Merge branch '1GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/net-queue

Tony Nguyen says:

====================
Intel Wired LAN Driver Updates 2022-12-15 (igc)

Muhammad Husaini Zulkifli says:

This patch series fixes bugs for the Time-Sensitive Networking(TSN)
Qbv Scheduling features.

An overview of each patch series is given below:

Patch 1: Using a first flag bit to schedule a packet to the next cycle if
packet cannot fit in current Qbv cycle.
Patch 2: Enable strict cycle for Qbv scheduling.
Patch 3: Prevent user to set basetime less than zero during tc config.
Patch 4: Allow the basetime enrollment with zero value.
Patch 5: Calculate the new end time value to exclude the time interval that
exceed the cycle time as user can specify the cycle time in tc config.
Patch 6: Resolve the HW bugs where the gate is not fully closed.
---
This contains the net patches from this original pull request:
https://lore.kernel.org/netdev/20221205212414.3197525-1-anthony.l.nguyen@intel.com/

====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/intel/igc/igc.h

@@ -94,6 +94,8 @@ struct igc_ring {
 	u8 queue_index;                 /* logical index of the ring*/
 	u8 reg_idx;                     /* physical index of the ring */
 	bool launchtime_enable;         /* true if LaunchTime is enabled */
+	ktime_t last_tx_cycle;          /* end of the cycle with a launchtime transmission */
+	ktime_t last_ff_cycle;          /* Last cycle with an active first flag */
 
 	u32 start_time;
 	u32 end_time;
@@ -182,6 +184,7 @@ struct igc_adapter {
 
 	ktime_t base_time;
 	ktime_t cycle_time;
+	bool qbv_enable;
 
 	/* OS defined structs */
 	struct pci_dev *pdev;

drivers/net/ethernet/intel/igc/igc_defines.h

@@ -321,6 +321,8 @@
 #define IGC_ADVTXD_L4LEN_SHIFT	8  /* Adv ctxt L4LEN shift */
 #define IGC_ADVTXD_MSS_SHIFT	16 /* Adv ctxt MSS shift */
 
+#define IGC_ADVTXD_TSN_CNTX_FIRST	0x00000080
+
 /* Transmit Control */
 #define IGC_TCTL_EN		0x00000002 /* enable Tx */
 #define IGC_TCTL_PSP		0x00000008 /* pad short packets */

drivers/net/ethernet/intel/igc/igc_main.c

@@ -1000,25 +1000,118 @@ static int igc_write_mc_addr_list(struct net_device *netdev)
 	return netdev_mc_count(netdev);
 }
 
-static __le32 igc_tx_launchtime(struct igc_adapter *adapter, ktime_t txtime)
+static __le32 igc_tx_launchtime(struct igc_ring *ring, ktime_t txtime,
+				bool *first_flag, bool *insert_empty)
 {
+	struct igc_adapter *adapter = netdev_priv(ring->netdev);
 	ktime_t cycle_time = adapter->cycle_time;
 	ktime_t base_time = adapter->base_time;
+	ktime_t now = ktime_get_clocktai();
+	ktime_t baset_est, end_of_cycle;
 	u32 launchtime;
+	s64 n;
 
-	/* FIXME: when using ETF together with taprio, we may have a
-	 * case where 'delta' is larger than the cycle_time, this may
-	 * cause problems if we don't read the current value of
-	 * IGC_BASET, as the value writen into the launchtime
-	 * descriptor field may be misinterpreted.
+	n = div64_s64(ktime_sub_ns(now, base_time), cycle_time);
+
+	baset_est = ktime_add_ns(base_time, cycle_time * (n));
+	end_of_cycle = ktime_add_ns(baset_est, cycle_time);
+
+	if (ktime_compare(txtime, end_of_cycle) >= 0) {
+		if (baset_est != ring->last_ff_cycle) {
+			*first_flag = true;
+			ring->last_ff_cycle = baset_est;
+
+			if (ktime_compare(txtime, ring->last_tx_cycle) > 0)
+				*insert_empty = true;
+		}
+	}
+
+	/* Introducing a window at end of cycle on which packets
+	 * potentially not honor launchtime. Window of 5us chosen
+	 * considering software update the tail pointer and packets
+	 * are dma'ed to packet buffer.
 	 */
-	div_s64_rem(ktime_sub_ns(txtime, base_time), cycle_time, &launchtime);
+	if ((ktime_sub_ns(end_of_cycle, now) < 5 * NSEC_PER_USEC))
+		netdev_warn(ring->netdev, "Packet with txtime=%llu may not be honoured\n",
+			    txtime);
+
+	ring->last_tx_cycle = end_of_cycle;
+
+	launchtime = ktime_sub_ns(txtime, baset_est);
+	if (launchtime > 0)
+		div_s64_rem(launchtime, cycle_time, &launchtime);
+	else
+		launchtime = 0;
 
