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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> | |
7dfb7103 | 16 | #include <linux/freezer.h> |
61a87122 TG |
17 | |
18 | #include "rtmutex.h" | |
19 | ||
20 | #define MAX_RT_TEST_THREADS 8 | |
21 | #define MAX_RT_TEST_MUTEXES 8 | |
22 | ||
23 | static spinlock_t rttest_lock; | |
24 | static atomic_t rttest_event; | |
25 | ||
26 | struct test_thread_data { | |
27 | int opcode; | |
28 | int opdata; | |
29 | int mutexes[MAX_RT_TEST_MUTEXES]; | |
30 | int bkl; | |
31 | int event; | |
32 | struct sys_device sysdev; | |
33 | }; | |
34 | ||
35 | static struct test_thread_data thread_data[MAX_RT_TEST_THREADS]; | |
36c8b586 | 36 | static struct task_struct *threads[MAX_RT_TEST_THREADS]; |
61a87122 TG |
37 | static struct rt_mutex mutexes[MAX_RT_TEST_MUTEXES]; |
38 | ||
39 | enum test_opcodes { | |
40 | RTTEST_NOP = 0, | |
41 | RTTEST_SCHEDOT, /* 1 Sched other, data = nice */ | |
42 | RTTEST_SCHEDRT, /* 2 Sched fifo, data = prio */ | |
43 | RTTEST_LOCK, /* 3 Lock uninterruptible, data = lockindex */ | |
44 | RTTEST_LOCKNOWAIT, /* 4 Lock uninterruptible no wait in wakeup, data = lockindex */ | |
45 | RTTEST_LOCKINT, /* 5 Lock interruptible, data = lockindex */ | |
46 | RTTEST_LOCKINTNOWAIT, /* 6 Lock interruptible no wait in wakeup, data = lockindex */ | |
47 | RTTEST_LOCKCONT, /* 7 Continue locking after the wakeup delay */ | |
48 | RTTEST_UNLOCK, /* 8 Unlock, data = lockindex */ | |
0bafd214 | 49 | RTTEST_LOCKBKL, /* 9 Lock BKL */ |
61a87122 TG |
50 | RTTEST_UNLOCKBKL, /* 10 Unlock BKL */ |
51 | RTTEST_SIGNAL, /* 11 Signal other test thread, data = thread id */ | |
52 | RTTEST_RESETEVENT = 98, /* 98 Reset event counter */ | |
53 | RTTEST_RESET = 99, /* 99 Reset all pending operations */ | |
54 | }; | |
55 | ||
56 | static int handle_op(struct test_thread_data *td, int lockwakeup) | |
57 | { | |
61a87122 TG |
58 | int i, id, ret = -EINVAL; |
59 | ||
60 | switch(td->opcode) { | |
61 | ||
62 | case RTTEST_NOP: | |
63 | return 0; | |
64 | ||
61a87122 TG |
65 | case RTTEST_LOCKCONT: |
66 | td->mutexes[td->opdata] = 1; | |
67 | td->event = atomic_add_return(1, &rttest_event); | |
68 | return 0; | |
69 | ||
70 | case RTTEST_RESET: | |
71 | for (i = 0; i < MAX_RT_TEST_MUTEXES; i++) { | |
72 | if (td->mutexes[i] == 4) { | |
73 | rt_mutex_unlock(&mutexes[i]); | |
74 | td->mutexes[i] = 0; | |
75 | } | |
76 | } | |
77 | ||
78 | if (!lockwakeup && td->bkl == 4) { | |
79 | unlock_kernel(); | |
80 | td->bkl = 0; | |
81 | } | |
82 | return 0; | |
83 | ||
84 | case RTTEST_RESETEVENT: | |
85 | atomic_set(&rttest_event, 0); | |
86 | return 0; | |
87 | ||
88 | default: | |
89 | if (lockwakeup) | |
90 | return ret; | |
91 | } | |
92 | ||
93 | switch(td->opcode) { | |
94 | ||
95 | case RTTEST_LOCK: | |
96 | case RTTEST_LOCKNOWAIT: | |
97 | id = td->opdata; | |
98 | if (id < 0 || id >= MAX_RT_TEST_MUTEXES) | |
99 | return ret; | |
100 | ||
101 | td->mutexes[id] = 1; | |
102 | td->event = atomic_add_return(1, &rttest_event); | |
103 | rt_mutex_lock(&mutexes[id]); | |
104 | td->event = atomic_add_return(1, &rttest_event); | |
105 | td->mutexes[id] = 4; | |
106 | return 0; | |
107 | ||
108 | case RTTEST_LOCKINT: | |
