v4.19.13 snapshot.
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
new file mode 100644
index 0000000..f17f602
--- /dev/null
+++ b/drivers/net/xen-netfront.c
@@ -0,0 +1,2225 @@
+/*
+ * 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.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/ethtool.h>
+#include <linux/if_ether.h>
+#include <net/tcp.h>
+#include <linux/udp.h>
+#include <linux/moduleparam.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <net/ip.h>
+
+#include <xen/xen.h>
+#include <xen/xenbus.h>
+#include <xen/events.h>
+#include <xen/page.h>
+#include <xen/platform_pci.h>
+#include <xen/grant_table.h>
+
+#include <xen/interface/io/netif.h>
+#include <xen/interface/memory.h>
+#include <xen/interface/grant_table.h>
+
+/* Module parameters */
+#define MAX_QUEUES_DEFAULT 8
+static unsigned int xennet_max_queues;
+module_param_named(max_queues, xennet_max_queues, uint, 0644);
+MODULE_PARM_DESC(max_queues,
+ "Maximum number of queues per virtual interface");
+
+static const struct ethtool_ops xennet_ethtool_ops;
+
+struct netfront_cb {
+ int pull_to;
+};
+
+#define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
+
+#define RX_COPY_THRESHOLD 256
+
+#define GRANT_INVALID_REF 0
+
+#define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE)
+#define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE)
+
+/* Minimum number of Rx slots (includes slot for GSO metadata). */
+#define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
+
+/* Queue name is interface name with "-qNNN" appended */
+#define QUEUE_NAME_SIZE (IFNAMSIZ + 6)
+
+/* IRQ name is queue name with "-tx" or "-rx" appended */
+#define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
+
+static DECLARE_WAIT_QUEUE_HEAD(module_wq);
+
+struct netfront_stats {
+ u64 packets;
+ u64 bytes;
+ struct u64_stats_sync syncp;
+};
+
+struct netfront_info;
+
+struct netfront_queue {
+ unsigned int id; /* Queue ID, 0-based */
+ char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
+ struct netfront_info *info;
+
+ struct napi_struct napi;
+
+ /* Split event channels support, tx_* == rx_* when using
+ * single event channel.
+ */
+ unsigned int tx_evtchn, rx_evtchn;
+ unsigned int tx_irq, rx_irq;
+ /* Only used when split event channels support is enabled */
+ char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
+ char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
+
+ spinlock_t tx_lock;
+ struct xen_netif_tx_front_ring tx;
+ int tx_ring_ref;
+
+ /*
+ * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
+ * are linked from tx_skb_freelist through skb_entry.link.
+ *
+ * NB. 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.
+ */
+ union skb_entry {
+ struct sk_buff *skb;
+ unsigned long link;
+ } tx_skbs[NET_TX_RING_SIZE];
+ grant_ref_t gref_tx_head;
+ grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
+ struct page *grant_tx_page[NET_TX_RING_SIZE];
+ unsigned tx_skb_freelist;
+
+ spinlock_t rx_lock ____cacheline_aligned_in_smp;
+ struct xen_netif_rx_front_ring rx;
+ int rx_ring_ref;
+
+ struct timer_list rx_refill_timer;
+
+ struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
+ grant_ref_t gref_rx_head;
+ grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
+};
+
+struct netfront_info {
+ struct list_head list;
+ struct net_device *netdev;
+
+ struct xenbus_device *xbdev;
+
+ /* Multi-queue support */
+ struct netfront_queue *queues;
+
+ /* Statistics */
+ struct netfront_stats __percpu *rx_stats;
+ struct netfront_stats __percpu *tx_stats;
+
+ atomic_t rx_gso_checksum_fixup;
+};
+
+struct netfront_rx_info {
+ struct xen_netif_rx_response rx;
+ struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
+};
+
+static void skb_entry_set_link(union skb_entry *list, unsigned short id)
+{
+ list->link = id;
+}
+
+static int skb_entry_is_link(const union skb_entry *list)
+{
+ BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
+ return (unsigned long)list->skb < PAGE_OFFSET;
+}
+
+/*
+ * Access macros for acquiring freeing slots in tx_skbs[].
+ */
+
+static void add_id_to_freelist(unsigned *head, union skb_entry *list,
+ unsigned short id)
+{
+ skb_entry_set_link(&list[id], *head);
+ *head = id;
+}
+
+static unsigned short get_id_from_freelist(unsigned *head,
+ union skb_entry *list)
+{
+ unsigned int id = *head;
+ *head = list[id].link;
+ return id;
+}
+
+static int xennet_rxidx(RING_IDX idx)
+{
+ return idx & (NET_RX_RING_SIZE - 1);
+}
+
+static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
+ RING_IDX ri)
+{
+ int i = xennet_rxidx(ri);
+ struct sk_buff *skb = queue->rx_skbs[i];
+ queue->rx_skbs[i] = NULL;
+ return skb;
+}
+
+static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
+ RING_IDX ri)
+{
+ int i = xennet_rxidx(ri);
+ grant_ref_t ref = queue->grant_rx_ref[i];
+ queue->grant_rx_ref[i] = GRANT_INVALID_REF;
+ return ref;
+}
+
+#ifdef CONFIG_SYSFS
+static const struct attribute_group xennet_dev_group;
+#endif
+
+static bool xennet_can_sg(struct net_device *dev)
+{
+ return dev->features & NETIF_F_SG;
+}
+
+
+static void rx_refill_timeout(struct timer_list *t)
+{
+ struct netfront_queue *queue = from_timer(queue, t, rx_refill_timer);
+ napi_schedule(&queue->napi);
+}
+
+static int netfront_tx_slot_available(struct netfront_queue *queue)
+{
+ return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
+ (NET_TX_RING_SIZE - XEN_NETIF_NR_SLOTS_MIN - 1);
+}
+
+static void xennet_maybe_wake_tx(struct netfront_queue *queue)
+{
+ struct net_device *dev = queue->info->netdev;
+ struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
+
+ if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
+ netfront_tx_slot_available(queue) &&
+ likely(netif_running(dev)))
+ netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
+}
+
+
+static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
+{
+ struct sk_buff *skb;
+ struct page *page;
+
+ skb = __netdev_alloc_skb(queue->info->netdev,
+ RX_COPY_THRESHOLD + NET_IP_ALIGN,
+ GFP_ATOMIC | __GFP_NOWARN);
+ if (unlikely(!skb))
+ return NULL;
+
+ page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
+ if (!page) {
+ kfree_skb(skb);
+ return NULL;
+ }
+ skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
+
+ /* Align ip header to a 16 bytes boundary */
+ skb_reserve(skb, NET_IP_ALIGN);
+ skb->dev = queue->info->netdev;
+
+ return skb;
+}
+
+
+static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
+{
+ RING_IDX req_prod = queue->rx.req_prod_pvt;
+ int notify;
+ int err = 0;
+
+ if (unlikely(!netif_carrier_ok(queue->info->netdev)))
+ return;
+
+ for (req_prod = queue->rx.req_prod_pvt;
+ req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
+ req_prod++) {
+ struct sk_buff *skb;
+ unsigned short id;
+ grant_ref_t ref;
+ struct page *page;
+ struct xen_netif_rx_request *req;
+
+ skb = xennet_alloc_one_rx_buffer(queue);
+ if (!skb) {
+ err = -ENOMEM;
+ break;
+ }
+
+ id = xennet_rxidx(req_prod);
+
+ BUG_ON(queue->rx_skbs[id]);
+ queue->rx_skbs[id] = skb;
+
+ ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
+ WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
+ queue->grant_rx_ref[id] = ref;
+
+ page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
+
+ req = RING_GET_REQUEST(&queue->rx, req_prod);
+ gnttab_page_grant_foreign_access_ref_one(ref,
+ queue->info->xbdev->otherend_id,
+ page,
+ 0);
+ req->id = id;
+ req->gref = ref;
+ }
+
+ queue->rx.req_prod_pvt = req_prod;
+
+ /* Try again later if there are not enough requests or skb allocation
+ * failed.
