2 * Network-device interface management.
4 * Copyright (c) 2004-2005, Keir Fraser
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License version 2
8 * as published by the Free Software Foundation; or, when distributed
9 * separately from the Linux kernel or incorporated into other
10 * software packages, subject to the following license:
12 * Permission is hereby granted, free of charge, to any person obtaining a copy
13 * of this source file (the "Software"), to deal in the Software without
14 * restriction, including without limitation the rights to use, copy, modify,
15 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
16 * and to permit persons to whom the Software is furnished to do so, subject to
17 * the following conditions:
19 * The above copyright notice and this permission notice shall be included in
20 * all copies or substantial portions of the Software.
22 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
23 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
24 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
25 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
26 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
27 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
33 #include <linux/kthread.h>
34 #include <linux/ethtool.h>
35 #include <linux/rtnetlink.h>
36 #include <linux/if_vlan.h>
38 #include <xen/events.h>
39 #include <asm/xen/hypercall.h>
41 #define XENVIF_QUEUE_LENGTH 32
42 #define XENVIF_NAPI_WEIGHT 64
44 int xenvif_schedulable(struct xenvif *vif)
46 return netif_running(vif->dev) && netif_carrier_ok(vif->dev);
49 static int xenvif_rx_schedulable(struct xenvif *vif)
51 return xenvif_schedulable(vif) && !xenvif_rx_ring_full(vif);
54 static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id)
56 struct xenvif *vif = dev_id;
58 if (RING_HAS_UNCONSUMED_REQUESTS(&vif->tx))
59 napi_schedule(&vif->napi);
64 static int xenvif_poll(struct napi_struct *napi, int budget)
66 struct xenvif *vif = container_of(napi, struct xenvif, napi);
69 work_done = xenvif_tx_action(vif, budget);
71 if (work_done < budget) {
75 /* It is necessary to disable IRQ before calling
76 * RING_HAS_UNCONSUMED_REQUESTS. Otherwise we might
77 * lose event from the frontend.
80 * RING_HAS_UNCONSUMED_REQUESTS
81 * <frontend generates event to trigger napi_schedule>
84 * This handler is still in scheduled state so the
85 * event has no effect at all. After __napi_complete
86 * this handler is descheduled and cannot get
87 * scheduled again. We lose event in this case and the ring
88 * will be completely stalled.
91 local_irq_save(flags);
93 RING_FINAL_CHECK_FOR_REQUESTS(&vif->tx, more_to_do);
95 __napi_complete(napi);
97 local_irq_restore(flags);
103 static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id)
105 struct xenvif *vif = dev_id;
107 if (xenvif_rx_schedulable(vif))
108 netif_wake_queue(vif->dev);
113 static irqreturn_t xenvif_interrupt(int irq, void *dev_id)
115 xenvif_tx_interrupt(irq, dev_id);
116 xenvif_rx_interrupt(irq, dev_id);
121 static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
123 struct xenvif *vif = netdev_priv(dev);
125 BUG_ON(skb->dev != dev);
127 /* Drop the packet if vif is not ready */
128 if (vif->task == NULL)
131 /* Drop the packet if the target domain has no receive buffers. */
132 if (!xenvif_rx_schedulable(vif))
135 /* Reserve ring slots for the worst-case number of fragments. */
136 vif->rx_req_cons_peek += xenvif_count_skb_slots(vif, skb);
138 if (vif->can_queue && xenvif_must_stop_queue(vif))
139 netif_stop_queue(dev);
141 xenvif_queue_tx_skb(vif, skb);
146 vif->dev->stats.tx_dropped++;
151 void xenvif_notify_tx_completion(struct xenvif *vif)
153 if (netif_queue_stopped(vif->dev) && xenvif_rx_schedulable(vif))
154 netif_wake_queue(vif->dev);
157 static struct net_device_stats *xenvif_get_stats(struct net_device *dev)
159 struct xenvif *vif = netdev_priv(dev);
160 return &vif->dev->stats;
163 static void xenvif_up(struct xenvif *vif)
