Commit Graph

960 Commits

Author SHA1 Message Date
DENG Qingfang
9200f515c4 net: dsa: tag_mtk: fix 802.1ad VLAN egress
A different TPID bit is used for 802.1ad VLAN frames.

Reported-by: Ilario Gelmetti <iochesonome@gmail.com>
Fixes: f0af34317f ("net: dsa: mediatek: combine MediaTek tag with VLAN tag")
Signed-off-by: DENG Qingfang <dqfext@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-01 15:29:43 -08:00
DENG Qingfang
9eb8bc593a net: dsa: tag_rtl4_a: fix egress tags
Commit 86dd9868b8 has several issues, but was accepted too soon
before anyone could take a look.

- Double free. dsa_slave_xmit() will free the skb if the xmit function
  returns NULL, but the skb is already freed by eth_skb_pad(). Use
  __skb_put_padto() to avoid that.
- Unnecessary allocation. It has been done by DSA core since commit
  a3b0b64797.
- A u16 pointer points to skb data. It should be __be16 for network
  byte order.
- Typo in comments. "numer" -> "number".

Fixes: 86dd9868b8 ("net: dsa: tag_rtl4_a: Support also egress tags")
Signed-off-by: DENG Qingfang <dqfext@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-01 13:09:55 -08:00
Arnd Bergmann
01c2c1ad8f net: dsa: tag_ocelot_8021q: fix driver dependency
When the ocelot driver code is in a library, the dsa tag
code cannot be built-in:

ld.lld: error: undefined symbol: ocelot_can_inject
>>> referenced by tag_ocelot_8021q.c
>>>               dsa/tag_ocelot_8021q.o:(ocelot_xmit) in archive net/built-in.a

ld.lld: error: undefined symbol: ocelot_port_inject_frame
>>> referenced by tag_ocelot_8021q.c
>>>               dsa/tag_ocelot_8021q.o:(ocelot_xmit) in archive net/built-in.a

Building the tag support only really makes sense for compile-testing
when the driver is available, so add a Kconfig dependency that prevents
the broken configuration while allowing COMPILE_TEST alternative when
MSCC_OCELOT_SWITCH_LIB is disabled entirely.  This case is handled
through the #ifdef check in include/soc/mscc/ocelot.h.

Fixes: 0a6f17c6ae ("net: dsa: tag_ocelot_8021q: add support for PTP timestamping")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20210225143910.3964364-2-arnd@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-26 15:29:53 -08:00
Florian Fainelli
94ead4caa0 net: dsa: Fix dependencies with HSR
The core DSA framework uses hsr_is_master() which would not resolve to a
valid symbol if HSR is built-into the kernel and DSA is a module.

Fixes: 18596f504a ("net: dsa: add support for offloading HSR")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: George McCollister <george.mccollister@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Tested-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20210220051222.15672-1-f.fainelli@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-22 18:50:42 -08:00
Linus Walleij
86dd9868b8 net: dsa: tag_rtl4_a: Support also egress tags
Support also transmitting frames using the custom "8899 A"
4 byte tag.

Qingfang came up with the solution: we need to pad the
ethernet frame to 60 bytes using eth_skb_pad(), then the
switch will happily accept frames with custom tags.

Cc: Mauri Sandberg <sandberg@mailfence.com>
Reported-by: DENG Qingfang <dqfext@gmail.com>
Fixes: efd7fe68f0 ("net: dsa: tag_rtl4_a: Implement Realtek 4 byte A tag")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-16 16:44:39 -08:00
Horatiu Vultur
a026c50b59 net: dsa: felix: Add support for MRP
Implement functions 'port_mrp_add', 'port_mrp_del',
'port_mrp_add_ring_role' and 'port_mrp_del_ring_role' to call the mrp
functions from ocelot.

Also all MRP frames that arrive to CPU on queue number OCELOT_MRP_CPUQ
will be forward by the SW.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-16 14:47:46 -08:00
Horatiu Vultur
c595c4330d net: dsa: add MRP support
Add support for offloading MRP in HW. Currently implement the switchdev
calls 'SWITCHDEV_OBJ_ID_MRP', 'SWITCHDEV_OBJ_ID_RING_ROLE_MRP',
to allow to create MRP instances and to set the role of these instances.

Add DSA_NOTIFIER_MRP_ADD/DEL and DSA_NOTIFIER_MRP_ADD/DEL_RING_ROLE
which calls to .port_mrp_add/del and .port_mrp_add/del_ring_role in the
DSA driver for the switch.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-16 14:47:46 -08:00
Vladimir Oltean
1f778d500d net: mscc: ocelot: avoid type promotion when calling ocelot_ifh_set_dest
Smatch is confused by the fact that a 32-bit BIT(port) macro is passed
as argument to the ocelot_ifh_set_dest function and warns:

ocelot_xmit() warn: should '(((1))) << (dp->index)' be a 64 bit type?
seville_xmit() warn: should '(((1))) << (dp->index)' be a 64 bit type?

The destination port mask is copied into a 12-bit field of the packet,
starting at bit offset 67 and ending at 56.

So this DSA tagging protocol supports at most 12 bits, which is clearly
less than 32. Attempting to send to a port number > 12 will cause the
packing() call to truncate way before there will be 32-bit truncation
due to type promotion of the BIT(port) argument towards u64.

Therefore, smatch's fears that BIT(port) will do the wrong thing and
cause unexpected truncation for "port" values >= 32 are unfounded.
Nonetheless, let's silence the warning by explicitly passing an u64
value to ocelot_ifh_set_dest, such that the compiler does not need to do
a questionable type promotion.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-15 12:42:19 -08:00
Vladimir Oltean
89153ed6eb net: dsa: propagate extack to .port_vlan_filtering
Some drivers can't dynamically change the VLAN filtering option, or
impose some restrictions, it would be nice to propagate this info
through netlink instead of printing it to a kernel log that might never
be read. Also netlink extack includes the module that emitted the
message, which means that it's easier to figure out which ones are
driver-generated errors as opposed to command misuse.

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>
2021-02-14 17:38:12 -08:00
Vladimir Oltean
31046a5fd9 net: dsa: propagate extack to .port_vlan_add
Allow drivers to communicate their restrictions to user space directly,
instead of printing to the kernel log. Where the conversion would have
been lossy and things like VLAN ID could no longer be conveyed (due to
the lack of support for printf format specifier in netlink extack), I
chose to keep the messages in full form to the kernel log only, and
leave it up to individual driver maintainers to move more messages to
extack.

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>
2021-02-14 17:38:11 -08:00
Vladimir Oltean
0a6f17c6ae net: dsa: tag_ocelot_8021q: add support for PTP timestamping
For TX timestamping, we use the felix_txtstamp method which is common
with the regular (non-8021q) ocelot tagger. This method says that skb
deferral is needed, prepares a timestamp request ID, and puts a clone of
the skb in a queue waiting for the timestamp IRQ.

felix_txtstamp is called by dsa_skb_tx_timestamp() just before the
tagger's xmit method. In the tagger xmit, we divert the packets
classified by dsa_skb_tx_timestamp() as PTP towards the MMIO-based
injection registers, and we declare them as dead towards dsa_slave_xmit.
If not PTP, we proceed with normal tag_8021q stuff.

Then the timestamp IRQ fires, the clone queued up from felix_txtstamp is
matched to the TX timestamp retrieved from the switch's FIFO based on
the timestamp request ID, and the clone is delivered to the stack.

