--- /dev/null
+/*
+ * 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/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
+
+void xenvif_get(struct xenvif *vif)
+{
+ atomic_inc(&vif->refcnt);
+}
+
+void xenvif_put(struct xenvif *vif)
+{
+ if (atomic_dec_and_test(&vif->refcnt))
+ wake_up(&vif->waiting_to_free);
+}
+
+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) && !xen_netbk_rx_ring_full(vif);
+}
+
+static irqreturn_t xenvif_interrupt(int irq, void *dev_id)
+{
+ struct xenvif *vif = dev_id;
+
+ if (vif->netbk == NULL)
+ return IRQ_NONE;
+
+ xen_netbk_schedule_xenvif(vif);
+
+ if (xenvif_rx_schedulable(vif))
+ netif_wake_queue(vif->dev);
+
+ 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);
+
+ if (vif->netbk == 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 += xen_netbk_count_skb_slots(vif, skb);
+ xenvif_get(vif);
+
+ if (vif->can_queue && xen_netbk_must_stop_queue(vif))
+ netif_stop_queue(dev);
+
+ xen_netbk_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_receive_skb(struct xenvif *vif, struct sk_buff *skb)
+{
+ netif_rx_ni(skb);
+}
+
+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)
+{
+ xen_netbk_add_xenvif(vif);
+ enable_irq(vif->irq);
+ xen_netbk_check_rx_xenvif(vif);
+}
+
+static void xenvif_down(struct xenvif *vif)
+{
+ disable_irq(vif->irq);
+ xen_netbk_deschedule_xenvif(vif);
+ xen_netbk_remove_xenvif(vif);
+}
+
+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 void xenvif_set_features(struct xenvif *vif)
+{
+ struct net_device *dev = vif->dev;
+ u32 features = dev->features;
+
+ 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;
+
+ features &= ~(vif->features_disabled);
+
+ if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN)
+ dev->mtu = ETH_DATA_LEN;
+
+ dev->features = features;
+}
+
+static int xenvif_set_tx_csum(struct net_device *dev, u32 data)
+{
+ struct xenvif *vif = netdev_priv(dev);
+ if (data) {
+ if (!vif->csum)
+ return -EOPNOTSUPP;
+ vif->features_disabled &= ~NETIF_F_IP_CSUM;
+ } else {
+ vif->features_disabled |= NETIF_F_IP_CSUM;
+ }
+
+ xenvif_set_features(vif);
+ return 0;
+}
+
+static int xenvif_set_sg(struct net_device *dev, u32 data)
+{
+ struct xenvif *vif = netdev_priv(dev);
+ if (data) {
+ if (!vif->can_sg)
+ return -EOPNOTSUPP;
+ vif->features_disabled &= ~NETIF_F_SG;
+ } else {
+ vif->features_disabled |= NETIF_F_SG;
+ }
+
+ xenvif_set_features(vif);
+ return 0;
+}
+
+static int xenvif_set_tso(struct net_device *dev, u32 data)
+{
+ struct xenvif *vif = netdev_priv(dev);
+ if (data) {
+ if (!vif->gso && !vif->gso_prefix)
+ return -EOPNOTSUPP;
+ vif->features_disabled &= ~NETIF_F_TSO;
+ } else {
+ vif->features_disabled |= NETIF_F_TSO;
+ }
+
+ xenvif_set_features(vif);
+ return 0;
+}
+
+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 struct ethtool_ops xenvif_ethtool_ops = {
+ .get_tx_csum = ethtool_op_get_tx_csum,
+ .set_tx_csum = xenvif_set_tx_csum,
+ .get_sg = ethtool_op_get_sg,
+ .set_sg = xenvif_set_sg,
+ .get_tso = ethtool_op_get_tso,
+ .set_tso = xenvif_set_tso,
+ .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 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,
+};
+
+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] = {};
+
+ 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\n");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ SET_NETDEV_DEV(dev, parent);
+
+ vif = netdev_priv(dev);
+ vif->domid = domid;
+ vif->handle = handle;
+ vif->netbk = NULL;
+ vif->can_sg = 1;
+ vif->csum = 1;
+ atomic_set(&vif->refcnt, 1);
+ init_waitqueue_head(&vif->waiting_to_free);
+ vif->dev = dev;
+ INIT_LIST_HEAD(&vif->schedule_list);
+ INIT_LIST_HEAD(&vif->notify_list);
+
+ 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;
+ xenvif_set_features(vif);
+ SET_ETHTOOL_OPS(dev, &xenvif_ethtool_ops);
+
+ dev->tx_queue_len = XENVIF_QUEUE_LENGTH;
+
+ /*
+ * 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_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");
+ return vif;
+}
+
+int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
+ unsigned long rx_ring_ref, unsigned int evtchn)
+{
+ int err = -ENOMEM;
+
+ /* Already connected through? */
+ if (vif->irq)
+ return 0;
+
+ xenvif_set_features(vif);
+
+ err = xen_netbk_map_frontend_rings(vif, tx_ring_ref, rx_ring_ref);
+ if (err < 0)
+ goto err;
+
+ err = bind_interdomain_evtchn_to_irqhandler(
+ vif->domid, evtchn, xenvif_interrupt, 0,
+ vif->dev->name, vif);
+ if (err < 0)
+ goto err_unmap;
+ vif->irq = err;
+ disable_irq(vif->irq);
+
+ xenvif_get(vif);
+
+ rtnl_lock();
+ netif_carrier_on(vif->dev);
+ if (netif_running(vif->dev))
+ xenvif_up(vif);
+ rtnl_unlock();
+
+ return 0;
+err_unmap:
+ xen_netbk_unmap_frontend_rings(vif);
+err:
+ return err;
+}
+
+void xenvif_disconnect(struct xenvif *vif)
+{
+ struct net_device *dev = vif->dev;
+ if (netif_carrier_ok(dev)) {
+ rtnl_lock();
+ netif_carrier_off(dev); /* discard queued packets */
+ if (netif_running(dev))
+ xenvif_down(vif);
+ rtnl_unlock();
+ xenvif_put(vif);
+ }
+
+ atomic_dec(&vif->refcnt);
+ wait_event(vif->waiting_to_free, atomic_read(&vif->refcnt) == 0);
+
+ del_timer_sync(&vif->credit_timeout);
+
+ if (vif->irq)
+ unbind_from_irqhandler(vif->irq, vif);
+
+ unregister_netdev(vif->dev);
+
+ xen_netbk_unmap_frontend_rings(vif);
+
+ free_netdev(vif->dev);
+}
--- /dev/null
+/*
+ * Back-end of the driver for virtual network devices. This portion of the
+ * driver exports a 'unified' network-device interface that can be accessed
+ * by any operating system that implements a compatible front end. A
+ * reference front-end implementation can be found in:
+ * drivers/net/xen-netfront.c
+ *
+ * Copyright (c) 2002-2005, K A 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/if_vlan.h>
+#include <linux/udp.h>
+
+#include <net/tcp.h>
+
+#include <xen/events.h>
+#include <xen/interface/memory.h>
+
+#include <asm/xen/hypercall.h>
+#include <asm/xen/page.h>
+
+struct pending_tx_info {
+ struct xen_netif_tx_request req;
+ struct xenvif *vif;
+};
+typedef unsigned int pending_ring_idx_t;
+
+struct netbk_rx_meta {
+ int id;
+ int size;
+ int gso_size;
+};
+
+#define MAX_PENDING_REQS 256
+
+#define MAX_BUFFER_OFFSET PAGE_SIZE
+
+/* extra field used in struct page */
+union page_ext {
+ struct {
+#if BITS_PER_LONG < 64
+#define IDX_WIDTH 8
+#define GROUP_WIDTH (BITS_PER_LONG - IDX_WIDTH)
+ unsigned int group:GROUP_WIDTH;
+ unsigned int idx:IDX_WIDTH;
+#else
+ unsigned int group, idx;
+#endif
+ } e;
+ void *mapping;
+};
+
+struct xen_netbk {
+ wait_queue_head_t wq;
+ struct task_struct *task;
+
+ struct sk_buff_head rx_queue;
+ struct sk_buff_head tx_queue;
+
+ struct timer_list net_timer;
+
+ struct page *mmap_pages[MAX_PENDING_REQS];
+
+ pending_ring_idx_t pending_prod;
+ pending_ring_idx_t pending_cons;
+ struct list_head net_schedule_list;
+
+ /* Protect the net_schedule_list in netif. */
+ spinlock_t net_schedule_list_lock;
+
+ atomic_t netfront_count;
+
+ struct pending_tx_info pending_tx_info[MAX_PENDING_REQS];
+ struct gnttab_copy tx_copy_ops[MAX_PENDING_REQS];
+
+ u16 pending_ring[MAX_PENDING_REQS];
+
+ /*
+ * Given MAX_BUFFER_OFFSET of 4096 the worst case is that each
+ * head/fragment page uses 2 copy operations because it
+ * straddles two buffers in the frontend.
