[PATCH net-next v2 0/7] stmmac: add XDP ZC support

[PATCH net-next v2 0/7] stmmac: add XDP ZC support

[Ong Boon Leong]

Hi,

This is the v2 patch series to add XDP ZC support to stmmac driver.

Summary of v2 patch change:-

6/7: fix synchronize_rcu() is called stmmac_disable_all_queues() that is
     used by ndo_setup_tc().

 ########################################################################

Continuous burst traffics are generated by pktgen script and in the midst
of each packet processing operation by xdpsock the following tc-loop.sh
script is looped continuously:-

 #!/bin/bash
 tc qdisc del dev eth0 parent root
 tc qdisc add dev eth0 ingress
 tc qdisc add dev eth0 root mqprio num_tc 4 map 0 1 2 3 0 0 0 0 0 0 0 0 0 0 0 0 queues 1@0 1@1 1@2 1@3 hw 0
 tc filter add dev eth0 parent ffff: protocol 802.1Q flower vlan_prio 0 hw_tc 0
 tc filter add dev eth0 parent ffff: protocol 802.1Q flower vlan_prio 1 hw_tc 1
 tc filter add dev eth0 parent ffff: protocol 802.1Q flower vlan_prio 2 hw_tc 2
 tc filter add dev eth0 parent ffff: protocol 802.1Q flower vlan_prio 3 hw_tc 3
 tc qdisc list dev eth0
 tc filter show dev eth0 ingress

 On different ssh terminal
 $ while true; do ./tc-loop.sh; sleep 1; done

The v2 patch series have been tested using the xdpsock app:
 $ ./xdpsock -i eth0 -l -z

From xdpsock poller pps report and dmesg, we don't find any warning
related to rcu and the only difference when the script is executed is
the pps rate drops momentarily.

 sock0@eth0:0 l2fwd xdp-drv
                   pps            pkts           1.00
rx                 436347         191361334
tx                 436411         191361334

 sock0@eth0:0 l2fwd xdp-drv
                   pps            pkts           1.00
rx                 254117         191615476
tx                 254053         191615412

 sock0@eth0:0 l2fwd xdp-drv
                   pps            pkts           1.00
rx                 466395         192081924
tx                 466395         192081860

 sock0@eth0:0 l2fwd xdp-drv
                   pps            pkts           1.00
rx                 287410         192369365
tx                 287474         192369365

 sock0@eth0:0 l2fwd xdp-drv
                   pps            pkts           1.00
rx                 395853         192765329
tx                 395789         192765265

 sock0@eth0:0 l2fwd xdp-drv
                   pps            pkts           1.00
rx                 466132         193231514
tx                 466132         193231450

 ########################################################################

Based on the above result, the fix looks promising. Appreciate that if
community can help to review the patch series and provide me feedback
for improvement.

Thanks,
Boon Leong

 ------------------------------------------------------------------------
 History of patch series as follow:-

 v1: https://patchwork.kernel.org/project/netdevbpf/list/?series=465747&state=*

 ------------------------------------------------------------------------

Ong Boon Leong (7):
  net: stmmac: rearrange RX buffer allocation and free functions
  net: stmmac: introduce dma_recycle_rx_skbufs for
    stmmac_reinit_rx_buffers
  net: stmmac: refactor stmmac_init_rx_buffers for
    stmmac_reinit_rx_buffers
  net: stmmac: rearrange RX and TX desc init into per-queue basis
  net: stmmac: Refactor __stmmac_xdp_run_prog for XDP ZC
  net: stmmac: Enable RX via AF_XDP zero-copy
  net: stmmac: Add TX via XDP zero-copy socket

 drivers/net/ethernet/stmicro/stmmac/stmmac.h  |   24 +-
 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 1718 +++++++++++++----
 .../net/ethernet/stmicro/stmmac/stmmac_xdp.c  |   95 +
 .../net/ethernet/stmicro/stmmac/stmmac_xdp.h  |    3 +
 4 files changed, 1411 insertions(+), 429 deletions(-)

-- 
2.25.1

[PATCH net-next v2 1/7] net: stmmac: rearrange RX buffer allocation and free functions

[Ong Boon Leong]

This patch restructures the per RX queue buffer allocation from page_pool
to stmmac_alloc_rx_buffers().

We also rearrange dma_free_rx_skbufs() so that it can be used in
init_dma_rx_desc_rings() during freeing of RX buffer in the event of
page_pool allocation failure to replace the more efficient method earlier.
The replacement is needed to make the RX buffer alloc and free method
scalable to XDP ZC xsk_pool alloc and free later.

Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
---
 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 84 +++++++++++--------
 1 file changed, 47 insertions(+), 37 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 77285646c5fc..f6d3d26ce45a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1475,6 +1475,43 @@ static void stmmac_free_tx_buffer(struct stmmac_priv *priv, u32 queue, int i)
 	tx_q->tx_skbuff_dma[i].map_as_page = false;
 }
 
+/**
+ * dma_free_rx_skbufs - free RX dma buffers
+ * @priv: private structure
+ * @queue: RX queue index
+ */
+static void dma_free_rx_skbufs(struct stmmac_priv *priv, u32 queue)
+{
+	int i;
+
+	for (i = 0; i < priv->dma_rx_size; i++)
+		stmmac_free_rx_buffer(priv, queue, i);
+}
+
+static int stmmac_alloc_rx_buffers(struct stmmac_priv *priv, u32 queue,
+				   gfp_t flags)
+{
+	struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
+	int i;
+
+	for (i = 0; i < priv->dma_rx_size; i++) {
+		struct dma_desc *p;
+		int ret;
+
+		if (priv->extend_desc)
+			p = &((rx_q->dma_erx + i)->basic);
+		else
+			p = rx_q->dma_rx + i;
+
+		ret = stmmac_init_rx_buffers(priv, p, i, flags,
+					     queue);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 /**
  * stmmac_reinit_rx_buffers - reinit the RX descriptor buffer.
  * @priv: driver private structure
@@ -1547,15 +1584,14 @@ static void stmmac_reinit_rx_buffers(struct stmmac_priv *priv)
 	return;
 
 err_reinit_rx_buffers:
-	do {
-		while (--i >= 0)
-			stmmac_free_rx_buffer(priv, queue, i);
+	while (queue >= 0) {
+		dma_free_rx_skbufs(priv, queue);
 
 		if (queue == 0)
 			break;
 
-		i = priv->dma_rx_size;
-	} while (queue-- > 0);
+		queue--;
+	}
 }
 
 /**
@@ -1572,7 +1608,6 @@ static int init_dma_rx_desc_rings(struct net_device *dev, gfp_t flags)
 	u32 rx_count = priv->plat->rx_queues_to_use;
 	int ret = -ENOMEM;
 	int queue;
-	int i;
 
 	/* RX INITIALIZATION */
 	netif_dbg(priv, probe, priv->dev,
@@ -1580,7 +1615,7 @@ static int init_dma_rx_desc_rings(struct net_device *dev, gfp_t flags)
 
 	for (queue = 0; queue < rx_count; queue++) {
 		struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
-		int ret;
+
 
 		netif_dbg(priv, probe, priv->dev,
 			  "(%s) dma_rx_phy=0x%08x\n", __func__,
@@ -1596,22 +1631,12 @@ static int init_dma_rx_desc_rings(struct net_device *dev, gfp_t flags)
 			    "Register MEM_TYPE_PAGE_POOL RxQ-%d\n",
 			    rx_q->queue_index);
 
-		for (i = 0; i < priv->dma_rx_size; i++) {
-			struct dma_desc *p;
-
-			if (priv->extend_desc)
-				p = &((rx_q->dma_erx + i)->basic);
-			else
-				p = rx_q->dma_rx + i;
-
-			ret = stmmac_init_rx_buffers(priv, p, i, flags,
-						     queue);
-			if (ret)
-				goto err_init_rx_buffers;
-		}
+		ret = stmmac_alloc_rx_buffers(priv, queue, flags);
+		if (ret < 0)
+			goto err_init_rx_buffers;
 
 		rx_q->cur_rx = 0;
-		rx_q->dirty_rx = (unsigned int)(i - priv->dma_rx_size);
+		rx_q->dirty_rx = 0;
 
 		/* Setup the chained descriptor addresses */
 		if (priv->mode == STMMAC_CHAIN_MODE) {
@@ -1630,13 +1655,11 @@ static int init_dma_rx_desc_rings(struct net_device *dev, gfp_t flags)
 
 err_init_rx_buffers:
 	while (queue >= 0) {
-		while (--i >= 0)
-			stmmac_free_rx_buffer(priv, queue, i);
+		dma_free_rx_skbufs(priv, queue);
 
 		if (queue == 0)
 			break;
 
-		i = priv->dma_rx_size;
 		queue--;
 	}
 
@@ -1731,19 +1754,6 @@ static int init_dma_desc_rings(struct net_device *dev, gfp_t flags)
 	return ret;
 }
 
-/**
- * dma_free_rx_skbufs - free RX dma buffers
- * @priv: private structure
- * @queue: RX queue index
- */
-static void dma_free_rx_skbufs(struct stmmac_priv *priv, u32 queue)
-{
-	int i;
-
-	for (i = 0; i < priv->dma_rx_size; i++)
-		stmmac_free_rx_buffer(priv, queue, i);
-}
-
 /**
  * dma_free_tx_skbufs - free TX dma buffers
  * @priv: private structure
-- 
2.25.1

[PATCH net-next v2 2/7] net: stmmac: introduce dma_recycle_rx_skbufs for stmmac_reinit_rx_buffers

[Ong Boon Leong]

Rearrange RX buffer page_pool recycling logics into dma_recycle_rx_skbufs,
so that we prepare stmmac_reinit_rx_buffers() for XSK pool expansion.

Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
---
 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 44 ++++++++++++-------
 1 file changed, 27 insertions(+), 17 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index f6d3d26ce45a..a6c3414fd231 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1512,6 +1512,31 @@ static int stmmac_alloc_rx_buffers(struct stmmac_priv *priv, u32 queue,
 	return 0;
 }
 
+/**
+ * dma_recycle_rx_skbufs - recycle RX dma buffers
+ * @priv: private structure
+ * @queue: RX queue index
+ */
+static void dma_recycle_rx_skbufs(struct stmmac_priv *priv, u32 queue)
+{
+	struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
+	int i;
+
+	for (i = 0; i < priv->dma_rx_size; i++) {
+		struct stmmac_rx_buffer *buf = &rx_q->buf_pool[i];
+
+		if (buf->page) {
+			page_pool_recycle_direct(rx_q->page_pool, buf->page);
+			buf->page = NULL;
+		}
+
+		if (priv->sph && buf->sec_page) {
+			page_pool_recycle_direct(rx_q->page_pool, buf->sec_page);
+			buf->sec_page = NULL;
+		}
+	}
+}
+
 /**
  * stmmac_reinit_rx_buffers - reinit the RX descriptor buffer.
  * @priv: driver private structure
@@ -1524,23 +1549,8 @@ static void stmmac_reinit_rx_buffers(struct stmmac_priv *priv)
 	u32 queue;
 	int i;
 
-	for (queue = 0; queue < rx_count; queue++) {
-		struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
-
-		for (i = 0; i < priv->dma_rx_size; i++) {
-			struct stmmac_rx_buffer *buf = &rx_q->buf_pool[i];
-
-			if (buf->page) {
-				page_pool_recycle_direct(rx_q->page_pool, buf->page);
-				buf->page = NULL;
-			}
-
-			if (priv->sph && buf->sec_page) {
-				page_pool_recycle_direct(rx_q->page_pool, buf->sec_page);
-				buf->sec_page = NULL;
-			}
-		}
-	}
+	for (queue = 0; queue < rx_count; queue++)
+		dma_recycle_rx_skbufs(priv, queue);
 
 	for (queue = 0; queue < rx_count; queue++) {
 		struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
-- 
2.25.1

[PATCH net-next v2 3/7] net: stmmac: refactor stmmac_init_rx_buffers for stmmac_reinit_rx_buffers

[Ong Boon Leong]

The per-queue RX buffer allocation in stmmac_reinit_rx_buffers() can be
made to use stmmac_alloc_rx_buffers() by merging the page_pool alloc
checks for "buf->page" and "buf->sec_page" in stmmac_init_rx_buffers().

This is in preparation for XSK pool allocation later.

Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
---
 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 378 +++++++++---------
 1 file changed, 189 insertions(+), 189 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index a6c3414fd231..7e889ef0c7b5 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1388,12 +1388,14 @@ static int stmmac_init_rx_buffers(struct stmmac_priv *priv, struct dma_desc *p,
 	struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
 	struct stmmac_rx_buffer *buf = &rx_q->buf_pool[i];
 
-	buf->page = page_pool_dev_alloc_pages(rx_q->page_pool);
-	if (!buf->page)
-		return -ENOMEM;
-	buf->page_offset = stmmac_rx_offset(priv);
+	if (!buf->page) {
+		buf->page = page_pool_dev_alloc_pages(rx_q->page_pool);
+		if (!buf->page)
+			return -ENOMEM;
+		buf->page_offset = stmmac_rx_offset(priv);
+	}
 
-	if (priv->sph) {
+	if (priv->sph && !buf->sec_page) {
 		buf->sec_page = page_pool_dev_alloc_pages(rx_q->page_pool);
 		if (!buf->sec_page)
 			return -ENOMEM;
@@ -1547,48 +1549,16 @@ static void stmmac_reinit_rx_buffers(struct stmmac_priv *priv)
 {
 	u32 rx_count = priv->plat->rx_queues_to_use;
 	u32 queue;
-	int i;
 
 	for (queue = 0; queue < rx_count; queue++)
 		dma_recycle_rx_skbufs(priv, queue);
 
 	for (queue = 0; queue < rx_count; queue++) {
-		struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
-
-		for (i = 0; i < priv->dma_rx_size; i++) {
-			struct stmmac_rx_buffer *buf = &rx_q->buf_pool[i];
-			struct dma_desc *p;
-
-			if (priv->extend_desc)
-				p = &((rx_q->dma_erx + i)->basic);
-			else
-				p = rx_q->dma_rx + i;
-
-			if (!buf->page) {
-				buf->page = page_pool_dev_alloc_pages(rx_q->page_pool);
-				if (!buf->page)
-					goto err_reinit_rx_buffers;
-
-				buf->addr = page_pool_get_dma_addr(buf->page) +
-					    buf->page_offset;
-			}
-
-			if (priv->sph && !buf->sec_page) {
-				buf->sec_page = page_pool_dev_alloc_pages(rx_q->page_pool);
-				if (!buf->sec_page)
-					goto err_reinit_rx_buffers;
-
-				buf->sec_addr = page_pool_get_dma_addr(buf->sec_page);
-			}
+		int ret;
 
