Special locking primitives for use in Hydra kernels. These include a cache

invalidation after every lock to ensure that changes made by other CPUs are visible. This has nasty performance implications, but it does allow my Hydrated Risc PC to run printf() on all its CPUs at once without corrupting the message buffer.
2002-10-07 23:23:53 +00:00 · 2002-10-07 23:23:53 +00:00 · 8bd749851d
parent 5a9767e3de
commit 8bd749851d
1 changed files with 99 additions and 1 deletions
--- a/sys/arch/acorn32/include/lock.h
+++ b/sys/arch/acorn32/include/lock.h
@ -1,3 +1,101 @@
-/*	$NetBSD: lock.h,v 1.1 2001/10/05 22:27:51 reinoud Exp $	*/
+/*	$NetBSD: lock.h,v 1.2 2002/10/07 23:23:53 bjh21 Exp $	*/

+/*-
+ * Copyright (c) 2000, 2001 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Jason R. Thorpe.
+ *
+ * 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. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the NetBSD
+ *	Foundation, Inc. and its contributors.
+ * 4. Neither the name of The NetBSD Foundation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``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 FOUNDATION OR CONTRIBUTORS
+ * 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 _ACORN32_LOCK_H_
+#define _ACORN32_LOCK_H_
+
+#ifdef _KERNEL_OPT
+#include "opt_multiprocessor.h"
+#endif
+
+#if defined(_KERNEL) && defined(MULTIPROCESSOR)
+
+#include <arm/cpufunc.h>
+
+typedef	__volatile int __cpu_simple_lock_t;
+
+#define	__SIMPLELOCK_LOCKED	1
+#define	__SIMPLELOCK_UNLOCKED	0
+
+static __inline int
+__swp(int __val, __volatile int *__ptr)
+{
+
+	__asm __volatile("swp %0, %1, [%2]"
+	    : "=r" (__val) : "r" (__val), "r" (__ptr) : "memory");
+	return __val;
+}
+
+static __inline void __attribute__((__unused__))
+__cpu_simple_lock_init(__cpu_simple_lock_t *alp)
+{
+
+	*alp = __SIMPLELOCK_UNLOCKED;
+}
+
+static __inline void __attribute__((__unused__))
+__cpu_simple_lock(__cpu_simple_lock_t *alp)
+{
+
+	while (__swp(__SIMPLELOCK_LOCKED, alp) != __SIMPLELOCK_UNLOCKED)
+		continue;
+	cpu_idcache_wbinv_all();
+}
+
+static __inline int __attribute__((__unused__))
+__cpu_simple_lock_try(__cpu_simple_lock_t *alp)
+{
+	int __result;
+
+	__result = __swp(__SIMPLELOCK_LOCKED, alp) == __SIMPLELOCK_UNLOCKED;
+	if (__result)
+		cpu_idcache_wbinv_all();
+	return __result;
+}
+
+static __inline void __attribute__((__unused__))
+__cpu_simple_unlock(__cpu_simple_lock_t *alp)
+{
+
+	*alp = __SIMPLELOCK_UNLOCKED;
+}
+
+#else /* !(_KERNEL && MULTIPROCESSOR) */
 #include <arm/lock.h>
+#endif /* !(_KERNEL && MULTIPROCESSOR) */
+#endif