+ */
+ struct gnttab_copy grant_copy_op[2*XEN_NETIF_RX_RING_SIZE];
+ struct netbk_rx_meta meta[2*XEN_NETIF_RX_RING_SIZE];
+};
+
+static struct xen_netbk *xen_netbk;
+static int xen_netbk_group_nr;
+
+void xen_netbk_add_xenvif(struct xenvif *vif)
+{
+ int i;
+ int min_netfront_count;
+ int min_group = 0;
+ struct xen_netbk *netbk;
+
+ min_netfront_count = atomic_read(&xen_netbk[0].netfront_count);
+ for (i = 0; i < xen_netbk_group_nr; i++) {
+ int netfront_count = atomic_read(&xen_netbk[i].netfront_count);
+ if (netfront_count < min_netfront_count) {
+ min_group = i;
+ min_netfront_count = netfront_count;
+ }
+ }
+
+ netbk = &xen_netbk[min_group];
+
+ vif->netbk = netbk;
+ atomic_inc(&netbk->netfront_count);
+}
+
+void xen_netbk_remove_xenvif(struct xenvif *vif)
+{
+ struct xen_netbk *netbk = vif->netbk;
+ vif->netbk = NULL;
+ atomic_dec(&netbk->netfront_count);
+}
+
+static void xen_netbk_idx_release(struct xen_netbk *netbk, u16 pending_idx);
+static void make_tx_response(struct xenvif *vif,
+ struct xen_netif_tx_request *txp,
+ s8 st);
+static struct xen_netif_rx_response *make_rx_response(struct xenvif *vif,
+ u16 id,
+ s8 st,
+ u16 offset,
+ u16 size,
+ u16 flags);
+
+static inline unsigned long idx_to_pfn(struct xen_netbk *netbk,
+ unsigned int idx)
+{
+ return page_to_pfn(netbk->mmap_pages[idx]);
+}
+
+static inline unsigned long idx_to_kaddr(struct xen_netbk *netbk,
+ unsigned int idx)
+{
+ return (unsigned long)pfn_to_kaddr(idx_to_pfn(netbk, idx));
+}
+
+/* extra field used in struct page */
+static inline void set_page_ext(struct page *pg, struct xen_netbk *netbk,
+ unsigned int idx)
+{
+ unsigned int group = netbk - xen_netbk;
+ union page_ext ext = { .e = { .group = group + 1, .idx = idx } };
+
+ BUILD_BUG_ON(sizeof(ext) > sizeof(ext.mapping));
+ pg->mapping = ext.mapping;
+}
+
+static int get_page_ext(struct page *pg,
+ unsigned int *pgroup, unsigned int *pidx)
+{
+ union page_ext ext = { .mapping = pg->mapping };
+ struct xen_netbk *netbk;
+ unsigned int group, idx;
+
+ group = ext.e.group - 1;
+
+ if (group < 0 || group >= xen_netbk_group_nr)
+ return 0;
+
+ netbk = &xen_netbk[group];
+
+ idx = ext.e.idx;
+
+ if ((idx < 0) || (idx >= MAX_PENDING_REQS))
+ return 0;
+
+ if (netbk->mmap_pages[idx] != pg)
+ return 0;
+
+ *pgroup = group;
+ *pidx = idx;
+
+ return 1;
+}
+
+/*
+ * This is the amount of packet we copy rather than map, so that the
+ * guest can't fiddle with the contents of the headers while we do
+ * packet processing on them (netfilter, routing, etc).
+ */
+#define PKT_PROT_LEN (ETH_HLEN + \
+ VLAN_HLEN + \
+ sizeof(struct iphdr) + MAX_IPOPTLEN + \
+ sizeof(struct tcphdr) + MAX_TCP_OPTION_SPACE)
+
+static inline pending_ring_idx_t pending_index(unsigned i)
+{
+ return i & (MAX_PENDING_REQS-1);
+}
+
+static inline pending_ring_idx_t nr_pending_reqs(struct xen_netbk *netbk)
+{
+ return MAX_PENDING_REQS -
+ netbk->pending_prod + netbk->pending_cons;
+}
+
+static void xen_netbk_kick_thread(struct xen_netbk *netbk)
+{
+ wake_up(&netbk->wq);
+}
+
+static int max_required_rx_slots(struct xenvif *vif)
+{
+ int max = DIV_ROUND_UP(vif->dev->mtu, PAGE_SIZE);
+
+ if (vif->can_sg || vif->gso || vif->gso_prefix)
+ max += MAX_SKB_FRAGS + 1; /* extra_info + frags */
+
+ return max;
+}
+
+int xen_netbk_rx_ring_full(struct xenvif *vif)
+{
+ RING_IDX peek = vif->rx_req_cons_peek;
+ RING_IDX needed = max_required_rx_slots(vif);
+
+ return ((vif->rx.sring->req_prod - peek) < needed) ||
+ ((vif->rx.rsp_prod_pvt + XEN_NETIF_RX_RING_SIZE - peek) < needed);
+}
+
+int xen_netbk_must_stop_queue(struct xenvif *vif)
+{
+ if (!xen_netbk_rx_ring_full(vif))
+ return 0;
+
+ vif->rx.sring->req_event = vif->rx_req_cons_peek +
+ max_required_rx_slots(vif);
+ mb(); /* request notification /then/ check the queue */
+
+ return xen_netbk_rx_ring_full(vif);
+}
+
+/*
+ * Returns true if we should start a new receive buffer instead of
+ * adding 'size' bytes to a buffer which currently contains 'offset'
+ * bytes.
+ */
+static bool start_new_rx_buffer(int offset, unsigned long size, int head)
+{
+ /* simple case: we have completely filled the current buffer. */
+ if (offset == MAX_BUFFER_OFFSET)
+ return true;
+
+ /*
+ * complex case: start a fresh buffer if the current frag
+ * would overflow the current buffer but only if:
+ * (i) this frag would fit completely in the next buffer
+ * and (ii) there is already some data in the current buffer
+ * and (iii) this is not the head buffer.
+ *
+ * Where:
+ * - (i) stops us splitting a frag into two copies
+ * unless the frag is too large for a single buffer.
+ * - (ii) stops us from leaving a buffer pointlessly empty.
+ * - (iii) stops us leaving the first buffer
+ * empty. Strictly speaking this is already covered
+ * by (ii) but is explicitly checked because
+ * netfront relies on the first buffer being
+ * non-empty and can crash otherwise.
+ *
+ * This means we will effectively linearise small
+ * frags but do not needlessly split large buffers
+ * into multiple copies tend to give large frags their
+ * own buffers as before.
+ */
+ if ((offset + size > MAX_BUFFER_OFFSET) &&
+ (size <= MAX_BUFFER_OFFSET) && offset && !head)
+ return true;
+
+ return false;
+}
+
+/*
+ * Figure out how many ring slots we're going to need to send @skb to
+ * the guest. This function is essentially a dry run of
+ * netbk_gop_frag_copy.
+ */
+unsigned int xen_netbk_count_skb_slots(struct xenvif *vif, struct sk_buff *skb)
+{
+ unsigned int count;
+ int i, copy_off;
+
+ count = DIV_ROUND_UP(
+ offset_in_page(skb->data)+skb_headlen(skb), PAGE_SIZE);
+
+ copy_off = skb_headlen(skb) % PAGE_SIZE;
+
+ if (skb_shinfo(skb)->gso_size)
+ count++;
+
+ for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+ unsigned long size = skb_shinfo(skb)->frags[i].size;
+ unsigned long bytes;
+ while (size > 0) {
+ BUG_ON(copy_off > MAX_BUFFER_OFFSET);
+
+ if (start_new_rx_buffer(copy_off, size, 0)) {
+ count++;
+ copy_off = 0;
+ }
+
+ bytes = size;
+ if (copy_off + bytes > MAX_BUFFER_OFFSET)
+ bytes = MAX_BUFFER_OFFSET - copy_off;
+
+ copy_off += bytes;
+ size -= bytes;
+ }
+ }
+ return count;
+}
+
+struct netrx_pending_operations {
+ unsigned copy_prod, copy_cons;
+ unsigned meta_prod, meta_cons;
+ struct gnttab_copy *copy;
+ struct netbk_rx_meta *meta;
+ int copy_off;
+ grant_ref_t copy_gref;
+};
+
+static struct netbk_rx_meta *get_next_rx_buffer(struct xenvif *vif,
+ struct netrx_pending_operations *npo)
+{
+ struct netbk_rx_meta *meta;
+ struct xen_netif_rx_request *req;
+
+ req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
+
+ meta = npo->meta + npo->meta_prod++;
+ meta->gso_size = 0;
+ meta->size = 0;
+ meta->id = req->id;
+
+ npo->copy_off = 0;
+ npo->copy_gref = req->gref;
+
+ return meta;
+}
+
+/*
+ * Set up the grant operations for this fragment. If it's a flipping
+ * interface, we also set up the unmap request from here.
+ */
+static void netbk_gop_frag_copy(struct xenvif *vif, struct sk_buff *skb,
+ struct netrx_pending_operations *npo,
+ struct page *page, unsigned long size,
+ unsigned long offset, int *head)
+{
+ struct gnttab_copy *copy_gop;
+ struct netbk_rx_meta *meta;
+ /*
+ * These variables a used iff get_page_ext returns true,
+ * in which case they are guaranteed to be initialized.
+ */
+ unsigned int uninitialized_var(group), uninitialized_var(idx);
+ int foreign = get_page_ext(page, &group, &idx);
+ unsigned long bytes;
+
+ /* Data must not cross a page boundary. */
+ BUG_ON(size + offset > PAGE_SIZE);
+
+ meta = npo->meta + npo->meta_prod - 1;
+
+ while (size > 0) {
+ BUG_ON(npo->copy_off > MAX_BUFFER_OFFSET);
+
+ if (start_new_rx_buffer(npo->copy_off, size, *head)) {
+ /*
+ * Netfront requires there to be some data in the head
+ * buffer.
