sof-client-ipc-flood-test.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2//
  3// Copyright(c) 2022 Intel Corporation
  4//
  5// Authors: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
  6//	    Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
  7//
  8
  9#include <linux/auxiliary_bus.h>
 10#include <linux/completion.h>
 11#include <linux/debugfs.h>
 12#include <linux/ktime.h>
 13#include <linux/mod_devicetable.h>
 14#include <linux/module.h>
 15#include <linux/pm_runtime.h>
 16#include <linux/slab.h>
 17#include <linux/uaccess.h>
 18#include <sound/sof/header.h>
 19
 20#include "sof-client.h"
 21
 22#define MAX_IPC_FLOOD_DURATION_MS	1000
 23#define MAX_IPC_FLOOD_COUNT		10000
 24#define IPC_FLOOD_TEST_RESULT_LEN	512
 25#define SOF_IPC_CLIENT_SUSPEND_DELAY_MS	3000
 26
 27#define DEBUGFS_IPC_FLOOD_COUNT		"ipc_flood_count"
 28#define DEBUGFS_IPC_FLOOD_DURATION	"ipc_flood_duration_ms"
 29
 30struct sof_ipc_flood_priv {
 31	struct dentry *dfs_root;
 32	struct dentry *dfs_link[2];
 33	char *buf;
 34};
 35
 36static int sof_ipc_flood_dfs_open(struct inode *inode, struct file *file)
 37{
 38	struct sof_client_dev *cdev = inode->i_private;
 39	int ret;
 40
 41	if (sof_client_get_fw_state(cdev) == SOF_FW_CRASHED)
 42		return -ENODEV;
 43
 44	ret = debugfs_file_get(file->f_path.dentry);
 45	if (unlikely(ret))
 46		return ret;
 47
 48	ret = simple_open(inode, file);
 49	if (ret)
 50		debugfs_file_put(file->f_path.dentry);
 51
 52	return ret;
 53}
 54
 55/*
 56 * helper function to perform the flood test. Only one of the two params, ipc_duration_ms
 57 * or ipc_count, will be non-zero and will determine the type of test
 58 */
 59static int sof_debug_ipc_flood_test(struct sof_client_dev *cdev,
 60				    bool flood_duration_test,
 61				    unsigned long ipc_duration_ms,
 62				    unsigned long ipc_count)
 63{
 64	struct sof_ipc_flood_priv *priv = cdev->data;
 65	struct device *dev = &cdev->auxdev.dev;
 66	struct sof_ipc_cmd_hdr hdr;
 67	u64 min_response_time = U64_MAX;
 68	ktime_t start, end, test_end;
 69	u64 avg_response_time = 0;
 70	u64 max_response_time = 0;
 71	u64 ipc_response_time;
 72	int i = 0;
 73	int ret;
 74
 75	/* configure test IPC */
 76	hdr.cmd = SOF_IPC_GLB_TEST_MSG | SOF_IPC_TEST_IPC_FLOOD;
 77	hdr.size = sizeof(hdr);
 78
 79	/* set test end time for duration flood test */
 80	if (flood_duration_test)
 81		test_end = ktime_get_ns() + ipc_duration_ms * NSEC_PER_MSEC;
 82
 83	/* send test IPC's */
 84	while (1) {
 85		start = ktime_get();
 86		ret = sof_client_ipc_tx_message_no_reply(cdev, &hdr);
 87		end = ktime_get();
 88
 89		if (ret < 0)
 90			break;
 91
 92		/* compute min and max response times */
 93		ipc_response_time = ktime_to_ns(ktime_sub(end, start));
 94		min_response_time = min(min_response_time, ipc_response_time);
 95		max_response_time = max(max_response_time, ipc_response_time);
 96
 97		/* sum up response times */
 98		avg_response_time += ipc_response_time;
 99		i++;
100
101		/* test complete? */
102		if (flood_duration_test) {
103			if (ktime_to_ns(end) >= test_end)
104				break;
105		} else {
106			if (i == ipc_count)
107				break;
108		}
109	}
110
111	if (ret < 0)
112		dev_err(dev, "ipc flood test failed at %d iterations\n", i);
113
114	/* return if the first IPC fails */
115	if (!i)
116		return ret;
117
118	/* compute average response time */
119	do_div(avg_response_time, i);
120
121	/* clear previous test output */
122	memset(priv->buf, 0, IPC_FLOOD_TEST_RESULT_LEN);
123
124	if (!ipc_count) {
125		dev_dbg(dev, "IPC Flood test duration: %lums\n", ipc_duration_ms);
126		snprintf(priv->buf, IPC_FLOOD_TEST_RESULT_LEN,
127			 "IPC Flood test duration: %lums\n", ipc_duration_ms);
128	}
129
130	dev_dbg(dev, "IPC Flood count: %d, Avg response time: %lluns\n",
131		i, avg_response_time);
132	dev_dbg(dev, "Max response time: %lluns\n", max_response_time);
133	dev_dbg(dev, "Min response time: %lluns\n", min_response_time);
134
135	/* format output string and save test results */
136	snprintf(priv->buf + strlen(priv->buf),
137		 IPC_FLOOD_TEST_RESULT_LEN - strlen(priv->buf),
138		 "IPC Flood count: %d\nAvg response time: %lluns\n",
139		 i, avg_response_time);
140
141	snprintf(priv->buf + strlen(priv->buf),
142		 IPC_FLOOD_TEST_RESULT_LEN - strlen(priv->buf),
143		 "Max response time: %lluns\nMin response time: %lluns\n",
144		 max_response_time, min_response_time);
145
146	return ret;
147}
148
149/*
150 * Writing to the debugfs entry initiates the IPC flood test based on
151 * the IPC count or the duration specified by the user.
