Merge branch 'ice-restore-timestamp-config-after-reset'

Tony Nguyen says:

====================
ice: restore timestamp config after reset

Jake Keller says:

We recently discovered during internal validation that the ice driver has
not been properly restoring Tx timestamp configuration after a device reset,
which resulted in application failures after a device reset.

After some digging, it turned out this problem is two-fold. Since the
introduction of the PTP support the driver has been clobbering the storage
of the current timestamp configuration during reset. Thus after a reset, the
driver will no longer perform Tx or Rx timestamps, and will report
timestamp configuration as disabled if SIOCGHWTSTAMP ioctl is issued.

In addition, the recently merged auxiliary bus support code missed that
PFINT_TSYN_MSK must be reprogrammed on the clock owner for E822 devices.
Failure to restore this register configuration results in the driver no
longer responding to interrupts from other ports. Depending on the traffic
pattern, this can either result in increased latency responding to
timestamps on the non-owner ports, or it can result in the driver never
reporting any timestamps. The configuration of PFINT_TSYN_MSK was only done
during initialization. Due to this, the Tx timestamp issue persists even if
userspace reconfigures timestamping.

This series fixes both issues, as well as removes a redundant Tx ring field
since we can rely on the skb flag as the primary detector for a Tx timestamp
request.

Note that I don't think this series will directly apply to older stable
releases (even v6.6) as we recently refactored a lot of the PTP code to
support auxiliary bus. Patch 2/3 only matters for the post-auxiliary bus
implementation. The principle of patch 1/3 and 3/3 could apply as far back
as the initial PTP support, but I don't think it will apply cleanly as-is.
====================

Link: https://lore.kernel.org/r/20231121211259.3348630-1-anthony.l.nguyen@intel.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

5 files changed, 83 insertions, 82 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index 6607fa6fe55626..fb9c93f37e84f7 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -7401,15 +7401,6 @@ static void ice_rebuild(struct ice_pf *pf, enum ice_reset_req reset_type)
 		goto err_vsi_rebuild;
 	}
 
-	/* configure PTP timestamping after VSI rebuild */
-	if (test_bit(ICE_FLAG_PTP_SUPPORTED, pf->flags)) {
-		if (pf->ptp.tx_interrupt_mode == ICE_PTP_TX_INTERRUPT_SELF)
-			ice_ptp_cfg_timestamp(pf, false);
-		else if (pf->ptp.tx_interrupt_mode == ICE_PTP_TX_INTERRUPT_ALL)
-			/* for E82x PHC owner always need to have interrupts */
-			ice_ptp_cfg_timestamp(pf, true);
-	}
-
 	err = ice_vsi_rebuild_by_type(pf, ICE_VSI_SWITCHDEV_CTRL);
 	if (err) {
 		dev_err(dev, "Switchdev CTRL VSI rebuild failed: %d\n", err);
@@ -7461,6 +7452,9 @@ static void ice_rebuild(struct ice_pf *pf, enum ice_reset_req reset_type)
 	ice_plug_aux_dev(pf);
 	if (ice_is_feature_supported(pf, ICE_F_SRIOV_LAG))
 		ice_lag_rebuild(pf);
+
+	/* Restore timestamp mode settings after VSI rebuild */
+	ice_ptp_restore_timestamp_mode(pf);
 	return;
 
 err_vsi_rebuild:
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index 1eddcbe89b0c47..71f405f8a6fee6 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -256,48 +256,42 @@ ice_verify_pin_e810t(struct ptp_clock_info *info, unsigned int pin,
 }
 
 /**
- * ice_ptp_configure_tx_tstamp - Enable or disable Tx timestamp interrupt
- * @pf: The PF pointer to search in
- * @on: bool value for whether timestamp interrupt is enabled or disabled
+ * ice_ptp_cfg_tx_interrupt - Configure Tx timestamp interrupt for the device
+ * @pf: Board private structure
+ *
+ * Program the device to respond appropriately to the Tx timestamp interrupt
+ * cause.
  */
-static void ice_ptp_configure_tx_tstamp(struct ice_pf *pf, bool on)
+static void ice_ptp_cfg_tx_interrupt(struct ice_pf *pf)
 {
+	struct ice_hw *hw = &pf->hw;
+	bool enable;
 	u32 val;
 