109 | case RTTEST_LOCKINTNOWAIT: | |
110 | id = td->opdata; | |
111 | if (id < 0 || id >= MAX_RT_TEST_MUTEXES) | |
112 | return ret; | |
113 | ||
114 | td->mutexes[id] = 1; | |
115 | td->event = atomic_add_return(1, &rttest_event); | |
116 | ret = rt_mutex_lock_interruptible(&mutexes[id], 0); | |
117 | td->event = atomic_add_return(1, &rttest_event); | |
118 | td->mutexes[id] = ret ? 0 : 4; | |
119 | return ret ? -EINTR : 0; | |
120 | ||
121 | case RTTEST_UNLOCK: | |
122 | id = td->opdata; | |
123 | if (id < 0 || id >= MAX_RT_TEST_MUTEXES || td->mutexes[id] != 4) | |
124 | return ret; | |
125 | ||
126 | td->event = atomic_add_return(1, &rttest_event); | |
127 | rt_mutex_unlock(&mutexes[id]); | |
128 | td->event = atomic_add_return(1, &rttest_event); | |
129 | td->mutexes[id] = 0; | |
130 | return 0; | |
131 | ||
132 | case RTTEST_LOCKBKL: | |
133 | if (td->bkl) | |
134 | return 0; | |
135 | td->bkl = 1; | |
136 | lock_kernel(); | |
137 | td->bkl = 4; | |
138 | return 0; | |
139 | ||
140 | case RTTEST_UNLOCKBKL: | |
141 | if (td->bkl != 4) | |
142 | break; | |
143 | unlock_kernel(); | |
144 | td->bkl = 0; | |
145 | return 0; | |
146 | ||
147 | default: | |
148 | break; | |
149 | } | |
150 | return ret; | |
151 | } | |
152 | ||
153 | /* | |
154 | * Schedule replacement for rtsem_down(). Only called for threads with | |
155 | * PF_MUTEX_TESTER set. | |
156 | * | |
157 | * This allows us to have finegrained control over the event flow. | |
158 | * | |
159 | */ | |
160 | void schedule_rt_mutex_test(struct rt_mutex *mutex) | |
161 | { | |
162 | int tid, op, dat; | |
163 | struct test_thread_data *td; | |
164 | ||
165 | /* We have to lookup the task */ | |
166 | for (tid = 0; tid < MAX_RT_TEST_THREADS; tid++) { | |
167 | if (threads[tid] == current) | |
168 | break; | |
169 | } | |
170 | ||
171 | BUG_ON(tid == MAX_RT_TEST_THREADS); | |
172 | ||
173 | td = &thread_data[tid]; | |
174 | ||
175 | op = td->opcode; | |
176 | dat = td->opdata; | |
177 | ||
178 | switch (op) { | |
179 | case RTTEST_LOCK: | |
180 | case RTTEST_LOCKINT: | |
181 | case RTTEST_LOCKNOWAIT: | |
182 | case RTTEST_LOCKINTNOWAIT: | |
183 | if (mutex != &mutexes[dat]) | |
184 | break; | |
185 | ||
186 | if (td->mutexes[dat] != 1) | |
187 | break; | |
188 | ||
189 | td->mutexes[dat] = 2; | |
190 | td->event = atomic_add_return(1, &rttest_event); | |
191 | break; | |
192 | ||
193 | case RTTEST_LOCKBKL: | |
194 | default: | |
195 | break; | |
196 | } | |
197 | ||
198 | schedule(); | |
199 | ||
200 | ||
201 | switch (op) { | |
202 | case RTTEST_LOCK: | |
203 | case RTTEST_LOCKINT: | |
204 | if (mutex != &mutexes[dat]) | |
205 | return; | |
206 | ||
207 | if (td->mutexes[dat] != 2) | |
208 | return; | |
209 | ||
210 | td->mutexes[dat] = 3; | |
211 | td->event = atomic_add_return(1, &rttest_event); | |
212 | break; | |
213 | ||
214 | case RTTEST_LOCKNOWAIT: | |
215 | case RTTEST_LOCKINTNOWAIT: | |
216 | if (mutex != &mutexes[dat]) | |
217 | return; | |
218 | ||
219 | if (td->mutexes[dat] != 2) | |
220 | return; | |
221 | ||
222 | td->mutexes[dat] = 1; | |
223 | td->event = atomic_add_return(1, &rttest_event); | |
224 | return; | |
225 | ||
226 | case RTTEST_LOCKBKL: | |
227 | return; | |
228 | default: | |
