1 files changed, 29 insertions, 2 deletions

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 20abd912f0e4..50c95af0f017 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -313,7 +313,7 @@ int lapic_get_maxlvt(void)
 
 /* Clock divisor */
 #define APIC_DIVISOR 16
-#define TSC_DIVISOR  32
+#define TSC_DIVISOR  8
 
 /*
  * This function sets up the local APIC timer, with a timeout of
@@ -565,13 +565,37 @@ static void setup_APIC_timer(void)
                                     CLOCK_EVT_FEAT_DUMMY);
                 levt->set_next_event = lapic_next_deadline;
                 clockevents_config_and_register(levt,
-                                                (tsc_khz / TSC_DIVISOR) * 1000,
+                                                tsc_khz * (1000 / TSC_DIVISOR),
                                                 0xF, ~0UL);
         } else
                 clockevents_register_device(levt);
 }
 
 /*
+ * Install the updated TSC frequency from recalibration at the TSC
+ * deadline clockevent devices.
+ */
+static void __lapic_update_tsc_freq(void *info)
+{
+        struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
+
+        if (!this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
+                return;
+
+        clockevents_update_freq(levt, tsc_khz * (1000 / TSC_DIVISOR));
+}
+
+void lapic_update_tsc_freq(void)
+{
+        /*
+         * The clockevent device's ->mult and ->shift can both be
+         * changed. In order to avoid races, schedule the frequency
+         * update code on each CPU.
+         */
+        on_each_cpu(__lapic_update_tsc_freq, NULL, 0);
+}
+
+/*
  * In this functions we calibrate APIC bus clocks to the external timer.
  *
  * We want to do the calibration only once since we want to have local timer
@@ -1599,6 +1623,9 @@ void __init enable_IR_x2apic(void)
         unsigned long flags;
         int ret, ir_stat;
 
+        if (skip_ioapic_setup)
+                return;
+
         ir_stat = irq_remapping_prepare();
         if (ir_stat < 0 && !x2apic_supported())
                 return;