Merge branch '100GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/nex

t-queue

Tony Nguyen says:

====================
ice: detect and report PTP timestamp issues

Jacob Keller says:

This series fixes a few small issues with the cached PTP Hardware Clock
timestamp used for timestamp extension. It also introduces extra checks to
help detect issues with this logic, such as if the cached timestamp is not
updated within the 2 second window.

This introduces a few statistics similar to the ones already available in
other Intel drivers, including tx_hwtstamp_skipped and tx_hwtstamp_timeouts.

It is intended to aid in debugging issues we're seeing with some setups
which might be related to incorrect cached timestamp values.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -136,6 +136,11 @@ static const struct ice_stats ice_gstrings_pf_stats[] = {
 	ICE_PF_STAT("mac_remote_faults.nic", stats.mac_remote_faults),
 	ICE_PF_STAT("fdir_sb_match.nic", stats.fd_sb_match),
 	ICE_PF_STAT("fdir_sb_status.nic", stats.fd_sb_status),
+	ICE_PF_STAT("tx_hwtstamp_skipped", ptp.tx_hwtstamp_skipped),
+	ICE_PF_STAT("tx_hwtstamp_timeouts", ptp.tx_hwtstamp_timeouts),
+	ICE_PF_STAT("tx_hwtstamp_flushed", ptp.tx_hwtstamp_flushed),
+	ICE_PF_STAT("tx_hwtstamp_discarded", ptp.tx_hwtstamp_discarded),
+	ICE_PF_STAT("late_cached_phc_updates", ptp.late_cached_phc_updates),
 };
 
 static const u32 ice_regs_dump_list[] = {
@@ -2826,6 +2831,7 @@ ice_set_ringparam(struct net_device *netdev, struct ethtool_ringparam *ring,
 		tx_rings[i].count = new_tx_cnt;
 		tx_rings[i].desc = NULL;
 		tx_rings[i].tx_buf = NULL;
+		tx_rings[i].tx_tstamps = &pf->ptp.port.tx;
 		err = ice_setup_tx_ring(&tx_rings[i]);
 		if (err) {
 			while (i--)
@@ -2884,6 +2890,7 @@ ice_set_ringparam(struct net_device *netdev, struct ethtool_ringparam *ring,
 		/* clone ring and setup updated count */
 		rx_rings[i] = *vsi->rx_rings[i];
 		rx_rings[i].count = new_rx_cnt;
+		rx_rings[i].cached_phctime = pf->ptp.cached_phc_time;
 		rx_rings[i].desc = NULL;
 		rx_rings[i].rx_buf = NULL;
 		/* this is to allow wr32 to have something to write to

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

@@ -1522,6 +1522,7 @@ static int ice_vsi_alloc_rings(struct ice_vsi *vsi)
 		ring->netdev = vsi->netdev;
 		ring->dev = dev;
 		ring->count = vsi->num_rx_desc;
+		ring->cached_phctime = pf->ptp.cached_phc_time;
 		WRITE_ONCE(vsi->rx_rings[i], ring);
 	}
 

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

@@ -490,56 +490,6 @@ ice_ptp_read_src_clk_reg(struct ice_pf *pf, struct ptp_system_timestamp *sts)
 	return ((u64)hi << 32) | lo;
 }
 
-/**
- * ice_ptp_update_cached_phctime - Update the cached PHC time values
- * @pf: Board specific private structure
- *
- * This function updates the system time values which are cached in the PF
- * structure and the Rx rings.
- *
- * This function must be called periodically to ensure that the cached value
- * is never more than 2 seconds old. It must also be called whenever the PHC
- * time has been changed.
- *
- * Return:
- * * 0 - OK, successfully updated
- * * -EAGAIN - PF was busy, need to reschedule the update
- */
-static int ice_ptp_update_cached_phctime(struct ice_pf *pf)
-{
-	u64 systime;
-	int i;
-
-	if (test_and_set_bit(ICE_CFG_BUSY, pf->state))
-		return -EAGAIN;
-
-	/* Read the current PHC time */
-	systime = ice_ptp_read_src_clk_reg(pf, NULL);
-
-	/* Update the cached PHC time stored in the PF structure */
-	WRITE_ONCE(pf->ptp.cached_phc_time, systime);
-
-	ice_for_each_vsi(pf, i) {
-		struct ice_vsi *vsi = pf->vsi[i];
-		int j;
-
-		if (!vsi)
-			continue;
-
-		if (vsi->type != ICE_VSI_PF)
-			continue;
-
-		ice_for_each_rxq(vsi, j) {
-			if (!vsi->rx_rings[j])
-				continue;
-			WRITE_ONCE(vsi->rx_rings[j]->cached_phctime, systime);
-		}
-	}
-	clear_bit(ICE_CFG_BUSY, pf->state);
-
-	return 0;
-}
-
 /**
  * ice_ptp_extend_32b_ts - Convert a 32b nanoseconds timestamp to 64b
  * @cached_phc_time: recently cached copy of PHC time
@@ -636,94 +586,486 @@ static u64 ice_ptp_extend_32b_ts(u64 cached_phc_time, u32 in_tstamp)
 static u64 ice_ptp_extend_40b_ts(struct ice_pf *pf, u64 in_tstamp)
 {
 	const u64 mask = GENMASK_ULL(31, 0);
+	unsigned long discard_time;
+
+	/* Discard the hardware timestamp if the cached PHC time is too old */
+	discard_time = pf->ptp.cached_phc_jiffies + msecs_to_jiffies(2000);
+	if (time_is_before_jiffies(discard_time)) {
+		pf->ptp.tx_hwtstamp_discarded++;
+		return 0;
+	}
 
 	return ice_ptp_extend_32b_ts(pf->ptp.cached_phc_time,
 				     (in_tstamp >> 8) & mask);
 }
 
