The previous commit added the ability to throttle stations when they queue
too much airtime in the hardware. This commit enables the functionality by
calculating the expected airtime usage of each packet that is dequeued from
the TXQs in mac80211, and accounting that as pending airtime.

The estimated airtime for each skb is stored in the tx_info, so we can
subtract the same amount from the running total when the skb is freed or
recycled. The throttling mechanism relies on this accounting to be
accurate (i.e., that we are not freeing skbs without subtracting any
airtime they were accounted for), so we put the subtraction into
ieee80211_report_used_skb(). As an optimisation, we also subtract the
airtime on regular TX completion, zeroing out the value stored in the
packet afterwards, to avoid having to do an expensive lookup of the station
from the packet data on every packet.

This patch does *not* include any mechanism to wake a throttled TXQ again,
on the assumption that this will happen anyway as a side effect of whatever
freed the skb (most commonly a TX completion).
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20191119060610.76681-5-kyan@google.comSigned-off-by: Johannes Berg <johannes.berg@intel.com>

In order for the Fq_CoDel algorithm integrated in mac80211 layer to operate
effectively to control excessive queueing latency, the CoDel algorithm
requires an accurate measure of how long packets stays in the queue, AKA
sojourn time. The sojourn time measured at the mac80211 layer doesn't
include queueing latency in the lower layer (firmware/hardware) and CoDel
expects lower layer to have a short queue. However, most 802.11ac chipsets
offload tasks such TX aggregation to firmware or hardware, thus have a deep
lower layer queue.

Without a mechanism to control the lower layer queue size, packets only
stay in mac80211 layer transiently before being sent to firmware queue.
As a result, the sojourn time measured by CoDel in the mac80211 layer is
almost always lower than the CoDel latency target, hence CoDel does little
to control the latency, even when the lower layer queue causes excessive
latency.

The Byte Queue Limits (BQL) mechanism is commonly used to address the
similar issue with wired network interface. However, this method cannot be
applied directly to the wireless network interface. "Bytes" is not a
suitable measure of queue depth in the wireless network, as the data rate
can vary dramatically from station to station in the same network, from a
few Mbps to over Gbps.

This patch implements an Airtime-based Queue Limit (AQL) to make CoDel work
effectively with wireless drivers that utilized firmware/hardware
offloading. AQL allows each txq to release just enough packets to the lower
layer to form 1-2 large aggregations to keep hardware fully utilized and
retains the rest of the frames in mac80211 layer to be controlled by the
CoDel algorithm.
Signed-off-by: Kan Yan <kyan@google.com>
[ Toke: Keep API to set pending airtime internal, fix nits in commit msg ]
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20191119060610.76681-4-kyan@google.comSigned-off-by: Johannes Berg <johannes.berg@intel.com>

Felix recently added code to calculate airtime of packets to the mt76
driver. Import this into mac80211 so we can use it for airtime queue limit
calculations.

The airtime.c file is copied verbatim from the mt76 driver, and adjusted to
be usable in mac80211. This involves:

- Switching to mac80211 data structures.
- Adding support for 160 MHz channels and HE mode.
- Moving the symbol and duration calculations around a bit to avoid
  rounding with the higher rates and longer symbol times used for HE rates.

The per-rate TX rate calculation is also split out to its own function so
it can be used directly for the AQL calculations later.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20191119060610.76681-3-kyan@google.com
[fix HE_GROUP_IDX() to use 3 * bw, since there are 3 _gi values]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

When virt_wifi interface is created, virt_wifi_newlink() is called and
it calls register_netdevice().
if register_netdevice() fails, it internally would call
->priv_destructor(), which is virt_wifi_net_device_destructor() and
it frees netdev. but virt_wifi_newlink() still use netdev.
So, use-after-free would occur in virt_wifi_newlink().

