0005-x86-only-restore-TSC-if-we-have-IA32_TSC_ADJUST-or-d.patch

From 9a03dd4bf5be1056c513f7004e12fdc24fc33b22 Mon Sep 17 00:00:00 2001
From: Steven Noonan <steven@uplinklabs.net>
Date: Wed, 17 Nov 2021 11:58:46 -0800
Subject: [PATCH 31/37] x86: only restore TSC if we have IA32_TSC_ADJUST or
 directsync enabled

Otherwise we'd only be restoring the TSC for CPU0 on resume, which would
necessitate a TSC adjustment on other CPUs.

Signed-off-by: Steven Noonan <steven@uplinklabs.net>
---
 arch/x86/kernel/acpi/sleep.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
index 6829d11185f3..d8f7ec645f06 100644
--- a/arch/x86/kernel/acpi/sleep.c
+++ b/arch/x86/kernel/acpi/sleep.c
@@ -102,11 +102,15 @@ int x86_acpi_suspend_lowlevel(void)
 			header->pmode_misc_en_high))
 		header->pmode_behavior |=
 			(1 << WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE);
-	if (!rdmsr_safe(MSR_IA32_TSC,
+
+	if ((boot_cpu_has(X86_FEATURE_TSC_ADJUST) ||
+	     tsc_allow_direct_sync) &&
+	    !rdmsr_safe(MSR_IA32_TSC,
 	                &header->pmode_tsc_low,
 	                &header->pmode_tsc_high))
 		header->pmode_behavior |=
 			(1 << WAKEUP_BEHAVIOR_RESTORE_TSC);
+
 	header->realmode_flags = acpi_realmode_flags;
 	header->real_magic = 0x12345678;
 
-- 
2.39.0