1 files changed, 484 insertions, 0 deletions
diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
new file mode 100644
index 000000000000..01bb854c7f62
--- /dev/null
+++ b/drivers/net/xen-netback/interface.c
@@ -0,0 +1,484 @@
+/*
+ * Network-device interface management.
+ *
+ * Copyright (c) 2004-2005, Keir Fraser
+ *
+ * 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 "common.h"
+
+#include <linux/kthread.h>
+#include <linux/ethtool.h>
+#include <linux/rtnetlink.h>
+#include <linux/if_vlan.h>
+
+#include <xen/events.h>
+#include <asm/xen/hypercall.h>
+
+#define XENVIF_QUEUE_LENGTH 32
+#define XENVIF_NAPI_WEIGHT  64
+
+int xenvif_schedulable(struct xenvif *vif)
+{
+	return netif_running(vif->dev) && netif_carrier_ok(vif->dev);
+}
+
+static int xenvif_rx_schedulable(struct xenvif *vif)
+{
+	return xenvif_schedulable(vif) && !xenvif_rx_ring_full(vif);
+}
+
+static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id)
+{
+	struct xenvif *vif = dev_id;
+
+	if (RING_HAS_UNCONSUMED_REQUESTS(&vif->tx))
+		napi_schedule(&vif->napi);
+
+	return IRQ_HANDLED;
+}
+
+static int xenvif_poll(struct napi_struct *napi, int budget)
+{
+	struct xenvif *vif = container_of(napi, struct xenvif, napi);
+	int work_done;
+
+	work_done = xenvif_tx_action(vif, budget);
+
+	if (work_done < budget) {
+		int more_to_do = 0;
+		unsigned long flags;
+
+		/* It is necessary to disable IRQ before calling
+		 * RING_HAS_UNCONSUMED_REQUESTS. Otherwise we might
+		 * lose event from the frontend.
+		 *
+		 * Consider:
+		 *   RING_HAS_UNCONSUMED_REQUESTS
+		 *   <frontend generates event to trigger napi_schedule>
+		 *   __napi_complete
+		 *
+		 * This handler is still in scheduled state so the
+		 * event has no effect at all. After __napi_complete
+		 * this handler is descheduled and cannot get
+		 * scheduled again. We lose event in this case and the ring
+		 * will be completely stalled.
+		 */
+
+		local_irq_save(flags);
+
+		RING_FINAL_CHECK_FOR_REQUESTS(&vif->tx, more_to_do);
+		if (!more_to_do)
+			__napi_complete(napi);
+
+		local_irq_restore(flags);
+	}
+
+	return work_done;
+}
+
+static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id)
+{
+	struct xenvif *vif = dev_id;
+
+	if (xenvif_rx_schedulable(vif))
+		netif_wake_queue(vif->dev);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t xenvif_interrupt(int irq, void *dev_id)
+{
+	xenvif_tx_interrupt(irq, dev_id);
+	xenvif_rx_interrupt(irq, dev_id);
+
+	return IRQ_HANDLED;
+}
+
+static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct xenvif *vif = netdev_priv(dev);
+
+	BUG_ON(skb->dev != dev);
+
+	/* Drop the packet if vif is not ready */
