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- /*
- * RT-Mutex-tester: scriptable tester for rt mutexes
- *
- * started by Thomas Gleixner:
- *
- * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
- *
- */
- #include <linux/kthread.h>
- #include <linux/module.h>
- #include <linux/sched.h>
- #include <linux/smp_lock.h>
- #include <linux/spinlock.h>
- #include <linux/sysdev.h>
- #include <linux/timer.h>
- #include <linux/freezer.h>
- #include "rtmutex.h"
- #define MAX_RT_TEST_THREADS 8
- #define MAX_RT_TEST_MUTEXES 8
- static spinlock_t rttest_lock;
- static atomic_t rttest_event;
- struct test_thread_data {
- int opcode;
- int opdata;
- int mutexes[MAX_RT_TEST_MUTEXES];
- int bkl;
- int event;
- struct sys_device sysdev;
- };
- static struct test_thread_data thread_data[MAX_RT_TEST_THREADS];
- static struct task_struct *threads[MAX_RT_TEST_THREADS];
- static struct rt_mutex mutexes[MAX_RT_TEST_MUTEXES];
- enum test_opcodes {
- RTTEST_NOP = 0,
- RTTEST_SCHEDOT, /* 1 Sched other, data = nice */
- RTTEST_SCHEDRT, /* 2 Sched fifo, data = prio */
- RTTEST_LOCK, /* 3 Lock uninterruptible, data = lockindex */
- RTTEST_LOCKNOWAIT, /* 4 Lock uninterruptible no wait in wakeup, data = lockindex */
- RTTEST_LOCKINT, /* 5 Lock interruptible, data = lockindex */
- RTTEST_LOCKINTNOWAIT, /* 6 Lock interruptible no wait in wakeup, data = lockindex */
- RTTEST_LOCKCONT, /* 7 Continue locking after the wakeup delay */
- RTTEST_UNLOCK, /* 8 Unlock, data = lockindex */
- RTTEST_LOCKBKL, /* 9 Lock BKL */
- RTTEST_UNLOCKBKL, /* 10 Unlock BKL */
- RTTEST_SIGNAL, /* 11 Signal other test thread, data = thread id */
- RTTEST_RESETEVENT = 98, /* 98 Reset event counter */
- RTTEST_RESET = 99, /* 99 Reset all pending operations */
- };
- static int handle_op(struct test_thread_data *td, int lockwakeup)
- {
- int i, id, ret = -EINVAL;
- switch(td->opcode) {
- case RTTEST_NOP:
- return 0;
- case RTTEST_LOCKCONT:
- td->mutexes[td->opdata] = 1;
- td->event = atomic_add_return(1, &rttest_event);
- return 0;
- case RTTEST_RESET:
- for (i = 0; i < MAX_RT_TEST_MUTEXES; i++) {
- if (td->mutexes[i] == 4) {
- rt_mutex_unlock(&mutexes[i]);
- td->mutexes[i] = 0;
- }
- }
- if (!lockwakeup && td->bkl == 4) {
- unlock_kernel();
- td->bkl = 0;
- }
- return 0;
- case RTTEST_RESETEVENT:
- atomic_set(&rttest_event, 0);
- return 0;
- default:
- if (lockwakeup)
- return ret;
- }
- switch(td->opcode) {
- case RTTEST_LOCK:
- case RTTEST_LOCKNOWAIT:
- id = td->opdata;
- if (id < 0 || id >= MAX_RT_TEST_MUTEXES)
- return ret;
- td->mutexes[id] = 1;
- td->event = atomic_add_return(1, &rttest_event);
- rt_mutex_lock(&mutexes[id]);
- td->event = atomic_add_return(1, &rttest_event);
- td->mutexes[id] = 4;
- return 0;
- case RTTEST_LOCKINT:
- case RTTEST_LOCKINTNOWAIT:
- id = td->opdata;
- if (id < 0 || id >= MAX_RT_TEST_MUTEXES)
- return ret;
- td->mutexes[id] = 1;
- td->event = atomic_add_return(1, &rttest_event);
- ret = rt_mutex_lock_interruptible(&mutexes[id], 0);
- td->event = atomic_add_return(1, &rttest_event);
- td->mutexes[id] = ret ? 0 : 4;
- return ret ? -EINTR : 0;
- case RTTEST_UNLOCK:
- id = td->opdata;
- if (id < 0 || id >= MAX_RT_TEST_MUTEXES || td->mutexes[id] != 4)
- return ret;
- td->event = atomic_add_return(1, &rttest_event);
- rt_mutex_unlock(&mutexes[id]);
- td->event = atomic_add_return(1, &rttest_event);
- td->mutexes[id] = 0;
- return 0;
- case RTTEST_LOCKBKL:
- if (td->bkl)
- return 0;
- td->bkl = 1;
- lock_kernel();
- td->bkl = 4;
- return 0;
- case RTTEST_UNLOCKBKL:
- if (td->bkl != 4)
- break;
- unlock_kernel();
- td->bkl = 0;
- return 0;
- default:
- break;
- }
- return ret;
- }
- /*
- * Schedule replacement for rtsem_down(). Only called for threads with
- * PF_MUTEX_TESTER set.
