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linux/drivers/net/xen-netfront.c
Linus Torvalds 9479f0f801 Two fixes for regressions: 
* one is a workaround that will be removed in v3.5 with proper fix in the tip/x86 tree,
  * the other is to fix drivers to load on PV (a previous patch made them only
    load in PVonHVM mode).
 
 The rest are just minor fixes in the various drivers and some cleanup in the
 core code.
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Merge tag 'stable/for-linus-3.4-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull xen fixes from Konrad Rzeszutek Wilk:
 "Two fixes for regressions:
   * one is a workaround that will be removed in v3.5 with proper fix in
     the tip/x86 tree,
   * the other is to fix drivers to load on PV (a previous patch made
     them only load in PVonHVM mode).

  The rest are just minor fixes in the various drivers and some cleanup
  in the core code."

* tag 'stable/for-linus-3.4-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/pcifront: avoid pci_frontend_enable_msix() falsely returning success
  xen/pciback: fix XEN_PCI_OP_enable_msix result
  xen/smp: Remove unnecessary call to smp_processor_id()
  xen/x86: Workaround 'x86/ioapic: Add register level checks to detect bogus io-apic entries'
  xen: only check xen_platform_pci_unplug if hvm
2012-04-06 17:54:53 -07:00

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49 KiB
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/*
* 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.
*/
#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 <linux/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>
static const struct ethtool_ops xennet_ethtool_ops;
struct netfront_cb {
struct page *page;
unsigned offset;
};
#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, PAGE_SIZE)
#define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
#define TX_MAX_TARGET min_t(int, NET_TX_RING_SIZE, 256)
struct netfront_stats {
u64 rx_packets;
u64 tx_packets;
u64 rx_bytes;
u64 tx_bytes;
struct u64_stats_sync syncp;
};
struct netfront_info {
struct list_head list;
struct net_device *netdev;
struct napi_struct napi;
unsigned int evtchn;
struct xenbus_device *xbdev;
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];
unsigned tx_skb_freelist;
spinlock_t rx_lock ____cacheline_aligned_in_smp;
struct xen_netif_rx_front_ring rx;
int rx_ring_ref;
/* Receive-ring batched refills. */
#define RX_MIN_TARGET 8
#define RX_DFL_MIN_TARGET 64
#define RX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256)
unsigned rx_min_target, rx_max_target, rx_target;
struct sk_buff_head rx_batch;
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];
unsigned long rx_pfn_array[NET_RX_RING_SIZE];
struct multicall_entry rx_mcl[NET_RX_RING_SIZE+1];
struct mmu_update rx_mmu[NET_RX_RING_SIZE];
/* Statistics */
struct netfront_stats __percpu *stats;
unsigned long 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_info *np,
RING_IDX ri)
{
int i = xennet_rxidx(ri);
struct sk_buff *skb = np->rx_skbs[i];
np->rx_skbs[i] = NULL;
return skb;
}
static grant_ref_t xennet_get_rx_ref(struct netfront_info *np,
RING_IDX ri)
{
int i = xennet_rxidx(ri);
grant_ref_t ref = np->grant_rx_ref[i];
np->grant_rx_ref[i] = GRANT_INVALID_REF;
return ref;
}
#ifdef CONFIG_SYSFS
static int xennet_sysfs_addif(struct net_device *netdev);
static void xennet_sysfs_delif(struct net_device *netdev);
#else /* !CONFIG_SYSFS */
#define xennet_sysfs_addif(dev) (0)
#define xennet_sysfs_delif(dev) do { } while (0)
#endif
static bool xennet_can_sg(struct net_device *dev)
{
return dev->features & NETIF_F_SG;
}
static void rx_refill_timeout(unsigned long data)
{
struct net_device *dev = (struct net_device *)data;
struct netfront_info *np = netdev_priv(dev);
napi_schedule(&np->napi);
}
static int netfront_tx_slot_available(struct netfront_info *np)
{
return (np->tx.req_prod_pvt - np->tx.rsp_cons) <
(TX_MAX_TARGET - MAX_SKB_FRAGS - 2);
}
static void xennet_maybe_wake_tx(struct net_device *dev)
{
struct netfront_info *np = netdev_priv(dev);
if (unlikely(netif_queue_stopped(dev)) &&
netfront_tx_slot_available(np) &&
likely(netif_running(dev)))
netif_wake_queue(dev);
}
static void xennet_alloc_rx_buffers(struct net_device *dev)
{
unsigned short id;
struct netfront_info *np = netdev_priv(dev);
struct sk_buff *skb;
struct page *page;
int i, batch_target, notify;
RING_IDX req_prod = np->rx.req_prod_pvt;
grant_ref_t ref;
unsigned long pfn;
void *vaddr;
struct xen_netif_rx_request *req;
if (unlikely(!netif_carrier_ok(dev)))
return;
/*
* Allocate skbuffs greedily, even though we batch updates to the
* receive ring. This creates a less bursty demand on the memory
* allocator, so should reduce the chance of failed allocation requests
* both for ourself and for other kernel subsystems.