+ * Enough requests is quantified as the sum of newly created slots and
+ * the unconsumed slots at the backend.
+ */
+ if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN ||
+ unlikely(err)) {
+ mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
+ return;
+ }
+
+ wmb(); /* barrier so backend seens requests */
+
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
+ if (notify)
+ notify_remote_via_irq(queue->rx_irq);
+}
+
+static int xennet_open(struct net_device *dev)
+{
+ struct netfront_info *np = netdev_priv(dev);
+ unsigned int num_queues = dev->real_num_tx_queues;
+ unsigned int i = 0;
+ struct netfront_queue *queue = NULL;
+
+ if (!np->queues)
+ return -ENODEV;
+
+ for (i = 0; i < num_queues; ++i) {
+ queue = &np->queues[i];
+ napi_enable(&queue->napi);
+
+ spin_lock_bh(&queue->rx_lock);
+ if (netif_carrier_ok(dev)) {
+ xennet_alloc_rx_buffers(queue);
+ queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
+ if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
+ napi_schedule(&queue->napi);
+ }
+ spin_unlock_bh(&queue->rx_lock);
+ }
+
+ netif_tx_start_all_queues(dev);
+
+ return 0;
+}
+
+static void xennet_tx_buf_gc(struct netfront_queue *queue)
+{
+ RING_IDX cons, prod;
+ unsigned short id;
+ struct sk_buff *skb;
+ bool more_to_do;
+
+ BUG_ON(!netif_carrier_ok(queue->info->netdev));
+
+ do {
+ prod = queue->tx.sring->rsp_prod;
+ rmb(); /* Ensure we see responses up to 'rp'. */
+
+ for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
+ struct xen_netif_tx_response *txrsp;
+
+ txrsp = RING_GET_RESPONSE(&queue->tx, cons);
+ if (txrsp->status == XEN_NETIF_RSP_NULL)
+ continue;
+
+ id = txrsp->id;
+ skb = queue->tx_skbs[id].skb;
+ if (unlikely(gnttab_query_foreign_access(
+ queue->grant_tx_ref[id]) != 0)) {
+ pr_alert("%s: warning -- grant still in use by backend domain\n",
+ __func__);
+ BUG();
+ }
+ gnttab_end_foreign_access_ref(
+ queue->grant_tx_ref[id], GNTMAP_readonly);
+ gnttab_release_grant_reference(
+ &queue->gref_tx_head, queue->grant_tx_ref[id]);
+ queue->grant_tx_ref[id] = GRANT_INVALID_REF;
+ queue->grant_tx_page[id] = NULL;
+ add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id);
+ dev_kfree_skb_irq(skb);
+ }
+
+ queue->tx.rsp_cons = prod;
+
+ RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do);
+ } while (more_to_do);
+
+ xennet_maybe_wake_tx(queue);
+}
+
+struct xennet_gnttab_make_txreq {
+ struct netfront_queue *queue;
+ struct sk_buff *skb;
+ struct page *page;
+ struct xen_netif_tx_request *tx; /* Last request */
+ unsigned int size;
+};
+
+static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset,
+ unsigned int len, void *data)
+{
+ struct xennet_gnttab_make_txreq *info = data;
+ unsigned int id;
+ struct xen_netif_tx_request *tx;
+ grant_ref_t ref;
+ /* convenient aliases */
+ struct page *page = info->page;
+ struct netfront_queue *queue = info->queue;
+ struct sk_buff *skb = info->skb;
+
+ id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
+ tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
+ ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
+ WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
+
+ gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
+ gfn, GNTMAP_readonly);
+
+ queue->tx_skbs[id].skb = skb;
+ queue->grant_tx_page[id] = page;
+ queue->grant_tx_ref[id] = ref;
+
+ tx->id = id;
+ tx->gref = ref;
+ tx->offset = offset;
+ tx->size = len;
+ tx->flags = 0;
+
+ info->tx = tx;
+ info->size += tx->size;
+}
+
+static struct xen_netif_tx_request *xennet_make_first_txreq(
+ struct netfront_queue *queue, struct sk_buff *skb,
+ struct page *page, unsigned int offset, unsigned int len)
+{
+ struct xennet_gnttab_make_txreq info = {
+ .queue = queue,
+ .skb = skb,
+ .page = page,
+ .size = 0,
+ };
+
+ gnttab_for_one_grant(page, offset, len, xennet_tx_setup_grant, &info);
+
+ return info.tx;
+}
+
+static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset,
+ unsigned int len, void *data)
+{
+ struct xennet_gnttab_make_txreq *info = data;
+
+ info->tx->flags |= XEN_NETTXF_more_data;
+ skb_get(info->skb);
+ xennet_tx_setup_grant(gfn, offset, len, data);
+}
+
+static struct xen_netif_tx_request *xennet_make_txreqs(
+ struct netfront_queue *queue, struct xen_netif_tx_request *tx,
+ struct sk_buff *skb, struct page *page,
+ unsigned int offset, unsigned int len)
+{
+ struct xennet_gnttab_make_txreq info = {
+ .queue = queue,
+ .skb = skb,
+ .tx = tx,
+ };
+
+ /* Skip unused frames from start of page */
+ page += offset >> PAGE_SHIFT;
+ offset &= ~PAGE_MASK;
+
+ while (len) {
+ info.page = page;
+ info.size = 0;
+
+ gnttab_foreach_grant_in_range(page, offset, len,
+ xennet_make_one_txreq,
+ &info);
+
+ page++;
+ offset = 0;
+ len -= info.size;
+ }
+
+ return info.tx;
+}
+
+/*
+ * Count how many ring slots are required to send this skb. Each frag
+ * might be a compound page.
+ */
+static int xennet_count_skb_slots(struct sk_buff *skb)
+{
+ int i, frags = skb_shinfo(skb)->nr_frags;
+ int slots;
+
+ slots = gnttab_count_grant(offset_in_page(skb->data),
+ skb_headlen(skb));
+
+ for (i = 0; i < frags; i++) {
+ skb_frag_t *frag = skb_shinfo(skb)->frags + i;
+ unsigned long size = skb_frag_size(frag);
+ unsigned long offset = frag->page_offset;
+
+ /* Skip unused frames from start of page */
+ offset &= ~PAGE_MASK;
+
+ slots += gnttab_count_grant(offset, size);
+ }
+
+ return slots;
+}
+
+static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
+ struct net_device *sb_dev,
+ select_queue_fallback_t fallback)
+{
+ unsigned int num_queues = dev->real_num_tx_queues;
+ u32 hash;
+ u16 queue_idx;
+
+ /* First, check if there is only one queue */
+ if (num_queues == 1) {
+ queue_idx = 0;
+ } else {
+ hash = skb_get_hash(skb);
+ queue_idx = hash % num_queues;
+ }
+
+ return queue_idx;
+}
+
+#define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
+
+static netdev_tx_t xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct netfront_info *np = netdev_priv(dev);
+ struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
+ struct xen_netif_tx_request *tx, *first_tx;
+ unsigned int i;
+ int notify;
+ int slots;
+ struct page *page;
+ unsigned int offset;
+ unsigned int len;
+ unsigned long flags;
+ struct netfront_queue *queue = NULL;
+ unsigned int num_queues = dev->real_num_tx_queues;
+ u16 queue_index;
+ struct sk_buff *nskb;
+
+ /* Drop the packet if no queues are set up */
+ if (num_queues < 1)
+ goto drop;
+ /* Determine which queue to transmit this SKB on */
+ queue_index = skb_get_queue_mapping(skb);
+ queue = &np->queues[queue_index];
+
+ /* If skb->len is too big for wire format, drop skb and alert
+ * user about misconfiguration.
