44259b1abf
vread_tsc is short and hot, and it's userspace code so the usual reasons to enable -pg and turn off sibling calls don't apply. (OK, turning off sibling calls has no effect. But it might someday...) As an added benefit, tsc.c is profilable now. Signed-off-by: Andy Lutomirski <luto@mit.edu> Cc: Andi Kleen <andi@firstfloor.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Borislav Petkov <bp@amd64.org> Link: http://lkml.kernel.org/r/%3C99c6d7f5efa3ccb65b4ac6eb443e1ab7bad47d7b.1306156808.git.luto%40mit.edu%3E Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
69 lines
1.4 KiB
C
69 lines
1.4 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 shouldn't
|
|
* 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);
|
|
extern int check_tsc_unstable(void);
|
|
extern unsigned long native_calibrate_tsc(void);
|
|
|
|
#ifdef CONFIG_X86_64
|
|
extern cycles_t vread_tsc(void);
|
|
#endif
|
|
|
|
/*
|
|
* 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 *);
|
|
extern void save_sched_clock_state(void);
|
|
extern void restore_sched_clock_state(void);
|
|
|
|
#endif /* _ASM_X86_TSC_H */
|