net: ethtool: Add support for tsconfig command to get/set hwtstamp config

Introduce support for ETHTOOL_MSG_TSCONFIG_GET/SET ethtool netlink socket
to read and configure hwtstamp configuration of a PHC provider. Note that
simultaneous hwtstamp isn't supported; configuring a new one disables the
previous setting.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 99 insertions, 14 deletions

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index c585e2f0ddfa..a7ba6368a4d5 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -237,6 +237,8 @@ Userspace to kernel:
   ``ETHTOOL_MSG_MM_SET``                set MAC merge layer parameters
   ``ETHTOOL_MSG_MODULE_FW_FLASH_ACT``   flash transceiver module firmware
   ``ETHTOOL_MSG_PHY_GET``               get Ethernet PHY information
+  ``ETHTOOL_MSG_TSCONFIG_GET``          get hw timestamping configuration
+  ``ETHTOOL_MSG_TSCONFIG_SET``          set hw timestamping configuration
   ===================================== =================================
 
 Kernel to userspace:
@@ -286,6 +288,8 @@ Kernel to userspace:
   ``ETHTOOL_MSG_MODULE_FW_FLASH_NTF``      transceiver module flash updates
   ``ETHTOOL_MSG_PHY_GET_REPLY``            Ethernet PHY information
   ``ETHTOOL_MSG_PHY_NTF``                  Ethernet PHY information change
+  ``ETHTOOL_MSG_TSCONFIG_GET_REPLY``       hw timestamping configuration
+  ``ETHTOOL_MSG_TSCONFIG_SET_REPLY``       new hw timestamping configuration
   ======================================== =================================
 
 ``GET`` requests are sent by userspace applications to retrieve device
@@ -2244,6 +2248,75 @@ Kernel response contents:
 When ``ETHTOOL_A_PHY_UPSTREAM_TYPE`` is PHY_UPSTREAM_PHY, the PHY's parent is
 another PHY.
 
+TSCONFIG_GET
+============
+
+Retrieves the information about the current hardware timestamping source and
+configuration.
+
+It is similar to the deprecated ``SIOCGHWTSTAMP`` ioctl request.
+
+Request contents:
+
+  ====================================  ======  ==========================
+  ``ETHTOOL_A_TSCONFIG_HEADER``         nested  request header
+  ====================================  ======  ==========================
+
+Kernel response contents:
+
+  ======================================== ======  ============================
+  ``ETHTOOL_A_TSCONFIG_HEADER``            nested  request header
+  ``ETHTOOL_A_TSCONFIG_HWTSTAMP_PROVIDER`` nested  PTP hw clock provider
+  ``ETHTOOL_A_TSCONFIG_TX_TYPES``          bitset  hwtstamp Tx type
+  ``ETHTOOL_A_TSCONFIG_RX_FILTERS``        bitset  hwtstamp Rx filter
+  ``ETHTOOL_A_TSCONFIG_HWTSTAMP_FLAGS``	   u32     hwtstamp flags
+  ======================================== ======  ============================
+
+When set the ``ETHTOOL_A_TSCONFIG_HWTSTAMP_PROVIDER`` attribute identifies the
+source of the hw timestamping provider. It is composed by
+``ETHTOOL_A_TS_HWTSTAMP_PROVIDER_INDEX`` attribute which describe the index of
+the PTP device and ``ETHTOOL_A_TS_HWTSTAMP_PROVIDER_QUALIFIER`` which describe
+the qualifier of the timestamp.
+
+When set the ``ETHTOOL_A_TSCONFIG_TX_TYPES``, ``ETHTOOL_A_TSCONFIG_RX_FILTERS``
+and the ``ETHTOOL_A_TSCONFIG_HWTSTAMP_FLAGS`` attributes identify the Tx
+type, the Rx filter and the flags configured for the current hw timestamping
+provider. The attributes are propagated to the driver through the following
+structure:
+
+.. kernel-doc:: include/linux/net_tstamp.h
+    :identifiers: kernel_hwtstamp_config
+
+TSCONFIG_SET
+============
+
+Set the information about the current hardware timestamping source and
+configuration.
+
+It is similar to the deprecated ``SIOCSHWTSTAMP`` ioctl request.
+
+Request contents:
+
+  ======================================== ======  ============================
+  ``ETHTOOL_A_TSCONFIG_HEADER``            nested  request header
+  ``ETHTOOL_A_TSCONFIG_HWTSTAMP_PROVIDER`` nested  PTP hw clock provider
+  ``ETHTOOL_A_TSCONFIG_TX_TYPES``          bitset  hwtstamp Tx type
+  ``ETHTOOL_A_TSCONFIG_RX_FILTERS``        bitset  hwtstamp Rx filter
+  ``ETHTOOL_A_TSCONFIG_HWTSTAMP_FLAGS``	   u32     hwtstamp flags
+  ======================================== ======  ============================
+
+Kernel response contents:
+
+  ======================================== ======  ============================
+  ``ETHTOOL_A_TSCONFIG_HEADER``            nested  request header
+  ``ETHTOOL_A_TSCONFIG_HWTSTAMP_PROVIDER`` nested  PTP hw clock provider
+  ``ETHTOOL_A_TSCONFIG_TX_TYPES``          bitset  hwtstamp Tx type
+  ``ETHTOOL_A_TSCONFIG_RX_FILTERS``        bitset  hwtstamp Rx filter
+  ``ETHTOOL_A_TSCONFIG_HWTSTAMP_FLAGS``	   u32     hwtstamp flags
+  ======================================== ======  ============================
+
+For a description of each attribute, see ``TSCONFIG_GET``.
+
 Request translation
 ===================
 
