; + + np->stats.rx_packets++; + np->stats.rx_bytes += rx->status; + +#ifndef CONFIG_XEN_SHADOW_MODE + if (!xen_feature(XENFEAT_auto_translated_physmap)) { + /* Remap the page. */ + MULTI_update_va_mapping(mcl, (unsigned long)skb->head, + pfn_pte_ma(mfn, PAGE_KERNEL), + 0); + mcl++; + mmu->ptr = ((maddr_t)mfn << PAGE_SHIFT) + | MMU_MACHPHYS_UPDATE; + mmu->val = __pa(skb->head) >> PAGE_SHIFT; + mmu++; + + set_phys_to_machine(__pa(skb->head) >> PAGE_SHIFT, + mfn); + } +#endif + + __skb_queue_tail(&rxq, skb); + } + +#ifdef CONFIG_XEN_BALLOON + /* Some pages are no longer absent... */ + balloon_update_driver_allowance(-work_done); +#endif + + /* Do all the remapping work, and M2P updates, in one big hypercall. */ + if (likely((mcl - np->rx_mcl) != 0)) { + 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++; + (void)HYPERVISOR_multicall(np->rx_mcl, mcl - np->rx_mcl); + } + + while ((skb = __skb_dequeue(&rxq)) != NULL) { + if (skb->len > (dev->mtu + ETH_HLEN + 4)) { + if (net_ratelimit()) + printk(KERN_INFO "Received packet too big for " + "MTU (%d > %d)\n", + skb->len - ETH_HLEN - 4, dev->mtu); + skb->len = 0; + skb->tail = skb->data; + init_skb_shinfo(skb); + dev_kfree_skb(skb); + continue; + } + + /* + * Enough room in skbuff for the data we were passed? Also, + * Linux expects at least 16 bytes headroom in each rx buffer. + */ + if (unlikely(skb->tail > skb->end) || + unlikely((skb->data - skb->head) < 16)) { + if (net_ratelimit()) { + if (skb->tail > skb->end) + printk(KERN_INFO "Received packet " + "is %zd bytes beyond tail.\n", + skb->tail - skb->end); + else + printk(KERN_INFO "Received packet " + "is %zd bytes before head.\n", + 16 - (skb->data - skb->head)); + } + + nskb = __dev_alloc_skb(skb->len + 2, + GFP_ATOMIC|__GFP_NOWARN); + if (nskb != NULL) { + skb_reserve(nskb, 2); + skb_put(nskb, skb->len); + memcpy(nskb->data, skb->data, skb->len); + nskb->dev = skb->dev; + nskb->ip_summed = skb->ip_summed; + } + + /* Reinitialise and then destroy the old skbuff. */ + skb->len = 0; + skb->tail = skb->data; + init_skb_shinfo(skb); + dev_kfree_skb(skb); + + /* Switch old for new, if we copied the buffer. */ + if ((skb = nskb) == NULL) + continue; + } + + /* Set the shinfo area, which is hidden behind the data. */ + init_skb_shinfo(skb); + /* Ethernet work: Delayed to here as it peeks the header. */ + skb->protocol = eth_type_trans(skb, dev); + + /* Pass it up. */ + netif_receive_skb(skb); + dev->last_rx = jiffies; + } + + np->rx.rsp_cons = i; + + /* If we get a callback with very few responses, reduce fill target. */ + /* NB. Note exponential increase, linear decrease. */ + if (((np->rx.req_prod_pvt - np->rx.sring->rsp_prod) > + ((3*np->rx_target) / 4)) && + (--np->rx_target < np->rx_min_target)) + np->rx_target = np->rx_min_target; + + network_alloc_rx_buffers(dev); + + *pbudget -= work_done; + dev->quota -= work_done; + + if (work_done < budget) { + local_irq_save(flags); + + RING_FINAL_CHECK_FOR_RESPONSES(&np->rx, more_to_do); + if (!more_to_do) + __netif_rx_complete(dev); + + local_irq_restore(flags); + } + + spin_unlock(&np->rx_lock); + + return more_to_do; +} + + +static int network_close(struct net_device *dev) +{ + struct netfront_info *np = netdev_priv(dev); + netif_stop_queue(np->netdev); + return 0; +} + + +static struct net_device_stats *network_get_stats(struct net_device *dev) +{ + struct netfront_info *np = netdev_priv(dev); + return &np->stats; +} + +static int xennet_change_mtu(struct net_device *dev, int mtu) +{ + int max = xennet_can_sg(dev) ? 