Commit 262fba55 authored by Dave Hansen's avatar Dave Hansen
Browse files

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: default avatarDave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/20241213205030.9B42B458%40davehans-spike.ostc.intel.com
parent 8bd6821c

arch/x86/kernel/hpet.c

+0 −3
Original line number Diff line number Diff line
@@ -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) &&

arch/x86/kernel/smpboot.c

+0 −2
Original line number Diff line number Diff line
@@ -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;

drivers/acpi/acpi_pad.c

+0 −2
Original line number Diff line number Diff line
@@ -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);

drivers/idle/intel_idle.c

+0 −3
Original line number Diff line number Diff line
@@ -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) ||