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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/config.h>
#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 "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 synt
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