 /**
- * ice_ptp_read_time - Read the time from the device
- * @pf: Board private structure
- * @ts: timespec structure to hold the current time value
- * @sts: Optional parameter for holding a pair of system timestamps from
- *       the system clock. Will be ignored if NULL is given.
+ * ice_ptp_tx_tstamp_work - Process Tx timestamps for a port
+ * @work: pointer to the kthread_work struct
  *
- * This function reads the source clock registers and stores them in a timespec.
- * However, since the registers are 64 bits of nanoseconds, we must convert the
- * result to a timespec before we can return.
+ * Process timestamps captured by the PHY associated with this port. To do
+ * this, loop over each index with a waiting skb.
+ *
+ * If a given index has a valid timestamp, perform the following steps:
+ *
+ * 1) copy the timestamp out of the PHY register
+ * 4) clear the timestamp valid bit in the PHY register
+ * 5) unlock the index by clearing the associated in_use bit.
+ * 2) extend the 40b timestamp value to get a 64bit timestamp
+ * 3) send that timestamp to the stack
+ *
+ * After looping, if we still have waiting SKBs, then re-queue the work. This
+ * may cause us effectively poll even when not strictly necessary. We do this
+ * because it's possible a new timestamp was requested around the same time as
+ * the interrupt. In some cases hardware might not interrupt us again when the
+ * timestamp is captured.
+ *
+ * Note that we only take the tracking lock when clearing the bit and when
+ * checking if we need to re-queue this task. The only place where bits can be
+ * set is the hard xmit routine where an SKB has a request flag set. The only
+ * places where we clear bits are this work function, or the periodic cleanup
+ * thread. If the cleanup thread clears a bit we're processing we catch it
+ * when we lock to clear the bit and then grab the SKB pointer. If a Tx thread
+ * starts a new timestamp, we might not begin processing it right away but we
+ * will notice it at the end when we re-queue the work item. If a Tx thread
+ * starts a new timestamp just after this function exits without re-queuing,
+ * the interrupt when the timestamp finishes should trigger. Avoiding holding
+ * the lock for the entire function is important in order to ensure that Tx
+ * threads do not get blocked while waiting for the lock.
  */
-static void
-ice_ptp_read_time(struct ice_pf *pf, struct timespec64 *ts,
-		  struct ptp_system_timestamp *sts)
+static void ice_ptp_tx_tstamp_work(struct kthread_work *work)
 {
-	u64 time_ns = ice_ptp_read_src_clk_reg(pf, sts);
+	struct ice_ptp_port *ptp_port;
+	struct ice_ptp_tx *tx;
+	struct ice_pf *pf;
+	struct ice_hw *hw;
+	u8 idx;
 
-	*ts = ns_to_timespec64(time_ns);
+	tx = container_of(work, struct ice_ptp_tx, work);
+	if (!tx->init)
+		return;
+
+	ptp_port = container_of(tx, struct ice_ptp_port, tx);
+	pf = ptp_port_to_pf(ptp_port);
+	hw = &pf->hw;
+
+	for_each_set_bit(idx, tx->in_use, tx->len) {
+		struct skb_shared_hwtstamps shhwtstamps = {};
+		u8 phy_idx = idx + tx->quad_offset;
+		u64 raw_tstamp, tstamp;
+		struct sk_buff *skb;
+		int err;
+
+		ice_trace(tx_tstamp_fw_req, tx->tstamps[idx].skb, idx);
+
+		err = ice_read_phy_tstamp(hw, tx->quad, phy_idx,
+					  &raw_tstamp);
+		if (err)
+			continue;
+
+		ice_trace(tx_tstamp_fw_done, tx->tstamps[idx].skb, idx);
+
+		/* Check if the timestamp is invalid or stale */
+		if (!(raw_tstamp & ICE_PTP_TS_VALID) ||
+		    raw_tstamp == tx->tstamps[idx].cached_tstamp)
+			continue;
+
+		/* The timestamp is valid, so we'll go ahead and clear this
+		 * index and then send the timestamp up to the stack.
+		 */
+		spin_lock(&tx->lock);
+		tx->tstamps[idx].cached_tstamp = raw_tstamp;
+		clear_bit(idx, tx->in_use);
+		skb = tx->tstamps[idx].skb;
+		tx->tstamps[idx].skb = NULL;
+		spin_unlock(&tx->lock);
+
+		/* it's (unlikely but) possible we raced with the cleanup
+		 * thread for discarding old timestamp requests.
+		 */
+		if (!skb)
+			continue;
+
+		/* Extend the timestamp using cached PHC time */
+		tstamp = ice_ptp_extend_40b_ts(pf, raw_tstamp);
+		if (tstamp) {
+			shhwtstamps.hwtstamp = ns_to_ktime(tstamp);
+			ice_trace(tx_tstamp_complete, skb, idx);
+		}
+
+		skb_tstamp_tx(skb, &shhwtstamps);
+		dev_kfree_skb_any(skb);
+	}
+
+	/* Check if we still have work to do. If so, re-queue this task to
+	 * poll for remaining timestamps.
+	 */
+	spin_lock(&tx->lock);
+	if (!bitmap_empty(tx->in_use, tx->len))
+		kthread_queue_work(pf->ptp.kworker, &tx->work);
+	spin_unlock(&tx->lock);
 }
 
