On some dual-port forcedeth devices such as MCP55 10de:0373 (rev a3),
when autoneg & TX pause are enabled while port is connected but
interface is down, the NIC will eventually freeze (TX timeouts,
network unreachable).

This patch ensures that TX pause is not configured in hardware when
interface is down. The TX pause request will be honored when interface
is later configured.

Tested:
 - hardware is MCP55 device id 10de:0373 (rev a3), dual-port
 - eth0 connected and UP, eth1 connected but DOWN
 - without this patch, following sequence would brick NIC:
      ifconfig eth0 down
      ifconfig eth1 up
      ifconfig eth1 down
      ethtool -A eth1 autoneg off rx on tx off
      ifconfig eth1 up
      ifconfig eth1 down
      ethtool -A eth1 autoneg on rx on tx on
      ifconfig eth1 up
      ifconfig eth1 down
      ifup eth0
      sleep 120  # or longer
      ethtool eth1
   Just in case, sequence to un-brick:
      ifconfig eth0 down
      ethtool -A eth1 autoneg off rx on tx off
      ifconfig eth1 up
      ifconfig eth1 down
      ifup eth0
 - with this patch: no TX timeout after "bricking" sequence above

Details:
 - The following register accesses have been identified as the ones
   causing the NIC to freeze in "bricking" sequence above:
    - write NVREG_TX_PAUSEFRAME_ENABLE_V1 to eth1's register NvRegTxPauseFrame
    - write NVREG_MISC1_PAUSE_TX | NVREG_MISC1_FORCE to eth1's register NvRegMisc1
    - write 0 to eth1's register NvRegTransmitterControl
   This is what this patch avoids.
Signed-off-by: David Decotigny <decot@googlers.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Found by manual code inspection.

Tested: compile, reboot, ethtool -d ethX
Signed-off-by: David Decotigny <decot@googlers.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add support for an MDIO bus multiplexer controlled by a simple memory-mapped
device, like an FPGA.  The device must be memory-mapped and contain only
8-bit registers (which keeps things simple).

Tested on a Freescale P5020DS board which uses the "PIXIS" FPGA attached
to the localbus.
Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch cleans up the way device tree support is added in mdio-gpio
driver. I found lot of code duplication which is not necessary.
Also strangely a new platform driver was also introduced for device tree
support. All this forced me to do this cleanup patch.
After this patch, the driver probe checks the of_node pointer to get the
data from device tree.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch adds dummy functions in of_mdio.h, so that driver need not
ifdef there code with CONFIG_OF.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Let's fill IP header ident field with a meaningful value,
it might help some setups.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When moving a net device from one net namespace to another
net namespace,dev_change_net_namespace calls NETDEV_DOWN
event,so the original net namespace's dst entries which
beloned to this net device will be put into dst_garbage
list.

then dev_change_net_namespace will set this net device's
net to the new net namespace.

If we unregister this net device's driver, this will trigger
the NETDEV_UNREGISTER_FINAL event, dst_ifdown will be called,
and get this net device's dst entries from dst_garbage list,
put these entries' dev to the new net namespace's lo device.

It's not what we want,actually we need these dst entries hold
the original net namespace's lo device,this incorrect device
holding will trigger emg message like below.
unregister_netdevice: waiting for lo to become free. Usage count = 1

so we should call NETDEV_UNREGISTER_FINAL event in
dev_change_net_namespace too,in order to make sure dst entries
already in the dst_garbage list, we need rcu_barrier before we
call NETDEV_UNREGISTER_FINAL event.

With help form Eric Dumazet.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This is an initial merge in of Eric Biederman's work to start adding
user namespace support to the networking.
Signed-off-by: David S. Miller <davem@davemloft.net>

Ben Hutchings says:

====================
1. Change the TX path to stop queues earlier and avoid returning
NETDEV_TX_BUSY.
2. Remove some inefficiencies in soft-TSO.
3. Fix various bugs involving device state transitions and/or reset
scheduling by error handlers.
4. Take advantage of my previous change to operstate initialisation.
5. Miscellaneous cleanup.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

John W. Linville says:

