Commit | Line | Data |
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61a87122 TG |
1 | /* |
2 | * RT-Mutex-tester: scriptable tester for rt mutexes | |
3 | * | |
4 | * started by Thomas Gleixner: | |
5 | * | |
6 | * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com> | |
7 | * | |
8 | */ | |
997d3eaf | 9 | #include <linux/device.h> |
61a87122 | 10 | #include <linux/kthread.h> |
9984de1a | 11 | #include <linux/export.h> |
61a87122 | 12 | #include <linux/sched.h> |
61a87122 | 13 | #include <linux/spinlock.h> |
61a87122 | 14 | #include <linux/timer.h> |
7dfb7103 | 15 | #include <linux/freezer.h> |
61a87122 TG |
16 | |
17 | #include "rtmutex.h" | |
18 | ||
19 | #define MAX_RT_TEST_THREADS 8 | |
20 | #define MAX_RT_TEST_MUTEXES 8 | |
21 | ||
22 | static spinlock_t rttest_lock; | |
23 | static atomic_t rttest_event; | |
24 | ||
25 | struct test_thread_data { | |
26 | int opcode; | |
27 | int opdata; | |
28 | int mutexes[MAX_RT_TEST_MUTEXES]; | |
61a87122 | 29 | int event; |
997d3eaf | 30 | struct device dev; |
61a87122 TG |
31 | }; |
32 | ||
33 | static struct test_thread_data thread_data[MAX_RT_TEST_THREADS]; | |
36c8b586 | 34 | static struct task_struct *threads[MAX_RT_TEST_THREADS]; |
61a87122 TG |
35 | static struct rt_mutex mutexes[MAX_RT_TEST_MUTEXES]; |
36 | ||
37 | enum test_opcodes { | |
38 | RTTEST_NOP = 0, | |
39 | RTTEST_SCHEDOT, /* 1 Sched other, data = nice */ | |
40 | RTTEST_SCHEDRT, /* 2 Sched fifo, data = prio */ | |
41 | RTTEST_LOCK, /* 3 Lock uninterruptible, data = lockindex */ | |
42 | RTTEST_LOCKNOWAIT, /* 4 Lock uninterruptible no wait in wakeup, data = lockindex */ | |
43 | RTTEST_LOCKINT, /* 5 Lock interruptible, data = lockindex */ | |
44 | RTTEST_LOCKINTNOWAIT, /* 6 Lock interruptible no wait in wakeup, data = lockindex */ | |
45 | RTTEST_LOCKCONT, /* 7 Continue locking after the wakeup delay */ | |
46 | RTTEST_UNLOCK, /* 8 Unlock, data = lockindex */ | |
dbebbfbb TG |
47 | /* 9, 10 - reserved for BKL commemoration */ |
48 | RTTEST_SIGNAL = 11, /* 11 Signal other test thread, data = thread id */ | |
61a87122 TG |
49 | RTTEST_RESETEVENT = 98, /* 98 Reset event counter */ |
50 | RTTEST_RESET = 99, /* 99 Reset all pending operations */ | |
51 | }; | |
52 | ||
53 | static int handle_op(struct test_thread_data *td, int lockwakeup) | |
54 | { | |
61a87122 TG |
55 | int i, id, ret = -EINVAL; |
56 | ||
57 | switch(td->opcode) { | |
58 | ||
59 | case RTTEST_NOP: | |
60 | return 0; | |
61 | ||
61a87122 TG |
62 | case RTTEST_LOCKCONT: |
63 | td->mutexes[td->opdata] = 1; | |
64 | td->event = atomic_add_return(1, &rttest_event); | |
65 | return 0; | |
66 | ||
67 | case RTTEST_RESET: | |
68 | for (i = 0; i < MAX_RT_TEST_MUTEXES; i++) { | |
69 | if (td->mutexes[i] == 4) { | |
70 | rt_mutex_unlock(&mutexes[i]); | |
71 | td->mutexes[i] = 0; | |
72 | } | |
73 | } | |
61a87122 TG |
74 | return 0; |
75 | ||
76 | case RTTEST_RESETEVENT: | |
77 | atomic_set(&rttest_event, 0); | |
78 | return 0; | |
79 | ||
80 | default: | |
81 | if (lockwakeup) | |
82 | return ret; | |
83 | } | |
84 | ||
85 | switch(td->opcode) { | |
86 | ||
87 | case RTTEST_LOCK: | |
88 | case RTTEST_LOCKNOWAIT: | |
89 | id = td->opdata; | |
90 | if (id < 0 || id >= MAX_RT_TEST_MUTEXES) | |
91 | return ret; | |
92 | ||