 /**
- * ice_ptp_write_init - Set PHC time to provided value
- * @pf: Board private structure
- * @ts: timespec structure that holds the new time value
+ * ice_ptp_alloc_tx_tracker - Initialize tracking for Tx timestamps
+ * @tx: Tx tracking structure to initialize
  *
- * Set the PHC time to the specified time provided in the timespec.
+ * Assumes that the length has already been initialized. Do not call directly,
+ * use the ice_ptp_init_tx_e822 or ice_ptp_init_tx_e810 instead.
  */
-static int ice_ptp_write_init(struct ice_pf *pf, struct timespec64 *ts)
+static int
+ice_ptp_alloc_tx_tracker(struct ice_ptp_tx *tx)
 {
-	u64 ns = timespec64_to_ns(ts);
-	struct ice_hw *hw = &pf->hw;
+	tx->tstamps = kcalloc(tx->len, sizeof(*tx->tstamps), GFP_KERNEL);
+	if (!tx->tstamps)
+		return -ENOMEM;
 
-	return ice_ptp_init_time(hw, ns);
+	tx->in_use = bitmap_zalloc(tx->len, GFP_KERNEL);
+	if (!tx->in_use) {
+		kfree(tx->tstamps);
+		tx->tstamps = NULL;
+		return -ENOMEM;
+	}
+
+	spin_lock_init(&tx->lock);
+	kthread_init_work(&tx->work, ice_ptp_tx_tstamp_work);
+
+	tx->init = 1;
+
+	return 0;
 }
 
 /**
- * ice_ptp_write_adj - Adjust PHC clock time atomically
+ * ice_ptp_flush_tx_tracker - Flush any remaining timestamps from the tracker
  * @pf: Board private structure
- * @adj: Adjustment in nanoseconds
- *
- * Perform an atomic adjustment of the PHC time by the specified number of
- * nanoseconds.
+ * @tx: the tracker to flush
  */
-static int ice_ptp_write_adj(struct ice_pf *pf, s32 adj)
+static void
+ice_ptp_flush_tx_tracker(struct ice_pf *pf, struct ice_ptp_tx *tx)
 {
-	struct ice_hw *hw = &pf->hw;
+	u8 idx;
 
-	return ice_ptp_adj_clock(hw, adj);
+	for (idx = 0; idx < tx->len; idx++) {
+		u8 phy_idx = idx + tx->quad_offset;
+
+		spin_lock(&tx->lock);
+		if (tx->tstamps[idx].skb) {
+			dev_kfree_skb_any(tx->tstamps[idx].skb);
+			tx->tstamps[idx].skb = NULL;
+			pf->ptp.tx_hwtstamp_flushed++;
+		}
+		clear_bit(idx, tx->in_use);
+		spin_unlock(&tx->lock);
+
+		/* Clear any potential residual timestamp in the PHY block */
+		if (!pf->hw.reset_ongoing)
+			ice_clear_phy_tstamp(&pf->hw, tx->quad, phy_idx);
+	}
 }
 
 /**
- * ice_base_incval - Get base timer increment value
+ * ice_ptp_release_tx_tracker - Release allocated memory for Tx tracker
  * @pf: Board private structure
+ * @tx: Tx tracking structure to release
  *
- * Look up the base timer increment value for this device. The base increment
- * value is used to define the nominal clock tick rate. This increment value
- * is programmed during device initialization. It is also used as the basis
- * for calculating adjustments using scaled_ppm.
+ * Free memory associated with the Tx timestamp tracker.
  */
-static u64 ice_base_incval(struct ice_pf *pf)
+static void
+ice_ptp_release_tx_tracker(struct ice_pf *pf, struct ice_ptp_tx *tx)
 {
-	struct ice_hw *hw = &pf->hw;
-	u64 incval;
+	tx->init = 0;
 
-	if (ice_is_e810(hw))
-		incval = ICE_PTP_NOMINAL_INCVAL_E810;
-	else if (ice_e822_time_ref(hw) < NUM_ICE_TIME_REF_FREQ)
-		incval = ice_e822_nominal_incval(ice_e822_time_ref(hw));
-	else
-		incval = UNKNOWN_INCVAL_E822;
+	kthread_cancel_work_sync(&tx->work);
 
-	dev_dbg(ice_pf_to_dev(pf), "PTP: using base increment value of 0x%016llx\n",
-		incval);
+	ice_ptp_flush_tx_tracker(pf, tx);
 
-	return incval;
+	kfree(tx->tstamps);
+	tx->tstamps = NULL;
+
+	bitmap_free(tx->in_use);
+	tx->in_use = NULL;
+
+	tx->len = 0;
 }
 
