The __of_mdiobus_register() function was storing the device node in
dev.of_node without increasing its reference count. It implicitly relied
on the caller to maintain the allocated node until the mdiobus was
unregistered.

Now, __of_mdiobus_register() will acquire the node before assigning it,
and of_mdiobus_unregister_callback() will be called at the end of
mdio_unregister().

Drivers can now release the node immediately after MDIO registration.
Some of them are already doing that even before this patch.
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Saeed Mahameed says:

====================
mlx5-updates-2023-12-20

mlx5 Socket direct support and management PF profile.

Tariq Says:
===========
Support Socket-Direct multi-dev netdev

This series adds support for combining multiple devices (PFs) of the
same port under one netdev instance. Passing traffic through different
devices belonging to different NUMA sockets saves cross-numa traffic and
allows apps running on the same netdev from different numas to still
feel a sense of proximity to the device and achieve improved
performance.

We achieve this by grouping PFs together, and creating the netdev only
once all group members are probed. Symmetrically, we destroy the netdev
once any of the PFs is removed.

The channels are distributed between all devices, a proper configuration
would utilize the correct close numa when working on a certain app/cpu.

We pick one device to be a primary (leader), and it fills a special
role.  The other devices (secondaries) are disconnected from the network
in the chip level (set to silent mode). All RX/TX traffic is steered
through the primary to/from the secondaries.

Currently, we limit the support to PFs only, and up to two devices
(sockets).

===========

Armen Says:
===========
Management PF support and module integration

This patch rolls out comprehensive support for the Management Physical
Function (MGMT PF) within the mlx5 driver. It involves updating the
mlx5 interface header to introduce necessary definitions for MGMT PF
and adding a new management PF netdev profile, which will allow the host
side to communicate with the embedded linux on Blue-field devices.

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

As explained in commit e0378187 ("drop_monitor: Require
'CAP_SYS_ADMIN' when joining "events" group"), the "flags" field in the
multicast group structure reuses uAPI flags despite the field not being
exposed to user space. This makes it impossible to extend its use
without adding new uAPI flags, which is inappropriate for internal
kernel checks.

Solve this by adding internal flags (i.e., "GENL_MCAST_*") and convert
the existing users to use them instead of the uAPI flags.

Tested using the reproducers in commit 44ec98ea ("psample: Require
'CAP_NET_ADMIN' when joining "packets" group") and commit e0378187
("drop_monitor: Require 'CAP_SYS_ADMIN' when joining "events" group").

No functional changes intended.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Now that the driver core can properly handle constant struct bus_type,
move the iucv_bus variable to be a constant structure as well, placing
it into read-only memory which can not be modified at runtime.

Cc: Wenjia Zhang <wenjia@linux.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: linux-s390@vger.kernel.org
Cc: netdev@vger.kernel.org
Acked-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The kerneldoc comment for struct ethtool_fec_stats attempts to describe the
"total" and "lanes" fields of the ethtool_fec_stat substructure in a way
leading to these warnings:

  ./include/linux/ethtool.h:424: warning: Excess struct member 'lane' description in 'ethtool_fec_stats'
  ./include/linux/ethtool.h:424: warning: Excess struct member 'total' description in 'ethtool_fec_stats'

Reformat the comment to retain the information while eliminating the
warnings.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The kernel doc comments for struct ethtool_link_settings includes
documentation for three fields that were never present there, leading to
these docs-build warnings:

  ./include/uapi/linux/ethtool.h:2207: warning: Excess struct member 'supported' description in 'ethtool_link_settings'
  ./include/uapi/linux/ethtool.h:2207: warning: Excess struct member 'advertising' description in 'ethtool_link_settings'
  ./include/uapi/linux/ethtool.h:2207: warning: Excess struct member 'lp_advertising' description in 'ethtool_link_settings'

Remove the entries to make the warnings go away.  There was some
information there on how data in >link_mode_masks is formatted; move that
to the body of the comment to preserve it.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove a couple of kerneldoc entries for struct members that do not exist,
addressing these warnings:

  ./include/net/sock.h:548: warning: Excess struct member '__sk_flags_offset' description in 'sock'
  ./include/net/sock.h:548: warning: Excess struct member 'sk_padding' description in 'sock'
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

