Add SIOCGHWTSTAMP and SIOCSHWTSTAMP ioctl handlers to respond to
requests to enable timestamping support. If the request is for enabling
Rx timestamps, set a bit in the Rx descriptors to indicate that receive
timestamps should be reported.
Hardware captures receive timestamps in the PHY which only captures part
of the timer, and reports only 40 bits into the Rx descriptor. The upper
32 bits represent the contents of GLTSYN_TIME_L at the point of packet
reception, while the lower 8 bits represent the upper 8 bits of
GLTSYN_TIME_0.
The networking and PTP stack expect 64 bit timestamps in nanoseconds. To
support this, implement some logic to extend the timestamps by using the
full PHC time.
If the Rx timestamp was captured prior to the PHC time, then the real
timestamp is
PHC - (lower_32_bits(PHC) - timestamp)
If the Rx timestamp was captured after the PHC time, then the real
timestamp is
PHC + (timestamp - lower_32_bits(PHC))
These calculations are correct as long as neither the PHC timestamp nor
the Rx timestamps are more than 2^32-1 nanseconds old. Further, we can
detect when the Rx timestamp is before or after the PHC as long as the
PHC timestamp is no more than 2^31-1 nanoseconds old.
In that case, we calculate the delta between the lower 32 bits of the
PHC and the Rx timestamp. If it's larger than 2^31-1 then the Rx
timestamp must have been captured in the past. If it's smaller, then the
Rx timestamp must have been captured after PHC time.
Add an ice_ptp_extend_32b_ts function that relies on a cached copy of
the PHC time and implements this algorithm to calculate the proper upper
32bits of the Rx timestamps.
Cache the PHC time periodically in all of the Rx rings. This enables
each Rx ring to simply call the extension function with a recent copy of
the PHC time. By ensuring that the PHC time is kept up to date
periodically, we ensure this algorithm doesn't use stale data and
produce incorrect results.
To cache the time, introduce a kworker and a kwork item to periodically
store the Rx time. It might seem like we should use the .do_aux_work
interface of the PTP clock. This doesn't work because all PFs must cache
this time, but only one PF owns the PTP clock device.
Thus, the ice driver will manage its own kthread instead of relying on
the PTP do_aux_work handler.
With this change, the driver can now report Rx timestamps on all
incoming packets.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Now that the driver registers a PTP clock device that represents the
clock hardware, it is important that the clock index is reported via the
ethtool .get_ts_info callback.
The underlying hardware resource is shared between multiple PF
functions. Only one function owns the hardware resources associated with
a timer, but multiple functions may be associated with it for the
purposes of timestamping.
To support this, the owning PF will store the clock index into the
driver shared parameters buffer in firmware. Other PFs will look up the
clock index by reading the driver shared parameter on demand when
requested via the .get_ts_info ethtool function.
In this way, all functions which are tied to the same timer are able to
report the clock index. Userspace software such as ptp4l performs
a look up on the netdev to determine the associated clock, and all
commands to control or configure the clock will be handled through the
controlling PF.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Add a new ice_ptp.c file for holding the basic PTP clock interface
functions. If the device supports PTP, call the new ice_ptp_init and
ice_ptp_release functions where appropriate.
If the function owns the hardware resource associated with the PTP
hardware clock, register with the PTP_1588_CLOCK infrastructure to
allocate a new clock object that represents the device hardware clock.
Implement basic functionality for reading and setting the clock time,
performing clock adjustments, and adjusting the clock frequency.
Future changes will introduce functionality for handling related
features including Tx and Rx timestamps.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