+ */
+ if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
+ net_alert_ratelimited(
+ "xennet: skb->len = %u, too big for wire format\n",
+ skb->len);
+ goto drop;
+ }
+
+ slots = xennet_count_skb_slots(skb);
+ if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) {
+ net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
+ slots, skb->len);
+ if (skb_linearize(skb))
+ goto drop;
+ }
+
+ page = virt_to_page(skb->data);
+ offset = offset_in_page(skb->data);
+
+ /* The first req should be at least ETH_HLEN size or the packet will be
+ * dropped by netback.
+ */
+ if (unlikely(PAGE_SIZE - offset < ETH_HLEN)) {
+ nskb = skb_copy(skb, GFP_ATOMIC);
+ if (!nskb)
+ goto drop;
+ dev_consume_skb_any(skb);
+ skb = nskb;
+ page = virt_to_page(skb->data);
+ offset = offset_in_page(skb->data);
+ }
+
+ len = skb_headlen(skb);
+
+ spin_lock_irqsave(&queue->tx_lock, flags);
+
+ if (unlikely(!netif_carrier_ok(dev) ||
+ (slots > 1 && !xennet_can_sg(dev)) ||
+ netif_needs_gso(skb, netif_skb_features(skb)))) {
+ spin_unlock_irqrestore(&queue->tx_lock, flags);
+ goto drop;
+ }
+
+ /* First request for the linear area. */
+ first_tx = tx = xennet_make_first_txreq(queue, skb,
+ page, offset, len);
+ offset += tx->size;
+ if (offset == PAGE_SIZE) {
+ page++;
+ offset = 0;
+ }
+ len -= tx->size;
+
+ if (skb->ip_summed == CHECKSUM_PARTIAL)
+ /* local packet? */
+ tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
+ else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
+ /* remote but checksummed. */
+ tx->flags |= XEN_NETTXF_data_validated;
+
+ /* Optional extra info after the first request. */
+ if (skb_shinfo(skb)->gso_size) {
+ struct xen_netif_extra_info *gso;
+
+ gso = (struct xen_netif_extra_info *)
+ RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
+
+ tx->flags |= XEN_NETTXF_extra_info;
+
+ gso->u.gso.size = skb_shinfo(skb)->gso_size;
+ gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
+ XEN_NETIF_GSO_TYPE_TCPV6 :
+ XEN_NETIF_GSO_TYPE_TCPV4;
+ gso->u.gso.pad = 0;
+ gso->u.gso.features = 0;
+
+ gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
+ gso->flags = 0;
+ }
+
+ /* Requests for the rest of the linear area. */
+ tx = xennet_make_txreqs(queue, tx, skb, page, offset, len);
+
+ /* Requests for all the frags. */
+ for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+ skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+ tx = xennet_make_txreqs(queue, tx, skb,
+ skb_frag_page(frag), frag->page_offset,
+ skb_frag_size(frag));
+ }
+
+ /* First request has the packet length. */
+ first_tx->size = skb->len;
+
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
+ if (notify)
+ notify_remote_via_irq(queue->tx_irq);
+
+ u64_stats_update_begin(&tx_stats->syncp);
+ tx_stats->bytes += skb->len;
+ tx_stats->packets++;
+ u64_stats_update_end(&tx_stats->syncp);
+
+ /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
+ xennet_tx_buf_gc(queue);
+
+ if (!netfront_tx_slot_available(queue))
+ netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
+
+ spin_unlock_irqrestore(&queue->tx_lock, flags);
+
+ return NETDEV_TX_OK;
+
+ drop:
+ dev->stats.tx_dropped++;
+ dev_kfree_skb_any(skb);
+ return NETDEV_TX_OK;
+}
+
+static int xennet_close(struct net_device *dev)
+{
+ struct netfront_info *np = netdev_priv(dev);
+ unsigned int num_queues = dev->real_num_tx_queues;
+ unsigned int i;
+ struct netfront_queue *queue;
+ netif_tx_stop_all_queues(np->netdev);
+ for (i = 0; i < num_queues; ++i) {
+ queue = &np->queues[i];
+ napi_disable(&queue->napi);
+ }
+ return 0;
+}
+
+static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
+ grant_ref_t ref)
+{
+ int new = xennet_rxidx(queue->rx.req_prod_pvt);
+
+ BUG_ON(queue->rx_skbs[new]);
+ queue->rx_skbs[new] = skb;
+ queue->grant_rx_ref[new] = ref;
+ RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
+ RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
+ queue->rx.req_prod_pvt++;
+}
+
+static int xennet_get_extras(struct netfront_queue *queue,
+ struct xen_netif_extra_info *extras,
+ RING_IDX rp)
+
+{
+ struct xen_netif_extra_info *extra;
+ struct device *dev = &queue->info->netdev->dev;
+ RING_IDX cons = queue->rx.rsp_cons;
+ int err = 0;
+
+ do {
+ struct sk_buff *skb;
+ grant_ref_t ref;
+
+ if (unlikely(cons + 1 == rp)) {
+ if (net_ratelimit())
+ dev_warn(dev, "Missing extra info\n");
+ err = -EBADR;
+ break;
+ }
+
+ extra = (struct xen_netif_extra_info *)
+ RING_GET_RESPONSE(&queue->rx, ++cons);
+
+ if (unlikely(!extra->type ||
+ extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
+ if (net_ratelimit())
+ dev_warn(dev, "Invalid extra type: %d\n",
+ extra->type);
+ err = -EINVAL;
+ } else {
+ memcpy(&extras[extra->type - 1], extra,
+ sizeof(*extra));
+ }
+
+ skb = xennet_get_rx_skb(queue, cons);
+ ref = xennet_get_rx_ref(queue, cons);
+ xennet_move_rx_slot(queue, skb, ref);
+ } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
+
+ queue->rx.rsp_cons = cons;
+ return err;
+}
+
+static int xennet_get_responses(struct netfront_queue *queue,
+ struct netfront_rx_info *rinfo, RING_IDX rp,
+ struct sk_buff_head *list)
+{
+ struct xen_netif_rx_response *rx = &rinfo->rx;
+ struct xen_netif_extra_info *extras = rinfo->extras;
+ struct device *dev = &queue->info->netdev->dev;
+ RING_IDX cons = queue->rx.rsp_cons;
+ struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
+ grant_ref_t ref = xennet_get_rx_ref(queue, cons);
+ int max = XEN_NETIF_NR_SLOTS_MIN + (rx->status <= RX_COPY_THRESHOLD);
+ int slots = 1;
+ int err = 0;
+ unsigned long ret;
+
+ if (rx->flags & XEN_NETRXF_extra_info) {
+ err = xennet_get_extras(queue, extras, rp);
+ cons = queue->rx.rsp_cons;
+ }
+
+ for (;;) {
+ if (unlikely(rx->status < 0 ||
+ rx->offset + rx->status > XEN_PAGE_SIZE)) {
+ if (net_ratelimit())
+ dev_warn(dev, "rx->offset: %u, size: %d\n",
+ rx->offset, rx->status);
+ xennet_move_rx_slot(queue, skb, ref);
+ err = -EINVAL;
+ goto next;
+ }
+
+ /*
+ * 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 backend.
