And fix a couple of buglets (port option processing,
clean termination on SIGINT). This is preparatory work
for GRO tests.

rfc v2 -> rfc v3:
 - use ETH_MAX_MTU

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In some scenarios, the GRO engine can assemble an UDP GRO packet
that ultimately lands on a non GRO-enabled socket.
This patch tries to address the issue explicitly checking for the UDP
socket features before enqueuing the packet, and eventually segmenting
the unexpected GRO packet, as needed.

We must also cope with re-insertion requests: after segmentation the
UDP code calls the helper introduced by the previous patches, as needed.

Segmentation is performed by a common helper, which takes care of
updating socket and protocol stats is case of failure.

rfc v3 -> v1
 - fix compile issues with rxrpc
 - when gso_segment returns NULL, treat is as an error
 - added 'ipv4' argument to udp_rcv_segment()

rfc v2 -> rfc v3
 - moved udp_rcv_segment() into net/udp.h, account errors to socket
   and ns, always return NULL or segs list

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

So that we can re-use it at the UDP level in the next patch

rfc v3 -> v1:
 - add the helper declaration into the ipv6 header

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

So that we can re-use it at the UDP level in a later patch

rfc v3 -> v1
 - add the helper declaration into the ip header

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When UDP GRO is enabled, the UDP_GRO cmsg will carry the ingress
datagram size. User-space can use such info to compute the original
packets layout.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This is the RX counterpart of commit bec1f6f6

 ("udp: generate gso
with UDP_SEGMENT"). When UDP_GRO is enabled, such socket is also
eligible for GRO in the rx path: UDP segments directed to such socket
are assembled into a larger GSO_UDP_L4 packet.

The core UDP GRO support is enabled with setsockopt(UDP_GRO).

Initial benchmark numbers:

Before:
udp rx:   1079 MB/s   769065 calls/s

After:
udp rx:   1466 MB/s    24877 calls/s

This change introduces a side effect in respect to UDP tunnels:
after a UDP tunnel creation, now the kernel performs a lookup per ingress
UDP packet, while before such lookup happened only if the ingress packet
carried a valid internal header csum.

rfc v2 -> rfc v3:
 - fixed typos in macro name and comments
 - really enforce UDP_GRO_CNT_MAX, instead of UDP_GRO_CNT_MAX + 1
 - acquire socket lock in UDP_GRO setsockopt

rfc v1 -> rfc v2:
 - use a new option to enable UDP GRO
 - use static keys to protect the UDP GRO socket lookup

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The *encap_needed static keys are enabled by UDP tunnels
and several UDP encapsulations type, but they are never
turned off. This can cause unneeded overall performance
degradation for systems where such features are used
transiently.

This patch introduces complete book-keeping for such keys,
decreasing the usage at socket destruction time, if needed,
and avoiding that the same socket could increase the key
usage multiple times.

rfc v3 -> v1:
 - add socket lock around udp_tunnel_encap_enable()

rfc v2 -> rfc v3:
 - use udp_tunnel_encap_enable() in setsockopt()

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Mike Manning says:

====================
vrf: allow simultaneous service instances in default and other VRFs

Services currently have to be VRF-aware if they are using an unbound
socket. One cannot have multiple service instances running in the
default and other VRFs for services that are not VRF-aware and listen
on an unbound socket. This is because there is no easy way of isolating
packets received in the default VRF from those arriving in other VRFs.

This series provides this isolation for stream sockets subject to the
existing kernel parameter net.ipv4.tcp_l3mdev_accept not being set,
given that this is documented as allowing a single service instance to
work across all VRF domains. Similarly, net.ipv4.udp_l3mdev_accept is
checked for datagram sockets, and net.ipv4.raw_l3mdev_accept is
introduced for raw sockets. The functionality applies to UDP & TCP
services as well as those using raw sockets, and is for IPv4 and IPv6.

Example of running ssh instances in default and blue VRF:

$ /usr/sbin/sshd -D
$ ip vrf exec vrf-blue /usr/sbin/sshd
$ ss -ta | egrep 'State|ssh'
State   Recv-Q   Send-Q           Local Address:Port       Peer Address:Port
LISTEN  0        128           0.0.0.0%vrf-blue:ssh             0.0.0.0:*
LISTEN  0        128                    0.0.0.0:ssh             0.0.0.0:*
ESTAB   0        0              192.168.122.220:ssh       192.168.122.1:50282
LISTEN  0        128              [::]%vrf-blue:ssh                [::]:*
LISTEN  0        128                       [::]:ssh                [::]:*
ESTAB   0        0           [3000::2]%vrf-blue:ssh           [3000::9]:45896
ESTAB   0        0                    [2000::2]:ssh           [2000::9]:46398

