Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Merge in late fixes to prepare for the 6.5 net-next PR.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 117 insertions, 47 deletions

diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
index 18d4af934d8c..00a5ee487812 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -229,7 +229,10 @@ struct igc_adapter {
 
 	struct ptp_clock *ptp_clock;
 	struct ptp_clock_info ptp_caps;
-	struct work_struct ptp_tx_work;
+	/* Access to ptp_tx_skb and ptp_tx_start are protected by the
+	 * ptp_tx_lock.
+	 */
+	spinlock_t ptp_tx_lock;
 	struct sk_buff *ptp_tx_skb;
 	struct hwtstamp_config tstamp_config;
 	unsigned long ptp_tx_start;
@@ -429,7 +432,6 @@ enum igc_state_t {
 	__IGC_TESTING,
 	__IGC_RESETTING,
 	__IGC_DOWN,
-	__IGC_PTP_TX_IN_PROGRESS,
 };
 
 enum igc_tx_flags {
@@ -613,6 +615,7 @@ enum igc_ring_flags_t {
 	IGC_RING_FLAG_TX_CTX_IDX,
 	IGC_RING_FLAG_TX_DETECT_HANG,
 	IGC_RING_FLAG_AF_XDP_ZC,
+	IGC_RING_FLAG_TX_HWTSTAMP,
 };
 
 #define ring_uses_large_buffer(ring) \
@@ -669,6 +672,7 @@ int igc_ptp_set_ts_config(struct net_device *netdev, struct ifreq *ifr);
 int igc_ptp_get_ts_config(struct net_device *netdev, struct ifreq *ifr);
 void igc_ptp_tx_hang(struct igc_adapter *adapter);
 void igc_ptp_read(struct igc_adapter *adapter, struct timespec64 *ts);
+void igc_ptp_tx_tstamp_event(struct igc_adapter *adapter);
 
 #define igc_rx_pg_size(_ring) (PAGE_SIZE << igc_rx_pg_order(_ring))
 
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 5ed7901fd2fb..019ce91c45aa 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -1585,14 +1585,16 @@ done:
 		}
 	}
 
-	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)) {
+	if (unlikely(test_bit(IGC_RING_FLAG_TX_HWTSTAMP, &tx_ring->flags) &&
+		     skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)) {
 		/* FIXME: add support for retrieving timestamps from
 		 * the other timer registers before skipping the
 		 * timestamping request.
 		 */
-		if (adapter->tstamp_config.tx_type == HWTSTAMP_TX_ON &&
-		    !test_and_set_bit_lock(__IGC_PTP_TX_IN_PROGRESS,
-					   &adapter->state)) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&adapter->ptp_tx_lock, flags);
+		if (!adapter->ptp_tx_skb) {
 			skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
 			tx_flags |= IGC_TX_FLAGS_TSTAMP;
 
@@ -1601,6 +1603,8 @@ done:
 		} else {
 			adapter->tx_hwtstamp_skipped++;
 		}
+
+		spin_unlock_irqrestore(&adapter->ptp_tx_lock, flags);
 	}
 
 	if (skb_vlan_tag_present(skb)) {
@@ -5264,7 +5268,7 @@ static void igc_tsync_interrupt(struct igc_adapter *adapter)
 
 	if (tsicr & IGC_TSICR_TXTS) {
 		/* retrieve hardware timestamp */
-		schedule_work(&adapter->ptp_tx_work);
+		igc_ptp_tx_tstamp_event(adapter);
 		ack |= IGC_TSICR_TXTS;
 	}
 
diff --git a/drivers/net/ethernet/intel/igc/igc_ptp.c b/drivers/net/ethernet/intel/igc/igc_ptp.c
index 4e10ced736db..32ef112f8291 100644
--- a/drivers/net/ethernet/intel/igc/igc_ptp.c
+++ b/drivers/net/ethernet/intel/igc/igc_ptp.c
@@ -536,9 +536,34 @@ static void igc_ptp_enable_rx_timestamp(struct igc_adapter *adapter)
 	wr32(IGC_TSYNCRXCTL, val);
 }
 
+static void igc_ptp_clear_tx_tstamp(struct igc_adapter *adapter)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&adapter->ptp_tx_lock, flags);
+
+	dev_kfree_skb_any(adapter->ptp_tx_skb);
+	adapter->ptp_tx_skb = NULL;
+
+	spin_unlock_irqrestore(&adapter->ptp_tx_lock, flags);
+}
+
 static void igc_ptp_disable_tx_timestamp(struct igc_adapter *adapter)
 {
 	struct igc_hw *hw = &adapter->hw;
+	int i;
+
+	/* Clear the flags first to avoid new packets to be enqueued
+	 * for TX timestamping.
+	 */
+	for (i = 0; i < adapter->num_tx_queues; i++) {
+		struct igc_ring *tx_ring = adapter->tx_ring[i];
+
+		clear_bit(IGC_RING_FLAG_TX_HWTSTAMP, &tx_ring->flags);
+	}
+
+	/* Now we can clean the pending TX timestamp requests. */
+	igc_ptp_clear_tx_tstamp(adapter);
 
