Currently, if the user changes the pause settings, the default settings
will be restored after an interface down/up cycle, and also when
resuming from suspend. This doesn't seem to provide the best user
experience. Change this to keep user settings, and just ensure that in
jumbo mode pause is disabled.
Small drawback: When switching back mtu from jumbo to non-jumbo then
pause remains disabled (but user can enable it using ethtool).
I think that's a not too common scenario and acceptable.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
 - keep the ZC code, drop the code related to reinit
net/bridge/netfilter/ebtables.c
 - fix build after move to net_generic
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Pull networking fixes from Jakub Kicinski:
 "Networking fixes for 5.12-rc8, including fixes from netfilter, and
  bpf. BPF verifier changes stand out, otherwise things have slowed
  down.

  Current release - regressions:

   - gro: ensure frag0 meets IP header alignment

   - Revert "net: stmmac: re-init rx buffers when mac resume back"

   - ethernet: macb: fix the restore of cmp registers

  Previous releases - regressions:

   - ixgbe: Fix NULL pointer dereference in ethtool loopback test

   - ixgbe: fix unbalanced device enable/disable in suspend/resume

   - phy: marvell: fix detection of PHY on Topaz switches

   - make tcp_allowed_congestion_control readonly in non-init netns

   - xen-netback: Check for hotplug-status existence before watching

  Previous releases - always broken:

   - bpf: mitigate a speculative oob read of up to map value size by
     tightening the masking window

   - sctp: fix race condition in sctp_destroy_sock

   - sit, ip6_tunnel: Unregister catch-all devices

   - netfilter: nftables: clone set element expression template

   - netfilter: flowtable: fix NAT IPv6 offload mangling

   - net: geneve: check skb is large enough for IPv4/IPv6 header

   - netlink: don't call ->netlink_bind with table lock held"

* tag 'net-5.12-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (52 commits)
  netlink: don't call ->netlink_bind with table lock held
  MAINTAINERS: update my email
  bpf: Update selftests to reflect new error states
  bpf: Tighten speculative pointer arithmetic mask
  bpf: Move sanitize_val_alu out of op switch
  bpf: Refactor and streamline bounds check into helper
  bpf: Improve verifier error messages for users
  bpf: Rework ptr_limit into alu_limit and add common error path
  bpf: Ensure off_reg has no mixed signed bounds for all types
  bpf: Move off_reg into sanitize_ptr_alu
  bpf: Use correct permission flag for mixed signed bounds arithmetic
  ch_ktls: do not send snd_una update to TCB in middle
  ch_ktls: tcb close causes tls connection failure
  ch_ktls: fix device connection close
  ch_ktls: Fix kernel panic
  i40e: fix the panic when running bpf in xdpdrv mode
  net/mlx5e: fix ingress_ifindex check in mlx5e_flower_parse_meta
  net/mlx5e: Fix setting of RS FEC mode
  net/mlx5: Fix setting of devlink traps in switchdev mode
  Revert "net: stmmac: re-init rx buffers when mac resume back"
  ...

Merge tag 'libnvdimm-fixes-for-5.12-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm fixes from Dan Williams:
 "The largest change is for a regression that landed during -rc1 for
  block-device read-only handling. Vaibhav found a new use for the
  ability (originally introduced by virtio_pmem) to call back to the
  platform to flush data, but also found an original bug in that
  implementation. Lastly, Arnd cleans up some compile warnings in dax.

  This has all appeared in -next with no reported issues.

  Summary:

   - Fix a regression of read-only handling in the pmem driver

   - Fix a compile warning

   - Fix support for platform cache flush commands on powerpc/papr"

* tag 'libnvdimm-fixes-for-5.12-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm/region: Fix nvdimm_has_flush() to handle ND_REGION_ASYNC
  libnvdimm: Notify disk drivers to revalidate region read-only
  dax: avoid -Wempty-body warnings

Pull CXL memory class fixes from Dan Williams:
 "A collection of fixes for the CXL memory class driver introduced in
  this release cycle.

