The Linux device model permits both the ->shutdown and ->remove driver
methods to get called during a shutdown procedure. Example: a DSA switch
which sits on an SPI bus, and the SPI bus driver calls this on its
->shutdown method:

spi_unregister_controller
-> device_for_each_child(&ctlr->dev, NULL, __unregister);
   -> spi_unregister_device(to_spi_device(dev));
      -> device_del(&spi->dev);

So this is a simple pattern which can theoretically appear on any bus,
although the only other buses on which I've been able to find it are
I2C:

i2c_del_adapter
-> device_for_each_child(&adap->dev, NULL, __unregister_client);
   -> i2c_unregister_device(client);
      -> device_unregister(&client->dev);

The implication of this pattern is that devices on these buses can be
unregistered after having been shut down. The drivers for these devices
might choose to return early either from ->remove or ->shutdown if the
other callback has already run once, and they might choose that the
->shutdown method should only perform a subset of the teardown done by
->remove (to avoid unnecessary delays when rebooting).

So in other words, the device driver may choose on ->remove to not
do anything (therefore to not unregister an MDIO bus it has registered
on ->probe), because this ->remove is actually triggered by the
device_shutdown path, and its ->shutdown method has already run and done
the minimally required cleanup.

This used to be fine until the blamed commit, but now, the following
BUG_ON triggers:

void mdiobus_free(struct mii_bus *bus)
{
	/* For compatibility with error handling in drivers. */
	if (bus->state == MDIOBUS_ALLOCATED) {
		kfree(bus);
		return;
	}

	BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
	bus->state = MDIOBUS_RELEASED;

	put_device(&bus->dev);
}

In other words, there is an attempt to free an MDIO bus which was not
unregistered. The attempt to free it comes from the devres release
callbacks of the SPI device, which are executed after the device is
unregistered.

I'm not saying that the fact that MDIO buses allocated using devres
would automatically get unregistered wasn't strange. I'm just saying
that the commit didn't care about auditing existing call paths in the
kernel, and now, the following code sequences are potentially buggy:

(a) devm_mdiobus_alloc followed by plain mdiobus_register, for a device
    located on a bus that unregisters its children on shutdown. After
    the blamed patch, either both the alloc and the register should use
    devres, or none should.

(b) devm_mdiobus_alloc followed by plain mdiobus_register, and then no
    mdiobus_unregister at all in the remove path. After the blamed
    patch, nobody unregisters the MDIO bus anymore, so this is even more
    buggy than the previous case which needs a specific bus
    configuration to be seen, this one is an unconditional bug.

In this case, the Realtek drivers fall under category (b). To solve it,
we can register the MDIO bus under devres too, which restores the
previous behavior.

Fixes: ac3a68d5

 ("net: phy: don't abuse devres in devm_mdiobus_register()")
Reported-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Reported-by: Alvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

The Linux device model permits both the ->shutdown and ->remove driver
methods to get called during a shutdown procedure. Example: a DSA switch
which sits on an SPI bus, and the SPI bus driver calls this on its
->shutdown method:

spi_unregister_controller
-> device_for_each_child(&ctlr->dev, NULL, __unregister);
   -> spi_unregister_device(to_spi_device(dev));
      -> device_del(&spi->dev);

So this is a simple pattern which can theoretically appear on any bus,
although the only other buses on which I've been able to find it are
I2C:

i2c_del_adapter
-> device_for_each_child(&adap->dev, NULL, __unregister_client);
   -> i2c_unregister_device(client);
      -> device_unregister(&client->dev);

The implication of this pattern is that devices on these buses can be
unregistered after having been shut down. The drivers for these devices
might choose to return early either from ->remove or ->shutdown if the
other callback has already run once, and they might choose that the
->shutdown method should only perform a subset of the teardown done by
->remove (to avoid unnecessary delays when rebooting).

So in other words, the device driver may choose on ->remove to not
do anything (therefore to not unregister an MDIO bus it has registered
on ->probe), because this ->remove is actually triggered by the
device_shutdown path, and its ->shutdown method has already run and done
the minimally required cleanup.

This used to be fine until the blamed commit, but now, the following
BUG_ON triggers:

void mdiobus_free(struct mii_bus *bus)
{
	/* For compatibility with error handling in drivers. */
	if (bus->state == MDIOBUS_ALLOCATED) {
		kfree(bus);
		return;
	}

	BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
	bus->state = MDIOBUS_RELEASED;

	put_device(&bus->dev);
}

In other words, there is an attempt to free an MDIO bus which was not
unregistered. The attempt to free it comes from the devres release
callbacks of the SPI device, which are executed after the device is
unregistered.