====================
This is a batch of updates intended for 3.7.  The bulk of it is
mac80211 changes, including some mesh work from Thomas Pederson and
some multi-channel work from Johannes.  A variety of driver updates
and other bits are scattered in there as well.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Following commit 8f4cccbb ('net: Set device operstate at registration
time') it is now correct and preferable to set the carrier off before
registering a device.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

We also stop clearing *efx in efx_init_struct().  This is safe because
alloc_etherdev_mq() already clears it for us.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

RX DMA is limited by the length specified in each descriptor and not
by the MAC.  Over-length frames may get into the RX FIFO regardless of
the MAC settings, due to a hardware bug, but they will be truncated by
the packet DMA engine and reported as such in the completion event.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

We try to defer resets while the device is not READY, but we're not
doing this quite correctly.  In particular, changes to efx_nic::state
are documented as serialised by the RTNL lock, but they aren't.

1. We check whether a reset was requested during probe (suggesting
broken hardware) before we allow requested resets to be scheduled.
This leaves a window where a requested reset would be deferred
indefinitely.

2. Although we cancel the reset work item during device removal,
there are still later operations that can cause it to be scheduled
again.  We need to check the state before scheduling it.

3. Since the state can change between scheduling and running of
the work item, we still need to check it there, and we need to
do so *after* acquiring the RTNL lock which serialises state
changes.

4. We must cancel the reset work item during device removal, if the
state could ever have been READY.  This wasn't done in some of the
failure paths from efx_pci_probe().  Move the cancellation to
efx_pci_remove_main().
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

The current informational message doesn't properly explain what
happens, and could also appear if we defer a reset during
suspend/resume.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

efx_change_mtu() and efx_realloc_channels() each stop and start much
of the NIC, even if it has been disabled.  Since efx_start_all() is a
no-op when the NIC is disabled, this is probably harmless in the case
of efx_change_mtu(), but efx_realloc_channels() also reenables
interrupts which could be a bad thing to do.

Change efx_start_all() and efx_start_interrupts() to assert that the
NIC is not disabled, but make efx_stop_interrupts() do nothing if the
NIC is disabled (since it is already stopped), consistent with
efx_stop_all().

Update comments for efx_start_all() and efx_stop_all() to describe
their purpose and preconditions more accurately.

Add a common function to check and log if the NIC is disabled, and use
it in efx_net_open(), efx_change_mtu() and efx_realloc_channels().
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Interrupt state should be consistently guarded by the RTNL lock once
the net device is registered.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Currently we ignore and clear the disabled state.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

I don't think these PM functions can race with userland net device
operations, but it's much easier to reason about locking if state is
consistently guarded by the same lock.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

STATE_INIT and STATE_FINI are equivalent and represent incompletely
initialised states; combine them as STATE_UNINIT.

Rename STATE_RUNNING to STATE_READY, to avoid confusion with
netif_running() and IFF_RUNNING.

The comments do not quite match current usage, but this will be
corrected in subsequent fixes.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

We only use tso_state::full_packet_space to calculate the IPv4 tot_len
or IPv6 payload_len, not to set tso_state::packet_space.  Replace it
with an ip_base_len field holding the value of tot_len or payload_len
before including the TCP payload, which is much more useful when
constructing the new headers.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

TSO header buffers contain a control structure immediately followed by
the packet headers, and are kept on a free list when not in use.  This
complicates buffer management and tends to result in cache read misses
when we recycle such buffers (particularly if DMA-coherent memory
requires caches to be disabled).

Replace the free list with a simple mapping by descriptor index.  We
know that there is always a payload descriptor between any two
descriptors with TSO header buffers, so we can allocate only one
such buffer for each two descriptors.

While we're at it, use a standard error code for allocation failure,
not -1.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

We now have a definite upper bound on the number of descriptors per
skb; use that to stop the queue when the next packet might not fit.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Add a flags field to struct efx_tx_buffer, replacing the
continuation and map_single booleans.

Since a single descriptor cannot be both a TSO header and the last
descriptor for an skb, unionise efx_tx_buffer::{skb,tsoh} and add
flags for validity of these fields.

