<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/net/core/dev_ioctl.c, branch v6.9-rc4</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>net: partial revert of the "Make timestamping selectable: series</title>
<updated>2023-11-19T02:42:37+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2023-11-19T02:38:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=289354f21b2c3fac93e956efd45f256a88a4d997'/>
<id>289354f21b2c3fac93e956efd45f256a88a4d997</id>
<content type='text'>
Revert following commits:

commit acec05fb78ab ("net_tstamp: Add TIMESTAMPING SOFTWARE and HARDWARE mask")
commit 11d55be06df0 ("net: ethtool: Add a command to expose current time stamping layer")
commit bb8645b00ced ("netlink: specs: Introduce new netlink command to get current timestamp")
commit d905f9c75329 ("net: ethtool: Add a command to list available time stamping layers")
commit aed5004ee7a0 ("netlink: specs: Introduce new netlink command to list available time stamping layers")
commit 51bdf3165f01 ("net: Replace hwtstamp_source by timestamping layer")
commit 0f7f463d4821 ("net: Change the API of PHY default timestamp to MAC")
commit 091fab122869 ("net: ethtool: ts: Update GET_TS to reply the current selected timestamp")
commit 152c75e1d002 ("net: ethtool: ts: Let the active time stamping layer be selectable")
commit ee60ea6be0d3 ("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 &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Revert following commits:

commit acec05fb78ab ("net_tstamp: Add TIMESTAMPING SOFTWARE and HARDWARE mask")
commit 11d55be06df0 ("net: ethtool: Add a command to expose current time stamping layer")
commit bb8645b00ced ("netlink: specs: Introduce new netlink command to get current timestamp")
commit d905f9c75329 ("net: ethtool: Add a command to list available time stamping layers")
commit aed5004ee7a0 ("netlink: specs: Introduce new netlink command to list available time stamping layers")
commit 51bdf3165f01 ("net: Replace hwtstamp_source by timestamping layer")
commit 0f7f463d4821 ("net: Change the API of PHY default timestamp to MAC")
commit 091fab122869 ("net: ethtool: ts: Update GET_TS to reply the current selected timestamp")
commit 152c75e1d002 ("net: ethtool: ts: Let the active time stamping layer be selectable")
commit ee60ea6be0d3 ("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 &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: Change the API of PHY default timestamp to MAC</title>
<updated>2023-11-18T14:52:57+00:00</updated>
<author>
<name>Kory Maincent</name>
<email>kory.maincent@bootlin.com</email>
</author>
<published>2023-11-14T11:28:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0f7f463d4821a4f52fa5c0a961389e651d50c384'/>
<id>0f7f463d4821a4f52fa5c0a961389e651d50c384</id>
<content type='text'>
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 &lt;kory.maincent@bootlin.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;kory.maincent@bootlin.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: Replace hwtstamp_source by timestamping layer</title>
<updated>2023-11-18T14:52:57+00:00</updated>
<author>
<name>Kory Maincent</name>
<email>kory.maincent@bootlin.com</email>
</author>
<published>2023-11-14T11:28:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=51bdf3165f012827644c474a6d905baa3de3f1ea'/>
<id>51bdf3165f012827644c474a6d905baa3de3f1ea</id>
<content type='text'>
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 &lt;kory.maincent@bootlin.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;kory.maincent@bootlin.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: Make dev_set_hwtstamp_phylib accessible</title>
<updated>2023-11-18T14:52:57+00:00</updated>
<author>
<name>Kory Maincent</name>
<email>kory.maincent@bootlin.com</email>
</author>
<published>2023-11-14T11:28:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=011dd3b3f83f9c89605c640424e05845b84f2dad'/>
<id>011dd3b3f83f9c89605c640424e05845b84f2dad</id>
<content type='text'>
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 &lt;florian.fainelli@broadcom.com&gt;
Signed-off-by: Kory Maincent &lt;kory.maincent@bootlin.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;florian.fainelli@broadcom.com&gt;
Signed-off-by: Kory Maincent &lt;kory.maincent@bootlin.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dsa: Use conduit and user terms</title>
<updated>2023-10-24T20:08:14+00:00</updated>
<author>
<name>Florian Fainelli</name>
<email>florian.fainelli@broadcom.com</email>
</author>
<published>2023-10-23T18:17:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6ca80638b90cec66547011ee1ef79e534589989a'/>
<id>6ca80638b90cec66547011ee1ef79e534589989a</id>
<content type='text'>
Use more inclusive terms throughout the DSA subsystem by moving away
from "master" which is replaced by "conduit" and "slave" which is
replaced by "user". No functional changes.

