sound/soc/sof/sof-client-ipc-flood-test.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 //
 // Copyright(c) 2022 Intel Corporation. All rights reserved.
 //
 // Authors: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
 //	    Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
 //

 #include <linux/auxiliary_bus.h>
 #include <linux/completion.h>
 #include <linux/debugfs.h>
 #include <linux/ktime.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
 #include <sound/sof/header.h>

 #include "sof-client.h"

 #define MAX_IPC_FLOOD_DURATION_MS	1000
 #define MAX_IPC_FLOOD_COUNT		10000
 #define IPC_FLOOD_TEST_RESULT_LEN	512
 #define SOF_IPC_CLIENT_SUSPEND_DELAY_MS	3000

 #define DEBUGFS_IPC_FLOOD_COUNT		"ipc_flood_count"
 #define DEBUGFS_IPC_FLOOD_DURATION	"ipc_flood_duration_ms"

 struct sof_ipc_flood_priv {
 	struct dentry *dfs_root;
 	struct dentry *dfs_link[2];
 	char *buf;
 };

 static int sof_ipc_flood_dfs_open(struct inode *inode, struct file *file)
 {
 	struct sof_client_dev *cdev = inode->i_private;
 	int ret;

 	if (sof_client_get_fw_state(cdev) == SOF_FW_CRASHED)
 		return -ENODEV;

 	ret = debugfs_file_get(file->f_path.dentry);
 	if (unlikely(ret))
 		return ret;

 	ret = simple_open(inode, file);
 	if (ret)
 		debugfs_file_put(file->f_path.dentry);

 	return ret;
 }

 /*
  * helper function to perform the flood test. Only one of the two params, ipc_duration_ms
  * or ipc_count, will be non-zero and will determine the type of test
  */
 static int sof_debug_ipc_flood_test(struct sof_client_dev *cdev,
 				    bool flood_duration_test,
 				    unsigned long ipc_duration_ms,
 				    unsigned long ipc_count)
 {
 	struct sof_ipc_flood_priv *priv = cdev->data;
 	struct device *dev = &cdev->auxdev.dev;
 	struct sof_ipc_cmd_hdr hdr;
 	struct sof_ipc_reply reply;
 	u64 min_response_time = U64_MAX;
 	ktime_t start, end, test_end;
 	u64 avg_response_time = 0;
 	u64 max_response_time = 0;
 	u64 ipc_response_time;
 	int i = 0;
 	int ret;

 	/* configure test IPC */
 	hdr.cmd = SOF_IPC_GLB_TEST_MSG | SOF_IPC_TEST_IPC_FLOOD;
 	hdr.size = sizeof(hdr);

 	/* set test end time for duration flood test */
 	if (flood_duration_test)
 		test_end = ktime_get_ns() + ipc_duration_ms * NSEC_PER_MSEC;

 	/* send test IPC's */
 	while (1) {
 		start = ktime_get();
 		ret = sof_client_ipc_tx_message(cdev, &hdr, &reply, sizeof(reply));
 		end = ktime_get();

 		if (ret < 0)
 			break;

 		/* compute min and max response times */
 		ipc_response_time = ktime_to_ns(ktime_sub(end, start));
 		min_response_time = min(min_response_time, ipc_response_time);
 		max_response_time = max(max_response_time, ipc_response_time);

 		/* sum up response times */
 		avg_response_time += ipc_response_time;
 		i++;

 		/* test complete? */
 		if (flood_duration_test) {
 			if (ktime_to_ns(end) >= test_end)
 				break;
 		} else {
 			if (i == ipc_count)
 				break;
 		}
 	}

 	if (ret < 0)
 		dev_err(dev, "ipc flood test failed at %d iterations\n", i);

 	/* return if the first IPC fails */
 	if (!i)
 		return ret;

 	/* compute average response time */
 	do_div(avg_response_time, i);

