The commit 6b229cf7 ("udp: add batching to udp_rmem_release()")
reduced greatly the cacheline contention between the BH and the US
reader batching the rmem updates in most scenarios.

Such optimization is explicitly avoided if the US reader is faster
then BH processing.

My fault, I initially suggested this kind of behavior due to concerns
of possible regressions with small sk_rcvbuf values. Tests showed
such concerns are misplaced, so this commit relaxes the condition
for rmem bulk updates, obtaining small but measurable performance
gain in the scenario described above.
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch tries to add XDP_REDIRECT for virtio-net. The changes are
not complex as we could use exist XDP_TX helpers for most of the
work. The rest is passing the XDP_TX to NAPI handler for implementing
batching.

Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There's no need to add packet len average in the case of XDP_PASS
since it will be done soon after skb is created.

Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

CC: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make the driver react to device tree "fixed-link" declaration on CPU port.

- turn off autonegotiation
- force speed 10 or 100 mb/s
- force duplex mode
Signed-off-by: NEgil Hjelmeland <privat@egil-hjelmeland.no>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, when an interface is released from a bridge via
ioctl(), we get a RTM_DELLINK event through netlink:

Deleted 2: dummy0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 master bridge0 state UNKNOWN
    link/ether 6e:23:c2:54:3a:b3

Userspace has to interpret that as a removal from the bridge, not as a
complete removal of the interface. When an bridged interface is
completely removed, we get two events:

Deleted 2: dummy0: <BROADCAST,NOARP> mtu 1500 master bridge0 state DOWN
    link/ether 6e:23:c2:54:3a:b3
Deleted 2: dummy0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN group default
    link/ether 6e:23:c2:54:3a:b3 brd ff:ff:ff:ff:ff:ff

In constrast, when an interface is released from a bond, we get a
RTM_NEWLINK with only the new characteristics (no master):

3: dummy1: <BROADCAST,NOARP,SLAVE,UP,LOWER_UP> mtu 1500 qdisc noqueue master bond0 state UNKNOWN group default
    link/ether ae:dc:7a:8c:9a:3c brd ff:ff:ff:ff:ff:ff
3: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default
    link/ether ae:dc:7a:8c:9a:3c brd ff:ff:ff:ff:ff:ff
4: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default
    link/ether ae:dc:7a:8c:9a:3c brd ff:ff:ff:ff:ff:ff
3: dummy1: <BROADCAST,NOARP> mtu 1500 qdisc noqueue state DOWN group default
    link/ether ae:dc:7a:8c:9a:3c brd ff:ff:ff:ff:ff:ff
3: dummy1: <BROADCAST,NOARP> mtu 1500 qdisc noqueue state DOWN group default
    link/ether ca:c8:7b:66:f8:25 brd ff:ff:ff:ff:ff:ff
4: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default
    link/ether ae:dc:7a:8c:9a:3c brd ff:ff:ff:ff:ff:ff

Userland may be confused by the fact we say a link is deleted while
its characteristics are only modified. A first solution would have
been to turn the RTM_DELLINK event in del_nbp() into a RTM_NEWLINK
event. However, maybe some piece of userland is relying on this
RTM_DELLINK to detect when a bridged interface is released. Instead,
we also emit a RTM_NEWLINK event once the interface is
released (without master info).

Deleted 2: dummy0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 master bridge0 state UNKNOWN
    link/ether 8a:bb:e7:94:b1:f8
2: dummy0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default
    link/ether 8a:bb:e7:94:b1:f8 brd ff:ff:ff:ff:ff:ff

This is done only when using ioctl(). When using Netlink, such an
event is already automatically emitted in do_setlink().
Signed-off-by: NVincent Bernat <vincent@bernat.im>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch checks data first at one place, return if it's null.
Signed-off-by: NZhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In ipv6_skip_exthdr, the lengh of AH header is computed manually
as (hp->hdrlen+2)<<2. However, in include/linux/ipv6.h, a macro
named ipv6_authlen is already defined for exactly the same job. This
commit replaces the manual computation code with the macro.
Signed-off-by: NXiang Gao <qasdfgtyuiop@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Eric Dumazet says:

====================
net: speedup netns create/delete time

When rate of netns creation/deletion is high enough,
we observe softlockups in cleanup_net() caused by huge list
of netns and way too many rcu_barrier() calls.

This patch series does some optimizations in kobject,
and add batching to tunnels so that netns dismantles are
less costly.

IPv6 addrlabels also get a per netns list, and tcp_metrics
also benefit from batch flushing.

