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lock.h revision 1.11 
      1 /*	$NetBSD: lock.h,v 1.11 2003/02/25 23:29:53 matt 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 #ifdef _KERNEL
     37 #include <machine/cpu.h>
     38 #endif
     39 
     40 typedef __volatile int		__cpu_simple_lock_t;
     41 
     42 #define __SIMPLELOCK_LOCKED	1
     43 #define __SIMPLELOCK_UNLOCKED	0
     44 
     45 static __inline void
     46 __cpu_simple_lock_init(__cpu_simple_lock_t *alp)
     47 {
     48 #ifdef _KERNEL
     49 	__asm__ __volatile ("movl %0,%%r1;jsb Sunlock"
     50 		: /* No output */
     51 		: "g"(alp)
     52 		: "r1","cc","memory");
     53 #else
     54 	__asm__ __volatile ("bbcci $0,%0,1f;1:"
     55 		: /* No output */
     56 		: "m"(*alp)
     57 		: "cc");
     58 #endif
     59 }
     60 
     61 static __inline int
     62 __cpu_simple_lock_try(__cpu_simple_lock_t *alp)
     63 {
     64 	int ret;
     65 
     66 #ifdef _KERNEL
     67 	__asm__ __volatile ("movl %1,%%r1;jsb Slocktry;movl %%r0,%0"
     68 		: "=&r"(ret)
     69 		: "g"(alp)
     70 		: "r0","r1","cc","memory");
     71 #else
     72 	__asm__ __volatile ("clrl %0;bbssi $0,%1,1f;incl %0;1:"
     73 		: "=&r"(ret)
     74 		: "m"(*alp)
     75 		: "cc");
     76 #endif
     77 
     78 	return ret;
     79 }
     80 
     81 #ifdef _KERNEL
     82 #define	VAX_LOCK_CHECKS ((1 << IPI_SEND_CNCHAR) | (1 << IPI_DDB))
     83 #define	__cpu_simple_lock(alp)						\
     84 do {									\
     85 	struct cpu_info *__ci = curcpu();				\
     86 									\
     87 	while (__cpu_simple_lock_try(alp) == 0) {			\
     88 		int __s;						\
     89 									\
     90 		if (__ci->ci_ipimsgs & VAX_LOCK_CHECKS) {		\
     91 			__s = splipi();					\
     92 			cpu_handle_ipi();				\
     93 			splx(__s);					\
     94 		}							\
     95 	}								\
     96 } while (0)
     97 #else
     98 static __inline void
     99 __cpu_simple_lock(__cpu_simple_lock_t *alp)
    100 {
    101 	__asm__ __volatile ("1:bbssi $0,%0,1b"
    102 		: /* No outputs */
    103 		: "m"(*alp)
    104 		: "cc");
    105 }
    106 #endif /* _KERNEL */
    107 
    108 #if 0
    109 static __inline void
    110 __cpu_simple_lock(__cpu_simple_lock_t *alp)
    111 {
    112 	struct cpu_info *ci = curcpu();
    113 
    114 	while (__cpu_simple_lock_try(alp) == 0) {
    115 		int s;
    116 
    117 		if (ci->ci_ipimsgs & IPI_SEND_CNCHAR) {
    118 			s = splipi();
    119 			cpu_handle_ipi();
    120 			splx(s);
    121 		}
    122 	}
    123 
    124 #if 0
    125 	__asm__ __volatile ("movl %0,%%r1;jsb Slock"
    126 		: /* No output */
    127 		: "g"(alp)
    128 		: "r0","r1","cc","memory");
    129 #endif
    130 #if 0
    131 	__asm__ __volatile ("1:;bbssi $0, %0, 1b"
    132 		: /* No output */
    133 		: "m"(*alp));
    134 #endif
    135 }
    136 #endif
    137 
    138 static __inline void
    139 __cpu_simple_unlock(__cpu_simple_lock_t *alp)
    140 {
    141 #ifdef _KERNEL
    142 	__asm__ __volatile ("movl %0,%%r1;jsb Sunlock"
    143 		: /* No output */
    144 		: "g"(alp)
    145 		: "r1","cc","memory");
    146 #else
    147 	__asm__ __volatile ("bbcci $0,%0,1f;1:"
    148 		: /* No output */
    149 		: "m"(*alp)
    150 		: "cc");
    151 #endif
    152 }
    153 
    154 #if defined(MULTIPROCESSOR)
    155 /*
    156  * On the Vax, interprocessor interrupts can come in at device priority
    157  * level or lower. This can cause some problems while waiting for r/w
    158  * spinlocks from a high'ish priority level: IPIs that come in will not
    159  * be processed. This can lead to deadlock.
    160  *
    161  * This hook allows IPIs to be processed while a spinlock's interlock
    162  * is released.
    163  */
    164 #define SPINLOCK_SPIN_HOOK						\
    165 do {									\
    166 	struct cpu_info *__ci = curcpu();				\
    167 	int __s;							\
    168 									\
    169 	if (__ci->ci_ipimsgs != 0) {					\
    170 		/* printf("CPU %lu has IPIs pending\n",			\
    171 		    __ci->ci_cpuid); */					\
    172 		__s = splipi();						\
    173 		cpu_handle_ipi();					\
    174 		splx(__s);						\
    175 	}								\
    176 } while (0)
    177 #endif /* MULTIPROCESSOR */
    178 #endif /* _VAX_LOCK_H_ */
    179