-			stmmac_set_desc_addr(priv, p, buf->addr);
-			if (priv->sph)
-				stmmac_set_desc_sec_addr(priv, p, buf->sec_addr, true);
-			else
-				stmmac_set_desc_sec_addr(priv, p, buf->sec_addr, false);
-			if (priv->dma_buf_sz == BUF_SIZE_16KiB)
-				stmmac_init_desc3(priv, p);
-		}
+		ret = stmmac_alloc_rx_buffers(priv, queue, GFP_KERNEL);
+		if (ret < 0)
+			goto err_reinit_rx_buffers;
 	}
 
 	return;
@@ -1791,153 +1761,173 @@ static void stmmac_free_tx_skbufs(struct stmmac_priv *priv)
 }
 
 /**
- * free_dma_rx_desc_resources - free RX dma desc resources
+ * __free_dma_rx_desc_resources - free RX dma desc resources (per queue)
  * @priv: private structure
+ * @queue: RX queue index
  */
-static void free_dma_rx_desc_resources(struct stmmac_priv *priv)
+static void __free_dma_rx_desc_resources(struct stmmac_priv *priv, u32 queue)
 {
-	u32 rx_count = priv->plat->rx_queues_to_use;
-	u32 queue;
+	struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
 
-	/* Free RX queue resources */
-	for (queue = 0; queue < rx_count; queue++) {
-		struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
+	/* Release the DMA RX socket buffers */
+	dma_free_rx_skbufs(priv, queue);
 
-		/* Release the DMA RX socket buffers */
-		dma_free_rx_skbufs(priv, queue);
+	/* Free DMA regions of consistent memory previously allocated */
+	if (!priv->extend_desc)
+		dma_free_coherent(priv->device, priv->dma_rx_size *
+				  sizeof(struct dma_desc),
+				  rx_q->dma_rx, rx_q->dma_rx_phy);
+	else
+		dma_free_coherent(priv->device, priv->dma_rx_size *
+				  sizeof(struct dma_extended_desc),
+				  rx_q->dma_erx, rx_q->dma_rx_phy);
 
-		/* Free DMA regions of consistent memory previously allocated */
-		if (!priv->extend_desc)
-			dma_free_coherent(priv->device, priv->dma_rx_size *
-					  sizeof(struct dma_desc),
-					  rx_q->dma_rx, rx_q->dma_rx_phy);
-		else
-			dma_free_coherent(priv->device, priv->dma_rx_size *
-					  sizeof(struct dma_extended_desc),
-					  rx_q->dma_erx, rx_q->dma_rx_phy);
+	if (xdp_rxq_info_is_reg(&rx_q->xdp_rxq))
+		xdp_rxq_info_unreg(&rx_q->xdp_rxq);
 
-		if (xdp_rxq_info_is_reg(&rx_q->xdp_rxq))
-			xdp_rxq_info_unreg(&rx_q->xdp_rxq);
+	kfree(rx_q->buf_pool);
+	if (rx_q->page_pool)
+		page_pool_destroy(rx_q->page_pool);
+}
 
-		kfree(rx_q->buf_pool);
-		if (rx_q->page_pool)
-			page_pool_destroy(rx_q->page_pool);
-	}
+static void free_dma_rx_desc_resources(struct stmmac_priv *priv)
+{
+	u32 rx_count = priv->plat->rx_queues_to_use;
+	u32 queue;
+
+	/* Free RX queue resources */
+	for (queue = 0; queue < rx_count; queue++)
+		__free_dma_rx_desc_resources(priv, queue);
 }
 
 /**
- * free_dma_tx_desc_resources - free TX dma desc resources
+ * __free_dma_tx_desc_resources - free TX dma desc resources (per queue)
  * @priv: private structure
+ * @queue: TX queue index
  */
-static void free_dma_tx_desc_resources(struct stmmac_priv *priv)
+static void __free_dma_tx_desc_resources(struct stmmac_priv *priv, u32 queue)
 {
-	u32 tx_count = priv->plat->tx_queues_to_use;
-	u32 queue;
+	struct stmmac_tx_queue *tx_q = &priv->tx_queue[queue];
+	size_t size;
+	void *addr;
 
-	/* Free TX queue resources */
-	for (queue = 0; queue < tx_count; queue++) {
-		struct stmmac_tx_queue *tx_q = &priv->tx_queue[queue];
-		size_t size;
-		void *addr;
+	/* Release the DMA TX socket buffers */
+	dma_free_tx_skbufs(priv, queue);
+
+	if (priv->extend_desc) {
+		size = sizeof(struct dma_extended_desc);
+		addr = tx_q->dma_etx;
+	} else if (tx_q->tbs & STMMAC_TBS_AVAIL) {
+		size = sizeof(struct dma_edesc);
+		addr = tx_q->dma_entx;
+	} else {
+		size = sizeof(struct dma_desc);
+		addr = tx_q->dma_tx;
+	}
 
-		/* Release the DMA TX socket buffers */
-		dma_free_tx_skbufs(priv, queue);
+	size *= priv->dma_tx_size;
 
-		if (priv->extend_desc) {
-			size = sizeof(struct dma_extended_desc);
-			addr = tx_q->dma_etx;
-		} else if (tx_q->tbs & STMMAC_TBS_AVAIL) {
-			size = sizeof(struct dma_edesc);
-			addr = tx_q->dma_entx;
-		} else {
-			size = sizeof(struct dma_desc);
-			addr = tx_q->dma_tx;
-		}
+	dma_free_coherent(priv->device, size, addr, tx_q->dma_tx_phy);
 
-		size *= priv->dma_tx_size;
+	kfree(tx_q->tx_skbuff_dma);
+	kfree(tx_q->tx_skbuff);
+}
 
-		dma_free_coherent(priv->device, size, addr, tx_q->dma_tx_phy);
+static void free_dma_tx_desc_resources(struct stmmac_priv *priv)
+{
+	u32 tx_count = priv->plat->tx_queues_to_use;
+	u32 queue;
 
-		kfree(tx_q->tx_skbuff_dma);
-		kfree(tx_q->tx_skbuff);
-	}
+	/* Free TX queue resources */
+	for (queue = 0; queue < tx_count; queue++)
+		__free_dma_tx_desc_resources(priv, queue);
 }
 
 /**
- * alloc_dma_rx_desc_resources - alloc RX resources.
+ * __alloc_dma_rx_desc_resources - alloc RX resources (per queue).
  * @priv: private structure
+ * @queue: RX queue index
  * Description: according to which descriptor can be used (extend or basic)
  * this function allocates the resources for TX and RX paths. In case of
  * reception, for example, it pre-allocated the RX socket buffer in order to
  * allow zero-copy mechanism.
  */
-static int alloc_dma_rx_desc_resources(struct stmmac_priv *priv)
+static int __alloc_dma_rx_desc_resources(struct stmmac_priv *priv, u32 queue)
 {
+	struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
+	struct stmmac_channel *ch = &priv->channel[queue];
 	bool xdp_prog = stmmac_xdp_is_enabled(priv);
-	u32 rx_count = priv->plat->rx_queues_to_use;
-	int ret = -ENOMEM;
-	u32 queue;
+	struct page_pool_params pp_params = { 0 };
+	unsigned int num_pages;
+	int ret;
 
-	/* RX queues buffers and DMA */
-	for (queue = 0; queue < rx_count; queue++) {
-		struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
-		struct stmmac_channel *ch = &priv->channel[queue];
-		struct page_pool_params pp_params = { 0 };
-		unsigned int num_pages;
-		int ret;
+	rx_q->queue_index = queue;
+	rx_q->priv_data = priv;
+
+	pp_params.flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV;
+	pp_params.pool_size = priv->dma_rx_size;
+	num_pages = DIV_ROUND_UP(priv->dma_buf_sz, PAGE_SIZE);
+	pp_params.order = ilog2(num_pages);
+	pp_params.nid = dev_to_node(priv->device);
+	pp_params.dev = priv->device;
+	pp_params.dma_dir = xdp_prog ? DMA_BIDIRECTIONAL : DMA_FROM_DEVICE;
+	pp_params.offset = stmmac_rx_offset(priv);
+	pp_params.max_len = STMMAC_MAX_RX_BUF_SIZE(num_pages);
+
+	rx_q->page_pool = page_pool_create(&pp_params);
+	if (IS_ERR(rx_q->page_pool)) {
+		ret = PTR_ERR(rx_q->page_pool);
+		rx_q->page_pool = NULL;
+		return ret;
+	}
 
-		rx_q->queue_index = queue;
-		rx_q->priv_data = priv;
-
-		pp_params.flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV;
-		pp_params.pool_size = priv->dma_rx_size;
-		num_pages = DIV_ROUND_UP(priv->dma_buf_sz, PAGE_SIZE);
-		pp_params.order = ilog2(num_pages);
-		pp_params.nid = dev_to_node(priv->device);
-		pp_params.dev = priv->device;
-		pp_params.dma_dir = xdp_prog ? DMA_BIDIRECTIONAL : DMA_FROM_DEVICE;
-		pp_params.offset = stmmac_rx_offset(priv);
-		pp_params.max_len = STMMAC_MAX_RX_BUF_SIZE(num_pages);
-
-		rx_q->page_pool = page_pool_create(&pp_params);
-		if (IS_ERR(rx_q->page_pool)) {
-			ret = PTR_ERR(rx_q->page_pool);
-			rx_q->page_pool = NULL;
-			goto err_dma;
-		}
+	rx_q->buf_pool = kcalloc(priv->dma_rx_size,
+				 sizeof(*rx_q->buf_pool),
+				 GFP_KERNEL);
+	if (!rx_q->buf_pool)
+		return -ENOMEM;
 
-		rx_q->buf_pool = kcalloc(priv->dma_rx_size,
-					 sizeof(*rx_q->buf_pool),
-					 GFP_KERNEL);
-		if (!rx_q->buf_pool)
-			goto err_dma;
+	if (priv->extend_desc) {
+		rx_q->dma_erx = dma_alloc_coherent(priv->device,
+						   priv->dma_rx_size *
+						   sizeof(struct dma_extended_desc),
+						   &rx_q->dma_rx_phy,
+						   GFP_KERNEL);
+		if (!rx_q->dma_erx)
+			return -ENOMEM;
 
-		if (priv->extend_desc) {
-			rx_q->dma_erx = dma_alloc_coherent(priv->device,
-							   priv->dma_rx_size *
-							   sizeof(struct dma_extended_desc),
-							   &rx_q->dma_rx_phy,
-							   GFP_KERNEL);
-			if (!rx_q->dma_erx)
-				goto err_dma;
+	} else {
+		rx_q->dma_rx = dma_alloc_coherent(priv->device,
+						  priv->dma_rx_size *
+						  sizeof(struct dma_desc),
+						  &rx_q->dma_rx_phy,
+						  GFP_KERNEL);
+		if (!rx_q->dma_rx)
+			return -ENOMEM;
+	}
 
-		} else {
-			rx_q->dma_rx = dma_alloc_coherent(priv->device,
-							  priv->dma_rx_size *
-							  sizeof(struct dma_desc),
-							  &rx_q->dma_rx_phy,
-							  GFP_KERNEL);
-			if (!rx_q->dma_rx)
-				goto err_dma;
-		}
+	ret = xdp_rxq_info_reg(&rx_q->xdp_rxq, priv->dev,
+			       rx_q->queue_index,
+			       ch->rx_napi.napi_id);
+	if (ret) {
+		netdev_err(priv->dev, "Failed to register xdp rxq info\n");
+		return -EINVAL;
+	}
 
-		ret = xdp_rxq_info_reg(&rx_q->xdp_rxq, priv->dev,
-				       rx_q->queue_index,
-				       ch->rx_napi.napi_id);
-		if (ret) {
-			netdev_err(priv->dev, "Failed to register xdp rxq info\n");
+	return 0;
+}
+
+static int alloc_dma_rx_desc_resources(struct stmmac_priv *priv)
+{
+	u32 rx_count = priv->plat->rx_queues_to_use;
+	u32 queue;
+	int ret;
+
+	/* RX queues buffers and DMA */
+	for (queue = 0; queue < rx_count; queue++) {
+		ret = __alloc_dma_rx_desc_resources(priv, queue);
+		if (ret)
 			goto err_dma;
-		}
 	}
 
 	return 0;
@@ -1949,60 +1939,70 @@ static int alloc_dma_rx_desc_resources(struct stmmac_priv *priv)
 }
 
 /**
- * alloc_dma_tx_desc_resources - alloc TX resources.
+ * __alloc_dma_tx_desc_resources - alloc TX resources (per queue).
  * @priv: private structure
+ * @queue: TX queue index
  * Description: according to which descriptor can be used (extend or basic)
  * this function allocates the resources for TX and RX paths. In case of
  * reception, for example, it pre-allocated the RX socket buffer in order to
  * allow zero-copy mechanism.
  */
-static int alloc_dma_tx_desc_resources(struct stmmac_priv *priv)
+static int __alloc_dma_tx_desc_resources(struct stmmac_priv *priv, u32 queue)
 {
-	u32 tx_count = priv->plat->tx_queues_to_use;
-	int ret = -ENOMEM;
-	u32 queue;
+	struct stmmac_tx_queue *tx_q = &priv->tx_queue[queue];
+	size_t size;
+	void *addr;
 
-	/* TX queues buffers and DMA */
-	for (queue = 0; queue < tx_count; queue++) {
-		struct stmmac_tx_queue *tx_q = &priv->tx_queue[queue];
-		size_t size;
-		void *addr;
+	tx_q->queue_index = queue;
+	tx_q->priv_data = priv;
 
-		tx_q->queue_index = queue;
-		tx_q->priv_data = priv;
+	tx_q->tx_skbuff_dma = kcalloc(priv->dma_tx_size,
+				      sizeof(*tx_q->tx_skbuff_dma),
+				      GFP_KERNEL);
+	if (!tx_q->tx_skbuff_dma)
+		return -ENOMEM;
 