- *
- * This allows us to have finegrained control over the event flow.
- *
- */
- void schedule_rt_mutex_test(struct rt_mutex *mutex)
- {
- int tid, op, dat;
- struct test_thread_data *td;
- /* We have to lookup the task */
- for (tid = 0; tid < MAX_RT_TEST_THREADS; tid++) {
- if (threads[tid] == current)
- break;
- }
- BUG_ON(tid == MAX_RT_TEST_THREADS);
- td = &thread_data[tid];
- op = td->opcode;
- dat = td->opdata;
- switch (op) {
- case RTTEST_LOCK:
- case RTTEST_LOCKINT:
- case RTTEST_LOCKNOWAIT:
- case RTTEST_LOCKINTNOWAIT:
- if (mutex != &mutexes[dat])
- break;
- if (td->mutexes[dat] != 1)
- break;
- td->mutexes[dat] = 2;
- td->event = atomic_add_return(1, &rttest_event);
- break;
- case RTTEST_LOCKBKL:
- default:
- break;
- }
- schedule();
- switch (op) {
- case RTTEST_LOCK:
- case RTTEST_LOCKINT:
- if (mutex != &mutexes[dat])
- return;
- if (td->mutexes[dat] != 2)
- return;
- td->mutexes[dat] = 3;
- td->event = atomic_add_return(1, &rttest_event);
- break;
- case RTTEST_LOCKNOWAIT:
- case RTTEST_LOCKINTNOWAIT:
- if (mutex != &mutexes[dat])
- return;
- if (td->mutexes[dat] != 2)
- return;
- td->mutexes[dat] = 1;
- td->event = atomic_add_return(1, &rttest_event);
- return;
- case RTTEST_LOCKBKL:
- return;
- default:
- return;
- }
- td->opcode = 0;
- for (;;) {
- set_current_state(TASK_INTERRUPTIBLE);
- if (td->opcode > 0) {
- int ret;
- set_current_state(TASK_RUNNING);
- ret = handle_op(td, 1);
- set_current_state(TASK_INTERRUPTIBLE);
- if (td->opcode == RTTEST_LOCKCONT)
- break;
- td->opcode = ret;
- }
- /* Wait for the next command to be executed */
- schedule();
- }
- /* Restore previous command and data */
- td->opcode = op;
- td->opdata = dat;
- }
- static int test_func(void *data)
- {
- struct test_thread_data *td = data;
- int ret;
- current->flags |= PF_MUTEX_TESTER;
- allow_signal(SIGHUP);
- for(;;) {
- set_current_state(TASK_INTERRUPTIBLE);
- if (td->opcode > 0) {
- set_current_state(TASK_RUNNING);
- ret = handle_op(td, 0);
- set_current_state(TASK_INTERRUPTIBLE);
- td->opcode = ret;
- }
- /* Wait for the next command to be executed */
- schedule();
- try_to_freeze();
- if (signal_pending(current))
- flush_signals(current);
- if(kthread_should_stop())
- break;
- }
- return 0;
- }
- /**
- * sysfs_test_command - interface for test commands
- * @dev: thread reference
- * @buf: command for actual step
- * @count: length of buffer
- *
- * command syntax:
- *
- * opcode:data
- */
- static ssize_t sysfs_test_command(struct sys_device *dev, const char *buf,
- size_t count)
- {
- struct sched_param schedpar;
- struct test_thread_data *td;
- char cmdbuf[32];
- int op, dat, tid, ret;
- td = container_of(dev, struct test_thread_data, sysdev);
- tid = td->sysdev.id;
- /* strings from sysfs write are not 0 terminated! */
- if (count >= sizeof(cmdbuf))
- return -EINVAL;
- /* strip of \n: */