  The driver was primarily developed on a work-in-progress QEMU
  emulation of the interface and we have since found a couple places
  where it hid spec compliance bugs in the driver, or had a spec
  implementation bug itself.

  The biggest change here is replacing a percpu_ref with an rwsem to
  cleanup a couple bugs in the error unwind path during ioctl device
  init. Lastly there were some minor cleanups to not export the
  power-management sysfs-ABI for the ioctl device, use the proper sysfs
  helper for emitting values, and prevent subtle bugs as new
  administration commands are added to the supported list.

  The bulk of it has appeared in -next save for the top commit which was
  found today and validated on a fixed-up QEMU model.

  Summary:

   - Fix support for CXL memory devices with registers offset from the
     BAR base.

   - Fix the reporting of device capacity.

   - Fix the driver commands list definition to be disconnected from the
     UAPI command list.

   - Replace percpu_ref with rwsem to fix initialization error path.

   - Fix leaks in the driver initialization error path.

   - Drop the power/ directory from CXL device sysfs.

   - Use the recommended sysfs helper for attribute 'show'
     implementations"

* tag 'cxl-fixes-for-5.12-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl:
  cxl/mem: Fix memory device capacity probing
  cxl/mem: Fix register block offset calculation
  cxl/mem: Force array size of mem_commands[] to CXL_MEM_COMMAND_ID_MAX
  cxl/mem: Disable cxl device power management
  cxl/mem: Do not rely on device_add() side effects for dev_set_name() failures
  cxl/mem: Fix synchronization mechanism for device removal vs ioctl operations
  cxl/mem: Use sysfs_emit() for attribute show routines

Merge misc fixes from Andrew Morton:
 "12 patches.

  Subsystems affected by this patch series: mm (documentation, kasan,
  and pagemap), csky, ia64, gcov, and lib"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  lib: remove "expecting prototype" kernel-doc warnings
  gcov: clang: fix clang-11+ build
  mm: ptdump: fix build failure
  mm/mapping_dirty_helpers: guard hugepage pud's usage
  ia64: tools: remove duplicate definition of ia64_mf() on ia64
  ia64: tools: remove inclusion of ia64-specific version of errno.h header
  ia64: fix discontig.c section mismatches
  ia64: remove duplicate entries in generic_defconfig
  csky: change a Kconfig symbol name to fix e1000 build error
  kasan: remove redundant config option
  kasan: fix hwasan build for gcc
  mm: eliminate "expecting prototype" kernel-doc warnings

The CXL Identify Memory Device output payload emits capacity in 256MB
units. The driver is treating the capacity field as bytes. This was
missed because QEMU reports bytes when it should report bytes / 256MB.

Fixes: 8adaf747 ("cxl/mem: Find device capabilities")
Reviewed-by: NVishal Verma <vishal.l.verma@intel.com>
Cc: Ben Widawsky <ben.widawsky@intel.com>
Link: https://lore.kernel.org/r/161862021044.3259705.7008520073059739760.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by: NDan Williams <dan.j.williams@intel.com>

Mat Martineau says:

====================
mptcp: Fixes and tracepoints from the mptcp tree

Here's one more batch of changes that we've tested out in the MPTCP tree.

Patch 1 makes the MPTCP KUnit config symbol more consistent with other
subsystems.

Patch 2 fixes a couple of format specifiers in pr_debug()s

Patches 3-7 add four helpful tracepoints for MPTCP.

