Home | History | Annotate | Line # | Download | only in include
lock.h revision 1.9 
      1 /*	$NetBSD: lock.h,v 1.9 2002/09/12 07:31:13 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 typedef __volatile int		__cpu_simple_lock_t;
     37 
     38 #define __SIMPLELOCK_LOCKED	1
     39 #define __SIMPLELOCK_UNLOCKED	0
     40 
     41 static __inline void
     42 __cpu_simple_lock_init(__cpu_simple_lock_t *alp)
     43 {
     44 #ifdef _KERNEL
     45 	__asm__ __volatile ("movl %0,r1;jsb Sunlock"
     46 		: /* No output */
     47 		: "g"(alp)
     48 		: "r1","cc","memory");
     49 #else
     50 	__asm__ __volatile ("bbcci $0,%0,1f;1:"
     51 		: /* No output */
     52 		: "m"(*alp)
     53 		: "cc");
     54 #endif
     55 }
     56 
     57 static __inline int
     58 __cpu_simple_lock_try(__cpu_simple_lock_t *alp)
     59 {
     60 	int ret;
     61 
     62 #ifdef _KERNEL
     63 	__asm__ __volatile ("movl %1,r1;jsb Slocktry;movl r0,%0"
     64 		: "=&r"(ret)
     65 		: "g"(alp)
     66 		: "r0","r1","cc","memory");
     67 #else
     68 	__asm__ __volatile ("clrl %0;bbssi $0,%1,1f;incl %0;1:"
     69 		: "=&r"(ret)
     70 		: "m"(*alp)
     71 		: "cc");
     72 #endif
     73 
     74 	return ret;
     75 }
     76 
     77 #ifdef _KERNEL
     78 #define	VAX_LOCK_CHECKS ((1 << IPI_SEND_CNCHAR) | (1 << IPI_DDB))
     79 #define	__cpu_simple_lock(alp)						\
     80 do {									\
     81 	struct cpu_info *__ci = curcpu();				\
     82 									\
     83 	while (__cpu_simple_lock_try(alp) == 0) {			\
     84 		int __s;						\
     85 									\
     86 		if (__ci->ci_ipimsgs & VAX_LOCK_CHECKS) {		\
     87 			__s = splipi();					\
     88 			cpu_handle_ipi();				\
     89 			splx(__s);					\
     90 		}							\
     91 	}								\
     92 } while (0)
     93 #else
     94 static __inline void
     95 __cpu_simple_lock(__cpu_simple_lock_t *alp)
     96 {
     97 	__asm__ __volatile ("1:bbssi $0,%0,1b"
     98 		: /* No outputs */
     99 		: "m"(*alp)
    100 		: "cc");
    101 }
    102 #endif /* _KERNEL */
    103 
    104 #if 0
    105 static __inline void
    106 __cpu_simple_lock(__cpu_simple_lock_t *alp)
    107 {
    108 	struct cpu_info *ci = curcpu();
    109 
    110 	while (__cpu_simple_lock_try(alp) == 0) {
    111 		int s;
    112 
    113 		if (ci->ci_ipimsgs & IPI_SEND_CNCHAR) {
    114 			s = splipi();
    115 			cpu_handle_ipi();
    116 			splx(s);
    117 		}
    118 	}
    119 
    120 #if 0
    121 	__asm__ __volatile ("movl %0,r1;jsb Slock"
    122 		: /* No output */
    123 		: "g"(alp)
    124 		: "r0","r1","cc","memory");
    125 #endif
    126 #if 0
    127 	__asm__ __volatile ("1:;bbssi $0, %0, 1b"
    128 		: /* No output */
    129 		: "m"(*alp));
    130 #endif
    131 }
    132 #endif
    133 
    134 static __inline void
    135 __cpu_simple_unlock(__cpu_simple_lock_t *alp)
    136 {
    137 #ifdef _KERNEL
    138 	__asm__ __volatile ("movl %0,r1;jsb Sunlock"
    139 		: /* No output */
    140 		: "g"(alp)
    141 		: "r1","cc","memory");
    142 #else
    143 	__asm__ __volatile ("bbcci $0,%0,1f;1:"
    144 		: /* No output */
    145 		: "m"(*alp)
    146 		: "cc");
    147 #endif
    148 }
    149 
    150 #if defined(MULTIPROCESSOR)
    151 /*
    152  * On the Vax, interprocessor interrupts can come in at device priority
    153  * level or lower. This can cause some problems while waiting for r/w
    154  * spinlocks from a high'ish priority level: IPIs that come in will not
    155  * be processed. This can lead to deadlock.
    156  *
    157  * This hook allows IPIs to be processed while a spinlock's interlock
    158  * is released.
    159  */
    160 #define SPINLOCK_SPIN_HOOK						\
    161 do {									\
    162 	struct cpu_info *__ci = curcpu();				\
    163 	int __s;							\
    164 									\
    165 	if (__ci->ci_ipimsgs != 0) {					\
    166 		/* printf("CPU %lu has IPIs pending\n",			\
    167 		    __ci->ci_cpuid); */					\
    168 		__s = splipi();						\
    169 		cpu_handle_ipi();					\
    170 		splx(__s);						\
    171 	}								\
    172 } while (0)
    173 #endif /* MULTIPROCESSOR */
    174 #endif /* _VAX_LOCK_H_ */
    175