Inform TSC deadline clockevent device about recalibration

[kvmfornfv.git] / kernel / arch / x86 / kernel / apic / apic.c

diff --git a/kernel/arch/x86/kernel/apic/apic.c b/kernel/arch/x86/kernel/apic/apic.c
index d2eee3e..58e7cdb 100644 (file)
--- a/kernel/arch/x86/kernel/apic/apic.c
+++ b/kernel/arch/x86/kernel/apic/apic.c
@@ -563,6 +563,30 @@ static void setup_APIC_timer(void)
                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.
  *