+	if (vif->task == NULL)
+		goto drop;
+
+	/* Drop the packet if the target domain has no receive buffers. */
+	if (!xenvif_rx_schedulable(vif))
+		goto drop;
+
+	/* Reserve ring slots for the worst-case number of fragments. */
+	vif->rx_req_cons_peek += xenvif_count_skb_slots(vif, skb);
+
+	if (vif->can_queue && xenvif_must_stop_queue(vif))
+		netif_stop_queue(dev);
+
+	xenvif_queue_tx_skb(vif, skb);
+
+	return NETDEV_TX_OK;
+
+ drop:
+	vif->dev->stats.tx_dropped++;
+	dev_kfree_skb(skb);
+	return NETDEV_TX_OK;
+}
+
+void xenvif_notify_tx_completion(struct xenvif *vif)
+{
+	if (netif_queue_stopped(vif->dev) && xenvif_rx_schedulable(vif))
+		netif_wake_queue(vif->dev);
+}
+
+static struct net_device_stats *xenvif_get_stats(struct net_device *dev)
+{
+	struct xenvif *vif = netdev_priv(dev);
+	return &vif->dev->stats;
+}
+
+static void xenvif_up(struct xenvif *vif)
+{
+	napi_enable(&vif->napi);
+	enable_irq(vif->tx_irq);
+	if (vif->tx_irq != vif->rx_irq)
+		enable_irq(vif->rx_irq);
+	xenvif_check_rx_xenvif(vif);
+}
+
+static void xenvif_down(struct xenvif *vif)
+{
+	napi_disable(&vif->napi);
+	disable_irq(vif->tx_irq);
+	if (vif->tx_irq != vif->rx_irq)
+		disable_irq(vif->rx_irq);
+	del_timer_sync(&vif->credit_timeout);
+}
+
+static int xenvif_open(struct net_device *dev)
+{
+	struct xenvif *vif = netdev_priv(dev);
+	if (netif_carrier_ok(dev))
+		xenvif_up(vif);
+	netif_start_queue(dev);
+	return 0;
+}
+
+static int xenvif_close(struct net_device *dev)
+{
+	struct xenvif *vif = netdev_priv(dev);
+	if (netif_carrier_ok(dev))
+		xenvif_down(vif);
+	netif_stop_queue(dev);
+	return 0;
+}
+
+static int xenvif_change_mtu(struct net_device *dev, int mtu)
+{
+	struct xenvif *vif = netdev_priv(dev);
+	int max = vif->can_sg ? 65535 - VLAN_ETH_HLEN : ETH_DATA_LEN;
+
+	if (mtu > max)
+		return -EINVAL;
+	dev->mtu = mtu;
+	return 0;
+}
+
+static netdev_features_t xenvif_fix_features(struct net_device *dev,
+	netdev_features_t features)
+{
+	struct xenvif *vif = netdev_priv(dev);
+
+	if (!vif->can_sg)
+		features &= ~NETIF_F_SG;
+	if (!vif->gso && !vif->gso_prefix)
+		features &= ~NETIF_F_TSO;
+	if (!vif->csum)
+		features &= ~NETIF_F_IP_CSUM;
+
+	return features;
+}
+
+static const struct xenvif_stat {
+	char name[ETH_GSTRING_LEN];
+	u16 offset;
+} xenvif_stats[] = {
+	{
+		"rx_gso_checksum_fixup",
+		offsetof(struct xenvif, rx_gso_checksum_fixup)
+	},
+};
+
+static int xenvif_get_sset_count(struct net_device *dev, int string_set)
+{
+	switch (string_set) {
+	case ETH_SS_STATS:
+		return ARRAY_SIZE(xenvif_stats);
+	default:
+		return -EINVAL;
+	}
+}
+
+static void xenvif_get_ethtool_stats(struct net_device *dev,