-		tx_q->tx_skbuff_dma = kcalloc(priv->dma_tx_size,
-					      sizeof(*tx_q->tx_skbuff_dma),
-					      GFP_KERNEL);
-		if (!tx_q->tx_skbuff_dma)
-			goto err_dma;
+	tx_q->tx_skbuff = kcalloc(priv->dma_tx_size,
+				  sizeof(struct sk_buff *),
+				  GFP_KERNEL);
+	if (!tx_q->tx_skbuff)
+		return -ENOMEM;
 
-		tx_q->tx_skbuff = kcalloc(priv->dma_tx_size,
-					  sizeof(struct sk_buff *),
-					  GFP_KERNEL);
-		if (!tx_q->tx_skbuff)
-			goto err_dma;
+	if (priv->extend_desc)
+		size = sizeof(struct dma_extended_desc);
+	else if (tx_q->tbs & STMMAC_TBS_AVAIL)
+		size = sizeof(struct dma_edesc);
+	else
+		size = sizeof(struct dma_desc);
 
-		if (priv->extend_desc)
-			size = sizeof(struct dma_extended_desc);
-		else if (tx_q->tbs & STMMAC_TBS_AVAIL)
-			size = sizeof(struct dma_edesc);
-		else
-			size = sizeof(struct dma_desc);
+	size *= priv->dma_tx_size;
 
-		size *= priv->dma_tx_size;
+	addr = dma_alloc_coherent(priv->device, size,
+				  &tx_q->dma_tx_phy, GFP_KERNEL);
+	if (!addr)
+		return -ENOMEM;
 
-		addr = dma_alloc_coherent(priv->device, size,
-					  &tx_q->dma_tx_phy, GFP_KERNEL);
-		if (!addr)
-			goto err_dma;
+	if (priv->extend_desc)
+		tx_q->dma_etx = addr;
+	else if (tx_q->tbs & STMMAC_TBS_AVAIL)
+		tx_q->dma_entx = addr;
+	else
+		tx_q->dma_tx = addr;
 
-		if (priv->extend_desc)
-			tx_q->dma_etx = addr;
-		else if (tx_q->tbs & STMMAC_TBS_AVAIL)
-			tx_q->dma_entx = addr;
-		else
-			tx_q->dma_tx = addr;
+	return 0;
+}
+
+static int alloc_dma_tx_desc_resources(struct stmmac_priv *priv)
+{
+	u32 tx_count = priv->plat->tx_queues_to_use;
+	u32 queue;
+	int ret;
+
+	/* TX queues buffers and DMA */
+	for (queue = 0; queue < tx_count; queue++) {
+		ret = __alloc_dma_tx_desc_resources(priv, queue);
+		if (ret)
+			goto err_dma;
 	}
 
 	return 0;
-- 
2.25.1

[PATCH net-next v2 4/7] net: stmmac: rearrange RX and TX desc init into per-queue basis

[Ong Boon Leong]

Below functions are made to be per-queue in preparation of XDP ZC:

 __init_dma_rx_desc_rings(struct stmmac_priv *priv, u32 queue, gfp_t flags)
 __init_dma_tx_desc_rings(struct stmmac_priv *priv, u32 queue)

The original functions below are stay maintained for all queue usage:

 init_dma_rx_desc_rings(struct net_device *dev, gfp_t flags)
 init_dma_tx_desc_rings(struct net_device *dev)

Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
---
 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 180 ++++++++++--------
 1 file changed, 100 insertions(+), 80 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 7e889ef0c7b5..0804674e628e 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1575,60 +1575,70 @@ static void stmmac_reinit_rx_buffers(struct stmmac_priv *priv)
 }
 
 /**
- * init_dma_rx_desc_rings - init the RX descriptor rings
- * @dev: net device structure
+ * __init_dma_rx_desc_rings - init the RX descriptor ring (per queue)
+ * @priv: driver private structure
+ * @queue: RX queue index
  * @flags: gfp flag.
  * Description: this function initializes the DMA RX descriptors
  * and allocates the socket buffers. It supports the chained and ring
  * modes.
  */
-static int init_dma_rx_desc_rings(struct net_device *dev, gfp_t flags)
+static int __init_dma_rx_desc_rings(struct stmmac_priv *priv, u32 queue, gfp_t flags)
 {
-	struct stmmac_priv *priv = netdev_priv(dev);
-	u32 rx_count = priv->plat->rx_queues_to_use;
-	int ret = -ENOMEM;
-	int queue;
+	struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
+	int ret;
 
-	/* RX INITIALIZATION */
 	netif_dbg(priv, probe, priv->dev,
-		  "SKB addresses:\nskb\t\tskb data\tdma data\n");
+		  "(%s) dma_rx_phy=0x%08x\n", __func__,
+		  (u32)rx_q->dma_rx_phy);
 
-	for (queue = 0; queue < rx_count; queue++) {
-		struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
+	stmmac_clear_rx_descriptors(priv, queue);
 
+	WARN_ON(xdp_rxq_info_reg_mem_model(&rx_q->xdp_rxq,
+					   MEM_TYPE_PAGE_POOL,
+					   rx_q->page_pool));
 
-		netif_dbg(priv, probe, priv->dev,
-			  "(%s) dma_rx_phy=0x%08x\n", __func__,
-			  (u32)rx_q->dma_rx_phy);
+	netdev_info(priv->dev,
+		    "Register MEM_TYPE_PAGE_POOL RxQ-%d\n",
+		    rx_q->queue_index);
 
-		stmmac_clear_rx_descriptors(priv, queue);
+	ret = stmmac_alloc_rx_buffers(priv, queue, flags);
+	if (ret < 0)
+		return -ENOMEM;
 
-		WARN_ON(xdp_rxq_info_reg_mem_model(&rx_q->xdp_rxq,
-						   MEM_TYPE_PAGE_POOL,
-						   rx_q->page_pool));
+	rx_q->cur_rx = 0;
+	rx_q->dirty_rx = 0;
 
-		netdev_info(priv->dev,
-			    "Register MEM_TYPE_PAGE_POOL RxQ-%d\n",
-			    rx_q->queue_index);
+	/* Setup the chained descriptor addresses */
+	if (priv->mode == STMMAC_CHAIN_MODE) {
+		if (priv->extend_desc)
+			stmmac_mode_init(priv, rx_q->dma_erx,
+					 rx_q->dma_rx_phy,
+					 priv->dma_rx_size, 1);
+		else
+			stmmac_mode_init(priv, rx_q->dma_rx,
+					 rx_q->dma_rx_phy,
+					 priv->dma_rx_size, 0);
+	}
 
-		ret = stmmac_alloc_rx_buffers(priv, queue, flags);
-		if (ret < 0)
-			goto err_init_rx_buffers;
+	return 0;
+}
 
-		rx_q->cur_rx = 0;
-		rx_q->dirty_rx = 0;
+static int init_dma_rx_desc_rings(struct net_device *dev, gfp_t flags)
+{
+	struct stmmac_priv *priv = netdev_priv(dev);
+	u32 rx_count = priv->plat->rx_queues_to_use;
+	u32 queue;
+	int ret;
 
-		/* Setup the chained descriptor addresses */
-		if (priv->mode == STMMAC_CHAIN_MODE) {
-			if (priv->extend_desc)
-				stmmac_mode_init(priv, rx_q->dma_erx,
-						 rx_q->dma_rx_phy,
-						 priv->dma_rx_size, 1);
-			else
-				stmmac_mode_init(priv, rx_q->dma_rx,
-						 rx_q->dma_rx_phy,
-						 priv->dma_rx_size, 0);
-		}
+	/* RX INITIALIZATION */
+	netif_dbg(priv, probe, priv->dev,
+		  "SKB addresses:\nskb\t\tskb data\tdma data\n");
+
+	for (queue = 0; queue < rx_count; queue++) {
+		ret = __init_dma_rx_desc_rings(priv, queue, flags);
+		if (ret)
+			goto err_init_rx_buffers;
 	}
 
 	return 0;
@@ -1647,63 +1657,73 @@ static int init_dma_rx_desc_rings(struct net_device *dev, gfp_t flags)
 }
 
 /**
- * init_dma_tx_desc_rings - init the TX descriptor rings
- * @dev: net device structure.
+ * __init_dma_tx_desc_rings - init the TX descriptor ring (per queue)
+ * @priv: driver private structure
+ * @queue : TX queue index
  * Description: this function initializes the DMA TX descriptors
  * and allocates the socket buffers. It supports the chained and ring
  * modes.
  */
-static int init_dma_tx_desc_rings(struct net_device *dev)
+static int __init_dma_tx_desc_rings(struct stmmac_priv *priv, u32 queue)
 {
-	struct stmmac_priv *priv = netdev_priv(dev);
-	u32 tx_queue_cnt = priv->plat->tx_queues_to_use;
-	u32 queue;
+	struct stmmac_tx_queue *tx_q = &priv->tx_queue[queue];
 	int i;
 
-	for (queue = 0; queue < tx_queue_cnt; queue++) {
-		struct stmmac_tx_queue *tx_q = &priv->tx_queue[queue];
-
-		netif_dbg(priv, probe, priv->dev,
-			  "(%s) dma_tx_phy=0x%08x\n", __func__,
-			 (u32)tx_q->dma_tx_phy);
-
-		/* Setup the chained descriptor addresses */
-		if (priv->mode == STMMAC_CHAIN_MODE) {
-			if (priv->extend_desc)
-				stmmac_mode_init(priv, tx_q->dma_etx,
-						 tx_q->dma_tx_phy,
-						 priv->dma_tx_size, 1);
-			else if (!(tx_q->tbs & STMMAC_TBS_AVAIL))
-				stmmac_mode_init(priv, tx_q->dma_tx,
-						 tx_q->dma_tx_phy,
-						 priv->dma_tx_size, 0);
-		}
+	netif_dbg(priv, probe, priv->dev,
+		  "(%s) dma_tx_phy=0x%08x\n", __func__,
+		  (u32)tx_q->dma_tx_phy);
 
-		for (i = 0; i < priv->dma_tx_size; i++) {
-			struct dma_desc *p;
-			if (priv->extend_desc)
-				p = &((tx_q->dma_etx + i)->basic);
-			else if (tx_q->tbs & STMMAC_TBS_AVAIL)
-				p = &((tx_q->dma_entx + i)->basic);
-			else
-				p = tx_q->dma_tx + i;
+	/* Setup the chained descriptor addresses */
+	if (priv->mode == STMMAC_CHAIN_MODE) {
+		if (priv->extend_desc)
+			stmmac_mode_init(priv, tx_q->dma_etx,
+					 tx_q->dma_tx_phy,
+					 priv->dma_tx_size, 1);
+		else if (!(tx_q->tbs & STMMAC_TBS_AVAIL))
+			stmmac_mode_init(priv, tx_q->dma_tx,
+					 tx_q->dma_tx_phy,
+					 priv->dma_tx_size, 0);
+	}
 
-			stmmac_clear_desc(priv, p);
+	for (i = 0; i < priv->dma_tx_size; i++) {
+		struct dma_desc *p;
 
-			tx_q->tx_skbuff_dma[i].buf = 0;
-			tx_q->tx_skbuff_dma[i].map_as_page = false;
-			tx_q->tx_skbuff_dma[i].len = 0;
-			tx_q->tx_skbuff_dma[i].last_segment = false;
-			tx_q->tx_skbuff[i] = NULL;
-		}
+		if (priv->extend_desc)
+			p = &((tx_q->dma_etx + i)->basic);
+		else if (tx_q->tbs & STMMAC_TBS_AVAIL)
+			p = &((tx_q->dma_entx + i)->basic);
+		else
+			p = tx_q->dma_tx + i;
 
-		tx_q->dirty_tx = 0;
-		tx_q->cur_tx = 0;
-		tx_q->mss = 0;
+		stmmac_clear_desc(priv, p);
 
-		netdev_tx_reset_queue(netdev_get_tx_queue(priv->dev, queue));
+		tx_q->tx_skbuff_dma[i].buf = 0;
+		tx_q->tx_skbuff_dma[i].map_as_page = false;
+		tx_q->tx_skbuff_dma[i].len = 0;
+		tx_q->tx_skbuff_dma[i].last_segment = false;
+		tx_q->tx_skbuff[i] = NULL;
 	}
 
+	tx_q->dirty_tx = 0;
+	tx_q->cur_tx = 0;
+	tx_q->mss = 0;
+
+	netdev_tx_reset_queue(netdev_get_tx_queue(priv->dev, queue));
+
+	return 0;
+}
+
+static int init_dma_tx_desc_rings(struct net_device *dev)
+{
+	struct stmmac_priv *priv = netdev_priv(dev);
+	u32 tx_queue_cnt;
+	u32 queue;
+
+	tx_queue_cnt = priv->plat->tx_queues_to_use;
+
+	for (queue = 0; queue < tx_queue_cnt; queue++)
+		__init_dma_tx_desc_rings(priv, queue);
+
 	return 0;
 }
 
-- 
2.25.1

[PATCH net-next v2 5/7] net: stmmac: Refactor __stmmac_xdp_run_prog for XDP ZC

[Ong Boon Leong]

Prepare stmmac_xdp_run_prog() for AF_XDP zero-copy support which will be
added by upcoming patches by splitting out the XDP verdict processing
into __stmmac_xdp_run_prog() and it callable for XDP ZC path which does
not need to verify bpf_prog is not NULL.

The stmmac_xdp_run_prog() is used for regular XDP Rx path which requires
bpf_prog to be verified.

Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
---
 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 35 ++++++++++++-------
 1 file changed, 23 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 0804674e628e..329a3abbac76 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -4408,20 +4408,13 @@ static int stmmac_xdp_xmit_back(struct stmmac_priv *priv,
 	return res;
 }
 
-static struct sk_buff *stmmac_xdp_run_prog(struct stmmac_priv *priv,
-					   struct xdp_buff *xdp)
+/* This function assumes rcu_read_lock() is held by the caller. */
+static int __stmmac_xdp_run_prog(struct stmmac_priv *priv,
+				 struct bpf_prog *prog,
+				 struct xdp_buff *xdp)
 {
-	struct bpf_prog *prog;
-	int res;
 	u32 act;
-
-	rcu_read_lock();
-
-	prog = READ_ONCE(priv->xdp_prog);
-	if (!prog) {
-		res = STMMAC_XDP_PASS;
-		goto unlock;
-	}
+	int res;
 
 	act = bpf_prog_run_xdp(prog, xdp);
 	switch (act) {
@@ -4448,6 +4441,24 @@ static struct sk_buff *stmmac_xdp_run_prog(struct stmmac_priv *priv,
 		break;
 	}
 
+	return res;
+}
+
+static struct sk_buff *stmmac_xdp_run_prog(struct stmmac_priv *priv,
+					   struct xdp_buff *xdp)
+{
+	struct bpf_prog *prog;
+	int res;
+
+	rcu_read_lock();
+
+	prog = READ_ONCE(priv->xdp_prog);
+	if (!prog) {
+		res = STMMAC_XDP_PASS;
+		goto unlock;
+	}
+
+	res = __stmmac_xdp_run_prog(priv, prog, xdp);
 unlock:
 	rcu_read_unlock();
 	return ERR_PTR(-res);
-- 
2.25.1

[PATCH net-next v2 6/7] net: stmmac: Enable RX via AF_XDP zero-copy

[Ong Boon Leong]

This patch adds the support for receiving packet via AF_XDP zero-copy
mechanism.

