Merge branch 'net-thunderbolt-add-tracepoints'

Mika Westerberg says:

====================
net: thunderbolt: Add tracepoints

This series adds tracepoints and additional logging to the
Thunderbolt/USB4 networking driver. These are useful when debugging
possible issues.

Before that we move the driver into its own directory under drivers/net
so that we can add additional files without trashing the network drivers
main directory, and update the MAINTAINERS accordingly.

v1: https://lore.kernel.org/netdev/20230104081731.45928-1-mika.westerberg@linux.intel.com/
====================

Link: https://lore.kernel.org/r/20230111062633.1385-1-mika.westerberg@linux.intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

MAINTAINERS

@@ -20789,7 +20789,7 @@ M:	Mika Westerberg <mika.westerberg@linux.intel.com>
 M:	Yehezkel Bernat <YehezkelShB@gmail.com>
 L:	netdev@vger.kernel.org
 S:	Maintained
-F:	drivers/net/thunderbolt.c
+F:	drivers/net/thunderbolt/
 
 THUNDERX GPIO DRIVER
 M:	Robert Richter <rric@kernel.org>

drivers/net/Kconfig

@@ -583,18 +583,7 @@ config FUJITSU_ES
 	  This driver provides support for Extended Socket network device
 	  on Extended Partitioning of FUJITSU PRIMEQUEST 2000 E2 series.
 
-config USB4_NET
-	tristate "Networking over USB4 and Thunderbolt cables"
-	depends on USB4 && INET
-	help
-	  Select this if you want to create network between two computers
-	  over a USB4 and Thunderbolt cables. The driver supports Apple
-	  ThunderboltIP protocol and allows communication with any host
-	  supporting the same protocol including Windows and macOS.
-
-	  To compile this driver a module, choose M here. The module will be
-	  called thunderbolt-net.
-
+source "drivers/net/thunderbolt/Kconfig"
 source "drivers/net/hyperv/Kconfig"
 
 config NETDEVSIM

drivers/net/Makefile

@@ -84,8 +84,6 @@ obj-$(CONFIG_HYPERV_NET) += hyperv/
 obj-$(CONFIG_NTB_NETDEV) += ntb_netdev.o
 
 obj-$(CONFIG_FUJITSU_ES) += fjes/
-
-thunderbolt-net-y += thunderbolt.o
-obj-$(CONFIG_USB4_NET) += thunderbolt-net.o
+obj-$(CONFIG_USB4_NET) += thunderbolt/
 obj-$(CONFIG_NETDEVSIM) += netdevsim/
 obj-$(CONFIG_NET_FAILOVER) += net_failover.o

drivers/net/thunderbolt/Kconfig

@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config USB4_NET
+	tristate "Networking over USB4 and Thunderbolt cables"
+	depends on USB4 && INET
+	help
+	  Select this if you want to create network between two computers
+	  over a USB4 and Thunderbolt cables. The driver supports Apple
+	  ThunderboltIP protocol and allows communication with any host
+	  supporting the same protocol including Windows and macOS.
+
+	  To compile this driver a module, choose M here. The module will be
+	  called thunderbolt_net.

drivers/net/thunderbolt/Makefile

@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_USB4_NET) := thunderbolt_net.o
+thunderbolt_net-objs := main.o trace.o
+
+# Tracepoints need to know where to find trace.h
+CFLAGS_trace.o := -I$(src)

drivers/net/thunderbolt.c → drivers/net/thunderbolt/main.c

@@ -23,6 +23,8 @@
 
 #include <net/ip6_checksum.h>
 
+#include "trace.h"
+
 /* Protocol timeouts in ms */
 #define TBNET_LOGIN_DELAY	4500
 #define TBNET_LOGIN_TIMEOUT	500
@@ -305,6 +307,8 @@ static int tbnet_logout_request(struct tbnet *net)
 
 static void start_login(struct tbnet *net)
 {
+	netdev_dbg(net->dev, "login started\n");
+
 	mutex_lock(&net->connection_lock);
 	net->login_sent = false;
 	net->login_received = false;
@@ -318,6 +322,8 @@ static void stop_login(struct tbnet *net)
 {
 	cancel_delayed_work_sync(&net->login_work);
 	cancel_work_sync(&net->connected_work);
+
+	netdev_dbg(net->dev, "login stopped\n");
 }
 
 static inline unsigned int tbnet_frame_size(const struct tbnet_frame *tf)
@@ -349,6 +355,8 @@ static void tbnet_free_buffers(struct tbnet_ring *ring)
 			size = TBNET_RX_PAGE_SIZE;
 		}
 
