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Split pmtimer wait and tsc measurement from pmtimer tsc calibration.

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This commit is contained in:
Vladimir Serbinenko 2016-02-12 11:40:51 +01:00
parent 1933d37371
commit d9a3bfead8
3 changed files with 69 additions and 17 deletions
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47
grub-core/kern/i386/tsc_pmtimer.c
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@ -24,44 +24,35 @@
#include <grub/time.h>
#include <grub/misc.h>
#include <grub/i386/tsc.h>
#include <grub/i386/pmtimer.h>
#include <grub/acpi.h>
#include <grub/cpu/io.h>
int
grub_tsc_calibrate_from_pmtimer (void)
grub_uint64_t
grub_pmtimer_wait_count_tsc (grub_port_t pmtimer,
grub_uint16_t num_pm_ticks)
{
grub_uint32_t start;
grub_uint32_t last;
grub_uint32_t cur, end;
struct grub_acpi_fadt *fadt;
grub_port_t p;
grub_uint64_t start_tsc;
grub_uint64_t end_tsc;
int num_iter = 0;
fadt = grub_acpi_find_fadt ();
if (!fadt)
return 0;
p = fadt->pmtimer;
if (!p)
return 0;
start = grub_inl (p) & 0xffffff;
start = grub_inl (pmtimer) & 0xffffff;
last = start;
/* It's 3.579545 MHz clock. Wait 1 ms. */
end = start + 3580;
end = start + num_pm_ticks;
start_tsc = grub_get_tsc ();
while (1)
{
cur = grub_inl (p) & 0xffffff;
cur = grub_inl (pmtimer) & 0xffffff;
if (cur < last)
cur |= 0x1000000;
num_iter++;
if (cur >= end)
{
end_tsc = grub_get_tsc ();
grub_tsc_rate = grub_divmod64 ((1ULL << 32), end_tsc - start_tsc, 0);
return 1;
return end_tsc - start_tsc;
}
/* Check for broken PM timer.
50000000 TSCs is between 5 ms (10GHz) and 200 ms (250 MHz)
@ -73,3 +64,25 @@ grub_tsc_calibrate_from_pmtimer (void)
}
}
}
int
grub_tsc_calibrate_from_pmtimer (void)
{
struct grub_acpi_fadt *fadt;
grub_port_t pmtimer;
grub_uint64_t tsc_diff;
fadt = grub_acpi_find_fadt ();
if (!fadt)
return 0;
pmtimer = fadt->pmtimer;
if (!pmtimer)
return 0;
/* It's 3.579545 MHz clock. Wait 1 ms. */
tsc_diff = grub_pmtimer_wait_count_tsc (pmtimer, 3580);
if (tsc_diff == 0)
return 0;
grub_tsc_rate = grub_divmod64 ((1ULL << 32), tsc_diff, 0);
return 1;
}