On RX, thanks to the VCAP IS2 rule that redirects the frames with an
EtherType for 1588 towards two destinations:
- the CPU port module (for MMIO based extraction) and
- if the "no XTR IRQ" workaround is in place, the dsa_8021q CPU port
the relevant data path processing starts in the ptp_classify_raw BPF
classifier installed by DSA in the RX data path (post tagger, which is
completely unaware that it saw a PTP packet).

This time we can't reuse the same implementation of .port_rxtstamp that
also works with the default ocelot tagger. That is because felix_rxtstamp
is given an skb with a freshly stripped DSA header, and it says "I don't
need deferral for its RX timestamp, it's right in it, let me show you";
and it just points to the header right behind skb->data, from where it
unpacks the timestamp and annotates the skb with it.

The same thing cannot happen with tag_ocelot_8021q, because for one
thing, the skb did not have an extraction frame header in the first
place, but a VLAN tag with no timestamp information. So the code paths
in felix_rxtstamp for the regular and 8021q tagger are completely
independent. With tag_8021q, the timestamp must come from the packet's
duplicate delivered to the CPU port module, but there is potentially
complex logic to be handled [ and prone to reordering ] if we were to
just start reading packets from the CPU port module, and try to match
them to the one we received over Ethernet and which needs an RX
timestamp. So we do something simple: we tell DSA "give me some time to
think" (we request skb deferral by returning false from .port_rxtstamp)
and we just drop the frame we got over Ethernet with no attempt to match
it to anything - we just treat it as a notification that there's data to
be processed from the CPU port module's queues. Then we proceed to read
the packets from those, one by one, which we deliver up the stack,
timestamped, using netif_rx - the same function that any driver would
use anyway if it needed RX timestamp deferral. So the assumption is that
we'll come across the PTP packet that triggered the CPU extraction
notification eventually, but we don't know when exactly. Thanks to the
VCAP IS2 trap/redirect rule and the exclusion of the CPU port module
from the flooding replicators, only PTP frames should be present in the
CPU port module's RX queues anyway.

There is just one conflict between the VCAP IS2 trapping rule and the
semantics of the BPF classifier. Namely, ptp_classify_raw() deems
general messages as non-timestampable, but still, those are trapped to
the CPU port module since they have an EtherType of ETH_P_1588. So, if
the "no XTR IRQ" workaround is in place, we need to run another BPF
classifier on the frames extracted over MMIO, to avoid duplicates being
sent to the stack (once over Ethernet, once over MMIO). It doesn't look
like it's possible to install VCAP IS2 rules based on keys extracted
from the 1588 frame headers.

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>
2021-02-14 17:31:44 -08:00
Vladimir Oltean
c8c0ba4fe2 net: dsa: felix: setup MMIO filtering rules for PTP when using tag_8021q
Since the tag_8021q tagger is software-defined, it has no means by
itself for retrieving hardware timestamps of PTP event messages.

Because we do want to support PTP on ocelot even with tag_8021q, we need
to use the CPU port module for that. The RX timestamp is present in the
Extraction Frame Header. And because we can't use NPI mode which redirects
the CPU queues to an "external CPU" (meaning the ARM CPU running Linux),
then we need to poll the CPU port module through the MMIO registers to
retrieve TX and RX timestamps.

Sadly, on NXP LS1028A, the Felix switch was integrated into the SoC
without wiring the extraction IRQ line to the ARM GIC. So, if we want to
be notified of any PTP packets received on the CPU port module, we have
a problem.

There is a possible workaround, which is to use the Ethernet CPU port as
a notification channel that packets are available on the CPU port module
as well. When a PTP packet is received by the DSA tagger (without timestamp,
of course), we go to the CPU extraction queues, poll for it there, then
we drop the original Ethernet packet and masquerade the packet retrieved
over MMIO (plus the timestamp) as the original when we inject it up the
stack.

Create a quirk in struct felix is selected by the Felix driver (but not
by Seville, since that doesn't support PTP at all). We want to do this
such that the workaround is minimally invasive for future switches that
don't require this workaround.

The only traffic for which we need timestamps is PTP traffic, so add a
redirection rule to the CPU port module for this. Currently we only have
the need for PTP over L2, so redirection rules for UDP ports 319 and 320
are TBD for now.

Note that for the workaround of matching of PTP-over-Ethernet-port with
PTP-over-MMIO queues to work properly, both channels need to be
absolutely lossless. There are two parts to achieving that:
- We keep flow control enabled on the tag_8021q CPU port
- We put the DSA master interface in promiscuous mode, so it will never
  drop a PTP frame (for the profiles we are interested in, these are
  sent to the multicast MAC addresses of 01-80-c2-00-00-0e and
  01-1b-19-00-00-00).

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>
2021-02-14 17:31:44 -08:00
Vladimir Oltean
7c4bb540e9 net: dsa: tag_ocelot: create separate tagger for Seville
The ocelot tagger is a hot mess currently, it relies on memory
initialized by the attached driver for basic frame transmission.
This is against all that DSA tagging protocols stand for, which is that
the transmission and reception of a DSA-tagged frame, the data path,
should be independent from the switch control path, because the tag
protocol is in principle hot-pluggable and reusable across switches
(even if in practice it wasn't until very recently). But if another
driver like dsa_loop wants to make use of tag_ocelot, it couldn't.

This was done to have common code between Felix and Ocelot, which have
one bit difference in the frame header format. Quoting from commit
67c2404922 ("net: dsa: felix: create a template for the DSA tags on
xmit"):

    Other alternatives have been analyzed, such as:
    - Create a separate tag_seville.c: too much code duplication for just 1
      bit field difference.
    - Create a separate DSA_TAG_PROTO_SEVILLE under tag_ocelot.c, just like
      tag_brcm.c, which would have a separate .xmit function. Again, too
      much code duplication for just 1 bit field difference.
    - Allocate the template from the init function of the tag_ocelot.c
      module, instead of from the driver: couldn't figure out a method of
      accessing the correct port template corresponding to the correct
      tagger in the .xmit function.

The really interesting part is that Seville should have had its own
tagging protocol defined - it is not compatible on the wire with Ocelot,
even for that single bit. In principle, a packet generated by
DSA_TAG_PROTO_OCELOT when booted on NXP LS1028A would look in a certain
way, but when booted on NXP T1040 it would look differently. The reverse
is also true: a packet generated by a Seville switch would be
interpreted incorrectly by Wireshark if it was told it was generated by
an Ocelot switch.

Actually things are a bit more nuanced. If we concentrate only on the
DSA tag, what I said above is true, but Ocelot/Seville also support an
optional DSA tag prefix, which can be short or long, and it is possible
to distinguish the two taggers based on an integer constant put in that
prefix. Nonetheless, creating a separate tagger is still justified,
since the tag prefix is optional, and without it, there is again no way
to distinguish.

Claiming backwards binary compatibility is a bit more tough, since I've
already changed the format of tag_ocelot once, in commit 5124197ce5
("net: dsa: tag_ocelot: use a short prefix on both ingress and egress").
Therefore I am not very concerned with treating this as a bugfix and
backporting it to stable kernels (which would be another mess due to the
fact that there would be lots of conflicts with the other DSA_TAG_PROTO*
definitions). It's just simpler to say that the string values of the
taggers have ABI value starting with kernel 5.12, which will be when the
changing of tag protocol via /sys/class/net/<dsa-master>/dsa/tagging
goes live.

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>
2021-02-14 17:31:44 -08:00
Vladimir Oltean
62bf5fde5e net: dsa: tag_ocelot: single out PTP-related transmit tag processing
There is one place where we cannot avoid accessing driver data, and that
is 2-step PTP TX timestamping, since the switch wants us to provide a
timestamp request ID through the injection header, which naturally must
come from a sequence number kept by the driver (it is generated by the
.port_txtstamp method prior to the tagger's xmit).

