Remove the RTNL assertion in the nexthop notifier block. The assertion
is not needed given RTNL is never assumed to be taken.

This is a preparation for future patches where mlxsw will start handling
nexthop events that are not always sent with RTNL held.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Recently we had an interop issue where RARP packets got suppressed with
bridge neigh suppression enabled, but the check in the code was meant to
suppress GARP. Exclude RARP packets from it which would allow some VMWare
setups to work, to quote the report:
"Those RARP packets usually get generated by vMware to notify physical
switches when vMotion occurs. vMware may use random sip/tip or just use
sip=tip=0. So the RARP packet sometimes get properly flooded by the vtep
and other times get dropped by the logic"
Reported-by: Amer Abdalamer <amer@nvidia.com>
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

xps_queue_show is mostly made of an RCU read-side critical section and
calls bitmap_zalloc with GFP_KERNEL in the middle of it. That is not
allowed as this call may sleep and such behaviours aren't allowed in RCU
read-side critical sections. Fix this by using GFP_NOWAIT instead.

Fixes: 5478fcd0 ("net: embed nr_ids in the xps maps")
Reported-by: kernel test robot <oliver.sang@intel.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Get rid of the CONFIG_PM_SLEEP ifdefery to fix the build error
and use __maybe_unused for the suspend()/resume() hooks to avoid
build warning:

drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c:769:21:
 error: 'stmmac_runtime_suspend' undeclared here (not in a function); did you mean 'stmmac_suspend'?
  769 |  SET_RUNTIME_PM_OPS(stmmac_runtime_suspend, stmmac_runtime_resume, NULL)
      |                     ^~~~~~~~~~~~~~~~~~~~~~
./include/linux/pm.h:342:21: note: in definition of macro 'SET_RUNTIME_PM_OPS'
  342 |  .runtime_suspend = suspend_fn, \
      |                     ^~~~~~~~~~
drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c:769:45:
 error: 'stmmac_runtime_resume' undeclared here (not in a function)
  769 |  SET_RUNTIME_PM_OPS(stmmac_runtime_suspend, stmmac_runtime_resume, NULL)
      |                                             ^~~~~~~~~~~~~~~~~~~~~
./include/linux/pm.h:343:20: note: in definition of macro 'SET_RUNTIME_PM_OPS'
  343 |  .runtime_resume = resume_fn, \
      |                    ^~~~~~~~~

Fixes: 5ec55823 ("net: stmmac: add clocks management for gmac driver")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

s/verifed/verified/
Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

gcc warns about a pointless condition:

drivers/isdn/hardware/mISDN/hfcmulti.c: In function 'hfcmulti_interrupt':
drivers/isdn/hardware/mISDN/hfcmulti.c:2752:17: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
 2752 |                 ; /* external IRQ */

As the check has no effect, just remove it.
Suggested-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptype_all and ptype_base are declared in net/core/dev.c as non-static,
because they are used by net-procfs.c too. However, a "make W=1" build
complains that there was no previous declaration of ptype_all and
ptype_base in a header file, so this way of declaring things constitutes
a violation of coding style.

Let's move the extern declarations of ptype_all and ptype_base to the
linux/netdevice.h file, which is included by net-procfs.c too.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since their introduction in commit 04157469 ("net: Use static_key
for XPS maps"), xps_needed and xps_rxqs_needed were never used outside
net/core/dev.c, so I don't really understand why they were exported as
symbols in the first place.

This is needed in order to silence a "make W=1" warning about these
static keys not being declared as static variables, but not having a
previous declaration in a header file nonetheless.

Cc: Amritha Nambiar <amritha.nambiar@intel.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The only caller of br_vlan_tunnel_lookup, br_handle_ingress_vlan_tunnel,
extracts the tunnel_id from struct ip_tunnel_info::struct ip_tunnel_key::
tun_id which is a __be64 value.

The exact endianness does not seem to matter, because the tunnel id is
just used as a lookup key for the VLAN group's tunnel hash table, and
the value is not interpreted directly per se. Moreover,
rhashtable_lookup_fast treats the key argument as a const void *.

