Seccomp has always been a special candidate when it comes to preparation
of its filters in seccomp_prepare_filter(). Due to the extra checks and
filter rewrite it partially duplicates code and has BPF internals exposed.

This patch adds a generic API inside the BPF code code that seccomp can use
and thus keep it's filter preparation code minimal and better maintainable.
The other side-effect is that now classic JITs can add seccomp support as
well by only providing a BPF_LDX | BPF_W | BPF_ABS translation.

Tested with seccomp and BPF test suites.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Cc: Nicolas Schichan <nschichan@freebox.fr>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: NAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When seccomp BPF was added, it was discussed to add __GFP_NOWARN
flag for their configuration path as f.e. up to 32K allocations are
more prone to fail under stress. As we're going to reuse BPF API,
add __GFP_NOWARN flags where larger kmalloc() and friends allocations
could fail.

It doesn't make much sense to pass around __GFP_NOWARN everywhere as
an extra argument only for seccomp while we just as well could run
into similar issues for socket filters, where it's not desired to
have a user application throw a WARN() due to allocation failure.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Cc: Nicolas Schichan <nschichan@freebox.fr>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: NAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove the calls to bpf_check_classic(), bpf_convert_filter() and
bpf_migrate_runtime() and let bpf_prepare_filter() take care of that
instead.

seccomp_check_filter() is passed to bpf_prepare_filter() so that it
gets called from there, after bpf_check_classic().

We can now remove exposure of two internal classic BPF functions
previously used by seccomp. The export of bpf_check_classic() symbol,
previously known as sk_chk_filter(), was there since pre git times,
and no in-tree module was using it, therefore remove it.

Joint work with Daniel Borkmann.
Signed-off-by: NNicolas Schichan <nschichan@freebox.fr>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: NAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is in preparation for use by the seccomp code, the rationale is
not to duplicate additional code within the seccomp layer, but instead,
have it abstracted and hidden within the classic BPF API.

As an interim step, this now also makes bpf_prepare_filter() visible
(not as exported symbol though), so that seccomp can reuse that code
path instead of reimplementing it.

Joint work with Daniel Borkmann.
Signed-off-by: NNicolas Schichan <nschichan@freebox.fr>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: NAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Merge tag 'mac80211-next-for-davem-2015-05-06' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-next

Johannes Berg says:

====================
Lots of updates for net-next for this cycle. As usual, we have
a lot of small fixes and cleanups, the bigger items are:
 * proper mac80211 rate control locking, to fix some random crashes
   (this required changing other locking as well)
 * mac80211 "fast-xmit", a mechanism to reduce, in most cases, the
   amount of code we execute while going from ndo_start_xmit() to
   the driver
 * this also clears the way for properly supporting S/G and checksum
   and segmentation offloads
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Eric Dumazet says:

====================
tcp: more reliable window probes

This series address a problem caused by small rto_min timers in DC,
leading to either timer storms or early flow terminations.

We also add two new SNMP counters for proper monitoring :
TCPWinProbe and TCPKeepAlive

v2: added TCPKeepAlive counter, as suggested by Yuchung & Neal
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Diagnosing problems related to Window Probes has been hard because
we lack a counter.

TCPWinProbe counts the number of ACK packets a sender has to send
at regular intervals to make sure a reverse ACK packet opening back
a window had not been lost.

TCPKeepAlive counts the number of ACK packets sent to keep TCP
flows alive (SO_KEEPALIVE)
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Acked-by: NNeal Cardwell <ncardwell@google.com>
Acked-by: NNandita Dukkipati <nanditad@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With the advent of small rto timers in datacenter TCP,
(ip route ... rto_min x), the following can happen :

1) Qdisc is full, transmit fails.

   TCP sets a timer based on icsk_rto to retry the transmit, without
   exponential backoff.
   With low icsk_rto, and lot of sockets, all cpus are servicing timer
   interrupts like crazy.
   Intent of the code was to retry with a timer between 200 (TCP_RTO_MIN)
   and 500ms (TCP_RESOURCE_PROBE_INTERVAL)

2) Receivers can send zero windows if they don't drain their receive queue.

   TCP sends zero window probes, based on icsk_rto current value, with
   exponential backoff.
   With /proc/sys/net/ipv4/tcp_retries2 being 15 (or even smaller in
   some cases), sender can abort in less than one or two minutes !
   If receiver stops the sender, it obviously doesn't care of very tight
   rto. Probability of dropping the ACK reopening the window is not
   worth the risk.