 	wr32(IGC_TSYNCTXCTL, 0);
 }
@@ -546,12 +571,23 @@ static void igc_ptp_disable_tx_timestamp(struct igc_adapter *adapter)
 static void igc_ptp_enable_tx_timestamp(struct igc_adapter *adapter)
 {
 	struct igc_hw *hw = &adapter->hw;
+	int i;
 
 	wr32(IGC_TSYNCTXCTL, IGC_TSYNCTXCTL_ENABLED | IGC_TSYNCTXCTL_TXSYNSIG);
 
 	/* Read TXSTMP registers to discard any timestamp previously stored. */
 	rd32(IGC_TXSTMPL);
 	rd32(IGC_TXSTMPH);
+
+	/* The hardware is ready to accept TX timestamp requests,
+	 * notify the transmit path.
+	 */
+	for (i = 0; i < adapter->num_tx_queues; i++) {
+		struct igc_ring *tx_ring = adapter->tx_ring[i];
+
+		set_bit(IGC_RING_FLAG_TX_HWTSTAMP, &tx_ring->flags);
+	}
+
 }
 
 /**
@@ -603,6 +639,7 @@ static int igc_ptp_set_timestamp_mode(struct igc_adapter *adapter,
 	return 0;
 }
 
+/* Requires adapter->ptp_tx_lock held by caller. */
 static void igc_ptp_tx_timeout(struct igc_adapter *adapter)
 {
 	struct igc_hw *hw = &adapter->hw;
@@ -610,7 +647,6 @@ static void igc_ptp_tx_timeout(struct igc_adapter *adapter)
 	dev_kfree_skb_any(adapter->ptp_tx_skb);
 	adapter->ptp_tx_skb = NULL;
 	adapter->tx_hwtstamp_timeouts++;
-	clear_bit_unlock(__IGC_PTP_TX_IN_PROGRESS, &adapter->state);
 	/* Clear the tx valid bit in TSYNCTXCTL register to enable interrupt. */
 	rd32(IGC_TXSTMPH);
 	netdev_warn(adapter->netdev, "Tx timestamp timeout\n");
@@ -618,20 +654,20 @@ static void igc_ptp_tx_timeout(struct igc_adapter *adapter)
 
 void igc_ptp_tx_hang(struct igc_adapter *adapter)
 {
-	bool timeout = time_is_before_jiffies(adapter->ptp_tx_start +
-					      IGC_PTP_TX_TIMEOUT);
+	unsigned long flags;
 
-	if (!test_bit(__IGC_PTP_TX_IN_PROGRESS, &adapter->state))
-		return;
+	spin_lock_irqsave(&adapter->ptp_tx_lock, flags);
 
-	/* If we haven't received a timestamp within the timeout, it is
-	 * reasonable to assume that it will never occur, so we can unlock the
-	 * timestamp bit when this occurs.
-	 */
-	if (timeout) {
-		cancel_work_sync(&adapter->ptp_tx_work);
-		igc_ptp_tx_timeout(adapter);
-	}
+	if (!adapter->ptp_tx_skb)
+		goto unlock;
+
+	if (time_is_after_jiffies(adapter->ptp_tx_start + IGC_PTP_TX_TIMEOUT))
+		goto unlock;
+
+	igc_ptp_tx_timeout(adapter);
+
+unlock:
+	spin_unlock_irqrestore(&adapter->ptp_tx_lock, flags);
 }
 
 /**
@@ -641,20 +677,57 @@ void igc_ptp_tx_hang(struct igc_adapter *adapter)
  * If we were asked to do hardware stamping and such a time stamp is
  * available, then it must have been for this skb here because we only
  * allow only one such packet into the queue.
+ *
+ * Context: Expects adapter->ptp_tx_lock to be held by caller.
  */
 static void igc_ptp_tx_hwtstamp(struct igc_adapter *adapter)
 {
 	struct sk_buff *skb = adapter->ptp_tx_skb;
 	struct skb_shared_hwtstamps shhwtstamps;
 	struct igc_hw *hw = &adapter->hw;
+	u32 tsynctxctl;
 	int adjust = 0;
 	u64 regval;
 
 	if (WARN_ON_ONCE(!skb))
 		return;
 
