Skip to content

K
Kernel

openeuler / Kernel
接近 2 年 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 25 2月, 2022 3 次提交
  3. 23 2月, 2022 1 次提交
  5. 15 2月, 2022 1 次提交
  7. 14 2月, 2022 1 次提交
  9. 11 2月, 2022 2 次提交
  11. 09 2月, 2022 1 次提交
    • V
      net: dsa: mv88e6xxx: don't use devres for mdiobus · f53a2ce8
      由 Vladimir Oltean 提交于 
      As explained in commits:
74b6d7d1 ("net: dsa: realtek: register the MDIO bus under devres")
5135e96a ("net: dsa: don't allocate the slave_mii_bus using devres")

mdiobus_free() will panic when called from devm_mdiobus_free() <-
devres_release_all() <- __device_release_driver(), and that mdiobus was
not previously unregistered.

The mv88e6xxx is an MDIO device, so the initial set of constraints that
I thought would cause this (I2C or SPI buses which call ->remove on
->shutdown) do not apply. But there is one more which applies here.

If the DSA master itself is on a bus that calls ->remove from ->shutdown
(like dpaa2-eth, which is on the fsl-mc bus), there is a device link
between the switch and the DSA master, and device_links_unbind_consumers()
will unbind the Marvell switch driver on shutdown.

systemd-shutdown[1]: Powering off.
mv88e6085 0x0000000008b96000:00 sw_gl0: Link is Down
fsl-mc dpbp.9: Removing from iommu group 7
fsl-mc dpbp.8: Removing from iommu group 7
------------[ cut here ]------------
kernel BUG at drivers/net/phy/mdio_bus.c:677!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted 5.16.5-00040-gdc05f73788e5 #15
pc : mdiobus_free+0x44/0x50
lr : devm_mdiobus_free+0x10/0x20
Call trace:
 mdiobus_free+0x44/0x50
 devm_mdiobus_free+0x10/0x20
 devres_release_all+0xa0/0x100
 __device_release_driver+0x190/0x220
 device_release_driver_internal+0xac/0xb0
 device_links_unbind_consumers+0xd4/0x100
 __device_release_driver+0x4c/0x220
 device_release_driver_internal+0xac/0xb0
 device_links_unbind_consumers+0xd4/0x100
 __device_release_driver+0x94/0x220
 device_release_driver+0x28/0x40
 bus_remove_device+0x118/0x124
 device_del+0x174/0x420
 fsl_mc_device_remove+0x24/0x40
 __fsl_mc_device_remove+0xc/0x20
 device_for_each_child+0x58/0xa0
 dprc_remove+0x90/0xb0
 fsl_mc_driver_remove+0x20/0x5c
 __device_release_driver+0x21c/0x220
 device_release_driver+0x28/0x40
 bus_remove_device+0x118/0x124
 device_del+0x174/0x420
 fsl_mc_bus_remove+0x80/0x100
 fsl_mc_bus_shutdown+0xc/0x1c
 platform_shutdown+0x20/0x30
 device_shutdown+0x154/0x330
 kernel_power_off+0x34/0x6c
 __do_sys_reboot+0x15c/0x250
 __arm64_sys_reboot+0x20/0x30
 invoke_syscall.constprop.0+0x4c/0xe0
 do_el0_svc+0x4c/0x150
 el0_svc+0x24/0xb0
 el0t_64_sync_handler+0xa8/0xb0
 el0t_64_sync+0x178/0x17c

So the same treatment must be applied to all DSA switch drivers, which
is: either use devres for both the mdiobus allocation and registration,
or don't use devres at all.

The Marvell driver already has a good structure for mdiobus removal, so
just plug in mdiobus_free and get rid of devres.

Fixes: ac3a68d5 ("net: phy: don't abuse devres in devm_mdiobus_register()")
Reported-by: NRafael Richter <Rafael.Richter@gin.de>
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: NDaniel Klauer <daniel.klauer@gin.de>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
      f53a2ce8
  13. 07 2月, 2022 2 次提交
  15. 03 2月, 2022 5 次提交
  17. 31 1月, 2022 1 次提交
    • T
      net: dsa: mv88e6xxx: Improve performance of busy bit polling · 35da1dfd
      由 Tobias Waldekranz 提交于 
      Avoid a long delay when a busy bit is still set and has to be polled
again.

Measurements on a system with 2 Opals (6097F) and one Agate (6352)
show that even with this much tighter loop, we have about a 50% chance
of the bit being cleared on the first poll, all other accesses see the
bit being cleared on the second poll.

On a standard MDIO bus running MDC at 2.5MHz, a single access with 32
bits of preamble plus 32 bits of data takes 64*(1/2.5MHz) = 25.6us.

This means that mv88e6xxx_smi_direct_wait took 26us + CPU overhead in
the fast scenario, but 26us + 1500us + 26us + CPU overhead in the slow
case - bringing the average close to 1ms.

With this change in place, the slow case is closer to 2*26us + CPU
overhead, with the average well below 100us - a 10x improvement.