Lets change the base timer to be at least 200ms (TCP_RTO_MIN) for these
events (but not normal RTO based retransmits)

A followup patch adds a new SNMP counter, as it would have helped a lot
diagnosing this issue.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Acked-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The legacy netlink API treated EPERM (permission denied) as
"operation not supported".
Reported-by: NTomi Ollila <tomi.ollila@iki.fi>
Signed-off-by: NRichard Alpe <richard.alpe@ericsson.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add the ability to get or set the broadcast link window through the
new netlink API. The functionality was unintentionally missing from
the new netlink API. Adding this means that we also fix the breakage
in the old API when coming through the compat layer.

Fixes: 37e2d484 (tipc: convert legacy nl link prop set to nl compat)
Reported-by: NTomi Ollila <tomi.ollila@iki.fi>
Signed-off-by: NRichard Alpe <richard.alpe@ericsson.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Default link properties can be set for media or bearer. This
functionality was missed when introducing the NL compatibility layer.

This patch implements this functionality in the compat netlink
layer. It works the same way as it did in the old API. We search for
media and bearers matching the "link name". If we find a matching
media or bearer the link tolerance, priority or window is used as
default for new links on that media or bearer.

Fixes: 37e2d484 (tipc: convert legacy nl link prop set to nl compat)
Reported-by: NTomi Ollila <tomi.ollila@iki.fi>
Signed-off-by: NRichard Alpe <richard.alpe@ericsson.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implements t4_init_rss_mode() to initialize the rss_mode for all the ports. If
Tunnel All Lookup isn't specified in the global RSS Configuration, then we need
to specify a default Ingress Queue for any ingress packets which aren't hashed.
We'll use our first ingress queue.
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Sathya Perla says:

====================
be2net: patch-set

The following patch-set has two new feature additions, and a few
minor fixes and cleanups.
Pls consider applying to the net-next tree. Thanks.

v2 changes:
        a) dropped the "don't enable pause by default" patch
        b) described how the "spoof check" works in patch 1's commit log
	c) I had to update our email addresses from "@emulex" to
	   "@avagotech". I'll send a separate patch updating the
	   maintainers

Patch 1 adds support for the "spoofchk" knob for VFs.
When it is enabled, "spoof checking" is done for both MAC-address
and VLAN. For each VF, the HW ensures that the source MAC address
(or vlan) of every outgoing packet of the VF exists in the MAC-list
(or vlan-list) configured for RX filtering for that VF.
If not, the packet is dropped and an error is reported to the driver
in the TX completion.

Patch 2 improves interrupt moderation on Skyhawk-R chip by using
the EQ-DB mechanism to set a "re-arm to interrupt" delay. Currently
interrupt moderation is adjusted by calculating and configuring an
EQ-delay every second. This is done via a FW-cmd. This patch uses
the EQ_DB facility to calculate and set the interrupt delay every 1ms.
This helps moderating interrupts better when the traffic is bursty.

Patch 3 adds L3/L4 error accounting to BE3 VFs, by passing L3/4 error
packets to the network stack.

Patch 4 adds an extra FW-cmd error value check in the driver to identify
an "out of vlan filters" scenario.

Patch 5 stops enabling pause by default as this setting fails in
some HW-configs where priority pause is enabled in FW. If the user
tries to do the same, an appropriate error is returned via ethtool.

Patch 5 posts the full RXQ in be_open() to prevent packet drops due to
bursty traffic when the interface is enabled.

Patch 6 refactors the be_check_ufi_compatibility() routine, that checks
to see if a UFI file meant for a lower rev of a chip is being flashed
on a higher rev, to make it simpler.

Patch 7 replaces the usage of !be_physfn() macro with be_virtfn()
that is already avialble in the driver.

Patch 8 updates the year in the copyright text to 2015.

