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Annotation of sys/arch/sgi/sgi/mutex.c, Revision 1.1.1.1

1.1       nbrk        1: /*     $OpenBSD: mutex.c,v 1.2 2007/05/14 17:32:17 miod Exp $  */
                      2:
                      3: /*
                      4:  * Copyright (c) 2004 Artur Grabowski <art@openbsd.org>
                      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:  *
                     11:  * 1. Redistributions of source code must retain the above copyright
                     12:  *    notice, this list of conditions and the following disclaimer.
                     13:  * 2. The name of the author may not be used to endorse or promote products
                     14:  *    derived from this software without specific prior written permission.
                     15:  *
                     16:  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
                     17:  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
                     18:  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
                     19:  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
                     20:  * EXEMPLARY, OR CONSEQUENTIAL  DAMAGES (INCLUDING, BUT NOT LIMITED TO,
                     21:  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
                     22:  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
                     23:  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
                     24:  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
                     25:  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
                     26:  */
                     27:
                     28: #include <sys/param.h>
                     29: #include <sys/mutex.h>
                     30: #include <sys/systm.h>
                     31:
                     32: #include <machine/intr.h>
                     33:
                     34: #ifdef MULTIPROCESSOR
                     35: #error This code needs more work
                     36: #endif
                     37:
                     38: /*
                     39:  * Single processor systems don't need any mutexes, but they need the spl
                     40:  * raising semantics of the mutexes.
                     41:  */
                     42: void
                     43: mtx_init(struct mutex *mtx, int wantipl)
                     44: {
                     45:        mtx->mtx_lock = 0;
                     46:        /* We can't access imask[] here, since MUTEX_INITIALIZER can't. */
                     47:        mtx->mtx_wantipl = wantipl;
                     48:        mtx->mtx_oldcpl = IPL_NONE;
                     49: }
                     50:
                     51: void
                     52: mtx_enter(struct mutex *mtx)
                     53: {
                     54:        if (mtx->mtx_wantipl != IPL_NONE)
                     55:                mtx->mtx_oldcpl = splraise(imask[mtx->mtx_wantipl]);
                     56:
                     57:        MUTEX_ASSERT_UNLOCKED(mtx);
                     58:        mtx->mtx_lock = 1;
                     59: }
                     60:
                     61: void
                     62: mtx_leave(struct mutex *mtx)
                     63: {
                     64:        MUTEX_ASSERT_LOCKED(mtx);
                     65:        mtx->mtx_lock = 0;
                     66:        if (mtx->mtx_wantipl != IPL_NONE)
                     67:                splx(mtx->mtx_oldcpl);
                     68: }