This patch adds the fallback check in subflow_check_data_avail(). Only
do the fallback when the msk hasn't fallen back yet.
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When a bad checksum is detected and a single subflow is in use, don't
send RST + MP_FAIL, send data_ack + MP_FAIL instead.

So invoke tcp_send_active_reset() only when mptcp_has_another_subflow()
is true.
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

There is a spelling mistake in a netdev_info message. Fix it.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20220421085546.321792-1-colin.i.king@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

No need to add null check before call of_node_put(), since the
implementation of of_node_put() has done it.
Signed-off-by: Haowen Bai <baihaowen@meizu.com>
Link: https://lore.kernel.org/r/1650509283-26168-1-git-send-email-baihaowen@meizu.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Arun Ramadoss says:

====================
add ethtool SQI support for LAN87xx T1 Phy

This patch series add the Signal Quality Index measurement for the LAN87xx and
LAN937x T1 phy. Updated the maintainers file for microchip_t1.c.
====================

Link: https://lore.kernel.org/r/20220420152016.9680-1-arun.ramadoss@microchip.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

This patch add the support for measuring Signal Quality Index for
LAN87xx and LAN937x T1 Phy. It uses the SQI Method 5 for obtaining the
values.
Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

types_info->ini_files is an array of pointers
to struct mlxsw_linecard_ini_file.

Fix the kmalloc_array() argument to be of a size of a pointer.

Addresses-Coverity: ("Incorrect expression  (SIZEOF_MISMATCH)")
Fixes: b217127e ("mlxsw: core_linecards: Add line card objects and implement provisioning")
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/20220420142007.3041173-1-idosch@nvidia.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

qed_nvmetcp_ip_services.c and its corresponding header file were
introduced in commit 806ee7f8 ("qed: Add IP services APIs support")
but there's still no users for any of the functions they declare.
Since these files are effectively unused, let's just drop them.

Found by code inspection. Compile-tested only.
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Link: https://lore.kernel.org/r/351ac8c847980e22850eb390553f8cc0e1ccd0ce.1650545051.git.gnault@redhat.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

This patch converts the existing mediatek-net.txt binding file
in yaml format.
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Guillaume Nault says:

====================
ipv4: First steps toward removing RTO_ONLINK

RTO_ONLINK is a flag that allows to reduce the scope of route lookups.
It's stored in a normally unused bit of the ->flowi4_tos field, in
struct flowi4. However it has several problems:

 * This bit is also used by ECN. Although ECN bits are supposed to be
   cleared before doing a route lookup, it happened that some code
   paths didn't properly sanitise their ->flowi4_tos. So this mechanism
   is fragile and we had bugs in the past where ECN bits slipped in and
   could end up being erroneously interpreted as RTO_ONLINK.

 * A dscp_t type was recently introduced to ensure ECN bits are cleared
   during route lookups. ->flowi4_tos is the most important structure
   field to convert, but RTO_ONLINK prevents such conversion, as dscp_t
   mandates that ECN bits (where RTO_ONLINK is stored) be zero.

Therefore we need to stop using RTO_ONLINK altogether. Fortunately
RTO_ONLINK isn't a necessity. Instead of passing a flag in ->flowi4_tos
to tell the route lookup function to restrict the scope, we can simply
initialise the scope correctly.

Patch 1 does some preparatory work: it stops resetting ->flowi4_scope
automatically before a route lookup, thus allowing callers to set their
desired scope without having to rely on the RTO_ONLINK flag.

Patch 2-3 convert a few code paths to avoid relying on RTO_ONLINK.

More conversions will have to take place before we can eventually
remove this flag.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

All the *_redirect() and *_update_pmtu() functions initialise their
struct flowi4 variable with either __build_flow_key() or
build_sk_flow_key(). When sk is provided, these functions use
RT_CONN_FLAGS() to set ->flowi4_tos and always use RT_SCOPE_UNIVERSE
for ->flowi4_scope. Then they rely on ip_rt_fix_tos() to adjust the
scope based on the RTO_ONLINK bit and to mask the tos with
IPTOS_RT_MASK.