Patch 8 is a one-line refactor to use an available helper macro.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch used the macro helper mptcp_for_each_subflow() instead of
list_for_each_entry() in mptcp_close.
Signed-off-by: NGeliang Tang <geliangtang@gmail.com>
Signed-off-by: NMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch added a tracepoint in subflow_check_data_avail() to show the
mapping status.
Suggested-by: NPaolo Abeni <pabeni@redhat.com>
Acked-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NGeliang Tang <geliangtang@gmail.com>
Signed-off-by: NMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch added a tracepoint in ack_update_msk() to track the
incoming data_ack and window/snd_una updates.
Suggested-by: NPaolo Abeni <pabeni@redhat.com>
Acked-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NGeliang Tang <geliangtang@gmail.com>
Signed-off-by: NMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch added a tracepoint in the mapping status function
get_mapping_status() to dump every mpext field.
Suggested-by: NPaolo Abeni <pabeni@redhat.com>
Acked-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NGeliang Tang <geliangtang@gmail.com>
Signed-off-by: NMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch added a tracepoint in the packet scheduler function
mptcp_subflow_get_send().
Suggested-by: NPaolo Abeni <pabeni@redhat.com>
Acked-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NGeliang Tang <geliangtang@gmail.com>
Signed-off-by: NMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch moved the static function mptcp_subflow_active to protocol.h
as an inline one.
Acked-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NGeliang Tang <geliangtang@gmail.com>
Signed-off-by: NMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some of the sequence numbers are printed as the negative ones in the debug
log:

[   46.250932] MPTCP: DSS
[   46.250940] MPTCP: data_fin=0 dsn64=0 use_map=0 ack64=1 use_ack=1
[   46.250948] MPTCP: data_ack=2344892449471675613
[   46.251012] MPTCP: msk=000000006e157e3f status=10
[   46.251023] MPTCP: msk=000000006e157e3f snd_data_fin_enable=0 pending=0 snd_nxt=2344892449471700189 write_seq=2344892449471700189
[   46.251343] MPTCP: msk=00000000ec44a129 ssk=00000000f7abd481 sending dfrag at seq=-1658937016627538668 len=100 already sent=0
[   46.251360] MPTCP: data_seq=16787807057082012948 subflow_seq=1 data_len=100 dsn64=1

This patch used the format specifier %u instead of %d for the unsigned int
values to fix it.

Fixes: d9ca1de8 ("mptcp: move page frag allocation in mptcp_sendmsg()")
Reviewed-by: NMatthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: NGeliang Tang <geliangtang@gmail.com>
Signed-off-by: NMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Drop 'S' from end of CONFIG_MPTCP_KUNIT_TESTS in order to adhere to the
KUNIT *_KUNIT_TEST config name format.

Fixes: a00a5822 (mptcp: move crypto test to KUNIT)
Reviewed-by: NDavid Gow <davidgow@google.com>
Reviewed-by: NMatthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: NNico Pache <npache@redhat.com>
Signed-off-by: NMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Vladimir Oltean says:

====================
Fixups for XDP on NXP ENETC

After some more XDP testing on the NXP LS1028A, this is a set of 10 bug
fixes, simplifications and tweaks, ranging from addressing Toke's feedback
(the network stack can run concurrently with XDP on the same TX rings)
to fixing some OOM conditions seen under TX congestion.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Described in fd5736bf ("enetc: Workaround for MDIO register access
issue") is a workaround for a hardware bug that requires a register
access of the MDIO controller to never happen concurrently with a
register access of a port PF. To avoid that, a mutual exclusion scheme
with rwlocks was implemented - the port PF accessors are the 'read'
side, and the MDIO accessors are the 'write' side.

When we do XDP_REDIRECT between two ENETC interfaces, all is fine
because the MDIO lock is already taken from the NAPI poll loop.

But when the ingress interface is not ENETC, just the egress is, the
MDIO lock is not taken, so we might access the port PF registers
concurrently with MDIO, which will make the link flap due to wrong
values returned from the PHY.

To avoid this, let's just slap an enetc_lock_mdio/enetc_unlock_mdio at
the beginning and ending of enetc_xdp_xmit. The fact that the MDIO lock
is designed as a rwlock is important here, because the read side is
reentrant (that is one of the main reasons why we chose it). Usually,
the way we benefit of its reentrancy is by running the data path
concurrently on both CPUs, but in this case, we benefit from the
reentrancy by taking the lock even when the lock is already taken
(and that's the situation where ENETC is both the ingress and the egress
interface for XDP_REDIRECT, which was fine before and still is fine now).
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If the TX ring is congested, enetc_xdp_tx() returns false for the
current XDP frame (represented as an array of software BDs).