A freezable kernel thread can enter frozen state during freezing by
either calling try_to_freeze() or using wait_event_freezable() and its
variants. So for the following snippet of code in a kernel thread loop:
  wait_event_interruptible_timeout();
  try_to_freeze();

We can change it to a simple wait_event_freezable_timeout() and then
eliminate a function call.
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Radu Pirea says:

====================
Add MACsec support for TJA11XX C45 PHYs

This is the MACsec support for TJA11XX PHYs. The MACsec block encrypts
the ethernet frames on the fly and has no buffering. This operation will
grow the frames by 32 bytes. If the frames are sent back to back, the
MACsec block will not have enough room to insert the SecTAG and the ICV
and the frames will be dropped.

To mitigate this, the PHY can parse a specific ethertype with some
padding bytes and replace them with the SecTAG and ICV. These padding
bytes might be dummy or might contain information about TX SC that must
be used to encrypt the frame.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Implement mdo_insert_tx_tag to insert the TLV header in the ethernet
frame.
Signed-off-by: Radu Pirea (NXP OSS) <radu-nicolae.pirea@oss.nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add MACsec statistics callbacks.
The statistic registers must be set to 0 if the SC/SA is
deleted to read relevant values next time when the SC/SA is used.
Signed-off-by: Radu Pirea (NXP OSS) <radu-nicolae.pirea@oss.nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add MACsec support.
The MACsec block has four TX SCs and four RX SCs. The driver supports up
to four SecY. Each SecY with one TX SC and one RX SC.
The RX SCs can have two keys, key A and key B, written in hardware and
enabled at the same time.
The TX SCs can have two keys written in hardware, but only one can be
active at a given time.
On TX, the SC is selected using the MAC source address. Due of this
selection mechanism, each offloaded netdev must have a unique MAC
address.
On RX, the SC is selected by SCI(found in SecTAG or calculated using MAC
SA), or using RX SC 0 as implicit.
Signed-off-by: Radu Pirea (NXP OSS) <radu-nicolae.pirea@oss.nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Offloading MACsec in PHYs requires inserting the SecTAG and the ICV in
the ethernet frame. This operation will increase the frame size with up
to 32 bytes. If the frames are sent at line rate, the PHY will not have
enough room to insert the SecTAG and the ICV.

Some PHYs use a hardware buffer to store a number of ethernet frames and,
if it fills up, a pause frame is sent to the MAC to control the flow.
This HW implementation does not need any modification in the stack.

Other PHYs might offer to use a specific ethertype with some padding
bytes present in the ethernet frame. This ethertype and its associated
bytes will be replaced by the SecTAG and ICV.

mdo_insert_tx_tag allows the PHY drivers to add any specific tag in the
skb.
Signed-off-by: Radu Pirea (NXP OSS) <radu-nicolae.pirea@oss.nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Revert the MAC address if mdo_upd_secy fails. Offloaded MACsec device
might be left in an inconsistent state.
Signed-off-by: Radu Pirea (NXP OSS) <radu-nicolae.pirea@oss.nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add description for fields of struct macsec_context and struct
macsec_ops.
Signed-off-by: Radu Pirea (NXP OSS) <radu-nicolae.pirea@oss.nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Move sci_to_cpu to the MACsec header to use it in drivers.
Signed-off-by: Radu Pirea (NXP OSS) <radu-nicolae.pirea@oss.nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use skb_ensure_writable_head_tail to expand the skb if needed instead of
reimplementing a similar operation.
Signed-off-by: Radu Pirea (NXP OSS) <radu-nicolae.pirea@oss.nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Rename dsa_realloc_skb to skb_ensure_writable_head_tail and move it to
skbuff.c to use it as helper.
Signed-off-by: Radu Pirea (NXP OSS) <radu-nicolae.pirea@oss.nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

It appears that there is a typo in the code where the nlattr array is
being parsed with policy br_cfm_cc_ccm_tx_policy, but the instance is
being accessed via IFLA_BRIDGE_CFM_CC_RDI_INSTANCE, which is associated
with the policy br_cfm_cc_rdi_policy.

This problem was introduced by commit 2be665c3 ("bridge: cfm: Netlink
SET configuration Interface.").