152 */
153static ssize_t sof_ipc_flood_dfs_write(struct file *file, const char __user *buffer,
154				       size_t count, loff_t *ppos)
155{
156	struct sof_client_dev *cdev = file->private_data;
157	struct device *dev = &cdev->auxdev.dev;
158	unsigned long ipc_duration_ms = 0;
159	bool flood_duration_test = false;
160	unsigned long ipc_count = 0;
161	int err;
162	char *string;
163	int ret;
164
165	if (*ppos != 0)
166		return -EINVAL;
167
168	string = kzalloc(count + 1, GFP_KERNEL);
169	if (!string)
170		return -ENOMEM;
171
172	if (copy_from_user(string, buffer, count)) {
173		ret = -EFAULT;
174		goto out;
175	}
176
177	/*
178	 * write op is only supported for ipc_flood_count or
179	 * ipc_flood_duration_ms debugfs entries atm.
180	 * ipc_flood_count floods the DSP with the number of IPC's specified.
181	 * ipc_duration_ms test floods the DSP for the time specified
182	 * in the debugfs entry.
183	 */
184	if (debugfs_get_aux_num(file))
185		flood_duration_test = true;
186
187	/* test completion criterion */
188	if (flood_duration_test)
189		ret = kstrtoul(string, 0, &ipc_duration_ms);
190	else
191		ret = kstrtoul(string, 0, &ipc_count);
192	if (ret < 0)
193		goto out;
194
195	/* limit max duration/ipc count for flood test */
196	if (flood_duration_test) {
197		if (!ipc_duration_ms) {
198			ret = count;
199			goto out;
200		}
201
202		/* find the minimum. min() is not used to avoid warnings */
203		if (ipc_duration_ms > MAX_IPC_FLOOD_DURATION_MS)
204			ipc_duration_ms = MAX_IPC_FLOOD_DURATION_MS;
205	} else {
206		if (!ipc_count) {
207			ret = count;
208			goto out;
209		}
210
211		/* find the minimum. min() is not used to avoid warnings */
212		if (ipc_count > MAX_IPC_FLOOD_COUNT)
213			ipc_count = MAX_IPC_FLOOD_COUNT;
214	}
215
216	ret = pm_runtime_resume_and_get(dev);
217	if (ret < 0 && ret != -EACCES) {
218		dev_err_ratelimited(dev, "debugfs write failed to resume %d\n", ret);
219		goto out;
220	}
221
222	/* flood test */
223	ret = sof_debug_ipc_flood_test(cdev, flood_duration_test,
224				       ipc_duration_ms, ipc_count);
225
226	err = pm_runtime_put_autosuspend(dev);
227	if (err < 0)
228		dev_err_ratelimited(dev, "debugfs write failed to idle %d\n", err);
229
230	/* return count if test is successful */
231	if (ret >= 0)
232		ret = count;
233out:
234	kfree(string);
235	return ret;
236}
237
238/* return the result of the last IPC flood test */
239static ssize_t sof_ipc_flood_dfs_read(struct file *file, char __user *buffer,
240				      size_t count, loff_t *ppos)
241{
242	struct sof_client_dev *cdev = file->private_data;
243	struct sof_ipc_flood_priv *priv = cdev->data;
244	size_t size_ret;
245
246	if (*ppos)
247		return 0;
248
249	count = min_t(size_t, count, strlen(priv->buf));
250	size_ret = copy_to_user(buffer, priv->buf, count);
251	if (size_ret)
252		return -EFAULT;
253
254	*ppos += count;
255	return count;
256}
257
258static int sof_ipc_flood_dfs_release(struct inode *inode, struct file *file)
259{
260	debugfs_file_put(file->f_path.dentry);
261
262	return 0;
263}
264
265static const struct file_operations sof_ipc_flood_fops = {
266	.open = sof_ipc_flood_dfs_open,
267	.read = sof_ipc_flood_dfs_read,
268	.llseek = default_llseek,
269	.write = sof_ipc_flood_dfs_write,
270	.release = sof_ipc_flood_dfs_release,
271
272	.owner = THIS_MODULE,
273};
274
275/*
276 * The IPC test client creates a couple of debugfs entries that will be used
277 * flood tests. Users can write to these entries to execute the IPC flood test
278 * by specifying either the number of IPCs to flood the DSP with or the duration
279 * (in ms) for which the DSP should be flooded with test IPCs. At the
280 * end of each test, the average, min and max response times are reported back.
