Commit 6b8d5dde authored by Borislav Petkov (AMD)'s avatar Borislav Petkov (AMD)
Browse files

x86/tsc: Do feature check as the very first thing 



Do the feature check as the very first thing in the function. Everything
else comes after that and is meaningless work if the TSC CPUID bit is
not even set. Switch to cpu_feature_enabled() too, while at it.

No functional changes.

Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/Y5990CUCuWd5jfBH@zn.tnic
parent 8fe6d849

arch/x86/kernel/tsc.c

+5 −5
Original line number Diff line number Diff line
@@ -1509,6 +1509,11 @@ void __init tsc_early_init(void) 


void __init tsc_init(void)

{

	if (!cpu_feature_enabled(X86_FEATURE_TSC)) {

		setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);

		return;

	}



	/*

	 * native_calibrate_cpu_early can only calibrate using methods that are

	 * available early in boot.
@@ -1516,11 +1521,6 @@ void __init tsc_init(void) 
	if (x86_platform.calibrate_cpu == native_calibrate_cpu_early)

		x86_platform.calibrate_cpu = native_calibrate_cpu;



	if (!boot_cpu_has(X86_FEATURE_TSC)) {

		setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);

		return;

	}



	if (!tsc_khz) {

		/* We failed to determine frequencies earlier, try again */

		if (!determine_cpu_tsc_frequencies(false)) {