hvm: hpet: Tidy up hpet_to_ns_limit calculation.

Suggested by Haitao Shan @ Intel.
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
xen-unstable changeset:   16707:51aa2f884f6446b7e376a749ead8038359b70ec1
xen-unstable date:        Fri Jan 11 11:01:36 2008 +0000

diff --git a/xen/arch/x86/hvm/hpet.c b/xen/arch/x86/hvm/hpet.c
index af101ce060e756ff08e10edd454707371d683449..2815e6f97de6c9da03cf8482726d3a8b5dfbb445 100644 (file)
--- a/xen/arch/x86/hvm/hpet.c
+++ b/xen/arch/x86/hvm/hpet.c
@@ -479,7 +479,7 @@ void hpet_init(struct vcpu *v)
     h->tsc_freq = ticks_per_sec(v);
 
     h->hpet_to_ns_scale = ((S_TO_NS * TSC_PER_HPET_TICK) << 10) / h->tsc_freq;
-    h->hpet_to_ns_limit = (~0ULL >> 1) / h->hpet_to_ns_scale;
+    h->hpet_to_ns_limit = ~0ULL / h->hpet_to_ns_scale;
 
     /* 64-bit main counter; 3 timers supported; LegacyReplacementRoute. */
     h->hpet.capability = 0x8086A201ULL;