net: mvneta: fix operation in 10 Mbit/s mode

As reported by Maggie Mae Roxas, the mvneta driver doesn't behave
properly in 10 Mbit/s mode. This is due to a misconfiguration of the
MVNETA_GMAC_AUTONEG_CONFIG register: bit MVNETA_GMAC_CONFIG_MII_SPEED
must be set for a 100 Mbit/s speed, but cleared for a 10 Mbit/s speed,
which the driver was not properly doing. This commit adjusts that by
setting the MVNETA_GMAC_CONFIG_MII_SPEED bit only in 100 Mbit/s mode,
and relying on the fact that all the speed related bits of this
register are cleared at the beginning of the mvneta_adjust_link()
function.

This problem exists since c5aff18204da0 ("net: mvneta: driver for
Marvell Armada 370/XP network unit") which is the commit that
introduced the mvneta driver in the kernel.

Cc: <stable@vger.kernel.org> # v3.8+
Fixes: c5aff18204da0 ("net: mvneta: driver for Marvell Armada 370/XP network unit")
Reported-by: Maggie Mae Roxas <maggie.mae.roxas@gmail.com>
Cc: Maggie Mae Roxas <maggie.mae.roxas@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: fec: improve safety of suspend/resume/transmit timeout paths

We should hold the rtnl lock while suspending, resuming or processing
the transmit timeout to ensure that nothing will interfere while we
bring up, take down or restart the hardware.  The transmit timeout
could run if we're preempted during suspend.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: fec: ensure fec_enet_close() copes with resume failure

When the FEC is suspended, the device is detached.  Upon resume failure,
the device is left in detached mode, possibly with some of the required
clocks not running.  We don't want to be poking the device in that state
because as it may cause bus errors.

If the device is marked detached, avoid calling fec_stop().

This depends upon: "net:fec: improve safety of suspend/resume paths"

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: fec: only restart or stop the device if it is present and running

Avoid calling fec_restart() or fec_stop() while the device is down
or not present (iow suspended.)

Although the ndo_timeout method will only be called if the device is
present and running, we defer this to a work queue.  The work queue
can run independently, and so needs to repeat these checks to ensure
that a restart doesn't occur after the device has been taken down or
detached for suspend.  In this case, we call fec_restart() in the
resume path, so nothing is lost.

For fec_set_features, we add a call to fec_restart() in fec_enet_open()
to ensure that the hardware is appropriate programmed when the interface
is opened.  fec_set_features() call should not occur while we're
suspended, so we don't have to worry about that case.

The adjust_link needs similar treatment - this also is called from a
work queue, which may be run independently after we have taken the
device down and detached it.  In this case, we just mark the link
down and take no further action.  We will reset things appropriately
once the device is up and running again, at which point we will receive
another adjust_link callback.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: fec: move calls to quiesce/resume packet processing out of fec_restart()

Move the calls to quiesce and resume packet processing out of
fec_restart() to its call sites.  This is the first step in a two stage
clean up of this code, where we just move the calls out of fec_restart()
without changing them.  Not everywhere needs to issue these calls, and
not everywhere needs all of these calls to be issued.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: fec: remove inappropriate calls around fec_restart()

This is the second stage to "move calls to quiesce/resume packet
processing out of fec_restart()", where we remove calls which are not
appropriate to the call site.

In the majority of cases, there is no need to detach and reattach the
interface as we are holding the queue xmit lock across the reset.  The
exception to that is in fec_resume(), where we are already detached by
the suspend function.  Here, we can remove the call to detach the
interface.

We also do not need to stop the transmit queue.  Holding the xmit lock
is enough to ensure that the transmit packet processing is not running
while we perform our task.  However, since fec_restart() always cleans
the rings, we call netif_wake_queue() (or netif_device_attach() in the
case of resume) just before dropping the xmit lock.  This prevents the
watchdog firing.

Lastly, always call napi_enable() after the device has been reattached
in the resume path so that we know that the transmit packet processing
is already in an enabled state, so we don't call netif_wake_queue()
while detached.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: fec: quiesce packet processing before stopping device in fec_suspend()

fec_suspend() calls fec_stop() to stop the transmit ring while the
transmit packet processing is still active.  This can lead to the
transmit queue being restarted by an intervening packet queued for
transmission, or by the tx quirk timer expiring.

Fix this by disabling NAPI first, which will ensure that the NAPI
handlers are not running.  Then, take the transmit lock before
detaching the netif device.  This ensures that there are no races
with the transmit path - and also ensures that the watchdog won't
fire.

