[urcu.git] / include / urcu / system.h

// SPDX-FileCopyrightText: 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
//
// SPDX-License-Identifier: MIT

#ifndef _URCU_SYSTEM_H
#define _URCU_SYSTEM_H

/*
 * System definitions.
 */

#include <urcu/config.h>
#include <urcu/compiler.h>
#include <urcu/arch.h>

#ifdef CONFIG_RCU_USE_ATOMIC_BUILTINS

#define CMM_LOAD_SHARED(x)						\
	__atomic_load_n(cmm_cast_volatile(&(x)), __ATOMIC_RELAXED)

#define _CMM_LOAD_SHARED(x) CMM_LOAD_SHARED(x)

#define CMM_STORE_SHARED(x, v)					\
	__extension__						\
	({							\
		__typeof__(v) _v = (v);				\
		__atomic_store_n(cmm_cast_volatile(&(x)), _v,	\
				 __ATOMIC_RELAXED);		\
		_v;						\
	})

#define _CMM_STORE_SHARED(x, v) CMM_STORE_SHARED(x, v)

#else
/*
 * Identify a shared load. A cmm_smp_rmc() or cmm_smp_mc() should come
 * before the load.
 */
#define _CMM_LOAD_SHARED(p)	       CMM_ACCESS_ONCE(p)

/*
 * Load a data from shared memory, doing a cache flush if required.
 */
#define CMM_LOAD_SHARED(p)			\
	__extension__			\
	({				\
		cmm_smp_rmc();		\
		_CMM_LOAD_SHARED(p);	\
	})

/*
 * Identify a shared store. A cmm_smp_wmc() or cmm_smp_mc() should
 * follow the store.
 */
#define _CMM_STORE_SHARED(x, v)	__extension__ ({ CMM_ACCESS_ONCE(x) = (v); })

/*
 * Store v into x, where x is located in shared memory. Performs the
 * required cache flush after writing. Returns v.
 */
#define CMM_STORE_SHARED(x, v)						\
	__extension__							\
	({								\
		__typeof__(x) _v = _CMM_STORE_SHARED(x, v);		\
		cmm_smp_wmc();						\
		_v = _v;	/* Work around clang "unused result" */	\
	})

#endif	/* CONFIG_RCU_USE_ATOMIC_BUILTINS */

#endif /* _URCU_SYSTEM_H */
Commit	Line	Data
	1	// SPDX-FileCopyrightText: 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	2	//
	3	// SPDX-License-Identifier: MIT
	4
	5	#ifndef _URCU_SYSTEM_H
	6	#define _URCU_SYSTEM_H
	7
	8	/*
	9	* System definitions.
	10	*/
	11
	12	#include <urcu/config.h>
	13	#include <urcu/compiler.h>
	14	#include <urcu/arch.h>
	15
	16	#ifdef CONFIG_RCU_USE_ATOMIC_BUILTINS
	17
	18	#define CMM_LOAD_SHARED(x) \
	19	__atomic_load_n(cmm_cast_volatile(&(x)), __ATOMIC_RELAXED)
	20
	21	#define _CMM_LOAD_SHARED(x) CMM_LOAD_SHARED(x)
	22
	23	#define CMM_STORE_SHARED(x, v) \
	24	__extension__ \
	25	({ \
	26	__typeof__(v) _v = (v); \
	27	__atomic_store_n(cmm_cast_volatile(&(x)), _v, \
	28	__ATOMIC_RELAXED); \
	29	_v; \
	30	})
	31
	32	#define _CMM_STORE_SHARED(x, v) CMM_STORE_SHARED(x, v)
	33
	34	#else
	35	/*
	36	* Identify a shared load. A cmm_smp_rmc() or cmm_smp_mc() should come
	37	* before the load.
	38	*/
	39	#define _CMM_LOAD_SHARED(p) CMM_ACCESS_ONCE(p)
	40
	41	/*
	42	* Load a data from shared memory, doing a cache flush if required.
	43	*/
	44	#define CMM_LOAD_SHARED(p) \
	45	__extension__ \
	46	({ \
	47	cmm_smp_rmc(); \
	48	_CMM_LOAD_SHARED(p); \
	49	})
	50
	51	/*
	52	* Identify a shared store. A cmm_smp_wmc() or cmm_smp_mc() should
	53	* follow the store.
	54	*/
	55	#define _CMM_STORE_SHARED(x, v) __extension__ ({ CMM_ACCESS_ONCE(x) = (v); })
	56
	57	/*
	58	* Store v into x, where x is located in shared memory. Performs the
	59	* required cache flush after writing. Returns v.
	60	*/
	61	#define CMM_STORE_SHARED(x, v) \
	62	__extension__ \
	63	({ \
	64	__typeof__(x) _v = _CMM_STORE_SHARED(x, v); \
	65	cmm_smp_wmc(); \
	66	_v = _v; /* Work around clang "unused result" */ \
	67	})
	68
	69	#endif /* CONFIG_RCU_USE_ATOMIC_BUILTINS */
	70
	71	#endif /* _URCU_SYSTEM_H */