93 | td->mutexes[id] = 1; | |
94 | td->event = atomic_add_return(1, &rttest_event); | |
95 | rt_mutex_lock(&mutexes[id]); | |
96 | td->event = atomic_add_return(1, &rttest_event); | |
97 | td->mutexes[id] = 4; | |
98 | return 0; | |
99 | ||
100 | case RTTEST_LOCKINT: | |
101 | case RTTEST_LOCKINTNOWAIT: | |
102 | id = td->opdata; | |
103 | if (id < 0 || id >= MAX_RT_TEST_MUTEXES) | |
104 | return ret; | |
105 | ||
106 | td->mutexes[id] = 1; | |
107 | td->event = atomic_add_return(1, &rttest_event); | |
108 | ret = rt_mutex_lock_interruptible(&mutexes[id], 0); | |
109 | td->event = atomic_add_return(1, &rttest_event); | |
110 | td->mutexes[id] = ret ? 0 : 4; | |
111 | return ret ? -EINTR : 0; | |
112 | ||
113 | case RTTEST_UNLOCK: | |
114 | id = td->opdata; | |
115 | if (id < 0 || id >= MAX_RT_TEST_MUTEXES || td->mutexes[id] != 4) | |
116 | return ret; | |
117 | ||
118 | td->event = atomic_add_return(1, &rttest_event); | |
119 | rt_mutex_unlock(&mutexes[id]); | |
120 | td->event = atomic_add_return(1, &rttest_event); | |
121 | td->mutexes[id] = 0; | |
122 | return 0; | |
123 | ||
61a87122 TG |
124 | default: |
125 | break; | |
126 | } | |
127 | return ret; | |
128 | } | |
129 | ||
130 | /* | |
131 | * Schedule replacement for rtsem_down(). Only called for threads with | |
132 | * PF_MUTEX_TESTER set. | |
133 | * | |
134 | * This allows us to have finegrained control over the event flow. | |
135 | * | |
136 | */ | |
137 | void schedule_rt_mutex_test(struct rt_mutex *mutex) | |
138 | { | |
139 | int tid, op, dat; | |
140 | struct test_thread_data *td; | |
141 | ||
142 | /* We have to lookup the task */ | |
143 | for (tid = 0; tid < MAX_RT_TEST_THREADS; tid++) { | |
144 | if (threads[tid] == current) | |
145 | break; | |
146 | } | |
147 | ||
148 | BUG_ON(tid == MAX_RT_TEST_THREADS); | |
149 | ||
150 | td = &thread_data[tid]; | |
151 | ||
152 | op = td->opcode; | |
153 | dat = td->opdata; | |
154 | ||
155 | switch (op) { | |
156 | case RTTEST_LOCK: | |
157 | case RTTEST_LOCKINT: | |
158 | case RTTEST_LOCKNOWAIT: | |
159 | case RTTEST_LOCKINTNOWAIT: | |
160 | if (mutex != &mutexes[dat]) | |
161 | break; | |
162 | ||
163 | if (td->mutexes[dat] != 1) | |
164 | break; | |
165 | ||
166 | td->mutexes[dat] = 2; | |
167 | td->event = atomic_add_return(1, &rttest_event); | |
168 | break; | |
169 | ||
61a87122 TG |
170 | default: |
171 | break; | |
172 | } | |
173 | ||
174 | schedule(); | |
175 | ||
176 | ||
177 | switch (op) { | |
178 | case RTTEST_LOCK: | |
179 | case RTTEST_LOCKINT: | |
180 | if (mutex != &mutexes[dat]) | |
181 | return; | |
182 | ||
183 | if (td->mutexes[dat] != 2) | |
184 | return; | |
185 | ||
186 | td->mutexes[dat] = 3; | |
187 | td->event = atomic_add_return(1, &rttest_event); | |
188 | break; | |
189 | ||
190 | case RTTEST_LOCKNOWAIT: | |
191 | case RTTEST_LOCKINTNOWAIT: | |
192 | if (mutex != &mutexes[dat]) | |
193 | return; | |
194 | ||
195 | if (td->mutexes[dat] != 2) | |
196 | return; | |
197 | ||
198 | td->mutexes[dat] = 1; | |
199 | td->event = atomic_add_return(1, &rttest_event); | |
200 | return; | |
201 | ||
61a87122 TG |
202 | default: |
203 | return; | |
204 | } | |
205 | ||
206 | td->opcode = 0; | |
207 | ||
208 | for (;;) { | |
209 | set_current_state(TASK_INTERRUPTIBLE); | |
210 | ||