+ */
+ if (ref == GRANT_INVALID_REF) {
+ if (net_ratelimit())
+ dev_warn(dev, "Bad rx response id %d.\n",
+ rx->id);
+ err = -EINVAL;
+ goto next;
+ }
+
+ ret = gnttab_end_foreign_access_ref(ref, 0);
+ BUG_ON(!ret);
+
+ gnttab_release_grant_reference(&queue->gref_rx_head, ref);
+
+ __skb_queue_tail(list, skb);
+
+next:
+ if (!(rx->flags & XEN_NETRXF_more_data))
+ break;
+
+ if (cons + slots == rp) {
+ if (net_ratelimit())
+ dev_warn(dev, "Need more slots\n");
+ err = -ENOENT;
+ break;
+ }
+
+ rx = RING_GET_RESPONSE(&queue->rx, cons + slots);
+ skb = xennet_get_rx_skb(queue, cons + slots);
+ ref = xennet_get_rx_ref(queue, cons + slots);
+ slots++;
+ }
+
+ if (unlikely(slots > max)) {
+ if (net_ratelimit())
+ dev_warn(dev, "Too many slots\n");
+ err = -E2BIG;
+ }
+
+ if (unlikely(err))
+ queue->rx.rsp_cons = cons + slots;
+
+ return err;
+}
+
+static int xennet_set_skb_gso(struct sk_buff *skb,
+ struct xen_netif_extra_info *gso)
+{
+ if (!gso->u.gso.size) {
+ if (net_ratelimit())
+ pr_warn("GSO size must not be zero\n");
+ return -EINVAL;
+ }
+
+ if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
+ gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
+ if (net_ratelimit())
+ pr_warn("Bad GSO type %d\n", gso->u.gso.type);
+ return -EINVAL;
+ }
+
+ skb_shinfo(skb)->gso_size = gso->u.gso.size;
+ skb_shinfo(skb)->gso_type =
+ (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
+ SKB_GSO_TCPV4 :
+ SKB_GSO_TCPV6;
+
+ /* Header must be checked, and gso_segs computed. */
+ skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
+ skb_shinfo(skb)->gso_segs = 0;
+
+ return 0;
+}
+
+static RING_IDX xennet_fill_frags(struct netfront_queue *queue,
+ struct sk_buff *skb,
+ struct sk_buff_head *list)
+{
+ RING_IDX cons = queue->rx.rsp_cons;
+ struct sk_buff *nskb;
+
+ while ((nskb = __skb_dequeue(list))) {
+ struct xen_netif_rx_response *rx =
+ RING_GET_RESPONSE(&queue->rx, ++cons);
+ skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
+
+ if (skb_shinfo(skb)->nr_frags == MAX_SKB_FRAGS) {
+ unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
+
+ BUG_ON(pull_to <= skb_headlen(skb));
+ __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
+ }
+ if (unlikely(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS)) {
+ queue->rx.rsp_cons = ++cons;
+ kfree_skb(nskb);
+ return ~0U;
+ }
+
+ skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
+ skb_frag_page(nfrag),
+ rx->offset, rx->status, PAGE_SIZE);
+
+ skb_shinfo(nskb)->nr_frags = 0;
+ kfree_skb(nskb);
+ }
+
+ return cons;
+}
+
+static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
+{
+ bool recalculate_partial_csum = false;
+
+ /*
+ * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
+ * peers can fail to set NETRXF_csum_blank when sending a GSO
+ * frame. In this case force the SKB to CHECKSUM_PARTIAL and
+ * recalculate the partial checksum.
+ */
+ if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
+ struct netfront_info *np = netdev_priv(dev);
+ atomic_inc(&np->rx_gso_checksum_fixup);
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ recalculate_partial_csum = true;
+ }
+
+ /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
+ if (skb->ip_summed != CHECKSUM_PARTIAL)
+ return 0;
+
+ return skb_checksum_setup(skb, recalculate_partial_csum);
+}
+
+static int handle_incoming_queue(struct netfront_queue *queue,
+ struct sk_buff_head *rxq)
+{
+ struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats);
+ int packets_dropped = 0;
+ struct sk_buff *skb;
+
+ while ((skb = __skb_dequeue(rxq)) != NULL) {
+ int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
+
+ if (pull_to > skb_headlen(skb))
+ __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
+
+ /* Ethernet work: Delayed to here as it peeks the header. */
+ skb->protocol = eth_type_trans(skb, queue->info->netdev);
+ skb_reset_network_header(skb);
+
+ if (checksum_setup(queue->info->netdev, skb)) {
+ kfree_skb(skb);
+ packets_dropped++;
+ queue->info->netdev->stats.rx_errors++;
+ continue;
+ }
+
+ u64_stats_update_begin(&rx_stats->syncp);
+ rx_stats->packets++;
+ rx_stats->bytes += skb->len;
+ u64_stats_update_end(&rx_stats->syncp);
+
+ /* Pass it up. */
+ napi_gro_receive(&queue->napi, skb);
+ }
+
+ return packets_dropped;
+}
+
+static int xennet_poll(struct napi_struct *napi, int budget)
+{
+ struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
+ struct net_device *dev = queue->info->netdev;
+ struct sk_buff *skb;
+ struct netfront_rx_info rinfo;
+ struct xen_netif_rx_response *rx = &rinfo.rx;
+ struct xen_netif_extra_info *extras = rinfo.extras;
+ RING_IDX i, rp;
+ int work_done;
+ struct sk_buff_head rxq;
+ struct sk_buff_head errq;
+ struct sk_buff_head tmpq;
+ int err;
+
+ spin_lock(&queue->rx_lock);
+
+ skb_queue_head_init(&rxq);
+ skb_queue_head_init(&errq);
+ skb_queue_head_init(&tmpq);
+
+ rp = queue->rx.sring->rsp_prod;
+ rmb(); /* Ensure we see queued responses up to 'rp'. */
+
+ i = queue->rx.rsp_cons;
+ work_done = 0;
+ while ((i != rp) && (work_done < budget)) {
+ memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx));
+ memset(extras, 0, sizeof(rinfo.extras));
+
+ err = xennet_get_responses(queue, &rinfo, rp, &tmpq);
+
+ if (unlikely(err)) {
+err:
+ while ((skb = __skb_dequeue(&tmpq)))
+ __skb_queue_tail(&errq, skb);
+ dev->stats.rx_errors++;
+ i = queue->rx.rsp_cons;
+ continue;
+ }
+
+ skb = __skb_dequeue(&tmpq);
+
+ if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
+ struct xen_netif_extra_info *gso;
+ gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
+
+ if (unlikely(xennet_set_skb_gso(skb, gso))) {
+ __skb_queue_head(&tmpq, skb);
+ queue->rx.rsp_cons += skb_queue_len(&tmpq);
+ goto err;
+ }
+ }
+
+ NETFRONT_SKB_CB(skb)->pull_to = rx->status;
+ if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
+ NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
+
+ skb_shinfo(skb)->frags[0].page_offset = rx->offset;
+ skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
+ skb->data_len = rx->status;
+ skb->len += rx->status;
+
+ i = xennet_fill_frags(queue, skb, &tmpq);
+ if (unlikely(i == ~0U))
+ goto err;
+
+ if (rx->flags & XEN_NETRXF_csum_blank)
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ else if (rx->flags & XEN_NETRXF_data_validated)
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+ __skb_queue_tail(&rxq, skb);
+
+ queue->rx.rsp_cons = ++i;
+ work_done++;
+ }
+
+ __skb_queue_purge(&errq);
+
+ work_done -= handle_incoming_queue(queue, &rxq);
+
+ xennet_alloc_rx_buffers(queue);
+
+ if (work_done < budget) {
+ int more_to_do = 0;
+
+ napi_complete_done(napi, work_done);
+
+ RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
+ if (more_to_do)
+ napi_schedule(napi);
+ }
+
+ spin_unlock(&queue->rx_lock);
+
+ return work_done;
+}
+
+static int xennet_change_mtu(struct net_device *dev, int mtu)
+{
+ int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN;
+
+ if (mtu > max)
+ return -EINVAL;
+ dev->mtu = mtu;
+ return 0;
+}
+
+static void xennet_get_stats64(struct net_device *dev,
+ struct rtnl_link_stats64 *tot)
+{
+ struct netfront_info *np = netdev_priv(dev);
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu);
+ struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu);
+ u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
+ unsigned int start;
+
+ do {
+ start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
+ tx_packets = tx_stats->packets;
+ tx_bytes = tx_stats->bytes;
+ } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
+
+ do {
+ start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
+ rx_packets = rx_stats->packets;
+ rx_bytes = rx_stats->bytes;
+ } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
+
+ tot->rx_packets += rx_packets;
+ tot->tx_packets += tx_packets;
+ tot->rx_bytes += rx_bytes;
+ tot->tx_bytes += tx_bytes;
+ }
+
+ tot->rx_errors = dev->stats.rx_errors;
+ tot->tx_dropped = dev->stats.tx_dropped;
+}
+
+static void xennet_release_tx_bufs(struct netfront_queue *queue)
+{
+ struct sk_buff *skb;
+ int i;
+
+ for (i = 0; i < NET_TX_RING_SIZE; i++) {
+ /* Skip over entries which are actually freelist references */
+ if (skb_entry_is_link(&queue->tx_skbs[i]))
+ continue;
+
+ skb = queue->tx_skbs[i].skb;
+ get_page(queue->grant_tx_page[i]);
+ gnttab_end_foreign_access(queue->grant_tx_ref[i],
+ GNTMAP_readonly,
+ (unsigned long)page_address(queue->grant_tx_page[i]));
+ queue->grant_tx_page[i] = NULL;
+ queue->grant_tx_ref[i] = GRANT_INVALID_REF;
+ add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i);
+ dev_kfree_skb_irq(skb);
+ }
+}
+
+static void xennet_release_rx_bufs(struct netfront_queue *queue)
+{
+ int id, ref;
+
+ spin_lock_bh(&queue->rx_lock);
+
+ for (id = 0; id < NET_RX_RING_SIZE; id++) {
+ struct sk_buff *skb;
+ struct page *page;
+
+ skb = queue->rx_skbs[id];
+ if (!skb)
+ continue;
+
+ ref = queue->grant_rx_ref[id];
+ if (ref == GRANT_INVALID_REF)
+ continue;
+
+ page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
+
+ /* gnttab_end_foreign_access() needs a page ref until
+ * foreign access is ended (which may be deferred).