*/
batch_target = np->rx_target - (req_prod - np->rx.rsp_cons);
for (i = skb_queue_len(&np->rx_batch); i < batch_target; i++) {
skb = __netdev_alloc_skb(dev, RX_COPY_THRESHOLD + NET_IP_ALIGN,
GFP_ATOMIC | __GFP_NOWARN);
if (unlikely(!skb))
goto no_skb;
/* Align ip header to a 16 bytes boundary */
skb_reserve(skb, NET_IP_ALIGN);
page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
if (!page) {
kfree_skb(skb);
no_skb:
/* Any skbuffs queued for refill? Force them out. */
if (i != 0)
goto refill;
/* Could not allocate any skbuffs. Try again later. */
mod_timer(&np->rx_refill_timer,
jiffies + (HZ/10));
break;
}
__skb_fill_page_desc(skb, 0, page, 0, 0);
skb_shinfo(skb)->nr_frags = 1;
__skb_queue_tail(&np->rx_batch, skb);
}
/* Is the batch large enough to be worthwhile? */
if (i < (np->rx_target/2)) {
if (req_prod > np->rx.sring->req_prod)
goto push;
return;
}
/* Adjust our fill target if we risked running out of buffers. */
if (((req_prod - np->rx.sring->rsp_prod) < (np->rx_target / 4)) &&
((np->rx_target *= 2) > np->rx_max_target))
np->rx_target = np->rx_max_target;
refill:
for (i = 0; ; i++) {
skb = __skb_dequeue(&np->rx_batch);
if (skb == NULL)
break;
skb->dev = dev;
id = xennet_rxidx(req_prod + i);
BUG_ON(np->rx_skbs[id]);
np->rx_skbs[id] = skb;
ref = gnttab_claim_grant_reference(&np->gref_rx_head);
BUG_ON((signed short)ref < 0);
np->grant_rx_ref[id] = ref;
pfn = page_to_pfn(skb_frag_page(&skb_shinfo(skb)->frags[0]));
vaddr = page_address(skb_frag_page(&skb_shinfo(skb)->frags[0]));
req = RING_GET_REQUEST(&np->rx, req_prod + i);
gnttab_grant_foreign_access_ref(ref,
np->xbdev->otherend_id,
pfn_to_mfn(pfn),
0);
req->id = id;
req->gref = ref;
}
wmb(); /* barrier so backend seens requests */
/* Above is a suitable barrier to ensure backend will see requests. */
np->rx.req_prod_pvt = req_prod + i;
push:
RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->rx, notify);
if (notify)
notify_remote_via_irq(np->netdev->irq);
}
static int xennet_open(struct net_device *dev)
{
struct netfront_info *np = netdev_priv(dev);
napi_enable(&np->napi);
spin_lock_bh(&np->rx_lock);
if (netif_carrier_ok(dev)) {
xennet_alloc_rx_buffers(dev);
np->rx.sring->rsp_event = np->rx.rsp_cons + 1;
if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx))
napi_schedule(&np->napi);
}
spin_unlock_bh(&np->rx_lock);
netif_start_queue(dev);
return 0;
}
static void xennet_tx_buf_gc(struct net_device *dev)
{
RING_IDX cons, prod;
unsigned short id;
struct netfront_info *np = netdev_priv(dev);
struct sk_buff *skb;
BUG_ON(!netif_carrier_ok(dev));
do {
prod = np->tx.sring->rsp_prod;
rmb(); /* Ensure we see responses up to 'rp'. */
for (cons = np->tx.rsp_cons; cons != prod; cons++) {
struct xen_netif_tx_response *txrsp;
txrsp = RING_GET_RESPONSE(&np->tx, cons);
if (txrsp->status == XEN_NETIF_RSP_NULL)
continue;
id = txrsp->id;
skb = np->tx_skbs[id].skb;
if (unlikely(gnttab_query_foreign_access(
np->grant_tx_ref[id]) != 0)) {
printk(KERN_ALERT "xennet_tx_buf_gc: warning "
"-- grant still in use by backend "
"domain.\n");
BUG();
}
gnttab_end_foreign_access_ref(
np->grant_tx_ref[id], GNTMAP_readonly);
gnttab_release_grant_reference(
&np->gref_tx_head, np->grant_tx_ref[id]);
np->grant_tx_ref[id] = GRANT_INVALID_REF;
add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, id);
dev_kfree_skb_irq(skb);
}
np->tx.rsp_cons = prod;
/*
* Set a new event, then check for race with update of tx_cons.
* Note that it is essential to schedule a callback, no matter
* how few buffers are pending. Even if there is space in the
* transmit ring, higher layers may be blocked because too much
* data is outstanding: in such cases notification from Xen is
* likely to be the only kick that we'll get.
