This reverts commit 5a5abb1f ("tun, bpf: fix suspicious RCU usage
in tun_{attach, detach}_filter") and replaces it to use lock_sock around
sk_{attach,detach}_filter. The checks inside filter.c are updated with
lockdep_sock_is_held to check for proper socket locks.

It keeps the code cleaner by ensuring that only one lock governs the
socket filter instead of two independent locks.

Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The socket is either locked if we hold the slock spin_lock for
lock_sock_fast and unlock_sock_fast or we own the lock (sk_lock.owned
!= 0). Check for this and at the same time improve that the current
thread/cpu is really holding the lock.
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

During release_sock we use callbacks to finish the processing
of outstanding skbs on the socket. We actually are still locked,
sk_locked.owned == 1, but we already told lockdep that the mutex
is released. This could lead to false positives in lockdep for
lockdep_sock_is_held (we don't hold the slock spinlock during processing
the outstanding skbs).

I took over this patch from Eric Dumazet and tested it.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

David Ahern reported panics in __inet_hash() caused by my recent commit.

The reason is inet_reuseport_add_sock() was still using
sk_nulls_for_each_rcu() instead of sk_for_each_rcu().
SO_REUSEPORT enabled listeners were causing an instant crash.

While chasing this bug, I found that I forgot to clear SOCK_RCU_FREE
flag, as it is inherited from the parent at clone time.

Fixes: 3b24d854 ("tcp/dccp: do not touch listener sk_refcnt under synflood")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NDavid Ahern <dsa@cumulusnetworks.com>
Tested-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Jeff Kirsher says:

====================
1GbE Intel Wired LAN Driver Updates 2016-04-06

This series contains updates to e1000, e1000e, igb and Kconfig.

Alex fixes igb where we were casting the MAC address as __beXX and then
passing it into le32_to_cpu, when we could simply cast as __lexx to
maintain consistency since it is already little endian.  Then enabled
bulk free in transmit cleanup for igb.

John Holland enables igb to pickup the MAC address from a device tree
blob when CONFIG_OF has been enabled.

Doron Shikmoni fixes a bug in the output of "ethtool -m ethX" where
the data byte appeared duplicated.

Stefan fixes up e1000 and e1000e ethtool offline tests which were calling
dev_close() which causes IFF_UP to be cleared which removes teh interface
routes and some addresses, so use ndo_stop() instead.

Jiri Benc cleans up some old links in the Kconfig for Intel drivers where
we referred to a URL which is no longer valid.  I am so glad Jiri has the
time in his day to spend clicking on and testing all the URL links in the
the kernel.

Arika Chen reverts the addition of a 'rtnl_unlock()' which had a unmatched
'rtnl_lock()' call before it.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Jeff Kirsher says:

====================
40GbE Intel Wired LAN Driver Updates 2016-04-06

This series contains updates to i40e and i40evf.

Deepthi adds a debug message to display the MSIx vector count for hardware
capabilities.

Shannon removed the setting of debug_mask at startup to take care of an
issue where all the device capabilities getting printed when we had not
asked for it.  Moved the NVM status out of the admin queue structure,
since it should really stay with the other NVM data structures.

Akeem added the flush routine to the end of the reset flow to avoid
problems in the pass-through routines.

Jesse moves a local variable deeper into the depths of the driver
where the light is low and the context is great.  Then cleaned up
the tx_ring argument since it was not making good arguments.  Improved
performance by not "checking for FCoE" by re-ordering the FCoE checks.

Anjali adds the support for changing a VF from non-trusted to trusted
and vice-versa.

Mitch adds opcodes and structures to support RSS configuration by PF
driver on behalf of the VF driver.  Fixed how the VLAN feature flags
are set.

Kiran added defines for RSS, flow director, flexible payload and IPv6.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 3eb14ea8 ("igb: Fix a deadlock in
igb_sriov_reinit")
It is the same as commit f468adc9 ("igb: missing rtnl_unlock in
igb_sriov_reinit()")
There is no rtnl_lock() in igb_resume before, rtnl_unlock will cause a
deadlock.
Signed-off-by: NArika Chen <arika.chen@huawei.com>
Tested-by: NAaron Brown <aaron.f.brown@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

The Kconfig for Intel NICs references two different URLs for the "Adapter
& Driver ID Guide". Neither of those two links works. The current URL seems
to be
http://www.intel.com/content/www/us/en/support/network-and-i-o/ethernet-products/000005584.html
but given it's apparently constantly changing, there's no point in having it
in the help text.

Just keep a generic pointer to http://support.intel.com. Hopefully, this one
will have a longer live. It still works, at least.

