x86: fix debug message of CPU clock speed

Impact: Fixes incorrect printk

LOCAL APIC is corrected by PM-Timer, when SMI occurred while LOCAL APIC is calibrated.
In this case, LOCAL APIC debug message(Boot with apic=debug) is displayed correctly,
however, CPU clock speed debug message is displayed wrongly .

When SMI occured on my machine, which has 1.6GHz CPU, CPU clock speed is displayed
3622.0205 MHz as follow.

	CPU0: Intel(R) Xeon(R) CPU            5110  @ 1.60GHz stepping 06
	Using local APIC timer interrupts.
	calibrating APIC timer ...
	... lapic delta = 3773130
	... PM timer delta = 812434
	APIC calibration not consistent with PM Timer: 226ms instead of 100ms
	APIC delta adjusted to PM-Timer: 1662420 (3773130)
	..... delta 1662420
	..... mult: 71411249
	..... calibration result: 265987
	..... CPU clock speed is 3622.0205 MHz.  =====>  here
	..... host bus clock speed is 265.0987 MHz.

This patch fixes to displaying CPU clock speed correctly as follow.

	CPU0: Intel(R) Xeon(R) CPU            5110  @ 1.60GHz stepping 06
	Using local APIC timer interrupts.
	calibrating APIC timer ...
	... lapic delta = 3773131
	... PM timer delta = 812434
	APIC calibration not consistent with PM Timer: 226ms instead of 100ms
	APIC delta adjusted to PM-Timer: 1662420 (3773131)
	TSC delta adjusted to PM-Timer: 159592409 (362220564)
	..... delta 1662420
	..... mult: 71411249
	..... calibration result: 265987
	..... CPU clock speed is 1595.0924 MHz.
	..... host bus clock speed is 265.0987 MHz.

Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

diff --git a/arch/x86/kernel/apic.c b/arch/x86/kernel/apic.c
index 4b6df2469fe3ddda97dd7b901171b8bba5c483f0..7bcd746d704cc201d05c76019408c0c10ba78f2c 100644 (file)
--- a/arch/x86/kernel/apic.c
+++ b/arch/x86/kernel/apic.c
@@ -535,7 +535,8 @@ static void __init lapic_cal_handler(struct clock_event_device *dev)
        }
 }
 
-static int __init calibrate_by_pmtimer(long deltapm, long *delta)
+static int __init
+calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
 {
        const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
        const long pm_thresh = pm_100ms / 100;
@@ -557,18 +558,29 @@ static int __init calibrate_by_pmtimer(long deltapm, long *delta)
        if (deltapm > (pm_100ms - pm_thresh) &&
            deltapm < (pm_100ms + pm_thresh)) {
                apic_printk(APIC_VERBOSE, "... PM timer result ok\n");
-       } else {
-               res = (((u64)deltapm) *  mult) >> 22;
-               do_div(res, 1000000);
-               pr_warning("APIC calibration not consistent "
-                       "with PM Timer: %ldms instead of 100ms\n",
-                       (long)res);
-               /* Correct the lapic counter value */
-               res = (((u64)(*delta)) * pm_100ms);
+               return 0;
+       }
+
+       res = (((u64)deltapm) *  mult) >> 22;
+       do_div(res, 1000000);
+       pr_warning("APIC calibration not consistent "
+                  "with PM Timer: %ldms instead of 100ms\n",(long)res);
+
+       /* Correct the lapic counter value */
+       res = (((u64)(*delta)) * pm_100ms);
+       do_div(res, deltapm);
+       pr_info("APIC delta adjusted to PM-Timer: "
+               "%lu (%ld)\n", (unsigned long)res, *delta);
+       *delta = (long)res;
+
+       /* Correct the tsc counter value */
+       if (cpu_has_tsc) {
+               res = (((u64)(*deltatsc)) * pm_100ms);
                do_div(res, deltapm);
-               pr_info("APIC delta adjusted to PM-Timer: "
-                       "%lu (%ld)\n", (unsigned long)res, *delta);
-               *delta = (long)res;
+               apic_printk(APIC_VERBOSE, "TSC delta adjusted to "
+                                         "PM-Timer: %lu (%ld) \n",
+                                       (unsigned long)res, *deltatsc);
+               *deltatsc = (long)res;
        }
 
        return 0;
@@ -579,7 +591,7 @@ static int __init calibrate_APIC_clock(void)
        struct clock_event_device *levt = &__get_cpu_var(lapic_events);
        void (*real_handler)(struct clock_event_device *dev);
        unsigned long deltaj;
-       long delta;
+       long delta, deltatsc;
        int pm_referenced = 0;
 
        local_irq_disable();
@@ -609,9 +621,11 @@ static int __init calibrate_APIC_clock(void)
        delta = lapic_cal_t1 - lapic_cal_t2;
        apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
 
+       deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
+
        /* we trust the PM based calibration if possible */
        pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
-                                       &delta);
+                                       &delta, &deltatsc);
 
        /* Calculate the scaled math multiplication factor */
        lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS,
@@ -629,11 +643,10 @@ static int __init calibrate_APIC_clock(void)
                    calibration_result);
 
        if (cpu_has_tsc) {
-               delta = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
                apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
                            "%ld.%04ld MHz.\n",
-                           (delta / LAPIC_CAL_LOOPS) / (1000000 / HZ),
-                           (delta / LAPIC_CAL_LOOPS) % (1000000 / HZ));
+                           (deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
+                           (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
        }
 
        apic_printk(APIC_VERBOSE, "..... host bus clock speed is "