Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 763 insertions, 0 deletions

diff --git a/drivers/thunderbolt/dma_test.c b/drivers/thunderbolt/dma_test.c
new file mode 100644
index 000000000..519c67678
--- /dev/null
+++ b/drivers/thunderbolt/dma_test.c
@@ -0,0 +1,763 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DMA traffic test driver
+ *
+ * Copyright (C) 2020, Intel Corporation
+ * Authors: Isaac Hazan <isaac.hazan@intel.com>
+ *	    Mika Westerberg <mika.westerberg@linux.intel.com>
+ */
+
+#include <linux/completion.h>
+#include <linux/debugfs.h>
+#include <linux/module.h>
+#include <linux/sizes.h>
+#include <linux/thunderbolt.h>
+
+#define DMA_TEST_TX_RING_SIZE		64
+#define DMA_TEST_RX_RING_SIZE		256
+#define DMA_TEST_FRAME_SIZE		SZ_4K
+#define DMA_TEST_DATA_PATTERN		0x0123456789abcdefLL
+#define DMA_TEST_MAX_PACKETS		1000
+
+enum dma_test_frame_pdf {
+	DMA_TEST_PDF_FRAME_START = 1,
+	DMA_TEST_PDF_FRAME_END,
+};
+
+struct dma_test_frame {
+	struct dma_test *dma_test;
+	void *data;
+	struct ring_frame frame;
+};
+
+enum dma_test_test_error {
+	DMA_TEST_NO_ERROR,
+	DMA_TEST_INTERRUPTED,
+	DMA_TEST_BUFFER_ERROR,
+	DMA_TEST_DMA_ERROR,
+	DMA_TEST_CONFIG_ERROR,
+	DMA_TEST_SPEED_ERROR,
+	DMA_TEST_WIDTH_ERROR,
+	DMA_TEST_BONDING_ERROR,
+	DMA_TEST_PACKET_ERROR,
+};
+
+static const char * const dma_test_error_names[] = {
+	[DMA_TEST_NO_ERROR] = "no errors",
+	[DMA_TEST_INTERRUPTED] = "interrupted by signal",
+	[DMA_TEST_BUFFER_ERROR] = "no memory for packet buffers",
+	[DMA_TEST_DMA_ERROR] = "DMA ring setup failed",
+	[DMA_TEST_CONFIG_ERROR] = "configuration is not valid",
+	[DMA_TEST_SPEED_ERROR] = "unexpected link speed",
+	[DMA_TEST_WIDTH_ERROR] = "unexpected link width",
+	[DMA_TEST_BONDING_ERROR] = "lane bonding configuration error",
+	[DMA_TEST_PACKET_ERROR] = "packet check failed",
+};
+
+enum dma_test_result {
+	DMA_TEST_NOT_RUN,
+	DMA_TEST_SUCCESS,
+	DMA_TEST_FAIL,
+};
+
+static const char * const dma_test_result_names[] = {
+	[DMA_TEST_NOT_RUN] = "not run",
+	[DMA_TEST_SUCCESS] = "success",
+	[DMA_TEST_FAIL] = "failed",
+};
+
+/**
+ * struct dma_test - DMA test device driver private data
+ * @svc: XDomain service the driver is bound to
+ * @xd: XDomain the service belongs to
+ * @rx_ring: Software ring holding RX frames
+ * @rx_hopid: HopID used for receiving frames
+ * @tx_ring: Software ring holding TX frames
+ * @tx_hopid: HopID used for sending fames
+ * @packets_to_send: Number of packets to send
+ * @packets_to_receive: Number of packets to receive
+ * @packets_sent: Actual number of packets sent
+ * @packets_received: Actual number of packets received
+ * @link_speed: Expected link speed (Gb/s), %0 to use whatever is negotiated
+ * @link_width: Expected link width (Gb/s), %0 to use whatever is negotiated
+ * @crc_errors: Number of CRC errors during the test run
+ * @buffer_overflow_errors: Number of buffer overflow errors during the test
+ *			    run
+ * @result: Result of the last run
+ * @error_code: Error code of the last run
