[userspace-rcu.git] / include / urcu / system.h

#ifndef _URCU_SYSTEM_H
#define _URCU_SYSTEM_H

/*
 * system.h
 *
 * System definitions.
 *
 * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 */

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

/*
 * 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 /* _URCU_SYSTEM_H */
Commit	Line	Data
7e30abe3 MD	1	#ifndef _URCU_SYSTEM_H
	2	#define _URCU_SYSTEM_H
	3
	4	/*
	5	* system.h
	6	*
	7	* System definitions.
	8	*
6982d6d7	9	* Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
7e30abe3	10	*
3282a76b MD	11	* Permission is hereby granted, free of charge, to any person obtaining a copy
	12	* of this software and associated documentation files (the "Software"), to deal
	13	* in the Software without restriction, including without limitation the rights
	14	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	15	* copies of the Software, and to permit persons to whom the Software is
	16	* furnished to do so, subject to the following conditions:
7e30abe3	17	*
3282a76b MD	18	* The above copyright notice and this permission notice shall be included in
3282a76b MD	19	* all copies or substantial portions of the Software.
7e30abe3 MD	20	*/
	21
	22	#include <urcu/compiler.h>
	23	#include <urcu/arch.h>
	24
	25	/*
d0bbd9c2 MD	26	* Identify a shared load. A cmm_smp_rmc() or cmm_smp_mc() should come
d0bbd9c2 MD	27	* before the load.
7e30abe3	28	*/
f5ee48a3	29	#define _CMM_LOAD_SHARED(p) CMM_ACCESS_ONCE(p)
7e30abe3 MD	30
	31	/*
	32	* Load a data from shared memory, doing a cache flush if required.
	33	*/
6cf3827c	34	#define CMM_LOAD_SHARED(p) \
1b85da85	35	__extension__ \
7e30abe3	36	({ \
5481ddb3	37	cmm_smp_rmc(); \
6cf3827c	38	_CMM_LOAD_SHARED(p); \
7e30abe3 MD	39	})
	40
	41	/*
d0bbd9c2 MD	42	* Identify a shared store. A cmm_smp_wmc() or cmm_smp_mc() should
d0bbd9c2 MD	43	* follow the store.
7e30abe3	44	*/
1b85da85	45	#define _CMM_STORE_SHARED(x, v) __extension__ ({ CMM_ACCESS_ONCE(x) = (v); })
7e30abe3 MD	46
7e30abe3 MD	47	/*
d0bbd9c2 MD	48	* Store v into x, where x is located in shared memory. Performs the
d0bbd9c2 MD	49	* required cache flush after writing. Returns v.
7e30abe3	50	*/
79a8e6c3	51	#define CMM_STORE_SHARED(x, v) \
1b85da85	52	__extension__ \
79a8e6c3 MD	53	({ \
	54	__typeof__(x) _v = _CMM_STORE_SHARED(x, v); \
	55	cmm_smp_wmc(); \
	56	_v = _v; /* Work around clang "unused result" */ \
7e30abe3 MD	57	})
	58
	59	#endif /* _URCU_SYSTEM_H */