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lock.h revision 1.29 
      1 /*	$NetBSD: lock.h,v 1.29 2009/01/14 23:20:34 pooka Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2000 Ludd, University of Lule}, Sweden.
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *     This product includes software developed at Ludd, University of Lule}.
     18  * 4. The name of the author may not be used to endorse or promote products
     19  *    derived from this software without specific prior written permission
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 #ifndef _VAX_LOCK_H_
     34 #define _VAX_LOCK_H_
     35 
     36 #include <sys/param.h>
     37 
     38 #ifdef _KERNEL
     39 #ifdef _KERNEL_OPT
     40 #include "opt_multiprocessor.h"
     41 #include <machine/intr.h>
     42 #endif
     43 #include <machine/cpu.h>
     44 #endif
     45 
     46 static __inline int
     47 __SIMPLELOCK_LOCKED_P(__cpu_simple_lock_t *__ptr)
     48 {
     49 	return *__ptr == __SIMPLELOCK_LOCKED;
     50 }
     51 
     52 static __inline int
     53 __SIMPLELOCK_UNLOCKED_P(__cpu_simple_lock_t *__ptr)
     54 {
     55 	return *__ptr == __SIMPLELOCK_UNLOCKED;
     56 }
     57 
     58 static __inline void
     59 __cpu_simple_lock_clear(__cpu_simple_lock_t *__ptr)
     60 {
     61 	*__ptr = __SIMPLELOCK_UNLOCKED;
     62 }
     63 
     64 static __inline void
     65 __cpu_simple_lock_set(__cpu_simple_lock_t *__ptr)
     66 {
     67 	*__ptr = __SIMPLELOCK_LOCKED;
     68 }
     69 
     70 static __inline void __cpu_simple_lock_init(__cpu_simple_lock_t *);
     71 static __inline void
     72 __cpu_simple_lock_init(__cpu_simple_lock_t *__alp)
     73 {
     74 #ifdef _HARDKERNEL
     75 	__asm __volatile ("movl %0,%%r1;jsb Sunlock"
     76 		: /* No output */
     77 		: "g"(__alp)
     78 		: "r1","cc","memory");
     79 #else
     80 	__asm __volatile ("bbcci $0,%0,1f;1:"
     81 		: /* No output */
     82 		: "m"(*__alp)
     83 		: "cc");
     84 #endif
     85 }
     86 
     87 static __inline int __cpu_simple_lock_try(__cpu_simple_lock_t *);
     88 static __inline int
     89 __cpu_simple_lock_try(__cpu_simple_lock_t *__alp)
     90 {
     91 	int ret;
     92 
     93 #ifdef _HARDKERNEL
     94 	__asm __volatile ("movl %1,%%r1;jsb Slocktry;movl %%r0,%0"
     95 		: "=&r"(ret)
     96 		: "g"(__alp)
     97 		: "r0","r1","cc","memory");
     98 #else
     99 	__asm __volatile ("clrl %0;bbssi $0,%1,1f;incl %0;1:"
    100 		: "=&r"(ret)
    101 		: "m"(*__alp)
    102 		: "cc");
    103 #endif
    104 
    105 	return ret;
    106 }
    107 
    108 static __inline void __cpu_simple_lock(__cpu_simple_lock_t *);
    109 static __inline void
    110 __cpu_simple_lock(__cpu_simple_lock_t *__alp)
    111 {
    112 #if defined(_HARDKERNEL) && defined(MULTIPROCESSOR)
    113 	struct cpu_info * const __ci = curcpu();
    114 
    115 	while (__cpu_simple_lock_try(__alp) == 0) {
    116 #define	VAX_LOCK_CHECKS ((1 << IPI_SEND_CNCHAR) | (1 << IPI_DDB))
    117 		if (__ci->ci_ipimsgs & VAX_LOCK_CHECKS) {
    118 			cpu_handle_ipi();
    119 		}
    120 	}
    121 #else /* _HARDKERNEL && MULTIPROCESSOR */
    122 	__asm __volatile ("1:bbssi $0,%0,1b"
    123 		: /* No outputs */
    124 		: "m"(*__alp)
    125 		: "cc");
    126 #endif /* _HARDKERNEL && MULTIPROCESSOR */
    127 }
    128 
    129 static __inline void __cpu_simple_unlock(__cpu_simple_lock_t *);
    130 static __inline void
    131 __cpu_simple_unlock(__cpu_simple_lock_t *__alp)
    132 {
    133 #ifdef _HARDKERNEL
    134 	__asm __volatile ("movl %0,%%r1;jsb Sunlock"
    135 		: /* No output */
    136 		: "g"(__alp)
    137 		: "r1","cc","memory");
    138 #else
    139 	__asm __volatile ("bbcci $0,%0,1f;1:"
    140 		: /* No output */
    141 		: "m"(*__alp)
    142 		: "cc");
    143 #endif
    144 }
    145 
    146 #if defined(MULTIPROCESSOR)
    147 /*
    148  * On the Vax, interprocessor interrupts can come in at device priority
    149  * level or lower. This can cause some problems while waiting for r/w
    150  * spinlocks from a high'ish priority level: IPIs that come in will not
    151  * be processed. This can lead to deadlock.
    152  *
    153  * This hook allows IPIs to be processed while a spinlock's interlock
    154  * is released.
    155  */
    156 #define SPINLOCK_SPIN_HOOK						\
    157 do {									\
    158 	struct cpu_info * const __ci = curcpu();			\
    159 									\
    160 	if (__ci->ci_ipimsgs != 0) {					\
    161 		/* printf("CPU %lu has IPIs pending\n",			\
    162 		    __ci->ci_cpuid); */					\
    163 		cpu_handle_ipi();					\
    164 	}								\
    165 } while (/*CONSTCOND*/0)
    166 #endif /* MULTIPROCESSOR */
    167 
    168 static __inline void mb_read(void);
    169 static __inline void
    170 mb_read(void)
    171 {
    172 }
    173 
    174 static __inline void mb_write(void);
    175 static __inline void
    176 mb_write(void)
    177 {
    178 }
    179 #endif /* _VAX_LOCK_H_ */
    180