Path 9 bumps up the driver version to 10.6.02.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NSathya Perla <sathya.perla@avagotech.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NVasundhara Volam <vasundhara.volam@avagotech.com>
Signed-off-by: NSathya Perla <sathya.perla@avagotech.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use be_virtfn() to determine a VF instead of !be_physfn() for better
readability.
Signed-off-by: NSathya Perla <sathya.perla@avagotech.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The code in be_check_ufi_compatibility() checks to see if a UFI file meant
for a lower rev of a chip is being flashed on a higher rev, which is
disallowed. This patch re-writes the code needed for this check in a much
simpler manner.
Signed-off-by: NVasundhara Volam <vasundhara.volam@avagotech.com>
Signed-off-by: NSathya Perla <sathya.perla@avagotech.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When an RXQ is created in be_open(), the driver currently posts only
64 buffers. This sometimes results in packet drops when there is a traffic
burst as soon as the interface is enabled.
This patch fixes this problem by posting the full RXQ on interface enable.
Signed-off-by: NSuresh Reddy <Suresh.Reddy@avagotech.com>
Signed-off-by: NSathya Perla <sathya.perla@avagotech.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the FW runs out of vlan filters it can either return an
INSUFFICIENT_RESOURCES error or an INSUFFICIENT_VLANS error.
The driver currently checks only for the former error value.
This patch adds a check for the latter value too.
Signed-off-by: NKalesh AP <kalesh.purayil@emulex.com>
Signed-off-by: NSathya Perla <sathya.perla@avagotech.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently pkts with L3 or L4 errors received on PFs are not dropped
by the adapter, but instead sent to the stack. This helps the network stack
to better reflect error statistics. This was not being done on BE3 VFs.
This patch fixes this for BE3 VFs.
Signed-off-by: NSomnath Kotur <somnath.kotur@avagotech.com>
Signed-off-by: NSathya Perla <sathya.perla@avagotech.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently adaptive interrupt moderation is set by calculating
and configuring an EQ-delay every second. This is done via
a FW-cmd. But, on Skyhawk-R a "re-arm to interrupt" delay
can be set while ringing the EQ-DB. This patch uses this
facility to calculate and set the interrupt delay every 1ms.
This helps moderating interrupts better when the traffic
is bursty.
Signed-off-by: NPadmanabh Ratnakar <padmanabh.ratnakar@avagotech.com>
Signed-off-by: NSathya Perla <sathya.perla@avagotech.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds support for spoofchk configuration for VFs.
When it is enabled, "spoof checking" is done for both MAC-address and VLAN.
For each VF, the HW ensures that the source MAC address (or vlan) of
every outgoing packet exists in the MAC-list (or vlan-list) configured
for RX filtering for that VF. If not, the packet is dropped and an error
is reported to the driver in the TX completion; this is reflected in the
"tx_spoof_check_err" ethtool counter.
This feature is supported in Skyhawk FW version 10.6.31.0 and above.
Signed-off-by: NKalesh AP <kalesh.purayil@emulex.com>
Signed-off-by: NSathya Perla <sathya.perla@avagotech.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Shradha Shah says:

====================
sfc: Enabling EF10 Vf's, set up vswitching and bind the SFC driver to the VF's

This set of patches makes way for the implementation of EF10
SR-IOV driver starting with some cleanup code.
NIC specific SR-IOV functions are moved to their own header
and netdev_ops are made generic instead of being NIC specific

Next in line comes the patch to enable VF's using sriov_configure.
VEB vswitching hierarchy is set up next followed by patches to
prepare sfc driver to bind to enabled VF's

This is followed by patch to support use of shared RSS contexts
which makes VF's use shared RSS contexts in all cases.

Patch series ends with a patch to bind the sfc driver to the
enabled VF's which creates network interfaces corresponding to
the VF's.

Coming up soon are the patches to set_vf_mac, set_vf_config,
set_vf_vlan, vf_spoofcheck, etc.

These patches have been tested with and without CONFIG_SFC_SRIOV.
In the case of CONFIG_SFC_SRIOV=y enabling of VF's using
sriov_configure is also tested. The enabled VF's bind to the
installed sfc driver succesfully to create network interfaces.
In the case of CONFIG_SFC_SRIOV=n enabling of VF's using
sriov_configure returns the correct error message:
"Function not implemented".
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add the device ID of the VF to the PCI device ID table.

Added a boolean flag is_vf in efx_nic_type to differentiate
between a VF and PF at probe time. This flag is useful in later
patches while setting MAC address specially in the
PCI-passthrough case.
Signed-off-by: NShradha Shah <sshah@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allow PFs to allocate shared RSS contexts if we exhaust our
exclusive RSS contexts. Make VFs use shared RSS contexts in
all cases.
Spruce up error handling so that the shadow copy of the RSS
table is updated after successful update, rather than in all
cases, so that we report the actual contents of the RSS table
after a failure to set it, rather than what we'd like it to be.

