6a36958317
Some 'feature' BIOSes fiddle with the TSC_ADJUST register during suspend/resume which renders the TSC unusable. Add sanity checks into the resume path and restore the original value if it was adjusted. Reported-and-tested-by: Roland Scheidegger <rscheidegger_lists@hispeed.ch> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Bruce Schlobohm <bruce.schlobohm@intel.com> Cc: Kevin Stanton <kevin.b.stanton@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Allen Hung <allen_hung@dell.com> Cc: Borislav Petkov <bp@alien8.de> Link: http://lkml.kernel.org/r/20161213131211.317654500@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
67 lines
1.6 KiB
C
67 lines
1.6 KiB
C
/*
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* x86 TSC related functions
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*/
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#ifndef _ASM_X86_TSC_H
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#define _ASM_X86_TSC_H
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#include <asm/processor.h>
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#define NS_SCALE 10 /* 2^10, carefully chosen */
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#define US_SCALE 32 /* 2^32, arbitralrily chosen */
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/*
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* Standard way to access the cycle counter.
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*/
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typedef unsigned long long cycles_t;
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extern unsigned int cpu_khz;
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extern unsigned int tsc_khz;
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extern void disable_TSC(void);
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static inline cycles_t get_cycles(void)
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{
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#ifndef CONFIG_X86_TSC
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if (!boot_cpu_has(X86_FEATURE_TSC))
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return 0;
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#endif
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return rdtsc();
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}
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extern struct system_counterval_t convert_art_to_tsc(cycle_t art);
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extern void tsc_init(void);
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extern void mark_tsc_unstable(char *reason);
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extern int unsynchronized_tsc(void);
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extern int check_tsc_unstable(void);
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extern unsigned long native_calibrate_cpu(void);
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extern unsigned long native_calibrate_tsc(void);
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extern unsigned long long native_sched_clock_from_tsc(u64 tsc);
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extern int tsc_clocksource_reliable;
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/*
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* Boot-time check whether the TSCs are synchronized across
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* all CPUs/cores:
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*/
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#ifdef CONFIG_X86_TSC
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extern bool tsc_store_and_check_tsc_adjust(void);
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extern void tsc_verify_tsc_adjust(bool resume);
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extern void check_tsc_sync_source(int cpu);
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extern void check_tsc_sync_target(void);
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#else
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static inline bool tsc_store_and_check_tsc_adjust(void) { return false; }
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static inline void tsc_verify_tsc_adjust(bool resume) { }
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static inline void check_tsc_sync_source(int cpu) { }
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static inline void check_tsc_sync_target(void) { }
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#endif
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extern int notsc_setup(char *);
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extern void tsc_save_sched_clock_state(void);
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extern void tsc_restore_sched_clock_state(void);
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unsigned long cpu_khz_from_msr(void);
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#endif /* _ASM_X86_TSC_H */
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