linux.git/net/dsa, branch v5.2-rc2

treewide: Add SPDX license identifier - Makefile/Kconfig

2019-05-21T08:50:46+00:00

Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

net: dsa: Initialize DSA_SKB_CB(skb)->deferred_xmit variable

2019-05-12T20:19:46+00:00

The sk_buff control block can have any contents on xmit put there by the
stack, so initialization is mandatory, since we are checking its value
after the actual DSA xmit (the tagger may have changed it).

The DSA_SKB_ZERO() macro could have been used for this purpose, but:
- Zeroizing a 48-byte memory region in the hotpath is best avoided.
- It would have triggered a warning with newer compilers since
  __dsa_skb_cb contains a structure within a structure, and the {0}
  initializer was incorrect for that purpose.

So simply remove the DSA_SKB_ZERO() macro and initialize the
deferred_xmit variable by hand (which should be done for all further
dsa_skb_cb variables which need initialization - currently none - to
avoid the performance penalty).

Fixes: 97a69a0dea9a ("net: dsa: Add support for deferred xmit")
Signed-off-by: Vladimir Oltean 
Signed-off-by: David S. Miller

dsa: tag_brcm: Fix build error without CONFIG_NET_DSA_TAG_BRCM_PREPEND

2019-05-10T22:06:45+00:00

Fix gcc build error:

net/dsa/tag_brcm.c:211:16: error: brcm_prepend_netdev_ops undeclared here (not in a function); did you mean brcm_netdev_ops?
 DSA_TAG_DRIVER(brcm_prepend_netdev_ops);
                ^
./include/net/dsa.h:708:10: note: in definition of macro DSA_TAG_DRIVER
  .ops = &__ops,       \
          ^~~~~
./include/net/dsa.h:701:36: warning: dsa_tag_driver_brcm_prepend_netdev_ops defined but not used [-Wunused-variable]
 #define DSA_TAG_DRIVER_NAME(__ops) dsa_tag_driver ## _ ## __ops
                                    ^
./include/net/dsa.h:707:30: note: in expansion of macro DSA_TAG_DRIVER_NAME
 static struct dsa_tag_driver DSA_TAG_DRIVER_NAME(__ops) = {  \
                              ^~~~~~~~~~~~~~~~~~~
net/dsa/tag_brcm.c:211:1: note: in expansion of macro DSA_TAG_DRIVER
 DSA_TAG_DRIVER(brcm_prepend_netdev_ops);

Like the CONFIG_NET_DSA_TAG_BRCM case,
brcm_prepend_netdev_ops and DSA_TAG_PROTO_BRCM_PREPEND
should be wrappeed by CONFIG_NET_DSA_TAG_BRCM_PREPEND.

Reported-by: Hulk Robot 
Fixes: b74b70c44986 ("net: dsa: Support prepended Broadcom tag")
Signed-off-by: YueHaibing 
Reviewed-by: Andrew Lunn 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2019-05-08T00:22:09+00:00

Minor conflict with the DSA legacy code removal.

Signed-off-by: David S. Miller

net: dsa: support of_get_mac_address new ERR_PTR error

2019-05-07T19:22:47+00:00

There was NVMEM support added to of_get_mac_address, so it could now
return ERR_PTR encoded error values, so we need to adjust all current
users of of_get_mac_address to this new fact.

While at it, remove superfluous is_valid_ether_addr as the MAC address
returned from of_get_mac_address is always valid and checked by
is_valid_ether_addr anyway.

