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
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	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;
237out:
238	kfree(string);
239	return ret;
240}
241
242/* return the result of the last IPC flood test */
243static 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
269static 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
276static 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 */
295static 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
356static 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
371static const struct auxiliary_device_id sof_ipc_flood_client_id_table[] = {
372	{ .name = "snd_sof.ipc_flood" },
373	{},
374};
375MODULE_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 */
383static 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
390module_auxiliary_driver(sof_ipc_flood_client_drv);
391
392MODULE_DESCRIPTION("SOF IPC Flood Test Client Driver");
393MODULE_LICENSE("GPL");
394MODULE_IMPORT_NS(SND_SOC_SOF_CLIENT);
395