From: Borislav Petkov (AMD) <bp@alien8.de>
Date: Sun, 18 Dec 2022 20:53:36 +0000 (+0100)
Subject: x86/tsc: Do feature check as the very first thing
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=6b8d5dde5b6903baf82fc7400e0b3376b10805b4;p=linux.git

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: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/Y5990CUCuWd5jfBH@zn.tnic
---

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index eaeffef93a12a..aff1d79dd6ba2 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -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)) {