ice: Enable SW interrupt from FW for LL TS

Introduce new capability - Low Latency Timestamping with Interrupt.
On supported devices, driver can request a single timestamp from FW
without polling the register afterwards. Instead, FW can issue
a dedicated interrupt when the timestamp was read from the PHY register
and its value is available to read from the register.
This eliminates the need of bottom half scheduling, which results in
minimal delay for timestamping.

For this mode, allocate TS indices sequentially, so that timestamps are
always completed in FIFO manner.

Co-developed-by: Yochai Hagvi <yochai.hagvi@intel.com>
Signed-off-by: Yochai Hagvi <yochai.hagvi@intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Karol Kolacinski <karol.kolacinski@intel.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.h b/drivers/net/ethernet/intel/ice/ice_ptp.h
index 032653a7a133..087dd32d8762 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.h
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.h
@@ -131,6 +131,7 @@ enum ice_tx_tstamp_work {
  * @calibrating: if true, the PHY is calibrating the Tx offset. During this
  *               window, timestamps are temporarily disabled.
  * @verify_cached: if true, verify new timestamp differs from last read value
+ * @last_ll_ts_idx_read: index of the last LL TS read by the FW
  */
 struct ice_ptp_tx {
 	spinlock_t lock; /* lock protecting in_use bitmap */
@@ -143,6 +144,7 @@ struct ice_ptp_tx {
 	u8 init : 1;
 	u8 calibrating : 1;
 	u8 verify_cached : 1;
+	s8 last_ll_ts_idx_read;
 };
 
 /* Quad and port information for initializing timestamp blocks */
@@ -296,6 +298,8 @@ void ice_ptp_restore_timestamp_mode(struct ice_pf *pf);
 
 void ice_ptp_extts_event(struct ice_pf *pf);
 s8 ice_ptp_request_ts(struct ice_ptp_tx *tx, struct sk_buff *skb);
+void ice_ptp_req_tx_single_tstamp(struct ice_ptp_tx *tx, u8 idx);
+void ice_ptp_complete_tx_single_tstamp(struct ice_ptp_tx *tx);
 enum ice_tx_tstamp_work ice_ptp_process_ts(struct ice_pf *pf);
 
 u64 ice_ptp_get_rx_hwts(const union ice_32b_rx_flex_desc *rx_desc,
@@ -324,6 +328,11 @@ ice_ptp_request_ts(struct ice_ptp_tx *tx, struct sk_buff *skb)
 	return -1;
 }
 
+static inline void ice_ptp_req_tx_single_tstamp(struct ice_ptp_tx *tx, u8 idx)
+{ }
+
+static inline void ice_ptp_complete_tx_single_tstamp(struct ice_ptp_tx *tx) { }
+
 static inline bool ice_ptp_process_ts(struct ice_pf *pf)
 {
 	return true;