Michael Chan says:

====================
bnxt_en: Error recovery optimizations.

This series implements some optimizations to error recovery.  One
patch adds an echo/reply mechanism with firmware to enhance error
detection.  The other patches speed up the recovery process by
polling config space earlier and to selectively initialize
context memory during re-initialization.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

We currently only log the error recovery settings if it is enabled.
In some cases, firmware disables error recovery after it was
initially enabled.  Without logging anything, the user will not be
aware of this change in setting.

Log it when error recovery is disabled.  Also, change the reset count
value from hexadecimal to decimal.
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This is a new async message that the firmware can send to check if it
can communicate with the driver.  This is an added error detection
scheme that firmware can use if it suspects errors in the PCIe
interface.  When the driver receives this async message, it will reply
back echoing some data in the async message.  If the firmware is not
getting the reply with the proper data after some retries, error
recovery will kick in.
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Reviewed-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If firmware provides the offset to the "context kind" field of the
relevant context memory blocks, we'll initialize just that field for
each block instead of initializing all of context memory.

Populate the bnxt_mem_init structure with the proper offset returned
by firmware.  If it is older firmware and the information is not
available, we set the offset to an invalid value and fall back to
the old behavior of initializing every byte.  Otherwise, we initialize
only the "context kind" byte at the offset.
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, the driver calls memset() to set all relevant context memory
used by the chip to the initial value.  This can take many milliseconds
with the potentially large number of context pages allocated for the
chip.

To make this faster, we only need to initialize the "context kind" field
of each block of context memory.  This patch sets up the infrastructure
to do that with the bnxt_mem_init structure.  In the next patch, we'll
add the logic to obtain the offset of the "context kind" from the
firmware.  This patch is not changing the current behavior of calling
memset() to initialize all relevant context memory.
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

During some fatal firmware error conditions, the PCI config space
register 0x2e which normally contains the subsystem ID will become
0xffff.  This register will revert back to the normal value after
the chip has completed core reset.  If we detect this condition,
we can poll this config register immediately for the value to revert.
Because we use config read cycles to poll this register, there is no
possibility of Master Abort if we happen to read it during core reset.
This speeds up recovery significantly as we don't have to wait for the
conservative min_time before polling MMIO to see if the firmware has
come out of reset.  As soon as this register changes value we can
proceed to re-initialize the device.
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Reviewed-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Newer devices may have local context memory instead of relying on the
host for backing store. In these cases, HWRM_FUNC_BACKING_STORE_QCAPS
will return a zero entry size to indicate contexts for which the host
should not allocate backing store.

Selectively allocate context memory based on device capabilities and
only enable backing store for the appropriate contexts.
Signed-off-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The main changes are the echo request/response from firmware for error
detection and the NO_FCS feature to transmit frames without FCS.
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Alexander Lobakin says:

====================
skbuff: introduce skbuff_heads bulking and reusing

Currently, all sorts of skb allocation always do allocate
skbuff_heads one by one via kmem_cache_alloc().
On the other hand, we have percpu napi_alloc_cache to store
skbuff_heads queued up for freeing and flush them by bulks.

We can use this cache not only for bulk-wiping, but also to obtain
heads for new skbs and avoid unconditional allocations, as well as
for bulk-allocating (like XDP's cpumap code and veth driver already
do).

As this might affect latencies, cache pressure and lots of hardware
and driver-dependent stuff, this new feature is mostly optional and
can be issued via:
 - a new napi_build_skb() function (as a replacement for build_skb());
 - existing {,__}napi_alloc_skb() and napi_get_frags() functions;
 - __alloc_skb() with passing SKB_ALLOC_NAPI in flags.

iperf3 showed 35-70 Mbps bumps for both TCP and UDP while performing
VLAN NAT on 1.2 GHz MIPS board. The boost is likely to be bigger
on more powerful hosts and NICs with tens of Mpps.