+ */
+ BUG_ON(*head);
+
+ meta = get_next_rx_buffer(vif, npo);
+ }
+
+ bytes = size;
+ if (npo->copy_off + bytes > MAX_BUFFER_OFFSET)
+ bytes = MAX_BUFFER_OFFSET - npo->copy_off;
+
+ copy_gop = npo->copy + npo->copy_prod++;
+ copy_gop->flags = GNTCOPY_dest_gref;
+ if (foreign) {
+ struct xen_netbk *netbk = &xen_netbk[group];
+ struct pending_tx_info *src_pend;
+
+ src_pend = &netbk->pending_tx_info[idx];
+
+ copy_gop->source.domid = src_pend->vif->domid;
+ copy_gop->source.u.ref = src_pend->req.gref;
+ copy_gop->flags |= GNTCOPY_source_gref;
+ } else {
+ void *vaddr = page_address(page);
+ copy_gop->source.domid = DOMID_SELF;
+ copy_gop->source.u.gmfn = virt_to_mfn(vaddr);
+ }
+ copy_gop->source.offset = offset;
+ copy_gop->dest.domid = vif->domid;
+
+ copy_gop->dest.offset = npo->copy_off;
+ copy_gop->dest.u.ref = npo->copy_gref;
+ copy_gop->len = bytes;
+
+ npo->copy_off += bytes;
+ meta->size += bytes;
+
+ offset += bytes;
+ size -= bytes;
+
+ /* Leave a gap for the GSO descriptor. */
+ if (*head && skb_shinfo(skb)->gso_size && !vif->gso_prefix)
+ vif->rx.req_cons++;
+
+ *head = 0; /* There must be something in this buffer now. */
+
+ }
+}
+
+/*
+ * Prepare an SKB to be transmitted to the frontend.
+ *
+ * This function is responsible for allocating grant operations, meta
+ * structures, etc.
+ *
+ * It returns the number of meta structures consumed. The number of
+ * ring slots used is always equal to the number of meta slots used
+ * plus the number of GSO descriptors used. Currently, we use either
+ * zero GSO descriptors (for non-GSO packets) or one descriptor (for
+ * frontend-side LRO).
+ */
+static int netbk_gop_skb(struct sk_buff *skb,
+ struct netrx_pending_operations *npo)
+{
+ struct xenvif *vif = netdev_priv(skb->dev);
+ int nr_frags = skb_shinfo(skb)->nr_frags;
+ int i;
+ struct xen_netif_rx_request *req;
+ struct netbk_rx_meta *meta;
+ unsigned char *data;
+ int head = 1;
+ int old_meta_prod;
+
+ old_meta_prod = npo->meta_prod;
+
+ /* Set up a GSO prefix descriptor, if necessary */
+ if (skb_shinfo(skb)->gso_size && vif->gso_prefix) {
+ req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
+ meta = npo->meta + npo->meta_prod++;
+ meta->gso_size = skb_shinfo(skb)->gso_size;
+ meta->size = 0;
+ meta->id = req->id;
+ }
+
+ req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
+ meta = npo->meta + npo->meta_prod++;
+
+ if (!vif->gso_prefix)
+ meta->gso_size = skb_shinfo(skb)->gso_size;
+ else
+ meta->gso_size = 0;
+
+ meta->size = 0;
+ meta->id = req->id;
+ npo->copy_off = 0;
+ npo->copy_gref = req->gref;
+
+ data = skb->data;
+ while (data < skb_tail_pointer(skb)) {
+ unsigned int offset = offset_in_page(data);
+ unsigned int len = PAGE_SIZE - offset;
+
+ if (data + len > skb_tail_pointer(skb))
+ len = skb_tail_pointer(skb) - data;
+
+ netbk_gop_frag_copy(vif, skb, npo,
+ virt_to_page(data), len, offset, &head);
+ data += len;
+ }
+
+ for (i = 0; i < nr_frags; i++) {
+ netbk_gop_frag_copy(vif, skb, npo,
+ skb_shinfo(skb)->frags[i].page,
+ skb_shinfo(skb)->frags[i].size,
+ skb_shinfo(skb)->frags[i].page_offset,
+ &head);
+ }
+
+ return npo->meta_prod - old_meta_prod;
+}
+
+/*
+ * This is a twin to netbk_gop_skb. Assume that netbk_gop_skb was
+ * used to set up the operations on the top of
+ * netrx_pending_operations, which have since been done. Check that
+ * they didn't give any errors and advance over them.
+ */
+static int netbk_check_gop(struct xenvif *vif, int nr_meta_slots,
+ struct netrx_pending_operations *npo)
+{
+ struct gnttab_copy *copy_op;
+ int status = XEN_NETIF_RSP_OKAY;
+ int i;
+
+ for (i = 0; i < nr_meta_slots; i++) {
+ copy_op = npo->copy + npo->copy_cons++;
+ if (copy_op->status != GNTST_okay) {
+ netdev_dbg(vif->dev,
+ "Bad status %d from copy to DOM%d.\n",
+ copy_op->status, vif->domid);
+ status = XEN_NETIF_RSP_ERROR;
+ }
+ }
+
+ return status;
+}
+
+static void netbk_add_frag_responses(struct xenvif *vif, int status,
+ struct netbk_rx_meta *meta,
+ int nr_meta_slots)
+{
+ int i;
+ unsigned long offset;
+
+ /* No fragments used */
+ if (nr_meta_slots <= 1)
+ return;
+
+ nr_meta_slots--;
+
+ for (i = 0; i < nr_meta_slots; i++) {
+ int flags;
+ if (i == nr_meta_slots - 1)
+ flags = 0;
+ else
+ flags = XEN_NETRXF_more_data;
+
+ offset = 0;
+ make_rx_response(vif, meta[i].id, status, offset,
+ meta[i].size, flags);
+ }
+}
+
+struct skb_cb_overlay {
+ int meta_slots_used;
+};
+
+static void xen_netbk_rx_action(struct xen_netbk *netbk)
+{
+ struct xenvif *vif = NULL, *tmp;
+ s8 status;
+ u16 irq, flags;
+ struct xen_netif_rx_response *resp;
+ struct sk_buff_head rxq;
+ struct sk_buff *skb;
+ LIST_HEAD(notify);
+ int ret;
+ int nr_frags;
+ int count;
+ unsigned long offset;
+ struct skb_cb_overlay *sco;
+
+ struct netrx_pending_operations npo = {
+ .copy = netbk->grant_copy_op,
+ .meta = netbk->meta,
+ };
+
+ skb_queue_head_init(&rxq);
+
+ count = 0;
+
+ while ((skb = skb_dequeue(&netbk->rx_queue)) != NULL) {
+ vif = netdev_priv(skb->dev);
+ nr_frags = skb_shinfo(skb)->nr_frags;
+
+ sco = (struct skb_cb_overlay *)skb->cb;
+ sco->meta_slots_used = netbk_gop_skb(skb, &npo);
+
+ count += nr_frags + 1;
+
+ __skb_queue_tail(&rxq, skb);
+
+ /* Filled the batch queue? */
+ if (count + MAX_SKB_FRAGS >= XEN_NETIF_RX_RING_SIZE)
+ break;
+ }
+
+ BUG_ON(npo.meta_prod > ARRAY_SIZE(netbk->meta));
+
+ if (!npo.copy_prod)
+ return;
+
+ BUG_ON(npo.copy_prod > ARRAY_SIZE(netbk->grant_copy_op));
+ ret = HYPERVISOR_grant_table_op(GNTTABOP_copy, &netbk->grant_copy_op,
+ npo.copy_prod);
+ BUG_ON(ret != 0);
+
+ while ((skb = __skb_dequeue(&rxq)) != NULL) {
+ sco = (struct skb_cb_overlay *)skb->cb;
+
+ vif = netdev_priv(skb->dev);
+
+ if (netbk->meta[npo.meta_cons].gso_size && vif->gso_prefix) {
+ resp = RING_GET_RESPONSE(&vif->rx,
+ vif->rx.rsp_prod_pvt++);
+
+ resp->flags = XEN_NETRXF_gso_prefix | XEN_NETRXF_more_data;
+
+ resp->offset = netbk->meta[npo.meta_cons].gso_size;
+ resp->id = netbk->meta[npo.meta_cons].id;
+ resp->status = sco->meta_slots_used;
+
+ npo.meta_cons++;
+ sco->meta_slots_used--;
+ }
+
+
+ vif->dev->stats.tx_bytes += skb->len;
+ vif->dev->stats.tx_packets++;
+
+ status = netbk_check_gop(vif, sco->meta_slots_used, &npo);
+
+ if (sco->meta_slots_used == 1)
+ flags = 0;
+ else
+ flags = XEN_NETRXF_more_data;
+
+ if (skb->ip_summed == CHECKSUM_PARTIAL) /* local packet? */
+ flags |= XEN_NETRXF_csum_blank | XEN_NETRXF_data_validated;
+ else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
+ /* remote but checksummed. */
+ flags |= XEN_NETRXF_data_validated;
+
+ offset = 0;
+ resp = make_rx_response(vif, netbk->meta[npo.meta_cons].id,
+ status, offset,
+ netbk->meta[npo.meta_cons].size,
+ flags);
+
+ if (netbk->meta[npo.meta_cons].gso_size && !vif->gso_prefix) {
+ struct xen_netif_extra_info *gso =
+ (struct xen_netif_extra_info *)
+ RING_GET_RESPONSE(&vif->rx,
+ vif->rx.rsp_prod_pvt++);
+
+ resp->flags |= XEN_NETRXF_extra_info;
+
+ gso->u.gso.size = netbk->meta[npo.meta_cons].gso_size;
+ gso->u.gso.type = 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;
+ }
+
+ netbk_add_frag_responses(vif, status,
+ netbk->meta + npo.meta_cons + 1,
+ sco->meta_slots_used);
+
+ RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->rx, ret);
+ irq = vif->irq;
+ if (ret && list_empty(&vif->notify_list))
+ list_add_tail(&vif->notify_list, ¬ify);
+
+ xenvif_notify_tx_completion(vif);
+
+ xenvif_put(vif);
+ npo.meta_cons += sco->meta_slots_used;
+ dev_kfree_skb(skb);
+ }
+
+ list_for_each_entry_safe(vif, tmp, ¬ify, notify_list) {
