1 files changed, 31 insertions, 26 deletions

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index b7bcdd781651..ab6af775f06c 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -802,6 +802,24 @@ calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
 	return 0;
 }
 
+static int __init lapic_init_clockevent(void)
+{
+	if (!lapic_timer_frequency)
+		return -1;
+
+	/* Calculate the scaled math multiplication factor */
+	lapic_clockevent.mult = div_sc(lapic_timer_frequency/APIC_DIVISOR,
+					TICK_NSEC, lapic_clockevent.shift);
+	lapic_clockevent.max_delta_ns =
+		clockevent_delta2ns(0x7FFFFFFF, &lapic_clockevent);
+	lapic_clockevent.max_delta_ticks = 0x7FFFFFFF;
+	lapic_clockevent.min_delta_ns =
+		clockevent_delta2ns(0xF, &lapic_clockevent);
+	lapic_clockevent.min_delta_ticks = 0xF;
+
+	return 0;
+}
+
 static int __init calibrate_APIC_clock(void)
 {
 	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
@@ -810,25 +828,21 @@ static int __init calibrate_APIC_clock(void)
 	long delta, deltatsc;
 	int pm_referenced = 0;
 
-	/**
-	 * check if lapic timer has already been calibrated by platform
-	 * specific routine, such as tsc calibration code. if so, we just fill
+	if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
+		return 0;
+
+	/*
+	 * Check if lapic timer has already been calibrated by platform
+	 * specific routine, such as tsc calibration code. If so just fill
 	 * in the clockevent structure and return.
 	 */
-
-	if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) {
-		return 0;
-	} else if (lapic_timer_frequency) {
+	if (!lapic_init_clockevent()) {
 		apic_printk(APIC_VERBOSE, "lapic timer already calibrated %d\n",
-				lapic_timer_frequency);
-		lapic_clockevent.mult = div_sc(lapic_timer_frequency/APIC_DIVISOR,
-					TICK_NSEC, lapic_clockevent.shift);
-		lapic_clockevent.max_delta_ns =
-			clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);
-		lapic_clockevent.max_delta_ticks = 0x7FFFFF;
-		lapic_clockevent.min_delta_ns =
-			clockevent_delta2ns(0xF, &lapic_clockevent);
-		lapic_clockevent.min_delta_ticks = 0xF;
+			    lapic_timer_frequency);
+		/*
+		 * Direct calibration methods must have an always running
+		 * local APIC timer, no need for broadcast timer.
+		 */
 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
 		return 0;
 	}
@@ -869,17 +883,8 @@ static int __init calibrate_APIC_clock(void)
 	pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
 					&delta, &deltatsc);
 
-	/* Calculate the scaled math multiplication factor */
-	lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS,
-				       lapic_clockevent.shift);
-	lapic_clockevent.max_delta_ns =
-		clockevent_delta2ns(0x7FFFFFFF, &lapic_clockevent);
-	lapic_clockevent.max_delta_ticks = 0x7FFFFFFF;
-	lapic_clockevent.min_delta_ns =
-		clockevent_delta2ns(0xF, &lapic_clockevent);
-	lapic_clockevent.min_delta_ticks = 0xF;
-
 	lapic_timer_frequency = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
+	lapic_init_clockevent();
 
 	apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
 	apic_printk(APIC_VERBOSE, "..... mult: %u\n", lapic_clockevent.mult);