Initial Spring 2016 commit.

2015-12-23 00:50:04 +00:00
commit cafa9f5690
732 changed files with 92195 additions and 0 deletions
--- a/kern/include/spl.h
+++ b/kern/include/spl.h
@@ -0,0 +1,109 @@
+/*
+ * Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
+ *	The President and Fellows of Harvard College.
+ *
+ * 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. Neither the name of the University 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 UNIVERSITY 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 UNIVERSITY 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 _SPL_H_
+#define _SPL_H_
+
+#include <cdefs.h>
+
+/* Inlining support - for making sure an out-of-line copy gets built */
+#ifndef SPL_INLINE
+#define SPL_INLINE INLINE
+#endif
+
+/*
+ * Machine-independent interface to interrupt enable/disable.
+ *
+ * "spl" stands for "set priority level", and was originally the name of
+ * a VAX assembler instruction.
+ *
+ * The idea is that one can block less important interrupts while
+ * processing them, but still allow more urgent interrupts to interrupt
+ * that processing.
+ *
+ * Ordinarily there would be a whole bunch of defined interrupt
+ * priority levels and functions for setting them - spltty(),
+ * splbio(), etc., etc. But we don't support interrupt priorities in
+ * OS/161, so there are only three:
+ *
+ *      spl0()       sets IPL to 0, enabling all interrupts.
+ *      splhigh()    sets IPL to the highest value, disabling all interrupts.
+ *      splx(s)      sets IPL to S, enabling whatever state S represents.
+ *
+ * All three return the old interrupt state. Thus, these are commonly used
+ * as follows:
+ *
+ *      int s = splhigh();
+ *      [ code ]
+ *      splx(s);
+ *
+ * Note that these functions only affect interrupts on the current
+ * processor.
+ */
+
+SPL_INLINE int spl0(void);
+SPL_INLINE int splhigh(void);
+int splx(int);
+
+/*
+ * Integer interrupt priority levels.
+ */
+#define IPL_NONE   0
+#define IPL_HIGH   1
+
+/*
+ * Lower-level functions for explicitly raising and lowering
+ * particular interrupt levels. These are used by splx() and by the
+ * spinlock code.
+ *
+ * A previous setting of OLDIPL is cancelled and replaced with NEWIPL.
+ *
+ * For splraise, NEWIPL > OLDIPL, and for spllower, NEWIPL < OLDIPL.
+ */
+void splraise(int oldipl, int newipl);
+void spllower(int oldipl, int newipl);
+
+////////////////////////////////////////////////////////////
+
+SPL_INLINE
+int
+spl0(void)
+{
+	return splx(IPL_NONE);
+}
+
+SPL_INLINE
+int
+splhigh(void)
+{
+	return splx(IPL_HIGH);
+}
+
+
+#endif /* _SPL_H_ */