net: ethernet: ti: am65-cpsw: Fix hardware switch mode on suspend/resume

On low power during system suspend the ALE table context is lost.
Save the ALE context before suspend and restore it after resume.
Signed-off-by: NRoger Quadros <rogerq@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/ti/am65-cpsw-nuss.c

@@ -2712,6 +2712,7 @@ static int am65_cpsw_nuss_probe(struct platform_device *pdev)
 	struct clk *clk;
 	u64 id_temp;
 	int ret, i;
+	int ale_entries;
 
 	common = devm_kzalloc(dev, sizeof(struct am65_cpsw_common), GFP_KERNEL);
 	if (!common)
@@ -2807,6 +2808,10 @@ static int am65_cpsw_nuss_probe(struct platform_device *pdev)
 		goto err_of_clear;
 	}
 
+	ale_entries = common->ale->params.ale_entries;
+	common->ale_context = devm_kzalloc(dev,
+					   ale_entries * ALE_ENTRY_WORDS * sizeof(u32),
+					   GFP_KERNEL);
 	ret = am65_cpsw_init_cpts(common);
 	if (ret)
 		goto err_of_clear;
@@ -2877,6 +2882,7 @@ static int am65_cpsw_nuss_suspend(struct device *dev)
 	struct net_device *ndev;
 	int i, ret;
 
+	cpsw_ale_dump(common->ale, common->ale_context);
 	host_p->vid_context = readl(host_p->port_base + AM65_CPSW_PORT_VLAN_REG_OFFSET);
 	for (i = 0; i < common->port_num; i++) {
 		port = &common->ports[i];
@@ -2949,6 +2955,7 @@ static int am65_cpsw_nuss_resume(struct device *dev)
 	}
 
 	writel(host_p->vid_context, host_p->port_base + AM65_CPSW_PORT_VLAN_REG_OFFSET);
+	cpsw_ale_restore(common->ale, common->ale_context);
 
 	return 0;
 }

drivers/net/ethernet/ti/am65-cpsw-nuss.h

@@ -149,6 +149,8 @@ struct am65_cpsw_common {
 	struct net_device *hw_bridge_dev;
 	struct notifier_block am65_cpsw_netdevice_nb;
 	unsigned char switch_id[MAX_PHYS_ITEM_ID_LEN];
+	/* only for suspend/resume context restore */
+	u32			*ale_context;
 };
 
 struct am65_cpsw_ndev_stats {