I'm not saying that the fact that MDIO buses allocated using devres
would automatically get unregistered wasn't strange. I'm just saying
that the commit didn't care about auditing existing call paths in the
kernel, and now, the following code sequences are potentially buggy:

(a) devm_mdiobus_alloc followed by plain mdiobus_register, for a device
    located on a bus that unregisters its children on shutdown. After
    the blamed patch, either both the alloc and the register should use
    devres, or none should.

(b) devm_mdiobus_alloc followed by plain mdiobus_register, and then no
    mdiobus_unregister at all in the remove path. After the blamed
    patch, nobody unregisters the MDIO bus anymore, so this is even more
    buggy than the previous case which needs a specific bus
    configuration to be seen, this one is an unconditional bug.

In this case, DSA falls into category (a), it tries to be helpful and
registers an MDIO bus on behalf of the switch, which might be on such a
bus. I've no idea why it does it under devres.

It does this on probe:

	if (!ds->slave_mii_bus && ds->ops->phy_read)
		alloc and register mdio bus

and this on remove:

	if (ds->slave_mii_bus && ds->ops->phy_read)
		unregister mdio bus

I _could_ imagine using devres because the condition used on remove is
different than the condition used on probe. So strictly speaking, DSA
cannot determine whether the ds->slave_mii_bus it sees on remove is the
ds->slave_mii_bus that _it_ has allocated on probe. Using devres would
have solved that problem. But nonetheless, the existing code already
proceeds to unregister the MDIO bus, even though it might be
unregistering an MDIO bus it has never registered. So I can only guess
that no driver that implements ds->ops->phy_read also allocates and
registers ds->slave_mii_bus itself.

So in that case, if unregistering is fine, freeing must be fine too.

Stop using devres and free the MDIO bus manually. This will make devres
stop attempting to free a still registered MDIO bus on ->shutdown.

Fixes: ac3a68d5

 ("net: phy: don't abuse devres in devm_mdiobus_register()")
Reported-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch fixes a spelling typo in ice.rst

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since the blamed commit, dsa_tree_teardown_switches() was split into two
smaller functions, dsa_tree_teardown_switches and dsa_tree_teardown_ports.

However, the error path of dsa_tree_setup stopped calling dsa_tree_teardown_ports.

Fixes: a57d8c21

 ("net: dsa: flush switchdev workqueue before tearing down CPU/DSA ports")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Karsten Graul says:

====================
net/smc: fixes 2021-09-20

Please apply the following patches for smc to netdev's net tree.

The first patch adds a missing error check, and the second patch
fixes a possible leak of a lock in a worker.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

The abort_work is scheduled when a connection was detected to be
out-of-sync after a link failure. The work calls smc_conn_kill(),
which calls smc_close_active_abort() and that might end up calling
smc_close_cancel_work().
smc_close_cancel_work() cancels any pending close_work and tx_work but
needs to release the sock_lock before and acquires the sock_lock again
afterwards. So when the sock_lock was NOT acquired before then it may
be held after the abort_work completes. Thats why the sock_lock is
acquired before the call to smc_conn_kill() in __smc_lgr_terminate(),
but this is missing in smc_conn_abort_work().

Fix that by acquiring the sock_lock first and release it after the
call to smc_conn_kill().

Fixes: b286a065

 ("net/smc: handle incoming CDC validation message")
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Coverity stumbled over a missing error check in smc_clc_prfx_set():

*** CID 1475954:  Error handling issues  (CHECKED_RETURN)
/net/smc/smc_clc.c: 233 in smc_clc_prfx_set()
>>>     CID 1475954:  Error handling issues  (CHECKED_RETURN)
>>>     Calling "kernel_getsockname" without checking return value (as is done elsewhere 8 out of 10 times).
233     	kernel_getsockname(clcsock, (struct sockaddr *)&addrs);

Add the return code check in smc_clc_prfx_set().

Fixes: c246d942

 ("net/smc: restructure netinfo for CLC proposal msgs")
Reported-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Guangbin Huang says:

====================
net: hns3: add some fixes for -net

This series adds some fixes for the HNS3 ethernet driver.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

hclge_get_reset_status() should return the tqp reset status.
However, if the CMDQ fails, the caller will take it as tqp reset
success status by mistake. Therefore, uses a parameters to get
the tqp reset status instead.

