BSD 4_4_Lite2 release

[unix-history] / usr / src / sys / news3400 / include / param.h

diff --git a/usr/src/sys/news3400/include/param.h b/usr/src/sys/news3400/include/param.h
index cf08d90..75dee5c 100644 (file)
--- a/usr/src/sys/news3400/include/param.h
+++ b/usr/src/sys/news3400/include/param.h
@@ -37,13 +37,14 @@
  *
  * from: Utah $Hdr: machparam.h 1.11 89/08/14$
  *
  *
  * from: Utah $Hdr: machparam.h 1.11 89/08/14$
  *

- *     @(#)param.h     8.1 (Berkeley) 6/11/93
+ *     @(#)param.h     8.3 (Berkeley) 5/14/95

  */
 
 /*
  * Machine dependent constants for DEC Station 3100.
  */
 #define        MACHINE "news3400"
  */
 
 /*
  * Machine dependent constants for DEC Station 3100.
  */
 #define        MACHINE "news3400"

+#define NCPUS 1

 #define COFF
 
 /*
 #define COFF
 
 /*


@@ -121,9 +122,9 @@
 #define        btoc(x) (((unsigned)(x)+(NBPG-1))>>PGSHIFT)
 
 #define        btodb(bytes)                    /* calculates (bytes / DEV_BSIZE) */ \
 #define        btoc(x) (((unsigned)(x)+(NBPG-1))>>PGSHIFT)
 
 #define        btodb(bytes)                    /* calculates (bytes / DEV_BSIZE) */ \

-       ((unsigned)(bytes) >> DEV_BSHIFT)
+       ((bytes) >> DEV_BSHIFT)

 #define        dbtob(db)                       /* calculates (db * DEV_BSIZE) */ \
 #define        dbtob(db)                       /* calculates (db * DEV_BSIZE) */ \

-       ((unsigned)(db) << DEV_BSHIFT)
+       ((db) << DEV_BSHIFT)

 
 /*
  * Map a ``block device block'' to a file system block.
 
 /*
  * Map a ``block device block'' to a file system block.


@@ -212,3 +213,62 @@ extern char        *intrnames[];
 #define INTR_RENDER    44
 
 #define        NINTRSLOT       45              /* # of intrcnt[] slot */
 #define INTR_RENDER    44
 
 #define        NINTRSLOT       45              /* # of intrcnt[] slot */

+
+#ifndef _SIMPLELOCK_H_
+#define _SIMPLELOCK_H_
+/*
+ * A simple spin lock.
+ *
+ * This structure only sets one bit of data, but is sized based on the
+ * minimum word size that can be operated on by the hardware test-and-set
+ * instruction. It is only needed for multiprocessors, as uniprocessors
+ * will always run to completion or a sleep. It is an error to hold one
+ * of these locks while a process is sleeping.
+ */
+struct simplelock {
+       int     lock_data;
+};
+
+#if !defined(DEBUG) && NCPUS > 1
+/*
+ * The simple-lock routines are the primitives out of which the lock
+ * package is built. The machine-dependent code must implement an
+ * atomic test_and_set operation that indivisibly sets the simple lock
+ * to non-zero and returns its old value. It also assumes that the
+ * setting of the lock to zero below is indivisible. Simple locks may
+ * only be used for exclusive locks.
+ */
+static __inline void
+simple_lock_init(lkp)
+       struct simplelock *lkp;
+{
+
+       lkp->lock_data = 0;
+}
+
+static __inline void
+simple_lock(lkp)
+       __volatile struct simplelock *lkp;
+{
+
+       while (test_and_set(&lkp->lock_data))
+               continue;
+}
+
+static __inline int
+simple_lock_try(lkp)
+       __volatile struct simplelock *lkp;
+{
+
+       return (!test_and_set(&lkp->lock_data))
+}
+
+static __inline void
+simple_unlock(lkp)
+       __volatile struct simplelock *lkp;
+{
+
+       lkp->lock_data = 0;
+}
+#endif /* NCPUS > 1 */
+#endif /* !_SIMPLELOCK_H_ */