Populate context_size parameter when vacuously allocating RSS
context of size 1.
Signed-off-by: NShradha Shah <sshah@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

* Accept EPERM in some simple cases, the following cases are handled:
1) efx_mcdi_read_assertion()
Unprivileged PCI functions aren't allowed to GET_ASSERTS.
We return success as it's up to the primary PF to deal with asserts.
2) efx_mcdi_mon_probe() in efx_ef10_probe()
Unprivileged PCI functions aren't allowed to read sensor info, and
worrying about sensor data is the primary PF's job.
3) phy_op->reconfigure() in efx_init_port() and efx_reset_up()
Unprivileged functions aren't allowed to MC_CMD_SET_LINK, they just have
to accept the settings (including flow-control, which is what
efx_init_port() is worried about) they've been given.
4) Fallback to GET_WORKAROUNDS in efx_ef10_probe()
Unprivileged PCI functions aren't allowed to set workarounds. So if
efx_mcdi_set_workaround() fails EPERM, use efx_mcdi_get_workarounds()
to find out if workaround_35388 is enabled.
5) If DRV_ATTACH gets EPERM, try without specifying fw-variant
Unprivileged PCI functions have to use a FIRMWARE_ID of 0xffffffff
(MC_CMD_FW_DONT_CARE).
6) Don't try to exit_assertion unless one had fired
Previously we called efx_mcdi_exit_assertion even if
efx_mcdi_read_assertion had received MC_CMD_GET_ASSERTS_FLAGS_NO_FAILS.
This is unnecessary, and the resulting MC_CMD_REBOOT, even if the
AFTER_ASSERTION flag made it a no-op, would fail EPERM for unprivileged
PCI functions.
So make efx_mcdi_read_assertion return whether an assert happened, and only
call efx_mcdi_exit_assertion if it has.
Signed-off-by: NShradha Shah <sshah@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To be able to use MC_CMD_VADAPTOR_SET_MAC, vadaptors must be
manually allocated and freed as automatic vadaptors will disappear
when their reference_count reaches zero, which must happen before
the MAC address is changed.

Vadaptors are allocated and freed in the vswitching_probe/remove
functions for PFs and VFs, and this means that vadaptors are restored
correctly following an MC reboot or other reset when required.
Signed-off-by: NShradha Shah <sshah@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The parent PF creates vports for all its child VFs and adds MAC
addresses to these.  When the VF driver loads, it can make an MCDI
call to get the MAC address that the parent PF assigned it.

The parent PF also assigns a mac address to its own vport because
implicit creation of a vAdaptor will only work on evb ports with
MAC addresses assigned.

The vport MAC address needs to be stored in the PF's nic_data
struct as it can later be changed on the vadaptor (and its net_dev
struct). When removing a vport the original MAC address must be
deleted.

A new flag is needed in the VF data structure to identify whether
a vport has been assigned to the VF.  This is to determine whether
it needs to be un-assigned before freeing the vport.  Also,
attempting to un-assign a vport which is not assigned will result
in an EALREADY error.
Signed-off-by: NShradha Shah <sshah@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Added efx_nic_type structure for VF.
Mapped a different BAR for VF as it uses BAR 0 for memory.
Added functions sriov_init and sriov_fini.
Signed-off-by: NShradha Shah <sshah@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use MC_CMD_GET_FUNCTION_INFO to record the PF number in nic_data.
This will be needed when assigned vports to VFs.
Signed-off-by: NShradha Shah <sshah@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Adds functions to allocate and free vswitches and vports; vadaptors
are automatically allocated and freed when TX/RX queues are
initialised and finalised.  This vswitching structure is only created
if the firmware supports it, so a check that full-featured firmware
is running is performed first.

If the MC resets, the vswitching infrastructure will need to be
recreated, so mark the "must_probe_vswitching" flag when an MC reboot
is detected.

Don't try to create a vswitch if vf-count=0

This allocation of vswitches and vports does not currently support
configuring VLAN tags, but that can be added in a future change.
Signed-off-by: NShradha Shah <sshah@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The default port ID of EVB_PORT_ID_ASSIGNED is a "magic" number
for the MCFW to select the physical port of the PF.  If other
vswitches and vports are created on top of the default firmware
configuration, the ID of the newly created vport is then required
when passed to MCDI commands.  Currently, this doesn't happen so
the vport_id is never changed, but a subsequent patch will change
this behaviour so that other vswitches and vports are created.