Fixes: 46a3df9f

 ("net: hns3: Add HNS3 Acceleration Engine & Compatibility Layer Support")
Signed-off-by: Yufeng Mo <moyufeng@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The input parameters may not be reliable, so check the vlan id before
using it, otherwise may set wrong vlan id into hardware.

Fixes: dc8131d8

 ("net: hns3: Fix for packet loss due wrong filter config in VLAN tbls")
Signed-off-by: liaoguojia <liaoguojia@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The input parameters may not be reliable. Before using the
queue id, we should check this parameter. Otherwise, memory
overwriting may occur.

Fixes: d3410018

 ("net: hns3: refactor the mailbox message between PF and VF")
Signed-off-by: Yufeng Mo <moyufeng@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

vport_id include PF and VFs, vport_id = 0 means PF, other values mean VFs.
So the actual vf id is equal to vport_id minus 1.

Some VF print logs are actually vport, and logs of vf id actually use
vport id, so this patch fixes them.

Fixes: ac887be5 ("net: hns3: change print level of RAS error log from warning to error")
Fixes: adcf738b

 ("net: hns3: cleanup some print format warning")
Signed-off-by: Jiaran Zhang <zhangjiaran@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The vf id from ethtool is added 1 before configured to driver.
So it's necessary to minus 1 when printing it, in order to
keep consistent with user's configuration.

Fixes: dd74f815

 ("net: hns3: Add support for rule add/delete for flow director")
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When user change rss 'hfunc' without set rss 'hkey' by ethtool
-X command, the driver will ignore the 'hfunc' for the hkey is
NULL. It's unreasonable. So fix it.

Fixes: 46a3df9f ("net: hns3: Add HNS3 Acceleration Engine & Compatibility Layer Support")
Fixes: 374ad291

 ("net: hns3: Add RSS general configuration support for VF")
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Without CONFIG_COMMON_CLK, this fails to link:

arm-linux-gnueabi-ld: drivers/ptp/ptp_ocp.o: in function `ptp_ocp_register_i2c':
ptp_ocp.c:(.text+0xcc0): undefined reference to `__clk_hw_register_fixed_rate'
arm-linux-gnueabi-ld: ptp_ocp.c:(.text+0xcf4): undefined reference to `devm_clk_hw_register_clkdev'
arm-linux-gnueabi-ld: drivers/ptp/ptp_ocp.o: in function `ptp_ocp_detach':
ptp_ocp.c:(.text+0x1c24): undefined reference to `clk_hw_unregister_fixed_rate'

Fixes: a7e1abad

 ("ptp: Add clock driver for the OpenCompute TimeCard.")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The smallest TX ring size we support must fit a TX SKB with MAX_SKB_FRAGS
+ 1.  Because the first TX BD for a packet is always a long TX BD, we
need an extra TX BD to fit this packet.  Define BNXT_MIN_TX_DESC_CNT with
this value to make this more clear.  The current code uses a minimum
that is off by 1.  Fix it using this constant.

The tx_wake_thresh to determine when to wake up the TX queue is half the
ring size but we must have at least BNXT_MIN_TX_DESC_CNT for the next
packet which may have maximum fragments.  So the comparison of the
available TX BDs with tx_wake_thresh should be >= instead of > in the
current code.  Otherwise, at the smallest ring size, we will never wake
up the TX queue and will cause TX timeout.

Fixes: c0c050c5

 ("bnxt_en: New Broadcom ethernet driver.")
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadocm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The resilient nexthop group torture tests in fib_nexthop.sh exposed a
possible division by zero while replacing a resilient group [1]. The
division by zero occurs when the data path sees a resilient nexthop
group with zero buckets.

The tests replace a resilient nexthop group in a loop while traffic is
forwarded through it. The tests do not specify the number of buckets
while performing the replacement, resulting in the kernel allocating a
stub resilient table (i.e, 'struct nh_res_table') with zero buckets.

This table should never be visible to the data path, but the old nexthop
group (i.e., 'oldg') might still be used by the data path when the stub
table is assigned to it.

Fix this by only assigning the stub table to the old nexthop group after
making sure the group is no longer used by the data path.

