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Vladimir Oltean 72c3b0c735 net: dsa: felix: manage host flooding using a specific driver callback
At the time - commit 7569459a52 ("net: dsa: manage flooding on the CPU
ports") - not introducing a dedicated switch callback for host flooding
made sense, because for the only user, the felix driver, there was
nothing different to do for the CPU port than set the flood flags on the
CPU port just like on any other bridge port.

There are 2 reasons why this approach is not good enough, however.

(1) Other drivers, like sja1105, support configuring flooding as a
    function of {ingress port, egress port}, whereas the DSA
    ->port_bridge_flags() function only operates on an egress port.
    So with that driver we'd have useless host flooding from user ports
    which don't need it.

(2) Even with the felix driver, support for multiple CPU ports makes it
    difficult to piggyback on ->port_bridge_flags(). The way in which
    the felix driver is going to support host-filtered addresses with
    multiple CPU ports is that it will direct these addresses towards
    both CPU ports (in a sort of multicast fashion), then restrict the
    forwarding to only one of the two using the forwarding masks.
    Consequently, flooding will also be enabled towards both CPU ports.
    However, ->port_bridge_flags() gets passed the index of a single CPU
    port, and that leaves the flood settings out of sync between the 2
    CPU ports.

This is to say, it's better to have a specific driver method for host
flooding, which takes the user port as argument. This solves problem (1)
by allowing the driver to do different things for different user ports,
and problem (2) by abstracting the operation and letting the driver do
whatever, rather than explicitly making the DSA core point to the CPU
port it thinks needs to be touched.

This new method also creates a problem, which is that cross-chip setups
are not handled. However I don't have hardware right now where I can
test what is the proper thing to do, and there isn't hardware compatible
with multi-switch trees that supports host flooding. So it remains a
problem to be tackled in the future.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-05-12 16:38:55 -07:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-05-12 16:15:30 -07:00
block Revert "block: release rq qos structures for queue without disk" 2022-05-02 10:06:40 -06:00
certs Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
crypto for-5.18/64bit-pi-2022-03-25 2022-03-26 12:01:35 -07:00
Documentation Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-05-12 16:15:30 -07:00
drivers net: dsa: felix: manage host flooding using a specific driver callback 2022-05-12 16:38:55 -07:00
fs Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-05-12 16:15:30 -07:00
include net: dsa: felix: manage host flooding using a specific driver callback 2022-05-12 16:38:55 -07:00
init Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
ipc fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-05-12 16:15:30 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-05-12 16:15:30 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm/readahead: Fix readahead with large folios 2022-05-05 00:47:29 -04:00
net net: dsa: felix: manage host flooding using a specific driver callback 2022-05-12 16:38:55 -07:00
samples samples/bpf: Reduce the sampling interval in xdp1_user 2022-04-20 14:58:29 -07:00
scripts objtool: Enable unreachable warnings for CLANG LTO 2022-04-19 21:58:48 +02:00
security hardening updates for v5.18-rc1-fix1 2022-03-31 11:43:01 -07:00
sound ASoC: Fixes for v5.18 2022-05-08 10:49:25 +02:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-05-12 16:15:30 -07:00
usr Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
virt Merge branch 'kvm-fixes-for-5.18-rc5' into HEAD 2022-04-29 12:39:34 -04:00
.clang-format genirq/msi: Make interrupt allocation less convoluted 2021-12-16 22:22:20 +01:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap Networking fixes for 5.18-rc7, including fixes from wireless, 2022-05-12 11:51:45 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: replace a Microchip AT91 maintainer 2022-02-09 11:30:01 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-05-12 16:15:30 -07:00
Makefile Linux 5.18-rc6 2022-05-08 13:54:17 -07:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.