*/
np->tx.sring->rsp_event =
prod + ((np->tx.sring->req_prod - prod) >> 1) + 1;
mb(); /* update shared area */
} while ((cons == prod) && (prod != np->tx.sring->rsp_prod));
xennet_maybe_wake_tx(dev);
}
static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev,
struct xen_netif_tx_request *tx)
{
struct netfront_info *np = netdev_priv(dev);
char *data = skb->data;
unsigned long mfn;
RING_IDX prod = np->tx.req_prod_pvt;
int frags = skb_shinfo(skb)->nr_frags;
unsigned int offset = offset_in_page(data);
unsigned int len = skb_headlen(skb);
unsigned int id;
grant_ref_t ref;
int i;
/* While the header overlaps a page boundary (including being
larger than a page), split it it into page-sized chunks. */
while (len > PAGE_SIZE - offset) {
tx->size = PAGE_SIZE - offset;
tx->flags |= XEN_NETTXF_more_data;
len -= tx->size;
data += tx->size;
offset = 0;
id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
np->tx_skbs[id].skb = skb_get(skb);
tx = RING_GET_REQUEST(&np->tx, prod++);
tx->id = id;
ref = gnttab_claim_grant_reference(&np->gref_tx_head);
BUG_ON((signed short)ref < 0);
mfn = virt_to_mfn(data);
gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id,
mfn, GNTMAP_readonly);
tx->gref = np->grant_tx_ref[id] = ref;
tx->offset = offset;
tx->size = len;
tx->flags = 0;
}
/* Grant backend access to each skb fragment page. */
for (i = 0; i < frags; i++) {
skb_frag_t *frag = skb_shinfo(skb)->frags + i;
tx->flags |= XEN_NETTXF_more_data;
id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
np->tx_skbs[id].skb = skb_get(skb);
tx = RING_GET_REQUEST(&np->tx, prod++);
tx->id = id;
ref = gnttab_claim_grant_reference(&np->gref_tx_head);
BUG_ON((signed short)ref < 0);
mfn = pfn_to_mfn(page_to_pfn(skb_frag_page(frag)));
gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id,
mfn, GNTMAP_readonly);
tx->gref = np->grant_tx_ref[id] = ref;
tx->offset = frag->page_offset;
tx->size = skb_frag_size(frag);
tx->flags = 0;
}
np->tx.req_prod_pvt = prod;
}
static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
unsigned short id;
struct netfront_info *np = netdev_priv(dev);
struct netfront_stats *stats = this_cpu_ptr(np->stats);
struct xen_netif_tx_request *tx;
struct xen_netif_extra_info *extra;
char *data = skb->data;
RING_IDX i;
grant_ref_t ref;
unsigned long mfn;
int notify;
int frags = skb_shinfo(skb)->nr_frags;
unsigned int offset = offset_in_page(data);
unsigned int len = skb_headlen(skb);
unsigned long flags;
frags += DIV_ROUND_UP(offset + len, PAGE_SIZE);
if (unlikely(frags > MAX_SKB_FRAGS + 1)) {
printk(KERN_ALERT "xennet: skb rides the rocket: %d frags\n",
frags);
dump_stack();
goto drop;
}
spin_lock_irqsave(&np->tx_lock, flags);
if (unlikely(!netif_carrier_ok(dev) ||
(frags > 1 && !xennet_can_sg(dev)) ||
netif_needs_gso(skb, netif_skb_features(skb)))) {
spin_unlock_irqrestore(&np->tx_lock, flags);
goto drop;
}
i = np->tx.req_prod_pvt;
id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
np->tx_skbs[id].skb = skb;
tx = RING_GET_REQUEST(&np->tx, i);
tx->id = id;
ref = gnttab_claim_grant_reference(&np->gref_tx_head);
BUG_ON((signed short)ref < 0);
mfn = virt_to_mfn(data);
gnttab_grant_foreign_access_ref(
ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly);
tx->gref = np->grant_tx_ref[id] = ref;
tx->offset = offset;
tx->size = len;
extra = NULL;
tx->flags = 0;
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;
if (skb_shinfo(skb)->gso_size) {
struct xen_netif_extra_info *gso;
gso = (struct xen_netif_extra_info *)
RING_GET_REQUEST(&np->tx, ++i);
if (extra)
extra->flags |= XEN_NETIF_EXTRA_FLAG_MORE;
else
tx->flags |= XEN_NETTXF_extra_info;
gso->u.gso.size = skb_shinfo(skb)->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;
extra = gso;
}
np->tx.req_prod_pvt = i + 1;
xennet_make_frags(skb, dev, tx);
tx->size = skb->len;
RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->tx, notify);
if (notify)
notify_remote_via_irq(np->netdev->irq);
u64_stats_update_begin(&stats->syncp);
stats->tx_bytes += skb->len;
stats->tx_packets++;
u64_stats_update_end(&stats->syncp);
/* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
xennet_tx_buf_gc(dev);
if (!netfront_tx_slot_available(np))
netif_stop_queue(dev);
spin_unlock_irqrestore(&np->tx_lock, flags);
return NETDEV_TX_OK;
drop:
dev->stats.tx_dropped++;
dev_kfree_skb(skb);
return NETDEV_TX_OK;
}
static int xennet_close(struct net_device *dev)
{
struct netfront_info *np = netdev_priv(dev);
netif_stop_queue(np->netdev);
napi_disable(&np->napi);
return 0;
}
static void xennet_move_rx_slot(struct netfront_info *np, struct sk_buff *skb,
grant_ref_t ref)
{
int new = xennet_rxidx(np->rx.req_prod_pvt);
BUG_ON(np->rx_skbs[new]);
np->rx_skbs[new] = skb;
np->grant_rx_ref[new] = ref;
RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->id = new;
RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->gref = ref;
np->rx.req_prod_pvt++;
}
static int xennet_get_extras(struct netfront_info *np,
struct xen_netif_extra_info *extras,
RING_IDX rp)
{
struct xen_netif_extra_info *extra;
struct device *dev = &np->netdev->dev;
RING_IDX cons = np->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(&np->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(np, cons);
ref = xennet_get_rx_ref(np, cons);
xennet_move_rx_slot(np, skb, ref);
} while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
np->rx.rsp_cons = cons;
return err;
}
static int xennet_get_responses(struct netfront_info *np,
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 = &np->netdev->dev;
RING_IDX cons = np->rx.rsp_cons;
struct sk_buff *skb = xennet_get_rx_skb(np, cons);
grant_ref_t ref = xennet_get_rx_ref(np, cons);
int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
int frags = 1;
int err = 0;
unsigned long ret;
if (rx->flags & XEN_NETRXF_extra_info) {
err = xennet_get_extras(np, extras, rp);
cons = np->rx.rsp_cons;
}
for (;;) {
if (unlikely(rx->status < 0 ||
rx->offset + rx->status > PAGE_SIZE)) {
if (net_ratelimit())
dev_warn(dev, "rx->offset: %x, size: %u\n",
rx->offset, rx->status);
xennet_move_rx_slot(np, 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 backed.
