We currently do not perform accounting in the driver and thus can't
reject routes before resources are exceeded.

However, in order to make users aware of the fact that routes are no
longer offloaded we can return an error for routes configured after the
abort mechanism was triggered.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit 9776d325 ("net: Move call_fib_rule_notifiers up in
fib_nl_newrule") it is possible to forbid the installation of
unsupported FIB rules.

Have mlxsw return an error for non-default FIB rules in addition to the
existing extack message.

Example:
# ip rule add from 198.51.100.1 table 10
Error: mlxsw_spectrum: FIB rules not supported.

Note that offload is only aborted when non-default FIB rules are already
installed and merely replayed during module initialization.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Change the prefix for fib6_info struct elements from rt6i_ to fib6_.
rt6i_pcpu and rt6i_exception_bucket are left as is given that they
point to rt6_info entries.

Rename only; not functional change intended.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Convert all code paths referencing a FIB entry from
rt6_info to fib6_info.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce fib6_nh structure and move nexthop related data from
rt6_info and rt6_info.dst to fib6_nh. References to dev, gateway or
lwtstate from a FIB lookup perspective are converted to use fib6_nh;
datapath references to dst version are left as is.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Following previous patches driver is ready to handle notifications
arriving from ip6mr - start processing those when they arrive following
the same manner ipmr currently goes through.

This should enable driver to start offloading ipv6 multicast routes.
Signed-off-by: NYuval Mintz <yuvalm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

spectrum_router and spectrum_mr have several APIs that are used to
manipulate configurations originating from ipmr fib notifications.
Following previous patches all the protocol-specifics that are necessary
for the configuration are hidden within spectrum_mr. This allows us to
clean the API and make sure that other than choosing the mr_table based
on the fib notification family, spectrum_router wouldn't care about the
source of the notification when passing it onward to spectrum_mr.

This would later allow us to leverage the same code for fib
notifications originating from ip6mr.
Signed-off-by: NYuval Mintz <yuvalm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A step toward offloading IPv6 routing, this adds an additional
multicast routing table meant for IPv6 [with its underlying TCAM
region] and populates the default rule for IPv6 multicast packets.

Following this, ingress IPv6 multicast packets would be trapped and
delivered to the host CPU.
Signed-off-by: NYuval Mintz <yuvalm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since ipmr and ip6mr are using the same mr_mfc struct at their core, we
can now refactor the ipmr_cache_{hold,put} logic and apply refcounting
to both ipmr and ip6mr.
Signed-off-by: NYuval Mintz <yuvalm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Like vif notifications, move the notifier struct for MFC as well as its
helpers into a common file; Currently they're only used by ipmr.
Signed-off-by: NYuval Mintz <yuvalm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Update MTU of overlay loopback in accordance with the setting on the
tunnel netdevice.

Fixes: 0063587d ("mlxsw: spectrum: Support decap-only IP-in-IP tunnels")
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move the function so that it can be called without forward declaration
from a function that will be added in a follow-up patch.

Fixes: 0063587d ("mlxsw: spectrum: Support decap-only IP-in-IP tunnels")
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to abstract away access to the
ipv6.sysctl.multipath_hash_policy variable, which is not available on
systems compiled without IPv6 support, introduce a wrapper function
ip6_multipath_hash_policy() that falls back to 0 on non-IPv6 systems.

Use this wrapper from mlxsw/spectrum_router instead of a direct
reference.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Similar to 28678f07 ("mlxsw: spectrum_router: Update multipath hash
parameters upon netevents") for IPv4, make sure the kernel and asic are
using the same hash algorithm for path selection.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Tested-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rename NETEVENT_MULTIPATH_HASH_UPDATE to
NETEVENT_IPV4_MPATH_HASH_UPDATE to denote it relates to a change
in the IPv4 hash policy.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Reviewed-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For some netdevices, for which mlxsw offloads mirroring, may have a
complex relationship between the declared intent and low-level
device configuration.

Trying to accurately track which changes might influence offloading
decisions is finicky and error-prone. Instead, this patch introduces a
function mlxsw_sp_span_entry_respin, which re-queries the configuration
anew and, if different, removes the existing offloads and installs new
ones.