However, since other drivers like dsa_loop do not claim PTP support
anyway, the DSA_SKB_CB(skb)->clone will always be NULL anyway, so if we
move all PTP-related dereferences of struct ocelot and struct ocelot_port
into a separate function, we can effectively ensure that this is dead
code when the ocelot tagger is attached to non-ocelot switches, and the
stateful portion of the tagger is more self-contained.

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>
2021-02-14 17:31:44 -08:00
Vladimir Oltean
40d3f295b5 net: mscc: ocelot: use common tag parsing code with DSA
The Injection Frame Header and Extraction Frame Header that the switch
prepends to frames over the NPI port is also prepended to frames
delivered over the CPU port module's queues.

Let's unify the handling of the frame headers by making the ocelot
driver call some helpers exported by the DSA tagger. Among other things,
this allows us to get rid of the strange cpu_to_be32 when transmitting
the Injection Frame Header on ocelot, since the packing API uses
network byte order natively (when "quirks" is 0).

The comments above ocelot_gen_ifh talk about setting pop_cnt to 3, and
the cpu extraction queue mask to something, but the code doesn't do it,
so we don't do it either.

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>
2021-02-14 17:31:44 -08:00
Vladimir Oltean
8a678bb29b net: dsa: tag_ocelot: avoid accessing ds->priv in ocelot_rcv
Taggers should be written to do something valid irrespective of the
switch driver that they are attached to. This is even more true now,
because since the introduction of the .change_tag_protocol method, a
certain tagger is not necessarily strictly associated with a driver any
longer, and I would like to be able to test all taggers with dsa_loop in
the future.

In the case of ocelot, it needs to move the classified VLAN from the DSA
tag into the skb if the port is VLAN-aware. We can allow it to do that
by looking at the dp->vlan_filtering property, no need to invoke
structures which are specific to ocelot.

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>
2021-02-14 17:31:44 -08:00
Vladimir Oltean
a8b659e7ff net: dsa: act as passthrough for bridge port flags
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>
2021-02-12 17:08:04 -08:00
Vladimir Oltean
e18f4c18ab net: switchdev: pass flags and mask to both {PRE_,}BRIDGE_FLAGS attributes
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>
2021-02-12 17:08:04 -08:00
Vladimir Oltean
5e38c15856 net: dsa: configure better brport flags when ports leave the bridge
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>
2021-02-12 17:08:04 -08:00
Vladimir Oltean
4c08c586ff net: switchdev: propagate extack to port attributes
When a struct switchdev_attr is notified through switchdev, there is no
way to report informational messages, unlike for struct switchdev_obj.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-12 17:08:04 -08:00
George McCollister
bd62e6f5e6 net: dsa: xrs700x: add HSR offloading support
Add offloading for HSR/PRP (IEC 62439-3) tag insertion, tag removal
forwarding and duplication supported by the xrs7000 series switches.

Only HSR v1 and PRP v1 are supported by the xrs7000 series switches (HSR
v0 is not).

Signed-off-by: George McCollister <george.mccollister@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-11 13:24:45 -08:00
George McCollister
18596f504a net: dsa: add support for offloading HSR
Add support for offloading of HSR/PRP (IEC 62439-3) tag insertion
tag removal, duplicate generation and forwarding on DSA switches.

Add DSA_NOTIFIER_HSR_JOIN and DSA_NOTIFIER_HSR_LEAVE which trigger calls
to .port_hsr_join and .port_hsr_leave in the DSA driver for the switch.

The DSA switch driver should then set netdev feature flags for the
HSR/PRP operation that it offloads.
    NETIF_F_HW_HSR_TAG_INS
    NETIF_F_HW_HSR_TAG_RM
    NETIF_F_HW_HSR_FWD
    NETIF_F_HW_HSR_DUP

Signed-off-by: George McCollister <george.mccollister@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-11 13:24:45 -08:00
David S. Miller
dc9d87581d Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-02-10 13:30:12 -08:00
Vladimir Oltean
a324d3d48f net: dsa: make assisted_learning_on_cpu_port bypass offloaded LAG interfaces
Given the following topology, and focusing only on Box A:

         Box A
         +----------------------------------+
         | Board 1         br0              |
         |             +---------+          |
         |            /           \         |
         |            |           |         |
         |            |         bond0       |
         |            |        +-----+      |
         |192.168.1.1 |       /       \     |
         |  eno0     swp0    swp1    swp2   |
         +---|--------|-------|-------|-----+
             |        |       |       |
             +--------+       |       |
               Cable          |       |
                         Cable|       |Cable
               Cable          |       |
             +--------+       |       |
             |        |       |       |
         +---|--------|-------|-------|-----+
         |  eno0     swp0    swp1    swp2   |
         |192.168.1.2 |       \       /     |
         |            |        +-----+      |
         |            |         bond0       |
         |            |           |         |
         |            \           /         |
         |             +---------+          |
         | Board 2         br0              |
         +----------------------------------+
         Box B

The assisted_learning_on_cpu_port logic will see that swp0 is bridged
with a "foreign interface" (bond0) and will therefore install all
addresses learnt by the software bridge towards bond0 (including the
address of eno0 on Box B) as static addresses towards the CPU port.

But that's not what we want - bond0 is not really a "foreign interface"
but one we can offload including L2 forwarding from/towards it. So we
need to refine our logic for assisted learning such that, whenever we
see an address learnt on a non-DSA interface, we search through the tree
for any port that offloads that non-DSA interface.

Some confusion might arise as to why we search through the whole tree
instead of just the local switch returned by dsa_slave_dev_lower_find.
Or a different angle of the same confusion: why does
dsa_slave_dev_lower_find(br_dev) return a single dp that's under br_dev
instead of the whole list of bridged DSA ports?

To answer the second question, it should be enough to install the static
FDB entry on the CPU port of a single switch in the tree, because
dsa_port_fdb_add uses DSA_NOTIFIER_FDB_ADD which ensures that all other
switches in the tree get notified of that address, and add the entry
themselves using dsa_towards_port().

This should help understand the answer to the first question: the port
returned by dsa_slave_dev_lower_find may not be on the same switch as
the ports that offload the LAG. Nonetheless, if the driver implements
.crosschip_lag_join and .crosschip_bridge_join as mv88e6xxx does, there
still isn't any reason for trapping addresses learnt on the remote LAG
towards the CPU, and we should prevent that.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 14:51:51 -08:00
Vladimir Oltean
c0a8a9c274 net: dsa: automatically bring user ports down when master goes down
This is not fixing any actual bug that I know of, but having a DSA
interface that is up even when its lower (master) interface is down is
one of those things that just do not sound right.

Yes, DSA checks if the master is up before actually bringing the
user interface up, but nobody prevents bringing the master interface
down immediately afterwards... Then the user ports would attempt
dev_queue_xmit on an interface that is down, and wonder what's wrong.

This patch prevents that from happening. NETDEV_GOING_DOWN is the
notification emitted _before_ the master actually goes down, and we are
protected by the rtnl_mutex, so all is well.