XDP ZC uses 1:1 mapping of XDP buffer to receive packet, therefore the
use of split header is not used currently. The 'xdp_buff' is declared as
union together with a struct that contains 'page', 'addr' and
'page_offset' that are associated with primary buffer.

RX buffers are now allocated either via page_pool or xsk pool. For RX
buffers from xsk_pool they are allocated and deallocated using below
functions:

 * stmmac_alloc_rx_buffers_zc(struct stmmac_priv *priv, u32 queue)
 * dma_free_rx_xskbufs(struct stmmac_priv *priv, u32 queue)

With above functions now available, we then extend the following driver
functions to support XDP ZC:
 * stmmac_reinit_rx_buffers()
 * __init_dma_rx_desc_rings()
 * init_dma_rx_desc_rings()
 * __free_dma_rx_desc_resources()

Note: stmmac_alloc_rx_buffers_zc() may return -ENOMEM due to RX XDP
buffer pool is not allocated (e.g. samples/bpf/xdpsock TX-only). But,
it is still ok to let TX XDP ZC to continue, therefore, the -ENOMEM
is silently ignored to let the driver succcessfully transition to XDP
ZC mode for the said RX and TX queue.

As XDP ZC buffer size is different, the DMA buffer size is required
to be reprogrammed accordingly for RX DMA/Queue that is populated with
XDP buffer from XSK pool.

Next, to add or remove per-queue XSK pool, stmmac_xdp_setup_pool()
will call stmmac_xdp_enable_pool() or stmmac_xdp_disable_pool()
that in-turn coordinates the tearing down and setting up RX ring via
RX buffers and descriptors removal and reallocation through
stmmac_disable_rx_queue() and stmmac_enable_rx_queue(). In addition,
stmmac_xsk_wakeup() is added to initiate XDP RX buffer replenishing
by signalling user application to add available XDP frames back to
FILL queue.

For RX processing using XDP zero-copy buffer, stmmac_rx_zc() is
introduced which is implemented with the assumption that RX split
header is disabled. For XDP verdict is XDP_PASS, the XDP buffer is
copied into a sk_buff allocated through stmmac_construct_skb_zc()
and sent to Linux network GRO inside stmmac_dispatch_skb_zc(). Free RX
buffers are then replenished using stmmac_rx_refill_zc()

v2: introduce __stmmac_disable_all_queues() to contain the original code
    that does napi_disable() and then make stmmac_setup_tc_block_cb()
    to use it. Move synchronize_rcu() into stmmac_disable_all_queues()
    that eventually calls __stmmac_disable_all_queues(). Then,
    make both stmmac_release() and stmmac_suspend() to use
    stmmac_disable_all_queues(). Thanks David Miller for spotting the
    synchronize_rcu() issue in v1 patch.

Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac.h  |  18 +-
 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 600 +++++++++++++++++-
 .../net/ethernet/stmicro/stmmac/stmmac_xdp.c  |  87 +++
 .../net/ethernet/stmicro/stmmac/stmmac_xdp.h  |   3 +
 4 files changed, 679 insertions(+), 29 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index c49debb62b05..aa0db622ee69 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -77,9 +77,14 @@ struct stmmac_tx_queue {
 };
 
 struct stmmac_rx_buffer {
-	struct page *page;
-	dma_addr_t addr;
-	__u32 page_offset;
+	union {
+		struct {
+			struct page *page;
+			dma_addr_t addr;
+			__u32 page_offset;
+		};
+		struct xdp_buff *xdp;
+	};
 	struct page *sec_page;
 	dma_addr_t sec_addr;
 };
@@ -88,6 +93,7 @@ struct stmmac_rx_queue {
 	u32 rx_count_frames;
 	u32 queue_index;
 	struct xdp_rxq_info xdp_rxq;
+	struct xsk_buff_pool *xsk_pool;
 	struct page_pool *page_pool;
 	struct stmmac_rx_buffer *buf_pool;
 	struct stmmac_priv *priv_data;
@@ -95,6 +101,7 @@ struct stmmac_rx_queue {
 	struct dma_desc *dma_rx ____cacheline_aligned_in_smp;
 	unsigned int cur_rx;
 	unsigned int dirty_rx;
+	unsigned int buf_alloc_num;
 	u32 rx_zeroc_thresh;
 	dma_addr_t dma_rx_phy;
 	u32 rx_tail_addr;
@@ -283,6 +290,7 @@ struct stmmac_priv {
 	struct stmmac_rss rss;
 
 	/* XDP BPF Program */
+	unsigned long *af_xdp_zc_qps;
 	struct bpf_prog *xdp_prog;
 };
 
@@ -328,6 +336,10 @@ static inline unsigned int stmmac_rx_offset(struct stmmac_priv *priv)
 	return 0;
 }
 
+void stmmac_disable_rx_queue(struct stmmac_priv *priv, u32 queue);
+void stmmac_enable_rx_queue(struct stmmac_priv *priv, u32 queue);
+int stmmac_xsk_wakeup(struct net_device *dev, u32 queue, u32 flags);
+
 #if IS_ENABLED(CONFIG_STMMAC_SELFTESTS)
 void stmmac_selftest_run(struct net_device *dev,
 			 struct ethtool_test *etest, u64 *buf);
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 329a3abbac76..48e755ebcf2b 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -40,6 +40,7 @@
 #include <linux/udp.h>
 #include <linux/bpf_trace.h>
 #include <net/pkt_cls.h>
+#include <net/xdp_sock_drv.h>
 #include "stmmac_ptp.h"
 #include "stmmac.h"
 #include "stmmac_xdp.h"
@@ -69,6 +70,8 @@ MODULE_PARM_DESC(phyaddr, "Physical device address");
 #define STMMAC_TX_THRESH(x)	((x)->dma_tx_size / 4)
 #define STMMAC_RX_THRESH(x)	((x)->dma_rx_size / 4)
 
+#define STMMAC_RX_FILL_BATCH		16
+
 #define STMMAC_XDP_PASS		0
 #define STMMAC_XDP_CONSUMED	BIT(0)
 #define STMMAC_XDP_TX		BIT(1)
@@ -179,11 +182,7 @@ static void stmmac_verify_args(void)
 		eee_timer = STMMAC_DEFAULT_LPI_TIMER;
 }
 
-/**
- * stmmac_disable_all_queues - Disable all queues
- * @priv: driver private structure
- */
-static void stmmac_disable_all_queues(struct stmmac_priv *priv)
+static void __stmmac_disable_all_queues(struct stmmac_priv *priv)
 {
 	u32 rx_queues_cnt = priv->plat->rx_queues_to_use;
 	u32 tx_queues_cnt = priv->plat->tx_queues_to_use;
@@ -200,6 +199,28 @@ static void stmmac_disable_all_queues(struct stmmac_priv *priv)
 	}
 }
 
+/**
+ * stmmac_disable_all_queues - Disable all queues
+ * @priv: driver private structure
+ */
+static void stmmac_disable_all_queues(struct stmmac_priv *priv)
+{
+	u32 rx_queues_cnt = priv->plat->rx_queues_to_use;
+	struct stmmac_rx_queue *rx_q;
+	u32 queue;
+
+	/* synchronize_rcu() needed for pending XDP buffers to drain */
+	for (queue = 0; queue < rx_queues_cnt; queue++) {
+		rx_q = &priv->rx_queue[queue];
+		if (rx_q->xsk_pool) {
+			synchronize_rcu();
+			break;
+		}
+	}
+
+	__stmmac_disable_all_queues(priv);
+}
+
 /**
  * stmmac_enable_all_queues - Enable all queues
  * @priv: driver private structure
@@ -1509,6 +1530,8 @@ static int stmmac_alloc_rx_buffers(struct stmmac_priv *priv, u32 queue,
 					     queue);
 		if (ret)
 			return ret;
+
+		rx_q->buf_alloc_num++;
 	}
 
 	return 0;
@@ -1539,6 +1562,56 @@ static void dma_recycle_rx_skbufs(struct stmmac_priv *priv, u32 queue)
 	}
 }
 
+/**
+ * dma_free_rx_xskbufs - free RX dma buffers from XSK pool
+ * @priv: private structure
+ * @queue: RX queue index
+ */
+static void dma_free_rx_xskbufs(struct stmmac_priv *priv, u32 queue)
+{
+	struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
+	int i;
+
+	for (i = 0; i < priv->dma_rx_size; i++) {
+		struct stmmac_rx_buffer *buf = &rx_q->buf_pool[i];
+
+		if (!buf->xdp)
+			continue;
+
+		xsk_buff_free(buf->xdp);
+		buf->xdp = NULL;
+	}
+}
+
+static int stmmac_alloc_rx_buffers_zc(struct stmmac_priv *priv, u32 queue)
+{
+	struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
+	int i;
+
+	for (i = 0; i < priv->dma_rx_size; i++) {
+		struct stmmac_rx_buffer *buf;
+		dma_addr_t dma_addr;
+		struct dma_desc *p;
+
+		if (priv->extend_desc)
+			p = (struct dma_desc *)(rx_q->dma_erx + i);
+		else
+			p = rx_q->dma_rx + i;
+
+		buf = &rx_q->buf_pool[i];
+
+		buf->xdp = xsk_buff_alloc(rx_q->xsk_pool);
+		if (!buf->xdp)
+			return -ENOMEM;
+
+		dma_addr = xsk_buff_xdp_get_dma(buf->xdp);
+		stmmac_set_desc_addr(priv, p, dma_addr);
+		rx_q->buf_alloc_num++;
+	}
+
+	return 0;
+}
+
 /**
  * stmmac_reinit_rx_buffers - reinit the RX descriptor buffer.
  * @priv: driver private structure
@@ -1550,15 +1623,31 @@ static void stmmac_reinit_rx_buffers(struct stmmac_priv *priv)
 	u32 rx_count = priv->plat->rx_queues_to_use;
 	u32 queue;
 
-	for (queue = 0; queue < rx_count; queue++)
-		dma_recycle_rx_skbufs(priv, queue);
+	for (queue = 0; queue < rx_count; queue++) {
+		struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
+
+		if (rx_q->xsk_pool)
+			dma_free_rx_xskbufs(priv, queue);
+		else
+			dma_recycle_rx_skbufs(priv, queue);
+
+		rx_q->buf_alloc_num = 0;
+	}
 
 	for (queue = 0; queue < rx_count; queue++) {
+		struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
 		int ret;
 
-		ret = stmmac_alloc_rx_buffers(priv, queue, GFP_KERNEL);
-		if (ret < 0)
-			goto err_reinit_rx_buffers;
+		if (rx_q->xsk_pool) {
+			/* RX XDP ZC buffer pool may not be populated, e.g.
+			 * xdpsock TX-only.
+			 */
+			stmmac_alloc_rx_buffers_zc(priv, queue);
+		} else {
+			ret = stmmac_alloc_rx_buffers(priv, queue, GFP_KERNEL);
+			if (ret < 0)
+				goto err_reinit_rx_buffers;
+		}
 	}
 
 	return;
@@ -1574,6 +1663,14 @@ static void stmmac_reinit_rx_buffers(struct stmmac_priv *priv)
 	}
 }
 
+static struct xsk_buff_pool *stmmac_get_xsk_pool(struct stmmac_priv *priv, u32 queue)
+{
+	if (!stmmac_xdp_is_enabled(priv) || !test_bit(queue, priv->af_xdp_zc_qps))
+		return NULL;
+
+	return xsk_get_pool_from_qid(priv->dev, queue);
+}
+
 /**
  * __init_dma_rx_desc_rings - init the RX descriptor ring (per queue)
  * @priv: driver private structure
@@ -1594,17 +1691,37 @@ static int __init_dma_rx_desc_rings(struct stmmac_priv *priv, u32 queue, gfp_t f
 
 	stmmac_clear_rx_descriptors(priv, queue);
 
-	WARN_ON(xdp_rxq_info_reg_mem_model(&rx_q->xdp_rxq,
-					   MEM_TYPE_PAGE_POOL,
-					   rx_q->page_pool));
+	xdp_rxq_info_unreg_mem_model(&rx_q->xdp_rxq);
 
-	netdev_info(priv->dev,
-		    "Register MEM_TYPE_PAGE_POOL RxQ-%d\n",
-		    rx_q->queue_index);
+	rx_q->xsk_pool = stmmac_get_xsk_pool(priv, queue);
 
-	ret = stmmac_alloc_rx_buffers(priv, queue, flags);
-	if (ret < 0)
-		return -ENOMEM;
+	if (rx_q->xsk_pool) {
+		WARN_ON(xdp_rxq_info_reg_mem_model(&rx_q->xdp_rxq,
+						   MEM_TYPE_XSK_BUFF_POOL,
+						   NULL));
+		netdev_info(priv->dev,
+			    "Register MEM_TYPE_XSK_BUFF_POOL RxQ-%d\n",
+			    rx_q->queue_index);
+		xsk_pool_set_rxq_info(rx_q->xsk_pool, &rx_q->xdp_rxq);
+	} else {
+		WARN_ON(xdp_rxq_info_reg_mem_model(&rx_q->xdp_rxq,
+						   MEM_TYPE_PAGE_POOL,
+						   rx_q->page_pool));
+		netdev_info(priv->dev,
+			    "Register MEM_TYPE_PAGE_POOL RxQ-%d\n",
+			    rx_q->queue_index);
+	}
+
+	if (rx_q->xsk_pool) {
+		/* RX XDP ZC buffer pool may not be populated, e.g.
+		 * xdpsock TX-only.
+		 */
+		stmmac_alloc_rx_buffers_zc(priv, queue);
+	} else {
+		ret = stmmac_alloc_rx_buffers(priv, queue, flags);
+		if (ret < 0)
+			return -ENOMEM;
+	}
 
 	rx_q->cur_rx = 0;
 	rx_q->dirty_rx = 0;
@@ -1645,7 +1762,15 @@ static int init_dma_rx_desc_rings(struct net_device *dev, gfp_t flags)
 
 err_init_rx_buffers:
 	while (queue >= 0) {
-		dma_free_rx_skbufs(priv, queue);
+		struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
+
+		if (rx_q->xsk_pool)
+			dma_free_rx_xskbufs(priv, queue);
+		else
+			dma_free_rx_skbufs(priv, queue);
+
+		rx_q->buf_alloc_num = 0;
+		rx_q->xsk_pool = NULL;
 
 		if (queue == 0)
 			break;
@@ -1790,7 +1915,13 @@ static void __free_dma_rx_desc_resources(struct stmmac_priv *priv, u32 queue)
 	struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
 