This patch modifies __build_flow_key() and build_sk_flow_key() to
properly initialise ->flowi4_tos and ->flowi4_scope, so that the
ICMP redirects and PMTU handlers don't need an extra call to
ip_rt_fix_tos() before doing a fib lookup. That is, we:

  * Drop RT_CONN_FLAGS(): use ip_sock_rt_tos() and ip_sock_rt_scope()
    instead, so that we don't have to rely on ip_rt_fix_tos() to adjust
    the scope anymore.

  * Apply IPTOS_RT_MASK to the tos, so that we don't need
    ip_rt_fix_tos() to do it for us.

  * Drop the ip_rt_fix_tos() calls that now become useless.

The only remaining ip_rt_fix_tos() caller is ip_route_output_key_hash()
which needs it as long as external callers still use the RTO_ONLINK
flag.

Note:
  This patch also drops some useless RT_TOS() calls as IPTOS_RT_MASK is
  a stronger mask.
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Now that ip_rt_fix_tos() doesn't reset ->flowi4_scope unconditionally,
we don't have to rely on the RTO_ONLINK bit to properly set the scope
of a flowi4 structure. We can just set ->flowi4_scope explicitly and
avoid using RTO_ONLINK in ->flowi4_tos.

This patch converts callers of ip_route_connect(). Instead of setting
the tos parameter with RT_CONN_FLAGS(sk), as all callers do, we can:

  1- Drop the tos parameter from ip_route_connect(): its value was
     entirely based on sk, which is also passed as parameter.

  2- Set ->flowi4_scope depending on the SOCK_LOCALROUTE socket option
     instead of always initialising it with RT_SCOPE_UNIVERSE (let's
     define ip_sock_rt_scope() for this purpose).

  3- Avoid overloading ->flowi4_tos with RTO_ONLINK: since the scope is
     now properly initialised, we don't need to tell ip_rt_fix_tos() to
     adjust ->flowi4_scope for us. So let's define ip_sock_rt_tos(),
     which is the same as RT_CONN_FLAGS() but without the RTO_ONLINK
     bit overload.

Note:
  In the original ip_route_connect() code, __ip_route_output_key()
  might clear the RTO_ONLINK bit of fl4->flowi4_tos (because of
  ip_rt_fix_tos()). Therefore flowi4_update_output() had to reuse the
  original tos variable. Now that we don't set RTO_ONLINK any more,
  this is not a problem and we can use fl4->flowi4_tos in
  flowi4_update_output().
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

All callers already initialise ->flowi4_scope with RT_SCOPE_UNIVERSE,
either by manual field assignment, memset(0) of the whole structure or
implicit structure initialisation of on-stack variables
(RT_SCOPE_UNIVERSE actually equals 0).

Therefore, we don't need to always initialise ->flowi4_scope in
ip_rt_fix_tos(). We only need to reduce the scope to RT_SCOPE_LINK when
the special RTO_ONLINK flag is present in the tos.

This will allow some code simplification, like removing
ip_rt_fix_tos(). Also, the long term idea is to remove RTO_ONLINK
entirely by properly initialising ->flowi4_scope, instead of
overloading ->flowi4_tos with a special flag. Eventually, this will
allow to convert ->flowi4_tos to dscp_t.
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Radhey Shyam Pandey says:

====================
net: macb: Make ZynqMP SGMII phy configuration optional

This patchset drop phy-names property from MACB node and also make
SGMII Phy configuration optional. The motivation for this change
is to support traditional usescase in which first stage bootloader
does PS-GT configuration, and should still be supported in macb
driver.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

In the macb binding documentation "phys" is an optional property. Make
implementation in line with it. This change allows the traditional flow
in which first stage bootloader does PS-GT configuration to work along
with newer use cases in which PS-GT configuration is managed by the
phy-zynqmp driver.

It fixes below macb probe failure when macb DT node doesn't have SGMII
phys handle.
"macb ff0b0000.ethernet: error -ENODEV: failed to get PS-GTR PHY"
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Reviewed-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In zynqmp SGMII initialization, there is a single PHY so remove phy-names
property as there is no real need of having it.
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Kuniyuki Iwashima says:

====================
ipv6: Use ipv6_only_sock helper function.