Though it seems like a harmless typo since these two enum owns the exact
same value (1 here), it is quite misleading hence fix it by using the
correct enum IFLA_BRIDGE_CFM_CC_CCM_TX_INSTANCE here.
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Matthieu Baerts says:

====================
mptcp: cleanup and support more ephemeral ports sockopts

Patch 1 is a cleanup one: mptcp_is_tcpsk() helper was modifying sock_ops
in some cases which is unexpected with that name.

Patch 2 to 4 add support for two socket options: IP_LOCAL_PORT_RANGE and
IP_BIND_ADDRESS_NO_PORT. The first one is a preparation patch, the
second one adds the support while the last one modifies an existing
selftest to validate the new features.
====================
Signed-off-by: Matthieu Baerts <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since previous commit, MPTCP has support for IP_BIND_ADDRESS_NO_PORT and
IP_LOCAL_PORT_RANGE sockopts.

Add ip4_mptcp and ip6_mptcp fixture variants to ip_local_port_range
selftest to provide selftest coverage for these sockopts.
Acked-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Maxim Galaganov <max@internet.ru>
Signed-off-by: Matthieu Baerts <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Support for IP_BIND_ADDRESS_NO_PORT sockopt was introduced in [1].
Recently [2] allowed its value to be accessed without locking the
socket.

Support for (newer) IP_LOCAL_PORT_RANGE sockopt was introduced in [3].
In the same series a selftest was added in [4]. This selftest also
covers the IP_BIND_ADDRESS_NO_PORT sockopt.

This patch enables getsockopt()/setsockopt() on MPTCP sockets for these
socket options, syncing set values to subflows in sync_socket_options().
Ephemeral port range is synced to subflows, enabling NAT usecase
described in [3].

[1] commit 90c337da ("inet: add IP_BIND_ADDRESS_NO_PORT to overcome
bind(0) limitations")
[2] commit ca571e2e ("inet: move inet->bind_address_no_port to
inet->inet_flags")
[3] commit 91d0b78c ("inet: Add IP_LOCAL_PORT_RANGE socket option")
[4] commit ae543965 ("selftests/net: Cover the IP_LOCAL_PORT_RANGE
socket option")
Signed-off-by: Maxim Galaganov <max@internet.ru>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Next patch extends this function so that it's not specific to
IP_TRANSPARENT. Change function name to mptcp_setsockopt_sol_ip_set().
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Maxim Galaganov <max@internet.ru>
Signed-off-by: Matthieu Baerts <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Eric Dumazet suggests:

 > The fact that mptcp_is_tcpsk() was able to write over sock->ops was a
 > bit strange to me.
 > mptcp_is_tcpsk() should answer a question, with a read-only argument.

re-factor code to avoid overwriting sock_ops inside that function. Also,
change the helper name to reflect the semantics and to disambiguate from
its dual, sk_is_mptcp(). While at it, collapse mptcp_stream_accept() and
mptcp_accept() into a single function, where fallback / non-fallback are
separated into a single sk_is_mptcp() conditional.

Link: https://github.com/multipath-tcp/mptcp_net-next/issues/432Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Matthieu Baerts <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Better align function variables to open parenthesis as suggested by
checkpatch script for qca808x function to make code cleaner.

For cable_test_get_status function some additional rework was needed to
handle too long functions.
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Victor Nogueira says:

====================
net/sched: Introduce tc block ports tracking and use

__context__
The "tc block" is a collection of netdevs/ports which allow qdiscs to share
match-action block instances (as opposed to the traditional tc filter per
netdev/port)[1].

Up to this point in the implementation, the block is unaware of its ports.
This patch makes the tc block ports available to the datapath.

