include/asm-x86_64/timex.h

   1 /*
   2  * linux/include/asm-x86_64/timex.h
   3  *
   4  * x86-64 architecture timex specifications
   5  */
   6 #ifndef _ASMx8664_TIMEX_H
   7 #define _ASMx8664_TIMEX_H
   8
   9 #include <asm/8253pit.h>
  10 #include <asm/msr.h>
  11 #include <asm/vsyscall.h>
  12 #include <asm/hpet.h>
  13 #include <asm/system.h>
  14 #include <asm/processor.h>
  15 #include <linux/compiler.h>
  16
  17 #define CLOCK_TICK_RATE PIT_TICK_RATE   /* Underlying HZ */
  18
  19 typedef unsigned long long cycles_t;
  20
  21 static inline cycles_t get_cycles (void)
  22 {
  23         unsigned long long ret;
  24
  25         rdtscll(ret);
  26         return ret;
  27 }
  28
  29 /* Like get_cycles, but make sure the CPU is synchronized. */
  30 static __always_inline cycles_t get_cycles_sync(void)
  31 {
  32         unsigned long long ret;
  33         unsigned eax;
  34         /* Don't do an additional sync on CPUs where we know
  35            RDTSC is already synchronous. */
  36         alternative_io("cpuid", ASM_NOP2, X86_FEATURE_SYNC_RDTSC,
  37                           "=a" (eax), "0" (1) : "ebx","ecx","edx","memory");
  38         rdtscll(ret);
  39         return ret;
  40 }
  41
  42 extern unsigned int cpu_khz;
  43
  44 extern int read_current_timer(unsigned long *timer_value);
  45 #define ARCH_HAS_READ_CURRENT_TIMER     1
  46
  47 extern struct vxtime_data vxtime;
  48
  49 #endif