airoha: backport patch fixing out of order DMA for ethernet driver

Backport upstream patch fixing out of order DMA access for ethernet
driver. This is relevant in the context of QoS when packets doesn't
follow linear handling by QDMA HW.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

target/linux/airoha/patches-6.12/108-v6.19-net-airoha-Add-the-capability-to-consume-out-of-orde.patch

@@ -0,0 +1,245 @@
+From 3f47e67dff1f7266e112c50313d63824f6f17102 Mon Sep 17 00:00:00 2001
+From: Lorenzo Bianconi <lorenzo@kernel.org>
+Date: Thu, 6 Nov 2025 13:53:23 +0100
+Subject: [PATCH] net: airoha: Add the capability to consume out-of-order DMA
+ tx descriptors
+
+EN7581 and AN7583 SoCs are capable of DMA mapping non-linear tx skbs on
+non-consecutive DMA descriptors. This feature is useful when multiple
+flows are queued on the same hw tx queue since it allows to fully utilize
+the available tx DMA descriptors and to avoid the starvation of
+high-priority flow we have in the current codebase due to head-of-line
+blocking introduced by low-priority flows.
+
+Tested-by: Xuegang Lu <xuegang.lu@airoha.com>
+Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
+Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
+Link: https://patch.msgid.link/20251106-airoha-tx-linked-list-v2-1-0706d4a322bd@kernel.org
+Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+---
+ drivers/net/ethernet/airoha/airoha_eth.c | 85 +++++++++++-------------
+ drivers/net/ethernet/airoha/airoha_eth.h |  7 +-
+ 2 files changed, 45 insertions(+), 47 deletions(-)
+
+--- a/drivers/net/ethernet/airoha/airoha_eth.c
++++ b/drivers/net/ethernet/airoha/airoha_eth.c
+@@ -892,19 +892,13 @@ static int airoha_qdma_tx_napi_poll(stru
+ 
+ 		dma_unmap_single(eth->dev, e->dma_addr, e->dma_len,
+ 				 DMA_TO_DEVICE);
+-		memset(e, 0, sizeof(*e));
++		e->dma_addr = 0;
++		list_add_tail(&e->list, &q->tx_list);
++
+ 		WRITE_ONCE(desc->msg0, 0);
+ 		WRITE_ONCE(desc->msg1, 0);
+ 		q->queued--;
+ 
+-		/* completion ring can report out-of-order indexes if hw QoS
+-		 * is enabled and packets with different priority are queued
+-		 * to same DMA ring. Take into account possible out-of-order
+-		 * reports incrementing DMA ring tail pointer
+-		 */
+-		while (q->tail != q->head && !q->entry[q->tail].dma_addr)
+-			q->tail = (q->tail + 1) % q->ndesc;
+-
+ 		if (skb) {
+ 			u16 queue = skb_get_queue_mapping(skb);
+ 			struct netdev_queue *txq;
+@@ -949,6 +943,7 @@ static int airoha_qdma_init_tx_queue(str
+ 	q->ndesc = size;
+ 	q->qdma = qdma;
+ 	q->free_thr = 1 + MAX_SKB_FRAGS;
++	INIT_LIST_HEAD(&q->tx_list);
+ 
+ 	q->entry = devm_kzalloc(eth->dev, q->ndesc * sizeof(*q->entry),
+ 				GFP_KERNEL);
+@@ -961,9 +956,9 @@ static int airoha_qdma_init_tx_queue(str
+ 		return -ENOMEM;
+ 
+ 	for (i = 0; i < q->ndesc; i++) {
+-		u32 val;