We can then safely stop the ethernet device itself, knowing that the
rest of the driver is safely shut down.

On resume, we bring the device back up in reverse order - we restart
the device, reattach the device (under the tx lock), and then enable
the NAPI handlers.

We also need to adjust the close function to cope with this new
sequence, so that it's possible to cleanly close down the driver
after the hardware fails to resume (eg, due to the regulator_enable()
or pinctrl calls in the resume path returning an error.)

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: fec: quiesce packet processing before stopping device in fec_set_features()

fec_set_features() calls fec_stop() to stop the transmit ring while the
transmit queue is still active.  This can lead to the transmit ring
being restarted by an intervening packet queued for transmission, or
by the tx quirk timer expiring.

Fix this by disabling NAPI (which ensures that the NAPI handlers are
not running), and then take the transmit lock while we stop and
restart the adapter (which prevents new packets being queued).

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: fec: quiesce packet processing before changing features

Changing the features (receive checksumming) requires the hardware to be
reprogrammed, and also changes the checks in the receive packet
processing.

The current implementation has a race - fec_set_features() changes the
flags which alter the receive packet processing while the adapter is
active, and potentially receiving frames.  Only after we've modified
the software flag do we shutdown and reconfigure the hardware.

This can lead to packets being received and marked with a valid checksum
(via CHECKSUM_UNNECESSARY) when the hardware checksum validation has not
yet been enabled.

We must quiesce the device, then change the software configuration for
this feature, and then resume the device if it was previously running.

The resulting code structure also allows us to add other configuration
features in this path without having to quiesce and resume the network
interface and device.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: fec: quiesce packet processing when taking link down in fec_enet_adjust_link()

When the link goes down, the adjust_link method will be called, but
there is no synchronisation to ensure that we won't be processing some
last remaining packets via the NAPI handlers while performing a reset of
the device.

Add the necessary synchronisation to ensure that packet processing
is complete before we stop and reset the FEC.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: fec: clean up duplex mode handling

Many places call fec_restart() with the second parameter being some kind
of previously saved duplex value, but only two places call it with some
other setting.  This is at odds with how the other link settings are
handled, and used to be racy before the rtnl locks were added to
fec_restart()'s various call paths.

Clean this up so all link capabilities are handled in the same way -
saved into the fec_enet_private structure, and then fec_restart() acts
on those settings.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge branch 'fec-next'

Russell King says:

====================
Freescale ethernet driver updates (part 2)

Here's the second batch of patches for the Freescale FEC ethernet driver,
based upon the previous set of patches.  One further set of 7 patches
remains.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
Merge branches 'pci/host-rcar', 'pci/hotplug', 'pci/iommu', 'pci/misc' and 'pci/msi' into next

* pci/host-rcar:
  PCI: rcar: Remove rcar_pcie_setup_window() resource argument
  PCI: rcar: Cleanup style and formatting
  PCI: rcar: Use correct initial HW settings
  PCI: rcar: Remove redundant config accessor register number checks

* pci/hotplug:
  PCI: cpqphp: Remove unnecessary null test before debugfs_remove()
  PCI: pciehp: Clear Data Link Layer State Changed during init
  PCI: pciehp: Remove struct controller.no_cmd_complete
  PCI: pciehp: Remove assumptions about which commands cause completion events
  PCI: pciehp: Compute timeout from hotplug command start time
  PCI: pciehp: Wait for hotplug command completion lazily
  PCI: pciehp: Make pcie_wait_cmd() self-contained
  PCI: Prevent NULL dereference during pciehp probe

* pci/iommu:
  PCI: Add bridge DMA alias quirk for Intel 82801 bridge

* pci/misc:
  ACPI / PCI: Fix sysfs acpi_index and label errors
  PCI/portdrv: Remove warning about invalid IRQ for hot-added PCIe ports

* pci/msi:
  PCI/MSI: Cache Multiple Message Capable in struct msi_desc
  PCI/MSI: Remove unused msi_enabled_mask()
  PCI/MSI: Add internal msix_clear_and_set_ctrl() function
net: provide stubs for ip6_set_txhash and ip6_make_flowlabel

Commit cb1ce2ef387b ("ipv6: Implement automatic flow label generation
on transmit") introduced ip6_make_flowlabel, while commit b73c3d0e4f0e
("net: Save TX flow hash in sock and set in skbuf on xmit") introduced
ip6_set_txhash.

ip6_set_tx_hash() uses sk_v6_daddr which references
__sk_common.skc_v6_daddr from struct sock_common, which is gated with
IS_ENABLED(CONFIG_IPV6).

ip6_make_flowlabel() uses the ipv6 member from struct net which is
also gated with IS_ENABLED(CONFIG_IPV6).