Acked-by: Rob Herring &lt;robh@kernel.org&gt;
Acked-by: Stephen Hemminger &lt;stephen@networkplumber.org&gt;
Reviewed-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Signed-off-by: Florian Fainelli &lt;florian.fainelli@broadcom.com&gt;
Link: https://lore.kernel.org/r/20231023181729.1191071-2-florian.fainelli@broadcom.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Use more inclusive terms throughout the DSA subsystem by moving away
from "master" which is replaced by "conduit" and "slave" which is
replaced by "user". No functional changes.

Acked-by: Rob Herring &lt;robh@kernel.org&gt;
Acked-by: Stephen Hemminger &lt;stephen@networkplumber.org&gt;
Reviewed-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Signed-off-by: Florian Fainelli &lt;florian.fainelli@broadcom.com&gt;
Link: https://lore.kernel.org/r/20231023181729.1191071-2-florian.fainelli@broadcom.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: omit ndo_hwtstamp_get() call when possible in dev_set_hwtstamp_phylib()</title>
<updated>2023-08-06T12:25:10+00:00</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2023-08-04T13:49:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c35e927cbe09d38b2d72183bb215901183927c68'/>
<id>c35e927cbe09d38b2d72183bb215901183927c68</id>
<content type='text'>
Setting dev-&gt;priv_flags &amp; IFF_SEE_ALL_HWTSTAMP_REQUESTS is only legal
for drivers which were converted to ndo_hwtstamp_get() and
ndo_hwtstamp_set(), and it is only there that we call ndo_hwtstamp_set()
for a request that otherwise goes to phylib (for stuff like packet traps,
which need to be undone if phylib failed, hence the old_cfg logic).

The problem is that we end up calling ndo_hwtstamp_get() when we don't
need to (even if the SIOCSHWTSTAMP wasn't intended for phylib, or if it
was, but the driver didn't set IFF_SEE_ALL_HWTSTAMP_REQUESTS). For those
unnecessary conditions, we share a code path with virtual drivers (vlan,
macvlan, bonding) where ndo_hwtstamp_get() is implemented as
generic_hwtstamp_get_lower(), and may be resolved through
generic_hwtstamp_ioctl_lower() if the lower device is unconverted.

I.e. this situation:

$ ip link add link eno0 name eno0.100 type vlan id 100
$ hwstamp_ctl -i eno0.100 -t 1

We are unprepared to deal with this, because if ndo_hwtstamp_get() is
resolved through a legacy ndo_eth_ioctl(SIOCGHWTSTAMP) lower_dev
implementation, that needs a non-NULL old_cfg.ifr pointer, and we don't
have it.

But we don't even need to deal with it either. In the general case,
drivers may not even implement SIOCGHWTSTAMP handling, only SIOCSHWTSTAMP,
so it makes sense to completely avoid a SIOCGHWTSTAMP call if we can.

The solution is to split the single "if" condition into 3 smaller ones,
thus separating the decision to call ndo_hwtstamp_get() from the
decision to call ndo_hwtstamp_set(). The third "if" condition is
identical to the first one, and both are subsets of the second one.
Thus, the "cfg" argument of kernel_hwtstamp_config_changed() is always
valid.

