Proper refcounts will always warn splat when something goes wrong,
be it underflow, saturation or object resurrection. As these are always
a source of bugs, use it in cls_u32 as a safeguard to prevent/catch issues.
Another benefit is that the refcount API self documents the code, making
clear when transitions to dead are expected.

For such an update we had to make minor adaptations on u32 to fit the refcount
API. First we set explicitly to '1' when objects are created, then the
objects are alive until a 1 -> 0 happens, which is then released appropriately.

The above made clear some redundant operations in the u32 code
around the root_ht handling that were removed. The root_ht is created
with a refcnt set to 1. Then when it's associated with tcf_proto it increments the refcnt to 2.
Throughout the entire code the root_ht is an exceptional case and can never be referenced,
therefore the refcnt never incremented/decremented.
Its lifetime is always bound to tcf_proto, meaning if you delete tcf_proto
the root_ht is deleted as well. The code made up for the fact that root_ht refcnt is 2 and did
a double decrement to free it, which is not a fit for the refcount API.

Even though refcount_t is implemented using atomics, we should observe
a negligible control plane impact.
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20231114141856.974326-2-pctammela@mojatatu.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Revert following commits:

commit acec05fb ("net_tstamp: Add TIMESTAMPING SOFTWARE and HARDWARE mask")
commit 11d55be0 ("net: ethtool: Add a command to expose current time stamping layer")
commit bb8645b0 ("netlink: specs: Introduce new netlink command to get current timestamp")
commit d905f9c7 ("net: ethtool: Add a command to list available time stamping layers")
commit aed5004e ("netlink: specs: Introduce new netlink command to list available time stamping layers")
commit 51bdf316 ("net: Replace hwtstamp_source by timestamping layer")
commit 0f7f463d ("net: Change the API of PHY default timestamp to MAC")
commit 091fab12 ("net: ethtool: ts: Update GET_TS to reply the current selected timestamp")
commit 152c75e1 ("net: ethtool: ts: Let the active time stamping layer be selectable")
commit ee60ea6b ("netlink: specs: Introduce time stamping set command")

They need more time for reviews.

Link: https://lore.kernel.org/all/20231118183529.6e67100c@kernel.org/Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Mirsad proposed a patch to reduce the number of spinlock lock/unlock
operations and the function code size. This can be further improved
because the function sets a consecutive register block.
Suggested-by: Mirsad Todorovac <mirsad.todorovac@alu.unizg.hr>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Mirsad Todorovac <mirsad.todorovac@alu.unizg.hr>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlx5-updates-2023-11-13

1) Cleanup patches, leftovers from previous cycle

2) Allow sync reset flow when BF MGT interface device is present

3) Trivial ptp refactorings and improvements

4) Add local loopback counter to vport rep stats
Signed-off-by: David S. Miller <davem@davemloft.net>

This feature/cleanup patchset includes the following patches:

 - bump version strings, by Simon Wunderlich

 - Implement new multicast packet type, including its transmission,
   forwarding and parsing, by Linus Lüssing (3 patches)

 - Switch to new headers for sprintf and array size,
   by Sven Eckelmann (2 patches)
Signed-off-by: David S. Miller <davem@davemloft.net>

Petr Machata says:

====================
mlxsw: Add support for new reset flow

Ido Schimmel writes:

This patchset changes mlxsw to issue a PCI reset during probe and
devlink reload so that the PCI firmware could be upgraded without a
reboot.

Unlike the old version of this patchset [1], in this version the driver
no longer tries to issue a PCI reset by triggering a PCI link toggle on
its own, but instead calls the PCI core to issue the reset.

The PCI APIs require the device lock to be held which is why patches

Patches #7 adds reset method quirk for NVIDIA Spectrum devices.

Patch #8 adds a debug level print in PCI core so that device ready delay
will be printed even if it is shorter than one second.

Patches #9-#11 are straightforward preparations in mlxsw.

Patch #12 finally implements the new reset flow in mlxsw.

Patch #13 adds PCI reset handlers in mlxsw to avoid user space from
resetting the device from underneath an unaware driver. Instead, the
driver is gracefully de-initialized before the PCI reset and then
initialized again after it.

Patch #14 adds a PCI reset selftest to make sure this code path does not
regress.

