Thomas Gleixner | 61a8712 | 2006-06-27 02:54:56 -0700 | [diff] [blame] | 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]; |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 36 | static struct task_struct *threads[MAX_RT_TEST_THREADS]; |
Thomas Gleixner | 61a8712 | 2006-06-27 02:54:56 -0700 | [diff] [blame] | 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 */ |
Thomas Gleixner | 0bafd21 | 2006-06-27 02:55:01 -0700 | [diff] [blame] | 49 | RTTEST_LOCKBKL, /* 9 Lock BKL */ |
Thomas Gleixner | 61a8712 | 2006-06-27 02:54:56 -0700 | [diff] [blame] | 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 | { |
Thomas Gleixner | 61a8712 | 2006-06-27 02:54:56 -0700 | [diff] [blame] | 58 | int i, id, ret = -EINVAL; |
| 59 | |
| 60 | switch(td->opcode) { |
| 61 | |
| 62 | case RTTEST_NOP: |
| 63 | return 0; |
| 64 | |
Thomas Gleixner | 61a8712 | 2006-06-27 02:54:56 -0700 | [diff] [blame] | 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; |
| 263 | allow_signal(SIGHUP); |
| 264 | |
| 265 | for(;;) { |
| 266 | |
| 267 | set_current_state(TASK_INTERRUPTIBLE); |
| 268 | |
| 269 | if (td->opcode > 0) { |
| 270 | set_current_state(TASK_RUNNING); |
| 271 | ret = handle_op(td, 0); |
| 272 | set_current_state(TASK_INTERRUPTIBLE); |
| 273 | td->opcode = ret; |
| 274 | } |
| 275 | |
| 276 | /* Wait for the next command to be executed */ |
| 277 | schedule(); |
Luca Tettamanti | 60198f9 | 2006-07-14 00:24:13 -0700 | [diff] [blame] | 278 | try_to_freeze(); |
Thomas Gleixner | 61a8712 | 2006-06-27 02:54:56 -0700 | [diff] [blame] | 279 | |
| 280 | if (signal_pending(current)) |
| 281 | flush_signals(current); |
| 282 | |
| 283 | if(kthread_should_stop()) |
| 284 | break; |
| 285 | } |
| 286 | return 0; |
| 287 | } |
| 288 | |
| 289 | /** |
| 290 | * sysfs_test_command - interface for test commands |
| 291 | * @dev: thread reference |
| 292 | * @buf: command for actual step |
| 293 | * @count: length of buffer |
| 294 | * |
| 295 | * command syntax: |
| 296 | * |
| 297 | * opcode:data |
| 298 | */ |
| 299 | static ssize_t sysfs_test_command(struct sys_device *dev, const char *buf, |
| 300 | size_t count) |
| 301 | { |
Thomas Gleixner | 0bafd21 | 2006-06-27 02:55:01 -0700 | [diff] [blame] | 302 | struct sched_param schedpar; |
Thomas Gleixner | 61a8712 | 2006-06-27 02:54:56 -0700 | [diff] [blame] | 303 | struct test_thread_data *td; |
| 304 | char cmdbuf[32]; |
Thomas Gleixner | 0bafd21 | 2006-06-27 02:55:01 -0700 | [diff] [blame] | 305 | int op, dat, tid, ret; |
Thomas Gleixner | 61a8712 | 2006-06-27 02:54:56 -0700 | [diff] [blame] | 306 | |
| 307 | td = container_of(dev, struct test_thread_data, sysdev); |
| 308 | tid = td->sysdev.id; |
| 309 | |
| 310 | /* strings from sysfs write are not 0 terminated! */ |
| 311 | if (count >= sizeof(cmdbuf)) |
| 312 | return -EINVAL; |
| 313 | |
| 314 | /* strip of \n: */ |
| 315 | if (buf[count-1] == '\n') |
| 316 | count--; |
| 317 | if (count < 1) |
| 318 | return -EINVAL; |
| 319 | |
| 320 | memcpy(cmdbuf, buf, count); |
| 321 | cmdbuf[count] = 0; |
| 322 | |
| 323 | if (sscanf(cmdbuf, "%d:%d", &op, &dat) != 2) |
| 324 | return -EINVAL; |
| 325 | |
| 326 | switch (op) { |
Thomas Gleixner | 0bafd21 | 2006-06-27 02:55:01 -0700 | [diff] [blame] | 327 | case RTTEST_SCHEDOT: |
| 328 | schedpar.sched_priority = 0; |
| 329 | ret = sched_setscheduler(threads[tid], SCHED_NORMAL, &schedpar); |
| 330 | if (ret) |
| 331 | return ret; |
| 332 | set_user_nice(current, 0); |
| 333 | break; |
| 334 | |
| 335 | case RTTEST_SCHEDRT: |