+	switch (pf->ptp.tx_interrupt_mode) {
+	case ICE_PTP_TX_INTERRUPT_ALL:
+		/* React to interrupts across all quads. */
+		wr32(hw, PFINT_TSYN_MSK + (0x4 * hw->pf_id), (u32)0x1f);
+		enable = true;
+		break;
+	case ICE_PTP_TX_INTERRUPT_NONE:
+		/* Do not react to interrupts on any quad. */
+		wr32(hw, PFINT_TSYN_MSK + (0x4 * hw->pf_id), (u32)0x0);
+		enable = false;
+		break;
+	case ICE_PTP_TX_INTERRUPT_SELF:
+	default:
+		enable = pf->ptp.tstamp_config.tx_type == HWTSTAMP_TX_ON;
+		break;
+	}
+
 	/* Configure the Tx timestamp interrupt */
-	val = rd32(&pf->hw, PFINT_OICR_ENA);
-	if (on)
+	val = rd32(hw, PFINT_OICR_ENA);
+	if (enable)
 		val |= PFINT_OICR_TSYN_TX_M;
 	else
 		val &= ~PFINT_OICR_TSYN_TX_M;
-	wr32(&pf->hw, PFINT_OICR_ENA, val);
-}
-
-/**
- * ice_set_tx_tstamp - Enable or disable Tx timestamping
- * @pf: The PF pointer to search in
- * @on: bool value for whether timestamps are enabled or disabled
- */
-static void ice_set_tx_tstamp(struct ice_pf *pf, bool on)
-{
-	struct ice_vsi *vsi;
-	u16 i;
-
-	vsi = ice_get_main_vsi(pf);
-	if (!vsi)
-		return;
-
-	/* Set the timestamp enable flag for all the Tx rings */
-	ice_for_each_txq(vsi, i) {
-		if (!vsi->tx_rings[i])
-			continue;
-		vsi->tx_rings[i]->ptp_tx = on;
-	}
-
-	if (pf->ptp.tx_interrupt_mode == ICE_PTP_TX_INTERRUPT_SELF)
-		ice_ptp_configure_tx_tstamp(pf, on);
-
-	pf->ptp.tstamp_config.tx_type = on ? HWTSTAMP_TX_ON : HWTSTAMP_TX_OFF;
+	wr32(hw, PFINT_OICR_ENA, val);
 }
 
 /**
@@ -311,7 +305,7 @@ static void ice_set_rx_tstamp(struct ice_pf *pf, bool on)
 	u16 i;
 
 	vsi = ice_get_main_vsi(pf);
-	if (!vsi)
+	if (!vsi || !vsi->rx_rings)
 		return;
 
 	/* Set the timestamp flag for all the Rx rings */
@@ -320,23 +314,50 @@ static void ice_set_rx_tstamp(struct ice_pf *pf, bool on)
 			continue;
 		vsi->rx_rings[i]->ptp_rx = on;
 	}
+}
+
+/**
+ * ice_ptp_disable_timestamp_mode - Disable current timestamp mode
+ * @pf: Board private structure
+ *
+ * Called during preparation for reset to temporarily disable timestamping on
+ * the device. Called during remove to disable timestamping while cleaning up
+ * driver resources.
+ */
+static void ice_ptp_disable_timestamp_mode(struct ice_pf *pf)
+{
+	struct ice_hw *hw = &pf->hw;
+	u32 val;
+
+	val = rd32(hw, PFINT_OICR_ENA);
+	val &= ~PFINT_OICR_TSYN_TX_M;
+	wr32(hw, PFINT_OICR_ENA, val);
 
-	pf->ptp.tstamp_config.rx_filter = on ? HWTSTAMP_FILTER_ALL :
-					       HWTSTAMP_FILTER_NONE;
+	ice_set_rx_tstamp(pf, false);
 }
 