Clear all flags in free buffers (whereas previously the continuation
flag would be set).
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Reported-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

also, remove unused vlan_info definition from header

CC: Patrick McHardy <kaber@trash.net>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

When no one is listening on NL socket, -ESRCH is returned and warning
message is printed. This message is confusing people and in fact has no
meaning. So do not print it in this case.
Reported-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

Using eth_hw_addr_random() to generate a random Ethernet address
(MAC) to be used by a net device and set addr_assign_type.
Not need to duplicating its implementation.

spatch with a semantic match is used to found this problem.
(http://coccinelle.lip6.fr/)
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

Using eth_hw_addr_random() to generate a random Ethernet address
(MAC) to be used by a net device and set addr_assign_type.
Not need to duplicating its implementation.

spatch with a semantic match is used to found this problem.
(http://coccinelle.lip6.fr/)
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

Using is_zero_ether_addr() instead of directly use
memcmp() to determine if the ethernet address is all
zeros.

spatch with a semantic match is used to found this problem.
(http://coccinelle.lip6.fr/)
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

The operstate of a device is initially IF_OPER_UNKNOWN and is updated
asynchronously by linkwatch after each change of carrier state
reported by the driver.  The default carrier state of a net device is
on, and this will never be changed on drivers that do not support
carrier detection, thus the operstate remains IF_OPER_UNKNOWN.

For devices that do support carrier detection, the driver must set the
carrier state to off initially, then poll the hardware state when the
device is opened.  However, we must not activate linkwatch for a
unregistered device, and commit b4730016 ('net: Do not fire linkwatch
events until the device is registered.') ensured that we don't.  But
this means that the operstate for many devices that support carrier
detection remains IF_OPER_UNKNOWN when it should be IF_OPER_DOWN.

The same issue exists with the dormant state.

The proper initialisation sequence, avoiding a race with opening of
the device, is:

        rtnl_lock();
        rc = register_netdevice(dev);
        if (rc)
                goto out_unlock;
        netif_carrier_off(dev); /* or netif_dormant_on(dev) */
        rtnl_unlock();

but it seems silly that this should have to be repeated in so many
drivers.  Further, the operstate seen immediately after opening the
device may still be IF_OPER_UNKNOWN due to the asynchronous nature of
linkwatch.

Commit 22604c86 ('net: Fix for initial link state in 2.6.28') attempted
to fix this by setting the operstate synchronously, but it was
reverted as it could lead to deadlock.

This initialises the operstate synchronously at registration time
only.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Similar to fsl_pq_mdio.c, this driver is for the 10G MDIO controller on
Freescale Frame Manager Ethernet controllers.
Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The network classifier cgroup initalizes each cgroups instance classid value to
0.  However, the sock_update_classid function only updates classid's in sockets
if the tasks cgroup classid is not zero, and if it differs from the current
classid.  The later check is to prevent cache line dirtying, but the former is
detrimental, as it prevents resetting a classid for a cgroup to 0.  While this
is not a common action, it has administrative usefulness (if the admin wants to
disable classification of a certain group temporarily for instance).

Easy fix, just remove the zero check.  Tested successfully by myself
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next into for-davem

Antonio Quartulli says:

====================
Included changes:
- a set of codestyle rearrangements/fixes
- new feature to early detect new joining (mesh-unaware) clients
- a minor fix for the gw-feature
- substitution of shift operations with the BIT() macro
- reorganization of the main batman-adv structure (struct batadv_priv)
- some more (very) minor cleanups and fixes
===================
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch fixes a broken build due to a missing header:
...
  CC      net/ipv4/proc.o
In file included from include/net/net_namespace.h:15,
                 from net/ipv4/proc.c:35:
include/net/netns/packet.h:11: error: field 'sklist_lock' has incomplete type
...

The lock of netns_packet has been replaced by a recent patch to be a mutex instead of a spinlock,
but we need to replace the header file to be linux/mutex.h instead of linux/spinlock.h as well.

See commit 0fa7fa98:
packet: Protect packet sk list with mutex (v2) patch,
Signed-off-by: Rami Rosen <rosenr@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Eric Biederman pointed out that not holding RTNL while calling
call_netdevice_notifiers() was racy.

This patch is a direct transcription his feedback
against commit 0115e8e3 (net: remove delay at device dismantle)

Thanks Eric !
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Mahesh Bandewar <maheshb@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Gao feng <gaofeng@cn.fujitsu.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>