Therefore, there is no functional change associated with this patch,
just one to silence "make W=1" builds.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix the following coccicheck warnings:

./drivers/net/ethernet/chelsio/cxgb4/cudbg_lib.c:3540:2-8: WARNING: NULL
check before some freeing functions is not needed.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 0b529448 ("net: dsa: mv88e6xxx: scratch: Fixup kerneldoc")
has addressed some but not all kerneldoc warnings for the Global 2
Scratch register accessors. Namely, we have some mismatches between
the function names in the kerneldoc and the ones in the actual code.
Let's adjust the comments so that they match the functions they're
sitting next to.
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>

Michael Chan says:

====================
bnxt_en: Error recovery improvements.

This series contains some improvements for error recovery.  The main
changes are:

1. Keep better track of the health register mappings with the
"status_reliable" flag.

2. Don't wait for firmware responses if firmware is not healthy.

3. Better retry logic of the first firmware message.

4. Set the proper flag early to let the RDMA driver know that firmware
reset has been detected.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Two enhancements:

1. Read the health status first before sending the first
HWRM_VER_GET message to firmware instead of the other way around.
This guarantees we got the accurate health status before we attempt
to send the message.

2. We currently only retry sending the first HWRM_VER_GET message to
the firmware if the firmware is in the process of booting.  If the
firmware is in error state and is doing core dump for example, the
driver should also retry if the health register has the RECOVERING
flag set.  This flag indicates the firmware will undergo recovery
soon.  Modify the retry logic to retry for this case as well.
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Once the chip goes through reset, the register mapping may be lost
and any read of the mapped health registers may return garbage value
until the registers are mapped again in the init path.

Reading BNXT_FW_RESET_INPROG_REG after firmware reset will likely
return garbage value due to the above reason.  Reading this register
is for information purpose only so remove it.
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

During ifup, if the driver detects that firmware has gone through a
reset, it will go through a re-probe sequence.  If the RDMA driver is
loaded, the re-probe sequence includes calling the RDMA driver to stop.
We need to set the BNXT_STATE_FW_RESET_DET flag earlier so that it is
visible to the RDMA driver.  The RDMA driver's stop sequence is
different if firmware has gone through a reset.
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Reviewed-by: P B S Naresh Kumar <nareshkumar.pbs@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Check return value of call to bnxt_hwrm_func_resc_qcaps in
bnxt_hwrm_if_change and return failure on error.
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Scott Branden <scott.branden@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The original intent here is to allow commands during reset to succeed
without error when the device is disabled, to ensure that cleanup
completes normally during NIC close, where firmware is not necessarily
expected to respond.

The problem with faking success during reset's PCI disablement is that
unrelated ULP commands will also see inadvertent success during reset
when failure would otherwise be appropriate. It is better to return
a different error result such that reset related code can detect
this unique condition and ignore as appropriate.

Note, the pci_disable_device() when firmware is fatally wounded in
bnxt_fw_reset_close() does not need to be addressed, as subsequent
commands are already expected to fail due to the BNXT_NO_FW_ACCESS()
check in bnxt_hwrm_do_send_msg().
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Signed-off-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In situations where FW has crashed, the bnxt_hwrm_do_send_msg() call
will have to wait until timeout for each firmware message.  This
generally takes about half a second for each firmware message.  If we
try to unload the driver n this state, the unload sequence will take
a long time to complete.

Improve this by checking the health register if it is available and
abort the wait for the firmware response if the register shows that
firmware is not healthy.  The very first message HWRM_VER_GET is
excluded from this check because that message is used to poll for
firmware to come out of reset during error recovery.
Signed-off-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In order to read the firmware health status, we first need to determine
the register location and then the register may need to be mapped.
There are 2 code paths to do this.  The first one is done early as a
best effort attempt by the function bnxt_try_map_fw_health_reg().  The
second one is done later in the function bnxt_map_fw_health_regs()
after establishing communications with the firmware.  We currently
only set fw_health->status_reliable if we can successfully set up the
health register in the first code path.