281 * The results of the last flood test can be accessed by reading the debugfs
282 * entries.
283 */
284static int sof_ipc_flood_probe(struct auxiliary_device *auxdev,
285			       const struct auxiliary_device_id *id)
286{
287	struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
288	struct dentry *debugfs_root = sof_client_get_debugfs_root(cdev);
289	struct device *dev = &auxdev->dev;
290	struct sof_ipc_flood_priv *priv;
291
292	/* allocate memory for client data */
293	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
294	if (!priv)
295		return -ENOMEM;
296
297	priv->buf = devm_kmalloc(dev, IPC_FLOOD_TEST_RESULT_LEN, GFP_KERNEL);
298	if (!priv->buf)
299		return -ENOMEM;
300
301	cdev->data = priv;
302
303	/* create debugfs root folder with device name under parent SOF dir */
304	priv->dfs_root = debugfs_create_dir(dev_name(dev), debugfs_root);
305	if (!IS_ERR_OR_NULL(priv->dfs_root)) {
306		/* create read-write ipc_flood_count debugfs entry */
307		debugfs_create_file_aux_num(DEBUGFS_IPC_FLOOD_COUNT, 0644,
308				    priv->dfs_root, cdev, 0, &sof_ipc_flood_fops);
309
310		/* create read-write ipc_flood_duration_ms debugfs entry */
311		debugfs_create_file_aux_num(DEBUGFS_IPC_FLOOD_DURATION, 0644,
312				    priv->dfs_root, cdev, 1, &sof_ipc_flood_fops);
313
314		if (auxdev->id == 0) {
315			/*
316			 * Create symlinks for backwards compatibility to the
317			 * first IPC flood test instance
318			 */
319			char target[100];
320
321			snprintf(target, 100, "%s/" DEBUGFS_IPC_FLOOD_COUNT,
322				 dev_name(dev));
323			priv->dfs_link[0] =
324				debugfs_create_symlink(DEBUGFS_IPC_FLOOD_COUNT,
325						       debugfs_root, target);
326
327			snprintf(target, 100, "%s/" DEBUGFS_IPC_FLOOD_DURATION,
328				 dev_name(dev));
329			priv->dfs_link[1] =
330				debugfs_create_symlink(DEBUGFS_IPC_FLOOD_DURATION,
331						       debugfs_root, target);
332		}
333	}
334
335	/* enable runtime PM */
336	pm_runtime_set_autosuspend_delay(dev, SOF_IPC_CLIENT_SUSPEND_DELAY_MS);
337	pm_runtime_use_autosuspend(dev);
338	pm_runtime_enable(dev);
339	pm_runtime_mark_last_busy(dev);
340	pm_runtime_idle(dev);
341
342	return 0;
343}
344
345static void sof_ipc_flood_remove(struct auxiliary_device *auxdev)
346{
347	struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
348	struct sof_ipc_flood_priv *priv = cdev->data;
349
350	pm_runtime_disable(&auxdev->dev);
351
352	if (auxdev->id == 0) {
353		debugfs_remove(priv->dfs_link[0]);
354		debugfs_remove(priv->dfs_link[1]);
355	}
356
357	debugfs_remove_recursive(priv->dfs_root);
358}
359
360static const struct auxiliary_device_id sof_ipc_flood_client_id_table[] = {
361	{ .name = "snd_sof.ipc_flood" },
362	{},
363};
364MODULE_DEVICE_TABLE(auxiliary, sof_ipc_flood_client_id_table);
365
366/*
367 * No need for driver pm_ops as the generic pm callbacks in the auxiliary bus
368 * type are enough to ensure that the parent SOF device resumes to bring the DSP
369 * back to D0.
370 * Driver name will be set based on KBUILD_MODNAME.
371 */
372static struct auxiliary_driver sof_ipc_flood_client_drv = {
373	.probe = sof_ipc_flood_probe,
374	.remove = sof_ipc_flood_remove,
375
376	.id_table = sof_ipc_flood_client_id_table,
377};
378
379module_auxiliary_driver(sof_ipc_flood_client_drv);
380
381MODULE_LICENSE("GPL");
382MODULE_DESCRIPTION("SOF IPC Flood Test Client Driver");
383MODULE_IMPORT_NS("SND_SOC_SOF_CLIENT");