+ notify_remote_via_irq(vif->irq);
+ list_del_init(&vif->notify_list);
+ }
+
+ /* More work to do? */
+ if (!skb_queue_empty(&netbk->rx_queue) &&
+ !timer_pending(&netbk->net_timer))
+ xen_netbk_kick_thread(netbk);
+}
+
+void xen_netbk_queue_tx_skb(struct xenvif *vif, struct sk_buff *skb)
+{
+ struct xen_netbk *netbk = vif->netbk;
+
+ skb_queue_tail(&netbk->rx_queue, skb);
+
+ xen_netbk_kick_thread(netbk);
+}
+
+static void xen_netbk_alarm(unsigned long data)
+{
+ struct xen_netbk *netbk = (struct xen_netbk *)data;
+ xen_netbk_kick_thread(netbk);
+}
+
+static int __on_net_schedule_list(struct xenvif *vif)
+{
+ return !list_empty(&vif->schedule_list);
+}
+
+/* Must be called with net_schedule_list_lock held */
+static void remove_from_net_schedule_list(struct xenvif *vif)
+{
+ if (likely(__on_net_schedule_list(vif))) {
+ list_del_init(&vif->schedule_list);
+ xenvif_put(vif);
+ }
+}
+
+static struct xenvif *poll_net_schedule_list(struct xen_netbk *netbk)
+{
+ struct xenvif *vif = NULL;
+
+ spin_lock_irq(&netbk->net_schedule_list_lock);
+ if (list_empty(&netbk->net_schedule_list))
+ goto out;
+
+ vif = list_first_entry(&netbk->net_schedule_list,
+ struct xenvif, schedule_list);
+ if (!vif)
+ goto out;
+
+ xenvif_get(vif);
+
+ remove_from_net_schedule_list(vif);
+out:
+ spin_unlock_irq(&netbk->net_schedule_list_lock);
+ return vif;
+}
+
+void xen_netbk_schedule_xenvif(struct xenvif *vif)
+{
+ unsigned long flags;
+ struct xen_netbk *netbk = vif->netbk;
+
+ if (__on_net_schedule_list(vif))
+ goto kick;
+
+ spin_lock_irqsave(&netbk->net_schedule_list_lock, flags);
+ if (!__on_net_schedule_list(vif) &&
+ likely(xenvif_schedulable(vif))) {
+ list_add_tail(&vif->schedule_list, &netbk->net_schedule_list);
+ xenvif_get(vif);
+ }
+ spin_unlock_irqrestore(&netbk->net_schedule_list_lock, flags);
+
+kick:
+ smp_mb();
+ if ((nr_pending_reqs(netbk) < (MAX_PENDING_REQS/2)) &&
+ !list_empty(&netbk->net_schedule_list))
+ xen_netbk_kick_thread(netbk);
+}
+
+void xen_netbk_deschedule_xenvif(struct xenvif *vif)
+{
+ struct xen_netbk *netbk = vif->netbk;
+ spin_lock_irq(&netbk->net_schedule_list_lock);
+ remove_from_net_schedule_list(vif);
+ spin_unlock_irq(&netbk->net_schedule_list_lock);
+}
+
+void xen_netbk_check_rx_xenvif(struct xenvif *vif)
+{
+ int more_to_do;
+
+ RING_FINAL_CHECK_FOR_REQUESTS(&vif->tx, more_to_do);
+
+ if (more_to_do)
+ xen_netbk_schedule_xenvif(vif);
+}
+
+static void tx_add_credit(struct xenvif *vif)
+{
+ unsigned long max_burst, max_credit;
+
+ /*
+ * Allow a burst big enough to transmit a jumbo packet of up to 128kB.
+ * Otherwise the interface can seize up due to insufficient credit.
+ */
+ max_burst = RING_GET_REQUEST(&vif->tx, vif->tx.req_cons)->size;
+ max_burst = min(max_burst, 131072UL);
+ max_burst = max(max_burst, vif->credit_bytes);
+
+ /* Take care that adding a new chunk of credit doesn't wrap to zero. */
+ max_credit = vif->remaining_credit + vif->credit_bytes;
+ if (max_credit < vif->remaining_credit)
+ max_credit = ULONG_MAX; /* wrapped: clamp to ULONG_MAX */
+
+ vif->remaining_credit = min(max_credit, max_burst);
+}
+
+static void tx_credit_callback(unsigned long data)
+{
+ struct xenvif *vif = (struct xenvif *)data;
+ tx_add_credit(vif);
+ xen_netbk_check_rx_xenvif(vif);
+}
+
+static void netbk_tx_err(struct xenvif *vif,
+ struct xen_netif_tx_request *txp, RING_IDX end)
+{
+ RING_IDX cons = vif->tx.req_cons;
+
+ do {
+ make_tx_response(vif, txp, XEN_NETIF_RSP_ERROR);
+ if (cons >= end)
+ break;
+ txp = RING_GET_REQUEST(&vif->tx, cons++);
+ } while (1);
+ vif->tx.req_cons = cons;
+ xen_netbk_check_rx_xenvif(vif);
+ xenvif_put(vif);
+}
+
+static int netbk_count_requests(struct xenvif *vif,
+ struct xen_netif_tx_request *first,
+ struct xen_netif_tx_request *txp,
+ int work_to_do)
+{
+ RING_IDX cons = vif->tx.req_cons;
+ int frags = 0;
+
+ if (!(first->flags & XEN_NETTXF_more_data))
+ return 0;
+
+ do {
+ if (frags >= work_to_do) {
+ netdev_dbg(vif->dev, "Need more frags\n");
+ return -frags;
+ }
+
+ if (unlikely(frags >= MAX_SKB_FRAGS)) {
+ netdev_dbg(vif->dev, "Too many frags\n");
+ return -frags;
+ }
+
+ memcpy(txp, RING_GET_REQUEST(&vif->tx, cons + frags),
+ sizeof(*txp));
+ if (txp->size > first->size) {
+ netdev_dbg(vif->dev, "Frags galore\n");
+ return -frags;
+ }
+
+ first->size -= txp->size;
+ frags++;
+
+ if (unlikely((txp->offset + txp->size) > PAGE_SIZE)) {
+ netdev_dbg(vif->dev, "txp->offset: %x, size: %u\n",
+ txp->offset, txp->size);
+ return -frags;
+ }
+ } while ((txp++)->flags & XEN_NETTXF_more_data);
+ return frags;
+}
+
+static struct page *xen_netbk_alloc_page(struct xen_netbk *netbk,
+ struct sk_buff *skb,
+ unsigned long pending_idx)
+{
+ struct page *page;
+ page = alloc_page(GFP_KERNEL|__GFP_COLD);
+ if (!page)
+ return NULL;
+ set_page_ext(page, netbk, pending_idx);
+ netbk->mmap_pages[pending_idx] = page;
+ return page;
+}
+
+static struct gnttab_copy *xen_netbk_get_requests(struct xen_netbk *netbk,
+ struct xenvif *vif,
+ struct sk_buff *skb,
+ struct xen_netif_tx_request *txp,
+ struct gnttab_copy *gop)
+{
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
+ skb_frag_t *frags = shinfo->frags;
+ unsigned long pending_idx = *((u16 *)skb->data);
+ int i, start;
+
+ /* Skip first skb fragment if it is on same page as header fragment. */
+ start = ((unsigned long)shinfo->frags[0].page == pending_idx);
+
+ for (i = start; i < shinfo->nr_frags; i++, txp++) {
+ struct page *page;
+ pending_ring_idx_t index;
+ struct pending_tx_info *pending_tx_info =
+ netbk->pending_tx_info;
+
+ index = pending_index(netbk->pending_cons++);
+ pending_idx = netbk->pending_ring[index];
+ page = xen_netbk_alloc_page(netbk, skb, pending_idx);
+ if (!page)
+ return NULL;
+
+ netbk->mmap_pages[pending_idx] = page;
+
+ gop->source.u.ref = txp->gref;
+ gop->source.domid = vif->domid;
+ gop->source.offset = txp->offset;
+
+ gop->dest.u.gmfn = virt_to_mfn(page_address(page));
+ gop->dest.domid = DOMID_SELF;
+ gop->dest.offset = txp->offset;
+
+ gop->len = txp->size;
+ gop->flags = GNTCOPY_source_gref;
+
+ gop++;
+
+ memcpy(&pending_tx_info[pending_idx].req, txp, sizeof(*txp));
+ xenvif_get(vif);
+ pending_tx_info[pending_idx].vif = vif;
+ frags[i].page = (void *)pending_idx;
+ }
+
+ return gop;
+}
+
+static int xen_netbk_tx_check_gop(struct xen_netbk *netbk,
+ struct sk_buff *skb,
+ struct gnttab_copy **gopp)
+{
+ struct gnttab_copy *gop = *gopp;
+ int pending_idx = *((u16 *)skb->data);
+ struct pending_tx_info *pending_tx_info = netbk->pending_tx_info;
+ struct xenvif *vif = pending_tx_info[pending_idx].vif;
+ struct xen_netif_tx_request *txp;
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
+ int nr_frags = shinfo->nr_frags;
+ int i, err, start;
+
+ /* Check status of header. */
+ err = gop->status;
+ if (unlikely(err)) {
+ pending_ring_idx_t index;
+ index = pending_index(netbk->pending_prod++);
+ txp = &pending_tx_info[pending_idx].req;
+ make_tx_response(vif, txp, XEN_NETIF_RSP_ERROR);
+ netbk->pending_ring[index] = pending_idx;
+ xenvif_put(vif);
+ }
+
+ /* Skip first skb fragment if it is on same page as header fragment. */
+ start = ((unsigned long)shinfo->frags[0].page == pending_idx);
+
+ for (i = start; i < nr_frags; i++) {
+ int j, newerr;
+ pending_ring_idx_t index;
+
+ pending_idx = (unsigned long)shinfo->frags[i].page;
+
+ /* Check error status: if okay then remember grant handle. */
+ newerr = (++gop)->status;
+ if (likely(!newerr)) {
+ /* Had a previous error? Invalidate this fragment. */
