intel/iavf/iavf_ptp.c

14  * Disable timestamp reporting for all Rx rings.
26  * Enable timestamp reporting for all Rx rings.
41  * Note: this function always translates Rx timestamp requests for any packet
197  * @ts: storage for the timestamp value
198  * @sts: system timestamp values before and after the read
256  * iavf_ptp_cache_phc_time - Cache PHC time for performing timestamp extension
259  * Periodically cache the PHC time in order to allow for timestamp extension.
261  * nanoseconds. Timestamp extension allows calculating the corrected 64bit
262  * timestamp. This algorithm relies on the cached time being within ~1 second
263  * of the timestamp.
285  *      cached_phc_time is used by the Tx and Rx timestamp flows in order to
286  *      perform timestamp extension, by carefully comparing the timestamp
288  *      timestamp value to report to userspace. This algorithm only works if
289  *      the cached_phc_time is within ~1 second of the Tx or Rx timestamp
291  *      ensure that timestamp extension operates correctly.
422 	/* Check if the device lost access to Rx timestamp incoming packets */  in iavf_ptp_process_caps()
430  * iavf_ptp_extend_32b_timestamp - Convert a 32b nanoseconds timestamp to 64b
433  * @in_tstamp: Ingress/egress 32b nanoseconds timestamp value
438  * Extend the 32bit nanosecond timestamp using the following algorithm and
444  * 3) calculate the delta between the cached time and the timestamp
445  * 4) if the delta is smaller than 2^31 nanoseconds, then the timestamp was
446  *    captured after the PHC time. In this case, the full timestamp is just
449  *    timestamp was captured *before* the PHC time, i.e. because the PHC
450  *    cache was updated after the timestamp was captured by hardware. In this
451  *    case, the full timestamp is the cached time minus the inverse delta.
453  * This algorithm works even if the PHC time was updated after a Tx timestamp
454  * was requested, but before the Tx timestamp event was reported from
458  * date. If the timestamp was captured more than 2^31 nanoseconds after the
460  * overflowed more than once, and we might generate an incorrect timestamp.
463  * a second, and (b) discarding any Tx timestamp packet if it has waited for
464  * a timestamp for more than one second.
466  * Return: extended timestamp (to 64b).