+ * @complete: Used to wait for the Rx to complete
+ * @lock: Lock serializing access to this structure
+ */
+struct dma_test {
+	const struct tb_service *svc;
+	struct tb_xdomain *xd;
+	struct tb_ring *rx_ring;
+	int rx_hopid;
+	struct tb_ring *tx_ring;
+	int tx_hopid;
+	unsigned int packets_to_send;
+	unsigned int packets_to_receive;
+	unsigned int packets_sent;
+	unsigned int packets_received;
+	unsigned int link_speed;
+	enum tb_link_width link_width;
+	unsigned int crc_errors;
+	unsigned int buffer_overflow_errors;
+	enum dma_test_result result;
+	enum dma_test_test_error error_code;
+	struct completion complete;
+	struct mutex lock;
+};
+
+/* DMA test property directory UUID: 3188cd10-6523-4a5a-a682-fdca07a248d8 */
+static const uuid_t dma_test_dir_uuid =
+	UUID_INIT(0x3188cd10, 0x6523, 0x4a5a,
+		  0xa6, 0x82, 0xfd, 0xca, 0x07, 0xa2, 0x48, 0xd8);
+
+static struct tb_property_dir *dma_test_dir;
+static void *dma_test_pattern;
+
+static void dma_test_free_rings(struct dma_test *dt)
+{
+	if (dt->rx_ring) {
+		tb_xdomain_release_in_hopid(dt->xd, dt->rx_hopid);
+		tb_ring_free(dt->rx_ring);
+		dt->rx_ring = NULL;
+	}
+	if (dt->tx_ring) {
+		tb_xdomain_release_out_hopid(dt->xd, dt->tx_hopid);
+		tb_ring_free(dt->tx_ring);
+		dt->tx_ring = NULL;
+	}
+}
+
+static int dma_test_start_rings(struct dma_test *dt)
+{
+	unsigned int flags = RING_FLAG_FRAME;
+	struct tb_xdomain *xd = dt->xd;
+	int ret, e2e_tx_hop = 0;
+	struct tb_ring *ring;
+
+	/*
+	 * If we are both sender and receiver (traffic goes over a
+	 * special loopback dongle) enable E2E flow control. This avoids
+	 * losing packets.
+	 */
+	if (dt->packets_to_send && dt->packets_to_receive)
+		flags |= RING_FLAG_E2E;
+
+	if (dt->packets_to_send) {
+		ring = tb_ring_alloc_tx(xd->tb->nhi, -1, DMA_TEST_TX_RING_SIZE,
+					flags);
+		if (!ring)
+			return -ENOMEM;
+
+		dt->tx_ring = ring;
+		e2e_tx_hop = ring->hop;
+
+		tb_ring_throttling(ring, 128000);
+
+		ret = tb_xdomain_alloc_out_hopid(xd, -1);
+		if (ret < 0) {
+			dma_test_free_rings(dt);
+			return ret;
+		}
+
+		dt->tx_hopid = ret;
+
+	}
+
+	if (dt->packets_to_receive) {
+		u16 sof_mask, eof_mask;
+
+		sof_mask = BIT(DMA_TEST_PDF_FRAME_START);
+		eof_mask = BIT(DMA_TEST_PDF_FRAME_END);
+
+		ring = tb_ring_alloc_rx(xd->tb->nhi, -1, DMA_TEST_RX_RING_SIZE,
+					flags, e2e_tx_hop, sof_mask, eof_mask,
+					NULL, NULL);
+		if (!ring) {
+			dma_test_free_rings(dt);
+			return -ENOMEM;
+		}
+
+		dt->rx_ring = ring;
+
+		tb_ring_throttling(ring, 128000);
+
+		ret = tb_xdomain_alloc_in_hopid(xd, -1);
+		if (ret < 0) {
+			dma_test_free_rings(dt);
+			return ret;
+		}
+
+		dt->rx_hopid = ret;
+	}
+
+	ret = tb_xdomain_enable_paths(dt->xd, dt->tx_hopid,
+				      dt->tx_ring ? dt->tx_ring->hop : -1,
+				      dt->rx_hopid,
+				      dt->rx_ring ? dt->rx_ring->hop : -1);
+	if (ret) {
+		dma_test_free_rings(dt);
+		return ret;
+	}
+
+	if (dt->tx_ring)
+		tb_ring_start(dt->tx_ring);
+	if (dt->rx_ring)
+		tb_ring_start(dt->rx_ring);
+
+	return 0;
+}
+