+ if (unlikely(err))
+ xen_netbk_idx_release(netbk, pending_idx);
+ continue;
+ }
+
+ /* Error on this fragment: respond to client with an error. */
+ txp = &netbk->pending_tx_info[pending_idx].req;
+ make_tx_response(vif, txp, XEN_NETIF_RSP_ERROR);
+ index = pending_index(netbk->pending_prod++);
+ netbk->pending_ring[index] = pending_idx;
+ xenvif_put(vif);
+
+ /* Not the first error? Preceding frags already invalidated. */
+ if (err)
+ continue;
+
+ /* First error: invalidate header and preceding fragments. */
+ pending_idx = *((u16 *)skb->data);
+ xen_netbk_idx_release(netbk, pending_idx);
+ for (j = start; j < i; j++) {
+ pending_idx = (unsigned long)shinfo->frags[i].page;
+ xen_netbk_idx_release(netbk, pending_idx);
+ }
+
+ /* Remember the error: invalidate all subsequent fragments. */
+ err = newerr;
+ }
+
+ *gopp = gop + 1;
+ return err;
+}
+
+static void xen_netbk_fill_frags(struct xen_netbk *netbk, struct sk_buff *skb)
+{
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
+ int nr_frags = shinfo->nr_frags;
+ int i;
+
+ for (i = 0; i < nr_frags; i++) {
+ skb_frag_t *frag = shinfo->frags + i;
+ struct xen_netif_tx_request *txp;
+ unsigned long pending_idx;
+
+ pending_idx = (unsigned long)frag->page;
+
+ txp = &netbk->pending_tx_info[pending_idx].req;
+ frag->page = virt_to_page(idx_to_kaddr(netbk, pending_idx));
+ frag->size = txp->size;
+ frag->page_offset = txp->offset;
+
+ skb->len += txp->size;
+ skb->data_len += txp->size;
+ skb->truesize += txp->size;
+
+ /* Take an extra reference to offset xen_netbk_idx_release */
+ get_page(netbk->mmap_pages[pending_idx]);
+ xen_netbk_idx_release(netbk, pending_idx);
+ }
+}
+
+static int xen_netbk_get_extras(struct xenvif *vif,
+ struct xen_netif_extra_info *extras,
+ int work_to_do)
+{
+ struct xen_netif_extra_info extra;
+ RING_IDX cons = vif->tx.req_cons;
+
+ do {
+ if (unlikely(work_to_do-- <= 0)) {
+ netdev_dbg(vif->dev, "Missing extra info\n");
+ return -EBADR;
+ }
+
+ memcpy(&extra, RING_GET_REQUEST(&vif->tx, cons),
+ sizeof(extra));
+ if (unlikely(!extra.type ||
+ extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
+ vif->tx.req_cons = ++cons;
+ netdev_dbg(vif->dev,
+ "Invalid extra type: %d\n", extra.type);
+ return -EINVAL;
+ }
+
+ memcpy(&extras[extra.type - 1], &extra, sizeof(extra));
+ vif->tx.req_cons = ++cons;
+ } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE);
+
+ return work_to_do;
+}
+
+static int netbk_set_skb_gso(struct xenvif *vif,
+ struct sk_buff *skb,
+ struct xen_netif_extra_info *gso)
+{
+ if (!gso->u.gso.size) {
+ netdev_dbg(vif->dev, "GSO size must not be zero.\n");
+ return -EINVAL;
+ }
+
+ /* Currently only TCPv4 S.O. is supported. */
+ if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4) {
+ netdev_dbg(vif->dev, "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 = SKB_GSO_TCPV4;
+
+ /* 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 int checksum_setup(struct xenvif *vif, struct sk_buff *skb)
+{
+ struct iphdr *iph;
+ unsigned char *th;
+ int err = -EPROTO;
+ int recalculate_partial_csum = 0;
+
+ /*
+ * 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)) {
+ vif->rx_gso_checksum_fixup++;
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ recalculate_partial_csum = 1;
+ }
+
+ /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
+ if (skb->ip_summed != CHECKSUM_PARTIAL)
+ return 0;
+
+ if (skb->protocol != htons(ETH_P_IP))
+ goto out;
+
+ iph = (void *)skb->data;
+ th = skb->data + 4 * iph->ihl;
+ if (th >= skb_tail_pointer(skb))
+ goto out;
+
+ skb->csum_start = th - skb->head;
+ switch (iph->protocol) {
+ case IPPROTO_TCP:
+ skb->csum_offset = offsetof(struct tcphdr, check);
+
+ if (recalculate_partial_csum) {
+ struct tcphdr *tcph = (struct tcphdr *)th;
+ tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
+ skb->len - iph->ihl*4,
+ IPPROTO_TCP, 0);
+ }
+ break;
+ case IPPROTO_UDP:
+ skb->csum_offset = offsetof(struct udphdr, check);
+
+ if (recalculate_partial_csum) {
+ struct udphdr *udph = (struct udphdr *)th;
+ udph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
+ skb->len - iph->ihl*4,
+ IPPROTO_UDP, 0);
+ }
+ break;
+ default:
+ if (net_ratelimit())
+ netdev_err(vif->dev,
+ "Attempting to checksum a non-TCP/UDP packet, dropping a protocol %d packet\n",
+ iph->protocol);
+ goto out;
+ }
+
+ if ((th + skb->csum_offset + 2) > skb_tail_pointer(skb))
+ goto out;
+
+ err = 0;
+
+out:
+ return err;
+}
+
+static bool tx_credit_exceeded(struct xenvif *vif, unsigned size)
+{
+ unsigned long now = jiffies;
+ unsigned long next_credit =
+ vif->credit_timeout.expires +
+ msecs_to_jiffies(vif->credit_usec / 1000);
+
+ /* Timer could already be pending in rare cases. */
+ if (timer_pending(&vif->credit_timeout))
+ return true;
+
+ /* Passed the point where we can replenish credit? */
+ if (time_after_eq(now, next_credit)) {
+ vif->credit_timeout.expires = now;
+ tx_add_credit(vif);
+ }
+
+ /* Still too big to send right now? Set a callback. */
+ if (size > vif->remaining_credit) {
+ vif->credit_timeout.data =
+ (unsigned long)vif;
+ vif->credit_timeout.function =
+ tx_credit_callback;
+ mod_timer(&vif->credit_timeout,
+ next_credit);
+
+ return true;
+ }
+
+ return false;
+}
+
+static unsigned xen_netbk_tx_build_gops(struct xen_netbk *netbk)
+{
+ struct gnttab_copy *gop = netbk->tx_copy_ops, *request_gop;
+ struct sk_buff *skb;
+ int ret;
+
+ while (((nr_pending_reqs(netbk) + MAX_SKB_FRAGS) < MAX_PENDING_REQS) &&
+ !list_empty(&netbk->net_schedule_list)) {
+ struct xenvif *vif;
+ struct xen_netif_tx_request txreq;
+ struct xen_netif_tx_request txfrags[MAX_SKB_FRAGS];
+ struct page *page;
+ struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX-1];
+ u16 pending_idx;
+ RING_IDX idx;
+ int work_to_do;
+ unsigned int data_len;
+ pending_ring_idx_t index;
+
+ /* Get a netif from the list with work to do. */
+ vif = poll_net_schedule_list(netbk);
+ if (!vif)
+ continue;
+
+ RING_FINAL_CHECK_FOR_REQUESTS(&vif->tx, work_to_do);
+ if (!work_to_do) {
+ xenvif_put(vif);
+ continue;
+ }
+
+ idx = vif->tx.req_cons;
+ rmb(); /* Ensure that we see the request before we copy it. */
+ memcpy(&txreq, RING_GET_REQUEST(&vif->tx, idx), sizeof(txreq));
+
+ /* Credit-based scheduling. */
+ if (txreq.size > vif->remaining_credit &&
+ tx_credit_exceeded(vif, txreq.size)) {
+ xenvif_put(vif);
+ continue;
+ }
+
+ vif->remaining_credit -= txreq.size;
+
+ work_to_do--;
+ vif->tx.req_cons = ++idx;
+
+ memset(extras, 0, sizeof(extras));
+ if (txreq.flags & XEN_NETTXF_extra_info) {
+ work_to_do = xen_netbk_get_extras(vif, extras,
+ work_to_do);
+ idx = vif->tx.req_cons;
+ if (unlikely(work_to_do < 0)) {
+ netbk_tx_err(vif, &txreq, idx);
+ continue;
+ }
+ }
+
+ ret = netbk_count_requests(vif, &txreq, txfrags, work_to_do);
+ if (unlikely(ret < 0)) {
+ netbk_tx_err(vif, &txreq, idx - ret);
+ continue;
+ }
+ idx += ret;
+
+ if (unlikely(txreq.size < ETH_HLEN)) {
+ netdev_dbg(vif->dev,
+ "Bad packet size: %d\n", txreq.size);
+ netbk_tx_err(vif, &txreq, idx);
+ continue;
+ }
+
+ /* No crossing a page as the payload mustn't fragment. */
+ if (unlikely((txreq.offset + txreq.size) > PAGE_SIZE)) {
+ netdev_dbg(vif->dev,
+ "txreq.offset: %x, size: %u, end: %lu\n",
+ txreq.offset, txreq.size,
+ (txreq.offset&~PAGE_MASK) + txreq.size);
+ netbk_tx_err(vif, &txreq, idx);
+ continue;
+ }
+
+ index = pending_index(netbk->pending_cons);
+ pending_idx = netbk->pending_ring[index];
+
+ data_len = (txreq.size > PKT_PROT_LEN &&
+ ret < MAX_SKB_FRAGS) ?