 	/* clear previous test output */
 	memset(priv->buf, 0, IPC_FLOOD_TEST_RESULT_LEN);

 	if (!ipc_count) {
 		dev_dbg(dev, "IPC Flood test duration: %lums\n", ipc_duration_ms);
 		snprintf(priv->buf, IPC_FLOOD_TEST_RESULT_LEN,
 			 "IPC Flood test duration: %lums\n", ipc_duration_ms);
 	}

 	dev_dbg(dev, "IPC Flood count: %d, Avg response time: %lluns\n",
 		i, avg_response_time);
 	dev_dbg(dev, "Max response time: %lluns\n", max_response_time);
 	dev_dbg(dev, "Min response time: %lluns\n", min_response_time);

 	/* format output string and save test results */
 	snprintf(priv->buf + strlen(priv->buf),
 		 IPC_FLOOD_TEST_RESULT_LEN - strlen(priv->buf),
 		 "IPC Flood count: %d\nAvg response time: %lluns\n",
 		 i, avg_response_time);

 	snprintf(priv->buf + strlen(priv->buf),
 		 IPC_FLOOD_TEST_RESULT_LEN - strlen(priv->buf),
 		 "Max response time: %lluns\nMin response time: %lluns\n",
 		 max_response_time, min_response_time);

 	return ret;
 }

 /*
  * Writing to the debugfs entry initiates the IPC flood test based on
  * the IPC count or the duration specified by the user.
  */
 static ssize_t sof_ipc_flood_dfs_write(struct file *file, const char __user *buffer,
 				       size_t count, loff_t *ppos)
 {
 	struct sof_client_dev *cdev = file->private_data;
 	struct device *dev = &cdev->auxdev.dev;
 	unsigned long ipc_duration_ms = 0;
 	bool flood_duration_test = false;
 	unsigned long ipc_count = 0;
 	struct dentry *dentry;
 	int err;
 	size_t size;
 	char *string;
 	int ret;

 	string = kzalloc(count + 1, GFP_KERNEL);
 	if (!string)
 		return -ENOMEM;

 	size = simple_write_to_buffer(string, count, ppos, buffer, count);

 	/*
 	 * write op is only supported for ipc_flood_count or
 	 * ipc_flood_duration_ms debugfs entries atm.
 	 * ipc_flood_count floods the DSP with the number of IPC's specified.
 	 * ipc_duration_ms test floods the DSP for the time specified
 	 * in the debugfs entry.
 	 */
 	dentry = file->f_path.dentry;
 	if (strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_COUNT) &&
 	    strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_DURATION)) {
 		ret = -EINVAL;
 		goto out;
 	}

 	if (!strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_DURATION))
 		flood_duration_test = true;

 	/* test completion criterion */
 	if (flood_duration_test)
 		ret = kstrtoul(string, 0, &ipc_duration_ms);
 	else
 		ret = kstrtoul(string, 0, &ipc_count);
 	if (ret < 0)
 		goto out;

 	/* limit max duration/ipc count for flood test */
 	if (flood_duration_test) {
 		if (!ipc_duration_ms) {
 			ret = size;
 			goto out;
 		}

 		/* find the minimum. min() is not used to avoid warnings */
 		if (ipc_duration_ms > MAX_IPC_FLOOD_DURATION_MS)
 			ipc_duration_ms = MAX_IPC_FLOOD_DURATION_MS;
 	} else {
 		if (!ipc_count) {
 			ret = size;
 			goto out;
 		}

 		/* find the minimum. min() is not used to avoid warnings */
 		if (ipc_count > MAX_IPC_FLOOD_COUNT)
 			ipc_count = MAX_IPC_FLOOD_COUNT;
 	}

 	ret = pm_runtime_resume_and_get(dev);
 	if (ret < 0 && ret != -EACCES) {
 		dev_err_ratelimited(dev, "debugfs write failed to resume %d\n", ret);
 		goto out;
 	}