65535 - ETH_HLEN : ETH_DATA_LEN; + + if (mtu > max) + return -EINVAL; + dev->mtu = mtu; + return 0; +} + +static int xennet_set_sg(struct net_device *dev, u32 data) +{ + if (data) { + struct netfront_info *np = netdev_priv(dev); + int val; + + if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg", + "%d", &val) < 0) + val = 0; + if (!val) + return -ENOSYS; + } else if (dev->mtu > ETH_DATA_LEN) + dev->mtu = ETH_DATA_LEN; + + return ethtool_op_set_sg(dev, data); +} + +static void xennet_set_features(struct net_device *dev) +{ + xennet_set_sg(dev, 1); +} + +static void network_connect(struct net_device *dev) +{ + struct netfront_info *np; + int i, requeue_idx; + struct netif_tx_request *tx; + struct sk_buff *skb; + + xennet_set_features(dev); + + np = netdev_priv(dev); + spin_lock_irq(&np->tx_lock); + spin_lock(&np->rx_lock); + + /* Recovery procedure: */ + + /* + * Step 1: Rebuild the RX and TX ring contents. + * NB. We could just free the queued TX packets now but we hope + * that sending them out might do some good. We have to rebuild + * the RX ring because some of our pages are currently flipped out + * so we can't just free the RX skbs. + * NB2. Freelist index entries are always going to be less than + * PAGE_OFFSET, whereas pointers to skbs will always be equal or + * greater than PAGE_OFFSET: we use this property to distinguish + * them. + */ + + /* + * Rebuild the TX buffer freelist and the TX ring itself. + * NB. This reorders packets. We could keep more private state + * to avoid this but maybe it doesn't matter so much given the + * interface has been down. + */ + for (requeue_idx = 0, i = 1; i <= NET_TX_RING_SIZE; i++) { + if ((unsigned long)np->tx_skbs[i] < PAGE_OFFSET) + continue; + + skb = np->tx_skbs[i]; + + tx = RING_GET_REQUEST(&np->tx, requeue_idx); + requeue_idx++; + + tx->id = i; + gnttab_grant_foreign_access_ref( + np->grant_tx_ref[i], np->xbdev->otherend_id, + virt_to_mfn(np->tx_skbs[i]->data), + GNTMAP_readonly); + tx->gref = np->grant_tx_ref[i]; + tx->offset = (unsigned long)skb->data & ~PAGE_MASK; + tx->size = skb->len; + tx->flags = (skb->ip_summed == CHECKSUM_HW) ? + NETTXF_csum_blank : 0; + + np->stats.tx_bytes += skb->len; + np->stats.tx_packets++; + } + + np->tx.req_prod_pvt = requeue_idx; + RING_PUSH_REQUESTS(&np->tx); + + /* Rebuild the RX buffer freelist and the RX ring itself. */ + for (requeue_idx = 0, i = 1; i <= NET_RX_RING_SIZE; i++) { + if ((unsigned long)np->rx_skbs[i] < PAGE_OFFSET) + continue; + gnttab_grant_foreign_transfer_ref( + np->grant_rx_ref[i], np->xbdev->otherend_id, + __pa(np->rx_skbs[i]->data) >> PAGE_SHIFT); + RING_GET_REQUEST(&np->rx, requeue_idx)->gref = + np->grant_rx_ref[i]; + RING_GET_REQUEST(&np->rx, requeue_idx)->id = i; + requeue_idx++; + } + + np->rx.req_prod_pvt = requeue_idx; + RING_PUSH_REQUESTS(&np->rx); + + /* + * Step 2: All public and private state should now be sane. Get + * ready to start sending and receiving packets and give the driver + * domain a kick because we've probably just requeued some + * packets. + */ + netif_carrier_on(dev); + notify_remote_via_irq(np->irq); + network_tx_buf_gc(dev); + + spin_unlock(&np->rx_lock); + spin_unlock_irq(&np->tx_lock); +} + +static void show_device(struct netfront_info *np) +{ +#ifdef DEBUG + if (np) { + IPRINTK("\n", + np->handle, + netif_carrier_ok(np->netdev) ? "on" : "off", + netif_running(np->netdev) ? "open" : "closed", + np->evtchn, + np->tx, + np->rx); + } else + IPRINTK("\n"); +#endif +} + +static void netif_uninit(struct net_device *dev) +{ + struct netfront_info *np = netdev_priv(dev); + gnttab_free_grant_references(np->gref_tx_head); + gnttab_free_grant_references(np->gref_rx_head); +} + +static struct ethtool_ops network_ethtool_ops = +{ + .get_tx_csum = ethtool_op_get_tx_csum, + .set_tx_csum = ethtool_op_set_tx_csum, + .get_sg = ethtool_op_get_sg, + .set_sg = xennet_set_sg, +}; + +/* + * Nothing to do here. Virtual interface is point-to-point and the + * physical interface is probably promiscuous anyway. + */ +static void network_set_multicast_list(struct net_device *dev) +{ +} + +/** Create a network device. + * @param handle device handle + * @param val return parameter for created device + * @return 0 on success, error code otherwise + */ +static struct net_device * __devinit create_netdev(int handle, + struct xenbus_device *dev) +{ + int i, err = 0; + struct net_device *netdev = NULL; + struct netfront_info *np = NULL; + + netdev = alloc_etherdev(sizeof(struct netfront_info)); + if (!netdev) { + printk(KERN_WARNING "%s> alloc_etherdev failed.\n", + __FUNCTION__); + return ERR_PTR(-ENOMEM); + } + + np = netdev_priv(netdev); + np->handle = handle; + np->xbdev = dev; + + netif_carrier_off(netdev); + + spin_lock_init(&np->tx_lock); + spin_lock_init(&np->rx_lock); + + skb_queue_head_init(&np->rx_batch); + np->rx_target = RX_DFL_MIN_TARGET; + np->rx_min_target = RX_DFL_MIN_TARGET; + np->rx_max_target = RX_MAX_TARGET; + + init_timer(&np->rx_refill_timer); + np->rx_refill_timer.data = (unsigned long)netdev; + np->rx_refill_timer.function = rx_refill_timeout; + + /* Initialise {tx,rx}_skbs as a free chain containing every entry. */ + for (i = 0; i <= NET_TX_RING_SIZE; i++) { + np->tx_skbs[i] = (void *)((unsigned long) i+1); + np->grant_tx_ref[i] = GRANT_INVALID_REF; + } + + for (i = 0; i <= NET_RX_RING_SIZE; i++) { + np->rx_skbs[i] = (void *)((unsigned long) i+1); + np->grant_rx_ref[i] = GRANT_INVALID_REF; + } + + /* A grant for every tx ring slot */ + if (gnttab_alloc_grant_references(TX_MAX_TARGET, + &np->gref_tx_head) < 0) { + printk(KERN_ALERT "#### netfront can't alloc tx grant refs\n"); + err = -ENOMEM; + goto exit; + } + /* A grant for every rx ring slot */ + if (gnttab_alloc_grant_references(RX_MAX_TARGET, + &np->gref_rx_head) < 0) { + printk(KERN_ALERT "#### netfront can't alloc rx grant refs\n"); + err = -ENOMEM; + goto exit_free_tx; + } + + netdev->open = network_open; + netdev->hard_start_xmit = network_start_xmit; + netdev->stop = network_close; + netdev->get_stats = network_get_stats; + netdev->poll = netif_poll; + netdev->set_multicast_list = network_set_multicast_list; + netdev->uninit = netif_uninit; + netdev->change_mtu = xennet_change_mtu; + netdev->weight = 64; + netdev->features = NETIF_F_IP_CSUM; + + SET_ETHTOOL_OPS(netdev, &network_ethtool_ops); + SET_MODULE_OWNER(netdev); + SET_NETDEV_DEV(netdev, &dev->dev); + + err = register_netdev(netdev); + if (err) { + printk(KERN_WARNING "%s> register_netdev err=%d\n", + __FUNCTION__, err); + goto exit_free_rx; + } + + err = xennet_sysfs_addif(netdev); + if (err) { + /* This can be non-fatal: it only means no tuning parameters */ + printk(KERN_WARNING "%s> add sysfs failed err=%d\n", + __FUNCTION__, err); + } + + np->netdev = netdev; + + return