Tested with fib_nexthops.sh:

Tests passed: 222
Tests failed:   0

[1]
 divide error: 0000 [#1] PREEMPT SMP KASAN
 CPU: 0 PID: 1850 Comm: ping Not tainted 5.14.0-custom-10271-ga86eb53057fe #1107
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 04/01/2014
 RIP: 0010:nexthop_select_path+0x2d2/0x1a80
[...]
 Call Trace:
  fib_select_multipath+0x79b/0x1530
  fib_select_path+0x8fb/0x1c10
  ip_route_output_key_hash_rcu+0x1198/0x2da0
  ip_route_output_key_hash+0x190/0x340
  ip_route_output_flow+0x21/0x120
  raw_sendmsg+0x91d/0x2e10
  inet_sendmsg+0x9e/0xe0
  __sys_sendto+0x23d/0x360
  __x64_sys_sendto+0xe1/0x1b0
  do_syscall_64+0x35/0x80
  entry_SYSCALL_64_after_hwframe+0x44/0xae

Cc: stable@vger.kernel.org
Fixes: 283a72a5

 ("nexthop: Add implementation of resilient next-hop groups")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The process will cause napi.state to contain NAPI_STATE_SCHED and
not in the poll_list, which will cause napi_disable() to get stuck.

The prefix "NAPI_STATE_" is removed in the figure below, and
NAPI_STATE_HASHED is ignored in napi.state.

                      CPU0       |                   CPU1       | napi.state
===============================================================================
napi_disable()                   |                              | SCHED | NPSVC
napi_enable()                    |                              |
{                                |                              |
    smp_mb__before_atomic();     |                              |
    clear_bit(SCHED, &n->state); |                              | NPSVC
                                 | napi_schedule_prep()         | SCHED | NPSVC
                                 | napi_poll()                  |
                                 |   napi_complete_done()       |
                                 |   {                          |
                                 |      if (n->state & (NPSVC | | (1)
                                 |               _BUSY_POLL)))  |
                                 |           return false;      |
                                 |     ................         |
                                 |   }                          | SCHED | NPSVC
                                 |                              |
    clear_bit(NPSVC, &n->state); |                              | SCHED
}                                |                              |
                                 |                              |
napi_schedule_prep()             |                              | SCHED | MISSED (2)

(1) Here return direct. Because of NAPI_STATE_NPSVC exists.
(2) NAPI_STATE_SCHED exists. So not add napi.poll_list to sd->poll_list

Since NAPI_STATE_SCHED already exists and napi is not in the
sd->poll_list queue, NAPI_STATE_SCHED cannot be cleared and will always
exist.

1. This will cause this queue to no longer receive packets.
2. If you encounter napi_disable under the protection of rtnl_lock, it
   will cause the entire rtnl_lock to be locked, affecting the overall
   system.

This patch uses cmpxchg to implement napi_enable(), which ensures that
there will be no race due to the separation of clear two bits.

Fixes: 2d8bff12

 ("netpoll: Close race condition between poll_one_napi and napi_disable")
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Makefile uses TEST_PROGS instead of TEST_GEN_PROGS to define
executables. TEST_PROGS is for shell scripts that need to be
installed and run by the common lib.mk framework. The common
framework doesn't touch TEST_PROGS when it does build and clean.

As a result "make kselftest-clean" and "make clean" fail to remove
executables. Run and install work because the common framework runs
and installs TEST_PROGS. Build works because the Makefile defines
"all" rule which is unnecessary if TEST_GEN_PROGS is used.

Use TEST_GEN_PROGS so the common framework can handle build/run/
install/clean properly.

Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Any link state change that's done prior to net device registration
isn't reflected on the state, thus the operational state is left
obsolete, with 'UNKNOWN' status.

To resolve the issue, query link state from FW upon open operations
to ensure operational state is updated.

Fixes: c27a02cd

 ("mlx4_en: Add driver for Mellanox ConnectX 10GbE NIC")
Signed-off-by: Lama Kayal <lkayal@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix the args to fprintf(). Splitting the message ends up passing
incorrect arg for "sigurg %d" and an extra arg overall. The test
result message ends up incorrect.

test_unix_oob.c: In function ‘main’:
test_unix_oob.c:274:43: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘char *’ [-Wformat=]
  274 |   fprintf(stderr, "Test 3 failed, sigurg %d len %d OOB %c ",
      |                                          ~^
      |                                           |
      |                                           int
      |                                          %s
  275 |   "atmark %d\n", signal_recvd, len, oob, atmark);
      |   ~~~~~~~~~~~~~
      |   |
      |   char *
test_unix_oob.c:274:19: warning: too many arguments for format [-Wformat-extra-args]
  274 |   fprintf(stderr, "Test 3 failed, sigurg %d len %d OOB %c ",

Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Due to the inclusion of nvmem handling into the mac-address getter
function of_get_mac_address() by
commit d01f449c ("of_net: add NVMEM support to of_get_mac_address")
it is now possible to get a -EPROBE_DEFER return code. Which did cause
bgmac to assign a random ethernet address.