Fixes: d01f449c008a ("of_net: add NVMEM support to of_get_mac_address")
Signed-off-by: Petr Štetiar 
Tested-by: Vladimir Oltean 
Signed-off-by: David S. Miller

net: dsa: Fix error cleanup path in dsa_init_module

2019-05-07T19:17:23+00:00

BUG: unable to handle kernel paging request at ffffffffa01c5430
PGD 3270067 P4D 3270067 PUD 3271063 PMD 230bc5067 PTE 0
Oops: 0000 [#1
CPU: 0 PID: 6159 Comm: modprobe Not tainted 5.1.0+ #33
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
RIP: 0010:raw_notifier_chain_register+0x16/0x40
Code: 63 f8 66 90 e9 5d ff ff ff 90 90 90 90 90 90 90 90 90 90 90 55 48 8b 07 48 89 e5 48 85 c0 74 1c 8b 56 10 3b 50 10 7e 07 eb 12 <39> 50 10 7c 0d 48 8d 78 08 48 8b 40 08 48 85 c0 75 ee 48 89 46 08
RSP: 0018:ffffc90001c33c08 EFLAGS: 00010282
RAX: ffffffffa01c5420 RBX: ffffffffa01db420 RCX: 4fcef45928070a8b
RDX: 0000000000000000 RSI: ffffffffa01db420 RDI: ffffffffa01b0068
RBP: ffffc90001c33c08 R08: 000000003e0a33d0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000094443661 R12: ffff88822c320700
R13: ffff88823109be80 R14: 0000000000000000 R15: ffffc90001c33e78
FS:  00007fab8bd08540(0000) GS:ffff888237a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffa01c5430 CR3: 00000002297ea000 CR4: 00000000000006f0
Call Trace:
 register_netdevice_notifier+0x43/0x250
 ? 0xffffffffa01e0000
 dsa_slave_register_notifier+0x13/0x70 [dsa_core
 ? 0xffffffffa01e0000
 dsa_init_module+0x2e/0x1000 [dsa_core
 do_one_initcall+0x6c/0x3cc
 ? do_init_module+0x22/0x1f1
 ? rcu_read_lock_sched_held+0x97/0xb0
 ? kmem_cache_alloc_trace+0x325/0x3b0
 do_init_module+0x5b/0x1f1
 load_module+0x1db1/0x2690
 ? m_show+0x1d0/0x1d0
 __do_sys_finit_module+0xc5/0xd0
 __x64_sys_finit_module+0x15/0x20
 do_syscall_64+0x6b/0x1d0
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Cleanup allocated resourses if there are errors,
otherwise it will trgger memleak.

Fixes: c9eb3e0f8701 ("net: dsa: Add support for learning FDB through notification")
Signed-off-by: YueHaibing 
Reviewed-by: Vivien Didelot 
Reviewed-by: Andrew Lunn 
Signed-off-by: David S. Miller

net: dsa: sja1105: Add support for traffic through standalone ports

2019-05-06T04:52:42+00:00

In order to support this, we are creating a make-shift switch tag out of
a VLAN trunk configured on the CPU port. Termination of normal traffic
on switch ports only works when not under a vlan_filtering bridge.
Termination of management (PTP, BPDU) traffic works under all
circumstances because it uses a different tagging mechanism
(incl_srcpt). We are making use of the generic CONFIG_NET_DSA_TAG_8021Q
code and leveraging it from our own CONFIG_NET_DSA_TAG_SJA1105.

There are two types of traffic: regular and link-local.

The link-local traffic received on the CPU port is trapped from the
switch's regular forwarding decisions because it matched one of the two
DMAC filters for management traffic.

On transmission, the switch requires special massaging for these
link-local frames. Due to a weird implementation of the switching IP, by
default it drops link-local frames that originate on the CPU port.
It needs to be told where to forward them to, through an SPI command
("management route") that is valid for only a single frame.
So when we're sending link-local traffic, we are using the
dsa_defer_xmit mechanism.

Signed-off-by: Vladimir Oltean 
Reviewed-by: Florian Fainelli 
Signed-off-by: David S. Miller

net: dsa: Add support for deferred xmit

2019-05-06T04:52:42+00:00

Some hardware needs to take work to get convinced to receive frames on
the CPU port (such as the sja1105 which takes temporary L2 forwarding
rules over SPI that last for a single frame). Such work needs a
sleepable context, and because the regular .ndo_start_xmit is atomic,
this cannot be done in the tagger. So introduce a generic DSA mechanism
that sets up a transmit skb queue and a workqueue for deferred
transmission.

