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From: Dave Hansen <dave.hansen@linux.intel.com>
To: linux-kernel@vger.kernel.org
Cc: x86@kernel.org,tglx@linutronix.de,bp@alien8.de,rafael@kernel.org,lenb@kernel.org,dave.jiang@intel.com,irenic.rajneesh@gmail.com,david.e.box@intel.com,Dave
	Hansen <dave.hansen@linux.intel.com>
Subject: [PATCH 03/11] x86/cpu: Remove unnecessary MwAIT leaf checks
Date: Wed, 20 Nov 2024 11:53:31 -0800	[thread overview]
Message-ID: <20241120195331.08EA36C8@davehans-spike.ostc.intel.com> (raw)
In-Reply-To: <20241120195327.26E06A69@davehans-spike.ostc.intel.com>


From: Dave Hansen <dave.hansen@linux.intel.com>

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@linux.intel.com>
---

 b/arch/x86/kernel/hpet.c    |    3 ---
 b/arch/x86/kernel/smpboot.c |    2 --
 b/drivers/acpi/acpi_pad.c   |    2 --
 b/drivers/idle/intel_idle.c |    3 ---
 4 files changed, 10 deletions(-)

diff -puN arch/x86/kernel/hpet.c~mwait-leaf-checks-2 arch/x86/kernel/hpet.c
--- a/arch/x86/kernel/hpet.c~mwait-leaf-checks-2	2024-11-20 11:44:16.665629466 -0800
+++ b/arch/x86/kernel/hpet.c	2024-11-20 11:44:16.673629773 -0800
@@ -928,9 +928,6 @@ static bool __init mwait_pc10_supported(
 	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 -puN arch/x86/kernel/smpboot.c~mwait-leaf-checks-2 arch/x86/kernel/smpboot.c
--- a/arch/x86/kernel/smpboot.c~mwait-leaf-checks-2	2024-11-20 11:44:16.669629620 -0800
+++ b/arch/x86/kernel/smpboot.c	2024-11-20 11:44:16.673629773 -0800
@@ -1291,8 +1291,6 @@ 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 -puN drivers/acpi/acpi_pad.c~mwait-leaf-checks-2 drivers/acpi/acpi_pad.c
--- a/drivers/acpi/acpi_pad.c~mwait-leaf-checks-2	2024-11-20 11:44:16.669629620 -0800
+++ b/drivers/acpi/acpi_pad.c	2024-11-20 11:44:16.673629773 -0800
@@ -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 -puN drivers/idle/intel_idle.c~mwait-leaf-checks-2 drivers/idle/intel_idle.c
--- a/drivers/idle/intel_idle.c~mwait-leaf-checks-2	2024-11-20 11:44:16.669629620 -0800
+++ b/drivers/idle/intel_idle.c	2024-11-20 11:44:16.673629773 -0800
@@ -2269,9 +2269,6 @@ 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) ||
_

  parent reply	other threads:[~2024-11-20 19:53 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-11-20 19:53 [PATCH 00/11] x86/cpu: Centralize and standardize CPUID leaf naming Dave Hansen
2024-11-20 19:53 ` [PATCH 01/11] x86/cpu: Move MWAIT leaf definition to common header Dave Hansen
2024-11-26  3:20   ` Zhao Liu
2024-11-20 19:53 ` [PATCH 02/11] x86/cpu: Use MWAIT leaf definition Dave Hansen
2024-11-26  3:24   ` Zhao Liu
2024-11-20 19:53 ` Dave Hansen [this message]
2024-11-20 19:53 ` [PATCH 04/11] x86/acpi: Check MWAIT feature instead of CPUID level Dave Hansen
2024-11-21 15:33   ` Sean Christopherson
2024-11-21 21:46     ` Dave Hansen
2024-11-20 19:53 ` [PATCH 05/11] x86/cpu: Refresh DCA leaf reading code Dave Hansen
2024-11-26  4:11   ` Zhao Liu
2024-11-26  3:55     ` Dave Hansen
2024-11-20 19:53 ` [PATCH 06/11] x86/cpu: Move TSC CPUID leaf definition Dave Hansen
2024-11-26  4:23   ` Zhao Liu
2024-11-20 19:53 ` [PATCH 07/11] x86/tsc: Move away from TSC leaf magic numbers Dave Hansen
2024-11-20 19:53 ` [PATCH 08/11] x86/tsc: Remove CPUID "frequency" " Dave Hansen
2024-11-26  4:37   ` Zhao Liu
2024-11-20 19:53 ` [PATCH 09/11] x86/fpu: Move CPUID leaf definitions to common code Dave Hansen
2024-11-26  4:43   ` Zhao Liu
2024-11-20 19:53 ` [PATCH 10/11] x86/fpu: Remove unnecessary CPUID level check Dave Hansen
2024-11-21 15:45   ` Sean Christopherson
2024-11-22 17:46     ` Dave Hansen
2024-11-20 19:53 ` [PATCH 11/11] x86/cpu: Make all all CPUID leaf names consistent Dave Hansen
2024-11-20 20:23   ` Dave Jiang
  -- strict thread matches above, loose matches on Subject: below --
2024-10-30 21:33 [PATCH 00/11] x86/cpu: Centralize and standardize CPUID leaf naming Dave Hansen
2024-10-30 21:33 ` [PATCH 03/11] x86/cpu: Remove unnecessary MwAIT leaf checks Dave Hansen

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