The first patch removes __ipv6_only_sock(), and the second replaces
ipv6only tests with ipv6_only_sock().
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch replaces some sk_ipv6only tests with ipv6_only_sock().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since commit 9fe516ba ("inet: move ipv6only in sock_common"),
ipv6_only_sock() and __ipv6_only_sock() are the same macro.  Let's
remove the one.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Smatch reports this issue
sr9800.h:166:53: warning: symbol 'SR9800_BULKIN_SIZE' was not declared. Should it be static?

Global variables should not be defined in header files.
This only works because sr9800.h in only included by sr9800.c
Change the storage-class specifier to static.
And since it does not change add type qualifier const.
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts commit b6177d32

ip-link command is testing kernel capability by sending a RTM_NEWLINK
request, without any argument. It accepts everything in reply, except
EOPNOTSUPP and EINVAL (functions iplink_have_newlink / accept_msg)

So we must keep compatiblity here, invalid empty message should not
return EINVAL
Signed-off-by: Florent Fourcot <florent.fourcot@wifirst.fr>
Tested-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The NFP driver already supports assignment of 802.1Q VLANs to VFs

e.g.
 # ip link set $DEV vf $VF_NUM vlan $VLAN_ID [proto 802.1Q]

This patch enhances the NFP driver to also allow assingment of
802.1ad VLANs to VFs.

e.g.
 # ip link set $DEV vf $VF_NUM vlan $VLAN_ID proto 802.1ad
Signed-off-by: Bin Chen <bin.chen@corigine.com>
Signed-off-by: Baowen Zheng <baowen.zheng@corigine.com>
Signed-off-by: Yinjun Zhang <yunjin.zhang@corigine.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Using pm_runtime_resume_and_get() to replace pm_runtime_get_sync and
pm_runtime_put_noidle. This change is just to simplify the code, no
actual functional changes.
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix mistake in the original patch where limits were specified but the
handler didn't take care of the limits.
Signed-off-by: Arun Ajith S <aajith@arista.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Variable status is being assigned a value that is never read, it is
being re-assigned again later on. The assignment is redundant and can
be removed.

Cleans up clang scan build warning:
drivers/net/ethernet/myricom/myri10ge/myri10ge.c:582:7: warning: Although
the value stored to 'status' is used in the enclosing expression, the
value is never actually read from 'status' [deadcode.DeadStores]
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

It is unnecessary to call spin_lock_bh() for you are already in a tasklet.
Signed-off-by: Yunbo Yu <yuyunbo519@gmail.com>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/microchip/lan966x/lan966x_main.c
  d08ed852 ("net: lan966x: Make sure to release ptp interrupt")
  c8349639 ("net: lan966x: Add FDMA functionality")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Pull networking fixes from Paolo Abeni:
 "Including fixes from xfrm and can.

  Current release - regressions:

   - rxrpc: restore removed timer deletion

  Current release - new code bugs:

   - gre: fix device lookup for l3mdev use-case

   - xfrm: fix egress device lookup for l3mdev use-case

  Previous releases - regressions:

   - sched: cls_u32: fix netns refcount changes in u32_change()

   - smc: fix sock leak when release after smc_shutdown()

   - xfrm: limit skb_page_frag_refill use to a single page

   - eth: atlantic: invert deep par in pm functions, preventing null
     derefs

   - eth: stmmac: use readl_poll_timeout_atomic() in atomic state

  Previous releases - always broken:

   - gre: fix skb_under_panic on xmit

   - openvswitch: fix OOB access in reserve_sfa_size()

   - dsa: hellcreek: calculate checksums in tagger

   - eth: ice: fix crash in switchdev mode

   - eth: igc:
      - fix infinite loop in release_swfw_sync
      - fix scheduling while atomic"