The new driver callback (.port_deferred_xmit) is in dsa_switch and not
in the tagger because the operations that require sleeping typically
also involve interacting with the hardware, and not simply skb
manipulations. Therefore having it there simplifies the structure a bit
and makes it unnecessary to export functions from the driver to the
tagger.

The driver is responsible of calling dsa_enqueue_skb which transfers it
to the master netdevice. This is so that it has a chance of performing
some more work afterwards, such as cleanup or TX timestamping.

To tell DSA that skb xmit deferral is required, I have thought about
changing the return type of the tagger .xmit from struct sk_buff * into
a enum dsa_tx_t that could potentially encode a DSA_XMIT_DEFER value.

But the trailer tagger is reallocating every skb on xmit and therefore
making a valid use of the pointer return value. So instead of reworking
the API in complicated ways, right now a boolean property in the newly
introduced DSA_SKB_CB is set.

Signed-off-by: Vladimir Oltean 
Reviewed-by: Florian Fainelli 
Signed-off-by: David S. Miller

net: dsa: Allow drivers to filter packets they can decode source port from

2019-05-06T04:52:42+00:00

Frames get processed by DSA and redirected to switch port net devices
based on the ETH_P_XDSA multiplexed packet_type handler found by the
network stack when calling eth_type_trans().

The running assumption is that once the DSA .rcv function is called, DSA
is always able to decode the switch tag in order to change the skb->dev
from its master.

However there are tagging protocols (such as the new DSA_TAG_PROTO_SJA1105,
user of DSA_TAG_PROTO_8021Q) where this assumption is not completely
true, since switch tagging piggybacks on the absence of a vlan_filtering
bridge. Moreover, management traffic (BPDU, PTP) for this switch doesn't
rely on switch tagging, but on a different mechanism. So it would make
sense to at least be able to terminate that.

Having DSA receive traffic it can't decode would put it in an impossible
situation: the eth_type_trans() function would invoke the DSA .rcv(),
which could not change skb->dev, then eth_type_trans() would be invoked
again, which again would call the DSA .rcv, and the packet would never
be able to exit the DSA filter and would spiral in a loop until the
whole system dies.

This happens because eth_type_trans() doesn't actually look at the skb
(so as to identify a potential tag) when it deems it as being
ETH_P_XDSA. It just checks whether skb->dev has a DSA private pointer
installed (therefore it's a DSA master) and that there exists a .rcv
callback (everybody except DSA_TAG_PROTO_NONE has that). This is
understandable as there are many switch tags out there, and exhaustively
checking for all of them is far from ideal.

The solution lies in introducing a filtering function for each tagging
protocol. In the absence of a filtering function, all traffic is passed
to the .rcv DSA callback. The tagging protocol should see the filtering
function as a pre-validation that it can decode the incoming skb. The
traffic that doesn't match the filter will bypass the DSA .rcv callback
and be left on the master netdevice, which wasn't previously possible.

Signed-off-by: Vladimir Oltean 
Reviewed-by: Florian Fainelli 
Signed-off-by: David S. Miller

net: dsa: Optional VLAN-based port separation for switches without tagging

2019-05-06T04:52:42+00:00

This patch provides generic DSA code for using VLAN (802.1Q) tags for
the same purpose as a dedicated switch tag for injection/extraction.
It is based on the discussions and interest that has been so far
expressed in https://www.spinics.net/lists/netdev/msg556125.html.

Unlike all other DSA-supported tagging protocols, CONFIG_NET_DSA_TAG_8021Q
does not offer a complete solution for drivers (nor can it). Instead, it
provides generic code that driver can opt into calling:
- dsa_8021q_xmit: Inserts a VLAN header with the specified contents.
  Can be called from another tagging protocol's xmit function.
  Currently the LAN9303 driver is inserting headers that are simply
  802.1Q with custom fields, so this is an opportunity for code reuse.
- dsa_8021q_rcv: Retrieves the TPID and TCI from a VLAN-tagged skb.
  Removing the VLAN header is left as a decision for the caller to make.
- dsa_port_setup_8021q_tagging: For each user port, installs an Rx VID
  and a Tx VID, for proper untagged traffic identification on ingress
  and steering on egress. Also sets up the VLAN trunk on the upstream
  (CPU or DSA) port. Drivers are intentionally left to call this
  function explicitly, depending on the context and hardware support.
  The expected switch behavior and VLAN semantics should not be violated
  under any conditions. That is, after calling
  dsa_port_setup_8021q_tagging, the hardware should still pass all
  ingress traffic, be it tagged or untagged.

