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 	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  */
153 static 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 	struct dentry *dentry;
162 	int err;
163 	size_t size;
164 	char *string;
165 	int ret;
166 
167 	string = kzalloc(count + 1, GFP_KERNEL);
168 	if (!string)
169 		return -ENOMEM;
170 
171 	size = simple_write_to_buffer(string, count, ppos, buffer, count);
172 
173 	/*
174 	 * write op is only supported for ipc_flood_count or
175 	 * ipc_flood_duration_ms debugfs entries atm.
176 	 * ipc_flood_count floods the DSP with the number of IPC's specified.
177 	 * ipc_duration_ms test floods the DSP for the time specified
178 	 * in the debugfs entry.
179 	 */
180 	dentry = file->f_path.dentry;
181 	if (strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_COUNT) &&
182 	    strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_DURATION)) {
183 		ret = -EINVAL;
184 		goto out;
185 	}
186 
187 	if (!strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_DURATION))
188 		flood_duration_test = true;
189 
190 	/* test completion criterion */
191 	if (flood_duration_test)
192 		ret = kstrtoul(string, 0, &ipc_duration_ms);
193 	else
194 		ret = kstrtoul(string, 0, &ipc_count);
195 	if (ret < 0)
196 		goto out;
197 
198 	/* limit max duration/ipc count for flood test */
199 	if (flood_duration_test) {
200 		if (!ipc_duration_ms) {
201 			ret = size;
202 			goto out;
203 		}
204 
205 		/* find the minimum. min() is not used to avoid warnings */
206 		if (ipc_duration_ms > MAX_IPC_FLOOD_DURATION_MS)
207 			ipc_duration_ms = MAX_IPC_FLOOD_DURATION_MS;
208 	} else {
209 		if (!ipc_count) {
210 			ret = size;
211 			goto out;
212 		}
213 
214 		/* find the minimum. min() is not used to avoid warnings */
215 		if (ipc_count > MAX_IPC_FLOOD_COUNT)
216 			ipc_count = MAX_IPC_FLOOD_COUNT;
217 	}
218 
219 	ret = pm_runtime_resume_and_get(dev);
220 	if (ret < 0 && ret != -EACCES) {
221 		dev_err_ratelimited(dev, "debugfs write failed to resume %d\n", ret);
222 		goto out;
223 	}
224 
225 	/* flood test */
226 	ret = sof_debug_ipc_flood_test(cdev, flood_duration_test,
227 				       ipc_duration_ms, ipc_count);
228 
229 	pm_runtime_mark_last_busy(dev);
230 	err = pm_runtime_put_autosuspend(dev);
231 	if (err < 0)
232 		dev_err_ratelimited(dev, "debugfs write failed to idle %d\n", err);
233 
234 	/* return size if test is successful */
235 	if (ret >= 0)
236 		ret = size;
237 out:
238 	kfree(string);
239 	return ret;
240 }
241 
242 /* return the result of the last IPC flood test */
243 static ssize_t sof_ipc_flood_dfs_read(struct file *file, char __user *buffer,
244 				      size_t count, loff_t *ppos)
245 {
246 	struct sof_client_dev *cdev = file->private_data;
247 	struct sof_ipc_flood_priv *priv = cdev->data;
248 	size_t size_ret;
249 
250 	struct dentry *dentry;
251 
252 	dentry = file->f_path.dentry;
253 	if (!strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_COUNT) ||
254 	    !strcmp(dentry->d_name.name, DEBUGFS_IPC_FLOOD_DURATION)) {
255 		if (*ppos)
256 			return 0;
257 
258 		count = min_t(size_t, count, strlen(priv->buf));
259 		size_ret = copy_to_user(buffer, priv->buf, count);
260 		if (size_ret)
261 			return -EFAULT;
262 
263 		*ppos += count;
264 		return count;
265 	}
266 	return count;
267 }
268 
269 static int sof_ipc_flood_dfs_release(struct inode *inode, struct file *file)
270 {
271 	debugfs_file_put(file->f_path.dentry);
272 
273 	return 0;
274 }
275 
276 static const struct file_operations sof_ipc_flood_fops = {
277 	.open = sof_ipc_flood_dfs_open,
278 	.read = sof_ipc_flood_dfs_read,
279 	.llseek = default_llseek,
280 	.write = sof_ipc_flood_dfs_write,
281 	.release = sof_ipc_flood_dfs_release,
282 
283 	.owner = THIS_MODULE,
284 };
285 
286 /*
287  * The IPC test client creates a couple of debugfs entries that will be used
288  * flood tests. Users can write to these entries to execute the IPC flood test
289  * by specifying either the number of IPCs to flood the DSP with or the duration
290  * (in ms) for which the DSP should be flooded with test IPCs. At the
291  * end of each test, the average, min and max response times are reported back.
