xref: /linux/sound/soc/sof/sof-client-ipc-flood-test.c (revision f2745dc0ba3dadd8fa2b2c33f48253d78e133a12)
1 // SPDX-License-Identifier: GPL-2.0-only
2 //
3 // Copyright(c) 2022 Intel Corporation. All rights reserved.
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 
30 struct sof_ipc_flood_priv {
31 	struct dentry *dfs_root;
32 	struct dentry *dfs_link[2];
33 	char *buf;
34 };
35 
36 static 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  */
59 static 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 	struct sof_ipc_reply reply;
68 	u64 min_response_time = U64_MAX;
69 	ktime_t start, end, test_end;
70 	u64 avg_response_time = 0;
71 	u64 max_response_time = 0;
72 	u64 ipc_response_time;
73 	int i = 0;
74 	int ret;
75 
76 	/* configure test IPC */
77 	hdr.cmd = SOF_IPC_GLB_TEST_MSG | SOF_IPC_TEST_IPC_FLOOD;
78 	hdr.size = sizeof(hdr);
79 
80 	/* set test end time for duration flood test */
81 	if (flood_duration_test)
82 		test_end = ktime_get_ns() + ipc_duration_ms * NSEC_PER_MSEC;
83 
84 	/* send test IPC's */
85 	while (1) {
86 		start = ktime_get();
87 		ret = sof_client_ipc_tx_message(cdev, &hdr, &reply, sizeof(reply));
88 		end = ktime_get();
89 
90 		if (ret < 0)
91 			break;
92 
93 		/* compute min and max response times */
94 		ipc_response_time = ktime_to_ns(ktime_sub(end, start));
95 		min_response_time = min(min_response_time, ipc_response_time);
96 		max_response_time = max(max_response_time, ipc_response_time);
97 
98 		/* sum up response times */
99 		avg_response_time += ipc_response_time;
100 		i++;
101 
102 		/* test complete? */
103 		if (flood_duration_test) {
104 			if (ktime_to_ns(end) >= test_end)
105 				break;
106 		} else {
107 			if (i == ipc_count)
108 				break;
109 		}
110 	}
111 
112 	if (ret < 0)
113 		dev_err(dev, "ipc flood test failed at %d iterations\n", i);
114 
115 	/* return if the first IPC fails */
116 	if (!i)
117 		return ret;
118 
119 	/* compute average response time */
120 	do_div(avg_response_time, i);
121 
122 	/* clear previous test output */
123 	memset(priv->buf, 0, IPC_FLOOD_TEST_RESULT_LEN);
124 
125 	if (!ipc_count) {
126 		dev_dbg(dev, "IPC Flood test duration: %lums\n", ipc_duration_ms);
127 		snprintf(priv->buf, IPC_FLOOD_TEST_RESULT_LEN,
128 			 "IPC Flood test duration: %lums\n", ipc_duration_ms);
129 	}
130 
131 	dev_dbg(dev, "IPC Flood count: %d, Avg response time: %lluns\n",
132 		i, avg_response_time);
133 	dev_dbg(dev, "Max response time: %lluns\n", max_response_time);
134 	dev_dbg(dev, "Min response time: %lluns\n", min_response_time);
135 
136 	/* format output string and save test results */
137 	snprintf(priv->buf + strlen(priv->buf),
138 		 IPC_FLOOD_TEST_RESULT_LEN - strlen(priv->buf),
139 		 "IPC Flood count: %d\nAvg response time: %lluns\n",
140 		 i, avg_response_time);
141 
142 	snprintf(priv->buf + strlen(priv->buf),
143 		 IPC_FLOOD_TEST_RESULT_LEN - strlen(priv->buf),
144 		 "Max response time: %lluns\nMin response time: %lluns\n",
145 		 max_response_time, min_response_time);
146 
147 	return ret;
148 }
149 
150 /*
151  * Writing to the debugfs entry initiates the IPC flood test based on
152  * the IPC count or the duration specified by the user.
153  */
154 static ssize_t sof_ipc_flood_dfs_write(struct file *file, const char __user *buffer,
155 				       size_t count, loff_t *ppos)
156 {
157 	struct sof_client_dev *cdev = file->private_data;
158 	struct device *dev = &cdev->auxdev.dev;
159 	unsigned long ipc_duration_ms = 0;
160 	bool flood_duration_test = false;
161 	unsigned long ipc_count = 0;
162 	struct dentry *dentry;
163 	int err;
164 	size_t size;
165 	char *string;
166 	int ret;
167 
168 	string = kzalloc(count + 1, GFP_KERNEL);
169 	if (!string)
170 		return -ENOMEM;
171 
172 	size = simple_write_to_buffer(string, count, ppos, buffer, count);
173 
174 	/*
175 	 * write op is only supported for ipc_flood_count or
176 	 * ipc_flood_duration_ms debugfs entries atm.