This array of software TX BDs is constructed in enetc_rx_swbd_to_xdp_tx_swbd
from software BDs freshly cleaned from the RX ring. The issue is that we
scrub the RX software BDs too soon, more precisely before we know that
we can enqueue the TX BDs successfully into the TX ring.

If we can't enqueue them (and enetc_xdp_tx returns false), we call
enetc_xdp_drop which attempts to recycle the buffers held by the RX
software BDs. But because we scrubbed those RX BDs already, two things
happen:

(a) we leak their memory
(b) we populate the RX software BD ring with an all-zero rx_swbd
    structure, which makes the buffer refill path allocate more memory.

enetc_refill_rx_ring
-> if (unlikely(!rx_swbd->page))
   -> enetc_new_page

That is a recipe for fast OOM.

Fixes: 7ed2bc80 ("net: enetc: add support for XDP_TX")
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the XDP program returns an invalid action, we should free the RX
buffer.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It is possible for one CPU to perform TX hashing (see netdev_pick_tx)
between the 8 ENETC TX rings, and the TX hashing to select TX queue 1.

At the same time, it is possible for the other CPU to already use TX
ring 1 for XDP (either XDP_TX or XDP_REDIRECT). Since there is no mutual
exclusion between XDP and the network stack, we run into an issue
because the ENETC TX procedure is not reentrant.

The obvious approach would be to just make XDP take the lock of the
network stack's TX queue corresponding to the ring it's about to enqueue
in.

For XDP_REDIRECT, this is quite straightforward, a lock at the beginning
and end of enetc_xdp_xmit() should do the trick.

But for XDP_TX, it's a bit more complicated. For one, we do TX batching
all by ourselves for frames with the XDP_TX verdict. This is something
we would like to keep the way it is, for performance reasons. But
batching means that the network stack's lock should be kept from the
first enqueued XDP_TX frame and until we ring the doorbell. That is
mostly fine, except for cases when in the same NAPI loop we have mixed
XDP_TX and XDP_REDIRECT frames. So if enetc_xdp_xmit() gets called while
we are holding the lock from the RX NAPI, then bam, deadlock. The naive
answer could be 'just flush the XDP_TX frames first, then release the
network stack's TX queue lock, then call xdp_do_flush_map()'. But even
xdp_do_redirect() is capable of flushing the batched XDP_REDIRECT
frames, so unless we unlock/relock the TX queue around xdp_do_redirect(),
there simply isn't any clean way to protect XDP_TX from concurrent
network stack .ndo_start_xmit() on another CPU.

So we need to take a different approach, and that is to reserve two
rings for the sole use of XDP. We leave TX rings
0..ndev->real_num_tx_queues-1 to be handled by the network stack, and we
pick them from the end of the priv->tx_ring array.

We make an effort to keep the mapping done by enetc_alloc_msix() which
decides which CPU handles the TX completions of which TX ring in its
NAPI poll. So the XDP TX ring of CPU 0 is handled by TX ring 6, and the
XDP TX ring of CPU 1 is handled by TX ring 7.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that commit d6a2829e ("net: enetc: increase RX ring default
size") has increased the RX ring size, it is quite easy to congest the
TX rings when the traffic is predominantly XDP_TX, as the RX ring is
quite a bit larger than the TX one.

Since we bit the bullet and did the expensive thing already (larger RX
rings consume more memory pages), it seems quite foolish to keep the TX
rings small. So make them equally sized with TX.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

xdp_do_redirect already contains:
-> dev_map_enqueue
   -> __xdp_enqueue
      -> bq_enqueue
         -> bq_xmit_all // if we have more than 16 frames

So the logic from enetc will never be hit, because ENETC_DEFAULT_TX_WORK
is 128.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the code path below fails:

enetc_clean_rx_ring_xdp // XDP_PASS
-> enetc_build_skb
   -> enetc_map_rx_buff_to_skb
      -> build_skb

enetc_clean_rx_ring_xdp will 'break', but that 'break' instruction isn't
strong enough to actually break the NAPI poll loop, just the switch/case
statement for XDP actions. So we increment rx_frm_cnt and go to the next
frames minding our own business.