+		trace_tbnet_free_frame(i, tf->page, tf->frame.buffer_phy, dir);
+
 		if (tf->frame.buffer_phy)
 			dma_unmap_page(dma_dev, tf->frame.buffer_phy, size,
 				       dir);
@@ -374,6 +382,8 @@ static void tbnet_tear_down(struct tbnet *net, bool send_logout)
 		int ret, retries = TBNET_LOGOUT_RETRIES;
 
 		while (send_logout && retries-- > 0) {
+			netdev_dbg(net->dev, "sending logout request %u\n",
+				   retries);
 			ret = tbnet_logout_request(net);
 			if (ret != -ETIMEDOUT)
 				break;
@@ -400,6 +410,8 @@ static void tbnet_tear_down(struct tbnet *net, bool send_logout)
 	net->login_sent = false;
 	net->login_received = false;
 
+	netdev_dbg(net->dev, "network traffic stopped\n");
+
 	mutex_unlock(&net->connection_lock);
 }
 
@@ -431,12 +443,15 @@ static int tbnet_handle_packet(const void *buf, size_t size, void *data)
 
 	switch (pkg->hdr.type) {
 	case TBIP_LOGIN:
+		netdev_dbg(net->dev, "remote login request received\n");
 		if (!netif_running(net->dev))
 			break;
 
 		ret = tbnet_login_response(net, route, sequence,
 					   pkg->hdr.command_id);
 		if (!ret) {
+			netdev_dbg(net->dev, "remote login response sent\n");
+
 			mutex_lock(&net->connection_lock);
 			net->login_received = true;
 			net->remote_transmit_path = pkg->transmit_path;
@@ -458,9 +473,12 @@ static int tbnet_handle_packet(const void *buf, size_t size, void *data)
 		break;
 
 	case TBIP_LOGOUT:
+		netdev_dbg(net->dev, "remote logout request received\n");
 		ret = tbnet_logout_response(net, route, sequence, command_id);
-		if (!ret)
+		if (!ret) {
+			netdev_dbg(net->dev, "remote logout response sent\n");
 			queue_work(system_long_wq, &net->disconnect_work);
+		}
 		break;
 
 	default:
@@ -512,6 +530,9 @@ static int tbnet_alloc_rx_buffers(struct tbnet *net, unsigned int nbuffers)
 		tf->frame.buffer_phy = dma_addr;
 		tf->dev = net->dev;
 
+		trace_tbnet_alloc_rx_frame(index, tf->page, dma_addr,
+					   DMA_FROM_DEVICE);
+
 		tb_ring_rx(ring->ring, &tf->frame);
 
 		ring->prod++;
@@ -588,6 +609,8 @@ static int tbnet_alloc_tx_buffers(struct tbnet *net)
 		tf->frame.callback = tbnet_tx_callback;
 		tf->frame.sof = TBIP_PDF_FRAME_START;
 		tf->frame.eof = TBIP_PDF_FRAME_END;
+
+		trace_tbnet_alloc_tx_frame(i, tf->page, dma_addr, DMA_TO_DEVICE);
 	}
 
 	ring->cons = 0;
@@ -612,6 +635,8 @@ static void tbnet_connected_work(struct work_struct *work)
 	if (!connected)
 		return;
 
+	netdev_dbg(net->dev, "login successful, enabling paths\n");
+
 	ret = tb_xdomain_alloc_in_hopid(net->xd, net->remote_transmit_path);
 	if (ret != net->remote_transmit_path) {
 		netdev_err(net->dev, "failed to allocate Rx HopID\n");
@@ -647,6 +672,8 @@ static void tbnet_connected_work(struct work_struct *work)
 
 	netif_carrier_on(net->dev);
 	netif_start_queue(net->dev);
+
+	netdev_dbg(net->dev, "network traffic started\n");
 	return;
 
 err_free_tx_buffers:
@@ -668,15 +695,22 @@ static void tbnet_login_work(struct work_struct *work)
 	if (netif_carrier_ok(net->dev))
 		return;
 
