linux-kernel - [PATCH v2 14/17] x86/acpi/cstate: Improve Intel Family model checks

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Message-ID: <20250211194407.2577252-15-sohil.mehta@intel.com>
Date: Tue, 11 Feb 2025 19:44:04 +0000
From: Sohil Mehta <sohil.mehta@...el.com>
To: x86@...nel.org,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	Tony Luck <tony.luck@...el.com>
Cc: Peter Zijlstra <peterz@...radead.org>,
	Ingo Molnar <mingo@...hat.com>,
	Arnaldo Carvalho de Melo <acme@...nel.org>,
	Namhyung Kim <namhyung@...nel.org>,
	Mark Rutland <mark.rutland@....com>,
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
	Jiri Olsa <jolsa@...nel.org>,
	Ian Rogers <irogers@...gle.com>,
	Adrian Hunter <adrian.hunter@...el.com>,
	Kan Liang <kan.liang@...ux.intel.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Borislav Petkov <bp@...en8.de>,
	"H . Peter Anvin" <hpa@...or.com>,
	"Rafael J . Wysocki" <rafael@...nel.org>,
	Len Brown <lenb@...nel.org>,
	Andy Lutomirski <luto@...nel.org>,
	Viresh Kumar <viresh.kumar@...aro.org>,
	Fenghua Yu <fenghua.yu@...el.com>,
	Jean Delvare <jdelvare@...e.com>,
	Guenter Roeck <linux@...ck-us.net>,
	Zhang Rui <rui.zhang@...el.com>,
	Andrew Cooper <andrew.cooper3@...rix.com>,
	David Laight <david.laight.linux@...il.com>,
	Sohil Mehta <sohil.mehta@...el.com>,
	linux-perf-users@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	linux-acpi@...r.kernel.org,
	linux-pm@...r.kernel.org,
	linux-hwmon@...r.kernel.org
Subject: [PATCH v2 14/17] 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[1][2] since the
initial commit ee1ca48fae7e ("ACPI: Disable ARB_DISABLE on platforms
where it is not needed").

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

[2]: commit 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>

---

v2: Improve commit message.

---
 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 300dac505d7f..fae52a15d9b9 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 5854f0b8f0f1..444602a0a3dd 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>
@@ -47,12 +48,11 @@ 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 &&
-- 
2.43.0