Note on skbuff_heads from distant slabs or pfmemalloc'ed slabs:
 - kmalloc()/kmem_cache_alloc() itself allows by default allocating
   memory from the remote nodes to defragment their slabs. This is
   controlled by sysctl, but according to this, skbuff_head from a
   remote node is an OK case;
 - The easiest way to check if the slab of skbuff_head is remote or
   pfmemalloc'ed is:

	if (!dev_page_is_reusable(virt_to_head_page(skb)))
		/* drop it */;

   ...*but*, regarding that most slabs are built of compound pages,
   virt_to_head_page() will hit unlikely-branch every single call.
   This check costed at least 20 Mbps in test scenarios and seems
   like it'd be better to _not_ do this.

Since v5 [4]:
 - revert flags-to-bool conversion and simplify flags testing in
   __alloc_skb() (Alexander Duyck).

Since v4 [3]:
 - rebase on top of net-next and address kernel build robot issue;
 - reorder checks a bit in __alloc_skb() to make new condition even
   more harmless.

Since v3 [2]:
 - make the feature mostly optional, so driver developers could
   decide whether to use it or not (Paolo Abeni).
   This reuses the old flag for __alloc_skb() and introduces
   a new napi_build_skb();
 - reduce bulk-allocation size from 32 to 16 elements (also Paolo).
   This equals to the value of XDP's devmap and veth batch processing
   (which were tested a lot) and should be sane enough;
 - don't waste cycles on explicit in_serving_softirq() check.

Since v2 [1]:
 - also cover {,__}alloc_skb() and {,__}build_skb() cases (became handy
   after the changes that pass tiny skbs requests to kmalloc layer);
 - cover the cache with KASAN instrumentation (suggested by Eric
   Dumazet, help of Dmitry Vyukov);
 - completely drop redundant __kfree_skb_flush() (also Eric);
 - lots of code cleanups;
 - expand the commit message with NUMA and pfmemalloc points (Jakub).

Since v1 [0]:
 - use one unified cache instead of two separate to greatly simplify
   the logics and reduce hotpath overhead (Edward Cree);
 - new: recycle also GRO_MERGED_FREE skbs instead of immediate
   freeing;
 - correct performance numbers after optimizations and performing
   lots of tests for different use cases.

[0] https://lore.kernel.org/netdev/20210111182655.12159-1-alobakin@pm.me
[1] https://lore.kernel.org/netdev/20210113133523.39205-1-alobakin@pm.me
[2] https://lore.kernel.org/netdev/20210209204533.327360-1-alobakin@pm.me
[3] https://lore.kernel.org/netdev/20210210162732.80467-1-alobakin@pm.me
[4] https://lore.kernel.org/netdev/20210211185220.9753-1-alobakin@pm.me
====================
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

napi_frags_finish() and napi_skb_finish() can only be called inside
NAPI Rx context, so we can feed NAPI cache with skbuff_heads that
got NAPI_MERGED_FREE verdict instead of immediate freeing.
Replace __kfree_skb() with __kfree_skb_defer() in napi_skb_finish()
and move napi_skb_free_stolen_head() to skbuff.c, so it can drop skbs
to NAPI cache.
As many drivers call napi_alloc_skb()/napi_get_frags() on their
receive path, this becomes especially useful.
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: David S. Miller <davem@davemloft.net>

{,__}napi_alloc_skb() is mostly used either for optional non-linear
receive methods (usually controlled via Ethtool private flags and off
by default) and/or for Rx copybreaks.
Use __napi_build_skb() here for obtaining skbuff_heads from NAPI cache
instead of inplace allocations. This includes both kmalloc and page
frag paths.
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: David S. Miller <davem@davemloft.net>

Reuse the old and forgotten SKB_ALLOC_NAPI to add an option to get
an skbuff_head from the NAPI cache instead of inplace allocation
inside __alloc_skb().
This implies that the function is called from softirq or BH-off
context, not for allocating a clone or from a distant node.

Cc: Alexander Duyck <alexander.duyck@gmail.com> # Simplified flags check
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of just bulk-flushing skbuff_heads queued up through
napi_consume_skb() or __kfree_skb_defer(), try to reuse them
on allocation path.
If the cache is empty on allocation, bulk-allocate the first
16 elements, which is more efficient than per-skb allocation.
If the cache is full on freeing, bulk-wipe the second half of
the cache (32 elements).
This also includes custom KASAN poisoning/unpoisoning to be
double sure there are no use-after-free cases.