+	netdev_dbg(net->dev, "sending login request, retries=%u\n",
+		   net->login_retries);
+
 	ret = tbnet_login_request(net, net->login_retries % 4);
 	if (ret) {
+		netdev_dbg(net->dev, "sending login request failed, ret=%d\n",
+			   ret);
 		if (net->login_retries++ < TBNET_LOGIN_RETRIES) {
 			queue_delayed_work(system_long_wq, &net->login_work,
 					   delay);
 		} else {
 			netdev_info(net->dev, "ThunderboltIP login timed out\n");
 		}
 	} else {
+		netdev_dbg(net->dev, "received login reply\n");
+
 		net->login_retries = 0;
 
 		mutex_lock(&net->connection_lock);
@@ -807,12 +841,16 @@ static int tbnet_poll(struct napi_struct *napi, int budget)
 
 		hdr = page_address(page);
 		if (!tbnet_check_frame(net, tf, hdr)) {
+			trace_tbnet_invalid_rx_ip_frame(hdr->frame_size,
+				hdr->frame_id, hdr->frame_index, hdr->frame_count);
 			__free_pages(page, TBNET_RX_PAGE_ORDER);
 			dev_kfree_skb_any(net->skb);
 			net->skb = NULL;
 			continue;
 		}
 
+		trace_tbnet_rx_ip_frame(hdr->frame_size, hdr->frame_id,
+					hdr->frame_index, hdr->frame_count);
 		frame_size = le32_to_cpu(hdr->frame_size);
 
 		skb = net->skb;
@@ -846,6 +884,7 @@ static int tbnet_poll(struct napi_struct *napi, int budget)
 
 		if (last) {
 			skb->protocol = eth_type_trans(skb, net->dev);
+			trace_tbnet_rx_skb(skb);
 			napi_gro_receive(&net->napi, skb);
 			net->skb = NULL;
 		}
@@ -965,6 +1004,8 @@ static bool tbnet_xmit_csum_and_map(struct tbnet *net, struct sk_buff *skb,
 		for (i = 0; i < frame_count; i++) {
 			hdr = page_address(frames[i]->page);
 			hdr->frame_count = cpu_to_le32(frame_count);
+			trace_tbnet_tx_ip_frame(hdr->frame_size, hdr->frame_id,
+						hdr->frame_index, hdr->frame_count);
 			dma_sync_single_for_device(dma_dev,
 				frames[i]->frame.buffer_phy,
 				tbnet_frame_size(frames[i]), DMA_TO_DEVICE);
@@ -1029,6 +1070,8 @@ static bool tbnet_xmit_csum_and_map(struct tbnet *net, struct sk_buff *skb,
 		len = le32_to_cpu(hdr->frame_size) - offset;
 		wsum = csum_partial(dest, len, wsum);
 		hdr->frame_count = cpu_to_le32(frame_count);
+		trace_tbnet_tx_ip_frame(hdr->frame_size, hdr->frame_id,
+					hdr->frame_index, hdr->frame_count);
 
 		offset = 0;
 	}
@@ -1071,6 +1114,8 @@ static netdev_tx_t tbnet_start_xmit(struct sk_buff *skb,
 	bool unmap = false;
 	void *dest;
 
+	trace_tbnet_tx_skb(skb);
+
 	nframes = DIV_ROUND_UP(data_len, TBNET_MAX_PAYLOAD_SIZE);
 	if (tbnet_available_buffers(&net->tx_ring) < nframes) {
 		netif_stop_queue(net->dev);
@@ -1177,6 +1222,7 @@ static netdev_tx_t tbnet_start_xmit(struct sk_buff *skb,
 	net->stats.tx_packets++;
 	net->stats.tx_bytes += skb->len;
 
+	trace_tbnet_consume_skb(skb);
 	dev_consume_skb_any(skb);
 
 	return NETDEV_TX_OK;

drivers/net/thunderbolt/trace.c

@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Tracepoints for Thunderbolt/USB4 networking driver
+ *
+ * Copyright (C) 2023, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
+ */
+
+#define CREATE_TRACE_POINTS
+#include "trace.h"