Furthermore, remove a link to "the latest Intel PRO/100 network driver for
Linux", this has no place in the mainline kernel and the latest Linux driver
it offers is from 2006, anyway.
Signed-off-by: NJiri Benc <jbenc@redhat.com>
Tested-by: NAaron Brown <aaron.f.brown@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Correctly set the VLAN feature flags after setting the rest of the
netdev flags. And don't set them in hw_features, because these can't be
controlled by the VF driver.
Signed-off-by: NMitch Williams <mitch.a.williams@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Signed-off-by: NHarshitha Ramamurthy <harshitha.ramamurthy@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Add defines for input set mask (RSS, flow director, flexible payload),
including defines specific to IPv6.

Change-ID: Ie95ef7d0916a4d6ca011c194283f959774c8dce9
Signed-off-by: NKiran Patil <kiran.patil@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

The logic that checks AQ events for NVM done events is better kept
in nvm.c with the rest of the nvmupdate handling code.

Change-ID: I2ea58980df8ecaa3726b28a37bff3dfcb8df03dc
Signed-off-by: NShannon Nelson <shannon.nelson@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Add opcodes and structures to support RSS configuration by PF driver on
behalf of the VF drivers. This reduces complexity in the VF driver and
allows us to support future hardware designs without modifying the VF
driver.

Change-ID: I8c75765c630eacb71f95967f1109a198542593ac
Signed-off-by: NMitch Williams <mitch.a.williams@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

The NVM update status info should stay collected together, not
spread across different structs.

Change-ID: Ic16f9e9fd79945d865bb7226184c889884585025
Signed-off-by: NShannon Nelson <shannon.nelson@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

The VFs can request their queues to be set up into polling mode, rather
than interrupt mode, which works well for supporting things like DPDK,
but this should not be available when working in an multi-function
support device.

Change-ID: Id36792e4e7422db8f2033336507211f68f14ff6f
Signed-off-by: NShannon Nelson <shannon.nelson@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch adds hook to support changing a VF from not-trusted
to trusted and vice-versa. Fixed the wrappers and function prototype.
Changed the dmesg to reflex the current state better. This patch also
disables turning on/off trusted VF in MFP mode.

Change-ID: Ibcd910935c01f0be1f3fdd6d427230291ee92ebe
Signed-off-by: NAnjali Singhai Jain <anjali.singhai@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

As it turns out, calling into other files from hot path hurts
performance a lot.  In this case the majority of the time we
call "check FCoE" and the packet is *not* FCoE, but this call
was taking 5% of our total cycles spent on receive.

Change-ID: I080552c26e7060bc7b78504dc2763f6f0b3d8c76
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Some of the tx_ring arguments can be deleted since they are not used.

Change-ID: I99275b0f191d7f63ec2f05061919904940c36f31
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

A local variable could move down inside the context where it is used.

Change-ID: I9caba9e1eacf921037077f2665cbce83fd8e95d6
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch moves the HW flush routine to the end of the reset flow,
after the completion of writing to the device VFLR registers- the
benefit is to avoid problems in the passthrough routines.

Change-ID: Ieb56866f21895e6c1fc514b7328c3df79807a57c
Signed-off-by: NAkeem G Abodunrin <akeem.g.abodunrin@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Don't set our internal debug_mask at startup unless we get specific signal
to from the debug module parameter.

This should take care of the issue with all the device capabilities getting
printed even when we hadn't asked for the debug info.

Change-ID: I7fbc6bd8b11ed9b0631ec018ff36015a04100b6c
Signed-off-by: NShannon Nelson <shannon.nelson@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Display MSIx vector count for HW capabilities.

Change-ID: I4b41e9b50360cf660e7fbcb85b9390fedcf313b1
Signed-off-by: NDeepthi Kavalur <deepthi.kavalur@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Calling dev_close() causes IFF_UP to be cleared which will remove the
interfaces routes and some addresses. That's probably not what the user
intended when running the offline selftest. Besides this does not happen
if the interface is brought down before the test, so the current
behaviour is inconsistent.
Instead call the net_device_ops ndo_stop function directly and avoid
touching IFF_UP at all.
Signed-off-by: NStefan Assmann <sassmann@kpanic.de>
Tested-by: NAaron Brown <aaron.f.brown@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Jiri Pirko says:

====================
mlxsw: Introduce support for Data Center Bridging

Ido says:

This patchset introduces support for Quality of Service (QoS) as part of the
IEEE Data Center Bridiging (DCB) standards.

Patches 1-9 do the required device initialization. Specifically, patches 1-6
initialize the ports' headroom buffers, which are used at ingress to store
incoming packets while they go through the switch's pipeline. Patches 7-9
complete them by initializing the egress scheduling.

