--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/arch/x86/include/asm/tsc.h	Sun Jan 11 20:20:11 2009 +0100
@@ -0,0 +1,68 @@
+/*
+ * 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)
+{
+	cycles_t cycles;
+
+	/*
+	 * We only do VDSOs on TSC capable CPUs, so this shouldnt
+	 * access boot_cpu_data (which is not VDSO-safe):
+	 */
+#ifndef CONFIG_X86_TSC
+	if (!cpu_has_tsc)
+		return 0;
+#endif
+	rdtsc_barrier();
+	cycles = (cycles_t)__native_read_tsc();
+	rdtsc_barrier();
+
+	return cycles;
+}
+
+extern void tsc_init(void);
+extern void mark_tsc_unstable(char *reason);
+extern int unsynchronized_tsc(void);
+int check_tsc_unstable(void);
+
+/*
+ * 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 *);
+
+#endif /* _ASM_X86_TSC_H */