++		u32 val = FIELD_PREP(QDMA_DESC_DONE_MASK, 1);
+ 
+-		val = FIELD_PREP(QDMA_DESC_DONE_MASK, 1);
++		list_add_tail(&q->entry[i].list, &q->tx_list);
+ 		WRITE_ONCE(q->desc[i].ctrl, cpu_to_le32(val));
+ 	}
+ 
+@@ -973,9 +968,9 @@ static int airoha_qdma_init_tx_queue(str
+ 
+ 	airoha_qdma_wr(qdma, REG_TX_RING_BASE(qid), dma_addr);
+ 	airoha_qdma_rmw(qdma, REG_TX_CPU_IDX(qid), TX_RING_CPU_IDX_MASK,
+-			FIELD_PREP(TX_RING_CPU_IDX_MASK, q->head));
++			FIELD_PREP(TX_RING_CPU_IDX_MASK, 0));
+ 	airoha_qdma_rmw(qdma, REG_TX_DMA_IDX(qid), TX_RING_DMA_IDX_MASK,
+-			FIELD_PREP(TX_RING_DMA_IDX_MASK, q->head));
++			FIELD_PREP(TX_RING_DMA_IDX_MASK, 0));
+ 
+ 	return 0;
+ }
+@@ -1031,17 +1026,21 @@ static int airoha_qdma_init_tx(struct ai
+ static void airoha_qdma_cleanup_tx_queue(struct airoha_queue *q)
+ {
+ 	struct airoha_eth *eth = q->qdma->eth;
++	int i;
+ 
+ 	spin_lock_bh(&q->lock);
+-	while (q->queued) {
+-		struct airoha_queue_entry *e = &q->entry[q->tail];
++	for (i = 0; i < q->ndesc; i++) {
++		struct airoha_queue_entry *e = &q->entry[i];
++
++		if (!e->dma_addr)
++			continue;
+ 
+ 		dma_unmap_single(eth->dev, e->dma_addr, e->dma_len,
+ 				 DMA_TO_DEVICE);
+ 		dev_kfree_skb_any(e->skb);
++		e->dma_addr = 0;
+ 		e->skb = NULL;
+-
+-		q->tail = (q->tail + 1) % q->ndesc;
++		list_add_tail(&e->list, &q->tx_list);
+ 		q->queued--;
+ 	}
+ 	spin_unlock_bh(&q->lock);
+@@ -1883,20 +1882,6 @@ static u32 airoha_get_dsa_tag(struct sk_
+ #endif
+ }
+ 
+-static bool airoha_dev_tx_queue_busy(struct airoha_queue *q, u32 nr_frags)
+-{
+-	u32 tail = q->tail <= q->head ? q->tail + q->ndesc : q->tail;
+-	u32 index = q->head + nr_frags;
+-
+-	/* completion napi can free out-of-order tx descriptors if hw QoS is
+-	 * enabled and packets with different priorities are queued to the same
+-	 * DMA ring. Take into account possible out-of-order reports checking
+-	 * if the tx queue is full using circular buffer head/tail pointers
+-	 * instead of the number of queued packets.
+-	 */
+-	return index >= tail;
+-}
+-
+ static int airoha_get_fe_port(struct airoha_gdm_port *port)
+ {
+ 	struct airoha_qdma *qdma = port->qdma;
+@@ -1919,8 +1904,10 @@ static netdev_tx_t airoha_dev_xmit(struc
+ 	struct airoha_gdm_port *port = netdev_priv(dev);
+ 	struct airoha_qdma *qdma = port->qdma;
+ 	u32 nr_frags, tag, msg0, msg1, len;
++	struct airoha_queue_entry *e;
+ 	struct netdev_queue *txq;
+ 	struct airoha_queue *q;
++	LIST_HEAD(tx_list);
+ 	void *data;
+ 	int i, qid;
+ 	u16 index;
+@@ -1966,7 +1953,7 @@ static netdev_tx_t airoha_dev_xmit(struc
+ 	txq = netdev_get_tx_queue(dev, qid);
+ 	nr_frags = 1 + skb_shinfo(skb)->nr_frags;
+ 
+-	if (airoha_dev_tx_queue_busy(q, nr_frags)) {
++	if (q->queued + nr_frags >= q->ndesc) {
+ 		/* not enough space in the queue */
+ 		netif_tx_stop_queue(txq);
+ 		spin_unlock_bh(&q->lock);
