/* SPDX-License-Identifier: GPL-2.0 */
|
/*
|
* RT Mutexes: blocking mutual exclusion locks with PI support
|
*
|
* started by Ingo Molnar and Thomas Gleixner:
|
*
|
* Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
|
* Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
|
*
|
* This file contains the private data structure and API definitions.
|
*/
|
|
#ifndef __KERNEL_RTMUTEX_COMMON_H
|
#define __KERNEL_RTMUTEX_COMMON_H
|
|
#include <linux/rtmutex.h>
|
#include <linux/sched/wake_q.h>
|
#include <linux/sched/debug.h>
|
|
/*
|
* This is the control structure for tasks blocked on a rt_mutex,
|
* which is allocated on the kernel stack on of the blocked task.
|
*
|
* @tree_entry: pi node to enqueue into the mutex waiters tree
|
* @pi_tree_entry: pi node to enqueue into the mutex owner waiters tree
|
* @task: task reference to the blocked task
|
*/
|
struct rt_mutex_waiter {
|
struct rb_node tree_entry;
|
struct rb_node pi_tree_entry;
|
struct task_struct *task;
|
struct rt_mutex *lock;
|
int prio;
|
bool savestate;
|
u64 deadline;
|
};
|
|
/*
|
* Various helpers to access the waiters-tree:
|
*/
|
|
#ifdef CONFIG_RT_MUTEXES
|
|
static inline int rt_mutex_has_waiters(struct rt_mutex *lock)
|
{
|
return !RB_EMPTY_ROOT(&lock->waiters.rb_root);
|
}
|
|
static inline struct rt_mutex_waiter *
|
rt_mutex_top_waiter(struct rt_mutex *lock)
|
{
|
struct rb_node *leftmost = rb_first_cached(&lock->waiters);
|
struct rt_mutex_waiter *w = NULL;
|
|
if (leftmost) {
|
w = rb_entry(leftmost, struct rt_mutex_waiter, tree_entry);
|
BUG_ON(w->lock != lock);
|
}
|
return w;
|
}
|
|
static inline int task_has_pi_waiters(struct task_struct *p)
|
{
|
return !RB_EMPTY_ROOT(&p->pi_waiters.rb_root);
|
}
|
|
static inline struct rt_mutex_waiter *
|
task_top_pi_waiter(struct task_struct *p)
|
{
|
return rb_entry(p->pi_waiters.rb_leftmost,
|
struct rt_mutex_waiter, pi_tree_entry);
|
}
|
|
#else
|
|
static inline int rt_mutex_has_waiters(struct rt_mutex *lock)
|
{
|
return false;
|
}
|
|
static inline struct rt_mutex_waiter *
|
rt_mutex_top_waiter(struct rt_mutex *lock)
|
{
|
return NULL;
|
}
|
|
static inline int task_has_pi_waiters(struct task_struct *p)
|
{
|
return false;
|
}
|
|
static inline struct rt_mutex_waiter *
|
task_top_pi_waiter(struct task_struct *p)
|
{
|
return NULL;
|
}
|
|
#endif
|
|
/*
|
* lock->owner state tracking:
|
*/
|
#define RT_MUTEX_HAS_WAITERS 1UL
|
|
static inline struct task_struct *rt_mutex_owner(struct rt_mutex *lock)
|
{
|
unsigned long owner = (unsigned long) READ_ONCE(lock->owner);
|
|
return (struct task_struct *) (owner & ~RT_MUTEX_HAS_WAITERS);
|
}
|
|
/*
|
* Constants for rt mutex functions which have a selectable deadlock
|
* detection.
|
*
|
* RT_MUTEX_MIN_CHAINWALK: Stops the lock chain walk when there are
|
* no further PI adjustments to be made.
|
*
|
* RT_MUTEX_FULL_CHAINWALK: Invoke deadlock detection with a full
|
* walk of the lock chain.
|
*/
|
enum rtmutex_chainwalk {
|
RT_MUTEX_MIN_CHAINWALK,
|
RT_MUTEX_FULL_CHAINWALK,
|
};
|
|
/*
|
* PI-futex support (proxy locking functions, etc.):
|
*/
|
#define PI_WAKEUP_INPROGRESS ((struct rt_mutex_waiter *) 1)
|
#define PI_REQUEUE_INPROGRESS ((struct rt_mutex_waiter *) 2)
|
|
extern struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock);
|
extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
|
struct task_struct *proxy_owner);
|
extern void rt_mutex_proxy_unlock(struct rt_mutex *lock);
|
extern void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter, bool savetate);
|
extern int __rt_mutex_start_proxy_lock(struct rt_mutex *lock,
|
struct rt_mutex_waiter *waiter,
|
struct task_struct *task);
|
extern int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
|
struct rt_mutex_waiter *waiter,
|
struct task_struct *task);
|
extern int rt_mutex_wait_proxy_lock(struct rt_mutex *lock,
|
struct hrtimer_sleeper *to,
|
struct rt_mutex_waiter *waiter);
|
extern bool rt_mutex_cleanup_proxy_lock(struct rt_mutex *lock,
|
struct rt_mutex_waiter *waiter);
|
|
extern int rt_mutex_futex_trylock(struct rt_mutex *l);
|
extern int __rt_mutex_futex_trylock(struct rt_mutex *l);
|
|
extern void rt_mutex_futex_unlock(struct rt_mutex *lock);
|
extern bool __rt_mutex_futex_unlock(struct rt_mutex *lock,
|
struct wake_q_head *wqh,
|
struct wake_q_head *wq_sleeper);
|
|
extern void rt_mutex_postunlock(struct wake_q_head *wake_q,
|
struct wake_q_head *wake_sleeper_q);
|
|
/* RW semaphore special interface */
|
struct ww_acquire_ctx;
|
|
extern int __rt_mutex_lock_state(struct rt_mutex *lock, int state);
|
extern int __rt_mutex_trylock(struct rt_mutex *lock);
|
extern void __rt_mutex_unlock(struct rt_mutex *lock);
|
int __sched rt_mutex_slowlock_locked(struct rt_mutex *lock, int state,
|
struct hrtimer_sleeper *timeout,
|
enum rtmutex_chainwalk chwalk,
|
struct ww_acquire_ctx *ww_ctx,
|
struct rt_mutex_waiter *waiter);
|
void __sched rt_spin_lock_slowlock_locked(struct rt_mutex *lock,
|
struct rt_mutex_waiter *waiter,
|
unsigned long flags);
|
void __sched rt_spin_lock_slowunlock(struct rt_mutex *lock);
|
|
#ifdef CONFIG_DEBUG_RT_MUTEXES
|
# include "rtmutex-debug.h"
|
#else
|
# include "rtmutex.h"
|
#endif
|
|
#endif
|
