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mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-14 00:04:00 +08:00
linux-next/net/core/link_watch.c
Linus Torvalds aecdc33e11 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking changes from David Miller:

 1) GRE now works over ipv6, from Dmitry Kozlov.

 2) Make SCTP more network namespace aware, from Eric Biederman.

 3) TEAM driver now works with non-ethernet devices, from Jiri Pirko.

 4) Make openvswitch network namespace aware, from Pravin B Shelar.

 5) IPV6 NAT implementation, from Patrick McHardy.

 6) Server side support for TCP Fast Open, from Jerry Chu and others.

 7) Packet BPF filter supports MOD and XOR, from Eric Dumazet and Daniel
    Borkmann.

 8) Increate the loopback default MTU to 64K, from Eric Dumazet.

 9) Use a per-task rather than per-socket page fragment allocator for
    outgoing networking traffic.  This benefits processes that have very
    many mostly idle sockets, which is quite common.

    From Eric Dumazet.

10) Use up to 32K for page fragment allocations, with fallbacks to
    smaller sizes when higher order page allocations fail.  Benefits are
    a) less segments for driver to process b) less calls to page
    allocator c) less waste of space.

    From Eric Dumazet.

11) Allow GRO to be used on GRE tunnels, from Eric Dumazet.

12) VXLAN device driver, one way to handle VLAN issues such as the
    limitation of 4096 VLAN IDs yet still have some level of isolation.
    From Stephen Hemminger.

13) As usual there is a large boatload of driver changes, with the scale
    perhaps tilted towards the wireless side this time around.

Fix up various fairly trivial conflicts, mostly caused by the user
namespace changes.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1012 commits)
  hyperv: Add buffer for extended info after the RNDIS response message.
  hyperv: Report actual status in receive completion packet
  hyperv: Remove extra allocated space for recv_pkt_list elements
  hyperv: Fix page buffer handling in rndis_filter_send_request()
  hyperv: Fix the missing return value in rndis_filter_set_packet_filter()
  hyperv: Fix the max_xfer_size in RNDIS initialization
  vxlan: put UDP socket in correct namespace
  vxlan: Depend on CONFIG_INET
  sfc: Fix the reported priorities of different filter types
  sfc: Remove EFX_FILTER_FLAG_RX_OVERRIDE_IP
  sfc: Fix loopback self-test with separate_tx_channels=1
  sfc: Fix MCDI structure field lookup
  sfc: Add parentheses around use of bitfield macro arguments
  sfc: Fix null function pointer in efx_sriov_channel_type
  vxlan: virtual extensible lan
  igmp: export symbol ip_mc_leave_group
  netlink: add attributes to fdb interface
  tg3: unconditionally select HWMON support when tg3 is enabled.
  Revert "net: ti cpsw ethernet: allow reading phy interface mode from DT"
  gre: fix sparse warning
  ...
2012-10-02 13:38:27 -07:00

