1 files changed, 29 insertions, 30 deletions

diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c
index bda052e..968f401 100644
--- a/arch/powerpc/kvm/emulate.c
+++ b/arch/powerpc/kvm/emulate.c
@@ -13,6 +13,7 @@
  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  *
  * Copyright IBM Corp. 2007
+ * Copyright 2011 Freescale Semiconductor, Inc.
  *
  * Authors: Hollis Blanchard <hollisb@us.ibm.com>
  */
@@ -69,57 +70,55 @@
 #define OP_STH  44
 #define OP_STHU 45
 
-#ifdef CONFIG_PPC_BOOK3S
-static int kvmppc_dec_enabled(struct kvm_vcpu *vcpu)
-{
-	return 1;
-}
-#else
-static int kvmppc_dec_enabled(struct kvm_vcpu *vcpu)
-{
-	/* On BOOKE, DEC = 0 is as good as decrementer not enabled */
-	return (vcpu->arch.tcr & TCR_DIE) && vcpu->arch.dec;
-}
-#endif
-
 void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
 {
 	unsigned long dec_nsec;
 	unsigned long long dec_time;
 
 	pr_debug("mtDEC: %x\n", vcpu->arch.dec);
+	hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
+
 #ifdef CONFIG_PPC_BOOK3S
 	/* mtdec lowers the interrupt line when positive. */
 	kvmppc_core_dequeue_dec(vcpu);
 
 	/* POWER4+ triggers a dec interrupt if the value is < 0 */
 	if (vcpu->arch.dec & 0x80000000) {
-		hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
 		kvmppc_core_queue_dec(vcpu);
 		return;
 	}
 #endif
-	if (kvmppc_dec_enabled(vcpu)) {
-		/* The decrementer ticks at the same rate as the timebase, so
-		 * that's how we convert the guest DEC value to the number of
-		 * host ticks. */
-
-		hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
-		dec_time = vcpu->arch.dec;
-		dec_time *= 1000;
-		do_div(dec_time, tb_ticks_per_usec);
-		dec_nsec = do_div(dec_time, NSEC_PER_SEC);
-		hrtimer_start(&vcpu->arch.dec_timer,
-			ktime_set(dec_time, dec_nsec), HRTIMER_MODE_REL);
-		vcpu->arch.dec_jiffies = get_tb();
-	} else {
-		hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
-	}
+
+#ifdef CONFIG_BOOKE
+	/* On BOOKE, DEC = 0 is as good as decrementer not enabled */
+	if (vcpu->arch.dec == 0)
+		return;
+#endif
+
+	/*
+	 * The decrementer ticks at the same rate as the timebase, so
+	 * that's how we convert the guest DEC value to the number of
+	 * host ticks.
+	 */
+
+	dec_time = vcpu->arch.dec;
+	dec_time *= 1000;
+	do_div(dec_time, tb_ticks_per_usec);
+	dec_nsec = do_div(dec_time, NSEC_PER_SEC);
+	hrtimer_start(&vcpu->arch.dec_timer,
+		ktime_set(dec_time, dec_nsec), HRTIMER_MODE_REL);
+	vcpu->arch.dec_jiffies = get_tb();
 }
 
 u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb)
 {
 	u64 jd = tb - vcpu->arch.dec_jiffies;
+
+#ifdef CONFIG_BOOKE
+	if (vcpu->arch.dec < jd)
+		return 0;
+#endif
+
 	return vcpu->arch.dec - jd;
 }