@@ -2352,4 +2425,6 @@ are netlink only.
   n/a                                 ``ETHTOOL_MSG_MM_SET``
   n/a                                 ``ETHTOOL_MSG_MODULE_FW_FLASH_ACT``
   n/a                                 ``ETHTOOL_MSG_PHY_GET``
+  ``SIOCGHWTSTAMP``                   ``ETHTOOL_MSG_TSCONFIG_GET``
+  ``SIOCSHWTSTAMP``                   ``ETHTOOL_MSG_TSCONFIG_SET``
   =================================== =====================================
diff --git a/Documentation/networking/timestamping.rst b/Documentation/networking/timestamping.rst
index b37bfbfc7d79..61ef9da10e28 100644
--- a/Documentation/networking/timestamping.rst
+++ b/Documentation/networking/timestamping.rst
@@ -525,8 +525,8 @@ implicitly defined. ts[0] holds a software timestamp if set, ts[1]
 is again deprecated and ts[2] holds a hardware timestamp if set.
 
 
-3. Hardware Timestamping configuration: SIOCSHWTSTAMP and SIOCGHWTSTAMP
-=======================================================================
+3. Hardware Timestamping configuration: ETHTOOL_MSG_TSCONFIG_SET/GET
+====================================================================
 
 Hardware time stamping must also be initialized for each device driver
 that is expected to do hardware time stamping. The parameter is defined in
@@ -539,12 +539,14 @@ include/uapi/linux/net_tstamp.h as::
 	};
 
 Desired behavior is passed into the kernel and to a specific device by
-calling ioctl(SIOCSHWTSTAMP) with a pointer to a struct ifreq whose
-ifr_data points to a struct hwtstamp_config. The tx_type and
-rx_filter are hints to the driver what it is expected to do. If
-the requested fine-grained filtering for incoming packets is not
-supported, the driver may time stamp more than just the requested types
-of packets.
+calling the tsconfig netlink socket ``ETHTOOL_MSG_TSCONFIG_SET``.
+The ``ETHTOOL_A_TSCONFIG_TX_TYPES``, ``ETHTOOL_A_TSCONFIG_RX_FILTERS`` and
+``ETHTOOL_A_TSCONFIG_HWTSTAMP_FLAGS`` netlink attributes are then used to set
+the struct hwtstamp_config accordingly.
+
+The ``ETHTOOL_A_TSCONFIG_HWTSTAMP_PROVIDER`` netlink nested attribute is used
+to select the source of the hardware time stamping. It is composed of an index
+for the device source and a qualifier for the type of time stamping.
 
 Drivers are free to use a more permissive configuration than the requested
 configuration. It is expected that drivers should only implement directly the
@@ -563,9 +565,16 @@ Only a processes with admin rights may change the configuration. User
 space is responsible to ensure that multiple processes don't interfere
 with each other and that the settings are reset.
 
-Any process can read the actual configuration by passing this
-structure to ioctl(SIOCGHWTSTAMP) in the same way.  However, this has
-not been implemented in all drivers.
+Any process can read the actual configuration by requesting tsconfig netlink
+socket ``ETHTOOL_MSG_TSCONFIG_GET``.
+
+The legacy configuration is the use of the ioctl(SIOCSHWTSTAMP) with a pointer
+to a struct ifreq whose ifr_data points to a struct hwtstamp_config.
+The tx_type and rx_filter are hints to the driver what it is expected to do.
+If the requested fine-grained filtering for incoming packets is not
+supported, the driver may time stamp more than just the requested types
+of packets. ioctl(SIOCGHWTSTAMP) is used in the same way as the
+ioctl(SIOCSHWTSTAMP). However, this has not been implemented in all drivers.
 
 ::
 
@@ -610,9 +619,10 @@ not been implemented in all drivers.
 --------------------------------------------------------
 
 A driver which supports hardware time stamping must support the
-SIOCSHWTSTAMP ioctl and update the supplied struct hwtstamp_config with
-the actual values as described in the section on SIOCSHWTSTAMP.  It
-should also support SIOCGHWTSTAMP.
+ndo_hwtstamp_set NDO or the legacy SIOCSHWTSTAMP ioctl and update the
+supplied struct hwtstamp_config with the actual values as described in
+the section on SIOCSHWTSTAMP. It should also support ndo_hwtstamp_get or
+the legacy SIOCGHWTSTAMP.
 
 Time stamps for received packets must be stored in the skb. To get a pointer
 to the shared time stamp structure of the skb call skb_hwtstamps(). Then