 /**
- * ice_ptp_cfg_timestamp - Configure timestamp for init/deinit
+ * ice_ptp_restore_timestamp_mode - Restore timestamp configuration
  * @pf: Board private structure
- * @ena: bool value to enable or disable time stamp
  *
- * This function will configure timestamping during PTP initialization
- * and deinitialization
+ * Called at the end of rebuild to restore timestamp configuration after
+ * a device reset.
  */
-void ice_ptp_cfg_timestamp(struct ice_pf *pf, bool ena)
+void ice_ptp_restore_timestamp_mode(struct ice_pf *pf)
 {
-	ice_set_tx_tstamp(pf, ena);
-	ice_set_rx_tstamp(pf, ena);
+	struct ice_hw *hw = &pf->hw;
+	bool enable_rx;
+
+	ice_ptp_cfg_tx_interrupt(pf);
+
+	enable_rx = pf->ptp.tstamp_config.rx_filter == HWTSTAMP_FILTER_ALL;
+	ice_set_rx_tstamp(pf, enable_rx);
+
+	/* Trigger an immediate software interrupt to ensure that timestamps
+	 * which occurred during reset are handled now.
+	 */
+	wr32(hw, PFINT_OICR, PFINT_OICR_TSYN_TX_M);
+	ice_flush(hw);
 }
 
 /**
@@ -2037,10 +2058,10 @@ ice_ptp_set_timestamp_mode(struct ice_pf *pf, struct hwtstamp_config *config)
 {
 	switch (config->tx_type) {
 	case HWTSTAMP_TX_OFF:
-		ice_set_tx_tstamp(pf, false);
+		pf->ptp.tstamp_config.tx_type = HWTSTAMP_TX_OFF;
 		break;
 	case HWTSTAMP_TX_ON:
-		ice_set_tx_tstamp(pf, true);
+		pf->ptp.tstamp_config.tx_type = HWTSTAMP_TX_ON;
 		break;
 	default:
 		return -ERANGE;
@@ -2048,7 +2069,7 @@ ice_ptp_set_timestamp_mode(struct ice_pf *pf, struct hwtstamp_config *config)
 
 	switch (config->rx_filter) {
 	case HWTSTAMP_FILTER_NONE:
-		ice_set_rx_tstamp(pf, false);
+		pf->ptp.tstamp_config.rx_filter = HWTSTAMP_FILTER_NONE;
 		break;
 	case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
 	case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
@@ -2064,12 +2085,15 @@ ice_ptp_set_timestamp_mode(struct ice_pf *pf, struct hwtstamp_config *config)
 	case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
 	case HWTSTAMP_FILTER_NTP_ALL:
 	case HWTSTAMP_FILTER_ALL:
-		ice_set_rx_tstamp(pf, true);
+		pf->ptp.tstamp_config.rx_filter = HWTSTAMP_FILTER_ALL;
 		break;
 	default:
 		return -ERANGE;
 	}
 
+	/* Immediately update the device timestamping mode */
+	ice_ptp_restore_timestamp_mode(pf);
+
 	return 0;
 }
 
@@ -2737,7 +2761,7 @@ void ice_ptp_prepare_for_reset(struct ice_pf *pf)
 	clear_bit(ICE_FLAG_PTP, pf->flags);
 
 	/* Disable timestamping for both Tx and Rx */
-	ice_ptp_cfg_timestamp(pf, false);
+	ice_ptp_disable_timestamp_mode(pf);
 
 	kthread_cancel_delayed_work_sync(&ptp->work);
 
@@ -2803,15 +2827,7 @@ static int ice_ptp_init_owner(struct ice_pf *pf)
 	/* Release the global hardware lock */
 	ice_ptp_unlock(hw);
 