Test commands:
    ip link add dummy0 type dummy
    modprobe bonding
    ip link add bonding_masters link dummy0 type virt_wifi

Splat looks like:
[  202.220554] BUG: KASAN: use-after-free in virt_wifi_newlink+0x88b/0x9a0 [virt_wifi]
[  202.221659] Read of size 8 at addr ffff888061629cb8 by task ip/852

[  202.222896] CPU: 1 PID: 852 Comm: ip Not tainted 5.4.0-rc5 #3
[  202.223765] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[  202.225073] Call Trace:
[  202.225532]  dump_stack+0x7c/0xbb
[  202.226869]  print_address_description.constprop.5+0x1be/0x360
[  202.229362]  __kasan_report+0x12a/0x16f
[  202.230714]  kasan_report+0xe/0x20
[  202.232595]  virt_wifi_newlink+0x88b/0x9a0 [virt_wifi]
[  202.233370]  __rtnl_newlink+0xb9f/0x11b0
[  202.244909]  rtnl_newlink+0x65/0x90
[ ... ]

Cc: stable@vger.kernel.org
Fixes: c7cdba31 ("mac80211-next: rtnetlink wifi simulation device")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Link: https://lore.kernel.org/r/20191121122645.9355-1-ap420073@gmail.com
[trim stack dump a bit]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Commit 7b6ddeaf ("mac80211: use QoS NDP for AP probing")
let STAs send QoS Null frames as PS triggers if the AP was
a QoS STA.  However, the mac80211 PS stack relies on an
interface flag IEEE80211_STA_NULLFUNC_ACKED for
determining trigger frame ACK, which was not being set for
acked non-QoS Null frames. The effect is an inability to
trigger hardware sleep via IEEE80211_CONF_PS since the QoS
Null frame was seemingly never acked.

This bug only applies to drivers which set both
IEEE80211_HW_REPORTS_TX_ACK_STATUS and
IEEE80211_HW_PS_NULLFUNC_STACK.

Detect the acked QoS Null frame to restore STA power save.

Fixes: 7b6ddeaf ("mac80211: use QoS NDP for AP probing")
Signed-off-by: Thomas Pedersen <thomas@adapt-ip.com>
Link: https://lore.kernel.org/r/20191119053538.25979-4-thomas@adapt-ip.comSigned-off-by: Johannes Berg <johannes.berg@intel.com>

This is useful during testing to eg. check the currently
configured HW power save state.
Signed-off-by: Thomas Pedersen <thomas@adapt-ip.com>
Link: https://lore.kernel.org/r/20191119053538.25979-3-thomas@adapt-ip.comSigned-off-by: Johannes Berg <johannes.berg@intel.com>

In ieee80211_tx_status() we don't have an sdata struct when looking up the
destination sta. Instead, we just do a lookup by the vif addr that is the
source of the packet being completed. Factor this out into a new sta_info
getter helper, since we need to use it for accounting AQL as well.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20191112130835.382062-1-toke@redhat.com
[remove internal rcu_read_lock(), document instead]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Add a note with a use-case for the monitor-to-dev injection
mechanism in mac80211, reported by Ben Greear.

Change-Id: I6456997ef9bc40b24ede860b6ef2fed5af49cf44
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

While using ARCH=mips CROSS_COMPILE=mips-linux-gnu- command to compile,
make C=2 drivers/net/ethernet/freescale/enetc/enetc.o

one warning can be found:
drivers/net/ethernet/freescale/enetc/enetc.c:1439:5:
warning: symbol 'enetc_setup_tc_mqprio' was not declared.
Should it be static?

This patch make symbol enetc_setup_tc_mqprio static.
Fixes: 34c6adf1 ("enetc: Configure the Time-Aware Scheduler via tc-taprio offload")
Signed-off-by: Mao Wenan <maowenan@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Paolo Abeni says:

====================
net: introduce and use route hint

This series leverages the listification infrastructure to avoid
unnecessary route lookup on ingress packets. In absence of custom rules,
packets with equal daddr will usually land on the same dst.

When processing packet bursts (lists) we can easily reference the previous
dst entry. When we hit the 'same destination' condition we can avoid the
route lookup, coping the already available dst.

Detailed performance numbers are available in the individual commit
messages.

v3 -> v4:
 - move helpers to their own patches (Eric D.)
 - enable hints for SUBTREE builds (David A.)
 - re-enable hints for ipv4 forward (David A.)

v2 -> v3:
 - use fib*_has_custom_rules() helpers (David A.)
 - add ip*_extract_route_hint() helper (Edward C.)
 - use prev skb as hint instead of copying data (Willem )

v1 -> v2:
 - fix build issue with !CONFIG_IP*_MULTIPLE_TABLES
 - fix potential race in ip6_list_rcv_finish()
====================
Acked-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This is alike the previous change, with some additional ipv4 specific
quirk. Even when using the route hint we still have to do perform
additional per packet checks about source address validity: a new
helper is added to wrap them.