 	return cpu_to_le32(launchtime);
 }
 
+static int igc_init_empty_frame(struct igc_ring *ring,
+				struct igc_tx_buffer *buffer,
+				struct sk_buff *skb)
+{
+	unsigned int size;
+	dma_addr_t dma;
+
+	size = skb_headlen(skb);
+
+	dma = dma_map_single(ring->dev, skb->data, size, DMA_TO_DEVICE);
+	if (dma_mapping_error(ring->dev, dma)) {
+		netdev_err_once(ring->netdev, "Failed to map DMA for TX\n");
+		return -ENOMEM;
+	}
+
+	buffer->skb = skb;
+	buffer->protocol = 0;
+	buffer->bytecount = skb->len;
+	buffer->gso_segs = 1;
+	buffer->time_stamp = jiffies;
+	dma_unmap_len_set(buffer, len, skb->len);
+	dma_unmap_addr_set(buffer, dma, dma);
+
+	return 0;
+}
+
+static int igc_init_tx_empty_descriptor(struct igc_ring *ring,
+					struct sk_buff *skb,
+					struct igc_tx_buffer *first)
+{
+	union igc_adv_tx_desc *desc;
+	u32 cmd_type, olinfo_status;
+	int err;
+
+	if (!igc_desc_unused(ring))
+		return -EBUSY;
+
+	err = igc_init_empty_frame(ring, first, skb);
+	if (err)
+		return err;
+
+	cmd_type = IGC_ADVTXD_DTYP_DATA | IGC_ADVTXD_DCMD_DEXT |
+		   IGC_ADVTXD_DCMD_IFCS | IGC_TXD_DCMD |
+		   first->bytecount;
+	olinfo_status = first->bytecount << IGC_ADVTXD_PAYLEN_SHIFT;
+
+	desc = IGC_TX_DESC(ring, ring->next_to_use);
+	desc->read.cmd_type_len = cpu_to_le32(cmd_type);
+	desc->read.olinfo_status = cpu_to_le32(olinfo_status);
+	desc->read.buffer_addr = cpu_to_le64(dma_unmap_addr(first, dma));
+
+	netdev_tx_sent_queue(txring_txq(ring), skb->len);
+
+	first->next_to_watch = desc;
+
+	ring->next_to_use++;
+	if (ring->next_to_use == ring->count)
+		ring->next_to_use = 0;
+
+	return 0;
+}
+
+#define IGC_EMPTY_FRAME_SIZE 60
+
 static void igc_tx_ctxtdesc(struct igc_ring *tx_ring,
-			    struct igc_tx_buffer *first,
+			    __le32 launch_time, bool first_flag,
 			    u32 vlan_macip_lens, u32 type_tucmd,
 			    u32 mss_l4len_idx)
 {
@@ -1037,26 +1130,17 @@ static void igc_tx_ctxtdesc(struct igc_ring *tx_ring,
 	if (test_bit(IGC_RING_FLAG_TX_CTX_IDX, &tx_ring->flags))
 		mss_l4len_idx |= tx_ring->reg_idx << 4;
 
+	if (first_flag)
+		mss_l4len_idx |= IGC_ADVTXD_TSN_CNTX_FIRST;
+
 	context_desc->vlan_macip_lens	= cpu_to_le32(vlan_macip_lens);
 	context_desc->type_tucmd_mlhl	= cpu_to_le32(type_tucmd);
 	context_desc->mss_l4len_idx	= cpu_to_le32(mss_l4len_idx);
-
-	/* We assume there is always a valid Tx time available. Invalid times
-	 * should have been handled by the upper layers.
-	 */
-	if (tx_ring->launchtime_enable) {
-		struct igc_adapter *adapter = netdev_priv(tx_ring->netdev);
-		ktime_t txtime = first->skb->tstamp;
-
-		skb_txtime_consumed(first->skb);
-		context_desc->launch_time = igc_tx_launchtime(adapter,
-							      txtime);
-	} else {
-		context_desc->launch_time = 0;
-	}
+	context_desc->launch_time	= launch_time;
 }
 