The pipeline mentioned above determines the packet's egress port(s) and
traffic class. Ideally, once out of the pipeline the packet moves to the
switch's shared buffer (to be introduced in Jiri's patchset, currently
default values are used) and scheduled for transmission according to its
traffic class. The egress scheduling is configured according to the 802.1Qaz
standard, which is part of the DCB infrastructure supported by Linux. This
is introduced in patches 10-12.

Even after going through the pipeline packets are not always eligible to
enter the shared buffer. This is determined by the amount of available space
and the quotas associated with the packet. However, if flow control is
enabled and the packet is associated with the lossless flow, then it will
stay in the headroom and won't be discarded. This is introduced in patches
13-17.

Please check individual commit messages for more info, as I tried to keep
them pretty detailed.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement the appropriate DCB ops and allow a user to configure certain
traffic classes as lossless.

The operation configures PFC for both the egress (respecting PFC frames)
and ingress (sending PFC frames) parts of the port.

At egress, when a PFC frame is received for a PFC enabled priority, then
all the priorities mapped to the same TC are stopped.

At ingress, the priority group (PG) buffers to which the enabled PFC
priorities are mapped are configured to be lossless. PFC frames will be
transmitted when the Xoff threshold is crossed.

The user-supplied delay parameter is used to determine the PG's size
according to the following formula:

PG_SIZE = PG_SIZE_LOSSY + delay * CELL_FACTOR + MTU

In the worst case scenario the delay will be made up of packets that
are all of size CELL_SIZE + 1, which means each packet will require
almost twice its true size when buffered in the switch. We therefore
multiply this value by the "cell factor", which is close to 2.

Another MTU is added in case the transmitting host already started
transmitting a maximum length frame when the PFC packet was received.

As with PAUSE enabled ports, when the port's MTU is changed both the
PGs' size and threshold are adjusted accordingly.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We are going to add support for PFC as part of DCB ops, which requires us
to report the number of PFC frames sent and received per priority.

Add per priority counters in order to report number of PFC frames sent
and received per priority.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a packet ingress the switch it's placed in its assigned priority
group (PG) buffer in the port's headroom buffer while it goes through
the switch's pipeline. After going through the pipeline - which
determines its egress port(s) and traffic class - it's moved to the
switch's shared buffer awaiting transmission.

However, some packets are not eligible to enter the shared buffer due to
exceeded quotas or insufficient space. Marking their associated PGs as
lossless will cause the packets to accumulate in the PG buffer. Another
reason for packets accumulation are complicated pipelines (e.g.
involving a lot of ACLs).

To prevent packets from being dropped a user can enable PAUSE frames on
the port. This will mark all the active PGs as lossless and set their
size according to the maximum delay, as it's not configured by user.

                         +----------------+   +
                         |                |   |
                         |                |   |
                         |                |   |
                         |                |   |
                         |                |   |
                         |                |   | Delay
                         |                |   |
                         |                |   |
                         |                |   |
                         |                |   |
                         |                |   |
    Xon/Xoff threshold   +----------------+   +
                         |                |   |
                         |                |   | 2 * MTU
                         |                |   |
                         +----------------+   +

The delay (612 [Cells]) was calculated according to worst-case scenario
involving maximum MTU and 100m cables.

After marking the PGs as lossless the device is configured to respect
incoming PAUSE frames (Rx PAUSE) and generate PAUSE frames (Tx PAUSE)
according to user's settings.

Whenever the port's headroom configuration changes we take into account
the PAUSE configuration, so that we correctly set the PG's type (lossy /
lossless), size and threshold. This can happen when:

a) The port's MTU changes, as it directly affects the PG's size.

b) A PG is created following user configuration, by binding a priority
to it.

Note that the relevant SUPPORTED flags were already mistakenly set by
the driver before this commit.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When configuring PAUSE frames and PFC we'll need to configure the
Xon/Xoff threshold for the priority group (PG) buffers.

Add the Xon/Xoff threshold fields to the PBMC register so that we can
configure these when needed.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add the Port Flow Control Configuration (PFCC) register, which
configures both flow control and Priority-based Flow Control (PFC).
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allow a user to set maximum rate for a particular TC using DCB ops.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement the appropriate DCB ops and allow a user to configure:
	* Priority to traffic class (TC) mapping with a total of 8
	  supported TCs
	* Transmission selection algorithm (TSA) for each TC and the
	  corresponding weights in case of weighted round robin (WRR)

As previously explained, we treat the priority group (PG) buffer in the
port's headroom as the ingress counterpart of the egress TC. Therefore,
when a certain priority to TC mapping is configured, we also configure
the port's headroom buffer.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce basic infrastructure for DCB and add the missing ops in
following patches.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Before introducing support for DCB ops we should first make sure we
initialize the relevant parts in the device correctly. Specifically, the
egress scheduling.