+ */
+ get_page(page);
+ gnttab_end_foreign_access(ref, 0,
+ (unsigned long)page_address(page));
+ queue->grant_rx_ref[id] = GRANT_INVALID_REF;
+
+ kfree_skb(skb);
+ }
+
+ spin_unlock_bh(&queue->rx_lock);
+}
+
+static netdev_features_t xennet_fix_features(struct net_device *dev,
+ netdev_features_t features)
+{
+ struct netfront_info *np = netdev_priv(dev);
+
+ if (features & NETIF_F_SG &&
+ !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0))
+ features &= ~NETIF_F_SG;
+
+ if (features & NETIF_F_IPV6_CSUM &&
+ !xenbus_read_unsigned(np->xbdev->otherend,
+ "feature-ipv6-csum-offload", 0))
+ features &= ~NETIF_F_IPV6_CSUM;
+
+ if (features & NETIF_F_TSO &&
+ !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0))
+ features &= ~NETIF_F_TSO;
+
+ if (features & NETIF_F_TSO6 &&
+ !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0))
+ features &= ~NETIF_F_TSO6;
+
+ return features;
+}
+
+static int xennet_set_features(struct net_device *dev,
+ netdev_features_t features)
+{
+ if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
+ netdev_info(dev, "Reducing MTU because no SG offload");
+ dev->mtu = ETH_DATA_LEN;
+ }
+
+ return 0;
+}
+
+static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
+{
+ struct netfront_queue *queue = dev_id;
+ unsigned long flags;
+
+ spin_lock_irqsave(&queue->tx_lock, flags);
+ xennet_tx_buf_gc(queue);
+ spin_unlock_irqrestore(&queue->tx_lock, flags);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
+{
+ struct netfront_queue *queue = dev_id;
+ struct net_device *dev = queue->info->netdev;
+
+ if (likely(netif_carrier_ok(dev) &&
+ RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)))
+ napi_schedule(&queue->napi);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t xennet_interrupt(int irq, void *dev_id)
+{
+ xennet_tx_interrupt(irq, dev_id);
+ xennet_rx_interrupt(irq, dev_id);
+ return IRQ_HANDLED;
+}
+
+#ifdef CONFIG_NET_POLL_CONTROLLER
+static void xennet_poll_controller(struct net_device *dev)
+{
+ /* Poll each queue */
+ struct netfront_info *info = netdev_priv(dev);
+ unsigned int num_queues = dev->real_num_tx_queues;
+ unsigned int i;
+ for (i = 0; i < num_queues; ++i)
+ xennet_interrupt(0, &info->queues[i]);
+}
+#endif
+
+static const struct net_device_ops xennet_netdev_ops = {
+ .ndo_open = xennet_open,
+ .ndo_stop = xennet_close,
+ .ndo_start_xmit = xennet_start_xmit,
+ .ndo_change_mtu = xennet_change_mtu,
+ .ndo_get_stats64 = xennet_get_stats64,
+ .ndo_set_mac_address = eth_mac_addr,
+ .ndo_validate_addr = eth_validate_addr,
+ .ndo_fix_features = xennet_fix_features,
+ .ndo_set_features = xennet_set_features,
+ .ndo_select_queue = xennet_select_queue,
+#ifdef CONFIG_NET_POLL_CONTROLLER
+ .ndo_poll_controller = xennet_poll_controller,
+#endif
+};
+
+static void xennet_free_netdev(struct net_device *netdev)
+{
+ struct netfront_info *np = netdev_priv(netdev);
+
+ free_percpu(np->rx_stats);
+ free_percpu(np->tx_stats);
+ free_netdev(netdev);
+}
+
+static struct net_device *xennet_create_dev(struct xenbus_device *dev)
+{
+ int err;
+ struct net_device *netdev;
+ struct netfront_info *np;
+
+ netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
+ if (!netdev)
+ return ERR_PTR(-ENOMEM);
+
+ np = netdev_priv(netdev);
+ np->xbdev = dev;
+
+ np->queues = NULL;
+
+ err = -ENOMEM;
+ np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
+ if (np->rx_stats == NULL)
+ goto exit;
+ np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
+ if (np->tx_stats == NULL)
+ goto exit;
+
+ netdev->netdev_ops = &xennet_netdev_ops;
+
+ netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
+ NETIF_F_GSO_ROBUST;
+ netdev->hw_features = NETIF_F_SG |
+ NETIF_F_IPV6_CSUM |
+ NETIF_F_TSO | NETIF_F_TSO6;
+
+ /*
+ * Assume that all hw features are available for now. This set
+ * will be adjusted by the call to netdev_update_features() in
+ * xennet_connect() which is the earliest point where we can
+ * negotiate with the backend regarding supported features.
+ */
+ netdev->features |= netdev->hw_features;
+
+ netdev->ethtool_ops = &xennet_ethtool_ops;
+ netdev->min_mtu = ETH_MIN_MTU;
+ netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE;
+ SET_NETDEV_DEV(netdev, &dev->dev);
+
+ np->netdev = netdev;
+
+ netif_carrier_off(netdev);
+
+ xenbus_switch_state(dev, XenbusStateInitialising);
+ wait_event(module_wq,
+ xenbus_read_driver_state(dev->otherend) !=
+ XenbusStateClosed &&
+ xenbus_read_driver_state(dev->otherend) !=
+ XenbusStateUnknown);
+ return netdev;
+
+ exit:
+ xennet_free_netdev(netdev);
+ return ERR_PTR(err);
+}
+
+/**
+ * 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.