 	/* Release the DMA RX socket buffers */
-	dma_free_rx_skbufs(priv, queue);
+	if (rx_q->xsk_pool)
+		dma_free_rx_xskbufs(priv, queue);
+	else
+		dma_free_rx_skbufs(priv, queue);
+
+	rx_q->buf_alloc_num = 0;
+	rx_q->xsk_pool = NULL;
 
 	/* Free DMA regions of consistent memory previously allocated */
 	if (!priv->extend_desc)
@@ -2222,12 +2353,24 @@ static void stmmac_dma_operation_mode(struct stmmac_priv *priv)
 
 	/* configure all channels */
 	for (chan = 0; chan < rx_channels_count; chan++) {
+		struct stmmac_rx_queue *rx_q = &priv->rx_queue[chan];
+		u32 buf_size;
+
 		qmode = priv->plat->rx_queues_cfg[chan].mode_to_use;
 
 		stmmac_dma_rx_mode(priv, priv->ioaddr, rxmode, chan,
 				rxfifosz, qmode);
-		stmmac_set_dma_bfsize(priv, priv->ioaddr, priv->dma_buf_sz,
-				chan);
+
+		if (rx_q->xsk_pool) {
+			buf_size = xsk_pool_get_rx_frame_size(rx_q->xsk_pool);
+			stmmac_set_dma_bfsize(priv, priv->ioaddr,
+					      buf_size,
+					      chan);
+		} else {
+			stmmac_set_dma_bfsize(priv, priv->ioaddr,
+					      priv->dma_buf_sz,
+					      chan);
+		}
 	}
 
 	for (chan = 0; chan < tx_channels_count; chan++) {
@@ -2638,7 +2781,7 @@ static int stmmac_init_dma_engine(struct stmmac_priv *priv)
 				    rx_q->dma_rx_phy, chan);
 
 		rx_q->rx_tail_addr = rx_q->dma_rx_phy +
-				     (priv->dma_rx_size *
+				     (rx_q->buf_alloc_num *
 				      sizeof(struct dma_desc));
 		stmmac_set_rx_tail_ptr(priv, priv->ioaddr,
 				       rx_q->rx_tail_addr, chan);
@@ -4479,6 +4622,302 @@ static void stmmac_finalize_xdp_rx(struct stmmac_priv *priv,
 		xdp_do_flush();
 }
 
+static struct sk_buff *stmmac_construct_skb_zc(struct stmmac_channel *ch,
+					       struct xdp_buff *xdp)
+{
+	unsigned int metasize = xdp->data - xdp->data_meta;
+	unsigned int datasize = xdp->data_end - xdp->data;
+	struct sk_buff *skb;
+
+	skb = __napi_alloc_skb(&ch->rx_napi,
+			       xdp->data_end - xdp->data_hard_start,
+			       GFP_ATOMIC | __GFP_NOWARN);
+	if (unlikely(!skb))
+		return NULL;
+
+	skb_reserve(skb, xdp->data - xdp->data_hard_start);
+	memcpy(__skb_put(skb, datasize), xdp->data, datasize);
+	if (metasize)
+		skb_metadata_set(skb, metasize);
+
+	return skb;
+}
+
+static void stmmac_dispatch_skb_zc(struct stmmac_priv *priv, u32 queue,
+				   struct dma_desc *p, struct dma_desc *np,
+				   struct xdp_buff *xdp)
+{
+	struct stmmac_channel *ch = &priv->channel[queue];
+	unsigned int len = xdp->data_end - xdp->data;
+	enum pkt_hash_types hash_type;
+	int coe = priv->hw->rx_csum;
+	struct sk_buff *skb;
+	u32 hash;
+
+	skb = stmmac_construct_skb_zc(ch, xdp);
+	if (!skb) {
+		priv->dev->stats.rx_dropped++;
+		return;
+	}
+
+	stmmac_get_rx_hwtstamp(priv, p, np, skb);
+	stmmac_rx_vlan(priv->dev, skb);
+	skb->protocol = eth_type_trans(skb, priv->dev);
+
+	if (unlikely(!coe))
+		skb_checksum_none_assert(skb);
+	else
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+	if (!stmmac_get_rx_hash(priv, p, &hash, &hash_type))
+		skb_set_hash(skb, hash, hash_type);
+
+	skb_record_rx_queue(skb, queue);
+	napi_gro_receive(&ch->rx_napi, skb);
+
+	priv->dev->stats.rx_packets++;
+	priv->dev->stats.rx_bytes += len;
+}
+
+static bool stmmac_rx_refill_zc(struct stmmac_priv *priv, u32 queue, u32 budget)
+{
+	struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
+	unsigned int entry = rx_q->dirty_rx;
+	struct dma_desc *rx_desc = NULL;
+	bool ret = true;
+
+	budget = min(budget, stmmac_rx_dirty(priv, queue));
+
+	while (budget-- > 0 && entry != rx_q->cur_rx) {
+		struct stmmac_rx_buffer *buf = &rx_q->buf_pool[entry];
+		dma_addr_t dma_addr;
+		bool use_rx_wd;
+
+		if (!buf->xdp) {
+			buf->xdp = xsk_buff_alloc(rx_q->xsk_pool);
+			if (!buf->xdp) {
+				ret = false;
+				break;
+			}
+		}
+
+		if (priv->extend_desc)
+			rx_desc = (struct dma_desc *)(rx_q->dma_erx + entry);
+		else
+			rx_desc = rx_q->dma_rx + entry;
+
+		dma_addr = xsk_buff_xdp_get_dma(buf->xdp);
+		stmmac_set_desc_addr(priv, rx_desc, dma_addr);
+		stmmac_set_desc_sec_addr(priv, rx_desc, 0, false);
+		stmmac_refill_desc3(priv, rx_q, rx_desc);
+
+		rx_q->rx_count_frames++;
+		rx_q->rx_count_frames += priv->rx_coal_frames[queue];
+		if (rx_q->rx_count_frames > priv->rx_coal_frames[queue])
+			rx_q->rx_count_frames = 0;
+
+		use_rx_wd = !priv->rx_coal_frames[queue];
+		use_rx_wd |= rx_q->rx_count_frames > 0;
+		if (!priv->use_riwt)
+			use_rx_wd = false;
+
+		dma_wmb();
+		stmmac_set_rx_owner(priv, rx_desc, use_rx_wd);
+
+		entry = STMMAC_GET_ENTRY(entry, priv->dma_rx_size);
+	}
+
+	if (rx_desc) {
+		rx_q->dirty_rx = entry;
+		rx_q->rx_tail_addr = rx_q->dma_rx_phy +
+				     (rx_q->dirty_rx * sizeof(struct dma_desc));
+		stmmac_set_rx_tail_ptr(priv, priv->ioaddr, rx_q->rx_tail_addr, queue);
+	}
+
+	return ret;
+}
+
+static int stmmac_rx_zc(struct stmmac_priv *priv, int limit, u32 queue)
+{
+	struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
+	unsigned int count = 0, error = 0, len = 0;
+	int dirty = stmmac_rx_dirty(priv, queue);
+	unsigned int next_entry = rx_q->cur_rx;
+	unsigned int desc_size;
+	struct bpf_prog *prog;
+	bool failure = false;
+	int xdp_status = 0;
+	int status = 0;
+
+	if (netif_msg_rx_status(priv)) {
+		void *rx_head;
+
+		netdev_dbg(priv->dev, "%s: descriptor ring:\n", __func__);
+		if (priv->extend_desc) {
+			rx_head = (void *)rx_q->dma_erx;
+			desc_size = sizeof(struct dma_extended_desc);
+		} else {
+			rx_head = (void *)rx_q->dma_rx;
+			desc_size = sizeof(struct dma_desc);
+		}
+
+		stmmac_display_ring(priv, rx_head, priv->dma_rx_size, true,
+				    rx_q->dma_rx_phy, desc_size);
+	}
+	while (count < limit) {
+		struct stmmac_rx_buffer *buf;
+		unsigned int buf1_len = 0;
+		struct dma_desc *np, *p;
+		int entry;
+		int res;
+
+		if (!count && rx_q->state_saved) {
+			error = rx_q->state.error;
+			len = rx_q->state.len;
+		} else {
+			rx_q->state_saved = false;
+			error = 0;
+			len = 0;
+		}
+
+		if (count >= limit)
+			break;
+
+read_again:
+		buf1_len = 0;
+		entry = next_entry;
+		buf = &rx_q->buf_pool[entry];
+
+		if (dirty >= STMMAC_RX_FILL_BATCH) {
+			failure = failure ||
+				  !stmmac_rx_refill_zc(priv, queue, dirty);
+			dirty = 0;
+		}
+
+		if (priv->extend_desc)
+			p = (struct dma_desc *)(rx_q->dma_erx + entry);
+		else
+			p = rx_q->dma_rx + entry;
+
+		/* read the status of the incoming frame */
+		status = stmmac_rx_status(priv, &priv->dev->stats,
+					  &priv->xstats, p);
+		/* check if managed by the DMA otherwise go ahead */
+		if (unlikely(status & dma_own))
+			break;
+
+		/* Prefetch the next RX descriptor */
+		rx_q->cur_rx = STMMAC_GET_ENTRY(rx_q->cur_rx,
+						priv->dma_rx_size);
+		next_entry = rx_q->cur_rx;
+
+		if (priv->extend_desc)
+			np = (struct dma_desc *)(rx_q->dma_erx + next_entry);
+		else
+			np = rx_q->dma_rx + next_entry;
+
+		prefetch(np);
+
+		if (priv->extend_desc)
+			stmmac_rx_extended_status(priv, &priv->dev->stats,
+						  &priv->xstats,
+						  rx_q->dma_erx + entry);
+		if (unlikely(status == discard_frame)) {
+			xsk_buff_free(buf->xdp);
+			buf->xdp = NULL;
+			dirty++;
+			error = 1;
+			if (!priv->hwts_rx_en)
+				priv->dev->stats.rx_errors++;
+		}
+
+		if (unlikely(error && (status & rx_not_ls)))
+			goto read_again;
+		if (unlikely(error)) {
+			count++;
+			continue;
+		}
+
+		/* Ensure a valid XSK buffer before proceed */
+		if (!buf->xdp)
+			break;
+
+		/* XSK pool expects RX frame 1:1 mapped to XSK buffer */
+		if (likely(status & rx_not_ls)) {
+			xsk_buff_free(buf->xdp);
+			buf->xdp = NULL;
+			dirty++;
+			count++;
+			goto read_again;
+		}
+
+		/* XDP ZC Frame only support primary buffers for now */
+		buf1_len = stmmac_rx_buf1_len(priv, p, status, len);
+		len += buf1_len;
+
+		/* ACS is set; GMAC core strips PAD/FCS for IEEE 802.3
+		 * Type frames (LLC/LLC-SNAP)
+		 *
+		 * llc_snap is never checked in GMAC >= 4, so this ACS
+		 * feature is always disabled and packets need to be
+		 * stripped manually.
+		 */
+		if (likely(!(status & rx_not_ls)) &&
+		    (likely(priv->synopsys_id >= DWMAC_CORE_4_00) ||
+		     unlikely(status != llc_snap))) {
+			buf1_len -= ETH_FCS_LEN;
+			len -= ETH_FCS_LEN;
+		}
+
+		/* RX buffer is good and fit into a XSK pool buffer */
+		buf->xdp->data_end = buf->xdp->data + buf1_len;
+		xsk_buff_dma_sync_for_cpu(buf->xdp, rx_q->xsk_pool);
+
+		rcu_read_lock();
+		prog = READ_ONCE(priv->xdp_prog);
+		res = __stmmac_xdp_run_prog(priv, prog, buf->xdp);
+		rcu_read_unlock();
+
+		switch (res) {
+		case STMMAC_XDP_PASS:
+			stmmac_dispatch_skb_zc(priv, queue, p, np, buf->xdp);
+			xsk_buff_free(buf->xdp);
+			break;
+		case STMMAC_XDP_CONSUMED:
+			xsk_buff_free(buf->xdp);
+			priv->dev->stats.rx_dropped++;
+			break;
+		case STMMAC_XDP_TX:
+		case STMMAC_XDP_REDIRECT:
+			xdp_status |= res;
+			break;
+		}
+
+		buf->xdp = NULL;
+		dirty++;
+		count++;
+	}
+
+	if (status & rx_not_ls) {
+		rx_q->state_saved = true;
+		rx_q->state.error = error;
+		rx_q->state.len = len;
+	}
+
+	stmmac_finalize_xdp_rx(priv, xdp_status);
+
+	if (xsk_uses_need_wakeup(rx_q->xsk_pool)) {
+		if (failure || stmmac_rx_dirty(priv, queue) > 0)
+			xsk_set_rx_need_wakeup(rx_q->xsk_pool);
+		else
+			xsk_clear_rx_need_wakeup(rx_q->xsk_pool);
+
+		return (int)count;
+	}
+
+	return failure ? limit : (int)count;
+}
+
 /**
  * stmmac_rx - manage the receive process
  * @priv: driver private structure
@@ -4766,12 +5205,17 @@ static int stmmac_napi_poll_rx(struct napi_struct *napi, int budget)
 	struct stmmac_channel *ch =
 		container_of(napi, struct stmmac_channel, rx_napi);
 	struct stmmac_priv *priv = ch->priv_data;
+	struct stmmac_rx_queue *rx_q;
 	u32 chan = ch->index;
 	int work_done;
 
 	priv->xstats.napi_poll++;
 
-	work_done = stmmac_rx(priv, budget, chan);
+	rx_q = &priv->rx_queue[chan];
+
+	work_done = rx_q->xsk_pool ?
+		    stmmac_rx_zc(priv, budget, chan) :
+		    stmmac_rx(priv, budget, chan);
 	if (work_done < budget && napi_complete_done(napi, work_done)) {
 		unsigned long flags;
 
