Commit 051790ee authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Ingo Molnar
Browse files

locking/spinlock: Provide RT specific spinlock_t 



RT replaces spinlocks with a simple wrapper around an rtmutex, which turns
spinlocks on RT into 'sleeping' spinlocks. The actual implementation of the
spinlock API differs from a regular rtmutex, as it does neither handle
timeouts nor signals and it is state preserving across the lock operation.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.654230709@linutronix.de
parent e4e17af3

include/linux/spinlock_types.h

+26 −0
Original line number Diff line number Diff line
@@ -11,6 +11,9 @@ 


#include <linux/spinlock_types_raw.h>



#ifndef CONFIG_PREEMPT_RT



/* Non PREEMPT_RT kernels map spinlock to raw_spinlock */

typedef struct spinlock {

	union {

		struct raw_spinlock rlock;
@@ -39,6 +42,29 @@ typedef struct spinlock { 


#define DEFINE_SPINLOCK(x)	spinlock_t x = __SPIN_LOCK_UNLOCKED(x)



#else /* !CONFIG_PREEMPT_RT */



/* PREEMPT_RT kernels map spinlock to rt_mutex */

#include <linux/rtmutex.h>



typedef struct spinlock {

	struct rt_mutex_base	lock;

#ifdef CONFIG_DEBUG_LOCK_ALLOC

	struct lockdep_map	dep_map;

#endif

} spinlock_t;



#define __SPIN_LOCK_UNLOCKED(name)				\

	{							\

		.lock = __RT_MUTEX_BASE_INITIALIZER(name.lock),	\

		SPIN_DEP_MAP_INIT(name)				\

	}



#define DEFINE_SPINLOCK(name)					\

	spinlock_t name = __SPIN_LOCK_UNLOCKED(name)



#endif /* CONFIG_PREEMPT_RT */



#include <linux/rwlock_types.h>



#endif /* __LINUX_SPINLOCK_TYPES_H */