+@@ -1975,11 +1962,13 @@ static netdev_tx_t airoha_dev_xmit(struc
+ 
+ 	len = skb_headlen(skb);
+ 	data = skb->data;
+-	index = q->head;
++
++	e = list_first_entry(&q->tx_list, struct airoha_queue_entry,
++			     list);
++	index = e - q->entry;
+ 
+ 	for (i = 0; i < nr_frags; i++) {
+ 		struct airoha_qdma_desc *desc = &q->desc[index];
+-		struct airoha_queue_entry *e = &q->entry[index];
+ 		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+ 		dma_addr_t addr;
+ 		u32 val;
+@@ -1989,7 +1978,14 @@ static netdev_tx_t airoha_dev_xmit(struc
+ 		if (unlikely(dma_mapping_error(dev->dev.parent, addr)))
+ 			goto error_unmap;
+ 
+-		index = (index + 1) % q->ndesc;
++		list_move_tail(&e->list, &tx_list);
++		e->skb = i ? NULL : skb;
++		e->dma_addr = addr;
++		e->dma_len = len;
++
++		e = list_first_entry(&q->tx_list, struct airoha_queue_entry,
++				     list);
++		index = e - q->entry;
+ 
+ 		val = FIELD_PREP(QDMA_DESC_LEN_MASK, len);
+ 		if (i < nr_frags - 1)
+@@ -2002,15 +1998,9 @@ static netdev_tx_t airoha_dev_xmit(struc
+ 		WRITE_ONCE(desc->msg1, cpu_to_le32(msg1));
+ 		WRITE_ONCE(desc->msg2, cpu_to_le32(0xffff));
+ 
+-		e->skb = i ? NULL : skb;
+-		e->dma_addr = addr;
+-		e->dma_len = len;
+-
+ 		data = skb_frag_address(frag);
+ 		len = skb_frag_size(frag);
+ 	}
+-
+-	q->head = index;
+ 	q->queued += i;
+ 
+ 	skb_tx_timestamp(skb);
+@@ -2019,7 +2009,7 @@ static netdev_tx_t airoha_dev_xmit(struc
+ 	if (netif_xmit_stopped(txq) || !netdev_xmit_more())
+ 		airoha_qdma_rmw(qdma, REG_TX_CPU_IDX(qid),
+ 				TX_RING_CPU_IDX_MASK,
+-				FIELD_PREP(TX_RING_CPU_IDX_MASK, q->head));
++				FIELD_PREP(TX_RING_CPU_IDX_MASK, index));
+ 
+ 	if (q->ndesc - q->queued < q->free_thr)
+ 		netif_tx_stop_queue(txq);
+@@ -2029,10 +2019,13 @@ static netdev_tx_t airoha_dev_xmit(struc
+ 	return NETDEV_TX_OK;
+ 
+ error_unmap:
+-	for (i--; i >= 0; i--) {
+-		index = (q->head + i) % q->ndesc;
+-		dma_unmap_single(dev->dev.parent, q->entry[index].dma_addr,
+-				 q->entry[index].dma_len, DMA_TO_DEVICE);
++	while (!list_empty(&tx_list)) {
++		e = list_first_entry(&tx_list, struct airoha_queue_entry,
++				     list);
++		dma_unmap_single(dev->dev.parent, e->dma_addr, e->dma_len,
++				 DMA_TO_DEVICE);
++		e->dma_addr = 0;
++		list_move_tail(&e->list, &q->tx_list);
+ 	}
+ 
+ 	spin_unlock_bh(&q->lock);
+--- a/drivers/net/ethernet/airoha/airoha_eth.h
++++ b/drivers/net/ethernet/airoha/airoha_eth.h
+@@ -169,7 +169,10 @@ enum trtcm_param {
+ struct airoha_queue_entry {
+ 	union {
+ 		void *buf;
+-		struct sk_buff *skb;
++		struct {
++			struct list_head list;
++			struct sk_buff *skb;
++		};
+ 	};
+ 	dma_addr_t dma_addr;
+ 	u16 dma_len;
+@@ -193,6 +196,8 @@ struct airoha_queue {
+ 	struct napi_struct napi;
+ 	struct page_pool *page_pool;
+ 	struct sk_buff *skb;
++
++	struct list_head tx_list;
+ };
+ 
+ struct airoha_tx_irq_queue {