This translates to real-world winnings. On a 3-chip 20-port system,
the modprobe time drops by 88%:

Before:

root@coronet:~# time modprobe mv88e6xxx
real    0m 15.99s
user    0m 0.00s
sys     0m 1.52s

After:

root@coronet:~# time modprobe mv88e6xxx
real    0m 2.21s
user    0m 0.00s
sys     0m 1.54s
Signed-off-by: NTobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      35da1dfd
  19. 13 12月, 2021 1 次提交
  21. 12 12月, 2021 1 次提交
  23. 10 12月, 2021 1 次提交
  25. 09 12月, 2021 9 次提交
    • R
      net: dsa: mv88e6xxx: fix "don't use PHY_DETECT on internal PHY's" · 2b29cb9e
      由 Russell King (Oracle) 提交于 
      This commit fixes a misunderstanding in commit 4a3e0aed ("net: dsa:
mv88e6xxx: don't use PHY_DETECT on internal PHY's").

For Marvell DSA switches with the PHY_DETECT bit (for non-6250 family
devices), controls whether the PPU polls the PHY to retrieve the link,
speed, duplex and pause status to update the port configuration. This
applies for both internal and external PHYs.

For some switches such as 88E6352 and 88E6390X, PHY_DETECT has an
additional function of enabling auto-media mode between the internal
PHY and SERDES blocks depending on which first gains link.

The original intention of commit 5d5b231d (net: dsa: mv88e6xxx: use
PHY_DETECT in mac_link_up/mac_link_down) was to allow this bit to be
used to detect when this propagation is enabled, and allow software to
update the port configuration. This has found to be necessary for some
switches which do not automatically propagate status from the SERDES to
the port, which includes the 88E6390. However, commit 4a3e0aed
("net: dsa: mv88e6xxx: don't use PHY_DETECT on internal PHY's") breaks
this assumption.

Maarten Zanders has confirmed that the issue he was addressing was for
an 88E6250 switch, which does not have a PHY_DETECT bit in bit 12, but
instead a link status bit. Therefore, mv88e6xxx_port_ppu_updates() does
not report correctly.

This patch resolves the above issues by reverting Maarten's change and
instead making mv88e6xxx_port_ppu_updates() indicate whether the port
is internal for the 88E6250 family of switches.

  Yes, you're right, I'm targeting the 6250 family. And yes, your
  suggestion would solve my case and is a better implementation for
  the other devices (as far as I can see).

Fixes: 4a3e0aed ("net: dsa: mv88e6xxx: don't use PHY_DETECT on internal PHY's")
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Tested-by: NMaarten Zanders <maarten.zanders@mind.be>
Link: https://lore.kernel.org/r/E1muXm7-00EwJB-7n@rmk-PC.armlinux.org.ukSigned-off-by: NJakub Kicinski <kuba@kernel.org>
      2b29cb9e
    • V
      net: dsa: eliminate dsa_switch_ops :: port_bridge_tx_fwd_{,un}offload · 857fdd74
      由 Vladimir Oltean 提交于 
      We don't really need new switch API for these, and with new switches
which intend to add support for this feature, it will become cumbersome
to maintain.

The change consists in restructuring the two drivers that implement this
offload (sja1105 and mv88e6xxx) such that the offload is enabled and
disabled from the ->port_bridge_{join,leave} methods instead of the old
->port_bridge_tx_fwd_{,un}offload.

The only non-trivial change is that mv88e6xxx_map_virtual_bridge_to_pvt()
has been moved to avoid a forward declaration, and the
mv88e6xxx_reg_lock() calls from inside it have been removed, since
locking is now done from mv88e6xxx_port_bridge_{join,leave}.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NAlvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
      857fdd74
    • V
      net: dsa: add a "tx_fwd_offload" argument to ->port_bridge_join · b079922b
      由 Vladimir Oltean 提交于 
      This is a preparation patch for the removal of the DSA switch methods
->port_bridge_tx_fwd_offload() and ->port_bridge_tx_fwd_unoffload().
The plan is for the switch to report whether it offloads TX forwarding
directly as a response to the ->port_bridge_join() method.

This change deals with the noisy portion of converting all existing
function prototypes to take this new boolean pointer argument.
The bool is placed in the cross-chip notifier structure for bridge join,
and a reference to it is provided to drivers. In the next change, DSA
will then actually look at this value instead of calling
->port_bridge_tx_fwd_offload().
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NAlvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
      b079922b
    • V
      net: dsa: keep the bridge_dev and bridge_num as part of the same structure · d3eed0e5
      由 Vladimir Oltean 提交于 
      The main desire behind this is to provide coherent bridge information to
the fast path without locking.

For example, right now we set dp->bridge_dev and dp->bridge_num from
separate code paths, it is theoretically possible for a packet
transmission to read these two port properties consecutively and find a
bridge number which does not correspond with the bridge device.

Another desire is to start passing more complex bridge information to
dsa_switch_ops functions. For example, with FDB isolation, it is
expected that drivers will need to be passed the bridge which requested
an FDB/MDB entry to be offloaded, and along with that bridge_dev, the
associated bridge_num should be passed too, in case the driver might
want to implement an isolation scheme based on that number.

