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x86: TSC: use one set of reference variables

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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Thomas Gleixner 2008-09-04 15:18:53 +00:00 committed by Ingo Molnar
parent d683ef7afe
commit 827014be05
1 changed files with 11 additions and 11 deletions
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22
arch/x86/kernel/tsc.c
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@ -104,7 +104,7 @@ __setup("notsc", notsc_setup);
/*
* Read TSC and the reference counters. Take care of SMI disturbance
*/
static u64 tsc_read_refs(u64 *pm, u64 *hpet)
static u64 tsc_read_refs(u64 *p, int hpet)
{
u64 t1, t2;
int i;
@ -112,9 +112,9 @@ static u64 tsc_read_refs(u64 *pm, u64 *hpet)
for (i = 0; i < MAX_RETRIES; i++) {
t1 = get_cycles();
if (hpet)
*hpet = hpet_readl(HPET_COUNTER) & 0xFFFFFFFF;
*p = hpet_readl(HPET_COUNTER) & 0xFFFFFFFF;
else
*pm = acpi_pm_read_early();
*p = acpi_pm_read_early();
t2 = get_cycles();
if ((t2 - t1) < SMI_TRESHOLD)
return t2;
@ -228,7 +228,7 @@ static unsigned long pit_calibrate_tsc(void)
*/
unsigned long native_calibrate_tsc(void)
{
u64 tsc1, tsc2, delta, pm1, pm2, hpet1, hpet2;
u64 tsc1, tsc2, delta, ref1, ref2;
unsigned long tsc_pit_min = ULONG_MAX, tsc_ref_min = ULONG_MAX;
unsigned long flags;
int hpet = is_hpet_enabled(), i;
@ -267,16 +267,16 @@ unsigned long native_calibrate_tsc(void)
* read the end value.
*/
local_irq_save(flags);
tsc1 = tsc_read_refs(&pm1, hpet ? &hpet1 : NULL);
tsc1 = tsc_read_refs(&ref1, hpet);
tsc_pit_khz = pit_calibrate_tsc();
tsc2 = tsc_read_refs(&pm2, hpet ? &hpet2 : NULL);
tsc2 = tsc_read_refs(&ref2, hpet);
local_irq_restore(flags);
/* Pick the lowest PIT TSC calibration so far */
tsc_pit_min = min(tsc_pit_min, tsc_pit_khz);
/* hpet or pmtimer available ? */
if (!hpet && !pm1 && !pm2)
if (!hpet && !ref1 && !ref2)
continue;
/* Check, whether the sampling was disturbed by an SMI */
@ -285,9 +285,9 @@ unsigned long native_calibrate_tsc(void)
tsc2 = (tsc2 - tsc1) * 1000000LL;
if (hpet)
tsc2 = calc_hpet_ref(tsc2, hpet1, hpet2);
tsc2 = calc_hpet_ref(tsc2, ref1, ref2);
else
tsc2 = calc_pmtimer_ref(tsc2, pm1, pm2);
tsc2 = calc_pmtimer_ref(tsc2, ref1, ref2);
tsc_ref_min = min(tsc_ref_min, (unsigned long) tsc2);
}
@ -301,7 +301,7 @@ unsigned long native_calibrate_tsc(void)
"SMI disturbance.\n");
/* We don't have an alternative source, disable TSC */
if (!hpet && !pm1 && !pm2) {
if (!hpet && !ref1 && !ref2) {
printk("TSC: No reference (HPET/PMTIMER) available\n");
return 0;
}
@ -321,7 +321,7 @@ unsigned long native_calibrate_tsc(void)
}
/* We don't have an alternative source, use the PIT calibration value */
if (!hpet && !pm1 && !pm2) {
if (!hpet && !ref1 && !ref2) {
printk(KERN_INFO "TSC: Using PIT calibration value\n");
return tsc_pit_min;
}