177 	 * ipc_flood_count floods the DSP with the number of IPC's specified.
178 	 * ipc_duration_ms test floods the DSP for the time specified
179 	 * in the debugfs entry.
180 	 */
181 	dentry = file->f_path.dentry;
182 	if (strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_COUNT) &&
183 	    strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_DURATION)) {
184 		ret = -EINVAL;
185 		goto out;
186 	}
187 
188 	if (!strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_DURATION))
189 		flood_duration_test = true;
190 
191 	/* test completion criterion */
192 	if (flood_duration_test)
193 		ret = kstrtoul(string, 0, &ipc_duration_ms);
194 	else
195 		ret = kstrtoul(string, 0, &ipc_count);
196 	if (ret < 0)
197 		goto out;
198 
199 	/* limit max duration/ipc count for flood test */
200 	if (flood_duration_test) {
201 		if (!ipc_duration_ms) {
202 			ret = size;
203 			goto out;
204 		}
205 
206 		/* find the minimum. min() is not used to avoid warnings */
207 		if (ipc_duration_ms > MAX_IPC_FLOOD_DURATION_MS)
208 			ipc_duration_ms = MAX_IPC_FLOOD_DURATION_MS;
209 	} else {
210 		if (!ipc_count) {
211 			ret = size;
212 			goto out;
213 		}
214 
215 		/* find the minimum. min() is not used to avoid warnings */
216 		if (ipc_count > MAX_IPC_FLOOD_COUNT)
217 			ipc_count = MAX_IPC_FLOOD_COUNT;
218 	}
219 
220 	ret = pm_runtime_resume_and_get(dev);
221 	if (ret < 0 && ret != -EACCES) {
222 		dev_err_ratelimited(dev, "debugfs write failed to resume %d\n", ret);
223 		goto out;
224 	}
225 
226 	/* flood test */
227 	ret = sof_debug_ipc_flood_test(cdev, flood_duration_test,
228 				       ipc_duration_ms, ipc_count);
229 
230 	pm_runtime_mark_last_busy(dev);
231 	err = pm_runtime_put_autosuspend(dev);
232 	if (err < 0)
233 		dev_err_ratelimited(dev, "debugfs write failed to idle %d\n", err);
234 
235 	/* return size if test is successful */
236 	if (ret >= 0)
237 		ret = size;
238 out:
239 	kfree(string);
240 	return ret;
241 }
242 
243 /* return the result of the last IPC flood test */
244 static ssize_t sof_ipc_flood_dfs_read(struct file *file, char __user *buffer,
245 				      size_t count, loff_t *ppos)
246 {
247 	struct sof_client_dev *cdev = file->private_data;
248 	struct sof_ipc_flood_priv *priv = cdev->data;
249 	size_t size_ret;
250 
251 	struct dentry *dentry;
252 
253 	dentry = file->f_path.dentry;
254 	if (!strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_COUNT) ||
255 	    !strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_DURATION)) {
256 		if (*ppos)
257 			return 0;
258 
259 		count = min_t(size_t, count, strlen(priv->buf));
260 		size_ret = copy_to_user(buffer, priv->buf, count);
261 		if (size_ret)
262 			return -EFAULT;
263 
264 		*ppos += count;
265 		return count;
266 	}
267 	return count;
268 }
269 
270 static int sof_ipc_flood_dfs_release(struct inode *inode, struct file *file)
271 {
272 	debugfs_file_put(file->f_path.dentry);
273 
274 	return 0;
275 }
276 
277 static const struct file_operations sof_ipc_flood_fops = {
278 	.open = sof_ipc_flood_dfs_open,
279 	.read = sof_ipc_flood_dfs_read,
280 	.llseek = default_llseek,
281 	.write = sof_ipc_flood_dfs_write,
282 	.release = sof_ipc_flood_dfs_release,
283 
284 	.owner = THIS_MODULE,
285 };
286 
287 /*
288  * The IPC test client creates a couple of debugfs entries that will be used
289  * flood tests. Users can write to these entries to execute the IPC flood test
290  * by specifying either the number of IPCs to flood the DSP with or the duration
291  * (in ms) for which the DSP should be flooded with test IPCs. At the
292  * end of each test, the average, min and max response times are reported back.
