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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) { | |
0fc86c7b | 79 | #ifdef CONFIG_LOCK_KERNEL |
61a87122 | 80 | unlock_kernel(); |
0fc86c7b | 81 | #endif |
61a87122 TG |
82 | td->bkl = 0; |
83 | } | |
84 | return 0; | |
85 | ||
86 | case RTTEST_RESETEVENT: | |
87 | atomic_set(&rttest_event, 0); | |
88 | return 0; | |
89 | ||
90 | default: | |
91 | if (lockwakeup) | |
92 | return ret; | |
93 | } | |
94 | ||
95 | switch(td->opcode) { | |
96 | ||
97 | case RTTEST_LOCK: | |
98 | case RTTEST_LOCKNOWAIT: | |
99 | id = td->opdata; | |
100 | if (id < 0 || id >= MAX_RT_TEST_MUTEXES) | |
101 | return ret; | |
102 | ||
103 | td->mutexes[id] = 1; | |
104 | td->event = atomic_add_return(1, &rttest_event); | |
105 | rt_mutex_lock(&mutexes[id]); | |
106 | td->event = atomic_add_return(1, &rttest_event); | |
107 | td->mutexes[id] = 4; | |
108 | return 0; | |
109 | ||
110 | case RTTEST_LOCKINT: | |
111 | case RTTEST_LOCKINTNOWAIT: | |
112 | id = td->opdata; | |
113 | if (id < 0 || id >= MAX_RT_TEST_MUTEXES) | |
114 | return ret; | |
115 | ||
116 | td->mutexes[id] = 1; | |
117 | td->event = atomic_add_return(1, &rttest_event); | |
118 | ret = rt_mutex_lock_interruptible(&mutexes[id], 0); | |
119 | td->event = atomic_add_return(1, &rttest_event); | |
120 | td->mutexes[id] = ret ? 0 : 4; | |
121 | return ret ? -EINTR : 0; | |
122 | ||
123 | case RTTEST_UNLOCK: | |
124 | id = td->opdata; | |
125 | if (id < 0 || id >= MAX_RT_TEST_MUTEXES || td->mutexes[id] != 4) | |
126 | return ret; | |
127 | ||
128 | td->event = atomic_add_return(1, &rttest_event); | |
129 | rt_mutex_unlock(&mutexes[id]); | |
130 | td->event = atomic_add_return(1, &rttest_event); | |
131 | td->mutexes[id] = 0; | |
132 | return 0; | |
133 | ||
134 | case RTTEST_LOCKBKL: | |
135 | if (td->bkl) | |
136 | return 0; | |
137 | td->bkl = 1; | |
0fc86c7b | 138 | #ifdef CONFIG_LOCK_KERNEL |
61a87122 | 139 | lock_kernel(); |
0fc86c7b | 140 | #endif |
61a87122 TG |
141 | td->bkl = 4; |
142 | return 0; | |
143 | ||
144 | case RTTEST_UNLOCKBKL: | |
145 | if (td->bkl != 4) | |
146 | break; | |
0fc86c7b | 147 | #ifdef CONFIG_LOCK_KERNEL |
61a87122 | 148 | unlock_kernel(); |
0fc86c7b | 149 | #endif |
61a87122 TG |
150 | td->bkl = 0; |
151 | return 0; | |
152 | ||
153 | default: | |
154 | break; | |
155 | } | |
156 | return ret; | |
157 | } | |
158 | ||
159 | /* | |
160 | * Schedule replacement for rtsem_down(). Only called for threads with | |
161 | * PF_MUTEX_TESTER set. | |
162 | * | |
163 | * This allows us to have finegrained control over the event flow. | |
164 | * | |
165 | */ | |
166 | void schedule_rt_mutex_test(struct rt_mutex *mutex) | |
167 | { | |
168 | int tid, op, dat; | |
169 | struct test_thread_data *td; | |
170 | ||
171 | /* We have to lookup the task */ | |
172 | for (tid = 0; tid < MAX_RT_TEST_THREADS; tid++) { | |
173 | if (threads[tid] == current) | |
174 | break; | |
175 | } | |
176 | ||
177 | BUG_ON(tid == MAX_RT_TEST_THREADS); | |
178 | ||
179 | td = &thread_data[tid]; | |
180 | ||
181 | op = td->opcode; | |
182 | dat = td->opdata; | |
183 | ||
184 | switch (op) { | |
185 | case RTTEST_LOCK: | |
186 | case RTTEST_LOCKINT: | |
187 | case RTTEST_LOCKNOWAIT: | |
188 | case RTTEST_LOCKINTNOWAIT: | |
189 | if (mutex != &mutexes[dat]) | |
190 | break; | |
191 | ||
192 | if (td->mutexes[dat] != 1) | |
193 | break; | |
194 | ||
195 | td->mutexes[dat] = 2; | |
196 | td->event = atomic_add_return(1, &rttest_event); | |
197 | break; | |
198 | ||
199 | case RTTEST_LOCKBKL: | |
200 | default: | |
201 | break; | |
202 | } | |