+				     struct ethtool_stats *stats, u64 * data)
+{
+	void *vif = netdev_priv(dev);
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
+		data[i] = *(unsigned long *)(vif + xenvif_stats[i].offset);
+}
+
+static void xenvif_get_strings(struct net_device *dev, u32 stringset, u8 * data)
+{
+	int i;
+
+	switch (stringset) {
+	case ETH_SS_STATS:
+		for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
+			memcpy(data + i * ETH_GSTRING_LEN,
+			       xenvif_stats[i].name, ETH_GSTRING_LEN);
+		break;
+	}
+}
+
+static const struct ethtool_ops xenvif_ethtool_ops = {
+	.get_link	= ethtool_op_get_link,
+
+	.get_sset_count = xenvif_get_sset_count,
+	.get_ethtool_stats = xenvif_get_ethtool_stats,
+	.get_strings = xenvif_get_strings,
+};
+
+static const struct net_device_ops xenvif_netdev_ops = {
+	.ndo_start_xmit	= xenvif_start_xmit,
+	.ndo_get_stats	= xenvif_get_stats,
+	.ndo_open	= xenvif_open,
+	.ndo_stop	= xenvif_close,
+	.ndo_change_mtu	= xenvif_change_mtu,
+	.ndo_fix_features = xenvif_fix_features,
+	.ndo_set_mac_address = eth_mac_addr,
+	.ndo_validate_addr   = eth_validate_addr,
+};
+
+struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
+			    unsigned int handle)
+{
+	int err;
+	struct net_device *dev;
+	struct xenvif *vif;
+	char name[IFNAMSIZ] = {};
+	int i;
+
+	snprintf(name, IFNAMSIZ - 1, "vif%u.%u", domid, handle);
+	dev = alloc_netdev(sizeof(struct xenvif), name, ether_setup);
+	if (dev == NULL) {
+		pr_warn("Could not allocate netdev for %s\n", name);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	SET_NETDEV_DEV(dev, parent);
+
+	vif = netdev_priv(dev);
+	vif->domid  = domid;
+	vif->handle = handle;
+	vif->can_sg = 1;
+	vif->csum = 1;
+	vif->dev = dev;
+
+	vif->credit_bytes = vif->remaining_credit = ~0UL;
+	vif->credit_usec  = 0UL;
+	init_timer(&vif->credit_timeout);
+	/* Initialize 'expires' now: it's used to track the credit window. */
+	vif->credit_timeout.expires = jiffies;
+
+	dev->netdev_ops	= &xenvif_netdev_ops;
+	dev->hw_features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_TSO;
+	dev->features = dev->hw_features;
+	SET_ETHTOOL_OPS(dev, &xenvif_ethtool_ops);
+
+	dev->tx_queue_len = XENVIF_QUEUE_LENGTH;
+
+	skb_queue_head_init(&vif->rx_queue);
+	skb_queue_head_init(&vif->tx_queue);
+
+	vif->pending_cons = 0;
+	vif->pending_prod = MAX_PENDING_REQS;
+	for (i = 0; i < MAX_PENDING_REQS; i++)
+		vif->pending_ring[i] = i;
+	for (i = 0; i < MAX_PENDING_REQS; i++)
+		vif->mmap_pages[i] = NULL;
+
+	/*
+	 * Initialise a dummy MAC address. We choose the numerically
+	 * largest non-broadcast address to prevent the address getting
+	 * stolen by an Ethernet bridge for STP purposes.