-	if (pf->ptp.tx_interrupt_mode == ICE_PTP_TX_INTERRUPT_ALL) {
-		/* The clock owner for this device type handles the timestamp
-		 * interrupt for all ports.
-		 */
-		ice_ptp_configure_tx_tstamp(pf, true);
-
-		/* React on all quads interrupts for E82x */
-		wr32(hw, PFINT_TSYN_MSK + (0x4 * hw->pf_id), (u32)0x1f);
-
+	if (!ice_is_e810(hw)) {
 		/* Enable quad interrupts */
 		err = ice_ptp_tx_ena_intr(pf, true, itr);
 		if (err)
@@ -2881,13 +2897,6 @@ static int ice_ptp_init_port(struct ice_pf *pf, struct ice_ptp_port *ptp_port)
 	case ICE_PHY_E810:
 		return ice_ptp_init_tx_e810(pf, &ptp_port->tx);
 	case ICE_PHY_E822:
-		/* Non-owner PFs don't react to any interrupts on E82x,
-		 * neither on own quad nor on others
-		 */
-		if (!ice_ptp_pf_handles_tx_interrupt(pf)) {
-			ice_ptp_configure_tx_tstamp(pf, false);
-			wr32(hw, PFINT_TSYN_MSK + (0x4 * hw->pf_id), (u32)0x0);
-		}
 		kthread_init_delayed_work(&ptp_port->ov_work,
 					  ice_ptp_wait_for_offsets);
 
@@ -3032,6 +3041,9 @@ void ice_ptp_init(struct ice_pf *pf)
 	/* Start the PHY timestamping block */
 	ice_ptp_reset_phy_timestamping(pf);
 
+	/* Configure initial Tx interrupt settings */
+	ice_ptp_cfg_tx_interrupt(pf);
+
 	set_bit(ICE_FLAG_PTP, pf->flags);
 	err = ice_ptp_init_work(pf, ptp);
 	if (err)
@@ -3067,7 +3079,7 @@ void ice_ptp_release(struct ice_pf *pf)
 		return;
 
 	/* Disable timestamping for both Tx and Rx */
-	ice_ptp_cfg_timestamp(pf, false);
+	ice_ptp_disable_timestamp_mode(pf);
 
 	ice_ptp_remove_auxbus_device(pf);
 
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.h b/drivers/net/ethernet/intel/ice/ice_ptp.h
index 8f6f9439275643..06a330867fc9be 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.h
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.h
@@ -292,7 +292,7 @@ int ice_ptp_clock_index(struct ice_pf *pf);
 struct ice_pf;
 int ice_ptp_set_ts_config(struct ice_pf *pf, struct ifreq *ifr);
 int ice_ptp_get_ts_config(struct ice_pf *pf, struct ifreq *ifr);
-void ice_ptp_cfg_timestamp(struct ice_pf *pf, bool ena);
+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);
@@ -317,8 +317,7 @@ static inline int ice_ptp_get_ts_config(struct ice_pf *pf, struct ifreq *ifr)
 	return -EOPNOTSUPP;
 }
 
-static inline void ice_ptp_cfg_timestamp(struct ice_pf *pf, bool ena) { }
-
+static inline void ice_ptp_restore_timestamp_mode(struct ice_pf *pf) { }
 static inline void ice_ptp_extts_event(struct ice_pf *pf) { }
 static inline s8
 ice_ptp_request_ts(struct ice_ptp_tx *tx, struct sk_buff *skb)
diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c
index 52d0a126eb6161..9e97ea86306867 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx.c
+++ b/drivers/net/ethernet/intel/ice/ice_txrx.c
@@ -2306,9 +2306,6 @@ ice_tstamp(struct ice_tx_ring *tx_ring, struct sk_buff *skb,
 	if (likely(!(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)))
 		return;
 
-	if (!tx_ring->ptp_tx)
-		return;
-
 	/* Tx timestamps cannot be sampled when doing TSO */
 	if (first->tx_flags & ICE_TX_FLAGS_TSO)
 		return;
diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.h b/drivers/net/ethernet/intel/ice/ice_txrx.h
index 166413fc33f48f..daf7b9dbb1435a 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx.h
+++ b/drivers/net/ethernet/intel/ice/ice_txrx.h
@@ -380,7 +380,6 @@ struct ice_tx_ring {
 #define ICE_TX_FLAGS_RING_VLAN_L2TAG2	BIT(2)
 	u8 flags;
 	u8 dcb_tc;			/* Traffic class of ring */
-	u8 ptp_tx;
 } ____cacheline_internodealigned_in_smp;
 
 static inline bool ice_ring_uses_build_skb(struct ice_rx_ring *ring)