| 336 | schedpar.sched_priority = dat; |
| 337 | ret = sched_setscheduler(threads[tid], SCHED_FIFO, &schedpar); |
| 338 | if (ret) |
| 339 | return ret; |
| 340 | break; |
| 341 | |
Thomas Gleixner | 61a8712 | 2006-06-27 02:54:56 -0700 | [diff] [blame] | 342 | case RTTEST_SIGNAL: |
| 343 | send_sig(SIGHUP, threads[tid], 0); |
| 344 | break; |
| 345 | |
| 346 | default: |
| 347 | if (td->opcode > 0) |
| 348 | return -EBUSY; |
| 349 | td->opdata = dat; |
| 350 | td->opcode = op; |
| 351 | wake_up_process(threads[tid]); |
| 352 | } |
| 353 | |
| 354 | return count; |
| 355 | } |
| 356 | |
| 357 | /** |
| 358 | * sysfs_test_status - sysfs interface for rt tester |
| 359 | * @dev: thread to query |
| 360 | * @buf: char buffer to be filled with thread status info |
| 361 | */ |
| 362 | static ssize_t sysfs_test_status(struct sys_device *dev, char *buf) |
| 363 | { |
| 364 | struct test_thread_data *td; |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 365 | struct task_struct *tsk; |
Thomas Gleixner | 61a8712 | 2006-06-27 02:54:56 -0700 | [diff] [blame] | 366 | char *curr = buf; |
Thomas Gleixner | 61a8712 | 2006-06-27 02:54:56 -0700 | [diff] [blame] | 367 | int i; |
| 368 | |
| 369 | td = container_of(dev, struct test_thread_data, sysdev); |
| 370 | tsk = threads[td->sysdev.id]; |
| 371 | |
| 372 | spin_lock(&rttest_lock); |
| 373 | |
| 374 | curr += sprintf(curr, |
| 375 | "O: %4d, E:%8d, S: 0x%08lx, P: %4d, N: %4d, B: %p, K: %d, M:", |
| 376 | td->opcode, td->event, tsk->state, |
| 377 | (MAX_RT_PRIO - 1) - tsk->prio, |
| 378 | (MAX_RT_PRIO - 1) - tsk->normal_prio, |
| 379 | tsk->pi_blocked_on, td->bkl); |
| 380 | |
| 381 | for (i = MAX_RT_TEST_MUTEXES - 1; i >=0 ; i--) |
| 382 | curr += sprintf(curr, "%d", td->mutexes[i]); |
| 383 | |
| 384 | spin_unlock(&rttest_lock); |
| 385 | |
| 386 | curr += sprintf(curr, ", T: %p, R: %p\n", tsk, |
| 387 | mutexes[td->sysdev.id].owner); |
| 388 | |
| 389 | return curr - buf; |
| 390 | } |
| 391 | |
| 392 | static SYSDEV_ATTR(status, 0600, sysfs_test_status, NULL); |
| 393 | static SYSDEV_ATTR(command, 0600, NULL, sysfs_test_command); |
| 394 | |
| 395 | static struct sysdev_class rttest_sysclass = { |
| 396 | set_kset_name("rttest"), |
| 397 | }; |
| 398 | |
| 399 | static int init_test_thread(int id) |
| 400 | { |
| 401 | thread_data[id].sysdev.cls = &rttest_sysclass; |
| 402 | thread_data[id].sysdev.id = id; |
| 403 | |
| 404 | threads[id] = kthread_run(test_func, &thread_data[id], "rt-test-%d", id); |
| 405 | if (IS_ERR(threads[id])) |
| 406 | return PTR_ERR(threads[id]); |
| 407 | |
| 408 | return sysdev_register(&thread_data[id].sysdev); |
| 409 | } |
| 410 | |
| 411 | static int init_rttest(void) |
| 412 | { |
| 413 | int ret, i; |
| 414 | |
| 415 | spin_lock_init(&rttest_lock); |
| 416 | |
| 417 | for (i = 0; i < MAX_RT_TEST_MUTEXES; i++) |
| 418 | rt_mutex_init(&mutexes[i]); |
| 419 | |
| 420 | ret = sysdev_class_register(&rttest_sysclass); |
| 421 | if (ret) |
| 422 | return ret; |
| 423 | |
| 424 | for (i = 0; i < MAX_RT_TEST_THREADS; i++) { |
| 425 | ret = init_test_thread(i); |
| 426 | if (ret) |
| 427 | break; |
| 428 | ret = sysdev_create_file(&thread_data[i].sysdev, &attr_status); |
| 429 | if (ret) |
| 430 | break; |
| 431 | ret = sysdev_create_file(&thread_data[i].sysdev, &attr_command); |
| 432 | if (ret) |
| 433 | break; |
| 434 | } |
| 435 | |
| 436 | printk("Initializing RT-Tester: %s\n", ret ? "Failed" : "OK" ); |
| 437 | |
| 438 | return ret; |
| 439 | } |
| 440 | |
| 441 | device_initcall(init_rttest); |