net: ethernet: ti am65_cpsw: Drop separate TX completion functions

Drop separate TX completion functions for SKB and XDP. To do that
use the SW_DATA mechanism to store ndev and skb/xdpf for TX packets.

Use BUILD_BUG_ON_MSG() to fail build if SW_DATA size exceeds whats
available. i.e. AM65_CPSW_NAV_SW_DATA_SIZE.

Signed-off-by: Roger Quadros <rogerq@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: rogerq

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

@@ -830,19 +830,19 @@ static void am65_cpsw_nuss_tx_cleanup(void *data, dma_addr_t desc_dma)
 {
 	struct am65_cpsw_tx_chn *tx_chn = data;
 	enum am65_cpsw_tx_buf_type buf_type;
+	struct am65_cpsw_tx_swdata *swdata;
 	struct cppi5_host_desc_t *desc_tx;
 	struct xdp_frame *xdpf;
 	struct sk_buff *skb;
-	void **swdata;
 
 	desc_tx = k3_cppi_desc_pool_dma2virt(tx_chn->desc_pool, desc_dma);
 	swdata = cppi5_hdesc_get_swdata(desc_tx);
 	buf_type = am65_cpsw_nuss_buf_type(tx_chn, desc_dma);
 	if (buf_type == AM65_CPSW_TX_BUF_TYPE_SKB) {
-		skb = *(swdata);
+		skb = swdata->skb;
 		dev_kfree_skb_any(skb);
 	} else {
-		xdpf = *(swdata);
+		xdpf = swdata->xdpf;
 		xdp_return_frame(xdpf);
 	}
 
@@ -1099,10 +1099,10 @@ static int am65_cpsw_xdp_tx_frame(struct net_device *ndev,
 	struct am65_cpsw_common *common = am65_ndev_to_common(ndev);
 	struct am65_cpsw_port *port = am65_ndev_to_port(ndev);
 	struct cppi5_host_desc_t *host_desc;
+	struct am65_cpsw_tx_swdata *swdata;
 	struct netdev_queue *netif_txq;
 	dma_addr_t dma_desc, dma_buf;
 	u32 pkt_len = xdpf->len;
-	void **swdata;
 	int ret;
 
 	host_desc = k3_cppi_desc_pool_alloc(tx_chn->desc_pool);
@@ -1132,7 +1132,8 @@ static int am65_cpsw_xdp_tx_frame(struct net_device *ndev,
 	cppi5_hdesc_attach_buf(host_desc, dma_buf, pkt_len, dma_buf, pkt_len);
 
 	swdata = cppi5_hdesc_get_swdata(host_desc);
-	*(swdata) = xdpf;
+	swdata->ndev = ndev;
+	swdata->xdpf = xdpf;
 
 	/* Report BQL before sending the packet */
 	netif_txq = netdev_get_tx_queue(ndev, tx_chn->id);
@@ -1435,52 +1436,6 @@ static int am65_cpsw_nuss_rx_poll(struct napi_struct *napi_rx, int budget)
 	return num_rx;
 }
 
-static struct sk_buff *
-am65_cpsw_nuss_tx_compl_packet_skb(struct am65_cpsw_tx_chn *tx_chn,
-				   dma_addr_t desc_dma)
-{
-	struct cppi5_host_desc_t *desc_tx;
-	struct sk_buff *skb;
-	void **swdata;
-
-	desc_tx = k3_cppi_desc_pool_dma2virt(tx_chn->desc_pool,
-					     desc_dma);
-	swdata = cppi5_hdesc_get_swdata(desc_tx);
-	skb = *(swdata);
-	am65_cpsw_nuss_xmit_free(tx_chn, desc_tx);
-
-	am65_cpts_tx_timestamp(tx_chn->common->cpts, skb);
-
-	dev_sw_netstats_tx_add(skb->dev, 1, skb->len);
-
-	return skb;
-}
-
-static struct xdp_frame *
-am65_cpsw_nuss_tx_compl_packet_xdp(struct am65_cpsw_common *common,
-				   struct am65_cpsw_tx_chn *tx_chn,
-				   dma_addr_t desc_dma,
-				   struct net_device **ndev)
-{
-	struct cppi5_host_desc_t *desc_tx;
-	struct am65_cpsw_port *port;
-	struct xdp_frame *xdpf;
-	u32 port_id = 0;
-	void **swdata;
-
-	desc_tx = k3_cppi_desc_pool_dma2virt(tx_chn->desc_pool, desc_dma);
-	cppi5_desc_get_tags_ids(&desc_tx->hdr, NULL, &port_id);
-	swdata = cppi5_hdesc_get_swdata(desc_tx);
-	xdpf = *(swdata);
-	am65_cpsw_nuss_xmit_free(tx_chn, desc_tx);
-
-	port = am65_common_get_port(common, port_id);
-	dev_sw_netstats_tx_add(port->ndev, 1, xdpf->len);
-	*ndev = port->ndev;
-
-	return xdpf;
-}
-
 static void am65_cpsw_nuss_tx_wake(struct am65_cpsw_tx_chn *tx_chn, struct net_device *ndev,
 				   struct netdev_queue *netif_txq)
 {
@@ -1503,6 +1458,8 @@ static int am65_cpsw_nuss_tx_compl_packets(struct am65_cpsw_common *common,
 {
 	bool single_port = AM65_CPSW_IS_CPSW2G(common);
 	enum am65_cpsw_tx_buf_type buf_type;
+	struct am65_cpsw_tx_swdata *swdata;
+	struct cppi5_host_desc_t *desc_tx;
 	struct device *dev = common->dev;
 	struct am65_cpsw_tx_chn *tx_chn;
 	struct netdev_queue *netif_txq;
@@ -1533,15 +1490,18 @@ static int am65_cpsw_nuss_tx_compl_packets(struct am65_cpsw_common *common,
 			break;
 		}
 