+ PKT_PROT_LEN : txreq.size;
+
+ skb = alloc_skb(data_len + NET_SKB_PAD + NET_IP_ALIGN,
+ GFP_ATOMIC | __GFP_NOWARN);
+ if (unlikely(skb == NULL)) {
+ netdev_dbg(vif->dev,
+ "Can't allocate a skb in start_xmit.\n");
+ netbk_tx_err(vif, &txreq, idx);
+ break;
+ }
+
+ /* Packets passed to netif_rx() must have some headroom. */
+ skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
+
+ if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
+ struct xen_netif_extra_info *gso;
+ gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
+
+ if (netbk_set_skb_gso(vif, skb, gso)) {
+ kfree_skb(skb);
+ netbk_tx_err(vif, &txreq, idx);
+ continue;
+ }
+ }
+
+ /* XXX could copy straight to head */
+ page = xen_netbk_alloc_page(netbk, skb, pending_idx);
+ if (!page) {
+ kfree_skb(skb);
+ netbk_tx_err(vif, &txreq, idx);
+ continue;
+ }
+
+ netbk->mmap_pages[pending_idx] = page;
+
+ gop->source.u.ref = txreq.gref;
+ gop->source.domid = vif->domid;
+ gop->source.offset = txreq.offset;
+
+ gop->dest.u.gmfn = virt_to_mfn(page_address(page));
+ gop->dest.domid = DOMID_SELF;
+ gop->dest.offset = txreq.offset;
+
+ gop->len = txreq.size;
+ gop->flags = GNTCOPY_source_gref;
+
+ gop++;
+
+ memcpy(&netbk->pending_tx_info[pending_idx].req,
+ &txreq, sizeof(txreq));
+ netbk->pending_tx_info[pending_idx].vif = vif;
+ *((u16 *)skb->data) = pending_idx;
+
+ __skb_put(skb, data_len);
+
+ skb_shinfo(skb)->nr_frags = ret;
+ if (data_len < txreq.size) {
+ skb_shinfo(skb)->nr_frags++;
+ skb_shinfo(skb)->frags[0].page =
+ (void *)(unsigned long)pending_idx;
+ } else {
+ /* Discriminate from any valid pending_idx value. */
+ skb_shinfo(skb)->frags[0].page = (void *)~0UL;
+ }
+
+ __skb_queue_tail(&netbk->tx_queue, skb);
+
+ netbk->pending_cons++;
+
+ request_gop = xen_netbk_get_requests(netbk, vif,
+ skb, txfrags, gop);
+ if (request_gop == NULL) {
+ kfree_skb(skb);
+ netbk_tx_err(vif, &txreq, idx);
+ continue;
+ }
+ gop = request_gop;
+
+ vif->tx.req_cons = idx;
+ xen_netbk_check_rx_xenvif(vif);
+
+ if ((gop-netbk->tx_copy_ops) >= ARRAY_SIZE(netbk->tx_copy_ops))
+ break;
+ }
+
+ return gop - netbk->tx_copy_ops;
+}
+
+static void xen_netbk_tx_submit(struct xen_netbk *netbk)
+{
+ struct gnttab_copy *gop = netbk->tx_copy_ops;
+ struct sk_buff *skb;
+
+ while ((skb = __skb_dequeue(&netbk->tx_queue)) != NULL) {
+ struct xen_netif_tx_request *txp;
+ struct xenvif *vif;
+ u16 pending_idx;
+ unsigned data_len;
+
+ pending_idx = *((u16 *)skb->data);
+ vif = netbk->pending_tx_info[pending_idx].vif;
+ txp = &netbk->pending_tx_info[pending_idx].req;
+
+ /* Check the remap error code. */
+ if (unlikely(xen_netbk_tx_check_gop(netbk, skb, &gop))) {
+ netdev_dbg(vif->dev, "netback grant failed.\n");
+ skb_shinfo(skb)->nr_frags = 0;
+ kfree_skb(skb);
+ continue;
+ }
+
+ data_len = skb->len;
+ memcpy(skb->data,
+ (void *)(idx_to_kaddr(netbk, pending_idx)|txp->offset),
+ data_len);
+ if (data_len < txp->size) {
+ /* Append the packet payload as a fragment. */
+ txp->offset += data_len;
+ txp->size -= data_len;
+ } else {
+ /* Schedule a response immediately. */
+ xen_netbk_idx_release(netbk, pending_idx);
+ }
+
+ if (txp->flags & XEN_NETTXF_csum_blank)
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ else if (txp->flags & XEN_NETTXF_data_validated)
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+ xen_netbk_fill_frags(netbk, skb);
+
+ /*
+ * If the initial fragment was < PKT_PROT_LEN then
+ * pull through some bytes from the other fragments to
+ * increase the linear region to PKT_PROT_LEN bytes.
+ */
+ if (skb_headlen(skb) < PKT_PROT_LEN && skb_is_nonlinear(skb)) {
+ int target = min_t(int, skb->len, PKT_PROT_LEN);
+ __pskb_pull_tail(skb, target - skb_headlen(skb));
+ }
+
+ skb->dev = vif->dev;
+ skb->protocol = eth_type_trans(skb, skb->dev);
+
+ if (checksum_setup(vif, skb)) {
+ netdev_dbg(vif->dev,
+ "Can't setup checksum in net_tx_action\n");
+ kfree_skb(skb);
+ continue;
+ }
+
+ vif->dev->stats.rx_bytes += skb->len;
+ vif->dev->stats.rx_packets++;
+
+ xenvif_receive_skb(vif, skb);
+ }
+}
+
+/* Called after netfront has transmitted */
+static void xen_netbk_tx_action(struct xen_netbk *netbk)
+{
+ unsigned nr_gops;
+ int ret;
+
+ nr_gops = xen_netbk_tx_build_gops(netbk);
+
+ if (nr_gops == 0)
+ return;
+ ret = HYPERVISOR_grant_table_op(GNTTABOP_copy,
+ netbk->tx_copy_ops, nr_gops);
+ BUG_ON(ret);
+
+ xen_netbk_tx_submit(netbk);
+
+}
+
+static void xen_netbk_idx_release(struct xen_netbk *netbk, u16 pending_idx)
+{
+ struct xenvif *vif;
+ struct pending_tx_info *pending_tx_info;
+ pending_ring_idx_t index;
+
+ /* Already complete? */
+ if (netbk->mmap_pages[pending_idx] == NULL)
+ return;
+
+ pending_tx_info = &netbk->pending_tx_info[pending_idx];
+
+ vif = pending_tx_info->vif;
+
+ make_tx_response(vif, &pending_tx_info->req, XEN_NETIF_RSP_OKAY);
+
+ index = pending_index(netbk->pending_prod++);
+ netbk->pending_ring[index] = pending_idx;
+
+ xenvif_put(vif);
+
+ netbk->mmap_pages[pending_idx]->mapping = 0;
+ put_page(netbk->mmap_pages[pending_idx]);
+ netbk->mmap_pages[pending_idx] = NULL;
+}
+
+static void make_tx_response(struct xenvif *vif,
+ struct xen_netif_tx_request *txp,
+ s8 st)
+{
+ RING_IDX i = vif->tx.rsp_prod_pvt;
+ struct xen_netif_tx_response *resp;
+ int notify;
+
+ resp = RING_GET_RESPONSE(&vif->tx, i);
+ resp->id = txp->id;
+ resp->status = st;
+
+ if (txp->flags & XEN_NETTXF_extra_info)
+ RING_GET_RESPONSE(&vif->tx, ++i)->status = XEN_NETIF_RSP_NULL;
+
+ vif->tx.rsp_prod_pvt = ++i;
+ RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->tx, notify);
+ if (notify)
+ notify_remote_via_irq(vif->irq);
+}
+
+static struct xen_netif_rx_response *make_rx_response(struct xenvif *vif,
+ u16 id,
+ s8 st,
+ u16 offset,
+ u16 size,
+ u16 flags)
+{
+ RING_IDX i = vif->rx.rsp_prod_pvt;
+ struct xen_netif_rx_response *resp;
+
+ resp = RING_GET_RESPONSE(&vif->rx, i);
+ resp->offset = offset;
+ resp->flags = flags;
+ resp->id = id;
+ resp->status = (s16)size;
+ if (st < 0)
+ resp->status = (s16)st;
+
+ vif->rx.rsp_prod_pvt = ++i;
+
+ return resp;
+}
+
+static inline int rx_work_todo(struct xen_netbk *netbk)
+{
+ return !skb_queue_empty(&netbk->rx_queue);
+}
+
+static inline int tx_work_todo(struct xen_netbk *netbk)
+{
+
+ if (((nr_pending_reqs(netbk) + MAX_SKB_FRAGS) < MAX_PENDING_REQS) &&
+ !list_empty(&netbk->net_schedule_list))
+ return 1;
+
+ return 0;
+}
+
+static int xen_netbk_kthread(void *data)
+{
+ struct xen_netbk *netbk = data;
+ while (!kthread_should_stop()) {
+ wait_event_interruptible(netbk->wq,
+ rx_work_todo(netbk) ||
+ tx_work_todo(netbk) ||
+ kthread_should_stop());
+ cond_resched();
+
+ if (kthread_should_stop())
+ break;
+
+ if (rx_work_todo(netbk))
+ xen_netbk_rx_action(netbk);
+
+ if (tx_work_todo(netbk))
+ xen_netbk_tx_action(netbk);
+ }
+
+ return 0;
+}
+
+void xen_netbk_unmap_frontend_rings(struct xenvif *vif)
+{
+ struct gnttab_unmap_grant_ref op;
+
+ if (vif->tx.sring) {
+ gnttab_set_unmap_op(&op, (unsigned long)vif->tx_comms_area->addr,