Improve the scheme by setting the fw_health->status_reliable flag if
either (or both) code paths can successfully set up the health
register.  This flag is relied upon during run-time when we need to
check the health status.  So this will make it work better.

During ifdown, if the health register is mapped, we need to invalidate
the health register mapping because a potential fw reset will reset
the mapping.  Similarly, we need to do the same after firmware reset
during recovery.  We'll remap it during ifup.
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Reviewed-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Huazhong Tan says:

====================
net: hns3: refactor and new features for flow director

This patchset refactor some functions and add some new features for
flow director.

patch 1~3: refactor large functions
patch 4, 7: add traffic class and user-def field support for ethtool
patch 5: refactor flow director configuration
patch 6: clean up for hns3_del_all_fd_entries()

change log:
V1->V2: modifies patch 5 as Jakub suggested, keep configuring
	ethtool/tc flower rules synchronously while aRFS
	asynchronously.
	changes the usecnt of user-def rule checking in patch 7.
	removes previous patches 8 and 9 from this series, since
	there are issues that need further discussion.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

For DEVICE_VERSION_V3, the hardware supports to match specified
data in the specified offset of packet payload. Each layer can
have one offset, and can't be masked when configure flow director
rule by ethtool command. The layer is selected based on the
flow-type, ether for L2, ip4/ipv6 for L3, and tcp4/tcp6/udp4/udp6
for L4. For example, tcp4/tcp6/udp4/udp6 rules share the same
user-def offset, but each rule can have its own user-def value.

For the user-def field of ethtool -N/U command is 64 bits long.
The bit 0~15 is used for user-def value, and bit 32~47 for user-def
offset in HNS3 driver.
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

For only PF driver can configure flow director rule, it's
better to call hclge_del_all_fd_entries() directly in hclge
layer, rather than call hns3_del_all_fd_entries() in hns3
layer. Then the ae_algo->ops.del_all_fd_entries can be removed.
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, the flow director rule of aRFS is configured in
the IO path. It's time-consuming. So move out the configuration,
and configure it asynchronously. And keep ethtool and tc flower
rule using synchronous way, otherwise the application maybe
unable to know the rule is installed or pending.

Add a state member for each flow director rule to indicate the
rule state. There are 4 states:
TO_ADD: the rule is waiting to add to hardware
TO_DEL: the rule is waiting to remove from hardware
DELETED: the rule has been removed from hardware. It's a middle
        state, used to remove the rule node in the fd_rule_list.
ACTIVE: the rule is already added in hardware

For asynchronous way, when receive a new request to add or delete
flow director rule by aRFS, update the rule list, then request to
schedule the service task to finish the configuration.

For synchronous way, when receive a new request to add or delete
flow director rule by ethtool or tc flower, configure hardware
directly, then update the rule list if success.
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The hardware supports to parse and match the traffic class field
of IPv6 packet for flow director, uses the same tuple as ip tos.
So removes the limitation of configure 'tclass' by driver.
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, there are too many branches for hclge_fd_convert_tuple().
And it may be more when add new tuples. Refactor it by sorting the
tuples according to their length. So it only needs several KEY_OPT
now, and being flexible to add new tuples.
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The process of function hclge_fd_get_tuple() is complex and
prolix. To make it more readable, extract the process of each
flow-type tuple to a single function.
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The process of function hclge_add_fd_entry() is complex and
prolix. To make it more readable, extract the process of
fs->ring_cookie to a single function.
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

s/unrequired/"not required"/
s/consme/consume/ .....two different places
s/accros/across/
Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Acked-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

s/subsytem/subsystem/
Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

s/packaet/packet/
Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Cristian Ciocaltea says:

====================
Add support for Actions Semi Owl Ethernet MAC

This patch series adds support for the Ethernet MAC found on the Actions
Semi Owl family of SoCs.

For the moment I have only tested the driver on RoseapplePi SBC, which is
based on the S500 SoC variant. It might work on S900 as well, but I cannot
tell for sure since the S900 datasheet I currently have doesn't provide
any information regarding the MAC registers - so I couldn't check the
compatibility with S500.