Call this function strategically at event handlers that might influence
the mirroring configuration.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When mlxsw replaces (or deletes) a route it removes the offload
indication from the replaced route. This is problematic for IPv4 routes,
as the offload indication is stored in the fib_info which is usually
shared between multiple routes.

Instead of unconditionally clearing the offload indication, only clear
it if no other route is using the fib_info.

Fixes: 3984d1a8 ("mlxsw: spectrum_router: Provide offload indication using nexthop flags")
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Reported-by: NAlexander Petrovskiy <alexpe@mellanox.com>
Tested-by: NAlexander Petrovskiy <alexpe@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use NL_SET_ERR_MSG_MOD helper which adds the module name instead
of specifying the prefix each time.
Signed-off-by: NArkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

struct ip_tunnel_parm, where GRE and several other tunnel types hold
information, is IPv4-specific. The current router / ipip code in mlxsw
however uses it as if it were generic.

Make it clear that it's not. Rename many functions from _params_ to
_params4_. mlxsw_sp_ipip_parms_saddr() and _daddr() take a proto
argument to dispatch on it. Move the dispatch logic to
mlxsw_sp_ipip_netdev_saddr() and _daddr(), and replace with
single-protocol functions.

In struct mlxsw_sp_ipip_entry, move the "parms" field to a (for the time
being, singleton) union. Update users throughout.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since mlxsw_sp_fib_create() and mlxsw_sp_mr_table_create()
use ERR_PTR macro to propagate int err through return of a pointer,
the return value is not NULL in case of failure. So if one
of the calls fails, one of vr->fib4, vr->fib6 or vr->mr4_table
is not NULL and mlxsw_sp_vr_is_used wrongly assumes
that vr is in use which leads to crash like following one:

[ 1293.949291] BUG: unable to handle kernel NULL pointer dereference at 00000000000006c9
[ 1293.952729] IP: mlxsw_sp_mr_table_flush+0x15/0x70 [mlxsw_spectrum]

Fix this by using local variables to hold the pointers and set vr->*
only in case everything went fine.

Fixes: 76610ebb ("mlxsw: spectrum_router: Refactor virtual router handling")
Fixes: a3d9bc50 ("mlxsw: spectrum_router: Extend virtual routers with IPv6 support")
Fixes: d42b0965 ("mlxsw: spectrum_router: Add multicast routes notification handling functionality")
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Driver periodically samples all neighbors configured in device
in order to update the kernel regarding their state. When finding
an entry configured in HW that doesn't show in neigh_lookup()
driver logs an error message.
This introduces a race when removing multiple neighbors -
it's possible that a given entry would still be configured in HW
as its removal is still being processed but is already removed
from the kernel's neighbor tables.

Simply remove the error message and gracefully accept such events.

Fixes: c723c735 ("mlxsw: spectrum_router: Periodically update the kernel's neigh table")
Fixes: 60f040ca ("mlxsw: spectrum_router: Periodically dump active IPv6 neighbours")
Signed-off-by: NYuval Mintz <yuvalm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In commit fc922bb0 ("mlxsw: spectrum_router: Use one LPM tree for
all virtual routers") I tried to make sure only used prefix lengths are
present in the LPM tree shared between all virtual routers.

However, this optimization had to be removed in commit a69518cf
("mlxsw: spectrum_router: Avoid expensive lookup during route removal"),
since determining the used prefix lengths required us to traverse all
the active virtual routers, which could result in a hung task depending
on the number of VRFs and whether routes were removed due to abort or
not.

Re-introduce the optimization by moving the prefix usage accounting from
the virtual routers to the LPM tree, as this accounting is only used in
order to determine the tree's structure.

To make the sharing of the trees more explicit, the two trees (for IPv4
and IPv6) are stored in the shared router struct and upon the creation
of a virtual router it is immediately bound to both.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Next patch will try to optimize the LPM tree and make sure only used
prefix lengths are present, to avoid unnecessary look-ups.

Pass the currently removed FIB node to the unlinking function as its
associated prefix length is a potential candidate for removal from the
tree.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, each FIB (IPv4 / IPv6) in a virtual router holds a prefix
usage that is used to choose a matching LPM tree, but also to check if
the FIB is empty, so that the LPM tree could be unbound.

