diff mbox series

[net-next,v2,1/8] net: stmmac: Initial support for TBS

Message ID d72e539523e063a391391d447ece658524bb8d57.1578920366.git.Jose.Abreu@synopsys.com (mailing list archive)
State New, archived
Headers show
Series net: stmmac: ETF support | expand

Commit Message

Jose Abreu Jan. 13, 2020, 1:02 p.m. UTC 
Adds the initial hooks for TBS support. This needs a 32 byte descriptor
in order for it to work with current HW. Adds all the logic for Enhanced
Descriptors in main core but no HW related logic for now.

Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>

---
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Jose Abreu <joabreu@synopsys.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: netdev@vger.kernel.org
Cc: linux-stm32@st-md-mailman.stormreply.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
---
 drivers/net/ethernet/stmicro/stmmac/descs.h       |   9 ++
 drivers/net/ethernet/stmicro/stmmac/hwif.h        |   7 ++
 drivers/net/ethernet/stmicro/stmmac/stmmac.h      |   3 +
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 137 +++++++++++++++++-----
 include/linux/stmmac.h                            |   1 +
 5 files changed, 125 insertions(+), 32 deletions(-)

Comments

Jakub Kicinski Jan. 13, 2020, 2:54 p.m. UTC | #1 
On Mon, 13 Jan 2020 14:02:36 +0100, Jose Abreu wrote:
> Adds the initial hooks for TBS support. This needs a 32 byte descriptor
> in order for it to work with current HW. Adds all the logic for Enhanced
> Descriptors in main core but no HW related logic for now.
> 
> Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>

> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> index f98c5eefb382..dceaeb72a414 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> @@ -42,10 +42,13 @@ struct stmmac_tx_info {
>  /* Frequently used values are kept adjacent for cache effect */
>  struct stmmac_tx_queue {
>  	u32 tx_count_frames;
> +	int tbs_avail;
> +	int tbs_en;

These could be bool or a bitfield?

>  	struct timer_list txtimer;
>  	u32 queue_index;
>  	struct stmmac_priv *priv_data;
>  	struct dma_extended_desc *dma_etx ____cacheline_aligned_in_smp;
> +	struct dma_edesc *dma_entx ____cacheline_aligned_in_smp;

Won't this create a cache line-sized hole? Is the structure member
supposed to be aligned or the data its pointing to?

>  	struct dma_desc *dma_tx;
>  	struct sk_buff **tx_skbuff;
>  	struct stmmac_tx_info *tx_skbuff_dma;

> diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
> index 0531afa9b21e..19190c609282 100644
> --- a/include/linux/stmmac.h
> +++ b/include/linux/stmmac.h
> @@ -139,6 +139,7 @@ struct stmmac_txq_cfg {
>  	u32 low_credit;
>  	bool use_prio;
>  	u32 prio;
> +	int tbs_en;

also bool?

>  };
>  
>  struct plat_stmmacenet_data {
Jose Abreu Jan. 13, 2020, 3:10 p.m. UTC | #2 
From: Jakub Kicinski <kuba@kernel.org>
Date: Jan/13/2020, 14:54:06 (UTC+00:00)

> > +	int tbs_avail;
> > +	int tbs_en;
> 
> These could be bool or a bitfield?

I'm tempted to not use bool since I read this: 
https://lkml.org/lkml/2017/11/21/384

---
Thanks,
Jose Miguel Abreu
diff mbox series

Patch

diff --git a/drivers/net/ethernet/stmicro/stmmac/descs.h b/drivers/net/ethernet/stmicro/stmmac/descs.h
index 9f0b9a9e63b3..49d6a866244f 100644
--- a/drivers/net/ethernet/stmicro/stmmac/descs.h
+++ b/drivers/net/ethernet/stmicro/stmmac/descs.h
@@ -171,6 +171,15 @@  struct dma_extended_desc {
 	__le32 des7;	/* Tx/Rx Timestamp High */
 };
 
