mlxsw: Convert does-RIF-have-this-netdev queries to a dedicated helper

In a number of places, a netdevice underlying a RIF is obtained only to
compare it to another pointer. In order to clean up the interface between
the router and the other modules, add a new helper to specifically answer
this question, and convert the relevant uses to this new interface.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: Convert RIF-has-netdevice queries to a dedicated helper

In a number of places, a netdevice underlying a RIF is obtained only to
check if it a NULL pointer. In order to clean up the interface between the
router and the other modules, add a new helper to specifically answer this
question, and convert the relevant uses to this new interface.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_mr: Update egress RIF list before route's action

Each multicast route that is forwarding packets (as opposed to trapping
them) points to a list of egress router interfaces (RIFs) through which
packets are replicated.

A route's action can transition from trap to forward when a RIF is
created for one of the route's egress virtual interfaces (eVIF). When
this happens, the route's action is first updated and only later the
list of egress RIFs is committed to the device.

This results in the route pointing to an invalid list. In case the list
pointer is out of range (due to uninitialized memory), the device will
complain:

mlxsw_spectrum2 0000:06:00.0: EMAD reg access failed (tid=5733bf490000905c,reg_id=300f(pefa),type=write,status=7(bad parameter))

Fix this by first committing the list of egress RIFs to the device and
only later update the route's action.

Note that a fix is not needed in the reverse function (i.e.,
mlxsw_sp_mr_route_evif_unresolve()), as there the route's action is
first updated and only later the RIF is removed from the list.

Cc: stable@vger.kernel.org
Fixes: c011ec1bbfd6 ("mlxsw: spectrum: Add the multicast routing offloading logic")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://lore.kernel.org/r/20210506072308.3834303-1-idosch@idosch.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mlxsw: spectrum_mr: Use flexible-array member instead of zero-length array

Suppresses the following coccinelle warning:

drivers/net/ethernet/mellanox/mlxsw/spectrum_mr.c:18:15-19: WARNING use flexible-array member instead

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_mr: Fix list iteration in error path

list_for_each_entry_from_reverse() iterates backwards over the list from
the current position, but in the error path we should start from the
previous position.

Fix this by using list_for_each_entry_continue_reverse() instead.

This suppresses the following error from coccinelle:

drivers/net/ethernet/mellanox/mlxsw//spectrum_mr.c:655:34-38: ERROR:
invalid reference to the index variable of the iterator on line 636

Fixes: c011ec1bbfd6 ("mlxsw: spectrum: Add the multicast routing offloading logic")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_mr: Protect multicast route list with a lock

Protect the per-table multicast route list with a lock and remove RTNL
from the delayed work that periodically updates the kernel about packets
and bytes statistics from each multicast route.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_mr: Protect multicast table list with a lock

The multicast table list is traversed from a delayed work that
periodically updates the kernel about packets and bytes statistics from
each multicast route.

The list is currently protected by RTNL, but subsequent patches will
remove the driver's dependence on this contended lock.

In order to be able to remove dependence on RTNL in the next patch,
guard this list with a dedicated mutex.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_mr: Publish multicast route after writing it to the device

The driver periodically traverses the linked list of multicast routes
and updates the kernel about packets and bytes statistics from each
multicast route. These statistics are read from a counter associated
with the route when it is written to the device.

Currently, multicast routes are published via this linked list before
they are associated with a counter. Despite that, it is not possible for
the driver to access an invalid counter because the delayed work that
reads the statistics and multicast route addition / deletion are
mutually exclusive using RTNL.

In order to be able to remove RTNL, the list needs to be protected by a
dedicated lock, but any route published via the list must have an
associated counter, otherwise the driver will access an invalid counter.

Solve this by re-ordering the operations during multicast route addition
so that the route is only added to the linked list after it was written
to the device. Similarly, during deletion the route is first removed
from the linked list before its deletion from the device.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: Replace zero-length array with flexible-array member

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
int stuff;
struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Tested-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: Replace license text with SPDX identifiers and adjust copyrights

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_mr_tcam: Push Spectrum-specific operations into a separate file

Since Spectrum-2 has different handling of TCAM, push Spectrum MR TCAM
bits to a separate file accessible by ops which allows to implement
Spectrum-2 specific ops.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_mr: Add ipv6 specific operations

Populate the various operation structures meant for IPv6 with logic
unique to that protocol suite.

Signed-off-by: Yuval Mintz <yuvalm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_router: Make IPMR-related APIs family agnostic

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: Yuval Mintz <yuvalm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_mr: Convert into using mr_mfc

Current multicast routing logic in driver assumes it's always meant to
deal with IPv4 multicast routes, leaving several placeholders for
later IPv6 support [currently usually WARN()].