@@ -5254,7 +5698,7 @@ static int stmmac_setup_tc_block_cb(enum tc_setup_type type, void *type_data,
 	if (!tc_cls_can_offload_and_chain0(priv->dev, type_data))
 		return ret;
 
-	stmmac_disable_all_queues(priv);
+	__stmmac_disable_all_queues(priv);
 
 	switch (type) {
 	case TC_SETUP_CLSU32:
@@ -5675,6 +6119,9 @@ static int stmmac_bpf(struct net_device *dev, struct netdev_bpf *bpf)
 	switch (bpf->command) {
 	case XDP_SETUP_PROG:
 		return stmmac_xdp_set_prog(priv, bpf->prog, bpf->extack);
+	case XDP_SETUP_XSK_POOL:
+		return stmmac_xdp_setup_pool(priv, bpf->xsk.pool,
+					     bpf->xsk.queue_id);
 	default:
 		return -EOPNOTSUPP;
 	}
@@ -5722,6 +6169,102 @@ static int stmmac_xdp_xmit(struct net_device *dev, int num_frames,
 	return nxmit;
 }
 
+void stmmac_disable_rx_queue(struct stmmac_priv *priv, u32 queue)
+{
+	struct stmmac_channel *ch = &priv->channel[queue];
+	unsigned long flags;
+
+	spin_lock_irqsave(&ch->lock, flags);
+	stmmac_disable_dma_irq(priv, priv->ioaddr, queue, 1, 0);
+	spin_unlock_irqrestore(&ch->lock, flags);
+
+	stmmac_stop_rx_dma(priv, queue);
+	__free_dma_rx_desc_resources(priv, queue);
+}
+
+void stmmac_enable_rx_queue(struct stmmac_priv *priv, u32 queue)
+{
+	struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
+	struct stmmac_channel *ch = &priv->channel[queue];
+	unsigned long flags;
+	u32 buf_size;
+	int ret;
+
+	ret = __alloc_dma_rx_desc_resources(priv, queue);
+	if (ret) {
+		netdev_err(priv->dev, "Failed to alloc RX desc.\n");
+		return;
+	}
+
+	ret = __init_dma_rx_desc_rings(priv, queue, GFP_KERNEL);
+	if (ret) {
+		__free_dma_rx_desc_resources(priv, queue);
+		netdev_err(priv->dev, "Failed to init RX desc.\n");
+		return;
+	}
+
+	stmmac_clear_rx_descriptors(priv, queue);
+
+	stmmac_init_rx_chan(priv, priv->ioaddr, priv->plat->dma_cfg,
+			    rx_q->dma_rx_phy, rx_q->queue_index);
+
+	rx_q->rx_tail_addr = rx_q->dma_rx_phy + (rx_q->buf_alloc_num *
+			     sizeof(struct dma_desc));
+	stmmac_set_rx_tail_ptr(priv, priv->ioaddr,
+			       rx_q->rx_tail_addr, rx_q->queue_index);
+
+	if (rx_q->xsk_pool && rx_q->buf_alloc_num) {
+		buf_size = xsk_pool_get_rx_frame_size(rx_q->xsk_pool);
+		stmmac_set_dma_bfsize(priv, priv->ioaddr,
+				      buf_size,
+				      rx_q->queue_index);
+	} else {
+		stmmac_set_dma_bfsize(priv, priv->ioaddr,
+				      priv->dma_buf_sz,
+				      rx_q->queue_index);
+	}
+
+	stmmac_start_rx_dma(priv, queue);
+
+	spin_lock_irqsave(&ch->lock, flags);
+	stmmac_enable_dma_irq(priv, priv->ioaddr, queue, 1, 0);
+	spin_unlock_irqrestore(&ch->lock, flags);
+}
+
+int stmmac_xsk_wakeup(struct net_device *dev, u32 queue, u32 flags)
+{
+	struct stmmac_priv *priv = netdev_priv(dev);
+	struct stmmac_rx_queue *rx_q;
+	struct stmmac_channel *ch;
+
+	if (test_bit(STMMAC_DOWN, &priv->state) ||
+	    !netif_carrier_ok(priv->dev))
+		return -ENETDOWN;
+
+	if (!stmmac_xdp_is_enabled(priv))
+		return -ENXIO;
+
+	if (queue >= priv->plat->rx_queues_to_use)
+		return -EINVAL;
+
+	rx_q = &priv->rx_queue[queue];
+	ch = &priv->channel[queue];
+
+	if (!rx_q->xsk_pool)
+		return -ENXIO;
+
+	if (flags & XDP_WAKEUP_RX &&
+	    !napi_if_scheduled_mark_missed(&ch->rx_napi)) {
+		/* EQoS does not have per-DMA channel SW interrupt,
+		 * so we schedule RX Napi straight-away.
+		 */
+		if (likely(napi_schedule_prep(&ch->rx_napi)))
+			__napi_schedule(&ch->rx_napi);
+	}
+
+	return 0;
+}
+
 static const struct net_device_ops stmmac_netdev_ops = {
 	.ndo_open = stmmac_open,
 	.ndo_start_xmit = stmmac_xmit,
@@ -5742,6 +6285,7 @@ static const struct net_device_ops stmmac_netdev_ops = {
 	.ndo_vlan_rx_kill_vid = stmmac_vlan_rx_kill_vid,
 	.ndo_bpf = stmmac_bpf,
 	.ndo_xdp_xmit = stmmac_xdp_xmit,
+	.ndo_xsk_wakeup = stmmac_xsk_wakeup,
 };
 
 static void stmmac_reset_subtask(struct stmmac_priv *priv)
@@ -6075,6 +6619,10 @@ int stmmac_dvr_probe(struct device *device,
 	/* Verify driver arguments */
 	stmmac_verify_args();
 
+	priv->af_xdp_zc_qps = bitmap_zalloc(MTL_MAX_TX_QUEUES, GFP_KERNEL);
+	if (!priv->af_xdp_zc_qps)
+		return -ENOMEM;
+
 	/* Allocate workqueue */
 	priv->wq = create_singlethread_workqueue("stmmac_wq");
 	if (!priv->wq) {
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_xdp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_xdp.c
index bf38d231860b..caff0dfc6f4b 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_xdp.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_xdp.c
@@ -1,9 +1,96 @@
 // SPDX-License-Identifier: GPL-2.0
 /* Copyright (c) 2021, Intel Corporation. */
 
+#include <net/xdp_sock_drv.h>
+
 #include "stmmac.h"
 #include "stmmac_xdp.h"
 
+static int stmmac_xdp_enable_pool(struct stmmac_priv *priv,
+				  struct xsk_buff_pool *pool, u16 queue)
+{
+	struct stmmac_channel *ch = &priv->channel[queue];
+	bool need_update;
+	u32 frame_size;
+	int err;
+
+	if (queue >= priv->plat->rx_queues_to_use)
+		return -EINVAL;
+
+	frame_size = xsk_pool_get_rx_frame_size(pool);
+	/* XDP ZC does not span multiple frame, make sure XSK pool buffer
+	 * size can at least store Q-in-Q frame.
+	 */
+	if (frame_size < ETH_FRAME_LEN + VLAN_HLEN * 2)
+		return -EOPNOTSUPP;
+
+	err = xsk_pool_dma_map(pool, priv->device, STMMAC_RX_DMA_ATTR);
+	if (err) {
+		netdev_err(priv->dev, "Failed to map xsk pool\n");
+		return err;
+	}
+
+	need_update = netif_running(priv->dev) && stmmac_xdp_is_enabled(priv);
+
+	if (need_update) {
+		stmmac_disable_rx_queue(priv, queue);
+		napi_disable(&ch->rx_napi);
+	}
+
+	set_bit(queue, priv->af_xdp_zc_qps);
+
+	if (need_update) {
+		napi_enable(&ch->rx_napi);
+		stmmac_enable_rx_queue(priv, queue);
+
+		err = stmmac_xsk_wakeup(priv->dev, queue, XDP_WAKEUP_RX);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+static int stmmac_xdp_disable_pool(struct stmmac_priv *priv, u16 queue)
+{
+	struct stmmac_channel *ch = &priv->channel[queue];
+	struct xsk_buff_pool *pool;
+	bool need_update;
+
+	if (queue >= priv->plat->rx_queues_to_use)
+		return -EINVAL;
+
+	pool = xsk_get_pool_from_qid(priv->dev, queue);
+	if (!pool)
+		return -EINVAL;
+
+	need_update = netif_running(priv->dev) && stmmac_xdp_is_enabled(priv);
+
+	if (need_update) {
+		stmmac_disable_rx_queue(priv, queue);
+		synchronize_rcu();
+		napi_disable(&ch->rx_napi);
+	}
+
+	xsk_pool_dma_unmap(pool, STMMAC_RX_DMA_ATTR);
+
+	clear_bit(queue, priv->af_xdp_zc_qps);
+
+	if (need_update) {
+		napi_enable(&ch->rx_napi);
+		stmmac_enable_rx_queue(priv, queue);
+	}
+
+	return 0;
+}
+
+int stmmac_xdp_setup_pool(struct stmmac_priv *priv, struct xsk_buff_pool *pool,
+			  u16 queue)
+{
+	return pool ? stmmac_xdp_enable_pool(priv, pool, queue) :
+		      stmmac_xdp_disable_pool(priv, queue);
+}
+
 int stmmac_xdp_set_prog(struct stmmac_priv *priv, struct bpf_prog *prog,
 			struct netlink_ext_ack *extack)
 {
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_xdp.h b/drivers/net/ethernet/stmicro/stmmac/stmmac_xdp.h
index 93948569d92a..896dc987d4ef 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_xdp.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_xdp.h
@@ -5,7 +5,10 @@
 #define _STMMAC_XDP_H_
 
 #define STMMAC_MAX_RX_BUF_SIZE(num)	(((num) * PAGE_SIZE) - XDP_PACKET_HEADROOM)
+#define STMMAC_RX_DMA_ATTR	(DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING)
 
+int stmmac_xdp_setup_pool(struct stmmac_priv *priv, struct xsk_buff_pool *pool,
+			  u16 queue);
 int stmmac_xdp_set_prog(struct stmmac_priv *priv, struct bpf_prog *prog,
 			struct netlink_ext_ack *extack);
 
-- 
2.25.1

[PATCH net-next v2 7/7] net: stmmac: Add TX via XDP zero-copy socket

[Ong Boon Leong]

We add the support of XDP ZC TX submission and cleaning into
stmmac_tx_clean(). The function is made to clean as many TX complete
frames as possible, i.e. limit by priv->dma_tx_size instead of NAPI
budget. For TX ring that is associated with XSK pool, the function
stmmac_xdp_xmit_zc() is introduced to TX frame buffers from XSK pool by
using xsk_tx_peek_desc(). To make stmmac_tx_clean() support the cleaning
of XSK TX frames, STMMAC_TXBUF_T_XSK_TX TX buffer type is introduced.

As stmmac_tx_clean() uses the return value to cue whether NAPI function
should continue to poll, we augment the caller of stmmac_tx_clean() to
pass NAPI budget instead of priv->dma_tx_size through 'budget' input and
made stmmac_tx_clean() to always clean up-to the TX ring size instead.
This allows us to use the return boolean status of stmmac_xdp_xmit_zc()
to decide if XSK TX work is done or not: If true, set 'xmits' to return
'budget - 1' so that NAPI poll may exit. Else, set 'xmits' to return
'budget' to make NAPI poll continue to poll since XSK TX work is not
done. Finally, at the end of stmmac_tx_clean(), the function now take
a maximum value between 'count' and 'xmits' so that status from both
TX cleaning and XSK TX (only for XDP ZC) is considered.

This patch adds a new NAPI poll called stmmac_napi_poll_rxtx() that is
meant to be enabled/disabled for RX and TX ring that are bound to XSK
pool. This NAPI poll function starts with cleaning TX ring, then submits
XSK TX frames to TX ring before proceed to perform RX operations, i.e.
, receiving RX frames and replenishing RX ring with RX free buffers
obtained from XSK pool. Therefore, during XSK RX and TX setup, the driver
enables stmmac_napi_poll_rxtx() for RX and TX operations, then during
XSK RX and TX pool tear-down, the driver reenables the exisiting
independent NAPI poll functions accordingly: stmmac_napi_poll_rx() and
stmmac_napi_poll_tx().

Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac.h  |   6 +
 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 317 ++++++++++++++++--
 .../net/ethernet/stmicro/stmmac/stmmac_xdp.c  |  16 +-
 3 files changed, 310 insertions(+), 29 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index aa0db622ee69..3d9ceb6234eb 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -40,6 +40,7 @@ enum stmmac_txbuf_type {
 	STMMAC_TXBUF_T_SKB,
 	STMMAC_TXBUF_T_XDP_TX,
 	STMMAC_TXBUF_T_XDP_NDO,
+	STMMAC_TXBUF_T_XSK_TX,
 };
 
 struct stmmac_tx_info {
@@ -69,6 +70,8 @@ struct stmmac_tx_queue {
 		struct xdp_frame **xdpf;
 	};
 	struct stmmac_tx_info *tx_skbuff_dma;
+	struct xsk_buff_pool *xsk_pool;
+	u32 xsk_frames_done;
 	unsigned int cur_tx;
 	unsigned int dirty_tx;
 	dma_addr_t dma_tx_phy;
@@ -116,6 +119,7 @@ struct stmmac_rx_queue {
 struct stmmac_channel {
 	struct napi_struct rx_napi ____cacheline_aligned_in_smp;
 	struct napi_struct tx_napi ____cacheline_aligned_in_smp;
+	struct napi_struct rxtx_napi ____cacheline_aligned_in_smp;
 	struct stmmac_priv *priv_data;
 	spinlock_t lock;
 	u32 index;
@@ -338,6 +342,8 @@ static inline unsigned int stmmac_rx_offset(struct stmmac_priv *priv)
 
 void stmmac_disable_rx_queue(struct stmmac_priv *priv, u32 queue);
 void stmmac_enable_rx_queue(struct stmmac_priv *priv, u32 queue);
+void stmmac_disable_tx_queue(struct stmmac_priv *priv, u32 queue);
+void stmmac_enable_tx_queue(struct stmmac_priv *priv, u32 queue);
 int stmmac_xsk_wakeup(struct net_device *dev, u32 queue, u32 flags);
 
 #if IS_ENABLED(CONFIG_STMMAC_SELFTESTS)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 48e755ebcf2b..d10a67f0b21c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -70,6 +70,9 @@ MODULE_PARM_DESC(phyaddr, "Physical device address");
 #define STMMAC_TX_THRESH(x)	((x)->dma_tx_size / 4)
 #define STMMAC_RX_THRESH(x)	((x)->dma_rx_size / 4)
 
+/* Limit to make sure XDP TX and slow path can coexist */
+#define STMMAC_XSK_TX_BUDGET_MAX	256
+#define STMMAC_TX_XSK_AVAIL		16
 #define STMMAC_RX_FILL_BATCH		16
 
 #define STMMAC_XDP_PASS		0
@@ -120,6 +123,8 @@ static irqreturn_t stmmac_mac_interrupt(int irq, void *dev_id);
 static irqreturn_t stmmac_safety_interrupt(int irq, void *dev_id);
 static irqreturn_t stmmac_msi_intr_tx(int irq, void *data);
 static irqreturn_t stmmac_msi_intr_rx(int irq, void *data);
+static void stmmac_tx_timer_arm(struct stmmac_priv *priv, u32 queue);
+static void stmmac_flush_tx_descriptors(struct stmmac_priv *priv, int queue);
 
 #ifdef CONFIG_DEBUG_FS
 static const struct net_device_ops stmmac_netdev_ops;
@@ -192,6 +197,12 @@ static void __stmmac_disable_all_queues(struct stmmac_priv *priv)
 	for (queue = 0; queue < maxq; queue++) {
 		struct stmmac_channel *ch = &priv->channel[queue];
 
+		if (stmmac_xdp_is_enabled(priv) &&
+		    test_bit(queue, priv->af_xdp_zc_qps)) {
+			napi_disable(&ch->rxtx_napi);
+			continue;
+		}
+
 		if (queue < rx_queues_cnt)
 			napi_disable(&ch->rx_napi);
 		if (queue < tx_queues_cnt)
@@ -235,6 +246,12 @@ static void stmmac_enable_all_queues(struct stmmac_priv *priv)
 	for (queue = 0; queue < maxq; queue++) {
 		struct stmmac_channel *ch = &priv->channel[queue];
 
+		if (stmmac_xdp_is_enabled(priv) &&
+		    test_bit(queue, priv->af_xdp_zc_qps)) {
+			napi_enable(&ch->rxtx_napi);
+			continue;
+		}
+
 		if (queue < rx_queues_cnt)
 			napi_enable(&ch->rx_napi);
 		if (queue < tx_queues_cnt)
@@ -1488,6 +1505,9 @@ static void stmmac_free_tx_buffer(struct stmmac_priv *priv, u32 queue, int i)
 		tx_q->xdpf[i] = NULL;
 	}
 
+	if (tx_q->tx_skbuff_dma[i].buf_type == STMMAC_TXBUF_T_XSK_TX)
+		tx_q->xsk_frames_done++;
+
 	if (tx_q->tx_skbuff[i] &&
 	    tx_q->tx_skbuff_dma[i].buf_type == STMMAC_TXBUF_T_SKB) {
 		dev_kfree_skb_any(tx_q->tx_skbuff[i]);
@@ -1810,6 +1830,8 @@ static int __init_dma_tx_desc_rings(struct stmmac_priv *priv, u32 queue)
 					 priv->dma_tx_size, 0);
 	}
 
+	tx_q->xsk_pool = stmmac_get_xsk_pool(priv, queue);
+
 	for (i = 0; i < priv->dma_tx_size; i++) {
 		struct dma_desc *p;
 
@@ -1886,10 +1908,19 @@ static int init_dma_desc_rings(struct net_device *dev, gfp_t flags)
  */
 static void dma_free_tx_skbufs(struct stmmac_priv *priv, u32 queue)
 {
+	struct stmmac_tx_queue *tx_q = &priv->tx_queue[queue];
 	int i;
 
+	tx_q->xsk_frames_done = 0;
+
 	for (i = 0; i < priv->dma_tx_size; i++)
 		stmmac_free_tx_buffer(priv, queue, i);
+
+	if (tx_q->xsk_pool && tx_q->xsk_frames_done) {
+		xsk_tx_completed(tx_q->xsk_pool, tx_q->xsk_frames_done);
+		tx_q->xsk_frames_done = 0;
+		tx_q->xsk_pool = NULL;
+	}
 }
 
 /**
@@ -2010,6 +2041,7 @@ static int __alloc_dma_rx_desc_resources(struct stmmac_priv *priv, u32 queue)
 	bool xdp_prog = stmmac_xdp_is_enabled(priv);
 	struct page_pool_params pp_params = { 0 };
 	unsigned int num_pages;
+	unsigned int napi_id;
 	int ret;
 
 	rx_q->queue_index = queue;
@@ -2057,9 +2089,15 @@ static int __alloc_dma_rx_desc_resources(struct stmmac_priv *priv, u32 queue)
 			return -ENOMEM;
 	}
 
+	if (stmmac_xdp_is_enabled(priv) &&
+	    test_bit(queue, priv->af_xdp_zc_qps))
+		napi_id = ch->rxtx_napi.napi_id;
+	else
+		napi_id = ch->rx_napi.napi_id;
+
 	ret = xdp_rxq_info_reg(&rx_q->xdp_rxq, priv->dev,
 			       rx_q->queue_index,
-			       ch->rx_napi.napi_id);
+			       napi_id);
 	if (ret) {
 		netdev_err(priv->dev, "Failed to register xdp rxq info\n");
 		return -EINVAL;
@@ -2381,6 +2419,101 @@ static void stmmac_dma_operation_mode(struct stmmac_priv *priv)
 	}
 }
 
+static bool stmmac_xdp_xmit_zc(struct stmmac_priv *priv, u32 queue, u32 budget)
+{
+	struct netdev_queue *nq = netdev_get_tx_queue(priv->dev, queue);
+	struct stmmac_tx_queue *tx_q = &priv->tx_queue[queue];
+	struct xsk_buff_pool *pool = tx_q->xsk_pool;
+	unsigned int entry = tx_q->cur_tx;
+	struct dma_desc *tx_desc = NULL;
+	struct xdp_desc xdp_desc;
+	bool work_done = true;
+
+	/* Avoids TX time-out as we are sharing with slow path */
+	nq->trans_start = jiffies;
+
+	budget = min(budget, stmmac_tx_avail(priv, queue));
+
+	while (budget-- > 0) {
+		dma_addr_t dma_addr;
+		bool set_ic;
+
+		/* We are sharing with slow path and stop XSK TX desc submission when
+		 * available TX ring is less than threshold.
+		 */
+		if (unlikely(stmmac_tx_avail(priv, queue) < STMMAC_TX_XSK_AVAIL) ||
+		    !netif_carrier_ok(priv->dev)) {
+			work_done = false;
+			break;
+		}
+
+		if (!xsk_tx_peek_desc(pool, &xdp_desc))
+			break;
+
+		if (likely(priv->extend_desc))
+			tx_desc = (struct dma_desc *)(tx_q->dma_etx + entry);
+		else if (tx_q->tbs & STMMAC_TBS_AVAIL)
+			tx_desc = &tx_q->dma_entx[entry].basic;
+		else
+			tx_desc = tx_q->dma_tx + entry;
+
+		dma_addr = xsk_buff_raw_get_dma(pool, xdp_desc.addr);
+		xsk_buff_raw_dma_sync_for_device(pool, dma_addr, xdp_desc.len);
+
+		tx_q->tx_skbuff_dma[entry].buf_type = STMMAC_TXBUF_T_XSK_TX;
+
+		/* To return XDP buffer to XSK pool, we simple call
+		 * xsk_tx_completed(), so we don't need to fill up
+		 * 'buf' and 'xdpf'.
+		 */
+		tx_q->tx_skbuff_dma[entry].buf = 0;
+		tx_q->xdpf[entry] = NULL;
+
+		tx_q->tx_skbuff_dma[entry].map_as_page = false;
+		tx_q->tx_skbuff_dma[entry].len = xdp_desc.len;
+		tx_q->tx_skbuff_dma[entry].last_segment = true;
+		tx_q->tx_skbuff_dma[entry].is_jumbo = false;
+
+		stmmac_set_desc_addr(priv, tx_desc, dma_addr);
+
+		tx_q->tx_count_frames++;
+
+		if (!priv->tx_coal_frames[queue])
+			set_ic = false;
+		else if (tx_q->tx_count_frames % priv->tx_coal_frames[queue] == 0)
+			set_ic = true;
+		else
+			set_ic = false;
+
+		if (set_ic) {
+			tx_q->tx_count_frames = 0;
+			stmmac_set_tx_ic(priv, tx_desc);
+			priv->xstats.tx_set_ic_bit++;
+		}
+
+		stmmac_prepare_tx_desc(priv, tx_desc, 1, xdp_desc.len,
+				       true, priv->mode, true, true,
+				       xdp_desc.len);
+
+		stmmac_enable_dma_transmission(priv, priv->ioaddr);
+
+		tx_q->cur_tx = STMMAC_GET_ENTRY(tx_q->cur_tx, priv->dma_tx_size);
+		entry = tx_q->cur_tx;
+	}
+
+	if (tx_desc) {
+		stmmac_flush_tx_descriptors(priv, queue);
+		xsk_tx_release(pool);
+	}
+
+	/* Return true if all of the 3 conditions are met
+	 *  a) TX Budget is still available
+	 *  b) work_done = true when XSK TX desc peek is empty (no more
+	 *     pending XSK TX for transmission)
+	 */
+	return !!budget && work_done;
+}
+
 /**
  * stmmac_tx_clean - to manage the transmission completion
  * @priv: driver private structure
@@ -2392,14 +2525,18 @@ static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue)
 {
 	struct stmmac_tx_queue *tx_q = &priv->tx_queue[queue];
 	unsigned int bytes_compl = 0, pkts_compl = 0;
-	unsigned int entry, count = 0;
+	unsigned int entry, xmits = 0, count = 0;
 
 	__netif_tx_lock_bh(netdev_get_tx_queue(priv->dev, queue));
 
 	priv->xstats.tx_clean++;
 
+	tx_q->xsk_frames_done = 0;
+
 	entry = tx_q->dirty_tx;
-	while ((entry != tx_q->cur_tx) && (count < budget)) {
+
+	/* Try to clean all TX complete frame in 1 shot */
+	while ((entry != tx_q->cur_tx) && count < priv->dma_tx_size) {
 		struct xdp_frame *xdpf;
 		struct sk_buff *skb;
 		struct dma_desc *p;
@@ -2484,6 +2621,9 @@ static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue)
 			tx_q->xdpf[entry] = NULL;
 		}
 
+		if (tx_q->tx_skbuff_dma[entry].buf_type == STMMAC_TXBUF_T_XSK_TX)
+			tx_q->xsk_frames_done++;
+
 		if (tx_q->tx_skbuff_dma[entry].buf_type == STMMAC_TXBUF_T_SKB) {
 			if (likely(skb)) {
 				pkts_compl++;
@@ -2511,6 +2651,28 @@ static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue)
 		netif_tx_wake_queue(netdev_get_tx_queue(priv->dev, queue));
 	}
 
+	if (tx_q->xsk_pool) {
+		bool work_done;
+
+		if (tx_q->xsk_frames_done)
+			xsk_tx_completed(tx_q->xsk_pool, tx_q->xsk_frames_done);
+
+		if (xsk_uses_need_wakeup(tx_q->xsk_pool))
+			xsk_set_tx_need_wakeup(tx_q->xsk_pool);
+
+		/* For XSK TX, we try to send as many as possible.
+		 * If XSK work done (XSK TX desc empty and budget still
+		 * available), return "budget - 1" to reenable TX IRQ.
+		 * Else, return "budget" to make NAPI continue polling.
+		 */
+		work_done = stmmac_xdp_xmit_zc(priv, queue,
+					       STMMAC_XSK_TX_BUDGET_MAX);
+		if (work_done)
+			xmits = budget - 1;
+		else
+			xmits = budget;
+	}
+
 	if (priv->eee_enabled && !priv->tx_path_in_lpi_mode &&
 	    priv->eee_sw_timer_en) {
 		stmmac_enable_eee_mode(priv);
@@ -2525,7 +2687,8 @@ static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue)
 
 	__netif_tx_unlock_bh(netdev_get_tx_queue(priv->dev, queue));
 
-	return count;
+	/* Combine decisions from TX clean and XSK TX */
+	return max(count, xmits);
 }
 
 /**
@@ -2607,24 +2770,31 @@ static int stmmac_napi_check(struct stmmac_priv *priv, u32 chan, u32 dir)
 {
 	int status = stmmac_dma_interrupt_status(priv, priv->ioaddr,
 						 &priv->xstats, chan, dir);
+	struct stmmac_rx_queue *rx_q = &priv->rx_queue[chan];
+	struct stmmac_tx_queue *tx_q = &priv->tx_queue[chan];
 	struct stmmac_channel *ch = &priv->channel[chan];
+	struct napi_struct *rx_napi;
+	struct napi_struct *tx_napi;
 	unsigned long flags;
 
+	rx_napi = rx_q->xsk_pool ? &ch->rxtx_napi : &ch->rx_napi;
+	tx_napi = tx_q->xsk_pool ? &ch->rxtx_napi : &ch->tx_napi;
+
 	if ((status & handle_rx) && (chan < priv->plat->rx_queues_to_use)) {
-		if (napi_schedule_prep(&ch->rx_napi)) {
+		if (napi_schedule_prep(rx_napi)) {
 			spin_lock_irqsave(&ch->lock, flags);
 			stmmac_disable_dma_irq(priv, priv->ioaddr, chan, 1, 0);
 			spin_unlock_irqrestore(&ch->lock, flags);
-			__napi_schedule(&ch->rx_napi);
+			__napi_schedule(rx_napi);
 		}
 	}
 
 	if ((status & handle_tx) && (chan < priv->plat->tx_queues_to_use)) {
-		if (napi_schedule_prep(&ch->tx_napi)) {
+		if (napi_schedule_prep(tx_napi)) {
 			spin_lock_irqsave(&ch->lock, flags);
 			stmmac_disable_dma_irq(priv, priv->ioaddr, chan, 0, 1);
 			spin_unlock_irqrestore(&ch->lock, flags);
-			__napi_schedule(&ch->tx_napi);
+			__napi_schedule(tx_napi);
 		}
 	}
 
