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