+ */
+static int netfront_probe(struct xenbus_device *dev,
+ const struct xenbus_device_id *id)
+{
+ int err;
+ struct net_device *netdev;
+ struct netfront_info *info;
+
+ netdev = xennet_create_dev(dev);
+ if (IS_ERR(netdev)) {
+ err = PTR_ERR(netdev);
+ xenbus_dev_fatal(dev, err, "creating netdev");
+ return err;
+ }
+
+ info = netdev_priv(netdev);
+ dev_set_drvdata(&dev->dev, info);
+#ifdef CONFIG_SYSFS
+ info->netdev->sysfs_groups[0] = &xennet_dev_group;
+#endif
+
+ return 0;
+}
+
+static void xennet_end_access(int ref, void *page)
+{
+ /* This frees the page as a side-effect */
+ if (ref != GRANT_INVALID_REF)
+ gnttab_end_foreign_access(ref, 0, (unsigned long)page);
+}
+
+static void xennet_disconnect_backend(struct netfront_info *info)
+{
+ unsigned int i = 0;
+ unsigned int num_queues = info->netdev->real_num_tx_queues;
+
+ netif_carrier_off(info->netdev);
+
+ for (i = 0; i < num_queues && info->queues; ++i) {
+ struct netfront_queue *queue = &info->queues[i];
+
+ del_timer_sync(&queue->rx_refill_timer);
+
+ if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
+ unbind_from_irqhandler(queue->tx_irq, queue);
+ if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
+ unbind_from_irqhandler(queue->tx_irq, queue);
+ unbind_from_irqhandler(queue->rx_irq, queue);
+ }
+ queue->tx_evtchn = queue->rx_evtchn = 0;
+ queue->tx_irq = queue->rx_irq = 0;
+
+ if (netif_running(info->netdev))
+ napi_synchronize(&queue->napi);
+
+ xennet_release_tx_bufs(queue);
+ xennet_release_rx_bufs(queue);
+ gnttab_free_grant_references(queue->gref_tx_head);
+ gnttab_free_grant_references(queue->gref_rx_head);
+
+ /* End access and free the pages */
+ xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
+ xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
+
+ queue->tx_ring_ref = GRANT_INVALID_REF;
+ queue->rx_ring_ref = GRANT_INVALID_REF;
+ queue->tx.sring = NULL;
+ queue->rx.sring = NULL;
+ }
+}
+
+/**
+ * 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_get_drvdata(&dev->dev);
+
+ dev_dbg(&dev->dev, "%s\n", dev->nodename);
+
+ xennet_disconnect_backend(info);
+ return 0;
+}
+
+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;
+}
+
+static int setup_netfront_single(struct netfront_queue *queue)
+{
+ int err;
+
+ err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
+ if (err < 0)
+ goto fail;
+
+ err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
+ xennet_interrupt,
+ 0, queue->info->netdev->name, queue);
+ if (err < 0)
+ goto bind_fail;
+ queue->rx_evtchn = queue->tx_evtchn;
+ queue->rx_irq = queue->tx_irq = err;
+
+ return 0;
+
+bind_fail:
+ xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
+ queue->tx_evtchn = 0;
+fail:
+ return err;
+}
+
+static int setup_netfront_split(struct netfront_queue *queue)
+{
+ int err;
+
+ err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
+ if (err < 0)
+ goto fail;
+ err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
+ if (err < 0)
+ goto alloc_rx_evtchn_fail;
+
+ snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
+ "%s-tx", queue->name);
+ err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
+ xennet_tx_interrupt,
+ 0, queue->tx_irq_name, queue);
+ if (err < 0)
+ goto bind_tx_fail;
+ queue->tx_irq = err;
+
+ snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
+ "%s-rx", queue->name);
+ err = bind_evtchn_to_irqhandler(queue->rx_evtchn,
+ xennet_rx_interrupt,
+ 0, queue->rx_irq_name, queue);
+ if (err < 0)
+ goto bind_rx_fail;
+ queue->rx_irq = err;
+
+ return 0;
+
+bind_rx_fail:
+ unbind_from_irqhandler(queue->tx_irq, queue);
+ queue->tx_irq = 0;
+bind_tx_fail:
+ xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
+ queue->rx_evtchn = 0;
+alloc_rx_evtchn_fail:
+ xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
+ queue->tx_evtchn = 0;
+fail:
+ return err;
+}
+
+static int setup_netfront(struct xenbus_device *dev,
+ struct netfront_queue *queue, unsigned int feature_split_evtchn)
+{
+ struct xen_netif_tx_sring *txs;
+ struct xen_netif_rx_sring *rxs;
+ grant_ref_t gref;
+ int err;
+
+ queue->tx_ring_ref = GRANT_INVALID_REF;
+ queue->rx_ring_ref = GRANT_INVALID_REF;
+ queue->rx.sring = NULL;
+ queue->tx.sring = NULL;
+
+ txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
+ if (!txs) {
+ err = -ENOMEM;
+ xenbus_dev_fatal(dev, err, "allocating tx ring page");
+ goto fail;
+ }
+ SHARED_RING_INIT(txs);
+ FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
+
+ err = xenbus_grant_ring(dev, txs, 1, &gref);
+ if (err < 0)
+ goto grant_tx_ring_fail;
+ queue->tx_ring_ref = gref;
+
+ rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
+ if (!rxs) {
+ err = -ENOMEM;
+ xenbus_dev_fatal(dev, err, "allocating rx ring page");
+ goto alloc_rx_ring_fail;
+ }
+ SHARED_RING_INIT(rxs);
+ FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
+
+ err = xenbus_grant_ring(dev, rxs, 1, &gref);
+ if (err < 0)
+ goto grant_rx_ring_fail;
+ queue->rx_ring_ref = gref;
+
+ if (feature_split_evtchn)
+ err = setup_netfront_split(queue);
+ /* setup single event channel if
+ * a) feature-split-event-channels == 0
+ * b) feature-split-event-channels == 1 but failed to setup
+ */
+ if (!feature_split_evtchn || (feature_split_evtchn && err))
+ err = setup_netfront_single(queue);
+
+ if (err)
+ goto alloc_evtchn_fail;
+
+ return 0;
+
+ /* If we fail to setup netfront, it is safe to just revoke access to
+ * granted pages because backend is not accessing it at this point.
+ */
+alloc_evtchn_fail:
+ gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0);
+grant_rx_ring_fail:
+ free_page((unsigned long)rxs);
+alloc_rx_ring_fail:
+ gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0);
+grant_tx_ring_fail:
+ free_page((unsigned long)txs);
+fail:
+ return err;
+}
+
+/* Queue-specific initialisation
+ * This used to be done in xennet_create_dev() but must now
+ * be run per-queue.
+ */
+static int xennet_init_queue(struct netfront_queue *queue)
+{
+ unsigned short i;
+ int err = 0;
+ char *devid;
+
+ spin_lock_init(&queue->tx_lock);
+ spin_lock_init(&queue->rx_lock);
+
+ timer_setup(&queue->rx_refill_timer, rx_refill_timeout, 0);
+
+ devid = strrchr(queue->info->xbdev->nodename, '/') + 1;
+ snprintf(queue->name, sizeof(queue->name), "vif%s-q%u",
+ devid, queue->id);
+
+ /* Initialise tx_skbs as a free chain containing every entry. */
+ queue->tx_skb_freelist = 0;
+ for (i = 0; i < NET_TX_RING_SIZE; i++) {
+ skb_entry_set_link(&queue->tx_skbs[i], i+1);
+ queue->grant_tx_ref[i] = GRANT_INVALID_REF;
+ queue->grant_tx_page[i] = NULL;
+ }
+
+ /* Clear out rx_skbs */
+ for (i = 0; i < NET_RX_RING_SIZE; i++) {
+ queue->rx_skbs[i] = NULL;
+ queue->grant_rx_ref[i] = GRANT_INVALID_REF;
+ }
+
+ /* A grant for every tx ring slot */
+ if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
+ &queue->gref_tx_head) < 0) {
+ pr_alert("can't alloc tx grant refs\n");
+ err = -ENOMEM;
+ goto exit;
+ }
+
+ /* A grant for every rx ring slot */
+ if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
+ &queue->gref_rx_head) < 0) {
+ pr_alert("can't alloc rx grant refs\n");
+ err = -ENOMEM;
+ goto exit_free_tx;
+ }
+
+ return 0;
+
+ exit_free_tx:
+ gnttab_free_grant_references(queue->gref_tx_head);
+ exit:
+ return err;
+}
+
+static int write_queue_xenstore_keys(struct netfront_queue *queue,
+ struct xenbus_transaction *xbt, int write_hierarchical)
+{
+ /* Write the queue-specific keys into XenStore in the traditional
+ * way for a single queue, or in a queue subkeys for multiple
+ * queues.