211 | if (td->opcode > 0) { | |
212 | int ret; | |
213 | ||
214 | set_current_state(TASK_RUNNING); | |
215 | ret = handle_op(td, 1); | |
216 | set_current_state(TASK_INTERRUPTIBLE); | |
217 | if (td->opcode == RTTEST_LOCKCONT) | |
218 | break; | |
219 | td->opcode = ret; | |
220 | } | |
221 | ||
222 | /* Wait for the next command to be executed */ | |
223 | schedule(); | |
224 | } | |
225 | ||
226 | /* Restore previous command and data */ | |
227 | td->opcode = op; | |
228 | td->opdata = dat; | |
229 | } | |
230 | ||
231 | static int test_func(void *data) | |
232 | { | |
233 | struct test_thread_data *td = data; | |
234 | int ret; | |
235 | ||
236 | current->flags |= PF_MUTEX_TESTER; | |
83144186 | 237 | set_freezable(); |
61a87122 TG |
238 | allow_signal(SIGHUP); |
239 | ||
240 | for(;;) { | |
241 | ||
242 | set_current_state(TASK_INTERRUPTIBLE); | |
243 | ||
244 | if (td->opcode > 0) { | |
245 | set_current_state(TASK_RUNNING); | |
246 | ret = handle_op(td, 0); | |
247 | set_current_state(TASK_INTERRUPTIBLE); | |
248 | td->opcode = ret; | |
249 | } | |
250 | ||
251 | /* Wait for the next command to be executed */ | |
252 | schedule(); | |
60198f99 | 253 | try_to_freeze(); |
61a87122 TG |
254 | |
255 | if (signal_pending(current)) | |
256 | flush_signals(current); | |
257 | ||
258 | if(kthread_should_stop()) | |
259 | break; | |
260 | } | |
261 | return 0; | |
262 | } | |
263 | ||
264 | /** | |
265 | * sysfs_test_command - interface for test commands | |
266 | * @dev: thread reference | |
267 | * @buf: command for actual step | |
268 | * @count: length of buffer | |
269 | * | |
270 | * command syntax: | |
271 | * | |
272 | * opcode:data | |
273 | */ | |
997d3eaf | 274 | static ssize_t sysfs_test_command(struct device *dev, struct device_attribute *attr, |
4a0b2b4d | 275 | const char *buf, size_t count) |
61a87122 | 276 | { |
0bafd214 | 277 | struct sched_param schedpar; |
61a87122 TG |
278 | struct test_thread_data *td; |
279 | char cmdbuf[32]; | |
0bafd214 | 280 | int op, dat, tid, ret; |
61a87122 | 281 | |
997d3eaf KS |
282 | td = container_of(dev, struct test_thread_data, dev); |
283 | tid = td->dev.id; | |
61a87122 TG |
284 | |
285 | /* strings from sysfs write are not 0 terminated! */ | |
286 | if (count >= sizeof(cmdbuf)) | |
287 | return -EINVAL; | |
288 | ||
289 | /* strip of \n: */ | |
290 | if (buf[count-1] == '\n') | |
291 | count--; | |
292 | if (count < 1) | |
293 | return -EINVAL; | |
294 | ||
295 | memcpy(cmdbuf, buf, count); | |
296 | cmdbuf[count] = 0; | |
297 | ||
298 | if (sscanf(cmdbuf, "%d:%d", &op, &dat) != 2) | |
299 | return -EINVAL; | |
300 | ||
301 | switch (op) { | |
0bafd214 TG |
302 | case RTTEST_SCHEDOT: |
303 | schedpar.sched_priority = 0; | |
304 | ret = sched_setscheduler(threads[tid], SCHED_NORMAL, &schedpar); | |
305 | if (ret) | |
306 | return ret; | |
307 | set_user_nice(current, 0); | |
308 | break; | |
309 | ||
310 | case RTTEST_SCHEDRT: | |
311 | schedpar.sched_priority = dat; | |
312 | ret = sched_setscheduler(threads[tid], SCHED_FIFO, &schedpar); | |
313 | if (ret) | |
314 | return ret; | |
315 | break; | |
316 | ||
61a87122 TG |
317 | case RTTEST_SIGNAL: |
318 | send_sig(SIGHUP, threads[tid], 0); | |
319 | break; | |
320 | ||
321 | default: | |
322 | if (td->opcode > 0) | |