To not change current behaviour, introduce a new function,
napi_build_skb(), to optionally use a new approach later
in drivers.

Note on selected bulk size, 16:
 - this equals to XDP_BULK_QUEUE_SIZE, DEV_MAP_BULK_SIZE
   and especially VETH_XDP_BATCH, which is also used to
   bulk-allocate skbuff_heads and was tested on powerful
   setups;
 - this also showed the best performance in the actual
   test series (from the array of {8, 16, 32}).

Suggested-by: Edward Cree <ecree.xilinx@gmail.com> # Divide on two halves
Suggested-by: Eric Dumazet <edumazet@google.com>   # KASAN poisoning
Cc: Dmitry Vyukov <dvyukov@google.com>             # Help with KASAN
Cc: Paolo Abeni <pabeni@redhat.com>                # Reduced batch size
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: David S. Miller <davem@davemloft.net>

NAPI cache structures will be used for allocating skbuff_heads,
so move their declarations a bit upper.
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: David S. Miller <davem@davemloft.net>

This function isn't much needed as NAPI skb queue gets bulk-freed
anyway when there's no more room, and even may reduce the efficiency
of bulk operations.
It will be even less needed after reusing skb cache on allocation path,
so remove it and this way lighten network softirqs a bit.
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: David S. Miller <davem@davemloft.net>

Just call __build_skb_around() instead of open-coding it.
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use unlikely() annotations for skbuff_head and data similarly to the
two other allocation functions and remove totally redundant goto.
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: David S. Miller <davem@davemloft.net>

__build_skb_around() can never fail and always returns passed skb.
Make it return void to simplify and optimize the code.
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: David S. Miller <davem@davemloft.net>

Eversince the introduction of __kmalloc_reserve(), "ip" argument
hasn't been used. _RET_IP_ is embedded inside
kmalloc_node_track_caller().
Remove the redundant macro and rename the function after it.
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: David S. Miller <davem@davemloft.net>

In preparation before reusing several functions in all three skb
allocation variants, move __alloc_skb() next to the
__netdev_alloc_skb() and __napi_alloc_skb().
No functional changes.
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: David S. Miller <davem@davemloft.net>

Robert Hancock says:

====================
Xilinx axienet updates

Updates to the Xilinx AXI Ethernet driver to add support for an additional
ethtool operation, and to support dynamic switching between 1000BaseX and
SGMII interface modes.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Newer versions of the Xilinx AXI Ethernet core (specifically version 7.2 or
later) allow the core to be configured with a PHY interface mode of "Both",
allowing either 1000BaseX or SGMII modes to be selected at runtime. Add
support for this in the driver to allow better support for applications
which can use both fiber and copper SFP modules.
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Document the new xlnx,switch-x-sgmii attribute which is used to indicate
that the Ethernet core supports dynamic switching between 1000BaseX and
SGMII.
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Hook up the nway_reset ethtool operation to the corresponding phylink
function so that "ethtool -r" can be supported.
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Eric Dumazet says:

====================
tcp: mem pressure vs SO_RCVLOWAT

First patch fixes an issue for applications using SO_RCVLOWAT
to reduce context switches.

Second patch is a cleanup.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Both tcp_data_ready() and tcp_stream_is_readable() share the same logic.

Add tcp_epollin_ready() helper to avoid duplication.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

While commit 24adbc16 ("tcp: fix SO_RCVLOWAT hangs with fat skbs")
fixed an issue vs too small sk_rcvbuf for given sk_rcvlowat constraint,
it missed to address issue caused by memory pressure.

1) If we are under memory pressure and socket receive queue is empty.
First incoming packet is allowed to be queued, after commit
76dfa608 ("tcp: allow one skb to be received per socket under memory pressure")

But we do not send EPOLLIN yet, in case tcp_data_ready() sees sk_rcvlowat
is bigger than skb length.