292  * The results of the last flood test can be accessed by reading the debugfs
293  * entries.
294  */
295 static int sof_ipc_flood_probe(struct auxiliary_device *auxdev,
296 			       const struct auxiliary_device_id *id)
297 {
298 	struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
299 	struct dentry *debugfs_root = sof_client_get_debugfs_root(cdev);
300 	struct device *dev = &auxdev->dev;
301 	struct sof_ipc_flood_priv *priv;
302 
303 	/* allocate memory for client data */
304 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
305 	if (!priv)
306 		return -ENOMEM;
307 
308 	priv->buf = devm_kmalloc(dev, IPC_FLOOD_TEST_RESULT_LEN, GFP_KERNEL);
309 	if (!priv->buf)
310 		return -ENOMEM;
311 
312 	cdev->data = priv;
313 
314 	/* create debugfs root folder with device name under parent SOF dir */
315 	priv->dfs_root = debugfs_create_dir(dev_name(dev), debugfs_root);
316 	if (!IS_ERR_OR_NULL(priv->dfs_root)) {
317 		/* create read-write ipc_flood_count debugfs entry */
318 		debugfs_create_file(DEBUGFS_IPC_FLOOD_COUNT, 0644, priv->dfs_root,
319 				    cdev, &sof_ipc_flood_fops);
320 
321 		/* create read-write ipc_flood_duration_ms debugfs entry */
322 		debugfs_create_file(DEBUGFS_IPC_FLOOD_DURATION, 0644,
323 				    priv->dfs_root, cdev, &sof_ipc_flood_fops);
324 
325 		if (auxdev->id == 0) {
326 			/*
327 			 * Create symlinks for backwards compatibility to the
328 			 * first IPC flood test instance
329 			 */
330 			char target[100];
331 
332 			snprintf(target, 100, "%s/" DEBUGFS_IPC_FLOOD_COUNT,
333 				 dev_name(dev));
334 			priv->dfs_link[0] =
335 				debugfs_create_symlink(DEBUGFS_IPC_FLOOD_COUNT,
336 						       debugfs_root, target);
337 
338 			snprintf(target, 100, "%s/" DEBUGFS_IPC_FLOOD_DURATION,
339 				 dev_name(dev));
340 			priv->dfs_link[1] =
341 				debugfs_create_symlink(DEBUGFS_IPC_FLOOD_DURATION,
342 						       debugfs_root, target);
343 		}
344 	}
345 
346 	/* enable runtime PM */
347 	pm_runtime_set_autosuspend_delay(dev, SOF_IPC_CLIENT_SUSPEND_DELAY_MS);
348 	pm_runtime_use_autosuspend(dev);
349 	pm_runtime_enable(dev);
350 	pm_runtime_mark_last_busy(dev);
351 	pm_runtime_idle(dev);
352 
353 	return 0;
354 }
355 
356 static void sof_ipc_flood_remove(struct auxiliary_device *auxdev)
357 {
358 	struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
359 	struct sof_ipc_flood_priv *priv = cdev->data;
360 
361 	pm_runtime_disable(&auxdev->dev);
362 
363 	if (auxdev->id == 0) {
364 		debugfs_remove(priv->dfs_link[0]);
365 		debugfs_remove(priv->dfs_link[1]);
366 	}
367 
368 	debugfs_remove_recursive(priv->dfs_root);
369 }
370 
371 static const struct auxiliary_device_id sof_ipc_flood_client_id_table[] = {
372 	{ .name = "snd_sof.ipc_flood" },
373 	{},
374 };
375 MODULE_DEVICE_TABLE(auxiliary, sof_ipc_flood_client_id_table);
376 
377 /*
378  * No need for driver pm_ops as the generic pm callbacks in the auxiliary bus
379  * type are enough to ensure that the parent SOF device resumes to bring the DSP
380  * back to D0.
381  * Driver name will be set based on KBUILD_MODNAME.
382  */
383 static struct auxiliary_driver sof_ipc_flood_client_drv = {
384 	.probe = sof_ipc_flood_probe,
385 	.remove = sof_ipc_flood_remove,
386 
387 	.id_table = sof_ipc_flood_client_id_table,
388 };
389 
390 module_auxiliary_driver(sof_ipc_flood_client_drv);
391 
392 MODULE_DESCRIPTION("SOF IPC Flood Test Client Driver");
393 MODULE_LICENSE("GPL");
394 MODULE_IMPORT_NS(SND_SOC_SOF_CLIENT);
395