[1] https://lore.kernel.org/netdev/cover.1679502371.git.petrm@nvidia.com/
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Test that PCI reset works correctly by verifying that only the expected
reset methods are supported and that after issuing the reset the ifindex
of the port changes.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Implement reset_prepare() and reset_done() handlers that are invoked by
the PCI core before and after issuing a PCI reset, respectively.

Specifically, implement reset_prepare() by calling
mlxsw_core_bus_device_unregister() and reset_done() by calling
mlxsw_core_bus_device_register(). This is the same implementation as the
reload_{down,up}() devlink operations with the following differences:

1. The devlink instance is unregistered and then registered again after
   the reset.

2. A reset via the device's command interface (using MRSR register) is
   not issued during reset_done() as PCI core already issued a PCI
   reset.

Tested:

 # for i in $(seq 1 10); do echo 1 > /sys/bus/pci/devices/0000\:01\:00.0/reset; done
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The driver resets the device during probe and during a devlink reload.
The current reset method reloads the current firmware version or a
pending one, if one was previously flashed using devlink. However, the
current reset method does not result in a PCI hot reset, preventing the
PCI firmware from being upgraded, unless the system is rebooted.

To solve this problem, a new reset command (6) was implemented in the
firmware. Unlike the current command (1), after issuing the new command
the device will not start the reset immediately, but only after a PCI
hot reset.

Implement the new reset method by first verifying that it is supported
by the current firmware version by querying the Management Capabilities
Mask (MCAM) register. If supported, issue the new reset command (6) via
MRSR register followed by a PCI reset by calling
__pci_reset_function_locked().

Once the PCI firmware is operational, go back to the regular reset flow
and wait for the entire device to become ready. That is, repeatedly read
the "system_status" register from the BAR until a value of "FW_READY"
(0x5E) appears.

Tested:

 # for i in $(seq 1 10); do devlink dev reload pci/0000:01:00.0; done
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

In general, the existing flow of software reset in the driver is:
1. Wait for system ready status.
2. Send MRSR command, to start the reset.
3. Wait for system ready status.

This flow will be extended once a new reset command is supported. As a
preparation, move step #2 to a separate function.
Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

In the next patches, mlxsw_pci_sw_reset() will be extended to support
more reset types and will not necessarily issue a software reset. Rename
the function to reflect that.
Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently mlxsw_reg_mrsr_pack() always sets 'command=1'. As preparation for
support of new reset flow, pass the command as an argument to the
function and add an enum for this field.

For now, always pass 'command=1' to the pack() function.
Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, the time it took a PCI device to become ready after reset is
only printed if it was longer than 1000ms ('PCI_RESET_WAIT'). However,
for debugging purposes it is useful to know this time even if it was
shorter. For example, with the device I am working on, hardware
engineers asked to verify that it becomes ready on the first try (no
delay).

To that end, add a debug level print that can be enabled using dynamic
debug. Example:

 # echo 1 > /sys/bus/pci/devices/0000\:01\:00.0/reset
 # dmesg -c | grep ready
 # echo "file drivers/pci/pci.c +p" > /sys/kernel/debug/dynamic_debug/control
 # echo 1 > /sys/bus/pci/devices/0000\:01\:00.0/reset
 # dmesg -c | grep ready
 [  396.060335] mlxsw_spectrum4 0000:01:00.0: ready 0ms after bus reset
 # echo "file drivers/pci/pci.c -p" > /sys/kernel/debug/dynamic_debug/control
 # echo 1 > /sys/bus/pci/devices/0000\:01\:00.0/reset
 # dmesg -c | grep ready
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Spectrum-{1,2,3,4} devices report that a D3hot->D0 transition causes a
reset (i.e., they advertise NoSoftRst-). However, this transition does
not have any effect on the device: It continues to be operational and
network ports remain up. Advertising this support makes it seem as if a
PM reset is viable for these devices. Mark it as unavailable to skip it
when testing reset methods.

Before:

 # cat /sys/bus/pci/devices/0000\:03\:00.0/reset_method
 pm bus

After:

 # cat /sys/bus/pci/devices/0000\:03\:00.0/reset_method
 bus
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add an assert to verify that the device lock is always held throughout
reload operations.