2) Then, when next packet comes, it is dropped, and we directly
call sk->sk_data_ready().

3) If application is using poll(), tcp_poll() will then use
tcp_stream_is_readable() and decide the socket receive queue is
not yet filled, so nothing will happen.

Even when sender retransmits packets, phases 2) & 3) repeat
and flow is effectively frozen, until memory pressure is off.

Fix is to consider tcp_under_memory_pressure() to take care
of global memory pressure or memcg pressure.

Fixes: 24adbc16 ("tcp: fix SO_RCVLOWAT hangs with fat skbs")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Arjun Roy <arjunroy@google.com>
Suggested-by: Wei Wang <weiwan@google.com>
Reviewed-by: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Tony Nguyen says:

====================
40GbE Intel Wired LAN Driver Updates 2021-02-12

This series contains updates to i40e, ice, and ixgbe drivers.

Maciej does cleanups on the following drivers.
For i40e, removes redundant check for XDP prog, cleans up no longer
relevant information, and removes an unused function argument.
For ice, removes local variable use, instead returning values directly.
Moves skb pointer from buffer to ring and removes an unneeded check for
xdp_prog in zero copy path. Also removes a redundant MTU check when
changing it.
For i40e, ice, and ixgbe, stores the rx_offset in the Rx ring as
the value is constant so there's no need for continual calls.

Bjorn folds a decrement into a while statement.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Guillaume Nault says:

====================
selftests: tc: Test tc-flower's MPLS features

A couple of patches for exercising the MPLS filters of tc-flower.

Patch 1 tests basic MPLS matching features: those that only work on the
first label stack entry (that is, the mpls_label, mpls_tc, mpls_bos and
mpls_ttl options).

Patch 2 tests the more generic "mpls" and "lse" options, which allow
matching MPLS fields beyond the first stack entry.

In both patches, special care is taken to skip these new tests for
incompatible versions of tc.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Add tests in tc_flower.sh for generic matching on MPLS Label Stack
Entries. The label, tc, bos and ttl fields are tested for the first
and second labels. For each field, the minimal and maximal values are
tested (the former at depth 1 and the later at depth 2).
There are also tests for matching the presence of a label stack entry
at a given depth.

In order to reduce the amount of code, all "lse" subcommands are tested
in match_mpls_lse_test(). Action "continue" is used, so that test
packets are evaluated by all filters. Then, we can verify if each
filter matched the expected number of packets.

Some versions of tc-flower produced invalid json output when dumping
MPLS filters with depth > 1. Skip the test if tc isn't recent enough.
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add tests in tc_flower.sh for mpls_label, mpls_tc, mpls_bos and
mpls_ttl. For each keyword, test the minimal and maximal values.

Selectively skip these new mpls tests for tc versions that don't
support them.
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Vladimir Oltean says:

====================
Cleanup in brport flags switchdev offload for DSA

The initial goal of this series was to have better support for
standalone ports mode on the DSA drivers like ocelot/felix and sja1105.
This turned out to require some API adjustments in both directions:
to the information presented to and by the switchdev notifier, and to
the API presented to the switch drivers by the DSA layer.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The chip can configure unicast flooding, broadcast flooding and learning.
Learning is per port, while flooding is per {ingress, egress} port pair
and we need to configure the same value for all possible ingress ports
towards the requested one.

While multicast flooding is not officially supported, we can hack it by
using a feature of the second generation (P/Q/R/S) devices, which is that
FDB entries are maskable, and multicast addresses always have an odd
first octet. So by putting a match-all for 00:01:00:00:00:00 addr and
00:01:00:00:00:00 mask at the end of the FDB, we make sure that it is
always checked last, and does not take precedence in front of any other
MDB. So it behaves effectively as an unknown multicast entry.