target/linux/airoha/patches-6.12/116-02-net-airoha-deassert-XSI-line-on-hw-init.patch

@@ -13,7 +13,7 @@ Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
 
 --- a/drivers/net/ethernet/airoha/airoha_eth.c
 +++ b/drivers/net/ethernet/airoha/airoha_eth.c
-@@ -1383,6 +1383,10 @@ static int airoha_hw_init(struct platfor
+@@ -1382,6 +1382,10 @@ static int airoha_hw_init(struct platfor
  	if (err)
  		return err;
  

target/linux/airoha/patches-6.12/116-06-net-airoha-add-initial-fixup-for-GDM3-4-port-support.patch

@@ -28,7 +28,7 @@ Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
  
  	airoha_fe_crsn_qsel_init(eth);
  
-@@ -1625,7 +1627,8 @@ static int airoha_dev_open(struct net_de
+@@ -1624,7 +1626,8 @@ static int airoha_dev_open(struct net_de
  	if (err)
  		return err;
  

target/linux/airoha/patches-6.12/116-07-airoha-ethernet-drop-xsi-mac-reset.patch

@@ -15,7 +15,7 @@ Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
 
 --- a/drivers/net/ethernet/airoha/airoha_eth.c
 +++ b/drivers/net/ethernet/airoha/airoha_eth.c
-@@ -3095,7 +3095,6 @@ static void airoha_remove(struct platfor
+@@ -3088,7 +3088,6 @@ static void airoha_remove(struct platfor
  }
  
  static const char * const en7581_xsi_rsts_names[] = {
@@ -23,7 +23,7 @@ Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
  	"hsi0-mac",
  	"hsi1-mac",
  	"hsi-mac",
-@@ -3127,7 +3126,6 @@ static int airoha_en7581_get_src_port_id
+@@ -3120,7 +3119,6 @@ static int airoha_en7581_get_src_port_id
  }
  
  static const char * const an7583_xsi_rsts_names[] = {

target/linux/airoha/patches-6.12/116-10-net-airoha-add-phylink-support-for-GDM2-4.patch

@@ -35,7 +35,7 @@ Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
  static void airoha_set_macaddr(struct airoha_gdm_port *port, const u8 *addr)
  {
  	struct airoha_eth *eth = port->qdma->eth;
-@@ -1622,6 +1628,17 @@ static int airoha_dev_open(struct net_de
+@@ -1621,6 +1627,17 @@ static int airoha_dev_open(struct net_de
  	struct airoha_gdm_port *port = netdev_priv(dev);
  	struct airoha_qdma *qdma = port->qdma;
  
@@ -53,7 +53,7 @@ Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
  	netif_tx_start_all_queues(dev);
  	err = airoha_set_vip_for_gdm_port(port, true);
  	if (err)
-@@ -1675,6 +1692,11 @@ static int airoha_dev_stop(struct net_de
+@@ -1674,6 +1691,11 @@ static int airoha_dev_stop(struct net_de
  		}
  	}
  
@@ -65,7 +65,7 @@ Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
  	return 0;
  }
  
-@@ -2823,6 +2845,20 @@ static const struct ethtool_ops airoha_e
+@@ -2816,6 +2838,20 @@ static const struct ethtool_ops airoha_e
  	.get_link		= ethtool_op_get_link,
  };
  
@@ -86,7 +86,7 @@ Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
  static int airoha_metadata_dst_alloc(struct airoha_gdm_port *port)
  {
  	int i;
-@@ -2867,6 +2903,99 @@ bool airoha_is_valid_gdm_port(struct air
+@@ -2860,6 +2896,99 @@ bool airoha_is_valid_gdm_port(struct air
  	return false;
  }
  
@@ -186,7 +186,7 @@ Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
  static int airoha_alloc_gdm_port(struct airoha_eth *eth,
  				 struct device_node *np, int index)
  {
-@@ -2945,6 +3074,12 @@ static int airoha_alloc_gdm_port(struct
+@@ -2938,6 +3067,12 @@ static int airoha_alloc_gdm_port(struct
  	if (err)
  		return err;
  
@@ -199,7 +199,7 @@ Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
  	err = register_netdev(dev);
  	if (err)
  		goto free_metadata_dst;
-@@ -3060,6 +3195,10 @@ error_hw_cleanup:
+@@ -3053,6 +3188,10 @@ error_hw_cleanup:
  		if (port && port->dev->reg_state == NETREG_REGISTERED) {
  			unregister_netdev(port->dev);
  			airoha_metadata_dst_free(port);
@@ -210,7 +210,7 @@ Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
  		}
  	}
  	free_netdev(eth->napi_dev);
-@@ -3087,6 +3226,10 @@ static void airoha_remove(struct platfor
+@@ -3080,6 +3219,10 @@ static void airoha_remove(struct platfor
  		airoha_dev_stop(port->dev);
  		unregister_netdev(port->dev);
  		airoha_metadata_dst_free(port);
@@ -223,7 +223,7 @@ Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
  
 --- a/drivers/net/ethernet/airoha/airoha_eth.h
 +++ b/drivers/net/ethernet/airoha/airoha_eth.h
-@@ -531,6 +531,10 @@ struct airoha_gdm_port {
+@@ -536,6 +536,10 @@ struct airoha_gdm_port {
  	struct net_device *dev;
  	int id;
  

target/linux/airoha/patches-6.12/606-net-airoha-disable-external-phy-code-if-PCS_AIROHA-i.patch