This exact issue happened on my Meraki MR32. The nvmem provider is
an EEPROM (at24c64) which gets instantiated once the module
driver is loaded... This happens once the filesystem becomes available.

With this patch, bgmac_probe() will propagate the -EPROBE_DEFER error.
Then the driver subsystem will reschedule the probe at a later time.

Cc: Petr Štetiar <ynezz@true.cz>
Cc: Michael Walle <michael@walle.cc>
Fixes: d01f449c

 ("of_net: add NVMEM support to of_get_mac_address")
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The MODULE_DEVICE_TABLE already creates proper alias for platform
driver.  Having another MODULE_ALIAS causes the alias to be duplicated.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Colin Foster says:

====================
ocelot phylink fixes

When the ocelot driver was migrated to phylink, e6e12df6

 ("net:
mscc: ocelot: convert to phylink") there were two additional writes to
registers that became stale. One write was to DEV_CLOCK_CFG and one was
to ANA_PFC_PCF_CFG.

Both of these writes referenced the variable "speed" which originally
was set to OCELOT_SPEED_{10,100,1000,2500}. These macros expand to
values of 3, 2, 1, or 0, respectively. After the update, the variable
speed is set to SPEED_{10,100,1000,2500} which expand to 10, 100, 1000,
and 2500. So invalid values were getting written to the two registers,
which would lead to either a lack of functionality or undefined
funcationality.

Fixing these values was the intent of v1 of this patch set - submitted
as "[PATCH v1 net] net: ethernet: mscc: ocelot: bug fix when writing MAC
speed"

During that review it was determined that both writes were actually
unnecessary. DEV_CLOCK_CFG is a duplicate write, so can be removed
entirely. This was accidentally submitted as as a new, lone patch titled
"[PATCH v1 net] net: mscc: ocelot: remove buggy duplicate write to
DEV_CLOCK_CFG". This is part of what is considered v2 of this patch set.

Additionally, the write to ANA_PFC_PFC_CFG is also unnecessary. Priority
flow contol is disabled, so configuring it is useless and should be
removed. This was also submitted as a new, lone patch titled "[PATCH v1
net] net: mscc: ocelot: remove buggy and useless write to ANA_PFC_PFC_CFG".
This is the rest of what is considered v2 of this patch set.

v3
Identical to v2, but fixes the patch numbering to v3 and submitting the
two changes as a patch set.

v2
Note: I misunderstood and submitted two new "v1" patches instead of a
single "v2" patch set.
- Remove the buggy writes altogher
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

When updating ocelot to use phylink, a second write to DEV_CLOCK_CFG was
mistakenly left in. It used the variable "speed" which, previously, would
would have been assigned a value of OCELOT_SPEED_1000. In phylink the
variable is be SPEED_1000, which is invalid for the
DEV_CLOCK_LINK_SPEED macro. Removing it as unnecessary and buggy.

Fixes: e6e12df6

 ("net: mscc: ocelot: convert to phylink")
Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

A useless write to ANA_PFC_PFC_CFG was left in while refactoring ocelot to
phylink. Since priority flow control is disabled, writing the speed has no
effect.

Further, it was using ethtool.h SPEED_ instead of OCELOT_SPEED_ macros,
which are incorrectly offset for GENMASK.

Lastly, for priority flow control to properly function, some scenarios
would rely on the rate adaptation from the PCS while the MAC speed would
be fixed. So it isn't used, and even if it was, neither "speed" nor
"mac_speed" are necessarily the correct values to be used.

