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-rw-r--r--arch/x86/kernel/apic/apic.c28
1 files changed, 26 insertions, 2 deletions
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 20abd912f0e4..cea4fc19e844 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