For those of you reading this because you were doing switch testing
such as latency measurements for autonomously forwarded traffic, and you
needed a controlled environment with no extra packets sent by the
network stack, this patch breaks that, because now the user ports go
down too, which may shut down the PHY etc. But please don't do it like
that, just do instead:

tc qdisc add dev eno2 clsact
tc filter add dev eno2 egress flower action drop

Tested with two cascaded DSA switches:
$ ip link set eno2 down
sja1105 spi2.0 sw0p2: Link is Down
mscc_felix 0000:00:00.5 swp0: Link is Down
fsl_enetc 0000:00:00.2 eno2: Link is Down

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 14:42:57 -08:00
Vladimir Oltean
9d5ef190e5 net: dsa: automatically bring up DSA master when opening user port
DSA wants the master interface to be open before the user port is due to
historical reasons. The promiscuity of interfaces that are down used to
have issues, as referenced Lennert Buytenhek in commit df02c6ff2e
("dsa: fix master interface allmulti/promisc handling").

The bugfix mentioned there, commit b6c40d68ff ("net: only invoke
dev->change_rx_flags when device is UP"), was basically a "don't do
that" approach to working around the promiscuity while down issue.

Further work done by Vlad Yasevich in commit d2615bf450 ("net: core:
Always propagate flag changes to interfaces") has resolved the
underlying issue, and it is strictly up to the DSA and 8021q drivers
now, it is no longer mandated by the networking core that the master
interface must be up when changing its promiscuity.

From DSA's point of view, deciding to error out in dsa_slave_open
because the master isn't up is
(a) a bad user experience and
(b) knocking at an open door.
Even if there still was an issue with promiscuity while down, DSA could
still just open the master and avoid it.

Doing it this way has the additional benefit that user space can now
remove DSA-specific workarounds, like systemd-networkd with BindCarrier:
https://github.com/systemd/systemd/issues/7478

And we can finally remove one of the 2 bullets in the "Common pitfalls
using DSA setups" chapter.

Tested with two cascaded DSA switches:

$ ip link set sw0p2 up
fsl_enetc 0000:00:00.2 eno2: configuring for fixed/internal link mode
fsl_enetc 0000:00:00.2 eno2: Link is Up - 1Gbps/Full - flow control rx/tx
mscc_felix 0000:00:00.5 swp0: configuring for fixed/sgmii link mode
mscc_felix 0000:00:00.5 swp0: Link is Up - 1Gbps/Full - flow control off
8021q: adding VLAN 0 to HW filter on device swp0
sja1105 spi2.0 sw0p2: configuring for phy/rgmii-id link mode
IPv6: ADDRCONF(NETDEV_CHANGE): eno2: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): swp0: link becomes ready

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 14:42:57 -08:00
Vladimir Oltean
8fd54a73b7 net: dsa: call teardown method on probe failure
Since teardown is supposed to undo the effects of the setup method, it
should be called in the error path for dsa_switch_setup, not just in
dsa_switch_teardown.

Fixes: 5e3f847a02 ("net: dsa: Add teardown callback for drivers")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210204163351.2929670-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-04 20:22:00 -08:00
Vladimir Oltean
99b8202b17 net: dsa: fix SWITCHDEV_ATTR_ID_BRIDGE_VLAN_FILTERING getting ignored
The bridge emits VLAN filtering events and quite a few others via
switchdev with orig_dev = br->dev. After the blamed commit, these events
started getting ignored.

The point of the patch was to not offload switchdev objects for ports
that didn't go through dsa_port_bridge_join, because the configuration
is unsupported:
- ports that offload a bonding/team interface go through
  dsa_port_bridge_join when that bonding/team interface is later bridged
  with another switch port or LAG
- ports that don't offload LAG don't get notified of the bridge that is
  on top of that LAG.

Sadly, a check is missing, which is that the orig_dev is equal to the
bridge device. This check is compatible with the original intention,
because ports that don't offload bridging because they use a software
LAG don't have dp->bridge_dev set.

On a semi-related note, we should not offload switchdev objects or
populate dp->bridge_dev if the driver doesn't implement .port_bridge_join
either. However there is no regression associated with that, so it can
be done separately.

Fixes: 5696c8aedf ("net: dsa: Don't offload port attributes on standalone ports")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Tobias Waldekranz <tobias@waldekranz.com>
Tested-by: Tobias Waldekranz <tobias@waldekranz.com>
Link: https://lore.kernel.org/r/20210202233109.1591466-1-olteanv@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-03 18:25:49 -08:00
Vladimir Oltean
7c83a7c539 net: dsa: add a second tagger for Ocelot switches based on tag_8021q
There are use cases for which the existing tagger, based on the NPI
(Node Processor Interface) functionality, is insufficient.

Namely:
- Frames injected through the NPI port bypass the frame analyzer, so no
  source address learning is performed, no TSN stream classification,
  etc.
- Flow control is not functional over an NPI port (PAUSE frames are
  encapsulated in the same Extraction Frame Header as all other frames)
- There can be at most one NPI port configured for an Ocelot switch. But
  in NXP LS1028A and T1040 there are two Ethernet CPU ports. The non-NPI
  port is currently either disabled, or operated as a plain user port
  (albeit an internally-facing one). Having the ability to configure the
  two CPU ports symmetrically could pave the way for e.g. creating a LAG
  between them, to increase bandwidth seamlessly for the system.

So there is a desire to have an alternative to the NPI mode. This change
keeps the default tagger for the Seville and Felix switches as "ocelot",
but it can be changed via the following device attribute:

echo ocelot-8021q > /sys/class/<dsa-master>/dsa/tagging

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-29 21:25:27 -08:00
Vladimir Oltean
53da0ebaad net: dsa: allow changing the tag protocol via the "tagging" device attribute
Currently DSA exposes the following sysfs:
$ cat /sys/class/net/eno2/dsa/tagging
ocelot

which is a read-only device attribute, introduced in the kernel as
commit 98cdb48071 ("net: dsa: Expose tagging protocol to user-space"),
and used by libpcap since its commit 993db3800d7d ("Add support for DSA
link-layer types").

It would be nice if we could extend this device attribute by making it
writable:
$ echo ocelot-8021q > /sys/class/net/eno2/dsa/tagging

This is useful with DSA switches that can make use of more than one
tagging protocol. It may be useful in dsa_loop in the future too, to
perform offline testing of various taggers, or for changing between dsa
and edsa on Marvell switches, if that is desirable.

In terms of implementation, drivers can support this feature by
implementing .change_tag_protocol, which should always leave the switch
in a consistent state: either with the new protocol if things went well,
or with the old one if something failed. Teardown of the old protocol,
if necessary, must be handled by the driver.

Some things remain as before:
- The .get_tag_protocol is currently only called at probe time, to load
  the initial tagging protocol driver. Nonetheless, new drivers should
  report the tagging protocol in current use now.
- The driver should manage by itself the initial setup of tagging
  protocol, no later than the .setup() method, as well as destroying
  resources used by the last tagger in use, no earlier than the
  .teardown() method.

For multi-switch DSA trees, error handling is a bit more complicated,
since e.g. the 5th out of 7 switches may fail to change the tag
protocol. When that happens, a revert to the original tag protocol is
attempted, but that may fail too, leaving the tree in an inconsistent
state despite each individual switch implementing .change_tag_protocol
transactionally. Since the intersection between drivers that implement
.change_tag_protocol and drivers that support D in DSA is currently the
empty set, the possibility for this error to happen is ignored for now.

