ic_dev_xid is only used in __init ic_bootp_recv under IPCONFIG_BOOTP
and __init ic_dynamic under IPCONFIG_DYNAMIC(which is itself defined
with the same IPCONFIG_BOOTP)

This patch fixes the following warning when IPCONFIG_BOOTP is not set:
>> net/ipv4/ipconfig.c:146:15: warning: 'ic_dev_xid' defined but not used [-Wunused-variable]
    static __be32 ic_dev_xid;  /* Device under configuration */
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: netdev@vger.kernel.org
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

phy_suspend and phy_resume are two commonly used helper functions that
need to be exported for Ethernet drivers to be built as modules

Fixes: 40755a0f ("net: systemport: add suspend and resume support")
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Russell King says:

====================
Freescale ethernet driver updates (part 3)

Here's the third batch of patches for the Freescale FEC ethernet driver,
based upon the previous set of patches.  This concludes the changes I
currently have prepared and have been reviewed for the next merge window
at this time.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Both transmit and receive use the same infrastructure for calculating
the packet timestamp.  Rather than duplicating the code, provide a
function to do this common work.  Model this function in the Intel
e1000e version which avoids calling ns_to_ktime() within the spinlock;
the spinlock is critical for timecounter_cyc2time() but not
ns_to_ktime().
Acked-by: NRichard Cochran <richardcochran@gmail.com>
Acked-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove a useless status check in the transmit reap path - we have
already checked that the BD_ENET_TX_READY bit is clear, and as the
hardware only ever clears this bit, there is no way this test can ever
be true.
Acked-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When we timeout on transmit, it would be useful to dump the transmit
ring, so we can see the ring state.  This can be helpful to diagnose
the cause of transmit timeouts.
Acked-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This allows us to merge two separate preprocessor conditionals together.
Acked-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NFugang Duan <B38611@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NFugang Duan <B38611@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NFugang Duan <B38611@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NDavid Decotigny <decot@googlers.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NZoltan 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: NDavid S. Miller <davem@davemloft.net>

Commit cb1ce2ef ("ipv6: Implement automatic flow label generation
on transmit") introduced ip6_make_flowlabel, while commit b73c3d0e
("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: cb1ce2ef ("ipv6: Implement automatic flow label generation on transmit")
Fixes: b73c3d0e ("net: Save TX flow hash in sock and set in skbuf on xmit")
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NDavid S. Miller <davem@davemloft.net>

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: NFugang Duan <B38611@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NFugang Duan <B38611@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NFugang Duan <B38611@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NFugang Duan <B38611@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NFugang Duan <B38611@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NFugang Duan <B38611@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NFugang Duan <B38611@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NFugang Duan <B38611@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NFugang Duan <B38611@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NFugang Duan <B38611@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Amir Vadai says:

====================
Mellanox driver update Jul-08-2014

This patch set introduce some small bug fixes.
Most of the patches are small fixes to cornet case bugs.
The patch by Noa ("Fix mac_hash database inconsistency") was sent in the past
[1] and was droped because a fix to the bonding code was supposed to make it
unnecessary. After a second look on the patch, it is still needed even
after the direct access to dev_addr by the bonding will be fixed.

Patches were applied and tested over commit bd4578bc
("drivers/net/hyperv/netvsc.c: remove unnecessary null test before kfree")

[1] - http://permalink.gmane.org/gmane.linux.network/315900
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Using a local copy of dev_addr in mlx4_en_set_mac() to prevent dev_addr
from being modified during error flow or when dev_addr is modified in
another context (which is another problem that is being discussed over
the mailing list [1]).
Also fixing bad naming of priv->prev_mac into priv->current_mac.

[1] - http://patchwork.ozlabs.org/patch/351489/Reviewed-by: NEyal Perry <eyalpe@mellanox.com>
Signed-off-by: NNoa Osherovich <noaos@mellanox.com>
Signed-off-by: NAmir Vadai <amirv@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