Reported-by: Eric Dumazet &lt;edumazet@google.com&gt;
Closes: https://lore.kernel.org/netdev/CANn89iLOspJsvjPj+y8jikg7erXDomWe8sqHMdfL_2LQSFrPAg@mail.gmail.com/
Fixes: fd770e856e22 ("net: remove phy_has_hwtstamp() -&gt; phy_mii_ioctl() decision from converted drivers")
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Setting dev-&gt;priv_flags &amp; IFF_SEE_ALL_HWTSTAMP_REQUESTS is only legal
for drivers which were converted to ndo_hwtstamp_get() and
ndo_hwtstamp_set(), and it is only there that we call ndo_hwtstamp_set()
for a request that otherwise goes to phylib (for stuff like packet traps,
which need to be undone if phylib failed, hence the old_cfg logic).

The problem is that we end up calling ndo_hwtstamp_get() when we don't
need to (even if the SIOCSHWTSTAMP wasn't intended for phylib, or if it
was, but the driver didn't set IFF_SEE_ALL_HWTSTAMP_REQUESTS). For those
unnecessary conditions, we share a code path with virtual drivers (vlan,
macvlan, bonding) where ndo_hwtstamp_get() is implemented as
generic_hwtstamp_get_lower(), and may be resolved through
generic_hwtstamp_ioctl_lower() if the lower device is unconverted.

I.e. this situation:

$ ip link add link eno0 name eno0.100 type vlan id 100
$ hwstamp_ctl -i eno0.100 -t 1

We are unprepared to deal with this, because if ndo_hwtstamp_get() is
resolved through a legacy ndo_eth_ioctl(SIOCGHWTSTAMP) lower_dev
implementation, that needs a non-NULL old_cfg.ifr pointer, and we don't
have it.

But we don't even need to deal with it either. In the general case,
drivers may not even implement SIOCGHWTSTAMP handling, only SIOCSHWTSTAMP,
so it makes sense to completely avoid a SIOCGHWTSTAMP call if we can.

The solution is to split the single "if" condition into 3 smaller ones,
thus separating the decision to call ndo_hwtstamp_get() from the
decision to call ndo_hwtstamp_set(). The third "if" condition is
identical to the first one, and both are subsets of the second one.
Thus, the "cfg" argument of kernel_hwtstamp_config_changed() is always
valid.

Reported-by: Eric Dumazet &lt;edumazet@google.com&gt;
Closes: https://lore.kernel.org/netdev/CANn89iLOspJsvjPj+y8jikg7erXDomWe8sqHMdfL_2LQSFrPAg@mail.gmail.com/
Fixes: fd770e856e22 ("net: remove phy_has_hwtstamp() -&gt; phy_mii_ioctl() decision from converted drivers")
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: remove phy_has_hwtstamp() -&gt; phy_mii_ioctl() decision from converted drivers</title>
<updated>2023-08-03T02:11:06+00:00</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2023-08-01T14:28:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fd770e856e226f80fe6e1dc9d1861bcb135cdf0b'/>
<id>fd770e856e226f80fe6e1dc9d1861bcb135cdf0b</id>
<content type='text'>
It is desirable that the new .ndo_hwtstamp_set() API gives more
uniformity, less overhead and future flexibility w.r.t. the PHY
timestamping behavior.

Currently there are some drivers which allow PHY timestamping through
the procedure mentioned in Documentation/networking/timestamping.rst.
They don't do anything locally if phy_has_hwtstamp() is set, except for
lan966x which installs PTP packet traps.

Centralize that behavior in a new dev_set_hwtstamp_phylib() code
function, which calls either phy_mii_ioctl() for the phylib PHY,
or .ndo_hwtstamp_set() of the netdev, based on a single policy
(currently simplistic: phy_has_hwtstamp()).

Any driver converted to .ndo_hwtstamp_set() will automatically opt into
the centralized phylib timestamping policy. Unconverted drivers still
get to choose whether they let the PHY handle timestamping or not.