+		desc_tx = k3_cppi_desc_pool_dma2virt(tx_chn->desc_pool,
+						     desc_dma);
+		swdata = cppi5_hdesc_get_swdata(desc_tx);
+		ndev = swdata->ndev;
 		buf_type = am65_cpsw_nuss_buf_type(tx_chn, desc_dma);
 		if (buf_type == AM65_CPSW_TX_BUF_TYPE_SKB) {
-			skb = am65_cpsw_nuss_tx_compl_packet_skb(tx_chn, desc_dma);
-			ndev = skb->dev;
+			skb = swdata->skb;
+			am65_cpts_tx_timestamp(tx_chn->common->cpts, skb);
 			pkt_len = skb->len;
 			napi_consume_skb(skb, budget);
 		} else {
-			xdpf = am65_cpsw_nuss_tx_compl_packet_xdp(common, tx_chn,
-								  desc_dma, &ndev);
+			xdpf = swdata->xdpf;
 			pkt_len = xdpf->len;
 			if (buf_type == AM65_CPSW_TX_BUF_TYPE_XDP_TX)
 				xdp_return_frame_rx_napi(xdpf);
@@ -1551,7 +1511,8 @@ static int am65_cpsw_nuss_tx_compl_packets(struct am65_cpsw_common *common,
 
 		total_bytes += pkt_len;
 		num_tx++;
-
+		am65_cpsw_nuss_xmit_free(tx_chn, desc_tx);
+		dev_sw_netstats_tx_add(ndev, 1, pkt_len);
 		if (!single_port) {
 			/* as packets from multi ports can be interleaved
 			 * on the same channel, we have to figure out the
@@ -1634,12 +1595,12 @@ static netdev_tx_t am65_cpsw_nuss_ndo_slave_xmit(struct sk_buff *skb,
 	struct am65_cpsw_common *common = am65_ndev_to_common(ndev);
 	struct cppi5_host_desc_t *first_desc, *next_desc, *cur_desc;
 	struct am65_cpsw_port *port = am65_ndev_to_port(ndev);
+	struct am65_cpsw_tx_swdata *swdata;
 	struct device *dev = common->dev;
 	struct am65_cpsw_tx_chn *tx_chn;
 	struct netdev_queue *netif_txq;
 	dma_addr_t desc_dma, buf_dma;
 	int ret, q_idx, i;
-	void **swdata;
 	u32 *psdata;
 	u32 pkt_len;
 
@@ -1685,7 +1646,8 @@ static netdev_tx_t am65_cpsw_nuss_ndo_slave_xmit(struct sk_buff *skb,
 	k3_udma_glue_tx_dma_to_cppi5_addr(tx_chn->tx_chn, &buf_dma);
 	cppi5_hdesc_attach_buf(first_desc, buf_dma, pkt_len, buf_dma, pkt_len);
 	swdata = cppi5_hdesc_get_swdata(first_desc);
-	*(swdata) = skb;
+	swdata->ndev = ndev;
+	swdata->skb = skb;
 	psdata = cppi5_hdesc_get_psdata(first_desc);
 
 	/* HW csum offload if enabled */
@@ -3527,6 +3489,10 @@ static int am65_cpsw_nuss_probe(struct platform_device *pdev)
 	__be64 id_temp;
 	int ret, i;
 
+	BUILD_BUG_ON_MSG(sizeof(struct am65_cpsw_tx_swdata) > AM65_CPSW_NAV_SW_DATA_SIZE,
+			 "TX SW_DATA size exceeds AM65_CPSW_NAV_SW_DATA_SIZE");
+	BUILD_BUG_ON_MSG(sizeof(struct am65_cpsw_swdata) > AM65_CPSW_NAV_SW_DATA_SIZE,
+			 "SW_DATA size exceeds AM65_CPSW_NAV_SW_DATA_SIZE");
 	common = devm_kzalloc(dev, sizeof(struct am65_cpsw_common), GFP_KERNEL);
 	if (!common)
 		return -ENOMEM;

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

@@ -104,6 +104,14 @@ struct am65_cpsw_rx_flow {
 	char name[32];
 };
 
+struct am65_cpsw_tx_swdata {
+	struct net_device *ndev;
+	union {
+		struct sk_buff *skb;
+		struct xdp_frame *xdpf;
+	};
+};
+
 struct am65_cpsw_swdata {
 	u32 flow_id;
 	struct page *page;