Fixes: e6e12df6

 ("net: mscc: ocelot: convert to phylink")
Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

lock_sock_fast() and lock_sock_nested() contain lockdep annotations for the
sock::sk_lock.owned 'mutex'. sock::sk_lock.owned is not a regular mutex. It
is just lockdep wise equivalent. In fact it's an open coded trivial mutex
implementation with some interesting features.

sock::sk_lock.slock is a regular spinlock protecting the 'mutex'
representation sock::sk_lock.owned which is a plain boolean. If 'owned' is
true, then some other task holds the 'mutex', otherwise it is uncontended.
As this locking construct is obviously endangered by lock ordering issues as
any other locking primitive it got lockdep annotated via a dedicated
dependency map sock::sk_lock.dep_map which has to be updated at the lock
and unlock sites.

lock_sock_nested() is a straight forward 'mutex' lock operation:

  might_sleep();
  spin_lock_bh(sock::sk_lock.slock)
  while (!try_lock(sock::sk_lock.owned)) {
      spin_unlock_bh(sock::sk_lock.slock);
      wait_for_release();
      spin_lock_bh(sock::sk_lock.slock);
  }

The lockdep annotation for sock::sk_lock.owned is for unknown reasons
_after_ the lock has been acquired, i.e. after the code block above and
after releasing sock::sk_lock.slock, but inside the bottom halves disabled
region:

  spin_unlock(sock::sk_lock.slock);
  mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
  local_bh_enable();

The placement after the unlock is obvious because otherwise the
mutex_acquire() would nest into the spin lock held region.

But that's from the lockdep perspective still the wrong place:

 1) The mutex_acquire() is issued _after_ the successful acquisition which
    is pointless because in a dead lock scenario this point is never
    reached which means that if the deadlock is the first instance of
    exposing the wrong lock order lockdep does not have a chance to detect
    it.

 2) It only works because lockdep is rather lax on the context from which
    the mutex_acquire() is issued. Acquiring a mutex inside a bottom halves
    and therefore non-preemptible region is obviously invalid, except for a
    trylock which is clearly not the case here.

    This 'works' stops working on RT enabled kernels where the bottom halves
    serialization is done via a local lock, which exposes this misplacement
    because the 'mutex' and the local lock nest the wrong way around and
    lockdep complains rightfully about a lock inversion.

The placement is wrong since the initial commit a5b5bb9a

 ("[PATCH]
lockdep: annotate sk_locks") which introduced this.

Fix it by moving the mutex_acquire() in front of the actual lock
acquisition, which is what the regular mutex_lock() operation does as well.

lock_sock_fast() is not that straight forward. It looks at the first glance
like a convoluted trylock operation:

  spin_lock_bh(sock::sk_lock.slock)
  if (!sock::sk_lock.owned)
      return false;
  while (!try_lock(sock::sk_lock.owned)) {
      spin_unlock_bh(sock::sk_lock.slock);
      wait_for_release();
      spin_lock_bh(sock::sk_lock.slock);
  }
  spin_unlock(sock::sk_lock.slock);
  mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
  local_bh_enable();
  return true;

But that's not the case: lock_sock_fast() is an interesting optimization
for short critical sections which can run with bottom halves disabled and
sock::sk_lock.slock held. This allows to shortcut the 'mutex' operation in
the non contended case by preventing other lockers to acquire
sock::sk_lock.owned because they are blocked on sock::sk_lock.slock, which
in turn avoids the overhead of doing the heavy processing in release_sock()
including waking up wait queue waiters.

In the contended case, i.e. when sock::sk_lock.owned == true the behavior
is the same as lock_sock_nested().

Semantically this shortcut means, that the task acquired the 'mutex' even
if it does not touch the sock::sk_lock.owned field in the non-contended
case. Not telling lockdep about this shortcut acquisition is hiding
potential lock ordering violations in the fast path.

As a consequence the same reasoning as for the above lock_sock_nested()
case vs. the placement of the lockdep annotation applies.

The current placement of the lockdep annotation was just copied from
the original lock_sock(), now renamed to lock_sock_nested(),
implementation.

Fix this by moving the mutex_acquire() in front of the actual lock
acquisition and adding the corresponding mutex_release() into
unlock_sock_fast(). Also document the fast path return case with a comment.

Reported-by: Sebastian Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: netdev@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The file sja1105.txt was converted to nxp,sja1105.yaml.

Signed-off-by: Alejandro Concepcion-Rodriguez <asconcepcion@acoro.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>

When IGC=y and PTP_1588_CLOCK=m, the ptp_*() interface family is
not available to the igc driver. Make this driver depend on
PTP_1588_CLOCK_OPTIONAL so that it will build without errors.

Various igc commits have used ptp_*() functions without checking
that PTP_1588_CLOCK is enabled. Fix all of these here.

