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  1. 25 Oct, 2021 6 commits
    • Vladimir Oltean's avatar
      net: mscc: ocelot: serialize access to the MAC table · 2468346c
      Vladimir Oltean authored 
      DSA would like to remove the rtnl_lock from its
SWITCHDEV_FDB_{ADD,DEL}_TO_DEVICE handlers, and the felix driver uses
the same MAC table functions as ocelot.

This means that the MAC table functions will no longer be implicitly
serialized with respect to each other by the rtnl_mutex, we need to add
a dedicated lock in ocelot for the non-atomic operations of selecting a
MAC table row, reading/writing what we want and polling for completion.
Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      2468346c
    • Vladimir Oltean's avatar
      net: dsa: sja1105: serialize access to the dynamic config interface · eb016afd
      Vladimir Oltean authored 
      The sja1105 hardware seems as concurrent as can be, but when we create a
background script that adds/removes a rain of FDB entries without the
rtnl_mutex taken, then in parallel we do another operation like run
'bridge fdb show', we can notice these errors popping up:

sja1105 spi2.0: port 2 failed to read back entry for 00:01:02:03:00:40 vid 0: -ENOENT
sja1105 spi2.0: port 2 failed to add 00:01:02:03:00:40 vid 0 to fdb: -2
sja1105 spi2.0: port 2 failed to read back entry for 00:01:02:03:00:46 vid 0: -ENOENT
sja1105 spi2.0: port 2 failed to add 00:01:02:03:00:46 vid 0 to fdb: -2

Luckily what is going on does not require a major rework in the driver.
The sja1105_dynamic_config_read() function sends multiple SPI buffers to
the peripheral until the operation completes. We should not do anything
until the hardware clears the VALID bit.

But since there is no locking (i.e. right now we are implicitly
serialized by the rtnl_mutex, but if we remove that), it might be
possible that the process which performs the dynamic config read is
preempted and another one performs a dynamic config write.

What will happen in that case is that sja1105_dynamic_config_read(),
when it resumes, expects to see VALIDENT set for the entry it reads
back. But it won't.

This can be corrected by introducing a mutex for serializing SPI
accesses to the dynamic config interface which should be atomic with
respect to each other.
Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      eb016afd
    • Vladimir Oltean's avatar
      net: dsa: sja1105: wait for dynamic config command completion on writes too · df405910
      Vladimir Oltean authored 
      The hardware manual says that software should attempt a new dynamic
config access (be it a a write or a read-back) only while the VALID bit
is cleared. The VALID bit is set by software to 1, and it remains set as
long as the hardware is still processing the request.

Currently the driver only polls for the command completion only for
reads, because that's when we need the actual data read back. Writes
have been more or less "asynchronous", although this has never been an
observable issue.

This change makes sja1105_dynamic_config_write poll the VALID bit as
well, to absolutely ensure that a follow-up access to the static config
finds the VALID bit cleared.

So VALID means "work in progress", while VALIDENT means "entry being
read is valid". On reads we check the VALIDENT bit too, while on writes
that bit is not always defined. So we need to factor it out of the loop,
and make the loop provide back the unpacked command structure, so that
sja1105_dynamic_config_read can check the VALIDENT bit.

The change also attempts to convert the open-coded loop to use the
read_poll_timeout macro, since I know this will come up during review.
It's more code, but hey, it uses read_poll_timeout!

Tested on SJA1105T, SJA1105S, SJA1110A.
Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      df405910
    • Vladimir Oltean's avatar
      net: dsa: avoid refcount warnings when ->port_{fdb,mdb}_del returns error · 232deb3f
      Vladimir Oltean authored 
      At present, when either of ds->ops->port_fdb_del() or ds->ops->port_mdb_del()
return a non-zero error code, we attempt to save the day and keep the
data structure associated with that switchdev object, as the deletion
procedure did not complete.

However, the way in which we do this is suspicious to the checker in
lib/refcount.c, who thinks it is buggy to increment a refcount that
became zero, and that this is indicative of a use-after-free.

Fixes: 161ca59d ("net: dsa: reference count the MDB entries at the cross-chip notifier level")
Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      232deb3f
    • David S. Miller's avatar
      Revert "Merge branch 'dsa-rtnl'" · 2d7e73f0
      David S. Miller authored 
      This reverts commit 965e6b26, reversing
changes made to 4d98bb0d.
      2d7e73f0
    • David S. Miller's avatar
      Merge tag 'linux-can-next-for-5.16-20211024' of... · 12f241f2
      David S. Miller authored 
      Merge tag 'linux-can-next-for-5.16-20211024' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next

Marc Kleine-Budde says:

====================
pull-request: can-next 2021-10-24

this is a pull request of 15 patches for net-next/master.

The first patch is by Thomas Gleixner and makes use of
hrtimer_forward_now() in the CAN broad cast manager (bcm).

The next patch is by me and changes the type of the variables used in
the CAN bit timing calculation can_fixup_bittiming() to unsigned int.

Vincent Mailhol provides 6 patches targeting the CAN device
infrastructure. The CAN-FD specific Transmitter Delay Compensation
(TDC) is updated and configuration via the CAN netlink interface is
added.

Qing Wang's patch updates the at91 and janz-ican3 drivers to use
sysfs_emit() instead of snprintf() in the sysfs show functions.

Geert Uytterhoeven's patch drops the unneeded ARM dependency from the
rar Kconfig.

Cai Huoqing's patch converts the mscan driver to make use of the
dev_err_probe() helper function.

A patch by me against the gsusb driver changes the printf format
strings to use %u to print unsigned values.

Stephane Grosjean's patch updates the peak_usb CAN-FD driver to use
the 64 bit timestamps provided by the hardware.

The last 2 patches target the xilinx_can driver. Michal Simek provides
a patch that removes repeated word from the kernel-doc and Dongliang
Mu's patch removes a redundant netif_napi_del() from the xcan_remove()
function.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      12f241f2
  3. 24 Oct, 2021 34 commits
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