simple single-processor only mutex implementation

ok miod@

4 files changed, 129 insertions, 2 deletions

diff --git a/sys/arch/alpha/alpha/mutex.c b/sys/arch/alpha/alpha/mutex.c
new file mode 100644
index 00000000000..6aa273d4838
--- /dev/null
+++ b/sys/arch/alpha/alpha/mutex.c
@@ -0,0 +1,66 @@
+/*	$OpenBSD: mutex.c,v 1.1 2007/05/05 21:05:43 martin 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. 
+ */
+
+#include <sys/param.h>
+#include <sys/mutex.h>
+#include <sys/systm.h>
+
+#include <machine/intr.h>
+
+#ifdef MULTIPROCESSOR
+#error This code needs more work
+#endif
+
+/*
+ * Single processor systems don't need any mutexes, but they need the spl
+ * raising semantics of the mutexes.
+ */
+void
+mtx_init(struct mutex *mtx, int wantipl)
+{
+	mtx->mtx_oldipl = 0;
+	mtx->mtx_wantipl = wantipl;
+	mtx->mtx_lock = 0;
+}
+
+void
+mtx_enter(struct mutex *mtx)
+{
+	if (mtx->mtx_wantipl != IPL_NONE)
+		mtx->mtx_oldipl = _splraise(mtx->mtx_wantipl);
+	MUTEX_ASSERT_UNLOCKED(mtx);
+	mtx->mtx_lock = 1;
+}
+
+void
+mtx_leave(struct mutex *mtx)
+{
+	MUTEX_ASSERT_LOCKED(mtx);
+	mtx->mtx_lock = 0;
+	if (mtx->mtx_wantipl != IPL_NONE)
+		splx(mtx->mtx_oldipl);
+}
diff --git a/sys/arch/alpha/conf/files.alpha b/sys/arch/alpha/conf/files.alpha
index a56f1413fcd..8d381894645 100644
--- a/sys/arch/alpha/conf/files.alpha
+++ b/sys/arch/alpha/conf/files.alpha
@@ -1,4 +1,4 @@
-#	$OpenBSD: files.alpha,v 1.79 2007/04/13 08:31:50 martin Exp $
+#	$OpenBSD: files.alpha,v 1.80 2007/05/05 21:05:43 martin Exp $
 #	$NetBSD: files.alpha,v 1.32 1996/11/25 04:03:21 cgd Exp $
 #
 # alpha-specific configuration info
@@ -305,6 +305,7 @@ file	arch/alpha/alpha/fp_complete.c		!no_ieee
 file	arch/alpha/alpha/vm_machdep.c
 file	arch/alpha/alpha/disksubr.c
 file	arch/alpha/dev/bus_dma.c
+file	arch/alpha/alpha/mutex.c
 
 #
 # Network protocol checksum routines
diff --git a/sys/arch/alpha/include/_types.h b/sys/arch/alpha/include/_types.h
index 480e591a94a..8c9072e020a 100644
--- a/sys/arch/alpha/include/_types.h
+++ b/sys/arch/alpha/include/_types.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: _types.h,v 1.4 2007/04/23 10:07:43 art Exp $	*/
+/*	$OpenBSD: _types.h,v 1.5 2007/05/05 21:05:43 martin Exp $	*/
 
 /*-
  * Copyright (c) 1990, 1993
@@ -123,5 +123,6 @@ typedef	void *			__wctype_t;
 #define __HAVE_CPUINFO
 #define __HAVE_GENERIC_SOFT_INTERRUPTS
 #define __HAVE_TIMECOUNTER
+#define __HAVE_MUTEX */
 
 #endif	/* _ALPHA__TYPES_H_ */
diff --git a/sys/arch/alpha/include/mutex.h b/sys/arch/alpha/include/mutex.h
new file mode 100644
index 00000000000..5740ee0fab8
--- /dev/null
+++ b/sys/arch/alpha/include/mutex.h
@@ -0,0 +1,59 @@
+/*	$OpenBSD: mutex.h,v 1.1 2007/05/05 21:05:43 martin 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. 
+ */
+
+#ifndef _ALPHA_MUTEX_H_
+#define _ALPHA_MUTEX_H_
+
+/*
+ * Simple non-mp implementation.
+ */
+struct mutex {
+	int mtx_lock;
+	int mtx_wantipl;
+	int mtx_oldipl;
+};
+
+void mtx_init(struct mutex *, int);
+
+#define MUTEX_INITIALIZER(ipl) { 0, (ipl), 0 }
+
+#ifdef DIAGNOSTIC
+#define MUTEX_ASSERT_LOCKED(mtx) do {					\
+	if ((mtx)->mtx_lock == 0)					\
+		panic("mutex %p not held in %s", (mtx), __func__);	\
+} while (0)
+
+#define MUTEX_ASSERT_UNLOCKED(mtx) do {					\
+	if ((mtx)->mtx_lock != 0)					\
+		panic("mutex %p held in %s", (mtx), __func__);		\
+} while (0)
+#else
+#define MUTEX_ASSERT_LOCKED(mtx) do { } while (0)
+#define MUTEX_ASSERT_UNLOCKED(mtx) do { } while (0)
+#endif
+
+#endif	/* _ALPHA_MUTEX_H_ */