*/
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(&np->gref_rx_head, ref);
__skb_queue_tail(list, skb);
next:
if (!(rx->flags & XEN_NETRXF_more_data))
break;
if (cons + frags == rp) {
if (net_ratelimit())
dev_warn(dev, "Need more frags\n");
err = -ENOENT;
break;
}
rx = RING_GET_RESPONSE(&np->rx, cons + frags);
skb = xennet_get_rx_skb(np, cons + frags);
ref = xennet_get_rx_ref(np, cons + frags);
frags++;
}
if (unlikely(frags > max)) {
if (net_ratelimit())
dev_warn(dev, "Too many frags\n");
err = -E2BIG;
}
if (unlikely(err))
np->rx.rsp_cons = cons + frags;
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())
printk(KERN_WARNING "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) {
if (net_ratelimit())
printk(KERN_WARNING "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 RING_IDX xennet_fill_frags(struct netfront_info *np,
struct sk_buff *skb,
struct sk_buff_head *list)
{
struct skb_shared_info *shinfo = skb_shinfo(skb);
int nr_frags = shinfo->nr_frags;
RING_IDX cons = np->rx.rsp_cons;
struct sk_buff *nskb;
while ((nskb = __skb_dequeue(list))) {
struct xen_netif_rx_response *rx =
RING_GET_RESPONSE(&np->rx, ++cons);
skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
__skb_fill_page_desc(skb, nr_frags,
skb_frag_page(nfrag),
rx->offset, rx->status);
skb->data_len += rx->status;
skb_shinfo(nskb)->nr_frags = 0;
kfree_skb(nskb);
nr_frags++;
}
shinfo->nr_frags = nr_frags;
return cons;
}
static int checksum_setup(struct net_device *dev, 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)) {
struct netfront_info *np = netdev_priv(dev);
np->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())
printk(KERN_ERR "Attempting to checksum a non-"
"TCP/UDP packet, dropping a protocol"
" %d packet", iph->protocol);
goto out;
}
if ((th + skb->csum_offset + 2) > skb_tail_pointer(skb))
goto out;
err = 0;
out:
return err;
}
static int handle_incoming_queue(struct net_device *dev,
struct sk_buff_head *rxq)
{
struct netfront_info *np = netdev_priv(dev);
struct netfront_stats *stats = this_cpu_ptr(np->stats);
int packets_dropped = 0;
struct sk_buff *skb;
while ((skb = __skb_dequeue(rxq)) != NULL) {
struct page *page = NETFRONT_SKB_CB(skb)->page;
void *vaddr = page_address(page);
unsigned offset = NETFRONT_SKB_CB(skb)->offset;
memcpy(skb->data, vaddr + offset,
skb_headlen(skb));
if (page != skb_frag_page(&skb_shinfo(skb)->frags[0]))
__free_page(page);
/* Ethernet work: Delayed to here as it peeks the header. */
skb->protocol = eth_type_trans(skb, dev);
if (checksum_setup(dev, skb)) {
kfree_skb(skb);
packets_dropped++;
dev->stats.rx_errors++;
continue;
}
u64_stats_update_begin(&stats->syncp);
stats->rx_packets++;
stats->rx_bytes += skb->len;
u64_stats_update_end(&stats->syncp);
/* Pass it up. */
netif_receive_skb(skb);
}
return packets_dropped;
}
static int xennet_poll(struct napi_struct *napi, int budget)
{
struct netfront_info *np = container_of(napi, struct netfront_info, napi);
struct net_device *dev = np->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;
unsigned long flags;
unsigned int len;
int err;
spin_lock(&np->rx_lock);
skb_queue_head_init(&rxq);
skb_queue_head_init(&errq);
skb_queue_head_init(&tmpq);
rp = np->rx.sring->rsp_prod;
rmb(); /* Ensure we see queued responses up to 'rp'. */
i = np->rx.rsp_cons;
work_done = 0;
while ((i != rp) && (work_done < budget)) {
memcpy(rx, RING_GET_RESPONSE(&np->rx, i), sizeof(*rx));
memset(extras, 0, sizeof(rinfo.extras));
err = xennet_get_responses(np, &rinfo, rp, &tmpq);
if (unlikely(err)) {
err:
while ((skb = __skb_dequeue(&tmpq)))
__skb_queue_tail(&errq, skb);
dev->stats.rx_errors++;
i = np->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);
np->rx.rsp_cons += skb_queue_len(&tmpq);
goto err;
}
}
NETFRONT_SKB_CB(skb)->page =
skb_frag_page(&skb_shinfo(skb)->frags[0]);
NETFRONT_SKB_CB(skb)->offset = rx->offset;
len = rx->status;
if (len > RX_COPY_THRESHOLD)
len = RX_COPY_THRESHOLD;
skb_put(skb, len);
if (rx->status > len) {
skb_shinfo(skb)->frags[0].page_offset =
rx->offset + len;
skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status - len);
skb->data_len = rx->status - len;
} else {
__skb_fill_page_desc(skb, 0, NULL, 0, 0);
skb_shinfo(skb)->nr_frags = 0;
}
i = xennet_fill_frags(np, skb, &tmpq);
/*
* Truesize approximates the size of true data plus
* any supervisor overheads. Adding hypervisor
* overheads has been shown to significantly reduce
* achievable bandwidth with the default receive
* buffer size. It is therefore not wise to account
* for it here.