@@ -28,7 +28,7 @@ Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
  
  static void airoha_set_macaddr(struct airoha_gdm_port *port, const u8 *addr)
  {
-@@ -1631,6 +1633,7 @@ static int airoha_dev_open(struct net_de
+@@ -1630,6 +1632,7 @@ static int airoha_dev_open(struct net_de
  	struct airoha_gdm_port *port = netdev_priv(dev);
  	struct airoha_qdma *qdma = port->qdma;
  
@@ -36,7 +36,7 @@ Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
  	if (airhoa_is_phy_external(port)) {
  		err = phylink_of_phy_connect(port->phylink, dev->dev.of_node, 0);
  		if (err) {
-@@ -1641,6 +1644,7 @@ static int airoha_dev_open(struct net_de
+@@ -1640,6 +1643,7 @@ static int airoha_dev_open(struct net_de
  
  		phylink_start(port->phylink);
  	}
@@ -44,7 +44,7 @@ Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
  
  	netif_tx_start_all_queues(dev);
  	err = airoha_set_vip_for_gdm_port(port, true);
-@@ -1695,10 +1699,12 @@ static int airoha_dev_stop(struct net_de
+@@ -1694,10 +1698,12 @@ static int airoha_dev_stop(struct net_de
  		}
  	}
  
@@ -57,7 +57,7 @@ Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
  
  	return 0;
  }
-@@ -2848,6 +2854,7 @@ static const struct ethtool_ops airoha_e
+@@ -2841,6 +2847,7 @@ static const struct ethtool_ops airoha_e
  	.get_link		= ethtool_op_get_link,
  };
  
@@ -65,7 +65,7 @@ Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
  static struct phylink_pcs *airoha_phylink_mac_select_pcs(struct phylink_config *config,
  							 phy_interface_t interface)
  {
-@@ -2861,6 +2868,7 @@ static void airoha_mac_config(struct phy
+@@ -2854,6 +2861,7 @@ static void airoha_mac_config(struct phy
  			      const struct phylink_link_state *state)
  {
  }
@@ -73,7 +73,7 @@ Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
  
  static int airoha_metadata_dst_alloc(struct airoha_gdm_port *port)
  {
-@@ -2906,6 +2914,7 @@ bool airoha_is_valid_gdm_port(struct air
+@@ -2899,6 +2907,7 @@ bool airoha_is_valid_gdm_port(struct air
  	return false;
  }
  
@@ -81,7 +81,7 @@ Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
  static void airoha_mac_link_up(struct phylink_config *config, struct phy_device *phy,
  			       unsigned int mode, phy_interface_t interface,
  			       int speed, int duplex, bool tx_pause, bool rx_pause)
-@@ -2998,6 +3007,7 @@ static int airoha_setup_phylink(struct n
+@@ -2991,6 +3000,7 @@ static int airoha_setup_phylink(struct n
  
  	return 0;
  }
@@ -89,7 +89,7 @@ Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
  
  static int airoha_alloc_gdm_port(struct airoha_eth *eth,
  				 struct device_node *np, int index)
-@@ -3077,11 +3087,13 @@ static int airoha_alloc_gdm_port(struct
+@@ -3070,11 +3080,13 @@ static int airoha_alloc_gdm_port(struct
  	if (err)
  		return err;
  
@@ -103,7 +103,7 @@ Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
  
  	err = register_netdev(dev);
  	if (err)
-@@ -3198,10 +3210,12 @@ error_hw_cleanup:
+@@ -3191,10 +3203,12 @@ error_hw_cleanup:
  		if (port && port->dev->reg_state == NETREG_REGISTERED) {
  			unregister_netdev(port->dev);
  			airoha_metadata_dst_free(port);
@@ -116,7 +116,7 @@ Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
  		}
  	}
  	free_netdev(eth->napi_dev);
-@@ -3229,10 +3243,12 @@ static void airoha_remove(struct platfor
+@@ -3222,10 +3236,12 @@ static void airoha_remove(struct platfor
  		airoha_dev_stop(port->dev);
  		unregister_netdev(port->dev);
  		airoha_metadata_dst_free(port);
@@ -131,7 +131,7 @@ Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
  
 --- a/drivers/net/ethernet/airoha/airoha_eth.h
 +++ b/drivers/net/ethernet/airoha/airoha_eth.h
-@@ -531,9 +531,11 @@ struct airoha_gdm_port {
+@@ -536,9 +536,11 @@ struct airoha_gdm_port {
  	struct net_device *dev;
  	int id;