+/* Enhanced descriptor for TBS */
+struct dma_edesc {
+	__le32 des4;
+	__le32 des5;
+	__le32 des6;
+	__le32 des7;
+	struct dma_desc basic;
+};
+
 /* Transmit checksum insertion control */
 #define	TX_CIC_FULL	3	/* Include IP header and pseudoheader */
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.h b/drivers/net/ethernet/stmicro/stmmac/hwif.h
index 905a6f0edaca..71c23cbd7af8 100644
--- a/drivers/net/ethernet/stmicro/stmmac/hwif.h
+++ b/drivers/net/ethernet/stmicro/stmmac/hwif.h
@@ -29,6 +29,7 @@  struct stmmac_extra_stats;
 struct stmmac_safety_stats;
 struct dma_desc;
 struct dma_extended_desc;
+struct dma_edesc;
 
 /* Descriptors helpers */
 struct stmmac_desc_ops {
@@ -95,6 +96,7 @@  struct stmmac_desc_ops {
 	void (*set_vlan_tag)(struct dma_desc *p, u16 tag, u16 inner_tag,
 			     u32 inner_type);
 	void (*set_vlan)(struct dma_desc *p, u32 type);
+	void (*set_tbs)(struct dma_edesc *p, u32 sec, u32 nsec);
 };
 
 #define stmmac_init_rx_desc(__priv, __args...) \
@@ -157,6 +159,8 @@  struct stmmac_desc_ops {
 	stmmac_do_void_callback(__priv, desc, set_vlan_tag, __args)
 #define stmmac_set_desc_vlan(__priv, __args...) \
 	stmmac_do_void_callback(__priv, desc, set_vlan, __args)
+#define stmmac_set_desc_tbs(__priv, __args...) \
+	stmmac_do_void_callback(__priv, desc, set_tbs, __args)
 
 struct stmmac_dma_cfg;
 struct dma_features;
@@ -210,6 +214,7 @@  struct stmmac_dma_ops {
 	void (*qmode)(void __iomem *ioaddr, u32 channel, u8 qmode);
 	void (*set_bfsize)(void __iomem *ioaddr, int bfsize, u32 chan);
 	void (*enable_sph)(void __iomem *ioaddr, bool en, u32 chan);
+	int (*enable_tbs)(void __iomem *ioaddr, bool en, u32 chan);
 };
 
 #define stmmac_reset(__priv, __args...) \
@@ -268,6 +273,8 @@  struct stmmac_dma_ops {
 	stmmac_do_void_callback(__priv, dma, set_bfsize, __args)
 #define stmmac_enable_sph(__priv, __args...) \
 	stmmac_do_void_callback(__priv, dma, enable_sph, __args)
+#define stmmac_enable_tbs(__priv, __args...) \
+	stmmac_do_callback(__priv, dma, enable_tbs, __args)
 
 struct mac_device_info;
 struct net_device;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index f98c5eefb382..dceaeb72a414 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -42,10 +42,13 @@  struct stmmac_tx_info {
 /* Frequently used values are kept adjacent for cache effect */
 struct stmmac_tx_queue {
 	u32 tx_count_frames;
+	int tbs_avail;
+	int tbs_en;
 	struct timer_list txtimer;
 	u32 queue_index;
 	struct stmmac_priv *priv_data;
 	struct dma_extended_desc *dma_etx ____cacheline_aligned_in_smp;
+	struct dma_edesc *dma_entx ____cacheline_aligned_in_smp;
 	struct dma_desc *dma_tx;
 	struct sk_buff **tx_skbuff;
 	struct stmmac_tx_info *tx_skbuff_dma;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index f113138df0d9..82bf81b7ae76 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1090,6 +1090,8 @@  static void stmmac_display_tx_rings(struct stmmac_priv *priv)
 
 		if (priv->extend_desc)
 			head_tx = (void *)tx_q->dma_etx;
+		else if (tx_q->tbs_avail)
+			head_tx = (void *)tx_q->dma_entx;
 		else
 			head_tx = (void *)tx_q->dma_tx;
 
