[mirror_edk2.git] / StdLib / Include / Arm / machine / lock.h

/*	$NetBSD: lock.h,v 1.7 2005/12/28 19:09:29 perry Exp $	*/\r
\r
/*-\r
 * Copyright (c) 2000, 2001 The NetBSD Foundation, Inc.\r
 * All rights reserved.\r
 *\r
 * This code is derived from software contributed to The NetBSD Foundation\r
 * by Jason R. Thorpe.\r
 *\r
 * Redistribution and use in source and binary forms, with or without\r
 * modification, are permitted provided that the following conditions\r
 * are met:\r
 * 1. Redistributions of source code must retain the above copyright\r
 *    notice, this list of conditions and the following disclaimer.\r
 * 2. Redistributions in binary form must reproduce the above copyright\r
 *    notice, this list of conditions and the following disclaimer in the\r
 *    documentation and/or other materials provided with the distribution.\r
 * 3. All advertising materials mentioning features or use of this software\r
 *    must display the following acknowledgement:\r
 *	This product includes software developed by the NetBSD\r
 *	Foundation, Inc. and its contributors.\r
 * 4. Neither the name of The NetBSD Foundation nor the names of its\r
 *    contributors may be used to endorse or promote products derived\r
 *    from this software without specific prior written permission.\r
 *\r
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS\r
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED\r
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR\r
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS\r
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR\r
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF\r
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS\r
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN\r
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)\r
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE\r
 * POSSIBILITY OF SUCH DAMAGE.\r
 */\r
\r
/*\r
 * Machine-dependent spin lock operations.\r
 *\r
 * NOTE: The SWP insn used here is available only on ARM architecture\r
 * version 3 and later (as well as 2a).  What we are going to do is\r
 * expect that the kernel will trap and emulate the insn.  That will\r
 * be slow, but give us the atomicity that we need.\r
 */\r
\r
#ifndef _ARM_LOCK_H_\r
#define	_ARM_LOCK_H_\r
\r
static __inline int\r
__swp(int __val, volatile int *__ptr)\r
{\r
\r
	__asm volatile("swp %0, %1, [%2]"\r
	    : "=r" (__val) : "r" (__val), "r" (__ptr) : "memory");\r
	return __val;\r
}\r
\r
static __inline void __attribute__((__unused__))\r
__cpu_simple_lock_init(__cpu_simple_lock_t *alp)\r
{\r
\r
	*alp = __SIMPLELOCK_UNLOCKED;\r
}\r
\r
static __inline void __attribute__((__unused__))\r
__cpu_simple_lock(__cpu_simple_lock_t *alp)\r
{\r
\r
	while (__swp(__SIMPLELOCK_LOCKED, alp) != __SIMPLELOCK_UNLOCKED)\r
		continue;\r
}\r
\r
static __inline int __attribute__((__unused__))\r
__cpu_simple_lock_try(__cpu_simple_lock_t *alp)\r
{\r
\r
	return (__swp(__SIMPLELOCK_LOCKED, alp) == __SIMPLELOCK_UNLOCKED);\r
}\r
\r
static __inline void __attribute__((__unused__))\r
__cpu_simple_unlock(__cpu_simple_lock_t *alp)\r
{\r
\r
	*alp = __SIMPLELOCK_UNLOCKED;\r
}\r
\r
#endif /* _ARM_LOCK_H_ */\r
Commit	Line	Data
2aa62f2b	1	/* $NetBSD: lock.h,v 1.7 2005/12/28 19:09:29 perry Exp $ */\r
	2	\r
	3	/*-\r
	4	* Copyright (c) 2000, 2001 The NetBSD Foundation, Inc.\r
	5	* All rights reserved.\r
	6	*\r
	7	* This code is derived from software contributed to The NetBSD Foundation\r
	8	* by Jason R. Thorpe.\r
	9	*\r
	10	* Redistribution and use in source and binary forms, with or without\r
	11	* modification, are permitted provided that the following conditions\r
	12	* are met:\r
	13	* 1. Redistributions of source code must retain the above copyright\r
	14	* notice, this list of conditions and the following disclaimer.\r
	15	* 2. Redistributions in binary form must reproduce the above copyright\r
	16	* notice, this list of conditions and the following disclaimer in the\r
	17	* documentation and/or other materials provided with the distribution.\r
	18	* 3. All advertising materials mentioning features or use of this software\r
	19	* must display the following acknowledgement:\r
	20	* This product includes software developed by the NetBSD\r
	21	* Foundation, Inc. and its contributors.\r
	22	* 4. Neither the name of The NetBSD Foundation nor the names of its\r
	23	* contributors may be used to endorse or promote products derived\r
	24	* from this software without specific prior written permission.\r
	25	*\r
	26	* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS\r
	27	* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED\r
	28	* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR\r
	29	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS\r
	30	* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR\r
	31	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF\r
	32	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS\r
	33	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN\r
	34	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)\r
	35	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE\r
	36	* POSSIBILITY OF SUCH DAMAGE.\r
	37	*/\r
	38	\r
	39	/*\r
	40	* Machine-dependent spin lock operations.\r
	41	*\r
	42	* NOTE: The SWP insn used here is available only on ARM architecture\r
	43	* version 3 and later (as well as 2a). What we are going to do is\r
	44	* expect that the kernel will trap and emulate the insn. That will\r
	45	* be slow, but give us the atomicity that we need.\r
	46	*/\r
	47	\r
	48	#ifndef _ARM_LOCK_H_\r
	49	#define _ARM_LOCK_H_\r
	50	\r
	51	static __inline int\r
	52	__swp(int __val, volatile int *__ptr)\r
	53	{\r
	54	\r
	55	__asm volatile("swp %0, %1, [%2]"\r
	56	: "=r" (__val) : "r" (__val), "r" (__ptr) : "memory");\r
	57	return __val;\r
	58	}\r
	59	\r
	60	static __inline void __attribute__((__unused__))\r
	61	__cpu_simple_lock_init(__cpu_simple_lock_t *alp)\r
	62	{\r
	63	\r
	64	*alp = __SIMPLELOCK_UNLOCKED;\r
65	}\r
66	\r
67	static __inline void __attribute__((__unused__))\r
68	__cpu_simple_lock(__cpu_simple_lock_t *alp)\r
69	{\r
70	\r
71	while (__swp(__SIMPLELOCK_LOCKED, alp) != __SIMPLELOCK_UNLOCKED)\r
72	continue;\r
73	}\r
74	\r
75	static __inline int __attribute__((__unused__))\r
76	__cpu_simple_lock_try(__cpu_simple_lock_t *alp)\r
77	{\r
78	\r
79	return (__swp(__SIMPLELOCK_LOCKED, alp) == __SIMPLELOCK_UNLOCKED);\r
80	}\r
81	\r
82	static __inline void __attribute__((__unused__))\r
83	__cpu_simple_unlock(__cpu_simple_lock_t *alp)\r
84	{\r
85	\r
86	*alp = __SIMPLELOCK_UNLOCKED;\r
87	}\r
88	\r
89	#endif /* _ARM_LOCK_H_ */\r