We already pass the {bridge_dev, bridge_num} pair to the TX forwarding
offload switch API, however we'd like to remove that and squash it into
the basic bridge join/leave API. So that means we need to pass this
pair to the bridge join/leave API.

During dsa_port_bridge_leave, first we unset dp->bridge_dev, then we
call the driver's .port_bridge_leave with what used to be our
dp->bridge_dev, but provided as an argument.

When bridge_dev and bridge_num get folded into a single structure, we
need to preserve this behavior in dsa_port_bridge_leave: we need a copy
of what used to be in dp->bridge.

Switch drivers check bridge membership by comparing dp->bridge_dev with
the provided bridge_dev, but now, if we provide the struct dsa_bridge as
a pointer, they cannot keep comparing dp->bridge to the provided
pointer, since this only points to an on-stack copy. To make this
obvious and prevent driver writers from forgetting and doing stupid
things, in this new API, the struct dsa_bridge is provided as a full
structure (not very large, contains an int and a pointer) instead of a
pointer. An explicit comparison function needs to be used to determine
bridge membership: dsa_port_offloads_bridge().
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NAlvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
      d3eed0e5
    • V
      net: dsa: hide dp->bridge_dev and dp->bridge_num in drivers behind helpers · 41fb0cf1
      由 Vladimir Oltean 提交于 
      The location of the bridge device pointer and number is going to change.
It is not going to be kept individually per port, but in a common
structure allocated dynamically and which will have lockdep validation.

Use the helpers to access these elements so that we have a migration
path to the new organization.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
      41fb0cf1
    • V
      net: dsa: mv88e6xxx: compute port vlan membership based on dp->bridge_dev comparison · 65144067
      由 Vladimir Oltean 提交于 
      The goal of this change is to reduce mv88e6xxx_port_vlan() to a form
where dsa_port_bridge_same() can be used, since the dp->bridge_dev
pointer will be hidden in a future change.

To do that, we observe that the "br" pointer is deduced from a
dp->bridge_dev in both cases (of a physical switch port as well as a
virtual bridge). So instead of keeping the "br" pointer, we can just
keep the "dp" pointer from which "br" gets derived.

In the last iteration over switch ports, we must use another iterator
variable, "other_dp"since now we use the "dp" variable to keep an
indirect reference to the bridge. While at it, the old code used to
filter only the ports which were part of the same switch as "ds".
There exists a dedicated DSA port iterator for that:
dsa_switch_for_each_port (which skips the ports in the tree that belong
to non-local switches), so we can just use that.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
      65144067
    • V
      net: dsa: mv88e6xxx: iterate using dsa_switch_for_each_user_port in mv88e6xxx_port_check_hw_vlan · 0493fa79
      由 Vladimir Oltean 提交于 
      Avoid a plethora of dsa_to_port() calls (some hidden behind
dsa_is_*_port and some in plain sight) by keeping two struct dsa_port
references: one to the port passed as argument, and another to the other
ports of the switch that we're iterating over.

This isn't called from the DSA initialization path, so there is no risk
that we have user ports without a dp->slave populated. So the combined
checks that a port isn't a DSA port, a CPU port, or doesn't have a slave
net device (therefore is unused), are strictly equivalent to the simple
check that the port is a user port. This is already handled by the DSA
iterator.

i gets replaced by other_dp->index, dsa_is_*_port calls get replaced by
dsa_port_is_*, and dsa_to_port gets replaced by the respective pointer
directly.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
      0493fa79
    • V
      net: dsa: assign a bridge number even without TX forwarding offload · 947c8746
      由 Vladimir Oltean 提交于 
      The service where DSA assigns a unique bridge number for each forwarding
domain is useful even for drivers which do not implement the TX
forwarding offload feature.

For example, drivers might use the dp->bridge_num for FDB isolation.

So rename ds->num_fwd_offloading_bridges to ds->max_num_bridges, and
calculate a unique bridge_num for all drivers that set this value.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NAlvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
      947c8746
    • V
      net: dsa: make dp->bridge_num one-based · 3f9bb030
      由 Vladimir Oltean 提交于 
      I have seen too many bugs already due to the fact that we must encode an
invalid dp->bridge_num as a negative value, because the natural tendency
is to check that invalid value using (!dp->bridge_num). Latest example
can be seen in commit 1bec0f05 ("net: dsa: fix bridge_num not
getting cleared after ports leaving the bridge").

Convert the existing users to assume that dp->bridge_num == 0 is the
encoding for invalid, and valid bridge numbers start from 1.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NAlvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
      3f9bb030
  27. 10 11月, 2021 1 次提交
  29. 24 10月, 2021 1 次提交
    • S
      net: convert users of bitmap_foo() to linkmode_foo() · 4973056c
      由 Sean Anderson 提交于 
      This converts instances of
	bitmap_foo(args..., __ETHTOOL_LINK_MODE_MASK_NBITS)
to
	linkmode_foo(args...)