 	/* flood test */
 	ret = sof_debug_ipc_flood_test(cdev, flood_duration_test,
 				       ipc_duration_ms, ipc_count);

 	pm_runtime_mark_last_busy(dev);
 	err = pm_runtime_put_autosuspend(dev);
 	if (err < 0)
 		dev_err_ratelimited(dev, "debugfs write failed to idle %d\n", err);

 	/* return size if test is successful */
 	if (ret >= 0)
 		ret = size;
 out:
 	kfree(string);
 	return ret;
 }

 /* return the result of the last IPC flood test */
 static ssize_t sof_ipc_flood_dfs_read(struct file *file, char __user *buffer,
 				      size_t count, loff_t *ppos)
 {
 	struct sof_client_dev *cdev = file->private_data;
 	struct sof_ipc_flood_priv *priv = cdev->data;
 	size_t size_ret;

 	struct dentry *dentry;

 	dentry = file->f_path.dentry;
 	if (!strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_COUNT) ||
 	    !strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_DURATION)) {
 		if (*ppos)
 			return 0;

 		count = min_t(size_t, count, strlen(priv->buf));
 		size_ret = copy_to_user(buffer, priv->buf, count);
 		if (size_ret)
 			return -EFAULT;

 		*ppos += count;
 		return count;
 	}
 	return count;
 }

 static int sof_ipc_flood_dfs_release(struct inode *inode, struct file *file)
 {
 	debugfs_file_put(file->f_path.dentry);

 	return 0;
 }

 static const struct file_operations sof_ipc_flood_fops = {
 	.open = sof_ipc_flood_dfs_open,
 	.read = sof_ipc_flood_dfs_read,
 	.llseek = default_llseek,
 	.write = sof_ipc_flood_dfs_write,
 	.release = sof_ipc_flood_dfs_release,

 	.owner = THIS_MODULE,
 };

 /*
  * The IPC test client creates a couple of debugfs entries that will be used
  * flood tests. Users can write to these entries to execute the IPC flood test
  * by specifying either the number of IPCs to flood the DSP with or the duration
  * (in ms) for which the DSP should be flooded with test IPCs. At the
  * end of each test, the average, min and max response times are reported back.
  * The results of the last flood test can be accessed by reading the debugfs
  * entries.
  */
 static int sof_ipc_flood_probe(struct auxiliary_device *auxdev,
 			       const struct auxiliary_device_id *id)
 {
 	struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
 	struct dentry *debugfs_root = sof_client_get_debugfs_root(cdev);
 	struct device *dev = &auxdev->dev;
 	struct sof_ipc_flood_priv *priv;

 	/* allocate memory for client data */
 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;

 	priv->buf = devm_kmalloc(dev, IPC_FLOOD_TEST_RESULT_LEN, GFP_KERNEL);
 	if (!priv->buf)
 		return -ENOMEM;

 	cdev->data = priv;

 	/* create debugfs root folder with device name under parent SOF dir */
 	priv->dfs_root = debugfs_create_dir(dev_name(dev), debugfs_root);
 	if (!IS_ERR_OR_NULL(priv->dfs_root)) {
 		/* create read-write ipc_flood_count debugfs entry */
 		debugfs_create_file(DEBUGFS_IPC_FLOOD_COUNT, 0644, priv->dfs_root,
 				    cdev, &sof_ipc_flood_fops);

 		/* create read-write ipc_flood_duration_ms debugfs entry */
 		debugfs_create_file(DEBUGFS_IPC_FLOOD_DURATION, 0644,
 				    priv->dfs_root, cdev, &sof_ipc_flood_fops);

 		if (auxdev->id == 0) {
 			/*
 			 * Create symlinks for backwards compatibility to the
 			 * first IPC flood test instance
 			 */
 			char target[100];

 			snprintf(target, 100, "%s/" DEBUGFS_IPC_FLOOD_COUNT,
 				 dev_name(dev));
 			priv->dfs_link[0] =
 				debugfs_create_symlink(DEBUGFS_IPC_FLOOD_COUNT,
 						       debugfs_root, target);

 			snprintf(target, 100, "%s/" DEBUGFS_IPC_FLOOD_DURATION,
 				 dev_name(dev));
 			priv->dfs_link[1] =
 				debugfs_create_symlink(DEBUGFS_IPC_FLOOD_DURATION,
 						       debugfs_root, target);
 		}
 	}