Tested the following flows with netdevsim and mlxsw while lockdep is
enabled:

netdevsim:

 # echo "10 1" > /sys/bus/netdevsim/new_device
 # devlink dev reload netdevsim/netdevsim10
 # ip netns add bla
 # devlink dev reload netdevsim/netdevsim10 netns bla
 # ip netns del bla
 # echo 10 > /sys/bus/netdevsim/del_device

mlxsw:

 # devlink dev reload pci/0000:01:00.0
 # ip netns add bla
 # devlink dev reload pci/0000:01:00.0 netns bla
 # ip netns del bla
 # echo 1 > /sys/bus/pci/devices/0000\:01\:00.0/remove
 # echo 1 > /sys/bus/pci/rescan
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Device drivers register with devlink from their probe routines (under
the device lock) by acquiring the devlink instance lock and calling
devl_register().

Drivers that support a devlink reload usually implement the
reload_{down, up}() operations in a similar fashion to their remove and
probe routines, respectively.

However, while the remove and probe routines are invoked with the device
lock held, the reload operations are only invoked with the devlink
instance lock held. It is therefore impossible for drivers to acquire
the device lock from their reload operations, as this would result in
lock inversion.

The motivating use case for invoking the reload operations with the
device lock held is in mlxsw which needs to trigger a PCI reset as part
of the reload. The driver cannot call pci_reset_function() as this
function acquires the device lock. Instead, it needs to call
__pci_reset_function_locked which expects the device lock to be held.

To that end, adjust devlink to always acquire the device lock before the
devlink instance lock when performing a reload.

Do that when reload is explicitly triggered by user space by specifying
the 'DEVLINK_NL_FLAG_NEED_DEV_LOCK' flag in the pre_doit and post_doit
operations of the reload command.

A previous patch already handled the case where reload is invoked as
part of netns dismantle.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Introduce a new private flag ('DEVLINK_NL_FLAG_NEED_DEV_LOCK') to allow
netlink commands to specify that they need to acquire the device lock in
their pre_doit operation and release it in their post_doit operation.

The reload command will use this flag in the subsequent patch.

No functional changes intended.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, private flags (e.g., 'DEVLINK_NL_FLAG_NEED_PORT') are only
used in pre_doit operations, but a subsequent patch will need to
conditionally lock and unlock the device lock in pre and post doit
operations, respectively.

As a preparation, enable the use of private flags in post_doit
operations in a similar fashion to how it is done for pre_doit
operations.

No functional changes intended.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Device drivers register with devlink from their probe routines (under
the device lock) by acquiring the devlink instance lock and calling
devl_register().

Drivers that support a devlink reload usually implement the
reload_{down, up}() operations in a similar fashion to their remove and
probe routines, respectively.

However, while the remove and probe routines are invoked with the device
lock held, the reload operations are only invoked with the devlink
instance lock held. It is therefore impossible for drivers to acquire
the device lock from their reload operations, as this would result in
lock inversion.

The motivating use case for invoking the reload operations with the
device lock held is in mlxsw which needs to trigger a PCI reset as part
of the reload. The driver cannot call pci_reset_function() as this
function acquires the device lock. Instead, it needs to call
__pci_reset_function_locked which expects the device lock to be held.

To that end, adjust devlink to always acquire the device lock before the
devlink instance lock when performing a reload.

For now, only do that when reload is triggered as part of netns
dismantle. Subsequent patches will handle the case where reload is
explicitly triggered by user space.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The flags are not used outside of the C file so move them there.
Suggested-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Patrick Williams says:

====================
net/ncsi: Add NC-SI 1.2 Get MC MAC Address command

NC-SI 1.2 has now been published[1] and adds a new command for "Get MC
MAC Address".  This is often used by BMCs to get the assigned MAC
address for the channel used by the BMC.

This change set has been tested on a Broadcomm 200G NIC with updated
firmware for NC-SI 1.2 and at least one other non-public NIC design.

1. https://www.dmtf.org/sites/default/files/standards/documents/DSP0222_1.2.0.pdf
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This change adds support for the NC-SI 1.2 Get MC MAC Address command,
specified here:

https://www.dmtf.org/sites/default/files/standards/documents/DSP0222_1.2.0.pdf

It serves the exact same function as the existing OEM Get MAC Address
commands, so if a channel reports that it supports NC-SI 1.2, we prefer
to use the standard command rather than the OEM command.