Netdev drivers with integrated PHY drivers that don't use phylib
presumably don't set dev-&gt;phydev, and those will always see
HWTSTAMP_SOURCE_NETDEV requests even when converted. The timestamping
policy will remain 100% up to them.

Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Jacob Keller &lt;jacob.e.keller@intel.com&gt;
Tested-by: Horatiu Vultur &lt;horatiu.vultur@microchip.com&gt;
Link: https://lore.kernel.org/r/20230801142824.1772134-13-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
It is desirable that the new .ndo_hwtstamp_set() API gives more
uniformity, less overhead and future flexibility w.r.t. the PHY
timestamping behavior.

Currently there are some drivers which allow PHY timestamping through
the procedure mentioned in Documentation/networking/timestamping.rst.
They don't do anything locally if phy_has_hwtstamp() is set, except for
lan966x which installs PTP packet traps.

Centralize that behavior in a new dev_set_hwtstamp_phylib() code
function, which calls either phy_mii_ioctl() for the phylib PHY,
or .ndo_hwtstamp_set() of the netdev, based on a single policy
(currently simplistic: phy_has_hwtstamp()).

Any driver converted to .ndo_hwtstamp_set() will automatically opt into
the centralized phylib timestamping policy. Unconverted drivers still
get to choose whether they let the PHY handle timestamping or not.

Netdev drivers with integrated PHY drivers that don't use phylib
presumably don't set dev-&gt;phydev, and those will always see
HWTSTAMP_SOURCE_NETDEV requests even when converted. The timestamping
policy will remain 100% up to them.

Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Jacob Keller &lt;jacob.e.keller@intel.com&gt;
Tested-by: Horatiu Vultur &lt;horatiu.vultur@microchip.com&gt;
Link: https://lore.kernel.org/r/20230801142824.1772134-13-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: add hwtstamping helpers for stackable net devices</title>
<updated>2023-08-03T02:11:05+00:00</updated>
<author>
<name>Maxim Georgiev</name>
<email>glipus@gmail.com</email>
</author>
<published>2023-08-01T14:28:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e47d01fea663b1fe58d0a493efc9ed667f70242e'/>
<id>e47d01fea663b1fe58d0a493efc9ed667f70242e</id>
<content type='text'>
The stackable net devices with hwtstamping support (vlan, macvlan,
bonding) only pass the hwtstamping ops to the lower (real) device.

These drivers are the first that need to be converted to the new
timestamping API, because if they aren't prepared to handle that,
then no real device driver cannot be converted to the new API either.

After studying what vlan_dev_ioctl(), macvlan_eth_ioctl() and
bond_eth_ioctl() have in common, here we propose two generic
implementations of ndo_hwtstamp_get() and ndo_hwtstamp_set() which
can be called by those 3 drivers, with "dev" being their lower device.

These helpers cover both cases, when the lower driver is converted to
the new API or unconverted.

We need some hacks in case of an unconverted driver, namely to stuff
some pointers in struct kernel_hwtstamp_config which shouldn't have
been there (since the new API isn't supposed to need it). These will
be removed when all drivers will have been converted to the new API.

Signed-off-by: Maxim Georgiev &lt;glipus@gmail.com&gt;
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Jacob Keller &lt;jacob.e.keller@intel.com&gt;
Link: https://lore.kernel.org/r/20230801142824.1772134-3-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The stackable net devices with hwtstamping support (vlan, macvlan,
bonding) only pass the hwtstamping ops to the lower (real) device.

These drivers are the first that need to be converted to the new
timestamping API, because if they aren't prepared to handle that,
then no real device driver cannot be converted to the new API either.

After studying what vlan_dev_ioctl(), macvlan_eth_ioctl() and
bond_eth_ioctl() have in common, here we propose two generic
implementations of ndo_hwtstamp_get() and ndo_hwtstamp_set() which
can be called by those 3 drivers, with "dev" being their lower device.

