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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 | */ | |
61a87122 TG |
9 | #include <linux/kthread.h> |
10 | #include <linux/module.h> | |
11 | #include <linux/sched.h> | |
12 | #include <linux/smp_lock.h> | |
13 | #include <linux/spinlock.h> | |
14 | #include <linux/sysdev.h> | |
15 | #include <linux/timer.h> | |
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]; | |
29 | int bkl; | |
30 | int event; | |
31 | struct sys_device sysdev; | |
32 | }; | |
33 | ||
34 | static struct test_thread_data thread_data[MAX_RT_TEST_THREADS]; | |
36c8b586 | 35 | static struct task_struct *threads[MAX_RT_TEST_THREADS]; |
61a87122 TG |
36 | static struct rt_mutex mutexes[MAX_RT_TEST_MUTEXES]; |
37 | ||
38 | enum test_opcodes { | |
39 | RTTEST_NOP = 0, | |
40 | RTTEST_SCHEDOT, /* 1 Sched other, data = nice */ | |
41 | RTTEST_SCHEDRT, /* 2 Sched fifo, data = prio */ | |
42 | RTTEST_LOCK, /* 3 Lock uninterruptible, data = lockindex */ | |
43 | RTTEST_LOCKNOWAIT, /* 4 Lock uninterruptible no wait in wakeup, data = lockindex */ | |
44 | RTTEST_LOCKINT, /* 5 Lock interruptible, data = lockindex */ | |
45 | RTTEST_LOCKINTNOWAIT, /* 6 Lock interruptible no wait in wakeup, data = lockindex */ | |
46 | RTTEST_LOCKCONT, /* 7 Continue locking after the wakeup delay */ | |
47 | RTTEST_UNLOCK, /* 8 Unlock, data = lockindex */ | |
0bafd214 | 48 | RTTEST_LOCKBKL, /* 9 Lock BKL */ |
61a87122 TG |
49 | RTTEST_UNLOCKBKL, /* 10 Unlock BKL */ |
50 | RTTEST_SIGNAL, /* 11 Signal other test thread, data = thread id */ | |
51 | RTTEST_RESETEVENT = 98, /* 98 Reset event counter */ | |
52 | RTTEST_RESET = 99, /* 99 Reset all pending operations */ | |
53 | }; | |
54 | ||
55 | static int handle_op(struct test_thread_data *td, int lockwakeup) | |
56 | { | |
61a87122 TG |
57 | int i, id, ret = -EINVAL; |
58 | ||
59 | switch(td->opcode) { | |
60 | ||
61 | case RTTEST_NOP: | |
62 | return 0; | |
63 | ||
61a87122 TG |
64 | case RTTEST_LOCKCONT: |
65 | td->mutexes[td->opdata] = 1; | |
66 | td->event = atomic_add_return(1, &rttest_event); | |
67 | return 0; | |
68 | ||
69 | case RTTEST_RESET: | |
70 | for (i = 0; i < MAX_RT_TEST_MUTEXES; i++) { | |
71 | if (td->mutexes[i] == 4) { | |
72 | rt_mutex_unlock(&mutexes[i]); | |
73 | td->mutexes[i] = 0; | |
74 | } | |
75 | } | |
76 | ||
77 | if (!lockwakeup && td->bkl == 4) { | |
78 | unlock_kernel(); | |
79 | td->bkl = 0; | |
80 | } | |
81 | return 0; | |
82 | ||
83 | case RTTEST_RESETEVENT: | |
84 | atomic_set(&rttest_event, 0); | |
85 | return 0; | |
86 | ||
87 | default: | |
88 | if (lockwakeup) | |
89 | return ret; | |
90 | } | |
91 | ||
92 | switch(td->opcode) { | |
93 | ||
94 | case RTTEST_LOCK: | |
95 | case RTTEST_LOCKNOWAIT: | |
96 | id = td->opdata; | |
97 | if (id < 0 || id >= MAX_RT_TEST_MUTEXES) | |
98 | return ret; | |
99 | ||
100 | td->mutexes[id] = 1; | |
101 | td->event = atomic_add_return(1, &rttest_event); | |
102 | rt_mutex_lock(&mutexes[id]); | |
103 | td->event = atomic_add_return(1, &rttest_event); | |
104 | td->mutexes[id] = 4; | |
105 | return 0; | |
106 | ||
107 | case RTTEST_LOCKINT: | |
108 | case RTTEST_LOCKINTNOWAIT: | |
