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lock.h revision 1.6
      1  1.6  christos /*	$NetBSD: lock.h,v 1.6 2017/09/17 00:01:07 christos Exp $	*/
      2  1.1    cherry 
      3  1.1    cherry /*-
      4  1.1    cherry  * Copyright (c) 2000 The NetBSD Foundation, Inc.
      5  1.1    cherry  * All rights reserved.
      6  1.1    cherry  *
      7  1.1    cherry  * This code is derived from software contributed to The NetBSD Foundation
      8  1.1    cherry  * by Jason R. Thorpe.
      9  1.1    cherry  *
     10  1.1    cherry  * Redistribution and use in source and binary forms, with or without
     11  1.1    cherry  * modification, are permitted provided that the following conditions
     12  1.1    cherry  * are met:
     13  1.1    cherry  * 1. Redistributions of source code must retain the above copyright
     14  1.1    cherry  *    notice, this list of conditions and the following disclaimer.
     15  1.1    cherry  * 2. Redistributions in binary form must reproduce the above copyright
     16  1.1    cherry  *    notice, this list of conditions and the following disclaimer in the
     17  1.1    cherry  *    documentation and/or other materials provided with the distribution.
     18  1.1    cherry  *
     19  1.1    cherry  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  1.1    cherry  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  1.1    cherry  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  1.1    cherry  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  1.1    cherry  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  1.1    cherry  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  1.1    cherry  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  1.1    cherry  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  1.1    cherry  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  1.1    cherry  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  1.1    cherry  * POSSIBILITY OF SUCH DAMAGE.
     30  1.1    cherry  */
     31  1.1    cherry 
     32  1.1    cherry /*
     33  1.1    cherry  * Machine-dependent spin lock operations.
     34  1.1    cherry  */
     35  1.1    cherry 
     36  1.1    cherry #ifndef _IA64_LOCK_H_
     37  1.1    cherry #define	_IA64_LOCK_H_
     38  1.1    cherry 
     39  1.2     kochi static __inline int
     40  1.6  christos __SIMPLELOCK_LOCKED_P(const __cpu_simple_lock_t *__ptr)
     41  1.2     kochi {
     42  1.2     kochi 	return *__ptr == __SIMPLELOCK_LOCKED;
     43  1.2     kochi }
     44  1.2     kochi 
     45  1.2     kochi static __inline int
     46  1.6  christos __SIMPLELOCK_UNLOCKED_P(const __cpu_simple_lock_t *__ptr)
     47  1.2     kochi {
     48  1.2     kochi 	return *__ptr == __SIMPLELOCK_UNLOCKED;
     49  1.2     kochi }
     50  1.2     kochi 
     51  1.2     kochi static __inline void
     52  1.2     kochi __cpu_simple_lock_set(__cpu_simple_lock_t *__ptr)
     53  1.2     kochi {
     54  1.2     kochi 
     55  1.2     kochi 	*__ptr = __SIMPLELOCK_LOCKED;
     56  1.2     kochi }
     57  1.2     kochi 
     58  1.2     kochi static __inline void
     59  1.2     kochi __cpu_simple_lock_clear(__cpu_simple_lock_t *__ptr)
     60  1.2     kochi {
     61  1.2     kochi 
     62  1.2     kochi 	*__ptr = __SIMPLELOCK_UNLOCKED;
     63  1.2     kochi }
     64  1.2     kochi 
     65  1.2     kochi #ifdef _KERNEL
     66  1.2     kochi 
     67  1.2     kochi #define	SPINLOCK_SPIN_HOOK	/* nothing */
     68  1.2     kochi #define	SPINLOCK_BACKOFF_HOOK	/* XXX(kochi): hint@pause */
     69  1.2     kochi 
     70  1.2     kochi #endif
     71  1.2     kochi 
     72  1.2     kochi static __inline void __cpu_simple_lock_init(__cpu_simple_lock_t *)
     73  1.2     kochi 	__unused;
     74  1.2     kochi static __inline void __cpu_simple_lock(__cpu_simple_lock_t *)
     75  1.2     kochi 	__unused;
     76  1.2     kochi static __inline int __cpu_simple_lock_try(__cpu_simple_lock_t *)
     77  1.2     kochi 	__unused;
     78  1.2     kochi static __inline void __cpu_simple_unlock(__cpu_simple_lock_t *)
     79  1.2     kochi 	__unused;
     80  1.2     kochi 
     81  1.2     kochi static __inline void
     82  1.2     kochi __cpu_simple_lock_init(__cpu_simple_lock_t *lockp)
     83  1.2     kochi {
     84  1.2     kochi 
     85  1.2     kochi 	*lockp = __SIMPLELOCK_UNLOCKED;
     86  1.2     kochi 	__insn_barrier();
     87  1.2     kochi }
     88  1.2     kochi 
     89  1.2     kochi static __inline int
     90  1.2     kochi __cpu_simple_lock_try(__cpu_simple_lock_t *lockp)
     91  1.2     kochi {
     92  1.2     kochi 	uint8_t val;
     93  1.2     kochi 
     94  1.2     kochi 	val = __SIMPLELOCK_LOCKED;
     95  1.4  kiyohara 	__asm volatile ("xchg1 %0=[%1],%2" :
     96  1.2     kochi 	    "=r" (val)
     97  1.4  kiyohara 	    :"r" (lockp), "r" (val)
     98  1.4  kiyohara 	    :"memory");
     99  1.2     kochi 	return val == __SIMPLELOCK_UNLOCKED;
    100  1.2     kochi }
    101  1.2     kochi 
    102  1.2     kochi static __inline void
    103  1.2     kochi __cpu_simple_lock(__cpu_simple_lock_t *lockp)
    104  1.2     kochi {
    105  1.2     kochi 
    106  1.2     kochi 	while (!__cpu_simple_lock_try(lockp))
    107  1.2     kochi 		/* nothing */;
    108  1.2     kochi 	__insn_barrier();
    109  1.2     kochi }
    110  1.2     kochi 
    111  1.2     kochi static __inline void
    112  1.2     kochi __cpu_simple_unlock(__cpu_simple_lock_t *lockp)
    113  1.2     kochi {
    114  1.2     kochi 
    115  1.2     kochi 	__insn_barrier();
    116  1.2     kochi 	*lockp = __SIMPLELOCK_UNLOCKED;
    117  1.2     kochi }
    118  1.1    cherry 
    119  1.5     scole /* XXX mf.a overkill for these? */
    120  1.5     scole static __inline void
    121  1.5     scole mb_read(void)
    122  1.5     scole {
    123  1.5     scole 	__asm __volatile("mf.a	\n"
    124  1.5     scole 			 "mf	\n" ::: "memory");
    125  1.5     scole }
    126  1.5     scole 
    127  1.5     scole static __inline void
    128  1.5     scole mb_write(void)
    129  1.5     scole {
    130  1.5     scole 	__asm __volatile("mf.a	\n"
    131  1.5     scole 			 "mf	\n" ::: "memory");
    132  1.5     scole }
    133  1.5     scole 
    134  1.5     scole static __inline void
    135  1.5     scole mb_memory(void)
    136  1.5     scole {
    137  1.5     scole 	__asm __volatile("mf.a	\n"
    138  1.5     scole 			 "mf	\n" ::: "memory");
    139  1.5     scole }
    140  1.5     scole 
    141  1.1    cherry #endif /* _IA64_LOCK_H_ */
    142