Hints are explicitly disabled if the destination is a local broadcast,
that keeps the code simple and local broadcast are a slower path anyway.

UDP flood performances vs recvmmsg() receiver:

vanilla		patched		delta
Kpps		Kpps		%
1683		1871		+11

In the worst case scenario - each packet has a different
destination address - the performance delta is within noise
range.

v3 -> v4:
 - re-enable hints for forward

v2 -> v3:
 - really fix build (sic) and hint usage check
 - use fib4_has_custom_rules() helpers (David A.)
 - add ip_extract_route_hint() helper (Edward C.)
 - use prev skb as hint instead of copying data (Willem)

v1 -> v2:
 - fix build issue with !CONFIG_IP_MULTIPLE_TABLES
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

So that we can use it in the next patch.
Additionally constify the helper argument.
Suggested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When doing RX batch packet processing, we currently always repeat
the route lookup for each ingress packet. When no custom rules are
in place, and there aren't routes depending on source addresses,
we know that packets with the same destination address will use
the same dst.

This change tries to avoid per packet route lookup caching
the destination address of the latest successful lookup, and
reusing it for the next packet when the above conditions are
in place. Ingress traffic for most servers should fit.

The measured performance delta under UDP flood vs a recvmmsg
receiver is as follow:

vanilla		patched		delta
Kpps		Kpps		%
1431		1674		+17

In the worst-case scenario - each packet has a different
destination address - the performance delta is within noise
range.

v3 -> v4:
 - support hints for SUBFLOW build, too (David A.)
 - several style fixes (Eric)

v2 -> v3:
 - add fib6_has_custom_rules() helpers (David A.)
 - add ip6_extract_route_hint() helper (Edward C.)
 - use hint directly in ip6_list_rcv_finish() (Willem)

v1 -> v2:
 - fix build issue with !CONFIG_IPV6_MULTIPLE_TABLES
 - fix potential race when fib6_has_custom_rules is set
   while processing a packet batch
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use a per namespace counter, increment it on successful creation
of any route using the source address, decrement it on deletion
of such routes.

This allows us to check easily if the routing decision in the
current namespace depends on the packet source. Will be used
by the next patch.
Suggested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

It wraps the namespace field with the same name, to easily
access it regardless of build options.
Suggested-by: David Ahern <dsahern@gmail.com>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Yangbo Lu says:

====================
Support PTP clock and hardware timestamping for DSA Felix driver

This patch-set is to support PTP clock and hardware timestamping
for DSA Felix driver. Some functions in ocelot.c/ocelot_board.c
driver were reworked/exported, so that DSA Felix driver was able
to reuse them as much as possible.

On TX path, timestamping works on packet which requires timestamp.
The injection header will be configured accordingly, and skb clone
requires timestamp will be added into a list. The TX timestamp
is final handled in threaded interrupt handler when PTP timestamp
FIFO is ready.
On RX path, timestamping is always working. The RX timestamp could
be got from extraction header.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch is to reuse ocelot functions as possible to enable PTP
clock and to support hardware timestamping on Felix.
On TX path, timestamping works on packet which requires timestamp.
The injection header will be configured accordingly, and skb clone
requires timestamp will be added into a list. The TX timestamp
is final handled in threaded interrupt handler when PTP timestamp
FIFO is ready.
On RX path, timestamping is always working. The RX timestamp could
be got from extraction header.
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch is to define PTP registers for felix_vsc9959.
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Convert to use ocelot_port_add_txtstamp_skb() for adding skbs which
require TX timestamp into list. Export it so that DSA Felix driver
could reuse it too.
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The method getting TX timestamp by reading timestamp FIFO and
matching skbs list is common for DSA Felix driver too.
So move code out of ocelot_board.c, convert to use
ocelot_get_txtstamp() function and export it.
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Export ocelot_hwstamp_get/set functions so that DSA driver
is able to reuse them.
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Report from Dan Carpenter,

 net/core/skmsg.c:792 sk_psock_write_space()
 error: we previously assumed 'psock' could be null (see line 790)

 net/core/skmsg.c
   789 psock = sk_psock(sk);
   790 if (likely(psock && sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)))
 Check for NULL
   791 schedule_work(&psock->work);
   792 write_space = psock->saved_write_space;
                     ^^^^^^^^^^^^^^^^^^^^^^^^
   793          rcu_read_unlock();
   794          write_space(sk);