Verified with an invalid MAC address and 2 valid ones:

[   55.137072] ftgmac100 1e690000.ftgmac eth0: NCSI: Received 3 provisioned MAC addresses
[   55.137614] ftgmac100 1e690000.ftgmac eth0: NCSI: MAC address 0: 00:00:00:00:00:00
[   55.138026] ftgmac100 1e690000.ftgmac eth0: NCSI: MAC address 1: fa:ce:b0:0c:20:22
[   55.138528] ftgmac100 1e690000.ftgmac eth0: NCSI: MAC address 2: fa:ce:b0:0c:20:23
[   55.139241] ftgmac100 1e690000.ftgmac eth0: NCSI: Unable to assign 00:00:00:00:00:00 to device
[   55.140098] ftgmac100 1e690000.ftgmac eth0: NCSI: Set MAC address to fa:ce:b0:0c:20:22
Signed-off-by: Peter Delevoryas <peter@pjd.dev>
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Signed-off-by: David S. Miller <davem@davemloft.net>

The netlink interface for major and minor version numbers doesn't actually
return the major and minor version numbers.

It reports a u32 that contains the (major, minor, update, alpha1)
components as the major version number, and then alpha2 as the minor
version number.

For whatever reason, the u32 byte order was reversed (ntohl): maybe it was
assumed that the encoded value was a single big-endian u32, and alpha2 was
the minor version.

The correct way to get the supported NC-SI version from the network
controller is to parse the Get Version ID response as described in 8.4.44
of the NC-SI spec[1].

    Get Version ID Response Packet Format

              Bits
            +--------+--------+--------+--------+
     Bytes  | 31..24 | 23..16 | 15..8  | 7..0   |
    +-------+--------+--------+--------+--------+
    | 0..15 | NC-SI Header                      |
    +-------+--------+--------+--------+--------+
    | 16..19| Response code   | Reason code     |
    +-------+--------+--------+--------+--------+
    |20..23 | Major  | Minor  | Update | Alpha1 |
    +-------+--------+--------+--------+--------+
    |24..27 |         reserved         | Alpha2 |
    +-------+--------+--------+--------+--------+
    |            .... other stuff ....          |

The major, minor, and update fields are all binary-coded decimal (BCD)
encoded [2]. The spec provides examples below the Get Version ID response
format in section 8.4.44.1, but for practical purposes, this is an example
from a live network card:

    root@bmc:~# ncsi-util 0x15
    NC-SI Command Response:
    cmd: GET_VERSION_ID(0x15)
    Response: COMMAND_COMPLETED(0x0000)  Reason: NO_ERROR(0x0000)
    Payload length = 40

    20: 0xf1 0xf1 0xf0 0x00 <<<<<<<<< (major, minor, update, alpha1)
    24: 0x00 0x00 0x00 0x00 <<<<<<<<< (_, _, _, alpha2)

    28: 0x6d 0x6c 0x78 0x30
    32: 0x2e 0x31 0x00 0x00
    36: 0x00 0x00 0x00 0x00
    40: 0x16 0x1d 0x07 0xd2
    44: 0x10 0x1d 0x15 0xb3
    48: 0x00 0x17 0x15 0xb3
    52: 0x00 0x00 0x81 0x19

This should be parsed as "1.1.0".

"f" in the upper-nibble means to ignore it, contributing zero.

If both nibbles are "f", I think the whole field is supposed to be ignored.
Major and minor are "required", meaning they're not supposed to be "ff",
but the update field is "optional" so I think it can be ff. I think the
simplest thing to do is just set the major and minor to zero instead of
juggling some conditional logic or something.

bcd2bin() from "include/linux/bcd.h" seems to assume both nibbles are 0-9,
so I've provided a custom BCD decoding function.

Alpha1 and alpha2 are ISO/IEC 8859-1 encoded, which just means ASCII
characters as far as I can tell, although the full encoding table for
non-alphabetic characters is slightly different (I think).

I imagine the alpha fields are just supposed to be alphabetic characters,
but I haven't seen any network cards actually report a non-zero value for
either.

If people wrote software against this netlink behavior, and were parsing
the major and minor versions themselves from the u32, then this would
definitely break their code.