+ */
+ struct xenbus_device *dev = queue->info->xbdev;
+ int err;
+ const char *message;
+ char *path;
+ size_t pathsize;
+
+ /* Choose the correct place to write the keys */
+ if (write_hierarchical) {
+ pathsize = strlen(dev->nodename) + 10;
+ path = kzalloc(pathsize, GFP_KERNEL);
+ if (!path) {
+ err = -ENOMEM;
+ message = "out of memory while writing ring references";
+ goto error;
+ }
+ snprintf(path, pathsize, "%s/queue-%u",
+ dev->nodename, queue->id);
+ } else {
+ path = (char *)dev->nodename;
+ }
+
+ /* Write ring references */
+ err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
+ queue->tx_ring_ref);
+ if (err) {
+ message = "writing tx-ring-ref";
+ goto error;
+ }
+
+ err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
+ queue->rx_ring_ref);
+ if (err) {
+ message = "writing rx-ring-ref";
+ goto error;
+ }
+
+ /* Write event channels; taking into account both shared
+ * and split event channel scenarios.
+ */
+ if (queue->tx_evtchn == queue->rx_evtchn) {
+ /* Shared event channel */
+ err = xenbus_printf(*xbt, path,
+ "event-channel", "%u", queue->tx_evtchn);
+ if (err) {
+ message = "writing event-channel";
+ goto error;
+ }
+ } else {
+ /* Split event channels */
+ err = xenbus_printf(*xbt, path,
+ "event-channel-tx", "%u", queue->tx_evtchn);
+ if (err) {
+ message = "writing event-channel-tx";
+ goto error;
+ }
+
+ err = xenbus_printf(*xbt, path,
+ "event-channel-rx", "%u", queue->rx_evtchn);
+ if (err) {
+ message = "writing event-channel-rx";
+ goto error;
+ }
+ }
+
+ if (write_hierarchical)
+ kfree(path);
+ return 0;
+
+error:
+ if (write_hierarchical)
+ kfree(path);
+ xenbus_dev_fatal(dev, err, "%s", message);
+ return err;
+}
+
+static void xennet_destroy_queues(struct netfront_info *info)
+{
+ unsigned int i;
+
+ for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
+ struct netfront_queue *queue = &info->queues[i];
+
+ if (netif_running(info->netdev))
+ napi_disable(&queue->napi);
+ netif_napi_del(&queue->napi);
+ }
+
+ kfree(info->queues);
+ info->queues = NULL;
+}
+
+static int xennet_create_queues(struct netfront_info *info,
+ unsigned int *num_queues)
+{
+ unsigned int i;
+ int ret;
+
+ info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue),
+ GFP_KERNEL);
+ if (!info->queues)
+ return -ENOMEM;
+
+ for (i = 0; i < *num_queues; i++) {
+ struct netfront_queue *queue = &info->queues[i];
+
+ queue->id = i;
+ queue->info = info;
+
+ ret = xennet_init_queue(queue);
+ if (ret < 0) {
+ dev_warn(&info->xbdev->dev,
+ "only created %d queues\n", i);
+ *num_queues = i;
+ break;
+ }
+
+ netif_napi_add(queue->info->netdev, &queue->napi,
+ xennet_poll, 64);
+ if (netif_running(info->netdev))
+ napi_enable(&queue->napi);
+ }
+
+ netif_set_real_num_tx_queues(info->netdev, *num_queues);
+
+ if (*num_queues == 0) {
+ dev_err(&info->xbdev->dev, "no queues\n");
+ return -EINVAL;
+ }
+ return 0;
+}
+
+/* Common code used when first setting up, and when resuming. */
+static int talk_to_netback(struct xenbus_device *dev,
+ struct netfront_info *info)
+{
+ const char *message;
+ struct xenbus_transaction xbt;
+ int err;
+ unsigned int feature_split_evtchn;
+ unsigned int i = 0;
+ unsigned int max_queues = 0;
+ struct netfront_queue *queue = NULL;
+ unsigned int num_queues = 1;
+
+ info->netdev->irq = 0;
+
+ /* Check if backend supports multiple queues */
+ max_queues = xenbus_read_unsigned(info->xbdev->otherend,
+ "multi-queue-max-queues", 1);
+ num_queues = min(max_queues, xennet_max_queues);
+
+ /* Check feature-split-event-channels */
+ feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend,
+ "feature-split-event-channels", 0);
+
+ /* Read mac addr. */
+ err = xen_net_read_mac(dev, info->netdev->dev_addr);
+ if (err) {
+ xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
+ goto out_unlocked;
+ }
+
+ rtnl_lock();
+ if (info->queues)
+ xennet_destroy_queues(info);
+
+ err = xennet_create_queues(info, &num_queues);
+ if (err < 0) {
+ xenbus_dev_fatal(dev, err, "creating queues");
+ kfree(info->queues);
+ info->queues = NULL;
+ goto out;
+ }
+ rtnl_unlock();
+
+ /* Create shared ring, alloc event channel -- for each queue */
+ for (i = 0; i < num_queues; ++i) {
+ queue = &info->queues[i];
+ err = setup_netfront(dev, queue, feature_split_evtchn);
+ if (err)
+ goto destroy_ring;
+ }
+
+again:
+ err = xenbus_transaction_start(&xbt);
+ if (err) {
+ xenbus_dev_fatal(dev, err, "starting transaction");
+ goto destroy_ring;
+ }
+
+ if (xenbus_exists(XBT_NIL,
+ info->xbdev->otherend, "multi-queue-max-queues")) {
+ /* Write the number of queues */
+ err = xenbus_printf(xbt, dev->nodename,
+ "multi-queue-num-queues", "%u", num_queues);
+ if (err) {
+ message = "writing multi-queue-num-queues";
+ goto abort_transaction_no_dev_fatal;
+ }
+ }
+
+ if (num_queues == 1) {
+ err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
+ if (err)
+ goto abort_transaction_no_dev_fatal;
+ } else {
+ /* Write the keys for each queue */
+ for (i = 0; i < num_queues; ++i) {
+ queue = &info->queues[i];
+ err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */
+ if (err)
+ goto abort_transaction_no_dev_fatal;
+ }
+ }
+
+ /* The remaining keys are not queue-specific */
+ err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
+ 1);
+ if (err) {
+ message = "writing request-rx-copy";
+ goto abort_transaction;
+ }
+
+ err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
+ if (err) {
+ message = "writing feature-rx-notify";
+ goto abort_transaction;
+ }
+
+ err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
+ if (err) {
+ message = "writing feature-sg";
+ goto abort_transaction;
+ }
+
+ err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
+ if (err) {
+ message = "writing feature-gso-tcpv4";
+ goto abort_transaction;
+ }
+
+ err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
+ if (err) {
+ message = "writing feature-gso-tcpv6";
+ goto abort_transaction;
+ }
+
+ err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
+ "1");
+ if (err) {
+ message = "writing feature-ipv6-csum-offload";
+ 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_dev_fatal(dev, err, "%s", message);
+abort_transaction_no_dev_fatal:
+ xenbus_transaction_end(xbt, 1);
+ destroy_ring:
+ xennet_disconnect_backend(info);
+ rtnl_lock();
+ xennet_destroy_queues(info);
+ out:
+ rtnl_unlock();
+out_unlocked:
+ device_unregister(&dev->dev);
+ return err;
+}
+
+static int xennet_connect(struct net_device *dev)
+{
+ struct netfront_info *np = netdev_priv(dev);
+ unsigned int num_queues = 0;
+ int err;
+ unsigned int j = 0;
+ struct netfront_queue *queue = NULL;
+
+ if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) {
+ dev_info(&dev->dev,
+ "backend does not support copying receive path\n");
+ return -ENODEV;
+ }
+
+ err = talk_to_netback(np->xbdev, np);
+ if (err)
+ return err;
+
+ /* talk_to_netback() sets the correct number of queues */
+ num_queues = dev->real_num_tx_queues;
+
+ if (dev->reg_state == NETREG_UNINITIALIZED) {
+ err = register_netdev(dev);
+ if (err) {
+ pr_warn("%s: register_netdev err=%d\n", __func__, err);
+ device_unregister(&np->xbdev->dev);
+ return err;
+ }
+ }
+
+ rtnl_lock();
+ netdev_update_features(dev);
+ rtnl_unlock();
+
+ /*
+ * 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(np->netdev);
+ for (j = 0; j < num_queues; ++j) {
+ queue = &np->queues[j];
+
+ notify_remote_via_irq(queue->tx_irq);
+ if (queue->tx_irq != queue->rx_irq)
+ notify_remote_via_irq(queue->rx_irq);
+
+ spin_lock_irq(&queue->tx_lock);
+ xennet_tx_buf_gc(queue);
+ spin_unlock_irq(&queue->tx_lock);
+
+ spin_lock_bh(&queue->rx_lock);
+ xennet_alloc_rx_buffers(queue);
+ spin_unlock_bh(&queue->rx_lock);
+ }
+
+ return 0;
+}
+
+/**
+ * Callback received when the backend's state changes.
