Each port for a given ICSSG instance has their own set of
Tx and Rx queues. These functions will be further used while
performing ndo_bpf operations to set up the Tx/Rx queues for
a given port.

Signed-off-by: Meghana Malladi <m-malladi@ti.com>
---
 drivers/net/ethernet/ti/icssg/icssg_common.c |   6 +-
 drivers/net/ethernet/ti/icssg/icssg_prueth.c | 193 +++++++++++++------
 drivers/net/ethernet/ti/icssg/icssg_prueth.h |   2 +
 3 files changed, 139 insertions(+), 62 deletions(-)

diff --git a/drivers/net/ethernet/ti/icssg/icssg_common.c b/drivers/net/ethernet/ti/icssg/icssg_common.c
index 57e5f1c88f50..5d31873492b6 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_common.c
+++ b/drivers/net/ethernet/ti/icssg/icssg_common.c
@@ -804,7 +804,7 @@ static int emac_rx_packet(struct prueth_emac *emac, u32 flow_id, u32 *xdp_state)
 	return ret;
 }
 
-static void prueth_rx_cleanup(void *data, dma_addr_t desc_dma)
+void prueth_rx_cleanup(void *data, dma_addr_t desc_dma)
 {
 	struct prueth_rx_chn *rx_chn = data;
 	struct cppi5_host_desc_t *desc_rx;
@@ -822,6 +822,7 @@ static void prueth_rx_cleanup(void *data, dma_addr_t desc_dma)
 
 	k3_cppi_desc_pool_free(rx_chn->desc_pool, desc_rx);
 }
+EXPORT_SYMBOL_GPL(prueth_rx_cleanup);
 
 static int prueth_tx_ts_cookie_get(struct prueth_emac *emac)
 {
@@ -1025,7 +1026,7 @@ enum netdev_tx icssg_ndo_start_xmit(struct sk_buff *skb, struct net_device *ndev
 }
 EXPORT_SYMBOL_GPL(icssg_ndo_start_xmit);
 
-static void prueth_tx_cleanup(void *data, dma_addr_t desc_dma)
+void prueth_tx_cleanup(void *data, dma_addr_t desc_dma)
 {
 	struct prueth_tx_chn *tx_chn = data;
 	struct cppi5_host_desc_t *desc_tx;
@@ -1051,6 +1052,7 @@ static void prueth_tx_cleanup(void *data, dma_addr_t desc_dma)
 
 	prueth_xmit_free(tx_chn, desc_tx);
 }
+EXPORT_SYMBOL_GPL(prueth_tx_cleanup);
 
 irqreturn_t prueth_rx_irq(int irq, void *dev_id)
 {
diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.c b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
index dadce6009791..ab8c240a6e8a 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_prueth.c
+++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
@@ -727,6 +727,103 @@ static int icssg_update_vlan_mcast(struct net_device *vdev, int vid,
 	return 0;
 }
 