I manually fixed up some lines to prevent them from being excessively
long. Otherwise, this change was generated with the following semantic
patch:

// Generated with
// echo linux/linkmode.h > includes
// git grep -Flf includes include/ | cut -f 2- -d / | cat includes - \
// | sort | uniq | tee new_includes | wc -l && mv new_includes includes
// and repeating until the number stopped going up
@i@
@@

(
 #include <linux/acpi_mdio.h>
|
 #include <linux/brcmphy.h>
|
 #include <linux/dsa/loop.h>
|
 #include <linux/dsa/sja1105.h>
|
 #include <linux/ethtool.h>
|
 #include <linux/ethtool_netlink.h>
|
 #include <linux/fec.h>
|
 #include <linux/fs_enet_pd.h>
|
 #include <linux/fsl/enetc_mdio.h>
|
 #include <linux/fwnode_mdio.h>
|
 #include <linux/linkmode.h>
|
 #include <linux/lsm_audit.h>
|
 #include <linux/mdio-bitbang.h>
|
 #include <linux/mdio.h>
|
 #include <linux/mdio-mux.h>
|
 #include <linux/mii.h>
|
 #include <linux/mii_timestamper.h>
|
 #include <linux/mlx5/accel.h>
|
 #include <linux/mlx5/cq.h>
|
 #include <linux/mlx5/device.h>
|
 #include <linux/mlx5/driver.h>
|
 #include <linux/mlx5/eswitch.h>
|
 #include <linux/mlx5/fs.h>
|
 #include <linux/mlx5/port.h>
|
 #include <linux/mlx5/qp.h>
|
 #include <linux/mlx5/rsc_dump.h>
|
 #include <linux/mlx5/transobj.h>
|
 #include <linux/mlx5/vport.h>
|
 #include <linux/of_mdio.h>
|
 #include <linux/of_net.h>
|
 #include <linux/pcs-lynx.h>
|
 #include <linux/pcs/pcs-xpcs.h>
|
 #include <linux/phy.h>
|
 #include <linux/phy_led_triggers.h>
|
 #include <linux/phylink.h>
|
 #include <linux/platform_data/bcmgenet.h>
|
 #include <linux/platform_data/xilinx-ll-temac.h>
|
 #include <linux/pxa168_eth.h>
|
 #include <linux/qed/qed_eth_if.h>
|
 #include <linux/qed/qed_fcoe_if.h>
|
 #include <linux/qed/qed_if.h>
|
 #include <linux/qed/qed_iov_if.h>
|
 #include <linux/qed/qed_iscsi_if.h>
|
 #include <linux/qed/qed_ll2_if.h>
|
 #include <linux/qed/qed_nvmetcp_if.h>
|
 #include <linux/qed/qed_rdma_if.h>
|
 #include <linux/sfp.h>
|
 #include <linux/sh_eth.h>
|
 #include <linux/smsc911x.h>
|
 #include <linux/soc/nxp/lpc32xx-misc.h>
|
 #include <linux/stmmac.h>
|
 #include <linux/sunrpc/svc_rdma.h>
|
 #include <linux/sxgbe_platform.h>
|
 #include <net/cfg80211.h>
|
 #include <net/dsa.h>
|
 #include <net/mac80211.h>
|
 #include <net/selftests.h>
|
 #include <rdma/ib_addr.h>
|
 #include <rdma/ib_cache.h>
|
 #include <rdma/ib_cm.h>
|
 #include <rdma/ib_hdrs.h>
|
 #include <rdma/ib_mad.h>
|
 #include <rdma/ib_marshall.h>
|
 #include <rdma/ib_pack.h>
|
 #include <rdma/ib_pma.h>
|
 #include <rdma/ib_sa.h>
|
 #include <rdma/ib_smi.h>
|
 #include <rdma/ib_umem.h>
|
 #include <rdma/ib_umem_odp.h>
|
 #include <rdma/ib_verbs.h>
|
 #include <rdma/iw_cm.h>
|
 #include <rdma/mr_pool.h>
|
 #include <rdma/opa_addr.h>
|
 #include <rdma/opa_port_info.h>
|
 #include <rdma/opa_smi.h>
|
 #include <rdma/opa_vnic.h>
|
 #include <rdma/rdma_cm.h>
|
 #include <rdma/rdma_cm_ib.h>
|
 #include <rdma/rdmavt_cq.h>
|
 #include <rdma/rdma_vt.h>
|
 #include <rdma/rdmavt_qp.h>
|
 #include <rdma/rw.h>
|
 #include <rdma/tid_rdma_defs.h>
|
 #include <rdma/uverbs_ioctl.h>
|
 #include <rdma/uverbs_named_ioctl.h>
|
 #include <rdma/uverbs_std_types.h>
|
 #include <rdma/uverbs_types.h>
|
 #include <soc/mscc/ocelot.h>
|
 #include <soc/mscc/ocelot_ptp.h>
|
 #include <soc/mscc/ocelot_vcap.h>
|
 #include <trace/events/ib_mad.h>
|
 #include <trace/events/rdma_core.h>
|
 #include <trace/events/rdma.h>
|
 #include <trace/events/rpcrdma.h>
|
 #include <uapi/linux/ethtool.h>
|
 #include <uapi/linux/ethtool_netlink.h>
|
 #include <uapi/linux/mdio.h>
|
 #include <uapi/linux/mii.h>
)