Next patches will remove the reliance on the per-FIB prefix usage for
LPM tree matching. Keeping it only to check if the FIB is empty is a
waste, since we can use the nodes ({Prefix, Length}) list instead.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a new LPM tree is created, we try to replace the trees in the
existing virtual routers with it. If we fail, the tree needs to be
freed.

Currently, this does not happen in the unlikely case where we fail to
bind the tree to the first virtual router, since its reference count
never transitions from 1 to 0.

Fix that by taking a reference before binding the tree.

Fixes: fc922bb0 ("mlxsw: spectrum_router: Use one LPM tree for all virtual routers")
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When routing ip packets, the kernel is setting the SKB's priority
based on the tos field of the packet.
Imitate this behavior in the mlxsw router, having the internal
switch priority of a routed packet determined according to its DS
field.
Signed-off-by: NYuval Mintz <yuvalm@mellanox.com>
Signed-off-by: NNogah Frankel <nogahf@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit eb789980 ("mlxsw: spectrum_router: Populate adjacency
entries according to weights") the driver includes support for
non-equal-cost multipath, but IPv4 nexthops were the only user.

Now that the kernel supports weighted IPv6 nexthops, we can extend the
driver to support it as well.

This is done by assigning each nexthop its configured weight, so that it
will be populated accordingly in the device's adjacency table. The
`weight` parameter is also taken into account when comparing nexthop
groups in order not to consolidate non-identical groups.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When we remove the neighbour associated with a nexthop we should always
refuse to write the nexthop to the adjacency table. Regardless if it is
already present in the table or not.

Otherwise, we risk dereferencing the NULL pointer that was set instead
of the neighbour.

Fixes: a7ff87ac ("mlxsw: spectrum_router: Implement next-hop routing")
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Reported-by: NAlexander Petrovskiy <alexpe@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 63dd00fa.

RAUHT DELETE_ALL seems to trigger a bug in FW. That manifests by later
calls to RAUHT ADD of an IPv6 neighbor to fail with "bad parameter"
error code.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Fixes: 63dd00fa ("mlxsw: spectrum_router: Add batch neighbour deletion")
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The function mlxsw_sp_nexthop_rif_update() walks the list of nexthops
associated with a RIF, and updates the corresponding entries in the
switch. It is used in particular when a tunnel underlay netdevice moves
to a different VRF, and all the nexthops are migrated over to a new RIF.
The problem is that each nexthop holds a reference to its RIF, and that
is not updated. So after the old RIF is gone, further activity on these
nexthops (such as downing the underlay netdevice) dereferences a
dangling pointer.

Fix the issue by updating rif of impacted nexthops before calling
mlxsw_sp_nexthop_rif_update().

Fixes: 0c5f1cd5 ("mlxsw: spectrum_router: Generalize __mlxsw_sp_ipip_entry_update_tunnel()")
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some tunnels that are offloadable on their own can nonetheless be
demoted to slow path if their local address is in conflict with that of
another tunnel. When a route is formed for such a tunnel,
mlxsw_sp_nexthop_ipip_init() fails to find the corresponding IPIP entry,
and that triggers a FIB abort.

Resolve the problem by not assuming that a tunnel for which
mlxsw_sp_ipip_ops.can_offload() holds also automatically has an IPIP
entry.

Fixes: af641713 ("mlxsw: spectrum_router: Onload conflicting tunnels")
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The mlxsw driver currently doesn't offload GRE tunnels if they have the
same local address and use the same underlay VRF. When such a situation
arises, the tunnels in conflict are demoted to slow path.

However, the current code only verifies this condition on tunnel
creation and tunnel change, not when a tunnel is moved to a different
VRF. When the tunnel has no bound device, underlay and overlay are the
same. Thus moving a tunnel moves the underlay as well, and that can
cause local address conflict.

So modify mlxsw_sp_netdevice_ipip_ol_vrf_event() to check if there are
any conflicting tunnels, and demote them if yes.

Fixes: af641713 ("mlxsw: spectrum_router: Onload conflicting tunnels")
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a new local route is added, an IPIP entry is looked up to determine
whether the route should be offloaded as a tunnel decap or as a trap.
That decision should take into account whether the tunnel netdevice in
question is actually IFF_UP, and only install a decap offload if it is.