-	regval = rd32(IGC_TXSTMPL);
-	regval |= (u64)rd32(IGC_TXSTMPH) << 32;
+	tsynctxctl = rd32(IGC_TSYNCTXCTL);
+	tsynctxctl &= IGC_TSYNCTXCTL_TXTT_0;
+	if (tsynctxctl) {
+		regval = rd32(IGC_TXSTMPL);
+		regval |= (u64)rd32(IGC_TXSTMPH) << 32;
+	} else {
+		/* There's a bug in the hardware that could cause
+		 * missing interrupts for TX timestamping. The issue
+		 * is that for new interrupts to be triggered, the
+		 * IGC_TXSTMPH_0 register must be read.
+		 *
+		 * To avoid discarding a valid timestamp that just
+		 * happened at the "wrong" time, we need to confirm
+		 * that there was no timestamp captured, we do that by
+		 * assuming that no two timestamps in sequence have
+		 * the same nanosecond value.
+		 *
+		 * So, we read the "low" register, read the "high"
+		 * register (to latch a new timestamp) and read the
+		 * "low" register again, if "old" and "new" versions
+		 * of the "low" register are different, a valid
+		 * timestamp was captured, we can read the "high"
+		 * register again.
+		 */
+		u32 txstmpl_old, txstmpl_new;
+
+		txstmpl_old = rd32(IGC_TXSTMPL);
+		rd32(IGC_TXSTMPH);
+		txstmpl_new = rd32(IGC_TXSTMPL);
+
+		if (txstmpl_old == txstmpl_new)
+			return;
+
+		regval = txstmpl_new;
+		regval |= (u64)rd32(IGC_TXSTMPH) << 32;
+	}
 	if (igc_ptp_systim_to_hwtstamp(adapter, &shhwtstamps, regval))
 		return;
 
@@ -676,13 +749,7 @@ static void igc_ptp_tx_hwtstamp(struct igc_adapter *adapter)
 	shhwtstamps.hwtstamp =
 		ktime_add_ns(shhwtstamps.hwtstamp, adjust);
 
-	/* Clear the lock early before calling skb_tstamp_tx so that
-	 * applications are not woken up before the lock bit is clear. We use
-	 * a copy of the skb pointer to ensure other threads can't change it
-	 * while we're notifying the stack.
-	 */
 	adapter->ptp_tx_skb = NULL;
-	clear_bit_unlock(__IGC_PTP_TX_IN_PROGRESS, &adapter->state);
 
 	/* Notify the stack and free the skb after we've unlocked */
 	skb_tstamp_tx(skb, &shhwtstamps);
@@ -690,27 +757,25 @@ static void igc_ptp_tx_hwtstamp(struct igc_adapter *adapter)
 }
 
 /**
- * igc_ptp_tx_work
- * @work: pointer to work struct
+ * igc_ptp_tx_tstamp_event
+ * @adapter: board private structure
  *
- * This work function polls the TSYNCTXCTL valid bit to determine when a
- * timestamp has been taken for the current stored skb.
+ * Called when a TX timestamp interrupt happens to retrieve the
+ * timestamp and send it up to the socket.
  */
-static void igc_ptp_tx_work(struct work_struct *work)
+void igc_ptp_tx_tstamp_event(struct igc_adapter *adapter)
 {
-	struct igc_adapter *adapter = container_of(work, struct igc_adapter,
-						   ptp_tx_work);
-	struct igc_hw *hw = &adapter->hw;
-	u32 tsynctxctl;
+	unsigned long flags;
 
-	if (!test_bit(__IGC_PTP_TX_IN_PROGRESS, &adapter->state))
-		return;
+	spin_lock_irqsave(&adapter->ptp_tx_lock, flags);
 
-	tsynctxctl = rd32(IGC_TSYNCTXCTL);
-	if (WARN_ON_ONCE(!(tsynctxctl & IGC_TSYNCTXCTL_TXTT_0)))
-		return;
+	if (!adapter->ptp_tx_skb)
+		goto unlock;
 
 	igc_ptp_tx_hwtstamp(adapter);
+
+unlock:
+	spin_unlock_irqrestore(&adapter->ptp_tx_lock, flags);
 }
 
 /**
@@ -959,8 +1024,8 @@ void igc_ptp_init(struct igc_adapter *adapter)
 		return;
 	}
 
+	spin_lock_init(&adapter->ptp_tx_lock);
 	spin_lock_init(&adapter->tmreg_lock);
-	INIT_WORK(&adapter->ptp_tx_work, igc_ptp_tx_work);
 
 	adapter->tstamp_config.rx_filter = HWTSTAMP_FILTER_NONE;
 	adapter->tstamp_config.tx_type = HWTSTAMP_TX_OFF;
@@ -1020,10 +1085,7 @@ void igc_ptp_suspend(struct igc_adapter *adapter)
 	if (!(adapter->ptp_flags & IGC_PTP_ENABLED))
 		return;
 
-	cancel_work_sync(&adapter->ptp_tx_work);
-	dev_kfree_skb_any(adapter->ptp_tx_skb);
-	adapter->ptp_tx_skb = NULL;
-	clear_bit_unlock(__IGC_PTP_TX_IN_PROGRESS, &adapter->state);
+	igc_ptp_clear_tx_tstamp(adapter);
 
 	if (pci_device_is_present(adapter->pdev)) {
 		igc_ptp_time_save(adapter);