 /**
- * ice_ptp_reset_ts_memory_quad - Reset timestamp memory for one quad
- * @pf: The PF private data structure
- * @quad: The quad (0-4)
- */
-static void ice_ptp_reset_ts_memory_quad(struct ice_pf *pf, int quad)
+ * ice_ptp_init_tx_e822 - Initialize tracking for Tx timestamps
+ * @pf: Board private structure
+ * @tx: the Tx tracking structure to initialize
+ * @port: the port this structure tracks
+ *
+ * Initialize the Tx timestamp tracker for this port. For generic MAC devices,
+ * the timestamp block is shared for all ports in the same quad. To avoid
+ * ports using the same timestamp index, logically break the block of
+ * registers into chunks based on the port number.
+ */
+static int
+ice_ptp_init_tx_e822(struct ice_pf *pf, struct ice_ptp_tx *tx, u8 port)
+{
+	tx->quad = port / ICE_PORTS_PER_QUAD;
+	tx->quad_offset = (port % ICE_PORTS_PER_QUAD) * INDEX_PER_PORT;
+	tx->len = INDEX_PER_PORT;
+
+	return ice_ptp_alloc_tx_tracker(tx);
+}
+
+/**
+ * ice_ptp_init_tx_e810 - Initialize tracking for Tx timestamps
+ * @pf: Board private structure
+ * @tx: the Tx tracking structure to initialize
+ *
+ * Initialize the Tx timestamp tracker for this PF. For E810 devices, each
+ * port has its own block of timestamps, independent of the other ports.
+ */
+static int
+ice_ptp_init_tx_e810(struct ice_pf *pf, struct ice_ptp_tx *tx)
+{
+	tx->quad = pf->hw.port_info->lport;
+	tx->quad_offset = 0;
+	tx->len = INDEX_PER_QUAD;
+
+	return ice_ptp_alloc_tx_tracker(tx);
+}
+
+/**
+ * ice_ptp_tx_tstamp_cleanup - Cleanup old timestamp requests that got dropped
+ * @pf: pointer to the PF struct
+ * @tx: PTP Tx tracker to clean up
+ *
+ * Loop through the Tx timestamp requests and see if any of them have been
+ * waiting for a long time. Discard any SKBs that have been waiting for more
+ * than 2 seconds. This is long enough to be reasonably sure that the
+ * timestamp will never be captured. This might happen if the packet gets
+ * discarded before it reaches the PHY timestamping block.
+ */
+static void ice_ptp_tx_tstamp_cleanup(struct ice_pf *pf, struct ice_ptp_tx *tx)
+{
+	struct ice_hw *hw = &pf->hw;
+	u8 idx;
+
+	if (!tx->init)
+		return;
+
+	for_each_set_bit(idx, tx->in_use, tx->len) {
+		struct sk_buff *skb;
+		u64 raw_tstamp;
+
+		/* Check if this SKB has been waiting for too long */
+		if (time_is_after_jiffies(tx->tstamps[idx].start + 2 * HZ))
+			continue;
+
+		/* Read tstamp to be able to use this register again */
+		ice_read_phy_tstamp(hw, tx->quad, idx + tx->quad_offset,
+				    &raw_tstamp);
+
+		spin_lock(&tx->lock);
+		skb = tx->tstamps[idx].skb;
+		tx->tstamps[idx].skb = NULL;
+		clear_bit(idx, tx->in_use);
+		spin_unlock(&tx->lock);
+
+		/* Count the number of Tx timestamps which have timed out */
+		pf->ptp.tx_hwtstamp_timeouts++;
+
+		/* Free the SKB after we've cleared the bit */
+		dev_kfree_skb_any(skb);
+	}
+}
+
+/**
+ * ice_ptp_update_cached_phctime - Update the cached PHC time values
+ * @pf: Board specific private structure
+ *
+ * This function updates the system time values which are cached in the PF
+ * structure and the Rx rings.
+ *
+ * This function must be called periodically to ensure that the cached value
+ * is never more than 2 seconds old.
+ *
+ * Note that the cached copy in the PF PTP structure is always updated, even
+ * if we can't update the copy in the Rx rings.
+ *
+ * Return:
+ * * 0 - OK, successfully updated
+ * * -EAGAIN - PF was busy, need to reschedule the update
+ */
+static int ice_ptp_update_cached_phctime(struct ice_pf *pf)
+{
+	struct device *dev = ice_pf_to_dev(pf);
+	unsigned long update_before;
+	u64 systime;
+	int i;
+
+	update_before = pf->ptp.cached_phc_jiffies + msecs_to_jiffies(2000);
+	if (pf->ptp.cached_phc_time &&
+	    time_is_before_jiffies(update_before)) {
+		unsigned long time_taken = jiffies - pf->ptp.cached_phc_jiffies;
+
+		dev_warn(dev, "%u msecs passed between update to cached PHC time\n",
+			 jiffies_to_msecs(time_taken));
+		pf->ptp.late_cached_phc_updates++;
+	}
+
+	/* Read the current PHC time */
+	systime = ice_ptp_read_src_clk_reg(pf, NULL);
+
+	/* Update the cached PHC time stored in the PF structure */
+	WRITE_ONCE(pf->ptp.cached_phc_time, systime);
+	WRITE_ONCE(pf->ptp.cached_phc_jiffies, jiffies);
+
+	if (test_and_set_bit(ICE_CFG_BUSY, pf->state))
+		return -EAGAIN;
+
+	ice_for_each_vsi(pf, i) {
+		struct ice_vsi *vsi = pf->vsi[i];
+		int j;
+
+		if (!vsi)
+			continue;
+
+		if (vsi->type != ICE_VSI_PF)
+			continue;
+
+		ice_for_each_rxq(vsi, j) {
+			if (!vsi->rx_rings[j])
+				continue;
+			WRITE_ONCE(vsi->rx_rings[j]->cached_phctime, systime);