323 | return -EBUSY; | |
324 | td->opdata = dat; | |
325 | td->opcode = op; | |
326 | wake_up_process(threads[tid]); | |
327 | } | |
328 | ||
329 | return count; | |
330 | } | |
331 | ||
332 | /** | |
333 | * sysfs_test_status - sysfs interface for rt tester | |
334 | * @dev: thread to query | |
335 | * @buf: char buffer to be filled with thread status info | |
336 | */ | |
997d3eaf | 337 | static ssize_t sysfs_test_status(struct device *dev, struct device_attribute *attr, |
4a0b2b4d | 338 | char *buf) |
61a87122 TG |
339 | { |
340 | struct test_thread_data *td; | |
36c8b586 | 341 | struct task_struct *tsk; |
61a87122 | 342 | char *curr = buf; |
61a87122 TG |
343 | int i; |
344 | ||
997d3eaf KS |
345 | td = container_of(dev, struct test_thread_data, dev); |
346 | tsk = threads[td->dev.id]; | |
61a87122 TG |
347 | |
348 | spin_lock(&rttest_lock); | |
349 | ||
350 | curr += sprintf(curr, | |
ccaa8d65 | 351 | "O: %4d, E:%8d, S: 0x%08lx, P: %4d, N: %4d, B: %p, M:", |
61a87122 TG |
352 | td->opcode, td->event, tsk->state, |
353 | (MAX_RT_PRIO - 1) - tsk->prio, | |
354 | (MAX_RT_PRIO - 1) - tsk->normal_prio, | |
ccaa8d65 | 355 | tsk->pi_blocked_on); |
61a87122 TG |
356 | |
357 | for (i = MAX_RT_TEST_MUTEXES - 1; i >=0 ; i--) | |
358 | curr += sprintf(curr, "%d", td->mutexes[i]); | |
359 | ||
360 | spin_unlock(&rttest_lock); | |
361 | ||
362 | curr += sprintf(curr, ", T: %p, R: %p\n", tsk, | |
997d3eaf | 363 | mutexes[td->dev.id].owner); |
61a87122 TG |
364 | |
365 | return curr - buf; | |
366 | } | |
367 | ||
997d3eaf KS |
368 | static DEVICE_ATTR(status, 0600, sysfs_test_status, NULL); |
369 | static DEVICE_ATTR(command, 0600, NULL, sysfs_test_command); | |
61a87122 | 370 | |
997d3eaf | 371 | static struct bus_type rttest_subsys = { |
af5ca3f4 | 372 | .name = "rttest", |
997d3eaf | 373 | .dev_name = "rttest", |
61a87122 TG |
374 | }; |
375 | ||
376 | static int init_test_thread(int id) | |
377 | { | |
997d3eaf KS |
378 | thread_data[id].dev.bus = &rttest_subsys; |
379 | thread_data[id].dev.id = id; | |
61a87122 TG |
380 | |
381 | threads[id] = kthread_run(test_func, &thread_data[id], "rt-test-%d", id); | |
382 | if (IS_ERR(threads[id])) | |
383 | return PTR_ERR(threads[id]); | |
384 | ||
997d3eaf | 385 | return device_register(&thread_data[id].dev); |
61a87122 TG |
386 | } |
387 | ||
388 | static int init_rttest(void) | |
389 | { | |
390 | int ret, i; | |
391 | ||
392 | spin_lock_init(&rttest_lock); | |
393 | ||
394 | for (i = 0; i < MAX_RT_TEST_MUTEXES; i++) | |
395 | rt_mutex_init(&mutexes[i]); | |
396 | ||
997d3eaf | 397 | ret = subsys_system_register(&rttest_subsys, NULL); |
61a87122 TG |
398 | if (ret) |
399 | return ret; | |
400 | ||
401 | for (i = 0; i < MAX_RT_TEST_THREADS; i++) { | |
402 | ret = init_test_thread(i); | |
403 | if (ret) | |
404 | break; | |
997d3eaf | 405 | ret = device_create_file(&thread_data[i].dev, &dev_attr_status); |
61a87122 TG |
406 | if (ret) |
407 | break; | |
997d3eaf | 408 | ret = device_create_file(&thread_data[i].dev, &dev_attr_command); |
61a87122 TG |
409 | if (ret) |
410 | break; | |
411 | } | |
412 | ||
413 | printk("Initializing RT-Tester: %s\n", ret ? "Failed" : "OK" ); | |
414 | ||
415 | return ret; | |
416 | } | |
417 | ||
418 | device_initcall(init_rttest); |