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syscall_time: Handle by McKernel

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refs: #1036
Change-Id: Ifa81b613c7ee8d95ae7cdf3dd54643f60526fa73
This commit is contained in:
Ken Sato
2018-09-05 16:07:43 +09:00
committed by Masamichi Takagi
parent 5e760db417
commit c23bc8d401
11 changed files with 332 additions and 52 deletions
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45
arch/x86_64/kernel/vsyscall.c
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@ -31,51 +31,6 @@ struct tod_data_s tod_data
.version = IHK_ATOMIC64_INIT(0),
};
static inline void cpu_pause_for_vsyscall(void)
{
asm volatile ("pause" ::: "memory");
return;
} /* cpu_pause_for_vsyscall() */
static inline void calculate_time_from_tsc(struct timespec *ts)
{
long ver;
unsigned long current_tsc;
__time_t sec_delta;
long ns_delta;
for (;;) {
while ((ver = ihk_atomic64_read(&tod_data.version)) & 1) {
/* settimeofday() is in progress */
cpu_pause_for_vsyscall();
}
rmb();
*ts = tod_data.origin;
rmb();
if (ver == ihk_atomic64_read(&tod_data.version)) {
break;
}
/* settimeofday() has intervened */
cpu_pause_for_vsyscall();
}
current_tsc = rdtsc();
sec_delta = current_tsc / tod_data.clocks_per_sec;
ns_delta = NS_PER_SEC * (current_tsc % tod_data.clocks_per_sec)
/ tod_data.clocks_per_sec;
/* calc. of ns_delta overflows if clocks_per_sec exceeds 18.44 GHz */
ts->tv_sec += sec_delta;
ts->tv_nsec += ns_delta;
if (ts->tv_nsec >= NS_PER_SEC) {
ts->tv_nsec -= NS_PER_SEC;
++ts->tv_sec;
}
return;
} /* calculate_time_from_tsc() */
int vsyscall_gettimeofday(struct timeval *tv, void *tz)
{
int error;