Similar story for S700: the datasheet I own is incomplete, but it seems
the MAC is advertised with Gigabit capabilities. For that reason most
probably we need to extend the current implementation in order to support
this SoC variant as well.

Please note that for testing the driver it is also necessary to update the
S500 clock subsystem:

https://lore.kernel.org/lkml/cover.1615221459.git.cristian.ciocaltea@gmail.com/

The DTS changes for the S500 SBCs will be provided separately.

Thanks,
Cristi

Changes in v3:
 - Dropped the 'debug' module parameter and passed the default NETIF_MSG flags
to netif_msg_init(), according to David's review

 - Removed the owl_emac_generate_mac_addr() function and the related
OWL_EMAC_GEN_ADDR_SYS_SN config option until a portable solution to get
the system serial number is found - when building on arm64 the following
error is thrown (as reported by Rob's kernel bot):
 '[...]/owl-emac.c:9:10: fatal error: asm/system_info.h: No such file or directory'

 - Rebased patchset on v5.12-rc4

Changes in v2:
* According to Philipp's review
 - Requested exclusive control over serial line via
   devm_reset_control_get_exclusive()
 - Optimized error handling by using dev_err_probe()

* According to Andrew's review
 - Dropped the inline keywords
 - Applied Reverse Christmas Tree format to local variable declarations
 - Renamed owl_emac_phy_config() to owl_emac_update_link_state()
 - Documented the purpose of the special descriptor used in the context of
   owl_emac_setup_frame_xmit()
 - Updated comment inside owl_emac_mdio_clock_enable() regarding the MDC
   clock divider setup
 - Indicated MAC support for symmetric pause via phy_set_sym_pause()
   in owl_emac_phy_init()
 - Changed the MAC addr generation algorithm in owl_emac_generate_mac_addr()
   by setting the locally administered bit in byte 0 and replacing bytes 1 & 2
   with additional entries from enc_sn
 - Moved devm_add_action_or_reset() before clk_set_rate() in owl_emac_probe()

* Other
 - Added SMII interface support: updated owl_emac_core_sw_reset(), added
   owl_emac_clk_set_rate(), updated description in the YAML binding
 - Changed OWL_EMAC_TX_TIMEOUT from 0.05*HZ to 2*HZ
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Add entries for Actions Semi Owl Ethernet MAC binding and driver.
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add new driver for the Ethernet MAC used on the Actions Semi Owl
family of SoCs.

Currently this has been tested only on the Actions Semi S500 SoC
variant.
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add devicetree binding for the Ethernet MAC present on the Actions
Semi Owl family of SoCs.

For the moment advertise only the support for the Actions Semi S500 SoC
variant.
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The existing code is functionally correct: iproute2 parses the ip_flags
argument for tc-flower and really packs it as big endian into the
TCA_FLOWER_KEY_FLAGS netlink attribute. But there is a problem in the
fact that W=1 builds complain:

net/sched/cls_flower.c:1047:15: warning: cast to restricted __be32

This is because we should use the dedicated helper for obtaining a
__be32 pointer to the netlink attribute, not a u32 one. This ensures
type correctness for be32_to_cpu.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

A make W=1 build complains that:

net/sched/cls_flower.c:214:20: warning: cast from restricted __be16
net/sched/cls_flower.c:214:20: warning: incorrect type in argument 1 (different base types)
net/sched/cls_flower.c:214:20:    expected unsigned short [usertype] val
net/sched/cls_flower.c:214:20:    got restricted __be16 [usertype] dst

This is because we use htons on struct flow_dissector_key_ports members
src and dst, which are defined as __be16, so they are already in network
byte order, not host. The byte swap function for the other direction
should have been used.

Because htons and ntohs do the same thing (either both swap, or none
does), this change has no functional effect except to silence the
warnings.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add a function to set the dynamic queue limit minimum value.

Some specific drivers might have legitimate reasons to configure
dql.min_limit to a given value. Typically, this is the case when the
PDU of the protocol is smaller than the packet size to used to
carry those frames to the device.