For the first generation switches, this feature is not available, so
unknown multicast will always be treated the same as unknown unicast.
So the only thing we can do is request the user to offload the settings
for these 2 flags in tandem, i.e.

ip link set swp2 type bridge_slave flood off
Error: sja1105: This chip cannot configure multicast flooding independently of unicast.
ip link set swp2 type bridge_slave flood off mcast_flood off
ip link set swp2 type bridge_slave mcast_flood on
Error: sja1105: This chip cannot configure multicast flooding independently of unicast.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We should not be unconditionally enabling address learning, since doing
that is actively detrimential when a port is standalone and not offloading
a bridge. Namely, if a port in the switch is standalone and others are
offloading the bridge, then we could enter a situation where we learn an
address towards the standalone port, but the bridged ports could not
forward the packet there, because the CPU is the only path between the
standalone and the bridged ports. The solution of course is to not
enable address learning unless the bridge asks for it.

We need to set up the initial port flags for no learning and flooding
everything, and also when the port joins and leaves the bridge.
The flood configuration was already configured ok for standalone mode
in ocelot_init, we just need to disable learning in ocelot_init_port.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In preparation of offloading the bridge port flags which have
independent settings for unknown multicast and for broadcast, we should
also start reserving one destination Port Group ID for the flooding of
broadcast packets, to allow configuring it individually.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ocelot_init sets up PGID_MC to include the CPU port module, and that is
fine, but the ocelot-8021q tagger removes the CPU port module from the
unknown multicast replicator. So after a transition from the default
ocelot tagger towards ocelot-8021q and then again towards ocelot,
multicast flooding towards the CPU port module will be disabled.

Fixes: e21268ef ("net: dsa: felix: perform switch setup for tag_8021q")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

There are multiple ways in which a PORT_BRIDGE_FLAGS attribute can be
expressed by the bridge through switchdev, and not all of them can be
emulated by DSA mid-layer API at the same time.

One possible configuration is when the bridge offloads the port flags
using a mask that has a single bit set - therefore only one feature
should change. However, DSA currently groups together unicast and
multicast flooding in the .port_egress_floods method, which limits our
options when we try to add support for turning off broadcast flooding:
do we extend .port_egress_floods with a third parameter which b53 and
mv88e6xxx will ignore? But that means that the DSA layer, which
currently implements the PRE_BRIDGE_FLAGS attribute all by itself, will
see that .port_egress_floods is implemented, and will report that all 3
types of flooding are supported - not necessarily true.

Another configuration is when the user specifies more than one flag at
the same time, in the same netlink message. If we were to create one
individual function per offloadable bridge port flag, we would limit the
expressiveness of the switch driver of refusing certain combinations of
flag values. For example, a switch may not have an explicit knob for
flooding of unknown multicast, just for flooding in general. In that
case, the only correct thing to do is to allow changes to BR_FLOOD and
BR_MCAST_FLOOD in tandem, and never allow mismatched values. But having
a separate .port_set_unicast_flood and .port_set_multicast_flood would
not allow the driver to possibly reject that.

Also, DSA doesn't consider it necessary to inform the driver that a
SWITCHDEV_ATTR_ID_BRIDGE_MROUTER attribute was offloaded, because it
just calls .port_egress_floods for the CPU port. When we'll add support
for the plain SWITCHDEV_ATTR_ID_PORT_MROUTER, that will become a real
problem because the flood settings will need to be held statefully in
the DSA middle layer, otherwise changing the mrouter port attribute will
impact the flooding attribute. And that's _assuming_ that the underlying
hardware doesn't have anything else to do when a multicast router
attaches to a port than flood unknown traffic to it.  If it does, there
will need to be a dedicated .port_set_mrouter anyway.

So we need to let the DSA drivers see the exact form that the bridge
passes this switchdev attribute in, otherwise we are standing in the
way. Therefore we also need to use this form of language when
communicating to the driver that it needs to configure its initial
(before bridge join) and final (after bridge leave) port flags.

The b53 and mv88e6xxx drivers are converted to the passthrough API and
their implementation of .port_egress_floods is split into two: a
function that configures unicast flooding and another for multicast.
The mv88e6xxx implementation is quite hairy, and it turns out that
the implementations of unknown unicast flooding are actually the same
for 6185 and for 6352:

behind the confusing names actually lie two individual bits:
NO_UNKNOWN_MC -> FLOOD_UC = 0x4 = BIT(2)
NO_UNKNOWN_UC -> FLOOD_MC = 0x8 = BIT(3)

so there was no reason to entangle them in the first place.