+static void prueth_destroy_txq(struct prueth_emac *emac)
+{
+	int ret, i;
+
+	atomic_set(&emac->tdown_cnt, emac->tx_ch_num);
+	/* ensure new tdown_cnt value is visible */
+	smp_mb__after_atomic();
+	/* tear down and disable UDMA channels */
+	reinit_completion(&emac->tdown_complete);
+	for (i = 0; i < emac->tx_ch_num; i++)
+		k3_udma_glue_tdown_tx_chn(emac->tx_chns[i].tx_chn, false);
+
+	ret = wait_for_completion_timeout(&emac->tdown_complete,
+					  msecs_to_jiffies(1000));
+	if (!ret)
+		netdev_err(emac->ndev, "tx teardown timeout\n");
+
+	for (i = 0; i < emac->tx_ch_num; i++) {
+		k3_udma_glue_reset_tx_chn(emac->tx_chns[i].tx_chn,
+					  &emac->tx_chns[i],
+					  prueth_tx_cleanup);
+		k3_udma_glue_disable_tx_chn(emac->tx_chns[i].tx_chn);
+		napi_disable(&emac->tx_chns[i].napi_tx);
+		hrtimer_cancel(&emac->tx_chns[i].tx_hrtimer);
+	}
+}
+
+static void prueth_destroy_rxq(struct prueth_emac *emac)
+{
+	int i;
+
+	/* tear down and disable UDMA channels */
+	reinit_completion(&emac->tdown_complete);
+	k3_udma_glue_tdown_rx_chn(emac->rx_chns.rx_chn, true);
+
+	wait_for_completion_timeout(&emac->tdown_complete,
+				    msecs_to_jiffies(1000));
+
+	for (i = 0; i < PRUETH_MAX_RX_FLOWS; i++) {
+		k3_udma_glue_reset_rx_chn(emac->rx_chns.rx_chn, i,
+					  &emac->rx_chns,
+					  prueth_rx_cleanup);
+	}
+	napi_disable(&emac->napi_rx);
+	hrtimer_cancel(&emac->rx_hrtimer);
+	prueth_destroy_xdp_rxqs(emac);
+	k3_udma_glue_disable_rx_chn(emac->rx_chns.rx_chn);
+
+	emac->rx_chns.pg_pool = NULL;
+}
+
+static int prueth_create_txq(struct prueth_emac *emac)
+{
+	int ret, i;
+
+	for (i = 0; i < emac->tx_ch_num; i++) {
+		ret = k3_udma_glue_enable_tx_chn(emac->tx_chns[i].tx_chn);
+		if (ret)
+			goto reset_tx_chan;
+		napi_enable(&emac->tx_chns[i].napi_tx);
+	}
+	return 0;
+
+reset_tx_chan:
+	/* Since interface is not yet up, there is wouldn't be
+	 * any SKB for completion. So set false to free_skb
+	 */
+	prueth_reset_tx_chan(emac, i, false);
+	return ret;
+}
+
+static int prueth_create_rxq(struct prueth_emac *emac)
+{
+	int ret;
+
+	ret = prueth_prepare_rx_chan(emac, &emac->rx_chns, PRUETH_MAX_PKT_SIZE);
+	if (ret)
+		return ret;
+
+	ret = prueth_create_xdp_rxqs(emac);
+	if (ret)
+		goto reset_rx_chn;
+
+	ret = k3_udma_glue_enable_rx_chn(emac->rx_chns.rx_chn);
+	if (ret)
+		goto destroy_xdp_rxqs;
+
+	napi_enable(&emac->napi_rx);
+	return 0;
+
+destroy_xdp_rxqs:
+	prueth_destroy_xdp_rxqs(emac);
+reset_rx_chn:
+	prueth_reset_rx_chan(&emac->rx_chns, PRUETH_MAX_RX_FLOWS, false);
+	return ret;
+}
+
 /**
  * emac_ndo_open - EMAC device open
  * @ndev: network adapter device
@@ -738,7 +835,7 @@ static int icssg_update_vlan_mcast(struct net_device *vdev, int vid,
 static int emac_ndo_open(struct net_device *ndev)
 {
 	struct prueth_emac *emac = netdev_priv(ndev);
-	int ret, i, num_data_chn = emac->tx_ch_num;
+	int ret, num_data_chn = emac->tx_ch_num;
 	struct icssg_flow_cfg __iomem *flow_cfg;
 	struct prueth *prueth = emac->prueth;
 	int slice = prueth_emac_slice(emac);
@@ -811,28 +908,13 @@ static int emac_ndo_open(struct net_device *ndev)
 		goto stop;
 
 	/* Prepare RX */
-	ret = prueth_prepare_rx_chan(emac, &emac->rx_chns, PRUETH_MAX_PKT_SIZE);
+	ret = prueth_create_rxq(emac);
 	if (ret)
 		goto free_tx_ts_irq;
 