This gives me one order of magnitude gain.
(~50 ms -> ~5 ms for one netns create/delete pair)

Tested:

for i in `seq 1 40`
do
 (for j in `seq 1 100` ; do  unshare -n /bin/true >/dev/null ; done) &
done
wait ; grep net_namespace /proc/slabinfo

Before patch series :

$ time ./add_del_unshare.sh
net_namespace        116    258   5504    1    2 : tunables    8    4    0 : slabdata    116    258      0

real	3m24.910s
user	0m0.747s
sys	0m43.162s

After :
$ time ./add_del_unshare.sh
net_namespace        135    291   5504    1    2 : tunables    8    4    0 : slabdata    135    291      0

real	0m22.117s
user	0m0.728s
sys	0m35.328s
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement exit_batch() method to dismantle more devices
per round.

(rtnl_lock() ...
 unregister_netdevice_many() ...
 rtnl_unlock())

Tested:
$ cat add_del_unshare.sh
for i in `seq 1 40`
do
 (for j in `seq 1 100` ; do unshare -n /bin/true >/dev/null ; done) &
done
wait ; grep net_namespace /proc/slabinfo

Before patch :
$ time ./add_del_unshare.sh
net_namespace        126    282   5504    1    2 : tunables    8    4    0 : slabdata    126    282      0

real    1m38.965s
user    0m0.688s
sys     0m37.017s

After patch:
$ time ./add_del_unshare.sh
net_namespace        135    291   5504    1    2 : tunables    8    4    0 : slabdata    135    291      0

real	0m22.117s
user	0m0.728s
sys	0m35.328s
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement exit_batch() method to dismantle more devices
per round.

(rtnl_lock() ...
 unregister_netdevice_many() ...
 rtnl_unlock())

Tested:
$ cat add_del_unshare.sh
for i in `seq 1 40`
do
 (for j in `seq 1 100` ; do unshare -n /bin/true >/dev/null ; done) &
done
wait ; grep net_namespace /proc/slabinfo

Before patch :
$ time ./add_del_unshare.sh
net_namespace        110    267   5504    1    2 : tunables    8    4    0 : slabdata    110    267      0

real    3m25.292s
user    0m0.644s
sys     0m40.153s

After patch:

$ time ./add_del_unshare.sh
net_namespace        126    282   5504    1    2 : tunables    8    4    0 : slabdata    126    282      0

real	1m38.965s
user	0m0.688s
sys	0m37.017s
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When dealing with a list of dismantling netns, we can scan
tcp_metrics once, saving cpu cycles.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Having a global list of labels do not scale to thousands of
netns in the cloud era. This causes quadratic behavior on
netns creation and deletion.

This is time having a per netns list of ~10 labels.

Tested:

$ time perf record (for f in `seq 1 3000` ; do ip netns add tast$f; done)
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 3.637 MB perf.data (~158898 samples) ]

real    0m20.837s # instead of 0m24.227s
user    0m0.328s
sys     0m20.338s # instead of 0m23.753s

    16.17%       ip  [kernel.kallsyms]  [k] netlink_broadcast_filtered
    12.30%       ip  [kernel.kallsyms]  [k] netlink_has_listeners
     6.76%       ip  [kernel.kallsyms]  [k] _raw_spin_lock_irqsave
     5.78%       ip  [kernel.kallsyms]  [k] memset_erms
     5.77%       ip  [kernel.kallsyms]  [k] kobject_uevent_env
     5.18%       ip  [kernel.kallsyms]  [k] refcount_sub_and_test
     4.96%       ip  [kernel.kallsyms]  [k] _raw_read_lock
     3.82%       ip  [kernel.kallsyms]  [k] refcount_inc_not_zero
     3.33%       ip  [kernel.kallsyms]  [k] _raw_spin_unlock_irqrestore
     2.11%       ip  [kernel.kallsyms]  [k] unmap_page_range
     1.77%       ip  [kernel.kallsyms]  [k] __wake_up
     1.69%       ip  [kernel.kallsyms]  [k] strlen
     1.17%       ip  [kernel.kallsyms]  [k] __wake_up_common
     1.09%       ip  [kernel.kallsyms]  [k] insert_header
     1.04%       ip  [kernel.kallsyms]  [k] page_remove_rmap
     1.01%       ip  [kernel.kallsyms]  [k] consume_skb
     0.98%       ip  [kernel.kallsyms]  [k] netlink_trim
     0.51%       ip  [kernel.kallsyms]  [k] kernfs_link_sibling
     0.51%       ip  [kernel.kallsyms]  [k] filemap_map_pages
     0.46%       ip  [kernel.kallsyms]  [k] memcpy_erms
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We can build one skb and let it be cloned in netlink.