@depends on i@
expression list args;
@@

(
- bitmap_zero(args, __ETHTOOL_LINK_MODE_MASK_NBITS)
+ linkmode_zero(args)
|
- bitmap_copy(args, __ETHTOOL_LINK_MODE_MASK_NBITS)
+ linkmode_copy(args)
|
- bitmap_and(args, __ETHTOOL_LINK_MODE_MASK_NBITS)
+ linkmode_and(args)
|
- bitmap_or(args, __ETHTOOL_LINK_MODE_MASK_NBITS)
+ linkmode_or(args)
|
- bitmap_empty(args, ETHTOOL_LINK_MODE_MASK_NBITS)
+ linkmode_empty(args)
|
- bitmap_andnot(args, __ETHTOOL_LINK_MODE_MASK_NBITS)
+ linkmode_andnot(args)
|
- bitmap_equal(args, __ETHTOOL_LINK_MODE_MASK_NBITS)
+ linkmode_equal(args)
|
- bitmap_intersects(args, __ETHTOOL_LINK_MODE_MASK_NBITS)
+ linkmode_intersects(args)
|
- bitmap_subset(args, __ETHTOOL_LINK_MODE_MASK_NBITS)
+ linkmode_subset(args)
)

Add missing linux/mii.h include to mellanox. -DaveM
Signed-off-by: NSean Anderson <sean.anderson@seco.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      4973056c
  31. 12 10月, 2021 1 次提交
  33. 09 10月, 2021 2 次提交
    • V
      net: dsa: mv88e6xxx: isolate the ATU databases of standalone and bridged ports · 5bded825
      由 Vladimir Oltean 提交于 
      Similar to commit 6087175b ("net: dsa: mt7530: use independent VLAN
learning on VLAN-unaware bridges"), software forwarding between an
unoffloaded LAG port (a bonding interface with an unsupported policy)
and a mv88e6xxx user port directly under a bridge is broken.

We adopt the same strategy, which is to make the standalone ports not
find any ATU entry learned on a bridge port.

Theory: the mv88e6xxx ATU is looked up by FID and MAC address. There are
as many FIDs as VIDs (4096). The FID is derived from the VID when
possible (the VTU maps a VID to a FID), with a fallback to the port
based default FID value when not (802.1Q Mode is disabled on the port,
or the classified VID isn't present in the VTU).

The mv88e6xxx driver makes the following use of FIDs and VIDs:

- the port's DefaultVID (to which untagged & pvid-tagged packets get
  classified) is 0 and is absent from the VTU, so this kind of packets is
  processed in FID 0, the default FID assigned by mv88e6xxx_setup_port.

- every time a bridge VLAN is created, mv88e6xxx_port_vlan_join() ->
  mv88e6xxx_atu_new() associates a FID with that VID which increases
  linearly starting from 1. Like this:

  bridge vlan add dev lan0 vid 100 # FID 1
  bridge vlan add dev lan1 vid 100 # still FID 1
  bridge vlan add dev lan2 vid 1024 # FID 2

The FID allocation made by the driver is sub-optimal for the following
reasons:

(a) A standalone port has a DefaultPVID of 0 and a default FID of 0 too.
    A VLAN-unaware bridged port has a DefaultPVID of 0 and a default FID
    of 0 too. The difference is that the bridged ports may learn ATU
    entries, while the standalone port has the requirement that it must
    not, and must not find them either. Standalone ports must not use
    the same FID as ports belonging to a bridge. All standalone ports
    can use the same FID, since the ATU will never have an entry in
    that FID.

(b) Multiple VLAN-unaware bridges will all use a DefaultPVID of 0 and a
    default FID of 0 on all their ports. The FDBs will not be isolated
    between these bridges. Every VLAN-unaware bridge must use the same
    FID on all its ports, different from the FID of other bridge ports.

(c) Each bridge VLAN uses a unique FID which is useful for Independent
    VLAN Learning, but the same VLAN ID on multiple VLAN-aware bridges
    will result in the same FID being used by mv88e6xxx_atu_new().
    The correct behavior is for VLAN 1 in br0 to have a different FID
    compared to VLAN 1 in br1.

This patch cannot fix all the above. Traditionally the DSA framework did
not care about this, and the reality is that DSA core involvement is
needed for the aforementioned issues to be solved. The only thing we can
solve here is an issue which does not require API changes, and that is
issue (a), aka use a different FID for standalone ports vs ports under
VLAN-unaware bridges.

The first step is deciding what VID and FID to use for standalone ports,
and what VID and FID for bridged ports. The 0/0 pair for standalone
ports is what they used up till now, let's keep using that. For bridged
ports, there are 2 cases:

- VLAN-aware ports will never end up using the port default FID, because
  packets will always be classified to a VID in the VTU or dropped
  otherwise. The FID is the one associated with the VID in the VTU.

- On VLAN-unaware ports, we _could_ leave their DefaultVID (pvid) at
  zero (just as in the case of standalone ports), and just change the
  port's default FID from 0 to a different number (say 1).