203 | ||
204 | schedule(); | |
205 | ||
206 | ||
207 | switch (op) { | |
208 | case RTTEST_LOCK: | |
209 | case RTTEST_LOCKINT: | |
210 | if (mutex != &mutexes[dat]) | |
211 | return; | |
212 | ||
213 | if (td->mutexes[dat] != 2) | |
214 | return; | |
215 | ||
216 | td->mutexes[dat] = 3; | |
217 | td->event = atomic_add_return(1, &rttest_event); | |
218 | break; | |
219 | ||
220 | case RTTEST_LOCKNOWAIT: | |
221 | case RTTEST_LOCKINTNOWAIT: | |
222 | if (mutex != &mutexes[dat]) | |
223 | return; | |
224 | ||
225 | if (td->mutexes[dat] != 2) | |
226 | return; | |
227 | ||
228 | td->mutexes[dat] = 1; | |
229 | td->event = atomic_add_return(1, &rttest_event); | |
230 | return; | |
231 | ||
232 | case RTTEST_LOCKBKL: | |
233 | return; | |
234 | default: | |
235 | return; | |
236 | } | |
237 | ||
238 | td->opcode = 0; | |
239 | ||
240 | for (;;) { | |
241 | set_current_state(TASK_INTERRUPTIBLE); | |
242 | ||
243 | if (td->opcode > 0) { | |
244 | int ret; | |
245 | ||
246 | set_current_state(TASK_RUNNING); | |
247 | ret = handle_op(td, 1); | |
248 | set_current_state(TASK_INTERRUPTIBLE); | |
249 | if (td->opcode == RTTEST_LOCKCONT) | |
250 | break; | |
251 | td->opcode = ret; | |
252 | } | |
253 | ||
254 | /* Wait for the next command to be executed */ | |
255 | schedule(); | |
256 | } | |
257 | ||
258 | /* Restore previous command and data */ | |
259 | td->opcode = op; | |
260 | td->opdata = dat; | |
261 | } | |
262 | ||
263 | static int test_func(void *data) | |
264 | { | |
265 | struct test_thread_data *td = data; | |
266 | int ret; | |
267 | ||
268 | current->flags |= PF_MUTEX_TESTER; | |
83144186 | 269 | set_freezable(); |
61a87122 TG |
270 | allow_signal(SIGHUP); |
271 | ||
272 | for(;;) { | |
273 | ||
274 | set_current_state(TASK_INTERRUPTIBLE); | |
275 | ||
276 | if (td->opcode > 0) { | |
277 | set_current_state(TASK_RUNNING); | |
278 | ret = handle_op(td, 0); | |
279 | set_current_state(TASK_INTERRUPTIBLE); | |
280 | td->opcode = ret; | |
281 | } | |
282 | ||
283 | /* Wait for the next command to be executed */ | |
284 | schedule(); | |
60198f99 | 285 | try_to_freeze(); |
61a87122 TG |
286 | |
287 | if (signal_pending(current)) | |
288 | flush_signals(current); | |
289 | ||
290 | if(kthread_should_stop()) | |
291 | break; | |
292 | } | |
293 | return 0; | |
294 | } | |
295 | ||
296 | /** | |
297 | * sysfs_test_command - interface for test commands | |
298 | * @dev: thread reference | |
299 | * @buf: command for actual step | |
300 | * @count: length of buffer | |
301 | * | |
302 | * command syntax: | |
303 | * | |
304 | * opcode:data | |
305 | */ | |
4a0b2b4d AK |
306 | static ssize_t sysfs_test_command(struct sys_device *dev, struct sysdev_attribute *attr, |
307 | const char *buf, size_t count) | |
61a87122 | 308 | { |
0bafd214 | 309 | struct sched_param schedpar; |
61a87122 TG |
310 | struct test_thread_data *td; |
311 | char cmdbuf[32]; | |
0bafd214 | 312 | int op, dat, tid, ret; |
61a87122 TG |
313 | |
314 | td = container_of(dev, struct test_thread_data, sysdev); | |
315 | tid = td->sysdev.id; | |
316 | ||
317 | /* strings from sysfs write are not 0 terminated! */ | |
318 | if (count >= sizeof(cmdbuf)) | |
319 | return -EINVAL; | |
320 | ||
321 | /* strip of \n: */ | |
322 | if (buf[count-1] == '\n') | |
323 | count--; | |
324 | if (count < 1) | |
325 | return -EINVAL; | |
326 | ||
327 | memcpy(cmdbuf, buf, count); | |
328 | cmdbuf[count] = 0; | |
329 | ||
330 | if (sscanf(cmdbuf, "%d:%d", &op, &dat) != 2) | |
331 | return -EINVAL; | |
332 | ||
333 | switch (op) { | |
0bafd214 TG |
334 | case RTTEST_SCHEDOT: |