@@ -1167,6 +1169,9 @@  static void stmmac_clear_tx_descriptors(struct stmmac_priv *priv, u32 queue)
 		if (priv->extend_desc)
 			stmmac_init_tx_desc(priv, &tx_q->dma_etx[i].basic,
 					priv->mode, (i == DMA_TX_SIZE - 1));
+		else if (tx_q->tbs_avail)
+			stmmac_init_tx_desc(priv, &tx_q->dma_entx[i].basic,
+					priv->mode, (i == DMA_TX_SIZE - 1));
 		else
 			stmmac_init_tx_desc(priv, &tx_q->dma_tx[i],
 					priv->mode, (i == DMA_TX_SIZE - 1));
@@ -1383,7 +1388,7 @@  static int init_dma_tx_desc_rings(struct net_device *dev)
 			if (priv->extend_desc)
 				stmmac_mode_init(priv, tx_q->dma_etx,
 						tx_q->dma_tx_phy, DMA_TX_SIZE, 1);
-			else
+			else if (!tx_q->tbs_avail)
 				stmmac_mode_init(priv, tx_q->dma_tx,
 						tx_q->dma_tx_phy, DMA_TX_SIZE, 0);
 		}
@@ -1392,6 +1397,8 @@  static int init_dma_tx_desc_rings(struct net_device *dev)
 			struct dma_desc *p;
 			if (priv->extend_desc)
 				p = &((tx_q->dma_etx + i)->basic);
+			else if (tx_q->tbs_avail)
+				p = &((tx_q->dma_entx + i)->basic);
 			else
 				p = tx_q->dma_tx + i;
 
@@ -1516,14 +1523,18 @@  static void free_dma_tx_desc_resources(struct stmmac_priv *priv)
 		dma_free_tx_skbufs(priv, queue);
 
 		/* Free DMA regions of consistent memory previously allocated */
-		if (!priv->extend_desc)
-			dma_free_coherent(priv->device,
-					  DMA_TX_SIZE * sizeof(struct dma_desc),
-					  tx_q->dma_tx, tx_q->dma_tx_phy);
-		else
+		if (priv->extend_desc)
 			dma_free_coherent(priv->device, DMA_TX_SIZE *
 					  sizeof(struct dma_extended_desc),
 					  tx_q->dma_etx, tx_q->dma_tx_phy);
+		else if (tx_q->tbs_avail)
+			dma_free_coherent(priv->device,
+					  DMA_TX_SIZE * sizeof(struct dma_edesc),
+					  tx_q->dma_entx, tx_q->dma_tx_phy);
+		else
+			dma_free_coherent(priv->device,
+					  DMA_TX_SIZE * sizeof(struct dma_desc),
+					  tx_q->dma_tx, tx_q->dma_tx_phy);
 
 		kfree(tx_q->tx_skbuff_dma);
 		kfree(tx_q->tx_skbuff);
@@ -1639,6 +1650,13 @@  static int alloc_dma_tx_desc_resources(struct stmmac_priv *priv)
 							   GFP_KERNEL);
 			if (!tx_q->dma_etx)
 				goto err_dma;
+		} else if (tx_q->tbs_avail) {
+			tx_q->dma_entx = dma_alloc_coherent(priv->device,
+							  DMA_TX_SIZE * sizeof(struct dma_edesc),
+							  &tx_q->dma_tx_phy,
+							  GFP_KERNEL);
+			if (!tx_q->dma_entx)
+				goto err_dma;
 		} else {
 			tx_q->dma_tx = dma_alloc_coherent(priv->device,
 							  DMA_TX_SIZE * sizeof(struct dma_desc),
@@ -1885,6 +1903,8 @@  static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue)
 
 		if (priv->extend_desc)
 			p = (struct dma_desc *)(tx_q->dma_etx + entry);
+		else if (tx_q->tbs_avail)
+			p = &tx_q->dma_entx[entry].basic;
 		else
 			p = tx_q->dma_tx + entry;
 
