1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2014 Google, Inc.
4  */
5 
6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7 
8 #include <linux/delay.h>
9 #include <linux/init.h>
10 #include <linux/hrtimer.h>
11 #include <linux/module.h>
12 #include <linux/platform_device.h>
13 #include <linux/time.h>
14 #include <linux/numa.h>
15 #include <linux/nodemask.h>
16 #include <linux/topology.h>
17 
18 #define TEST_PROBE_DELAY	(5 * 1000)	/* 5 sec */
19 #define TEST_PROBE_THRESHOLD	(TEST_PROBE_DELAY / 2)
20 
21 static atomic_t warnings, errors, timeout, async_completed;
22 
test_probe(struct platform_device * pdev)23 static int test_probe(struct platform_device *pdev)
24 {
25 	struct device *dev = &pdev->dev;
26 
27 	/*
28 	 * Determine if we have hit the "timeout" limit for the test if we
29 	 * have then report it as an error, otherwise we wil sleep for the
30 	 * required amount of time and then report completion.
31 	 */
32 	if (atomic_read(&timeout)) {
33 		dev_err(dev, "async probe took too long\n");
34 		atomic_inc(&errors);
35 	} else {
36 		dev_dbg(&pdev->dev, "sleeping for %d msecs in probe\n",
37 			 TEST_PROBE_DELAY);
38 		msleep(TEST_PROBE_DELAY);
39 		dev_dbg(&pdev->dev, "done sleeping\n");
40 	}
41 
42 	/*
43 	 * Report NUMA mismatch if device node is set and we are not
44 	 * performing an async init on that node.
45 	 */
46 	if (dev->driver->probe_type == PROBE_PREFER_ASYNCHRONOUS) {
47 		if (IS_ENABLED(CONFIG_NUMA) &&
48 		    dev_to_node(dev) != numa_node_id()) {
49 			dev_warn(dev, "NUMA node mismatch %d != %d\n",
50 				 dev_to_node(dev), numa_node_id());
51 			atomic_inc(&warnings);
52 		}
53 
54 		atomic_inc(&async_completed);
55 	}
56 
57 	return 0;
58 }
59 
60 static struct platform_driver async_driver = {
61 	.driver = {
62 		.name = "test_async_driver",
63 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
64 	},
65 	.probe = test_probe,
66 };
67 
68 static struct platform_driver sync_driver = {
69 	.driver = {
70 		.name = "test_sync_driver",
71 		.probe_type = PROBE_FORCE_SYNCHRONOUS,
72 	},
73 	.probe = test_probe,
74 };
75 
76 static struct platform_device *async_dev[NR_CPUS * 2];
77 static struct platform_device *sync_dev[2];
78 
79 static struct platform_device *
test_platform_device_register_node(char * name,int id,int nid)80 test_platform_device_register_node(char *name, int id, int nid)
81 {
82 	struct platform_device *pdev;
83 	int ret;
84 
85 	pdev = platform_device_alloc(name, id);
86 	if (!pdev)
87 		return ERR_PTR(-ENOMEM);
88 
89 	if (nid != NUMA_NO_NODE)
90 		set_dev_node(&pdev->dev, nid);
91 
92 	ret = platform_device_add(pdev);
93 	if (ret) {
94 		platform_device_put(pdev);
95 		return ERR_PTR(ret);
96 	}
97 
98 	return pdev;
99 
100 }
101 
test_async_probe_init(void)102 static int __init test_async_probe_init(void)
103 {
104 	struct platform_device **pdev = NULL;
105 	int async_id = 0, sync_id = 0;
106 	unsigned long long duration;
107 	ktime_t calltime;
108 	int err, nid, cpu;
109 
110 	pr_info("registering first set of asynchronous devices...\n");
111 
112 	for_each_online_cpu(cpu) {
113 		nid = cpu_to_node(cpu);
114 		pdev = &async_dev[async_id];
115 		*pdev =	test_platform_device_register_node("test_async_driver",
116 							   async_id,
117 							   nid);
118 		if (IS_ERR(*pdev)) {
119 			err = PTR_ERR(*pdev);
120 			*pdev = NULL;
121 			pr_err("failed to create async_dev: %d\n", err);
122 			goto err_unregister_async_devs;
123 		}
124 
125 		async_id++;
126 	}
127 
128 	pr_info("registering asynchronous driver...\n");
129 	calltime = ktime_get();
130 	err = platform_driver_register(&async_driver);
131 	if (err) {
132 		pr_err("Failed to register async_driver: %d\n", err);
133 		goto err_unregister_async_devs;
134 	}
135 
136 	duration = (unsigned long long)ktime_ms_delta(ktime_get(), calltime);
137 	pr_info("registration took %lld msecs\n", duration);
138 	if (duration > TEST_PROBE_THRESHOLD) {
139 		pr_err("test failed: probe took too long\n");
140 		err = -ETIMEDOUT;
141 		goto err_unregister_async_driver;
142 	}
143 
144 	pr_info("registering second set of asynchronous devices...\n");
145 	calltime = ktime_get();
146 	for_each_online_cpu(cpu) {
147 		nid = cpu_to_node(cpu);
148 		pdev = &async_dev[async_id];
149 
150 		*pdev = test_platform_device_register_node("test_async_driver",
151 							   async_id,
152 							   nid);
153 		if (IS_ERR(*pdev)) {
154 			err = PTR_ERR(*pdev);
155 			*pdev = NULL;
156 			pr_err("failed to create async_dev: %d\n", err);
157 			goto err_unregister_async_driver;