+	 * (FE:FF:FF:FF:FF:FF)
+	 */
+	memset(dev->dev_addr, 0xFF, ETH_ALEN);
+	dev->dev_addr[0] &= ~0x01;
+
+	netif_napi_add(dev, &vif->napi, xenvif_poll, XENVIF_NAPI_WEIGHT);
+
+	netif_carrier_off(dev);
+
+	err = register_netdev(dev);
+	if (err) {
+		netdev_warn(dev, "Could not register device: err=%d\n", err);
+		free_netdev(dev);
+		return ERR_PTR(err);
+	}
+
+	netdev_dbg(dev, "Successfully created xenvif\n");
+
+	__module_get(THIS_MODULE);
+
+	return vif;
+}
+
+int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
+		   unsigned long rx_ring_ref, unsigned int tx_evtchn,
+		   unsigned int rx_evtchn)
+{
+	int err = -ENOMEM;
+
+	/* Already connected through? */
+	if (vif->tx_irq)
+		return 0;
+
+	err = xenvif_map_frontend_rings(vif, tx_ring_ref, rx_ring_ref);
+	if (err < 0)
+		goto err;
+
+	if (tx_evtchn == rx_evtchn) {
+		/* feature-split-event-channels == 0 */
+		err = bind_interdomain_evtchn_to_irqhandler(
+			vif->domid, tx_evtchn, xenvif_interrupt, 0,
+			vif->dev->name, vif);
+		if (err < 0)
+			goto err_unmap;
+		vif->tx_irq = vif->rx_irq = err;
+		disable_irq(vif->tx_irq);
+	} else {
+		/* feature-split-event-channels == 1 */
+		snprintf(vif->tx_irq_name, sizeof(vif->tx_irq_name),
+			 "%s-tx", vif->dev->name);
+		err = bind_interdomain_evtchn_to_irqhandler(
+			vif->domid, tx_evtchn, xenvif_tx_interrupt, 0,
+			vif->tx_irq_name, vif);
+		if (err < 0)
+			goto err_unmap;
+		vif->tx_irq = err;
+		disable_irq(vif->tx_irq);
+
+		snprintf(vif->rx_irq_name, sizeof(vif->rx_irq_name),
+			 "%s-rx", vif->dev->name);
+		err = bind_interdomain_evtchn_to_irqhandler(
+			vif->domid, rx_evtchn, xenvif_rx_interrupt, 0,
+			vif->rx_irq_name, vif);
+		if (err < 0)
+			goto err_tx_unbind;
+		vif->rx_irq = err;
+		disable_irq(vif->rx_irq);
+	}
+
+	init_waitqueue_head(&vif->wq);
+	vif->task = kthread_create(xenvif_kthread,
+				   (void *)vif, "%s", vif->dev->name);
+	if (IS_ERR(vif->task)) {
+		pr_warn("Could not allocate kthread for %s\n", vif->dev->name);
+		err = PTR_ERR(vif->task);
+		goto err_rx_unbind;
+	}
+
+	rtnl_lock();
+	if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN)
+		dev_set_mtu(vif->dev, ETH_DATA_LEN);
+	netdev_update_features(vif->dev);
+	netif_carrier_on(vif->dev);
+	if (netif_running(vif->dev))
+		xenvif_up(vif);
+	rtnl_unlock();
+
+	wake_up_process(vif->task);
+
+	return 0;
+
+err_rx_unbind:
+	unbind_from_irqhandler(vif->rx_irq, vif);
+	vif->rx_irq = 0;
+err_tx_unbind:
+	unbind_from_irqhandler(vif->tx_irq, vif);
+	vif->tx_irq = 0;
+err_unmap:
+	xenvif_unmap_frontend_rings(vif);
+err:
+	module_put(THIS_MODULE);
+	return err;
+}
+
+void xenvif_carrier_off(struct xenvif *vif)
+{
+	struct net_device *dev = vif->dev;
+
+	rtnl_lock();
+	netif_carrier_off(dev); /* discard queued packets */
+	if (netif_running(dev))
+		xenvif_down(vif);
+	rtnl_unlock();
+}
+
+void xenvif_disconnect(struct xenvif *vif)
+{
+	if (netif_carrier_ok(vif->dev))
+		xenvif_carrier_off(vif);
+
+	if (vif->tx_irq) {
+		if (vif->tx_irq == vif->rx_irq)
+			unbind_from_irqhandler(vif->tx_irq, vif);
+		else {
+			unbind_from_irqhandler(vif->tx_irq, vif);
+			unbind_from_irqhandler(vif->rx_irq, vif);
+		}
+		vif->tx_irq = 0;
+	}
+
+	if (vif->task)
+		kthread_stop(vif->task);
+
+	xenvif_unmap_frontend_rings(vif);
+}
+
+void xenvif_free(struct xenvif *vif)
+{
+	netif_napi_del(&vif->napi);
+
+	unregister_netdev(vif->dev);
+
+	free_netdev(vif->dev);
+
+	module_put(THIS_MODULE);
+}