[linux-2.6-block.git] / include / linux / rwbase_rt.h

// SPDX-License-Identifier: GPL-2.0-only
#ifndef _LINUX_RWBASE_RT_H
#define _LINUX_RWBASE_RT_H

#include <linux/rtmutex.h>
#include <linux/atomic.h>

#define READER_BIAS		(1U << 31)
#define WRITER_BIAS		(1U << 30)

struct rwbase_rt {
	atomic_t		readers;
	struct rt_mutex_base	rtmutex;
};

#define __RWBASE_INITIALIZER(name)				\
{								\
	.readers = ATOMIC_INIT(READER_BIAS),			\
	.rtmutex = __RT_MUTEX_BASE_INITIALIZER(name.rtmutex),	\
}

#define init_rwbase_rt(rwbase)					\
	do {							\
		rt_mutex_base_init(&(rwbase)->rtmutex);		\
		atomic_set(&(rwbase)->readers, READER_BIAS);	\
	} while (0)


static __always_inline bool rw_base_is_locked(const struct rwbase_rt *rwb)
{
	return atomic_read(&rwb->readers) != READER_BIAS;
}

static __always_inline bool rw_base_is_write_locked(const struct rwbase_rt *rwb)
{
	return atomic_read(&rwb->readers) == WRITER_BIAS;
}

static __always_inline bool rw_base_is_contended(const struct rwbase_rt *rwb)
{
	return atomic_read(&rwb->readers) > 0;
}

#endif /* _LINUX_RWBASE_RT_H */
Commit	Line	Data
943f0edb TG	1	// SPDX-License-Identifier: GPL-2.0-only
	2	#ifndef _LINUX_RWBASE_RT_H
	3	#define _LINUX_RWBASE_RT_H
	4
	5	#include <linux/rtmutex.h>
	6	#include <linux/atomic.h>
	7
	8	#define READER_BIAS (1U << 31)
	9	#define WRITER_BIAS (1U << 30)
	10
	11	struct rwbase_rt {
	12	atomic_t readers;
	13	struct rt_mutex_base rtmutex;
	14	};
	15
	16	#define __RWBASE_INITIALIZER(name) \
	17	{ \
	18	.readers = ATOMIC_INIT(READER_BIAS), \
	19	.rtmutex = __RT_MUTEX_BASE_INITIALIZER(name.rtmutex), \
	20	}
	21
	22	#define init_rwbase_rt(rwbase) \
	23	do { \
	24	rt_mutex_base_init(&(rwbase)->rtmutex); \
	25	atomic_set(&(rwbase)->readers, READER_BIAS); \
	26	} while (0)
	27
	28
f70405af	29	static __always_inline bool rw_base_is_locked(const struct rwbase_rt *rwb)
943f0edb TG	30	{
	31	return atomic_read(&rwb->readers) != READER_BIAS;
	32	}
	33
fa1f5116	34	static __always_inline bool rw_base_is_write_locked(const struct rwbase_rt *rwb)
f70405af	35	{
fa1f5116	36	return atomic_read(&rwb->readers) == WRITER_BIAS;
f70405af MWO	37	}
	38
	39	static __always_inline bool rw_base_is_contended(const struct rwbase_rt *rwb)
943f0edb TG	40	{
	41	return atomic_read(&rwb->readers) > 0;
	42	}
	43
	44	#endif /* _LINUX_RWBASE_RT_H */