 	/* enable runtime PM */
 	pm_runtime_set_autosuspend_delay(dev, SOF_IPC_CLIENT_SUSPEND_DELAY_MS);
 	pm_runtime_use_autosuspend(dev);
 	pm_runtime_enable(dev);
 	pm_runtime_mark_last_busy(dev);
 	pm_runtime_idle(dev);

 	return 0;
 }

 static void sof_ipc_flood_remove(struct auxiliary_device *auxdev)
 {
 	struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
 	struct sof_ipc_flood_priv *priv = cdev->data;

 	pm_runtime_disable(&auxdev->dev);

 	if (auxdev->id == 0) {
 		debugfs_remove(priv->dfs_link[0]);
 		debugfs_remove(priv->dfs_link[1]);
 	}

 	debugfs_remove_recursive(priv->dfs_root);
 }

 static const struct auxiliary_device_id sof_ipc_flood_client_id_table[] = {
 	{ .name = "snd_sof.ipc_flood" },
 	{},
 };
 MODULE_DEVICE_TABLE(auxiliary, sof_ipc_flood_client_id_table);

 /*
  * No need for driver pm_ops as the generic pm callbacks in the auxiliary bus
  * type are enough to ensure that the parent SOF device resumes to bring the DSP
  * back to D0.
  * Driver name will be set based on KBUILD_MODNAME.
  */
 static struct auxiliary_driver sof_ipc_flood_client_drv = {
 	.probe = sof_ipc_flood_probe,
 	.remove = sof_ipc_flood_remove,

 	.id_table = sof_ipc_flood_client_id_table,
 };

 module_auxiliary_driver(sof_ipc_flood_client_drv);

 MODULE_DESCRIPTION("SOF IPC Flood Test Client Driver");
 MODULE_LICENSE("GPL");
 MODULE_IMPORT_NS(SND_SOC_SOF_CLIENT);
	// SPDX-License-Identifier: GPL-2.0-only
	//
	// Copyright(c) 2022 Intel Corporation. All rights reserved.
	//
	// Authors: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
	// Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
	//

	#include <linux/auxiliary_bus.h>
	#include <linux/completion.h>
	#include <linux/debugfs.h>
	#include <linux/ktime.h>
	#include <linux/mod_devicetable.h>
	#include <linux/module.h>
	#include <linux/pm_runtime.h>
	#include <linux/slab.h>
	#include <linux/uaccess.h>
	#include <sound/sof/header.h>

	#include "sof-client.h"

	#define MAX_IPC_FLOOD_DURATION_MS 1000
	#define MAX_IPC_FLOOD_COUNT 10000
	#define IPC_FLOOD_TEST_RESULT_LEN 512
	#define SOF_IPC_CLIENT_SUSPEND_DELAY_MS 3000

	#define DEBUGFS_IPC_FLOOD_COUNT "ipc_flood_count"
	#define DEBUGFS_IPC_FLOOD_DURATION "ipc_flood_duration_ms"

	struct sof_ipc_flood_priv {
	struct dentry *dfs_root;
	struct dentry *dfs_link[2];
	char *buf;
	};

	static int sof_ipc_flood_dfs_open(struct inode inode, struct file file)
	{
	struct sof_client_dev *cdev = inode->i_private;
	int ret;

	if (sof_client_get_fw_state(cdev) == SOF_FW_CRASHED)
	return -ENODEV;

	ret = debugfs_file_get(file->f_path.dentry);
	if (unlikely(ret))
	return ret;

	ret = simple_open(inode, file);
	if (ret)
	debugfs_file_put(file->f_path.dentry);

