1 files changed, 74 insertions, 0 deletions
diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h
new file mode 100644
index 000000000..196cf01f5
--- /dev/null
+++ b/arch/x86/include/asm/tsc.h
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * 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)
+{
+	if (!IS_ENABLED(CONFIG_X86_TSC) &&
+	    !cpu_feature_enabled(X86_FEATURE_TSC))
+		return 0;
+	return rdtsc();
+}
+#define get_cycles get_cycles
+
+extern struct system_counterval_t convert_art_to_tsc(u64 art);
+extern struct system_counterval_t convert_art_ns_to_tsc(u64 art_ns);
+
+extern void tsc_early_init(void);
+extern void tsc_init(void);
+extern void mark_tsc_unstable(char *reason);
+extern int unsynchronized_tsc(void);
+extern int check_tsc_unstable(void);
+extern void mark_tsc_async_resets(char *reason);
+extern unsigned long native_calibrate_cpu_early(void);
+extern unsigned long native_calibrate_tsc(void);
+extern unsigned long long native_sched_clock_from_tsc(u64 tsc);
+
+extern int tsc_clocksource_reliable;
+#ifdef CONFIG_X86_TSC
+extern bool tsc_async_resets;
+#else
+# define tsc_async_resets	false
+#endif
+
+/*
+ * Boot-time check whether the TSCs are synchronized across
+ * all CPUs/cores:
+ */
+#ifdef CONFIG_X86_TSC
+extern bool tsc_store_and_check_tsc_adjust(bool bootcpu);
+extern void tsc_verify_tsc_adjust(bool resume);
+extern void check_tsc_sync_source(int cpu);
+extern void check_tsc_sync_target(void);
+#else
+static inline bool tsc_store_and_check_tsc_adjust(bool bootcpu) { return false; }
+static inline void tsc_verify_tsc_adjust(bool resume) { }
+static inline void check_tsc_sync_source(int cpu) { }
+static inline void check_tsc_sync_target(void) { }
+#endif
+
+extern int notsc_setup(char *);
+extern void tsc_save_sched_clock_state(void);
+extern void tsc_restore_sched_clock_state(void);
+
+unsigned long cpu_khz_from_msr(void);
+
+#endif /* _ASM_X86_TSC_H */