Ensure psock dereference on line 792 only occurs if psock is not null.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 604326b4 ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The 0-DAY found that audit_log_task is not declared under
CONFIG_AUDITSYSCALL which causes compilation error when
it is not defined:

    kernel/bpf/syscall.o: In function `bpf_audit_prog.isra.30':
 >> syscall.c:(.text+0x860): undefined reference to `audit_log_task'

Adding the audit_log_task declaration and stub within
CONFIG_AUDITSYSCALL ifdef.

Fixes: 91e6015b ("bpf: Emit audit messages upon successful prog load and unload")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Adjust indentation from spaces to tab (+optional two spaces) as in
coding style.  This fixes various indentation mixups (seven spaces,
tab+one space, etc).
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Adjust indentation from spaces to tab (+optional two spaces) as in
coding style.  This fixes various indentation mixups (seven spaces,
tab+one space, etc).
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

As Jakub suggested on another patch, it's better to do the check
on erspan options before allocating memory.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

LWTUNNEL_IP(6)_OPTS are the new items in ip(6)_tun_policy, which
are parsed by nla_parse_nested_deprecated(). We should check it
strictly by setting .strict_start_type = LWTUNNEL_IP(6)_OPTS.

This patch also adds missing LWTUNNEL_IP6_OPTS in ip6_tun_policy.

Fixes: 4ece4778 ("lwtunnel: add options setting and dumping for geneve")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ct_policy and mpls_policy are parsed with nla_parse_nested(), which
does NL_VALIDATE_STRICT validation, strict_start_type is not needed
to set as it is actually trying to make some attributes parsed with
NL_VALIDATE_STRICT.

This patch is to remove it, and do the same on rtm_nh_policy which
is parsed by nlmsg_parse().
Suggested-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Xin Long says:

====================
net: sched: support vxlan and erspan options

This patchset is to add vxlan and erspan options support in
cls_flower and act_tunnel_key. The form is pretty much like
geneve_opts in:

  https://patchwork.ozlabs.org/patch/935272/
  https://patchwork.ozlabs.org/patch/954564/

but only one option is allowed for vxlan and erspan.

v1->v2:
  - see each patch changelog.
====================
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch is to allow matching options in erspan.

The options can be described in the form:
VER:INDEX:DIR:HWID/VER:INDEX_MASK:DIR_MASK:HWID_MASK.
When ver is set to 1, index will be applied while dir
and hwid will be ignored, and when ver is set to 2,
dir and hwid will be used while index will be ignored.

Different from geneve, only one option can be set. And
also, geneve options, vxlan options or erspan options
can't be set at the same time.

  # ip link add name erspan1 type erspan external
  # tc qdisc add dev erspan1 ingress
  # tc filter add dev erspan1 protocol ip parent ffff: \
      flower \
        enc_src_ip 10.0.99.192 \
        enc_dst_ip 10.0.99.193 \
        enc_key_id 11 \
        erspan_opts 1:12:0:0/1:ffff:0:0 \
        ip_proto udp \
        action mirred egress redirect dev eth0

v1->v2:
  - improve some err msgs of extack.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch is to allow matching gbp option in vxlan.

The options can be described in the form GBP/GBP_MASK,
where GBP is represented as a 32bit hexadecimal value.
Different from geneve, only one option can be set. And
also, geneve options and vxlan options can't be set at
the same time.

  # ip link add name vxlan0 type vxlan dstport 0 external
  # tc qdisc add dev vxlan0 ingress
  # tc filter add dev vxlan0 protocol ip parent ffff: \
      flower \
        enc_src_ip 10.0.99.192 \
        enc_dst_ip 10.0.99.193 \
        enc_key_id 11 \
        vxlan_opts 01020304/ffffffff \
        ip_proto udp \
        action mirred egress redirect dev eth0

v1->v2:
  - add .strict_start_type for enc_opts_policy as Jakub noticed.
  - use Duplicate instead of Wrong in err msg for extack as Jakub
    suggested.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch is to allow setting erspan options using the
act_tunnel_key action. Different from geneve options,
only one option can be set. And also, geneve options,
vxlan options or erspan options can't be set at the
same time.