For uniformity with the other tagging protocols, a module for the
dsa_8021q_netdev_ops structure is registered, but the typical usage is
to set up another tagging protocol which selects CONFIG_NET_DSA_TAG_8021Q,
and calls the API from tag_8021q.h. Null function definitions are also
provided so that a "depends on" is not forced in the Kconfig.

This tagging protocol only works when switch ports are standalone, or
when they are added to a VLAN-unaware bridge. It will probably remain
this way for the reasons below.

When added to a bridge that has vlan_filtering 1, the bridge core will
install its own VLANs and reset the pvids through switchdev. For the
bridge core, switchdev is a write-only pipe. All VLAN-related state is
kept in the bridge core and nothing is read from DSA/switchdev or from
the driver. So the bridge core will break this port separation because
it will install the vlan_default_pvid into all switchdev ports.

Even if we could teach the bridge driver about switchdev preference of a
certain vlan_default_pvid (task difficult in itself since the current
setting is per-bridge but we would need it per-port), there would still
exist many other challenges.

Firstly, in the DSA rcv callback, a driver would have to perform an
iterative reverse lookup to find the correct switch port. That is
because the port is a bridge slave, so its Rx VID (port PVID) is subject
to user configuration. How would we ensure that the user doesn't reset
the pvid to a different value (which would make an O(1) translation
impossible), or to a non-unique value within this DSA switch tree (which
would make any translation impossible)?

Finally, not all switch ports are equal in DSA, and that makes it
difficult for the bridge to be completely aware of this anyway.
The CPU port needs to transmit tagged packets (VLAN trunk) in order for
the DSA rcv code to be able to decode source information.
But the bridge code has absolutely no idea which switch port is the CPU
port, if nothing else then just because there is no netdevice registered
by DSA for the CPU port.
Also DSA does not currently allow the user to specify that they want the
CPU port to do VLAN trunking anyway. VLANs are added to the CPU port
using the same flags as they were added on the user port.

So the VLANs installed by dsa_port_setup_8021q_tagging per driver
request should remain private from the bridge's and user's perspective,
and should not alter the VLAN semantics observed by the user.

In the current implementation a VLAN range ending at 4095 (VLAN_N_VID)
is reserved for this purpose. Each port receives a unique Rx VLAN and a
unique Tx VLAN. Separate VLANs are needed for Rx and Tx because they
serve different purposes: on Rx the switch must process traffic as
untagged and process it with a port-based VLAN, but with care not to
hinder bridging. On the other hand, the Tx VLAN is where the
reachability restrictions are imposed, since by tagging frames in the
xmit callback we are telling the switch onto which port to steer the
frame.

Some general guidance on how this support might be employed for
real-life hardware (some comments made by Florian Fainelli):

- If the hardware supports VLAN tag stacking, it should somehow back
  up its private VLAN settings when the bridge tries to override them.
  Then the driver could re-apply them as outer tags. Dedicating an outer
  tag per bridge device would allow identical inner tag VID numbers to
  co-exist, yet preserve broadcast domain isolation.

- If the switch cannot handle VLAN tag stacking, it should disable this
  port separation when added as slave to a vlan_filtering bridge, in
  that case having reduced functionality.

- Drivers for old switches that don't support the entire VLAN_N_VID
  range will need to rework the current range selection mechanism.

Signed-off-by: Vladimir Oltean 
Reviewed-by: Florian Fainelli 
Reviewed-by: Vivien Didelot 
Signed-off-by: David S. Miller