109 | id = td->opdata; | |
110 | if (id < 0 || id >= MAX_RT_TEST_MUTEXES) | |
111 | return ret; | |
112 | ||
113 | td->mutexes[id] = 1; | |
114 | td->event = atomic_add_return(1, &rttest_event); | |
115 | ret = rt_mutex_lock_interruptible(&mutexes[id], 0); | |
116 | td->event = atomic_add_return(1, &rttest_event); | |
117 | td->mutexes[id] = ret ? 0 : 4; | |
118 | return ret ? -EINTR : 0; | |
119 | ||
120 | case RTTEST_UNLOCK: | |
121 | id = td->opdata; | |
122 | if (id < 0 || id >= MAX_RT_TEST_MUTEXES || td->mutexes[id] != 4) | |
123 | return ret; | |
124 | ||
125 | td->event = atomic_add_return(1, &rttest_event); | |
126 | rt_mutex_unlock(&mutexes[id]); | |
127 | td->event = atomic_add_return(1, &rttest_event); | |
128 | td->mutexes[id] = 0; | |
129 | return 0; | |
130 | ||
131 | case RTTEST_LOCKBKL: | |
132 | if (td->bkl) | |
133 | return 0; | |
134 | td->bkl = 1; | |
135 | lock_kernel(); | |
136 | td->bkl = 4; | |
137 | return 0; | |
138 | ||
139 | case RTTEST_UNLOCKBKL: | |
140 | if (td->bkl != 4) | |
141 | break; | |
142 | unlock_kernel(); | |
143 | td->bkl = 0; | |
144 | return 0; | |
145 | ||
146 | default: | |
147 | break; | |
148 | } | |
149 | return ret; | |
150 | } | |
151 | ||
152 | /* | |
153 | * Schedule replacement for rtsem_down(). Only called for threads with | |
154 | * PF_MUTEX_TESTER set. | |
155 | * | |
156 | * This allows us to have finegrained control over the event flow. | |
157 | * | |
158 | */ | |
159 | void schedule_rt_mutex_test(struct rt_mutex *mutex) | |
160 | { | |
161 | int tid, op, dat; | |
162 | struct test_thread_data *td; | |
163 | ||
164 | /* We have to lookup the task */ | |
165 | for (tid = 0; tid < MAX_RT_TEST_THREADS; tid++) { | |
166 | if (threads[tid] == current) | |
167 | break; | |
168 | } | |
169 | ||
170 | BUG_ON(tid == MAX_RT_TEST_THREADS); | |
171 | ||
172 | td = &thread_data[tid]; | |
173 | ||
174 | op = td->opcode; | |
175 | dat = td->opdata; | |
176 | ||
177 | switch (op) { | |
178 | case RTTEST_LOCK: | |
179 | case RTTEST_LOCKINT: | |
180 | case RTTEST_LOCKNOWAIT: | |
181 | case RTTEST_LOCKINTNOWAIT: | |
182 | if (mutex != &mutexes[dat]) | |
183 | break; | |
184 | ||
185 | if (td->mutexes[dat] != 1) | |
186 | break; | |
187 | ||
188 | td->mutexes[dat] = 2; | |
189 | td->event = atomic_add_return(1, &rttest_event); | |
190 | break; | |
191 | ||
192 | case RTTEST_LOCKBKL: | |
193 | default: | |
194 | break; | |
195 | } | |
196 | ||
197 | schedule(); | |
198 | ||
199 | ||
200 | switch (op) { | |
201 | case RTTEST_LOCK: | |
202 | case RTTEST_LOCKINT: | |
203 | if (mutex != &mutexes[dat]) | |
204 | return; | |
205 | ||
206 | if (td->mutexes[dat] != 2) | |
207 | return; | |
208 | ||
209 | td->mutexes[dat] = 3; | |
210 | td->event = atomic_add_return(1, &rttest_event); | |
211 | break; | |
212 | ||
213 | case RTTEST_LOCKNOWAIT: | |
214 | case RTTEST_LOCKINTNOWAIT: | |
215 | if (mutex != &mutexes[dat]) | |
216 | return; | |
217 | ||
218 | if (td->mutexes[dat] != 2) | |
219 | return; | |
220 | ||
221 | td->mutexes[dat] = 1; | |
222 | td->event = atomic_add_return(1, &rttest_event); | |
223 | return; | |
224 | ||
225 | case RTTEST_LOCKBKL: | |