	return ret;
	}

	/*
	* helper function to perform the flood test. Only one of the two params, ipc_duration_ms
	* or ipc_count, will be non-zero and will determine the type of test
	*/
	static int sof_debug_ipc_flood_test(struct sof_client_dev *cdev,
	bool flood_duration_test,
	unsigned long ipc_duration_ms,
	unsigned long ipc_count)
	{
	struct sof_ipc_flood_priv *priv = cdev->data;
	struct device *dev = &cdev->auxdev.dev;
	struct sof_ipc_cmd_hdr hdr;
	struct sof_ipc_reply reply;
	u64 min_response_time = U64_MAX;
	ktime_t start, end, test_end;
	u64 avg_response_time = 0;
	u64 max_response_time = 0;
	u64 ipc_response_time;
	int i = 0;
	int ret;

	/* configure test IPC */
	hdr.cmd = SOF_IPC_GLB_TEST_MSG \| SOF_IPC_TEST_IPC_FLOOD;
	hdr.size = sizeof(hdr);

	/* set test end time for duration flood test */
	if (flood_duration_test)
	test_end = ktime_get_ns() + ipc_duration_ms * NSEC_PER_MSEC;

	/* send test IPC's */
	while (1) {
	start = ktime_get();
	ret = sof_client_ipc_tx_message(cdev, &hdr, &reply, sizeof(reply));
	end = ktime_get();

	if (ret < 0)
	break;

	/* compute min and max response times */
	ipc_response_time = ktime_to_ns(ktime_sub(end, start));
	min_response_time = min(min_response_time, ipc_response_time);
	max_response_time = max(max_response_time, ipc_response_time);

	/* sum up response times */
	avg_response_time += ipc_response_time;
	i++;

	/* test complete? */
	if (flood_duration_test) {
	if (ktime_to_ns(end) >= test_end)
	break;
	} else {
	if (i == ipc_count)
	break;
	}
	}

	if (ret < 0)
	dev_err(dev, "ipc flood test failed at %d iterations\n", i);

	/* return if the first IPC fails */
	if (!i)
	return ret;

	/* compute average response time */
	do_div(avg_response_time, i);

	/* clear previous test output */
	memset(priv->buf, 0, IPC_FLOOD_TEST_RESULT_LEN);

	if (!ipc_count) {
	dev_dbg(dev, "IPC Flood test duration: %lums\n", ipc_duration_ms);
	snprintf(priv->buf, IPC_FLOOD_TEST_RESULT_LEN,
	"IPC Flood test duration: %lums\n", ipc_duration_ms);
	}

	dev_dbg(dev, "IPC Flood count: %d, Avg response time: %lluns\n",
	i, avg_response_time);
	dev_dbg(dev, "Max response time: %lluns\n", max_response_time);
	dev_dbg(dev, "Min response time: %lluns\n", min_response_time);

	/* format output string and save test results */
	snprintf(priv->buf + strlen(priv->buf),
	IPC_FLOOD_TEST_RESULT_LEN - strlen(priv->buf),
	"IPC Flood count: %d\nAvg response time: %lluns\n",
	i, avg_response_time);

	snprintf(priv->buf + strlen(priv->buf),
	IPC_FLOOD_TEST_RESULT_LEN - strlen(priv->buf),
	"Max response time: %lluns\nMin response time: %lluns\n",
	max_response_time, min_response_time);

	return ret;
	}

	/*
	* Writing to the debugfs entry initiates the IPC flood test based on
	* the IPC count or the duration specified by the user.
	*/
	static ssize_t sof_ipc_flood_dfs_write(struct file file, const char __user buffer,
	size_t count, loff_t *ppos)
	{
	struct sof_client_dev *cdev = file->private_data;
	struct device *dev = &cdev->auxdev.dev;
	unsigned long ipc_duration_ms = 0;
	bool flood_duration_test = false;
	unsigned long ipc_count = 0;
	struct dentry *dentry;
	int err;
	size_t size;
	char *string;
	int ret;

	string = kzalloc(count + 1, GFP_KERNEL);
	if (!string)
	return -ENOMEM;

	size = simple_write_to_buffer(string, count, ppos, buffer, count);