Fixes these build errors:

ld: drivers/net/ethernet/intel/igc/igc_main.o: in function `igc_msix_other':
igc_main.c:(.text+0x6494): undefined reference to `ptp_clock_event'
ld: igc_main.c:(.text+0x64ef): undefined reference to `ptp_clock_event'
ld: igc_main.c:(.text+0x6559): undefined reference to `ptp_clock_event'
ld: drivers/net/ethernet/intel/igc/igc_ethtool.o: in function `igc_ethtool_get_ts_info':
igc_ethtool.c:(.text+0xc7a): undefined reference to `ptp_clock_index'
ld: drivers/net/ethernet/intel/igc/igc_ptp.o: in function `igc_ptp_feature_enable_i225':
igc_ptp.c:(.text+0x330): undefined reference to `ptp_find_pin'
ld: igc_ptp.c:(.text+0x36f): undefined reference to `ptp_find_pin'
ld: drivers/net/ethernet/intel/igc/igc_ptp.o: in function `igc_ptp_init':
igc_ptp.c:(.text+0x11cd): undefined reference to `ptp_clock_register'
ld: drivers/net/ethernet/intel/igc/igc_ptp.o: in function `igc_ptp_stop':
igc_ptp.c:(.text+0x12dd): undefined reference to `ptp_clock_unregister'
ld: drivers/platform/x86/dell/dell-wmi-privacy.o: in function `dell_privacy_wmi_probe':

Fixes: 64433e5b ("igc: Enable internal i225 PPS")
Fixes: 60dbede0 ("igc: Add support for ethtool GET_TS_INFO command")
Fixes: 87938851 ("igc: enable auxiliary PHC functions for the i225")
Fixes: 5f295805

 ("igc: Add basic skeleton for PTP")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Ederson de Souza <ederson.desouza@intel.com>
Cc: Tony Nguyen <anthony.l.nguyen@intel.com>
Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
Cc: intel-wired-lan@lists.osuosl.org
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The only struct dim_sample member that does not get
initialized by dim_update_sample() is comp_ctr. (There
is special API to initialize comp_ctr:
dim_update_sample_with_comps(), and it is currently used
only for RDMA.) comp_ctr is used to compute curr_stats->cmps
and curr_stats->cpe_ratio (see dim_calc_stats()) which in
turn are consumed by the rdma_dim_*() API.  Therefore,
functionally, the net_dim*() API consumers are not affected.
Nevertheless, fix the computation of statistics based
on an uninitialized variable, even if the mentioned statistics
are not used at the moment.

Fixes: ae0e6a5d

 ("enetc: Add adaptive interrupt coalescing")
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

irq_set_affinity_hit() stores a reference to the cpumask_t
parameter in the irq descriptor, and that reference can be
accessed later from irq_affinity_hint_proc_show(). Since
the cpu_mask parameter passed to irq_set_affinity_hit() has
only temporary storage (it's on the stack memory), later
accesses to it are illegal. Thus reads from the corresponding
procfs affinity_hint file can result in paging request oops.

The issue is fixed by the get_cpu_mask() helper, which provides
a permanent storage for the cpumask_t parameter.

Fixes: d4fd0404

 ("enetc: Introduce basic PF and VF ENETC ethernet drivers")
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We try to use build_skb() if we had sufficient tailroom. But we forget
to release the unused pages chained via private in big mode which will
leak pages. Fixing this by release the pages after building the skb in
big mode.

Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Fixes: fb32856b

 ("virtio-net: page_to_skb() use build_skb when there's sufficient tailroom")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When re-entering the main loop of xenvif_tx_check_gop() a 2nd time, the
special considerations for the head of the SKB no longer apply. Don't
mistakenly report ERROR to the frontend for the first entry in the list,
even if - from all I can tell - this shouldn't matter much as the overall
transmit will need to be considered failed anyway.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Vladimir Oltean says:

====================
Make DSA switch drivers compatible with masters which unregister on shutdown

Changes in v2:
- fix build for b53_mmap
- use unregister_netdevice_many

It was reported by Lino here:

https://lore.kernel.org/netdev/20210909095324.12978-1-LinoSanfilippo@gmx.de/

that when the DSA master attempts to unregister its net_device on
shutdown, DSA should prevent that operation from succeeding because it
holds a reference to it. This hangs the shutdown process.

This issue was essentially introduced in commit 2f1e8ea7

 ("net: dsa:
link interfaces with the DSA master to get rid of lockdep warnings").
The present series patches all DSA drivers to handle that case,
depending on whether those drivers were introduced before or after the
offending commit, a different Fixes: tag is specified for them.