*
* After alloc_skb(RX_COPY_THRESHOLD), truesize is set
* to RX_COPY_THRESHOLD + the supervisor
* overheads. Here, we add the size of the data pulled
* in xennet_fill_frags().
*
* We also adjust for any unused space in the main
* data area by subtracting (RX_COPY_THRESHOLD -
* len). This is especially important with drivers
* which split incoming packets into header and data,
* using only 66 bytes of the main data area (see the
* e1000 driver for example.) On such systems,
* without this last adjustement, our achievable
* receive throughout using the standard receive
* buffer size was cut by 25%(!!!).
*/
skb->truesize += skb->data_len - (RX_COPY_THRESHOLD - len);
skb->len += skb->data_len;
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);
np->rx.rsp_cons = ++i;
work_done++;
}
__skb_queue_purge(&errq);
work_done -= handle_incoming_queue(dev, &rxq);
/* If we get a callback with very few responses, reduce fill target. */
/* NB. Note exponential increase, linear decrease. */
if (((np->rx.req_prod_pvt - np->rx.sring->rsp_prod) >
((3*np->rx_target) / 4)) &&
(--np->rx_target < np->rx_min_target))
np->rx_target = np->rx_min_target;
xennet_alloc_rx_buffers(dev);
if (work_done < budget) {
int more_to_do = 0;
local_irq_save(flags);
RING_FINAL_CHECK_FOR_RESPONSES(&np->rx, more_to_do);
if (!more_to_do)
__napi_complete(napi);
local_irq_restore(flags);
}
spin_unlock(&np->rx_lock);
return work_done;
}
static int xennet_change_mtu(struct net_device *dev, int mtu)
{
int max = xennet_can_sg(dev) ? 65535 - ETH_HLEN : ETH_DATA_LEN;
if (mtu > max)
return -EINVAL;
dev->mtu = mtu;
return 0;
}
static struct rtnl_link_stats64 *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 *stats = per_cpu_ptr(np->stats, cpu);
u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
unsigned int start;
do {
start = u64_stats_fetch_begin_bh(&stats->syncp);
rx_packets = stats->rx_packets;
tx_packets = stats->tx_packets;
rx_bytes = stats->rx_bytes;
tx_bytes = stats->tx_bytes;
} while (u64_stats_fetch_retry_bh(&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;
return tot;
}
static void xennet_release_tx_bufs(struct netfront_info *np)
{
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(&np->tx_skbs[i]))
continue;
skb = np->tx_skbs[i].skb;
gnttab_end_foreign_access_ref(np->grant_tx_ref[i],
GNTMAP_readonly);
gnttab_release_grant_reference(&np->gref_tx_head,
np->grant_tx_ref[i]);
np->grant_tx_ref[i] = GRANT_INVALID_REF;
add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, i);
dev_kfree_skb_irq(skb);
}
}
static void xennet_release_rx_bufs(struct netfront_info *np)
{
struct mmu_update *mmu = np->rx_mmu;
struct multicall_entry *mcl = np->rx_mcl;
struct sk_buff_head free_list;
struct sk_buff *skb;
unsigned long mfn;
int xfer = 0, noxfer = 0, unused = 0;
int id, ref;
dev_warn(&np->netdev->dev, "%s: fix me for copying receiver.\n",
__func__);
return;
skb_queue_head_init(&free_list);
spin_lock_bh(&np->rx_lock);
for (id = 0; id < NET_RX_RING_SIZE; id++) {
ref = np->grant_rx_ref[id];
if (ref == GRANT_INVALID_REF) {
unused++;
continue;
}
skb = np->rx_skbs[id];
mfn = gnttab_end_foreign_transfer_ref(ref);
gnttab_release_grant_reference(&np->gref_rx_head, ref);
np->grant_rx_ref[id] = GRANT_INVALID_REF;
if (0 == mfn) {
skb_shinfo(skb)->nr_frags = 0;
dev_kfree_skb(skb);
noxfer++;
continue;
}
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
/* Remap the page. */
const struct page *page =
skb_frag_page(&skb_shinfo(skb)->frags[0]);
unsigned long pfn = page_to_pfn(page);
void *vaddr = page_address(page);
MULTI_update_va_mapping(mcl, (unsigned long)vaddr,
mfn_pte(mfn, PAGE_KERNEL),
0);
mcl++;
mmu->ptr = ((u64)mfn << PAGE_SHIFT)
| MMU_MACHPHYS_UPDATE;
mmu->val = pfn;
mmu++;
set_phys_to_machine(pfn, mfn);
}
__skb_queue_tail(&free_list, skb);
xfer++;
}
dev_info(&np->netdev->dev, "%s: %d xfer, %d noxfer, %d unused\n",
__func__, xfer, noxfer, unused);
if (xfer) {
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
/* Do all the remapping work and M2P updates. */
MULTI_mmu_update(mcl, np->rx_mmu, mmu - np->rx_mmu,
NULL, DOMID_SELF);
mcl++;
HYPERVISOR_multicall(np->rx_mcl, mcl - np->rx_mcl);
}
}
__skb_queue_purge(&free_list);
spin_unlock_bh(&np->rx_lock);
}
static void xennet_uninit(struct net_device *dev)
{
struct netfront_info *np = netdev_priv(dev);
