diff --git a/arch/x86/include/asm/timex.h b/arch/x86/include/asm/timex.h
index 1375cfc93960..627802b6204c 100644
--- a/arch/x86/include/asm/timex.h
+++ b/arch/x86/include/asm/timex.h
@@ -4,6 +4,15 @@
 #include <asm/processor.h>
 #include <asm/tsc.h>
 
+static inline unsigned long random_get_entropy(void)
+{
+	if (!IS_ENABLED(CONFIG_X86_TSC) &&
+	    !cpu_feature_enabled(X86_FEATURE_TSC))
+		return random_get_entropy_fallback();
+	return rdtsc();
+}
+#define random_get_entropy random_get_entropy
+
 /* Assume we use the PIT time source for the clock tick */
 #define CLOCK_TICK_RATE		PIT_TICK_RATE
 
diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h
index 33b6365c22fe..23235c5ef1a1 100644
--- a/arch/x86/include/asm/tsc.h
+++ b/arch/x86/include/asm/tsc.h
@@ -21,13 +21,12 @@ extern void disable_TSC(void);
 
 static inline cycles_t get_cycles(void)
 {
-#ifndef CONFIG_X86_TSC
-	if (!boot_cpu_has(X86_FEATURE_TSC))
+	if (!IS_ENABLED(CONFIG_X86_TSC) &&
+	    !cpu_feature_enabled(X86_FEATURE_TSC))
 		return 0;
-#endif
-
 	return rdtsc();
 }
+#define get_cycles get_cycles
 
 extern struct system_counterval_t convert_art_to_tsc(cycle_t art);