* tag 'net-5.18-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (37 commits)
  drivers: net: hippi: Fix deadlock in rr_close()
  selftests: mlxsw: vxlan_flooding_ipv6: Prevent flooding of unwanted packets
  selftests: mlxsw: vxlan_flooding: Prevent flooding of unwanted packets
  nfc: MAINTAINERS: add Bug entry
  net: stmmac: Use readl_poll_timeout_atomic() in atomic state
  doc/ip-sysctl: add bc_forwarding
  netlink: reset network and mac headers in netlink_dump()
  net: mscc: ocelot: fix broken IP multicast flooding
  net: dsa: hellcreek: Calculate checksums in tagger
  net: atlantic: invert deep par in pm functions, preventing null derefs
  can: isotp: stop timeout monitoring when no first frame was sent
  bonding: do not discard lowest hash bit for non layer3+4 hashing
  net: lan966x: Make sure to release ptp interrupt
  ipv6: make ip6_rt_gc_expire an atomic_t
  net: Handle l3mdev in ip_tunnel_init_flow
  l3mdev: l3mdev_master_upper_ifindex_by_index_rcu should be using netdev_master_upper_dev_get_rcu
  net/sched: cls_u32: fix possible leak in u32_init_knode()
  net/sched: cls_u32: fix netns refcount changes in u32_change()
  powerpc: Update MAINTAINERS for ibmvnic and VAS
  net: restore alpha order to Ethernet devices in config
  ...

Use kzalloc rather than duplicating its implementation, which
makes code simple and easy to understand.
Signed-off-by: Haowen Bai <baihaowen@meizu.com>
Link: https://lore.kernel.org/r/1650277333-31090-1-git-send-email-baihaowen@meizu.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

Using pm_runtime_resume_and_get is more appropriate
for simplifing code
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn>
Link: https://lore.kernel.org/r/20220418062921.2557884-1-chi.minghao@zte.com.cnSigned-off-by: Paolo Abeni <pabeni@redhat.com>

There is a deadlock in rr_close(), which is shown below:

   (Thread 1)                |      (Thread 2)
                             | rr_open()
rr_close()                   |  add_timer()
 spin_lock_irqsave() //(1)   |  (wait a time)
 ...                         | rr_timer()
 del_timer_sync()            |  spin_lock_irqsave() //(2)
 (wait timer to stop)        |  ...

We hold rrpriv->lock in position (1) of thread 1 and
use del_timer_sync() to wait timer to stop, but timer handler
also need rrpriv->lock in position (2) of thread 2.
As a result, rr_close() will block forever.

This patch extracts del_timer_sync() from the protection of
spin_lock_irqsave(), which could let timer handler to obtain
the needed lock.
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Link: https://lore.kernel.org/r/20220417125519.82618-1-duoming@zju.edu.cnSigned-off-by: Paolo Abeni <pabeni@redhat.com>

Pull xtensa fixes from Max Filippov:

 - fix patching CPU selection in patch_text

 - fix potential deadlock in ISS platform serial driver

 - fix potential register clobbering in coprocessor exception handler

* tag 'xtensa-20220416' of https://github.com/jcmvbkbc/linux-xtensa:
  xtensa: fix a7 clobbering in coprocessor context load/store
  arch: xtensa: platforms: Fix deadlock in rs_close()
  xtensa: patch_text: Fixup last cpu should be master

Pull erofs fixes from Gao Xiang:
 "One patch to fix a use-after-free race related to the on-stack
  z_erofs_decompressqueue, which happens very rarely but needs to be
  fixed properly soon.

  The other patch fixes some sysfs Sphinx warnings"

* tag 'erofs-for-5.18-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
  Documentation/ABI: sysfs-fs-erofs: Fix Sphinx errors
  erofs: fix use-after-free of on-stack io[]

This reverts commit 5a519c8f.

It turns out that making the pipe almost arbitrarily large has some
rather unexpected downsides.  The kernel test robot reports a kernel
warning that is due to pipe->max_usage now growing to the point where
the iter_file_splice_write() buffer allocation can no longer be
satisfied as a slab allocation, and the

        int nbufs = pipe->max_usage;
        struct bio_vec *array = kcalloc(nbufs, sizeof(struct bio_vec),
                                        GFP_KERNEL);

code sequence there will now always fail as a result.

That code could be modified to use kvcalloc() too, but I feel very
uncomfortable making those kinds of changes for a very niche use case
that really should have other options than make these kinds of
fundamental changes to pipe behavior.

Maybe the CRIU process dumping should be multi-threaded, and use
multiple pipes and multiple cores, rather than try to use one larger
pipe to minimize splice() calls.
Reported-by: kernel test robot <oliver.sang@intel.com>
Link: https://lore.kernel.org/all/20220420073717.GD16310@xsang-OptiPlex-9020/
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The first "if" condition in __memcpy_flushcache is supposed to align the
"dest" variable to 8 bytes and copy data up to this alignment.  However,
this condition may misbehave if "size" is greater than 4GiB.

