Merge branch 'ice-fix-timestamping-in-reset-process'

Tony Nguyen says:

====================
ice: fix timestamping in reset process

Karol Kolacinski says:

PTP reset process has multiple places where timestamping can end up in
an incorrect state.

This series introduces a proper state machine for PTP and refactors
a large part of the code to ensure that timestamping does not break.

The following are changes since commit 91374ba5:
  net: dsa: mt7530: support OF-based registration of switch MDIO bus
and are available in the git repository at:
  git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/next-queue 100GbE
====================

Link: https://lore.kernel.org/r/20240125215757.2601799-1-anthony.l.nguyen@intel.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/intel/ice/ice.h

@@ -493,7 +493,6 @@ enum ice_pf_flags {
 	ICE_FLAG_DCB_ENA,
 	ICE_FLAG_FD_ENA,
 	ICE_FLAG_PTP_SUPPORTED,		/* PTP is supported by NVM */
-	ICE_FLAG_PTP,			/* PTP is enabled by software */
 	ICE_FLAG_ADV_FEATURES,
 	ICE_FLAG_TC_MQPRIO,		/* support for Multi queue TC */
 	ICE_FLAG_CLS_FLOWER,

drivers/net/ethernet/intel/ice/ice_ethtool.c

@@ -3360,7 +3360,7 @@ ice_get_ts_info(struct net_device *dev, struct ethtool_ts_info *info)
 	struct ice_pf *pf = ice_netdev_to_pf(dev);
 
 	/* only report timestamping if PTP is enabled */
-	if (!test_bit(ICE_FLAG_PTP, pf->flags))
+	if (pf->ptp.state != ICE_PTP_READY)
 		return ethtool_op_get_ts_info(dev, info);
 
 	info->so_timestamping = SOF_TIMESTAMPING_TX_SOFTWARE |

drivers/net/ethernet/intel/ice/ice_main.c

@@ -613,7 +613,7 @@ ice_prepare_for_reset(struct ice_pf *pf, enum ice_reset_req reset_type)
 	ice_pf_dis_all_vsi(pf, false);
 
 	if (test_bit(ICE_FLAG_PTP_SUPPORTED, pf->flags))
-		ice_ptp_prepare_for_reset(pf);
+		ice_ptp_prepare_for_reset(pf, reset_type);
 
 	if (ice_is_feature_supported(pf, ICE_F_GNSS))
 		ice_gnss_exit(pf);
@@ -7548,7 +7548,7 @@ static void ice_rebuild(struct ice_pf *pf, enum ice_reset_req reset_type)
 	 * fail.
 	 */
 	if (test_bit(ICE_FLAG_PTP_SUPPORTED, pf->flags))
-		ice_ptp_reset(pf);
+		ice_ptp_rebuild(pf, reset_type);
 
 	if (ice_is_feature_supported(pf, ICE_F_GNSS))
 		ice_gnss_init(pf);

drivers/net/ethernet/intel/ice/ice_ptp.h

@@ -100,7 +100,7 @@ struct ice_perout_channel {
  * the last timestamp we read for a given index. If the current timestamp
  * value is the same as the cached value, we assume a new timestamp hasn't
  * been captured. This avoids reporting stale timestamps to the stack. This is
- * only done if the verify_cached flag is set in ice_ptp_tx structure.
+ * only done if the has_ready_bitmap flag is not set in ice_ptp_tx structure.
  */
 struct ice_tx_tstamp {
 	struct sk_buff *skb;
@@ -130,7 +130,9 @@ enum ice_tx_tstamp_work {
  * @init: if true, the tracker is initialized;
  * @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
+ * @has_ready_bitmap: if true, the hardware has a valid Tx timestamp ready
+ *                    bitmap register. If false, fall back to verifying new
+ *                    timestamp values against previously cached copy.
  * @last_ll_ts_idx_read: index of the last LL TS read by the FW
  */
 struct ice_ptp_tx {
@@ -143,7 +145,7 @@ struct ice_ptp_tx {
 	u8 len;
 	u8 init : 1;
 	u8 calibrating : 1;
-	u8 verify_cached : 1;
+	u8 has_ready_bitmap : 1;
 	s8 last_ll_ts_idx_read;
 };
 
@@ -203,8 +205,17 @@ struct ice_ptp_port_owner {
 
 #define GLTSYN_TGT_H_IDX_MAX		4
 
+enum ice_ptp_state {
+	ICE_PTP_UNINIT = 0,
+	ICE_PTP_INITIALIZING,
+	ICE_PTP_READY,
+	ICE_PTP_RESETTING,
+	ICE_PTP_ERROR,
+};
+
 /**
  * struct ice_ptp - data used for integrating with CONFIG_PTP_1588_CLOCK
+ * @state: current state of PTP state machine
  * @tx_interrupt_mode: the TX interrupt mode for the PTP clock
  * @port: data for the PHY port initialization procedure
  * @ports_owner: data for the auxiliary driver owner
@@ -227,6 +238,7 @@ struct ice_ptp_port_owner {
  * @late_cached_phc_updates: number of times cached PHC update is late
  */
 struct ice_ptp {
+	enum ice_ptp_state state;
 	enum ice_ptp_tx_interrupt tx_interrupt_mode;
 	struct ice_ptp_port port;
 	struct ice_ptp_port_owner ports_owner;
@@ -304,8 +316,9 @@ 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,
 			const struct ice_pkt_ctx *pkt_ctx);
-void ice_ptp_reset(struct ice_pf *pf);
-void ice_ptp_prepare_for_reset(struct ice_pf *pf);
+void ice_ptp_rebuild(struct ice_pf *pf, enum ice_reset_req reset_type);
+void ice_ptp_prepare_for_reset(struct ice_pf *pf,
+			       enum ice_reset_req reset_type);
 void ice_ptp_init(struct ice_pf *pf);
 void ice_ptp_release(struct ice_pf *pf);
 void ice_ptp_link_change(struct ice_pf *pf, u8 port, bool linkup);
@@ -345,8 +358,15 @@ ice_ptp_get_rx_hwts(const union ice_32b_rx_flex_desc *rx_desc,
 	return 0;
 }
 
-static inline void ice_ptp_reset(struct ice_pf *pf) { }
-static inline void ice_ptp_prepare_for_reset(struct ice_pf *pf) { }
+static inline void ice_ptp_rebuild(struct ice_pf *pf,
+				   enum ice_reset_req reset_type)
+{
+}
+
+static inline void ice_ptp_prepare_for_reset(struct ice_pf *pf,
+					     enum ice_reset_req reset_type)
+{
+}
 static inline void ice_ptp_init(struct ice_pf *pf) { }
 static inline void ice_ptp_release(struct ice_pf *pf) { }
 static inline void ice_ptp_link_change(struct ice_pf *pf, u8 port, bool linkup)