165 napi_enable(&vif->napi);
166 enable_irq(vif->tx_irq);
167 if (vif->tx_irq != vif->rx_irq)
168 enable_irq(vif->rx_irq);
169 xenvif_check_rx_xenvif(vif);
172 static void xenvif_down(struct xenvif *vif)
174 napi_disable(&vif->napi);
175 disable_irq(vif->tx_irq);
176 if (vif->tx_irq != vif->rx_irq)
177 disable_irq(vif->rx_irq);
178 del_timer_sync(&vif->credit_timeout);
181 static int xenvif_open(struct net_device *dev)
183 struct xenvif *vif = netdev_priv(dev);
184 if (netif_carrier_ok(dev))
186 netif_start_queue(dev);
190 static int xenvif_close(struct net_device *dev)
192 struct xenvif *vif = netdev_priv(dev);
193 if (netif_carrier_ok(dev))
195 netif_stop_queue(dev);
199 static int xenvif_change_mtu(struct net_device *dev, int mtu)
201 struct xenvif *vif = netdev_priv(dev);
202 int max = vif->can_sg ? 65535 - VLAN_ETH_HLEN : ETH_DATA_LEN;
210 static netdev_features_t xenvif_fix_features(struct net_device *dev,
211 netdev_features_t features)
213 struct xenvif *vif = netdev_priv(dev);
216 features &= ~NETIF_F_SG;
217 if (!vif->gso && !vif->gso_prefix)
218 features &= ~NETIF_F_TSO;
220 features &= ~NETIF_F_IP_CSUM;
222 features &= ~NETIF_F_IPV6_CSUM;
227 static const struct xenvif_stat {
228 char name[ETH_GSTRING_LEN];
232 "rx_gso_checksum_fixup",
233 offsetof(struct xenvif, rx_gso_checksum_fixup)
237 static int xenvif_get_sset_count(struct net_device *dev, int string_set)
239 switch (string_set) {
241 return ARRAY_SIZE(xenvif_stats);
247 static void xenvif_get_ethtool_stats(struct net_device *dev,
248 struct ethtool_stats *stats, u64 * data)
250 void *vif = netdev_priv(dev);
253 for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
254 data[i] = *(unsigned long *)(vif + xenvif_stats[i].offset);
257 static void xenvif_get_strings(struct net_device *dev, u32 stringset, u8 * data)
263 for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
264 memcpy(data + i * ETH_GSTRING_LEN,
265 xenvif_stats[i].name, ETH_GSTRING_LEN);
270 static const struct ethtool_ops xenvif_ethtool_ops = {
271 .get_link = ethtool_op_get_link,
273 .get_sset_count = xenvif_get_sset_count,
274 .get_ethtool_stats = xenvif_get_ethtool_stats,
275 .get_strings = xenvif_get_strings,
278 static const struct net_device_ops xenvif_netdev_ops = {
279 .ndo_start_xmit = xenvif_start_xmit,
280 .ndo_get_stats = xenvif_get_stats,
281 .ndo_open = xenvif_open,
282 .ndo_stop = xenvif_close,
283 .ndo_change_mtu = xenvif_change_mtu,
284 .ndo_fix_features = xenvif_fix_features,
285 .ndo_set_mac_address = eth_mac_addr,
286 .ndo_validate_addr = eth_validate_addr,
289 struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
293 struct net_device *dev;
295 char name[IFNAMSIZ] = {};
298 snprintf(name, IFNAMSIZ - 1, "vif%u.%u", domid, handle);
299 dev = alloc_netdev(sizeof(struct xenvif), name, ether_setup);
301 pr_warn("Could not allocate netdev for %s\n", name);
302 return ERR_PTR(-ENOMEM);
305 SET_NETDEV_DEV(dev, parent);
307 vif = netdev_priv(dev);
309 vif->handle = handle;
314 vif->credit_bytes = vif->remaining_credit = ~0UL;
315 vif->credit_usec = 0UL;
316 init_timer(&vif->credit_timeout);
317 /* Initialize 'expires' now: it's used to track the credit window. */
318 vif->credit_timeout.expires = jiffies;
320 dev->netdev_ops = &xenvif_netdev_ops;
321 dev->hw_features = NETIF_F_SG |
322 NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
324 dev->features = dev->hw_features | NETIF_F_RXCSUM;
325 SET_ETHTOOL_OPS(dev, &xenvif_ethtool_ops);
327 dev->tx_queue_len = XENVIF_QUEUE_LENGTH;
329 skb_queue_head_init(&vif->rx_queue);
330 skb_queue_head_init(&vif->tx_queue);
332 vif->pending_cons = 0;
333 vif->pending_prod = MAX_PENDING_REQS;
334 for (i = 0; i < MAX_PENDING_REQS; i++)
335 vif->pending_ring[i] = i;
336 for (i = 0; i < MAX_PENDING_REQS; i++)
337 vif->mmap_pages[i] = NULL;
340 * Initialise a dummy MAC address. We choose the numerically
341 * largest non-broadcast address to prevent the address getting
342 * stolen by an Ethernet bridge for STP purposes.