However, Tobias points out that there is one more requirement to cater to:
cross-chip bridging. The Marvell DSA header does not carry the FID in
it, only the VID. So once a packet crosses a DSA link, if it has a VID
of zero it will get classified to the default FID of that cascade port.
Relying on a port default FID for upstream cascade ports results in
contradictions: a default FID of 0 breaks ATU isolation of bridged ports
on the downstream switch, a default FID of 1 breaks standalone ports on
the downstream switch.

So not only must standalone ports have different FIDs compared to
bridged ports, they must also have different DefaultVID values.
IEEE 802.1Q defines two reserved VID values: 0 and 4095. So we simply
choose 4095 as the DefaultVID of ports belonging to VLAN-unaware
bridges, and VID 4095 maps to FID 1.

For the xmit operation to look up the same ATU database, we need to put
VID 4095 in DSA tags sent to ports belonging to VLAN-unaware bridges
too. All shared ports are configured to map this VID to the bridging
FID, because they are members of that VLAN in the VTU. Shared ports
don't need to have 802.1QMode enabled in any way, they always parse the
VID from the DSA header, they don't need to look at the 802.1Q header.

We install VID 4095 to the VTU in mv88e6xxx_setup_port(), with the
mention that mv88e6xxx_vtu_setup() which was located right below that
call was flushing the VTU so those entries wouldn't be preserved.
So we need to relocate the VTU flushing prior to the port initialization
during ->setup(). Also note that this is why it is safe to assume that
VID 4095 will get associated with FID 1: the user ports haven't been
created, so there is no avenue for the user to create a bridge VLAN
which could otherwise race with the creation of another FID which would
otherwise use up the non-reserved FID value of 1.

[ Currently mv88e6xxx_port_vlan_join() doesn't have the option of
  specifying a preferred FID, it always calls mv88e6xxx_atu_new(). ]

mv88e6xxx_port_db_load_purge() is the function to access the ATU for
FDB/MDB entries, and it used to determine the FID to use for
VLAN-unaware FDB entries (VID=0) using mv88e6xxx_port_get_fid().
But the driver only called mv88e6xxx_port_set_fid() once, during probe,
so no surprises, the port FID was always 0, the call to get_fid() was
redundant. As much as I would have wanted to not touch that code, the
logic is broken when we add a new FID which is not the port-based
default. Now the port-based default FID only corresponds to standalone
ports, and FDB/MDB entries belong to the bridging service. So while in
the future, when the DSA API will support FDB isolation, we will have to
figure out the FID based on the bridge number, for now there's a single
bridging FID, so hardcode that.

Lastly, the tagger needs to check, when it is transmitting a VLAN
untagged skb, whether it is sending it towards a bridged or a standalone
port. When we see it is bridged we assume the bridge is VLAN-unaware.
Not because it cannot be VLAN-aware but:

- if we are transmitting from a VLAN-aware bridge we are likely doing so
  using TX forwarding offload. That code path guarantees that skbs have
  a vlan hwaccel tag in them, so we would not enter the "else" branch
  of the "if (skb->protocol == htons(ETH_P_8021Q))" condition.

- if we are transmitting on behalf of a VLAN-aware bridge but with no TX
  forwarding offload (no PVT support, out of space in the PVT, whatever),
  we would indeed be transmitting with VLAN 4095 instead of the bridge
  device's pvid. However we would be injecting a "From CPU" frame, and
  the switch won't learn from that - it only learns from "Forward" frames.
  So it is inconsequential for address learning. And VLAN 4095 is
  absolutely enough for the frame to exit the switch, since we never
  remove that VLAN from any port.

Fixes: 57e661aa ("net: dsa: mv88e6xxx: Link aggregation support")
Reported-by: NTobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
      5bded825
    • V
      net: dsa: mv88e6xxx: keep the pvid at 0 when VLAN-unaware · 8b6836d8
      由 Vladimir Oltean 提交于 
      The VLAN support in mv88e6xxx has a loaded history. Commit 2ea7a679
("net: dsa: Don't add vlans when vlan filtering is disabled") noticed
some issues with VLAN and decided the best way to deal with them was to
make the DSA core ignore VLANs added by the bridge while VLAN awareness
is turned off. Those issues were never explained, just presented as
"at least one corner case".

That approach had problems of its own, presented by
commit 54a0ed0d ("net: dsa: provide an option for drivers to always
receive bridge VLANs") for the DSA core, followed by
commit 1fb74191 ("net: dsa: mv88e6xxx: fix vlan setup") which
applied ds->configure_vlan_while_not_filtering = true for mv88e6xxx in
particular.

We still don't know what corner case Andrew saw when he wrote
commit 2ea7a679 ("net: dsa: Don't add vlans when vlan filtering is
disabled"), but Tobias now reports that when we use TX forwarding
offload, pinging an external station from the bridge device is broken if
the front-facing DSA user port has flooding turned off. The full
description is in the link below, but for short, when a mv88e6xxx port
is under a VLAN-unaware bridge, it inherits that bridge's pvid.
So packets ingressing a user port will be classified to e.g. VID 1
(assuming that value for the bridge_default_pvid), whereas when
tag_dsa.c xmits towards a user port, it always sends packets using a VID
of 0 if that port is standalone or under a VLAN-unaware bridge - or at
least it did so prior to commit d82f8ab0 ("net: dsa: tag_dsa:
offload the bridge forwarding process").