229 | return; | |
230 | } | |
231 | ||
232 | td->opcode = 0; | |
233 | ||
234 | for (;;) { | |
235 | set_current_state(TASK_INTERRUPTIBLE); | |
236 | ||
237 | if (td->opcode > 0) { | |
238 | int ret; | |
239 | ||
240 | set_current_state(TASK_RUNNING); | |
241 | ret = handle_op(td, 1); | |
242 | set_current_state(TASK_INTERRUPTIBLE); | |
243 | if (td->opcode == RTTEST_LOCKCONT) | |
244 | break; | |
245 | td->opcode = ret; | |
246 | } | |
247 | ||
248 | /* Wait for the next command to be executed */ | |
249 | schedule(); | |
250 | } | |
251 | ||
252 | /* Restore previous command and data */ | |
253 | td->opcode = op; | |
254 | td->opdata = dat; | |
255 | } | |
256 | ||
257 | static int test_func(void *data) | |
258 | { | |
259 | struct test_thread_data *td = data; | |
260 | int ret; | |
261 | ||
262 | current->flags |= PF_MUTEX_TESTER; | |
83144186 | 263 | set_freezable(); |
61a87122 TG |
264 | allow_signal(SIGHUP); |
265 | ||
266 | for(;;) { | |
267 | ||
268 | set_current_state(TASK_INTERRUPTIBLE); | |
269 | ||
270 | if (td->opcode > 0) { | |
271 | set_current_state(TASK_RUNNING); | |
272 | ret = handle_op(td, 0); | |
273 | set_current_state(TASK_INTERRUPTIBLE); | |
274 | td->opcode = ret; | |
275 | } | |
276 | ||
277 | /* Wait for the next command to be executed */ | |
278 | schedule(); | |
60198f99 | 279 | try_to_freeze(); |
61a87122 TG |
280 | |
281 | if (signal_pending(current)) | |
282 | flush_signals(current); | |
283 | ||
284 | if(kthread_should_stop()) | |
285 | break; | |
286 | } | |
287 | return 0; | |
288 | } | |
289 | ||
290 | /** | |
291 | * sysfs_test_command - interface for test commands | |
292 | * @dev: thread reference | |
293 | * @buf: command for actual step | |
294 | * @count: length of buffer | |
295 | * | |
296 | * command syntax: | |
297 | * | |
298 | * opcode:data | |
299 | */ | |
4a0b2b4d AK |
300 | static ssize_t sysfs_test_command(struct sys_device *dev, struct sysdev_attribute *attr, |
301 | const char *buf, size_t count) | |
61a87122 | 302 | { |
0bafd214 | 303 | struct sched_param schedpar; |
61a87122 TG |
304 | struct test_thread_data *td; |
305 | char cmdbuf[32]; | |
0bafd214 | 306 | int op, dat, tid, ret; |
61a87122 TG |
307 | |
308 | td = container_of(dev, struct test_thread_data, sysdev); | |
309 | tid = td->sysdev.id; | |
310 | ||
311 | /* strings from sysfs write are not 0 terminated! */ | |
312 | if (count >= sizeof(cmdbuf)) | |
313 | return -EINVAL; | |
314 | ||
315 | /* strip of \n: */ | |
316 | if (buf[count-1] == '\n') | |
317 | count--; | |
318 | if (count < 1) | |
319 | return -EINVAL; | |
320 | ||
321 | memcpy(cmdbuf, buf, count); | |
322 | cmdbuf[count] = 0; | |
323 | ||
324 | if (sscanf(cmdbuf, "%d:%d", &op, &dat) != 2) | |
325 | return -EINVAL; | |
326 | ||
327 | switch (op) { | |
0bafd214 TG |
328 | case RTTEST_SCHEDOT: |
329 | schedpar.sched_priority = 0; | |
330 | ret = sched_setscheduler(threads[tid], SCHED_NORMAL, &schedpar); | |
331 | if (ret) | |
332 | return ret; | |
333 | set_user_nice(current, 0); | |
334 | break; | |
335 | ||
336 | case RTTEST_SCHEDRT: | |
337 | schedpar.sched_priority = dat; | |
338 | ret = sched_setscheduler(threads[tid], SCHED_FIFO, &schedpar); | |
339 | if (ret) | |
340 | return ret; | |