@@ -1993,6 +2013,9 @@  static void stmmac_tx_err(struct stmmac_priv *priv, u32 chan)
 		if (priv->extend_desc)
 			stmmac_init_tx_desc(priv, &tx_q->dma_etx[i].basic,
 					priv->mode, (i == DMA_TX_SIZE - 1));
+		else if (tx_q->tbs_avail)
+			stmmac_init_tx_desc(priv, &tx_q->dma_entx[i].basic,
+					priv->mode, (i == DMA_TX_SIZE - 1));
 		else
 			stmmac_init_tx_desc(priv, &tx_q->dma_tx[i],
 					priv->mode, (i == DMA_TX_SIZE - 1));
@@ -2632,6 +2655,13 @@  static int stmmac_hw_setup(struct net_device *dev, bool init_ptp)
 	if (priv->dma_cap.vlins)
 		stmmac_enable_vlan(priv, priv->hw, STMMAC_VLAN_INSERT);
 
+	/* TBS */
+	for (chan = 0; chan < tx_cnt; chan++) {
+		struct stmmac_tx_queue *tx_q = &priv->tx_queue[chan];
+
+		stmmac_enable_tbs(priv, priv->ioaddr, tx_q->tbs_avail, chan);
+	}
+
 	/* Start the ball rolling... */
 	stmmac_start_all_dma(priv);
 
@@ -2689,6 +2719,16 @@  static int stmmac_open(struct net_device *dev)
 
 	priv->rx_copybreak = STMMAC_RX_COPYBREAK;
 
+	/* Earlier check for TBS */
+	for (chan = 0; chan < priv->plat->tx_queues_to_use; chan++) {
+		struct stmmac_tx_queue *tx_q = &priv->tx_queue[chan];
+		int tbs_en = priv->plat->tx_queues_cfg[chan].tbs_en;
+
+		tx_q->tbs_avail = tbs_en;
+		if (stmmac_enable_tbs(priv, priv->ioaddr, tbs_en, chan))
+			tx_q->tbs_avail = 0;
+	}
+
 	ret = alloc_dma_desc_resources(priv);
 	if (ret < 0) {
 		netdev_err(priv->dev, "%s: DMA descriptors allocation failed\n",
@@ -2837,7 +2877,11 @@  static bool stmmac_vlan_insert(struct stmmac_priv *priv, struct sk_buff *skb,
 
 	tag = skb_vlan_tag_get(skb);
 
-	p = tx_q->dma_tx + tx_q->cur_tx;
+	if (tx_q->tbs_avail)
+		p = &tx_q->dma_entx[tx_q->cur_tx].basic;
+	else
+		p = &tx_q->dma_tx[tx_q->cur_tx];
+
 	if (stmmac_set_desc_vlan_tag(priv, p, tag, inner_tag, inner_type))
 		return false;
 
@@ -2872,7 +2916,11 @@  static void stmmac_tso_allocator(struct stmmac_priv *priv, dma_addr_t des,
 
 		tx_q->cur_tx = STMMAC_GET_ENTRY(tx_q->cur_tx, DMA_TX_SIZE);
 		WARN_ON(tx_q->tx_skbuff[tx_q->cur_tx]);
-		desc = tx_q->dma_tx + tx_q->cur_tx;
+
+		if (tx_q->tbs_avail)
+			desc = &tx_q->dma_entx[tx_q->cur_tx].basic;
+		else
+			desc = &tx_q->dma_tx[tx_q->cur_tx];
 
