2 * RT-Mutex-tester: scriptable tester for rt mutexes
4 * started by Thomas Gleixner:
6 * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
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>
20 #define MAX_RT_TEST_THREADS 8
21 #define MAX_RT_TEST_MUTEXES 8
23 static spinlock_t rttest_lock;
24 static atomic_t rttest_event;
26 struct test_thread_data {
29 int mutexes[MAX_RT_TEST_MUTEXES];
32 struct sys_device sysdev;
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];
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 */
56 static int handle_op(struct test_thread_data *td, int lockwakeup)
58 struct sched_param schedpar;
59 int i, id, ret = -EINVAL;
67 schedpar.sched_priority = 0;
68 ret = sched_setscheduler(current, SCHED_NORMAL, &schedpar);
70 set_user_nice(current, 0);
74 schedpar.sched_priority = td->opdata;
75 return sched_setscheduler(current, SCHED_FIFO, &schedpar);
78 td->mutexes[td->opdata] = 1;
79 td->event = atomic_add_return(1, &rttest_event);
83 for (i = 0; i < MAX_RT_TEST_MUTEXES; i++) {
84 if (td->mutexes[i] == 4) {
85 rt_mutex_unlock(&mutexes[i]);
90 if (!lockwakeup && td->bkl == 4) {
96 case RTTEST_RESETEVENT:
97 atomic_set(&rttest_event, 0);
108 case RTTEST_LOCKNOWAIT:
110 if (id < 0 || id >= MAX_RT_TEST_MUTEXES)
114 td->event = atomic_add_return(1, &rttest_event);
115 rt_mutex_lock(&mutexes[id]);
116 td->event = atomic_add_return(1, &rttest_event);
121 case RTTEST_LOCKINTNOWAIT:
123 if (id < 0 || id >= MAX_RT_TEST_MUTEXES)
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;
135 if (id < 0 || id >= MAX_RT_TEST_MUTEXES || td->mutexes[id] != 4)
138 td->event = atomic_add_return(1, &rttest_event);
139 rt_mutex_unlock(&mutexes[id]);
140 td->event = atomic_add_return(1, &rttest_event);
152 case RTTEST_UNLOCKBKL:
166 * Schedule replacement for rtsem_down(). Only called for threads with
167 * PF_MUTEX_TESTER set.
169 * This allows us to have finegrained control over the event flow.
172 void schedule_rt_mutex_test(struct rt_mutex *mutex)
175 struct test_thread_data *td;
177 /* We have to lookup the task */
178 for (tid = 0; tid < MAX_RT_TEST_THREADS; tid++) {
179 if (threads[tid] == current)
183 BUG_ON(tid == MAX_RT_TEST_THREADS);
185 td = &thread_data[tid];
193 case RTTEST_LOCKNOWAIT:
194 case RTTEST_LOCKINTNOWAIT:
195 if (mutex != &mutexes[dat])
198 if (td->mutexes[dat] != 1)
201 td->mutexes[dat] = 2;
202 td->event = atomic_add_return(1, &rttest_event);
216 if (mutex != &mutexes[dat])
219 if (td->mutexes[dat] != 2)
222 td->mutexes[dat] = 3;
223 td->event = atomic_add_return(1, &rttest_event);
226 case RTTEST_LOCKNOWAIT:
227 case RTTEST_LOCKINTNOWAIT:
228 if (mutex != &mutexes[dat])
231 if (td->mutexes[dat] != 2)
234 td->mutexes[dat] = 1;
235 td->event = atomic_add_return(1, &rttest_event);
247 set_current_state(TASK_INTERRUPTIBLE);
249 if (td->opcode > 0) {
252 set_current_state(TASK_RUNNING);
253 ret = handle_op(td, 1);
254 set_current_state(TASK_INTERRUPTIBLE);
255 if (td->opcode == RTTEST_LOCKCONT)
260 /* Wait for the next command to be executed */
264 /* Restore previous command and data */
269 static int test_func(void *data)
271 struct test_thread_data *td = data;
274 current->flags |= PF_MUTEX_TESTER;
275 allow_signal(SIGHUP);
279 set_current_state(TASK_INTERRUPTIBLE);
281 if (td->opcode > 0) {
282 set_current_state(TASK_RUNNING);
283 ret = handle_op(td, 0);
284 set_current_state(TASK_INTERRUPTIBLE);
288 /* Wait for the next command to be executed */
291 if (signal_pending(current))
292 flush_signals(current);
294 if(kthread_should_stop())
301 * sysfs_test_command - interface for test commands
302 * @dev: thread reference
303 * @buf: command for actual step
304 * @count: length of buffer
310 static ssize_t sysfs_test_command(struct sys_device *dev, const char *buf,
313 struct test_thread_data *td;
317 td = container_of(dev, struct test_thread_data, sysdev);
320 /* strings from sysfs write are not 0 terminated! */
321 if (count >= sizeof(cmdbuf))
325 if (buf[count-1] == '\n')
330 memcpy(cmdbuf, buf, count);
333 if (sscanf(cmdbuf, "%d:%d", &op, &dat) != 2)
338 send_sig(SIGHUP, threads[tid], 0);
346 wake_up_process(threads[tid]);
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
357 static ssize_t sysfs_test_status(struct sys_device *dev, char *buf)
359 struct test_thread_data *td;
364 td = container_of(dev, struct test_thread_data, sysdev);
365 tsk = threads[td->sysdev.id];
367 spin_lock(&rttest_lock);
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);
376 for (i = MAX_RT_TEST_MUTEXES - 1; i >=0 ; i--)
377 curr += sprintf(curr, "%d", td->mutexes[i]);
379 spin_unlock(&rttest_lock);
381 curr += sprintf(curr, ", T: %p, R: %p\n", tsk,
382 mutexes[td->sysdev.id].owner);
387 static SYSDEV_ATTR(status, 0600, sysfs_test_status, NULL);
388 static SYSDEV_ATTR(command, 0600, NULL, sysfs_test_command);
390 static struct sysdev_class rttest_sysclass = {
391 set_kset_name("rttest"),
394 static int init_test_thread(int id)
396 thread_data[id].sysdev.cls = &rttest_sysclass;
397 thread_data[id].sysdev.id = id;
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]);
403 return sysdev_register(&thread_data[id].sysdev);
406 static int init_rttest(void)
410 spin_lock_init(&rttest_lock);
412 for (i = 0; i < MAX_RT_TEST_MUTEXES; i++)
413 rt_mutex_init(&mutexes[i]);
415 ret = sysdev_class_register(&rttest_sysclass);
419 for (i = 0; i < MAX_RT_TEST_THREADS; i++) {
420 ret = init_test_thread(i);
423 ret = sysdev_create_file(&thread_data[i].sysdev, &attr_status);
426 ret = sysdev_create_file(&thread_data[i].sysdev, &attr_command);
431 printk("Initializing RT-Tester: %s\n", ret ? "Failed" : "OK" );
436 device_initcall(init_rttest);