This is much faster, and use less memory (all clones will
share the same skb->head)

Tested:

time perf record (for f in `seq 1 3000` ; do ip netns add tast$f; done)
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 4.110 MB perf.data (~179584 samples) ]

real    0m24.227s # instead of 0m52.554s
user    0m0.329s
sys 0m23.753s # instead of 0m51.375s

    14.77%       ip  [kernel.kallsyms]  [k] __ip6addrlbl_add
    14.56%       ip  [kernel.kallsyms]  [k] netlink_broadcast_filtered
    11.65%       ip  [kernel.kallsyms]  [k] netlink_has_listeners
     6.19%       ip  [kernel.kallsyms]  [k] _raw_spin_lock_irqsave
     5.66%       ip  [kernel.kallsyms]  [k] kobject_uevent_env
     4.97%       ip  [kernel.kallsyms]  [k] memset_erms
     4.67%       ip  [kernel.kallsyms]  [k] refcount_sub_and_test
     4.41%       ip  [kernel.kallsyms]  [k] _raw_read_lock
     3.59%       ip  [kernel.kallsyms]  [k] refcount_inc_not_zero
     3.13%       ip  [kernel.kallsyms]  [k] _raw_spin_unlock_irqrestore
     1.55%       ip  [kernel.kallsyms]  [k] __wake_up
     1.20%       ip  [kernel.kallsyms]  [k] strlen
     1.03%       ip  [kernel.kallsyms]  [k] __wake_up_common
     0.93%       ip  [kernel.kallsyms]  [k] consume_skb
     0.92%       ip  [kernel.kallsyms]  [k] netlink_trim
     0.87%       ip  [kernel.kallsyms]  [k] insert_header
     0.63%       ip  [kernel.kallsyms]  [k] unmap_page_range
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

No need to iterate over strings, just copy in one efficient memcpy() call.

Tested:
time perf record "(for f in `seq 1 3000` ; do ip netns add tast$f; done)"
[ perf record: Woken up 10 times to write data ]
[ perf record: Captured and wrote 8.224 MB perf.data (~359301 samples) ]

real    0m52.554s  # instead of 1m7.492s
user    0m0.309s
sys 0m51.375s # instead of 1m6.875s

     9.88%       ip  [kernel.kallsyms]  [k] netlink_broadcast_filtered
     8.86%       ip  [kernel.kallsyms]  [k] string
     7.37%       ip  [kernel.kallsyms]  [k] __ip6addrlbl_add
     5.68%       ip  [kernel.kallsyms]  [k] netlink_has_listeners
     5.52%       ip  [kernel.kallsyms]  [k] memcpy_erms
     4.76%       ip  [kernel.kallsyms]  [k] __alloc_skb
     4.54%       ip  [kernel.kallsyms]  [k] vsnprintf
     3.94%       ip  [kernel.kallsyms]  [k] format_decode
     3.80%       ip  [kernel.kallsyms]  [k] kmem_cache_alloc_node_trace
     3.71%       ip  [kernel.kallsyms]  [k] kmem_cache_alloc_node
     3.66%       ip  [kernel.kallsyms]  [k] kobject_uevent_env
     3.38%       ip  [kernel.kallsyms]  [k] strlen
     2.65%       ip  [kernel.kallsyms]  [k] _raw_spin_lock_irqsave
     2.20%       ip  [kernel.kallsyms]  [k] kfree
     2.09%       ip  [kernel.kallsyms]  [k] memset_erms
     2.07%       ip  [kernel.kallsyms]  [k] ___cache_free
     1.95%       ip  [kernel.kallsyms]  [k] kmem_cache_free
     1.91%       ip  [kernel.kallsyms]  [k] _raw_read_lock
     1.45%       ip  [kernel.kallsyms]  [k] ksize
     1.25%       ip  [kernel.kallsyms]  [k] _raw_spin_unlock_irqrestore
     1.00%       ip  [kernel.kallsyms]  [k] widen_string
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This removes some #ifdef pollution and will ease follow up patches.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

gen estimator has been rewritten in commit 1c0d32fd
("net_sched: gen_estimator: complete rewrite of rate estimators"),
the caller no longer needs to wait for a grace period. So this
patch gets rid of it.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If the hash to port mapping table does not have a valid port (i.e. when
a port goes down), fall back to the simple hashing mechanism to avoid
dropping packets.
Signed-off-by: NJim Hanko <hanko@drivescale.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Florian Westphal says:

====================
test_rhashtable: don't allocate huge static array

Add a test case for the rhlist interface.
While at it, cleanup current rhashtable test a bit and add a check
for max_size support.