The device supports a superset of the 802.1Qaz standard with 4 hierarchy
levels that can be linked to each other in multiple ways and with
different transmission selection algorithms (TSA) employed between them.

However, since we only intend to support the 802.1Qaz standard we
flatten the hierarchies and let the user configure via DCB ops the TSA
and max rate shaper at the subgroup hierarchy (see figure below) and the
mapping between switch priority to traffic class. By default, all switch
priorities are mapped to traffic class 0, strict priority is employed
and max shaper is disabled.

Default configuration:

         switch priority 0      ...         switch priority 7
                 +                                  +
                 |                                  |
                 +----------------------------------+
                 |
              +--v--+                          +-----+
Traffic Class |     |                          |     |
  Hierarchy   | TC0 |           ...            | TC7 |
              |     |                          |     |
              +--+--+                          +--+--+
                 |                                |
              +--v--+                          +--v--+
  Subgroup    | SG0 |                          | SG7 |
  Hierarchy   |     |                          |     |
              +-----+                          +-----+
              | TSA |                          | TSA |
              +-----+           ...            +-----+
              | MAX |                          | MAX |
              +--+--+                          +--+--+
                 |                                |
                 +---------------+----------------+
                                 |
                              +--v--+
                      Group   |     |
                    Hierarchy | GR0 |
                              |     |
                              +--+--+
                                 |
                              +--v--+
                      Port    |     |
                    Hierarchy | PR0 |
                              |     |
                              +-----+
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As part of DCB ops we'll have to configure the priority to traffic class
mapping of a port.

Add the QoS Switch Traffic Class Table (QTCT) register, which configures
the mapping between the packet switch priority and traffic class on the
transmit port.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We are going to introduce support for DCB, so we need to be able to
configure the traffic selection algorithm (TSA) used by each traffic
class (TC), as well as the bandwidth percentage allocated to each TC in
case of ETS.

Add the QoS ETS Element Configuration register, which controls the
above parameters.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In addition to the priority group (PG) buffers in the headroom, the
device enables the allocation of headroom shared buffer, which can
be shared between different PGs.

However, we are not going to use the headroom shared buffer and instead
allow the user to use its size for PGs or the switch's shared buffer.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The last field of the PBMC register is at offset 0x64 and its size is
0x8, so the correct register's length is 0x6C bytes.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When packets ingress the switch they are assigned a switch priority and
directed to the corresponding priority group (PG) buffer in the port's
headroom buffer.

Since we now map all switch priorities to priority group 0 (PG0) by
default, there is no need to allocate the other priority groups during
initialization. The only exception is PG9, which is used for control
traffic.

At minimum, the PG should be able to store the currently classified
packet (pipeline latency isn't 0) and also the packets arriving during
the classification time. However, an incoming packet will not be
buffered if there is no available MTU-sized buffer space for storing it.

The buffer needed to accommodate for pipeline latency is variable and
needs to take into account both the current link speed and current
latency of the pipeline, which is time-dependent. Testing showed that
setting the PG's size to twice the current MTU is optimal.

Since PG9 is used strictly for control packets and not subject to flow
control, we are not going to resize it according to user configuration,
so we simply set it according to worst case scenario, which is twice the
maximum MTU.

In any case, later patches in the series will allow a user to direct
lossless flows to other PGs than PG0 and set their size to accommodate
for round-trip propagation delay.

The above change also requires us to resize the PG buffer whenever the
port's MTU is changed.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Buffers in the switch store packets in units called buffer cells. Add a
helper to convert from bytes to cells, so that the actual number of
cells required (result is round up) is returned.

Also, drop the SB (shared buffer) acronym from the BYTES_PER_CELL macro,
as this unit is also used in the ports' buffers and not only the
switch's shared buffer.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

During transmission, the skb's priority is used to map the skb to a
traffic class, where the idea is to group priorities with similar
characteristics (e.g. lossy, lossless) to the same traffic class. By
default, all priorities are mapped to traffic class 0.

In the device, we model the skb's priority as the switch priority, which
is assigned to a packet according to its PCP value and ingress port
(untagged packets are assigned the port's default switch priority - 0).

At ingress, the packet is directed to a priority group (PG) buffer in
the port's headroom buffer according to the packet's switch priority and
switch priority to buffer mapping.

While it's possible to configure the egress mapping between skb's
priority (switch priority) and traffic class, there is no mechanism to
configure the ingress mapping to a PG.

In order to keep things simple and since grouping certain priorities into
a traffic class at egress also implies they should be grouped the same
at ingress, treat a PG as the ingress counterpart of an egress traffic
class.

Having established the above, during initialization map all the switch
priorities to PG0 in accordance with the Linux defaults for traffic
class mapping.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>