+		}
+	}
+	clear_bit(ICE_CFG_BUSY, pf->state);
+
+	return 0;
+}
+
+/**
+ * ice_ptp_reset_cached_phctime - Reset cached PHC time after an update
+ * @pf: Board specific private structure
+ *
+ * This function must be called when the cached PHC time is no longer valid,
+ * such as after a time adjustment. It discards any outstanding Tx timestamps,
+ * and updates the cached PHC time for both the PF and Rx rings. If updating
+ * the PHC time cannot be done immediately, a warning message is logged and
+ * the work item is scheduled.
+ *
+ * These steps are required in order to ensure that we do not accidentally
+ * report a timestamp extended by the wrong PHC cached copy. Note that we
+ * do not directly update the cached timestamp here because it is possible
+ * this might produce an error when ICE_CFG_BUSY is set. If this occurred, we
+ * would have to try again. During that time window, timestamps might be
+ * requested and returned with an invalid extension. Thus, on failure to
+ * immediately update the cached PHC time we would need to zero the value
+ * anyways. For this reason, we just zero the value immediately and queue the
+ * update work item.
+ */
+static void ice_ptp_reset_cached_phctime(struct ice_pf *pf)
+{
+	struct device *dev = ice_pf_to_dev(pf);
+	int err;
+
+	/* Update the cached PHC time immediately if possible, otherwise
+	 * schedule the work item to execute soon.
+	 */
+	err = ice_ptp_update_cached_phctime(pf);
+	if (err) {
+		/* If another thread is updating the Rx rings, we won't
+		 * properly reset them here. This could lead to reporting of
+		 * invalid timestamps, but there isn't much we can do.
+		 */
+		dev_warn(dev, "%s: ICE_CFG_BUSY, unable to immediately update cached PHC time\n",
+			 __func__);
+
+		/* Queue the work item to update the Rx rings when possible */
+		kthread_queue_delayed_work(pf->ptp.kworker, &pf->ptp.work,
+					   msecs_to_jiffies(10));
+	}
+
+	/* Flush any outstanding Tx timestamps */
+	ice_ptp_flush_tx_tracker(pf, &pf->ptp.port.tx);
+}
+
+/**
+ * ice_ptp_read_time - Read the time from the device
+ * @pf: Board private structure
+ * @ts: timespec structure to hold the current time value
+ * @sts: Optional parameter for holding a pair of system timestamps from
+ *       the system clock. Will be ignored if NULL is given.
+ *
+ * This function reads the source clock registers and stores them in a timespec.
+ * However, since the registers are 64 bits of nanoseconds, we must convert the
+ * result to a timespec before we can return.
+ */
+static void
+ice_ptp_read_time(struct ice_pf *pf, struct timespec64 *ts,
+		  struct ptp_system_timestamp *sts)
+{
+	u64 time_ns = ice_ptp_read_src_clk_reg(pf, sts);
+
+	*ts = ns_to_timespec64(time_ns);
+}
+
+/**
+ * ice_ptp_write_init - Set PHC time to provided value
+ * @pf: Board private structure
+ * @ts: timespec structure that holds the new time value
+ *
+ * Set the PHC time to the specified time provided in the timespec.
+ */
+static int ice_ptp_write_init(struct ice_pf *pf, struct timespec64 *ts)
+{
+	u64 ns = timespec64_to_ns(ts);
+	struct ice_hw *hw = &pf->hw;
+
+	return ice_ptp_init_time(hw, ns);
+}
+
+/**
+ * ice_ptp_write_adj - Adjust PHC clock time atomically
+ * @pf: Board private structure
+ * @adj: Adjustment in nanoseconds
+ *
+ * Perform an atomic adjustment of the PHC time by the specified number of
+ * nanoseconds.
+ */
+static int ice_ptp_write_adj(struct ice_pf *pf, s32 adj)
+{
+	struct ice_hw *hw = &pf->hw;
+
+	return ice_ptp_adj_clock(hw, adj);
+}
+
+/**
+ * ice_base_incval - Get base timer increment value
+ * @pf: Board private structure
+ *
+ * Look up the base timer increment value for this device. The base increment
+ * value is used to define the nominal clock tick rate. This increment value
+ * is programmed during device initialization. It is also used as the basis
+ * for calculating adjustments using scaled_ppm.
+ */
+static u64 ice_base_incval(struct ice_pf *pf)
+{
+	struct ice_hw *hw = &pf->hw;
+	u64 incval;
+
+	if (ice_is_e810(hw))
+		incval = ICE_PTP_NOMINAL_INCVAL_E810;
+	else if (ice_e822_time_ref(hw) < NUM_ICE_TIME_REF_FREQ)
+		incval = ice_e822_nominal_incval(ice_e822_time_ref(hw));
+	else
+		incval = UNKNOWN_INCVAL_E822;
+
+	dev_dbg(ice_pf_to_dev(pf), "PTP: using base increment value of 0x%016llx\n",
+		incval);
+
+	return incval;
+}
+
+/**
+ * ice_ptp_reset_ts_memory_quad - Reset timestamp memory for one quad
+ * @pf: The PF private data structure
+ * @quad: The quad (0-4)
+ */
+static void ice_ptp_reset_ts_memory_quad(struct ice_pf *pf, int quad)
 {
 	struct ice_hw *hw = &pf->hw;
 