158 		}
159 
160 		async_id++;
161 	}
162 
163 	duration = (unsigned long long)ktime_ms_delta(ktime_get(), calltime);
164 	dev_info(&(*pdev)->dev,
165 		 "registration took %lld msecs\n", duration);
166 	if (duration > TEST_PROBE_THRESHOLD) {
167 		dev_err(&(*pdev)->dev,
168 			"test failed: probe took too long\n");
169 		err = -ETIMEDOUT;
170 		goto err_unregister_async_driver;
171 	}
172 
173 
174 	pr_info("registering first synchronous device...\n");
175 	nid = cpu_to_node(cpu);
176 	pdev = &sync_dev[sync_id];
177 
178 	*pdev = test_platform_device_register_node("test_sync_driver",
179 						   sync_id,
180 						   NUMA_NO_NODE);
181 	if (IS_ERR(*pdev)) {
182 		err = PTR_ERR(*pdev);
183 		*pdev = NULL;
184 		pr_err("failed to create sync_dev: %d\n", err);
185 		goto err_unregister_async_driver;
186 	}
187 
188 	sync_id++;
189 
190 	pr_info("registering synchronous driver...\n");
191 	calltime = ktime_get();
192 	err = platform_driver_register(&sync_driver);
193 	if (err) {
194 		pr_err("Failed to register async_driver: %d\n", err);
195 		goto err_unregister_sync_devs;
196 	}
197 
198 	duration = (unsigned long long)ktime_ms_delta(ktime_get(), calltime);
199 	pr_info("registration took %lld msecs\n", duration);
200 	if (duration < TEST_PROBE_THRESHOLD) {
201 		dev_err(&(*pdev)->dev,
202 			"test failed: probe was too quick\n");
203 		err = -ETIMEDOUT;
204 		goto err_unregister_sync_driver;
205 	}
206 
207 	pr_info("registering second synchronous device...\n");
208 	pdev = &sync_dev[sync_id];
209 	calltime = ktime_get();
210 
211 	*pdev = test_platform_device_register_node("test_sync_driver",
212 						   sync_id,
213 						   NUMA_NO_NODE);
214 	if (IS_ERR(*pdev)) {
215 		err = PTR_ERR(*pdev);
216 		*pdev = NULL;
217 		pr_err("failed to create sync_dev: %d\n", err);
218 		goto err_unregister_sync_driver;
219 	}
220 
221 	sync_id++;
222 
223 	duration = (unsigned long long)ktime_ms_delta(ktime_get(), calltime);
224 	dev_info(&(*pdev)->dev,
225 		 "registration took %lld msecs\n", duration);
226 	if (duration < TEST_PROBE_THRESHOLD) {
227 		dev_err(&(*pdev)->dev,
228 			"test failed: probe was too quick\n");
229 		err = -ETIMEDOUT;
230 		goto err_unregister_sync_driver;
231 	}
232 
233 	/*
234 	 * The async events should have completed while we were taking care
235 	 * of the synchronous events. We will now terminate any outstanding
236 	 * asynchronous probe calls remaining by forcing timeout and remove
237 	 * the driver before we return which should force the flush of the
238 	 * pending asynchronous probe calls.
239 	 *
240 	 * Otherwise if they completed without errors or warnings then
241 	 * report successful completion.
242 	 */
243 	if (atomic_read(&async_completed) != async_id) {
244 		pr_err("async events still pending, forcing timeout\n");
245 		atomic_inc(&timeout);
246 		err = -ETIMEDOUT;
247 	} else if (!atomic_read(&errors) && !atomic_read(&warnings)) {
248 		pr_info("completed successfully\n");
249 		return 0;
250 	}
251 
252 err_unregister_sync_driver:
253 	platform_driver_unregister(&sync_driver);
254 err_unregister_sync_devs:
255 	while (sync_id--)
256 		platform_device_unregister(sync_dev[sync_id]);
257 err_unregister_async_driver:
258 	platform_driver_unregister(&async_driver);
259 err_unregister_async_devs:
260 	while (async_id--)
261 		platform_device_unregister(async_dev[async_id]);
262 
263 	/*
264 	 * If err is already set then count that as an additional error for
265 	 * the test. Otherwise we will report an invalid argument error and
266 	 * not count that as we should have reached here as a result of
267 	 * errors or warnings being reported by the probe routine.
268 	 */
269 	if (err)
270 		atomic_inc(&errors);
271 	else
272 		err = -EINVAL;
273 
274 	pr_err("Test failed with %d errors and %d warnings\n",
275 	       atomic_read(&errors), atomic_read(&warnings));
276 
277 	return err;
278 }
279 module_init(test_async_probe_init);
280 
test_async_probe_exit(void)281 static void __exit test_async_probe_exit(void)
282 {
283 	int id = 2;
284 
285 	platform_driver_unregister(&async_driver);
286 	platform_driver_unregister(&sync_driver);
287 
288 	while (id--)
289 		platform_device_unregister(sync_dev[id]);
290 
291 	id = NR_CPUS * 2;
292 	while (id--)
293 		platform_device_unregister(async_dev[id]);
294 }
295 module_exit(test_async_probe_exit);
296 
297 MODULE_DESCRIPTION("Test module for asynchronous driver probing");
298 MODULE_AUTHOR("Dmitry Torokhov <dtor@chromium.org>");
299 MODULE_LICENSE("GPL");
300