-	ret = prueth_create_xdp_rxqs(emac);
-	if (ret)
-		goto reset_rx_chn;
-
-	ret = k3_udma_glue_enable_rx_chn(emac->rx_chns.rx_chn);
+	ret = prueth_create_txq(emac);
 	if (ret)
-		goto destroy_xdp_rxqs;
-
-	for (i = 0; i < emac->tx_ch_num; i++) {
-		ret = k3_udma_glue_enable_tx_chn(emac->tx_chns[i].tx_chn);
-		if (ret)
-			goto reset_tx_chan;
-	}
-
-	/* Enable NAPI in Tx and Rx direction */
-	for (i = 0; i < emac->tx_ch_num; i++)
-		napi_enable(&emac->tx_chns[i].napi_tx);
-	napi_enable(&emac->napi_rx);
+		goto destroy_rxq;
 
 	/* start PHY */
 	phy_start(ndev->phydev);
@@ -843,15 +925,8 @@ static int emac_ndo_open(struct net_device *ndev)
 
 	return 0;
 
-reset_tx_chan:
-	/* Since interface is not yet up, there is wouldn't be
-	 * any SKB for completion. So set false to free_skb
-	 */
-	prueth_reset_tx_chan(emac, i, false);
-destroy_xdp_rxqs:
-	prueth_destroy_xdp_rxqs(emac);
-reset_rx_chn:
-	prueth_reset_rx_chan(&emac->rx_chns, max_rx_flows, false);
+destroy_rxq:
+	prueth_destroy_rxq(emac);
 free_tx_ts_irq:
 	free_irq(emac->tx_ts_irq, emac);
 stop:
@@ -881,9 +956,6 @@ static int emac_ndo_stop(struct net_device *ndev)
 {
 	struct prueth_emac *emac = netdev_priv(ndev);
 	struct prueth *prueth = emac->prueth;
-	int rx_flow = PRUETH_RX_FLOW_DATA;
-	int max_rx_flows;
-	int ret, i;
 
 	/* inform the upper layers. */
 	netif_tx_stop_all_queues(ndev);
@@ -897,32 +969,8 @@ static int emac_ndo_stop(struct net_device *ndev)
 	else
 		__dev_mc_unsync(ndev, icssg_prueth_del_mcast);
 
-	atomic_set(&emac->tdown_cnt, emac->tx_ch_num);
-	/* ensure new tdown_cnt value is visible */
-	smp_mb__after_atomic();
-	/* tear down and disable UDMA channels */
-	reinit_completion(&emac->tdown_complete);
-	for (i = 0; i < emac->tx_ch_num; i++)
-		k3_udma_glue_tdown_tx_chn(emac->tx_chns[i].tx_chn, false);
-
-	ret = wait_for_completion_timeout(&emac->tdown_complete,
-					  msecs_to_jiffies(1000));
-	if (!ret)
-		netdev_err(ndev, "tx teardown timeout\n");
-
-	prueth_reset_tx_chan(emac, emac->tx_ch_num, true);
-	for (i = 0; i < emac->tx_ch_num; i++) {
-		napi_disable(&emac->tx_chns[i].napi_tx);
-		hrtimer_cancel(&emac->tx_chns[i].tx_hrtimer);
-	}
-
-	max_rx_flows = PRUETH_MAX_RX_FLOWS;
-	k3_udma_glue_tdown_rx_chn(emac->rx_chns.rx_chn, true);
-
-	prueth_reset_rx_chan(&emac->rx_chns, max_rx_flows, true);
-	prueth_destroy_xdp_rxqs(emac);
-	napi_disable(&emac->napi_rx);
-	hrtimer_cancel(&emac->rx_hrtimer);
+	prueth_destroy_txq(emac);
+	prueth_destroy_rxq(emac);
 
 	cancel_work_sync(&emac->rx_mode_work);
 
@@ -935,10 +983,10 @@ static int emac_ndo_stop(struct net_device *ndev)
 
 	free_irq(emac->tx_ts_irq, emac);
 
