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;
225 static const struct xenvif_stat {
226 char name[ETH_GSTRING_LEN];
230 "rx_gso_checksum_fixup",
231 offsetof(struct xenvif, rx_gso_checksum_fixup)
235 static int xenvif_get_sset_count(struct net_device *dev, int string_set)
237 switch (string_set) {
239 return ARRAY_SIZE(xenvif_stats);
245 static void xenvif_get_ethtool_stats(struct net_device *dev,
246 struct ethtool_stats *stats, u64 * data)
248 void *vif = netdev_priv(dev);
251 for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
252 data[i] = *(unsigned long *)(vif + xenvif_stats[i].offset);
255 static void xenvif_get_strings(struct net_device *dev, u32 stringset, u8 * data)
261 for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
262 memcpy(data + i * ETH_GSTRING_LEN,
263 xenvif_stats[i].name, ETH_GSTRING_LEN);
268 static const struct ethtool_ops xenvif_ethtool_ops = {
269 .get_link = ethtool_op_get_link,
271 .get_sset_count = xenvif_get_sset_count,
272 .get_ethtool_stats = xenvif_get_ethtool_stats,
273 .get_strings = xenvif_get_strings,
276 static const struct net_device_ops xenvif_netdev_ops = {
277 .ndo_start_xmit = xenvif_start_xmit,
278 .ndo_get_stats = xenvif_get_stats,
279 .ndo_open = xenvif_open,
280 .ndo_stop = xenvif_close,
281 .ndo_change_mtu = xenvif_change_mtu,
282 .ndo_fix_features = xenvif_fix_features,
283 .ndo_set_mac_address = eth_mac_addr,
284 .ndo_validate_addr = eth_validate_addr,
287 struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
291 struct net_device *dev;
293 char name[IFNAMSIZ] = {};
296 snprintf(name, IFNAMSIZ - 1, "vif%u.%u", domid, handle);
297 dev = alloc_netdev(sizeof(struct xenvif), name, ether_setup);
299 pr_warn("Could not allocate netdev for %s\n", name);
300 return ERR_PTR(-ENOMEM);
303 SET_NETDEV_DEV(dev, parent);
305 vif = netdev_priv(dev);
307 vif->handle = handle;
312 vif->credit_bytes = vif->remaining_credit = ~0UL;
313 vif->credit_usec = 0UL;
314 init_timer(&vif->credit_timeout);
315 /* Initialize 'expires' now: it's used to track the credit window. */
316 vif->credit_timeout.expires = jiffies;
318 dev->netdev_ops = &xenvif_netdev_ops;
319 dev->hw_features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_TSO;
320 dev->features = dev->hw_features;
321 SET_ETHTOOL_OPS(dev, &xenvif_ethtool_ops);
323 dev->tx_queue_len = XENVIF_QUEUE_LENGTH;
325 skb_queue_head_init(&vif->rx_queue);
326 skb_queue_head_init(&vif->tx_queue);
328 vif->pending_cons = 0;
329 vif->pending_prod = MAX_PENDING_REQS;
330 for (i = 0; i < MAX_PENDING_REQS; i++)
331 vif->pending_ring[i] = i;
332 for (i = 0; i < MAX_PENDING_REQS; i++)
333 vif->mmap_pages[i] = NULL;
336 * Initialise a dummy MAC address. We choose the numerically
337 * largest non-broadcast address to prevent the address getting
338 * stolen by an Ethernet bridge for STP purposes.
339 * (FE:FF:FF:FF:FF:FF)
341 memset(dev->dev_addr, 0xFF, ETH_ALEN);
342 dev->dev_addr[0] &= ~0x01;
344 netif_napi_add(dev, &vif->napi, xenvif_poll, XENVIF_NAPI_WEIGHT);
346 netif_carrier_off(dev);
348 err = register_netdev(dev);
350 netdev_warn(dev, "Could not register device: err=%d\n", err);
355 netdev_dbg(dev, "Successfully created xenvif\n");
357 __module_get(THIS_MODULE);
362 int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
363 unsigned long rx_ring_ref, unsigned int tx_evtchn,
364 unsigned int rx_evtchn)
368 /* Already connected through? */
372 err = xenvif_map_frontend_rings(vif, tx_ring_ref, rx_ring_ref);
376 if (tx_evtchn == rx_evtchn) {
377 /* feature-split-event-channels == 0 */
378 err = bind_interdomain_evtchn_to_irqhandler(
379 vif->domid, tx_evtchn, xenvif_interrupt, 0,
380 vif->dev->name, vif);
383 vif->tx_irq = vif->rx_irq = err;
384 disable_irq(vif->tx_irq);
386 /* feature-split-event-channels == 1 */
387 snprintf(vif->tx_irq_name, sizeof(vif->tx_irq_name),
388 "%s-tx", vif->dev->name);
389 err = bind_interdomain_evtchn_to_irqhandler(
390 vif->domid, tx_evtchn, xenvif_tx_interrupt, 0,
391 vif->tx_irq_name, vif);
395 disable_irq(vif->tx_irq);
397 snprintf(vif->rx_irq_name, sizeof(vif->rx_irq_name),
398 "%s-rx", vif->dev->name);
399 err = bind_interdomain_evtchn_to_irqhandler(
400 vif->domid, rx_evtchn, xenvif_rx_interrupt, 0,
401 vif->rx_irq_name, vif);
405 disable_irq(vif->rx_irq);
408 init_waitqueue_head(&vif->wq);
409 vif->task = kthread_create(xenvif_kthread,
410 (void *)vif, "%s", vif->dev->name);
411 if (IS_ERR(vif->task)) {
412 pr_warn("Could not allocate kthread for %s\n", vif->dev->name);
413 err = PTR_ERR(vif->task);
418 if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN)
419 dev_set_mtu(vif->dev, ETH_DATA_LEN);
420 netdev_update_features(vif->dev);
421 netif_carrier_on(vif->dev);
422 if (netif_running(vif->dev))
426 wake_up_process(vif->task);
431 unbind_from_irqhandler(vif->rx_irq, vif);
434 unbind_from_irqhandler(vif->tx_irq, vif);
437 xenvif_unmap_frontend_rings(vif);
439 module_put(THIS_MODULE);
443 void xenvif_carrier_off(struct xenvif *vif)
445 struct net_device *dev = vif->dev;
448 netif_carrier_off(dev); /* discard queued packets */
449 if (netif_running(dev))
454 void xenvif_disconnect(struct xenvif *vif)
456 if (netif_carrier_ok(vif->dev))
457 xenvif_carrier_off(vif);
460 if (vif->tx_irq == vif->rx_irq)
461 unbind_from_irqhandler(vif->tx_irq, vif);
463 unbind_from_irqhandler(vif->tx_irq, vif);
464 unbind_from_irqhandler(vif->rx_irq, vif);
470 kthread_stop(vif->task);
472 xenvif_unmap_frontend_rings(vif);
475 void xenvif_free(struct xenvif *vif)
477 netif_napi_del(&vif->napi);
479 unregister_netdev(vif->dev);
481 free_netdev(vif->dev);
483 module_put(THIS_MODULE);