+ */
+static void netback_changed(struct xenbus_device *dev,
+ enum xenbus_state backend_state)
+{
+ struct netfront_info *np = dev_get_drvdata(&dev->dev);
+ struct net_device *netdev = np->netdev;
+
+ dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
+
+ wake_up_all(&module_wq);
+
+ switch (backend_state) {
+ case XenbusStateInitialising:
+ case XenbusStateInitialised:
+ case XenbusStateReconfiguring:
+ case XenbusStateReconfigured:
+ case XenbusStateUnknown:
+ break;
+
+ case XenbusStateInitWait:
+ if (dev->state != XenbusStateInitialising)
+ break;
+ if (xennet_connect(netdev) != 0)
+ break;
+ xenbus_switch_state(dev, XenbusStateConnected);
+ break;
+
+ case XenbusStateConnected:
+ netdev_notify_peers(netdev);
+ break;
+
+ case XenbusStateClosed:
+ if (dev->state == XenbusStateClosed)
+ break;
+ /* Missed the backend's CLOSING state -- fallthrough */
+ case XenbusStateClosing:
+ xenbus_frontend_closed(dev);
+ break;
+ }
+}
+
+static const struct xennet_stat {
+ char name[ETH_GSTRING_LEN];
+ u16 offset;
+} xennet_stats[] = {
+ {
+ "rx_gso_checksum_fixup",
+ offsetof(struct netfront_info, rx_gso_checksum_fixup)
+ },
+};
+
+static int xennet_get_sset_count(struct net_device *dev, int string_set)
+{
+ switch (string_set) {
+ case ETH_SS_STATS:
+ return ARRAY_SIZE(xennet_stats);
+ default:
+ return -EINVAL;
+ }
+}
+
+static void xennet_get_ethtool_stats(struct net_device *dev,
+ struct ethtool_stats *stats, u64 * data)
+{
+ void *np = netdev_priv(dev);
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
+ data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
+}
+
+static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
+{
+ int i;
+
+ switch (stringset) {
+ case ETH_SS_STATS:
+ for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
+ memcpy(data + i * ETH_GSTRING_LEN,
+ xennet_stats[i].name, ETH_GSTRING_LEN);
+ break;
+ }
+}
+
+static const struct ethtool_ops xennet_ethtool_ops =
+{
+ .get_link = ethtool_op_get_link,
+
+ .get_sset_count = xennet_get_sset_count,
+ .get_ethtool_stats = xennet_get_ethtool_stats,
+ .get_strings = xennet_get_strings,
+};
+
+#ifdef CONFIG_SYSFS
+static ssize_t show_rxbuf(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
+}
+
+static ssize_t store_rxbuf(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ char *endp;
+ unsigned long target;
+
+ if (!capable(CAP_NET_ADMIN))
+ return -EPERM;
+
+ target = simple_strtoul(buf, &endp, 0);
+ if (endp == buf)
+ return -EBADMSG;
+
+ /* rxbuf_min and rxbuf_max are no longer configurable. */
+
+ return len;
+}
+
+static DEVICE_ATTR(rxbuf_min, 0644, show_rxbuf, store_rxbuf);
+static DEVICE_ATTR(rxbuf_max, 0644, show_rxbuf, store_rxbuf);
+static DEVICE_ATTR(rxbuf_cur, 0444, show_rxbuf, NULL);
+
+static struct attribute *xennet_dev_attrs[] = {
+ &dev_attr_rxbuf_min.attr,
+ &dev_attr_rxbuf_max.attr,
+ &dev_attr_rxbuf_cur.attr,
+ NULL
+};
+
+static const struct attribute_group xennet_dev_group = {
+ .attrs = xennet_dev_attrs
+};
+#endif /* CONFIG_SYSFS */
+
+static int xennet_remove(struct xenbus_device *dev)
+{
+ struct netfront_info *info = dev_get_drvdata(&dev->dev);
+
+ dev_dbg(&dev->dev, "%s\n", dev->nodename);
+
+ if (xenbus_read_driver_state(dev->otherend) != XenbusStateClosed) {
+ xenbus_switch_state(dev, XenbusStateClosing);
+ wait_event(module_wq,
+ xenbus_read_driver_state(dev->otherend) ==
+ XenbusStateClosing ||
+ xenbus_read_driver_state(dev->otherend) ==
+ XenbusStateUnknown);
+
+ xenbus_switch_state(dev, XenbusStateClosed);
+ wait_event(module_wq,
+ xenbus_read_driver_state(dev->otherend) ==
+ XenbusStateClosed ||
+ xenbus_read_driver_state(dev->otherend) ==
+ XenbusStateUnknown);
+ }
+
+ xennet_disconnect_backend(info);
+
+ if (info->netdev->reg_state == NETREG_REGISTERED)
+ unregister_netdev(info->netdev);
+
+ if (info->queues) {
+ rtnl_lock();
+ xennet_destroy_queues(info);
+ rtnl_unlock();
+ }
+ xennet_free_netdev(info->netdev);
+
+ return 0;
+}
+
+static const struct xenbus_device_id netfront_ids[] = {
+ { "vif" },
+ { "" }
+};
+
+static struct xenbus_driver netfront_driver = {
+ .ids = netfront_ids,
+ .probe = netfront_probe,
+ .remove = xennet_remove,
+ .resume = netfront_resume,
+ .otherend_changed = netback_changed,
+};
+
+static int __init netif_init(void)
+{
+ if (!xen_domain())
+ return -ENODEV;
+
+ if (!xen_has_pv_nic_devices())
+ return -ENODEV;
+
+ pr_info("Initialising Xen virtual ethernet driver\n");
+
+ /* Allow as many queues as there are CPUs inut max. 8 if user has not
+ * specified a value.
+ */
+ if (xennet_max_queues == 0)
+ xennet_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT,
+ num_online_cpus());
+
+ return xenbus_register_frontend(&netfront_driver);
+}
+module_init(netif_init);
+
+
+static void __exit netif_exit(void)
+{
+ xenbus_unregister_driver(&netfront_driver);
+}
+module_exit(netif_exit);
+
+MODULE_DESCRIPTION("Xen virtual network device frontend");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("xen:vif");
+MODULE_ALIAS("xennet");