Instead let's do what the skb NAPI poll function does, and break the
loop now, waiting for the memory pressure to go away. Otherwise the next
calls to build_skb() are likely to fail too.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When receiving a frame with errors, currently we do nothing with it (we
don't construct an skb or an xdp_buff), we just exit the NAPI poll loop.

Let's put the buffer back into the RX ring (similar to XDP_DROP).
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

enetc_put_xdp_buff has nothing to do with XDP, frankly, it is just a
helper to populate the recycle end of the shadow RX BD ring
(next_to_alloc) with a given buffer.

On the other hand, enetc_put_rx_buff plays more tricks than its name
would suggest.

So let's rename enetc_put_rx_buff into enetc_flip_rx_buff to reflect the
half-page buffer reuse tricks that it employs, and enetc_put_xdp_buff
into enetc_put_rx_buff which suggests a more garden-variety operation.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Later in enetc_clean_tx_ring we have:

		/* Scrub the swbd here so we don't have to do that
		 * when we reuse it during xmit
		 */
		memset(tx_swbd, 0, sizeof(*tx_swbd));

So these assignments are unnecessary.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Tony Nguyen says:

====================
1GbE Intel Wired LAN Driver Updates 2021-04-16

This series contains updates to igb and igc drivers.

Ederson adjusts Tx buffer distributions in Qav mode to improve
TSN-aware traffic for igb. He also enable PPS support and auxiliary PHC
functions for igc.

Grzegorz checks that the MTA register was properly written and
retries if not for igb.

Sasha adds reporting of EEE low power idle counters to ethtool and fixes
a return value being overwritten through looping for igc.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix the following out-of-bounds warning:

net/core/flow_dissector.c:835:3: warning: 'memcpy' offset [33, 48] from the object at 'flow_keys' is out of the bounds of referenced subobject 'ipv6_src' with type '__u32[4]' {aka 'unsigned int[4]'} at offset 16 [-Warray-bounds]

The problem is that the original code is trying to copy data into a
couple of struct members adjacent to each other in a single call to
memcpy().  So, the compiler legitimately complains about it. As these
are just a couple of members, fix this by copying each one of them in
separate calls to memcpy().

This helps with the ongoing efforts to globally enable -Warray-bounds
and get us closer to being able to tighten the FORTIFY_SOURCE routines
on memcpy().

Link: https://github.com/KSPP/linux/issues/109Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NGustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When I added support to allow generic netlink multicast groups to be
restricted to subscribers with CAP_NET_ADMIN I was unaware that a
genl_bind implementation already existed in the past.

It was reverted due to ABBA deadlock:

1. ->netlink_bind gets called with the table lock held.
2. genetlink bind callback is invoked, it grabs the genl lock.

But when a new genl subsystem is (un)registered, these two locks are
taken in reverse order.

One solution would be to revert again and add a comment in genl
referring 1e82a62f, "genetlink: remove genl_bind").

This would need a second change in mptcp to not expose the raw token
value anymore, e.g.  by hashing the token with a secret key so userspace
can still associate subflow events with the correct mptcp connection.

However, Paolo Abeni reminded me to double-check why the netlink table is
locked in the first place.

I can't find one.  netlink_bind() is already called without this lock
when userspace joins a group via NETLINK_ADD_MEMBERSHIP setsockopt.
Same holds for the netlink_unbind operation.

Digging through the history, commit f7736080
("netlink: access nlk groups safely in netlink bind and getname")
expanded the lock scope.

commit 3a20773b ("net: netlink: cap max groups which will be considered in netlink_bind()")
... removed the nlk->ngroups access that the lock scope
extension was all about.

Reduce the lock scope again and always call ->netlink_bind without
the table lock.

The Fixes tag should be vs. the patch mentioned in the link below,
but that one got squash-merged into the patch that came earlier in the
series.

