net: ti: icssg-prueth: introduce and use prueth_swdata struct for SWDATA

We have different cases for SWDATA (skb, page, cmd, etc)
so it is better to have a dedicated data structure for that.
We can embed the type field inside the struct and use it
to interpret the data in completion handlers.

Signed-off-by: Roger Quadros <[email protected]>
Signed-off-by: MD Danish Anwar <[email protected]>
Signed-off-by: Meghana Malladi <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>

Author: rogerq

drivers/net/ethernet/ti/icssg/icssg_common.c

@@ -136,12 +136,12 @@ int emac_tx_complete_packets(struct prueth_emac *emac, int chn,
 	struct net_device *ndev = emac->ndev;
 	struct cppi5_host_desc_t *desc_tx;
 	struct netdev_queue *netif_txq;
+	struct prueth_swdata *swdata;
 	struct prueth_tx_chn *tx_chn;
 	unsigned int total_bytes = 0;
 	struct sk_buff *skb;
 	dma_addr_t desc_dma;
 	int res, num_tx = 0;
-	void **swdata;
 
 	tx_chn = &emac->tx_chns[chn];
 
@@ -161,16 +161,11 @@ int emac_tx_complete_packets(struct prueth_emac *emac, int chn,
 		desc_tx = k3_cppi_desc_pool_dma2virt(tx_chn->desc_pool,
 						     desc_dma);
 		swdata = cppi5_hdesc_get_swdata(desc_tx);
-
-		/* was this command's TX complete? */
-		if (emac->is_sr1 && *(swdata) == emac->cmd_data) {
-			prueth_xmit_free(tx_chn, desc_tx);
-			continue;
-		}
-
-		skb = *(swdata);
 		prueth_xmit_free(tx_chn, desc_tx);
+		if (swdata->type != PRUETH_SWDATA_SKB)
+			continue;
 
+		skb = swdata->data.skb;
 		ndev = skb->dev;
 		ndev->stats.tx_packets++;
 		ndev->stats.tx_bytes += skb->len;
@@ -472,9 +467,9 @@ int prueth_dma_rx_push_mapped(struct prueth_emac *emac,
 {
 	struct net_device *ndev = emac->ndev;
 	struct cppi5_host_desc_t *desc_rx;
+	struct prueth_swdata *swdata;
 	dma_addr_t desc_dma;
 	dma_addr_t buf_dma;
-	void **swdata;
 
 	buf_dma = page_pool_get_dma_addr(page) + PRUETH_HEADROOM;
 	desc_rx = k3_cppi_desc_pool_alloc(rx_chn->desc_pool);
@@ -490,7 +485,8 @@ int prueth_dma_rx_push_mapped(struct prueth_emac *emac,
 	cppi5_hdesc_attach_buf(desc_rx, buf_dma, buf_len, buf_dma, buf_len);
 
 	swdata = cppi5_hdesc_get_swdata(desc_rx);
-	*swdata = page;
+	swdata->type = PRUETH_SWDATA_PAGE;
+	swdata->data.page = page;
 
 	return k3_udma_glue_push_rx_chn(rx_chn->rx_chn, PRUETH_RX_FLOW_DATA,
 					desc_rx, desc_dma);
@@ -539,11 +535,11 @@ static int emac_rx_packet(struct prueth_emac *emac, u32 flow_id)
 	u32 buf_dma_len, pkt_len, port_id = 0;
 	struct net_device *ndev = emac->ndev;
 	struct cppi5_host_desc_t *desc_rx;
+	struct prueth_swdata *swdata;
 	dma_addr_t desc_dma, buf_dma;
 	struct page *page, *new_page;
 	struct page_pool *pool;
 	struct sk_buff *skb;
-	void **swdata;
 	u32 *psdata;
 	void *pa;
 	int ret;
@@ -561,7 +557,13 @@ static int emac_rx_packet(struct prueth_emac *emac, u32 flow_id)
 
 	desc_rx = k3_cppi_desc_pool_dma2virt(rx_chn->desc_pool, desc_dma);
 	swdata = cppi5_hdesc_get_swdata(desc_rx);
-	page = *swdata;
+	if (swdata->type != PRUETH_SWDATA_PAGE) {
+		netdev_err(ndev, "rx_pkt: invalid swdata->type %d\n", swdata->type);
+		k3_cppi_desc_pool_free(rx_chn->desc_pool, desc_rx);
+		return 0;
+	}
+
+	page = swdata->data.page;
 	page_pool_dma_sync_for_cpu(pool, page, 0, PAGE_SIZE);
 	cppi5_hdesc_get_obuf(desc_rx, &buf_dma, &buf_dma_len);
 	k3_udma_glue_rx_cppi5_to_dma_addr(rx_chn->rx_chn, &buf_dma);
@@ -626,15 +628,18 @@ static 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;
+	struct prueth_swdata *swdata;
 	struct page_pool *pool;
 	struct page *page;
-	void **swdata;
 
 	pool = rx_chn->pg_pool;
 	desc_rx = k3_cppi_desc_pool_dma2virt(rx_chn->desc_pool, desc_dma);
 	swdata = cppi5_hdesc_get_swdata(desc_rx);
-	page = *swdata;
-	page_pool_recycle_direct(pool, page);
+	if (swdata->type == PRUETH_SWDATA_PAGE) {
+		page = swdata->data.page;
+		page_pool_recycle_direct(pool, page);
+	}
+
 	k3_cppi_desc_pool_free(rx_chn->desc_pool, desc_rx);
 }
 