293  * The results of the last flood test can be accessed by reading the debugfs
294  * entries.
295  */
296 static int sof_ipc_flood_probe(struct auxiliary_device *auxdev,
297 			       const struct auxiliary_device_id *id)
298 {
299 	struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
300 	struct dentry *debugfs_root = sof_client_get_debugfs_root(cdev);
301 	struct device *dev = &auxdev->dev;
302 	struct sof_ipc_flood_priv *priv;
303 
304 	/* allocate memory for client data */
305 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
306 	if (!priv)
307 		return -ENOMEM;
308 
309 	priv->buf = devm_kmalloc(dev, IPC_FLOOD_TEST_RESULT_LEN, GFP_KERNEL);
310 	if (!priv->buf)
311 		return -ENOMEM;
312 
313 	cdev->data = priv;
314 
315 	/* create debugfs root folder with device name under parent SOF dir */
316 	priv->dfs_root = debugfs_create_dir(dev_name(dev), debugfs_root);
317 	if (!IS_ERR_OR_NULL(priv->dfs_root)) {
318 		/* create read-write ipc_flood_count debugfs entry */
319 		debugfs_create_file(DEBUGFS_IPC_FLOOD_COUNT, 0644, priv->dfs_root,
320 				    cdev, &sof_ipc_flood_fops);
321 
322 		/* create read-write ipc_flood_duration_ms debugfs entry */
323 		debugfs_create_file(DEBUGFS_IPC_FLOOD_DURATION, 0644,
324 				    priv->dfs_root, cdev, &sof_ipc_flood_fops);
325 
326 		if (auxdev->id == 0) {
327 			/*
328 			 * Create symlinks for backwards compatibility to the
329 			 * first IPC flood test instance
330 			 */
331 			char target[100];
332 
333 			snprintf(target, 100, "%s/" DEBUGFS_IPC_FLOOD_COUNT,
334 				 dev_name(dev));
335 			priv->dfs_link[0] =
336 				debugfs_create_symlink(DEBUGFS_IPC_FLOOD_COUNT,
337 						       debugfs_root, target);
338 
339 			snprintf(target, 100, "%s/" DEBUGFS_IPC_FLOOD_DURATION,
340 				 dev_name(dev));
341 			priv->dfs_link[1] =
342 				debugfs_create_symlink(DEBUGFS_IPC_FLOOD_DURATION,
343 						       debugfs_root, target);
344 		}
345 	}
346 
347 	/* enable runtime PM */
348 	pm_runtime_set_autosuspend_delay(dev, SOF_IPC_CLIENT_SUSPEND_DELAY_MS);
349 	pm_runtime_use_autosuspend(dev);
350 	pm_runtime_enable(dev);
351 	pm_runtime_mark_last_busy(dev);
352 	pm_runtime_idle(dev);
353 
354 	return 0;
355 }
356 
357 static void sof_ipc_flood_remove(struct auxiliary_device *auxdev)
358 {
359 	struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
360 	struct sof_ipc_flood_priv *priv = cdev->data;
361 
362 	pm_runtime_disable(&auxdev->dev);
363 
364 	if (auxdev->id == 0) {
365 		debugfs_remove(priv->dfs_link[0]);
366 		debugfs_remove(priv->dfs_link[1]);
367 	}
368 
369 	debugfs_remove_recursive(priv->dfs_root);
370 }
371 
372 static const struct auxiliary_device_id sof_ipc_flood_client_id_table[] = {
373 	{ .name = "snd_sof.ipc_flood" },
374 	{},
375 };
376 MODULE_DEVICE_TABLE(auxiliary, sof_ipc_flood_client_id_table);
377 
378 /*
379  * No need for driver pm_ops as the generic pm callbacks in the auxiliary bus
380  * type are enough to ensure that the parent SOF device resumes to bring the DSP
381  * back to D0.
382  * Driver name will be set based on KBUILD_MODNAME.
383  */
384 static struct auxiliary_driver sof_ipc_flood_client_drv = {
385 	.probe = sof_ipc_flood_probe,
386 	.remove = sof_ipc_flood_remove,
387 
388 	.id_table = sof_ipc_flood_client_id_table,
389 };
390 
391 module_auxiliary_driver(sof_ipc_flood_client_drv);
392 
393 MODULE_DESCRIPTION("SOF IPC Flood Test Client Driver");
394 MODULE_LICENSE("GPL");
395 MODULE_IMPORT_NS(SND_SOC_SOF_CLIENT);
396