In any case, when there is a conversation between the CPU and a station
connected to a user port, the station's MAC address is learned in VID 1
but the CPU tries to transmit through VID 0. The packets reach the
intended station, but via flooding and not by virtue of matching the
existing ATU entry.

DSA has established (and enforced in other drivers: sja1105, felix,
mt7530) that a VLAN-unaware port should use a private pvid, and not
inherit the one from the bridge. The bridge's pvid should only be
inherited when that bridge is VLAN-aware, so all state transitions need
to be handled. On the other hand, all bridge VLANs should sit in the VTU
starting with the moment when the bridge offloads them via switchdev,
they are just not used.

This solves the problem that Tobias sees because packets ingressing on
VLAN-unaware user ports now get classified to VID 0, which is also the
VID used by tag_dsa.c on xmit.

Fixes: d82f8ab0 ("net: dsa: tag_dsa: offload the bridge forwarding process")
Link: https://patchwork.kernel.org/project/netdevbpf/patch/20211003222312.284175-2-vladimir.oltean@nxp.com/#24491503Reported-by: NTobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
      8b6836d8
  35. 27 9月, 2021 3 次提交
  37. 19 9月, 2021 2 次提交
    • V
      net: dsa: tear down devlink port regions when tearing down the devlink port on error · fd292c18
      由 Vladimir Oltean 提交于 
      Commit 86f8b1c0 ("net: dsa: Do not make user port errors fatal")
decided it was fine to ignore errors on certain ports that fail to
probe, and go on with the ports that do probe fine.

Commit fb6ec87f ("net: dsa: Fix type was not set for devlink port")
noticed that devlink_port_type_eth_set(dlp, dp->slave); does not get
called, and devlink notices after a timeout of 3600 seconds and prints a
WARN_ON. So it went ahead to unregister the devlink port. And because
there exists an UNUSED port flavour, we actually re-register the devlink
port as UNUSED.

Commit 08156ba4 ("net: dsa: Add devlink port regions support to
DSA") added devlink port regions, which are set up by the driver and not
by DSA.

When we trigger the devlink port deregistration and reregistration as
unused, devlink now prints another WARN_ON, from here:

devlink_port_unregister:
	WARN_ON(!list_empty(&devlink_port->region_list));

So the port still has regions, which makes sense, because they were set
up by the driver, and the driver doesn't know we're unregistering the
devlink port.

Somebody needs to tear them down, and optionally (actually it would be
nice, to be consistent) set them up again for the new devlink port.

But DSA's layering stays in our way quite badly here.

The options I've considered are:

1. Introduce a function in devlink to just change a port's type and
   flavour. No dice, devlink keeps a lot of state, it really wants the
   port to not be registered when you set its parameters, so changing
   anything can only be done by destroying what we currently have and
   recreating it.

2. Make DSA cache the parameters passed to dsa_devlink_port_region_create,
   and the region returned, keep those in a list, then when the devlink
   port unregister needs to take place, the existing devlink regions are
   destroyed by DSA, and we replay the creation of new regions using the
   cached parameters. Problem: mv88e6xxx keeps the region pointers in
   chip->ports[port].region, and these will remain stale after DSA frees
   them. There are many things DSA can do, but updating mv88e6xxx's
   private pointers is not one of them.

3. Just let the driver do it (i.e. introduce a very specific method
   called ds->ops->port_reinit_as_unused, which unregisters its devlink
   port devlink regions, then the old devlink port, then registers the
   new one, then the devlink port regions for it). While it does work,
   as opposed to the others, it's pretty horrible from an API
   perspective and we can do better.

4. Introduce a new pair of methods, ->port_setup and ->port_teardown,
   which in the case of mv88e6xxx must register and unregister the
   devlink port regions. Call these 2 methods when the port must be
   reinitialized as unused.

Naturally, I went for the 4th approach.

Fixes: 08156ba4 ("net: dsa: Add devlink port regions support to DSA")
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      fd292c18
    • V
      net: dsa: be compatible with masters which unregister on shutdown · 0650bf52
      由 Vladimir Oltean 提交于 
      Lino reports that on his system with bcmgenet as DSA master and KSZ9897
as a switch, rebooting or shutting down never works properly.

What does the bcmgenet driver have special to trigger this, that other
DSA masters do not? It has an implementation of ->shutdown which simply
calls its ->remove implementation. Otherwise said, it unregisters its
network interface on shutdown.

This message can be seen in a loop, and it hangs the reboot process there:

unregister_netdevice: waiting for eth0 to become free. Usage count = 3

So why 3?

A usage count of 1 is normal for a registered network interface, and any
virtual interface which links itself as an upper of that will increment
it via dev_hold. In the case of DSA, this is the call path:

dsa_slave_create
-> netdev_upper_dev_link
   -> __netdev_upper_dev_link
      -> __netdev_adjacent_dev_insert
         -> dev_hold

So a DSA switch with 3 interfaces will result in a usage count elevated
by two, and netdev_wait_allrefs will wait until they have gone away.