[1] https://www.dmtf.org/sites/default/files/standards/documents/DSP0222_1.0.0.pdf
[2] https://en.wikipedia.org/wiki/Binary-coded_decimal
[2] https://en.wikipedia.org/wiki/ISO/IEC_8859-1Signed-off-by: Peter Delevoryas <peter@pjd.dev>
Fixes: 138635cc ("net/ncsi: NCSI response packet handler")
Signed-off-by: David S. Miller <davem@davemloft.net>

Background:

1. CONFIG_NCSI_OEM_CMD_KEEP_PHY

If this is enabled, we send an extra OEM Intel command in the probe
sequence immediately after discovering a channel (e.g. after "Clear
Initial State").

2. CONFIG_NCSI_OEM_CMD_GET_MAC

If this is enabled, we send one of 3 OEM "Get MAC Address" commands from
Broadcom, Mellanox (Nvidida), and Intel in the *configuration* sequence
for a channel.

3. mellanox,multi-host (or mlx,multi-host)

Introduced by this patch:

https://lore.kernel.org/all/20200108234341.2590674-1-vijaykhemka@fb.com/

Which was actually originally from cosmo.chou@quantatw.com:

https://github.com/facebook/openbmc-linux/commit/9f132a10ec48db84613519258cd8a317fb9c8f1b

Cosmo claimed that the Nvidia ConnectX-4 and ConnectX-6 NIC's don't
respond to Get Version ID, et. al in the probe sequence unless you send
the Set MC Affinity command first.

Problem Statement:

We've been using a combination of #ifdef code blocks and IS_ENABLED()
conditions to conditionally send these OEM commands.

It makes adding any new code around these commands hard to understand.

Solution:

In this patch, I just want to remove the conditionally compiled blocks
of code, and always use IS_ENABLED(...) to do dynamic control flow.

I don't think the small amount of code this adds to non-users of the OEM
Kconfigs is a big deal.
Signed-off-by: Peter Delevoryas <peter@pjd.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>

Kory Maincent says:

====================
net: Make timestamping selectable

Up until now, there was no way to let the user select the layer at
which time stamping occurs. The stack assumed that PHY time stamping
is always preferred, but some MAC/PHY combinations were buggy.

This series updates the default MAC/PHY default timestamping and aims to
allow the user to select the desired layer administratively.

Changes in v2:
- Move selected_timestamping_layer variable of the concerned patch.
- Use sysfs_streq instead of strmcmp.
- Use the PHY timestamp only if available.

Changes in v3:
- Expose the PTP choice to ethtool instead of sysfs.
  You can test it with the ethtool source on branch feature_ptp of:
  https://github.com/kmaincent/ethtool
- Added a devicetree binding to select the preferred timestamp.

Changes in v4:
- Move on to ethtool netlink instead of ioctl.
- Add a netdev notifier to allow packet trapping by the MAC in case of PHY
  time stamping.
- Add a PHY whitelist to not break the old PHY default time-stamping
  preference API.

Changes in v5:
- Update to ndo_hwstamp_get/set. This bring several new patches.
- Add few patches to make the glue.
- Convert macb to ndo_hwstamp_get/set.
- Add netlink specs description of new ethtool commands.
- Removed netdev notifier.
- Split the patches that expose the timestamping to userspace to separate
  the core and ethtool development.
- Add description of software timestamping.
- Convert PHYs hwtstamp callback to use kernel_hwtstamp_config.

Changes in v6:
- Few fixes from the reviews.
- Replace the allowlist to default_timestamp flag to know which phy is
  using old API behavior.
- Rename the timestamping layer enum values.
- Move to a simple enum instead of the mix between enum and bitfield.
- Update ts_info and ts-set in software timestamping case.

Changes in v7:
- Fix a temporary build error.
- Link to v6: https://lore.kernel.org/r/20231019-feature_ptp_netnext-v6-0-71affc27b0e5@bootlin.com
====================
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add a new commands allowing to set the time stamping.