+static void dma_test_stop_rings(struct dma_test *dt)
+{
+	int ret;
+
+	if (dt->rx_ring)
+		tb_ring_stop(dt->rx_ring);
+	if (dt->tx_ring)
+		tb_ring_stop(dt->tx_ring);
+
+	ret = tb_xdomain_disable_paths(dt->xd, dt->tx_hopid,
+				       dt->tx_ring ? dt->tx_ring->hop : -1,
+				       dt->rx_hopid,
+				       dt->rx_ring ? dt->rx_ring->hop : -1);
+	if (ret)
+		dev_warn(&dt->svc->dev, "failed to disable DMA paths\n");
+
+	dma_test_free_rings(dt);
+}
+
+static void dma_test_rx_callback(struct tb_ring *ring, struct ring_frame *frame,
+				 bool canceled)
+{
+	struct dma_test_frame *tf = container_of(frame, typeof(*tf), frame);
+	struct dma_test *dt = tf->dma_test;
+	struct device *dma_dev = tb_ring_dma_device(dt->rx_ring);
+
+	dma_unmap_single(dma_dev, tf->frame.buffer_phy, DMA_TEST_FRAME_SIZE,
+			 DMA_FROM_DEVICE);
+	kfree(tf->data);
+
+	if (canceled) {
+		kfree(tf);
+		return;
+	}
+
+	dt->packets_received++;
+	dev_dbg(&dt->svc->dev, "packet %u/%u received\n", dt->packets_received,
+		dt->packets_to_receive);
+
+	if (tf->frame.flags & RING_DESC_CRC_ERROR)
+		dt->crc_errors++;
+	if (tf->frame.flags & RING_DESC_BUFFER_OVERRUN)
+		dt->buffer_overflow_errors++;
+
+	kfree(tf);
+
+	if (dt->packets_received == dt->packets_to_receive)
+		complete(&dt->complete);
+}
+
+static int dma_test_submit_rx(struct dma_test *dt, size_t npackets)
+{
+	struct device *dma_dev = tb_ring_dma_device(dt->rx_ring);
+	int i;
+
+	for (i = 0; i < npackets; i++) {
+		struct dma_test_frame *tf;
+		dma_addr_t dma_addr;
+
+		tf = kzalloc_obj(*tf);
+		if (!tf)
+			return -ENOMEM;
+
+		tf->data = kzalloc(DMA_TEST_FRAME_SIZE, GFP_KERNEL);
+		if (!tf->data) {
+			kfree(tf);
+			return -ENOMEM;
+		}
+
+		dma_addr = dma_map_single(dma_dev, tf->data, DMA_TEST_FRAME_SIZE,
+					  DMA_FROM_DEVICE);
+		if (dma_mapping_error(dma_dev, dma_addr)) {
+			kfree(tf->data);
+			kfree(tf);
+			return -ENOMEM;
+		}
+
+		tf->frame.buffer_phy = dma_addr;
+		tf->frame.callback = dma_test_rx_callback;
+		tf->dma_test = dt;
+		INIT_LIST_HEAD(&tf->frame.list);
+
+		tb_ring_rx(dt->rx_ring, &tf->frame);
+	}
+
+	return 0;
+}
+
+static void dma_test_tx_callback(struct tb_ring *ring, struct ring_frame *frame,
+				 bool canceled)
+{
+	struct dma_test_frame *tf = container_of(frame, typeof(*tf), frame);
+	struct dma_test *dt = tf->dma_test;
+	struct device *dma_dev = tb_ring_dma_device(dt->tx_ring);
+
+	dma_unmap_single(dma_dev, tf->frame.buffer_phy, DMA_TEST_FRAME_SIZE,
+			 DMA_TO_DEVICE);
+	kfree(tf->data);
+	kfree(tf);
+}
+
+static int dma_test_submit_tx(struct dma_test *dt, size_t npackets)
+{
+	struct device *dma_dev = tb_ring_dma_device(dt->tx_ring);
+	int i;
+
+	for (i = 0; i < npackets; i++) {
+		struct dma_test_frame *tf;
+		dma_addr_t dma_addr;
+
+		tf = kzalloc_obj(*tf);
+		if (!tf)
+			return -ENOMEM;
+
+		tf->frame.size = 0; /* means 4096 */
+		tf->dma_test = dt;
+
+		tf->data = kmemdup(dma_test_pattern, DMA_TEST_FRAME_SIZE, GFP_KERNEL);
+		if (!tf->data) {
+			kfree(tf);
+			return -ENOMEM;
+		}
+
+		dma_addr = dma_map_single(dma_dev, tf->data, DMA_TEST_FRAME_SIZE,