v1:
   - Address Paolo Abeni's comments (patch 4/5)
   - Fix build when CONFIG_NET_L3_MASTER_DEV not defined (patch 1/5)
v2:
   - Address David Aherns' comments (patches 4/5 and 5/5)
   - Remove patches 3/5 and 5/5 from series for individual submissions
   - Include a sysctl for raw sockets as recommended by David Ahern
   - Expand series into 10 patches and provide improved descriptions
v3:
   - Update description for patch 1/10 and remove patch 6/10
v4:
   - Set default to enabled for raw socket sysctl as recommended by David Ahern
v5:
   - Address review comments from David Ahern in patches 2-5
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

For bound udp sockets in a vrf, also check the sdif to get the index
for ingress devices enslaved to an l3mdev.

Signed-off-by: Dewi Morgan <morgand@vyatta.att-mail.com>
Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If the skb for multicast packets marked as enslaved to a VRF are
received, then the secondary device index should be used to obtain
the real device. And verify the multicast address against the
enslaved rather than the l3mdev device.

Signed-off-by: Dewi Morgan <morgand@vyatta.att-mail.com>
Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If link-local packets are marked as enslaved to a VRF, then to allow
ping to the link-local from a vrf, the error handling for IPV6_PKTINFO
needs to be relaxed to also allow the pkt ipi6_ifindex to be that of a
slave device to the vrf.

Note that the real device also needs to be retrieved in icmp6_iif()
to set the ipv6 flow oif to this for icmp echo reply handling. The
recent commit 24b711ed

 ("net/ipv6: Fix linklocal to global address
with VRF") takes care of this, so the sdif does not need checking here.

This fix makes ping to link-local consistent with that to global
addresses, in that this can now be done from within the same VRF that
the address is in.

Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The skb for packets that are multicast or to a link-local address are
not marked as being enslaved to a VRF, if they are received on a socket
bound to the VRF. This is needed for ND and it is preferable for the
kernel not to have to deal with the additional use-cases if ll or mcast
packets are handled as enslaved. However, this does not allow service
instances listening on unbound and bound to VRF sockets to distinguish
the VRF used, if packets are sent as multicast or to a link-local
address. The fix is for the VRF driver to also mark these skb as being
enslaved to the VRF.

Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When there exist a pair of raw sockets one unbound and one bound
to a VRF but equal in all other respects, when a packet is received
in the VRF context, __raw_v4_lookup() matches on both sockets.

This results in the packet being delivered over both sockets,
instead of only the raw socket bound to the VRF. The bound device
checks in __raw_v4_lookup() are replaced with a call to
raw_sk_bound_dev_eq() which correctly handles whether the packet
should be delivered over the unbound socket in such cases.

In __raw_v6_lookup() the match on the device binding of the socket is
similarly updated to use raw_sk_bound_dev_eq() which matches the
handling in __raw_v4_lookup().

Importantly raw_sk_bound_dev_eq() takes the raw_l3mdev_accept sysctl
into account.

Signed-off-by: Duncan Eastoe <deastoe@vyatta.att-mail.com>
Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add a sysctl raw_l3mdev_accept to control raw socket lookup in a manner
similar to use of tcp_l3mdev_accept for stream and of udp_l3mdev_accept
for datagram sockets. Have this default to enabled for reasons of
backwards compatibility. This is so as to specify the output device
with cmsg and IP_PKTINFO, but using a socket not bound to the
corresponding VRF. This allows e.g. older ping implementations to be
run with specifying the device but without executing it in the VRF.
If the option is disabled, packets received in a VRF context are only
handled by a raw socket bound to the VRF, and correspondingly packets
in the default VRF are only handled by a socket not bound to any VRF.

Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ensure an unbound datagram skt is chosen when not in a VRF. The check
for a device match in compute_score() for UDP must be performed when
there is no device match. For this, a failure is returned when there is
no device match. This ensures that bound sockets are never selected,
even if there is no unbound socket.

Allow IPv6 packets to be sent over a datagram skt bound to a VRF. These
packets are currently blocked, as flowi6_oif was set to that of the
master vrf device, and the ipi6_ifindex is that of the slave device.
Allow these packets to be sent by checking the device with ipi6_ifindex
has the same L3 scope as that of the bound device of the skt, which is
the master vrf device. Note that this check always succeeds if the skt
is unbound.

