x86: TSC: separate hpet/pmtimer calculation out

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index aa11413e7c1d271a4a2f54a5f707b5ffe6271324..ebb9bf824a07713026c620b9728a68f38446f57d 100644 (file)
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -122,6 +122,43 @@ static u64 tsc_read_refs(u64 *pm, u64 *hpet)
        return ULLONG_MAX;
 }
 
+/*
+ * Calculate the TSC frequency from HPET reference
+ */
+static unsigned long calc_hpet_ref(u64 deltatsc, u64 hpet1, u64 hpet2)
+{
+       u64 tmp;
+
+       if (hpet2 < hpet1)
+               hpet2 += 0x100000000ULL;
+       hpet2 -= hpet1;
+       tmp = ((u64)hpet2 * hpet_readl(HPET_PERIOD));
+       do_div(tmp, 1000000);
+       do_div(deltatsc, tmp);
+
+       return (unsigned long) deltatsc;
+}
+
+/*
+ * Calculate the TSC frequency from PMTimer reference
+ */
+static unsigned long calc_pmtimer_ref(u64 deltatsc, u64 pm1, u64 pm2)
+{
+       u64 tmp;
+
+       if (!pm1 && !pm2)
+               return ULONG_MAX;
+
+       if (pm2 < pm1)
+               pm2 += (u64)ACPI_PM_OVRRUN;
+       pm2 -= pm1;
+       tmp = pm2 * 1000000000LL;
+       do_div(tmp, PMTMR_TICKS_PER_SEC);
+       do_div(deltatsc, tmp);
+
+       return (unsigned long) deltatsc;
+}
+
 #define CAL_MS         50
 #define CAL_LATCH      (CLOCK_TICK_RATE / (1000 / CAL_MS))
 #define CAL_PIT_LOOPS  5000
@@ -247,22 +284,11 @@ unsigned long native_calibrate_tsc(void)
                        continue;
 
                tsc2 = (tsc2 - tsc1) * 1000000LL;
+               if (hpet)
+                       tsc2 = calc_hpet_ref(tsc2, hpet1, hpet2);
+               else
+                       tsc2 = calc_pmtimer_ref(tsc2, pm1, pm2);
 
-               if (hpet) {
-                       if (hpet2 < hpet1)
-                               hpet2 += 0x100000000ULL;
-                       hpet2 -= hpet1;
-                       tsc1 = ((u64)hpet2 * hpet_readl(HPET_PERIOD));
-                       do_div(tsc1, 1000000);
-               } else {
-                       if (pm2 < pm1)
-                               pm2 += (u64)ACPI_PM_OVRRUN;
-                       pm2 -= pm1;
-                       tsc1 = pm2 * 1000000000LL;
-                       do_div(tsc1, PMTMR_TICKS_PER_SEC);
-               }
-
-               do_div(tsc2, tsc1);
                tsc_ref_min = min(tsc_ref_min, (unsigned long) tsc2);
        }