netdev; + + exit_free_rx: + gnttab_free_grant_references(np->gref_rx_head); + exit_free_tx: + gnttab_free_grant_references(np->gref_tx_head); + exit: + free_netdev(netdev); + return ERR_PTR(err); +} + +#ifdef CONFIG_SYSFS +static ssize_t show_rxbuf_min(struct class_device *cd, char *buf) +{ + struct net_device *netdev = container_of(cd, struct net_device, + class_dev); + struct netfront_info *info = netdev_priv(netdev); + + return sprintf(buf, "%u\n", info->rx_min_target); +} + +static ssize_t store_rxbuf_min(struct class_device *cd, + const char *buf, size_t len) +{ + struct net_device *netdev = container_of(cd, struct net_device, + class_dev); + struct netfront_info *np = netdev_priv(netdev); + char *endp; + unsigned long target; + + if (!capable(CAP_NET_ADMIN)) + return -EPERM; + + target = simple_strtoul(buf, &endp, 0); + if (endp == buf) + return -EBADMSG; + + if (target < RX_MIN_TARGET) + target = RX_MIN_TARGET; + if (target > RX_MAX_TARGET) + target = RX_MAX_TARGET; + + spin_lock(&np->rx_lock); + if (target > np->rx_max_target) + np->rx_max_target = target; + np->rx_min_target = target; + if (target > np->rx_target) + np->rx_target = target; + + network_alloc_rx_buffers(netdev); + + spin_unlock(&np->rx_lock); + return len; +} + +static ssize_t show_rxbuf_max(struct class_device *cd, char *buf) +{ + struct net_device *netdev = container_of(cd, struct net_device, + class_dev); + struct netfront_info *info = netdev_priv(netdev); + + return sprintf(buf, "%u\n", info->rx_max_target); +} + +static ssize_t store_rxbuf_max(struct class_device *cd, + const char *buf, size_t len) +{ + struct net_device *netdev = container_of(cd, struct net_device, + class_dev); + struct netfront_info *np = netdev_priv(netdev); + char *endp; + unsigned long target; + + if (!capable(CAP_NET_ADMIN)) + return -EPERM; + + target = simple_strtoul(buf, &endp, 0); + if (endp == buf) + return -EBADMSG; + + if (target < RX_MIN_TARGET) + target = RX_MIN_TARGET; + if (target > RX_MAX_TARGET) + target = RX_MAX_TARGET; + + spin_lock(&np->rx_lock); + if (target < np->rx_min_target) + np->rx_min_target = target; + np->rx_max_target = target; + if (target < np->rx_target) + np->rx_target = target; + + network_alloc_rx_buffers(netdev); + + spin_unlock(&np->rx_lock); + return len; +} + +static ssize_t show_rxbuf_cur(struct class_device *cd, char *buf) +{ + struct net_device *netdev = container_of(cd, struct net_device, + class_dev); + struct netfront_info *info = netdev_priv(netdev); + + return sprintf(buf, "%u\n", info->rx_target); +} + +static const struct class_device_attribute xennet_attrs[] = { + __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf_min, store_rxbuf_min), + __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf_max, store_rxbuf_max), + __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf_cur, NULL), +}; + +static int xennet_sysfs_addif(struct net_device *netdev) +{ + int i; + int error = 0; + + for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) { + error = class_device_create_file(&netdev->class_dev, + &xennet_attrs[i]); + if (error) + goto fail; + } + return 0; + + fail: + while (--i >= 0) + class_device_remove_file(&netdev->class_dev, + &xennet_attrs[i]); + return error; +} + +static void xennet_sysfs_delif(struct net_device *netdev) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) { + class_device_remove_file(&netdev->class_dev, + &xennet_attrs[i]); + } +} + +#endif /* CONFIG_SYSFS */ + + +/* + * We use this notifier to send out a fake ARP reply to reset switches and + * router ARP caches when an IP interface is brought up on a VIF. + */ +static int +inetdev_notify(struct notifier_block *this, unsigned long event, void *ptr) +{ + struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; + struct net_device *dev = ifa->ifa_dev->dev; + + /* UP event and is it one of our devices? */ + if (event == NETDEV_UP && dev->open == network_open) + (void)send_fake_arp(dev); + + return NOTIFY_DONE; +} + + +/* ** Close down ** */ + + +/** + * Handle the change of state of the backend to Closing. We must delete our + * device-layer structures now, to ensure that writes are flushed through to + * the backend. Once is this done, we can switch to Closed in + * acknowledgement. + */ +static void netfront_closing(struct xenbus_device *dev) +{ + struct netfront_info *info = dev->dev.driver_data; + + DPRINTK("netfront_closing: %s removed\n", dev->nodename); + + close_netdev(info); + + xenbus_switch_state(dev, XenbusStateClosed); +} + + +static int __devexit netfront_remove(struct xenbus_device *dev) +{ + struct netfront_info *info = dev->dev.driver_data; + + DPRINTK("%s\n", dev->nodename); + + netif_disconnect_backend(info); + free_netdev(info->netdev); + + return 0; +} + + +static void close_netdev(struct netfront_info *info) +{ + del_timer_sync(&info->rx_refill_timer); + + xennet_sysfs_delif(info->netdev); + unregister_netdev(info->netdev); +} + + +static void netif_disconnect_backend(struct netfront_info *info) +{ + /* Stop old i/f to prevent errors whilst we rebuild the state. */ + spin_lock_irq(&info->tx_lock); + spin_lock(&info->rx_lock); + netif_carrier_off(info->netdev); + spin_unlock(&info->rx_lock); + spin_unlock_irq(&info->tx_lock); + + if (info->irq) + unbind_from_irqhandler(info->irq, info->netdev); + info->evtchn = info->irq = 0; + + end_access(info->tx_ring_ref, info->tx.sring); + end_access(info->rx_ring_ref, info->rx.sring); + info->tx_ring_ref = GRANT_INVALID_REF; + info->rx_ring_ref = GRANT_INVALID_REF; + info->tx.sring = NULL; + info->rx.sring = NULL; +} + + +static void netif_free(struct netfront_info *info) +{ + close_netdev(info); + netif_disconnect_backend(info); + free_netdev(info->netdev); +} + + +static void end_access(int ref, void *page) +{ + if (ref != GRANT_INVALID_REF) + gnttab_end_foreign_access(ref, 0, (unsigned long)page); +} + + +/* ** Driver registration ** */ + + +static struct xenbus_device_id netfront_ids[] = { + { "vif" }, + { "" } +}; + + +static struct xenbus_driver netfront = { + .name = "vif", + .owner = THIS_MODULE, + .ids = netfront_ids, + .probe = netfront_probe, + .remove = __devexit_p(netfront_remove), + .resume = netfront_resume, + .otherend_changed = backend_changed, +}; + + +static struct notifier_block notifier_inetdev = { + .notifier_call = inetdev_notify, +}; + +static int __init netif_init(void) +{ + if (xen_start_info->flags & SIF_INITDOMAIN) + return 0; + + IPRINTK("Initialising virtual ethernet driver.\n"); + + (void)register_inetaddr_notifier(¬ifier_inetdev); + + return xenbus_register_frontend(&netfront); +} +module_init(netif_init); + + +static void __exit netif_exit(void) +{ + unregister_inetaddr_notifier(¬ifier_inetdev); + + return xenbus_unregister_driver(&netfront); +} +module_exit(netif_exit); + +MODULE_LICENSE("Dual BSD/GPL"); -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/