-	free_irq(emac->rx_chns.irq[rx_flow], emac);
+	free_irq(emac->rx_chns.irq[PRUETH_RX_FLOW_DATA], emac);
 	prueth_ndev_del_tx_napi(emac, emac->tx_ch_num);
 
-	prueth_cleanup_rx_chns(emac, &emac->rx_chns, max_rx_flows);
+	prueth_cleanup_rx_chns(emac, &emac->rx_chns, PRUETH_MAX_RX_FLOWS);
 	prueth_cleanup_tx_chns(emac);
 
 	prueth->emacs_initialized--;
@@ -1122,11 +1170,36 @@ static int emac_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frame
 static int emac_xdp_setup(struct prueth_emac *emac, struct netdev_bpf *bpf)
 {
 	struct bpf_prog *prog = bpf->prog;
+	struct bpf_prog *old_prog;
+	int ret;
 
 	if (!emac->xdpi.prog && !prog)
 		return 0;
 
-	WRITE_ONCE(emac->xdp_prog, prog);
+	if (netif_running(emac->ndev)) {
+		prueth_destroy_txq(emac);
+		prueth_destroy_rxq(emac);
+	}
+
+	old_prog = xchg(&emac->xdp_prog, prog);
+	if (old_prog)
+		bpf_prog_put(old_prog);
+
+	if (netif_running(emac->ndev)) {
+		ret = prueth_create_rxq(emac);
+		if (ret) {
+			netdev_err(emac->ndev, "Failed to create RX queue: %d\n", ret);
+			return ret;
+		}
+
+		ret = prueth_create_txq(emac);
+		if (ret) {
+			netdev_err(emac->ndev, "Failed to create TX queue: %d\n", ret);
+			prueth_destroy_rxq(emac);
+			emac->xdp_prog = NULL;
+			return ret;
+		}
+	}
 
 	xdp_attachment_setup(&emac->xdpi, bpf);
 
diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.h b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
index ca8a22a4a5da..e0dadbfca45a 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_prueth.h
+++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
@@ -497,5 +497,7 @@ u32 emac_xmit_xdp_frame(struct prueth_emac *emac,
 			struct xdp_frame *xdpf,
 			struct page *page,
 			unsigned int q_idx);
+void prueth_rx_cleanup(void *data, dma_addr_t desc_dma);
+void prueth_tx_cleanup(void *data, dma_addr_t desc_dma);
 
 #endif /* __NET_TI_ICSSG_PRUETH_H */
-- 
2.43.0

On Mon, 1 Sep 2025 15:32:22 +0530 Meghana Malladi wrote:
>  	if (!emac->xdpi.prog && !prog)
>  		return 0;
>  
> -	WRITE_ONCE(emac->xdp_prog, prog);
> +	if (netif_running(emac->ndev)) {
> +		prueth_destroy_txq(emac);
> +		prueth_destroy_rxq(emac);
> +	}
> +
> +	old_prog = xchg(&emac->xdp_prog, prog);
> +	if (old_prog)
> +		bpf_prog_put(old_prog);
> +
> +	if (netif_running(emac->ndev)) {
> +		ret = prueth_create_rxq(emac);

shutting the device down and freeing all rx memory for reconfig is not
okay. If the system is low on memory the Rx buffer allocations may fail
and system may drop off the network. You must either pre-allocate or
avoid freeing the memory, and just restart the queues.

> +		if (ret) {
> +			netdev_err(emac->ndev, "Failed to create RX queue: %d\n", ret);
> +			return ret;
> +		}
> +
> +		ret = prueth_create_txq(emac);
> +		if (ret) {
> +			netdev_err(emac->ndev, "Failed to create TX queue: %d\n", ret);
> +			prueth_destroy_rxq(emac);
> +			emac->xdp_prog = NULL;
> +			return ret;
> +		}
> +	}
>  
>  	xdp_attachment_setup(&emac->xdpi, bpf);