-static void igc_tx_csum(struct igc_ring *tx_ring, struct igc_tx_buffer *first)
+static void igc_tx_csum(struct igc_ring *tx_ring, struct igc_tx_buffer *first,
+			__le32 launch_time, bool first_flag)
 {
 	struct sk_buff *skb = first->skb;
 	u32 vlan_macip_lens = 0;
@@ -1096,7 +1180,8 @@ static void igc_tx_csum(struct igc_ring *tx_ring, struct igc_tx_buffer *first)
 	vlan_macip_lens |= skb_network_offset(skb) << IGC_ADVTXD_MACLEN_SHIFT;
 	vlan_macip_lens |= first->tx_flags & IGC_TX_FLAGS_VLAN_MASK;
 
-	igc_tx_ctxtdesc(tx_ring, first, vlan_macip_lens, type_tucmd, 0);
+	igc_tx_ctxtdesc(tx_ring, launch_time, first_flag,
+			vlan_macip_lens, type_tucmd, 0);
 }
 
 static int __igc_maybe_stop_tx(struct igc_ring *tx_ring, const u16 size)
@@ -1320,6 +1405,7 @@ static int igc_tx_map(struct igc_ring *tx_ring,
 
 static int igc_tso(struct igc_ring *tx_ring,
 		   struct igc_tx_buffer *first,
+		   __le32 launch_time, bool first_flag,
 		   u8 *hdr_len)
 {
 	u32 vlan_macip_lens, type_tucmd, mss_l4len_idx;
@@ -1406,8 +1492,8 @@ static int igc_tso(struct igc_ring *tx_ring,
 	vlan_macip_lens |= (ip.hdr - skb->data) << IGC_ADVTXD_MACLEN_SHIFT;
 	vlan_macip_lens |= first->tx_flags & IGC_TX_FLAGS_VLAN_MASK;
 
-	igc_tx_ctxtdesc(tx_ring, first, vlan_macip_lens,
-			type_tucmd, mss_l4len_idx);
+	igc_tx_ctxtdesc(tx_ring, launch_time, first_flag,
+			vlan_macip_lens, type_tucmd, mss_l4len_idx);
 
 	return 1;
 }
@@ -1415,11 +1501,14 @@ static int igc_tso(struct igc_ring *tx_ring,
 static netdev_tx_t igc_xmit_frame_ring(struct sk_buff *skb,
 				       struct igc_ring *tx_ring)
 {
+	bool first_flag = false, insert_empty = false;
 	u16 count = TXD_USE_COUNT(skb_headlen(skb));
 	__be16 protocol = vlan_get_protocol(skb);
 	struct igc_tx_buffer *first;
+	__le32 launch_time = 0;
 	u32 tx_flags = 0;
 	unsigned short f;
+	ktime_t txtime;
 	u8 hdr_len = 0;
 	int tso = 0;
 
@@ -1433,11 +1522,40 @@ static netdev_tx_t igc_xmit_frame_ring(struct sk_buff *skb,
 		count += TXD_USE_COUNT(skb_frag_size(
 						&skb_shinfo(skb)->frags[f]));
 
-	if (igc_maybe_stop_tx(tx_ring, count + 3)) {
+	if (igc_maybe_stop_tx(tx_ring, count + 5)) {
 		/* this is a hard error */
 		return NETDEV_TX_BUSY;
 	}
 
+	if (!tx_ring->launchtime_enable)
+		goto done;
+
+	txtime = skb->tstamp;
+	skb->tstamp = ktime_set(0, 0);
+	launch_time = igc_tx_launchtime(tx_ring, txtime, &first_flag, &insert_empty);
+
+	if (insert_empty) {
+		struct igc_tx_buffer *empty_info;
+		struct sk_buff *empty;
+		void *data;
+
+		empty_info = &tx_ring->tx_buffer_info[tx_ring->next_to_use];
+		empty = alloc_skb(IGC_EMPTY_FRAME_SIZE, GFP_ATOMIC);
+		if (!empty)
+			goto done;
+
+		data = skb_put(empty, IGC_EMPTY_FRAME_SIZE);
+		memset(data, 0, IGC_EMPTY_FRAME_SIZE);
+
+		igc_tx_ctxtdesc(tx_ring, 0, false, 0, 0, 0);
+
+		if (igc_init_tx_empty_descriptor(tx_ring,
+						 empty,
+						 empty_info) < 0)
+			dev_kfree_skb_any(empty);
+	}
+
+done:
 	/* record the location of the first descriptor for this packet */
 	first = &tx_ring->tx_buffer_info[tx_ring->next_to_use];
 	first->type = IGC_TX_BUFFER_TYPE_SKB;
@@ -1474,11 +1592,11 @@ static netdev_tx_t igc_xmit_frame_ring(struct sk_buff *skb,
 	first->tx_flags = tx_flags;
 	first->protocol = protocol;
 
