Update of /cvsroot/linux-vax/kernel-2.4/include/asm-vax
In directory usw-pr-cvs1:/tmp/cvs-serv25353/include/asm-vax
Modified Files:
delay.h
Log Message:
Bring forward all 2.2 work from before new year. This should give us
all a (somewhat) bootable kernel.
Index: delay.h
===================================================================
RCS file: /cvsroot/linux-vax/kernel-2.4/include/asm-vax/delay.h,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -r1.1 -r1.2
--- delay.h 2001/01/17 16:18:52 1.1
+++ delay.h 2001/01/26 00:27:00 1.2
@@ -3,11 +3,52 @@
extern unsigned long loops_per_sec;
-/* Bodies of these functions moved to arch/vax/kernel/delay.c
- since we can't inline stuff until we compile with
- optimizations */
-void __delay(unsigned long loops);
-void udelay(unsigned long usecs);
+/*
+ * Copyright (C) 1993 Linus Torvalds
+ *
+ * Delay routines, using a pre-computed "loops_per_second" value.
+ * VAX port Copyright 1998 atp.
+ */
+
+/* well, if you have CISC instructions lying around, might as well use them*/
+extern __inline__ void
+__delay(unsigned long loops)
+{
+ __asm__ __volatile__("1:\tsobgtr %0, 1b\n" : "=r" (loops) : "0" (loops));
+}
+
+/*
+ * division by multiplication: you don't have to worry about
+ * loss of precision.
+ *
+ * Use only for very small delays ( < 1 msec). Should probably use a
+ * lookup table, really, as the multiplications take much too long with
+ * short delays. This is a "reasonable" implementation, though (and the
+ * first constant multiplications gets optimized away if the delay is
+ * a constant)
+ */
+extern __inline__ void
+__udelay(unsigned long usecs, unsigned long lpj)
+{
+ struct {
+ unsigned long lo;
+ unsigned long hi;
+ } prod;
+
+ usecs *= 0x000010c6UL * HZ; /* (2**32 / 1000000) * HZ */
+ __asm__("emul %1,%2,$0,%0"
+ :"=g" (prod)
+ :"g" (usecs),"g" (lpj));
+ __delay(prod.hi);
+}
+
+#ifdef __SMP__
+#define udelay(usecs) \
+ __udelay(usecs, cpu_data[smp_processor_id()].loops_per_jiffy)
+#else
+#define udelay(usecs) \
+ __udelay(usecs, loops_per_jiffy)
+#endif
#endif /* _VAX_DELAY_H */
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