Testing:

$ insmod mscc_felix.ko
[   79.549784] mscc_felix 0000:00:00.5: Adding to iommu group 14
[   79.565712] mscc_felix 0000:00:00.5: Failed to register DSA switch: -517
$ insmod tag_ocelot.ko
$ rmmod mscc_felix.ko
$ insmod mscc_felix.ko
[   97.261724] libphy: VSC9959 internal MDIO bus: probed
[   97.267363] mscc_felix 0000:00:00.5: Found PCS at internal MDIO address 0
[   97.274998] mscc_felix 0000:00:00.5: Found PCS at internal MDIO address 1
[   97.282561] mscc_felix 0000:00:00.5: Found PCS at internal MDIO address 2
[   97.289700] mscc_felix 0000:00:00.5: Found PCS at internal MDIO address 3
[   97.599163] mscc_felix 0000:00:00.5 swp0 (uninitialized): PHY [0000:00:00.3:10] driver [Microsemi GE VSC8514 SyncE] (irq=POLL)
[   97.862034] mscc_felix 0000:00:00.5 swp1 (uninitialized): PHY [0000:00:00.3:11] driver [Microsemi GE VSC8514 SyncE] (irq=POLL)
[   97.950731] mscc_felix 0000:00:00.5 swp0: configuring for inband/qsgmii link mode
[   97.964278] 8021q: adding VLAN 0 to HW filter on device swp0
[   98.146161] mscc_felix 0000:00:00.5 swp2 (uninitialized): PHY [0000:00:00.3:12] driver [Microsemi GE VSC8514 SyncE] (irq=POLL)
[   98.238649] mscc_felix 0000:00:00.5 swp1: configuring for inband/qsgmii link mode
[   98.251845] 8021q: adding VLAN 0 to HW filter on device swp1
[   98.433916] mscc_felix 0000:00:00.5 swp3 (uninitialized): PHY [0000:00:00.3:13] driver [Microsemi GE VSC8514 SyncE] (irq=POLL)
[   98.485542] mscc_felix 0000:00:00.5: configuring for fixed/internal link mode
[   98.503584] mscc_felix 0000:00:00.5: Link is Up - 2.5Gbps/Full - flow control rx/tx
[   98.527948] device eno2 entered promiscuous mode
[   98.544755] DSA: tree 0 setup

$ ping 10.0.0.1
PING 10.0.0.1 (10.0.0.1): 56 data bytes
64 bytes from 10.0.0.1: seq=0 ttl=64 time=2.337 ms
64 bytes from 10.0.0.1: seq=1 ttl=64 time=0.754 ms
^C
 -  10.0.0.1 ping statistics  -
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 0.754/1.545/2.337 ms

$ cat /sys/class/net/eno2/dsa/tagging
ocelot
$ cat ./test_ocelot_8021q.sh
        #!/bin/bash

        ip link set swp0 down
        ip link set swp1 down
        ip link set swp2 down
        ip link set swp3 down
        ip link set swp5 down
        ip link set eno2 down
        echo ocelot-8021q > /sys/class/net/eno2/dsa/tagging
        ip link set eno2 up
        ip link set swp0 up
        ip link set swp1 up
        ip link set swp2 up
        ip link set swp3 up
        ip link set swp5 up
$ ./test_ocelot_8021q.sh
./test_ocelot_8021q.sh: line 9: echo: write error: Protocol not available
$ rmmod tag_ocelot.ko
rmmod: can't unload module 'tag_ocelot': Resource temporarily unavailable
$ insmod tag_ocelot_8021q.ko
$ ./test_ocelot_8021q.sh
$ cat /sys/class/net/eno2/dsa/tagging
ocelot-8021q
$ rmmod tag_ocelot.ko
$ rmmod tag_ocelot_8021q.ko
rmmod: can't unload module 'tag_ocelot_8021q': Resource temporarily unavailable
$ ping 10.0.0.1
PING 10.0.0.1 (10.0.0.1): 56 data bytes
64 bytes from 10.0.0.1: seq=0 ttl=64 time=0.953 ms
64 bytes from 10.0.0.1: seq=1 ttl=64 time=0.787 ms
64 bytes from 10.0.0.1: seq=2 ttl=64 time=0.771 ms
$ rmmod mscc_felix.ko
[  645.544426] mscc_felix 0000:00:00.5: Link is Down
[  645.838608] DSA: tree 0 torn down
$ rmmod tag_ocelot_8021q.ko

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-29 21:24:39 -08:00
Vladimir Oltean
357f203bb3 net: dsa: keep a copy of the tagging protocol in the DSA switch tree
Cascading DSA switches can be done multiple ways. There is the brute
force approach / tag stacking, where one upstream switch, located
between leaf switches and the host Ethernet controller, will just
happily transport the DSA header of those leaf switches as payload.
For this kind of setups, DSA works without any special kind of treatment
compared to a single switch - they just aren't aware of each other.
Then there's the approach where the upstream switch understands the tags
it transports from its leaves below, as it doesn't push a tag of its own,
but it routes based on the source port & switch id information present
in that tag (as opposed to DMAC & VID) and it strips the tag when
egressing a front-facing port. Currently only Marvell implements the
latter, and Marvell DSA trees contain only Marvell switches.

So it is safe to say that DSA trees already have a single tag protocol
shared by all switches, and in fact this is what makes the switches able
to understand each other. This fact is also implied by the fact that
currently, the tagging protocol is reported as part of a sysfs installed
on the DSA master and not per port, so it must be the same for all the
ports connected to that DSA master regardless of the switch that they
belong to.

It's time to make this official and enforce it (yes, this also means we
won't have any "switch understands tag to some extent but is not able to
speak it" hardware oddities that we'll support in the future).

This is needed due to the imminent introduction of the dsa_switch_ops::
change_tag_protocol driver API. When that is introduced, we'll have
to notify switches of the tagging protocol that they're configured to
use. Currently the tag_ops structure pointer is held only for CPU ports.
But there are switches which don't have CPU ports and nonetheless still
need to be configured. These would be Marvell leaf switches whose
upstream port is just a DSA link. How do we inform these of their
tagging protocol setup/deletion?

One answer to the above would be: iterate through the DSA switch tree's
ports once, list the CPU ports, get their tag_ops, then iterate again
now that we have it, and notify everybody of that tag_ops. But what to
do if conflicts appear between one cpu_dp->tag_ops and another? There's
no escaping the fact that conflict resolution needs to be done, so we
can be upfront about it.

Ease our work and just keep the master copy of the tag_ops inside the
struct dsa_switch_tree. Reference counting is now moved to be per-tree
too, instead of per-CPU port.

There are many places in the data path that access master->dsa_ptr->tag_ops
and we would introduce unnecessary performance penalty going through yet
another indirection, so keep those right where they are.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-29 21:24:31 -08:00
Vladimir Oltean
886f8e26f5 net: dsa: document the existing switch tree notifiers and add a new one
The existence of dsa_broadcast has generated some confusion in the past:
https://www.mail-archive.com/netdev@vger.kernel.org/msg365042.html

So let's document the existing dsa_port_notify and dsa_broadcast
functions and explain when each of them should be used.

Also, in fact, the in-between function has always been there but was
lacking a name, and is the main reason for this patch: dsa_tree_notify.
Refactor dsa_broadcast to use it.

This patch also moves dsa_broadcast (a top-level function) to dsa2.c,
where it really belonged in the first place, but had no companion so it
stood with dsa_port_notify.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-29 21:24:30 -08:00
Vladimir Oltean
9c7caf2806 net: dsa: tag_8021q: add helpers to deduce whether a VLAN ID is RX or TX VLAN
The sja1105 implementation can be blind about this, but the felix driver
doesn't do exactly what it's being told, so it needs to know whether it
is a TX or an RX VLAN, so it can install the appropriate type of TCAM
rule.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-29 21:24:30 -08:00
Vladimir Oltean
2a6ef76303 net: dsa: add ops for devlink-sb
Switches that care about QoS might have hardware support for reserving
buffer pools for individual ports or traffic classes, and configuring
their sizes and thresholds. Through devlink-sb (shared buffers), this is
all configurable, as well as their occupancy being viewable.