The vport_id recorded in nic_data is only relevant for PFs.
VFs will have their vports created by their parent PF, and in
that case the parent PF will record the vport ID of each VF.
For a VF, nic_data->vport_id is expected to remain at the default
value.
Signed-off-by: NShradha Shah <sshah@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The (future) code to add/remove vswitches and vports will be
dependent on the firmware variant.
To simplify the checking of the firmware variant, record
values for rx_dpcpu_fw_id and tx_dpcpu_fw_id in EF10 nic_data.

There was only one place where this was previously used:
efx_mcdi_print_fwver() in ethtool.c.
The MC_CMD_GET_CAPABILITIES can be replaced and the values from
nic_data used instead.

Note that the printing of "?" if the MC command fails or if the
outlength is incorrect no longer apply, because errors are returned
in efx_ef10_init_datapath_caps() in both of these cases.
Signed-off-by: NShradha Shah <sshah@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The TX_DOMAIN field is currently reserved but its safer to set
it to 0 for future compatibility.
Signed-off-by: NShradha Shah <sshah@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds support for the use of sriov_configure on EF10
to enable Virtual Functions while the driver is loaded.
Signed-off-by: NShradha Shah <sshah@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The efx_vf struct contains Siena-specific fields for VFs,
so rename to siena_vf.
Also move it into the siena_nic_data struct, as EF10 will
track its VFs in its own ef10_nic_data, storing much less
information about them since VFDI is no longer used.
Signed-off-by: NShradha Shah <sshah@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sfc: Own header for nic-specific sriov functions, single instance of netdev_ops and sriov removed from Falcon code

By putting all the efx_{siena,ef10}_sriov_* declarations in
{siena,ef10}_sriov.h, ensure they cannot be called from nic-generic code.
Also fixes up an instance of this, where mcdi.c was calling
efx_siena_sriov_flr.

The single instance of netdev_ops should call general high level
functions that can then call something adapter specific in efx_nic_type.
We should only do adapter specialisation via efx_nic_type.

Removal of sriov functionality from the Falcon code means that tests
are needed for the presence of some callbacks.
Signed-off-by: NShradha Shah <sshah@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Andrew Lunn says:

====================
More Marvell DSA refactring and fixup

This patch setup continues the refactoring and cleanup of the Marvell
DSA drivers.

Patch #1 Centralizes the duplicated parts of port setup and global
setup into the shared mv88e6xxx.

Patch #2 Centralizes looping over the ports setting them up

Patch #3 Uses mnemonics for the remaining register access in the
drivers.

Patch #4 The 6172 is actually a member of the 6352 family. This moves
the probe code into the correct driver.

Patch #5 Adds more members of the 6171 family to the 6171 driver. The
new devices are untested.

Patch #6 The 6185 is a member of the 6131 family. Add it to the probe
code of the 6131 driver.

Patch #7 and Patch #8 Simply the mutex's in mv88e6xxx.c. The SMI bus
is the bottleneck, not the granularity of the mutex's so simply the
code down to a single mutex.

Patch #8 Fixes a false positive lockdep splat, due to nested uses of
MDIO busses.

Patch #9 Fixes another false positive lockdep splat with the transmit
queue because of stacked Ethernet devices.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

DSA stacks an Ethernet device on top of an Ethernet device. This can
cause false positive lockdep splats for the transmit queue:
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>

=============================================
[ INFO: possible recursive locking detected ]
4.0.0-rc7-01838-g70621a215fc7 #386 Not tainted
---------------------------------------------
kworker/0:0/4 is trying to acquire lock:
 (_xmit_ETHER#2){+.-...}, at: [<c040e95c>] sch_direct_xmit+0xa8/0x1fc

but task is already holding lock:
 (_xmit_ETHER#2){+.-...}, at: [<c03f4208>] __dev_queue_xmit+0x4d4/0x56c

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(_xmit_ETHER#2);
  lock(_xmit_ETHER#2);

To avoid this, walk the tq queues of the dsa slaves and set a lockdep
class.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

DSA can have nested MDIO busses, where the Ethernet MDIO bus is used
to access an MDIO bus within the switch which has the PHYs connected
to it. This nesting causes lockdep to give false positives. Use
mutex_lock_nested() to avoid this.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>