+ GNTMAP_host_map, vif->tx_shmem_handle);
+
+ if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1))
+ BUG();
+ }
+
+ if (vif->rx.sring) {
+ gnttab_set_unmap_op(&op, (unsigned long)vif->rx_comms_area->addr,
+ GNTMAP_host_map, vif->rx_shmem_handle);
+
+ if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1))
+ BUG();
+ }
+ if (vif->rx_comms_area)
+ free_vm_area(vif->rx_comms_area);
+ if (vif->tx_comms_area)
+ free_vm_area(vif->tx_comms_area);
+}
+
+int xen_netbk_map_frontend_rings(struct xenvif *vif,
+ grant_ref_t tx_ring_ref,
+ grant_ref_t rx_ring_ref)
+{
+ struct gnttab_map_grant_ref op;
+ struct xen_netif_tx_sring *txs;
+ struct xen_netif_rx_sring *rxs;
+
+ int err = -ENOMEM;
+
+ vif->tx_comms_area = alloc_vm_area(PAGE_SIZE);
+ if (vif->tx_comms_area == NULL)
+ goto err;
+
+ vif->rx_comms_area = alloc_vm_area(PAGE_SIZE);
+ if (vif->rx_comms_area == NULL)
+ goto err;
+
+ gnttab_set_map_op(&op, (unsigned long)vif->tx_comms_area->addr,
+ GNTMAP_host_map, tx_ring_ref, vif->domid);
+
+ if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
+ BUG();
+
+ if (op.status) {
+ netdev_warn(vif->dev,
+ "failed to map tx ring. err=%d status=%d\n",
+ err, op.status);
+ err = op.status;
+ goto err;
+ }
+
+ vif->tx_shmem_ref = tx_ring_ref;
+ vif->tx_shmem_handle = op.handle;
+
+ txs = (struct xen_netif_tx_sring *)vif->tx_comms_area->addr;
+ BACK_RING_INIT(&vif->tx, txs, PAGE_SIZE);
+
+ gnttab_set_map_op(&op, (unsigned long)vif->rx_comms_area->addr,
+ GNTMAP_host_map, rx_ring_ref, vif->domid);
+
+ if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
+ BUG();
+
+ if (op.status) {
+ netdev_warn(vif->dev,
+ "failed to map rx ring. err=%d status=%d\n",
+ err, op.status);
+ err = op.status;
+ goto err;
+ }
+
+ vif->rx_shmem_ref = rx_ring_ref;
+ vif->rx_shmem_handle = op.handle;
+ vif->rx_req_cons_peek = 0;
+
+ rxs = (struct xen_netif_rx_sring *)vif->rx_comms_area->addr;
+ BACK_RING_INIT(&vif->rx, rxs, PAGE_SIZE);
+
+ return 0;
+
+err:
+ xen_netbk_unmap_frontend_rings(vif);
+ return err;
+}
+
+static int __init netback_init(void)
+{
+ int i;
+ int rc = 0;
+ int group;
+
+ if (!xen_pv_domain())
+ return -ENODEV;
+
+ xen_netbk_group_nr = num_online_cpus();
+ xen_netbk = vzalloc(sizeof(struct xen_netbk) * xen_netbk_group_nr);
+ if (!xen_netbk) {
+ printk(KERN_ALERT "%s: out of memory\n", __func__);
+ return -ENOMEM;
+ }
+
+ for (group = 0; group < xen_netbk_group_nr; group++) {
+ struct xen_netbk *netbk = &xen_netbk[group];
+ skb_queue_head_init(&netbk->rx_queue);
+ skb_queue_head_init(&netbk->tx_queue);
+
+ init_timer(&netbk->net_timer);
+ netbk->net_timer.data = (unsigned long)netbk;
+ netbk->net_timer.function = xen_netbk_alarm;
+
+ netbk->pending_cons = 0;
+ netbk->pending_prod = MAX_PENDING_REQS;
+ for (i = 0; i < MAX_PENDING_REQS; i++)
+ netbk->pending_ring[i] = i;
+
+ init_waitqueue_head(&netbk->wq);
+ netbk->task = kthread_create(xen_netbk_kthread,
+ (void *)netbk,
+ "netback/%u", group);
+
+ if (IS_ERR(netbk->task)) {
+ printk(KERN_ALERT "kthread_run() fails at netback\n");
+ del_timer(&netbk->net_timer);
+ rc = PTR_ERR(netbk->task);
+ goto failed_init;
+ }
+
+ kthread_bind(netbk->task, group);
+
+ INIT_LIST_HEAD(&netbk->net_schedule_list);
+
+ spin_lock_init(&netbk->net_schedule_list_lock);
+
+ atomic_set(&netbk->netfront_count, 0);
+
+ wake_up_process(netbk->task);
+ }
+
+ rc = xenvif_xenbus_init();
+ if (rc)
+ goto failed_init;
+
+ return 0;
+
+failed_init:
+ while (--group >= 0) {
+ struct xen_netbk *netbk = &xen_netbk[group];
+ for (i = 0; i < MAX_PENDING_REQS; i++) {
+ if (netbk->mmap_pages[i])
+ __free_page(netbk->mmap_pages[i]);
+ }
+ del_timer(&netbk->net_timer);
+ kthread_stop(netbk->task);
+ }
+ vfree(xen_netbk);
+ return rc;
+
+}
+
+module_init(netback_init);
+
+MODULE_LICENSE("Dual BSD/GPL");
--- /dev/null
+/*
+ * Xenbus code for netif backend
+ *
+ * Copyright (C) 2005 Rusty Russell <rusty@rustcorp.com.au>
+ * 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 as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+*/
+
+#include "common.h"
+
+struct backend_info {
+ struct xenbus_device *dev;
+ struct xenvif *vif;
+ enum xenbus_state frontend_state;
+ struct xenbus_watch hotplug_status_watch;
+ int have_hotplug_status_watch:1;
+};
+
+static int connect_rings(struct backend_info *);
+static void connect(struct backend_info *);
+static void backend_create_xenvif(struct backend_info *be);
+static void unregister_hotplug_status_watch(struct backend_info *be);
+
+static int netback_remove(struct xenbus_device *dev)
+{
+ struct backend_info *be = dev_get_drvdata(&dev->dev);
+
+ unregister_hotplug_status_watch(be);
+ if (be->vif) {
+ kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
+ xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");
+ xenvif_disconnect(be->vif);
+ be->vif = NULL;
+ }
+ kfree(be);
+ dev_set_drvdata(&dev->dev, NULL);
+ return 0;
+}
+
+
+/**
+ * Entry point to this code when a new device is created. Allocate the basic
+ * structures and switch to InitWait.
+ */
+static int netback_probe(struct xenbus_device *dev,
+ const struct xenbus_device_id *id)
+{
+ const char *message;
+ struct xenbus_transaction xbt;
+ int err;
+ int sg;
+ struct backend_info *be = kzalloc(sizeof(struct backend_info),
+ GFP_KERNEL);
+ if (!be) {
+ xenbus_dev_fatal(dev, -ENOMEM,
+ "allocating backend structure");
+ return -ENOMEM;
+ }
+
+ be->dev = dev;
+ dev_set_drvdata(&dev->dev, be);
+
+ sg = 1;
+
+ do {
+ err = xenbus_transaction_start(&xbt);
+ if (err) {
+ xenbus_dev_fatal(dev, err, "starting transaction");
+ goto fail;
+ }
+
+ err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", sg);
+ if (err) {
+ message = "writing feature-sg";
+ goto abort_transaction;
+ }
+
+ err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4",
+ "%d", sg);
+ if (err) {
+ message = "writing feature-gso-tcpv4";
+ goto abort_transaction;
+ }
+
+ /* We support rx-copy path. */
+ err = xenbus_printf(xbt, dev->nodename,
+ "feature-rx-copy", "%d", 1);
+ if (err) {
+ message = "writing feature-rx-copy";
+ goto abort_transaction;
+ }
+
+ /*
+ * We don't support rx-flip path (except old guests who don't
+ * grok this feature flag).
+ */
+ err = xenbus_printf(xbt, dev->nodename,
+ "feature-rx-flip", "%d", 0);
+ if (err) {
+ message = "writing feature-rx-flip";
+ goto abort_transaction;
+ }
+
+ err = xenbus_transaction_end(xbt, 0);
+ } while (err == -EAGAIN);
+
+ if (err) {
+ xenbus_dev_fatal(dev, err, "completing transaction");
+ goto fail;
+ }
+
+ err = xenbus_switch_state(dev, XenbusStateInitWait);
+ if (err)
+ goto fail;
+
+ /* This kicks hotplug scripts, so do it immediately. */
+ backend_create_xenvif(be);
+
+ return 0;
+
+abort_transaction:
+ xenbus_transaction_end(xbt, 1);
+ xenbus_dev_fatal(dev, err, "%s", message);
+fail:
+ pr_debug("failed");
+ netback_remove(dev);
+ return err;
+}
+
+
+/*
+ * Handle the creation of the hotplug script environment. We add the script
+ * and vif variables to the environment, for the benefit of the vif-* hotplug
+ * scripts.