 		curr_addr = des + (total_len - tmp_len);
 		if (priv->dma_cap.addr64 <= 32)
@@ -2923,13 +2971,13 @@  static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct dma_desc *desc, *first, *mss_desc = NULL;
 	struct stmmac_priv *priv = netdev_priv(dev);
+	int desc_size, tmp_pay_len = 0, first_tx;
 	int nfrags = skb_shinfo(skb)->nr_frags;
 	u32 queue = skb_get_queue_mapping(skb);
 	unsigned int first_entry, tx_packets;
-	int tmp_pay_len = 0, first_tx;
 	struct stmmac_tx_queue *tx_q;
-	u8 proto_hdr_len, hdr;
 	bool has_vlan, set_ic;
+	u8 proto_hdr_len, hdr;
 	u32 pay_len, mss;
 	dma_addr_t des;
 	int i;
@@ -2966,7 +3014,11 @@  static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	/* set new MSS value if needed */
 	if (mss != tx_q->mss) {
-		mss_desc = tx_q->dma_tx + tx_q->cur_tx;
+		if (tx_q->tbs_avail)
+			mss_desc = &tx_q->dma_entx[tx_q->cur_tx].basic;
+		else
+			mss_desc = &tx_q->dma_tx[tx_q->cur_tx];
+
 		stmmac_set_mss(priv, mss_desc, mss);
 		tx_q->mss = mss;
 		tx_q->cur_tx = STMMAC_GET_ENTRY(tx_q->cur_tx, DMA_TX_SIZE);
@@ -2986,7 +3038,10 @@  static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
 	first_entry = tx_q->cur_tx;
 	WARN_ON(tx_q->tx_skbuff[first_entry]);
 
-	desc = tx_q->dma_tx + first_entry;
+	if (tx_q->tbs_avail)
+		desc = &tx_q->dma_entx[first_entry].basic;
+	else
+		desc = &tx_q->dma_tx[first_entry];
 	first = desc;
 
 	if (has_vlan)
@@ -3058,7 +3113,11 @@  static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
 		set_ic = false;
 
 	if (set_ic) {
-		desc = &tx_q->dma_tx[tx_q->cur_tx];
+		if (tx_q->tbs_avail)
+			desc = &tx_q->dma_entx[tx_q->cur_tx].basic;
+		else
+			desc = &tx_q->dma_tx[tx_q->cur_tx];
+
 		tx_q->tx_count_frames = 0;
 		stmmac_set_tx_ic(priv, desc);
 		priv->xstats.tx_set_ic_bit++;
@@ -3121,16 +3180,18 @@  static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
 		pr_info("%s: curr=%d dirty=%d f=%d, e=%d, f_p=%p, nfrags %d\n",
 			__func__, tx_q->cur_tx, tx_q->dirty_tx, first_entry,
 			tx_q->cur_tx, first, nfrags);
-
-		stmmac_display_ring(priv, (void *)tx_q->dma_tx, DMA_TX_SIZE, 0);
-
 		pr_info(">>> frame to be transmitted: ");
 		print_pkt(skb->data, skb_headlen(skb));
 	}
 
 	netdev_tx_sent_queue(netdev_get_tx_queue(dev, queue), skb->len);
 
-	tx_q->tx_tail_addr = tx_q->dma_tx_phy + (tx_q->cur_tx * sizeof(*desc));
+	if (tx_q->tbs_avail)
+		desc_size = sizeof(struct dma_edesc);
+	else
+		desc_size = sizeof(struct dma_desc);
+
+	tx_q->tx_tail_addr = tx_q->dma_tx_phy + (tx_q->cur_tx * desc_size);
 	stmmac_set_tx_tail_ptr(priv, priv->ioaddr, tx_q->tx_tail_addr, queue);
 	stmmac_tx_timer_arm(priv, queue);
 
@@ -3160,10 +3221,11 @@  static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 	u32 queue = skb_get_queue_mapping(skb);
 	int nfrags = skb_shinfo(skb)->nr_frags;
 	int gso = skb_shinfo(skb)->gso_type;
+	struct dma_edesc *tbs_desc = NULL;
+	int entry, desc_size, first_tx;
 	struct dma_desc *desc, *first;
 	struct stmmac_tx_queue *tx_q;
 	bool has_vlan, set_ic;
-	int entry, first_tx;
 	dma_addr_t des;
 
 	tx_q = &priv->tx_queue[queue];
@@ -3203,6 +3265,8 @@  static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	if (likely(priv->extend_desc))
 		desc = (struct dma_desc *)(tx_q->dma_etx + entry);
+	else if (tx_q->tbs_avail)
+		desc = &tx_q->dma_entx[entry].basic;
 	else
 		desc = tx_q->dma_tx + entry;
 
