linux-kernel - [tip: x86/cpu] x86/acpi/cstate: Improve Intel Family model checks

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Message-ID: <174232406995.14745.1531093518030939482.tip-bot2@tip-bot2>
Date: Tue, 18 Mar 2025 18:54:29 -0000
From: "tip-bot2 for Sohil Mehta" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: Sohil Mehta <sohil.mehta@...el.com>, Ingo Molnar <mingo@...nel.org>,
 Dave Hansen <dave.hansen@...ux.intel.com>,
 "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>, x86@...nel.org,
 linux-kernel@...r.kernel.org
Subject: [tip: x86/cpu] x86/acpi/cstate: Improve Intel Family model checks

The following commit has been merged into the x86/cpu branch of tip:

Commit-ID:     38ed76e1aed9116dd549e3c6e3ab9581ff6dbd05
Gitweb:        https://git.kernel.org/tip/38ed76e1aed9116dd549e3c6e3ab9581ff6dbd05
Author:        Sohil Mehta <sohil.mehta@...el.com>
AuthorDate:    Wed, 19 Feb 2025 18:41:26 
Committer:     Ingo Molnar <mingo@...nel.org>
CommitterDate: Tue, 18 Mar 2025 19:33:46 +01:00

x86/acpi/cstate: Improve Intel Family model checks

Update the Intel Family checks to consistently use Family 15 instead of
Family 0xF. Also, get rid of one of last usages of x86_model by using
the new VFM checks.

Update the incorrect comment since the check has changed since the
initial commit:

  ee1ca48fae7e ("ACPI: Disable ARB_DISABLE on platforms where it is not needed")

The two changes were:

 - 3e2ada5867b7 ("ACPI: fix Compaq Evo N800c (Pentium 4m) boot hang regression")
   removed the P4 - Family 15.

 - 03a05ed11529 ("ACPI: Use the ARB_DISABLE for the CPU which model id is less than 0x0f.")
   got rid of CORE_YONAH - Family 6, model E.

Signed-off-by: Sohil Mehta <sohil.mehta@...el.com>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Acked-by: Dave Hansen <dave.hansen@...ux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Link: https://lore.kernel.org/r/20250219184133.816753-9-sohil.mehta@intel.com
---
 arch/x86/include/asm/intel-family.h | 3 +++
 arch/x86/kernel/acpi/cstate.c       | 8 ++++----
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/intel-family.h b/arch/x86/include/asm/intel-family.h
index 4296c8e..51ea366 100644
--- a/arch/x86/include/asm/intel-family.h
+++ b/arch/x86/include/asm/intel-family.h
@@ -187,6 +187,9 @@
 #define INTEL_XEON_PHI_KNL		IFM(6, 0x57) /* Knights Landing */
 #define INTEL_XEON_PHI_KNM		IFM(6, 0x85) /* Knights Mill */
 
+/* Notational marker denoting the last Family 6 model */
+#define INTEL_FAM6_LAST			IFM(6, 0xFF)
+
 /* Family 15 - NetBurst */
 #define INTEL_P4_WILLAMETTE		IFM(15, 0x01) /* Also Xeon Foster */
 #define INTEL_P4_PRESCOTT		IFM(15, 0x03)
diff --git a/arch/x86/kernel/acpi/cstate.c b/arch/x86/kernel/acpi/cstate.c
index d255842..d5ac341 100644
--- a/arch/x86/kernel/acpi/cstate.c
+++ b/arch/x86/kernel/acpi/cstate.c
@@ -13,6 +13,7 @@
 #include <linux/sched.h>
 
 #include <acpi/processor.h>
+#include <asm/cpu_device_id.h>
 #include <asm/cpuid.h>
 #include <asm/mwait.h>
 #include <asm/special_insns.h>
@@ -48,12 +49,11 @@ void acpi_processor_power_init_bm_check(struct acpi_processor_flags *flags,
 	/*
 	 * On all recent Intel platforms, ARB_DISABLE is a nop.
 	 * So, set bm_control to zero to indicate that ARB_DISABLE
-	 * is not required while entering C3 type state on
-	 * P4, Core and beyond CPUs
+	 * is not required while entering C3 type state.
 	 */
 	if (c->x86_vendor == X86_VENDOR_INTEL &&
-	    (c->x86 > 0xf || (c->x86 == 6 && c->x86_model >= 0x0f)))
-			flags->bm_control = 0;
+	    (c->x86 > 15 || (c->x86_vfm >= INTEL_CORE2_MEROM && c->x86_vfm <= INTEL_FAM6_LAST)))
+		flags->bm_control = 0;
 
 	if (c->x86_vendor == X86_VENDOR_CENTAUR) {
 		if (c->x86 > 6 || (c->x86 == 6 && c->x86_model == 0x0f &&