@@ -2822,16 +2992,18 @@ static enum hrtimer_restart stmmac_tx_timer(struct hrtimer *t)
 	struct stmmac_tx_queue *tx_q = container_of(t, struct stmmac_tx_queue, txtimer);
 	struct stmmac_priv *priv = tx_q->priv_data;
 	struct stmmac_channel *ch;
+	struct napi_struct *napi;
 
 	ch = &priv->channel[tx_q->queue_index];
+	napi = tx_q->xsk_pool ? &ch->rxtx_napi : &ch->tx_napi;
 
-	if (likely(napi_schedule_prep(&ch->tx_napi))) {
+	if (likely(napi_schedule_prep(napi))) {
 		unsigned long flags;
 
 		spin_lock_irqsave(&ch->lock, flags);
 		stmmac_disable_dma_irq(priv, priv->ioaddr, ch->index, 0, 1);
 		spin_unlock_irqrestore(&ch->lock, flags);
-		__napi_schedule(&ch->tx_napi);
+		__napi_schedule(napi);
 	}
 
 	return HRTIMER_NORESTART;
@@ -4629,7 +4801,7 @@ static struct sk_buff *stmmac_construct_skb_zc(struct stmmac_channel *ch,
 	unsigned int datasize = xdp->data_end - xdp->data;
 	struct sk_buff *skb;
 
-	skb = __napi_alloc_skb(&ch->rx_napi,
+	skb = __napi_alloc_skb(&ch->rxtx_napi,
 			       xdp->data_end - xdp->data_hard_start,
 			       GFP_ATOMIC | __GFP_NOWARN);
 	if (unlikely(!skb))
@@ -4673,7 +4845,7 @@ static void stmmac_dispatch_skb_zc(struct stmmac_priv *priv, u32 queue,
 		skb_set_hash(skb, hash, hash_type);
 
 	skb_record_rx_queue(skb, queue);
-	napi_gro_receive(&ch->rx_napi, skb);
+	napi_gro_receive(&ch->rxtx_napi, skb);
 
 	priv->dev->stats.rx_packets++;
 	priv->dev->stats.rx_bytes += len;
@@ -5205,17 +5377,12 @@ static int stmmac_napi_poll_rx(struct napi_struct *napi, int budget)
 	struct stmmac_channel *ch =
 		container_of(napi, struct stmmac_channel, rx_napi);
 	struct stmmac_priv *priv = ch->priv_data;
-	struct stmmac_rx_queue *rx_q;
 	u32 chan = ch->index;
 	int work_done;
 
 	priv->xstats.napi_poll++;
 
-	rx_q = &priv->rx_queue[chan];
-
-	work_done = rx_q->xsk_pool ?
-		    stmmac_rx_zc(priv, budget, chan) :
-		    stmmac_rx(priv, budget, chan);
+	work_done = stmmac_rx(priv, budget, chan);
 	if (work_done < budget && napi_complete_done(napi, work_done)) {
 		unsigned long flags;
 
@@ -5237,7 +5404,7 @@ static int stmmac_napi_poll_tx(struct napi_struct *napi, int budget)
 
 	priv->xstats.napi_poll++;
 
-	work_done = stmmac_tx_clean(priv, priv->dma_tx_size, chan);
+	work_done = stmmac_tx_clean(priv, budget, chan);
 	work_done = min(work_done, budget);
 
 	if (work_done < budget && napi_complete_done(napi, work_done)) {
@@ -5251,6 +5418,42 @@ static int stmmac_napi_poll_tx(struct napi_struct *napi, int budget)
 	return work_done;
 }
 
+static int stmmac_napi_poll_rxtx(struct napi_struct *napi, int budget)
+{
+	struct stmmac_channel *ch =
+		container_of(napi, struct stmmac_channel, rxtx_napi);
+	struct stmmac_priv *priv = ch->priv_data;
+	int rx_done, tx_done;
+	u32 chan = ch->index;
+
+	priv->xstats.napi_poll++;
+
+	tx_done = stmmac_tx_clean(priv, budget, chan);
+	tx_done = min(tx_done, budget);
+
+	rx_done = stmmac_rx_zc(priv, budget, chan);
+
+	/* If either TX or RX work is not complete, return budget
+	 * and keep pooling
+	 */
+	if (tx_done >= budget || rx_done >= budget)
+		return budget;
+
+	/* all work done, exit the polling mode */
+	if (napi_complete_done(napi, rx_done)) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&ch->lock, flags);
+		/* Both RX and TX work done are compelte,
+		 * so enable both RX & TX IRQs.
+		 */
+		stmmac_enable_dma_irq(priv, priv->ioaddr, chan, 1, 1);
+		spin_unlock_irqrestore(&ch->lock, flags);
+	}
+
+	return min(rx_done, budget - 1);
+}
+
 /**
  *  stmmac_tx_timeout
  *  @dev : Pointer to net device structure
@@ -6231,10 +6434,63 @@ void stmmac_enable_rx_queue(struct stmmac_priv *priv, u32 queue)
 	spin_unlock_irqrestore(&ch->lock, flags);
 }
 
+void stmmac_disable_tx_queue(struct stmmac_priv *priv, u32 queue)
+{
+	struct stmmac_channel *ch = &priv->channel[queue];
+	unsigned long flags;
+
+	spin_lock_irqsave(&ch->lock, flags);
+	stmmac_disable_dma_irq(priv, priv->ioaddr, queue, 0, 1);
+	spin_unlock_irqrestore(&ch->lock, flags);
+
+	stmmac_stop_tx_dma(priv, queue);
+	__free_dma_tx_desc_resources(priv, queue);
+}
+
+void stmmac_enable_tx_queue(struct stmmac_priv *priv, u32 queue)
+{
+	struct stmmac_tx_queue *tx_q = &priv->tx_queue[queue];
+	struct stmmac_channel *ch = &priv->channel[queue];
+	unsigned long flags;
+	int ret;
+
+	ret = __alloc_dma_tx_desc_resources(priv, queue);
+	if (ret) {
+		netdev_err(priv->dev, "Failed to alloc TX desc.\n");
+		return;
+	}
+
+	ret = __init_dma_tx_desc_rings(priv, queue);
+	if (ret) {
+		__free_dma_tx_desc_resources(priv, queue);
+		netdev_err(priv->dev, "Failed to init TX desc.\n");
+		return;
+	}
+
+	stmmac_clear_tx_descriptors(priv, queue);
+
+	stmmac_init_tx_chan(priv, priv->ioaddr, priv->plat->dma_cfg,
+			    tx_q->dma_tx_phy, tx_q->queue_index);
+
+	if (tx_q->tbs & STMMAC_TBS_AVAIL)
+		stmmac_enable_tbs(priv, priv->ioaddr, 1, tx_q->queue_index);
+
+	tx_q->tx_tail_addr = tx_q->dma_tx_phy;
+	stmmac_set_tx_tail_ptr(priv, priv->ioaddr,
+			       tx_q->tx_tail_addr, tx_q->queue_index);
+
+	stmmac_start_tx_dma(priv, queue);
+
+	spin_lock_irqsave(&ch->lock, flags);
+	stmmac_enable_dma_irq(priv, priv->ioaddr, queue, 0, 1);
+	spin_unlock_irqrestore(&ch->lock, flags);
+}
+
 int stmmac_xsk_wakeup(struct net_device *dev, u32 queue, u32 flags)
 {
 	struct stmmac_priv *priv = netdev_priv(dev);
 	struct stmmac_rx_queue *rx_q;
+	struct stmmac_tx_queue *tx_q;
 	struct stmmac_channel *ch;
 
 	if (test_bit(STMMAC_DOWN, &priv->state) ||
@@ -6244,22 +6500,23 @@ int stmmac_xsk_wakeup(struct net_device *dev, u32 queue, u32 flags)
 	if (!stmmac_xdp_is_enabled(priv))
 		return -ENXIO;
 
-	if (queue >= priv->plat->rx_queues_to_use)
+	if (queue >= priv->plat->rx_queues_to_use ||
+	    queue >= priv->plat->tx_queues_to_use)
 		return -EINVAL;
 
 	rx_q = &priv->rx_queue[queue];
+	tx_q = &priv->tx_queue[queue];
 	ch = &priv->channel[queue];
 
-	if (!rx_q->xsk_pool)
+	if (!rx_q->xsk_pool && !tx_q->xsk_pool)
 		return -ENXIO;
 
-	if (flags & XDP_WAKEUP_RX &&
-	    !napi_if_scheduled_mark_missed(&ch->rx_napi)) {
+	if (!napi_if_scheduled_mark_missed(&ch->rxtx_napi)) {
 		/* EQoS does not have per-DMA channel SW interrupt,
 		 * so we schedule RX Napi straight-away.
 		 */
-		if (likely(napi_schedule_prep(&ch->rx_napi)))
-			__napi_schedule(&ch->rx_napi);
+		if (likely(napi_schedule_prep(&ch->rxtx_napi)))
+			__napi_schedule(&ch->rxtx_napi);
 	}
 
 	return 0;
@@ -6444,6 +6701,12 @@ static void stmmac_napi_add(struct net_device *dev)
 					  stmmac_napi_poll_tx,
 					  NAPI_POLL_WEIGHT);
 		}
+		if (queue < priv->plat->rx_queues_to_use &&
+		    queue < priv->plat->tx_queues_to_use) {
+			netif_napi_add(dev, &ch->rxtx_napi,
+				       stmmac_napi_poll_rxtx,
+				       NAPI_POLL_WEIGHT);
+		}
 	}
 }
 
@@ -6461,6 +6724,10 @@ static void stmmac_napi_del(struct net_device *dev)
 			netif_napi_del(&ch->rx_napi);
 		if (queue < priv->plat->tx_queues_to_use)
 			netif_napi_del(&ch->tx_napi);
+		if (queue < priv->plat->rx_queues_to_use &&
+		    queue < priv->plat->tx_queues_to_use) {
+			netif_napi_del(&ch->rxtx_napi);
+		}
 	}
 }
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_xdp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_xdp.c
index caff0dfc6f4b..105821b53020 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_xdp.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_xdp.c
@@ -14,7 +14,8 @@ static int stmmac_xdp_enable_pool(struct stmmac_priv *priv,
 	u32 frame_size;
 	int err;
 
-	if (queue >= priv->plat->rx_queues_to_use)
+	if (queue >= priv->plat->rx_queues_to_use ||
+	    queue >= priv->plat->tx_queues_to_use)
 		return -EINVAL;
 
 	frame_size = xsk_pool_get_rx_frame_size(pool);
@@ -34,14 +35,17 @@ static int stmmac_xdp_enable_pool(struct stmmac_priv *priv,
 
 	if (need_update) {
 		stmmac_disable_rx_queue(priv, queue);
+		stmmac_disable_tx_queue(priv, queue);
 		napi_disable(&ch->rx_napi);
+		napi_disable(&ch->tx_napi);
 	}
 
 	set_bit(queue, priv->af_xdp_zc_qps);
 
 	if (need_update) {
-		napi_enable(&ch->rx_napi);
+		napi_enable(&ch->rxtx_napi);
 		stmmac_enable_rx_queue(priv, queue);
+		stmmac_enable_tx_queue(priv, queue);
 
 		err = stmmac_xsk_wakeup(priv->dev, queue, XDP_WAKEUP_RX);
 		if (err)
@@ -57,7 +61,8 @@ static int stmmac_xdp_disable_pool(struct stmmac_priv *priv, u16 queue)
 	struct xsk_buff_pool *pool;
 	bool need_update;
 
-	if (queue >= priv->plat->rx_queues_to_use)
+	if (queue >= priv->plat->rx_queues_to_use ||
+	    queue >= priv->plat->tx_queues_to_use)
 		return -EINVAL;
 
 	pool = xsk_get_pool_from_qid(priv->dev, queue);
@@ -68,8 +73,9 @@ static int stmmac_xdp_disable_pool(struct stmmac_priv *priv, u16 queue)
 
 	if (need_update) {
 		stmmac_disable_rx_queue(priv, queue);
+		stmmac_disable_tx_queue(priv, queue);
 		synchronize_rcu();
-		napi_disable(&ch->rx_napi);
+		napi_disable(&ch->rxtx_napi);
 	}
 
 	xsk_pool_dma_unmap(pool, STMMAC_RX_DMA_ATTR);
@@ -78,7 +84,9 @@ static int stmmac_xdp_disable_pool(struct stmmac_priv *priv, u16 queue)
 
 	if (need_update) {
 		napi_enable(&ch->rx_napi);
+		napi_enable(&ch->tx_napi);
 		stmmac_enable_rx_queue(priv, queue);
+		stmmac_enable_tx_queue(priv, queue);
 	}
 
 	return 0;
-- 
2.25.1

Re: [PATCH net-next v2 0/7] stmmac: add XDP ZC support

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (refs/heads/master):

On Tue, 13 Apr 2021 17:36:19 +0800 you wrote:
> Hi,
> 
> This is the v2 patch series to add XDP ZC support to stmmac driver.
> 
> Summary of v2 patch change:-
> 
> 6/7: fix synchronize_rcu() is called stmmac_disable_all_queues() that is
>      used by ndo_setup_tc().
> 
> [...]

Here is the summary with links:
  - [net-next,v2,1/7] net: stmmac: rearrange RX buffer allocation and free functions
    https://git.kernel.org/netdev/net-next/c/4298255f26fa
  - [net-next,v2,2/7] net: stmmac: introduce dma_recycle_rx_skbufs for stmmac_reinit_rx_buffers
    https://git.kernel.org/netdev/net-next/c/80f573c995fc
  - [net-next,v2,3/7] net: stmmac: refactor stmmac_init_rx_buffers for stmmac_reinit_rx_buffers
    https://git.kernel.org/netdev/net-next/c/da5ec7f22a0f
  - [net-next,v2,4/7] net: stmmac: rearrange RX and TX desc init into per-queue basis
    https://git.kernel.org/netdev/net-next/c/de0b90e52a11
  - [net-next,v2,5/7] net: stmmac: Refactor __stmmac_xdp_run_prog for XDP ZC
    https://git.kernel.org/netdev/net-next/c/bba71cac680f
  - [net-next,v2,6/7] net: stmmac: Enable RX via AF_XDP zero-copy
    https://git.kernel.org/netdev/net-next/c/bba2556efad6
  - [net-next,v2,7/7] net: stmmac: Add TX via XDP zero-copy socket
    https://git.kernel.org/netdev/net-next/c/132c32ee5bc0

You are awesome, thank you!
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