The approach taken by this series solves the issue in essentially the
same way as Lino's patches, except for three key differences:

- this series takes a more minimal approach in what is done on shutdown,
  we do not attempt a full tree teardown as that is not strictly
  necessary. I might revisit this if there are compelling reasons to do
  otherwise

- this series fixes the issues for all DSA drivers, not just KSZ9897

- this series works even if the ->remove driver method gets called for
  the same device too, not just ->shutdown. This is really possible to
  happen for SPI device drivers, and potentially possible for other bus
  device drivers too.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

Since commit 2f1e8ea7 ("net: dsa: link interfaces with the DSA
master to get rid of lockdep warnings"), DSA gained a requirement which
it did not fulfill, which is to unlink itself from the DSA master at
shutdown time.

Since the Arrow SpeedChips XRS700x driver was introduced after the bad
commit, it has never worked with DSA masters which decide to unregister
their net_device on shutdown, effectively hanging the reboot process.
To fix that, we need to call dsa_switch_shutdown.

These devices can be connected by I2C or by MDIO, and if I search for
I2C or MDIO bus drivers that implement their ->shutdown by redirecting
it to ->remove I don't see any, however this does not mean it would not
be possible. To be compatible with that pattern, it is necessary to
implement an "if this then not that" scheme, to avoid ->remove and
->shutdown from being called both for the same struct device.

Fixes: ee00b24f ("net: dsa: add Arrow SpeedChips XRS700x driver")
Link: https://lore.kernel.org/netdev/20210909095324.12978-1-LinoSanfilippo@gmx.de/


Reported-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: George McCollister <george.mccollister@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since commit 2f1e8ea7 ("net: dsa: link interfaces with the DSA
master to get rid of lockdep warnings"), DSA gained a requirement which
it did not fulfill, which is to unlink itself from the DSA master at
shutdown time.

Since the Microchip sub-driver for KSZ8863 was introduced after the bad
commit, it has never worked with DSA masters which decide to unregister
their net_device on shutdown, effectively hanging the reboot process.
To fix that, we need to call dsa_switch_shutdown.

Since this driver expects the MDIO bus to be backed by mdio_bitbang, I
don't think there is currently any MDIO bus driver which implements its
->shutdown by redirecting it to ->remove, but in any case, to be
compatible with that pattern, it is necessary to implement an "if this
then not that" scheme, to avoid ->remove and ->shutdown from being
called both for the same struct device.

Fixes: 60a36476 ("net: dsa: microchip: Add Microchip KSZ8863 SMI based driver support")
Link: https://lore.kernel.org/netdev/20210909095324.12978-1-LinoSanfilippo@gmx.de/


Reported-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
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>

Since commit 2f1e8ea7 ("net: dsa: link interfaces with the DSA
master to get rid of lockdep warnings"), DSA gained a requirement which
it did not fulfill, which is to unlink itself from the DSA master at
shutdown time.

Since the hellcreek driver was introduced after the bad commit, it has
never worked with DSA masters which decide to unregister their
net_device on shutdown, effectively hanging the reboot process.

Hellcreek is a platform device driver, so we probably cannot have the
oddities of ->shutdown and ->remove getting both called for the exact
same struct device. But to be in line with the pattern from the other
device drivers which are on slow buses, implement the same "if this then
not that" pattern of either running the ->shutdown or the ->remove hook.
The driver's current ->remove implementation makes that very easy
because it already zeroes out its device_drvdata on ->remove.

Fixes: e4b27ebc ("net: dsa: Add DSA driver for Hirschmann Hellcreek switches")
Link: https://lore.kernel.org/netdev/20210909095324.12978-1-LinoSanfilippo@gmx.de/


Reported-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Kurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

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: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

MDIO-attached devices might have interrupts and other things that might
need quiesced when we kexec into a new kernel. Things are even more
creepy when those interrupt lines are shared, and in that case it is
absolutely mandatory to disable all interrupt sources.

Moreover, MDIO devices might be DSA switches, and DSA needs its own
shutdown method to unlink from the DSA master, which is a new
requirement that appeared after commit 2f1e8ea7

 ("net: dsa: link
interfaces with the DSA master to get rid of lockdep warnings").

So introduce a ->shutdown method in the MDIO device driver structure.

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: David S. Miller <davem@davemloft.net>