@@ -3232,6 +3296,8 @@  static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
 		if (likely(priv->extend_desc))
 			desc = (struct dma_desc *)(tx_q->dma_etx + entry);
+		else if (tx_q->tbs_avail)
+			desc = &tx_q->dma_entx[entry].basic;
 		else
 			desc = tx_q->dma_tx + entry;
 
@@ -3278,6 +3344,8 @@  static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 	if (set_ic) {
 		if (likely(priv->extend_desc))
 			desc = &tx_q->dma_etx[entry].basic;
+		else if (tx_q->tbs_avail)
+			desc = &tx_q->dma_entx[entry].basic;
 		else
 			desc = &tx_q->dma_tx[entry];
 
@@ -3295,20 +3363,11 @@  static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 	tx_q->cur_tx = entry;
 
 	if (netif_msg_pktdata(priv)) {
-		void *tx_head;
-
 		netdev_dbg(priv->dev,
 			   "%s: curr=%d dirty=%d f=%d, e=%d, first=%p, nfrags=%d",
 			   __func__, tx_q->cur_tx, tx_q->dirty_tx, first_entry,
 			   entry, first, nfrags);
 
-		if (priv->extend_desc)
-			tx_head = (void *)tx_q->dma_etx;
-		else
-			tx_head = (void *)tx_q->dma_tx;
-
-		stmmac_display_ring(priv, tx_head, DMA_TX_SIZE, false);
-
 		netdev_dbg(priv->dev, ">>> frame to be transmitted: ");
 		print_pkt(skb->data, skb->len);
 	}
@@ -3354,12 +3413,19 @@  static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
 		/* Prepare the first descriptor setting the OWN bit too */
 		stmmac_prepare_tx_desc(priv, first, 1, nopaged_len,
-				csum_insertion, priv->mode, 1, last_segment,
+				csum_insertion, priv->mode, 0, last_segment,
 				skb->len);
-	} else {
-		stmmac_set_tx_owner(priv, first);
 	}
 
+	if (tx_q->tbs_en) {
+		struct timespec64 ts = ns_to_timespec64(skb->tstamp);
+
+		tbs_desc = &tx_q->dma_entx[first_entry];
+		stmmac_set_desc_tbs(priv, tbs_desc, ts.tv_sec, ts.tv_nsec);
+	}
+
+	stmmac_set_tx_owner(priv, first);
+
 	/* The own bit must be the latest setting done when prepare the
 	 * descriptor and then barrier is needed to make sure that
 	 * all is coherent before granting the DMA engine.
@@ -3370,7 +3436,14 @@  static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	stmmac_enable_dma_transmission(priv, priv->ioaddr);
 
-	tx_q->tx_tail_addr = tx_q->dma_tx_phy + (tx_q->cur_tx * sizeof(*desc));
+	if (likely(priv->extend_desc))
+		desc_size = sizeof(struct dma_extended_desc);
+	else if (tx_q->tbs_avail)
+		desc_size = sizeof(struct dma_edesc);
+	else
+		desc_size = sizeof(struct dma_desc);
+
+	tx_q->tx_tail_addr = tx_q->dma_tx_phy + (tx_q->cur_tx * desc_size);
 	stmmac_set_tx_tail_ptr(priv, priv->ioaddr, tx_q->tx_tail_addr, queue);
 	stmmac_tx_timer_arm(priv, queue);
 
@@ -4193,7 +4266,7 @@  static int stmmac_rings_status_show(struct seq_file *seq, void *v)
 			seq_printf(seq, "Extended descriptor ring:\n");
 			sysfs_display_ring((void *)tx_q->dma_etx,
 					   DMA_TX_SIZE, 1, seq);
-		} else {
+		} else if (!tx_q->tbs_avail) {
 			seq_printf(seq, "Descriptor ring:\n");
 			sysfs_display_ring((void *)tx_q->dma_tx,
 					   DMA_TX_SIZE, 0, seq);
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index 0531afa9b21e..19190c609282 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -139,6 +139,7 @@  struct stmmac_txq_cfg {
 	u32 low_credit;
 	bool use_prio;
 	u32 prio;
+	int tbs_en;
 };
 
 struct plat_stmmacenet_data {