226 | return; | |
227 | default: | |
228 | return; | |
229 | } | |
230 | ||
231 | td->opcode = 0; | |
232 | ||
233 | for (;;) { | |
234 | set_current_state(TASK_INTERRUPTIBLE); | |
235 | ||
236 | if (td->opcode > 0) { | |
237 | int ret; | |
238 | ||
239 | set_current_state(TASK_RUNNING); | |
240 | ret = handle_op(td, 1); | |
241 | set_current_state(TASK_INTERRUPTIBLE); | |
242 | if (td->opcode == RTTEST_LOCKCONT) | |
243 | break; | |
244 | td->opcode = ret; | |
245 | } | |
246 | ||
247 | /* Wait for the next command to be executed */ | |
248 | schedule(); | |
249 | } | |
250 | ||
251 | /* Restore previous command and data */ | |
252 | td->opcode = op; | |
253 | td->opdata = dat; | |
254 | } | |
255 | ||
256 | static int test_func(void *data) | |
257 | { | |
258 | struct test_thread_data *td = data; | |
259 | int ret; | |
260 | ||
261 | current->flags |= PF_MUTEX_TESTER; | |
262 | allow_signal(SIGHUP); | |
263 | ||
264 | for(;;) { | |
265 | ||
266 | set_current_state(TASK_INTERRUPTIBLE); | |
267 | ||
268 | if (td->opcode > 0) { | |
269 | set_current_state(TASK_RUNNING); | |
270 | ret = handle_op(td, 0); | |
271 | set_current_state(TASK_INTERRUPTIBLE); | |
272 | td->opcode = ret; | |
273 | } | |
274 | ||
275 | /* Wait for the next command to be executed */ | |
276 | schedule(); | |
60198f99 | 277 | try_to_freeze(); |
61a87122 TG |
278 | |
279 | if (signal_pending(current)) | |
280 | flush_signals(current); | |
281 | ||
282 | if(kthread_should_stop()) | |
283 | break; | |
284 | } | |
285 | return 0; | |
286 | } | |
287 | ||
288 | /** | |
289 | * sysfs_test_command - interface for test commands | |
290 | * @dev: thread reference | |
291 | * @buf: command for actual step | |
292 | * @count: length of buffer | |
293 | * | |
294 | * command syntax: | |
295 | * | |
296 | * opcode:data | |
297 | */ | |
298 | static ssize_t sysfs_test_command(struct sys_device *dev, const char *buf, | |
299 | size_t count) | |
300 | { | |
0bafd214 | 301 | struct sched_param schedpar; |
61a87122 TG |
302 | struct test_thread_data *td; |
303 | char cmdbuf[32]; | |
0bafd214 | 304 | int op, dat, tid, ret; |
61a87122 TG |
305 | |
306 | td = container_of(dev, struct test_thread_data, sysdev); | |
307 | tid = td->sysdev.id; | |
308 | ||
309 | /* strings from sysfs write are not 0 terminated! */ | |
310 | if (count >= sizeof(cmdbuf)) | |
311 | return -EINVAL; | |
312 | ||
313 | /* strip of \n: */ | |
314 | if (buf[count-1] == '\n') | |
315 | count--; | |
316 | if (count < 1) | |
317 | return -EINVAL; | |
318 | ||
319 | memcpy(cmdbuf, buf, count); | |
320 | cmdbuf[count] = 0; | |
321 | ||
322 | if (sscanf(cmdbuf, "%d:%d", &op, &dat) != 2) | |
323 | return -EINVAL; | |
324 | ||
325 | switch (op) { | |
0bafd214 TG |
326 | case RTTEST_SCHEDOT: |
327 | schedpar.sched_priority = 0; | |
328 | ret = sched_setscheduler(threads[tid], SCHED_NORMAL, &schedpar); | |
329 | if (ret) | |
330 | return ret; | |
331 | set_user_nice(current, 0); | |
332 | break; | |
333 | ||
334 | case RTTEST_SCHEDRT: | |
335 | schedpar.sched_priority = dat; | |
336 | ret = sched_setscheduler(threads[tid], SCHED_FIFO, &schedpar); | |
337 | if (ret) | |