343 * (FE:FF:FF:FF:FF:FF)
345 memset(dev->dev_addr, 0xFF, ETH_ALEN);
346 dev->dev_addr[0] &= ~0x01;
348 netif_napi_add(dev, &vif->napi, xenvif_poll, XENVIF_NAPI_WEIGHT);
350 netif_carrier_off(dev);
352 err = register_netdev(dev);
354 netdev_warn(dev, "Could not register device: err=%d\n", err);
359 netdev_dbg(dev, "Successfully created xenvif\n");
361 __module_get(THIS_MODULE);
366 int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
367 unsigned long rx_ring_ref, unsigned int tx_evtchn,
368 unsigned int rx_evtchn)
372 /* Already connected through? */
376 err = xenvif_map_frontend_rings(vif, tx_ring_ref, rx_ring_ref);
380 if (tx_evtchn == rx_evtchn) {
381 /* feature-split-event-channels == 0 */
382 err = bind_interdomain_evtchn_to_irqhandler(
383 vif->domid, tx_evtchn, xenvif_interrupt, 0,
384 vif->dev->name, vif);
387 vif->tx_irq = vif->rx_irq = err;
388 disable_irq(vif->tx_irq);
390 /* feature-split-event-channels == 1 */
391 snprintf(vif->tx_irq_name, sizeof(vif->tx_irq_name),
392 "%s-tx", vif->dev->name);
393 err = bind_interdomain_evtchn_to_irqhandler(
394 vif->domid, tx_evtchn, xenvif_tx_interrupt, 0,
395 vif->tx_irq_name, vif);
399 disable_irq(vif->tx_irq);
401 snprintf(vif->rx_irq_name, sizeof(vif->rx_irq_name),
402 "%s-rx", vif->dev->name);
403 err = bind_interdomain_evtchn_to_irqhandler(
404 vif->domid, rx_evtchn, xenvif_rx_interrupt, 0,
405 vif->rx_irq_name, vif);
409 disable_irq(vif->rx_irq);
412 init_waitqueue_head(&vif->wq);
413 vif->task = kthread_create(xenvif_kthread,
414 (void *)vif, "%s", vif->dev->name);
415 if (IS_ERR(vif->task)) {
416 pr_warn("Could not allocate kthread for %s\n", vif->dev->name);
417 err = PTR_ERR(vif->task);
422 if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN)
423 dev_set_mtu(vif->dev, ETH_DATA_LEN);
424 netdev_update_features(vif->dev);
425 netif_carrier_on(vif->dev);
426 if (netif_running(vif->dev))
430 wake_up_process(vif->task);
435 unbind_from_irqhandler(vif->rx_irq, vif);
438 unbind_from_irqhandler(vif->tx_irq, vif);
441 xenvif_unmap_frontend_rings(vif);
443 module_put(THIS_MODULE);
447 void xenvif_carrier_off(struct xenvif *vif)
449 struct net_device *dev = vif->dev;
452 netif_carrier_off(dev); /* discard queued packets */
453 if (netif_running(dev))
458 void xenvif_disconnect(struct xenvif *vif)
460 if (netif_carrier_ok(vif->dev))
461 xenvif_carrier_off(vif);
464 if (vif->tx_irq == vif->rx_irq)
465 unbind_from_irqhandler(vif->tx_irq, vif);
467 unbind_from_irqhandler(vif->tx_irq, vif);
468 unbind_from_irqhandler(vif->rx_irq, vif);
474 kthread_stop(vif->task);
476 xenvif_unmap_frontend_rings(vif);
479 void xenvif_free(struct xenvif *vif)
481 netif_napi_del(&vif->napi);
483 unregister_netdev(vif->dev);
485 free_netdev(vif->dev);
487 module_put(THIS_MODULE);