-	tso = igc_tso(tx_ring, first, &hdr_len);
+	tso = igc_tso(tx_ring, first, launch_time, first_flag, &hdr_len);
 	if (tso < 0)
 		goto out_drop;
 	else if (!tso)
-		igc_tx_csum(tx_ring, first);
+		igc_tx_csum(tx_ring, first, launch_time, first_flag);
 
 	igc_tx_map(tx_ring, first, hdr_len);
 
@@ -5925,10 +6043,16 @@ static int igc_save_qbv_schedule(struct igc_adapter *adapter,
 	bool queue_configured[IGC_MAX_TX_QUEUES] = { };
 	u32 start_time = 0, end_time = 0;
 	size_t n;
+	int i;
+
+	adapter->qbv_enable = qopt->enable;
 
 	if (!qopt->enable)
 		return igc_tsn_clear_schedule(adapter);
 
+	if (qopt->base_time < 0)
+		return -ERANGE;
+
 	if (adapter->base_time)
 		return -EALREADY;
 
@@ -5940,10 +6064,24 @@ static int igc_save_qbv_schedule(struct igc_adapter *adapter,
 
 	for (n = 0; n < qopt->num_entries; n++) {
 		struct tc_taprio_sched_entry *e = &qopt->entries[n];
-		int i;
 
 		end_time += e->interval;
 
+		/* If any of the conditions below are true, we need to manually
+		 * control the end time of the cycle.
+		 * 1. Qbv users can specify a cycle time that is not equal
+		 * to the total GCL intervals. Hence, recalculation is
+		 * necessary here to exclude the time interval that
+		 * exceeds the cycle time.
+		 * 2. According to IEEE Std. 802.1Q-2018 section 8.6.9.2,
+		 * once the end of the list is reached, it will switch
+		 * to the END_OF_CYCLE state and leave the gates in the
+		 * same state until the next cycle is started.
+		 */
+		if (end_time > adapter->cycle_time ||
+		    n + 1 == qopt->num_entries)
+			end_time = adapter->cycle_time;
+
 		for (i = 0; i < adapter->num_tx_queues; i++) {
 			struct igc_ring *ring = adapter->tx_ring[i];
 
@@ -5964,6 +6102,18 @@ static int igc_save_qbv_schedule(struct igc_adapter *adapter,
 		start_time += e->interval;
 	}
 
+	/* Check whether a queue gets configured.
+	 * If not, set the start and end time to be end time.
+	 */
+	for (i = 0; i < adapter->num_tx_queues; i++) {
+		if (!queue_configured[i]) {
+			struct igc_ring *ring = adapter->tx_ring[i];
+
+			ring->start_time = end_time;
+			ring->end_time = end_time;
+		}
+	}
+
 	return 0;
 }
 

drivers/net/ethernet/intel/igc/igc_tsn.c

@@ -36,7 +36,7 @@ static unsigned int igc_tsn_new_flags(struct igc_adapter *adapter)
 {
 	unsigned int new_flags = adapter->flags & ~IGC_FLAG_TSN_ANY_ENABLED;
 
-	if (adapter->base_time)
+	if (adapter->qbv_enable)
 		new_flags |= IGC_FLAG_TSN_QBV_ENABLED;
 
 	if (is_any_launchtime(adapter))
@@ -140,15 +140,8 @@ static int igc_tsn_enable_offload(struct igc_adapter *adapter)
 		wr32(IGC_STQT(i), ring->start_time);
 		wr32(IGC_ENDQT(i), ring->end_time);
 
-		if (adapter->base_time) {
-			/* If we have a base_time we are in "taprio"
-			 * mode and we need to be strict about the
-			 * cycles: only transmit a packet if it can be
-			 * completed during that cycle.
-			 */
-			txqctl |= IGC_TXQCTL_STRICT_CYCLE |
-				IGC_TXQCTL_STRICT_END;
-		}
+		txqctl |= IGC_TXQCTL_STRICT_CYCLE |
+			IGC_TXQCTL_STRICT_END;
 
 		if (ring->launchtime_enable)
 			txqctl |= IGC_TXQCTL_QUEUE_MODE_LAUNCHT;