Options are expressed as ver:index:dir:hwid, when ver
is set to 1, index will be applied while dir and hwid
will be ignored, and when ver is set to 2, dir and
hwid will be used while index will be ignored.

  # ip link add name erspan1 type erspan external
  # tc qdisc add dev eth0 ingress
  # tc filter add dev eth0 protocol ip parent ffff: \
           flower indev eth0 \
              ip_proto udp \
              action tunnel_key \
                  set src_ip 10.0.99.192 \
                  dst_ip 10.0.99.193 \
                  dst_port 6081 \
                  id 11 \
  		erspan_opts 1:2:0:0 \
          action mirred egress redirect dev erspan1

v1->v2:
  - do the validation when dst is not yet allocated as Jakub suggested.
  - use Duplicate instead of Wrong in err msg for extack.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch is to allow setting vxlan options using the
act_tunnel_key action. Different from geneve options,
only one option can be set. And also, geneve options
and vxlan options can't be set at the same time.

gbp is the only param for vxlan options:

  # ip link add name vxlan0 type vxlan dstport 0 external
  # tc qdisc add dev eth0 ingress
  # tc filter add dev eth0 protocol ip parent ffff: \
           flower indev eth0 \
              ip_proto udp \
              action tunnel_key \
                  set src_ip 10.0.99.192 \
                  dst_ip 10.0.99.193 \
                  dst_port 6081 \
                  id 11 \
  		  vxlan_opts 01020304 \
          action mirred egress redirect dev vxlan0

v1->v2:
  - add .strict_start_type for enc_opts_policy as Jakub noticed.
  - use Duplicate instead of Wrong in err msg for extack as Jakub
    suggested.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If rvu_get_blkaddr() fails, then this rvu_cgx_nix_cuml_stats() returns
zero and we write some uninitialized data into the debugfs output.

On the error paths, the use of the uninitialized "*stat" is harmless,
but it will lead to a Smatch warning (static analysis) and a UBSan
warning (runtime analysis) so we should prevent that as well.

Fixes: f967488d ("octeontx2-af: Add per CGX port level NIX Rx/Tx counters")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If transport->init() fails, we can't assign the transport to the
socket, because it's not initialized correctly, and any future
calls to the transport callbacks would have an unexpected behavior.

Fixes: c0cfa2d8 ("vsock: add multi-transports support")
Reported-and-tested-by: syzbot+e2e5c07bf353b2f79daa@syzkaller.appspotmail.com
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Jorgen Hansen <jhansen@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add support for the soft status and control register, which allows
TX_FAULT and RX_LOS to be monitored and TX_DISABLE to be set.  We
make use of this when the board does not support GPIOs for these
signals.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Russell King says:

====================
Add rudimentary SFP module quirk support

The SFP module EEPROM describes the capabilities of the module, but
doesn't describe the host interface.  We have a certain amount of
guess-work to work out how to configure the host - which works most
of the time.

However, there are some (such as GPON) modules which are able to
support different host interfaces, such as 1000BASE-X and 2500BASE-X.
The module will switch between each mode until it achieves link with
the host.

There is no defined way to describe this in the SFP EEPROM, so we can
only recognise the module and handle it appropriately.  This series
adds the necessary recognition of the modules using a quirk system,
and tweaks the support mask to allow them to link with the host at
2500BASE-X, thereby allowing the user to achieve full line rate.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Marc Micalizzi reports that Huawei MA5671A and Alcatel/Lucent G-010S-P
modules are capable of 2500base-X, but incorrectly report their
capabilities in the EEPROM.  It seems rather common that GPON modules
mis-report.

Let's fix these modules by adding some quirks.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add support for applying module quirks to the list of supported
ethtool link modes.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

snprintf returns the number of chars that would be written, not number
of chars that were actually written. As such, 'offs' may get larger than
'tbl.maxlen', causing the 'tbl.maxlen - offs' being < 0, and since the
parameter is size_t, it would overflow.

Since using scnprintf may hide the limit error, while the buffer is still
enough now, let's just add a WARN_ON_ONCE in case it reach the limit
in future.

v2: Use WARN_ON_ONCE as Jiri and Eric suggested.
Suggested-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>