The following commit has been merged into the x86/cpu branch of tip: Commit-ID: 060da9df542689301d6ca28ca29c71585d8a5a24 Gitweb: https://git.kernel.org/tip/060da9df542689301d6ca28ca29c71585d8a5a24 Author: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> AuthorDate: Fri, 13 Dec 2024 12:50:30 -08:00 Committer: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> CommitterDate: Wed, 18 Dec 2024 05:24:42 -08:00 x86/cpu: Remove unnecessary MwAIT leaf checks The CPUID leaf dependency checker will remove X86_FEATURE_MWAIT if the CPUID level is below the required level (CPUID_MWAIT_LEAF). Thus, if you check X86_FEATURE_MWAIT you do not need to also check the CPUID level. Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/all/20241213205030.9B42B458%40davehans-spike.ostc.intel.com --- arch/x86/kernel/hpet.c | 3 --- arch/x86/kernel/smpboot.c | 2 -- drivers/acpi/acpi_pad.c | 2 -- drivers/idle/intel_idle.c | 3 --- 4 files changed, 10 deletions(-) diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c index 2593504..953de5b 100644 --- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -928,9 +928,6 @@ static bool __init mwait_pc10_supported(void) if (!cpu_feature_enabled(X86_FEATURE_MWAIT)) return false; - if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF) - return false; - cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates); return (ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) && diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 52b0d30..116c46f 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1292,8 +1292,6 @@ static inline void mwait_play_dead(void) return; if (!this_cpu_has(X86_FEATURE_CLFLUSH)) return; - if (__this_cpu_read(cpu_info.cpuid_level) < CPUID_MWAIT_LEAF) - return; eax = CPUID_MWAIT_LEAF; ecx = 0; diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c index b561974..f3cffae 100644 --- a/drivers/acpi/acpi_pad.c +++ b/drivers/acpi/acpi_pad.c @@ -47,8 +47,6 @@ static void power_saving_mwait_init(void) if (!boot_cpu_has(X86_FEATURE_MWAIT)) return; - if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF) - return; cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &edx); diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 5d8ed1a..efa32d2 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -2317,9 +2317,6 @@ static int __init intel_idle_init(void) return -ENODEV; } - if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF) - return -ENODEV; - cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates); if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
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