xennet_release_tx_bufs(np);
xennet_release_rx_bufs(np);
gnttab_free_grant_references(np->gref_tx_head);
gnttab_free_grant_references(np->gref_rx_head);
}
static netdev_features_t xennet_fix_features(struct net_device *dev,
netdev_features_t features)
{
struct netfront_info *np = netdev_priv(dev);
int val;
if (features & NETIF_F_SG) {
if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
"%d", &val) < 0)
val = 0;
if (!val)
features &= ~NETIF_F_SG;
}
if (features & NETIF_F_TSO) {
if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
"feature-gso-tcpv4", "%d", &val) < 0)
val = 0;
if (!val)
features &= ~NETIF_F_TSO;
}
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_interrupt(int irq, void *dev_id)
{
struct net_device *dev = dev_id;
struct netfront_info *np = netdev_priv(dev);
unsigned long flags;
spin_lock_irqsave(&np->tx_lock, flags);
if (likely(netif_carrier_ok(dev))) {
xennet_tx_buf_gc(dev);
/* Under tx_lock: protects access to rx shared-ring indexes. */
if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx))
napi_schedule(&np->napi);
}
spin_unlock_irqrestore(&np->tx_lock, flags);
return IRQ_HANDLED;
}
#ifdef CONFIG_NET_POLL_CONTROLLER
static void xennet_poll_controller(struct net_device *dev)
{
xennet_interrupt(0, dev);
}
#endif
static const struct net_device_ops xennet_netdev_ops = {
.ndo_open = xennet_open,
.ndo_uninit = xennet_uninit,
.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,
#ifdef CONFIG_NET_POLL_CONTROLLER
.ndo_poll_controller = xennet_poll_controller,
#endif
};
static struct net_device * __devinit xennet_create_dev(struct xenbus_device *dev)
{
int i, err;
struct net_device *netdev;
struct netfront_info *np;
netdev = alloc_etherdev(sizeof(struct netfront_info));
if (!netdev)
return ERR_PTR(-ENOMEM);
np = netdev_priv(netdev);
np->xbdev = dev;
spin_lock_init(&np->tx_lock);
spin_lock_init(&np->rx_lock);
skb_queue_head_init(&np->rx_batch);
np->rx_target = RX_DFL_MIN_TARGET;
np->rx_min_target = RX_DFL_MIN_TARGET;
np->rx_max_target = RX_MAX_TARGET;
init_timer(&np->rx_refill_timer);
np->rx_refill_timer.data = (unsigned long)netdev;
np->rx_refill_timer.function = rx_refill_timeout;
err = -ENOMEM;
np->stats = alloc_percpu(struct netfront_stats);
if (np->stats == NULL)
goto exit;
/* Initialise tx_skbs as a free chain containing every entry. */
np->tx_skb_freelist = 0;
for (i = 0; i < NET_TX_RING_SIZE; i++) {
skb_entry_set_link(&np->tx_skbs[i], i+1);
np->grant_tx_ref[i] = GRANT_INVALID_REF;
}
/* Clear out rx_skbs */
for (i = 0; i < NET_RX_RING_SIZE; i++) {
np->rx_skbs[i] = NULL;
np->grant_rx_ref[i] = GRANT_INVALID_REF;
}
/* A grant for every tx ring slot */
if (gnttab_alloc_grant_references(TX_MAX_TARGET,
&np->gref_tx_head) < 0) {
printk(KERN_ALERT "#### netfront can't alloc tx grant refs\n");
err = -ENOMEM;
goto exit_free_stats;
}
/* A grant for every rx ring slot */
if (gnttab_alloc_grant_references(RX_MAX_TARGET,
&np->gref_rx_head) < 0) {
printk(KERN_ALERT "#### netfront can't alloc rx grant refs\n");
err = -ENOMEM;
goto exit_free_tx;
}
netdev->netdev_ops = &xennet_netdev_ops;
netif_napi_add(netdev, &np->napi, xennet_poll, 64);
netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
NETIF_F_GSO_ROBUST;
netdev->hw_features = NETIF_F_IP_CSUM | NETIF_F_SG | NETIF_F_TSO;
/*
* 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;
SET_ETHTOOL_OPS(netdev, &xennet_ethtool_ops);
SET_NETDEV_DEV(netdev, &dev->dev);
np->netdev = netdev;
netif_carrier_off(netdev);
return netdev;
exit_free_tx:
gnttab_free_grant_references(np->gref_tx_head);
exit_free_stats:
free_percpu(np->stats);
exit:
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 __devinit 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);
err = register_netdev(info->netdev);
if (err) {
printk(KERN_WARNING "%s: register_netdev err=%d\n",
__func__, err);
goto fail;
}
err = xennet_sysfs_addif(info->netdev);
if (err) {
unregister_netdev(info->netdev);
printk(KERN_WARNING "%s: add sysfs failed err=%d\n",
__func__, err);
goto fail;
}
return 0;
fail:
free_netdev(netdev);
dev_set_drvdata(&dev->dev, NULL);
return err;
}
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)
{
/* Stop old i/f to prevent errors whilst we rebuild the state. */
spin_lock_bh(&info->rx_lock);
spin_lock_irq(&info->tx_lock);
netif_carrier_off(info->netdev);
spin_unlock_irq(&info->tx_lock);