Other stacked interfaces, like VLAN, watch NETDEV_UNREGISTER events and
delete themselves, but DSA cannot just vanish and go poof, at most it
can unbind itself from the switch devices, but that must happen strictly
earlier compared to when the DSA master unregisters its net_device, so
reacting on the NETDEV_UNREGISTER event is way too late.

It seems that it is a pretty established pattern to have a driver's
->shutdown hook redirect to its ->remove hook, so the same code is
executed regardless of whether the driver is unbound from the device, or
the system is just shutting down. As Florian puts it, it is quite a big
hammer for bcmgenet to unregister its net_device during shutdown, but
having a common code path with the driver unbind helps ensure it is well
tested.

So DSA, for better or for worse, has to live with that and engage in an
arms race of implementing the ->shutdown hook too, from all individual
drivers, and do something sane when paired with masters that unregister
their net_device there. The only sane thing to do, of course, is to
unlink from the master.

However, complications arise really quickly.

The pattern of redirecting ->shutdown to ->remove is not unique to
bcmgenet or even to net_device drivers. In fact, SPI controllers do it
too (see dspi_shutdown -> dspi_remove), and presumably, I2C controllers
and MDIO controllers do it too (this is something I have not researched
too deeply, but even if this is not the case today, it is certainly
plausible to happen in the future, and must be taken into consideration).

Since DSA switches might be SPI devices, I2C devices, MDIO devices, the
insane implication is that for the exact same DSA switch device, we
might have both ->shutdown and ->remove getting called.

So we need to do something with that insane environment. The pattern
I've come up with is "if this, then not that", so if either ->shutdown
or ->remove gets called, we set the device's drvdata to NULL, and in the
other hook, we check whether the drvdata is NULL and just do nothing.
This is probably not necessary for platform devices, just for devices on
buses, but I would really insist for consistency among drivers, because
when code is copy-pasted, it is not always copy-pasted from the best
sources.

So depending on whether the DSA switch's ->remove or ->shutdown will get
called first, we cannot really guarantee even for the same driver if
rebooting will result in the same code path on all platforms. But
nonetheless, we need to do something minimally reasonable on ->shutdown
too to fix the bug. Of course, the ->remove will do more (a full
teardown of the tree, with all data structures freed, and this is why
the bug was not caught for so long). The new ->shutdown method is kept
separate from dsa_unregister_switch not because we couldn't have
unregistered the switch, but simply in the interest of doing something
quick and to the point.

The big question is: does the DSA switch's ->shutdown get called earlier
than the DSA master's ->shutdown? If not, there is still a risk that we
might still trigger the WARN_ON in unregister_netdevice that says we are
attempting to unregister a net_device which has uppers. That's no good.
Although the reference to the master net_device won't physically go away
even if DSA's ->shutdown comes afterwards, remember we have a dev_hold
on it.

The answer to that question lies in this comment above device_link_add:

 * A side effect of the link creation is re-ordering of dpm_list and the
 * devices_kset list by moving the consumer device and all devices depending
 * on it to the ends of these lists (that does not happen to devices that have
 * not been registered when this function is called).

so the fact that DSA uses device_link_add towards its master is not
exactly for nothing. device_shutdown() walks devices_kset from the back,
so this is our guarantee that DSA's shutdown happens before the master's
shutdown.

Fixes: 2f1e8ea7 ("net: dsa: link interfaces with the DSA master to get rid of lockdep warnings")
Link: https://lore.kernel.org/netdev/20210909095324.12978-1-LinoSanfilippo@gmx.de/Reported-by: NLino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      0650bf52
  39. 09 8月, 2021 1 次提交
    • V
      net: dsa: centralize fast ageing when address learning is turned off · 045c45d1
      由 Vladimir Oltean 提交于 
      Currently DSA leaves it down to device drivers to fast age the FDB on a
port when address learning is disabled on it. There are 2 reasons for
doing that in the first place:

- when address learning is disabled by user space, through
  IFLA_BRPORT_LEARNING or the brport_attr_learning sysfs, what user
  space typically wants to achieve is to operate in a mode with no
  dynamic FDB entry on that port. But if the port is already up, some
  addresses might have been already learned on it, and it seems silly to
  wait for 5 minutes for them to expire until something useful can be
  done.

- when a port leaves a bridge and becomes standalone, DSA turns off
  address learning on it. This also has the nice side effect of flushing
  the dynamically learned bridge FDB entries on it, which is a good idea
  because standalone ports should not have bridge FDB entries on them.

We let drivers manage fast ageing under this condition because if DSA
were to do it, it would need to track each port's learning state, and
act upon the transition, which it currently doesn't.

But there are 2 reasons why doing it is better after all:

- drivers might get it wrong and not do it (see b53_port_set_learning)

- we would like to flush the dynamic entries from the software bridge
  too, and letting drivers do that would be another pain point

So track the port learning state and trigger a fast age process
automatically within DSA.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      045c45d1