Add the plumbing in DSA for these operations.

Individual drivers still need to call devlink_sb_register() with the
shared buffers they want to expose. A helper was not created in DSA for
this purpose (unlike, say, dsa_devlink_params_register), since in my
opinion it does not bring any benefit over plainly calling
devlink_sb_register() directly.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-15 20:02:34 -08:00
Vladimir Oltean
0ee2af4ebb net: dsa: set configure_vlan_while_not_filtering to true by default
As explained in commit 54a0ed0df4 ("net: dsa: provide an option for
drivers to always receive bridge VLANs"), DSA has historically been
skipping VLAN switchdev operations when the bridge wasn't in
vlan_filtering mode, but the reason why it was doing that has never been
clear. So the configure_vlan_while_not_filtering option is there merely
to preserve functionality for existing drivers. It isn't some behavior
that drivers should opt into. Ideally, when all drivers leave this flag
set, we can delete the dsa_port_skip_vlan_configuration() function.

New drivers always seem to omit setting this flag, for some reason. So
let's reverse the logic: the DSA core sets it by default to true before
the .setup() callback, and legacy drivers can turn it off. This way, new
drivers get the new behavior by default, unless they explicitly set the
flag to false, which is more obvious during review.

Remove the assignment from drivers which were setting it to true, and
add the assignment to false for the drivers that didn't previously have
it. This way, it should be easier to see how many we have left.

The following drivers: lan9303, mv88e6060 were skipped from setting this
flag to false, because they didn't have any VLAN offload ops in the
first place.

The Broadcom Starfighter 2 driver calls the common b53_switch_alloc and
therefore also inherits the configure_vlan_while_not_filtering=true
behavior.

Also, print a message through netlink extack every time a VLAN has been
skipped. This is mildly annoying on purpose, so that (a) it is at least
clear that VLANs are being skipped - the legacy behavior in itself is
confusing, and the extack should be much more difficult to miss, unlike
kernel logs - and (b) people have one more incentive to convert to the
new behavior.

No behavior change except for the added prints is intended at this time.

$ ip link add br0 type bridge vlan_filtering 0
$ ip link set sw0p2 master br0
[   60.315148] br0: port 1(sw0p2) entered blocking state
[   60.320350] br0: port 1(sw0p2) entered disabled state
[   60.327839] device sw0p2 entered promiscuous mode
[   60.334905] br0: port 1(sw0p2) entered blocking state
[   60.340142] br0: port 1(sw0p2) entered forwarding state
Warning: dsa_core: skipping configuration of VLAN. # This was the pvid
$ bridge vlan add dev sw0p2 vid 100
Warning: dsa_core: skipping configuration of VLAN.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210115231919.43834-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-15 17:29:40 -08:00
George McCollister
54a52823a2 dsa: add support for Arrow XRS700x tag trailer
Add support for Arrow SpeedChips XRS700x single byte tag trailer. This
is modeled on tag_trailer.c which works in a similar way.

Signed-off-by: George McCollister <george.mccollister@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-15 15:36:31 -08:00
Jakub Kicinski
1d9f03c0a1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-14 18:34:50 -08:00
Tobias Waldekranz
5b60dadb71 net: dsa: tag_dsa: Support reception of packets from LAG devices
Packets ingressing on a LAG that egress on the CPU port, which are not
classified as management, will have a FORWARD tag that does not
contain the normal source device/port tuple. Instead the trunk bit
will be set, and the port field holds the LAG id.

Since the exact source port information is not available in the tag,
frames are injected directly on the LAG interface and thus do never
pass through any DSA port interface on ingress.

Management frames (TO_CPU) are not affected and will pass through the
DSA port interface as usual.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-14 17:11:56 -08:00
Tobias Waldekranz
058102a6e9 net: dsa: Link aggregation support
Monitor the following events and notify the driver when:

- A DSA port joins/leaves a LAG.
- A LAG, made up of DSA ports, joins/leaves a bridge.
- A DSA port in a LAG is enabled/disabled (enabled meaning
  "distributing" in 802.3ad LACP terms).

When a LAG joins a bridge, the DSA subsystem will treat that as each
individual port joining the bridge. The driver may look at the port's
LAG device pointer to see if it is associated with any LAG, if that is
required. This is analogue to how switchdev events are replicated out
to all lower devices when reaching e.g. a LAG.

Drivers can optionally request that DSA maintain a linear mapping from
a LAG ID to the corresponding netdev by setting ds->num_lag_ids to the
desired size.

In the event that the hardware is not capable of offloading a
particular LAG for any reason (the typical case being use of exotic
modes like broadcast), DSA will take a hands-off approach, allowing
the LAG to be formed as a pure software construct. This is reported
back through the extended ACK, but is otherwise transparent to the
user.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Tested-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-14 17:11:56 -08:00
Tobias Waldekranz
5696c8aedf net: dsa: Don't offload port attributes on standalone ports
In a situation where a standalone port is indirectly attached to a
bridge (e.g. via a LAG) which is not offloaded, do not offload any
port attributes either. The port should behave as a standard NIC.

Previously, on mv88e6xxx, this meant that in the following setup:

     br0
     /
  team0
   / \
swp0 swp1

If vlan filtering was enabled on br0, swp0's and swp1's QMode was set
to "secure". This caused all untagged packets to be dropped, as their
default VID (0) was not loaded into the VTU.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-14 17:11:55 -08:00
Oleksij Rempel
c2ec5f2ecf net: dsa: add optional stats64 support
Allow DSA drivers to export stats64

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-12 20:17:09 -08:00
Vladimir Oltean
91158e1680 net: dsa: clear devlink port type before unregistering slave netdevs
Florian reported a use-after-free bug in devlink_nl_port_fill found with
KASAN:

(devlink_nl_port_fill)
(devlink_port_notify)
(devlink_port_unregister)
(dsa_switch_teardown.part.3)
(dsa_tree_teardown_switches)
(dsa_unregister_switch)
(bcm_sf2_sw_remove)
(platform_remove)
(device_release_driver_internal)
(device_links_unbind_consumers)
(device_release_driver_internal)
(device_driver_detach)
(unbind_store)

Allocated by task 31:
 alloc_netdev_mqs+0x5c/0x50c
 dsa_slave_create+0x110/0x9c8
 dsa_register_switch+0xdb0/0x13a4
 b53_switch_register+0x47c/0x6dc
 bcm_sf2_sw_probe+0xaa4/0xc98
 platform_probe+0x90/0xf4
 really_probe+0x184/0x728
 driver_probe_device+0xa4/0x278
 __device_attach_driver+0xe8/0x148
 bus_for_each_drv+0x108/0x158

Freed by task 249:
 free_netdev+0x170/0x194
 dsa_slave_destroy+0xac/0xb0
 dsa_port_teardown.part.2+0xa0/0xb4
 dsa_tree_teardown_switches+0x50/0xc4
 dsa_unregister_switch+0x124/0x250
 bcm_sf2_sw_remove+0x98/0x13c
 platform_remove+0x44/0x5c
 device_release_driver_internal+0x150/0x254
 device_links_unbind_consumers+0xf8/0x12c
 device_release_driver_internal+0x84/0x254
 device_driver_detach+0x30/0x34
 unbind_store+0x90/0x134

What happens is that devlink_port_unregister emits a netlink
DEVLINK_CMD_PORT_DEL message which associates the devlink port that is
getting unregistered with the ifindex of its corresponding net_device.
Only trouble is, the net_device has already been unregistered.

It looks like we can stub out the search for a corresponding net_device
if we clear the devlink_port's type. This looks like a bit of a hack,
but also seems to be the reason why the devlink_port_type_clear function
exists in the first place.