Fixes: 0063587d ("mlxsw: spectrum: Support decap-only IP-in-IP tunnels")
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In commit 4a3c67a6 ("mlxsw: spectrum_router: Don't batch neighbour
deletion") I removed the support for batch deletion of neighbours on a
router interface (RIF) since at that time the firmware did not support
it for IPv6 neighbours.

This is now supported by the version enforced by the driver, so there is
no reason to delete neighbours one by one anymore.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the bound device of a tunnel device is down, encapsulated packets
are not egressed anymore, but tunnel decap still works. Extend
mlxsw_sp_nexthop_rif_update() to take IFF_UP into consideration when
deciding whether a given next hop should be offloaded.

Because the new logic was added to mlxsw_sp_nexthop_rif_update(), this
fixes the case where a newly-added tunnel has a down bound device, which
would previously be fully offloaded. Now the down state of the bound
device is noted and next hops forwarding to such tunnel are not
offloaded.

In addition to that, notice NETDEV_UP and NETDEV_DOWN of a bound device
to force refresh of tunnel encap route offloads.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Changes to L3 tunnel netdevices (through `ip tunnel change' as well as
`ip link set') lead to NETDEV_CHANGE being generated on the tunnel
device. Because what is relevant for the tunnel in question depends on
the tunnel type, handling of the event is dispatched to the IPIP module
through a newly-added interface mlxsw_sp_ipip_ops.ol_netdev_change().

IPIP tunnels now remember the last set of tunnel parameters in struct
mlxsw_sp_ipip_entry.parms, and use it to figure out what exactly has
changed.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a bound device of a tunnel netdevice changes VRF, the loopback RIF
that backs the tunnel needs to be updated and existing encapsulating
routes need to be refreshed.

Note that several tunnels can share the same bound device, in which case
all the impacted tunnels need to be updated.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The approach for offloading IP tunnels implemented currently by mlxsw
doesn't allow two tunnels that have the same local IP address in the
same (underlay) VRF. Previously, offloads were introduced on demand as
encap routes were formed. When such a route was created that would cause
offload of a conflicting tunnel, mlxsw_sp_ipip_entry_create() would
detect it and return -EEXIST, which would propagate up and cause FIB
abort.

Now however IPIP entries are created as soon as an offloadable netdevice
is created, and the failure prevents creation of such device.
Furthermore, if the driver is installed at the point where such
conflicting tunnels exist, the failure actually prevents successful
modprobe.

Furthermore, follow-up patches implement handling of NETDEV_CHANGE due
to the local address change. However, NETDEV_CHANGE can't be vetoed. The
failure merely means that the offloads weren't updated, but the change
in Linux configuration is not rolled back. It is thus desirable to have
a robust way of handling these conflicts, which can later be reused for
handling NETDEV_CHANGE as well.

To fix this, when a conflicting tunnel is created, instead of failing,
simply pull the old tunnel to slow path and reject offloading the
new one.

Introduce two functions: mlxsw_sp_ipip_entry_demote_tunnel() and
mlxsw_sp_ipip_demote_tunnel_by_saddr() to handle this. Make them both
public, because they will be useful later on in this patchset.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When trying to determine whether there are other offloaded tunnels with
the same local address, mlxsw_sp_ipip_entry_create() should look for a
tunnel with matching UL protocol, matching saddr, in the same VRF.
However instead of taking into account the UL protocol of the tunnel
netdevice (which mlxsw_sp_ipip_entry_saddr_matches() then compares to
the UL protocol of inspected IPIP entry), it deduces the UL protocol
from the inspected IPIP entry (and that's compared to itself).

This is currently immaterial, because only one tunnel type is offloaded,
and therefore the UL protocol always matches, but introducing support
for a tunnel with IPv6 underlay would uncover this error.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The work that needs to be done to update HW configuration in response to
changes is similar to what __mlxsw_sp_ipip_entry_update_tunnel() already
does, but with a number of twists: each change requires a different
subset of things to happen. Extend the function to support all these
uses, and allow finely-grained configuration of what should happen at
each call through a suite of function arguments.

Publish the updated function to allow use from the spectrum_ipip module.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>