These helpers cover both cases, when the lower driver is converted to
the new API or unconverted.

We need some hacks in case of an unconverted driver, namely to stuff
some pointers in struct kernel_hwtstamp_config which shouldn't have
been there (since the new API isn't supposed to need it). These will
be removed when all drivers will have been converted to the new API.

Signed-off-by: Maxim Georgiev &lt;glipus@gmail.com&gt;
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Jacob Keller &lt;jacob.e.keller@intel.com&gt;
Link: https://lore.kernel.org/r/20230801142824.1772134-3-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: add NDOs for configuring hardware timestamping</title>
<updated>2023-08-03T02:11:05+00:00</updated>
<author>
<name>Maxim Georgiev</name>
<email>glipus@gmail.com</email>
</author>
<published>2023-08-01T14:28:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=66f7223039c0cef81221e9779520479895995815'/>
<id>66f7223039c0cef81221e9779520479895995815</id>
<content type='text'>
Current hardware timestamping API for NICs requires implementing
.ndo_eth_ioctl() for SIOCGHWTSTAMP and SIOCSHWTSTAMP.

That API has some boilerplate such as request parameter translation
between user and kernel address spaces, handling possible translation
failures correctly, etc. Since it is the same all across the board, it
would be desirable to handle it through generic code.

Here we introduce .ndo_hwtstamp_get() and .ndo_hwtstamp_set(), which
implement that boilerplate and allow drivers to just act upon requests.

Suggested-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Maxim Georgiev &lt;glipus@gmail.com&gt;
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Jacob Keller &lt;jacob.e.keller@intel.com&gt;
Tested-by: Horatiu Vultur &lt;horatiu.vultur@microchip.com&gt;
Link: https://lore.kernel.org/r/20230801142824.1772134-2-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Current hardware timestamping API for NICs requires implementing
.ndo_eth_ioctl() for SIOCGHWTSTAMP and SIOCSHWTSTAMP.

That API has some boilerplate such as request parameter translation
between user and kernel address spaces, handling possible translation
failures correctly, etc. Since it is the same all across the board, it
would be desirable to handle it through generic code.

Here we introduce .ndo_hwtstamp_get() and .ndo_hwtstamp_set(), which
implement that boilerplate and allow drivers to just act upon requests.

Suggested-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Maxim Georgiev &lt;glipus@gmail.com&gt;
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Jacob Keller &lt;jacob.e.keller@intel.com&gt;
Tested-by: Horatiu Vultur &lt;horatiu.vultur@microchip.com&gt;
Link: https://lore.kernel.org/r/20230801142824.1772134-2-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dsa: replace NETDEV_PRE_CHANGE_HWTSTAMP notifier with a stub</title>
<updated>2023-04-09T14:35:49+00:00</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2023-04-06T11:42:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5a17818682cf43ad0fdd6035945f3b7a8c9dc5e9'/>
<id>5a17818682cf43ad0fdd6035945f3b7a8c9dc5e9</id>
<content type='text'>
There was a sort of rush surrounding commit 88c0a6b503b7 ("net: create a
netdev notifier for DSA to reject PTP on DSA master"), due to a desire
to convert DSA's attempt to deny TX timestamping on a DSA master to
something that doesn't block the kernel-wide API conversion from
ndo_eth_ioctl() to ndo_hwtstamp_set().

What was required was a mechanism that did not depend on ndo_eth_ioctl(),
and what was provided was a mechanism that did not depend on
ndo_eth_ioctl(), while at the same time introducing something that
wasn't absolutely necessary - a new netdev notifier.

There have been objections from Jakub Kicinski that using notifiers in
general when they are not absolutely necessary creates complications to
the control flow and difficulties to maintainers who look at the code.
So there is a desire to not use notifiers.