For the datapath we provide a use case of the tc block in a mirred
action in patch 3. For users can levarage mirred to do something like
the following:

$ tc qdisc add dev ens7 ingress_block 22 clsact
$ tc qdisc add dev ens8 ingress_block 22 clsact
$ tc qdisc add dev ens9 ingress_block 22 clsact
$ tc filter add block 22 protocol ip pref 25 \
  flower dst_ip 192.168.0.0/16 action mirred egress mirror blockid 22

In this case, if the packet arrives on ens8, it will be copied and sent to
all ports in the block excluding ens8. Note that the packet is still in
the pipeline at this point - meaning other actions could be added after the
mirror because mirred copies/clones the skb. Example the following is
valid:

$ tc filter add block 22 protocol ip pref 25 flower dst_ip 192.168.0.0/16 \
action mirred egress mirror blockid 22 \
action vlan push id 123 \
action mirred egress redirect dev dummy0

redirect behavior always steals the packet from the pipeline and therefore
the skb is no longer available for a subsequent action as illustrated above
(in redirecting to dummy0).

The behavior of redirecting to a tc block is therefore adapted to work in
the same manner. So a setup as such:
$ tc qdisc add dev ens7 ingress_block 22
$ tc qdisc add dev ens8 ingress_block 22
$ tc qdisc add dev ens9 ingress_block 22
$ tc filter add block 22 protocol ip pref 25 \
  flower dst_ip 192.168.0.0/16 action mirred egress redirect blockid 22

for a matching packet arriving on ens7 will first send a copy/clone to ens8
(as in the "mirror" behavior) then to ens9 as in the redirect behavior
above. Once this processing is done - no other actions are able to process
this skb. i.e it is removed from the "pipeline".

In this case, if the packet arrives on ens8, it will be copied and sent to
all ports in the block excluding ens8.

Patch 1 separates/exports mirror and redirect functions from act_mirred
Patch 2 introduces the required infra.
Patch 3 Allows mirred to blocks

Subsequent patches will come with tdc test cases.

__Acknowledgements__
Suggestions from Vlad Buslov and Marcelo Ricardo Leitner made this patchset
better. The idea of integrating the ports into the tc block was suggested
by Jiri Pirko.

[1] See commit ca46abd6 ("Merge branch'net-sched-allow-qdiscs-to-share-filter-block-instances'")

Changes in v2:
  - Remove RFC tag
  - Add more details in patch 0(Jiri)
  - When CONFIG_NET_TC_SKB_EXT is selected we have unused qdisc_cb
    Reported-by: kernel test robot <lkp@intel.com> (and
horms@kernel.org)
  - Fix bad dev dereference in printk of blockcast action (Simon)

Changes in v3:
  - Add missing xa_destroy (pointed out by Vlad)
  - Remove bugfix pointed by Vlad (will send in separate patch)
  - Removed ports from subject in patch #2 and typos (suggested by
    Marcelo)
  - Remove net_notice_ratelimited debug messages in error
    cases (suggested by Marcelo)
  - Minor changes to appease sparse's lock context warning

Changes in v4:
  - Avoid code repetition using gotos in cast_one (suggested by Paolo)
  - Fix typo in cover letter (pointed out by Paolo)
  - Create a module description for act_blockcast
    (reported by Paolo and CI)

Changes in v5:
  - Add new patch which separated mirred into mirror and redirect
    functions (suggested by Jiri)
  - Instead of repeating the code to mirror in blockcast use mirror
    exported function by patch1 (tcf_mirror_act)
  - Make Block ID into act_blockcast's parameter passed by user space
    instead of always getting it from SKB (suggested by Jiri)
  - Add tx_type parameter which will specify what transmission behaviour
    we want (as described earlier)

Changes in v6:
  - Remove blockcast and make it a part of mirred (suggestd by Jiri)
  - Block ID is now a mirred parameter
  - We now allow redirecting and mirroring to either ingress or egress

Changes in v7:
  - Remove set but not used variable in tcf_mirred_act (pointed out by
    Jakub)

Changes in v8:
  - Fix uapi issues (pointed out by Jiri)
  - Separate last patch into 3 - two as preparations for adding
    block ID to mirred and one allowing mirred to block (suggested by Jiri)
  - Remove declaration initialisation of eg_block and in_block in
    qdisc_block_add_dev (suggested by Jiri)
  - Avoid unnecessary if guards in qdisc_block_add_dev (suggested by Jiri)
  - Remove unncessary block_index retrieval in __qdisc_destroy
    (suggested by Jiri)
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

So far the mirred action has dealt with syntax that handles
mirror/redirection for netdev. A matching packet is redirected or mirrored
to a target netdev.

