local_lock_internal.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_LOCAL_LOCK_H
# error "Do not include directly, include linux/local_lock.h"
#endif

#include <linux/percpu-defs.h>
#include <linux/lockdep.h>

#ifndef CONFIG_PREEMPT_RT

typedef struct {
#ifdef CONFIG_DEBUG_LOCK_ALLOC
	struct lockdep_map	dep_map;
	struct task_struct	*owner;
#endif
} local_lock_t;

#ifdef CONFIG_DEBUG_LOCK_ALLOC
# define LOCAL_LOCK_DEBUG_INIT(lockname)		\
	.dep_map = {					\
		.name = #lockname,			\
		.wait_type_inner = LD_WAIT_CONFIG,	\
		.lock_type = LD_LOCK_PERCPU,		\
		.dmap = DEPT_MAP_INITIALIZER(lockname, NULL),\
	},						\
	.owner = NULL,

static inline void local_lock_acquire(local_lock_t *l)
{
	lock_map_acquire(&l->dep_map);
	DEBUG_LOCKS_WARN_ON(l->owner);
	l->owner = current;
}

static inline void local_lock_release(local_lock_t *l)
{
	DEBUG_LOCKS_WARN_ON(l->owner != current);
	l->owner = NULL;
	lock_map_release(&l->dep_map);
}

static inline void local_lock_debug_init(local_lock_t *l)
{
	l->owner = NULL;
}
#else /* CONFIG_DEBUG_LOCK_ALLOC */
# define LOCAL_LOCK_DEBUG_INIT(lockname)
static inline void local_lock_acquire(local_lock_t *l) { }
static inline void local_lock_release(local_lock_t *l) { }
static inline void local_lock_debug_init(local_lock_t *l) { }
#endif /* !CONFIG_DEBUG_LOCK_ALLOC */

#define INIT_LOCAL_LOCK(lockname)	{ LOCAL_LOCK_DEBUG_INIT(lockname) }

#define __local_lock_init(lock)					\
do {								\
	static struct lock_class_key __key;			\
								\
	debug_check_no_locks_freed((void *)lock, sizeof(*lock));\
	lockdep_init_map_type(&(lock)->dep_map, #lock, &__key,  \
			      0, LD_WAIT_CONFIG, LD_WAIT_INV,	\
			      LD_LOCK_PERCPU);			\
	local_lock_debug_init(lock);				\
} while (0)

#define __local_lock(lock)					\
	do {							\
		preempt_disable();				\
		local_lock_acquire(this_cpu_ptr(lock));		\
	} while (0)

#define __local_lock_irq(lock)					\
	do {							\
		local_irq_disable();				\
		local_lock_acquire(this_cpu_ptr(lock));		\
	} while (0)

#define __local_lock_irqsave(lock, flags)			\
	do {							\
		local_irq_save(flags);				\
		local_lock_acquire(this_cpu_ptr(lock));		\
	} while (0)

#define __local_unlock(lock)					\
	do {							\
		local_lock_release(this_cpu_ptr(lock));		\
		preempt_enable();				\
	} while (0)

#define __local_unlock_irq(lock)				\
	do {							\
		local_lock_release(this_cpu_ptr(lock));		\
		local_irq_enable();				\
	} while (0)

#define __local_unlock_irqrestore(lock, flags)			\
	do {							\
		local_lock_release(this_cpu_ptr(lock));		\
		local_irq_restore(flags);			\
	} while (0)

#else /* !CONFIG_PREEMPT_RT */

/*
 * On PREEMPT_RT local_lock maps to a per CPU spinlock, which protects the
 * critical section while staying preemptible.
 */
typedef spinlock_t local_lock_t;

#define INIT_LOCAL_LOCK(lockname) __LOCAL_SPIN_LOCK_UNLOCKED((lockname))

#define __local_lock_init(l)					\
	do {							\
		local_spin_lock_init((l));			\
	} while (0)

#define __local_lock(__lock)					\
	do {							\
		migrate_disable();				\
		spin_lock(this_cpu_ptr((__lock)));		\
	} while (0)

#define __local_lock_irq(lock)			__local_lock(lock)

#define __local_lock_irqsave(lock, flags)			\
	do {							\
		typecheck(unsigned long, flags);		\
		flags = 0;					\
		__local_lock(lock);				\
	} while (0)

#define __local_unlock(__lock)					\
	do {							\
		spin_unlock(this_cpu_ptr((__lock)));		\
		migrate_enable();				\
	} while (0)

#define __local_unlock_irq(lock)		__local_unlock(lock)

#define __local_unlock_irqrestore(lock, flags)	__local_unlock(lock)

#endif /* CONFIG_PREEMPT_RT */