linux/include/asm-x86/tsc.h
Vegard Nossum 77ef50a522 x86: consolidate header guards
This patch is the result of an automatic script that consolidates the
format of all the headers in include/asm-x86/.

The format:

1. No leading underscore. Names with leading underscores are reserved.
2. Pathname components are separated by two underscores. So we can
   distinguish between mm_types.h and mm/types.h.
3. Everything except letters and numbers are turned into single
   underscores.

Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
2008-07-22 21:31:34 +02:00

63 lines
1.2 KiB
C

/*
* x86 TSC related functions
*/
#ifndef ASM_X86__TSC_H
#define ASM_X86__TSC_H
#include <asm/processor.h>
#define NS_SCALE 10 /* 2^10, carefully chosen */
#define US_SCALE 32 /* 2^32, arbitralrily chosen */
/*
* Standard way to access the cycle counter.
*/
typedef unsigned long long cycles_t;
extern unsigned int cpu_khz;
extern unsigned int tsc_khz;
extern void disable_TSC(void);
static inline cycles_t get_cycles(void)
{
unsigned long long ret = 0;
#ifndef CONFIG_X86_TSC
if (!cpu_has_tsc)
return 0;
#endif
rdtscll(ret);
return ret;
}
static __always_inline cycles_t vget_cycles(void)
{
/*
* We only do VDSOs on TSC capable CPUs, so this shouldnt
* access boot_cpu_data (which is not VDSO-safe):
*/
#ifndef CONFIG_X86_TSC
if (!cpu_has_tsc)
return 0;
#endif
return (cycles_t)__native_read_tsc();
}
extern void tsc_init(void);
extern void mark_tsc_unstable(char *reason);
extern int unsynchronized_tsc(void);
int check_tsc_unstable(void);
/*
* Boot-time check whether the TSCs are synchronized across
* all CPUs/cores:
*/
extern void check_tsc_sync_source(int cpu);
extern void check_tsc_sync_target(void);
extern int notsc_setup(char *);
#endif /* ASM_X86__TSC_H */