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gettimeofday(): an implementation based on CPU invariant TSC support

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This commit is contained in:
Balazs Gerofi
2015-08-24 23:41:31 +02:00
parent b8f166e608
commit 9ae5bcf46e
8 changed files with 193 additions and 33 deletions
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32
arch/x86/kernel/cpu.c
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@ -67,6 +67,7 @@ void assign_processor_id(void);
void arch_delay(int);
void x86_set_warm_reset(unsigned long ip, char *first_page_va);
void x86_init_perfctr(void);
int gettime_local_support = 0;
extern int kprintf(const char *format, ...);
@ -569,6 +570,29 @@ static void check_no_execute(void)
return;
}
void init_gettime_support(void)
{
uint64_t op;
uint64_t eax;
uint64_t ebx;
uint64_t ecx;
uint64_t edx;
/* Check if Invariant TSC supported.
* Processor’s support for invariant TSC is indicated by
* CPUID.80000007H:EDX[8].
* See page 2498 of the Intel64 and IA-32 Architectures Software
* Developer’s Manual - combined */
op = 0x80000007;
asm volatile("cpuid" : "=a"(eax),"=b"(ebx),"=c"(ecx),"=d"(edx) : "a" (op));
if (edx & (1 << 8)) {
gettime_local_support = 1;
kprintf("Invariant TSC supported.\n");
}
}
void init_cpu(void)
{
enable_page_protection_fault();
@ -595,6 +619,8 @@ void setup_x86(void)
init_cpu();
init_gettime_support();
kprintf("setup_x86 done.\n");
}
@ -1316,3 +1342,9 @@ ihk_mc_user_context_t *lookup_user_context(struct process *proc)
return uctx;
} /* lookup_user_context() */
void zero_tsc(void)
{
wrmsr(MSR_IA32_TIME_STAMP_COUNTER, 0);
}

4
arch/x86/kernel/include/syscall_list.h
View File

@ -50,7 +50,7 @@ SYSCALL_HANDLED(29, shmget)
SYSCALL_HANDLED(30, shmat)
SYSCALL_HANDLED(31, shmctl)
SYSCALL_HANDLED(34, pause)
SYSCALL_DELEGATED(35, nanosleep)
SYSCALL_HANDLED(35, nanosleep)
SYSCALL_HANDLED(39, getpid)
SYSCALL_HANDLED(56, clone)
SYSCALL_DELEGATED(57, fork)
@ -67,7 +67,7 @@ SYSCALL_DELEGATED(70, msgrcv)
SYSCALL_DELEGATED(72, fcntl)
SYSCALL_DELEGATED(79, getcwd)
SYSCALL_DELEGATED(89, readlink)
SYSCALL_DELEGATED(96, gettimeofday)
SYSCALL_HANDLED(96, gettimeofday)
SYSCALL_HANDLED(97, getrlimit)
SYSCALL_HANDLED(101, ptrace)
SYSCALL_HANDLED(102, getuid)