Example usage :
./ynl/cli.py --spec netlink/specs/ethtool.yaml --no-schema \
	     --do ts-list-get \
	     --json '{"header":{"dev-name":"eth0"}}'
{'header': {'dev-index': 3, 'dev-name': 'eth0'},
 'ts-list-layer': b'\x02\x00\x00\x00\x01\x00\x00\x00\x05\x00\x00\x00'}

./ynl/cli.py --spec netlink/specs/ethtool.yaml --no-schema --do ts-set \
	     --json '{"header":{"dev-name":"eth0"}, "ts-layer":5}'
none

./ynl/cli.py --spec netlink/specs/ethtool.yaml --no-schema --do ts-get \
	     --json '{"header":{"dev-name":"eth0"}}'
{'header': {'dev-index': 3, 'dev-name': 'eth0'}, 'ts-layer': 5}
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Now that the current timestamp is saved in a variable lets add the
ETHTOOL_MSG_TS_SET ethtool netlink socket to make it selectable.
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

As the default selected timestamp API change we have to change also the
timestamp return by ethtool. This patch return now the current selected
timestamp.
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Change the API to select MAC default time stamping instead of the PHY.
Indeed the PHY is closer to the wire therefore theoretically it has less
delay than the MAC timestamping but the reality is different. Due to lower
time stamping clock frequency, latency in the MDIO bus and no PHC hardware
synchronization between different PHY, the PHY PTP is often less precise
than the MAC. The exception is for PHY designed specially for PTP case but
these devices are not very widespread. For not breaking the compatibility I
introduce a default_timestamp flag in phy_device that is set by the phy
driver to know we are using the old API behavior.

The phy_set_timestamp function is called at each call of phy_attach_direct.
In case of MAC driver using phylink this function is called when the
interface is turned up. Then if the interface goes down and up again the
last choice of timestamp will be overwritten by the default choice.
A solution could be to cache the timestamp status but it can bring other
issues. In case of SFP, if we change the module, it doesn't make sense to
blindly re-set the timestamp back to PHY, if the new module has a PHY with
mediocre timestamping capabilities.
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Replace hwtstamp_source which is only used by the kernel_hwtstamp_config
structure by the more widely use timestamp_layer structure. This is done
to prepare the support of selectable timestamping source.
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add a new commands allowing to list available time stamping layers on a
netdevice's link.

Example usage :
./ynl/cli.py --spec netlink/specs/ethtool.yaml --no-schema \
	     --do ts-list-get \
	     --json '{"header":{"dev-name":"eth0"}}'
{'header': {'dev-index': 3, 'dev-name': 'eth0'},
 'ts-list-layer': b'\x01\x00\x00\x00\x05\x00\x00\x00'}
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Introduce a new netlink message that lists all available time stamping
layers on a given interface.
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add a new commands allowing to get the current time stamping on a
netdevice's link.

Example usage :
./ynl/cli.py --spec netlink/specs/ethtool.yaml --no-schema --do ts-get \
	     --json '{"header":{"dev-name":"eth0"}}'
{'header': {'dev-index': 3, 'dev-name': 'eth0'}, 'ts-layer': 1}
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Time stamping on network packets may happen either in the MAC or in
the PHY, but not both.  In preparation for making the choice
selectable, expose both the current layers via ethtool.

In accordance with the kernel implementation as it stands, the current
layer will always read as "phy" when a PHY time stamping device is
present. Future patches will allow changing the current layer
administratively.
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Timestamping software or hardware flags are often used as a group,
therefore adding these masks will easier future use.

I did not use SOF_TIMESTAMPING_SYS_HARDWARE flag as it is deprecated and
not use at all.
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In case of no phc we should not return SOFTWARE TIMESTAMPING flags as we do
not know whether the netdev supports of timestamping.
Remove it from the lan8841_ts_info and simply return 0.
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Make the dev_set_hwtstamp_phylib function accessible in prevision to use
it from ethtool to reset the tstamp current configuration.
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The hardware timestamping through ndo_eth_ioctl() is going away.
Convert the macb driver to the new API before that can be removed.
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The vlan, macvlan and the bonding drivers call their "real" device driver
in order to report the time stamping capabilities.  Provide a core
ethtool helper function to avoid copy/paste in the stack.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

__phy_hwtstamp_set function were calling the phy_mii_ioctl function
which will then use the ifreq pointer to call the hwtstamp callback.
Now that ifreq has been removed from the hwstamp callback parameters
it seems more logical to not go through the phy_mii_ioctl function and pass
directly kernel_hwtstamp_config parameter to the hwtstamp callback.

Lets do the same for __phy_hwtstamp_get function and return directly
EOPNOTSUPP as SIOCGHWTSTAMP is not supported for now for the PHYs.
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>