@@ -1509,7 +1851,7 @@ ice_ptp_settime64(struct ptp_clock_info *info, const struct timespec64 *ts)
 	ice_ptp_unlock(hw);
 
 	if (!err)
-		ice_ptp_update_cached_phctime(pf);
+		ice_ptp_reset_cached_phctime(pf);
 
 	/* Reenable periodic outputs */
 	ice_ptp_enable_all_clkout(pf);
@@ -1588,7 +1930,7 @@ static int ice_ptp_adjtime(struct ptp_clock_info *info, s64 delta)
 		return err;
 	}
 
-	ice_ptp_update_cached_phctime(pf);
+	ice_ptp_reset_cached_phctime(pf);
 
 	return 0;
 }
@@ -1796,26 +2138,31 @@ void
 ice_ptp_rx_hwtstamp(struct ice_rx_ring *rx_ring,
 		    union ice_32b_rx_flex_desc *rx_desc, struct sk_buff *skb)
 {
+	struct skb_shared_hwtstamps *hwtstamps;
+	u64 ts_ns, cached_time;
 	u32 ts_high;
-	u64 ts_ns;
 
-	/* Populate timesync data into skb */
-	if (rx_desc->wb.time_stamp_low & ICE_PTP_TS_VALID) {
-		struct skb_shared_hwtstamps *hwtstamps;
+	if (!(rx_desc->wb.time_stamp_low & ICE_PTP_TS_VALID))
+		return;
 
-		/* Use ice_ptp_extend_32b_ts directly, using the ring-specific
-		 * cached PHC value, rather than accessing the PF. This also
-		 * allows us to simply pass the upper 32bits of nanoseconds
-		 * directly. Calling ice_ptp_extend_40b_ts is unnecessary as
-		 * it would just discard these bits itself.
-		 */
-		ts_high = le32_to_cpu(rx_desc->wb.flex_ts.ts_high);
-		ts_ns = ice_ptp_extend_32b_ts(rx_ring->cached_phctime, ts_high);
+	cached_time = READ_ONCE(rx_ring->cached_phctime);
 
-		hwtstamps = skb_hwtstamps(skb);
-		memset(hwtstamps, 0, sizeof(*hwtstamps));
-		hwtstamps->hwtstamp = ns_to_ktime(ts_ns);
-	}
+	/* Do not report a timestamp if we don't have a cached PHC time */
+	if (!cached_time)
+		return;
+
+	/* Use ice_ptp_extend_32b_ts directly, using the ring-specific cached
+	 * PHC value, rather than accessing the PF. This also allows us to
+	 * simply pass the upper 32bits of nanoseconds directly. Calling
+	 * ice_ptp_extend_40b_ts is unnecessary as it would just discard these
+	 * bits itself.
+	 */
+	ts_high = le32_to_cpu(rx_desc->wb.flex_ts.ts_high);
+	ts_ns = ice_ptp_extend_32b_ts(cached_time, ts_high);
+
+	hwtstamps = skb_hwtstamps(skb);
+	memset(hwtstamps, 0, sizeof(*hwtstamps));
+	hwtstamps->hwtstamp = ns_to_ktime(ts_ns);
 }
 
 /**
@@ -2015,112 +2362,6 @@ static long ice_ptp_create_clock(struct ice_pf *pf)
 	return 0;
 }
 
-/**
- * ice_ptp_tx_tstamp_work - Process Tx timestamps for a port
- * @work: pointer to the kthread_work struct
- *
- * Process timestamps captured by the PHY associated with this port. To do
- * this, loop over each index with a waiting skb.
- *
- * If a given index has a valid timestamp, perform the following steps:
- *
- * 1) copy the timestamp out of the PHY register
- * 4) clear the timestamp valid bit in the PHY register
- * 5) unlock the index by clearing the associated in_use bit.
- * 2) extend the 40b timestamp value to get a 64bit timestamp
- * 3) send that timestamp to the stack
- *
- * After looping, if we still have waiting SKBs, then re-queue the work. This
- * may cause us effectively poll even when not strictly necessary. We do this
- * because it's possible a new timestamp was requested around the same time as
- * the interrupt. In some cases hardware might not interrupt us again when the
- * timestamp is captured.
- *
- * Note that we only take the tracking lock when clearing the bit and when
- * checking if we need to re-queue this task. The only place where bits can be
- * set is the hard xmit routine where an SKB has a request flag set. The only
- * places where we clear bits are this work function, or the periodic cleanup
- * thread. If the cleanup thread clears a bit we're processing we catch it
- * when we lock to clear the bit and then grab the SKB pointer. If a Tx thread
- * starts a new timestamp, we might not begin processing it right away but we
- * will notice it at the end when we re-queue the work item. If a Tx thread
- * starts a new timestamp just after this function exits without re-queuing,
- * the interrupt when the timestamp finishes should trigger. Avoiding holding
- * the lock for the entire function is important in order to ensure that Tx
- * threads do not get blocked while waiting for the lock.
- */
-static void ice_ptp_tx_tstamp_work(struct kthread_work *work)
-{
-	struct ice_ptp_port *ptp_port;
-	struct ice_ptp_tx *tx;
-	struct ice_pf *pf;
-	struct ice_hw *hw;
-	u8 idx;
-
-	tx = container_of(work, struct ice_ptp_tx, work);
-	if (!tx->init)
-		return;
-
-	ptp_port = container_of(tx, struct ice_ptp_port, tx);
-	pf = ptp_port_to_pf(ptp_port);
-	hw = &pf->hw;
-
-	for_each_set_bit(idx, tx->in_use, tx->len) {
-		struct skb_shared_hwtstamps shhwtstamps = {};
-		u8 phy_idx = idx + tx->quad_offset;
-		u64 raw_tstamp, tstamp;
-		struct sk_buff *skb;
-		int err;
-
-		ice_trace(tx_tstamp_fw_req, tx->tstamps[idx].skb, idx);
-
-		err = ice_read_phy_tstamp(hw, tx->quad, phy_idx,
-					  &raw_tstamp);
-		if (err)
-			continue;
-
-		ice_trace(tx_tstamp_fw_done, tx->tstamps[idx].skb, idx);
-
-		/* Check if the timestamp is invalid or stale */
-		if (!(raw_tstamp & ICE_PTP_TS_VALID) ||
-		    raw_tstamp == tx->tstamps[idx].cached_tstamp)
-			continue;
-
-		/* The timestamp is valid, so we'll go ahead and clear this
-		 * index and then send the timestamp up to the stack.
-		 */
-		spin_lock(&tx->lock);
-		tx->tstamps[idx].cached_tstamp = raw_tstamp;
-		clear_bit(idx, tx->in_use);
-		skb = tx->tstamps[idx].skb;
-		tx->tstamps[idx].skb = NULL;
-		spin_unlock(&tx->lock);
-
-		/* it's (unlikely but) possible we raced with the cleanup
-		 * thread for discarding old timestamp requests.
-		 */
-		if (!skb)
-			continue;
-
-		/* Extend the timestamp using cached PHC time */
-		tstamp = ice_ptp_extend_40b_ts(pf, raw_tstamp);
-		shhwtstamps.hwtstamp = ns_to_ktime(tstamp);
-
-		ice_trace(tx_tstamp_complete, skb, idx);
-
-		skb_tstamp_tx(skb, &shhwtstamps);
-		dev_kfree_skb_any(skb);
-	}
-
-	/* Check if we still have work to do. If so, re-queue this task to
-	 * poll for remaining timestamps.
-	 */
-	spin_lock(&tx->lock);
-	if (!bitmap_empty(tx->in_use, tx->len))
-		kthread_queue_work(pf->ptp.kworker, &tx->work);
-	spin_unlock(&tx->lock);
-}
-
 /**
  * ice_ptp_request_ts - Request an available Tx timestamp index
  * @tx: the PTP Tx timestamp tracker to request from
@@ -2173,167 +2414,6 @@ void ice_ptp_process_ts(struct ice_pf *pf)
 		kthread_queue_work(pf->ptp.kworker, &pf->ptp.port.tx.work);
 }
 