+ */
+static int netback_uevent(struct xenbus_device *xdev,
+ struct kobj_uevent_env *env)
+{
+ struct backend_info *be = dev_get_drvdata(&xdev->dev);
+ char *val;
+
+ val = xenbus_read(XBT_NIL, xdev->nodename, "script", NULL);
+ if (IS_ERR(val)) {
+ int err = PTR_ERR(val);
+ xenbus_dev_fatal(xdev, err, "reading script");
+ return err;
+ } else {
+ if (add_uevent_var(env, "script=%s", val)) {
+ kfree(val);
+ return -ENOMEM;
+ }
+ kfree(val);
+ }
+
+ if (!be || !be->vif)
+ return 0;
+
+ return add_uevent_var(env, "vif=%s", be->vif->dev->name);
+}
+
+
+static void backend_create_xenvif(struct backend_info *be)
+{
+ int err;
+ long handle;
+ struct xenbus_device *dev = be->dev;
+
+ if (be->vif != NULL)
+ return;
+
+ err = xenbus_scanf(XBT_NIL, dev->nodename, "handle", "%li", &handle);
+ if (err != 1) {
+ xenbus_dev_fatal(dev, err, "reading handle");
+ return;
+ }
+
+ be->vif = xenvif_alloc(&dev->dev, dev->otherend_id, handle);
+ if (IS_ERR(be->vif)) {
+ err = PTR_ERR(be->vif);
+ be->vif = NULL;
+ xenbus_dev_fatal(dev, err, "creating interface");
+ return;
+ }
+
+ kobject_uevent(&dev->dev.kobj, KOBJ_ONLINE);
+}
+
+
+static void disconnect_backend(struct xenbus_device *dev)
+{
+ struct backend_info *be = dev_get_drvdata(&dev->dev);
+
+ if (be->vif) {
+ xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");
+ xenvif_disconnect(be->vif);
+ be->vif = NULL;
+ }
+}
+
+/**
+ * Callback received when the frontend's state changes.
+ */
+static void frontend_changed(struct xenbus_device *dev,
+ enum xenbus_state frontend_state)
+{
+ struct backend_info *be = dev_get_drvdata(&dev->dev);
+
+ pr_debug("frontend state %s", xenbus_strstate(frontend_state));
+
+ be->frontend_state = frontend_state;
+
+ switch (frontend_state) {
+ case XenbusStateInitialising:
+ if (dev->state == XenbusStateClosed) {
+ printk(KERN_INFO "%s: %s: prepare for reconnect\n",
+ __func__, dev->nodename);
+ xenbus_switch_state(dev, XenbusStateInitWait);
+ }
+ break;
+
+ case XenbusStateInitialised:
+ break;
+
+ case XenbusStateConnected:
+ if (dev->state == XenbusStateConnected)
+ break;
+ backend_create_xenvif(be);
+ if (be->vif)
+ connect(be);
+ break;
+
+ case XenbusStateClosing:
+ if (be->vif)
+ kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
+ disconnect_backend(dev);
+ xenbus_switch_state(dev, XenbusStateClosing);
+ break;
+
+ case XenbusStateClosed:
+ xenbus_switch_state(dev, XenbusStateClosed);
+ if (xenbus_dev_is_online(dev))
+ break;
+ /* fall through if not online */
+ case XenbusStateUnknown:
+ device_unregister(&dev->dev);
+ break;
+
+ default:
+ xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
+ frontend_state);
+ break;
+ }
+}
+
+
+static void xen_net_read_rate(struct xenbus_device *dev,
+ unsigned long *bytes, unsigned long *usec)
+{
+ char *s, *e;
+ unsigned long b, u;
+ char *ratestr;
+
+ /* Default to unlimited bandwidth. */
+ *bytes = ~0UL;
+ *usec = 0;
+
+ ratestr = xenbus_read(XBT_NIL, dev->nodename, "rate", NULL);
+ if (IS_ERR(ratestr))
+ return;
+
+ s = ratestr;
+ b = simple_strtoul(s, &e, 10);
+ if ((s == e) || (*e != ','))
+ goto fail;
+
+ s = e + 1;
+ u = simple_strtoul(s, &e, 10);
+ if ((s == e) || (*e != '\0'))
+ goto fail;
+
+ *bytes = b;
+ *usec = u;
+
+ kfree(ratestr);
+ return;
+
+ fail:
+ pr_warn("Failed to parse network rate limit. Traffic unlimited.\n");
+ kfree(ratestr);
+}
+
+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 void unregister_hotplug_status_watch(struct backend_info *be)
+{
+ if (be->have_hotplug_status_watch) {
+ unregister_xenbus_watch(&be->hotplug_status_watch);
+ kfree(be->hotplug_status_watch.node);
+ }
+ be->have_hotplug_status_watch = 0;
+}
+
+static void hotplug_status_changed(struct xenbus_watch *watch,
+ const char **vec,
+ unsigned int vec_size)
+{
+ struct backend_info *be = container_of(watch,
+ struct backend_info,
+ hotplug_status_watch);
+ char *str;
+ unsigned int len;
+
+ str = xenbus_read(XBT_NIL, be->dev->nodename, "hotplug-status", &len);
+ if (IS_ERR(str))
+ return;
+ if (len == sizeof("connected")-1 && !memcmp(str, "connected", len)) {
+ xenbus_switch_state(be->dev, XenbusStateConnected);
+ /* Not interested in this watch anymore. */
+ unregister_hotplug_status_watch(be);
+ }
+ kfree(str);
+}
+
+static void connect(struct backend_info *be)
+{
+ int err;
+ struct xenbus_device *dev = be->dev;
+
+ err = connect_rings(be);
+ if (err)
+ return;
+
+ err = xen_net_read_mac(dev, be->vif->fe_dev_addr);
+ if (err) {
+ xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
+ return;
+ }
+
+ xen_net_read_rate(dev, &be->vif->credit_bytes,
+ &be->vif->credit_usec);
+ be->vif->remaining_credit = be->vif->credit_bytes;
+
+ unregister_hotplug_status_watch(be);
+ err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch,
+ hotplug_status_changed,
+ "%s/%s", dev->nodename, "hotplug-status");
+ if (err) {
+ /* Switch now, since we can't do a watch. */
+ xenbus_switch_state(dev, XenbusStateConnected);
+ } else {
+ be->have_hotplug_status_watch = 1;
+ }
+
+ netif_wake_queue(be->vif->dev);
+}
+
+
+static int connect_rings(struct backend_info *be)
+{
+ struct xenvif *vif = be->vif;
+ struct xenbus_device *dev = be->dev;
+ unsigned long tx_ring_ref, rx_ring_ref;
+ unsigned int evtchn, rx_copy;
+ int err;
+ int val;
+
+ err = xenbus_gather(XBT_NIL, dev->otherend,
+ "tx-ring-ref", "%lu", &tx_ring_ref,
+ "rx-ring-ref", "%lu", &rx_ring_ref,
+ "event-channel", "%u", &evtchn, NULL);
+ if (err) {
+ xenbus_dev_fatal(dev, err,
+ "reading %s/ring-ref and event-channel",
+ dev->otherend);
+ return err;
+ }
+
+ err = xenbus_scanf(XBT_NIL, dev->otherend, "request-rx-copy", "%u",
+ &rx_copy);
+ if (err == -ENOENT) {
+ err = 0;
+ rx_copy = 0;
+ }
+ if (err < 0) {
+ xenbus_dev_fatal(dev, err, "reading %s/request-rx-copy",
+ dev->otherend);
+ return err;
+ }
+ if (!rx_copy)
+ return -EOPNOTSUPP;
+
+ if (vif->dev->tx_queue_len != 0) {
+ if (xenbus_scanf(XBT_NIL, dev->otherend,
+ "feature-rx-notify", "%d", &val) < 0)
+ val = 0;
+ if (val)
+ vif->can_queue = 1;
+ else
+ /* Must be non-zero for pfifo_fast to work. */
+ vif->dev->tx_queue_len = 1;
+ }
+
+ if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-sg",
+ "%d", &val) < 0)
+ val = 0;
+ vif->can_sg = !!val;
+
+ if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4",
+ "%d", &val) < 0)
+ val = 0;
+ vif->gso = !!val;
+
+ if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4-prefix",
+ "%d", &val) < 0)
+ val = 0;
+ vif->gso_prefix = !!val;
+
+ if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-no-csum-offload",
+ "%d", &val) < 0)
+ val = 0;
+ vif->csum = !val;
+
+ /* Map the shared frame, irq etc. */
+ err = xenvif_connect(vif, tx_ring_ref, rx_ring_ref, evtchn);
+ if (err) {
+ xenbus_dev_fatal(dev, err,
+ "mapping shared-frames %lu/%lu port %u",
+ tx_ring_ref, rx_ring_ref, evtchn);
+ return err;
+ }
+ return 0;
+}
+
+
+/* ** Driver Registration ** */
+
+
+static const struct xenbus_device_id netback_ids[] = {
+ { "vif" },
+ { "" }
+};
+
+
+static struct xenbus_driver netback = {
+ .name = "vif",
+ .owner = THIS_MODULE,
+ .ids = netback_ids,
+ .probe = netback_probe,
+ .remove = netback_remove,
+ .uevent = netback_uevent,
+ .otherend_changed = frontend_changed,
+};
+
+int xenvif_xenbus_init(void)
+{
+ return xenbus_register_backend(&netback);
+}
projects / GitHub / LineageOS / android_kernel_samsung_universal7580.git / commitdiff