	/*
	* write op is only supported for ipc_flood_count or
	* ipc_flood_duration_ms debugfs entries atm.
	* ipc_flood_count floods the DSP with the number of IPC's specified.
	* ipc_duration_ms test floods the DSP for the time specified
	* in the debugfs entry.
	*/
	dentry = file->f_path.dentry;
	if (strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_COUNT) &&
	strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_DURATION)) {
	ret = -EINVAL;
	goto out;
	}

	if (!strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_DURATION))
	flood_duration_test = true;

	/* test completion criterion */
	if (flood_duration_test)
	ret = kstrtoul(string, 0, &ipc_duration_ms);
	else
	ret = kstrtoul(string, 0, &ipc_count);
	if (ret < 0)
	goto out;

	/* limit max duration/ipc count for flood test */
	if (flood_duration_test) {
	if (!ipc_duration_ms) {
	ret = size;
	goto out;
	}

	/* find the minimum. min() is not used to avoid warnings */
	if (ipc_duration_ms > MAX_IPC_FLOOD_DURATION_MS)
	ipc_duration_ms = MAX_IPC_FLOOD_DURATION_MS;
	} else {
	if (!ipc_count) {
	ret = size;
	goto out;
	}

	/* find the minimum. min() is not used to avoid warnings */
	if (ipc_count > MAX_IPC_FLOOD_COUNT)
	ipc_count = MAX_IPC_FLOOD_COUNT;
	}

	ret = pm_runtime_resume_and_get(dev);
	if (ret < 0 && ret != -EACCES) {
	dev_err_ratelimited(dev, "debugfs write failed to resume %d\n", ret);
	goto out;
	}

	/* flood test */
	ret = sof_debug_ipc_flood_test(cdev, flood_duration_test,
	ipc_duration_ms, ipc_count);

	pm_runtime_mark_last_busy(dev);
	err = pm_runtime_put_autosuspend(dev);
	if (err < 0)
	dev_err_ratelimited(dev, "debugfs write failed to idle %d\n", err);

	/* return size if test is successful */
	if (ret >= 0)
	ret = size;
	out:
	kfree(string);
	return ret;
	}

	/* return the result of the last IPC flood test */
	static ssize_t sof_ipc_flood_dfs_read(struct file file, char __user buffer,
	size_t count, loff_t *ppos)
	{
	struct sof_client_dev *cdev = file->private_data;
	struct sof_ipc_flood_priv *priv = cdev->data;
	size_t size_ret;

	struct dentry *dentry;

	dentry = file->f_path.dentry;
	if (!strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_COUNT) \|\|
	!strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_DURATION)) {
	if (*ppos)
	return 0;

	count = min_t(size_t, count, strlen(priv->buf));
	size_ret = copy_to_user(buffer, priv->buf, count);
	if (size_ret)
	return -EFAULT;

	*ppos += count;
	return count;
	}
	return count;
	}

	static int sof_ipc_flood_dfs_release(struct inode inode, struct file file)
	{
	debugfs_file_put(file->f_path.dentry);

	return 0;
	}

	static const struct file_operations sof_ipc_flood_fops = {
	.open = sof_ipc_flood_dfs_open,
	.read = sof_ipc_flood_dfs_read,
	.llseek = default_llseek,
	.write = sof_ipc_flood_dfs_write,
	.release = sof_ipc_flood_dfs_release,

	.owner = THIS_MODULE,
	};