In this patch we enable mirred to mirror to a tc block as well.
IOW, the new syntax looks as follows:
... mirred <ingress | egress> <mirror | redirect> [index INDEX] < <blockid BLOCKID> | <dev <devname>> >

Examples of mirroring or redirecting to a tc block:
$ tc filter add block 22 protocol ip pref 25 \
  flower dst_ip 192.168.0.0/16 action mirred egress mirror blockid 22

$ tc filter add block 22 protocol ip pref 25 \
  flower dst_ip 10.10.10.10/32 action mirred egress redirect blockid 22
Co-developed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Co-developed-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The act of replacing a device will be repeated by the init logic for the
block ID in the patch that allows mirred to a block. Therefore we
encapsulate this functionality in a function (tcf_mirred_replace_dev) so
that we can reuse it and avoid code repetition.
Co-developed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Co-developed-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

As a preparation for adding block ID to mirred, separate the part of
mirred that redirect/mirrors to a dev into a specific function so that it
can be called by blockcast for each dev.

Also improve readability. Eg. rename use_reinsert to dont_clone and skb2
to skb_to_send.
Co-developed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Co-developed-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The datapath can now find the block of the port in which the packet arrived
at.

In the next patch we show a possible usage of this patch in a new
version of mirred that multicasts to all ports except for the port in
which the packet arrived on.
Co-developed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Co-developed-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This commit makes tc blocks track which ports have been added to them.
And, with that, we'll be able to use this new information to send
packets to the block's ports. Which will be done in the patch #3 of this
series.
Suggested-by: Jiri Pirko <jiri@nvidia.com>
Co-developed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Co-developed-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since there are no more users of the macro let's finally
burn it
Signed-off-by: Denis Kirjanov <dkirjanov@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

SOCK_DEBUG comes from the old days. Let's
move logging to standard net core ratelimited logging functions
Signed-off-by: Denis Kirjanov <dkirjanov@suse.de>

changes in v2:
 - remove SOCK_DEBUG macro altogether
Signed-off-by: David S. Miller <davem@davemloft.net>

Wen Gu says:

====================
net/smc: implement SMCv2.1 virtual ISM device support

The fourth edition of SMCv2 adds the SMC version 2.1 feature updates for
SMC-Dv2 with virtual ISM. Virtual ISM are created and supported mainly by
OS or hypervisor software, comparable to IBM ISM which is based on platform
firmware or hardware.

With the introduction of virtual ISM, SMCv2.1 makes some updates:

- Introduce feature bitmask to indicate supplemental features.
- Reserve a range of CHIDs for virtual ISM.
- Support extended GIDs (128 bits) in CLC handshake.

So this patch set aims to implement these updates in Linux kernel. And it
acts as the first part of SMC-D virtual ISM extension & loopback-ism [1].

[1] https://lore.kernel.org/netdev/1695568613-125057-1-git-send-email-guwen@linux.alibaba.com/

v8->v7:
- Patch #7: v7 mistakenly changed the type of gid_ext in
  smc_clc_msg_accept_confirm to u64 instead of __be64 as previous versions
  when fixing the rebase conflicts. So fix this mistake.

v7->v6:
Link: https://lore.kernel.org/netdev/20231219084536.8158-1-guwen@linux.alibaba.com/
- Collect the Reviewed-by tag in v6;
- Patch #3: redefine the struct smc_clc_msg_accept_confirm;
- Patch #7: Because that the Patch #3 already adds '__packed' to
  smc_clc_msg_accept_confirm, so Patch #7 doesn't need to do the same thing.
  But this is a minor change, so I kept the 'Reviewed-by' tag.

Other changes in previous versions but not yet acked:
- Patch #1: Some minor changes in subject and fix the format issue
  (length exceeds 80 columns) compared to v3.
- Patch #5: removes useless ini->feature_mask assignment in __smc_connect()
  and smc_listen_v2_check() compared to v4.
- Patch #8: new added, compared to v3.

v6->v5:
Link: https://lore.kernel.org/netdev/1702371151-125258-1-git-send-email-guwen@linux.alibaba.com/
- Add 'Reviewed-by' label given in the previous versions:
  * Patch #4, #6, #9, #10 have nothing changed since v3;
- Patch #2:
  * fix the format issue (Alignment should match open parenthesis) compared to v5;
  * remove useless clc->hdr.length assignment in smcr_clc_prep_confirm_accept()
    compared to v5;
- Patch #3: new added compared to v5.
- Patch #7: some minor changes like aclc_v2->aclc or clc_v2->clc compared to v5
  due to the introduction of Patch #3. Since there were no major changes, I kept
  the 'Reviewed-by' label.