+					  DMA_TO_DEVICE);
+		if (dma_mapping_error(dma_dev, dma_addr)) {
+			kfree(tf->data);
+			kfree(tf);
+			return -ENOMEM;
+		}
+
+		tf->frame.buffer_phy = dma_addr;
+		tf->frame.callback = dma_test_tx_callback;
+		tf->frame.sof = DMA_TEST_PDF_FRAME_START;
+		tf->frame.eof = DMA_TEST_PDF_FRAME_END;
+		INIT_LIST_HEAD(&tf->frame.list);
+
+		dt->packets_sent++;
+		dev_dbg(&dt->svc->dev, "packet %u/%u sent\n", dt->packets_sent,
+			dt->packets_to_send);
+
+		tb_ring_tx(dt->tx_ring, &tf->frame);
+	}
+
+	return 0;
+}
+
+#define DMA_TEST_DEBUGFS_ATTR(__fops, __get, __validate, __set)	\
+static int __fops ## _show(void *data, u64 *val)		\
+{								\
+	struct tb_service *svc = data;				\
+	struct dma_test *dt = tb_service_get_drvdata(svc);	\
+	int ret;						\
+								\
+	ret = mutex_lock_interruptible(&dt->lock);		\
+	if (ret)						\
+		return ret;					\
+	__get(dt, val);						\
+	mutex_unlock(&dt->lock);				\
+	return 0;						\
+}								\
+static int __fops ## _store(void *data, u64 val)		\
+{								\
+	struct tb_service *svc = data;				\
+	struct dma_test *dt = tb_service_get_drvdata(svc);	\
+	int ret;						\
+								\
+	ret = __validate(val);					\
+	if (ret)						\
+		return ret;					\
+	ret = mutex_lock_interruptible(&dt->lock);		\
+	if (ret)						\
+		return ret;					\
+	__set(dt, val);						\
+	mutex_unlock(&dt->lock);				\
+	return 0;						\
+}								\
+DEFINE_DEBUGFS_ATTRIBUTE(__fops ## _fops, __fops ## _show,	\
+			 __fops ## _store, "%llu\n")
+
+static void lanes_get(const struct dma_test *dt, u64 *val)
+{
+	*val = dt->link_width;
+}
+
+static int lanes_validate(u64 val)
+{
+	return val > 2 ? -EINVAL : 0;
+}
+
+static void lanes_set(struct dma_test *dt, u64 val)
+{
+	dt->link_width = val;
+}
+DMA_TEST_DEBUGFS_ATTR(lanes, lanes_get, lanes_validate, lanes_set);
+
+static void speed_get(const struct dma_test *dt, u64 *val)
+{
+	*val = dt->link_speed;
+}
+
+static int speed_validate(u64 val)
+{
+	switch (val) {
+	case 40:
+	case 20:
+	case 10:
+	case 0:
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static void speed_set(struct dma_test *dt, u64 val)
+{
+	dt->link_speed = val;
+}
+DMA_TEST_DEBUGFS_ATTR(speed, speed_get, speed_validate, speed_set);
+
+static void packets_to_receive_get(const struct dma_test *dt, u64 *val)
+{
+	*val = dt->packets_to_receive;
+}
+
+static int packets_to_receive_validate(u64 val)
+{
+	return val > DMA_TEST_MAX_PACKETS ? -EINVAL : 0;
+}
+
+static void packets_to_receive_set(struct dma_test *dt, u64 val)
+{
+	dt->packets_to_receive = val;
+}
+DMA_TEST_DEBUGFS_ATTR(packets_to_receive, packets_to_receive_get,
+		      packets_to_receive_validate, packets_to_receive_set);
+
+static void packets_to_send_get(const struct dma_test *dt, u64 *val)
+{
+	*val = dt->packets_to_send;
+}
+
+static int packets_to_send_validate(u64 val)
+{
+	return val > DMA_TEST_MAX_PACKETS ? -EINVAL : 0;
+}
+
+static void packets_to_send_set(struct dma_test *dt, u64 val)
+{
+	dt->packets_to_send = val;
+}