338 | return ret; | |
339 | break; | |
340 | ||
61a87122 TG |
341 | case RTTEST_SIGNAL: |
342 | send_sig(SIGHUP, threads[tid], 0); | |
343 | break; | |
344 | ||
345 | default: | |
346 | if (td->opcode > 0) | |
347 | return -EBUSY; | |
348 | td->opdata = dat; | |
349 | td->opcode = op; | |
350 | wake_up_process(threads[tid]); | |
351 | } | |
352 | ||
353 | return count; | |
354 | } | |
355 | ||
356 | /** | |
357 | * sysfs_test_status - sysfs interface for rt tester | |
358 | * @dev: thread to query | |
359 | * @buf: char buffer to be filled with thread status info | |
360 | */ | |
361 | static ssize_t sysfs_test_status(struct sys_device *dev, char *buf) | |
362 | { | |
363 | struct test_thread_data *td; | |
36c8b586 | 364 | struct task_struct *tsk; |
61a87122 | 365 | char *curr = buf; |
61a87122 TG |
366 | int i; |
367 | ||
368 | td = container_of(dev, struct test_thread_data, sysdev); | |
369 | tsk = threads[td->sysdev.id]; | |
370 | ||
371 | spin_lock(&rttest_lock); | |
372 | ||
373 | curr += sprintf(curr, | |
374 | "O: %4d, E:%8d, S: 0x%08lx, P: %4d, N: %4d, B: %p, K: %d, M:", | |
375 | td->opcode, td->event, tsk->state, | |
376 | (MAX_RT_PRIO - 1) - tsk->prio, | |
377 | (MAX_RT_PRIO - 1) - tsk->normal_prio, | |
378 | tsk->pi_blocked_on, td->bkl); | |
379 | ||
380 | for (i = MAX_RT_TEST_MUTEXES - 1; i >=0 ; i--) | |
381 | curr += sprintf(curr, "%d", td->mutexes[i]); | |
382 | ||
383 | spin_unlock(&rttest_lock); | |
384 | ||
385 | curr += sprintf(curr, ", T: %p, R: %p\n", tsk, | |
386 | mutexes[td->sysdev.id].owner); | |
387 | ||
388 | return curr - buf; | |
389 | } | |
390 | ||
391 | static SYSDEV_ATTR(status, 0600, sysfs_test_status, NULL); | |
392 | static SYSDEV_ATTR(command, 0600, NULL, sysfs_test_command); | |
393 | ||
394 | static struct sysdev_class rttest_sysclass = { | |
395 | set_kset_name("rttest"), | |
396 | }; | |
397 | ||
398 | static int init_test_thread(int id) | |
399 | { | |
400 | thread_data[id].sysdev.cls = &rttest_sysclass; | |
401 | thread_data[id].sysdev.id = id; | |
402 | ||
403 | threads[id] = kthread_run(test_func, &thread_data[id], "rt-test-%d", id); | |
404 | if (IS_ERR(threads[id])) | |
405 | return PTR_ERR(threads[id]); | |
406 | ||
407 | return sysdev_register(&thread_data[id].sysdev); | |
408 | } | |
409 | ||
410 | static int init_rttest(void) | |
411 | { | |
412 | int ret, i; | |
413 | ||
414 | spin_lock_init(&rttest_lock); | |
415 | ||
416 | for (i = 0; i < MAX_RT_TEST_MUTEXES; i++) | |
417 | rt_mutex_init(&mutexes[i]); | |
418 | ||
419 | ret = sysdev_class_register(&rttest_sysclass); | |
420 | if (ret) | |
421 | return ret; | |
422 | ||
423 | for (i = 0; i < MAX_RT_TEST_THREADS; i++) { | |
424 | ret = init_test_thread(i); | |
425 | if (ret) | |
426 | break; | |
427 | ret = sysdev_create_file(&thread_data[i].sysdev, &attr_status); | |
428 | if (ret) | |
429 | break; | |
430 | ret = sysdev_create_file(&thread_data[i].sysdev, &attr_command); | |
431 | if (ret) | |
432 | break; | |
433 | } | |
434 | ||
435 | printk("Initializing RT-Tester: %s\n", ret ? "Failed" : "OK" ); | |
436 | ||
437 | return ret; | |
438 | } | |
439 | ||
440 | device_initcall(init_rttest); |