-/**
- * ice_ptp_alloc_tx_tracker - Initialize tracking for Tx timestamps
- * @tx: Tx tracking structure to initialize
- *
- * Assumes that the length has already been initialized. Do not call directly,
- * use the ice_ptp_init_tx_e822 or ice_ptp_init_tx_e810 instead.
- */
-static int
-ice_ptp_alloc_tx_tracker(struct ice_ptp_tx *tx)
-{
-	tx->tstamps = kcalloc(tx->len, sizeof(*tx->tstamps), GFP_KERNEL);
-	if (!tx->tstamps)
-		return -ENOMEM;
-
-	tx->in_use = bitmap_zalloc(tx->len, GFP_KERNEL);
-	if (!tx->in_use) {
-		kfree(tx->tstamps);
-		tx->tstamps = NULL;
-		return -ENOMEM;
-	}
-
-	spin_lock_init(&tx->lock);
-	kthread_init_work(&tx->work, ice_ptp_tx_tstamp_work);
-
-	tx->init = 1;
-
-	return 0;
-}
-
-/**
- * ice_ptp_flush_tx_tracker - Flush any remaining timestamps from the tracker
- * @pf: Board private structure
- * @tx: the tracker to flush
- */
-static void
-ice_ptp_flush_tx_tracker(struct ice_pf *pf, struct ice_ptp_tx *tx)
-{
-	u8 idx;
-
-	for (idx = 0; idx < tx->len; idx++) {
-		u8 phy_idx = idx + tx->quad_offset;
-
-		spin_lock(&tx->lock);
-		if (tx->tstamps[idx].skb) {
-			dev_kfree_skb_any(tx->tstamps[idx].skb);
-			tx->tstamps[idx].skb = NULL;
-		}
-		clear_bit(idx, tx->in_use);
-		spin_unlock(&tx->lock);
-
-		/* Clear any potential residual timestamp in the PHY block */
-		if (!pf->hw.reset_ongoing)
-			ice_clear_phy_tstamp(&pf->hw, tx->quad, phy_idx);
-	}
-}
-
-/**
- * ice_ptp_release_tx_tracker - Release allocated memory for Tx tracker
- * @pf: Board private structure
- * @tx: Tx tracking structure to release
- *
- * Free memory associated with the Tx timestamp tracker.
- */
-static void
-ice_ptp_release_tx_tracker(struct ice_pf *pf, struct ice_ptp_tx *tx)
-{
-	tx->init = 0;
-
-	kthread_cancel_work_sync(&tx->work);
-
-	ice_ptp_flush_tx_tracker(pf, tx);
-
-	kfree(tx->tstamps);
-	tx->tstamps = NULL;
-
-	bitmap_free(tx->in_use);
-	tx->in_use = NULL;
-
-	tx->len = 0;
-}
-
-/**
- * ice_ptp_init_tx_e822 - Initialize tracking for Tx timestamps
- * @pf: Board private structure
- * @tx: the Tx tracking structure to initialize
- * @port: the port this structure tracks
- *
- * Initialize the Tx timestamp tracker for this port. For generic MAC devices,
- * the timestamp block is shared for all ports in the same quad. To avoid
- * ports using the same timestamp index, logically break the block of
- * registers into chunks based on the port number.
- */
-static int
-ice_ptp_init_tx_e822(struct ice_pf *pf, struct ice_ptp_tx *tx, u8 port)
-{
-	tx->quad = port / ICE_PORTS_PER_QUAD;
-	tx->quad_offset = (port % ICE_PORTS_PER_QUAD) * INDEX_PER_PORT;
-	tx->len = INDEX_PER_PORT;
-
-	return ice_ptp_alloc_tx_tracker(tx);
-}
-
-/**
- * ice_ptp_init_tx_e810 - Initialize tracking for Tx timestamps
- * @pf: Board private structure
- * @tx: the Tx tracking structure to initialize
- *
- * Initialize the Tx timestamp tracker for this PF. For E810 devices, each
- * port has its own block of timestamps, independent of the other ports.
- */
-static int
-ice_ptp_init_tx_e810(struct ice_pf *pf, struct ice_ptp_tx *tx)
-{
-	tx->quad = pf->hw.port_info->lport;
-	tx->quad_offset = 0;
-	tx->len = INDEX_PER_QUAD;
-
-	return ice_ptp_alloc_tx_tracker(tx);
-}
-
-/**
- * ice_ptp_tx_tstamp_cleanup - Cleanup old timestamp requests that got dropped
- * @hw: pointer to the hw struct
- * @tx: PTP Tx tracker to clean up
- *
- * Loop through the Tx timestamp requests and see if any of them have been
- * waiting for a long time. Discard any SKBs that have been waiting for more
- * than 2 seconds. This is long enough to be reasonably sure that the
- * timestamp will never be captured. This might happen if the packet gets
- * discarded before it reaches the PHY timestamping block.
- */
-static void ice_ptp_tx_tstamp_cleanup(struct ice_hw *hw, struct ice_ptp_tx *tx)
-{
-	u8 idx;
-
-	if (!tx->init)
-		return;
-
-	for_each_set_bit(idx, tx->in_use, tx->len) {
-		struct sk_buff *skb;
-		u64 raw_tstamp;
-
-		/* Check if this SKB has been waiting for too long */
-		if (time_is_after_jiffies(tx->tstamps[idx].start + 2 * HZ))
-			continue;
-
-		/* Read tstamp to be able to use this register again */
-		ice_read_phy_tstamp(hw, tx->quad, idx + tx->quad_offset,
-				    &raw_tstamp);
-
-		spin_lock(&tx->lock);
-		skb = tx->tstamps[idx].skb;
-		tx->tstamps[idx].skb = NULL;
-		clear_bit(idx, tx->in_use);
-		spin_unlock(&tx->lock);
-
-		/* Free the SKB after we've cleared the bit */
-		dev_kfree_skb_any(skb);
-	}
-}
-
 static void ice_ptp_periodic_work(struct kthread_work *work)
 {
 	struct ice_ptp *ptp = container_of(work, struct ice_ptp, work.work);
@@ -2345,7 +2425,7 @@ static void ice_ptp_periodic_work(struct kthread_work *work)
 