+DMA_TEST_DEBUGFS_ATTR(packets_to_send, packets_to_send_get,
+		      packets_to_send_validate, packets_to_send_set);
+
+static int dma_test_set_bonding(struct dma_test *dt)
+{
+	switch (dt->link_width) {
+	case TB_LINK_WIDTH_DUAL:
+		return tb_xdomain_lane_bonding_enable(dt->xd);
+	case TB_LINK_WIDTH_SINGLE:
+		tb_xdomain_lane_bonding_disable(dt->xd);
+		fallthrough;
+	default:
+		return 0;
+	}
+}
+
+static bool dma_test_validate_config(struct dma_test *dt)
+{
+	if (!dt->packets_to_send && !dt->packets_to_receive)
+		return false;
+	if (dt->packets_to_send && dt->packets_to_receive &&
+	    dt->packets_to_send != dt->packets_to_receive)
+		return false;
+	return true;
+}
+
+static void dma_test_check_errors(struct dma_test *dt, int ret)
+{
+	if (!dt->error_code) {
+		if (dt->link_speed && dt->xd->link_speed != dt->link_speed) {
+			dt->error_code = DMA_TEST_SPEED_ERROR;
+		} else if (dt->link_width && dt->link_width != dt->xd->link_width) {
+			dt->error_code = DMA_TEST_WIDTH_ERROR;
+		} else if (dt->packets_to_send != dt->packets_sent ||
+			 dt->packets_to_receive != dt->packets_received ||
+			 dt->crc_errors || dt->buffer_overflow_errors) {
+			dt->error_code = DMA_TEST_PACKET_ERROR;
+		} else {
+			return;
+		}
+	}
+
+	dt->result = DMA_TEST_FAIL;
+}
+
+static int test_store(void *data, u64 val)
+{
+	struct tb_service *svc = data;
+	struct dma_test *dt = tb_service_get_drvdata(svc);
+	int ret;
+
+	if (val != 1)
+		return -EINVAL;
+
+	ret = mutex_lock_interruptible(&dt->lock);
+	if (ret)
+		return ret;
+
+	dt->packets_sent = 0;
+	dt->packets_received = 0;
+	dt->crc_errors = 0;
+	dt->buffer_overflow_errors = 0;
+	dt->result = DMA_TEST_SUCCESS;
+	dt->error_code = DMA_TEST_NO_ERROR;
+
+	dev_dbg(&svc->dev, "DMA test starting\n");
+	if (dt->link_speed)
+		dev_dbg(&svc->dev, "link_speed: %u Gb/s\n", dt->link_speed);
+	if (dt->link_width)
+		dev_dbg(&svc->dev, "link_width: %u\n", dt->link_width);
+	dev_dbg(&svc->dev, "packets_to_send: %u\n", dt->packets_to_send);
+	dev_dbg(&svc->dev, "packets_to_receive: %u\n", dt->packets_to_receive);
+
+	if (!dma_test_validate_config(dt)) {
+		dev_err(&svc->dev, "invalid test configuration\n");
+		dt->error_code = DMA_TEST_CONFIG_ERROR;
+		goto out_unlock;
+	}
+
+	ret = dma_test_set_bonding(dt);
+	if (ret) {
+		dev_err(&svc->dev, "failed to set lanes\n");
+		dt->error_code = DMA_TEST_BONDING_ERROR;
+		goto out_unlock;
+	}
+
+	ret = dma_test_start_rings(dt);
+	if (ret) {
+		dev_err(&svc->dev, "failed to enable DMA rings\n");
+		dt->error_code = DMA_TEST_DMA_ERROR;
+		goto out_unlock;
+	}
+
+	if (dt->packets_to_receive) {
+		reinit_completion(&dt->complete);
+		ret = dma_test_submit_rx(dt, dt->packets_to_receive);
+		if (ret) {
+			dev_err(&svc->dev, "failed to submit receive buffers\n");
+			dt->error_code = DMA_TEST_BUFFER_ERROR;
+			goto out_stop;
+		}
+	}
+
+	if (dt->packets_to_send) {
+		ret = dma_test_submit_tx(dt, dt->packets_to_send);
+		if (ret) {
+			dev_err(&svc->dev, "failed to submit transmit buffers\n");
+			dt->error_code = DMA_TEST_BUFFER_ERROR;