Even though the right datagram skt is now selected by compute_score(),
a different skt is being returned that is bound to the wrong vrf. The
difference between these and stream sockets is the handling of the skt
option for SO_REUSEPORT. While the handling when adding a skt for reuse
correctly checks that the bound device of the skt is a match, the skts
in the hashslot are already incorrect. So for the same hash, a skt for
the wrong vrf may be selected for the required port. The root cause is
that the skt is immediately placed into a slot when it is created,
but when the skt is then bound using SO_BINDTODEVICE, it remains in the
same slot. The solution is to move the skt to the correct slot by
forcing a rehash.

Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The commit a04a480d

 ("net: Require exact match for TCP socket
lookups if dif is l3mdev") only ensures that the correct socket is
selected for packets in a VRF. However, there is no guarantee that
the unbound socket will be selected for packets when not in a VRF.
By checking for a device match in compute_score() also for the case
when there is no bound device and attaching a score to this, the
unbound socket is selected. And if a failure is returned when there
is no device match, this ensures that bound sockets are never selected,
even if there is no unbound socket.

Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Change the inet socket lookup to avoid packets arriving on a device
enslaved to an l3mdev from matching unbound sockets by removing the
wildcard for non sk_bound_dev_if and instead relying on check against
the secondary device index, which will be 0 when the input device is
not enslaved to an l3mdev and so match against an unbound socket and
not match when the input device is enslaved.

Change the socket binding to take the l3mdev into account to allow an
unbound socket to not conflict sockets bound to an l3mdev given the
datapath isolation now guaranteed.

Signed-off-by: Robert Shearman <rshearma@vyatta.att-mail.com>
Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c: In function 'hclge_log_and_clear_ppp_error':
drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_err.c:821:24: warning:
 variable 'reset_level' set but not used [-Wunused-but-set-variable]
  enum hnae3_reset_type reset_level = HNAE3_NONE_RESET;

It never used since introduction in commit
01865a50

 ("net: hns3: Add enable and process hw errors of TM scheduler")

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jakub Kicinski says:

====================
nfp: more set actions and notifier refactor

This series brings updates to flower offload code.  First Pieter adds
support for setting TTL, ToS, Flow Label and Hop Limit fields in IPv4
and IPv6 headers.

Remaining 5 patches deal with factoring out netdev notifiers from flower
code.  We already have two instances, and more is coming, so it's time
to move to one central notifier which then feeds individual feature
handlers.

I start that part by cleaning up the existing notifiers.  Next a central
notifier is added, and used by flower offloads.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

Use driver's common notifier for LAG and tunnel configuration.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Code interested in networking events registers its own notifier
handlers.  Create one device-wide notifier instance.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp_fl_lag_changels_event() never fails, and therefore we would
never return NOTIFY_BAD for NETDEV_CHANGELOWERSTATE.  Make this
clearer by changing nfp_fl_lag_changels_event()'s return type
to void.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Returning an error from a notifier means we want to veto the change.
We shouldn't veto NETDEV_UNREGISTER just because we couldn't find
the tracking info for given master.

I can't seem to find a way to trigger this unless we have some
other bug, so it's probably not fix-worthy.

While at it move the checking if the netdev really is of interest
into the handling functions, like we do for other events.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

For flower tunnel offloads FW has to be informed about MAC addresses
of tunnel devices.  We use a netdev notifier to keep track of these
addresses.

Remove unnecessary loop over netdevices after notifier is registered.
The intention of the loop was to catch devices which already existed
on the system before nfp driver got loaded, but netdev notifier will
replay NETDEV_REGISTER events.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add ipv6 set flow label and hop limit action offload. Since pedit sets
headers per 4 byte word, we need to ensure that setting either version,
priority, payload_len or nexthdr does not get offloaded.

Signed-off-by: Pieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add ipv4 set ttl and tos action offload. Since pedit sets headers per 4
byte word, we need to ensure that setting either version, ihl, protocol,
total length or checksum does not get offloaded.

Signed-off-by: Pieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Huazhong Tan says:

====================
hns3: provide new interfaces & bugfixes & code optimization

This patchset provides some reset interfaces for RAS & RoCE, also
some bugfixes and optimization related to reset.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

It is not necessary to reallocate the descriptor and remap the
descriptor memory in reset process, otherwise it may cause memory
not freed problem.

Also, this patch initializes the cmd queue's spinlocks in
hclgevf_alloc_cmd_queue, and take the spinlocks when reinitializing
cmd queue' registers.

