bitkeeper revision 1.952 (40c8935a3XSRdQfnx5RoO7XgaggvOQ)

Towards x86_64 support. Merged a bunch of the existing x86_64 stuff
back into a generic 'x86' architecture. Aim is to share as much
as possible between 32- and 64-bit worlds.

1 files changed, 29 insertions, 0 deletions

diff --git a/xen/arch/x86/delay.c b/xen/arch/x86/delay.c
new file mode 100644
index 0000000000..cde5e18b5f
--- /dev/null
+++ b/xen/arch/x86/delay.c
@@ -0,0 +1,29 @@
+/*
+ *	Precise Delay Loops for i386
+ *
+ *	Copyright (C) 1993 Linus Torvalds
+ *	Copyright (C) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
+ *
+ *	The __delay function must _NOT_ be inlined as its execution time
+ *	depends wildly on alignment on many x86 processors. The additional
+ *	jump magic is needed to get the timing stable on all the CPU's
+ *	we have to worry about.
+ */
+
+#include <xen/config.h>
+#include <xen/delay.h>
+#include <asm/msr.h>
+#include <asm/processor.h>
+
+void __udelay(unsigned long usecs)
+{
+    unsigned long ticks = usecs * ticks_per_usec;
+    unsigned long s, e;
+
+    rdtscl(s);
+    do
+    {
+        rep_nop();
+        rdtscl(e);
+    } while ((e-s) < ticks);
+}