[PATCH] x86/cpu: Enable SD_ASYM_PACKING for PKG domain on systems with AMD preferred cores

[Mario Limonciello]

From: Mario Limonciello <mario.limonciello@xxxxxxx>

For the scheduler to use and prefer AMD preferred core rankings set
SD_ASYM_PACKING for x86_die_flags().

Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
---
 arch/x86/kernel/smpboot.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index b5a8f0891135b..419e7ae096395 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -62,6 +62,8 @@
 #include <linux/mc146818rtc.h>
 #include <linux/acpi.h>
 
+#include <acpi/cppc_acpi.h>
+
 #include <asm/acpi.h>
 #include <asm/cacheinfo.h>
 #include <asm/desc.h>
@@ -497,10 +499,19 @@ static int x86_cluster_flags(void)
 
 static int x86_die_flags(void)
 {
-	if (cpu_feature_enabled(X86_FEATURE_HYBRID_CPU) ||
-	    cpu_feature_enabled(X86_FEATURE_AMD_HETEROGENEOUS_CORES))
+	if (cpu_feature_enabled(X86_FEATURE_HYBRID_CPU))
 		return x86_sched_itmt_flags();
 
+	switch (boot_cpu_data.x86_vendor) {
+	case X86_VENDOR_AMD:
+	case X86_VENDOR_HYGON:
+		bool prefcore = false;
+
+		amd_detect_prefcore(&prefcore);
+		if (prefcore || cpu_feature_enabled(X86_FEATURE_AMD_HETEROGENEOUS_CORES))
+			return x86_sched_itmt_flags();
+	};
+
 	return 0;
 }
 

base-commit: 40384c840ea1944d7c5a392e8975ed088ecf0b37
-- 
2.43.0