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#include <linux/sched.h>
#include <litmus/litmus.h>
#include <litmus/fdso.h>
#ifdef CONFIG_LITMUS_LOCKING
#include <litmus/sched_plugin.h>
#include <litmus/trace.h>
#include <litmus/wait.h>
static int create_generic_lock(void** obj_ref, obj_type_t type, void* __user arg);
static int open_generic_lock(struct od_table_entry* entry, void* __user arg);
static int close_generic_lock(struct od_table_entry* entry);
static void destroy_generic_lock(obj_type_t type, void* sem);
struct fdso_ops generic_lock_ops = {
.create = create_generic_lock,
.open = open_generic_lock,
.close = close_generic_lock,
.destroy = destroy_generic_lock
};
static inline bool is_lock(struct od_table_entry* entry)
{
return entry->class == &generic_lock_ops;
}
static inline struct litmus_lock* get_lock(struct od_table_entry* entry)
{
BUG_ON(!is_lock(entry));
return (struct litmus_lock*) entry->obj->obj;
}
static int create_generic_lock(void** obj_ref, obj_type_t type, void* __user arg)
{
struct litmus_lock* lock;
int err;
err = litmus->allocate_lock(&lock, type, arg);
if (err == 0)
*obj_ref = lock;
return err;
}
static int open_generic_lock(struct od_table_entry* entry, void* __user arg)
{
struct litmus_lock* lock = get_lock(entry);
if (lock->ops->open)
return lock->ops->open(lock, arg);
else
return 0; /* default: any task can open it */
}
static int close_generic_lock(struct od_table_entry* entry)
{
struct litmus_lock* lock = get_lock(entry);
if (lock->ops->close)
return lock->ops->close(lock);
else
return 0; /* default: closing succeeds */
}
static void destroy_generic_lock(obj_type_t type, void* obj)
{
struct litmus_lock* lock = (struct litmus_lock*) obj;
lock->ops->deallocate(lock);
}
asmlinkage long sys_litmus_lock(int lock_od)
{
long err = -EINVAL;
struct od_table_entry* entry;
struct litmus_lock* l;
if (has_control_page(current))
TS_SYSCALL_IN_START(&get_control_page(current)->ts_syscall_start);
TS_SYSCALL_IN_END;
TS_LOCK_START;
entry = get_entry_for_od(lock_od);
if (entry && is_lock(entry)) {
l = get_lock(entry);
TRACE_CUR("attempts to lock 0x%p\n", l);
err = l->ops->lock(l);
}
/* Note: task my have been suspended or preempted in between! Take
* this into account when computing overheads. */
TS_LOCK_END;
TS_SYSCALL_OUT_START;
return err;
}
asmlinkage long sys_litmus_unlock(int lock_od)
{
long err = -EINVAL;
struct od_table_entry* entry;
struct litmus_lock* l;
if (has_control_page(current))
TS_SYSCALL_IN_START(&get_control_page(current)->ts_syscall_start);
TS_SYSCALL_IN_END;
TS_UNLOCK_START;
entry = get_entry_for_od(lock_od);
if (entry && is_lock(entry)) {
l = get_lock(entry);
TRACE_CUR("attempts to unlock 0x%p\n", l);
err = l->ops->unlock(l);
}
/* Note: task my have been preempted in between! Take this into
* account when computing overheads. */
TS_UNLOCK_END;
TS_SYSCALL_OUT_START;
return err;
}
struct task_struct* __waitqueue_remove_first(wait_queue_head_t *wq)
{
wait_queue_t* q;
struct task_struct* t = NULL;
if (waitqueue_active(wq)) {
q = list_entry(wq->task_list.next,
wait_queue_t, task_list);
t = (struct task_struct*) q->private;
__remove_wait_queue(wq, q);
}
return(t);
}
unsigned int __add_wait_queue_prio_exclusive(
wait_queue_head_t* head,
prio_wait_queue_t *new)
{
struct list_head *pos;
unsigned int passed = 0;
new->wq.flags |= WQ_FLAG_EXCLUSIVE;
/* find a spot where the new entry is less than the next */
list_for_each(pos, &head->task_list) {
prio_wait_queue_t* queued = list_entry(pos, prio_wait_queue_t,
wq.task_list);
if (unlikely(lt_before(new->priority, queued->priority))) {
/* pos is not less than new, thus insert here */
__list_add(&new->wq.task_list, pos->prev, pos);
goto out;
}
passed++;
}
/* if we get to this point either the list is empty or every entry
* queued element is less than new.
* Let's add new to the end. */
list_add_tail(&new->wq.task_list, &head->task_list);
out:
return passed;
}
#else
struct fdso_ops generic_lock_ops = {};
asmlinkage long sys_litmus_lock(int sem_od)
{
return -ENOSYS;
}
asmlinkage long sys_litmus_unlock(int sem_od)
{
return -ENOSYS;
}
#endif
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