335 | schedpar.sched_priority = 0; | |
336 | ret = sched_setscheduler(threads[tid], SCHED_NORMAL, &schedpar); | |
337 | if (ret) | |
338 | return ret; | |
339 | set_user_nice(current, 0); | |
340 | break; | |
341 | ||
342 | case RTTEST_SCHEDRT: | |
343 | schedpar.sched_priority = dat; | |
344 | ret = sched_setscheduler(threads[tid], SCHED_FIFO, &schedpar); | |
345 | if (ret) | |
346 | return ret; | |
347 | break; | |
348 | ||
61a87122 TG |
349 | case RTTEST_SIGNAL: |
350 | send_sig(SIGHUP, threads[tid], 0); | |
351 | break; | |
352 | ||
353 | default: | |
354 | if (td->opcode > 0) | |
355 | return -EBUSY; | |
356 | td->opdata = dat; | |
357 | td->opcode = op; | |
358 | wake_up_process(threads[tid]); | |
359 | } | |
360 | ||
361 | return count; | |
362 | } | |
363 | ||
364 | /** | |
365 | * sysfs_test_status - sysfs interface for rt tester | |
366 | * @dev: thread to query | |
367 | * @buf: char buffer to be filled with thread status info | |
368 | */ | |
4a0b2b4d AK |
369 | static ssize_t sysfs_test_status(struct sys_device *dev, struct sysdev_attribute *attr, |
370 | char *buf) | |
61a87122 TG |
371 | { |
372 | struct test_thread_data *td; | |
36c8b586 | 373 | struct task_struct *tsk; |
61a87122 | 374 | char *curr = buf; |
61a87122 TG |
375 | int i; |
376 | ||
377 | td = container_of(dev, struct test_thread_data, sysdev); | |
378 | tsk = threads[td->sysdev.id]; | |
379 | ||
380 | spin_lock(&rttest_lock); | |
381 | ||
382 | curr += sprintf(curr, | |
383 | "O: %4d, E:%8d, S: 0x%08lx, P: %4d, N: %4d, B: %p, K: %d, M:", | |
384 | td->opcode, td->event, tsk->state, | |
385 | (MAX_RT_PRIO - 1) - tsk->prio, | |
386 | (MAX_RT_PRIO - 1) - tsk->normal_prio, | |
387 | tsk->pi_blocked_on, td->bkl); | |
388 | ||
389 | for (i = MAX_RT_TEST_MUTEXES - 1; i >=0 ; i--) | |
390 | curr += sprintf(curr, "%d", td->mutexes[i]); | |
391 | ||
392 | spin_unlock(&rttest_lock); | |
393 | ||
394 | curr += sprintf(curr, ", T: %p, R: %p\n", tsk, | |
395 | mutexes[td->sysdev.id].owner); | |
396 | ||
397 | return curr - buf; | |
398 | } | |
399 | ||
400 | static SYSDEV_ATTR(status, 0600, sysfs_test_status, NULL); | |
401 | static SYSDEV_ATTR(command, 0600, NULL, sysfs_test_command); | |
402 | ||
403 | static struct sysdev_class rttest_sysclass = { | |
af5ca3f4 | 404 | .name = "rttest", |
61a87122 TG |
405 | }; |
406 | ||
407 | static int init_test_thread(int id) | |
408 | { | |
409 | thread_data[id].sysdev.cls = &rttest_sysclass; | |
410 | thread_data[id].sysdev.id = id; | |
411 | ||
412 | threads[id] = kthread_run(test_func, &thread_data[id], "rt-test-%d", id); | |
413 | if (IS_ERR(threads[id])) | |
414 | return PTR_ERR(threads[id]); | |
415 | ||
416 | return sysdev_register(&thread_data[id].sysdev); | |
417 | } | |
418 | ||
419 | static int init_rttest(void) | |
420 | { | |
421 | int ret, i; | |
422 | ||
423 | spin_lock_init(&rttest_lock); | |
424 | ||
425 | for (i = 0; i < MAX_RT_TEST_MUTEXES; i++) | |
426 | rt_mutex_init(&mutexes[i]); | |
427 | ||
428 | ret = sysdev_class_register(&rttest_sysclass); | |
429 | if (ret) | |
430 | return ret; | |
431 | ||
432 | for (i = 0; i < MAX_RT_TEST_THREADS; i++) { | |
433 | ret = init_test_thread(i); | |
434 | if (ret) | |
435 | break; | |
436 | ret = sysdev_create_file(&thread_data[i].sysdev, &attr_status); | |
437 | if (ret) | |
438 | break; | |
439 | ret = sysdev_create_file(&thread_data[i].sysdev, &attr_command); | |
440 | if (ret) | |
441 | break; | |
442 | } | |
443 | ||
444 | printk("Initializing RT-Tester: %s\n", ret ? "Failed" : "OK" ); | |
445 | ||
446 | return ret; | |
447 | } | |
448 | ||
449 | device_initcall(init_rttest); |