Fixes: 4d54cc32 ("mptcp: avoid lock_fast usage in accept path")
Link: https://lore.kernel.org/mptcp/20210213000001.379332-8-mathew.j.martineau@linux.intel.com/T/#u
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Xin Long <lucien.xin@gmail.com>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Sean Tranchetti <stranche@codeaurora.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Jakub Kicinski says:

====================
ethtool: add uAPI for reading standard stats

Continuing the effort of providing a unified access method
to standard stats, and explicitly tying the definitions to
the standards this series adds an API for general stats
which do no fit into more targeted control APIs.

There is nothing clever here, just a netlink API for dumping
statistics defined by standards and RFCs which today end up
in ethtool -S under infinite variations of names.

This series adds basic IEEE stats (for PHY, MAC, Ctrl frames)
and RMON stats. AFAICT other RFCs only duplicate the IEEE
stats.

This series does _not_ add a netlink API to read driver-defined
stats. There seems to be little to gain from moving that part
to netlink.

The netlink message format is very simple, and aims to allow
adding stats and groups with no changes to user tooling (which
IIUC is expected for ethtool).

On user space side we can re-use -S, and make it dump
standard stats if --groups are defined.

$ ethtool -S eth0 --groups eth-phy eth-mac eth-ctrl rmon
Stats for eth0:
eth-phy-SymbolErrorDuringCarrier: 0
eth-mac-FramesTransmittedOK: 0
eth-mac-FrameTooLongErrors: 0
eth-ctrl-MACControlFramesTransmitted: 0
eth-ctrl-MACControlFramesReceived: 1
eth-ctrl-UnsupportedOpcodesReceived: 0
rmon-etherStatsUndersizePkts: 0
rmon-etherStatsJabbers: 0
rmon-rx-etherStatsPkts64Octets: 1
rmon-rx-etherStatsPkts128to255Octets: 0
rmon-rx-etherStatsPkts1024toMaxOctets: 1
rmon-tx-etherStatsPkts64Octets: 1
rmon-tx-etherStatsPkts128to255Octets: 0
rmon-tx-etherStatsPkts1024toMaxOctets: 1

v1:

Driver support for mlxsw, mlx5 and bnxt included.

Compared to the RFC I went ahead with wrapping the stats into
a 1:1 nest. Now IDs of stats can start from 0, at a cost of
slightly "careful" u64 alignment handling.

v2:

Add missing kdoc in patch 5.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add support for PHY/MAC/Ctrl/RMON stats.
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Most of the names seem to strongly correlate with names from
the standard and RFC. Whether ..+good_frames are indeed Frames..OK
I'm the least sure of.
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

mlxsw has nicely grouped stats, add support for standard uAPI.
I'm guessing the register access part. Compile tested only.
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Most devices maintain RMON (RFC 2819) stats - particularly
the "histogram" of packets received by size. Unlike other
RFCs which duplicate IEEE stats, the short/oversized frame
counters in RMON don't seem to match IEEE stats 1-to-1 either,
so expose those, too. Do not expose basic packet, CRC errors
etc - those are already otherwise covered.

Because standard defines packet ranges only up to 1518, and
everything above that should theoretically be "oversized"
- devices often create their own ranges.

Going beyond what the RFC defines - expose the "histogram"
in the Tx direction (assume for now that the ranges will
be the same).
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Number of devices maintains the standard-based MAC control
counters for control frames. Add a API for those.
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Most of the MAC statistics are included in
struct rtnl_link_stats64, but some fields
are aggregated. Besides it's good to expose
these clearly hardware stats separately.
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add an interface for reading standard stats, including
stats which don't have a corresponding control interface.

Start with IEEE 802.3 PHY stats. There seems to be only
one stat to expose there.

Define API to not require user space changes when new
stats or groups are added. Groups are based on bitset,
stats have a string set associated.

v1: wrap stats in a nest
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add documentation for ETHTOOL_MSG_STATS_GET.
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make the lack of expectations for switching NICs explicit,
describe the new stats.
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>