341 | break; | |
342 | ||
61a87122 TG |
343 | case RTTEST_SIGNAL: |
344 | send_sig(SIGHUP, threads[tid], 0); | |
345 | break; | |
346 | ||
347 | default: | |
348 | if (td->opcode > 0) | |
349 | return -EBUSY; | |
350 | td->opdata = dat; | |
351 | td->opcode = op; | |
352 | wake_up_process(threads[tid]); | |
353 | } | |
354 | ||
355 | return count; | |
356 | } | |
357 | ||
358 | /** | |
359 | * sysfs_test_status - sysfs interface for rt tester | |
360 | * @dev: thread to query | |
361 | * @buf: char buffer to be filled with thread status info | |
362 | */ | |
4a0b2b4d AK |
363 | static ssize_t sysfs_test_status(struct sys_device *dev, struct sysdev_attribute *attr, |
364 | char *buf) | |
61a87122 TG |
365 | { |
366 | struct test_thread_data *td; | |
36c8b586 | 367 | struct task_struct *tsk; |
61a87122 | 368 | char *curr = buf; |
61a87122 TG |
369 | int i; |
370 | ||
371 | td = container_of(dev, struct test_thread_data, sysdev); | |
372 | tsk = threads[td->sysdev.id]; | |
373 | ||
374 | spin_lock(&rttest_lock); | |
375 | ||
376 | curr += sprintf(curr, | |
377 | "O: %4d, E:%8d, S: 0x%08lx, P: %4d, N: %4d, B: %p, K: %d, M:", | |
378 | td->opcode, td->event, tsk->state, | |
379 | (MAX_RT_PRIO - 1) - tsk->prio, | |
380 | (MAX_RT_PRIO - 1) - tsk->normal_prio, | |
381 | tsk->pi_blocked_on, td->bkl); | |
382 | ||
383 | for (i = MAX_RT_TEST_MUTEXES - 1; i >=0 ; i--) | |
384 | curr += sprintf(curr, "%d", td->mutexes[i]); | |
385 | ||
386 | spin_unlock(&rttest_lock); | |
387 | ||
388 | curr += sprintf(curr, ", T: %p, R: %p\n", tsk, | |
389 | mutexes[td->sysdev.id].owner); | |
390 | ||
391 | return curr - buf; | |
392 | } | |
393 | ||
394 | static SYSDEV_ATTR(status, 0600, sysfs_test_status, NULL); | |
395 | static SYSDEV_ATTR(command, 0600, NULL, sysfs_test_command); | |
396 | ||
397 | static struct sysdev_class rttest_sysclass = { | |
af5ca3f4 | 398 | .name = "rttest", |
61a87122 TG |
399 | }; |
400 | ||
401 | static int init_test_thread(int id) | |
402 | { | |
403 | thread_data[id].sysdev.cls = &rttest_sysclass; | |
404 | thread_data[id].sysdev.id = id; | |
405 | ||
406 | threads[id] = kthread_run(test_func, &thread_data[id], "rt-test-%d", id); | |
407 | if (IS_ERR(threads[id])) | |
408 | return PTR_ERR(threads[id]); | |
409 | ||
410 | return sysdev_register(&thread_data[id].sysdev); | |
411 | } | |
412 | ||
413 | static int init_rttest(void) | |
414 | { | |
415 | int ret, i; | |
416 | ||
417 | spin_lock_init(&rttest_lock); | |
418 | ||
419 | for (i = 0; i < MAX_RT_TEST_MUTEXES; i++) | |
420 | rt_mutex_init(&mutexes[i]); | |
421 | ||
422 | ret = sysdev_class_register(&rttest_sysclass); | |
423 | if (ret) | |
424 | return ret; | |
425 | ||
426 | for (i = 0; i < MAX_RT_TEST_THREADS; i++) { | |
427 | ret = init_test_thread(i); | |
428 | if (ret) | |
429 | break; | |
430 | ret = sysdev_create_file(&thread_data[i].sysdev, &attr_status); | |
431 | if (ret) | |
432 | break; | |
433 | ret = sysdev_create_file(&thread_data[i].sysdev, &attr_command); | |
434 | if (ret) | |
435 | break; | |
436 | } | |
437 | ||
438 | printk("Initializing RT-Tester: %s\n", ret ? "Failed" : "OK" ); | |
439 | ||
440 | return ret; | |
441 | } | |
442 | ||
443 | device_initcall(init_rttest); |