[PATCH v7 065/120] x86/hpet: Use parsed CPUID(0x5)
From: Ahmed S. Darwish
Date: Thu May 28 2026 - 12:06:57 EST
Use parsed CPUID(0x5) instead of doing ugly bitwise operations and a direct
CPUID query.
Signed-off-by: Ahmed S. Darwish <darwi@xxxxxxxxxxxxx>
---
arch/x86/kernel/hpet.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 8dc7b710e125..6f6f4e5072f2 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -11,7 +11,6 @@
#include <asm/irq_remapping.h>
#include <asm/hpet.h>
#include <asm/time.h>
-#include <asm/mwait.h>
#include <asm/msr.h>
#undef pr_fmt
@@ -913,19 +912,15 @@ static bool __init hpet_counting(void)
static bool __init mwait_pc10_supported(void)
{
- unsigned int eax, ebx, ecx, mwait_substates;
+ const struct leaf_0x5_0 *l5 = cpuid_leaf(&boot_cpu_data, 0x5);
if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
return false;
- if (!cpu_feature_enabled(X86_FEATURE_MWAIT))
+ if (!l5 || !cpu_feature_enabled(X86_FEATURE_MWAIT))
return false;
- cpuid(CPUID_LEAF_MWAIT, &eax, &ebx, &ecx, &mwait_substates);
-
- return (ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) &&
- (ecx & CPUID5_ECX_INTERRUPT_BREAK) &&
- (mwait_substates & (0xF << 28));
+ return l5->mwait_ext && l5->mwait_irq_break && l5->n_c7_substates;
}
/*
--
2.54.0