Fixes: 3122433eb5 ("net: dsa: Register devlink ports before calling DSA driver setup()")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Florian fainelli <f.fainelli@gmail.com>
Reported-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210112004831.3778323-1-olteanv@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-12 18:48:50 -08:00
Vladimir Oltean
07b90056cb net: dsa: unbind all switches from tree when DSA master unbinds
Currently the following happens when a DSA master driver unbinds while
there are DSA switches attached to it:

$ echo 0000:00:00.5 > /sys/bus/pci/drivers/mscc_felix/unbind
------------[ cut here ]------------
WARNING: CPU: 0 PID: 392 at net/core/dev.c:9507
Call trace:
 rollback_registered_many+0x5fc/0x688
 unregister_netdevice_queue+0x98/0x120
 dsa_slave_destroy+0x4c/0x88
 dsa_port_teardown.part.16+0x78/0xb0
 dsa_tree_teardown_switches+0x58/0xc0
 dsa_unregister_switch+0x104/0x1b8
 felix_pci_remove+0x24/0x48
 pci_device_remove+0x48/0xf0
 device_release_driver_internal+0x118/0x1e8
 device_driver_detach+0x28/0x38
 unbind_store+0xd0/0x100

Located at the above location is this WARN_ON:

	/* Notifier chain MUST detach us all upper devices. */
	WARN_ON(netdev_has_any_upper_dev(dev));

Other stacked interfaces, like VLAN, do indeed listen for
NETDEV_UNREGISTER on the real_dev and also unregister themselves at that
time, which is clearly the behavior that rollback_registered_many
expects. But DSA interfaces are not VLAN. They have backing hardware
(platform devices, PCI devices, MDIO, SPI etc) which have a life cycle
of their own and we can't just trigger an unregister from the DSA
framework when we receive a netdev notifier that the master unregisters.

Luckily, there is something we can do, and that is to inform the driver
core that we have a runtime dependency to the DSA master interface's
device, and create a device link where that is the supplier and we are
the consumer. Having this device link will make the DSA switch unbind
before the DSA master unbinds, which is enough to avoid the WARN_ON from
rollback_registered_many.

Note that even before the blamed commit, DSA did nothing intelligent
when the master interface got unregistered either. See the discussion
here:
https://lore.kernel.org/netdev/20200505210253.20311-1-f.fainelli@gmail.com/
But this time, at least the WARN_ON is loud enough that the
upper_dev_link commit can be blamed.

The advantage with this approach vs dev_hold(master) in the attached
link is that the latter is not meant for long term reference counting.
With dev_hold, the only thing that will happen is that when the user
attempts an unbind of the DSA master, netdev_wait_allrefs will keep
waiting and waiting, due to DSA keeping the refcount forever. DSA would
not access freed memory corresponding to the master interface, but the
unbind would still result in a freeze. Whereas with device links,
graceful teardown is ensured. It even works with cascaded DSA trees.

$ echo 0000:00:00.2 > /sys/bus/pci/drivers/fsl_enetc/unbind
[ 1818.797546] device swp0 left promiscuous mode
[ 1819.301112] sja1105 spi2.0: Link is Down
[ 1819.307981] DSA: tree 1 torn down
[ 1819.312408] device eno2 left promiscuous mode
[ 1819.656803] mscc_felix 0000:00:00.5: Link is Down
[ 1819.667194] DSA: tree 0 torn down
[ 1819.711557] fsl_enetc 0000:00:00.2 eno2: Link is Down

This approach allows us to keep the DSA framework absolutely unchanged,
and the driver core will just know to unbind us first when the master
goes away - as opposed to the large (and probably impossible) rework
required if attempting to listen for NETDEV_UNREGISTER.

As per the documentation at Documentation/driver-api/device_link.rst,
specifying the DL_FLAG_AUTOREMOVE_CONSUMER flag causes the device link
to be automatically purged when the consumer fails to probe or later
unbinds. So we don't need to keep the consumer_link variable in struct
dsa_switch.

Fixes: 2f1e8ea726 ("net: dsa: link interfaces with the DSA master to get rid of lockdep warnings")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210111230943.3701806-1-olteanv@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-12 18:48:40 -08:00
Vladimir Oltean
417b99bf75 net: dsa: remove obsolete comments about switchdev transactions
Now that all port object notifiers were converted to be non-transactional,
we can remove the comments that say otherwise.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-11 16:00:57 -08:00
Vladimir Oltean
1958d5815c net: dsa: remove the transactional logic from VLAN objects
It should be the driver's business to logically separate its VLAN
offloading into a preparation and a commit phase, and some drivers don't
need / can't do this.

So remove the transactional shim from DSA and let drivers propagate
errors directly from the .port_vlan_add callback.

It would appear that the code has worse error handling now than it had
before. DSA is the only in-kernel user of switchdev that offloads one
switchdev object to more than one port: for every VLAN object offloaded
to a user port, that VLAN is also offloaded to the CPU port. So the
"prepare for user port -> check for errors -> prepare for CPU port ->
check for errors -> commit for user port -> commit for CPU port"
sequence appears to make more sense than the one we are using now:
"offload to user port -> check for errors -> offload to CPU port ->
check for errors", but it is really a compromise. In the new way, we can
catch errors from the commit phase that we previously had to ignore.
But we have our hands tied and cannot do any rollback now: if we add a
VLAN on the CPU port and it fails, we can't do the rollback by simply
deleting it from the user port, because the switchdev API is not so nice
with us: it could have simply been there already, even with the same
flags. So we don't even attempt to rollback anything on addition error,
just leave whatever VLANs managed to get offloaded right where they are.
This should not be a problem at all in practice.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-11 16:00:57 -08:00
Vladimir Oltean
a52b2da778 net: dsa: remove the transactional logic from MDB entries
For many drivers, the .port_mdb_prepare callback was not a good opportunity
to avoid any error condition, and they would suppress errors found during
the actual commit phase.

Where a logical separation between the prepare and the commit phase
existed, the function that used to implement the .port_mdb_prepare
callback still exists, but now it is called directly from .port_mdb_add,
which was modified to return an int code.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de> # hellcreek
Reviewed-by: Linus Wallei <linus.walleij@linaro.org> # RTL8366
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-11 16:00:57 -08:00
Vladimir Oltean
77b61365ec net: dsa: remove the transactional logic from ageing time notifiers
Remove the shim introduced in DSA for offloading the bridge ageing time
from switchdev, by first checking whether the ageing time is within the
range limits requested by the driver.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-11 16:00:57 -08:00
Vladimir Oltean
bae33f2b5a net: switchdev: remove the transaction structure from port attributes
Since the introduction of the switchdev API, port attributes were
transmitted to drivers for offloading using a two-step transactional
model, with a prepare phase that was supposed to catch all errors, and a
commit phase that was supposed to never fail.

Some classes of failures can never be avoided, like hardware access, or
memory allocation. In the latter case, merely attempting to move the
memory allocation to the preparation phase makes it impossible to avoid
memory leaks, since commit 91cf8eceff ("switchdev: Remove unused
transaction item queue") which has removed the unused mechanism of
passing on the allocated memory between one phase and another.

It is time we admit that separating the preparation from the commit
phase is something that is best left for the driver to decide, and not
something that should be baked into the API, especially since there are
no switchdev callers that depend on this.

This patch removes the struct switchdev_trans member from switchdev port
attribute notifier structures, and converts drivers to not look at this
member.

In part, this patch contains a revert of my previous commit 2e554a7a5d
("net: dsa: propagate switchdev vlan_filtering prepare phase to
drivers").