@@ -671,13 +676,13 @@ enum netdev_tx icssg_ndo_start_xmit(struct sk_buff *skb, struct net_device *ndev
 	struct prueth_emac *emac = netdev_priv(ndev);
 	struct prueth *prueth = emac->prueth;
 	struct netdev_queue *netif_txq;
+	struct prueth_swdata *swdata;
 	struct prueth_tx_chn *tx_chn;
 	dma_addr_t desc_dma, buf_dma;
 	u32 pkt_len, dst_tag_id;
 	int i, ret = 0, q_idx;
 	bool in_tx_ts = 0;
 	int tx_ts_cookie;
-	void **swdata;
 	u32 *epib;
 
 	pkt_len = skb_headlen(skb);
@@ -739,7 +744,8 @@ enum netdev_tx icssg_ndo_start_xmit(struct sk_buff *skb, struct net_device *ndev
 	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->type = PRUETH_SWDATA_SKB;
+	swdata->data.skb = skb;
 
 	/* Handle the case where skb is fragmented in pages */
 	cur_desc = first_desc;
@@ -842,15 +848,17 @@ static 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;
+	struct prueth_swdata *swdata;
 	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);
-	prueth_xmit_free(tx_chn, desc_tx);
+	if (swdata->type == PRUETH_SWDATA_SKB) {
+		skb = swdata->data.skb;
+		dev_kfree_skb_any(skb);
+	}
 
-	dev_kfree_skb_any(skb);
+	prueth_xmit_free(tx_chn, desc_tx);
 }
 
 irqreturn_t prueth_rx_irq(int irq, void *dev_id)

drivers/net/ethernet/ti/icssg/icssg_prueth.c

@@ -1522,6 +1522,9 @@ static int prueth_probe(struct platform_device *pdev)
 
 	np = dev->of_node;
 
+	BUILD_BUG_ON_MSG((sizeof(struct prueth_swdata) > PRUETH_NAV_SW_DATA_SIZE),
+			 "insufficient SW_DATA size");
+
 	prueth = devm_kzalloc(dev, sizeof(*prueth), GFP_KERNEL);
 	if (!prueth)
 		return -ENOMEM;

drivers/net/ethernet/ti/icssg/icssg_prueth.h

@@ -136,6 +136,22 @@ struct prueth_rx_chn {
 	struct page_pool *pg_pool;
 };
 
+enum prueth_swdata_type {
+	PRUETH_SWDATA_INVALID = 0,
+	PRUETH_SWDATA_SKB,
+	PRUETH_SWDATA_PAGE,
+	PRUETH_SWDATA_CMD,
+};
+
+struct prueth_swdata {
+	enum prueth_swdata_type type;
+	union prueth_data {
+		struct sk_buff *skb;
+		struct page *page;
+		u32 cmd;
+	} data;
+};
+
 /* There are 4 Tx DMA channels, but the highest priority is CH3 (thread 3)
  * and lower three are lower priority channels or threads.
  */

drivers/net/ethernet/ti/icssg/icssg_prueth_sr1.c

@@ -84,7 +84,7 @@ static int emac_send_command_sr1(struct prueth_emac *emac, u32 cmd)
 	__le32 *data = emac->cmd_data;
 	dma_addr_t desc_dma, buf_dma;
 	struct prueth_tx_chn *tx_chn;
-	void **swdata;
+	struct prueth_swdata *swdata;
 	int ret = 0;
 	u32 *epib;
 
@@ -122,7 +122,8 @@ static int emac_send_command_sr1(struct prueth_emac *emac, u32 cmd)
 
 	cppi5_hdesc_attach_buf(first_desc, buf_dma, pkt_len, buf_dma, pkt_len);
 	swdata = cppi5_hdesc_get_swdata(first_desc);
-	*swdata = data;
+	swdata->type = PRUETH_SWDATA_CMD;
+	swdata->data.cmd = le32_to_cpu(data[0]);
 
 	cppi5_hdesc_set_pktlen(first_desc, pkt_len);
 	desc_dma = k3_cppi_desc_pool_virt2dma(tx_chn->desc_pool, first_desc);
@@ -275,9 +276,9 @@ static struct page *prueth_process_rx_mgm(struct prueth_emac *emac,
 	struct net_device *ndev = emac->ndev;
 	struct cppi5_host_desc_t *desc_rx;
 	struct page *page, *new_page;
+	struct prueth_swdata *swdata;
 	dma_addr_t desc_dma, buf_dma;
 	u32 buf_dma_len;
-	void **swdata;
 	int ret;
 
 	ret = k3_udma_glue_pop_rx_chn(rx_chn->rx_chn, flow_id, &desc_dma);
@@ -299,7 +300,7 @@ static struct page *prueth_process_rx_mgm(struct prueth_emac *emac,
 	}
 
 	swdata = cppi5_hdesc_get_swdata(desc_rx);
-	page = *swdata;
+	page = swdata->data.page;
 	cppi5_hdesc_get_obuf(desc_rx, &buf_dma, &buf_dma_len);
 
 	dma_unmap_single(rx_chn->dma_dev, buf_dma, buf_dma_len, DMA_FROM_DEVICE);