mirror of
https://github.com/torvalds/linux.git
synced 2024-11-01 09:41:44 +00:00
b74f05d61b
Upon resume from hibernation, CPU 0's hvclock area contains the old values for system_time and tsc_timestamp. It is necessary for the hypervisor to update these values with uptodate ones before the CPU uses them. Abstract TSC's save/restore sched_clock_state functions and use restore_state to write to KVM_SYSTEM_TIME MSR, forcing an update. Also move restore_sched_clock_state before __restore_processor_state, since the later calls CONFIG_LOCK_STAT's lockstat_clock (also for TSC). Thanks to Igor Mammedov for tracking it down. Fixes suspend-to-disk with kvmclock. Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
68 lines
1.4 KiB
C
68 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);
|
|
|
|
extern int tsc_clocksource_reliable;
|
|
|
|
/*
|
|
* 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 tsc_save_sched_clock_state(void);
|
|
extern void tsc_restore_sched_clock_state(void);
|
|
|
|
#endif /* _ASM_X86_TSC_H */
|