This patch changes the driver's internal multicast route struct into
holding a common mr_mfc instead of the IPv4 mfc_cache.
The various placeholders are grouped into 2:
- Functions that require only the common bits; These remain and the
restriction for IPv4-only is lifted.
- Function that require IPv4-specifics - for handling these functions
we add sets of operations that encapsulate the protocol differences

Signed-off-by: Yuval Mintz <yuvalm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_mr: Pass protocol as part of catchall route params

Since commit c011ec1bbfd6 ("mlxsw: spectrum: Add the multicast routing
offloading logic") spectrum_mr did not populate the protocol portion of
the catcahall_route_params; mr-tcam logic worked correctly for ipv4
since the enum value for MLXSW_SP_L3_PROTO_IPV4 is '0'.

Explicitly fill the protocol as we'll soon need to differentiate between
ipv4 and ipv6.

Signed-off-by: Yuval Mintz <yuvalm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ip6mr: Add refcounting to mfc

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: Yuval Mintz <yuvalm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipmr, ip6mr: Make mfc_cache a common structure

mfc_cache and mfc6_cache are almost identical - the main difference is
in the origin/group addresses and comparison-key. Make a common
structure encapsulating most of the multicast routing logic - mr_mfc
and convert both ipmr and ip6mr into using it.

For easy conversion [casting, in this case] mr_mfc has to be the first
field inside every multicast routing abstraction utilizing it.

Signed-off-by: Yuval Mintz <yuvalm@mellanox.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum: mr: Make the function mlxsw_sp_mr_dev_vif_lookup static

The function is only used internally in spectrum_mr.c and is not declared
in the header file, thus make it static.

Cleans up sparse warning:
symbol 'mlxsw_sp_mr_dev_vif_lookup' was not declared. Should it be static?

Fixes: c011ec1bbfd6 ("mlxsw: spectrum: Add the multicast routing offloading logic")
Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum: mr: Fix various endianness issues

Fix various endianness issues in comparisons and assignments. The fix is
entirely cosmetic as all the values fixed are endianness-agnostic.

Cleans up sparse warnings:
spectrum_mr.c:156:49: warning: restricted __be32 degrades to integer
spectrum_mr.c:206:26: warning: restricted __be32 degrades to integer
spectrum_mr.c:212:31: warning: incorrect type in assignment (different
base types)
spectrum_mr.c:212:31: expected restricted __be32 [usertype] addr4
spectrum_mr.c:212:31: got unsigned int
spectrum_mr.c:214:32: warning: incorrect type in assignment (different
base types)
spectrum_mr.c:214:32: expected restricted __be32 [usertype] addr4
spectrum_mr.c:214:32: got unsigned int
spectrum_mr.c:461:16: warning: restricted __be32 degrades to integer
spectrum_mr.c:461:49: warning: restricted __be32 degrades to integer

Fixes: c011ec1bbfd6 ("mlxsw: spectrum: Add the multicast routing offloading logic")
Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum: mr: Support trap-and-forward routes

Add the support of trap-and-forward route action in the multicast routing
offloading logic. A route will be set to trap-and-forward action if one (or
more) of its output interfaces is not offload-able, i.e. does not have a
valid Spectrum RIF.

This way, a route with mixed output VIFs list, which contains both
offload-able and un-offload-able devices can go through partial offloading
in hardware, and the rest will be done in the kernel ipmr module.

Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum: fix uninitialized value in err

In the unlikely event that mfc->mfc_un.res.ttls[i] is 255 for all
values of i from 0 to MAXIVS-1, the err is not set at all and hence
has a garbage value on the error return at the end of the function,
so initialize it to 0. Also, the error return check on err and goto
to err: inside the for loop makes it impossible for err to be zero
at the end of the for loop, so we can remove the redundant err check
at the end of the loop.

Detected by CoverityScan CID#1457207 ("Unitialized scalar value")

Fixes: c011ec1bbfd6 ("mlxsw: spectrum: Add the multicast routing offloading logic")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Yotam Gigi <yotamg@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum: Add the multicast routing offloading logic

Add the multicast router offloading logic, which is in charge of handling
the VIF and MFC notifications and translating it to the hardware logic API.

The offloading logic has to overcome several obstacles in order to safely
comply with the kernel multicast router user API:
- It must keep track of the mapping between VIFs to netdevices. The user
can add an MFC cache entry pointing to a VIF, delete the VIF and add
re-add it with a different netdevice. The offloading logic has to handle
this in order to be compatible with the kernel logic.
- It must keep track of the mapping between netdevices to spectrum RIFs,
as the current hardware implementation assume having a RIF for every
port in a multicast router.
- It must handle routes pointing to pimreg device to be trapped to the
kernel, as the packet should be delivered to userspace.
- It must handle routes pointing tunnel VIFs. The current implementation
does not support multicast forwarding to tunnels, thus routes that point
to a tunnel should be trapped to the kernel.
- It must be aware of proxy multicast routes, which include both (*,*)
routes and duplicate routes. Currently proxy routes are not offloaded
and trigger the abort mechanism: removal of all routes from hardware and
triggering the traffic to go through the kernel.

The multicast routing offloading logic also updates the counters of the
offloaded MFC routes in a periodic work.

Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>