Concrete example: a CAN (Control Area Network) device with an USB 2.0
interface.  The PDU of classical CAN protocol are roughly 16 bytes but
the USB packet size (which is used to carry the CAN frames to the
device) might be up to 512 bytes.  Wen small traffic burst occurs, BQL
algorithm is not able to immediately adjust and this would result in
having to send many small USB packets (i.e packet of 16 bytes for each
CAN frame). Filling up the USB packet with CAN frames is relatively
fast (small latency issue) but the gain of not having to send several
small USB packets is huge (big throughput increase). In this case,
forcing dql.min_limit to a given value that would allow to stuff the
USB packet is always a win.

This function is to be used by network drivers which are able to prove
through a rationale and through empirical tests on several environment
(with other applications, heavy context switching, virtualization...),
that they constantly reach better performances with a specific
predefined dql.min_limit value with no noticeable latency impact.
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

1. Remove CONFIG_HAVE_NET_DSA.

CONFIG_HAVE_NET_DSA is a legacy leftover from the times when drivers
should have selected CONFIG_NET_DSA manually.
Currently, all drivers has explicit 'depends on NET_DSA', so this is
no more needed.

2. CONFIG_HAVE_NET_DSA dependencies became CONFIG_NET_DSA's ones.

 - dropped !S390 dependency which was introduced to be sure NET_DSA
   can select CONFIG_PHYLIB. DSA migrated to Phylink almost 3 years
   ago and the PHY library itself doesn't depend on !S390 since
   commit 870a2b5e ("phylib: remove !S390 dependeny from Kconfig");
 - INET dependency is kept to be sure we can select NET_SWITCHDEV;
 - NETDEVICES dependency is kept to be sure we can select PHYLINK.

3. DSA drivers menu now depends on NET_DSA.

Instead on 'depends on NET_DSA' on every single driver, the entire
menu now depends on it. This eliminates a lot of duplicated lines
from Kconfig with no loss (when CONFIG_NET_DSA=m, drivers also can
be only m or n).
This also has a nice side effect that there's no more empty menu on
configurations without DSA.

4. Kbuild will now descend into 'drivers/net/dsa' only when
   CONFIG_NET_DSA is y or m.

This is safe since no objects inside this folder can be built without
DSA core, as well as when CONFIG_NET_DSA=m, no objects can be
built-in.
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts commit e9bf9694.

The topic of the reverted patch is the support for switches with global
VLAN filtering, added by commit 061f6a50 ("net: dsa: Add
ndo_vlan_rx_{add, kill}_vid implementation"). Be there a switch with 4
ports swp0 -> swp3, and the following setup:

ip link add br0 type bridge vlan_filtering 1
ip link set swp0 master br0
ip link set swp1 master br0

What would happen with VLAN-tagged traffic received on standalone ports
swp2 and swp3? Well, it would get dropped, were it not for the
.ndo_vlan_rx_add_vid and .ndo_vlan_rx_kill_vid implementations (called
from vlan_vid_add and vlan_vid_del respectively). Basically, for DSA
switches where VLAN filtering is a global attribute, we enforce the
standalone ports to have 'rx-vlan-filter: off [fixed]' in their ethtool
features, which lets the user know that all VLAN-tagged packets that are
not explicitly added in the RX filtering list are dropped.

As for the sja1105 driver, at the time of the reverted patch, it was
operating in a pretty handicapped mode when it had ports under a bridge
with vlan_filtering=1. Specifically, it was unable to terminate traffic
through the CPU port (for further explanation see "Traffic support" in
Documentation/networking/dsa/sja1105.rst).

However, since then, the sja1105 driver has made considerable progress,
and that limitation is no longer as severe now. Specifically, since
commit 2cafa72e ("net: dsa: sja1105: add a new
best_effort_vlan_filtering devlink parameter"), the driver is able to
perform CPU termination even when some ports are under bridges with
vlan_filtering=1. Then, since commit 8841f6e6 ("net: dsa: sja1105:
make devlink property best_effort_vlan_filtering true by default"), this
even became the default operating mode.

So we can now take advantage of the logic in the DSA core.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add support for the ethtool get_ringparam operation.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>