251 lines
5.4 KiB
C

/*
* Linux network device link state notification
*
* Author:
* Stefan Rompf <sux@loplof.de>
*
* 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.
*
*/
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/if.h>
#include <net/sock.h>
#include <net/pkt_sched.h>
#include <linux/rtnetlink.h>
#include <linux/jiffies.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/bitops.h>
#include <asm/types.h>
enum lw_bits {
LW_URGENT = 0,
};
static unsigned long linkwatch_flags;
static unsigned long linkwatch_nextevent;
static void linkwatch_event(struct work_struct *dummy);
static DECLARE_DELAYED_WORK(linkwatch_work, linkwatch_event);
static LIST_HEAD(lweventlist);
static DEFINE_SPINLOCK(lweventlist_lock);
static unsigned char default_operstate(const struct net_device *dev)
{
if (!netif_carrier_ok(dev))
return (dev->ifindex != dev->iflink ?
IF_OPER_LOWERLAYERDOWN : IF_OPER_DOWN);
if (netif_dormant(dev))
return IF_OPER_DORMANT;
return IF_OPER_UP;
}
static void rfc2863_policy(struct net_device *dev)
{
unsigned char operstate = default_operstate(dev);
if (operstate == dev->operstate)
return;
write_lock_bh(&dev_base_lock);
switch(dev->link_mode) {
case IF_LINK_MODE_DORMANT:
if (operstate == IF_OPER_UP)
operstate = IF_OPER_DORMANT;
break;
case IF_LINK_MODE_DEFAULT:
default:
break;
}
dev->operstate = operstate;
write_unlock_bh(&dev_base_lock);
}
void linkwatch_init_dev(struct net_device *dev)
{
/* Handle pre-registration link state changes */
if (!netif_carrier_ok(dev) || netif_dormant(dev))
rfc2863_policy(dev);
}
static bool linkwatch_urgent_event(struct net_device *dev)
{
if (!netif_running(dev))
return false;
if (dev->ifindex != dev->iflink)
return true;
return netif_carrier_ok(dev) && qdisc_tx_changing(dev);
}
static void linkwatch_add_event(struct net_device *dev)
{
unsigned long flags;
spin_lock_irqsave(&lweventlist_lock, flags);
if (list_empty(&dev->link_watch_list)) {
list_add_tail(&dev->link_watch_list, &lweventlist);
dev_hold(dev);
}
spin_unlock_irqrestore(&lweventlist_lock, flags);
}
static void linkwatch_schedule_work(int urgent)
{
unsigned long delay = linkwatch_nextevent - jiffies;
if (test_bit(LW_URGENT, &linkwatch_flags))
return;
/* Minimise down-time: drop delay for up event. */
if (urgent) {
if (test_and_set_bit(LW_URGENT, &linkwatch_flags))
return;
delay = 0;
}
/* If we wrap around we'll delay it by at most HZ. */
if (delay > HZ)
delay = 0;
/*
* If urgent, schedule immediate execution; otherwise, don't
* override the existing timer.
*/
if (test_bit(LW_URGENT, &linkwatch_flags))
mod_delayed_work(system_wq, &linkwatch_work, 0);
else
schedule_delayed_work(&linkwatch_work, delay);
}
static void linkwatch_do_dev(struct net_device *dev)
{
/*
* Make sure the above read is complete since it can be
* rewritten as soon as we clear the bit below.
*/
smp_mb__before_clear_bit();
/* We are about to handle this device,
* so new events can be accepted
*/
clear_bit(__LINK_STATE_LINKWATCH_PENDING, &dev->state);
rfc2863_policy(dev);
if (dev->flags & IFF_UP) {
if (netif_carrier_ok(dev))
dev_activate(dev);
else
dev_deactivate(dev);
netdev_state_change(dev);
}
dev_put(dev);
}
static void __linkwatch_run_queue(int urgent_only)
{
struct net_device *dev;
LIST_HEAD(wrk);
/*
* Limit the number of linkwatch events to one
* per second so that a runaway driver does not
* cause a storm of messages on the netlink
* socket. This limit does not apply to up events
* while the device qdisc is down.
*/
if (!urgent_only)
linkwatch_nextevent = jiffies + HZ;
/* Limit wrap-around effect on delay. */
else if (time_after(linkwatch_nextevent, jiffies + HZ))
linkwatch_nextevent = jiffies;
clear_bit(LW_URGENT, &linkwatch_flags);
spin_lock_irq(&lweventlist_lock);
list_splice_init(&lweventlist, &wrk);
while (!list_empty(&wrk)) {
dev = list_first_entry(&wrk, struct net_device, link_watch_list);
list_del_init(&dev->link_watch_list);
if (urgent_only && !linkwatch_urgent_event(dev)) {
list_add_tail(&dev->link_watch_list, &lweventlist);
continue;
}
spin_unlock_irq(&lweventlist_lock);
linkwatch_do_dev(dev);
spin_lock_irq(&lweventlist_lock);
}
if (!list_empty(&lweventlist))
linkwatch_schedule_work(0);
spin_unlock_irq(&lweventlist_lock);
}
void linkwatch_forget_dev(struct net_device *dev)
{
unsigned long flags;
int clean = 0;
spin_lock_irqsave(&lweventlist_lock, flags);
if (!list_empty(&dev->link_watch_list)) {
list_del_init(&dev->link_watch_list);
clean = 1;
}
spin_unlock_irqrestore(&lweventlist_lock, flags);
if (clean)
linkwatch_do_dev(dev);
}
/* Must be called with the rtnl semaphore held */
void linkwatch_run_queue(void)
{
__linkwatch_run_queue(0);
}
static void linkwatch_event(struct work_struct *dummy)
{
rtnl_lock();
__linkwatch_run_queue(time_after(linkwatch_nextevent, jiffies));
rtnl_unlock();
}
void linkwatch_fire_event(struct net_device *dev)
{
bool urgent = linkwatch_urgent_event(dev);
if (!test_and_set_bit(__LINK_STATE_LINKWATCH_PENDING, &dev->state)) {
linkwatch_add_event(dev);
} else if (!urgent)
return;
linkwatch_schedule_work(urgent);
}
EXPORT_SYMBOL(linkwatch_fire_event);