The statement min_t(unsigned, size, ALIGN(dest, 8) - dest); casts both
arguments to unsigned int and selects the smaller one.  However, the
cast truncates high bits in "size" and it results in misbehavior.

For example:

	suppose that size == 0x100000001, dest == 0x200000002
	min_t(unsigned, size, ALIGN(dest, 8) - dest) == min_t(0x1, 0xe) == 0x1;
	...
	dest += 0x1;

so we copy just one byte "and" dest remains unaligned.

This patch fixes the bug by replacing unsigned with size_t.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The test verifies that packets are correctly flooded by the bridge and
the VXLAN device by matching on the encapsulated packets at the other
end. However, if packets other than those generated by the test also
ingress the bridge (e.g., MLD packets), they will be flooded as well and
interfere with the expected count.

Make the test more robust by making sure that only the packets generated
by the test can ingress the bridge. Drop all the rest using tc filters
on the egress of 'br0' and 'h1'.

In the software data path, the problem can be solved by matching on the
inner destination MAC or dropping unwanted packets at the egress of the
VXLAN device, but this is not currently supported by mlxsw.

Fixes: d01724dd ("selftests: mlxsw: spectrum-2: Add a test for VxLAN flooding with IPv6")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Amit Cohen <amcohen@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The test verifies that packets are correctly flooded by the bridge and
the VXLAN device by matching on the encapsulated packets at the other
end. However, if packets other than those generated by the test also
ingress the bridge (e.g., MLD packets), they will be flooded as well and
interfere with the expected count.

Make the test more robust by making sure that only the packets generated
by the test can ingress the bridge. Drop all the rest using tc filters
on the egress of 'br0' and 'h1'.

In the software data path, the problem can be solved by matching on the
inner destination MAC or dropping unwanted packets at the egress of the
VXLAN device, but this is not currently supported by mlxsw.

Fixes: 94d302de ("selftests: mlxsw: Add a test for VxLAN flooding")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Amit Cohen <amcohen@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ido Schimmel says:

====================
mlxsw: Line cards status tracking

When a line card is provisioned, netdevs corresponding to the ports
found on the line card are registered. User space can then perform
various logical configurations (e.g., splitting, setting MTU) on these
netdevs.

However, since the line card is not present / powered on (i.e., it is
not in 'active' state), user space cannot access the various components
found on the line card. For example, user space cannot read the
temperature of gearboxes or transceiver modules found on the line card
via hwmon / thermal. Similarly, it cannot dump the EEPROM contents of
these transceiver modules. The above is only possible when the line card
becomes active.

This patchset solves the problem by tracking the status of each line
card and invoking callbacks from interested parties when a line card
becomes active / inactive.

Patchset overview:

Patch #1 adds the infrastructure in the line cards core that allows
users to registers a set of callbacks that are invoked when a line card
becomes active / inactive. To avoid races, if a line card is already
active during registration, the got_active() callback is invoked.

Patches #2-#3 are preparations.

Patch #4 changes the port module core to register a set of callbacks
with the line cards core. See detailed description with examples in the
commit message.

Patches #5-#6 do the same with regards to thermal / hwmon support, so
that user space will be able to monitor the temperature of various
components on the line card when it becomes active.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Add callback functions for line card 'hwmon' initialization and
de-initialization. Each line card is associated with the relevant
'hwmon' device, which may contain thermal attributes for the cages
and gearboxes found on this line card.

The line card 'hwmon' initialization / de-initialization APIs are to be
called when line card is set to active / inactive state by
got_active() / got_inactive() callbacks from line card state machine.

For example cage temperature for module #9 located at line card #7 will
be exposed by utility 'sensors' like:
linecard#07
front panel 009:	+32.0C  (crit = +70.0C, emerg = +80.0C)
And temperature for gearbox #3 located at line card #5 will be exposed
like:
linecard#05
gearbox 003:		+41.0C  (highest = +41.0C)
Signed-off-by: Vadim Pasternak <vadimp@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>