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lock.h revision 1.17
      1 /*	$NetBSD: lock.h,v 1.17 2005/07/20 17:48:17 he 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 #ifdef _KERNEL_OPT
     38 #include "opt_multiprocessor.h"
     39 #include <machine/intr.h>
     40 #endif
     41 #include <machine/cpu.h>
     42 #endif
     43 
     44 static __inline void
     45 __cpu_simple_lock_init(__cpu_simple_lock_t *alp)
     46 {
     47 #ifdef _KERNEL
     48 	__asm__ __volatile ("movl %0,%%r1;jsb Sunlock"
     49 		: /* No output */
     50 		: "g"(alp)
     51 		: "r1","cc","memory");
     52 #else
     53 	__asm__ __volatile ("bbcci $0,%0,1f;1:"
     54 		: /* No output */
     55 		: "m"(*alp)
     56 		: "cc");
     57 #endif
     58 }
     59 
     60 static __inline int
     61 __cpu_simple_lock_try(__cpu_simple_lock_t *alp)
     62 {
     63 	int ret;
     64 
     65 #ifdef _KERNEL
     66 	__asm__ __volatile ("movl %1,%%r1;jsb Slocktry;movl %%r0,%0"
     67 		: "=&r"(ret)
     68 		: "g"(alp)
     69 		: "r0","r1","cc","memory");
     70 #else
     71 	__asm__ __volatile ("clrl %0;bbssi $0,%1,1f;incl %0;1:"
     72 		: "=&r"(ret)
     73 		: "m"(*alp)
     74 		: "cc");
     75 #endif
     76 
     77 	return ret;
     78 }
     79 
     80 #ifdef _KERNEL
     81 #define	VAX_LOCK_CHECKS ((1 << IPI_SEND_CNCHAR) | (1 << IPI_DDB))
     82 #define	__cpu_simple_lock(alp)						\
     83 do {									\
     84 	struct cpu_info *__ci = curcpu();				\
     85 									\
     86 	while (__cpu_simple_lock_try(alp) == 0) {			\
     87 		int ___s;						\
     88 									\
     89 		if (__ci->ci_ipimsgs & VAX_LOCK_CHECKS) {		\
     90 			___s = splipi();				\
     91 			cpu_handle_ipi();				\
     92 			splx(___s);					\
     93 		}							\
     94 	}								\
     95 } while (0)
     96 #else
     97 static __inline void
     98 __cpu_simple_lock(__cpu_simple_lock_t *alp)
     99 {
    100 	__asm__ __volatile ("1:bbssi $0,%0,1b"
    101 		: /* No outputs */
    102 		: "m"(*alp)
    103 		: "cc");
    104 }
    105 #endif /* _KERNEL */
    106 
    107 #if 0
    108 static __inline void
    109 __cpu_simple_lock(__cpu_simple_lock_t *alp)
    110 {
    111 	struct cpu_info *ci = curcpu();
    112 
    113 	while (__cpu_simple_lock_try(alp) == 0) {
    114 		int s;
    115 
    116 		if (ci->ci_ipimsgs & IPI_SEND_CNCHAR) {
    117 			s = splipi();
    118 			cpu_handle_ipi();
    119 			splx(s);
    120 		}
    121 	}
    122 
    123 #if 0
    124 	__asm__ __volatile ("movl %0,%%r1;jsb Slock"
    125 		: /* No output */
    126 		: "g"(alp)
    127 		: "r0","r1","cc","memory");
    128 #endif
    129 #if 0
    130 	__asm__ __volatile ("1:;bbssi $0, %0, 1b"
    131 		: /* No output */
    132 		: "m"(*alp));
    133 #endif
    134 }
    135 #endif
    136 
    137 static __inline void
    138 __cpu_simple_unlock(__cpu_simple_lock_t *alp)
    139 {
    140 #ifdef _KERNEL
    141 	__asm__ __volatile ("movl %0,%%r1;jsb Sunlock"
    142 		: /* No output */
    143 		: "g"(alp)
    144 		: "r1","cc","memory");
    145 #else
    146 	__asm__ __volatile ("bbcci $0,%0,1f;1:"
    147 		: /* No output */
    148 		: "m"(*alp)
    149 		: "cc");
    150 #endif
    151 }
    152 
    153 #if defined(MULTIPROCESSOR)
    154 /*
    155  * On the Vax, interprocessor interrupts can come in at device priority
    156  * level or lower. This can cause some problems while waiting for r/w
    157  * spinlocks from a high'ish priority level: IPIs that come in will not
    158  * be processed. This can lead to deadlock.
    159  *
    160  * This hook allows IPIs to be processed while a spinlock's interlock
    161  * is released.
    162  */
    163 #define SPINLOCK_SPIN_HOOK						\
    164 do {									\
    165 	struct cpu_info *__ci = curcpu();				\
    166 	int ___s;							\
    167 									\
    168 	if (__ci->ci_ipimsgs != 0) {					\
    169 		/* printf("CPU %lu has IPIs pending\n",			\
    170 		    __ci->ci_cpuid); */					\
    171 		___s = splipi();					\
    172 		cpu_handle_ipi();					\
    173 		splx(___s);						\
    174 	}								\
    175 } while (0)
    176 #endif /* MULTIPROCESSOR */
    177 #endif /* _VAX_LOCK_H_ */
    178