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Fixed time processing.

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- arm64: Get TSC corresponding to boot time from IHK.

- x86_64: Calculate the current time using vdso.

Refs: #1186
Fujitsu: POSTK_DEBUG_ARCH_DEP_52
Change-Id: I293ba4bbe5390d50dea44b8a5b7471f59237daff
This commit is contained in:
Tomoki Shirasawa
2019-02-17 16:37:29 +09:00
committed by Masamichi Takagi
parent 07aa96ef95
commit 5bc54a3bbe
15 changed files with 471 additions and 88 deletions
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52
arch/x86_64/kernel/syscall.c
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@ -64,7 +64,6 @@ uintptr_t debug_constants[] = {
-1,
};
#ifdef POSTK_DEBUG_ARCH_DEP_52
#define VDSO_MAXPAGES 2
struct vdso {
long busy;
@ -80,8 +79,24 @@ struct vdso {
long hpet_phys;
void *pvti_virt;
long pvti_phys;
void *vgtod_virt;
};
struct vsyscall_gtod_data {
int seq;
struct {
int vclock_mode;
unsigned long cycle_last;
unsigned long mask;
unsigned int mult;
unsigned int shift;
} clock;
/* open coded 'struct timespec' */
time_t wall_time_sec;
unsigned long wall_time_snsec;
};
#endif /*POSTK_DEBUG_ARCH_DEP_52*/
static struct vdso vdso;
static size_t container_size = 0;
@ -2811,4 +2826,37 @@ time_t time(void) {
return ret;
}
void calculate_time_from_tsc(struct timespec *ts)
{
unsigned long seq;
unsigned long seq2;
unsigned long ns;
unsigned long delta;
struct vsyscall_gtod_data *gtod = vdso.vgtod_virt;
do {
for (;;) {
seq = ACCESS_ONCE(gtod->seq);
if (unlikely(seq & 1)) {
cpu_pause();
continue;
}
break;
}
rmb(); /* fetch sequence before time */
ts->tv_sec = gtod->wall_time_sec;
ns = gtod->wall_time_snsec;
delta = rdtsc() - gtod->clock.cycle_last;
ns += delta * gtod->clock.mult;
ns >>= gtod->clock.shift;
seq2 = ACCESS_ONCE(gtod->seq);
rmb(); /* fetch time before checking sequence */
} while (seq != seq2);
ts->tv_nsec = ns;
if (ts->tv_nsec >= NS_PER_SEC) {
ts->tv_nsec -= NS_PER_SEC;
++ts->tv_sec;
}
}
/*** End of File ***/