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-rw-r--r--kernel/arch/x86/include/asm/tsc.h71
1 files changed, 71 insertions, 0 deletions
diff --git a/kernel/arch/x86/include/asm/tsc.h b/kernel/arch/x86/include/asm/tsc.h
new file mode 100644
index 000000000..94605c0e9
--- /dev/null
+++ b/kernel/arch/x86/include/asm/tsc.h
@@ -0,0 +1,71 @@
+/*
+ * 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 int check_tsc_disabled(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);
+
+/* MSR based TSC calibration for Intel Atom SoC platforms */
+unsigned long try_msr_calibrate_tsc(void);
+
+#endif /* _ASM_X86_TSC_H */