arch/x86/include/asm/tsc.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * x86 TSC related functions
   4  */
   5 #ifndef _ASM_X86_TSC_H
   6 #define _ASM_X86_TSC_H
   7
   8 #include <asm/processor.h>
   9
  10 #define NS_SCALE        10 /* 2^10, carefully chosen */
  11 #define US_SCALE        32 /* 2^32, arbitralrily chosen */
  12
  13 /*
  14  * Standard way to access the cycle counter.
  15  */
  16 typedef unsigned long long cycles_t;
  17
  18 extern unsigned int cpu_khz;
  19 extern unsigned int tsc_khz;
  20
  21 extern void disable_TSC(void);
  22
  23 static inline cycles_t get_cycles(void)
  24 {
  25 #ifndef CONFIG_X86_TSC
  26         if (!boot_cpu_has(X86_FEATURE_TSC))
  27                 return 0;
  28 #endif
  29
  30         return rdtsc();
  31 }
  32
  33 extern struct system_counterval_t convert_art_to_tsc(u64 art);
  34
  35 extern void tsc_early_delay_calibrate(void);
  36 extern void tsc_init(void);
  37 extern void mark_tsc_unstable(char *reason);
  38 extern int unsynchronized_tsc(void);
  39 extern int check_tsc_unstable(void);
  40 extern void mark_tsc_async_resets(char *reason);
  41 extern unsigned long native_calibrate_cpu(void);
  42 extern unsigned long native_calibrate_tsc(void);
  43 extern unsigned long long native_sched_clock_from_tsc(u64 tsc);
  44
  45 extern int tsc_clocksource_reliable;
  46 #ifdef CONFIG_X86_TSC
  47 extern bool tsc_async_resets;
  48 #else
  49 # define tsc_async_resets       false
  50 #endif
  51
  52 /*
  53  * Boot-time check whether the TSCs are synchronized across
  54  * all CPUs/cores:
  55  */
  56 #ifdef CONFIG_X86_TSC
  57 extern bool tsc_store_and_check_tsc_adjust(bool bootcpu);
  58 extern void tsc_verify_tsc_adjust(bool resume);
  59 extern void check_tsc_sync_source(int cpu);
  60 extern void check_tsc_sync_target(void);
  61 #else
  62 static inline bool tsc_store_and_check_tsc_adjust(bool bootcpu) { return false; }
  63 static inline void tsc_verify_tsc_adjust(bool resume) { }
  64 static inline void check_tsc_sync_source(int cpu) { }
  65 static inline void check_tsc_sync_target(void) { }
  66 #endif
  67
  68 extern int notsc_setup(char *);
  69 extern void tsc_save_sched_clock_state(void);
  70 extern void tsc_restore_sched_clock_state(void);
  71
  72 unsigned long cpu_khz_from_msr(void);
  73
  74 #endif /* _ASM_X86_TSC_H */