LLC/SNAP 8 bytes should not be added as part of header calculation.
If used, payload will be decreased accordingly. For MTU of 1500
we'll set 1522 instead of 1523.
Signed-off-by: NYishai Hadas <yishaih@mellanox.com>
Reviewed-by: NLiran Liss <liranl@mellanox.com>
Signed-off-by: NEugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: NAmir Vadai <amirv@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Promiscous mode is only for MACs.
Should not disable/enable VLAN filter when entering/leaving promisuous mode.
Signed-off-by: NAviad Yehezkel <aviadye@mellanox.co.il>
Signed-off-by: NEugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: NAmir Vadai <amirv@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Verify port number to avoid crashes if port number is outside the range.
Signed-off-by: NEli Cohen <eli@mellanox.com>
Signed-off-by: NEugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: NAmir Vadai <amirv@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Loopback can't work when port is down.
Signed-off-by: NEugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: NAmir Vadai <amirv@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In 40GE we can't use the default bw units for set ratelimit (100 Mbps)
since the max is 255*100 Mbps = 25 Gbps (not suited for 40GE), thus we need 1 Gbps units.
But for 10GE 1 Gbps units might be too bruit so we use the following solution.

For user set ratelimit <= 25 Gbps:
        use 100 Mbps units * user_ratelimit (* 10).

For user set ratelimit > 25 Gbps:
        use 1 Gbps units * user_ratelimit.

For user set unlimited ratelimit (0 Gbps):
        use 1 Gbps units * MAX_RATELIMIT_DEFAULT (57)

Note: any value > 58 will damage the FW ratelimit computation, so we allow
      a max and any higher value will be pulled down to 57.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NEugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: NAmir Vadai <amirv@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Linus Lüssing says:

====================
bridge: multicast snooping exports #2

Some people pointed out to me that it might be helpful to add stubs for
the newly added multicast exports. That way e.g. batman-adv should continue
to be compile and useable without having to have a kernel compiled
with bridge code in the future. This is what the first patch is supposed
to do.

The second patch adds a third multicast export for the bridge which
e.g. batman-adv is supposed to use, too, soon: Just like the bridge
disables its multicast snooping activities if no querier is present,
batman-adv needs to do the same if bridges are involved.

These three exports should be the final ones needed to marry the bridge
multicast snooping with the batman-adv multicast optimizations recently
added for the 3.15 kernel, allowing to use these optimzations in common
setups having a bridge on top of e.g. bat0, too. So far these bridged
setups would fall back to simple flooding through the batman-adv mesh
network for any multicast packet entering bat0.

More information about the batman-adv multicast optimizations currently
implemented can be found here:

http://www.open-mesh.org/projects/batman-adv/wiki/Basic-multicast-optimizations

The integration on the batman-adv side could afterwards look like this,
for instance (now including the third export):

http://git.open-mesh.org/batman-adv.git/commitdiff/61e4f6af4b7a21ed4040f2e711d50c778e5b6d93?hp=6ae4281474675fbca5bedcf768972a32db586eb6
====================

With this patch other modules are able to ask the bridge whether an
IGMP or MLD querier exists on the according, bridged link layer.

Multicast snooping can only be performed if a valid, selected querier
exists on a link.

Just like the bridge only enables its multicast snooping if a querier
exists, e.g. batman-adv too can only activate its multicast
snooping in bridged scenarios if a querier is present.

For instance this export avoids having to reimplement IGMP/MLD
querier message snooping and parsing in e.g. batman-adv, when
multicast optimizations for bridged scenarios are added in the
future.
Signed-off-by: NLinus Lüssing <linus.luessing@web.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To make users (e.g. batman-adv soon) load- and runnable even if the
bridge was compiled without snooping capabilities - or even if the
kernel was compiled without any bridge code at all.
Signed-off-by: NLinus Lüssing <linus.luessing@web.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This fixes a regression bug caused by:
067608e9 ("tipc: introduce direct
iovec to buffer chain fragmentation function")

If data is sent on a nonblocking socket and the destination link
is congested, the buffer chain is leaked. We fix this by freeing
the chain in this case.
Signed-off-by: NErik Hugne <erik.hugne@ericsson.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This fixes issues with debug printk calls across the driver, normally
disabled; first compilation errors:

drivers/net/fddi/defxx.c:676:1: error: pasting "(" and ""In dfx_bus_init...\n"" does not give a valid preprocessing token
drivers/net/fddi/defxx.c:820:1: error: pasting "(" and ""In dfx_bus_uninit...\n"" does not give a valid preprocessing token

and so on, and then warnings:

drivers/net/fddi/defxx.c: In function 'dfx_driver_init':
drivers/net/fddi/defxx.c:1132: warning: format '%0X' expects type 'unsigned int', but argument 4 has type 'dma_addr_t'
drivers/net/fddi/defxx.c:1132: warning: format '%0X' expects type 'unsigned int', but argument 4 has type 'dma_addr_t'

etc.  Additionally casts are removed from virtual addresses and %p used.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Maciej W. Rozycki says:

====================
defxx: Fixes for 64-bit host support

 This mini patch series addresses issues with 64-bit host support for FDDI
interface boards supported by the defxx driver where DMA mapping
synchronisation is required on swiotlb systems.  While PDQ, the DMA engine
chip used with these boards, supports 48-bit addressing that would
normally suffice for typical 64-bit systems in existence, the host bus
interface chips used by individual implementations have their limitations
as follows:

* DEFTA or DEC FDDIcontroller/TURBOchannel -- there's no host bus
  interface chip, the PDQ connects to TURBOchannel directly; TURBOchannel
  supports DMA addressing of up to 16GB (34-bit addressing), however no
  TURBOchannel system has ever been made that supports more than 1GB of
  RAM, so in reality no remapping is ever required,

* DEFEA or DEC FDDIcontroller/EISA -- the ESIC EISA interface chip only
  supports 32-bit addressing, all accesses beyond 4GB have to be remapped,

* DEFPA or DEC FDDIcontroller/PCI -- the PFI PCI interface chip rev. 1 & 2
  only support 32-bit addressing, they have 32 AD lines only both on the
  PDQ and the PCI side, and consequently no Dual Address Cycle support, so
  all accesses beyond 4GB have to be remapped; the range of addressing
  supported by PFI rev. 3 is currently not certain, however the chip is
  backwards compatible with earlier revisions and will work with code that
  supports them.

Some other issues discovered in the course of correcting 64-bit support
have been fixed as well.  Each of the patches is functionally
self-contained and can be applied independentely, although there may be
mechanical dependencies making it necessary to apply patches in order.

 The driver suffers from non-standard formatting and while I did my best
with these bug fixes to follow our coding style, I found some pieces
hopeless, checkpatch.pl will complain.  I plan to reformat the whole
driver, that will inevitably require factoring out some pieces into
separate functions, but that's going to be a major effort and therefore I
want to do this separately, with no functional changes made at the same
time.  If anyone has specific suggestions as to how to reformat any of the
pieces submitted here for a better layout, then I'll be happy to take them
into account.

 And last but not least many thanks to Robert Coerver, who was the most
recent person to report this problem with the driver and was kind enough
to patiently try a few revisions of the driver update on his system as I
was finding and addressing issues.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This adds DMA synchronisation calls needed in the receive path:

1. To retrieve the Receive Status word that is prepended by the PDQ DMA
   engine in the receive buffer, and provides information about the
   frame received, including its size and any errors.

2. To make data received available for copying in the small-frame case
   (size <= SKBUFF_RX_COPYBREAK) where the original DMA buffer will be
   returned to the receive descriptor ring and therefore its mapping
   retained.

   With DMA mapping error handling in place, added by the other patch,
   this may now also trigger where an attempt to map a newly allocated
   buffer for DMA has failed.  In that case data from the original buffer
   will be copied out and the buffer returned to the DMA descriptor ring.

These calls may do nothing when data is in the host DMA addressing range
of the FDDI interface, such as always on 32-bit systems, however their
absence makes frame reception stop functioning reliably on systems that
have memory beyond the low 4GB of the address space.
Reported-by: NRobert Coerver <Robert.Coerver@ll.mit.edu>
Tested-by: NRobert Coerver <Robert.Coerver@ll.mit.edu>
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This adds error handling for DMA mapping requests; I think there isn't
much else to say about it.

A good side-effect is the mapping in the transmit path is now made with
the board lock released.  Also if DMA mapping fails for a newly
allocated receive buffer, then data from the old buffer will be copied
out (as is presently done for small frames only whose size does not
exceed SKBUFF_RX_COPYBREAK) and the original buffer returned, with its
mapping unchanged, to the DMA descriptor ring.
Reported-by: NRobert Coerver <Robert.Coerver@ll.mit.edu>
Tested-by: NRobert Coerver <Robert.Coerver@ll.mit.edu>
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Switch the two remaining places across the driver that use dev_alloc_skb
to netdev_alloc_skb.  Another place has already been converted to use
__netdev_alloc_skb, no idea why these two have been left behind.
Reported-by: NRobert Coerver <Robert.Coerver@ll.mit.edu>
Tested-by: NRobert Coerver <Robert.Coerver@ll.mit.edu>
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>