In addition to that, the notifier chain gets called even if there is no
DSA in the system and no one is interested in applying any restriction.

Take the model of udp_tunnel_nic_ops and introduce a stub mechanism,
through which net/core/dev_ioctl.c can call into DSA even when
CONFIG_NET_DSA=m.

Compared to the code that existed prior to the notifier conversion, aka
what was added in commits:
- 4cfab3566710 ("net: dsa: Add wrappers for overloaded ndo_ops")
- 3369afba1e46 ("net: Call into DSA netdevice_ops wrappers")

this is different because we are not overloading any struct
net_device_ops of the DSA master anymore, but rather, we are exposing a
rather specific functionality which is orthogonal to which API is used
to enable it - ndo_eth_ioctl() or ndo_hwtstamp_set().

Also, what is similar is that both approaches use function pointers to
get from built-in code to DSA.

There is no point in replicating the function pointers towards
__dsa_master_hwtstamp_validate() once for every CPU port (dev-&gt;dsa_ptr).
Instead, it is sufficient to introduce a singleton struct dsa_stubs,
built into the kernel, which contains a single function pointer to
__dsa_master_hwtstamp_validate().

I find this approach preferable to what we had originally, because
dev-&gt;dsa_ptr-&gt;netdev_ops-&gt;ndo_do_ioctl() used to require going through
struct dsa_port (dev-&gt;dsa_ptr), and so, this was incompatible with any
attempts to add any data encapsulation and hide DSA data structures from
the outside world.

Link: https://lore.kernel.org/netdev/20230403083019.120b72fd@kernel.org/
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There was a sort of rush surrounding commit 88c0a6b503b7 ("net: create a
netdev notifier for DSA to reject PTP on DSA master"), due to a desire
to convert DSA's attempt to deny TX timestamping on a DSA master to
something that doesn't block the kernel-wide API conversion from
ndo_eth_ioctl() to ndo_hwtstamp_set().

What was required was a mechanism that did not depend on ndo_eth_ioctl(),
and what was provided was a mechanism that did not depend on
ndo_eth_ioctl(), while at the same time introducing something that
wasn't absolutely necessary - a new netdev notifier.

There have been objections from Jakub Kicinski that using notifiers in
general when they are not absolutely necessary creates complications to
the control flow and difficulties to maintainers who look at the code.
So there is a desire to not use notifiers.

In addition to that, the notifier chain gets called even if there is no
DSA in the system and no one is interested in applying any restriction.

Take the model of udp_tunnel_nic_ops and introduce a stub mechanism,
through which net/core/dev_ioctl.c can call into DSA even when
CONFIG_NET_DSA=m.

Compared to the code that existed prior to the notifier conversion, aka
what was added in commits:
- 4cfab3566710 ("net: dsa: Add wrappers for overloaded ndo_ops")
- 3369afba1e46 ("net: Call into DSA netdevice_ops wrappers")

this is different because we are not overloading any struct
net_device_ops of the DSA master anymore, but rather, we are exposing a
rather specific functionality which is orthogonal to which API is used
to enable it - ndo_eth_ioctl() or ndo_hwtstamp_set().

Also, what is similar is that both approaches use function pointers to
get from built-in code to DSA.

There is no point in replicating the function pointers towards
__dsa_master_hwtstamp_validate() once for every CPU port (dev-&gt;dsa_ptr).
Instead, it is sufficient to introduce a singleton struct dsa_stubs,
built into the kernel, which contains a single function pointer to
__dsa_master_hwtstamp_validate().

I find this approach preferable to what we had originally, because
dev-&gt;dsa_ptr-&gt;netdev_ops-&gt;ndo_do_ioctl() used to require going through
struct dsa_port (dev-&gt;dsa_ptr), and so, this was incompatible with any
attempts to add any data encapsulation and hide DSA data structures from
the outside world.

Link: https://lore.kernel.org/netdev/20230403083019.120b72fd@kernel.org/
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
</feed>