No changes since v1, except in last patch.
kbuild robot complained about large onstack allocation caused by
struct rhltable when lockdep is enabled.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

also test rhltable.  rhltable remove operations are slow as
deletions require a list walk, thus test with 1/16th of the given
entry count number to get a run duration similar to rhashtable one.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

add a test that tries to insert more than max_size elements.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

pass the entries to test as an argument instead.
Followup patch will add an rhlist test case; rhlist delete opererations
are slow so we need to use a smaller number to test it.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Florian Fainelli says:

====================
net: dsa: b53/bcm_sf2 cleanups

This patch series is a first pass set of clean-ups to reduce the number of LOCs
between b53 and bcm_sf2 and sharing as many functions as possible.

There is a number of additional cleanups queued up locally that require more
thorough testing.

Changes in v3:

- remove one extra argument for the b53_build_io_op macro (David Laight)
- added additional Reviewed-by tags from Vivien

Changes in v2:

- added Reviewed-by tags from Vivien
- added a missing EXPORT_SYMBOL() in patch 8
- fixed a typo in patch 5
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Export b53_{enable,disable}_port and use these two functions in
bcm_sf2_port_setup and bcm_sf2_port_disable. The generic functions
cannot be used without wrapping because we need to manage additional
switch integration details (PHY, Broadcom tag etc.).
Reviewed-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The magic number 8 in 3 locations in bcm_sf2_cfp.c actually designates
the number of switch port egress queues, so use that define instead of
open-coding it.
Reviewed-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

bcm_sf2 and b53 do exactly the same thing, so share that piece.
Reviewed-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add support for enabling and disabling EEE, as well as re-negotiating it in
.adjust_link() and in .port_enable().
Reviewed-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move the bcm_sf2 EEE-related functions to the b53 driver because this is shared
code amongst Gigabit capable switch, only 5325 and 5365 are too old to support
that.
Reviewed-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In preparation for migrating the EEE code from bcm_sf2 to b53, define the full
EEE register page and offsets within that page.
Reviewed-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The code to enable Broadcom tags/headers is largely switch independent,
and in preparation for enabling it for multiple devices with b53, move
the code we have in bcm_sf2.c to b53_common.c
Reviewed-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of repeating the same pattern: acquire mutex, read/write,
release mutex, define a macro: b53_build_op() which takes the type
(read|write), I/O size, and value (scalar or pointer). This helps with
fixing bugs that could exist (e.g: missing barrier, lock etc.).
Reviewed-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is no need to configure the enabled ports once in bcm_sf2_sw_setup() and
then a second time around when dsa_switch_ops::port_enable is called, just do
it when port_enable is called which is better in terms of power consumption and
correctness.
Reviewed-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is no need to configure the enabled ports once in b53_setup() and then a
second time around when dsa_switch_ops::port_enable is called, just do it when
port_enable is called which is better in terms of power consumption and
correctness.
Reviewed-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In preparation for future changes allowing the configuring of multiple
CPU ports, make b53_enable_cpu_port() take a port argument.
Reviewed-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is not used anywhere, so remove it.
Reviewed-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Vivien Didelot says:

====================
net: dsa: move master ethtool code

The DSA core overrides the master device's ethtool_ops structure so that
it can inject statistics and such of its dedicated switch CPU port.

This ethtool code is currently called on unnecessary conditions or
before the master interface and its switch CPU port get wired up.
This patchset fixes this.

Similarly to slave.c where the DSA slave net_device is the entry point
of the dsa_slave_* functions, this patchset also isolates the master's
ethtool code in a new master.c file, where the DSA master net_device is
the entry point of the dsa_master_* functions.

This is a first step towards better control of the master device and
support for multiple CPU ports.
====================
Tested-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

DSA overrides the master device ethtool ops, so that it can inject stats
from its dedicated switch CPU port as well.

The related code is currently split in dsa.c and slave.c, but it only
scopes the master net device. Move it to a new master.c DSA core file.

This file will be later extented with master net device specific code.
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

DSA overrides the master's ethtool ops so that we can inject its CPU
port's statistics. Because of that, we need to setup the ethtool ops
after the master's dsa_ptr pointer has been assigned, not before.

This patch setups the ethtool ops after dsa_ptr is assigned, and
restores them before it gets cleared.
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a DSA switch tree is meant to be applied, it already has a CPU
port. Thus remove the condition of dst->cpu_dp.

Moreover, the next lines access dst->cpu_dp unconditionally.
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>