When CONFIG_IPV6 is disabled, we will hit a build failure that looks
like this when the compiler attempts inlining these functions:

  CC [M]  drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.o
In file included from include/net/inet_sock.h:27:0,
                 from include/net/ip.h:30,
                 from drivers/net/ethernet/broadcom/cnic.c:37:
include/net/ipv6.h: In function 'ip6_set_txhash':
include/net/sock.h:327:33: error: 'struct sock_common' has no member named 'skc_v6_daddr'
 #define sk_v6_daddr  __sk_common.skc_v6_daddr
                                 ^
include/net/ipv6.h:696:49: note: in expansion of macro 'sk_v6_daddr'
  keys.dst = (__force __be32)ipv6_addr_hash(&sk->sk_v6_daddr);
                                                 ^
In file included from include/net/inetpeer.h:15:0,
                 from include/net/route.h:28,
                 from include/net/ip.h:31,
                 from drivers/net/ethernet/broadcom/cnic.c:37:
include/net/ipv6.h: In function 'ip6_make_flowlabel':
include/net/ipv6.h:706:37: error: 'struct net' has no member named 'ipv6'
  if (!flowlabel && (autolabel || net->ipv6.sysctl.auto_flowlabels)) {
                                     ^

Fixes: cb1ce2ef387b ("ipv6: Implement automatic flow label generation on transmit")
Fixes: b73c3d0e4f0e ("net: Save TX flow hash in sock and set in skbuf on xmit")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
xen-netback: Adding debugfs "io_ring_qX" files

This patch adds debugfs capabilities to netback. There used to be a similar
patch floating around for classic kernel, but it used procfs. It is based on a
very similar blkback patch.
It creates xen-netback/[vifname]/io_ring_q[queueno] files, reading them output
various ring variables etc. Writing "kick" into it imitates an interrupt
happened, it can be useful to check whether the ring is just stalled due to a
missed interrupt.

Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Signed-off-by: David S. Miller <davem@davemloft.net>
netpoll: fix use after free

After a bonding master reclaims the netpoll info struct, slaves could
still hold a pointer to the reclaimed data. This patch fixes it: as
soon as netpoll_async_cleanup is called for a slave (eg. when
un-enslaved), we make sure that this slave doesn't point to the data.

Signed-off-by: David Decotigny <decot@googlers.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: mvneta: Fix big endian issue in mvneta_txq_desc_csum()

This commit fixes the command value generated for CSUM calculation
when running in big endian mode.  The Ethernet protocol ID for IP was
being unconditionally byte-swapped in the layer 3 protocol check (with
swab16), which caused the mvneta driver to not function correctly in
big endian mode.  This patch byte-swaps the ID conditionally with
htons.

Cc: <stable@vger.kernel.org> # v3.13+
Signed-off-by: Thomas Fitzsimmons <fitzsim@fitzsim.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: fec: better implementation of iMX6 ERR006358 quirk

Using a (delayed) workqueue for ERR006358 is not correct - a work queue
is a single-trigger device.  Once the work queue has been scheduled, it
can't be re-scheduled until it has been run.  This can cause problems -
with an appropriate packet timing, we can end up with packets queued,
but not sent by the hardware, resulting in the transmit timeout firing.

Re-implement this as per the workaround detailed in the ERR006358
documentation - if there are packets waiting to be sent when we service
the transmit ring, and we see that the transmitter is not running,
kick the transmitter to run the pending entries in the ring.

Testing here with a 10Mbit half duplex link sees the resulting iperf
TCP bandwidth increase from between 1 to 2Mbps to between 8 to 9Mbps.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: fec: replace delayed work with standard work

As of "better implementation of iMX6 ERR006358 quirk", we no longer have
a requirement for a delayed work.  Moreover, the work is now only used
for timeout purposes, so the timeout flag is also pointless - we set it
each time we queue the work, and the work clears it.

Replace the fec_enet_delayed_work struct with a standard work_struct,
resulting in simplified timeout handling code.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: fec: clear receive interrupts before processing a packet

Clear any pending receive interrupt before we process a pending packet.
This helps to avoid any spurious interrupts being raised after we have
fully cleaned the receive ring, while still allowing an interrupt to be
raised if we receive another packet.

The position of this is critical: we must do this prior to reading the
next packet status to avoid potentially dropping an interrupt when a
packet is still pending.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>