Fixes: fedd0c15

 ("net: hns3: Add HNS3 VF IMP(Integrated Management Proc) cmd interface")
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When hclge_reset() is called, it may fail for several reasons.
For example, an higher-level reset event occurs, memory allocation
failure, hardware reset timeout, etc. Therefore, it is necessary
to add corresponding error handling for these situations.
1. A high-level reset is required due to a high-level reset failure.
2. For memory allocation failure, a high-level reset is initiated by
the timer to recover. The reason for using the timer is to prevent this
new high-level reset to interrupt the reset process of other pf/vf;
3. For the case of hardware reset timeout, reschedule the reset task
to wait for the hardware to complete the reset.
For memory allocation failure and reset timeouts, in order to prevent
an infinite number of scheduled reset tasks, the number of error
recovery needs to be limited.

This patch also add some reset related debug log printing.

Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

While doing resetting, roce should do its uninitailization part
before nic's, and do its initialization part after nic's.

Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When doing PF reset, the driver needs to do some preparatory work
before asserting PF reset. Since when hardware is resetting, it
is necessary to stop tx/rx queue, clear hardware table, etc,
otherwise hardware may run into unrecoverable state if there is
still IO running when the hardware is resetting.

Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Saving reset related information in the hclge_dev/hclgevf_dev
structure is more suitable than the hnae3_handle, since hardware
related information is kept in these two structure.

Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When processing a higher level reset, the pending lower level reset
does not have to be processed anymore, because the higher level
reset is the superset of the lower level reset.

Therefore, when processing an higher level reset, the request of
lower level reset needs to be cleared.

Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

While hclge is going to reset, it will notify its client with
HNAE3_DOWN_CLIENT, so this client should get into a resetting
status from this moment, other operations from the stack need to
be blocked as well. And when the reset is finished, the client
will be notified with HNAE3_UP_CLIENT, so this is the end of
the resetting status.

This patch uses HNS3_NIC_STATE_RESETTING flag to implement that,
and adds hns3_nic_resetting() to indicate which operation is not
allowed.

Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

While hardware gets into reset status, the firmware will not respond to
driver's command request, which may cause ring not disabled problem
during reset process.

So this patch uses register instead of command to enable/disable the ring
in the enet while doing UP/DOWN operation.

Also, HNS3_RING_RX_VM_REG is previously unused, so change it to the
correct meaning, and add a wrapper function for readl().

Fixes: 46a3df9f

 ("net: hns3: Add HNS3 Acceleration Engine & Compatibility Layer Support")
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When doing a function reset, the hardware table should be cleared
before the hardware reset. In current code, this clearing is done
in hns3_reset_notify_uninit_enet, but it is too late, because
the hardware reset is already done, hns3_reset_notify_down_enet
is more suitable to do that.

Fixes: bb6b94a8

 ("net: hns3: Add reset interface implementation in client")
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The client needs to know if the hardware is resetting when
loading or unloading itself, because client may abort the loading
process or wait for the reset process to finish when unloading
if hardware is resetting.

So this patch provides these interfaces to do it.
1. get_hw_reset_stat, the reset status of hardware.
2. ae_dev_resetting, whether reset task is scheduling.
3. ae_dev_reset_cnt, how many reset has been done.

Also, the RoCE client needs some field in the hnae3_roce_private_info
to save its state, and process_hw_error interface in the
hnae3_client_ops to process hardware errors.

Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, when reset_event is called because of tx timeout, it will
upgrade the reset level (For PF, HNAE3_FUNC_RESET -> HNAE3_CORE_RESET
-> HNAE3_GLOBAL_RESET) if the time between the new reset and last reset
is within 20 secs, or restore the reset level to HNAE3_FUNC_RESET if
the time between the new reset and last reset is over 20 secs.

There is requirement that the caller needs to decide the reset level
when triggering a reset, for example, RAS recovery. So this patch
adds the set_default_reset_request to meet this requirement.

Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Besides of module_init and module_exit, the process of reset will
also uninitialize and initialize the enet client. When reset process
fails with enet client uninitialized, the module_exit does not need
to uninitialize the enet client, otherwise it may cause double
uninitialization problem.

So we need the HNS3_NIC_STATE_INITED flag to indicate whether
the enet client is initialized.

Also HNS3_NIC_STATE_REINITING is previously unused, so change it to
HNS3_NIC_STATE_INITED.

Fixes: bb6b94a8

 ("net: hns3: Add reset interface implementation in client")
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Florian Fainelli says:

====================
net: systemport: Unmap queues upon DSA unregister event

This patch series fixes the unbinding/binding of the bcm_sf2 switch
driver along with bcmsysport which monitors the switch port queues.
Because the driver was not processing the DSA_PORT_UNREGISTER event, we
would not be unmapping switch port/queues, which could cause incorrect
decisions to be made by the HW (e.g: queue always back-pressured).
====================

Signed-off-by: David S. Miller <davem@davemloft.net>