For the most part, the conversion was trivial except for:
- Rocker's world implementation based on Broadcom OF-DPA had an odd
  implementation of ofdpa_port_attr_bridge_flags_set. The conversion was
  done mechanically, by pasting the implementation twice, then only
  keeping the code that would get executed during prepare phase on top,
  then only keeping the code that gets executed during the commit phase
  on bottom, then simplifying the resulting code until this was obtained.
- DSA's offloading of STP state, bridge flags, VLAN filtering and
  multicast router could be converted right away. But the ageing time
  could not, so a shim was introduced and this was left for a further
  commit.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de> # hellcreek
Reviewed-by: Linus Walleij <linus.walleij@linaro.org> # RTL8366RB
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-11 16:00:57 -08:00
Vladimir Oltean
ffb68fc58e net: switchdev: remove the transaction structure from port object notifiers
Since the introduction of the switchdev API, port objects were
transmitted to drivers for offloading using a two-step transactional
model, with a prepare phase that was supposed to catch all errors, and a
commit phase that was supposed to never fail.

Some classes of failures can never be avoided, like hardware access, or
memory allocation. In the latter case, merely attempting to move the
memory allocation to the preparation phase makes it impossible to avoid
memory leaks, since commit 91cf8eceff ("switchdev: Remove unused
transaction item queue") which has removed the unused mechanism of
passing on the allocated memory between one phase and another.

It is time we admit that separating the preparation from the commit
phase is something that is best left for the driver to decide, and not
something that should be baked into the API, especially since there are
no switchdev callers that depend on this.

This patch removes the struct switchdev_trans member from switchdev port
object notifier structures, and converts drivers to not look at this
member.

Where driver conversion is trivial (like in the case of the Marvell
Prestera driver, NXP DPAA2 switch, TI CPSW, and Rocker drivers), it is
done in this patch.

Where driver conversion needs more attention (DSA, Mellanox Spectrum),
the conversion is left for subsequent patches and here we only fake the
prepare/commit phases at a lower level, just not in the switchdev
notifier itself.

Where the code has a natural structure that is best left alone as a
preparation and a commit phase (as in the case of the Ocelot switch),
that structure is left in place, just made to not depend upon the
switchdev transactional model.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-11 16:00:56 -08:00
Vladimir Oltean
b7a9e0da2d net: switchdev: remove vid_begin -> vid_end range from VLAN objects
The call path of a switchdev VLAN addition to the bridge looks something
like this today:

        nbp_vlan_init
        |  __br_vlan_set_default_pvid
        |  |                       |
        |  |    br_afspec          |
        |  |        |              |
        |  |        v              |
        |  | br_process_vlan_info  |
        |  |        |              |
        |  |        v              |
        |  |   br_vlan_info        |
        |  |       / \            /
        |  |      /   \          /
        |  |     /     \        /
        |  |    /       \      /
        v  v   v         v    v
      nbp_vlan_add   br_vlan_add ------+
       |              ^      ^ |       |
       |             /       | |       |
       |            /       /  /       |
       \ br_vlan_get_master/  /        v
        \        ^        /  /  br_vlan_add_existing
         \       |       /  /          |
          \      |      /  /          /
           \     |     /  /          /
            \    |    /  /          /
             \   |   /  /          /
              v  |   | v          /
              __vlan_add         /
                 / |            /
                /  |           /
               v   |          /
   __vlan_vid_add  |         /
               \   |        /
                v  v        v
      br_switchdev_port_vlan_add

The ranges UAPI was introduced to the bridge in commit bdced7ef78
("bridge: support for multiple vlans and vlan ranges in setlink and
dellink requests") (Jan 10 2015). But the VLAN ranges (parsed in br_afspec)
have always been passed one by one, through struct bridge_vlan_info
tmp_vinfo, to br_vlan_info. So the range never went too far in depth.

Then Scott Feldman introduced the switchdev_port_bridge_setlink function
in commit 47f8328bb1 ("switchdev: add new switchdev bridge setlink").
That marked the introduction of the SWITCHDEV_OBJ_PORT_VLAN, which made
full use of the range. But switchdev_port_bridge_setlink was called like
this:

br_setlink
-> br_afspec
-> switchdev_port_bridge_setlink

Basically, the switchdev and the bridge code were not tightly integrated.
Then commit 41c498b935 ("bridge: restore br_setlink back to original")
came, and switchdev drivers were required to implement
.ndo_bridge_setlink = switchdev_port_bridge_setlink for a while.

In the meantime, commits such as 0944d6b5a2 ("bridge: try switchdev op
first in __vlan_vid_add/del") finally made switchdev penetrate the
br_vlan_info() barrier and start to develop the call path we have today.
But remember, br_vlan_info() still receives VLANs one by one.

Then Arkadi Sharshevsky refactored the switchdev API in 2017 in commit
29ab586c3d ("net: switchdev: Remove bridge bypass support from
switchdev") so that drivers would not implement .ndo_bridge_setlink any
longer. The switchdev_port_bridge_setlink also got deleted.
This refactoring removed the parallel bridge_setlink implementation from
switchdev, and left the only switchdev VLAN objects to be the ones
offloaded from __vlan_vid_add (basically RX filtering) and  __vlan_add
(the latter coming from commit 9c86ce2c1a ("net: bridge: Notify about
bridge VLANs")).

That is to say, today the switchdev VLAN object ranges are not used in
the kernel. Refactoring the above call path is a bit complicated, when
the bridge VLAN call path is already a bit complicated.

Let's go off and finish the job of commit 29ab586c3d by deleting the
bogus iteration through the VLAN ranges from the drivers. Some aspects
of this feature never made too much sense in the first place. For
example, what is a range of VLANs all having the BRIDGE_VLAN_INFO_PVID
flag supposed to mean, when a port can obviously have a single pvid?
This particular configuration _is_ denied as of commit 6623c60dc2
("bridge: vlan: enforce no pvid flag in vlan ranges"), but from an API
perspective, the driver still has to play pretend, and only offload the
vlan->vid_end as pvid. And the addition of a switchdev VLAN object can
modify the flags of another, completely unrelated, switchdev VLAN
object! (a VLAN that is PVID will invalidate the PVID flag from whatever
other VLAN had previously been offloaded with switchdev and had that
flag. Yet switchdev never notifies about that change, drivers are
supposed to guess).

Nonetheless, having a VLAN range in the API makes error handling look
scarier than it really is - unwinding on errors and all of that.
When in reality, no one really calls this API with more than one VLAN.
It is all unnecessary complexity.

And despite appearing pretentious (two-phase transactional model and
all), the switchdev API is really sloppy because the VLAN addition and
removal operations are not paired with one another (you can add a VLAN
100 times and delete it just once). The bridge notifies through
switchdev of a VLAN addition not only when the flags of an existing VLAN
change, but also when nothing changes. There are switchdev drivers out
there who don't like adding a VLAN that has already been added, and
those checks don't really belong at driver level. But the fact that the
API contains ranges is yet another factor that prevents this from being
addressed in the future.

Of the existing switchdev pieces of hardware, it appears that only
Mellanox Spectrum supports offloading more than one VLAN at a time,
through mlxsw_sp_port_vlan_set. I have kept that code internal to the
driver, because there is some more bookkeeping that makes use of it, but
I deleted it from the switchdev API. But since the switchdev support for
ranges has already been de facto deleted by a Mellanox employee and
nobody noticed for 4 years, I'm going to assume it's not a biggie.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com> # switchdev and mlxsw
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de> # hellcreek
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-11 16:00:56 -08:00