spin_unlock_bh(&info->rx_lock);
if (info->netdev->irq)
unbind_from_irqhandler(info->netdev->irq, info->netdev);
info->evtchn = info->netdev->irq = 0;
/* End access and free the pages */
xennet_end_access(info->tx_ring_ref, info->tx.sring);
xennet_end_access(info->rx_ring_ref, info->rx.sring);
info->tx_ring_ref = GRANT_INVALID_REF;
info->rx_ring_ref = GRANT_INVALID_REF;
info->tx.sring = NULL;
info->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(struct xenbus_device *dev, struct netfront_info *info)
{
struct xen_netif_tx_sring *txs;
struct xen_netif_rx_sring *rxs;
int err;
struct net_device *netdev = info->netdev;
info->tx_ring_ref = GRANT_INVALID_REF;
info->rx_ring_ref = GRANT_INVALID_REF;
info->rx.sring = NULL;
info->tx.sring = NULL;
netdev->irq = 0;
err = xen_net_read_mac(dev, netdev->dev_addr);
if (err) {
xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
goto fail;
}
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(&info->tx, txs, PAGE_SIZE);
err = xenbus_grant_ring(dev, virt_to_mfn(txs));
if (err < 0) {
free_page((unsigned long)txs);
goto fail;
}
info->tx_ring_ref = err;
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 fail;
}
SHARED_RING_INIT(rxs);
FRONT_RING_INIT(&info->rx, rxs, PAGE_SIZE);
err = xenbus_grant_ring(dev, virt_to_mfn(rxs));
if (err < 0) {
free_page((unsigned long)rxs);
goto fail;
}
info->rx_ring_ref = err;
err = xenbus_alloc_evtchn(dev, &info->evtchn);
if (err)
goto fail;
err = bind_evtchn_to_irqhandler(info->evtchn, xennet_interrupt,
0, netdev->name, netdev);
if (err < 0)
goto fail;
netdev->irq = err;
return 0;
fail:
return err;
}
/* 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;
/* Create shared ring, alloc event channel. */
err = setup_netfront(dev, info);
if (err)
goto out;
again:
err = xenbus_transaction_start(&xbt);
if (err) {
xenbus_dev_fatal(dev, err, "starting transaction");
goto destroy_ring;
}
err = xenbus_printf(xbt, dev->nodename, "tx-ring-ref", "%u",
info->tx_ring_ref);
if (err) {
message = "writing tx ring-ref";
goto abort_transaction;
}
err = xenbus_printf(xbt, dev->nodename, "rx-ring-ref", "%u",
info->rx_ring_ref);
if (err) {
message = "writing rx ring-ref";
goto abort_transaction;
}
err = xenbus_printf(xbt, dev->nodename,
"event-channel", "%u", info->evtchn);
if (err) {
message = "writing event-channel";
goto abort_transaction;
}
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_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_transaction_end(xbt, 1);
xenbus_dev_fatal(dev, err, "%s", message);
destroy_ring:
xennet_disconnect_backend(info);
out:
return err;
}
static int xennet_connect(struct net_device *dev)
{
struct netfront_info *np = netdev_priv(dev);
int i, requeue_idx, err;
struct sk_buff *skb;
grant_ref_t ref;
struct xen_netif_rx_request *req;
unsigned int feature_rx_copy;
err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
"feature-rx-copy", "%u", &feature_rx_copy);
if (err != 1)
feature_rx_copy = 0;
if (!feature_rx_copy) {
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;
rtnl_lock();
netdev_update_features(dev);
rtnl_unlock();
spin_lock_bh(&np->rx_lock);
spin_lock_irq(&np->tx_lock);
/* Step 1: Discard all pending TX packet fragments. */
xennet_release_tx_bufs(np);
/* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */
for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) {
skb_frag_t *frag;
const struct page *page;
if (!np->rx_skbs[i])
continue;
skb = np->rx_skbs[requeue_idx] = xennet_get_rx_skb(np, i);
ref = np->grant_rx_ref[requeue_idx] = xennet_get_rx_ref(np, i);
req = RING_GET_REQUEST(&np->rx, requeue_idx);
frag = &skb_shinfo(skb)->frags[0];
page = skb_frag_page(frag);
gnttab_grant_foreign_access_ref(
ref, np->xbdev->otherend_id,
pfn_to_mfn(page_to_pfn(page)),
0);
req->gref = ref;
req->id = requeue_idx;
requeue_idx++;
}
np->rx.req_prod_pvt = requeue_idx;
/*
* Step 3: 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);
notify_remote_via_irq(np->netdev->irq);
xennet_tx_buf_gc(dev);
xennet_alloc_rx_buffers(dev);
spin_unlock_irq(&np->tx_lock);
spin_unlock_bh(&np->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));
switch (backend_state) {
case XenbusStateInitialising:
case XenbusStateInitialised:
case XenbusStateReconfiguring:
case XenbusStateReconfigured:
case XenbusStateUnknown:
case XenbusStateClosed:
break;
case XenbusStateInitWait:
if (dev->state != XenbusStateInitialising)
break;
if (xennet_connect(netdev) != 0)
break;
xenbus_switch_state(dev, XenbusStateConnected);
break;
case XenbusStateConnected:
netif_notify_peers(netdev);
break;
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] = *(unsigned long *)(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_min(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct net_device *netdev = to_net_dev(dev);
struct netfront_info *info = netdev_priv(netdev);
return sprintf(buf, "%u\n", info->rx_min_target);
}
static ssize_t store_rxbuf_min(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct net_device *netdev = to_net_dev(dev);
struct netfront_info *np = netdev_priv(netdev);
char *endp;
unsigned long target;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
target = simple_strtoul(buf, &endp, 0);
if (endp == buf)
return -EBADMSG;
if (target < RX_MIN_TARGET)
target = RX_MIN_TARGET;
if (target > RX_MAX_TARGET)
target = RX_MAX_TARGET;
spin_lock_bh(&np->rx_lock);
if (target > np->rx_max_target)
np->rx_max_target = target;
np->rx_min_target = target;
if (target > np->rx_target)
np->rx_target = target;
xennet_alloc_rx_buffers(netdev);
spin_unlock_bh(&np->rx_lock);
return len;
}
static ssize_t show_rxbuf_max(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct net_device *netdev = to_net_dev(dev);
struct netfront_info *info = netdev_priv(netdev);
return sprintf(buf, "%u\n", info->rx_max_target);
}
static ssize_t store_rxbuf_max(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct net_device *netdev = to_net_dev(dev);
struct netfront_info *np = netdev_priv(netdev);
char *endp;
unsigned long target;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
target = simple_strtoul(buf, &endp, 0);
if (endp == buf)
return -EBADMSG;
if (target < RX_MIN_TARGET)
target = RX_MIN_TARGET;
if (target > RX_MAX_TARGET)
target = RX_MAX_TARGET;
spin_lock_bh(&np->rx_lock);
if (target < np->rx_min_target)
np->rx_min_target = target;
np->rx_max_target = target;
if (target < np->rx_target)
np->rx_target = target;
xennet_alloc_rx_buffers(netdev);
spin_unlock_bh(&np->rx_lock);
return len;
}
static ssize_t show_rxbuf_cur(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct net_device *netdev = to_net_dev(dev);
struct netfront_info *info = netdev_priv(netdev);
return sprintf(buf, "%u\n", info->rx_target);
}
static struct device_attribute xennet_attrs[] = {
__ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf_min, store_rxbuf_min),
__ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf_max, store_rxbuf_max),
__ATTR(rxbuf_cur, S_IRUGO, show_rxbuf_cur, NULL),
};
static int xennet_sysfs_addif(struct net_device *netdev)
{
int i;
int err;
for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) {
err = device_create_file(&netdev->dev,
&xennet_attrs[i]);
if (err)
goto fail;
}
return 0;
fail:
while (--i >= 0)
device_remove_file(&netdev->dev, &xennet_attrs[i]);
return err;
}
static void xennet_sysfs_delif(struct net_device *netdev)
{
int i;
for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++)
device_remove_file(&netdev->dev, &xennet_attrs[i]);
}
#endif /* CONFIG_SYSFS */
static const struct xenbus_device_id netfront_ids[] = {
{ "vif" },
{ "" }
};
static int __devexit xennet_remove(struct xenbus_device *dev)
{
struct netfront_info *info = dev_get_drvdata(&dev->dev);
dev_dbg(&dev->dev, "%s\n", dev->nodename);
unregister_netdev(info->netdev);
xennet_disconnect_backend(info);
del_timer_sync(&info->rx_refill_timer);
xennet_sysfs_delif(info->netdev);
free_percpu(info->stats);
free_netdev(info->netdev);
return 0;
}
static DEFINE_XENBUS_DRIVER(netfront, ,
.probe = netfront_probe,
.remove = __devexit_p(xennet_remove),
.resume = netfront_resume,
.otherend_changed = netback_changed,
);
static int __init netif_init(void)
{
if (!xen_domain())
return -ENODEV;
if (xen_initial_domain())
return 0;
if (xen_hvm_domain() && !xen_platform_pci_unplug)
return -ENODEV;
printk(KERN_INFO "Initialising Xen virtual ethernet driver.\n");
return xenbus_register_frontend(&netfront_driver);
}
module_init(netif_init);
static void __exit netif_exit(void)
{
if (xen_initial_domain())
return;
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");
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