- if (buf[count-1] == '\n')
- count--;
- if (count < 1)
- return -EINVAL;
- memcpy(cmdbuf, buf, count);
- cmdbuf[count] = 0;
- if (sscanf(cmdbuf, "%d:%d", &op, &dat) != 2)
- return -EINVAL;
- switch (op) {
- case RTTEST_SCHEDOT:
- schedpar.sched_priority = 0;
- ret = sched_setscheduler(threads[tid], SCHED_NORMAL, &schedpar);
- if (ret)
- return ret;
- set_user_nice(current, 0);
- break;
- case RTTEST_SCHEDRT:
- schedpar.sched_priority = dat;
- ret = sched_setscheduler(threads[tid], SCHED_FIFO, &schedpar);
- if (ret)
- return ret;
- break;
- case RTTEST_SIGNAL:
- send_sig(SIGHUP, threads[tid], 0);
- break;
- default:
- if (td->opcode > 0)
- return -EBUSY;
- td->opdata = dat;
- td->opcode = op;
- wake_up_process(threads[tid]);
- }
- return count;
- }
- /**
- * sysfs_test_status - sysfs interface for rt tester
- * @dev: thread to query
- * @buf: char buffer to be filled with thread status info
- */
- static ssize_t sysfs_test_status(struct sys_device *dev, char *buf)
- {
- struct test_thread_data *td;
- struct task_struct *tsk;
- char *curr = buf;
- int i;
- td = container_of(dev, struct test_thread_data, sysdev);
- tsk = threads[td->sysdev.id];
- spin_lock(&rttest_lock);
- curr += sprintf(curr,
- "O: %4d, E:%8d, S: 0x%08lx, P: %4d, N: %4d, B: %p, K: %d, M:",
- td->opcode, td->event, tsk->state,
- (MAX_RT_PRIO - 1) - tsk->prio,
- (MAX_RT_PRIO - 1) - tsk->normal_prio,
- tsk->pi_blocked_on, td->bkl);
- for (i = MAX_RT_TEST_MUTEXES - 1; i >=0 ; i--)
- curr += sprintf(curr, "%d", td->mutexes[i]);
- spin_unlock(&rttest_lock);
- curr += sprintf(curr, ", T: %p, R: %p\n", tsk,
- mutexes[td->sysdev.id].owner);
- return curr - buf;
- }
- static SYSDEV_ATTR(status, 0600, sysfs_test_status, NULL);
- static SYSDEV_ATTR(command, 0600, NULL, sysfs_test_command);
- static struct sysdev_class rttest_sysclass = {
- set_kset_name("rttest"),
- };
- static int init_test_thread(int id)
- {
- thread_data[id].sysdev.cls = &rttest_sysclass;
- thread_data[id].sysdev.id = id;
- threads[id] = kthread_run(test_func, &thread_data[id], "rt-test-%d", id);
- if (IS_ERR(threads[id]))
- return PTR_ERR(threads[id]);
- return sysdev_register(&thread_data[id].sysdev);
- }
- static int init_rttest(void)
- {
- int ret, i;
- spin_lock_init(&rttest_lock);
- for (i = 0; i < MAX_RT_TEST_MUTEXES; i++)
- rt_mutex_init(&mutexes[i]);
- ret = sysdev_class_register(&rttest_sysclass);
- if (ret)
- return ret;
- for (i = 0; i < MAX_RT_TEST_THREADS; i++) {
- ret = init_test_thread(i);
- if (ret)
- break;
- ret = sysdev_create_file(&thread_data[i].sysdev, &attr_status);
- if (ret)
- break;
- ret = sysdev_create_file(&thread_data[i].sysdev, &attr_command);
- if (ret)
- break;
- }
- printk("Initializing RT-Tester: %s\n", ret ? "Failed" : "OK" );
- return ret;
- }
- device_initcall(init_rttest);
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