Whereas the 6185 writes to MV88E6185_PORT_CTL0_FORWARD_UNKNOWN of
PORT_CTL0, which has the exact same bit index. I have left the
implementations separate though, for the only reason that the names are
different enough to confuse me, since I am not able to double-check with
a user manual. The multicast flooding setting for 6185 is in a different
register than for 6352 though.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This switchdev attribute offers a counterproductive API for a driver
writer, because although br_switchdev_set_port_flag gets passed a
"flags" and a "mask", those are passed piecemeal to the driver, so while
the PRE_BRIDGE_FLAGS listener knows what changed because it has the
"mask", the BRIDGE_FLAGS listener doesn't, because it only has the final
value. But certain drivers can offload only certain combinations of
settings, like for example they cannot change unicast flooding
independently of multicast flooding - they must be both on or both off.
The way the information is passed to switchdev makes drivers not
expressive enough, and unable to reject this request ahead of time, in
the PRE_BRIDGE_FLAGS notifier, so they are forced to reject it during
the deferred BRIDGE_FLAGS attribute, where the rejection is currently
ignored.

This patch also changes drivers to make use of the "mask" field for edge
detection when possible.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

For a DSA switch port operating in standalone mode, address learning
doesn't make much sense since that is a bridge function. In fact,
address learning even breaks setups such as this one:

   +---------------------------------------------+
   |                                             |
   | +-------------------+                       |
   | |        br0        |    send      receive  |
   | +--------+-+--------+ +--------+ +--------+ |
   | |        | |        | |        | |        | |
   | |  swp0  | |  swp1  | |  swp2  | |  swp3  | |
   | |        | |        | |        | |        | |
   +-+--------+-+--------+-+--------+-+--------+-+
          |         ^           |          ^
          |         |           |          |
          |         +-----------+          |
          |                                |
          +--------------------------------+

because if the switch has a single FDB (can offload a single bridge)
then source address learning on swp3 can "steal" the source MAC address
of swp2 from br0's FDB, because learning frames coming from swp2 will be
done twice: first on the swp1 ingress port, second on the swp3 ingress
port. So the hardware FDB will become out of sync with the software
bridge, and when swp2 tries to send one more packet towards swp1, the
ASIC will attempt to short-circuit the forwarding path and send it
directly to swp3 (since that's the last port it learned that address on),
which it obviously can't, because swp3 operates in standalone mode.

So DSA drivers operating in standalone mode should still configure a
list of bridge port flags even when they are standalone. Currently DSA
attempts to call dsa_port_bridge_flags with 0, which disables egress
flooding of unknown unicast and multicast, something which doesn't make
much sense. For the switches that implement .port_egress_floods - b53
and mv88e6xxx, it probably doesn't matter too much either, since they
can possibly inject traffic from the CPU into a standalone port,
regardless of MAC DA, even if egress flooding is turned off for that
port, but certainly not all DSA switches can do that - sja1105, for
example, can't. So it makes sense to use a better common default there,
such as "flood everything".

It should also be noted that what DSA calls "dsa_port_bridge_flags()"
is a degenerate name for just calling .port_egress_floods(), since
nothing else is implemented - not learning, in particular. But disabling
address learning, something that this driver is also coding up for, will
be supported by individual drivers once .port_egress_floods is replaced
with a more generic .port_bridge_flags.

Previous attempts to code up this logic have been in the common bridge
layer, but as pointed out by Ido Schimmel, there are corner cases that
are missed when doing that:
https://patchwork.kernel.org/project/netdevbpf/patch/20210209151936.97382-5-olteanv@gmail.com/

So, at least for now, let's leave DSA in charge of setting port flags
before and after the bridge join and leave.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

For the netlink interface, propagate errors through extack rather than
simply printing them to the console. For the sysfs interface, we still
print to the console, but at least that's one layer higher than in
switchdev, which also allows us to silently ignore the offloading of
flags if that is ever needed in the future.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>