x86: Hypervisor detection and get tsc_freq from hypervisor

[linux-2.6-omap-h63xx.git] / arch / x86 / kernel / tsc.c

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 62348e4fd8d1e6af29d04726499b13794a78949e..6dbf0bcb44a8bc2d56b6778aa12a22484e7f691b 100644 (file)
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -15,6 +15,7 @@
 #include <asm/vgtod.h>
 #include <asm/time.h>
 #include <asm/delay.h>
+#include <asm/hypervisor.h>
 
 unsigned int cpu_khz;           /* TSC clocks / usec, not used here */
 EXPORT_SYMBOL(cpu_khz);
@@ -352,9 +353,15 @@ unsigned long native_calibrate_tsc(void)
 {
        u64 tsc1, tsc2, delta, ref1, ref2;
        unsigned long tsc_pit_min = ULONG_MAX, tsc_ref_min = ULONG_MAX;
-       unsigned long flags, latch, ms, fast_calibrate;
+       unsigned long flags, latch, ms, fast_calibrate, tsc_khz;
        int hpet = is_hpet_enabled(), i, loopmin;
 
+       tsc_khz = get_hypervisor_tsc_freq();
+       if (tsc_khz) {
+               printk(KERN_INFO "TSC: Frequency read from the hypervisor\n");
+               return tsc_khz;
+       }
+
        local_irq_save(flags);
        fast_calibrate = quick_pit_calibrate();
        local_irq_restore(flags);