Other changes in previous versions but not yet acked:
- Patch #1: Some minor changes in subject and fix the format issue
  (length exceeds 80 columns) compared to v3.
- Patch #5: removes useless ini->feature_mask assignment in __smc_connect()
  and smc_listen_v2_check() compared to v4.
- Patch #8: new added, compared to v3.

v5->v4:
Link: https://lore.kernel.org/netdev/1702021259-41504-1-git-send-email-guwen@linux.alibaba.com/
- Patch #6: improve the comment of SMCD_CLC_MAX_V2_GID_ENTRIES;
- Patch #4: remove useless ini->feature_mask assignment;

v4->v3:
https://lore.kernel.org/netdev/1701920994-73705-1-git-send-email-guwen@linux.alibaba.com/
- Patch #6: use SMCD_CLC_MAX_V2_GID_ENTRIES to indicate the max gid
  entries in CLC proposal and using SMC_MAX_V2_ISM_DEVS to indicate the
  max devices to propose;
- Patch #6: use i and i+1 in smc_find_ism_v2_device_serv();
- Patch #2: replace the large if-else block in smc_clc_send_confirm_accept()
  with 2 subfunctions;
- Fix missing byte order conversion of GID and token in CLC handshake,
  which is in a separate patch sending to net:
  https://lore.kernel.org/netdev/1701882157-87956-1-git-send-email-guwen@linux.alibaba.com/
- Patch #7: add extended GID in SMC-D lgr netlink attribute;

v3->v2:
https://lore.kernel.org/netdev/1701343695-122657-1-git-send-email-guwen@linux.alibaba.com/
- Rename smc_clc_fill_fce as smc_clc_fill_fce_v2x;
- Remove ISM_IDENT_MASK from drivers/s390/net/ism.h;
- Add explicitly assigning 'false' to ism_v2_capable in ism_dev_init();
- Remove smc_ism_set_v2_capable() helper for now, and introduce it in
  later loopback-ism implementation;

v2->v1:
- Fix sparse complaint;
- Rebase to the latest net-next;
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The System EID (SEID) is an internal EID that is used by the SMCv2
software stack that has a predefined and constant value representing
the s390 physical machine that the OS is executing on. So it should
be managed by SMC stack instead of ISM driver and be consistent for
all ISMv2 device (including virtual ISM devices) on s390 architecture.
Suggested-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-and-tested-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The system EID (SEID) is an internal EID used by SMC-D to represent the
s390 physical machine that OS is executing on. On s390 architecture, it
predefined by fixed string and part of cpuid and is enabled regardless
of whether underlay device is virtual ISM or platform firmware ISM.

However on non-s390 architectures where SMC-D can be used with virtual
ISM devices, there is no similar information to identify physical
machines, especially in virtualization scenarios. So in such cases, SEID
is forcibly disabled and the user-defined UEID will be used to represent
the communicable space.
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-and-tested-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Virtual ISM devices introduced in SMCv2.1 requires a 128 bit extended
GID vs. the existing ISM 64bit GID. So the 2nd 64 bit of extended GID
should be included in SMC-D linkgroup netlink attribute as well.
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

According to virtual ISM support feature defined by SMCv2.1, GIDs of
virtual ISM device are UUIDs defined by RFC4122, which are 128-bits
long. So some adaptation work is required. And note that the GIDs of
existing platform firmware ISM devices still remain 64-bits long.
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

According to virtual ISM support feature defined by SMCv2.1, CHIDs in
the range 0xFF00 to 0xFFFF are reserved for use by virtual ISM devices.

And two helpers are introduced to distinguish virtual ISM devices from
the existing platform firmware ISM devices.
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-and-tested-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This introduces virtual ISM device support feature to SMCv2.1 as the
first supplemental feature.
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>