	/*
	* The IPC test client creates a couple of debugfs entries that will be used
	* flood tests. Users can write to these entries to execute the IPC flood test
	* by specifying either the number of IPCs to flood the DSP with or the duration
	* (in ms) for which the DSP should be flooded with test IPCs. At the
	* end of each test, the average, min and max response times are reported back.
	* The results of the last flood test can be accessed by reading the debugfs
	* entries.
	*/
	static int sof_ipc_flood_probe(struct auxiliary_device *auxdev,
	const struct auxiliary_device_id *id)
	{
	struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
	struct dentry *debugfs_root = sof_client_get_debugfs_root(cdev);
	struct device *dev = &auxdev->dev;
	struct sof_ipc_flood_priv *priv;

	/* allocate memory for client data */
	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
	return -ENOMEM;

	priv->buf = devm_kmalloc(dev, IPC_FLOOD_TEST_RESULT_LEN, GFP_KERNEL);
	if (!priv->buf)
	return -ENOMEM;

	cdev->data = priv;

	/* create debugfs root folder with device name under parent SOF dir */
	priv->dfs_root = debugfs_create_dir(dev_name(dev), debugfs_root);
	if (!IS_ERR_OR_NULL(priv->dfs_root)) {
	/* create read-write ipc_flood_count debugfs entry */
	debugfs_create_file(DEBUGFS_IPC_FLOOD_COUNT, 0644, priv->dfs_root,
	cdev, &sof_ipc_flood_fops);

	/* create read-write ipc_flood_duration_ms debugfs entry */
	debugfs_create_file(DEBUGFS_IPC_FLOOD_DURATION, 0644,
	priv->dfs_root, cdev, &sof_ipc_flood_fops);

	if (auxdev->id == 0) {
	/*
	* Create symlinks for backwards compatibility to the
	* first IPC flood test instance
	*/
	char target[100];

	snprintf(target, 100, "%s/" DEBUGFS_IPC_FLOOD_COUNT,
	dev_name(dev));
	priv->dfs_link[0] =
	debugfs_create_symlink(DEBUGFS_IPC_FLOOD_COUNT,
	debugfs_root, target);

	snprintf(target, 100, "%s/" DEBUGFS_IPC_FLOOD_DURATION,
	dev_name(dev));
	priv->dfs_link[1] =
	debugfs_create_symlink(DEBUGFS_IPC_FLOOD_DURATION,
	debugfs_root, target);
	}
	}

	/* enable runtime PM */
	pm_runtime_set_autosuspend_delay(dev, SOF_IPC_CLIENT_SUSPEND_DELAY_MS);
	pm_runtime_use_autosuspend(dev);
	pm_runtime_enable(dev);
	pm_runtime_mark_last_busy(dev);
	pm_runtime_idle(dev);

	return 0;
	}

	static void sof_ipc_flood_remove(struct auxiliary_device *auxdev)
	{
	struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
	struct sof_ipc_flood_priv *priv = cdev->data;

	pm_runtime_disable(&auxdev->dev);

	if (auxdev->id == 0) {
	debugfs_remove(priv->dfs_link[0]);
	debugfs_remove(priv->dfs_link[1]);
	}

	debugfs_remove_recursive(priv->dfs_root);
	}

	static const struct auxiliary_device_id sof_ipc_flood_client_id_table[] = {
	{ .name = "snd_sof.ipc_flood" },
	{},
	};
	MODULE_DEVICE_TABLE(auxiliary, sof_ipc_flood_client_id_table);

	/*
	* No need for driver pm_ops as the generic pm callbacks in the auxiliary bus
	* type are enough to ensure that the parent SOF device resumes to bring the DSP
	* back to D0.
	* Driver name will be set based on KBUILD_MODNAME.
	*/
	static struct auxiliary_driver sof_ipc_flood_client_drv = {
	.probe = sof_ipc_flood_probe,
	.remove = sof_ipc_flood_remove,

	.id_table = sof_ipc_flood_client_id_table,
	};

	module_auxiliary_driver(sof_ipc_flood_client_drv);

	MODULE_DESCRIPTION("SOF IPC Flood Test Client Driver");
	MODULE_LICENSE("GPL");
	MODULE_IMPORT_NS(SND_SOC_SOF_CLIENT);