+			goto out_stop;
+		}
+	}
+
+	if (dt->packets_to_receive) {
+		ret = wait_for_completion_interruptible(&dt->complete);
+		if (ret) {
+			dt->error_code = DMA_TEST_INTERRUPTED;
+			goto out_stop;
+		}
+	}
+
+out_stop:
+	dma_test_stop_rings(dt);
+out_unlock:
+	dma_test_check_errors(dt, ret);
+	mutex_unlock(&dt->lock);
+
+	dev_dbg(&svc->dev, "DMA test %s\n", dma_test_result_names[dt->result]);
+	return ret;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(test_fops, NULL, test_store, "%llu\n");
+
+static int status_show(struct seq_file *s, void *not_used)
+{
+	struct tb_service *svc = s->private;
+	struct dma_test *dt = tb_service_get_drvdata(svc);
+	int ret;
+
+	ret = mutex_lock_interruptible(&dt->lock);
+	if (ret)
+		return ret;
+
+	seq_printf(s, "result: %s\n", dma_test_result_names[dt->result]);
+	if (dt->result == DMA_TEST_NOT_RUN)
+		goto out_unlock;
+
+	seq_printf(s, "packets received: %u\n", dt->packets_received);
+	seq_printf(s, "packets sent: %u\n", dt->packets_sent);
+	seq_printf(s, "CRC errors: %u\n", dt->crc_errors);
+	seq_printf(s, "buffer overflow errors: %u\n",
+		   dt->buffer_overflow_errors);
+	seq_printf(s, "error: %s\n", dma_test_error_names[dt->error_code]);
+
+out_unlock:
+	mutex_unlock(&dt->lock);
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(status);
+
+static void dma_test_debugfs_init(struct tb_service *svc)
+{
+	struct dentry *debugfs_dir;
+
+	debugfs_dir = debugfs_create_dir("dma_test", svc->debugfs_dir);
+
+	debugfs_create_file("lanes", 0600, debugfs_dir, svc, &lanes_fops);
+	debugfs_create_file("speed", 0600, debugfs_dir, svc, &speed_fops);
+	debugfs_create_file("packets_to_receive", 0600, debugfs_dir, svc,
+			    &packets_to_receive_fops);
+	debugfs_create_file("packets_to_send", 0600, debugfs_dir, svc,
+			    &packets_to_send_fops);
+	debugfs_create_file("status", 0400, debugfs_dir, svc, &status_fops);
+	debugfs_create_file("test", 0200, debugfs_dir, svc, &test_fops);
+}
+
+static int dma_test_probe(struct tb_service *svc)
+{
+	struct tb_xdomain *xd = tb_service_parent(svc);
+	struct dma_test *dt;
+
+	dt = devm_kzalloc(&svc->dev, sizeof(*dt), GFP_KERNEL);
+	if (!dt)
+		return -ENOMEM;
+
+	dt->svc = svc;
+	dt->xd = xd;
+	mutex_init(&dt->lock);
+	init_completion(&dt->complete);
+
+	tb_service_set_drvdata(svc, dt);
+	dma_test_debugfs_init(svc);
+
+	return 0;
+}
+
+static void dma_test_remove(struct tb_service *svc)
+{
+	struct dma_test *dt = tb_service_get_drvdata(svc);
+
+	mutex_lock(&dt->lock);
+	debugfs_lookup_and_remove("dma_test", svc->debugfs_dir);
+	mutex_unlock(&dt->lock);
+}
+
+static int __maybe_unused dma_test_suspend(struct device *dev)
+{
+	/*
+	 * No need to do anything special here. If userspace is writing
+	 * to the test attribute when suspend started, it comes out from
+	 * wait_for_completion_interruptible() with -ERESTARTSYS and the
+	 * DMA test fails tearing down the rings. Once userspace is
+	 * thawed the kernel restarts the write syscall effectively
+	 * re-running the test.