 	err = ice_ptp_update_cached_phctime(pf);
 
-	ice_ptp_tx_tstamp_cleanup(&pf->hw, &pf->ptp.port.tx);
+	ice_ptp_tx_tstamp_cleanup(pf, &pf->ptp.port.tx);
 
 	/* Run twice a second or reschedule if phc update failed */
 	kthread_queue_delayed_work(ptp->kworker, &ptp->work,

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

@@ -163,6 +163,7 @@ struct ice_ptp_port {
  * @work: delayed work function for periodic tasks
  * @extts_work: work function for handling external Tx timestamps
  * @cached_phc_time: a cached copy of the PHC time for timestamp extension
+ * @cached_phc_jiffies: jiffies when cached_phc_time was last updated
  * @ext_ts_chan: the external timestamp channel in use
  * @ext_ts_irq: the external timestamp IRQ in use
  * @kworker: kwork thread for handling periodic work
@@ -171,12 +172,19 @@ struct ice_ptp_port {
  * @clock: pointer to registered PTP clock device
  * @tstamp_config: hardware timestamping configuration
  * @reset_time: kernel time after clock stop on reset
+ * @tx_hwtstamp_skipped: number of Tx time stamp requests skipped
+ * @tx_hwtstamp_timeouts: number of Tx skbs discarded with no time stamp
+ * @tx_hwtstamp_flushed: number of Tx skbs flushed due to interface closed
+ * @tx_hwtstamp_discarded: number of Tx skbs discarded due to cached PHC time
+ *                         being too old to correctly extend timestamp
+ * @late_cached_phc_updates: number of times cached PHC update is late
  */
 struct ice_ptp {
 	struct ice_ptp_port port;
 	struct kthread_delayed_work work;
 	struct kthread_work extts_work;
 	u64 cached_phc_time;
+	unsigned long cached_phc_jiffies;
 	u8 ext_ts_chan;
 	u8 ext_ts_irq;
 	struct kthread_worker *kworker;
@@ -185,6 +193,11 @@ struct ice_ptp {
 	struct ptp_clock *clock;
 	struct hwtstamp_config tstamp_config;
 	u64 reset_time;
+	u32 tx_hwtstamp_skipped;
+	u32 tx_hwtstamp_timeouts;
+	u32 tx_hwtstamp_flushed;
+	u32 tx_hwtstamp_discarded;
+	u32 late_cached_phc_updates;
 };
 
 #define __ptp_port_to_ptp(p) \

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

@@ -2255,8 +2255,10 @@ ice_tstamp(struct ice_tx_ring *tx_ring, struct sk_buff *skb,
 
 	/* Grab an open timestamp slot */
 	idx = ice_ptp_request_ts(tx_ring->tx_tstamps, skb);
-	if (idx < 0)
+	if (idx < 0) {
+		tx_ring->vsi->back->ptp.tx_hwtstamp_skipped++;
 		return;
+	}
 
 	off->cd_qw1 |= (u64)(ICE_TX_DESC_DTYPE_CTX |
 			     (ICE_TX_CTX_DESC_TSYN << ICE_TXD_CTX_QW1_CMD_S) |