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Diffstat (limited to 'tboot/include/mutex.h')
-rw-r--r-- | tboot/include/mutex.h | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/tboot/include/mutex.h b/tboot/include/mutex.h new file mode 100644 index 0000000..d61bd99 --- /dev/null +++ b/tboot/include/mutex.h @@ -0,0 +1,58 @@ +/* $OpenBSD: mutex.h,v 1.6 2009/04/27 21:48:56 kettenis Exp $ */ +/* + * Copyright (c) 2004 Artur Grabowski <art@openbsd.org> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY + * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL + * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; + * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR + * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF + * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ +/* + * Portions copyright (c) 2010, Intel Corporation + */ + +#ifndef __MUTEX_H__ +#define __MUTEX_H__ + +/* + * A mutex is: + * - owned by a cpu. + * - non-recursive. + * - spinning. + * - not providing mutual exclusion between processes, only cpus. + * - providing interrupt blocking when necessary. + * + * Different mutexes can be nested, but not interleaved. This is ok: + * "mtx_enter(foo); mtx_enter(bar); mtx_leave(bar); mtx_leave(foo);" + * This is _not_ ok: + * "mtx_enter(foo); mtx_enter(bar); mtx_leave(foo); mtx_leave(bar);" + */ + +struct mutex { + __volatile__ uint64_t mtx_lock; +}; + +/* + * Some architectures need to do magic for the ipl, so they need a macro. + */ +void mtx_init(struct mutex *); +void mtx_enter(struct mutex *); +void mtx_leave(struct mutex *); + +#endif /* __MUTEX_H__ */ |