+	 */
+	return 0;
+}
+
+static int __maybe_unused dma_test_resume(struct device *dev)
+{
+	return 0;
+}
+
+static const struct dev_pm_ops dma_test_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(dma_test_suspend, dma_test_resume)
+};
+
+static const struct tb_service_id dma_test_ids[] = {
+	{ TB_SERVICE("dma_test", 1) },
+	{ }
+};
+MODULE_DEVICE_TABLE(tbsvc, dma_test_ids);
+
+static struct tb_service_driver dma_test_driver = {
+	.driver = {
+		.owner = THIS_MODULE,
+		.name = "thunderbolt_dma_test",
+		.pm = &dma_test_pm_ops,
+	},
+	.probe = dma_test_probe,
+	.remove = dma_test_remove,
+	.id_table = dma_test_ids,
+};
+
+static int __init dma_test_init(void)
+{
+	u64 data_value = DMA_TEST_DATA_PATTERN;
+	int i, ret;
+
+	dma_test_pattern = kmalloc(DMA_TEST_FRAME_SIZE, GFP_KERNEL);
+	if (!dma_test_pattern)
+		return -ENOMEM;
+
+	for (i = 0; i <	DMA_TEST_FRAME_SIZE / sizeof(data_value); i++)
+		((u32 *)dma_test_pattern)[i] = data_value++;
+
+	dma_test_dir = tb_property_create_dir(&dma_test_dir_uuid);
+	if (!dma_test_dir) {
+		ret = -ENOMEM;
+		goto err_free_pattern;
+	}
+
+	tb_property_add_immediate(dma_test_dir, "prtcid", 1);
+	tb_property_add_immediate(dma_test_dir, "prtcvers", 1);
+	tb_property_add_immediate(dma_test_dir, "prtcrevs", 0);
+	tb_property_add_immediate(dma_test_dir, "prtcstns", 0);
+
+	ret = tb_register_property_dir("dma_test", dma_test_dir);
+	if (ret)
+		goto err_free_dir;
+
+	ret = tb_register_service_driver(&dma_test_driver);
+	if (ret)
+		goto err_unregister_dir;
+
+	return 0;
+
+err_unregister_dir:
+	tb_unregister_property_dir("dma_test", dma_test_dir);
+err_free_dir:
+	tb_property_free_dir(dma_test_dir);
+err_free_pattern:
+	kfree(dma_test_pattern);
+
+	return ret;
+}
+module_init(dma_test_init);
+
+static void __exit dma_test_exit(void)
+{
+	tb_unregister_service_driver(&dma_test_driver);
+	tb_unregister_property_dir("dma_test", dma_test_dir);
+	tb_property_free_dir(dma_test_dir);
+	kfree(dma_test_pattern);
+}
+module_exit(dma_test_exit);
+
+MODULE_AUTHOR("Isaac Hazan <isaac.hazan@intel.com>");
+MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
+MODULE_DESCRIPTION("Thunderbolt/USB4 DMA traffic test driver");
+MODULE_LICENSE("GPL v2");