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_get_sync(dev);
221 	if (ret < 0 && ret != -EACCES) {
222 		dev_err_ratelimited(dev, "debugfs write failed to resume %d\n", ret);
223 		pm_runtime_put_noidle(dev);
224 		goto out;
225 	}
226 
227 	/* flood test */
228 	ret = sof_debug_ipc_flood_test(cdev, flood_duration_test,
229 				       ipc_duration_ms, ipc_count);
230 
231 	pm_runtime_mark_last_busy(dev);
232 	err = pm_runtime_put_autosuspend(dev);
233 	if (err < 0)
234 		dev_err_ratelimited(dev, "debugfs write failed to idle %d\n", err);
235 
236 	/* return size if test is successful */
237 	if (ret >= 0)
238 		ret = size;
239 out:
240 	kfree(string);
241 	return ret;
242 }
243 
244 /* return the result of the last IPC flood test */
245 static ssize_t sof_ipc_flood_dfs_read(struct file *file, char __user *buffer,
246 				      size_t count, loff_t *ppos)
247 {
248 	struct sof_client_dev *cdev = file->private_data;
249 	struct sof_ipc_flood_priv *priv = cdev->data;
250 	size_t size_ret;
251 
252 	struct dentry *dentry;
253 
254 	dentry = file->f_path.dentry;
255 	if (!strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_COUNT) ||
256 	    !strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_DURATION)) {
257 		if (*ppos)
258 			return 0;
259 
260 		count = min_t(size_t, count, strlen(priv->buf));
261 		size_ret = copy_to_user(buffer, priv->buf, count);
262 		if (size_ret)
263 			return -EFAULT;
264 
265 		*ppos += count;
266 		return count;
267 	}
268 	return count;
269 }
270 
271 static int sof_ipc_flood_dfs_release(struct inode *inode, struct file *file)
272 {
273 	debugfs_file_put(file->f_path.dentry);
274 
275 	return 0;
276 }
277 
278 static const struct file_operations sof_ipc_flood_fops = {
279 	.open = sof_ipc_flood_dfs_open,
280 	.read = sof_ipc_flood_dfs_read,
281 	.llseek = default_llseek,
282 	.write = sof_ipc_flood_dfs_write,
283 	.release = sof_ipc_flood_dfs_release,
284 
285 	.owner = THIS_MODULE,
286 };
287 
288 /*
289  * The IPC test client creates a couple of debugfs entries that will be used
290  * flood tests. Users can write to these entries to execute the IPC flood test
291  * by specifying either the number of IPCs to flood the DSP with or the duration
292  * (in ms) for which the DSP should be flooded with test IPCs. At the
293  * end of each test, the average, min and max response times are reported back.
294  * The results of the last flood test can be accessed by reading the debugfs
295  * entries.
296  */
297 static int sof_ipc_flood_probe(struct auxiliary_device *auxdev,
298 			       const struct auxiliary_device_id *id)
299 {
300 	struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
301 	struct dentry *debugfs_root = sof_client_get_debugfs_root(cdev);
302 	struct device *dev = &auxdev->dev;
303 	struct sof_ipc_flood_priv *priv;
304 
305 	/* allocate memory for client data */
306 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
307 	if (!priv)
308 		return -ENOMEM;
309 
310 	priv->buf = devm_kmalloc(dev, IPC_FLOOD_TEST_RESULT_LEN, GFP_KERNEL);
311 	if (!priv->buf)
312 		return -ENOMEM;
313 
314 	cdev->data = priv;
315 
316 	/* create debugfs root folder with device name under parent SOF dir */
317 	priv->dfs_root = debugfs_create_dir(dev_name(dev), debugfs_root);
318 	if (!IS_ERR_OR_NULL(priv->dfs_root)) {
319 		/* create read-write ipc_flood_count debugfs entry */
320 		debugfs_create_file(DEBUGFS_IPC_FLOOD_COUNT, 0644, priv->dfs_root,
321 				    cdev, &sof_ipc_flood_fops);
322 
323 		/* create read-write ipc_flood_duration_ms debugfs entry */
324 		debugfs_create_file(DEBUGFS_IPC_FLOOD_DURATION, 0644,
325 				    priv->dfs_root, cdev, &sof_ipc_flood_fops);
326 
327 		if (auxdev->id == 0) {
328 			/*
329 			 * Create symlinks for backwards compatibility to the
330 			 * first IPC flood test instance
331 			 */
332 			char target[100];
333 
334 			snprintf(target, 100, "%s/" DEBUGFS_IPC_FLOOD_COUNT,
335 				 dev_name(dev));
336 			priv->dfs_link[0] =
337 				debugfs_create_symlink(DEBUGFS_IPC_FLOOD_COUNT,
338 						       debugfs_root, target);
339 
340 			snprintf(target, 100, "%s/" DEBUGFS_IPC_FLOOD_DURATION,
341 				 dev_name(dev));
342 			priv->dfs_link[1] =
343 				debugfs_create_symlink(DEBUGFS_IPC_FLOOD_DURATION,
344 						       debugfs_root, target);
345 		}
346 	}
347 
348 	/* enable runtime PM */
349 	pm_runtime_set_autosuspend_delay(dev, SOF_IPC_CLIENT_SUSPEND_DELAY_MS);
350 	pm_runtime_use_autosuspend(dev);
351 	pm_runtime_enable(dev);
352 	pm_runtime_mark_last_busy(dev);
353 	pm_runtime_idle(dev);
354 
355 	return 0;
356 }
357 
358 static void sof_ipc_flood_remove(struct auxiliary_device *auxdev)
359 {
360 	struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
361 	struct sof_ipc_flood_priv *priv = cdev->data;
362 
363 	pm_runtime_disable(&auxdev->dev);
364 
365 	if (auxdev->id == 0) {
366 		debugfs_remove(priv->dfs_link[0]);
367 		debugfs_remove(priv->dfs_link[1]);
368 	}
369 
370 	debugfs_remove_recursive(priv->dfs_root);
371 }
372 
373 static const struct auxiliary_device_id sof_ipc_flood_client_id_table[] = {
374 	{ .name = "snd_sof.ipc_flood" },
375 	{},
376 };
377 MODULE_DEVICE_TABLE(auxiliary, sof_ipc_flood_client_id_table);
378 
379 /*
380  * No need for driver pm_ops as the generic pm callbacks in the auxiliary bus
381  * type are enough to ensure that the parent SOF device resumes to bring the DSP
382  * back to D0.
383  * Driver name will be set based on KBUILD_MODNAME.
384  */
385 static struct auxiliary_driver sof_ipc_flood_client_drv = {
386 	.probe = sof_ipc_flood_probe,
387 	.remove = sof_ipc_flood_remove,
388 
389 	.id_table = sof_ipc_flood_client_id_table,
390 };
391 
392 module_auxiliary_driver(sof_ipc_flood_client_drv);
393 
394 MODULE_DESCRIPTION("SOF IPC Flood Test Client Driver");
395 MODULE_LICENSE("GPL");
396 MODULE_IMPORT_NS(SND_SOC_SOF_CLIENT);
397