Return to lock.h CVS log

Up to [local] / sys / arch / powerpc / include

Annotation of sys/arch/powerpc/include/lock.h, Revision 1.1.1.1

1.1       nbrk        1: /*     $OpenBSD: lock.h,v 1.1 2007/03/20 20:59:53 kettenis Exp $       */
                      2: /*     $NetBSD: lock.h,v 1.8 2005/12/28 19:09:29 perry Exp $   */
                      3:
                      4: /*-
                      5:  * Copyright (c) 2000 The NetBSD Foundation, Inc.
                      6:  * All rights reserved.
                      7:  *
                      8:  * This code is derived from software contributed to The NetBSD Foundation
                      9:  * by Jason R. Thorpe.
                     10:  *
                     11:  * Redistribution and use in source and binary forms, with or without
                     12:  * modification, are permitted provided that the following conditions
                     13:  * are met:
                     14:  * 1. Redistributions of source code must retain the above copyright
                     15:  *    notice, this list of conditions and the following disclaimer.
                     16:  * 2. Redistributions in binary form must reproduce the above copyright
                     17:  *    notice, this list of conditions and the following disclaimer in the
                     18:  *    documentation and/or other materials provided with the distribution.
                     19:  * 3. All advertising materials mentioning features or use of this software
                     20:  *    must display the following acknowledgement:
                     21:  *     This product includes software developed by the NetBSD
                     22:  *     Foundation, Inc. and its contributors.
                     23:  * 4. Neither the name of The NetBSD Foundation nor the names of its
                     24:  *    contributors may be used to endorse or promote products derived
                     25:  *    from this software without specific prior written permission.
                     26:  *
                     27:  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
                     28:  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
                     29:  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
                     30:  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
                     31:  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
                     32:  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
                     33:  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
                     34:  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
                     35:  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
                     36:  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
                     37:  * POSSIBILITY OF SUCH DAMAGE.
                     38:  */
                     39:
                     40: /*
                     41:  * Machine-dependent spin lock operations.
                     42:  */
                     43:
                     44: #ifndef _POWERPC_LOCK_H_
                     45: #define _POWERPC_LOCK_H_
                     46:
                     47: typedef __volatile int          __cpu_simple_lock_t;
                     48:
                     49: #define __SIMPLELOCK_LOCKED     1
                     50: #define __SIMPLELOCK_UNLOCKED   0
                     51:
                     52: static __inline void
                     53: __cpu_simple_lock_init(__cpu_simple_lock_t *alp)
                     54: {
                     55:        *alp = __SIMPLELOCK_UNLOCKED;
                     56:        __asm volatile ("sync");
                     57: }
                     58:
                     59: static __inline void
                     60: __cpu_simple_lock(__cpu_simple_lock_t *alp)
                     61: {
                     62:        int old;
                     63:
                     64:        __asm volatile ("       \
                     65:                                \n\
                     66: 1:     lwarx   %0,0,%1         \n\
                     67:        cmpwi   %0,%2           \n\
                     68:        beq+    3f              \n\
                     69: 2:     lwzx    %0,0,%1         \n\
                     70:        cmpwi   %0,%2           \n\
                     71:        beq+    1b              \n\
                     72:        b       2b              \n\
                     73: 3:     stwcx.  %3,0,%1         \n\
                     74:        bne-    1b              \n\
                     75:        isync                   \n\
                     76:                                \n"
                     77:        : "=&r"(old)
                     78:        : "r"(alp), "I"(__SIMPLELOCK_UNLOCKED), "r"(__SIMPLELOCK_LOCKED)
                     79:        : "memory");
                     80: }
                     81:
                     82: static __inline int
                     83: __cpu_simple_lock_try(__cpu_simple_lock_t *alp)
                     84: {
                     85:        int old, dummy;
                     86:
                     87:        __asm volatile ("       \
                     88:                                \n\
                     89: 1:     lwarx   %0,0,%1         \n\
                     90:        cmpwi   %0,%2           \n\
                     91:        bne     2f              \n\
                     92:        stwcx.  %3,0,%1         \n\
                     93:        bne-    1b              \n\
                     94: 2:     stwcx.  %3,0,%4         \n\
                     95:        isync                   \n\
                     96:                                \n"
                     97:        : "=&r"(old)
                     98:        : "r"(alp), "I"(__SIMPLELOCK_UNLOCKED), "r"(__SIMPLELOCK_LOCKED),
                     99:          "r"(&dummy)
                    100:        : "memory");
                    101:
                    102:        return (old == __SIMPLELOCK_UNLOCKED);
                    103: }
                    104:
                    105: static __inline void
                    106: __cpu_simple_unlock(__cpu_simple_lock_t *alp)
                    107: {
                    108:        __asm volatile ("sync");
                    109:        *alp = __SIMPLELOCK_UNLOCKED;
                    110: }
                    111:
                    112: #endif /* _POWERPC_LOCK_H_ */